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1

Effect of gas and liquid flowrates on the size distribution of barium sulfate nanoparticles precipitated in a two phase flow capillary microreactor  

Microsoft Academic Search

Production of fine particles by precipitation is a relatively simple process but the control of product particle size distribution can be difficult. In recent years microreactors are being seen as effective devices to achieve this aim and in that the two-phase flow microreactor is a promising alternative. In the present work, fine (nano\\/micro) particles of barium sulfate have been produced

D. Jeevarathinam; A. K. Gupta; B. Pitchumani; Ratan Mohan

2011-01-01

2

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

3

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

4

Synthesis and surface properties of submicron barium sulfate particles  

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

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

Parameterization of sulfate removal by precipitation  

Microsoft Academic Search

The concentration of sulfate in precipitation is predicted to be directly proportional to the sulfate concentration of the air ingested into the cloud and inversely proportional to cloud water concentration. In addition, for light to moderate precipitation rates, the removal of airborne sulfate by precipitation is forecast to be strongly dependent upon the mechanism of precipitation formation. If the precipitation

B. C. Scott

1978-01-01

7

Surface Electrical Properties of Barium Sulfate Modified by Adsorption of Poly alpha, beta Aspartic Acid.  

PubMed

The surface electrical properties of precipitated barium sulfate in aqueous solution have been probed in the presence and absence of synthetic poly alpha, beta aspartic acid. The effect of cation type, ion concentration, and pH on the electrokinetic properties of barite with and without adsorbed polyaspartic acid has been analyzed to afford insights into the mechanism by which polyaspartic acid acts as an inhibitor of barium sulfate precipitation. In addition, vibrational spectroscopy has been employed to monitor bond changes within polyaspartic acid molecules adsorbed on precipitated barium sulfate. These studies have indicated that the surface electrical charge of "pure" barite differs significantly from that of barite precipitated in the presence of calcium ions. Moreover, the presence of the cations Ca2+ and Mg2+ in the suspending liquor has a marked influence of the measured electrokinetic properties. The infrared spectral studies strongly suggest that polyaspartic acid is bound to the barite via the backbone nitrogen atoms. This proposal in conjunction with the electrokinetic and adsorption data has allowed a tentative model of barium sulfate inhibition to be proposed; viz, calcium ions are needed to complex with the polyaspartic acid, first, to reduce the molecules electrical charge in order to promote adsorption onto a charged surface; second, to induce a conformational change in the molecule in order to allow optimal anchoring via the backbone nitrogen atoms; and, third, to reduce the solubility of the molecule in order to increase its surface activity. Copyright 1999 Academic Press. PMID:10092385

Collins

1999-04-15

8

Determination of gross alpha, plutonium, neptunium, and\\/or uranium by gross alpha counting on barium sulfate  

Microsoft Academic Search

Procedures are presented for rapid and specific separation of uranium, neptunium, and\\/or plutonium, either singly or sequentially by precipitation with barium sulfate under controlled oxidation conditions in a form suitable for direct ..cap alpha.. counting. If desired, all ..cap alpha.. emitters can be precipitated and counted simultaneously to permit a true gross ..cap alpha.. determination to be made. When isotopic

Claude W. Sill

1980-01-01

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

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

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

Development and Demonstration of a Sulfate Precipitation Process for Hanford Waste Tank 241-AN-107  

SciTech Connect

A series of precipitation experiments were conducted on Hanford waste tank 241-AN-107 samples in an effort to remove sulfate from the matrix. Calcium nitrate was added directly to AN-107 sub-samples to yield several combinations of Ca:CO{sub 3} mole ratios spanning a range of 0:1 to 3:1 to remove carbonate as insoluble CaCO{sub 3}. Similarly barium nitrate was added directly to the AN-107 aliquots, or to the calcium pretreated AN-107 aliquots, giving of Ba:SO{sub 4} mole ratios spanning a range of 1:1 to 5:1 to precipitate sulfate as BaSO{sub 4}. Initial bulk carbonate removal was required for successful follow-on barium sulfate precipitation. A {ge} 1:1 mole ratio of Ca:CO{sub 3} was found to lower the carbonate concentration such that Ba would react preferentially with the sulfate. A follow-on 1:1 mole ratio of Ba:SO{sub 4} resulted in 70% sulfate removal. The experiment was scaled up with a 735-mL aliquot of AN-107 for more complete testing. Calcium carbonate and barium sulfate settling rates were determined and fates of selected cations, anions, and radionuclides were followed through the various process steps. Seventy percent of the sulfate was removed in the scale-up test while recovering 63% of the filtrate volume. Surprisingly, during the scale-up test a sub-sample of the CaCO{sub 3}/241-AN-107 slurry was found to lose fluidity upon standing for {le} 2 days. Metathesis with BaCO{sub 3} at ambient temperature was also evaluated using batch contacts at various BaCO{sub 3}:SO{sub 4} mole ratios with no measurable success.

SK Fiskum; DE Kurath; BM Rapko

2000-08-16

14

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.

15

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,...

16

Technetium reduction and precipitation by sulfate?reducing bacteria  

Microsoft Academic Search

Resting cells of the sulfate?reducing bacterium Desulfovibrio desulfuricans ATCC 29577 were able to precipitate the radionuclide technetium, supplied as the pertechnetate anion (TcO4 ), under anaerobic conditions by two discrete mechanisms. Sulfidogenic cultures, supplied with sulfate and lactate as an electron acceptor and donor, respectively, precipitated the radionuclide as an insoluble sulfhide. Using electron microscopy in combination with energy?dispersive x?ray

J. R. Lloyd; V. A. Solé; K. Bosecker; L. E. Macaskie

1998-01-01

17

Potentiometric titration of sulfate with lead and barium ions with various indicating electrodes  

SciTech Connect

Several types of graphite were used as sensors in the potentiometric titration of 25 to 75 ..mu..mol of sulfate vs. lead(II) and barium(II) and compared with titrations obtained with a lead ion-selective electrode (ISE). Pyrolytic graphite and high-density graphite, conditioned in neutral potassium permanganate, were found to be good alternatives to the lead ISE. A qualitative study was made of a variety of commercially available ISE's and other materials as sensors in the titration of 5 ..mu..mol of sulfate vs lead(II). Every ISE and conducting material tested yielded a usable response. While that of the commonly used lead ISE was largest, some other ISE's and metal rods also function satisfactorily as sensors in this titration. All titrations were carried out in a partially nonaqueous medium, which is required even for the lead ISE at the low sulfate levels investigated. 18 references, 4 figures, 5 tables.

Selig, W.S.

1984-01-01

18

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

19

Barium enema  

MedlinePLUS

Barium enema is a special x-ray of the large intestine, which includes the colon and rectum. ... to a bag that holds a liquid containing barium sulfate. This is a contrast material that highlights ...

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

Uncertainties in the oxygen isotopic composition of barium sulfate induced by coprecipitation of nitrate  

E-print Network

sulfur species and results in the formation of acid rain.3,4 The pioneering work of Holt and Kumar,5 atmospheric aerosols or rain waters are probably severely biased because photochemical nitrate is usually also4 2À in clouds, fog and precipitation.13,14 `Primary' sulfate formed via high-temperature O2

Michalski, Greg

22

Barium Sulfate  

MedlinePLUS

... sure that you are also given directions for mixing and that you understand these directions. Ask your ... testing center if you have any questions about mixing your medication.You will be given specific directions ...

23

Treatment of hypercholesterolemia by precipitation of lipoproteins with dextran sulfate.  

PubMed

An on-line continuous system for the selective precipitation of low-density lipoproteins (LDL) and very low-density lipoproteins (VLDL) has been devised and tested. This system conserves high-density lipoproteins (HDL) and other plasma macromolecules. LDL and VLDL are precipitated from plasma using 10-35 mg/dl dextran sulfate (Mr 5,000) in the presence of 55 mM calcium with a reduced concentration of monovalent cations. The plasma is obtained by membrane filtration of whole blood using the COBE Centry TPE System (Cobe Laboratories Inc, Lakewood, Co.). The precipitated LDL plus VLDL is removed by filtration, and the electrolytes are restored by dialysis. The plasma minus LDL plus VLDL is then returned to the patient. Four patients with heterozygous familial hypercholesterolemia (type II) were treated 70 times. The mean pretreatment serum cholesterol was 383 mg/dl. The mean reductions in plasma components were: LDL plus VLDL 63%; HDL 27%; fibrinogen 19%; albumin 15%; IgG 20%; IgA 19%; IgM 25%; C3 30%; and C4 27%. The cholesterol returned to near normal values in approximately 2 weeks after each treatment. Four normal volunteers were each treated one time. These individuals had a mean pretreatment serum cholesterol of 201 mg/dl. The mean reduction in plasma components were: LDL plus VLDL 70%; HDL 27%; fibrinogen 24%; albumin 14%; IgG 18%; IgA 17%; IgM 20%; C3 27%; C4 22%; C3 proactivator 12%; alpha 1-antitrypsin 17%; ceruloplasma 17%; transferrin 18%; alpha 2-macroglobulin 17%; and orosomucoid 13%. It is our conclusion that dextran sulfate precipitation is an effective on-line means of selectively removing LDL plus VLDL from plasma while conserving HDL and other plasma macromolecules.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2456284

Antwiler, G D; Dau, P C; Lobdell, D D

1988-01-01

24

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

25

Deposition of nitrate-n and sulfate-s by precipitations in Schleswig-Holstein  

NASA Astrophysics Data System (ADS)

In order to quantify the atmospheric nitrate and sulfate deposition and to investigate factors related to the variability of deposition during 1983 and 1984, precipitation samples from five different meteorological stations in Schleswig-Holstein (Northern Germany) were collected in weekly intervals, using the bulk-sample method. The average element depositions in kg ha -1 a -1 were: 20 for S and 5.5 for N in List (North Sea Island Sylt) and Schleswig, 12 for S and 4.7 for N in Kiel, 16 for S and 4.3 for N in Luebeck and 18 for S and 4.2 for N in Quickborn near Hamburg. N and S concentrations showed a close relationship to the amount of precipitation and the following functions for the estimation of nitrate-N and sulfate-S deposition in Schleswig-Holstein could be derived: ( x = precipitation in mm a -1, y = N or S deposition in kg ha -1 a -1) NO 3-N: y = 0.003 x + 2.29; SO 4-S: y = 0.014 x + 4.71. According to these relationships most of the element deposition occurred during atmospheric conditions of predominating winds from the west. Especially in the case of S, atmospheric deposition is the only external source of S supply for plants on many agricultural soils. Sometimes the low sulfur input is not sufficient to cover the requirements of agricultural crops in Schleswig-Holstein. Due to the negative S balance in many soils, future increase of S deficiency is expected.

Schnug, E.; Holz, F.

26

Fabrication and surface properties of hydrophobic barium sulfate aggregates based on sodium cocoate modification  

NASA Astrophysics Data System (ADS)

Hydrophobic barium sulfate aggregates were fabricated by the direction of cocoate anions. At 30 °C, when the weight ratio of sodium cocoate to BaSO4 particles was 2.0 wt.%, the active ratio of the product reached 99.43% and the contact angle was greater than 120°. This method could not only simplify the complex modification process, but reduce energy consumption. The surface morphology, chemical structure and composition of BaSO4 aggregates were characterized by SEM, XRD, and FTIR. The results indicated that the as-synthesized BaSO4 particles were almond-liked and were composed of many interconnected nanoballs and that their surfaces were affected by cocoate anions. The adsorption of cocoate anions reversed the charge and weakened the surface polarity of BaSO4 particles, driving the formation of aggregates. And cocoate anions induced a change of the BaSO4 particles surface from hydrophilic to hydrophobic by a self-assembly and transformation process. Due to the self-assembled structure and the surface hydrophobicity, when adding the hydrophobic BaSO4 into PVC, the mechanical properties of PVC composite materials were significantly improved.

Hu, Linna; Wang, Guangxiu; Cao, Rong; Yang, Chun; Chen, Xi

2014-10-01

27

Selective Precipitation and Purification of Monovalent Proteins Using Oligovalent Ligands and Ammonium Sulfate  

E-print Network

and Ammonium Sulfate Katherine A. Mirica, Matthew R. Lockett, Phillip W. Snyder, Nathan D. Shapiro, Eric T ammonium sulfate and oligovalent ligands. The oligovalent ligands induce the formation of protein-ligand aggregates, and at an appropriate concentration of dissolved ammonium sulfate, these complexes precipitate

Weitz, David

28

Mineral leaching, iron precipitation, and the sulfate requirement for chemolithotrophic iron oxidation  

Microsoft Academic Search

The leaching of pyrite by Thiobacillus ferrooxidans results in formation of an aqueous Fe(III) sulfato complex that leaches pyrite and precipitates excess iron sulfate. However, until recently most general texts stated that the deposits formated by bacterial leaching of pyrite consited of ferric hydroxide, implying that the massive presence of sulfate played no role in the oxidation or precipitation of

Norman Lazaroff

1997-01-01

29

Precipitation method for barium metaborate (BaB2O4) synthesis from borax solution  

NASA Astrophysics Data System (ADS)

In this study, barium metaborate (BaB2O4, 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 ?-BaB2O4 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 (Na2B4O7?10H2O, BDH) and barium chloride (BaCI2?2H2O, 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

2013-12-01

30

Nature and spatial distribution of sulfur species in a sulfated barium-based commercial lean NOx trap catalyst  

SciTech Connect

We report observations of the nature and spatial distribution of sulfur species on a sulfated Ba-based commercial lean NO{sub x} trap (LNT) catalyst. The monolithic catalyst was sulfated in a bench flow reactor during 60/4-s NO{sub x} storage/reduction cycling to achieve a total sulfur loading of 3.4 g L{sup -1} of catalyst. Washcoat composition, structure and sulfur distribution were analyzed with electron probe microanalysis, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and temperature-programmed reduction. The most significant washcoat elements of catalytic relevance were Pt, Pd, Rh, Ba, Ce, Zr, Mg, Al, and these were present mainly in four distinct domains; Mg/Al mixed oxide with Pt, Ce; Al oxide with Rh, Pd; Ce/Zr mixed oxide with Pt, Pd, Ba (high Ba content); Ce/Zr mixed oxide with Pt, Pd, Ba (lower Ba content). Sulfur was present in the form of sulfates that decreased in concentration along the LNT axis from front to back. Barium showed the highest sulfur affinity leading to a plug-like axial progression of its sulfation. The sulfation of AI, Mg/Al, and Ce/Zr oxides was less vigorous with a more axially dispersed and less penetrating front.

Choi, Jae-Soon [ORNL; Partridge Jr, William P [ORNL; Lance, Michael J [ORNL; Walker, Larry R [ORNL; Pihl, Josh A [ORNL; Toops, Todd J [ORNL; FINNEY, Charles E A [ORNL; Daw, C Stuart [ORNL

2010-01-01

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, 103B:596-607, 2015. 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

2015-04-01

32

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

33

Co-precipitation of yttrium and barium fluorides from aqueous solutions  

SciTech Connect

Highlights: ? BaF{sub 2}–YF{sub 3} system has been studied under the non-equilibrium ambient conditions. ? Ba{sub 1?x}Y{sub x}F{sub 2+x} (x = 0.35–0.75) solid solution phase has cubic fluorite-type structure. ? Ba{sub 1?x}Y{sub x}F{sub 2+x} cubic crystal lattice parameter a{sub 0} does not change monotonously. ? Different types of lattice defects determine a dependency from sample composition. ? (H{sub 3}O{sup +})Y{sub 3}F{sub 10}{sup ?}·nH{sub 2}O phase precipitates from HF aqueous solutions instead of YF{sub 3}·nH{sub 2}O. -- Abstract: Co-precipitation of barium and yttrium fluorides from aqueous solutions at room temperature produced non-equilibrium Ba{sub 1?x}Y{sub x}F{sub 2+x} nanofluoride phase with face-centered cubic crystal lattice of fluorite-type with the composition interval of the homogeneity for x = 0.35–0.75. Lattice parameter a of this solid solution nanophase varied as a function of the sample chemical composition in a complex manner with two areas of linear dependency, from x = 0.35 to 0.45 and from x = 0.50 to 0.75. A plausible explanation of this phenomenon included a change of the type of crystal lattice defects and the manner of their population with the corresponding ions. An increase of the relative amount of yttrium in the HF reaction system led to the formation of hydroxonium salt of decafluorotriyttrium acid, (H{sub 3}O{sup +})Y{sub 3}F{sub 10}{sup ?}·nH{sub 2}O, instead of expected YF{sub 3} hydrate. No formation of oxyfluoride phases under acidic conditions has been observed.

Fedorov, Pavel P., E-mail: ppfedorov@yandex.ru [A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, 38 Vavilov Street, Moscow 119991 (Russian Federation); Mayakova, Maria N.; Kuznetsov, Sergey V.; Voronov, Valery V.; Ermakov, Roman P.; Samarina, Kseniya S.; Popov, Arthur I.; Osiko, Vyacheslav V. [A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, 38 Vavilov Street, Moscow 119991 (Russian Federation)] [A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, 38 Vavilov Street, Moscow 119991 (Russian Federation)

2012-07-15

34

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...

35

Structural and optical properties of Er3+/Yb3+ doped barium titanate phosphor prepared by co-precipitation method.  

PubMed

In the present work we have synthesized the Er(3+)/Yb(3+) codoped barium titanate phosphor via co-precipitation method and studied its upconversion emission properties. The prepared BaTiO3 powder was found in cubic phase as a major component and having good crystallinity revealed by the XRD analysis. Optical band gap of the cubic barium titanate was calculated using the diffuse reflectance absorption spectrum. Good green upconversion emission is observed from the samples when excited by 980 nm diode laser. The variation in upconversion emission intensity is studied with the increase in excitation power as well as temperature of the sample. It is found that the emission bands centred at 524 and 548 nm are thermally coupled and can act as a temperature sensor in the 300-480 K temperature range. PMID:24495836

Mahata, Manoj Kumar; Kumar, Kaushal; Rai, Vineet Kumar

2014-04-24

36

Sulfate Removal from Reject Brined in Inland Desalination with Zero Liquid Discharge  

E-print Network

in membrane processes is restricted by the ability of precipitation of scale-forming salts such as calcium sulfate, barium sulfate, and silica. Water recovery in inland RO desalination systems in most cases is limited by the concentration of these salts... calcium carbonate (CaCO3), calcium sulfate (CaSO4?xH2O), barium sulfate (BaSO4), strontium sulfate (SrSO4), silicates, calcium phosphate (Ca3PO4), and aluminosilicates (Antony et al., 2011). 2.6.2 Sulfate problem in ZLD desalination of brackish...

Almasri, Dema A

2013-07-03

37

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

38

New Method for Purifying Coxiella burnetii by Dextran Sulfate Precipitation Followed by Centrifugation  

PubMed Central

This paper describes a simple method for purifying Coxiella burnetii cultivated in the chick embryo. The procedure is based upon the preliminary clarification of infected whole-egg suspensions by precipitating the low-density lipoproteins and other extraneous solids with dextran sulfate, calcium chloride, and sodium chloride solutions, and then concentrating the rickettsiae by centrifugation. Images Fig. 2 PMID:14264856

Davis, J. L.; Patrick, W. C.

1965-01-01

39

A comparison of the dodecyl sulfate-induced precipitation of the myelin basic protein with other water-soluble proteins  

Microsoft Academic Search

The interactions of sodium dodecyl sulfate with a number of proteins were examined at a variety of pH values ranging from 4.8 to 11.6 The dodecyl sulfate-induced precipitation of some of these proteins was observed within a relatively limited range of total dodecyl sulfate concentration. Most of the basic proteins precipitated at low pH but as the isoelectric point of

John E. Moskaitis; Anthony T. Campagnoni

1986-01-01

40

Factors Affecting the Precipitation of Potassium Jarosite in Sulfate and Chloride Media  

NASA Astrophysics Data System (ADS)

The factors affecting the precipitation of potassium jarosite in both sulfate and chloride media were systematically investigated for the range of conditions likely to be encountered in hydrometallurgical practice. In sulfate solutions at 97 °C, the amount of precipitate increases with increasing retention times up to 10 hours, with increasing temperatures to approximately 100 °C, and with increasing ferric-ion concentrations. Despite the variations in the amount of precipitate, the composition remains nearly constant and is characteristic of that of potassium jarosite. The presence of potassium jarosite seed accelerates the rate of precipitation and results in near-maximum amounts of precipitate after just a few hours of reaction. The presence of ferrous sulfate has a negligible effect on both the product yield and composition. The amount of precipitate decreases with increasing acid concentrations, but the composition of the precipitates remains nearly constant, even for acid concentrations as high as 1.0 M H2SO4. Both the amount and composition of the precipitates vary as the K2SO4 concentration increases; in the presence of excess ferric ions, nearly complete K precipitation occurs. Small amounts of Cu2+, Zn2+, and Pb2+ are incorporated in the structure of potassium jarosite, and the amount increases with increasing concentrations of the divalent metal ions. Potassium jarosite is readily formed in chloride media at 140 °C, provided that an independent source of sulfate ions is available. A minimum K concentration is required in order to avoid the formation of hematite; at higher K concentrations, however, the product composition becomes nearly constant and reflects that of potassium jarosite. Both the product yield and composition are independent of the chloride concentration, added as LiCl, and the ferrous ion concentration, added as FeCl2. Although increasing concentrations of HCl result in a near-linear decrease in the amount of precipitate, the composition is independent of the HCl concentration and is characteristic of that of potassium jarosite. Increasing temperatures to 200 °C result in an increase in the product yield, but have no significant effect on the composition of the potassium jarosite precipitates.

Dutrizac, J. E.

2008-12-01

41

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

42

Evaluation of Radiation Dose Reduction during CT Scans Using Oxide Bismuth and Nano-Barium Sulfate Shields  

E-print Network

The purpose of the present study was to evaluate radiation dose reduction and image quality during CT scanning by using a new dose reduction fiber sheet (DRFS) with commercially available bismuth shields. These DRFS were composed of nano-barium sulfate (BaSO4), filling the gaps left by the large oxide bismuth (Bi2O3) particle sizes. The radiation dose was measured five times at directionss of 12 o'clock from the center of the polymethyl methacrylate (PMMA) head phantom to calculate an average value using a CT ionization chamber. The image quality measured CT transverse images of the PMMA head phantom depending on X-ray tube voltages and the type of shielding. Two regions of interest in CT transverse images were chosen from the right and left areas under the surface of the PMMA head phantom and from ion chamber holes located at directions of 12 o'clock from the center of the PMMA head phantom. The results of this study showed that the new DRFS shields could reduce dosages to 15.61%, 23.05%, and 22.71% more in ...

Seoung, Youl-Hun

2015-01-01

43

Speciation of iron and sulfate in acid waters: aqueous clusters to mineral precipitates.  

PubMed

Acid mine drainage (AMD) contaminates surface water bodies, groundwater, soils, and sediments at innumerable locations around the world. AMD usually originates by weathering of pyrite (FeS2) and is rich in Fe and sulfate. In this study, we investigated speciation of FeII, FeIII, and SO4 in acid waters by Fourier transform infrared and X-ray absorption spectroscopy. The molalities of sulfate (15 mmol/ kg) and iron (10, 20, and 50 mmol/kg), and pH (1, 2, and 3) were chosen to mimic the concentration of ions in AMD waters. Sulfate and FeII either associate in outer-sphere complexes or do not associate at all. In contrast, sulfate interacts strongly with FeIII. The predominating species in FeIII-SO4 solutions are hydrogen-bonded complexes; inner-sphere complexes account only for 10+/-10% of the total sulfate. Our results show that the mode of interaction between FeIII and sulfate is similar in aqueous phase and in nanocrystalline precipitate schwertmannite (approximately FeO(OH)3/4(SO4)1/8). Because of this similarity, schwert-mannite should be the phase that controls solubility and availability of FeIII, SO4, and indirectly also other components in the AMD solutions. PMID:15667094

Majzlan, Juraj; Myneni, Satish C B

2005-01-01

44

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...

45

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

46

Carbon isotope effects during precipitation of barium carbonate: implications for environmental studies  

Microsoft Academic Search

Here we demonstrate that precipitation of dissolved inorganic carbon (DIC) to at pH 10.26, 11.38 and 12.11 does not cause\\u000a measurable carbon isotope fractionation. However, NaOH solution prepared under standard laboratory procedure and used to increase\\u000a pH value for precipitation of BaCO3 can be contaminated by atmospheric CO2. In our experiment, ?13C value in the contaminant DIC was ?24.30‰, which

Anna Szynkiewicz; Mariusz Orion J?drysek; Marta Kurasiewicz

2006-01-01

47

Treatment of spent brine from a nitrate exchange process using combined biological denitrification and sulfate precipitation.  

PubMed

A combined biological denitrification and sulfate precipitation process was developed to treat and reuse the spent brine produced by a nitrate exchange system. Although the spent brine contained a relatively high salt concentration, more than 80% of NO3(-)-N fed into the denitrification reactors was removed at a nitrate-N loading rate of 2.2 g NO3(-)-N/l x day, regardless of the presence or absence of sulfate up to 8,000 mg/l. Sulfate present in the spent brine was successfully removed by the addition of BaCl2 and the settling velocity of BaSO4 suspension was remarkably enhanced by FeCl3 coagulation. Since most of the chloride consumed in regenerating the exhausted resins was replaced during chemical treatment with BaCl2 and FeCl3, it was possible to reuse the treated spent brine as a regenerant after compensating for the small amount of unreplaced NaCl. PMID:15137452

Bae, B U; Kim, C H; Kim, Y I

2004-01-01

48

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

49

Short-Range Dissolution-Precipitation Crystallization of Hydrothermal Barium Titanate  

SciTech Connect

A modified autoclave was used to investigate the crystallization mechanism of BaTiO3 during the hydrothermal reaction of Ba(OH)2 and TiO2 anatase. An uneven distribution of the crystallized BaTiO3 particles was observed: more than 99 wt% of total BaTiO3 articles remained where the precursor TiO2 was put; less than 1 wt% was collected from the areas away from the TiO2. According to the experimental observations in this work and proofs reported in the literature, we propose that the crystallization mechanism is dissolution-precipitation in nature, but the soluble Ti4+ species can only redisperse in a short distance away from TiO2 particles before precipitation. In another words, the nucleation of hydrothermal BaTiO3 starts at a low concentration of Ti4+. The mechanism of the Ba(OH)2-Ti(OH)4 reaction is a fast dehydration process.

Qi, Lai; Lee, Burtrand I.; Badheka, Prerak; Yoon, Dang-Hyok; Samuels, William D.; Exarhos, Gregory J.

2004-07-01

50

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

51

Total and non-seasalt sulfate and chloride measured in bulk precipitation samples from the Kilauea Volcano area, Hawaii  

USGS Publications Warehouse

Six-month cumulative precipitation samples provide estimates of bulk deposition of sulfate and chloride for the southeast part of the Island of Hawaii during four time periods: August 1991 to February 1992, February 1992 to September 1992, March 1993 to September 1993, and September 1993 to February 1994. Total estimated bulk deposition rates for sulfate ranged from 0.12 to 24 grams per square meter per 180 days, and non-seasalt sulfate deposition ranged from 0.06 to 24 grams per square meter per 180 days. Patterns of non-seasalt sulfate deposition were generally related to prevailing wind directions and the proximity of the collection site to large sources of sulfur gases, namely Kilauea Volcano's summit and East Rift Zone eruption. Total chloride deposition from bulk precipitation samples ranged from 0.01 to 17 grams per square meter per 180 days. Chloride appeared to be predominantly from oceanic sources, as non- seasalt chloride deposition was near zero for most sites.

Scholl, M.A.; Ingebritsen, S.E.

1995-01-01

52

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

53

Biologically-induced precipitation of sphalerite-wurtzite nanoparticles by sulfate-reducing bacteria: implications for acid mine drainage treatment.  

PubMed

Several experiments were conducted to evaluate zinc-tolerance of sulfate-reducing bacteria (SRB) obtained from three environmental samples, two inocula from sulfide-mining districts and another inoculum from a wastewater treatment plant. The populations of SRB resisted zinc concentrations of 260 mg/L for 42 days in a sulfate-rich medium. During the experiments, sulfate was reduced to sulfide and concentrations in solution decreased. Zinc concentrations also decreased from 260 mg/L to values below detection limit. Both decreases were consistent with the precipitation of newly-formed sphalerite and wurtzite, two polymorphs of ZnS, forming <2.5-?m-diameter spherical aggregates identified by microscopy and synchrotron-?-XRD. Sulfate and zinc are present in high concentrations in acid mine drainage (AMD) even after passive treatments based on limestone dissolution. The implementation of a SRB-based zinc removal step in these systems could completely reduce the mobility of all metals, which would improve the quality of stream sediments, water and soils in AMD-affected landscapes. PMID:22414495

Castillo, Julio; Pérez-López, Rafael; Caraballo, Manuel A; Nieto, José M; Martins, Mónica; Costa, M Clara; Olías, Manuel; Cerón, Juan C; Tucoulou, Rémi

2012-04-15

54

Modeling investigation of controlling factors in the increasing ratio of nitrate to non-seasalt sulfate in precipitation over Japan  

NASA Astrophysics Data System (ADS)

Anthropogenic emissions in East Asia have been increasing during the three decades since 1980, as the population of East Asia has grown and the economies in East Asian countries have expanded. This has been particularly true in China, where NOx emissions have been rising continuously. However, because of fuel-gas desulfurization systems introduced as part of China’s 11th Five-Year Plan (2006-2010), SO2 emissions in China reached a peak in 2005-2006 and have declined since then. These drastic changes in emission levels of acidifying species are likely to have caused substantial changes in the precipitation chemistry. The absolute concentration of compounds in precipitation is inherently linked to precipitation amount; therefore, we use the ratio of nitrate (NO) to non-seasalt sulfate (nss-SO2-) concentration in precipitation as an index for evaluating acidification, which we call Ratio. In this study, we analyzed the long-term behavior of Ratio in precipitation over the Japanese archipelago during 2000-2011 and estimated the factors responsible for changes in Ratio in precipitation by using a model simulation. This analysis showed that Ratio was relatively constant at 0.5-0.6 between 2000 and 2005, and subsequently increased to 0.6-0.7 between 2006 and 2011. These changes in Ratio corresponded remarkably well to the changes of NOx/SO2 emissions ratio in China; this correspondence suggests that anthropogenic emissions from China were responsible for most of the change in precipitation chemistry over Japan. Sensitivity analysis elucidated that the increase in NOx emissions and the decrease in SO2 emissions contributed equally to the increases in Ratio. Considering both emission changes in China enables to capture the observed increasing trend of Ratio in Japan.

Itahashi, Syuichi; Uno, Itsushi; Hayami, Hiroshi; Fujita, Shin-ichi

2014-08-01

55

Influence of sodium dodecyl sulfate and static magnetic field on the properties of freshly precipitated calcium carbonate.  

PubMed

Properties of calcium carbonate precipitated from aqueous solutions of CaCl(2) and Na(2)CO(3) in the presence of sodium dodecyl sulfate (SDS) and S-S 0.1 T magnetic field (MF) were studied. The nucleation and precipitation processes of CaCO(3) were investigated by pH and zeta potential measurements at 20 +/- 1 degrees C up to 2 h after mixing the solutions. Also the amounts of calcium carbonate deposited on the glass surfaces and its structure were examined. It was found that SDS influences the kinetics of precipitation, crystallographic forms, and crystal size of CaCO(3). The SDS effects are more pronounced in MF presence. A small amount of SDS accelerates transformation of vaterite into calcite, whereas increasing surfactant concentration moderates such a transformation. On the other hand, in all the systems, MF in the presence of SDS causes a slower transformation of vaterite into calcite. These effects are reflected in pH and zeta potential changes, although there is no clear dependence between the SDS amount present during the precipitation and changes of the parameters investigated. It seems that MF effect is most significant at a defined optimal SDS concentration. The results, however, do not allow suggestion of any detailed mechanism of the field interaction. PMID:16114911

Chibowski, Emil; Szczes, Aleksandra; Holysz, Lucyna

2005-08-30

56

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...

57

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...

58

Synthesis of BaSO nanoparticles by precipitation method using sodium hexa metaphosphate as a stabilizer  

NASA Astrophysics Data System (ADS)

We describe the synthesis and structure of Barium sulfate nanoparticles by precipitation method in the presence of water soluble inorganic stabilizing agent, sodium hexametaphosphate, (NaPO 3) 6. The structural parameters were refined by the Rietveld refinement method using powder X-ray diffraction data. Barium sulfate nanoparticles were crystallized in the orthorhombic structure with space group Pbnm (No. 62) having the lattice parameters a=7.215(1) (Å), b=8.949(1) (Å) and c=5.501(1) (Å) respectively. Transmission electron microscopy study reveals that the nanoparticles are size range, 30-50 nm. Fourier transform infrared spectra showed distinct absorption due to the SO 42- moiety at 1115 and 1084 cm -1 indicating formation of barium sulfate nanoparticles free from the phosphate group from the stabilizer used in the synthesis.

Gupta, Asha; Singh, Preetam; Shivakumara, C.

2010-03-01

59

STABLE SULFUR ISOTOPES OF SULFATE IN PRECIPITATION AND STREAM SOLUTIONS IN A NORTHERN HARDWOODS WATERSHED  

EPA Science Inventory

table 5 isotopes of 5042 in precipitation and stream solutions in a northern hardwoods watershed (Bear Brooks Watershed, Maine) were examined to determine sources of stream S042- and to identify watershed processes that may affect atmospherically deposited S042 prior to reaching ...

60

Trends in cation, nitrogen, sulfate and hydrogen ion concentrations in precipitation in the United States  

E-print Network

Industrial emissions of SO2 and NOx, resulting in the formation and deposition of sulfuric and nitric acids, legislation to control acid rain precursors in both Europe and the US has led to significant declines in both reductions in base cation inputs in precipitation could lessen the effect of air pollution control

Kurapov, Alexander

61

Rates of sulfate reduction and metal sulfide precipitation in a permeable reactive barrier  

Microsoft Academic Search

A full-scale reactive barrier, utilizing bacterially mediated SO4 reduction to promote metal sulfide precipitation and alkalinity generation, was installed in August 1995 at the Nickel Rim mine site near Sudbury, Ontario. Monitoring of groundwater chemistry over a 3-a period allows assessment of long-term reactive barrier performance. The overall rate of SO4 removal within the barrier declined with time by 30%

S. G. Benner; D. W. Blowes; C. J. Ptacek; K. U. Mayer

2002-01-01

62

Relative role of decreasing precipitation sulfate and climate on recent lake recovery  

NASA Astrophysics Data System (ADS)

In the last 2 decades, acidic sulfur (S) depositions and SO4 concentration in surface water significantly decreased in many regions of the world, while at the same time temperatures have been increasing, particularly in the decade 1995-2005, which was one of the warmest ever recorded in the Northern Hemisphere. Understanding the potentially antagonistic or additive effects of decreasing S depositions and increasing temperatures on lake chemistry is essential to adequately evaluate the effectiveness of reduction programs for S emissions. By assessing the rate of change in climate variables, precipitation SO4 and lake chemistry for 47 temperate and boreal catchments, we found that changes in climate, particularly higher annual temperatures, were more often correlated to lake's pH and alkalinity than was the rate of decreasing S depositions between 1989 and 2005. It suggests that the recent improvement in the acid-base status of the studied lakes that cover a large area of northeastern North America as well as a large array of acid-base conditions cannot be attributed solely to a decrease in SO4 precipitation, but also to climatic variations. Not taking this information into account could lead to an overestimation of the benefit of lower SO4 deposition on aquatic ecosystems recovery.

Houle, Daniel; Couture, Suzanne; Gagnon, Christian

2010-12-01

63

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).

64

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

65

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

66

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

67

Evaluation of feed COD\\/sulfate ratio as a control criterion for the biological hydrogen sulfide production and lead precipitation  

Microsoft Academic Search

The ability of sulfate-reducing bacteria to produce hydrogen sulfide and the high affinity of sulfide to react with divalent metallic cations represent an excellent option to remove heavy metals from wastewater. Different parameters have been proposed to control the hydrogen sulfide production by anaerobic bacteria, such as the organic and sulfate loading rates and the feed COD\\/SO42? ratio. This work

Antonio Velasco; Martha Ram ´ õrez; Tania Volke-Sep ´ ulveda; Armando Gonzalez-S; Sergio Revah

68

Evaluation of feed COD\\/sulfate ratio as a control criterion for the biological hydrogen sulfide production and lead precipitation  

Microsoft Academic Search

The ability of sulfate-reducing bacteria to produce hydrogen sulfide and the high affinity of sulfide to react with divalent metallic cations represent an excellent option to remove heavy metals from wastewater. Different parameters have been proposed to control the hydrogen sulfide production by anaerobic bacteria, such as the organic and sulfate loading rates and the feed COD\\/SO42? ratio. This work

Antonio Velasco; Martha Ramírez; Tania Volke-Sepúlveda; Armando González-Sánchez; Sergio Revah

2008-01-01

69

Temperature and seeding effects on the precipitation of scorodite from sulfate solutions under atmospheric-pressure conditions  

NASA Astrophysics Data System (ADS)

Arsenic is a major contaminant in the nonferrous extractive metallurgy. In the past 20 years, many studies have shown that it can be precipitated as relatively stable crystalline scorodite (FeAsO4·2H2O) by precipitation under ambient or elevated pressures. In the present study, an extensive program of scorodite precipitation tests under ambient pressure has shown that the rate of scorodite formation increases dramatically by a small increase in temperature from 85 °C to 100 °C. The beneficial effects of temperature are attributed to the higher thermodynamic stability of scorodite at elevated temperatures, but also to higher rates of secondary nuclei formation and crystal growth. In any case, irrespective of the precipitation temperature, the leachability of all scorodite precipitates observed in toxicity characterization leaching procedure (TCLP) tests is below 5 mg/L As. Another parameter examined in this study was seeding. It was observed that the higher the initial concentration of seed, the faster the precipitation. Precipitation of well-crystallized scorodite can be effected equally well on heterogeneous seed such as hematite (Fe2O3) or gypsum (CaSO4·2H2O) added externally or formed in situ.

Singhania, Shalabh; Wang, Qiankun; Filippou, Dimitrios; Demopoulos, George P.

2005-06-01

70

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

71

A partial equilibrium model to characterize the precipitation of ferric ion during the leaching of chalcopyrite with ferric sulfate  

NASA Astrophysics Data System (ADS)

A partial equilibrium model has been developed and used to characterize the conditions under which precipitation of ferric ion occurs during the dump leaching of chalcopyrite ores. The precipitates which have been considered include amorphous Fe(OH)3, ?-FeOOH (goethite), and Na+, K+, Ag+, Pb2+, and H3O+ jarosites. Solution of the model equations makes possible the determination of the concentrations of the solution species during leaching of the mineral. The concentration product for Fe(OH)3 (am) and ?-FeOOH was calculated for changing solution concentrations and compared with the solubility product constants to determine when precipitation would be expected thermodynamically. The K+, Na+, Ag+, and Pb2+ concentrations that would be necessary to satisfy the solubility product constants for the corresponding jarosites were calculated for various initial concentrations and varying amounts of O2 consumption.

Liddell, Knona C.; Bautista, Renato G.

1983-03-01

72

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

73

Effect of hydrolysis conditions on hydrous TiO2 polymorphs precipitated from a titanyl sulfate and sulfuric acid solution  

NASA Astrophysics Data System (ADS)

The relationship between hydrolysis conditions and hydrous titania polymorphs obtained in a titanyl sulfate and sulfuric acid solution was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The results revealed that the feeding rate of the titanyl sulfate stock solution, the concentration of sulfuric acid, and the seed dosage of rutile crystal could significantly affect the hydrolysis rate, thus influencing the titania crystal phase. Hydrous TiO2 in the form of rutile, anatase, or the mixture of both could be obtained in solutions of low titanium concentrations and 2.5wt% to 15wt% sulfuric acid at 100°C. When the hydrolysis rate of titanium expressed by TiO2 was more than or equal to 0.04 g/(L·min), the hydrolysate was almost phase-pure anatase, while the main phase state was rutile when the hydrolysis rate was less than or equal to 0.01 g/(L·min). With the hydrolysis rate between 0.02 and 0.03 g/(L·min), the hydrolysate contained almost equal magnitude of rutile and anatase. It seems that although rutile phase is thermodynamically stable in very acidic solutions, anatase is a kinetically stable phase.

Song, Hao; Liang, Bin; Lü, Li; Wu, Pan; Li, Chun

2012-07-01

74

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

75

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 ...

76

Sulfate-reducing bacteria-dominated biofilms that precipitate ZnS in a subsurface circumneutral-pH mine drainage system.  

PubMed

The microbial diversity of ZnS-forming biofilms in 8 degrees C, circumneutral-pH groundwater in tunnels within the abandoned Piquette Zn, Pb mine (Tennyson, Wisconsin, USA) has been investigated by molecular methods, fluorescence in situ hybridization (FISH), and cultivation techniques. These biofilms are growing on old mine timbers that generate locally anaerobic zones within the mine drainage system. Sulfate-reducing bacteria (SRB) exclusively of the family Desulfobacteriaceae comprise a significant fraction of the active microbiota. Desulfosporosinus strains were isolated, but could not be detected by molecular methods. Other important microbial clusters belonged to the beta-, gamma-, and epsilon-Proteobacteria, the Cytophaga/Flexibacter/Bacteroides-group (CFB), Planctomycetales, Spirochaetales, Clostridia, and green nonsulfur bacteria. Our investigations indicated a growth dependence of SRB on fermentative, cellulolytic, and organic acid-producing Clostridia. A few clones related to sulfur-oxidizing bacteria were detected, suggesting a sulfur cycle related to redox gradients within the biofilm. Sulfur oxidation prevents sulfide accumulation that would lead to precipitation of other sulfide phases. FISH analyses indicated that Desulfobacteriaceae populations were not early colonizers in freshly grown and ZnS-poor biofilms, whereas they were abundant in older, naturally established, and ZnS-rich biofilms. Gram-negative SRB have been detected in situ over a period of 6 months, supporting the important role of these organisms in selective ZnS precipitation in Tennyson mine. Results demonstrate the complex nature of biofilms responsible for in situ bioremediation of toxic metals in a subsurface mine drainage system. PMID:14994175

Labrenz, M; Banfield, J F

2004-04-01

77

Barium titanium glycolate: A new barium titanate powder precursor  

SciTech Connect

This paper describes the synthesis and structure of a barium titanium glycolate complex and the calcination into barium titanate preceramic powders that sinter into polycrystalline, tetragonal barium titanate having good dielectric properties.

Day, V.W.; Klemperer, W.G.; Payne, D.A. [Univ. of Nebraska, Lincoln, NE (United States)] [and others] [Univ. of Nebraska, Lincoln, NE (United States); and others

1996-02-01

78

Barium ferrite permanent magnets  

Microsoft Academic Search

1.We have selected and introduced the following optimum conditions for the preparation of isotropic barium ferrite magnets:a)Barium oxide content 15 ± 1%; b) kaolin content 1%; c) roasting of mixture of ferric oxide and barium salt at temperatures of 900–950‡ with five hours holding time; d) pressure during pressing 1.5–2 t\\/cm2; e) sintering of magnets at a temperature of 1160–1260‡

I. Yu. Gershov

1964-01-01

79

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

80

Chondroitin sulfate  

MedlinePLUS

... contain chondroitin sulfate, in combination with glucosamine sulfate, shark cartilage, and camphor. But as far as we ... containing chondroitin sulfate in combination with glucosamine sulfate, shark cartilage, and camphor seems to reduce arthritis symptoms. ...

81

The high-temperature sulphation behavior of barium-based sorbents during coal combustion  

SciTech Connect

In order to promote the sulfur removal efficiency during coal combustion, the high-temperature sulfation behavior of barium-based sorbents was studied. The sulfation product BaSO{sub 4} which did not decompose until 1,580 C had much better thermal stability than CaSO{sub 4} which rapidly decomposed at about 1,300 C. The desulfurization effect of barium salt Ba{sup 2+} was much better than calcium salt Ca{sup 2+} during coal combustion at about 1,200{approximately}1,300 C. The sulfur removal efficiency of barium-based sorbents could achieve 35.5% in industrial grate furnace.

Cheng, J.; Li, N.; Zhou, J.; Cao, X.; Liu, J.; Zhao, X.; Cen, K.

2000-07-01

82

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

83

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

84

Barium and molybdenum records in bivalve shells: Geochemical proxies for phytoplankton dynamics in coastal environments?  

E-print Network

Abstract Barium : calcium and molybdenum : calcium ratios were investigated in shells of the tropicalBarium and molybdenum records in bivalve shells: Geochemical proxies for phytoplankton dynamics coupled plasma mass spectrometer. Absolute dates of shell precipitation assigned on the basis of periodic

85

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

86

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

87

Formation of alkali and alkaline earth sulfates and magnesium fluoride when magnesite is roasted in rotary furnaces, and their deposition in the electrostatic precipitators  

Microsoft Academic Search

Conclusions It is found that the caustic dust released to the atmosphere or trapped from the flue gases of a rotary furnace for magnesite roasting contains sulfur trioxide, alkalies, and fluorine, which form simple and complex sulfates of the alkali and alkaline earth metals and magnesium fluoride. The highly disperse caustic dust which is returned to the roasting furnace, and

K. V. Simonov; L. D. Bocharov; V. M. Ust'yantsev

1979-01-01

88

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

89

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

90

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

91

Comparing the relationship between precipitation and river geochemistry  

NASA Astrophysics Data System (ADS)

The geochemistry of precipitation affects the geochemistry of river water. Ideally, studies of river biogeochemistry should therefore include collection and analyses of dry and wet deposition. The Global Rivers Observatory has studied the Fraser River near Vancouver since the summer of 2009 at roughly bi-weekly resolution. The interpretation of this temporal record of river biogeochemistry, particularly the various sources of solutes, could be improved with a better understanding of atmospheric contributions. In this study precipitation and river water will be analysed from the Fraser River basin for nutrients as well as major and select trace ion concentrations. The nutrients analyzed will include ammonium (NH4), nitrate and nitrate (NO3-NO2), phosphate (PO4) and silicate (SiO4). Major ions include sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chloride (Cl), and sulfate (SO4). Trace elements may include molybdenum, strontium, barium, uranium, rubidium, manganese and iron. Samples will be collected using the bulk method which collects both wet and dry deposition . Correlating precipitation chemistry with data on wind direction may help elucidate sources of nutrients and major ions. For instance, westerly sources may transport pollution from the City of Vancouver and agricultural lands in the Fraser delta. Such pollutants may increase the acidity of precipitation and imprint the water chemistry with a unique chemical signature . The results of this study will be helpful in correcting Fraser River water data for contributions from atmospheric deposition.

Epp, A.; Luymes, R.; Bennett, M.; DaSilva, J.; Marsh, S. J.; Gillies, S. L.; Peucker-Ehrenbrink, B.; Voss, B.

2013-12-01

92

Spatial and temporal variability of precipitation for selected regions of New York State and relationship to variability in sulfate deposition measurements  

SciTech Connect

The preliminary results are presented of a study aimed at quantifying the variability in precipitation data and its role in the modeling of acidic deposition processes. The character of this variability for various regions of New York State is assessed over a 30-year period, with emphasis on the Adirondack region. Spatial and temporal means as well as coefficients of variation are presented. Of the five regions where precipitation data are investigated, the Adirondacks have the greatest overall variability, around 23 percent, while Long Island has the least, about 17 percent. A proportionality factor, based on the coefficient of variation, is suggested to account for the precipitation variability in achieving targeted wet deposition threshold values.

Pagnotti, V.; Rao, S.T.

1986-04-01

93

Tailored Barium Swallow Study  

MedlinePLUS

Tailored Barium Swallow Study The TBS is a special study that is completed in radiology. The test evaluates the mouth and the throat ... and may be asked to feed the child. Study Participants You/Your child will drink liquids or ...

94

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

95

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

96

Kinetics and mechanisms of hydrothermal synthesis of barium titanate  

SciTech Connect

Reaction mechanisms for the hydrothermal synthesis of barium titanate are evaluated. Feedstocks of barium hydroxide octahydrate and anatase titania are reacted for varying durations (1--72 h) to provide intermediate-stage samples for characterization by transmission electron microscopy/energy-dispersive spectroscopy (TEM/EDS), X-ray diffractometry (XRD), and inductively coupled plasma spectroscopy (ICP) and XRD methods permits the analysis of data with the Johnson-Mehl-Avrami equation. This analysis reveals two reaction-rate regimes. Kinetic analysis, based on reaction progress, yields insight into the first reaction-rate regime but is inconclusive in the analysis of the second reaction-rate regime. In the first regime, at the early stage of barium titanate formation, a dissolution-precipitation mechanism dominates. In contrast, in the second regime, at longer reaction times, an in-situ transformation mechanism is probably dominant. However, multiple reaction mechanisms (e.g., in-situ transformation and dissolution-precipitation) may be competing for rate control. Alternatively, dissolution-precipitation may be the dominant mechanism throughout the barium titanate synthesis, with nucleation and growth controlling the first regime and dissolution rate controlling the second regime.

Eckert, J.O. Jr.; Hung-Houston, C.C.; Gersten, B.L.; Lencka, M.M.; Riman, R.E. [Rutgers Univ., Piscataway, NJ (United States). Dept. of Ceramics

1996-11-01

97

Detection of tyrosine sulfation on proteins.  

PubMed

Tyrosine sulfation is a post-translational modification (PTM) where a sulfate group is added to a tyrosine moiety. This PTM is responsible for strengthening interaction between proteins. One of the drawbacks of studying this PTM is the lack of an antibody that can detect all tyrosine-sulfated proteins. In addition, due to the labile nature of the tyrosine sulfate, other techniques such as mass spectrometry cannot be used to study this PTM unless special modification procedures are used. This requires considerable skill and knowledge of mass spectrometry. This unit describes an in vitro technique that can be used to study tyrosine-sulfated proteins by radiolabeling the recombinant protein. The protein is then subject to barium hydroxide hydrolysis and thin-layer electrophoresis (TLE). Co-localization of radioactive tyrosine-sulfate with nonradioactive tyrosine sulfate standard spiked in before TLE analysis identifies a protein as tyrosine-sulfated protein. The advantage of this technique is that, it identifies all tyrosine-sulfated proteins without any bias and is the only technique that identifies the tyrosine sulfate residues in the protein. © 2015 by John Wiley & Sons, Inc. PMID:25829299

Kanan, Yogita; Al Ubaidi, Muayyad R

2015-01-01

98

Silicosis in barium miners.  

PubMed Central

Four men who mined barytes in Scotland and who developed pneumoconiosis are described. Three developed progressive massive fibrosis, from which two died; and one developed a nodular simple pneumoconiosis after leaving the industry. The radiological and pathological features of the men's lungs were those of silicosis and high proportions of quartz were found in two of them post mortem. The quartz was inhaled from rocks associated with the barytes in the mines. The features of silicosis in barium miners are contrasted with the benign pneumoconiosis, baritosis, that occurs in workers exposed to crushed and ground insoluble barium salts. Diagnostic difficulties arise when silicosis develops in workers mining minerals known to cause a separate and benign pneumoconiosis. These difficulties are compounded when, as not infrequently happens, the silicotic lesions develop or progress after exposure to quartz has ceased. Images PMID:3787542

Seaton, A; Ruckley, V A; Addison, J; Brown, W R

1986-01-01

99

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

100

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

101

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

102

The effect of freezing on the sulfate-chloride and density-chloride ratios of sea-water  

E-print Network

an excess of barium chloride was added to a known volume oi' sea. - water sample which had been previously acidified, diluted, and warmed. According to Pier e and Haenisch (1948) the precipitate, barium sulphate, is thirty times more soluble in one normal... hydro- chloric acid than in pure water. In spite of this, the precipitation was carried out, in an acid medium because the precipitatis forms much larger crystals and ths carbonate and phosphate salts of barium are soluble in acid media whereas...

Burkhalter, Albert Charles

1967-01-01

103

An ultrafine barium ferrite powder of high coercivity from water-in-oil microemulsion  

Microsoft Academic Search

An ultrafine barium ferrite powder of high coercivity and high saturation magnetization has been successfully prepared from an inverse water-in-oil microemulsion consisting of cyclohexane, NP5\\/NP9, and an aqueous solution of mixed ferric nitrate and barium nitrate. An ammonium hydroxide solution was used as the precipitant to obtain the hydroxide precursor of particle size in the range of 10–30nm from the

Xiangyuan Liu; John Wang; Leong-Ming Gan; Sen-Choon Ng; Jun Ding

1998-01-01

104

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

105

Preparation of Acicular Barium Ferrite Particles and Their Magnetic Properties  

Microsoft Academic Search

Methods for producing acicular barium ferrite particles for use in coated tape media were studied, and their magnetic and other properties were investigated. Acicular ¿-FeOOH particles were dispersed in a BaCl2 solution, and NaHCO3 added to precipitate BaCO3 on the particle surfaces. After washing and addition of B2O3, P2O5, or Bi2O3, particles were fired at 800 to 900°C; addition of

M. Sugimoto; Y. Arai; H. Harada; T. Nukui

1985-01-01

106

Ferric sulfates on Mars  

NASA Astrophysics Data System (ADS)

Evidence is presented for the possible formation and existence of ferric sulfato complexes and hydroxo ferric sulfate minerals in the permafrost on Mars. Acidic groundwater, derived from atmospheric oxidation of volcanogenic H2S to H2SO4 aerosols, promoted chemical weathering of fayalitic olivines, iron-rich pyroxenes, plagioclase feldspar, and pyrrhotite-pentlandite mineral assemblages in crustal ultramafic and basic igneous rocks. The acidic groundwater entered into electrochemical reactions with the iron sulfides, yielding dissolved FeSO4+, Fe(SO4)2-, and FeOH2+ complex ions, and the precipitation of basic ferric sulfate minerals such as those belonging to the roemerite, copiapite, botryogen, and jarosite-alunite groups. These phases are stabilized at low temperatures and pH in Martian permafrost. The occurrence of jarosites in terrestrial arid regions suggests that they could also survive on the surface of Mars. Melting of the permafrost and raising of the pH may have initiated the hydrolysis of dissolved ferric sulfato complex ions and led to the precipitation of FeOOH, which reacted with precipitated silica to form phyllosilicates. Alternatively, degradation of the hydrolysate FeOOH to Fe2O3 during sublimation of permafrost exposed on Mars' surface may account for the presence of eolian maghemite suspected to be the magnetic mineral observed on the Viking Landers.

Burns, Roger G.

107

Ferric sulfates on Mars  

NASA Astrophysics Data System (ADS)

Evidence is presented for the possible formation and existence of ferric sulfato complexes and hydroxo ferric sulfate minerals in the permafrost on Mars. Acidic ground water, derived from atmospheric oxidation of volcanogenic H2S to H2SO4 aerosols, promoted chemical weathering of fyalitic olivines, iron-rich pyroxenes, plagioclase feldspar, and pyrrhotite-pentlandite mineral assemblages in crustal ultramafic and basic igneous rocks. The acidic groundwater entered into electrochemical reactions with the iron sulfides, yielding dissolved FeSO4+, Fe(SO4)2-, and FeOH2+ complex ions, and the precipitation of basic ferric sulfate minerals such as those belonging to the roemerite, copiapite, botryogen, and jarosite-alunite groups. These phases are stabilized at low temperatures and pH in Martian permafrost. The occurrence of jarosites in terrestrial arid regions suggests that they could also survive on the surface of mars. Melting of the permafrost and raising of the pH may have initiated the hydrolysis of dissolved ferric sulfato complex ions and led to the precipitation of FeOOH, which reacted with precipitated silica to form phyllosilicates. Alternatively, degradation of the hydrolysate FeOOH to Fe2O3 during sublimation of permafrost exposed on Mars' surface may account for the presence of eolian maghemite suspected to be the magnetic mineral observed on the Viking Landers.

Burns, Roger G.

1987-09-01

108

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

109

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

110

FLAME SPECTROPHOTOMETRIC STUDY OF BARIUM  

Microsoft Academic Search

Flame emission characteristics of the barium ionic doublet at 455.4 and ; 4193.4 m mu , the atomic resonance line at 553.6 m mu , and the BaOH and BaO ; bands at 489 and 513 m mu were studied. A prism flame spectrophotometer ; (Beckman DU) and a grating type (Jarrell-Ash Ebert) were used. Barium ; concentrations ranged from

J. C. Burger; T. C. Rains; H. E. Zittel; J. A. Dean

1961-01-01

111

Large-volume barium aspiration.  

PubMed

We present a case of large-volume barium aspiration in a 56-year-old woman with stage IV tongue squamous cell carcinoma and longstanding dysphagia. The patient rapidly developed hypoxemic respiratory failure from the resultant chemical pneumonitis. However, her respiratory status improved with supportive care alone in 48 hours. Barium aspiration is rare and often produces dramatic radiographic findings, but is generally associated with a favorable prognosis. PMID:25829647

Hundemer, Gregory L; Kumar, Varun; Vaduganathan, Muthiah

2015-04-01

112

Large-volume barium aspiration  

PubMed Central

We present a case of large-volume barium aspiration in a 56-year-old woman with stage IV tongue squamous cell carcinoma and longstanding dysphagia. The patient rapidly developed hypoxemic respiratory failure from the resultant chemical pneumonitis. However, her respiratory status improved with supportive care alone in 48 hours. Barium aspiration is rare and often produces dramatic radiographic findings, but is generally associated with a favorable prognosis. PMID:25829647

Hundemer, Gregory L.; Kumar, Varun

2015-01-01

113

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

114

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

115

Lead removal through biological sulfate reduction process  

Microsoft Academic Search

The feasibility of lead removal through biological sulfate reduction process with ethanol as electron donor was investigated. Sulfide-rich effluent from biological process was used to remove lead as lead sulfide precipitate. The experiments were divided into two stages; Stage I startup and operation of sulfidogenic process in a UASB reactor and Stage II lead sulfide precipitation. In Stage I, the

Tran Thi Hien Hoa; Warounsak Liamleam; Ajit P. Annachhatre

2007-01-01

116

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

117

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.

118

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

119

Fully-Ionized Barium Plasma Source  

Microsoft Academic Search

A device for generating a fully-ionized barium plasma column is described. It is similar to the previously described Q1 device except for the substitution of rhenium ionizing surfaces for tungsten, and barium for the alkali metals. The main motivation for the use of barium is that singly-ionized barium has its resonance lines in the visible wavelength range, and thus allows

N. Rynn; E. Hinnov; L. C. Johnson

1967-01-01

120

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

121

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

122

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

PubMed Central

Objective To describe our initial experience with CT-guided percutaneous barium marking for the localization of small pulmonary nodules prior to video-assisted thoracoscopic surgery (VATS). Materials and Methods From October 2010 to April 2011, 10 consecutive patients (4 men and 6 women; mean age, 60 years) underwent CT-guided percutaneous barium marking for the localization of 10 small pulmonary nodules (mean size, 7.6 mm; range, 3-14 mm): 6 pure ground-glass nodules, 3 part-solid nodules, and 1 solid nodule. A 140% barium sulfate suspension (mean amount, 0.2 mL; range, 0.15-0.25 mL) was injected around the nodules with a 21-gauge needle. The technical details, surgical findings and pathologic features associated with barium localizations were evaluated. Results All nodules were marked within 3 mm (mean distance, 1.1 mm; range, 0-3 mm) from the barium ball (mean diameter, 9.6 mm; range, 8-16 mm) formed by the injected barium suspension. Pneumothorax occurred in two cases, for which one needed aspiration. However, there were no other complications. All barium balls were palpable during VATS and visible on intraoperative fluoroscopy, and were completely resected. Both the whitish barium balls and target nodules were identifiable in the frozen specimens. Pathology revealed one invasive adenocarcinoma, five adenocarcinoma-in-situ, two atypical adenomatous hyperplasias, and two benign lesions. In all cases, there were acute inflammations around the barium balls which did not hamper the histological diagnosis of the nodules. Conclusion CT-guided percutaneous barium marking can be an effective, convenient and safe pre-operative localization procedure prior to VATS, enabling accurate resection and diagnosis of small or faint pulmonary nodules. PMID:23118567

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

2012-01-01

123

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

124

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

125

Diacetamidinium sulfate  

PubMed Central

In the crystal structure of the title compound, 2C2H7N2 +·SO4 2?, which contains four cations and two anions in the asymmetric unit, the ions are inter­connected by an extensive hydrogen-bonding system whereby two of the O atoms of sulfate ion are hydrogen-bonded to the amidinium H atoms of two cations, leading to the formation of two eight-membered rings. The two remaining O atoms inter­connect two H atoms of acetamidinium cations, forming an infinite chain. The C?N separations within the H2N?C?NH2 moieties are similar, with an average value of 1.305?(2)?Å, which is in good agreement with a delocalization model. PMID:21589618

Jalový, Zden?k; R?ži?ka, Aleš

2010-01-01

126

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

127

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

128

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

129

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2014 CFR

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

2014-07-01

130

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

131

Investigations on Barium Ferrite Magnets  

Microsoft Academic Search

Barium ferrite (BaO:6Fe2O3) has been investigated magnetically to test the predictions of fine particle theory in the region of grain sizes larger than the critical one for which no satisfactory theory exists as yet. Grain size and coercive force of polycrystalline magnets (nonoriented and crystal oriented) were closely related to sintering temperatures. A comparison of theoretical and observed temperature dependence

K. J. Sixtus; K. J. Kronenberg; R. K. Tenzer

1956-01-01

132

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

133

Barium in planktonic foraminifera  

SciTech Connect

Reconstructions of Ba distributions in ancient oceanic surface waters could provide new insight into paleoceanographic change. Calcite shells of planktonic foraminifera potentially provide a means of reconstructing such paleo-Ba distributions if lattice-bound Ba can be determined on shells recovered from deep-sea cores. Planktonic foraminifera shells from a series of cores were purified of non-lattice-bound Ba associated with organic or sedimentary phases by a combination of physical agitation, oxidative-reductive steps, acid leaches, and a novel alkaline-DTPA step to dissolve barite. A sequential dissolution of a large sample of cleaned shells of the planktonic foraminifer Globigerinoides conglobatus indicates homogeneous distribution of Ba in the shell material. Comparison of shells from sediments, sediment traps, and plankton tows indicates no significant differences in the Ba content of the purified shells. Variation in foraminiferal Ba contents between the Pacific, Atlantic, and Mediterranean Sea is consistent with the trend in surface seawater Ba. The calculated distribution coefficient for Ba incorporation in five species based on these data is 0.19 {plus minus} 0.05. Several species of the non-spinose planktonic foraminifera Globorotalia have Ba/Ca ratios ranging from 2 to 13 {mu}mol; these high Ba contents might be explained by differences in the way these foraminifera precipitate their shells. A temporal record of Ba/Ca in samples of Globigerinoides and Orbulina from a core in the northwest Atlantic suggests that the Ba concentration of surface waters at this site has not changed by more than 20% over the last 14 kyr.

Lea, D.W.; Boyle, E.A. (Massachusetts Inst. of Tech., Cambridge (United States))

1991-11-01

134

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

135

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

136

Novel Thermally Stable Poly (vinyl chloride) Composites for Sulfate Removal  

EPA Science Inventory

BaCO3 dispersed PVC composites were prepared through a polymer re-precipitation method. The composites were tested for sulfate removal using rapid small scale column test (RSSCT) and found to significantly reduce sulfate concentration. The method was extended to synthe...

137

Redox processes in highly yttrium-doped barium titanate  

SciTech Connect

The changes of microstructure occurring during oxidation of the reduced form of yttrium-doped barium titanate (Ba{sub 1-x}Y{sub x}{sup ?}Ti{sub 1-x}{sup 4+}Ti{sub x}{sup 3+}O{sub 3}) have been studied. Samples were sintered under reduction conditions at P{sub O{sub 2}}=10{sup -4}Pa and oxidized by annealing at high temperatures (1150 and 1350 deg. C) in air. Depending on yttrium concentration, the oxidation of the reduced form of the yttrium-doped BaTiO{sub 3} caused precipitation of the phase Ba{sub 6}Ti{sub 17}O{sub 40} or the phases Ba{sub 6}Ti{sub 17}O{sub 40} and Y{sub 2}Ti{sub 2}O{sub 7}. The precipitates had well-defined orientational relationships with the perovskite matrix. Oxidation of the reduced form of doped barium titanate results in formation of the phase Ba{sub 1-x}Y{sub x}{sup ?}Ti{sub 1-x/4}{sup 4+}(V{sub Ti}{sup -}bar ){sub x/4}O{sub 3} responsible for increase in the resistance of outer grain layers, which lie between grain boundaries and grain.

Belous, Anatolii [Department of Solid State Chemistry, V.I. Vernadskii Institute of General and Inorganic Chemistry, Ukrainian National Academy of Sciences, Institute of General and Inorganic Chemistry, 32/42, Palladin Ave, 03680 Kyiv 142 (Ukraine); V'yunov, Oleg [Department of Solid State Chemistry, V.I. Vernadskii Institute of General and Inorganic Chemistry, Ukrainian National Academy of Sciences, Institute of General and Inorganic Chemistry, 32/42, Palladin Ave, 03680 Kyiv 142 (Ukraine)]. E-mail: vyunov@ionc.kar.net; Kovalenko, Leonid [Department of Solid State Chemistry, V.I. Vernadskii Institute of General and Inorganic Chemistry, Ukrainian National Academy of Sciences, Institute of General and Inorganic Chemistry, 32/42, Palladin Ave, 03680 Kyiv 142 (Ukraine); Makovec, Darko [Jozef Stefan Institute, Ljubljana (Slovenia)

2005-05-15

138

Sol-gel synthesis of barium titanate powders using barium acetate and titanium(IV) isopropoxide  

SciTech Connect

A sol-gel process for low-temperature preparation of BaTiO{sub 3} powders is described. Chemical polymerization between barium acetate and titanium(IV) isopropoxide leads to the formation of barium titanate gels. After suitable drying and calcination treatments, the barium titanate gels were converted to BaTiO{sub 3} powders. The barium titanate gels and powders were characterized by TGA, DTA, and XRD. The results of these analyses indicate that it is possible to obtain stoichiometric (Ba/Ti = 0.99), homogeneous, high-purity BaTiO{sub 3} powders using relatively inexpensive barium acetate as a starting material.

Phule, P.P.; Risbud, S.H. (Univ. of Arizona, Tucson (USA))

1988-03-01

139

Noise characterisation of barium ferrite dispersions  

Microsoft Academic Search

Structural changes in barium ferrite dispersions during the milling process have been investigated by using noise measurements of the remanent states (DC modulation noise). Doped barium ferrite particles mixed with solvents, self wetting resins and binders were dispersed using a bead mill. Samples extracted at intervals during the process were coated onto PET film and magnetically oriented before drying. Tapes

S. M. McCann; P. M. Sollis; P. R. Bissell; T. Onions

1999-01-01

140

REMOVAL OF BARIUM AND RADIUM FROM GROUNDWATER  

EPA Science Inventory

A research project was undertaken to investigate processes for removing barium and radium from drinking water. Special emphasis was placed on ion exchange processes that can be used without adding large concentrations of sodium to the water. The wastes from radium and barium remo...

141

Tribological properties of barium ferrite films  

Microsoft Academic Search

Acoustic emission and friction coefficients have been measured during start-stop and continuous sliding for pure and doped barium ferrite films, without lubrication, and compared with concomitant surface topography and magnetic properties. Barium ferrite films averaging about 100 nm in thickness, were produced on thermally oxidized Si substrates by sputter deposition and then furnace or rapid thermal annealed in order to

M. Scherge; X. Sui; X. Ma; C. L. Bauer; M. S. Jhon; M. H. Kryder

1995-01-01

142

Bioremediation of acid mine water using facultatively methylotrophic metal-tolerant sulfate-reducing bacteria  

Microsoft Academic Search

A microbial process is proposed for the decontamination of acid uranium mine water high in sulfates and metals. Sulfate reducers are suitable for such a process. Anaerobic reduction of sulfate results in the formation of H2S which leads to an increase in pH and the precipitation of the metals. As cheap an readily available carbon and energy source methanol was

Barbara C. Hard; S. Friedrich; W. Babel

1997-01-01

143

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

144

Synthesis and characterization of Co–Sn substituted barium ferrite particles by a reverse microemulsion technique  

Microsoft Academic Search

A series of Co–Sn substituted barium ferrite particles have been successfully synthesized by a reverse microemulsion technique. The effects of heteroatom contents and precipitating agents were investigated, respectively. It was found that the presence of heteroatoms could enhance lattice parameters, affect morphology evolution and modulate magnetic properties. Particularly, an unusual saturation magnetization (>70.0emu\\/g) could be achieved under low heteroatoms concentration

Xiaojia Gao; Yunchen Du; Xinrong Liu; Ping Xu; Xijiang Han

2011-01-01

145

Magnetic properties of barium ferrite synthesized using a microemulsion mediated process  

Microsoft Academic Search

Ultrafine barium ferrite particles have been synthesized using a microemulsion mediated process. The aqueous cores (typically 10-25 nm in size) of water-in-oil microemulsions were used as constrained microreactors for the precipitation of precursor carbonates of Ba2+ and Fe3+. These precursors (5-15 nm in size) when heated at 950°C, transformed to the hexagonal ferrite BaFe12O19 as confirmed by X-ray diffraction. This

Vinod Pillai; Promod Kumar; D. O. Shah

1992-01-01

146

Crystallization of Chicken Egg White Lysozyme from Sulfate Salts  

NASA Technical Reports Server (NTRS)

It has been "known" that chicken egg white lysozyme does not crystallize from sulfate, particularly ammonium sulfate, salts, but instead gives amorphous precipitates. This has been the basis of several studies using lysozyme comparing macromolecule crystal nucleation and amorphous precipitation. Recently Ries-Kautt et al (Acta Cryst D50, (1994) 366) have shown that purified isoionic CEWL could be crystallized from low concentrations of sulfate at basic pH, and we subsequently showed that in fact CEWL could be purified in both the tetragonal and orthorhombic forms using ammonium sulfate over the pH range 4.0 to 7.8 (Acta Cryst D53, (1997) 795). We have now extended these observations to include a range of common sulfate salts, specifically sodium, potassium, rubidium, magnesium, and manganese sulfates. In all cases but the manganese sulfates both the familiar tetragonal and orthorhombic forms were obtained, with unit cell dimensions close to those known for the "classic" sodium chloride crystallized forms. Manganese sulfate has only yielded orthorhombic crystals to date. All crystallizations were carried out using low (typically less than or equal to 6 M) salt and high (greater than approximately 90 mg/ml) protein concentrations. As with ammonium sulfate, the tetragonal - orthorhombic phase shift appears to be a function of both the temperature and the protein concentration, with higher temperatures and concentrations favoring the orthorhombic and lower the tetragonal form. The phase change range is somewhat reduced for the sulfate salts, depending upon conditions being typically between approximately 15 - 20 C. Both the magnesium and manganese sulfates gave crystals at salt concentrations over 0.6 M as well, with magnesium sulfate giving a very slowly nucleating and growing hexagonal form. A triclinic crystal form, characterized by aggressively small crystals (typically 0.1 mm in size) has been occasionally obtained from ammonium sulfate. Finally, preliminary spot solubility determinations have suggested that in some cases the solubility increases with increasing salt concentrations.

Forsythe, Elizabeth; Pusey, Marc

1998-01-01

147

Preparation of BaHfO3:Ce3+ Fine Powders by Co-Precipitation Method  

NASA Astrophysics Data System (ADS)

Ultrafine powders of barium hafnate doped with trivalent cerium were prepared by co-precipitation method with ammonium bicarbonate and oxalate. An influence of the precipitant and annealing temperature on morphology, phase composition and photoluminescent properties of the powders has been studied.

Tretyak, E. V.; Antanovich, A. V.

2013-05-01

148

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

Microsoft Academic Search

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

Paphungkorn Teekayuttasakul; Ajit P. Annachhatre

2008-01-01

149

Observe Precipitation  

NSDL National Science Digital Library

Water that falls from the sky is called precipitation. Precipitation such as rain or snow can affect daily life; however, it is also a vital step in the water cycle, returning water from the atmosphere back to Earth's surface. This video segment shows three different types of precipitation: rain, hail, and snow. The segment is fifty-nine seconds in length. A background essay and list of discussion questions are also provided.

150

Barium ions for quantum computation  

NASA Astrophysics Data System (ADS)

Barium ion is investigated as a hyperfine qubit. 137Ba + is trapped in a linear Paul trap and laser cooled. Isotope selective photoionization is employed to improve trapping from an isotopically inpure source. Optical pumping into the magnetically insensitive 2S 1/2(F=2) mF = 0 state is shown, and readout by electron shelving into the 2D5/2 is demonstrated both directly and by adiabatic passage. Rabi flops between the 2S1/2 F=1 and F=2 states is accomplished by exposure to 8.037 GHz microwave radiation. Several methods of locking the cooling lasers have been attempted and are discussed. Stabilization of the infrared laser used to drive the D 5/2 ? S1/2 transition is of particular interest, and several novel technologies are tested in this purpose.

Dietrich, Matthew

151

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

152

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 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.degree. 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.

Zaromb, Solomon (95706 William Dr., Hinsdale, IL 60521); Lawson, Daniel B. (925 Putnam Dr., Lockport, IL 60441)

1994-01-01

153

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

154

Lead removal through biological sulfate reduction process.  

PubMed

The feasibility of lead removal through biological sulfate reduction process with ethanol as electron donor was investigated. Sulfide-rich effluent from biological process was used to remove lead as lead sulfide precipitate. The experiments were divided into two stages; Stage I startup and operation of sulfidogenic process in a UASB reactor and Stage II lead sulfide precipitation. In Stage I, the COD:S ratio was gradually reduced from 15:1 to 2:1. At the COD:S ratio of 2:1, sulfidogenic condition was achieved as identified by 80-85% of electron flow by sulfate reducing bacteria (SRB). COD and sulfate removal efficiency were approximately 78% and 50%, respectively. In Stage II, the effluent from UASB reactor containing sulfide in the range of 30-50 mg/L and lead-containing solution of 45-50 mg/L were fed continuously into the precipitation chamber in which the optimum pH for lead sulfide precipitation of 7.5-8.5 was maintained. It was found that lead removal of 85-95% was attained. PMID:17174088

Hien Hoa, Tran Thi; Liamleam, Warounsak; Annachhatre, Ajit P

2007-09-01

155

Geophysical disturbance environment during the NASA/MPE barium release at 5 earth radii on September 21, 1971.  

NASA Technical Reports Server (NTRS)

The geophysical disturbance environment was quiet during the NASA/MPE barium release at 5 earth radii on September 21, 1971. At the time of the release, the magnetosphere was in the late recovery phase of a principal magnetic storm, the provisional Dst value was -13 gammas, and the local horizontal disturbance at Great Whale River was near zero. Riometer and other observations indicated low-level widespread precipitation of high-energy electrons at Great Whale River before, during, and after the release. Cloudy sky at this station prevented optical observation of aurora. No magnetic or ionospheric effects attributable to the barium release were detected at Great Whale River.

Davis, T. N.; Stanley, G. M.; Boyd, J. S.

1973-01-01

156

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

157

Point defects and properties of barium titanate  

SciTech Connect

The authors consider the simple case of uniformly distributed atomic point defects over the volume of a barium titanate crystal. The diversity of phenomena associated with the transport of electric charge in barium titanate is determined by the distinctive features of its point defects: the existence of two regions of disorder, one of which corresponds to a compensated semiconductor while the other corresponds to an uncompensated semiconductor and a difference in the kinetics of the relaxation of two types of dominant atomic defects, viz., oxygen and barium vacancies. The authors have made a quantitative examination of the interrelation between the conditions of the preparation of materials based on barium titanate and their electrical conductivity.

Prisedskii, V.V.; Tret'yakov, Y.D.

1986-01-01

158

Spinwave spectrum for barium ferrite (abstract)  

Microsoft Academic Search

In order to determine whether barium ferrite will be suitable for microwave and millimeter wave device applications, it is essential to calculate the intrinsic ferrimagnetic resonance linewidth for perfect single crystals of this compound. The two mechanisms believed to be responsible for the intrinsic linewidth of barium ferrite, the Kasuya–LeCraw1 two-magnon one-phonon process and the two-magnon scattering caused by the

S. P. Marshall; J. B. Sokoloff

1990-01-01

159

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

160

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

161

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

162

Precipitation research  

Microsoft Academic Search

Major flood events during the past 4 yr in the United States have focused attention on the need for additional research relating to the measurement and estimation of areal distribution of precipitation. The characteristics of the precipitation associated with the storms that produced the major floods varied widely. Major flooding occurred over a large area of the lower Mississippi River

Eugene L. Peck

1975-01-01

163

Precipitation Rate  

NSDL National Science Digital Library

A GIF or Flash animation displays the actual monthly amount of precipitation (mm) reaching the surface. Focus on seasonal changes in precipitation associated with the north-south movement of the Intertropical Convergence Zone (ITC) in Africa and monsoonal patterns on the Indian subcontinent. In the Flash format, the animation can easily be rewound or paused to stress important points.

climvis.org

164

Sulfated glycans in inflammation.  

PubMed

Sulfated glycans such as glycosaminoglycans on proteoglycans are key players in both molecular and cellular events of inflammation. They participate in leukocyte rolling along the endothelial surface of inflamed sites; chemokine regulation and its consequential functions in leukocyte guidance, migration and activation; leukocyte transendothelial migration; and structural assembly of the subendothelial basement membrane responsible to control tissue entry of cells. Due to these and other functions, exogenous sulfated glycans of various structures and origins can be used to interventionally down-regulate inflammation processes. In this review article, discussion is given primarily on the anti-inflammatory functions of mammalian heparins, heparan sulfate, chondroitin sulfate, dermatan sulfate and related compounds as well as the holothurian fucosylated chondroitin sulfate and the brown algal fucoidans. Understanding the underlying mechanisms of action of these sulfated glycans in inflammation, helps research programs involved in developing new carbohydrate-based drugs aimed to combat acute and chronic inflammatory disorders. PMID:25576741

Pomin, Vitor H

2015-03-01

165

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

166

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

167

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

168

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 heterogenous catalyst for gasification.

Elliott, Douglas C; Oyler, James

2013-12-17

169

Thermochemical hydrogen production via a cycle using barium and sulfur - Reaction between barium sulfide and water  

NASA Technical Reports Server (NTRS)

The reaction between barium sulfide and water, a reaction found in several sulfur based thermochemical cycles, was investigated kinetically at 653-866 C. Gaseous products were hydrogen and hydrogen sulfide. The rate determining step for hydrogen formation was a surface reaction between barium sulfide and water. An expression was derived for the rate of hydrogen formation.

Ota, K.; Conger, W. L.

1977-01-01

170

Acid Precipitation  

NSDL National Science Digital Library

Acid precipitation will be defined. At different points in the lesson students will write balanced reactions for the formation acid precipitation from atmospheric sulfur and nitrogen oxides and the neutralization of acids by limestone. Students will determine which states are most at risk from acid precipitation and assess how that risk has changed from 1996 to 2006. Sources of atmospheric sulfur (burning of high-sulfur coal) and nitrogen oxides (automobile exhaust) will be listed. The buffering effect of limestone soils and its mitigating effect on acid precipitation will be discussed. Students will correlate these areas with sulfur and nitrogen oxide production, population, composition of coal fields, and soil composition. This resource includes both a teaching guide and student worksheets.

Tyser, Jim

171

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

172

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

173

Heparan Sulfate Proteoglycans  

PubMed Central

Heparan sulfate proteoglycans are found at the cell surface and in the extracellular matrix, where they interact with a plethora of ligands. Over the last decade, new insights have emerged regarding the mechanism and biological significance of these interactions. Here, we discuss changing views on the specificity of protein–heparan sulfate binding and the activity of HSPGs as receptors and coreceptors. Although few in number, heparan sulfate proteoglycans have profound effects at the cellular, tissue, and organismal level. PMID:21690215

Sarrazin, Stephane; Lamanna, William C.; Esko, Jeffrey D.

2011-01-01

174

Plagioclase dissolution during CO?-SO? 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

175

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

176

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

177

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

178

Properties and uses of barium ferrite ceramic magnets  

Microsoft Academic Search

1.Barium ferrite is a promising ceramic material for permanent magnets. It does not include scarce and expensive materials. It has a low density and high coercive force; components with barium ferrite magnets therefore have high stability in operation, and high maximum specific magnetic energy, especially in anisotropic magnets.2.For the successful use of barium ferrite magnets it is essential to consider

I. Yu. Gershov

1963-01-01

179

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

180

Magnetoresistive Conductive Polyaniline-Barium Titanate Nanocomposites with Negative Permittivity  

E-print Network

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

Guo, John Zhanhu

181

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

182

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 of crystals from barium titanate (BT) family make them promising candidates for various applications@uos.de; vgrachev@uos.de; schirmer@uos.de Abstract The results of the study of charge transfer processes in barium

Malovichko, Galina

183

Compact pulse forming line using barium titanate ceramic material  

Microsoft Academic Search

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

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

2011-01-01

184

Surface treatment of barium gallogermanate laser glass  

NASA Astrophysics Data System (ADS)

The surface of barium gallogermanate glass is modified through HCl solution etching to remove the surface defects and contaminations. The etching process and mechanism for barium gallogermanate glass in hydrochloric acid are investigated, and its optimum conditions are determined. However, the HCl etching induces the insoluble etch product containing minute crystal particles on glass surface. By heating BGG glass at the optical fiber drawing temperature, the deposited surface layer turned to be amorphous again and results in the increase of the transmittance of glass. The results indicated that the HCl etching combined with subsequent high-temperature heat treatment is an effective approach to improve the surface quality of barium gallogermanate glass, which would reduce the optical loss of the final optical fiber.

Yang, Gang; Qian, Qi; Yang, Zhongmin

2011-01-01

185

Sulfur isotopes as indicators of amended bacterial sulfate reduction processes influencing field scale uranium bioremediation.  

PubMed

Aqueous uranium (U(VI)) concentrations in a contaminated aquifer in Rifle Colorado have been successfully lowered through electron donor amended bioreduction. Samples collected during the acetate amendment experiment were analyzed for aqueous concentrations of Fe(ll), sulfate, sulfide, acetate, U(VI), and delta(34)S of sulfate and sulfide to explore the utility of sulfur isotopes as indicators of in situ acetate amended sulfate and uranium bioreduction processes. Enrichment of up to 7% per hundred in delta(34)S of sulfate in down-gradient monitoring wells indicates a transition to elevated bacterial sulfate reduction. A depletion in Fe(II), sulfate, and sulfide concentrations atthe height of sulfate reduction, along with an increase in the delta(34)S of sulfide to levels approaching the delta(34)S values of sulfate, indicates sulfate limited conditions concurrent with a rebound in U(VI) concentrations. Upon cessation of acetate amendment, sulfate and sulfide concentrations increased, while delta(34)S values of sulfide returned to less than -20% per hundred and sulfate delta(34)S decreased to near-background values, indicating lower levels of sulfate reduction accompanied by a corresponding drop in U(VI). Results indicate a transition between electron donor and sulfate-limited conditions at the height of sulfate reduction and suggest stability of biogenic FeS precipitates following the end of acetate amendment. PMID:19031870

Druhan, Jennifer L; Conrad, Mark E; Williams, Kenneth H; N'Guessan, Lucie; Long, Philip E; Hubbard, Susan S

2008-11-01

186

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

187

Intracytoplasmic barium salts in pleural fluid.  

PubMed

Cytological examination of the pleural effusion fluid obtained from a 66-yr-old Chinese lady showed numerous intra- and extracytoplasmic colourless refractile non-birefringent crystals. X-ray analysis of the crystals identified barium salts. On further inquiry, it was learnt that the fluid obtained had been placed in a specimen bottle provided by the x-ray department. This container was presumably contaminated with barium salts. The case highlights an unusual aspect of specimen contamination and the usefulness of x-ray analysis in the identification of crystals/substances. PMID:8165010

Chan, A C; Collins, R J; Cheung, T K

1993-10-01

188

Electric field tunable 60 GHz ferromagnetic resonance response in barium ferrite-barium strontium titanate multiferroic heterostructures  

E-print Network

barium strontium titanate films on Nb-doped strontium titanate substrates were capped with an unbondedElectric field tunable 60 GHz ferromagnetic resonance response in barium ferrite-barium strontium titanate multiferroic heterostructures Young-Yeal Song,1,a Jaydip Das,1 Pavol Krivosik,1,2 Nan Mo,1

Patton, Carl

189

Automotive sulfate emission data.  

PubMed Central

This paper discusses automotive sulfate emission results obtained by the Office of Mobile Source Air Pollution Control of EPA, General Motors, Ford, Chrysler, and Esso. This work has been directed towards obtaining sulfate emission factors for cars with and without catalyst. While the EPA and Chrysler investigations have found significant sulfate formation in noncatalyst cars, GM, Ford, and Esso have found only trace levels from noncatalyst cars. All of these investigators agree that much higher quantities of sulfate are emitted from catalyst cars. The work done to date shows pelleted catalysts to have much lower sulfate emissions over the low speed-EPA Federal Test Procedures than monolith catalysts. This is probably due to temporary storage of sulfates on the catalyst due to chemical interaction with the alumina pellets. The sulfate compounds are, to a large degree, emitted later under higher speed conditions which result in higher catalyst temperatures which decompose the alumina salt. Future work will be directed towards further elucidation of this storage mechanism as well as determining in detail how factors such as air injection rate and catalyst location affect sulfate emissions. PMID:50932

Somers, J H

1975-01-01

190

Allergy to protamine sulfate  

Microsoft Academic Search

Adverse responses to protamine sulfate have been identified for many years. The antigen-antibody response to protamine sulfate results in a type I anaphylactic reaction. Manifestations of allergic reactions include hypotension, bronchospasm, and skin and mucous membrane reactions. The severity of the adverse responses may vary from mild to causing death. Several potential risk factors for adverse reactions to protamine have

Renate Porsche; Zara R. Brenner

1999-01-01

191

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

192

Microcapsules with Intrinsic Barium Radiopacity for Immunoprotection and X-ray/CT imaging of Pancreatic Islet Cells  

PubMed Central

Microencapsulation is a commonly used technique for immunoprotection of engrafted therapeutic cells. We investigated a library of capsule formulations to determine the most optimal formulation for pancreatic beta islet cell transplantation, using barium as the gelating ion and clinical-grade protamine sulfate (PS) as a new cationic capsule cross-linker. Barium-gelated alginate/PS/alginate microcapsules (APSA, diameter = 444±21 ?m) proved to be mechanically stronger and supported a higher cell viability as compared to conventional alginate/poly-L-lysine/alginate (APLLA) capsules. Human pancreatic islets encapsulated inside APSA capsules, gelated with 20 mM barium as optimal concentration, exhibited a sustained morphological integrity, viability, and functionality for at least 3–4 weeks in vitro, with secreted human C-peptide levels of 0.2–160 pg/ml/islet. Unlike APLLA capsules that are gelled with calcium, barium-APSA capsules are intrinsically radiopaque and, when engrafted into mice, could be readily imaged in vivo with micro-computed tomography (CT). Without the need of adding contrast agents, these capsules offer a clinically applicable alternative for simultaneous immunoprotection and real-time, non-invasive X-ray/CT monitoring of engrafted cells during and after in vivo administration. PMID:22444642

Arifin, D.R.; Manek, S.; Call, E.; Arepally, A.; Bulte, J.W.M.

2012-01-01

193

Gas hydrate decomposition and migration of the sulfate/methane transition zone recorded by authigenic barite in cold seep sediments  

NASA Astrophysics Data System (ADS)

After deposition of sediments a whole suite of geochemical/biogeochemical and transport processes - subsumed under the term early diagenesis - can potentially alter the primary sediment composition. Post-depositional overprint is not only restricted to the topmost part of the sediment but well extends into more deeply buried sediments. A biogeochemical reaction front which is of particular importance for deep post-depositional alteration is the so-called sulfate/methane transition zone (SMTZ) where the anaerobic oxidation of methane (AOM) by sulfate occurs. This front is often located several meters to several tens of meters within the sediment and can heavily impact a number of sedimentary components and attributes - like carbonates, barite, iron oxide and iron sulfide minerals as well as rock magnetic properties (e.g., magnetic susceptibility). In this way the primary sediment composition is distinctly altered several thousands to tens of thousands of years after deposition. Identifying and quantifying such diagenetic overprint is of the utmost importance to accurately interpret the sedimentary record. In marine environments affected by hydrocarbon seepage and/or the presence of gas hydrates the geochemical zonation is often significantly condensed and the sulfate/methane transition zone is typically located close to the sediment surface - in this way impacting the initial sediment composition at relatively shallow depth. While the process of AOM induces the destruction of several primary sediment components it also goes along with the diagenetic formation of secondary signals. One of these diagenetically formed compounds is authigenic barite which precipitates slightly above the SMTZ. We demonstrate that - following the approach of Dickens (2001) - authigenic barite can be a valuable geochemical proxy to trace the downward migration of the SMTZ over time as a result of the decomposition of gas hydrates and/or a decrease in the upward flux of hydrocarbons. Reference Dickens, G.R. (2001) Sulfate profiles and barium fronts in sediment on the Blake Ridge: Present and past methane fluxes through a large gas hydrate reservoir. Geochim. Cosmochim. Acta, 65, 529-543.

Kasten, S.; Hensen, C.; Spiess, V.; Blumenberg, M.; Schneider, R. R.

2010-12-01

194

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.

195

Electric Tuning of Ferromagnetic Resonances in Hexagonal-Barium-Ferrite\\/Barium-Strontium-Titanate Heterostructures  

Microsoft Academic Search

This letter reports the first demonstration of a monolithic heterostructure with a large electric tuning of the ferromagnetic resonance (FMR) at millimeter-wave frequencies. The structure is composed of a barium-strontium-titanate (BST) film and two thin platinum electrodes, all grown on a barium ferrite slab with in-plane uniaxial anisotropy. The electric tuning of the FMR responses around 60 GHz was obtained

Young-Yeal Song; Jaydip Das; Pavol Krivosik; Hyung-Kee Seo; Mingzhong Wu

2010-01-01

196

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...

197

Precipitation Matters  

ERIC Educational Resources Information Center

Although weather, including its role in the water cycle, is included in most elementary science programs, any further examination of raindrops and snowflakes is rare. Together rain and snow make up most of the precipitation that replenishes Earth's life-sustaining fresh water supply. When viewed individually, raindrops and snowflakes are quite…

McDuffie, Thomas

2007-01-01

198

Nitrogen and sulfur content and pH of precipitation in Iowa  

Microsoft Academic Search

Ammonium-N, nitrate-N, sulfate-S, and phosphate-P concentrations, along with pH of precipitation samples, were measured at six sites in Iowa from Sept. 1971 through Dec. 1973. The amounts of nutrient constituents added by precipitation were determined. The annual amounts of NHâ-N and NOâ-N added by precipitation at each site were about equal. The annual amount of inorganicN added per hectare ranged

M. A. Tabatabai; J. M. Laflen

1976-01-01

199

Photometric determination of aluminum sulfate in a zinc-aluminum-containing bath in viscose manufacturing  

Microsoft Academic Search

A procecure has been developed for the photometric determination of the aluminum sulfate content of a mixed zinc-aluminum-containing precipitation bath in viscose manufacturing, using the bifunctional organic reagent chromazo-BRZ.

I. P. Smirnov

1990-01-01

200

Investigations on barium ferrite magnetic thin films  

Microsoft Academic Search

Summary form only given. Barium ferrite thin films are promising candidates for both longitudinal and perpendicular recording media. It is important to understand the time dependent phenomena in these thin films as many of the critical properties of magnetic recording media are directly related to it. The time dependent phenomenon is also known as magnetic viscosity. The magnetic viscosity parameter,

Wenjie Pang; Hong Sun

2002-01-01

201

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

202

Phase associations of barium in marine sediments  

Microsoft Academic Search

Barium (Ba) is associated with various phases in marine sediments, including carbonates, organic matter, opal, ferromanganese oxyhydroxides, terrestrial silicates and other detrital material, and barite. Using samples representing sediments from a wide variety of sedimentary environments and export production regimes, we show that there is a considerable range in Ba concentrations associated with five operationally defined phases using a sequential

Meagan Eagle Gonneea; Adina Paytan

2006-01-01

203

Allergy to protamine sulfate.  

PubMed

Adverse responses to protamine sulfate have been identified for many years. The antigen-antibody response to protamine sulfate results in a type I anaphylactic reaction. Manifestations of allergic reactions include hypotension, bronchospasm, and skin and mucous membrane reactions. The severity of the adverse responses may vary from mild to causing death. Several potential risk factors for adverse reactions to protamine have been identified, including insulin-dependent diabetes mellitus, vasectomy, allergy to fish, prior exposure to protamine sulfate, and the rate of infusion. A case study is presented, and strategies for improving patient outcomes are discussed. PMID:10580216

Porsche, R; Brenner, Z R

1999-01-01

204

Interactions of aminoalkylcarbamoyl cellulose derivatives and sodium dodecyl sulfate. 2. Foam stabilization  

Microsoft Academic Search

We have compared the interactions between polyquaternium 10 and sodium dodecyl sulfate with similar complexes of mono and diquaternary ammoniumalkylcarbamoyl cellulose derivatives by measuring the foaming efficiency and foam stability of their aqueous solutions. At approximately a 1:1 stoichiometric ratio of sodium dodecyl sulfate (SDS) to quaternary groups, an insoluble precipitate began to form. Maximum foamability and foam stabilization were

Melissa Manuszak Guerrini; Robert Y. Lochhead; William H. Daly

1999-01-01

205

Microbial sulfate reduction and its potential utility as an acid mine water pollution abatement procedure  

Microsoft Academic Search

The presence of high concentrations of sulfate, iron, and hydrogen (acid) ions in drainage from coal mines and other areas containing waste pyritic materials is a serious water pollution problem. Sulfate can be removed from solution by microbial reduction to sulfide and subsequent precipitation as FeS. A mixed culture of microorganisms degraded wood dust cellulose, and the degradation products served

J. H. Tuttle; P. R. Dugan; C. I. Randles

1969-01-01

206

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.

207

Acidic precipitation  

SciTech Connect

At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

Martin, H.C.

1987-01-01

208

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.

209

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 ...

210

Influence of precursor chemistry on the microstructure and crystallization of barium titanate thin films  

SciTech Connect

Since sol-gel derived barium titanate thin films often suffer from residual porosity, chemical modifications of barium titanium alkoxide sols were studied in order to determine if densification could be promoted prior to crystallization. Sol-gel derived barium titanate thin films were prepared on Si substrates using methoxypropoxide Ba-Ti double alkoxide sols or ethoxide based sols with acac and DEA additives. Decomposition and crystallization behavior were characterized using TGA/DTA and XRD, while the microstructure of the films was studied using analytical TEM. Heat treatments at 750{degrees}C by conventional furnace annealing yielded polycrystalline and randomly oriented BaTiO{sub 3}. All films were fine-grained and nanoporous, with grains and pores on the order of 25-50 nm. The uniform grain size in these materials suggests a similar controlling nucleation step for all these sol-gel derived materials, hypothesized to be the early fine scale precipitation of TiO{sub 2}. Residual organics in the various sols did not decompose until fairly high temperatures (620-650{degrees}C), possibly contributing to the residual porosity observed.

Gust, M.C.; Mecartney, M.L. [Univ. of California, Irvine, CA (United States); Momoda, L.A. [Hughes Research Labs., Malibu, CA (United States)

1995-12-31

211

A self-sustaining acid-base reaction in semi-aqueous media for synthesis of barium titanyl oxalate leading to BaTiO 3 powders  

Microsoft Academic Search

A self-sustaining controlled acid–base reaction between oxalotitanic acid [H2TiO(C2O4)2] (HTO) and barium hydroxide [Ba(OH)2·8H2O] at room temperature is utilized for the quantitative precipitation of barium titanyl oxalate (BTO). For this purpose, an intermediate soluble oxalotitanic acid precursor is generated by reacting 0.1 M solution of titanium tetrabutoxide in isopropanol (IPA) with 0.2 M solution of oxalic acid in IPA. Equimolar

Y. B Khollam; A. S Deshpande; H. S Potdar; S. B Deshpande; S. K Date; A. J Patil

2002-01-01

212

Numerical simulation of cementitious materials degradation under external sulfate attack  

Microsoft Academic Search

A numerical methodology is proposed in this paper to simulate the degradation of cementitious materials under external sulfate attack. The methodology includes diffusion of ions in and out of the structure, chemical reactions which lead to dissolution and precipitation of solids, and mechanical damage accumulation using a continuum damage mechanics approach. Diffusion of ions is assumed to occur under a

S. Sarkar; S. Mahadevan; J. C. L. Meeussen; H. van der Sloot; D. S. Kosson

2010-01-01

213

Remediation of Acid Mine Drainage with Sulfate Reducing Bacteria  

ERIC Educational Resources Information Center

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…

Hauri, James F.; Schaider, Laurel A.

2009-01-01

214

Sulfate reducing bacteria in microbial mats: Changing paradigms, new discoveries  

E-print Network

.T. Visscher a,* a Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Rd., Groton, CT, United States b Marine Geology and Geophysics, Rosenstiel School of Marine and Atmospheric Science precipitation via sulfate reduction are also discussed. D 2006 Elsevier B.V. All rights reserved. Keywords

215

Processing and Characterization of Proton Conducting Yttrium Doped Barium Zirconate for Solid Oxide Fuel Cell Applications  

NASA Astrophysics Data System (ADS)

To address the wide range of reported conductivities in literature and investigate the viability of yttrium-doped barium zirconate (BaZr 1-xYxO3-delta) as a membrane in electrochemical devices, the factors governing the protonic transport properties have been explored, with the aim of attaining reproducible proton conductivity in well-densified samples. It was found that a small initial particle size and high temperature sintering in the presence of excess barium were essential. By this procedure, BaZr0.8Y0.2O3 with 93-99% of theoretical density and high total (bulk plus grain boundary) conductivity could be reliably prepared. Samples sintered in the absence of excess barium displayed yttria precipitates and a bulk conductivity that was reduced by more than two orders of magnitude. Hydrogen transport across grain boundaries has been explored and the specific conductivity found to be two orders of magnitude lower than the bulk. Microstructural optimization of the total grain boundary conductivity included both decreasing total grain boundary density as well as improving intrinsic grain boundary properties. To investigate the influence of defect chemistry on stability, proton solubility, and proton mobility; samples with yttrium dopant concentration of 30 and 40 mol % were prepared in addition to the 20 Y mol %. Lattice parameters obtained suggests the solubility of yttrium in barium zirconate to be at least 40 mol %. Thermogravimetric analysis of the barium zirconate system showed excellent chemical stability under CO2 and protonic defects to be approaching theoretical hydrogen concentration for 20, 30, and 40 Y mol %. Significant hydroxyl-dopant associations were observed, especially at lower temperatures, which trap protons and impede transport. To simplify processing procedures, the influence of transitional metal oxides additives (especially zinc oxide) on the densification and electrical properties of doped barium zirconate have been examined. With the use of zinc oxide as a sintering aid, BaZr0.85Y0.15O3 was readily sintered to above 93% of theoretical density at 1300 °C. SEM investigations showed Zn accumulation in the intergranular regions. Electromotive force measurements of BaZr0.8Y0.2O3 showed the ionic transference number under fuel cell conditions to be at least 0.92 at 600 °C. Fuel cells based on BYZ20 were prepared and characterized.

Babilo, Peter

216

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

217

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

218

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

219

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

220

Band-Spectrum of Barium Oxide  

Microsoft Academic Search

THE introduction of barium salts to flames or arcs leads, in presence of oxygen, to the production of a characteristic band-spectrum attributed to BaO. Mecke and Guillery1 derived a band-head equation. Mahanti2 gave a new vibrational analysis and also made a rotational analysis. From this the spectrum was shown to arise from a 1Sigma - 1Sigma transition with B'e =

Albin Lagerqvist; Erland Lind; R. F. Barrow

1949-01-01

221

Mn2+, Ti4+ substituted barium ferrite  

Microsoft Academic Search

The substitution of iron by manganese in M-type barium ferrite BaFe12O19 has been investigated with the aim of elucidating its effect on the magnetic and magnetostrictive properties. Substitution of up to 0.4 manganese atoms per unit formula did not affect the magnetization whilst the anisotropy and magnetostriction decreased by 30% and 20%, respectively. Higher manganese contents gave rise to large

G. Turilli; F. Licci; S. Rinaldi; A. Deriu

1986-01-01

222

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

223

New barium ferrite particles: Spherical shape  

Microsoft Academic Search

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

Y. K. Hong; H. S. Jung

1999-01-01

224

Barium ferrite thin-film recording media  

Microsoft Academic Search

Both longitudinal and perpendicular barium ferrite thin films are being pursued as overcoatless magnetic recording media. In this paper, prior research on thin-film Ba ferrite is reviewed and the most recent results are presented. Self-textured high-coercivity longitudinal Ba ferrite thin films have been achieved using conventional rf diode sputtering. Microstructural studies show that c-axis in-plane oriented grains have a characteristic

Xiaoyu Sui; Matthias Scherge; Mark H. Kryder; John E. Snyder; Vincent G. Harris; Norman C. Koon

1996-01-01

225

New barium ferrite particles: Spherical shape  

Microsoft Academic Search

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 mum. Coercivity and saturation magnetization were in the range of 1000 to 5000 Oe and 49 to 53 emu\\/g, respectively. Crystallization of

Y. K. Hong; H. S. Jung

1999-01-01

226

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

227

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 < Teff < 6500, -1.2 < [Fe/H] < 0.0 and 1.4 < log g < 4.6 were derived, confirming that our sample contains giants, subgiants and dwarfs. The abundance results obtained for Li, Al, Na, alpha- and iron peak elements for the sample stars show that they are compatible with the values found in the literature for normal disk stars in the same range of metallicities. Enhancements of C, N and heavy elements relative to Fe, that characterise 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

228

Improving the magnetic properties of hydrothermally synthesized barium ferrite  

Microsoft Academic Search

The formation of fine barium ferrite (BaFe12O19) powders under hydrothermal conditions at [OH?]\\/[NO3?] ratio of 2 has been examined by employing barium nitrate and ferric nitrate as the starting materials. The effects of Ba\\/Fe ratio, reaction temperature and time on the formation, particle size, and magnetic properties of barium ferrite were studied. To further enhance the magnetic properties of hydrothermally

Xiangyuan Liu; John Wang; Leong-Ming Gan; Ser-Choon Ng

1999-01-01

229

An investigation of particle size effects in ultrafine barium ferrite  

Microsoft Academic Search

Ultrafine particles of barium ferrite in the size range 5-100 nm have been synthesized by thermal decomposition of a citrate precursor. The precursor decomposed at 425°C is amorphous, but crystalline barium ferrite starts forming at temperatures of 550°C and above. Barium ferrite which shows a monophase X-ray diffraction pattern and well-resolved Mössbauer spectra is obtained at 700°C. The Mössbauer spectra

V. K. Sankaranarayanan; Q. A. Pankhurst; D. P. E. Dickson; C. E. Johnson

1993-01-01

230

Barium hexaferrite suspensions for electrophoretic deposition.  

PubMed

In this investigation we have looked at the preparation of barium hexaferrite suspensions, with the stability of the magnetic barium hexaferrite particles being increased by the addition of a surfactant, dodecylbenzylsulfonic acid (DBSA). The influence of the solubility DBSA in different solvents and its adsorption onto the surfaces of particles with different sizes were determined from zeta-potential measurements. The most suitable and stable suspensions of barium hexaferrite particles, regardless of their sizes, were obtained in 1-butanol, and these were then used for a subsequent electrophoretic deposition. The microstructures of the deposits were examined with electron microscopy. The thickness and density of the deposits as a function of the electric field, the zeta-potential, the particle size, and the separation distance between the electrodes were investigated. The thickness of the deposits was found to increase with the increasing zeta-potential of the suspension and with the increasing separation distance between the electrodes. Denser deposits were obtained from the suspensions of smaller particles that had narrower particle size distributions. PMID:19541323

Ovtar, Simona; Lisjak, Darja; Drofenik, Miha

2009-09-15

231

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

232

Iron Reduction and Carbonate Precipitation by Shewanella oneidensis  

NASA Astrophysics Data System (ADS)

This study is to contribute to better understanding of how Archean microbes induced carbonate diagenesis in mats and stromatolites. Previous studies showed sulfate reduction, a common promoter of carbonate precipitation in modern mats[1], is likely to have been less effective in Archean mats in marine fluids lower in sulfate[2]. Alternatively, iron reduction produces far more alkalinity per unit carbon respired than sulfate reduction. Therefore, we hypothesize iron reduction can promote much more carbonate precipitation than sulfate reduction. Our study might also have some relevance to banded iron formation on which microbial iron reduction played a potential role[3]. To test our hypothesis, Shewanella oneidensis MR-1, a dissimilatory iron reducing bacterium will be cultured anaerobically (79%N2, 20%CO2 and 1%H2) in basal medium to trigger iron reduction. Lactate will be used as electron donor, and the electron acceptor will be fresh ferrihydrite. Culture medium will be added with various metal ions, such as Ca2+ and Mg2+, to obtain potential carbonate precipitate. Escherichia coli (with fumarate added as an electron acceptor) will be used to provide a comparison to live but non-iron- reduction cells. After 20 days incubation, precipitate will be collected, washed and identified by X-ray diffraction (XRD). Besides, iron reduction rate (ferrozine assay)[4], PH and amount of precipitate (carbonate and oxidize fractions)[5] will be measured over time to well understand how S. oneidensis drives carbonate precipitation.

Zeng, Z.; Tice, M. M.

2011-12-01

233

Hydrothermal crystallization of barium titanate: Mechanisms of nucleation and growth  

NASA Astrophysics Data System (ADS)

Barium titanate is synthesized under hydrothermal conditions by the reaction of a variety of titania precursors with aqueous solutions of Ba(OH)sb2 at 80sp°C. Particles processed at relatively low concentrations of Ba(OH)sb2 are micro-sized and highly aggregated, but increasing concentrations cause the particle size to decrease, resulting in nanometer-sized and fairly monodispersed particles. The change in particle size and morphology at various Ba(OH)sb2 concentrations is controlled by the dissolution of titania and precipitation of BaTiOsb3. In order to explain the origin of "raspberry-like" BaTiOsb3 particles and the generation of hierarchically ordered BaTiOsb3 aggregate comprised of primary, crystalline particles, which exhibit an unusually high degree of crystallographic alignment, the role of colloidal stability and therefore controlled aggregation of precipitated primary particles is taken into account. Formation of SrTiOsb3 on BaTiOsb3 particles reveal that two different morphologies for the growing SrTiOsb3 exists and that the form taken by SrTiOsb3 depends on the degree of supersaturation. In concentrated solutions, homogeneous nucleation and aggregation growth occur. In dilute solutions, heterogeneous nucleation and continuous growth of SrTiOsb3 promote epitaxial growth. BaTiOsb3 particles prepared by the alkoxide (Ti(OCsb3Hsb7)sb4) -hydroxide (Ba(OH)sb2) route under hydrothermal conditions show that secondary processed such as aggregation and recrystallization are important to control the particle size and morphology. Particle clustering, and rearrangement of nanometer-sized BaTiOsb3 particles, and particulate uniformity can then be explained in terms of solution reactions and colloidal behavior.

Chun, Chang-Min

234

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

235

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

236

Sulfates and phyllosilicates in Aureum Chaos, Mars  

NASA Astrophysics Data System (ADS)

Many Martian regions show a hydrated mineralogy indicating that aqueous processes played a major role in the planet's past. This study combines short wave infrared data, imagery and elevation data to identify these minerals in an equatorial chaotic terrain region and to find out their stratigraphy and geological context. Local Interior Layered Deposits (ILD) display three stratigraphic units: The lowest unit shows massive and also layered, monohydrated sulfate (MHS, best matching kieserite; 20-650 m thick), intercalated hydroxylated ferric sulfates (HFS, best matching jarosite) and ferric oxides. The overlying polyhydrated sulfate (PHS) is commonly layered (20-40 m thick), smooth to heavily fractured, partially with ferric oxides. Spectrally neutral, distinctly layered, bumpy cap rock (40-300 m thick) forms the top. Units are spectrally and morphologically similar to deposits of Aram Chaos (PHS, MHS, ferric oxides; texture of ILD and cap rock) and Juventae Chasma (HFS). Here, the phyllosilicate nontronite is found attributed to chaotic terrain as a light-toned fractured exposure but also within dark, smooth mantling. Coexisting sulfates and phyllosilicates demonstrate geochemical variations in the aqueous environment. Conversions between sulfates and iron oxides are considered, since we might be looking at alteration products instead of the parent rock material. Here, PHS occurs along mantling edges and flat surfaces of MHS without showing textural differences; making it a potential alteration product of MHS (e.g. due to surface exposure). Since the facies and timing of sulfate formation remain undefined, two different formation models are considered: contemporaneous ILD and PHS deposition with diagenetic sulfate conversion due to overburden (into MHS, iron oxides) later on; and groundwater evaporation. The first is less likely since a (sharp) PHS-MHS boundary is required that would indicate a diagenetic formation. The second is more consistent with our observations concerning the potential anhydrous cap rock. Groundwater would have penetrated into a pre-existing sulfate-free ILD whose permeability and porosity would have defined the rate of water absorption and sulfate precipitation that finally lead to its cementation. The surface ages of chaotic terrain (late Hesperian) and mantling deposits (mid to late Amazonian) further constrain the ILD age and potentially the emplacement of sulfates. We suggest that phyllosilicates in the mantling are allochthonous. In contrast, determining the deposition of in-situ phyllosilicates is theoretical; they could be Noachian (excavated material, following the 'phyllosian' era), or instead late Hesperian or even younger (syn- or post-chaotic). Alternatives, as known from Australian saline lakes, combine groundwater alteration with the observed mineralogy. There, close spatial and temporal associations of both mineral groups are explained by vertically separated geochemical environments (phyllosilicates in deep-, sulfates in shallow evaporitic facies). The preservation of nontronite, HFS and MHS displays that since their deposition a relatively dry environment with intermittent aqueous activity must have prevailed.

Sowe, M.; Wendt, L.; McGuire, P. C.; Neukum, G.

2012-12-01

237

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

238

Reduction of low-density lipoproteins with dextran sulfate in patients with familial hypercholesterolemia.  

PubMed

A novel on-line system for the selective precipitation of low-density lipoprotein (LDL) using dextran sulfate has been devised and tested in four patients with heterozygous familial hypercholesterolemia (type II). The mean pretreatment serum cholesterol was 410 mg/dl. Plasma was generated by membrane filtration and LDL and VLDL (very-low-density lipoprotein) were completely precipitated with 10-35 mg% dextran sulfate (Mr 5,000) in the presence of 55 mM Ca2+. The precipitate was removed by filtration and the excess Ca2+ by dialysis. For 41 procedures the mean reduction of plasma solutes was LDL + VLDL 65%, HDL 23%, fibrinogen 19%, albumin 15%, IgG 20%, IgA 19%, IgM 24%. We conclude that dextran sulfate precipitation is an effective method for selective on-line removal of LDL from plasma. PMID:2455708

Antwiler, G D; Dau, P C; Lobdell, D D

1988-01-01

239

21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.  

Code of Federal Regulations, 2012 CFR

... false Neomycin sulfate and polymyxin B sulfate ophthalmic solution...1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution...base), and 10,000 Units of polymyxin B sulfate. (b) Sponsor....

2012-04-01

240

21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.  

Code of Federal Regulations, 2010 CFR

... false Neomycin sulfate and polymyxin B sulfate ophthalmic solution...1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution...base), and 10,000 Units of polymyxin B sulfate. (b) Sponsor....

2010-04-01

241

21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.  

Code of Federal Regulations, 2011 CFR

... false Neomycin sulfate and polymyxin B sulfate ophthalmic solution...1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution...base), and 10,000 Units of polymyxin B sulfate. (b) Sponsor....

2011-04-01

242

21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.  

Code of Federal Regulations, 2013 CFR

... false Neomycin sulfate and polymyxin B sulfate ophthalmic solution...1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution...base), and 10,000 Units of polymyxin B sulfate. (b) Sponsor....

2013-04-01

243

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

244

PIMLUCK KIJJANAPANICH SULFATE REDUCTION  

E-print Network

Metals from Acid Mine Drainage 37 3.1 Introduction 38 3.2 Material and Methods 39 3.2.1 Acid mine drainage (AMD) 39 3.2.2 Sulfate reducing bacteria (SRB) inoculums 40 3.2.3 Organic substrates 40 3 Reduction in Gypsiferous Mine Soils from Nakhon Si Tham

Paris-Sud XI, Université de

245

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

246

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...

247

Laser Cooled Single Ion Spectroscopy of Magnesium and Barium  

Microsoft Academic Search

Individual ions of magnesium and barium have been isolated and confined in RF traps in an ultra high vacuum environment. The ion motion has been cooled by means of a resonant laser excitation. The single ions were detected by their laser induced fluorescence. The kinetic temperature of magnesium was measured to be less than 200 millidegrees Kelvin. In barium, a

Gary Robert Janik

1984-01-01

248

The application of barium ferrite particles in advanced recording media  

Microsoft Academic Search

Barium ferrite is a leading candidate material for advanced magnetic recording media. Tapes and disks made with it offer output amplitudes at recording densities of current interest (75-100 kfci) that far exceed those of advanced acicular oxides and are comparable to those of many commercially available media made with metallic particles (MP). The very high coercivity values available with barium

M. P. Sharrock; L. W. Carlson

1995-01-01

249

M-Type Barium Hexagonal Ferrite Films Mingzhong Wu  

E-print Network

-type barium hexagonal ferrite BaFe12O19 (BaM) films as a replacement for those magnetic garnets. BaM films can2 M-Type Barium Hexagonal Ferrite Films Mingzhong Wu Department of Physics, Colorado State University, Fort Collins, USA 1. Introduction Magnetic garnet materials such as yttrium iron garnet (YIG

250

Recording performance of longitudinal barium ferrite thin film media  

Microsoft Academic Search

The high density recording characteristics of barium ferrite thin film media have been investigated. High levels of overwrite are achieved. Media microstructures have been identified to have a close relation to the noise behavior in the barium ferrite thin films. A linear increase in noise spectra is observed, indicating the existence of transition noise. In addition, positive ?M peaks are

Xiaoyu Sui; A. Singh; Yinglian Chen; D. N. Lambeth; M. K. Krydeer

1995-01-01

251

Explanation of the apparent sublinear photoconductivity of photorefractive barium titanate  

Microsoft Academic Search

We explain the apparent sublinear intensity dependence of photoconductivity in barium titanate. In our model shallow acceptors act as a reservoir for charges optically excited from the donors. As this reservoir fills, the fraction of occupied donors changes appreciably, changing the lifetime of the free carriers. We identify two types of barium titanate crystals having quite different photorefractive characteristics, depending

Daniel Mahgerefteh; Jack Feinberg

1990-01-01

252

Barium strontium titanate powder obtained by polymeric precursor method  

SciTech Connect

Pure barium strontium titanate powder, with Ba/Sr ratio of 80/20 was prepared by the polymeric precursor method (also called Pechini process). The powder was obtained after a calcination at 800 deg. C for 8 h and characterized by XRD, IR, BET and SEM. The requirements to avoid barium carbonate as a secondary phase are presented and discussed in detail.

Ries, A.; Simoes, A.Z.; Cilense, M.; Zaghete, M.A.; Varela, J.A

2003-03-15

253

Calcium sulfate crystallization along citrus root channels in a Florida soil exhibiting acid sulfate properties  

SciTech Connect

The authors observed euhedral crystals in Manatee soil in a citrus grove in St. Lucie County, Florida. The material was identified as gypsum (CaSO/sub 4/ /times/ 2H/sub 2/O) using x-ray diffraction and infrared spectra. Photomicrography and scanning electron microscopy revealed that gypsum accumulated both in old root channels and within citrus root tissue of the Btg horizon. The subsurface horizons had elevated sulfate levels, a low initial pH, a drop (0.5 unit) in pH upon air-drying. Electrical conductivity paralleled the concentration of water-soluble sulfate. High levels of calcium and sulfate occurred for horizons above the water table. This accumulation is attributed to groundwater bearing these ions and subsequently discharging them to the overlying soil. Dead citrus roots appear to act as wicks to aid water transfer from lower to higher horizons. The roots and their empty channels provide spaces in which the gypsum can precipitate if the concentrations of calcium and sulfate in the evaporating groundwater exceed the solubility product of gypsum.

Syslo, S.K.; Myhre, D.L.; Harris, W.G.

1988-02-01

254

4, 29492971, 2004 Ammonium sulfate  

E-print Network

ACPD 4, 2949­2971, 2004 Ammonium sulfate ­ malonic acid aerosols C. F. Braban and J. P. D. Abbatt and Physics Discussions A study of the phase transition behavior of mixed ammonium sulfate ­ malonic acid Ammonium sulfate ­ malonic acid aerosols C. F. Braban and J. P. D. Abbatt Title Page Abstract Introduction

Paris-Sud XI, Université de

255

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

256

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

257

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

258

Relationship between microbial sulfate reduction rates and sulfur isotopic fractionation  

NASA Astrophysics Data System (ADS)

Sulfate reduction is one of the common processes to obtain energy for certain types of microorganisms.They use hydrogen gas or organic substrates as electron donor and sulfates as electron acceptor, and reduce sulfates to sulfides. Sulfate reducing microbes extend across domains Archea and Bacteria, and are believed to be one of the earliest forms of terrestrial life (Shen 2004). The origin of 34S-depleted (light) sulfide sulfur, especially ?34S < -30 ‰, around hydrothermal vents or beneath the sea-floor is speculated to be the products of sulfate reducers. But laboratory experiments using sulfate reducers fail to produce such light sulfur, and many models were proposed to explain the discrepancy. Canfield et al. (2006) proposed so-called "standard model" based on previous studies. The standard model explained the reason for the large fractionation by temperature dependence of sulfur isotopic fractionation factor and rate of sulfate reduction, which indicated the growth conditions of microbes. However, they failed to prove their model by their other experiments (Canfield et al., 2006). In this study, I performed laboratory culture experiment of sulfate reducing bacteria (SRB) to explain the 34S-depleted sulfide sulfur. [Experiments] To compare the result with Canfield et al. (2006), I used Desulfovibrio desulfuricans for my laboratory culture experiment. D. desulfuricans was inoculated into glass vials, which contain 40ml of liquid culture media slightly modified from DSMZ #63 medium.Excess amount of Fe (II) is added to the DSMZ#63 medium to precipitate sulfide as iron sulfide. The vials were incubated at 25°C, 30°C, and 37°C, respectively. 21 vials were used for one temperature and sulfide and sulfate was collected from each three glass vials at every 12 hours from 72 hours to 144 hours after start of incubation. The sulfide was precipitated as iron sulfide and the sulfate was precipitated as barite. Sulfur isotope compositions of sulfate and sulfide were measured by standard method using Delta Plus mass-spectrometer. [Results and Discussion] The fractionation between sulfide and sulfate ranged from 2.7 to 11.0. The fractionation values varied among the different incubation temperature and growth phase of D. desulfuricans. The maximum fractionation values of three incubation temperatures were 9.9, 11.0, and 9.7, for 25 °C, 30°C, and 37°C, respectively. These results were different from standard model and Canfield et al. (2006). I could not find the clear correlation between ?34S values and incubation temperatures in this experiment. The measured fractionation values during the incubation varied with incubation stage. The fractionation values clearly increased with incubation time at every temperature, and at 25°C ?34S value was 3.6 at the 72h and it increased to 7.9 at 144 hours. This indicated the difference of sulfate reduction rate due to the growth phase of SRB. In the early logarithmic growth phase, metabolic activity of SRB is high and sulfate reduction rate is fast. In contrast at the stationary phase, SRB stop growing and sulfate reduction rate get slower. My result suggested that the sulfur isotopic fractionation is controlled by growth phase of SRB and lighter sulfide would be produced by the stationary phase or half-dormant SRB in natural environment.

Matsu'Ura, F.

2009-12-01

259

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

260

Europium-doped barium bromide iodide  

SciTech Connect

Single crystals of Ba0.96Eu0.04BrI (barium europium bromide iodide) were grown by the Bridgman technique. The title compound adopts the ordered PbCl2 structure [Braekken (1932). Z. Kristallogr. 83, 222-282]. All atoms occupy the fourfold special positions (4c, site symmetry m) of the space group Pnma with a statistical distribution of Ba and Eu. They lie on the mirror planes, perpendicular to the b axis at y = +-0.25. Each cation is coordinated by nine anions in a tricapped trigonal prismatic arrangement.

Gundiah, Gautam; Hanrahan, Stephen M.; Hollander, Fredrick J.; Bourret-Courchesne, Edith D.

2009-10-21

261

Europium-doped barium bromide iodide.  

PubMed

Single crystals of Ba(0.96)Eu(0.04)BrI (barium europium bromide iodide) were grown by the Bridgman technique. The title compound adopts the ordered PbCl(2) structure [Braekken (1932 ?). Z. Kristallogr.83, 222-282]. All atoms occupy the fourfold special positions (4c, site symmetry m) of the space group Pnma with a statistical distribution of Ba and Eu. They lie on the mirror planes, perpendicular to the b axis at y = ±0.25. Each cation is coordinated by nine anions in a tricapped trigonal prismatic arrangement. PMID:21578035

Gundiah, Gautam; Hanrahan, Stephen M; Hollander, Frederick J; Bourret-Courchesne, Edith D

2009-01-01

262

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

263

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

264

Dielectric properties of barium titanate supramolecular nanocomposites.  

PubMed

Nanostructured dielectric composites can be obtained by dispersing high permittivity fillers, barium titanate (BTO) nanocubes, within a supramolecular framework. Thin films of BTO supramolecular nanocomposites exhibit a dielectric permittivity (?r) as high as 15 and a relatively low dielectric loss of ?0.1 at 1 kHz. These results demonstrate a new route to control the dispersion of high permittivity fillers toward high permittivity dielectric nanocomposites with low loss. Furthermore, the present study shows that the size distribution of nanofillers plays a key role in their spatial distribution and local ordering and alignment within supramolecular nanostructures. PMID:24584569

Lee, Keun Hyung; Kao, Joseph; Parizi, Saman Salemizadeh; Caruntu, Gabriel; Xu, Ting

2014-04-01

265

Improved Methodology for Bioremoval of Black Crusts on Historical Stone Artworks by Use of Sulfate-Reducing Bacteria  

Microsoft Academic Search

An improved methodology to remove black crusts from stone by using Desulfovibrio vulgaris subsp. vulgaris ATCC 29579, a sulfate-reducing bacterium, is presented. The strain removed 98% of the sulfates of the crust in a 45-h treatment. Precipitation of black iron sulfide was avoided using filtration of a medium devoid of iron. Among three cell carriers, Carbogel proved to be superior

Francesca Cappitelli; Elisabetta Zanardini; Giancarlo Ranalli; Emilio Mello; Daniele Daffonchio; Claudia Sorlini

2006-01-01

266

Barium ferrite powders prepared by microwave-induced hydrothermal reaction and magnetic property  

Microsoft Academic Search

We have prepared barium ferrite particles by the microwave-induced hydrothermal method. The crystallization of the barium ferrite particles is promoted within a short time by microwave irradiation because the seeds of barium ferrite having large permeability are rapidly heated through the interaction of barium ferrite with the magnetic component of the microwaves. Crystals having unusually low thickness were obtained compared

Tomohisa Yamauchi; Yasunori Tsukahara; Takao Sakata; Hirotaro Mori; Tsukasa Chikata; Shunsaku Katoh; Yuji Wada

2009-01-01

267

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"

268

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

269

Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems  

SciTech Connect

Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-(14C)glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo(14C)chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo(14C)chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo(14C) chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo(14C)chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo(14C)chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo(14C)chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo(14C)chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent.

Sugumaran, G.; Silbert, J.E.

1988-04-05

270

Influence of heat treatment conditions on the structure and magnetic properties of barium ferrite BaFe 12O 19 hollow microspheres of low density  

Microsoft Academic Search

Barium ferrite BaFe12O19 hollow microspheres of low density (about 2.50gcm?3) were synthesized without BaFe2O4 or other intermediate phase by spray pyrolysis technique, combined with co-precipitation precursor and followed further heat treatment. The relationships between the microstructure, magnetic properties and the sintering temperature, time were investigated. Hollow microspheres, constituted by nanometer particles, showed a broad particle distribution of 2–15?m. When the

Ping Ren; JianGuo Guan; XuDong Cheng

2006-01-01

271

Hygienic importance of increased barium content in some fresh waters.  

PubMed

In surface waters of the mining and processing areas of uranium ore there is an increased content of free and bound barium ions due to the use of barium salts for the treatment of waste and mine waters containing radium. In model experiments with the algae Ankistrodesmus falcatus, Chlorella kessleri and Scenedesmus obliquus, we studied the effect of Ba2+ on the accumulation of 226Ra. It was found that the accumulation of radium by algae is negatively influenced with barium concentrations higher than 1 mg.l-1. The accumulation of barium of organisms of primary production was studied using 133BaCl2. At a barium content in the medium of 4.0, 0.46 and 0.04 mu. l-1, the algae accumulated 30-60% of the added amount of barium during an exposure of 15 days. Biochemical analyses showed that barium is bound to the cellular membrane and to other components of the algal cell that cannot be extracted with water or alcohol. PMID:7462608

Havlík, B; Hanusová, J; Rálková, J

1980-01-01

272

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

273

Formation of acidic sulfates in kraft recovery boilers  

SciTech Connect

Acidic sulfates (NaHSO[sub 4] and Na[sub 2]S[sub 2]O[sub 7]) have been suggested as the cause of corrosive sticky deposits in recovery boilers. Recovery-boiler precipitator dusts and pure Na[sub 2]SO[sub 4] were examined for their tendency to form acidic sulfates in simulated flue gases. Formation was strongly influenced by temperature and by gas-phase concentrations of SO[sub x] and H[sub 2]O. Liquid NaHSO[sub 4] formed readily at 250 C at SO[sub x] concentration above 150 ppm. Formation reactions were hindered by Na[sub 2]CO[sub 3]. Under appropriate conditions, acidic sulfates can exist at tube surfaces near the furnace roof, at the upper screen tubes, and in the generating bank and economizer.

Poon, W.; Barham, D.; Tran, H. (Univ. of Toronto, Ontario (Canada))

1993-07-01

274

Microstructure and magnetism in barium strontium titanate (BSTO)-barium hexaferrite (BaM) multilayers  

SciTech Connect

High quality multilayers of barium ferrite (BaM) and barium strontium titanate (BSTO) were grown in optimized conditions on thermally oxidized Si(1 0 0) and Al{sub 2}O{sub 3} substrates using magnetron sputtering. As-grown films were amorphous and different annealing procedures were explored to stabilize crystalline phases. BSTO and BaM phases were identified using X-ray diffraction and cross-sectional scanning electron micrographs showed sharp interfaces between BSTO and BaM layers. Magnetic hysteresis loops obtained at various temperatures and field orientations showed a large coercivity ({approx}2500 Oe) consistent with the hard magnetic hexaferrite component. Hysteresis loops also revealed the distinct influence of magnetocrystalline and shape anisotropies at different temperature ranges.

Frey, N.A. [Materials Physics Laboratory, Physics Department, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Heindl, R. [Materials Physics Laboratory, Physics Department, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Srinath, S. [Materials Physics Laboratory, Physics Department, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Srikanth, H. [Materials Physics Laboratory, Physics Department, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States)]. E-mail: sharihar@cas.usf.edu; Dudney, N.J. [Solid State Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2005-08-11

275

Migration and redistribution of oxygen vacancy in barium titanate ceramics  

SciTech Connect

Degradation of barium titanate based multilayer capacitor mainly results from migration and redistribution of oxygen vacancy. For barium titanate ceramics, the authors observe an internal friction relaxation peak around 70 deg. C due to oxygen vacancy, and its relaxation strength differs greatly for specimen aged at 85 deg. C for 120 h and at 150 deg. C for 5 h. Two possible explanations are proposed, one based on symmetry-conforming short-range order while the other on the interaction between oxygen vacancy and domain wall during aging process. In any case, relaxation thermodynamics is a powerful tool to investigate the migration and redistribution of oxygen vacancy in barium titanate ceramics.

Chen, L.; Xiong, X. M.; Meng, H.; Lv, P.; Zhang, J. X. [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

2006-08-14

276

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

277

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

278

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

279

Extraction, isolation and analysis of chondroitin sulfate glycosaminoglycans.  

PubMed

Glycosaminoglycans (GAGs) including chondroitin sulfate (CS) and chondroitin sulfate/dermatan sulfate (CS/DS) copolymers are anionic straight chain polysaccharides. They are galactosamine containing GAGs (galactosaminoglycans) having wide range of applications in pharmaceutical, cosmetic and food industries. This article reviews techniques to isolate and characterize these galactosaminoglycans from animal and poultry tissues. Patent based information is also discussed. Cartilaginous tissues are the major source of CS consisting entirely of D-glucuronosyl-N-acetylgalactosamine repeating disaccharide units, in which the galactosamine is sulfated at C4 or C6. In contrast, most galactosaminoglycans in non-cartilaginous connective tissues (e.g. skin and tendon) are CS/DS copolymers comprised of varying proportions of D-glucuronosyl-N-acetylgalactosamine and L-iduronosyl-N-acetylgalactosamine. Tissues are digested with proteinase (e.g. papain) to liberate GAGs, which are fractionated to isolate and purify galactosaminoglycans. Common techniques used for fractionation of GAGs include: precipitation with different concentrations of ethanol; solubilization of GAG precipitated as GAG-quarternary ammonium compound complexes with different concentrations of NaCl; anion exchange chromatography and gel filtration chromatography. Purified galactosaminoglycans are examined by various methods including chondroitinase digestion, high performance liquid chromatography and electrophoresis. Histological methods are used to localize galactosaminoglycans in tissues. The patent information on the CS hydrolase and ultraviolet irradiation may be useful for the preparation of CS oligosaccharide. PMID:20653551

Nakano, Takuo; Betti, Mirko; Pietrasik, Zeb

2010-01-01

280

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

281

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

282

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

283

Ferric sulfates on Mars  

NASA Technical Reports Server (NTRS)

Evidence is presented for the possible existence of ferric sulfato complexes and hydroxo ferric sulfate minerals in the permafrost of Mars. A sequential combination of ten unique conditions during the cooling history of Mars is suggested which is believed to have generated an environment within Martian permafrost that has stabilized Fe(3+)-SO4(2-)-bearing species. It is argued that minerals belonging to the jarosite and copiapite groups could be present in Martian regolith analyzed in the Viking XRF measurements at Chryse and Utopia, and that maghemite suspected to be coating the Viking magnet arrays is a hydrolysate of dissolved ferric sulfato complexes from exposed Martian permafrost.

Burns, Roger G.

1987-01-01

284

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

285

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

286

How does sodium sulfate crystallize? Implications for the decay and testing of building materials  

Microsoft Academic Search

The fundamental behavior of sodium sulfate crystallization and induced decay in concrete and other building materials is still poorly understood, resulting in some misinterpretation and controversy. We experimentally show that under real world conditions, both thenardite (Na2SO4) and mirabilite (Na2SO4·10H2O) precipitate directly from a saturated sodium sulfate solution at room temperature (20°C). With decreasing relative humidity (RH) and increasing evaporation

Carlos Rodriguez-Navarro; Eric Doehne; Eduardo Sebastian

2000-01-01

287

A triangular heterometallic siloxide containing barium  

SciTech Connect

Reaction of KOSiPh[sub 3] with Ba[sub 3](OSiPh[sub 3])[sub 6](THF) in THF displaces barium from the triangular reagent to yield a colorless solid. Recrystallization in the presence of MeOC[sub 2]H[sub 4]OMe(DME) yields KBa[sub 2](OSiPh[sub 3])[sub 5](DME)[sub 2], characterized by [sup 1]H and [sup 29]Si NMR spectroscopy and X-ray diffraction. The molecule contains a triangular KBa[sub 2]([mu][sub 3]-OSiPh[sub 3])[sub 2]([mu][sub 2]-OSiPh[sub 3])[sub 3] core with [eta][sup 1] and [eta][sup 2]-DME ligation on each barium. The benzene-soluble molecule is fluxional in solution at both the OSiPh[sub 3] and the DME groups. At -70C in CH[sub 2]Cl[sub 2]/C[sub 6]D[sub 6], both [eta][sup 1]-DME/[eta][sup 2]-DME site exchange and intramolecular siloxide migration have been slowed, and the spectra are in agreement with retention of the solid-state structure in solution. Crystallographic data for KBa[sub 2](OSiPh[sub 3])[sub 5](DME)[sub 2] (-159C): a = 15.474 (3) [angstrom], b = 26.466 (6) [angstrom], c = 23.783 (5) [angstrom], [beta] = 99.80 (1)[degree] with Z = 4 in space group P2[sub 1]/n.

Coan, P.S.; Streib, W.E.; Caulton, K.G. (Indiana Univ., Bloomington (United States))

1991-12-25

288

Organics, soot, and ambient sulfate  

SciTech Connect

Evidence is presented for significant local sulfate formation, the existence of a chemical link between ambient sulfate and organic particulate material is postulated, and a new SO/sub 2/ oxidation process by a reaction between organic products of incomplete combustion and SO/sub 2/ is described. Specifically, results of field studies on the relationship among sulfate, SO/sub 2/, and carbonaceous particles, speciation of sulfate and nitrogenous species, and laboratory results on certain aspects of SO/sub 2/ oxidation are presented. It is concluded that in highly polluted atmospheres, large concentrations of ambient sulfate can be produced by conversion of locally emitted SO/sub 2/ by a process that is largely independent of SO/sub 2/ but proportional to soot concentration. Ambient sulfate from many locations is found as anomalous ammonium sulfate where charged organic nitrogen complexes substitute for ammonium ions. Such sulfate is found when the aerosol is rich in organic constituents. The reaction between pyrolysis products of hydrocarbon fuels and SO/sub 2/ is an efficient mechanism for sulfate ion formation. This reaction is strongly dependent on combustion conditions.

Novakov, T.

1982-09-01

289

Upper gastrointestinal barium evaluation of duodenal pathology: A pictorial review.  

PubMed

Like other parts of the gastrointestinal tract (GIT), duodenum is subject to a variety of lesions both congenital and acquired. However, unlike other parts of the GIT viz. esophagus, rest of the small intestine and large intestine, barium evaluation of duodenal lesions is technically more challenging and hence not frequently reported. With significant advances in computed tomography technology, a thorough evaluation including intraluminal, mural and extramural is feasible in a single non-invasive examination. Notwithstanding, barium evaluation still remains the initial and sometimes the only imaging study in several parts of the world. Hence, a thorough acquaintance with the morphology of various duodenal lesions on upper gastrointestinal barium examination is essential in guiding further evaluation. We reviewed our experience with various common and uncommon barium findings in duodenal abnormalities. PMID:25170399

Gupta, Pankaj; Debi, Uma; Sinha, Saroj Kant; Prasad, Kaushal Kishor

2014-08-28

290

Improved dielectric strength of barium titanate-polyvinylidene fluoride nanocomposite  

NASA Astrophysics Data System (ADS)

Barium titanate-polyvinydene fluoride nanocomposites with improved dielectric strength were prepared, in which on the surface of the barium titanate nanoparticle was coated. The results showed that the dielectric breakdown strength of the nanocomposites increase significantly up to 250 kV/mm and then decrease. Microstructural investigations revealed that the coated barium titanate nanoparticles were well-dispersed in polyvinydene fluoride. Fourier transform infrared spectroscopy confirmed that there is a large coverage of cross-linking in both interfaces of the barium titanate-titanate and the titanate-polyvinydene fluoride, which can connect the composites to form an organically integrated body, which result in the increase of the dielectric strength of the nanocomposites.

Dou, Xiaoliang; Liu, Xiaolin; Zhang, Yong; Feng, Huan; Chen, Jian-Feng; Du, Song

2009-09-01

291

Liquid-phase-deposited barium titanate thin films on silicon  

NASA Astrophysics Data System (ADS)

Using a mixture of hexafluorotitanic acid, barium nitrate and boric acid, high refractive index (1.54) barium titanate films can be deposited on silicon substrates. The deposited barium titanate films have featureless surfaces. The deposition temperature is near room temperature (80°C). However, there are many fluorine and silicon incorporations in the films. The refractive index of the as-deposited film is 1.54. By current-voltage measurement, the leakage current of the as-deposited film with a thickness of 1000 Å is about 9.48×10-7 A cm-2 at the electrical field intensity of 0.3 MV cm-1. By capacitance-voltage measurement, the effective oxide charge of the liquid-phase-deposited barium titanate film is 3.06×1011 cm-2 and the static dielectric constant is about 22.

Lee, Ming-Kwei; Liao, Hsin-Chih; Tung, Kuan-Wen; Shih, Chung-Min; Shih, Tsung-Hsiang

2002-01-01

292

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

293

Upper gastrointestinal barium evaluation of duodenal pathology: A pictorial review  

PubMed Central

Like other parts of the gastrointestinal tract (GIT), duodenum is subject to a variety of lesions both congenital and acquired. However, unlike other parts of the GIT viz. esophagus, rest of the small intestine and large intestine, barium evaluation of duodenal lesions is technically more challenging and hence not frequently reported. With significant advances in computed tomography technology, a thorough evaluation including intraluminal, mural and extramural is feasible in a single non-invasive examination. Notwithstanding, barium evaluation still remains the initial and sometimes the only imaging study in several parts of the world. Hence, a thorough acquaintance with the morphology of various duodenal lesions on upper gastrointestinal barium examination is essential in guiding further evaluation. We reviewed our experience with various common and uncommon barium findings in duodenal abnormalities. PMID:25170399

Gupta, Pankaj; Debi, Uma; Sinha, Saroj Kant; Prasad, Kaushal Kishor

2014-01-01

294

Study of the photovoltaic effect in thin film barium titanate  

NASA Technical Reports Server (NTRS)

The feasibility of making non-volatile digital memory devices of barium titanate, BaTiO3, that are integrated onto a silicon substrate with the required ferroelectric film produced by processing, compatible with silicon technology was examined.

Grannemann, W. W.; Dharmadhikari, V. S.

1983-01-01

295

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

296

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

297

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

298

Kinetics and mechanisms of hydrothermal synthesis of barium titanate  

Microsoft Academic Search

Reaction mechanisms for the hydrothermal synthesis of barium titanate are evaluated. Feedstocks of barium hydroxide octahydrate and anatase titania are reacted for varying durations (1--72 h) to provide intermediate-stage samples for characterization by transmission electron microscopy\\/energy-dispersive spectroscopy (TEM\\/EDS), X-ray diffractometry (XRD), and inductively coupled plasma spectroscopy (ICP) and XRD methods permits the analysis of data with the Johnson-Mehl-Avrami equation. This

James O. Eckert; Catherine C. Hung-Houston; Bonnie L. Gersten; Malgorzata M. Lencka; Richard E. Riman

1996-01-01

299

On the nature of defects in barium ferrite platelets  

Microsoft Academic Search

Barium ferrite (Ba.0.6Fe2O3) platelets of approximatelyfrac{1}{2}mum diameter and with intrinsic coercive force of about 5000 Oe were crystallized from a glass phase. To study the nature of the defects and their influence on the magnetic properties, the crystailized glass was plastically deformed by applying a pressure of 30 kbar in an opposed anvil press. Barium ferrite platelets were extracted from

D. Ratnam; W. Buessem

1970-01-01

300

'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

301

Thermal Decomposition of Barium Dioxodiaquaperoxyoxalato Uranate(VI) Hydrate  

Microsoft Academic Search

Barium dioxodiaquaperoxyoxalatouranate was obtained by reaction of uranyl nitrate with oxalic acid and then hydrogen peroxide\\u000a in the presence of barium ion. The complex was subjected to chemical analysis. The thermal decomposition behaviour of the\\u000a complex was studied using TG, DTG and DTA techniques. The solid complex salt and the intermediate product of its thermal decomposition\\u000a were characterized using IR

B. B. V. Sailaja; T. Kebede; M. S. Prasada Rao

2002-01-01

302

Neutron source, neutron density and the origin of barium stars  

Microsoft Academic Search

The authors present new high resolution spectra of the MgH profiles in nine barium stars, and determine, by spectral synthesis techniques, the magnesium isotopic ratios in each star. When compared with recent AGB nucleosynthesis calculations, they can emphatically rule out the operation of the 22Ne(alpha, n)25Mg reaction as the neutron source responsible for the s-process enhancements observed in these barium

Robert A. Malaney; David L. Lambert

1988-01-01

303

Sulfated polysaccharides (chondroitin sulfate and carrageenan) plus glucosamine sulfate are potent inhibitors of HIV.  

PubMed

Chondroitin sulfate, a fusion inhibitor found in human milk, appears to work by blocking the ability of a virus, such as HIV, to infect a cell. There are questions about whether cow or goat milk can offer the same fusion-inhibiting benefits. One sulfated monosaccharide, glucosamine 6-sulfate, appears to have significant anti-HIV activity. Carrageenan, a seaweed derivative, shows promise as a vaginal microbicide, and should be tested further to determine its effectiveness against HIV transmission. PMID:11366556

Konlee, M

1998-01-01

304

Preparation and magnetic properties of barium ferrites substituted with manganese, cobalt, and tin  

Microsoft Academic Search

Barium ferrites substituted by Mn–Sn, Co–Sn, and Mn–Co–Sn with general formulae BaFe12?2xMnxSnxO19 (x=0.2–1.0), BaFe12?2xCoxSnxO19 (x=0.2–0.8), and BaFe12?2xCox\\/2Mnx\\/2SnxO19 (x=0.1–0.6), respectively, have been prepared by a previously reported co-precipitation method. The efficiency of the method was refined by lowering the reaction temperature and shortening the required reaction time, due to which crystallinity improved and the value of saturated magnetization increased as well.

Yue Liu; Michael G. B. Drew; Ying Liu

2011-01-01

305

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

306

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

307

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

308

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

309

Cholesterol, Sulfate, and Heart Disease  

E-print Network

mitochondrial coenzyme Q10 through sta0n inhibi0on." *Do healthy people with highCholesterol, Sulfate, and Heart Disease Stephanie Seneff Wise Tradi0ons Workshop, London." -- Orville Wright #12;Outline · Introduc0on · Cholesterol sulfate · Blood clots

Seneff, Stephanie

310

Integral membrane heparan sulfate proteoglycans  

Microsoft Academic Search

Heparan sulfate is a regulatory polysac- charide. It modulates specific growth factor-receptor in- teractions, accelerates the formation of specific proteinase- proteinase inhibitor complexes, and mediates interactions of the cell surface with several enzymes and structural proteins. It abounds on the surfaces of embryonic cells, respecting or outlining morphogenetic rather than histo- logical boundaries. This cell surface-associated heparan sulfate is implanted

GUIDO DAVID

1993-01-01

311

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2012 CFR

...suspension in water of precipitated aluminum hydroxide. (h) The term blanc fixe...in water of co-precipitated aluminum hydroxide and barium sulfate. (j...the sum of the quantities of aluminum, iron, calcium, and...

2012-04-01

312

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2014 CFR

...suspension in water of precipitated aluminum hydroxide. (h) The term blanc fixe...in water of co-precipitated aluminum hydroxide and barium sulfate. (j...the sum of the quantities of aluminum, iron, calcium, and...

2014-04-01

313

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2010 CFR

...suspension in water of precipitated aluminum hydroxide. (h) The term blanc fixe...in water of co-precipitated aluminum hydroxide and barium sulfate. (j...the sum of the quantities of aluminum, iron, calcium, and...

2010-04-01

314

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2011 CFR

...suspension in water of precipitated aluminum hydroxide. (h) The term blanc fixe...in water of co-precipitated aluminum hydroxide and barium sulfate. (j...the sum of the quantities of aluminum, iron, calcium, and...

2011-04-01

315

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2013 CFR

...suspension in water of precipitated aluminum hydroxide. (h) The term blanc fixe...in water of co-precipitated aluminum hydroxide and barium sulfate. (j...the sum of the quantities of aluminum, iron, calcium, and...

2013-04-01

316

Molecular Structure of Sulfate ion  

NSDL National Science Digital Library

Sulfate is a naturally occurring substance that is found in minerals and rocks, and in soil it is one of the most predominant anions. This substance results from the oxidation of elemental sulfur, sulfides, or organic sulfur. While sulfate is one of the least toxic anions, it is monitored under the Safe Drinking Water Act (SDWA). The anion is used in mining, pulping, metal and plating industries, water and sewage treatment, leather processing and in the manufacture of numerous chemicals, dyes, glass, soaps, textiles, fungicides, insecticides, astringents, and emetics. Various sulfate salts are used in foods, the estimated daily intake of sulfate from the consumption of food is approximately 453 milligrams (mg). Sulfate can have a cathartic effect on humans which results in the purgation of the alimentary canal, when 1000-2000 mg is ingested.

2002-09-11

317

Regional Tropical Precipitation Change Mechanisms in ECHAM4\\/OPYC3 under Global Warming  

Microsoft Academic Search

Mechanisms of global warming impacts on regional tropical precipitation are examined in a coupled atmosphere-ocean general circulation model (ECHAM4\\/OPYC3). The pattern of the regional tropical precipitation changes, once established, tends to persist, growing in magnitude as greenhouse gases increase. The sulfate aerosol induces regional tropical precipitation anomalies similar to the greenhouse gases but with opposite sign, thus reducing the early

Chia Chou; J. David Neelin; Jien-Yi Tu; Cheng-Ta Chen

2006-01-01

318

Sulfation of von Willebrand factor  

SciTech Connect

von Willebrand factor (vWF) is a multimeric adhesive glycoprotein essential for normal hemostasis. We have discovered that cultured human umbilical vein endothelial cells incorporate inorganic sulfate into vWF. Following immunoisolation and analysis by polyacrylamide or agarose gel electrophoresis, metabolically labeled vWF was found to have incorporated (35S)-sulfate into all secreted multimer species. The time course of incorporation shows that sulfation occurs late in the biosynthesis of vWF, near the point at which multimerization occurs. Quantitative analysis suggests the presence, on average, of one molecule of sulfate per mature vWF subunit. Virtually all the detectable sulfate is released from the mature vWF subunit by treatment with endoglycosidases that remove asparagine-linked carbohydrates. Sulfated carbohydrate was localized first to the N-terminal half of the mature subunit (amino acids 1 through 1,365) by partial proteolytic digestion with protease V8; and subsequently to a smaller fragment within this region (amino acids 273 through 511) by sequential digestions with protease V8 and trypsin. Thus, the carbohydrate at asparagine 384 and/or 468 appears to be the site of sulfate modification. Sodium chlorate, an inhibitor of adenosine triphosphate-sulfurylase, blocks sulfation of vWF without affecting either the ability of vWF to assemble into high molecular weight multimers or the ability of vWF multimers to enter Weible-Palade bodies. The stability of vWF multimers in the presence of an endothelial cell monolayer also was unaffected by the sulfation state. Additionally, we have found that the cleaved propeptide of vWF is sulfated on asparagine-linked carbohydrate.

Carew, J.A.; Browning, P.J.; Lynch, D.C. (Harvard Medical School, Boston, MA (USA))

1990-12-15

319

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

320

Sequential precipitation of Cu and Fe using a three-stage sulfidogenic fluidized-bed reactor system  

Microsoft Academic Search

The exposure of sulfides, such as pyrite (FeS2) to water and air leads to the formation of acidic metal and sulfate containing waters, generally referred to as acid mine drainage (AMD). Under anaerobic conditions and in the presence of a suitable electron and carbon source, sulfate-reducing bacteria (SRB) can reduce sulfate to hydrogen sulfide which can precipitate metals as low-solubility

Deniz Ucar; Ozan K. Bekmezci; Anna H. Kaksonen; Erkan Sahinkaya

2011-01-01

321

Liberation of sulfate from sulfate esters by soils.  

PubMed Central

When incubated with acid, alkaline, and neutral soils, a variety of synthetic sulfate esters representing the various classes of these compounds was hydrolyzed by enzymes, probably of microbial origin. The appearance of sulfate in the soil water occurred immediately after introduction into the soils with some esters, whereas with others it occurred only after lag periods. Heat treatment destroyed the hydrolytic acitivity in the soils. The ester sulfate groups present in humic acid extracted from the soil appeared to be resistant to hydrolysis by a variety of sulfohydrolases extracted from bacteria and other organisms. Images PMID:938044

Houghton, C; Rose, R A

1976-01-01

322

Theoretical isotope shifts in neutral barium  

NASA Astrophysics Data System (ADS)

The present work deals with a set of problems in isotope shifts of neutral barium spectral lines. Some well-known transitions (6 s2 1S0-6 s 6 p 1,3P1o and 6 s2 1S0-6 p2 3P0) are 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 {? 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 6 s 5 d 3D1 ,2-6 s 6 p 1P1o transitions produces isotope shift values in conflict with the laser spectroscopy measurements of U. Dammalapati et al. [Eur. Phys. J. D 53, 1 (2009), 10.1140/epjd/e2009-00076-x].

Nazé, C.; Li, J. G.; Godefroid, M.

2015-03-01

323

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

324

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

325

Preparation and properties of barium ferrite using hot-rolled mill scale  

SciTech Connect

Commercial-quality barium ferrite was made on a laboratory scale by the solid-state reaction of raw hot-rolled mill scale and barium carbonate. The processing parameters are reported. The mechanism of ferrite formation is proposed.

Chien, Y.T.; Pan, H.C.; Ko, Y.C. (China Steel Corp., Kaohsiung, Taiwan (TW))

1989-08-01

326

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

327

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

328

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...

329

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

330

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

331

Creating unstable velocity-space distributions with barium injections  

SciTech Connect

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

Pongratz, M.B.

1983-01-01

332

Fabrication of Nanoparticles of Barium Carbonate\\/Oxalate Using Reverse Micelle Technique  

Microsoft Academic Search

Nanoparticles of barium carbonate\\/oxalate have been synthesized in situ from barium nitrate and ammonium carbonate\\/oxalate by reverse micelle method. These particles were characterized using transmission electron microscope (TEM), fourier transform infrared (FTIR) and x-ray diffraction (XRD). The results indicate that rod-like barium carbonate (BaCO3) and spherical barium oxalate (BaC2O4) nanoparticles can be fabricated with high crystallinity.

Poonam Sharma; H. S. Virk

2009-01-01

333

Magnetic properties of La–Co substituted barium ferrite thin films with large magnetic anisotropy  

Microsoft Academic Search

Barium ferrite thin films with lanthanum ions and cobalt ions substituted for barium ions and iron ions have been prepared by conventional diode sputtering method. The hexagonal magnetoplumbite structure was formed by an annealing at 800°C or above. La–Co-substituted barium ferrite thin films had large magnetic anisotropy compared with non-substituted barium ferrite thin films. Moreover, an attempt was also made

K. Kakizaki; H. Taguchi; N. Hiratsuka

2004-01-01

334

Cement composition and sulfate attack  

SciTech Connect

Four cements were used to address the effect of tricalcium silicate content of cement on external sulfate attack in sodium sulfate solution. The selected cements had similar fineness and Bogue-calculated tricalcium aluminate content but variable tricalcium silicates. Durability was assessed using linear expansion and compressive strength. Phases associated with deterioration were examined using scanning electron microscopy and X-ray diffraction. Mineralogical phase content of the as-received cements was studied by X-ray diffraction using two methods: internal standard and Rietveld analysis. The results indicate that phase content of cements determined by X-ray mineralogical analysis correlates better with the mortar performance in sulfate environment than Bogue content. Additionally, it was found that in cements containing triclacium aluminate only in the cubic form, the observed deterioration is affected by tricalcium silicate content. Morphological similarities between hydration products of high tricalcium aluminate and high tricalcium silicate cements exposed to sodium sulfate environment were also observed.

Shanahan, Natalya [Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL 33620 (United States); Zayed, Abla [Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL 33620 (United States)]. E-mail: zayed@eng.usf.edu

2007-04-15

335

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 Section...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2011-07-01

336

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 Section...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3 ). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2014-07-01

337

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 Section...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3 ). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2012-07-01

338

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 Section...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2010-07-01

339

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 Section...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3 ). (a) Chemical...chemical substance identified as barium manganese oxide (BaMnO3 ) (PMN...

2013-07-01

340

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

Code of Federal Regulations, 2012 CFR

...Barium azide-50 percent or more water wet. 173.182 Section...Barium azide—50 percent or more water wet. Barium azide...to take place when and where freezing weather is possible, a suitable...solution must be used to prevent freezing. Each packaging must...

2012-10-01

341

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

342

L = 1.24 Conjugate Magnetic Field Line Tracing Experiments With Barium Shaped Charges  

Microsoft Academic Search

Barium ions are well suited for tracing out magnetic field lines, because they resonantly scatter sunlight in several visible wavelengths and because ions are constrained to spiral about magnetic field lines while traveling freely parallel to the field. By use of high explosive shaped charges with hollow conical liners of barium metal, detonated above 500-km altitude, jets of barium plasma

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

1974-01-01

343

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

344

Synthesis of Barium Ferrite Ultrafine Particles by Coprecipitation in the Presence of Polyacrylic Acid  

Microsoft Academic Search

The barium ferrite ultrafine particles were synthesized by coprecipitation in an aqueous solution with polyacrylic acid (PAA) as a protective agent. Thermal analysis by TGA\\/DTA showed that the precursor could yield barium ferrite after calcination above 700°C for 2 h. By analyses of the XRD and electron diffraction pattern, the formation of pure barium ferrite was confirmed and the appropriate

Dong-Hwang Chen; Yuh-Yuh Chen

2001-01-01

345

Barium ferrite particulate tapes for high-band 8 mm VCR  

Microsoft Academic Search

Barium ferrite particulate media have been applied to recording tapes for a high-band 8 mm VCR, with full compatibility with metal particulate tapes, although they have remarkably different magnetic and recording characteristics. The compatibility of barium ferrite tapes to metal particulate tapes has been attained by adopting barium ferrite particles with an average diameter of 50 nm and a diameter

H. Yokoyama; T. Ito; M. Isshiki; K. Kurata; T. Fukaya

1992-01-01

346

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

E-print Network

on the magnetic properties of stoichiometric barium ferrite thin films have been previously reported.2 In our workBarium 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

Laughlin, David E.

347

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.

348

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.

349

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

350

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

2013-01-01

351

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Tannic acid and barium enema preparations. 201.304 Section...Products § 201.304 Tannic acid and barium enema preparations. (a) It has...practice for tannic acid to be added to barium enemas to improve X-ray...

2014-04-01

352

Spectroscopy of Eu3+ ions in congruent strontium barium niobate crystals  

E-print Network

Spectroscopy of Eu3+ ions in congruent strontium barium niobate crystals Ä. 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

353

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

354

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Tannic acid and barium enema preparations. 201.304 Section...Products § 201.304 Tannic acid and barium enema preparations. (a) It has...practice for tannic acid to be added to barium enemas to improve X-ray...

2013-04-01

355

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

356

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

2013-01-01

357

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

358

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

359

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

360

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

2010-01-01

361

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.

362

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Tannic acid and barium enema preparations. 201.304 Section...Products § 201.304 Tannic acid and barium enema preparations. (a) It has...practice for tannic acid to be added to barium enemas to improve X-ray...

2012-04-01

363

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

364

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

365

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

366

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

367

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

368

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

369

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

370

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.

371

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 attaining are arguably those of Iguchi et al.1 Using yttrium-doped barium cerate as an electrolyte, these authors

372

The enhanced and optimal piezoelectric coefficients in single crystalline barium titanate with engineered domain configurations  

E-print Network

The enhanced and optimal piezoelectric coefficients in single crystalline barium titanate the effective electromechanical moduli of tetragonal barium titanate poled along 111 direction, where that poling along 111 direction does not lead to the optimal domain configuration, since barium titanate poled

Li, Jiangyu

373

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

374

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

375

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.

376

Effect of depolarization and coercivity on actuation strains due to domain switching in barium titanate  

E-print Network

. The theoretical maximum actuation strain such as 1.1% for barium titanate crystals, however, has not been observed in thermally aged barium titanate BaTiO3 crystals.2 Burcsu et al. examined the 90°- switching-induced strainEffect of depolarization and coercivity on actuation strains due to domain switching in barium

Shu, Yi-Chung

377

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.

378

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

E-print Network

, 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 titanate with different morphol- ogies, particle sizes, and dispersions. Barium titanate exists in several

Dutta, Prabir K.

379

Polyaniline stabilized barium titanate nanoparticles reinforced epoxy nanocomposites with high dielectric  

E-print Network

Polyaniline stabilized barium titanate nanoparticles reinforced epoxy nanocomposites with high*b and Zhanhu Guo*a Epoxy polymer nanocomposites (PNCs) filled with both barium titanate (BaTiO3) (500 and 100 systems.7 Barium titanate (BaTiO3) exhibiting unique ferroelectricity,8 piezoelectricity9 and high

Guo, John Zhanhu

380

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.

381

Shape-Controlled Monocrystalline Ferroelectric Barium Titanate Nanostructures: From Nanotubes and Nanowires to Ordered Nanostructures  

E-print Network

Shape-Controlled Monocrystalline Ferroelectric Barium Titanate Nanostructures: From Nanotubes of barium titanate nanostructures using Na2Ti3O7 nanotubes and nanowires as synthetic precursors. A variety and nanowires and the temperature- dependent crystal structure of barium titanate. Various nanoblocks, including

Srinivasan, Gopalan

382

Strain effect on coercive field of epitaxial barium titanate thin films S. Choudhury,1,a  

E-print Network

Strain effect on coercive field of epitaxial barium titanate thin films S. Choudhury,1,a Y. L. Li,1 polarizations of 001 -oriented epitaxial barium titanate thin films using the phase-field approach by strain. We use 001 -oriented epitaxial barium titanate BTO thin films as a model system. In the phase

Chen, Long-Qing

383

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.

384

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

385

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

386

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.

387

Operation of multiple 90 switching systems in barium titanate single crystals under electromechanical loading  

E-print Network

Operation of multiple 90° switching systems in barium titanate single crystals under Hysteresis evolution of a 5 5 2 mm3 barium titanate single crystal during a combined electromechanical of barium titanate BaTiO3 single crystals under combined electrical and mechanical loadings was examined

Shu, Yi-Chung

388

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

389

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

390

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 the introduction of the dielectric barium titanate nanoparticle into Fe2O3/PU nanocomposites. The permeability (PU) nanocomposites reinforced with magnetic iron oxide nanoparticles and/or dielectric barium

Guo, John Zhanhu

391

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, delay lines, filters, and phase shifters for steerable antennas.1­3 Barium strontium titanate BaxSr1-x Received 8 April 2008; accepted 13 April 2008; published online 8 May 2008 Compositionally graded barium

Alpay, S. Pamir

392

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 layers on amorphous and silicon substrates. Growth of highly oriented barium titanate films of the thin films grown with and without oxygen plasma. We have shown that optical quality barium titanate

Atwater, Harry

393

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

394

21 CFR 184.1261 - Copper sulfate.  

Code of Federal Regulations, 2010 CFR

...Drugs 3 2010-04-01 2009-04-01 true Copper sulfate. 184.1261 Section 184.1261 Food...Specific Substances Affirmed as GRAS § 184.1261 Copper sulfate. (a) Copper sulfate (cupric sulfate, CuSO4 ·5H2...

2010-04-01

395

White dwarf kicks and implications for barium stars  

NASA Astrophysics Data System (ADS)

The barium stars have caused much grief in the field of binary stellar evolution. They are often eccentric when they should be circular and are not found to have periods longer than 104 days even though wind accretion should still be efficient at such separations. We address both these problems by introducing a kick to white dwarfs when they are born, thus solving the eccentricity problem, and imposing strong orbital angular momentum loss to shrink barium-star binaries down to the observed periods. Whilst our angular momentum prescription is hard to justify for the barium stars it shows that strong angular momentum loss is necessary to reproduce the observed period-eccentricity distribution. We are investigating whether this can be obtained from a circumbinary disc.

Izzard, R. G.; Church, R. P.; Dermine, T.

396

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

397

Barium Levels in Soils and Centella asiatica.  

PubMed

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

2013-08-01

398

Timed barium esophagram in achalasia types.  

PubMed

Relationships of timed barium esophagram (TBE) findings to achalasia types defined by high-resolution manometry (HRM) have not been elucidated. Therefore, we correlated preoperative TBE and HRM measurements in achalasia types and related these to patient symptoms and prior treatments. From 2006 to 2013, 248 achalasia patients underwent TBE and HRM before Heller myotomy. TBE height and width were recorded at 1 and 5 minutes; HRM measured lower esophageal sphincter mean basal pressure, integrated relaxation pressure (IRP), and mean esophageal body contraction amplitude. Achalasia was classified into types I (25%), II (65%), and III (9.7%). TBE height at 5 minutes was higher for I (median 8?cm; interquartile range 6-12) and II (8?cm; 8-11) than for III (1?cm; 0-7). TBE width at 5 minutes was widest (3?cm; 2-4), narrower in II (2?cm; 2-3), and narrowest in I (1?cm; 0-2), P?

Zanoni, A; Rice, T W; Lopez, R; Birgisson, S; Shay, S S; Thota, P N; Baker, M E; Raymond, D P; Blackstone, E H

2015-05-01

399

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

400

Steady-state interstitial water sulfate O-18/O-16 ratios as a function of salinity  

NASA Astrophysics Data System (ADS)

At ambient temperature and pH dissolved sulfate does not exchange isotopes with water to significant extent over millions of years. However, due to the formation of intermediate sulphur species during dissimilatory sulfate reduction, fast isotope exchange is observed under microbial mediation. The catalyzed oxygen isotope exchange between pore water sulfate and intracellular water upon sulfate reduction leads to the development of steady-state values for dissolve sulfate. At the same degrees of microbial conversion, sulfur isotope ratios may still proceed to increase due to continuous net sulfate reduction. Whereas the initial ratio of d34S-d18O variations in dissolved sulfate is controlled by metabolic rates (e.g., cellular sulfate reduction rates), the balance between sulfate reduction and sulphide oxidation, and the isotopic composition of cellular water, the steady state value is controlled only by oxygen isotope exchange with water. Although the exact relationship between measured steady-state values and equilibrium is still under debate, an ultimate control by both temperature and the oxygen isotope composition of water is expected. The latter is related to salinity and climate zone. In this study we show the results from interstitial waters obtained at different natural localities covering a wide range of salinity regimes and benthic metabolic rates. Sites include brackish coastal and euxinic systems in the Baltic Sea and the Black Sea, coastal sediments of the North Sea, and deep marine pore waters from the Mediterranean and the Pacific (ODP Legs 160, 161, 182, 201). Results are compared to previous findings by Fritz et al. (1989) on groundwaters and experimental studies by Mizutani & Rafter (1973). The field examples show that the pore waters reach steady-state values depending on the isotopic values of pore waters, and the rates can vary strongly with microbial activity in the specific setting. If conditions allow diagenetic barites to be formed in these environments at the diffusional sulfate-barium interface, these authigenic phases have the potential to serve as proxies for pore water salinity.

Wortmann, U. G.; Böttcher, M. E.; Blake, R. M.; Bernasconi, S. M.

2009-12-01

401

Calcium Sulfate Characterized by ChemCam/Curiosity at Gale Crater, Mars  

NASA Astrophysics Data System (ADS)

Within Gale crater an assemblage of veins were observed, mainly into Yellowknife Bay region. The ChemCam instrument was able to demonstrate they consist of Ca-sulfate veins. We interpret them as a precipitation posterior to the sediments they cross.

Nachon, M.; Clegg, S. M.; Mangold, N.; Schröder, S.; Kah, L. C.; Dromart, G.; Olilla, A.; Johnson, J. R.; Oehler, D. Z.; Bridges, J. C.; Le Mouélic, S.; Forni, O.; Wiens, R. C.; Rapin, W.; Anderson, R. B.; Blaney, D. L.; Bell, J. F.; Clark, B.; Cousin, A.; Dyar, M. D.; Ehlmann, B.; Fabre, C.; Gasnault, O.; Grotzinger, J.; Lasue, J.; Lewin, E.; Léveillé, R.; McLennan, S.; Maurice, S.; Meslin, P.-Y.; Rice, M.; Squyres, S. W.; Stack, K.; Sumner, D. Y.; Vaniman, D.; Wellington, D.

2014-07-01

402

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

403

Sulfate decomposition by bacterial leaching  

SciTech Connect

Sulfate disposal is the main problem of many industrial effluents, such as excess sulfuric acid, gypsum, coal desulfurization byproducts, acid-mine waters, and general metallurgical effluents. It has been established that sulfate present in wastes can be converted to elemental sulfur by bacterial mutualism. This study presents the results of an investigation of the industrial feasibility of utilizing a biological system capable of converting hydrous calcium sulfate (gypsum) to elemental sulfur. Gypsum, which was used in this study, is a byproduct of the fertilizer industry. The biological system is referred to as a bacterial mutualism, and involves Desulfovibrio desulfuricans for sulfate conversion and Chlorobium thiosulfatophilum for hydrogen sulfide conversion. Bacterial mutualism and utilization of sulfate were investigated by means of a two-stage anaerobic system. In the first stage, a gas purge system was used for sulfate conversion to sulfide, and it was found that maximum conversion is 34%. In the second stage, a static culture system was used for sulfide conversion to sulfur with a conversion of 92%. 14 refs., 5 tabs.

Deveci, N.; Delaloglu, C.G. [Istanbul Technical Univ. (Turkey)

1995-04-01

404

Compact pulse forming line using barium titanate ceramic material.  

PubMed

Ceramic material has very high relative permittivity, so compact pulse forming line can be made using these materials. Barium titanate (BaTiO(3)) 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. PMID:22129008

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

2011-11-01

405

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

406

Kriging direct and indirect estimates of sulfate deposition: A comparison. Forest Service research paper  

SciTech Connect

Due to logistical and cost constraints, acidic deposition is rarely measured at forest research or sampling locations. A crucial first step to assessing the effects of acid rain on forests is an accurate estimate of acidic deposition at forest sample sites. The authors examine two methods (direct and indirect) for estimating sulfate deposition at atmospherically unmonitored forest sites. The direct method only uses directly measured deposition data, while the indirect method additionally incorporates precipitation measurements from a spatially denser network of monitoring sites. Sulfate deposition values were estimated by point kriging using both the direct and indirect methods. By using the supplemental data from the precipitation monitoring network, estimates of sulfate deposition improved substantially, particularly at sites that are relatively isolated to the acid deposition monitoring network. Cross-validated procedures indicate that by using the indirect method, a reduction of approximately 20 to 25 percent in the predicted error sum of squares occurred.

Reams, G.A.; Huso, M.M.P.; Vong, R.J.; McCollum, J.M.

1997-08-01

407

Sulfate resistance of plain and blended cements exposed to varying concentrations of sodium sulfate  

Microsoft Academic Search

Concrete deterioration due to sulfate attack is the second major durability problem, after reinforcement corrosion. This type of deterioration is noted in the structures exposed to sulfate-bearing soils and groundwater. Though concrete deterioration due to sulfate attack is reported from many countries, the mechanisms of sulfate attack have not been thoroughly investigated, particularly the effect of sulfate concentration and the

S. U. Al-Dulaijan; M. Maslehuddin; M. M. Al-Zahrani; A. M. Sharif; M. Shameem; M. Ibrahim

2003-01-01

408

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

409

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

410

Study of the photovoltaic effect in thin film barium titanate  

NASA Technical Reports Server (NTRS)

The photoelectric effect in structures consisting of metal deposited barium titanate film silicon is described. A radio frequency sputtering technique is used to deposit ferroelectric barium titantate films on silicon and quartz. Film properties are measured and correlated with the photoelectric effect characteristics of the films. It was found that to obtain good quality pin hole free films, it is necessary to reduce the substrate temperature during the last part of the deposition. The switching ability of the device with internal applied voltage is improved when applied with a ferroelectric memory device.

Grannemann, W. W.; Dharmadhikari, V. S.

1981-01-01

411

Heparan sulfate proteoglycans in glomerular inflammation  

Microsoft Academic Search

Heparan sulfate proteoglycans in glomerular inflammation.Heparan sulfate proteoglycans (HSPGs) are glycoproteins consisting of a core protein to which linear heparan sulfate side chains are covalently attached. These heparan sulfate side chains can be modified at different positions by several enzymes, which include N-deacetylases, N- and O-sulfotransferases, and an epimerase. These heparan sulfate modifications give rise to an enormous structural diversity,

Angelique L. W. M. M. Rops; JOHAN VAN DER VLAG; Joost F. M. Lensen; Tessa J. M. Wijnhoven; Lambert P. W. J. van den Heuvel; Toin H. van Kuppevelt; Jo H. M. Berden

2004-01-01

412

Urban impacts on precipitation  

NASA Astrophysics Data System (ADS)

Weather and climate changes caused by human activities (e.g., greenhouse gas emissions, deforestation, and urbanization) have received much attention because of their impacts on human lives as well as scientific interests. The detection, understanding, and future projection of weather and climate changes due to urbanization are important subjects in the discipline of urban meteorology and climatology. This article reviews urban impacts on precipitation. Observational studies of changes in convective phenomena over and around cities are reviewed, with focus on precipitation enhancement downwind of cities. The proposed causative factors (urban heat island, large surface roughness, and higher aerosol concentration) and mechanisms of urban-induced and/or urban-modified precipitation are then reviewed and discussed, with focus on downwind precipitation enhancement. A universal mechanism of urban-induced precipitation is made through a thorough literature review and is as follows. The urban heat island produces updrafts on the leeward or downwind side of cities, and the urban heat island-induced updrafts initiate moist convection under favorable thermodynamic conditions, thus leading to surface precipitation. Surface precipitation is likely to further increase under higher aerosol concentrations if the air humidity is high and deep and strong convection occurs. It is not likely that larger urban surface roughness plays a major role in urbaninduced precipitation. Larger urban surface roughness can, however, disrupt or bifurcate precipitating convective systems formed outside cities while passing over the cities. Such urban-modified precipitating systems can either increase or decrease precipitation over and/or downwind of cities. Much effort is needed for in-depth or new understanding of urban precipitation anomalies, which includes local and regional modeling studies using advanced numerical models and analysis studies of long-term radar data.

Han, Ji-Young; Baik, Jong-Jin; Lee, Hyunho

2014-01-01

413

Precipitation Type Applet  

NSDL National Science Digital Library

This applet provides a simulation of the type of precipitation that results from adjusting the temperature (dry bulb and wet bulb) at different altitudes. An updraft in the cloud can be produced in order to see its influence on precipitation. The precipitation types that are simulated include snowflakes/ice crystals, supercooled droplets, raindrops, drizzle, sleet, snow grains, and freezing rain or drizzle on the ground.

Tom Whittaker

414

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.

415

Volumetric determination of uranium titanous sulfate as reductant before oxidimetric titration  

USGS Publications Warehouse

Need for a more rapid volumetric method for the routine determination of uranium in uranium-rich materials has led to the development of a method that uses titanous sulfate as a reductant before oxidimetric titration. Separation of the hydrogen sulfide group is not necessary. Interfering elements precipitated by cupferron are removed by automatic filtrations made simultaneously rather than by the longer chloroform extraction method. Uranium is reduced from VI to IV by addition of an excess of titanous sulfate solution, cupric ion serving as an indicator by forming red metallic copper when reduction is complete. The copper is reoxidized by addition of mercuric perchlorate. The reduced uranium is then determined by addition of excess ferric sulfate and titration with ceric sulfate. The method has proved to be rapid, accurate, and economical.

Wahlberg, J.S.; Skinner, D.L.; Rader, L.F., Jr.

1957-01-01

416

Precipitates in electrical steels  

NASA Astrophysics Data System (ADS)

Precipitates heavily influence the magnetic properties of electrical steels, either as a key controlled requirement as part of the manufacturing process or as an unwanted harmful residual in the final product. In this current work copper-manganese sulphides precipitates are the primary inhibitor species in the conventional grain-oriented (CGO) steels examined and grain boundary pinning is effective at a mean precipitate size of 30-70 nm. The growth of CuMnS has been studied and the results show that a precipitate size above ˜100 nm allows the onset of secondary recrystallisation in the heating conditions applied. The effect of precipitates on the magnetic properties of both grain-oriented and non-oriented steels in their final product form is then examined. Examples of grain-oriented material still containing large numbers of precipitates clearly show the detrimental effects with increases in total power loss of 40% or more. Loss deterioration by about 20% is also seen in samples of high silicon non-oriented material in which titanium carbo-nitride precipitates have been observed. In this case the precipitates are believed to have formed during cooling after final annealing. Finally a grain-oriented steel with a large number of very small precipitates, which do not seem to have any harmful effect on the magnetic properties, is demonstrated.

Jenkins, Keith; Lindenmo, Magnus

417

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 ...

Miss Brown

2009-10-21

418

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.

COMET

2005-06-24

419

Sulfate-rich Archean Oceans  

NASA Astrophysics Data System (ADS)

There is a widely held belief that prior to 2.4 Ga, the Archean oceans and atmosphere were reducing, and therefore sulfate poor (concentrations <0.1 mmol). However, there is mounting evidence from diverse rock types of Archean ages that sulfate concentrations were likely similar to those in the modern ocean (~28 mmol). In this study we demonstrate that in different lithologies, representing a wide range of marine environments, there is ubiquitous evidence for abundant seawater sulfate. One of the more apparent lines of evidence for sulfate rich Archean waters are bedded barite (BaSO4) deposits, such as those in the ~3.4 Ga Fig Tree Group, South Africa and ~3.5 Ga Dresser Formation, Western Australia (WA). These deposits are thick (>100 m), widely distributed (> km2), and contain only minor amounts of sulfides. These barite beds may have developed from reactions between Ba-rich hydrothermal fluids and evaporate bodies. Simple mass balance calculations suggest that the sulfate contents of the pre-evaporitic seawater must have been greater than ~1 mM. Some researchers have suggested that the SO4 for these beds was derived from the hydrolysis of SO2-rich magmatic fluids. However, this was unlikely as the reaction, 4SO2 + 4H2O ? 3H2SO4 + H2S would have produced large amounts of sulfide, as well as sulfate minerals. Many Archean-aged volcanogenic massive sulfide (VMS) deposits, much like those of the younger ages, record evidence for abundant seawater sulfate. As VMS deposits are most likely formed by submarine hydrothermal fluids that developed from seawater circulating through the seafloor rock, much of the seawater sulfate is reduced to from sulfides at depths. However, some residual sulfate in the hydrothermal fluids, with or without the addition of sulfate from the local seawater, can form sulfate minerals such as barite at near the seafloor. The d34S relationships between barites and pyrites in the Archean VMS deposits are similar to those of the younger VMS deposits, except for the lower d34S values for the seawater SO4. The abundance of pyrite in Archean black shales is also evidence of sulfate rich seawater. Pyrites in Archean-aged black shales were most likely the products of either bacterial or thermochemical sulfate reduction during diagenesis of the sediments. Their abundance in sedimentary rocks is determined by: (a) the availability of reactive carbon; (b) the availability of reactive Fe (Fe3+ hydroxides and Fe2+-rich pore fluid); (c) the sedimentation rate; and (d) the flux of SO42- in the sediments, which depends on the seawater SO42- contents. Contrary to a widely held belief, pyrite- and organic C rich black Archean shales are quite common, such as the 2.7 Ga Jeerinah and the 2.5 Ga McRae Shales in WA. Our modeling suggests that the formation of such pyrite-rich shales requires seawater SO4 contents greater than ~1 mM. As for the main source of SO4 in the Archean oceans, the current paradigm, based on mass independent fractionation of sulfur isotopes (MIF-S) in some pyrite and barite samples from some pre-2.4 Ga sedimentary rocks, postulates that the seawater SO4 was produced by UV photolysis of volcanic SO2 gas in an O2-poor atmosphere. However, the recent findings of the absence of MIF-S in many Archean sedimentary rocks, as well as those of oxidized paleosols of Archean ages, suggest that the abundant SO4 in the Archean oceans were generated by the oxidative weathering of sulfides.

Brainard, J. L.; Choney, A. P.; Ohmoto, H.

2012-12-01

420

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

421

Functions of Chondroitin Sulfate and Heparan Sulfate in the Developing Brain  

Microsoft Academic Search

Chondroitin sulfate and heparan sulfate proteoglycans are major components of the cell surface and extracellular matrix in\\u000a the brain. Both chondroitin sulfate and heparan sulfate are unbranched highly sulfated polysaccharides composed of repeating\\u000a disaccharide units of glucuronic acid and N-acetylgalactosamine, and glucuronic acid and N-acetylglucosamine, respectively. During their biosynthesis in the Golgi apparatus, these glycosaminoglycans are highly modified\\u000a by sulfation

N. Maeda; M. Ishii; K. Nishimura; K. Kamimura

2011-01-01

422

Localization and characterization of acharan sulfate in the body of the giant African snail Achatina fulica.  

PubMed

Acharan sulfate is a glycosaminoglycan (GAG), having the structure -->4)-2-acetamido-2-deoxy-alpha-D-glucopyranose(1-->4)-2-sulfo-alpha-L-idopyranosyluronic acid (1-->, isolated from the body of the giant African snail Achatina fulica. This GAG represents 3-5% of the dry weight of this snail's soft body tissues. Frozen sections and polyester wax sections of the snail's body were stained by Alcian blue-periodic acid-Schiff's reagent (PAS) to localize acharan sulfate. Alcian blue staining indicated that GAG was mainly secreted into the outer surface of the body from internal granules. A highly mucous material was collected and treated and the acharan sulfate was recovered by ethanol and cetyl pyridinium chloride precipitation. Crude acharan sulfate was purified by DEAE-Sephacel ion-exchange chromatography. Depolymerization of intact mucus and purified acharan sulfate fractions by heparin lyase II (heparitinase I) from Flavobacterium heparinum produced an unsaturated disaccharide as a major product, establishing the repeating unit of acharan sulfate. These results demonstrate that mucus in the granule and secreted to the outside of the body is composed entirely of acharan sulfate. PMID:11691628

Jeong, J; Toida, T; Muneta, Y; Kosiishi, I; Imanari, T; Linhardt, R J; Choi, H S; Wu, S J; Kim, Y S

2001-12-01

423

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...

424

Original article Response to barium selenate supplementation in sheep  

E-print Network

group did not receive any supplement of Se and/or vitamin E. The two groups were managed under the sameOriginal article Response to barium selenate supplementation in sheep kept at pasture supplements in the prevention of dis- orders related to Se deficiency in sheep maintained at pasture

Boyer, Edmond

425

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 ...

426

Magnetic and structural characteristics of sputtered barium ferrite thin films  

Microsoft Academic Search

? M curves have been measured on both randomly and perpendicularly oriented barium ferrite thin films. Compared with theoretical simulations, the shape and peak values of the ? M curves suggest that the intergranular exchange interaction in sputtered BaM thin films is negligible. This is similar to the case of oxide particulate media even though the sputtered films are much

Jinshan Li; Stephen S. Rosenbluem; Hidetaka Hayashi; Robert Sinclair

1996-01-01

427

Structure and magnetic properties of aerosol synthesized barium ferrite particles  

Microsoft Academic Search

The aerosol synthesis technique has been employed to produce barium ferrite particles. X-ray and electron diffraction, scanning and transmission microscopy methods were used to find detailed information on crystallography, morphology and chemical composition of as prepared and annealed powders. A detailed study has been made of the correlation between magnetic hysteresis parameters and the inner structure of submicrometer ferrite particles.

W. A. Kaczmarek; B. W. Ninham; A. Calka

1991-01-01

428

BARIUM AND RADIUM REMOVAL FROM GROUNDWATER BY ION EXCHANGE  

EPA Science Inventory

The primary objective of this study was to determine the applicability of weak acid exchange resin in the hydrogen form for removal of hardness, barium and radium from groundwater. Weak acid resin in the hydrogen form eliminates the addition of sodium to drinking water. The capac...

429

Long Term Magnetic Stability of Alnico and Barium Ferrite Magnets  

Microsoft Academic Search

Alnico and barium ferrite materials do not age at room temperature. The decreases in remanence, occurring with time, are adjustments by the magnet to its environment. Remanence adjustment proceeds with the logarithm of time and amounts to 2% or less one year after magnetization. Remanences in magnets with Hci > 2200 oe show no changes. Also, the smaller the irreversible

K. J. Kronenberg; M. A. Bohlmann

1960-01-01

430

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

431

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 ...

432

Electron Optical Studies of Barium Titanate Single Crystal Films  

Microsoft Academic Search

Thin single crystal films of barium titanate prepared by chemical thinning of single crystal plates are studied by transmission electron microscopy and electron diffraction. The films as thin as 1000 Å are found to have the same lattice parameters as the bulk crystals, giving no evidence for the existence of the anomalous surface layer proposed by Känzig et al. The

Michiyoshi Tanaka; Goro Honjo

1964-01-01

433

Nanoshell tubes of ferroelectric lead zirconate titanate and barium titanate  

Microsoft Academic Search

Wafer-scale fabrication of ferroelectric oxide nanoshell tubes as well as ordered nanotube arrays have been accomplished using a simple and convenient fabrication method that allows full tailoring of tube dimensions as well as array pattern and size. Using different silicon and alumina templates, barium titanate and lead zirconate titanate tubes with diameters ranging from 50 nm up to several micrometers

Yun Luo; Izabela Szafraniak; Nikolai D. Zakharov; Valanoor Nagarajan; Martin Steinhart; Ralf B. Wehrspohn; Joachim H. Wendorff; Ramamoorthy Ramesh; Marin Alexe

2003-01-01

434

Hierarchical Structure-Ferroelectricity Relationships of Barium Titanate Particles  

E-print Network

Review Hierarchical Structure-Ferroelectricity Relationships of Barium Titanate Particles Tu Lee structural levels and to thoroughly review the corresponding structure- ferroelectricity relationships at all). However, the inconsistency of the critical size in the literature, ranging from 15 to 200 nm in diameter,4

Aksay, Ilhan A.

435

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.

2012-04-06

436

Heparan sulfate signaling in cancer.  

PubMed

Heparan sulfate (HS) is a biopolymer consisting of variably sulfated repeating disaccharide units. The anticoagulant heparin is a highly sulfated intracellular variant of HS. HS has demonstrated roles in embryonic development, homeostasis, and human disease via non-covalent interactions with numerous cellular proteins, including growth factors and their receptors. HS can function as a co-receptor by enhancing receptor-complex formation. In other contexts, HS disrupts signaling complexes or serves as a ligand sink. The effects of HS on growth factor signaling are tightly regulated by the actions of sulfyltransferases, sulfatases, and heparanases. HS has important emerging roles in oncogenesis, and heparin derivatives represent potential therapeutic strategies for human cancers. Here we review recent insights into HS signaling in tumor proliferation, angiogenesis, metastasis, and differentiation. A cancer-specific understanding of HS signaling could uncover potential therapeutic targets in this highly actionable signaling network. PMID:24755488

Knelson, Erik H; Nee, Jasmine C; Blobe, Gerard C

2014-06-01

437

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

438

Early Triassic seawater sulfate drawdown  

NASA Astrophysics Data System (ADS)

The marine sulfur cycle is intimately linked to global carbon fluxes, atmospheric composition, and climate, yet relatively little is known about how it responded to the end-Permian biocrisis, the largest mass extinction of the Phanerozoic. Here, we analyze carbonate-associated-sulfate (CAS) from three Permo-Triassic sections in South China in order to document the behavior of the C-S cycle and its relationship to marine environmental changes during the mass extinction and its aftermath. We find that ?34SCAS varied from +9‰ to +44‰ at rates up to 100‰ Myr-1 during the Griesbachian-Smithian substages of the Early Triassic. We model the marine sulfur cycle to demonstrate that such rapid variation required drawdown of seawater sulfate concentrations to ?4 mM and a reduction in its residence time to ?200 kyr. This shorter residence time resulted in positive covariation with ?13Ccarb due to strong coupling of the organic carbon and pyrite burial fluxes. Carbon and sulfur isotopic shifts were associated with contemporaneous changes in climate, marine productivity, and microbial sulfate reduction rates, with negative shifts in ?13Ccarb and ?34SCAS linked to warming, decreased productivity, and reduced sulfate reduction. Sustained cooling during the Spathian re-invigorated oceanic overturning circulation, reduced marine anoxia, and limited pyrite burial. As seawater sulfate built to higher concentrations during the Spathian, the coupling of the marine C and S cycles came to an end and a general amelioration of marine environmental conditions set the stage for a recovery of invertebrate faunas. Variation in seawater sulfate during the Early Triassic was probably controlled by climate change, possibly linked to major eruptive phases of the Siberian Traps.

Song, Huyue; Tong, Jinnan; Algeo, Thomas J.; Song, Haijun; Qiu, Haiou; Zhu, Yuanyuan; Tian, Li; Bates, Steven; Lyons, Timothy W.; Luo, Genming; Kump, Lee R.

2014-03-01

439

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

440

Mineralogy and Organic Geochemistry of Acid Sulfate Environments from Valles Caldera, New Mexico: Habitability, Weathering and Biosignatures  

NASA Astrophysics Data System (ADS)

We report on the mineralogy, organic preservation potential and habitability of sulfate deposits in acid sulfate volcanic settings at Valles Caldera, New Mexico. Fumaroles and acidic springs are potential analogs for aqueous environments on Mars and may offer insights into habitability of sulfate deposits such as those at Meridiani Planum. Sulfates recently detected on Mars are posited to have formed from fluids derived from basaltic weathering and igneous volatile input, ultimately precipitating from acidic brines subjected to desiccation and freeze-thaw cycles (McClennan and Grotzinger, 2008). Key issues concerning martian sulfate deposits are their relationship to aqueous clay deposits, and whether or not specific sulfates deposits represent former habitable environments (see Soderblum and Bell, 2008; Tosca et al., 2008). Modern terrestrial volcanic fumaroles and hot springs precipitate various Ca-, Mg- and Fe- sulfates along with clays, and can help clarify whether certain acid sulfate mineral assemblages reflect habitable environments. Valles caldera is a resurgent caldera last active in the Pleistocene (1.4 - 1.0 Ma) that hosts several active fumaroles and over 40 geothermal exploration wells (see Goff, 2009). Fumaroles and associated mudpots and springs at Valles range from pH < 1 to 3, and affect argillic alteration upon rhylolitic tuffs and sedimentary deposits (Charles et al., 1986). We identified assemblages containing gypsum, quartz, Al-sulfates, elemental sulfur, clays and other minerals using XRD and SEM-EDS. Our previous research has shown that sulfates from different marine depositional environments display textural and morphological traits that are indicative of biological influence, or specific conditions in the depositional environments (Vogel et al., 2009). Gypsum crystals that develop in the presence of microbial biofilms in marine environments may have distorted crystal morphologies, biofilm - associated dissolution features, and accessory carbonate minerals. Gypsum from Valles Caldera fumaroles develops in the absence of microbial biofilms and differs from biologically influenced marine gypsum in terms of is highly prismatic morphology, lack of texture, and association with clays, and other sulfates. Studies of Valles gypsum crystals therefore support the uniqueness of the putative morphological biosignatures in marine gypsum. We also assayed organic matter from fumarole encrustations to understand how low pH and sulfate content may discriminate against or enhance preservation of specific classes of organic compounds in acid sulfate environments. Similar to gypsiferous marine environments, organics are characterized by abundant organosulfur complexes. Long chain alkanes (> nC22) are abundant from acid sulfate environments. As with hypersaline marine depositional environments, sulfidation appears to be a major diagenetic pathway for organic matter in acid sulfate environments.

Vogel, M. B.; Des Marais, D. J.; Jahnke, L. L.; Kubo, M.

2009-12-01

441

Sulfation of ceria-zirconia model automotive emissions control catalysts  

NASA Astrophysics Data System (ADS)

Cerium-zirconium mixed metal oxides are used in automotive emissions control catalysts to regulate the partial pressure of oxygen near the catalyst surface. The near surface oxygen partial pressure is regulated through transfer of atomic oxygen from the ceria-zirconia solid matrix to the platinum group metals to form metal oxides capable of oxidizing carbon monoxide and unburned hydrocarbons. Although the addition of zirconium in the cubic lattice of ceria increases the oxygen storage capacity and thermal stability of the ceria matrix, the cerium-zirconium oxide system remains particularly susceptible to deactivation from sulfur compounds. While the overall effect of sulfur on these systems is understood (partially irreversible deactivation), the fundamental and molecular interaction of sulfur with ceria-zirconia remains a challenging problem. Ceria-zirconia metal oxide solid solutions have been prepared through co-precipitation with nitrate precursors. The prepared powders were calcined and subsequently formed into planer wafers and characterized for chemical and physical attributes. The prepared samples were subsequently exposed to a sulfur dioxide based environment and characterized with spectroscopic techniques to characterize the extent of sulfation and the nature of surface sulfur species. The extent of sulfation of the model ceria-zirconia systems was characterized with Auger electron spectroscopy (AES) prior to and after treatment in a microreactor. Strong dependencies were observed between the atomic ratio of ceria to zirconia and the extent of sulfation. In addition, the partial pressure of sulfur dioxide during treatments also correlated to the extent of sulfation, while temperature only slightly effected the extent of sulfation. The AES data suggests the gas phase sulfur dioxide preferentially chemisorbs on surface ceria atoms and the extent of sulfation is heavily dependent on sulfur dioxide concentrations and only slightly dependent on catalyst temperatures, as confirmed by thermal programmed desorption (TPD). While hydrogen exposure indicated slight sulfur removal, exposure to a redox environment or atmosphere nearly eliminated the quantity of chemisorbed surface sulfur. The nature of sulfur removal is attributed to the inherent redox properties of ceria-zirconia systems. The complete analysis provides mechanistic insight into sulfation dependencies and fundamental information regarding sulfur adsorption on ceria-zirconia model automotive emissions control systems.

Nelson, Alan Edwin

442

In-situ transmission electron microscopy crystallization studies of sol-gel-derived barium titanate thin films  

SciTech Connect

Barium titanate (BaTiO{sub 3}) thin films that were derived from methoxypropoxide precursors were deposited onto (100) Si, Pt/Ti/SiO{sub 2}/(100) Si, and molecular-beam-epitaxy-grown (MBE-grown) (100) BaTiO{sub 3} on (100) Si substrates by spin coating. The crystallization behavior of the amorphous-gel films was characterized using in-situ transmission electron microscopy heating experiments, glancing-angle X-ray diffraction, and differential thermal analysis/thermogravimetric analysis. Amorphous-gel films crystallized at a temperature of {approximately}600 C to an intermediate nanoscale (5--10 nm) barium titanium carbonate phase, presumably BaTiO{sub 2}CO{sub 3}, that subsequently transformed to nanocrystalline (20--50 nm) BaTiO{sub 3}. Random nucleation in the bulk of the gel film was observed on all substrates. In addition, oriented growth of BaTiO{sub 3} was concurrently observed on MBE-grown BaTiO{sub 3} on (100) Si. High-temperature decomposition of the intermediate carbonate phase contributed to nanometer-scale residual porosity in the films. High concentrations of water of hydrolysis inhibited the formation of the intermediate carbonate phase; however, these sols precipitated and were not suitable for spin coating.

Gust, M.C.; Mecartney, M.L. [Univ. of California, Irvine, CA (United States). Dept. of Chemical and Biochemical Engineering; Evans, N.D. [Oak Ridge Inst. for Science and Education, TN (United States); Momoda, L.A. [Hughes Research Lab., Malibu, CA (United States)

1997-11-01

443

Volumetric determination of uranium using titanous sulfate as reductant before oxidimetric titration  

USGS Publications Warehouse

A new method for determining uranium in samples containing 0.05 percent or more U3O8, using titanous sulfate as reducing agent, is much shorter, faster, and has fewer interferences than conventional methods using reductor columns. The sample is dissolved with sulfuric, nitric, perchloric, and hydrofluoric acids. Elements that would otherwise form insoluble fluorides are kept in solution by complexing the fluoride ion with boric acid. A precipitation is made with cupferron to remove interfering elements. The solution is filtered to remove the precipitated cupferrates instead of extracting them with chloroform as is usually done. Filtration is preferred to extraction because any niobium that may be in solution forms an insoluble cupferrate that may be removed by filtering but is very difficult to extract with chloroform. Excess cupferron is destroyed by oxidizing with nitric and perchloric acids, and evaporating to dense fumes of sulfuric acid. The uranium is reduced to U(IV) by the addition of titanous sulfate, with cupric sulfate used as an indicator of the completeness of the reduction. Metallic copper is formed when all the uranium is reduced. The reduced copper is then reoxidized by the addition of mercuric perchlorate, an excess of ferric sulfate added, and the solution titrated immediately with standard ceric sulfate with ferroin as an indicator. Precision of the method compared favorable with methods in common use, both for uranium ores and for most types of uranium-rich materials.

Wahlberg, James S.; Skinner, Dwight L.; Rader, Lewis F.

1956-01-01

444

Simple oxalate precursor route for the preparation of barium-strontium titanate: Ba{sub 1-x}Sr{sub x}TiO{sub 3} powders  

SciTech Connect

A simple one-step cation-exchange reaction between the stoichiometric solutions of ammonium titanyl oxalate (ATO) and barium hydroxide+strontium nitrate at room temperature (RT) is investigated successfully for the quantitative precipitation of barium-strontium titanyl oxalate (BSTO): Ba{sub 1-x}Sr{sub x}TiO(C{sub 2}O{sub 4}){sub 2}.4H{sub 2}O (x=0.25) precursor powders with nearly theoretical yield ({>=}99%). The pyrolysis of BSTO at 730 deg. C/4 h in air produced barium-strontium titanate (Ba{sub 1-x}Sr{sub x}TiO{sub 3}; BST) powders. The characterization studies on BSTO and BST powders by using various physico-chemical techniques: micro- and chemical analysis, differential thermal analysis (DTA)/thermo-gravimetric analysis (TGA), XRD, FTIR, X-ray fluorescence (XRF) and scanning electron microscopy (SEM) revealed that the powders formed are cubic, highly pure, stoichiometric and sub-micron-sized with nearly uniform size and shape distribution. The ceramic compacts obtained by sintering the BST pellets at 1300 deg. C/4 h showed density {approx}95%, dielectric constant {epsilon}(Tc){approx}9500, tan {delta}{approx}0.15% and T{sub C}{approx}32 deg. C.

Khollam, Y.B. [Department of Physics, University of Pune, Pune-411 007 (India); Deshpande, S.B. [Physical and Materials Chemistry Division, National Chemical Laboratory, Pune-411 008 (India)]. E-mail: sbdesh@ems.ncl.res.in; Potdar, H.S. [Physical and Materials Chemistry Division, National Chemical Laboratory, Pune-411 008 (India); Bhoraskar, S.V. [Department of Physics, University of Pune, Pune-411 007 (India); Sainkar, S.R. [Physical and Materials Chemistry Division, National Chemical Laboratory, Pune-411 008 (India); Date, S.K. [Department of Physics, University of Pune, Pune-411 007 (India)

2005-01-15

445

Sulfate-rich Scapolite on Mars?  

NASA Astrophysics Data System (ADS)

Sulfate-rich scapolite may occur in Mars as a primary igneous occurrence or as a metosomatic replacement assemblage caused by hot sulfate-rich brine interactions with previously formed plagioclase assemblages.

Papike, J. J.; Karner, J. M.; Shearer, C. K.

2007-03-01

446

21 CFR 184.1315 - Ferrous sulfate.  

Code of Federal Regulations, 2010 CFR

... O, CAS Reg. No. 7782-63-0) is prepared by the action of sulfuric acid on iron. It occurs as pale, bluish-green crystals or granules. Progressive heating of ferrous sulfate heptahydrate produces ferrous sulfate (dried). Ferrous...

2010-04-01

447

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

448

Status of Copper Sulfate - 2010  

Technology Transfer Automated Retrieval System (TEKTRAN)

This is brief overview of the Technical Sections completed and being worked on for the New Animal Drug Application (NADA) for copper sulfate. Initial Label Claim (Ich on catfish): 1) Human Food Safety - Complete for all fin fish - February 2004. This includes human intestinal microflora issues,...

449

Status of copper sulfate - 2008  

Technology Transfer Automated Retrieval System (TEKTRAN)

This is brief overview of the Technical Sections completed and being worked on for the New Animal Drug Application (NADA) for copper sulfate. Initial Label Claim (Ich on catfish): 1) Human Food Safety - Complete for all fin fish – February 2004. This includes human intestinal microflora issues,...

450

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...

451

Efflorescence as a source of hydrated sulfate minerals in valley settings on Mars  

NASA Astrophysics Data System (ADS)

A distinctive sulfur cycle dominates many geological processes on Mars and hydrated sulfate minerals are found in numerous topographic settings with widespread occurrences on the Martian surface. However, many of the key processes controlling the hydrological transport of sulfur, including sulfur sources, climate and the depositional history that led to precipitation of these minerals, remain unclear. In this paper, we use a model for the formation of sulfate efflorescent salts (Mg-Ca-Na sulfates) in the Rio Puerco watershed of New Mexico, a terrestrial analog site from the semiarid Southwest U.S., to assess the origin and environmental conditions that may have controlled deposition of hydrated sulfates in Valles Marineris on Mars. Our terrestrial geochemical results (?S34 of -36.0 to +11.1‰) show that an ephemeral arid hydrological cycle that mobilizes sulfur present in the bedrock as sulfides, sulfate minerals, and dry/wet atmospheric deposition can lead to widespread surface accumulations of hydrated sulfate efflorescences. Repeating cycles of salt dissolution and reprecipitation appear to be major processes that migrate sulfate efflorescences to sites of surface deposition and ultimately increase the aqueous SO42- flux along the watershed (average 41,273 metric tons/yr). We suggest that similar shallow processes may explain the occurrence of hydrated sulfates detected on the scarps and valley floors of Valles Marineris on Mars. Our estimates of salt mass and distribution are in accord with studies that suggest a rather short-lived process of sulfate formation (minimum rough estimate ?100 to 1000 years) and restriction by prevailing arid conditions on Mars.

Szynkiewicz, Anna; Borrok, David M.; Vaniman, David T.

2014-05-01

452

Benzene Oxidation Coupled to Sulfate Reduction  

Microsoft Academic Search

(14C)benzene tracer was included with the benzene added to benzene-adapted sediments, 92% of the added radioactivity was recovered as 14CO2. Molybdate, an inhibitor of sulfate reduction, inhibited benzene uptake and production of 14CO2from ( 14 C)benzene. Benzene metabolism stopped when the sediments became sulfate depleted,andbenzeneuptakeresumedwhensulfatewasaddedagain.Thestoichiometryofbenzeneuptakeand sulfate reduction was consistent with the hypothesis that sulfate was the principal electron acceptor for

DEREK R. LOVLEY; JOHN D. COATES; JOAN C. WOODWARD; ANDELIZABETH J. P. PHILLIPS

1995-01-01

453

SULFATION OF FUCOIDIN IN FUCUS EMBRYOS  

Microsoft Academic Search

ABSTRACT Zygotes of the brown,alga Fucus,distichus,L. Powell accumulate,a sulfated polysaccharide,(fucoidin) in the cell wall at the site of rhizoid formation. Previous work,indicated that zygotes grown,in seawater,minus,sulfate do not sulfate the preformed,fucan (an unsulfated fucoidin) but form rhizoids. Under these condi- tions, we determined whether sulfation of the fucan is required for its localization in the rhizoid wall. This was accomplished,by

William E. Hogsett; Ralph S. Quatrano

454

Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [?4IdoA(2-Sulfate)?-1?3GalNAc(4-Sulfate)?-1?] motifs in dermatan sulfate on heparin cofactor II activity  

PubMed Central

Background Previously, we have reported the presence of highly sulfated dermatans in solitary ascidians from the orders Phlebobranchia (Phallusia nigra) and Stolidobranchia (Halocynthia pyriformis and Styela plicata). Despite the identical disaccharide backbone, consisting of [?4IdoA(2S)?-1?3GalNAc?-1?], those polymers differ in the position of sulfation on the N-Acetyl galactosamine, which can occur at carbon 4 or 6. We have shown that position rather than degree of sulfation is important for heparin cofactor II activity. As a consequence, 2,4- and 2,6-sulfated dermatans have high and low heparin cofactor II activities, respectively. In the present study we extended the disaccharide analysis of ascidian dermatan sulfates to additional species of the orders Stolidobranchia (Herdmania pallida, Halocynthia roretzi) and Phlebobranchia (Ciona intestinalis), aiming to investigate how sulfation evolved within Tunicata. In addition, we analysed how heparin cofactor II activity responds to dermatan sulfates containing different proportions of 2,6- or 2,4-disulfated units. Results Disaccharide analyses indicated a high content of disulfated disaccharide units in the dermatan sulfates from both orders. However, the degree of sulfation decreased from Stolidobranchia to Phlebobranchia. While 76% of the disaccharide units in dermatan sulfates from stolidobranch ascidians are disulfated, 53% of disulfated disaccharides are found in dermatan sulfates from phlebobranch ascidians. Besides this notable difference in the sulfation degree, dermatan sulfates from phlebobranch ascidians contain mainly 2,6-sulfated disaccharides whereas dermatan sulfate from the stolidobranch ascidians contain mostly 2,4-sulfated disaccharides, suggesting that the biosynthesis of dermatan sulfates might be differently regulated during tunicates evolution. Changes in the position of sulfation on N-acetylgalactosamine in the disaccharide [?4IdoA(2-Sulfate)?-1?3GalNAc?-1?] modulate heparin cofactor II activity of dermatan sulfate polymers. Thus, high and low heparin cofactor II stimulating activity is observed in 2,4-sulfated dermatan sulfates and 2,6-sulfated dermatan sulfates, respectively, confirming the clear correlation between the anticoagulant activities of dermatan sulfates and the presence of 2,4-sulfated units. Conclusions Our results indicate that in ascidian dermatan sulfates the position of sulfation on the GalNAc in the disaccharide [?4IdoA(2S)?-1?3GalNAc?-1?] is directly related to the taxon and that the 6-O sulfation is a novelty apparently restricted to the Phlebobranchia. We also show that the increased content of [?4IdoA(2S)?-1?3GalNAc(4S)?-1?] disaccharide units in dermatan sulfates from Stolidobranchia accounts for the increased heparin cofactor II stimulating activity. PMID:21619699

2011-01-01

455

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

456

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-) (?1940 mg L(-1)) and Fe(3+) (?112 mg L(-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

457

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

458

Quantitative Precipitation Forecasting Overview  

NSDL National Science Digital Library

In this module, Wes Junker, retired Senior Branch Forecaster at NCEP/HPC provides an introduction to Quantitative Precipitation Forecasting. This presentation assumes a familiarity with basic meteorological processes.

2014-09-14

459

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...

460

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

461

Map Maker - Precipitation  

USGS Multimedia Gallery

The National Atlas offered the Federal government's first on-line interactive Map Maker in 1997. A regional map of annual precipitation center on Oregon is shown. This image is simply a screen shot. Its source is listed below....

462

Crystallization of Chicken Egg White Lysozyme from Assorted Sulfate Salts  

NASA Technical Reports Server (NTRS)

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. Four different crystal morphologies have been obtained, depending upon the temperature, protein concentration, and precipitating salt employed, Crystals grown at 15 C were generally tetragonal, with space group P43212. Crystallization at 20 C typically resulted in the formation of orthorhombic crystals, space group P21212 1. The tetragonal much less than orthorhombic morphology 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 0.8 -1.2M magnesium sulfate at pH 7.6 - 8.0 gave a hexagonal (trigonal) crystal form, space group P3121, which diffracted to 2.8 A. Ammonium sulfate was also found to result in a monoclinic form, space group C2. Small twinned monoclinic crystals of approx. 0.2 mm on edge were grown by dialysis followed by seeded sitting drop crystallization.

Forsythe, Elizabeth L.; Snell, Edward H.; Malone, Christine C.; Pusey, Marc L.

1998-01-01

463

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

464

Removal of sulfide, sulfate and sulfite ions by electro coagulation.  

PubMed

The removal of various species of sulfur from beamhouse of tannery wastewater and also from synthetic samples was studied by electro-flotation technique. Consumable anodes of iron and aluminum and insoluble anode of titanium were tested as anodes. It was found that iron and aluminum anodes were effective for the removal of suspended solids, sulfide, sulfite and sulfate. Progress of simultaneous coagulation of suspended solids during electro-flotation was measured using particle size analysis. Coagulation was found to be essential for effective flotation of suspended solids. Metal ions generated in situ by electrolytic oxidation of anode were found to react with dissolved sulfide ions. Metal sulfides thus formed as colloidal suspension were coagulated and floated simultaneously by hydrogen bubbles generated from cathode. Simultaneous occurrence of precipitation, coagulation and flotation was observed during electro-flotation. X-ray diffraction studies were conducted to identify the nature of sulfide phase formed during electrolytic precipitation. The effect of pH, current density and initial concentration of pollutants was studied and the results are discussed. The removal of sulfite and sulfate ions is explained by zeta-potential measurements. PMID:15177743

Murugananthan, M; Raju, G Bhaskar; Prabhakar, S

2004-06-18

465

Amphorous hydrated Fe(III) sulfate: metastable product and bio-geochemical marker of iron oxidizing thiobacilli  

Microsoft Academic Search

Chemolithotrophic iron oxidation by Thiobacillus ferrooxidans and other iron oxidizing thiobacilli produce an Fe(III) sulfato complex that polymerizes as x-ray amorphous filaments approximately 40 nm in diameter. The precursor complex in solutionis seen by ATR-FTIR spectroscopy to have a sulfate spectrum resembling the v(subscript 3) and v(subscript 1) vibrational modes of the precipitated polymer. Chemically similar precipitates prepared by oxidation

Norman Lazaroff; John Jollie; Patrick R. Dugan

1998-01-01

466

Method of precipitating ADU  

SciTech Connect

A process is disclosed for improving the quality of an ammonium diuranate (ADU) precipitate. Ammonium hydroxide is added to a solution of uranyl fluoride in the presence of a polymer such as polyacrylic acid, polyacrylonitrile, or polyacrylamide. The presence of the polymer reduces the particle size of the precipitate and increases its settling rate. A reduced particle size provides an adu powder which is suitable for nuclear fuel fabrication and an increased settling rate enhances the dewatering operation of the adu slurry.

Chiang, P.T.

1981-03-10

467

Classi cation Precipitation  

E-print Network

.2 0.4 0.6 0.8 1 Probability Empirical Error Rate Possible Error distributions true error #12; Model on future inputs #12; rain snow 0 0.2 0.4 0.6 0.8 1 Precipitation Temperature Unknown Function Samples Training Sample #12; rain snow 0 0.2 0.4 0.6 0.8 1 1.2 1.4 Precipitation Temperature Learned Function

Langford, John

468

Comportement des materiaux cimentaires: Actions des sulfates et de la temperature  

NASA Astrophysics Data System (ADS)

The research work presented in this Ph.D. thesis is related to the nuclear waste underground repository concept. Concrete could be used in such a repository, and would be subjected to variations of temperature in presence of sulfate, a situation that could induce expansion of concrete. The research was lead in three parts: an experimental study of the possibility of an internal sulfate attack on mortars; an experimental study and modeling of the chemical equilibriums of the CaO-SiO2-Al2O 3-SO-H2O system; and a modeling of the mechanisms of internal and external sulfate attacks, and the effect of temperature. The results show that mortars can develop expansions after a steam-cure during hydration, but also when a long steam-cure is applied to one-year-old mortars, which is a new point. Ettringite precipitation can be considered as responsible for these expansions. The experimental study of the CaO-SiO2-Al2O 3-SO3-H2O system clarified the role of Calcium Silicate Hydrates (C-S-H) on chemical equilibriums of cementitious materials. Sulfate sorption on C-S-H has been studied in detail. The quantity of sulfate bound to the C-S-H mainly depends on the sulfate concentration in solution, on the Ca/Si ratio of the C-S-H and is not significantly influenced by temperature. Aluminium inclusion in the C-S-H seems to be a significant phenomenon. Temperature increases the calcium sulfoaluminate solubilities and thus increases sulfates concentration in solution. A modeling of the chemical system is proposed. Simulations of external sulfate attack (15 mmol/L of Na2SO 4) predict ettringite precipitation at 20 and 85°C. Simulation of internal sulfate attack was performed at a local scale (a hydrated cement grain). An initial inhomogeneity can lead, after a thermal curing at 85°C, to ettringite precipitation in zones originally free from ettringite. This new-formed ettringite could be the origin of the expansions.

Barbarulo, Remi

469

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

470

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

471

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

472

Polymerized complex route to barium titanate powders using barium-titanium mixed-metal citric acid complex  

SciTech Connect

Barium titanate (BaTiO{sub 3}) powders were prepared by a polymerized complex method based on the Pechini-type reaction route, wherein a mixed solution of citric acid (CA), ethylene glycol (EG), and barium and titanium ions, with a molar ratio of CA:EG:Ba:Ti = 10:40:1:1, was polymerized to form a transparent resin, which was used as a precursor for BaTiO{sub 3}. Characterization of the initial precursor solution of EG, CA, and barium and titanium ions by Raman scattering and {sup 13}C-NMR spectroscopy indicated that barium and titanium ions were simultaneously stabilized with CA to form a barium-titanium mixed-metal CA complex with a stoichiometry similar to Ba:Ti:CA = 1:1:3. Raman and {sup 13}C-NMR spectra of the liquid mixture at various reaction stages indicated that the fundamental coordination structure of the mixed-metal complex remained almost unchanged throughout the polymerization process. X-ray diffractometry (XRD) measurements indicated formation of pseudo-cubic BaTiO{sub 3} free from BaCo, and TiO{sub 2} when the barium-titanium polymeric precursor was heat-treated in air at 500 C for 8 h or at 600 C for 2 h. However, the Raman spectra of the same powders indicated the formation of tetragonal (rather than cubic) BaTiO{sub 3}, with traces of high-temperature hexagonal BaTiO{sub 3} and an intermediate phase, Ba{sub 2}Ti{sub 2}O{sub 5}{center_dot}CO{sub 3}. A solid-state reaction between BaCO{sub 3} and TiO{sub 2} was concluded as not being responsible for the BaTiO{sub 3} formation; rather, BaTiO{sub 3} formed directly by thermal decomposition of the intermediate Ba{sub 2}Ti{sub 2}O{sub 5}{center_dot}CO{sub 3} phase at temperatures >500 C. In addition, by Raman scattering measurements, the intermediate Ba{sub 2}Ti{sub 2}O{sub 5}{center_dot}CO{sub 3} phase was found to be unstable in ambient air, yielding BaCO{sub 3} as one of the decomposed products.

Arima, Momoko; Kakihana, Masato; Nakamura, Yoshiyuki; Yashima, Masatomo; Yoshimura, Masahiro [Tokyo Inst. of Tech., Yokohama (Japan)

1996-11-01

473

Elastic scattering of electrons by gadolinium and barium atoms  

NASA Astrophysics Data System (ADS)

Total and differential cross-sections for elastic scattering of electrons from gadolinium and barium atoms in a wide energy range were calculated. In the low- and intermediate-energy regions, the phase theory of elastic scattering was used. At low incident energies (<10 eV), an additional polarization potential was introduced. At high incident energies, the Born approximation (keV range) and the Rutherford formula (MeV range) were applied. Our results are in rather good agreement with experimental data of Romanyuk et al. (Pis'ma Zh. Eksp. Teor. Fiz. 32 (1980) 472) for elastic scattering of very-low-energy electrons from barium atoms which confirm its reliability. This agreement is important because these experimental results are in serious disagreement with theoretical calculations of Szmytkowski and Sienkiewicz (Phys. Rev. A 50 (1994) 4007).

Miloshevsky, G. V.; Tolkach, V. I.; Rozin, S.; Shani, G.

2000-08-01

474

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

475

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

476

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

477

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

478

Study of the photovoltaic effect in thin film barium titanate  

NASA Technical Reports Server (NTRS)

Ferroelectric films of barium titanate were synthesized on silicon and quartz substrates, and the photoelectric effect in the structure consisting of metal deposited ferroelectric barium titanate film silicon was studied. A photovoltage with polarity that depends on the direction of the remanent polarization was observed. The deposition of BaTiO3 on silicon and fused quartz substrates was accomplished by an rf sputtering technique. A series of experiments to study the growth of ferroelectric BaTiO3 films on single crystal silicon and fused quartz substrates were conducted. The ferroelectric character in these films was found on the basis of evidence from the polarization electric field hysteresis loops, capacitance voltage and capacitance temperature techniques and from X-ray diffraction studies.

Grannemann, W. W.; Dharmadhikari, V. S.

1982-01-01

479

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

480

Spectroscopy of barium attached to superfluid helium clusters  

NASA Astrophysics Data System (ADS)

To complement the data on absorption spectra of alkaline earth atoms attached to superfluid helium clusters we are reporting on barium atoms attached to 4HeN. The absorption spectrum of the lowest singlet transition is blue-shifted and strongly broadened compared to the corresponding unperturbed Ba (6s6p1Po1?6s21S0) transition in accord with the observations on Sr and Ca added to HeN [F. Stienkemeier, F. Meier, and H.O. Lutz: J. Chem. Phys. 107(24), 10816 (1997)]. Moreover, we compare the asymptotic values of shift and width of the excitation spectrum with increasing helium cluster size He ( 1000 up to 10000) to those found for barium atoms in bulk liquid helium.

Stienkemeier, F.; Meier, F.; Lutz, H. O.

481

Alterations in glycosaminoglycan concentration and sulfation during chondrocyte maturation  

Microsoft Academic Search

We have used antibodies to chondroitin 4- and 6-sulfate and keratan sulfate along with Alcian blue staining of sulfated proteoglycans to investigate changes in content and sulfation within the avian growth plate. In normal chicks, chondroitin 4- and 6-sulfate content were similar in the proliferating and transitional zones but in the hypertrophic zone, chondroitin 4- and 6-sulfate were slightly lower

C. Farquharson; C. C. Whitehead; N. Loveridge

1994-01-01

482

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

483

Nanoscale inhomogeneities in yttrium-barium-copper-oxide (YBCO) superconductors  

Microsoft Academic Search

X-ray diffraction studies at the Advanced Photon Source reveal that nanoscale inhomogeneities, electronic or structural in origin, form in yttrium-barium-copper-oxide (YBa_2Cu_3O_6+x) superconductors and coexist with the superconducting (SC) state. Diffuse scattering from these inhomogeneous superstructures is due to atomic displacements with respect to equilibrium lattice sites (Z. Islam et al. Phys. Rev. B 66, 92501 (2002)), that are characterized by

Zahirul Islam; S. K. Sinha; J. C. Lang; X. Liu; D. Haskel; S. C. Moss; G. Srajer; B. W. Veal; D. Wermeille; D. R. Lee; D. R. Haeffner; U. Welp; P. Wochner

2004-01-01

484

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

485

Synthesis and Electromagnetic Properties of Polyaniline-barium Ferrite Nanocomposite  

Microsoft Academic Search

The polyaniline (PANI)-barium ferrite composite with magnetic behavior was synthesized by in situ polymerization of aniline in the presence of BaFe12O19 nanoparticles of 60–80 nm in diameters. The structure, morphology and magnetic properties of samples were characterized by powder X-ray diffraction, Fourier transform infrared, scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometer technique. The results of spectroanalysis indicated

Yuan-Xun Li; Huai-Wu Zhang; Ying-Li Liu; John Q. Xiao

2007-01-01

486

In-situ laser deposition of barium ferrite films  

Microsoft Academic Search

Barium ferrite films with high coercivity, large magnetic anisotropy, good crystal orientation and crystallinity with hexagonal symmetry have been prepared on single crystal sapphire substrates by laser in-situ deposition. The structures of these films were characterized by X-ray diffractometry. X-ray diffraction pattern shows a preferential c-axis orientation normal to the film plane at a deposition temperature of 900°C. The magnetic

W. D. Song; Y. F. Lu; W. J. Wang; C. K. Ong; J. P. Wang; T. C. Chong

1999-01-01

487

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

488

Barium Ferrite Films Grown By Pulsed Laser Ablation  

Microsoft Academic Search

Abstract:available only.\\u000aIt is known that barium ferrite (BaFe12019) can grow with perpendicular anisotropy on A1203 a single crystal substrate,' but also on an amorphous substrate by using a ZnO buffer.2 Because of its large magnetic anisotropy which can easily overcome the shape anisotropy of the film, this material can exhibit high potentiality as media for magnetic and magneto-optic recording.

A. Lisfi; J. C. Lodder; P. de Haan; F. J. G. Roesthuis

1998-01-01

489

Oriented barium ferrite straight-field focusing structure  

Microsoft Academic Search

An oriented barium ferrite straight-field structure for focusing the electron beam of a klystron has been designed and successfully manufactured. The structure is a hollow tapered hexagon, circumscribed about a9frac{3}{4}-inch outside diameter and3frac{7}{8}-inch inside diameter. The overall height, including pole pieces, is9frac{3}{8}inches. The peak axial field strength, before field shaping, is 1000 gauss, and transverse fields are held to 1

I. Wagner

1970-01-01

490

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

491

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\\/