Note: This page contains sample records for the topic aluminum barium calcium from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

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. ...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. ...The chemical substance identified as barium calcium manganese strontium...

2010-07-01

2

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Barium calcium manganese strontium oxide. ...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. ...The chemical substance identified as barium calcium manganese strontium...

2009-07-01

3

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

4

Densities of liquid metals: calcium, strontium, barium  

Microsoft Academic Search

We report a method of measuring the densities of liquids at intermediate temperatures which employs Archimedes' Principle in a two-sinker arrangement. This method is then used to measure the densities of pure liquid calcium, strontium, and barium. We find ?(Ca) = 1.4931 ? 1.37 10 T(C) from 850 ? 950C, ?(Sr) = 2.5547 ? 2.83 10 T(C) from

S. Hiemstra; D. Prins; G. Gabrielse; J. B. Van Zytveld

1977-01-01

5

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

6

21 CFR 582.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum calcium silicate. 582.2122 Section 582.2122...Anticaking Agents § 582.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2013-04-01

7

21 CFR 182.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum calcium silicate. 182.2122 Section 182.2122...Anticaking Agents § 182.2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2...

2013-04-01

8

X-ray diffraction studies on aluminum-substituted barium hexaferrite  

Microsoft Academic Search

Effect of aluminum substitution in barium hexaferrite was studied following the hydrothermal precipitationcalcination techniques. It was attempted to prepare aluminum-substituted barium hexaferrites with compositions BaAlxFe12?xO19 having x=2,4, 6, 8 and 10. The precursors were prepared by using stoichiometric amounts of Ba, Al and Fe3+ nitrate solutions with urea as the precipitating agent. The hydrothermally prepared precursors were calcined at temperatures

D. Mishra; S. Anand; R. K. Panda; R. P. Das

2004-01-01

9

QUANTITATIVE RADIOCHEMICAL ANALYSIS BY ION EXCHANGE. V. CALCIUM, STRONTIUM, AND BARIUM  

Microsoft Academic Search

A procedure was developed for the separation of calcium, strontiums and ; barium from the rare earths and from each other. This is similar to the ion-; exchange method of Baerg and Bartholomew which elutes cerium, lanthanums ; strontiums and barium sequentially from a Dowex-50 Xl2, 87 deg C column using ; solutions of ammonium alpha -hydroxyisobutyrate. By lowering the

Wish

1959-01-01

10

Adjuvant properties of aluminum and calcium compounds.  

PubMed

It is likely that aluminum compounds will continue to be used with human vaccines for many years as a result of their excellent track record of safety and adjuvanticity with a variety of antigens. For infections that can be prevented by induction of serum antibodies, aluminum adjuvants formulated under optimal conditions are the adjuvants of choice. It is important to select carefully the type of aluminum adjuvant and optimize the conditions of adsorption for every antigen since the degree of adsorption of antigens onto aluminum adjuvants markedly affects immunogenicity. The mechanism of adjuvanticity of aluminum compounds includes formation of a depot at the site of injection from which antigen is released slowly; stimulation of immune-competent cells of the body through activation of complement, induction of eosinophilia, and activation of macrophages; and efficient uptake of aluminum-adsorbed antigen particles by antigen-presenting cells because of their particulate nature and optimal size (< 10 microns). Limitations of aluminum adjuvants include local reactions, production of IgE antibodies, ineffectiveness for some antigens, and inability to elicit cell-mediated immune responses especially cytotoxic T-cell responses. Calcium phosphate, which has adjuvant properties similar to aluminum adjuvants, has the potential advantages of being a natural component of the body and of not increasing IgE production. There is a need for alternative adjuvants, particularly for diseases in which cell-mediated immune responses are important for prevention or cure. PMID:7551219

Gupta, R K; Rost, B E; Relyveld, E; Siber, G R

1995-01-01

11

Coprecipitation of radium with barium sulfate from calcium-containing solutions  

Microsoft Academic Search

Precipitation of radium with barium sulfate from solutions obtained on treatment of thorium-containing industrial wastes has been studied by stepwise regressive analysis. The mathematical model of the process selected on an Elektronika-DZ-28 computer made it possible to prove that, unlike calcium-free solutions, coprecipitation of radium with barium sulfate from solutions highly concentrated in calcium depends on the ratio of the

A. V. Belkin; Yu. P. Kudryavskii; S. A. Anferov

1988-01-01

12

Barium oxide, calcium oxide, magnesia, and alkali oxide free glass  

DOEpatents

A glass composition consisting essentially of about 10-45 mole percent of SrO; about 35-75 mole percent SiO.sub.2; one or more compounds from the group of compounds consisting of La.sub.2O.sub.3, Al.sub.2O.sub.3, B.sub.2O.sub.3, and Ni; the La.sub.2O.sub.3 less than about 20 mole percent; the Al.sub.2O.sub.3 less than about 25 mole percent; the B.sub.2O.sub.3 less than about 15 mole percent; and the Ni less than about 5 mole percent. Preferably, the glass is substantially free of barium oxide, calcium oxide, magnesia, and alkali oxide. Preferably, the glass is used as a seal in a solid oxide fuel/electrolyzer cell (SOFC) stack. The SOFC stack comprises a plurality of SOFCs connected by one or more interconnect and manifold materials and sealed by the glass. Preferably, each SOFC comprises an anode, a cathode, and a solid electrolyte.

Lu, Peizhen Kathy; Mahapatra, Manoj Kumar

2013-09-24

13

The thermophysical properties of calcium and barium zirconium phosphate  

NASA Astrophysics Data System (ADS)

The thermophysical and structural properties of calcium and barium zirconium phosphate ceramics (CZP and BZP) have been investigated for their potential candidacy as actinide hosts for inert matrix fuels (IMF) in nuclear reactors. These phosphate ceramics, which can accommodate minor actinides as well as the resulting fission products, are found to be thermally stable to 1600 C in air, however they begin to decompose in an inert atmosphere above approximately 1400 C. The heat capacity, thermal conductivity and bulk thermal-expansion were measured from room temperature up to 1200 C. Structural changes in this temperature region as well as the anisotropic thermal-expansion behaviour were studied using high-temperature X-ray diffraction. A phase change from R-3 to R-3c was identified for Ba0.5Zr2(PO4)3 near 880 C. The thermal conductivity for these ceramics at 1000 C was found to be 1.0 W m-1 K-1, a relatively low thermal conductivity that was increased to 5.0 W m-1 K-1 at 1000 C for BZP:Ni (25:75 mass ratio) cermet composites.

Gregg, Daniel J.; Karatchevtseva, Inna; Triani, Gerry; Lumpkin, Gregory R.; Vance, Eric R.

2013-10-01

14

Coprecipitation of radium with barium sulfate from calcium-containing solutions  

SciTech Connect

Precipitation of radium with barium sulfate from solutions obtained on treatment of thorium-containing industrial wastes has been studied by stepwise regressive analysis. The mathematical model of the process selected on an Elektronika-DZ-28 computer made it possible to prove that, unlike calcium-free solutions, coprecipitation of radium with barium sulfate from solutions highly concentrated in calcium depends on the ratio of the amount of sulfuric acid to the sum of the amounts of barium, calcium, and magnesium, the influence of this factor on the degree of radium precipitation being negative: the radioactivity of the filtrate intensifies. This deviation from the mechanisms of radium coprecipitation in pure solutions has been explained by the phenomenon of blocking of the carrier surface by the calcium sulfate crystals.

Belkin, A.V.; Kudryavskii, Yu.P.; Anferov, S.A.

1988-11-01

15

Effects of strontium and barium ions on calcium bindings and transport in nerve cells  

Microsoft Academic Search

Absorption of strontium and barium ions by intracellular organelles after loading the cell with these cations together with their effects on Ca release from the intracellular stores were investigated in neurons isolated fromHelix pomatia using fura-2, a Ca-sensitive fluorescent probe. It was found that strontium ions can successively replace intracellular calcium ions in this response, whereas barium ions are not

Yu. M. Usachev; S. L. Mironov

1989-01-01

16

The comparative uptake and translocation by plants of calcium, strontium, barium and radium II. Triticum vulgare (wheat)  

Microsoft Academic Search

SummaryMeasurements were made of the concentrations of calcium, strontium, barium, Ra226 and Ra228 in ammonium acetate extracts of soil, and wheat plant tissues, from three sites.\\u000a \\u000a The ratios of strontium to calcium in the plants, relative to those in the soil extracts, varied little between soils, in\\u000a contrast with the ratios of barium and radium to calcium. The ratios of

K. A. Smith

1971-01-01

17

Effect of aluminum on rat brain. Enhancement by calcium deficiency.  

PubMed

Experimental aluminum intoxication was performed in rats both with normal diet and calcium-deficient diet feeding for 4 weeks in order to elucidate the neurotoxic effect of aluminum and the relationship between aluminum and calcium metabolism. Ultrastructural changes of the cerebrum were studied chronologically. In addition, the distribution of aluminum in the neurons was analyzed using an X-ray microprobe analysis. In the group with aluminum administration alone, the endothelial cells, pericytes, astrocytes and synapses showed only mild degenerative changes. However, no significant abnormality was present in the axons, dendrites and perikaryon of the neurons. No detectable aluminum was present in the neurons. When aluminum intoxication was coupled with calcium deficiency, morphologic changes as seen in the group with aluminum administration alone were observed in the blood vessels, astrocytes and synapses from the early stage. The synaptic degeneration was more prominent. The degenerative changes were also present in the axons, dendrites and even perikaryon. The presence of aluminum was demonstrated in the neurons. These results suggest that in the secondary hyperparathyroidism due to calcium deficiency, aluminum transportation to the neurons is enhanced and aluminum neurotoxicity causes more prominent degeneration. PMID:6479848

Taneda, M

1984-05-01

18

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.

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

2012-01-01

19

Precipitation of calcium, magnesium, strontium and barium in tissues of four Acacia species (Leguminosae: Mimosoideae).  

PubMed

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

2012-07-25

20

Superconductivity of strontium aluminum germanide and barium aluminum germanide Structure and Dynamics of strontium aluminum germanium hydride and barium aluminum germanium hydride  

NASA Astrophysics Data System (ADS)

The discovery of the superconductor MgB2 led to the increase of research activity for more compounds adopting the AlB 2 structure type and containing superconductive properties. The prominent successor compounds were the silicide systems, AeAlSi (Ae=Sr, Ba, Ca). Presented here is an extension of this investigation to the germanides, SrAlGe and BaAlGe. The ternary structures were synthesized through arc-melting elemental stoichiometric mixtures and structurally characterized by x-ray powder diffraction. Both crystallize as the hexagonal SrPtSb space group (P m2), a variant of the AlB2 structure type (P 6/mmm). The low temperature region was measured on a Vibrating Sample Magnetometer (VSM) and both present the onset of superconductivity below 7K. These compounds are susceptible to hydrogen absorption and the new polyanionic hydrides, SrAlGeH and BaAlGeH, structural and dynamic properties are presented. The hydrides were synthesized via two distinct methods. One method is the reaction of SrH2 (BaH2) with elemental mixture of the Al and Ge under pressurized hydrogen and the other is a hydrogenation of the SrAlGe and BaAlGe. Both crystallize in the trigonal SrAlSiH structure type (P3m1), as determined from Rietveld analysis on powder neutron diffraction measurements. The hydrogen is coordinated by both the active metal and aluminum atoms, providing a unique environment for studying metal-hydrogen interactions. When exposed to air, both the hydrides and alloys transform from a crystalline grey to an amorphous yellow powder accompanied by a dramatic volume increase. Infrared spectroscopy shows the disappearance of the bands associated with the Al-H bond and the appearance of Ge-H and O-H bands. This indicates the material reacts with atmospheric water.

Kranak, Verina Franika

21

Assessment of the solubility and bioaccessibility of barium and aluminum in soils affected by mine dust deposition.  

PubMed

Barium is a heavy metal to which human and animal receptors may be exposed in various settings--for example, in mineral extraction industries where the mining and milling of ores occurs. Aluminum is also an element abundant in soil and dust to which human and animal receptors may be exposed in association with such industries. This study investigated the solubility and bioaccessibility of barium and aluminum in simulated gastric fluids using an in vitro test method previously validated for lead. Soil samples were collected from the vicinity of a mine and transport road that generated fugitive dust containing barium as barite (BaSO4). It was found that barium bioaccessibility in different tundra soil and fugitive dust source materials varied greatly, between 0.07 and 66.0%, depending on sample location, grain size, solid-to-fluid ratio used in the in vitro experiments, and the analytical method selected for determining total barium concentrations in the sample substrates. For X-ray fluorescence spectrometry (XRF) analytical methods and a solid-to-fluid ratio of 1:100, barium bioaccessibility from the barite-rich mine waste rock and gyro crusher ore dust source materials was very low (0.07-0.36%). By contrast, the bioaccessibility of barium in tundra soil samples affected by fugitive dust deposition ranged from 3.8 to 19.5%. The relative solubility of barium measured in the simulated gastric fluids of this study is consistent with time-dependent dissolution of barite in mine waste rock and ore dust, and the presence of more soluble chemical forms in tundra soil. Laboratory XRF analysis was the only analytical method used in this study that accurately characterized total barium concentrations for all sample substrates. Aluminum bioaccessibility was distinguished from barium bioaccessibility by its generally lower values and smaller dependence on grain size and solid-to-fluid ratios. The range of aluminum bioaccessibility values (0.31-4.0%) is consistent with the predominance of aluminum in relatively insoluble aluminosilicate minerals. PMID:17695934

Shock, S S; Bessinger, B A; Lowney, Y W; Clark, J L

2007-07-01

22

Magnetic behavior and dielectric properties of aluminum substituted M-type barium hexaferrite  

NASA Astrophysics Data System (ADS)

Various parameters in the structural features of the aluminum substituted barium hexagonal ferrite particles BaAlxFe12?xO19 with 0?x?3.5 which were prepared by the solid state reaction method have been studied. The infrared transmission spectrum was measured in the wave number region 5000200 cm?1 at room temperature. The results were interpreted in terms of the vibrations of the isolated molecular units in such a way to preserve the tetrahedral and octahedral clusters of metal oxides in the barium aluminum hexagonal ferrites. The infrared features are assigned to FeO and BaO bonds in M-type hexagonal ferrite (BaFe12O19) molecules. Also, the results explain the structural model, based on the effect of aluminum substitution "AlO bond". On the other hand, the magnetic behavior of the samples was studied using the vibrating sample magnetometer technique. The saturation magnetization (Ms) and magneton number (nB) decrease with increasing Al3+ substitution from 61.2 to 28.9 emu/g and from 12.2 to 5.3 B respectively. Also, all samples were characterized using X-ray diffraction and the values of grain size, microstrain and dislocation density of all samples were calculated. The dielectric parameters and ac conductivity measurements were performed within a temperature range 293493 K. The ac conductivity showed a linear relation with the frequency power law with an exponent s?0.690.14 for BaFe12O19. It decreases with increasing temperature, indicating that the heterogeneous structures increase. While the dielectric constant (??) and the dielectric loss (??) decrease with increasing Al substitution.

El-Sayed, S. M.; Meaz, T. M.; Amer, M. A.; El Shersaby, H. A.

2013-10-01

23

Infrared studies of apatites. I. Vibrational assignments for calcium, strontium, and barium hydroxyapatities utilizing isotopic substitution  

Microsoft Academic Search

The infrared spectra of powdered calcium hydroxyapatite isotopically ; substituted with D, ¹⁸O, ⁴⁴Ca, and ⁴⁸Ca and infrared spectra of ; powdered strontium and barium hydroxyapatites and their deuterated analogs are ; reported at 48 and - 185 deg in the 4000-200cm-¹ region. Band ; assignments, based on isotopic frequency shifts, band intensity, band temperature ; dependency, and comparisons between

B. O. Fowler

1974-01-01

24

Synthesis of calcium, strontium, and barium fluorides by thermal decomposition of trifluoroacetates  

Microsoft Academic Search

Alkaline-metal (barium, strontium, and calcium) fluorides with a highly developed specific surface are synthesized by the\\u000a thermal decomposition of the corresponding metal trifluoroacetates in an inert atmosphere followed by annealing in an oxygen\\u000a flow at 500C. The specific surfaces of the synthesized samples are studied by comparative nitrogen adsorption. The resulting\\u000a specific surface values are 43.67, 36.52, and 23.98 m2\\/g

T. Yu. Glazunova; A. I. Boltalin; P. P. Fedorov

2006-01-01

25

A Comparative Study of the Synthesis of Calcium, Strontium, Barium, Cadmium, and Lead Apatites in Aqueous Solution  

Microsoft Academic Search

The aqueous syntheses of the hydroxy and halo apatites of calcium, strontium, barium, lead, and cadmium were explored. Because these cations represent the main group s? and p?fillers and a transition metal, they present different synthetic challenges. The alkaline earth cations and lead form hydrogen phosphates at slightly acidic and slightly basic conditions, the alkaline earths form the fluorides (MF2)

Natalie J. Flora; Keith W. Hamilton; Richard W. Schaeffer; Claude H. Yoder

2004-01-01

26

Interaction Studies Between Crofer-22APU Alloy And P{sub 2}O{sub 5} Containing Barium Calcium Alumino-borosilicate (BCABS) Sealant Glass-Ceramics  

SciTech Connect

We present the effect of P{sub 2}O{sub 5} addition on barium calcium aluminum borosilicate BCABS glasses of composition (mol %)35BaO-15CaO-5Al{sub 2}O{sub 3}-(37-x)SiO{sub 2}-8B{sub 2}O{sub 3}-xP{sub 2}O{sub 5}(0{<=}x{<=}5). The incorporation of P{sub 2}O{sub 5} increased network polymerization and crystallization tendency. However, addition of P{sub 2}O{sub 5} leads to the formation of Cr{sub 2}O{sub 3} at the interface, saturating it in the ions of the metal. This improves glass-to-metal bonding.

Ananthanarayanan, A. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); UCCS-Unite de Catalyse et Chimie du Solide-UMR CNRS 8181, Ecole Nationale Superieure de Chimie de Lille, Universite des Sciences et Technologies de Lille, BP 108, 59562 Villeneuve d'Ascq Cedex (France); Montagne, L.; Revel, B. [UCCS-Unite de Catalyse et Chimie du Solide-UMR CNRS 8181, Ecole Nationale Superieure de Chimie de Lille, Universite des Sciences et Technologies de Lille, BP 108, 59562 Villeneuve d'Ascq Cedex (France); Kothiyal, G. P. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2010-12-01

27

Intra-grain composition nonuniform barium strontium calcium titanate ceramics by sol-gel pervasion techniques  

NASA Astrophysics Data System (ADS)

The use of ferroelectric ceramics in microwave devices requires that they possess low-loss, frequency-stable and highly tunable properties. The problems of traditional barium strontium calcium titanate ceramics are higher loss and inappropriate work temperature dependence. In this work, a conventional mixed oxide route was used to prepare BaTiO3, SrTiO3 and CaTiO3 precursor powders. The BaTiO3, SrTiO3 and CaTiO3 powders were thoroughly ball mill mixed. They were then added to 5 wt% polyvinyl alcohol and pressed under a uni-axial pressure of 220 MPa into discs of 12 mm diameter. We introduced nano-grains of barium strontium titanate (BST) into the BSCT ceramic by nano-grain pervasion techniques to fabricate compositionally nonuniform BSCT ceramic samples. The nano-particles of BST are prepared with the sol-gel method. The sol-gel was subjected to ultrasonic irradiation and then vacuum methods in order to easily introduce nanoparticles into bulky BSCT. The ceramics do not show a sharp change in the dielectric constant and have a wide range of Curie temperature distribution. This is attributed to the presence of a compositionally nonuniform micro-area in the samples. Compared with uniform-composition BSCT, compositionally nonuniform BSCT has favourable dielectric properties. These results suggest that the compositionally nonuniform BSCT ceramics are promising candidates as tunable microwave elements.

Xu, Honghai; Jin, Dengren; Wu, Wenbiao; Cheng, Jinrong

2009-03-01

28

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

PubMed

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

Khan, Mohammad Mujahid Ali; Rafiuddin

2013-06-21

29

Density and surface tension of calcium, strontium, and barium in the liquid phase  

SciTech Connect

The method of maximum pressure in a gas bubble, with the aid of two capillary tubes of different diameter, was used to study the density and surface tension of alkaline-earth metals (Ca, Sr, Ba) in the liquid phase up to 1840/sup 0/K (Ca), 1683/sup 0/K (Sr), and 1852/sup 0/K (Ba). Experimental values of the investigated properties are presented along with parameters of approximating equations describing the change in the properties with temperature. An analysis is made of the literature data on the density and surface tension of liquid alkaline-earth metals. Recommended values of the properties of calcium, strontium, and barium up to 2000/sup 0/K are obtained from joint analysis of the data.

Shpil'rain, E.E.; Fomin, V.A.; Kachalov, V.V.

1986-09-01

30

Chemical Compatibility of Barium-Calcium-Aluminosilicate Based Sealing Glasses with Heat Resistant Alloys  

SciTech Connect

In most planar SOFC stacks operating at an intermediate temperature (700-800 degrees C), the interconnect is typically made from a ferritic stainless steel and has to be hermitically sealed to its adjacent components, such as the ceramic PEN (Positive electrode-Electrolyte-Negative electrode) by a sealing glass. To large extent the seal performance relies on the chemical compatibility of the sealing glass with the metallic interconnect. In this study, a barium-calcium-aluminosilicate (BCAS) based glass-ceramic, specifically developed as a sealant in SOFC stacks, and a ferritic stainless steel (446) were chosen as examples to investigate the chemical interactions or corrosions at the sealing glass interface with the ferritic stainless steels. Evaluation of the interfaces of coupon joints indicated that interactions between the BCAS glass-ceramic and the ferritic stainless steel depended on the exposure conditions. At the edges of joints, where oxygen or air was accessible, the interaction often led to the formation of BaCrO4, while in the interior of the joints, chromium or chromia dissolved into the glass to form a thin layer of chromium rich solid solution. It was also found that, in the interior of the joints, the interaction often resulted in the formation of pores aligning along the interface. The pore formation along the interface of sealing glass and ferritic stainless steel however could be avoided through a pre-heat treatment of the ferriitc stainless steel.

Yang, Zhenguo; Weil, K. Scott; Meinhardt, Kerry D.; Stevenson, Jeffry W.; Paxton, Dean M.; Xia, Guanguang; Kim, Dong-Sang

2003-01-02

31

Chemical Interactions of Barium-Calcium-Aluminosilicate Based Sealing Glasses with Oxidation Resistant Alloys  

SciTech Connect

In most planar SOFC stack designs, the interconnect, which is typically made from an oxidation resistant alloy, potentially including austenitic chromia-forming, ferritic chromia-forming, and alumina-forming alloys, has to be hermitically sealed to its adjacent components, usually by a sealing glass. To maintain the structural stability and minimize the degradation of stack performance, the sealing glass must be chemically compatible with the alloy used for the interconnect. In this work, Nicrofer6025, AISI446 and a Fecralloy were selected as examples of austenitic chromia-forming, ferritic chromia-forming, and alumina-forming alloys, respectively. Their chemical compatibility with a barium-calcium-aluminosilicate (BCAS) based glass, specifically developed as a sealant in SOFC stacks, was evaluated. It was found that the BCAS sealing glass interacted chemically with both the chromia-forming alloys and the alumina-forming alloys. The extent and nature of the interactions and their final products depended on the matrix alloy compositions, the exposure conditions and/or proximity of the glass/alloy interface to the ambient air. These interactions and their mechanisms will be discussed with the assistance of thermodynamic modeling.

Yang, Z Gary (BATTELLE (PACIFIC NW LAB)); Stevenson, Jeffry W. (BATTELLE (PACIFIC NW LAB)); Meinhardt, Kerry D. (BATTELLE (PACIFIC NW LAB))

2003-04-04

32

The Effects of Aluminum on the lnflux of Calcium, Potassium, Ammonium, Nitrate, and Phosphate in an Aluminum Sensitive Cultivar of Barley (Hordeum vdgare 1.)  

Microsoft Academic Search

~ ~ ~ ~~~ The mechanism by which aluminum interferes with ion influx is not known. In this study, the effects of aluminum on the influx of the cations calcium, potassium, and ammonium and the anions nitrate and phosphate were measured in an aluminum-sensitive cultivar of barley (Hordeum vdgare 1.). Aluminum (100 PM) was found to inhibit the influx of

Brian E. Nichol; Luis A. Oliveira; Mohamed Y. Siddiqi

1993-01-01

33

Nuclear magnetic resonance and X-ray evidence of crystal structure for acetates of calcium, strontium, and barium  

NASA Astrophysics Data System (ADS)

High-resolution 13C spectra of calcium acetate hemihydrate (CAH), strontium acetate hemihydrate (SAH), and barium acetate monohydrate (BAM) have been obtained using cross-polarization (CP), high-power decoupling, and magic-angle spinning (MAS). The results indicate the existence in each case of four nonequivalent crystallographic sites for the acetate groups. These findings have been confirmed for SAH and BAM by single-crystal X-ray diffraction studies. The carboxyl chemical shifts for CAH cover a range of 9.3 ppm and the lines are remarkably sharp, so that this material is suggested as a suitable standard for checking the performance of CP/MAS spectrometers

Groombridge, Christopher J.; Harris, Robin K.; Packer, Kenneth J.; Hursthouse, Michael B.; Walker, Nigel P. C.

1985-10-01

34

Aluminum is a weak agonist for the calcium-sensing receptor  

Microsoft Academic Search

Aluminum is a weak agonist for the calcium-sensing receptor.BackgroundAluminum (Al3+) has diverse biological effects mediated through activation of a putative extracellular cation-sensing receptor. A recently identified calcium-sensing receptor (CaSR), which has been identified in target tissues for Al3+, may transduce some of the biological effects of Al3+.MethodsTo test this possibility, we transfected human embryonic kidney 293 (HEK 293) cells with

Robert F. Spurney; Min Pi; Patrick Flannery; L. Darryl Quarles

1999-01-01

35

Eu-doped barium aluminum oxynitride with the {beta}-alumina-type structure as new blue-emitting phosphor  

SciTech Connect

Attractive new blue-emitting phosphors for use in low-pressure mercury gas discharge lamps are synthesized by Eu-substitution in the barium aluminum oxynitride host lattice with the {beta}-alumina-type structure. The emission spectra of these phosphors for 254 nm excitation show a band at about 450 nm with a shoulder at higher wavelength. The maximum quantum efficiency of these materials is about 85--90% just like commercial BaMgAl{sub 10}O{sub 17}:Eu with the {beta}-alumina type structure. The nonoptimized oxynitride phosphors are more sensitive to oxidation (at 873 K) and to short-term depreciation due to 185 nm irradiation compared to commercial BaMgAl{sub 10}O{sub 17}:Eu. However, the maintenance of the oxynitride phosphors in single component fluorescent lamps is improved. Calculations indicate that by using these phosphors in tricolor fluorescent lamps instead of BaMgAl{sub 10}O{sub 17}:Eu with the {beta}-alumina type structure, the color rendering index will improve while the lumen output remains high.

Jansen, S.R.; Migchels, J.M.; Hintzen, H.T.; Metselaar, R. [Eindhoven Univ. of Technology (Netherlands). Lab. of Solid State and Materials Chemistry

1999-02-01

36

Aluminum Alters Calcium Transport in Plasma Membrane and Endoplasmic Reticulum from Rat Brain.  

National Technical Information Service (NTIS)

Calcium is actively transported into intracellular organelles and out of the cytoplasm by Ca(2+)/Mg(2+)-ATPases located in the endoplasmic reticulum and plasma membranes. The authors studied the effects of aluminum on calcium transport in the adult rat br...

W. R. Mundy P. R. S. Kodavanti V. F. Dulchinos H. A. Tilson

1994-01-01

37

Low-calcium, high-aluminum diet-induced motor neuron pathology in cynomolgus monkeys.  

PubMed

Long-term epidemiological studies indicate that environmental factors play a causative role in high-incidence amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD) in the western Pacific. An increased risk for disease is acquired in youth and remains for life. The low concentrations of calcium and magnesium and high levels of aluminum in the soil and drinking water, along with the relative isolation of these populations, constitute an unusual environmental feature common to all three high-incidence foci. Studies of mineral deposition in brain tissue of Guamanian ALS and PD patients, as well as of neurologically normal Guamanians with neurofibrillary degeneration, demonstrate accumulations of calcium, aluminum and silicon in neurofibrillary tangle-bearing neurons. In an attempt to duplicate the low calcium and high aluminum and manganese in soil and drinking water in these foci, we maintained juvenile cynomolgus monkeys for 41 to 46 months on a low-calcium diet with or without supplemental aluminum and manganese. Experimental animals exhibited mild calcium and aluminum deposition and degenerative changes, compatible with those of early ALS and PD, in motor neurons of the spinal cord, brain stem, substantia nigra and cerebrum. Neuropathological findings included chromatolysis, aberrant perikaryal accumulation of phosphorylated neurofilament, neurofibrillary tangles, axonal spheroids, and basophilic and hyaline-like inclusions consisting of abnormal cytoskeletal elements by electron microscopy. The magnitude and extent of these lesions far exceeded those found in normal aged monkeys. PMID:2750490

Garruto, R M; Shankar, S K; Yanagihara, R; Salazar, A M; Amyx, H L; Gajdusek, D C

1989-01-01

38

Effect of multivalent salts -- calcium and aluminum -- on the flocculation of kaolin suspension with anionic polyacrylamide  

SciTech Connect

The effects of calcium and aluminum ions on the interaction behavior of anionic polyacrylamide (anionic PAM or HPAM) and kaolin are important in determining the efficient flocculation of kaolin. While kaolin surfaces are negatively charged in media such as water, they exhibit the positive surface charge characteristic at pH below 3.2 in the solution of calcium cation, and at pH below 9.2 in the solution of aluminum cation. The. experimental results show that both calcium and aluminum ions suppress the kaolin flocculation process. The results are analyzed and explained by molecular orbital theory, solution chemistry, infrared spectra, and electronic probe examination of kaolin treated with and without anionic PAM. Analysis results indicate that the specific adsorption of Ca[sup 2+], Al[sup 3+] and their hydroxo complexes on anionic PAM causes the loss of anionic character in the low pH range and leads to a low flocculation efficiency. In the high pH range, the poor kaolin flocculation can be attributed to precipitation of calcium and aluminum hydroxides on active functional groups, which inhibits the hydrogen bonding between anionic PAM and kaolin surfaces. At neutral pH values, the trivalent aluminum ion has more significant adverse effect on the kaolin flocculation than the divalent calcium ion.

Peng, F.F.; Di, P. (West Virginia Univ., Morgantown, WV (United States). Dept. of Mineral Processing Engineering)

1994-04-01

39

Microtopographical and Raman spectral studies on calcium sulphate dihydrate (gypsum) crystals grown in silica gel in the presence and absence of barium chloride as additive  

Microsoft Academic Search

A procedure for the growth of calcium sulphate dihydrate (gypsum) crystals, CaSO4 2H2O, by a gel technique in the presence of barium chloride as an additive as well as without the additive, is described. Optimum conditions for the growth of good quality crystals are worked out. Needle-shaped crystals with well-defined prism faces are obtained. Microtopographical studies of the crystals

P. Kumareson; S. Devanarayanan

1989-01-01

40

Enhancement of the Corrosion Resistance of Aluminum-Lithium Alloys by Microalloying with Calcium  

Microsoft Academic Search

The potentiodynamic method was applied to study the corrosion-electrochemical behavior in an electrolyte (3, 0.3, and 0.03% NaCl solution), of an aluminum-lithium alloy (6% Li) alloyed with calcium (0.01-0.5%).

M. T. Norova; I. N. Ganiev; Kh. M. Nazarov

2003-01-01

41

IMPLICATIONS OF THE CALCIUM-ALUMINUM EXCHANGE SYSTEM FOR THE EFFECT OF ACID PRECIPITATION ON SOILS  

EPA Science Inventory

Calcium-aluminum exchange isotherms were generated for three common ion exchange equilibrium equations, and their implications relative to the probable effects of acid rainfall are examined. The equations examined were those of Gaines and Thomas (1953), Vanselow (1932), and Gapon...

42

Experimental and theoretical study of molecular structure of beryllium, magnesium, calcium, strontium and barium 4-nitrobenzoates.  

PubMed

The influence of alkaline earth metal ions on the electronic system of 4-nitrobenzoic acid was studied in this paper. The vibrational (FT-IR) and NMR ((1)H and (13)C) spectra were recorded for 4-nitrobenzoic acid (4-nba) and its salts (4-nb). The assignment of vibrational spectra was done. Some shifts of band wavenumbers in alkaline earth metal 4-nitrobenzoates spectra were observed in the series from magnesium to barium salts. Good correlations between wavenumbers of the vibrational bands in the IR spectra of studied salts and ionic potential, electronegativity, inverse of atomic mass, ionic radius and ionization energy of studied metals were found. The regular changes in the chemical shifts of protons ((1)H NMR) and carbons ((13)C NMR) in the series of studied salts were also observed. Optimized geometrical structures of studied compounds were calculated by B3LYP method using 6-311++G(**) as well as LANL2DZ basis sets. Theoretical wavenumbers and intensities in IR and chemical shifts in NMR spectra were also obtained. The calculated parameters were compared with experimental data of studied compounds. PMID:23261035

Samsonowicz, M; Regulska, E; ?wis?ocka, R; Lewandowski, W

2012-12-05

43

Chemical Compatibility of Barium-Calcium-Aluminosilicate Based Sealing Glasses with Heat Resistant Alloys  

SciTech Connect

Over the past several years, advances in the design and fabrication of planar SOFCs have led to a steady reduction in the temperatures necessary for their operation. Consequently, it appears more realistic now to use low cost heat resistant alloys for interconnect sub-components in the SOFC stack. Considering these materials requirements, heat resistant alloys, which overall demonstrate oxidation resistance at elevated temperatures, could be potential candidates. Overall, the heat resistant alloys of interest may include superalloys and the stainless steels. Depending whether a chromia or alumina scale forms on the alloy surface for protection, these heat resistant alloys can be also classified into chromia or alumina formers, repetitively. To help screening alloys and understanding the interface of sealing glass, a couple of alloy compositions have been carefully chosen as a reprehensive of different groups of alloys for the study on their chemical compatibility with a barium-aluminosilicate base glass. These alloys selected are AL 29-4, Nicrofer 6025, and Fecralloy, representing chromia forming stainless steels, superalloys and alumina formers, respectively. Results of chemical and microstructural analyses on sealing glass interfaces with different alloys will be presented, and accordingly, the applicability of alloys in terms of sealing glass chemical compatibility will be discussed. Possible means of modification on alloys for an improved applicability will be elaborated as well.

Yang, Z Gary; Weil, K. Scott; Meinhardt, Kerry D.; Stevenson, Jeffry W.; Paxton, Dean M.; Xia, Gordon; Kim, Dong-Sang

2003-09-15

44

Calcium Modification of Spinel Inclusions in Aluminum-Killed Steel: Reaction Steps  

NASA Astrophysics Data System (ADS)

Calcium treatment is a well-established way to modify solid alumina inclusions to liquid or partially liquid calcium aluminates. Spinels (Al2O3 xMgO) can also form in liquid steel after aluminum deoxidation. Like alumina, the spinels can be modified readily to liquid inclusions by a calcium treatment. The modification of spinels was studied by observing the transient evolution of inclusions, in laboratory and industrial heats. Spinel modification involves the preferential reduction of MgO from the spinel, with Mg dissolving in the steel, and it proceeds through transient calcium sulfide formation, just like in the case of alumina inclusions. Because magnesium dissolves in steel after the calcium treatment of spinels, the reoxidation of the melt will produce new spinels.

Verma, Neerav; Pistorius, Petrus C.; Fruehan, Richard J.; Potter, Michael S.; Oltmann, Helmut G.; Pretorius, Eugene B.

2012-08-01

45

Chemical Compatibility of Barium-Calcium-Aluminosilicate Based Sealing Glasses with Ferritic Stainless Steel Interconnect in SOFCs  

SciTech Connect

In most planar SOFC stack designs, the interconnect, which is typically made from a ferritic stainless steel, is hermitically sealed to the ceramic PEN (Positive electrode-Electrolyte-Negative electrode) by a sealing glass. To maintain the structural stability and minimize degradation of the stack performance, the sealing glass must be chemically compatible with the stainless steel interconnect. In this study, a barium-calcium-aluminosilicate (BCAS) based glass-ceramic, specifically developed as a sealant in SOFC stacks, and a ferritic stainless steel (446) were selected as examples to increase the understanding the chemical compatibility issues in SOFC. Evaluation of the interfaces of coupon joints indicated that interactions between the BCAS glass-ceramic and the ferritic stainless steel was dependent on the exposure conditions. At the edges of joints, where oxygen or air was accessible, the interaction often led to the formation of BaCrO4, while in the interior of the joints, chromium or chromia dissolved into the glass to form a thin layer of chromium rich solid solution. It was also found that, in the interior of the joints, the interaction often resulted in the formation of pores aligned along the interface. It appears the pore formation along the interface can be avoided through a pre-heat treatment.

Yang, Z Gary; Meinhardt, Kerry D.; Stevenson, Jeffry W.

2003-08-01

46

Growth and Studies of Calcium Doped Laser Ablated Barium Titanate Thin Films  

Microsoft Academic Search

Ba1 ? xCaxTiO3 targets were prepared by conventional solid state reaction with varied amounts of the calcium content (5 at.%, 10 at.%) and the thin films were deposited on Pt(111) coated Si substrate using pulsed laser ablation technique. The thin films were deposited at different pressures and temperatures, so as to determine the optimized growth parameter for the good quality

P. Victor; R. Ranjith; A. K. Tyagi; S. Rajagopalan; S. B. Krupanidhi

2003-01-01

47

Experimental (FT-IR, FT-Raman, 1H NMR) and theoretical study of magnesium, calcium, strontium, and barium picolinates  

NASA Astrophysics Data System (ADS)

The experimental IR, Raman, and 1H NMR spectra of picolinic acid, as well as magnesium, calcium, strontium, and barium picolinates were registered, assigned and studied. Characteristic changes in the spectra of metal picolinates in comparison with the spectrum of ligand were observed, which lead to the conclusion that perturbation of the aromatic system of picolinates increases along with the series Mg ? Ca ? Sr ? Ba. Theoretical structures of beryllium and magnesium picolinates, as well as theoretical IR spectrum of magnesium picolinate were calculated in B3PW91/6-311++G(d, p) level. On the basis of calculated bond lengths in pyridine ring geometric, aromaticity indexes HOMA were calculated. The idea of these indexes is based on the fact that the essential factor in aromatic stabilization is the ? delocalization manifested in: planar geometry, equalization of the bond lengths and angles, and symmetry. The decidedly lower value of HOMA for magnesium picolinate (i.e. 0.545; 0.539) than that for beryllium picolinate (i.e. 0.998; 0.998) indicate higher aromatic properties of Be picolinate than of Mg picolinate. The comparison of theoretical and literature experimental structures of magnesium picolinate was done. The experimental structure contains two water molecules, so the calculations for hydrated magnesium picolinate were carried on, and the influence of coordinated water molecule on the structure of picolinates was discussed. The HOMAs for hydrated experimental and calculated Mg picolinate amount to 0.870; 0.743, and 0.900; 0.890, respectively, whereas for anhydrous structure, it is as described above, i.e. 0.545; 0.539. Thus, the calculations clearly showed that water molecules coordinated to the central atom weakens the effect of metal on the electronic system of ligand.

?widerski, G.; Kalinowska, M.; Wojtulewski, S.; Lewandowski, W.

2006-05-01

48

RenaGel, a nonabsorbed calcium- and aluminum-free phosphate binder, lowers serum phosphorus and parathyroid hormone  

Microsoft Academic Search

RenaGel, a nonabsorbed calcium- and aluminum-free phosphate binder, lowers serum phosphorus and parathyroid hormone.Background.This multicenter, open-label, dose-titration study assessed the safety and efficacy of RenaGel, a nonabsorbed calcium- and aluminum-free phosphate binder, in lowering serum phosphorus. Secondary outcomes were its effects on serum intact parathyroid hormone (iPTH) and serum lipids.Methods.Phosphate binders were discontinued during a two-week washout period. Patients whose

EDUARDO A SLATOPOLSKY; STEVEN K BURKE; MAUREEN A DILLON

1999-01-01

49

Thermodynamics of calcium and oxygen in molten titanium and titanium-aluminum alloy  

NASA Astrophysics Data System (ADS)

The deoxidation equilibrium of molten titanium and titanium-aluminum alloys saturated with solid CaO has been measured in the temperature range from 1823 to 2023 K. The equilibrium constant of reaction CaO (s)=Ca (mass pct in Ti,Ti-Al)+O (mass pct in Ti,Ti-Al) and the interaction parameter between calcium and oxygen were determined for Ti, TiAl, and TiAl3. The standard Gibbs energy of reaction for TiAl was obtained as follows: 11663_1996_Article_10_TeX2GIFE1.gif ? G^circ = 279,000 - 103TJ/mol The possibilities for the deoxidation of titanium and titanium-aluminum alloys by using calcium-based fluxes are discussed.

Tsukihashi, Fumitaka; Hatta, Toshiyuki; Tawara, Eiji

1996-12-01

50

Competitive Adsorption of Hydrogen, Calcium, Potassium, Magnesium, and Aluminum on Banana Roots: Experimental Data and Modeling  

Microsoft Academic Search

Aluminum (Al) adsorption on root exchange sites is one of the mechanisms that can be responsible for Al toxicity. Experimental measurements of calcium (Ca), magnesium (Mg), potassium (K), and Al adsorption on the main root axes of 5 banana cultivars (Grande Naine, Agbagba, Obino l'Ewa, Kayinja, and Igitsiri) were carried out at pH 3.75 and 4.25. The data obtained were

Gervais Rufyikiri; Jos G. Genon; Joseph E. Dufey; Bruno Delvaux

2003-01-01

51

Use of calcium\\/aluminum ratios as indicators of stress in forest ecosystems  

Microsoft Academic Search

The calcium\\/aluminum (Ca\\/Al) molar ratio of the soil solution provides a valuable measurement endpoint or ecological indicator for identification of approximate thresholds beyond which the risk of forest damage from Al stress and nutrient imbalances increases. The Ca\\/Al ratio can also be used as an indicator to assess forest ecosystem changes over time in response to acidic deposition, forest harvesting,

Christopher S. Cronan; David F. Grigal

1995-01-01

52

Characterization of Internal Capacitors Based on Glass-Added Barium Titanate  

NASA Astrophysics Data System (ADS)

Barium-calcium-aluminum-borosilicate glass is added as a sintering promoter to reduce the sintering temperature of barium titanate. The dielectric properties of the glass-added barium titanate-based internal capacitors are investigated. The dielectric constants of the composites were found to increase with sintering temperature. A capacitance of about 2.3 nF/cm2 with the dissipation factor of 2.9% is obtained for a 20 wt% glass-added BaTiO3 internal capacitor after being cofired with low dielectric constant ceramic substrate at 950C. The percent change of capacitance is confined within 10% and the dissipation factor is stable in the measured temperature range.

Chen, Lih-Shan; Fu, Shen-Li; Lin, Wen-Kuan; Huang, Kwan-Dar

2001-07-01

53

Lead isotopic ages of chondrules and calcium-aluminum-rich inclusions.  

PubMed

The lead-lead isochron age of chondrules in the CR chondrite Acfer 059 is 4564.7 +/- 0.6 million years ago (Ma), whereas the lead isotopic age of calcium-aluminum-rich inclusions (CAIs) in the CV chondrite Efremovka is 4567.2 +/- 0.6 Ma. This gives an interval of 2.5 +/- 1.2 million years (My) between formation of the CV CAIs and the CR chondrules and indicates that CAI- and chondrule-forming events lasted for at least 1.3 My. This time interval is consistent with a 2- to 3-My age difference between CR CAIs and chondrules inferred from the differences in their initial 26Al/27Al ratios and supports the chronological significance of the 26Al-26Mg systematics. PMID:12215641

Amelin, Yuri; Krot, Alexander N; Hutcheon, Ian D; Ulyanov, Alexander A

2002-09-01

54

Ab initio oscillator strengths and transition probabilities in aluminum-like calcium, Ca VIII  

SciTech Connect

An ab initio study of aluminum-like calcium is presented. The calculations are performed within the configuration interaction method in the basis of transformed radial orbitals with a variable parameter. Relativistic effects are accounted for within the Breit-Pauli approximation. Energy spectra, transition characteristics and lifetimes of excited levels of configurations 3s{sup 2}3p, 3s3p{sup 2}, 3s{sup 2}3d, 3p{sup 3}, 3s3p3d, 3p{sup 2}3d, 3s{sup 2}4s, 3s{sup 2}4p, 3s{sup 2}4d, 3s{sup 2}4f, 3s3p4s, and 3s3p4p are obtained. The results are compared with available experimental and theoretical data.

Karpuskiene, R. [Institute of Theoretical Physics and Astronomy of Vilnius University, A.Gostauto 12, 01108 Vilnius (Lithuania)], E-mail: karra@itpa.lt; Bogdanovich, P. [Institute of Theoretical Physics and Astronomy of Vilnius University, A.Gostauto 12, 01108 Vilnius (Lithuania)

2009-07-15

55

Effect of unintentionally extruded calcium hydroxide paste including barium sulfate as a radiopaquing agent in treatment of teeth with periapical lesions: report of a case.  

PubMed

Calcium hydroxide [Ca(OH)2] has been widely used as short- or long-term intracanal antibacterial dressing material after endodontic treatment. In general when used in endodontics, Ca(OH)2 paste is composed of the powder, a vehicle, and a radiopacifier. To provide radiopacity, barium sulfate (BaSO4) powder is usually added to the paste. In this case report, BaSO4:Ca(OH)2 powders (ratio 1:8) and distilled water were mixed and applied as dressing material after root canals of mandibular left canine and premolar teeth with periapical lesions. However, the prepared paste was unintentionally extruded into the periapical lesion during application. The patient was seen 12 and 36 months later, at which point periapical healing was evaluated. At this time, it was observed that the periapical lesion had disappeared, but white radiopaque spots were seen at the place where calcium hydroxide remnants had originally been present. The presented case report reveals that when Ca(OH)2 paste that included BaSO4 was applied as an intracanal dressing and extruded through the periapical lesion associated with pulpless teeth, it had no detrimental effect. However, healing might take longer when Ca(OH)2 paste including BaSO4 is used, so deliberate overextension is not advocated. PMID:18571001

Orucoglu, Hasan; Cobankara, Funda Kont

2008-05-22

56

Tantalum oxide and barium sulfate as radiopacifiers in injectable calcium phosphate-poly(lactic-co-glycolic acid) cements for monitoring in vivo degradation.  

PubMed

Monitoring the degradation of calcium phosphate-based bone substitute materials in vivo by means of noninvasive techniques (e.g., radiography) is often a problem due to the chemical resemblance of those substitutes with the mineral phase of bone. In the view of that, the present study aimed at enhancing the radiopacity of calcium phosphate cement enriched with poly(lactic-co-glycolic acid) (CPC-PLGA) microspheres, by adding tantalum oxide (Ta2 O5 ) or the more traditional radiopacifier barium sulfate (BaSO4 ). The radiopacifying capacity of these radiopacifiers was first evaluated in vitro by microcomputed tomography (?CT). Thereafter, both radiopacifiers were tested in vivo using a distal femoral condyle model in rabbits, with subsequent ex vivo ?CT analysis in parallel with histomorphometry. Addition of either one of the radiopacifiers proved to enhance radiopacity of CPC-PLGA in vitro. The in vivo experiment showed that both radiopacifiers did not induce alterations in biological performance compared to plain CPC-PLGA, hence both radiopacifiers can be considered safe and biocompatible. The histomorphometrical assessment of cement degradation and bone formation showed similar values for the three experimental groups. Interestingly, ?CT analysis showed that monitoring cement degradation becomes feasible upon incorporation of either type of radiopacifier, albeit that BaSO4 showed more accuracy compared to Ta2 O5 . 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. PMID:23613219

Hoekstra, Jan Willem M; van den Beucken, Jeroen J J P; Leeuwenburgh, Sander C G; Bronkhorst, Ewald M; Meijer, Gert J; Jansen, John A

2013-04-24

57

A thermodynamic investigation of barium and calcium sulfate stability in sediments at an oceanic ridge axis (Juan de Fuca, ODP legs 139 and 169)  

NASA Astrophysics Data System (ADS)

We have used a new thermodynamic model of barium and calcium sulfate solubilities in multicomponent electrolyte solutions (Monnin, 1999) to investigate the stabilities of barite and anhydrite in seawater or in marine sediment porewaters at high temperature and pressure. As a further test supplementing those previously carried out during model development, we have calculated the temperature at which standard seawater becomes saturated with respect to anhydrite. The model predicts that, upon heating at 500 bars, standard seawater becomes saturated with respect to anhydrite at 147 5C, which compares well with the literature value of 150C (Bishoff and Seyfried, 1978). At 20 bars the calculated saturation temperature is 117 3C. This points to a non negligible pressure effect even at moderate pressures. We have calculated the barite and anhydrite saturation indices for the in situ temperatures and pressures, from the composition of porewaters collected at ODP Sites 855, 856, 857, 858, 1035 and 1036 during ODP Legs 139 and 169 (Juan de Fuca and Gorda ridges, NE Pacific). Calculated saturation indices for porewater samples collected at depths corresponding to temperatures between 70 and 110-120C at an in situ pressure of about 260 bars yield equilibrium values for anhydrite and barite. Saturation indices of samples collected at depths where the temperature exceeds 110-120C, however, yield values indicating supersaturation with respect to anhydrite and undersaturation with respect to barite. This result is consistent with the redissolution of anhydrite during cooling, leading to the well documented sampling artifact affecting porewater compositions in high temperature marine sediments: anhydrite dissolution increases the porewater sulfate content, which in turn induces a loss of barium from solution through barite precipitation (the common ion effect). We postulate that this redissolution occurs in sediment samples for which the in situ temperature exceeds 110-120C: below this limit anhydrite remains at equilibrium or does not have time to significantly dissolve before porewaters are sampled.

Monnin, Christophe; Balleur, Sabine; Goffe, Bruno

2003-08-01

58

Aluminum speciation, vibrational entropy and short-range order in calcium aluminosilicate glasses  

NASA Astrophysics Data System (ADS)

The heat capacity and vibrational entropy of a calcium aluminate and three peraluminous calcium aluminosilicate glasses have been determined from 2 to 300 K by heat-pulse relaxation calorimetry. Together with previous adiabatic data for six other glasses in the system CaO-Al 2O 3-SiO 2, these results have been used to determine partial molar heat capacities and entropies for five species namely, SiO 2, CaO and three different sorts of Al 2O 3 in which Al is 4-, 5- and 6-fold coordinated by oxygen. Given the determining role of oxygen coordination on low-temperature heat capacity, the composition independent entropies found for SiO 2 and CaO indicate that short-range order around Si and Ca is not sensitive to aluminum speciation up to the highest fraction of 25% observed for VAl by NMR spectroscopy. Because of the higher room-temperature vibrational entropy of IVAl 2O 3 (72.8 J/mol K) compared to VAl 2O 3 (48.5 J/mol K), temperature-induced changes from IVAl to VAl give rise to a small negative contribution of the order of 1 J/mol K to the partial molar configurational heat capacity of Al 2O 3 in melts. Near 0 K, pure SiO 2 glass distinguishes itself by the importance of the calorimetric boson peak. On a g atom basis, the maximum of this peak varies with the composition of calcium aluminosilicate glasses by a factor of about 2. It does not show smooth variations, however, either as a function of SiO 2 content, at constant CaO/Al 2O 3 ratio, or as a function of Al 2O 3 content, at constant SiO 2 content.

Richet, Pascal; Nidaira, Atsusi; Neuville, Daniel R.; Atake, Tooru

2009-07-01

59

Modeling and minimization of barium sulfate scale  

Treesearch

Barium carbonate dissolves in the bleach plant when the pH drops below 7 and, if barium and ... at higher pH, but this will work only in mills where calcium scales are not a concern. A third option is to use crystal modifiers (scale inhibitors).

60

Calcium-aluminum-silicate-hydrate cement phases and rare Ca-zeolite association at Colle Fabbri, Central Italy  

Microsoft Academic Search

Very high temperature, Ca-rich alkaline magma intruded an argillite formation at Colle Fabbri, Central Italy, producing cordierite-tridymite\\u000a metamorphism in the country rocks. An intense Ba-rich sulphate-carbonate-alkaline hydrothermal plume produced a zone of mineralization\\u000a several meters thick around the igneous body. Reaction of hydrothermal fluids with country rocks formed calcium-silicate-hydrate\\u000a (CSH), i.e., tobermorite-afwillite-jennite; calcium-aluminum-silicate-hydrate (CASH) cement phases - i.e., thaumasite,

Francesco Stoppa; Fernando Scordari; Ernesto Mesto; Victor V. Sharygin; Giorgio Bortolozzi

2010-01-01

61

Enhanced type I immune response to a hepatitis B DNA vaccine by formulation with calcium- or aluminum phosphate  

Microsoft Academic Search

DNA vaccines induce protective humoral and cell-mediated immune responses in several animal models. When compared with conventional vaccines, however, DNA vaccines often induce lower antibody titers. We have now found that formulation of a DNA vaccine encoding hepatitis B surface antigen with calcium- or aluminum phosphate adjuvants can increase antibody titers by 10100-fold and decrease the immunogenic dose of DNA

Su Wang; Xu Liu; Karen Fisher; Jeffrey G Smith; Fei Chen; Timothy W Tobery; Jeffrey B Ulmer; Robert K Evans; Michael J Caulfield

2000-01-01

62

Source Assessment: Major Barium Chemicals.  

National Technical Information Service (NTIS)

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 eff...

H. D. Troy R. B. Rezink

1978-01-01

63

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,...

64

SOLAR WIND IMPLANTATION MODEL FOR {sup 10}Be IN CALCIUM-ALUMINUM INCLUSIONS  

SciTech Connect

We propose a model for the incorporation of {sup 10}Be within calcium-aluminum inclusions (CAIs) in primitive carbonaceous meteorites. In this model, {sup 10}Be is produced by energetic particle reactions in the proto-solar atmosphere of a more active proto-Sun characterized by energetic particle fluxes higher than contemporary particle fluxes. This {sup 10}Be is incorporated into the solar wind that is then implanted into CAI precursor material. This production mechanism is operational in the contemporary solar system implanting {sup 10}Be in lunar materials. The contemporary production rate of {sup 10}Be at the surface of the Sun is {approx}0.1 {sup 10}Be cm{sup -2} s{sup -1}. Scaling up the contemporary {sup 10}Be production in the proto-Sun by a factor of 10{sup 5} would increase the production rate to 10{sup 410}Be cm{sup -2} s{sup -1}. Using this enhanced production value in conjunction with refractory mass inflow rates at 0.06 AU from the proto-Sun we model {sup 10}Be concentrations in CAI precursors. We calculate the content of solar-wind-implanted {sup 10}Be would have been of the order of 10{sup 1210}Be g{sup -1} in CAIs, consistent with initial{sup 10}Be content found from boron-beryllium isotopic systematics in CAIs.

Bricker, Glynn E. [Department of Mathematics, Statistics, and Physics, Purdue University North Central, Schwarz Bldg, Westville, IN 46391 (United States); Caffee, Marc W., E-mail: gbricker@pnc.ed, E-mail: mcaffee@purdue.ed [Department of Physics, Primelab: Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States)

2010-12-10

65

Effect of calcium and aluminum concentrations on the survival of brown trout (Salmo trutta) at low pH  

SciTech Connect

In this paper, the results of experiments to determine the survival times of yolk sac fry of brown trout (Salmo trutta) in a range of pHs, calcium and aluminium solutions are described, and the relevance of the results to the field situation is also discussed. In the absence of aluminum, mortalities occur at pH 4.5 only with 0.25 and 0.5 mg 1/sup -1/ of calcium. In solutions containing 0.25 mg 1/sup -1/ of aluminium, however, a complete range of responses is seen, from no or very low survival with 0.25 mg 1/sup -1/ of calcium to almost complete survival with 2.0 mg 1/sup -1/ of calcium. Solutions containing 0.5 mg 1/sup -1/ of aluminium lead to almost complete mortalities with calcium concentrations of 0.25 and 0.5 mg 1/sup -1/ and still significant mortalities at higher calcium concentrations. In general, the effect of pH throughout the range tested is not so marked, but there is a tendency for higher pHs to be more toxic especially in solutions containing 0.5 mg 1/sup -1/ of aluminium.

Brown, D.J.A.

1983-01-01

66

Aluminum and acid effects on calcium and phosphorus metabolism in young growing chickens (Gallus gallus domesticus) and mallard ducks (Anas platyrhynchos).  

PubMed

Acidification is associated with increased mortality, reduced growth, and bone abnormalities in birds. Associated with acid deposition is an increase in aluminum availability due to solubilization from soil and other sources. (Conversely, experimental diets containing aluminum sulfate have much reduced pHs.) The present studies compare the effects of two levels of dietary acid (sulfuric acid) (0.122 and 0.56 mol H+ per kg feed; 0.056 and 0.277 mol sulfate per kg feed) and dietary aluminum (aluminum sulfate at 0.1 and 0.5%; sulfate at 0. 056 and 0.277 mol sulfate per kg feed) on bone growth, mineralization, and phosphorous/calcium homeostasis in growing birds (chickens and mallard ducks). Growth was reduced by the high acid (chicken) and aluminum (ducks and chickens) diets. A reduction in bone mineralization was observed in birds receiving aluminum-containing diets [low aluminum diet: decreased tibia ash, calcium, and phosphorus (chickens); high aluminum diet: decreased tibia dry weight, % of ash and mg; ash, calcium (chickens, ducks as % of ash), and phosphorus (chickens mg/duck, % of ash)]. Moreover, plasma concentrations of inorganic phosphate were reduced in chicks on the high aluminum diet. There were also marked decreases in bone growth and mineralization [tibia weight, ash (mg), calcium (mg), phosphorus (mg)] and plasma concentrations of 1,25-dihydroxy vitamin D3 in chicks on the high acid diet compared to those on a control diet. These changes were probably due to reduced feed intake; changes in bone indices being of a greater or similar magnitude in pairfed control. There was little change in bone indices, growth rate or feed consumption in ducklings receiving either the low or high acid diets. It is concluded that aluminum directly adversely affected bone mineralization whereas acid effects are mediated in part by changes in feed consumption. PMID:9601924

Capdevielle, M C; Hart, L E; Goff, J; Scanes, C G

1998-07-01

67

Calmodulin concentration in mucus of rainbow trout, Salmo gairdneri, exposed to combinations of acid, aluminum, and calcium  

SciTech Connect

As a result of increasing acidification in various watersheds elevated levels of aluminum have been observed in soil and surface water. The toxicity of Al to fish has been shown to be positively correlated with the concentration of inorganic monomeric. The exact mechanism(s) of Al toxicity is not fully understood. Recently, the presence of calmodulin (CaM), a calcium-regulating protein, has been reported in fish gills and mucus. Calmodulin selectively binds inorganic monomeric Al causing conformational changes in the protein. Aluminum-induced conformational changes cause a reduction in the ability of calmodulin to mediate Ca-dependent phosphodiesterase and ATPase activity. Calmodulin also plays a key role in coordinating the effects of secondary messenger systems in response to cellular stimulation. Given the involvement of calmodulin in numerous biochemical pathways, its interaction with aluminum may be a key lesion in the broadly defined syndrome of aluminum toxicity. The present study was undertaken to establish a relationship between Al concentration in aqueous solution and the quantity and activity of CaM in the mucus of adult rainbow trout (Salmo gairdneri). Fish were exposed to various levels of pH, Ca, and Al. Mucus was collected and the amount of CaM was determined. The ability of the Al-exposed CaM to activate the phosphodiesterase enzyme system was also evaluated.

Lewis, T.E. (Lockheed Engineering and Sciences Company, Las Vegas, NV (USA)); Yuan, Shixing; Haug, A. (Michigan State Univ., East Lansing (USA))

1990-03-01

68

Development of calcium zirconate-based hydrogen sensors with oxide reference electrodes for molten aluminum  

Microsoft Academic Search

Hydrogen is a major cause of gas porosity in aluminum and is frequently removed from the melt prior to casting. The degassing process can be better controlled if the hydrogen content in the melt is known. Thus, gas sensors which can make continuous in situ measurements in molten aluminum are needed. Current online hydrogen sensing systems are complex designs which

Vivek Krishnan

2006-01-01

69

Optimisation of the Selective Extraction of (Glucurono)arabinoxylans from Wheat Bran: Use of Barium and Calcium Hydroxide Solution at Elevated Temperatures  

Microsoft Academic Search

Two approaches were investigated in attempts to obtain a high extraction yield of (glucurono) arabinoxylans from water-unextractable cell wall material (WUS) of wheat bran using saturated barium hydroxide containing 026 M sodium borohydride. First, the effect of three pretreatments (autoclave treatment, alkaline peroxide and chlorite delignification) of the WUS prior to extraction appeared to have no effect on the extraction

M. E. F. Bergmans; G. Beldman; H. Gruppen; A. G. J. Voragen

1996-01-01

70

Early Life Stage Brook Trout (Salvelinus Fontinalis) Experiment to Determine the Effects of pH, Calcium and Aluminum in Low Conductivity Water.  

National Technical Information Service (NTIS)

Recruitment failure has been suggested as a mechanism leading to loss of fish populations in acidified streams and lakes. Numerous laboratory studies have investigated the effects of pH, aluminum, and calcium, alone or in combination, on early life stages...

C. G. Ingersoll H. L. Bergman J. Breck T. W. La Point

1984-01-01

71

Aluminum speciation, vibrational entropy and short-range order in calcium aluminosilicate glasses  

Microsoft Academic Search

The heat capacity and vibrational entropy of a calcium aluminate and three peraluminous calcium aluminosilicate glasses have been determined from 2 to 300K by heat-pulse relaxation calorimetry. Together with previous adiabatic data for six other glasses in the system CaOAl2O3SiO2, these results have been used to determine partial molar heat capacities and entropies for five species namely, SiO2, CaO and

Pascal Richet; Atsusi Nidaira; Daniel R. Neuville; Tooru Atake

2009-01-01

72

Temperature effects on non-bridging oxygen and aluminum coordination number in calcium aluminosilicate glasses and melts  

NASA Astrophysics Data System (ADS)

Configurational changes with temperature are important for the thermodynamic and transport properties of most aluminosilicate melts, but in general are not well understood. Here, we present high-resolution 27Al and 17O NMR data on several calcium aluminosilicate glasses prepared with varying quench rates and thus with fictive temperatures that span ranges up to about 200 K. In all compositions the content of five-coordinated aluminum increases with fictive temperature, in agreement with recent high temperature NMR data on melts. In a glass of CaAl 2Si 2O 8 ("anorthite") composition, the content of non-bridging oxygens also increases with temperature; however this effect was not observed in a sample with a much higher CaO/Al 2O 3 ratio. We present a consistent notation for reactions among structural species in these systems that clarify why in some cases, high-coordinated network cations may appear on the same side of the reaction, while in others they occur on the opposite sides: the key difference is in accounting for all coordination changes for oxygens. Mixing of non-bridging oxygens and of high-coordinated aluminum make significant contributions to the overall configurational entropy and heat capacity of the melts, as does the mixing of various bridging oxygens and of tetrahedral network cations. Other, less well known, types of increase in disorder with temperature may be important as well.

Stebbins, Jonathan F.; Dubinsky, Emily V.; Kanehashi, Koji; Kelsey, Kimberly E.

2008-02-01

73

Calcium  

MedlinePLUS

... Office of Dietary Supplements Dietary Supplement Fact Sheet: Calcium QuickFacts Datos en espaol Health Professional Other Resources Create PDF What is calcium and what does it do? Calcium is a ...

74

Electrical conduction transition and largely reduced leakage current in aluminum-doped barium strontium titanate thin films heteroepitaxially grown on Ir\\/MgO\\/Si(100)  

Microsoft Academic Search

Ba0.6Sr0.4Ti1-xAlxO3 (BSTA, x=0, 3 at. %, 6 at. %) thin films have been prepared on Ir\\/MgO-buffered silicon substrates by pulsed-laser deposition. All-epitaxial growth of BSTA\\/Ir\\/MgO\\/Si heterostructures has been evidenced by x-ray diffraction and reflection high-energy electron diffraction. A large reduction in the leakage current density of BSTA thin films was observed by aluminum doping. For 3 at. % Al-doped BSTA

T. L. Chen; X. M. Li; W. B. Wu; W. D. Yu; X. D. Gao; X. Zhang

2005-01-01

75

Electrical conduction transition and largely reduced leakage current in aluminum-doped barium strontium titanate thin films heteroepitaxially grown on Ir?MgO?Si(100)  

Microsoft Academic Search

Ba0.6Sr0.4Ti1?xAlxO3 (BSTA, x=0, 3 at. %, 6 at. %) thin films have been prepared on Ir?MgO-buffered silicon substrates by pulsed-laser deposition. All-epitaxial growth of BSTA?Ir?MgO?Si heterostructures has been evidenced by x-ray diffraction and reflection high-energy electron diffraction. A large reduction in the leakage current density of BSTA thin films was observed by aluminum doping. For 3 at. % Al-doped BSTA

T. L. Chen; X. M. Li; W. B. Wu; W. D. Yu; X. D. Gao; X. Zhang

2005-01-01

76

Aluminum effects on the kinetics of calcium uptake into cells of the wheat root apex  

Microsoft Academic Search

The effects of aluminum on the concentration-dependent kinetics of Ca2+ uptake were studied in two winter wheat (Triticum aestivum L.) cultivars, Al-tolerant Atlas 66 and Al-sensitive Scout 66. Seedlings were grown in 100 M CaCl2 solution (pH 4.5) for 3 d. Subsequently, net Ca2+ fluxes in intact roots were measured using a highly sensitive technique, employing a vibrating Ca2+-selective microelectrode.

Jianwei W. Huang; David L. Grunes; Leon V. Kochian

1992-01-01

77

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 ...

78

Effect of dietary aluminum sulfate on calcium and phosphorus metabolism of broiler chicks.  

PubMed

The effect of dietary aluminum sulfate on Ca and P metabolism was studied using 1-day-old male broiler chicks. In Experiment 1, practical diets providing .90% Ca plus .45% available P (Pav), .90% Ca plus .78% Pav, 1.80% Ca plus .45% Pav, or 1.80% Ca plus .90% Pav were fed with 0 or .392% A1 as aluminum sulfate for 21 days. The control diet (.90% Ca plus .45% Pav) without added A1 was fed to all chicks during Days 22 to 49. In general, A1 significantly (P less than .05) decreased BW gain, feed intake, gain:feed ratio, plasma inorganic P (Pi), tibia breaking strength, tibia weight, percentage of tibia ash, and plasma Zn, measured at Day 21. Elevating Pav increased BW gain, feed intake, gain:feed ratio, tibia weight and plasma Zn, and decreased plasma total Ca in the presence of .392% A1 plus 1.80% Ca. Plasma Pi, tibia breaking strength, and percentage of tibia ash were increased by raising dietary Pav in the presence of .392% A1 with either level of Ca. Negative effects of dietary A1 on feed intake and BW persisted through Day 49. In Experiment 2, a control diet (.90% Ca, .45% Pav) was fed for ad libitum access either alone or supplemented with .2% A1 as aluminum sulfate or with an equivalent amount of sulfate provided by potassium sulfate. The control diet was also pair-fed to chicks given .2% A1. Dietary A1 significantly depressed weight gain, feed intake, gain:feed ratio, and plasma Pi.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2395793

Hussein, A S; Cantor, A H; Johnson, T H; Yokel, R A

1990-06-01

79

Effects of calcium and aluminum chloride additions on foliar and throughfall chemistry in sugar maples  

Microsoft Academic Search

Calcium availability for sugar maple stands at the Hubbard Brook Experimental Forest (New Hampshire, USA) was tested by experimental addition of CaCl2 and AlCl3. Additions of 10gCam?2 represented the estimated loss from the soil exchange complex during the last 30 years due to acidic deposition. Four years of data from 12 throughfall collection sites were used to evaluate the influence

Torsten W Berger; Chris Eagar; Gene E Likens; Gerhard Stingeder

2001-01-01

80

21 CFR 73.1015 - Chromium-cobalt-aluminum oxide.  

Code of Federal Regulations, 2013 CFR

...chromium oxide, cobalt carbonate, and aluminum oxide. It may contain small amounts (less than 1 percent each) of oxides of barium, boron, silicon, and nickel. (b) Specifications. Chromium-cobalt-aluminum oxide shall conform to the...

2013-04-01

81

Barium appendicitis 1month after a barium meal.  

PubMed

Abstract Because barium sulfate (BaSO(4)) is not harmful to the mucosa, it is widely used for gastrointestinal imaging. Barium appendicitis is a very rare complication of barium meals and barium enema. We report a case of acute appendicitis associated with retained appendiceal barium. A 47-year-old man presented with right lower abdominal pain after upper gastrointestinal imaging was performed using barium 1month earlier. The abdominal plain roentgenogram showed an area of retained barium in the right lower quadrant. Multiplanar reconstruction of computed tomography scans showed barium retention in the appendix. Emergency appendectomy was performed. A cross section of the specimen revealed the barium mass. Barium-associated appendicitis is a very rare clinical entity but we should be cautious of this uncommon disease when we encounter barium deposits in the appendix after barium examination. This report is significant because barium was identified both macroscopically and microscopically. PMID:23294068

Urade, Masaaki; Shinbo, Toshihumi

82

Barium Appendicitis 1 Month After a Barium Meal  

PubMed Central

Because barium sulfate (BaSO4) is not harmful to the mucosa, it is widely used for gastrointestinal imaging. Barium appendicitis is a very rare complication of barium meals and barium enema. We report a case of acute appendicitis associated with retained appendiceal barium. A 47-year-old man presented with right lower abdominal pain after upper gastrointestinal imaging was performed using barium 1month earlier. The abdominal plain roentgenogram showed an area of retained barium in the right lower quadrant. Multiplanar reconstruction of computed tomography scans showed barium retention in the appendix. Emergency appendectomy was performed. A cross section of the specimen revealed the barium mass. Barium-associated appendicitis is a very rare clinical entity but we should be cautious of this uncommon disease when we encounter barium deposits in the appendix after barium examination. This report is significant because barium was identified both macroscopically and microscopically.

Urade, Masaaki; Shinbo, Toshihumi

2012-01-01

83

Calcium  

MedlinePLUS

... strong bones and teeth. Why Do I Need Calcium? Bones grow rapidly during adolescence, and teens need ... and canned salmon with bones. Back Continue Working Calcium Into Your Diet Looking for ways to up ...

84

Catalytic combustion of methane on substituted barium hexaaluminates  

Microsoft Academic Search

A solgel method using metallic barium, aluminum alkoxides and metal nitrates has been used to synthesize barium hexaaluminate partially substituted by either manganese, iron or both metal ions. The ?-alumina structure was obtained by calcination under oxygen at 1200C. X-ray analysis revealed that formation of a pure single phase BaMxAl12?xO19 occurred up to x=4 for Fe, x=3 for Mn and

P Artizzu-Duart; J. M Millet; N Guilhaume; E Garbowski; M Primet

2000-01-01

85

The simultaneous removal of calcium, magnesium and chloride ions from industrial wastewater using magnesium-aluminum oxide.  

PubMed

In this article, a method for simultaneous removal of calcium, magnesium and chloride by using Mg0.80Al0.20O1.10 as a Magnesium-Aluminum oxide (Mg?Al oxide) was investigated. Mg?Al oxide obtained by thermal decomposition of the Mg-Al layered double hydroxide (Mg-Al LDH). The synthesized Mg?Al oxide were characterized with respect to nitrogen physicosorption, X-ray diffraction (XRD) and field emission scan electron microscopy (FESEM) morphology. Due to high anion-exchange capacity of Mg?Al oxide, it was employed in simultaneously removal of Cl(-), Mg(+2) and Ca(+2) from distiller waste of a sodium carbonate production factory. For this purpose, experiments were designed to evaluate the effects of quantity of Mg?Al oxide, temperature and time on the removal process. The removal of Cl(-), Mg(+2) and Ca(+2) from wastewater was found 93.9%, 93.74% and 93.25% at 60C after 0.5h, respectively. Results showed that the removal of Cl(-), Mg(+2) and Ca(+2) by Mg?Al oxide increased with increasing temperature, time and Mg?Al oxide quantity. PMID:23647113

Hamidi, Roya; Kahforoushan, Davood; Fatehifar, Esmaeil

2013-01-01

86

Calcium phosphate sol-gel-derived coatings on titanium-aluminum-vanadium substrate for biomedical applications  

NASA Astrophysics Data System (ADS)

Osseointegration of implants to host bone is a necessary requirement for dental and orthopaedic implants. The rate and quality of osseointegration were enhanced through the use of calcium phosphate (Ca-P) films on metallic substrates. The present study investigates the characteristics of Ca-P films applied using sol-gel dip coating methods to sintered porous-surfaced implants. Ca-P films have been formed using Inorganic Route and Organic Route processes. It has been shown that both approaches resulted in the formation of carbonated hydroxyapatite but with different Ca/P ratios as well as different surface textures and film structures, the Inorganic Route-formed film being more porous at its outermost surface, and having a more irregular topography. An interfacial reaction product (calcium titanium oxide) was detected for the Inorganic Route-formed coatings while this interfacial phase was not detectable in the Organic Route-formed coatings. The interface tensile and shear adhesion strength properties of Ca-P films have been evaluated using an improved direct pull-off testing (ASTM C633) and a substrate straining method, respectively. For both Ca-P films, the adhesive tensile strength was higher than the failure stress of 38 MPa occurring between the Ca-P films and the glue or in the glue. A shear lag approach revealed a shear strength of 347 +/- 64MPa and 280 +/- 28MPa for the Inorganic Route and the Organic Route Ca-P films, respectively. In vivo animal model studies have been performed to compare the effect on early bone formation of sintered porous-surfaced implants that had been modified through the addition of Ca-P film. In Group I study (i.e. Inorganic Route-formed Ca-P-coated implants vs. non-coated implants), it has been found that the Inorganic Route-formed Ca-P film significantly enhances the early rate of bone ingrowth for sintered porous-surfaced implants. However, in Group II study (i.e. Organic Route-formed Ca-P-coated implants vs. non-coated implants), significant improvement was not observed for the Organic Route-formed Ca-P film. It is speculated that the slightly different surface topography and film density between the two Ca-P films result in a different amounts of protein adsorption on the implant surface at the early stage, which further affects the following processes leading to osseointegration.

Gan, Lu

87

Constraints on formation processes of two coarse-grained calcium- aluminum-rich inclusions: a study of mantles, islands and cores  

USGS Publications Warehouse

Many coarse-grained calcium- aluminum-rich inclusions (CAIs) contain features that are inconsistent with equilibrium liquid crystallization models of origin. Spinel-free islands (SFIs) in spinel-rich cores of Type B CAIs are examples of such features. One model previously proposed for the origin of Allende 5241, a Type B1 CAI containing SFIs, involves the capture and assimilation of xenoliths by a liquid droplet in the solar nebula (El Goresy et al, 1985; MacPherson et al 1989). This study reports new textural and chemical zoning data from 5241 and identifies previously unrecognized chemical zoning patterns in the melilite mantle and in a SFI. -from Author

Meeker, G. P.

1995-01-01

88

Final report on the safety assessment of aluminum silicate, calcium silicate, magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, sodium magnesium silicate, zirconium silicate, attapulgite, bentonite, Fuller's earth, hectorite, kaolin, lithium magnesium silicate, lithium magnesium sodium silicate, montmorillonite, pyrophyllite, and zeolite.  

PubMed

This report reviews the safety of Aluminum, Calcium, Lithium Magnesium, Lithium Magnesium Sodium, Magnesium Aluminum, Magnesium, Sodium Magnesium, and Zirconium Silicates, Magnesium Trisilicate, Attapulgite, Bentonite, Fuller's Earth, Hectorite, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite as used in cosmetic formulations. The common aspect of all these claylike ingredients is that they contain silicon, oxygen, and one or more metals. Many silicates occur naturally and are mined; yet others are produced synthetically. Typical cosmetic uses of silicates include abrasive, opacifying agent, viscosity-increasing agent, anticaking agent, emulsion stabilizer, binder, and suspending agent. Clay silicates (silicates containing water in their structure) primarily function as adsorbents, opacifiers, and viscosity-increasing agents. Pyrophyllite is also used as a colorant. The International Agency for Research on Cancer has ruled Attapulgite fibers >5 microm as possibly carcinogenic to humans, but fibers <5 microm were not classified as to their carcinogenicity to humans. Likewise, Clinoptilolite, Phillipsite, Mordenite, Nonfibrous Japanese Zeolite, and synthetic Zeolites were not classified as to their carcinogenicity to humans. These ingredients are not significantly toxic in oral acute or short-term oral or parenteral toxicity studies in animals. Inhalation toxicity, however, is readily demonstrated in animals. Particle size, fibrogenicity, concentration, and mineral composition had the greatest effect on toxicity. Larger particle size and longer and wider fibers cause more adverse effects. Magnesium Aluminum Silicate was a weak primary skin irritant in rabbits and had no cumulative skin irritation in guinea pigs. No gross effects were reported in any of these studies. Sodium Magnesium Silicate had no primary skin irritation in rabbits and had no cumulative skin irritation in guinea pigs. Hectorite was nonirritating to the skin of rabbits in a Draize primary skin irritation study. Magnesium Aluminum Silicate and Sodium Magnesium Silicate caused minimal eye irritation in a Draize eye irritation test. Bentonite caused severe iritis after injection into the anterior chamber of the eyes of rabbits and when injected intralamellarly, widespread corneal infiltrates and retrocorneal membranes were recorded. In a primary eye irritation study in rabbits, Hectorite was moderately irritating without washing and practically nonirritating to the eye with a washout. Rats tolerated a single dose of Zeolite A without any adverse reaction in the eye. Calcium Silicate had no discernible effect on nidation or on maternal or fetal survival in rabbits. Magnesium Aluminum Silicate had neither a teratogenic nor adverse effects on the mouse fetus. Female rats receiving a 20% Kaolin diet exhibited maternal anemia but no significant reduction in birth weight of the pups was recorded. Type A Zeolite produced no adverse effects on the dam, embryo, or fetus in either rats or rabbits at any dose level. Clinoptilolite had no effect on female rat reproductive performance. These ingredients were not genotoxic in the Ames bacterial test system. In primary hepatocyte cultures, the addition of Attapulgite had no significant unscheduled DNA synthesis. Attapulgite did cause significant increases in unscheduled DNA synthesis in rat pleural mesothelial cells, but no significant increase in sister chromosome exchanges were seen. Zeolite particles (<10 microm) produced statistically significant increase in the percentage of aberrant metaphases in human peripheral blood lymphocytes and cells collected by peritoneal lavage from exposed mice. Topical application of Magnesium Aluminum Silicate to human skin daily for 1 week produced no adverse effects. Occupational exposure to mineral dusts has been studied extensively. Fibrosis and pneumoconiosis have been documented in workers involved in the mining and processing of Aluminum Silicate, Calcium Silicate, Zirconium Silicate, Fuller's Earth, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite. The Cosmetic Ingre

Elmore, Amy R

2003-01-01

89

Isotopically uniform, 16O-depleted calcium, aluminum-rich inclusions in CH and CB carbonaceous chondrites  

NASA Astrophysics Data System (ADS)

In situ oxygen-isotope measurements of calcium-aluminum-rich inclusions (CAIs) from the metal-rich carbonaceous chondrites Isheyevo (CH/CB-like), Acfer 214 paired with Acfer 182 (CH), QUE 94411 paired with QUE 94627 (CBb), and Hammadah al Hamra 237 (CBb) revealed the presence of a common population of igneous, isotopically uniform, 16O-depleted inclusions: ?17O (average 2 standard deviations) = -7 4, -6 5, and -8 3, respectively. All CAIs from CBs and a significant fraction of those from CHs and Isheyevo are 16O-depleted. Most of the 16O-depleted CAIs consist of Ti-poor Al-diopside, spinel, melilite, and forsterite and surrounded by a single- and double-layered rim of forsterite diopside. The 16O-depleted CAIs composed of hibonite, grossite, melilite, and spinel, and surrounded by the multilayered melilite + diopside forsterite rims are less common. Some of the 16O-depleted refractory igneous inclusions composed of Al-diopside, forsterite, and spinel have chondrule-like textures (skeletal or barred). They are mineralogically most similar to Al-diopside-rich chondrules found in metal-rich carbonaceous chondrites and composed of Al-diopside, forsterite, Al-rich low-Ca pyroxene, glassy mesostasis, and spinel, suggesting there is a continuum between these objects. We suggest that (i) most of the isotopically uniform and 16O-depleted CAIs resulted from remelting of pre-existing, possibly 16O-rich refractory inclusions. The remelting may have occurred during formation of the magnesian, non-porphyritic (cryptocrystalline and skeletal) chondrules in CHs, CBs, and Isheyevo either by an unspecified, late, single-stage, highly-energetic event or in an impact-generated plume previously hypothesized for their origin; both mechanisms probably occurred in the solar nebula (i.e., in the presence of the nebula gas). The forsterite pyroxene rims around 16O-depleted CAIs may have resulted from evaporation-recondensation of silicon and magnesium during this event. Some of the Al-diopside-rich CAIs may have formed by evaporation of the Al-rich chondrule melts. (ii) In addition to these components, the CHs and Isheyevo contain a high abundance of chondrules and refractory inclusions formed by the commonly inferred nebular processes - evaporation, condensation, and incomplete melting of dust aggregates during multiple transient heating events. These include 16O-rich CAIs, amoeboid olivine aggregates, and ferromagnesian and aluminum-rich chondrules with porphyritic textures. Such components are also present in CB chondrites, but they are exceptionally rare. These observations indicate that there are multiple generations of CAIs in metal-rich carbonaceous chondrites. (iii) Because the isotopically uniform, 16O-depleted, igneous CAIs and the magnesian cryptocrystalline and skeletal olivine-pyroxene chondrules are found almost exclusively in metal-rich carbonaceous chondrites, the hypothesized impact-plume mechanism of chondrule formation and recycling of CAIs are not common processes.

Krot, Alexander N.; Nagashima, Kazuhide; Petaev, Michail I.

2012-04-01

90

Effects of aluminum and other cations on the structure of brain and liver chromatin  

SciTech Connect

The reactivity of aluminum and several other divalent and trivalent metallic cations toward chromatin from rat brain and liver has been investigated. Two criteria are used to determine the relative reactivity of these cations toward chromatin. The first involves the ability of the ions to compact the chromatin fibers to the point where chromatin precipitates. The second criterion measures the ability of cations to interfere with the accessibility of exogenous structural probes (nucleases) to chromatin. Of the divalent cations tested, nickel, cobalt, zinc, cadmium, and mercury were the most reactive toward chromatin, on the basis of their ability to induce precipitation of chromatin in the micromolar concentration range. The divalent cations magnesium, calcium, copper, strontium, and barium were much less effective, although all cations precipitate chromatin if their concentration is increased. Of the trivalent cations tested, aluminum indium, and gallium were very effective precipitants, whereas iron and scandium were without effect at the concentrations tested. Of all the cations tested, aluminum was the most reactive. Aluminum's ability to alter the structure of chromatin was investigated further by testing its ability to interfere with nuclease accessibility. This test confirmed that aluminum does induce considerable changes in chromatin structure at micromolar concentrations. Furthermore, chromatin from cortical areas of the brain was much more sensitive to aluminum than chromatin from liver. These results are discussed in light of the known toxicity of these cations, with particular emphasis on the possible role of aluminum in Alzheimer's disease.

Walker, P.R.; LeBlanc, J.; Sikorska, M. (National Research Council of Canada, Ottawa, Ontario)

1989-05-02

91

Barium and Radium Radiopolarography.  

National Technical Information Service (NTIS)

Radiopolarography has been applied to the study of two elements (barium and radium) which is difficult by classical polarography because of their strong electropositivity. Various parameters have been considered: nature, concentration and pH of supporting...

B. Fourest

1979-01-01

92

40 CFR 721.10667 - Slimes and sludges, aluminum and iron casting, wastewater treatment, solid waste.  

Code of Federal Regulations, 2013 CFR

...the treatment of wastewaters during aluminum and iron casting, machining and finishing operations. It may contain aluminum, barium, chromium, copper, iron, lead, manganese, nickel, and zinc.) is subject to reporting under this section for the...

2013-07-01

93

Calcium Entry Leads to Inactivation of Calcium Channel in Paramecium  

Microsoft Academic Search

Under depolarizing voltage clamp of Paramecium an inward calcium current developed and subsequently relaxed within 10 milliseconds. The relaxation was substantially slowed when most of the extracellular calcium was replaced by either strontium or barium. Evidence is presented that the relaxation is not accounted for by a drop in electromotive force acting on calcium, or by activation of a delayed

Paul Brehm; Roger Eckert

1978-01-01

94

Lower GI Series (Barium Enema)  

MedlinePLUS

... because the large intestine is filled with barium liquid. The barium liquid coats the lining of the large intestine and ... bowel prep instructions. Generally, patients follow a clear liquid diet for 1 to 3 days before the ...

95

21 CFR 82.1051 - Lakes (D&C).  

Code of Federal Regulations, 2013 CFR

...radical sodium, potassium, aluminum, barium, calcium, strontium, or zirconium...radical sodium, potassium, aluminum, barium, calcium, strontium, or zirconium...substratum is D&C Red No. 9Barium Lake, and a lake prepared by...

2013-04-01

96

Acid precipitation and food quality: Inhibition of growth and survival in black ducks and mallards by dietary aluminum, calcium and phosphorus  

USGS Publications Warehouse

In areas impacted by acid precipitation, water chemistry of acidic ponds and streams often changes, resulting in increased mobilization of aluminum and decreased concentration of calcium carbonate. Aluminum binds with phosphorus and inhibits its uptake by organisms. Thus, invertebrate food organisms used by waterfowl may have inadequate Ca and P or elevated Al for normal growth and development. Acid rain and its effects may be one of the factors negatively impacting American black ducks (Anas rubripes) in eastern North America. One-day old mallards (A. platyrhynchos) and black ducks were placed on one of three Ca:P regimens: low:low (LL), normal:normal (NN), and low:high (LH) with each regimen divided further into three or four Al levels for 10 weeks. Forty-five % of the black ducks died on nine different diets whereas only 28% of the mallards died on three different diets. Mortality was significantly related to diet in both species. Growth rates for body weight, culmens, wings, and tarsi of both species on control diets exceeded those on many treatment diets but the differences were less apparent for mallards than for black ducks. Differences among treatments were due to both Ca:P and Al levels.

Sparling, D.W.

1990-01-01

97

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

98

Salicylic acid alleviates aluminum toxicity in rice seedlings better than magnesium and calcium by reducing aluminum uptake, suppressing oxidative damage and increasing antioxidative defense.  

PubMed

Aluminum toxicity is a major constraint to crop production in acid soils. The present study was undertaken to examine the comparative ameliorating effects of salicylic acid, Ca and Mg on Al toxicity in rice (Oryza sativa L.) seedlings grown in hydroponics. Al treatment (0.5mM AlCl3) caused decrease in plant vigour, loss of root plasma membrane integrity, increased contents of O 2 (?-) , H2O2, lipid peroxidation, protein carbonyls and decline in the level of protein thiol. Al treatment caused significant changes in activity of antioxidative enzymes in rice seedlings. Exogenously added salicylic acid (60?M), Ca (1mM) and Mg (0.25mM) significantly alleviated Al toxicity effects in the seedlings marked by restoration of growth, suppression of Al uptake, restoration of root plasma membrane integrity and decline in O 2 (?-) , H2O2, lipid peroxidation and protein carbonyl contents. Salicylic acid, Ca and Mg suppressed Al-induced increase in SOD, GPX and APX activities while it elevated Al-induced decline in CAT activity. By histochemical staining of O 2 (?-) using NBT and H2O2 using DAB, it was further confirmed that added salicylic acid, Ca or Mg decreased Al-induced accumulation of O 2 (?-) and H2O2 in the leaf tissues. Results indicate that exogenously added salicylic acid, Ca or Mg alleviates Al toxicity in rice seedlings by suppressing Al uptake, restoring root membrane integrity, reducing ROS level and ROS induced oxidative damage and regulating the level of antioxidative enzyme activities. Further salicylic appears to be superior to Mg and Ca in alleviating Al toxicity effects in rice plants. PMID:23479061

Pandey, Poonam; Srivastava, Rajneesh Kumar; Dubey, R S

2013-03-13

99

Effect of calcium and aluminum concentrations on the survival of brown trout ( Salmo trutta ) at low pH  

Microsoft Academic Search

Experimental evidence suggests that the two most important ions with respect to survival of fish at low pHs are calcium (BROWN 1981, 1982a and b; BROWN and LYNAM 1981) and aluminium (SCHOFIELD and TROJNAR 1980; BAKER and SCHOFIELD 1980, 1982). A minimal concentration of the former ion is necessary for survival, and in general, elevated concentrations of aluminium reduce survival.

D. J. A. Brown

1983-01-01

100

Crystallization of calcium sulfate dihydrate under simulated conditions of phosphoric acid production in the presence of aluminum and magnesium ions  

Microsoft Academic Search

The effect of Al3+ and Mg2+ ions, as additives, on the crystallization of gypsum was studied under simulated conditions of the phosphoric acid production. Calcium hydrogen phosphate and sulfuric acid were mixed with dilute phosphoric acid at 80C, and the turbidity of the reaction mixture was measured at different time periods to calculate the induction time of gypsum crystals formation.

M. M. Rashad; M. H. H. Mahmoud; I. A. Ibrahim; E. A. Abdel-Aal

2004-01-01

101

Barium carbonate intoxication  

Microsoft Academic Search

A 22-year-old man attempted to commit suicide by swallowing an unknown amount of barium carbonate dissolved in hydrochloric acid. Shortly after ingestion, he developed crampy abdominal pain and generalized muscle weakness. About 2 h later, respiratory failure ensued necessitating orotracheal intubation and mechanical ventilation. Concomitantly, life-threatening arrhythmias including ventricular fibrillation occurred, and he had to be resuscitated for 45 min.

Th. F. Schorn; Ch. Olbricht; A. Schler; A. Franz; K. Wittek; H.-J. Balks; E. Hausmann; H.-H. Wellhoener

1991-01-01

102

Barium Vanadate Microspheres  

NASA Astrophysics Data System (ADS)

It has been found that many glass powders can form micro- or nanospheres when heated in a flame or by a laser. Much of the research in this area of microspheres has concentrated on making hollow spheres, called microballoons, of silica and borosilicate glasses. Our aim was to create highly porous barium vanadate microspheres for possible future applications in material storage. The surface area of porous spheres would provide a greater amount of bonding surface area for dopants than hollow spheres. Barium vanadate glass with a molar fraction of 0.4 to 0.6 barium oxide was used because this glass is stable and has a low Tg. Size distributions of the spheres were quantified and the extent of sphere formation and porosity was examined using a scanning electron microscope. The size of spheres formed is affected by powder size, dropping method, and flame position. The porosity of the microspheres is affected by flame temperature, time spent in flame, and the material onto which the spheres fall. The greatest porosity was achieved by first heating the glass powder at a low temperature and then immediately sending it through the flames of two MAPP gas torches at approximately 2100^oC onto a metal sheet.

Yosinski, Shari; Tweeton, Landon; Feller, Steve; Affatigato, Mario

2009-11-01

103

Temperature effects on non-bridging oxygen and aluminum coordination number in calcium aluminosilicate glasses and melts  

Microsoft Academic Search

Configurational changes with temperature are important for the thermodynamic and transport properties of most aluminosilicate melts, but in general are not well understood. Here, we present high-resolution 27Al and 17O NMR data on several calcium aluminosilicate glasses prepared with varying quench rates and thus with fictive temperatures that span ranges up to about 200K. In all compositions the content of

Jonathan F. Stebbins; Emily V. Dubinsky; Koji Kanehashi; Kimberly E. Kelsey

2008-01-01

104

Properties of Semiconductive Barium Titanates  

Microsoft Academic Search

The resistivity of barium titanate which is usually of the order of 1091012 ohm-cm, may be remarkably reduced with suitable control in valency. The valency-controlled barium titanate, whose resistivity is of the order of 10104 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

105

75 FR 33824 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013

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

2010-06-15

106

75 FR 19657 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013

...731-TA-149 (Third Review)] Barium Chloride From China AGENCY: United States International...the antidumping duty order on barium chloride from China...the antidumping duty order on barium chloride from China would be likely to lead...

2010-04-15

107

Barium isotope fractionation in the global barium cycle: Evidence from barium minerals and precipitation experiments  

NASA Astrophysics Data System (ADS)

In this study, we present first results from an ongoing investigation on the stable barium (Ba) isotope fractionation in the natural barium cycle. Stable Ba isotope signatures of international IAEA reference materials (synthetic barium sulfate and barium carbonate), and terrestrial Ba gangue minerals have been analyzed as a first approach to evaluate potential discriminating processes in the global geochemical barium cycle. Measurements were carried out on a multi-collector ICP-MS applying a 130Ba/135Ba double spike. Data are given as per mil deviations from a laboratory Ba nitrate standard solution in the d137/134Ba notation (external 2s stdev < 0.1 per mil). Whereas the various synthetic solid standards and p.a. quality synthetic barium chloride show very similar isotope results close to the nitrate standard solution, the terrestrial barium gangue minerals (four barites, one norsethite [BaMg(CO3)2]) were depleted in the heavy isotope (d137/134Ba values between 0 and -0.2 per mil). A natural barite, from an unknown Chinese locality, gave an isotope value of -0.4 per mil. Also measured high 34S/32S and 18O/16O ratios in this sample indicate that this barite has been formed under influence of microbial sulfate reduction, probably in a marine diagenetic environment. The observed natural discriminations are by far larger than the analytical uncertainty of the isotope measurements, indicating isotope discrimination in the natural barium cycle. Precipitation experiments from aqueous barium chloride solutions at temperatures of 20 and 80C indicate that the light Ba isotope is enriched in pure barium carbonate or barium sulfate compared to the aqueous solution. A maximum isotope fractionation of -0.3 per mil is observed, for both barium carbonate and sulfate, that seems to be influenced by precipitation rate (BaCO3) and/or the aqueous speciation, but less by temperature.

von Allmen, Katja; Bttcher, Michael E.; Samankassou, Elias; Ngler, Thomas F.

2010-05-01

108

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

109

Quench Rate Studies of Aluminum Coordination and Oxygen Speciation in Calcium Aluminosilicate Glasses: Implications for Temperature Effects on the Structure of Aluminosilicate Melts  

NASA Astrophysics Data System (ADS)

The atomic-scale structure of aluminosilicate glasses and melts is subject to temperature-induced rearrangement, which in turn controls variations in measurable thermodynamic properties. In order to investigate the effect of temperature on the structure of calcium aluminosilicate melts, we have used Al-27 MAS NMR, Al-27 3QMAS NMR, and O-17 MAS NMR to study fast- and slow-quenched calcium aluminosilicate glasses. Our previous work using O-17 3QMAS NMR to study lithium and sodium aluminosilicate glasses demonstrates disordering of bridging oxygen species with increasing sample fictive temperature, indicating temperature-induced rearrangement of framework units in the melt. Simple thermodynamic calculations using these results illustrate that while these structural changes may account for a portion of the experimentally-determined heat capacity of the melt, other modifications must occur to produce the observed temperature dependence of this property (Dubinsky and Stebbins 2006). The new data presented here allow us to observe changes in four-and five-coordinated aluminum and bridging and non- bridging oxygen (NBO) populations with fictive temperature in two calcium aluminosilicate glass compositions (CASx.y, where x=mol% Al2O3 and y=mol% SiO2) prepared by slow- and fast-quenching. We find that in CAS25.50 glasses, the percentage of five-coordinated Al per total Al increases from 7.61.9 to 9.42.4 and the percentage of NBO per total oxygen increases from 7.21.8 to 8.92.2 over a 150 to 200 degree fictive temperature interval. In CAS10.60 glasses representing a similar fictive temperature interval, we find that the percentage of five-coordinated Al per total Al increases from 4.01.0 to 4.91.2 and the percentage of non-bridging oxygen (NBO) per total oxygen increases from 22.82.3 to 23.02.3. Uncertainties in fitting procedures producing overlap in quantification of species in fast- and slow-quenched samples do not preclude the conclusion that robust changes in their relative proportions are visible in NMR spectra. Normalizing for sample composition, in both CAS25.50 and CAS10.60 glasses the increase in NBO over the studied fictive temperature interval exceeds the increase in five-coordinated Al, indicating that formation of these species is not necessarily coupled in a simple stoichiometric ratio. These results signify that complex structural changes involving high-coordinated Al and multiple high-coordinated oxygen species must be included in consideration of temperature effects on aluminosilicate melt structure.

Dubinsky, E. V.; Stebbins, J. F.

2006-12-01

110

AN ALUMINUM/CALCIUM-RICH, IRON-POOR, WHITE DWARF STAR: EVIDENCE FOR AN EXTRASOLAR PLANETARY LITHOSPHERE?  

SciTech Connect

The presence of elements heavier than helium in white dwarf atmospheres is often a signpost for the existence of rocky objects that currently or previously orbited these stars. We have measured the abundances of various elements in the hydrogen-atmosphere white dwarfs G149-28 and NLTT 43806. In comparison with other white dwarfs with atmospheres polluted by heavy elements, NLTT 43806 is substantially enriched in aluminum but relatively poor in iron. We compare the relative abundances of Al and eight other heavy elements seen in NLTT 43806 with the elemental composition of bulk Earth, with simulated extrasolar rocky planets, with solar system meteorites, with the atmospheric compositions of other polluted white dwarfs, and with the outer layers of the Moon and Earth. The best agreement is found with a model that involves accretion of a mixture of terrestrial crust and upper mantle material onto NLTT 43806. The implication is that NLTT 43806 is orbited by a differentiated rocky planet, perhaps quite similar to Earth, that has suffered a collision that stripped away some of its outer layers.

Zuckerman, B.; Klein, B.; Jura, M. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Koester, D. [Institut fur Theoretische Physik und Astrophysik, University of Kiel, 24098 Kiel (Germany); Dufour, P. [Departement de Physique, Universite de Montreal, Montreal, QC H3C 3J7 (Canada); Melis, Carl [Center for Astrophysics and Space Sciences, University of California, San Diego, CA 92093-0424 (United States)

2011-10-01

111

An Improved Qualitative Analysis Procedure for Aluminum Subgroup Cations.  

ERIC Educational Resources Information Center

Describes a procedure for the qualitative analysis of aluminum subgroup cations designed to avoid failure to obtain lead or barium chromate precipitates or failure to report aluminum hydroxide when present (due to staining). Provides a flow chart and step-by-step explanation for the new procedure, indicating significantly improved student results.

Kistner, C. R.; Robinson, Patricia J.

1983-01-01

112

Lack of effect of drinking water barium on cardiovascular risk factors  

SciTech Connect

Higher cardiovascular mortality has been associated in a single epidemiological study with higher levels of barium in drinking water. The purpose of this study was to determine whether drinking water barium at levels found in some U.S. communities-alters the known risk factors for cardiovascular disease. Eleven healthy men completed a 10-week dose-response protocol in which diet was controlled. Other aspects of the subjects' lifestyles known to affect cardiac risk factors were controlled, and the barium content (as barium chloride) of the drinking water was varied from 0, to 5 ppm, to 10 ppm. Multiple blood and urine samples, morning and evening blood pressure measurements, and 48-hr electrocardiographic monitoring were performed at each dose of barium. There were no changes in morning or evening systolic or diastolic blood pressures, plasma cholesterol or lipoprotein or apolipoprotein levels, serum potassium or glucose levels, or urine catecholamine levels. There were no arrythmias related to barium exposure detected on continuous electrocardiographic monitoring. A trend was seen toward increased total serum calcium levels with exposure to barium, which was of borderline statistical significance and of doubtful clinical significance. In summary, drinking water barium at levels of 5 and 10 ppm did not appear to affect any of the known modifiable cardiovascular risk factors.

Wones, R.G.; Stadler, B.L.; Frohman, L.A. (Univ. of Cincinnati College of Medicine, OH (USA))

1990-04-01

113

Factors controlling soil water and stream water aluminum concentrations after a clearcut in a forested watershed with calcium-poor soils  

USGS Publications Warehouse

The 24 ha Dry Creek watershed in the Catskill Mountains of southeastern New York State USA was clearcut during the winter of 1996-1997. The interactions among acidity, nitrate (NO3- ), aluminum (Al), and calcium (Ca2+) in streamwater, soil water, and groundwater were evaluated to determine how they affected the speciation, solubility, and concentrations of Al after the harvest. Watershed soils were characterized by low base saturation, high exchangeable Al concentrations, and low exchangeable base cation concentrations prior to the harvest. Mean streamwater NO3- concentration was about 20 ??mol l-1 for the 3 years before the harvest, increased sharply after the harvest, and peaked at 1,309 ??mol l -1 about 5 months after the harvest. Nitrate and inorganic monomeric aluminum (Alim) export increased by 4-fold during the first year after the harvest. Alim mobilization is of concern because it is toxic to some fish species and can inhibit the uptake of Ca2+ by tree roots. Organic complexation appeared to control Al solubility in the O horizon while ion exchange and possibly equilibrium with imogolite appeared to control Al solubility in the B horizon. Alim and NO3- concentrations were strongly correlated in B-horizon soil water after the clearcut (r2 = 0.96), especially at NO3- concentrations greater than 100 ??mol l-1. Groundwater entering the stream from perennial springs contained high concentrations of base cations and low concentrations of NO3- which mixed with acidic, high Alim soil water and decreased the concentration of Alim in streamwater after the harvest. Five years after the harvest soil water NO 3- concentrations had dropped below preharvest levels as the demand for nitrogen by regenerating vegetation increased, but groundwater NO3- concentrations remained elevated because groundwater has a longer residence time. As a result streamwater NO3- concentrations had not fallen below preharvest levels, even during the growing season, 5 years after the harvest because of the contribution of groundwater to the stream. Streamwater NO3- and Alim concentrations increased more than reported in previous forest harvesting studies and the recovery was slower likely because the watershed has experienced several decades of acid deposition that has depleted initially base-poor soils of exchangeable base cations and caused long-term acidification of the soil. ?? 2007 Springer Science+Business Media B.V.

McHale, M. R.; Burns, D. A.; Lawrence, G. B.; Murdoch, P. S.

2007-01-01

114

A Critical Examination of the X-wind Model for Chondrule and Calcium-rich, Aluminum-rich Inclusion Formation and Radionuclide Production  

NASA Astrophysics Data System (ADS)

Meteoritic data, especially regarding chondrules and calcium-rich, aluminum-rich inclusions (CAIs), and isotopic evidence for short-lived radionuclides (SLRs) in the solar nebula, potentially can constrain how planetary systems form. Interpretation of these data demands an astrophysical model, and the "X-wind" model of Shu et al. and collaborators has been advanced to explain the origin of chondrules, CAIs, and SLRs. It posits that chondrules and CAIs were thermally processed <0.1 AU from the protostar, then flung by a magnetocentrifugal outflow to the 2-3 AU region to be incorporated into chondrites. Here we critically examine key assumptions and predictions of the X-wind model. We find a number of internal inconsistencies: theory and observation show no solid material exists at 0.1 AU; particles at 0.1 AU cannot escape being accreted into the star; particles at 0.1 AU will collide at speeds high enough to destroy them; thermal sputtering will prevent growth of particles; and launching of particles in magnetocentrifugal outflows is not modeled, and may not be possible. We also identify a number of incorrect predictions of the X-wind model: the oxygen fugacity where CAIs form is orders of magnitude too oxidizing, chondrule cooling rates are orders of magnitude lower than those experienced by barred olivine chondrules, chondrule-matrix complementarity is not predicted, and the SLRs are not produced in their observed proportions. We conclude that the X-wind model is not relevant to chondrule and CAI formation and SLR production. We discuss more plausible models for chondrule and CAI formation and SLR production.

Desch, S. J.; Morris, M. A.; Connolly, H. C., Jr.; Boss, Alan P.

2010-12-01

115

A CRITICAL EXAMINATION OF THE X-WIND MODEL FOR CHONDRULE AND CALCIUM-RICH, ALUMINUM-RICH INCLUSION FORMATION AND RADIONUCLIDE PRODUCTION  

SciTech Connect

Meteoritic data, especially regarding chondrules and calcium-rich, aluminum-rich inclusions (CAIs), and isotopic evidence for short-lived radionuclides (SLRs) in the solar nebula, potentially can constrain how planetary systems form. Interpretation of these data demands an astrophysical model, and the 'X-wind' model of Shu et al. and collaborators has been advanced to explain the origin of chondrules, CAIs, and SLRs. It posits that chondrules and CAIs were thermally processed <0.1 AU from the protostar, then flung by a magnetocentrifugal outflow to the 2-3 AU region to be incorporated into chondrites. Here we critically examine key assumptions and predictions of the X-wind model. We find a number of internal inconsistencies: theory and observation show no solid material exists at 0.1 AU; particles at 0.1 AU cannot escape being accreted into the star; particles at 0.1 AU will collide at speeds high enough to destroy them; thermal sputtering will prevent growth of particles; and launching of particles in magnetocentrifugal outflows is not modeled, and may not be possible. We also identify a number of incorrect predictions of the X-wind model: the oxygen fugacity where CAIs form is orders of magnitude too oxidizing, chondrule cooling rates are orders of magnitude lower than those experienced by barred olivine chondrules, chondrule-matrix complementarity is not predicted, and the SLRs are not produced in their observed proportions. We conclude that the X-wind model is not relevant to chondrule and CAI formation and SLR production. We discuss more plausible models for chondrule and CAI formation and SLR production.

Desch, S. J.; Morris, M. A. [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287-1404 (United States); Connolly, H. C. [Kingsborough Community College and the Graduate Center of the City University of New York, 2001 Oriental Boulevard, Brooklyn, NY 11235-2398 (United States); Boss, Alan P., E-mail: steve.desch@asu.ed [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015-1305 (United States)

2010-12-10

116

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

117

Suicidal poisoning with barium chloride.  

PubMed

A 49-year-old male pharmacist suffering from depression phoned the emergency services telling of how he had ingested barium chloride. He was found semicomatose in bed and resuscitation attempts were to no avail and he died at the scene. A white plastic container labelled "Barium chloride... Poison", and a book with a writing on a blank page... "give sulphate... SO(4)" were found. At autopsy, 1l of whitish-yellow fluid was found in the stomach. Autopsy barium levels were: blood 9.9mg/l; bile 8.8mg/l; urine 6.3mg/l; gastric 10.0g/l. Cause of death was given as cardiorespiratory arrest due to barium chloride poisoning. The issue of barium toxicity in a variety of itatrogenic and non itatrogenic situation is discussed together with the two only other cases of suicidal barium ingestion, and the feasibility of early intervention at the scene by an emergency team. PMID:11376995

Jourdan, S; Bertoni, M; Sergio, P; Michele, P; Rossi, M

2001-06-15

118

Silico-ferrite of Calcium and Aluminum (SFCA) Iron Ore Sinter Bonding Phases: New Insights into Their Formation During Heating and Cooling  

NASA Astrophysics Data System (ADS)

The formation of silico-ferrite of calcium and aluminum (SFCA) and SFCA-I iron ore sinter phases during heating and cooling of synthetic iron ore sinter mixtures in the range 298 K to 1623 K (25 C to 1350 C) and at oxygen partial pressure of 5 10-3 atm has been characterized using in situ synchrotron X-ray diffraction. SFCA and SFCA-I are the key bonding phases in iron ore sinter, and an improved understanding of their formation mechanisms may lead to improved efficiency of industrial sintering processes. During heating, SFCA-I formation at 1327 K to 1392 K (1054 C to 1119 C) (depending on composition) was associated with the reaction of Fe2O3, 2CaOFe2O3, and SiO2. SFCA formation (1380 K to 1437 K [1107 C to 1164 C]) was associated with the reaction of CaOFe2O3, SiO2, and a phase with average composition 49.60, 9.09, 0.14, 7.93, and 32.15 wt pct Fe, Ca, Si, Al, and O, respectively. Increasing Al2O3 concentration in the starting sinter mixture increased the temperature range over which SFCA-I was stable before the formation of SFCA, and it stabilized SFCA to a higher temperature before it melted to form a Fe3O4 + melt phase assemblage (1486 K to 1581 K [1213 C to 1308 C]). During cooling, the first phase to crystallize from the melt (1452 K to 1561 K [1179 C to 1288 C]) was an Fe-rich phase, similar in composition to SFCA-I, and it had an average composition 58.88, 6.89, 0.82, 3.00, and 31.68 wt pct Fe, Ca, Si, Al, and O, respectively. At lower temperatures (1418 K to 1543 K [1145 C to 1270 C]), this phase reacted with melt to form SFCA. Increasing Al2O3 increased the temperature at which crystallization of the Fe-rich phase occurred, increased the temperature at which crystallization of SFCA occurred, and suppressed the formation of Fe2O3 (1358 K to 1418 K [1085 C to 1145 C]) to lower temperatures.

Webster, Nathan A. S.; Pownceby, Mark I.; Madsen, Ian C.; Kimpton, Justin A.

2012-12-01

119

Fabrication of aluminum nitride crucibles for molten salt and plutonium compatibility studies  

Microsoft Academic Search

The overall objective of this research was to fabricate a calcium oxide sinter-aided aluminum nitride crucible and determine the compatibility of this crucible with molten chloride salts and plutonium metal in the DOR process. Calcium oxide sinter-aided aluminum nitride was preferred over yttrium oxide sinter-aided aluminum nitride because of (1) the presence of calcium chloride, calcium oxide, and calcium metal

1991-01-01

120

Deflocculants for Tape Casting Barium Titanate.  

National Technical Information Service (NTIS)

The dispersion properties of disperants with barium titanate were studied. Rheological, settling, volume and adsorption isotherms were obtained for barium titanate in MEK-ethanol using a phosphate ester dispersant. Effects of storage conditions, dispersan...

W. R. Cannon

1983-01-01

121

Barium hexaferrite (M-phase) exhibiting superstructure  

Microsoft Academic Search

Barium hexaferrite (M-phase) prepared by the flux method is found to exhibit a ..sqrt..3a x ..sqrt..3a superstructure similar to barium hexaaluminate. Morgan and Shaw as well as Iyi et al have recently reported the formation of a barium-rich phase of barium hexaaluminate possessing a ..sqrt..3a x ..sqrt..3a superstructure of the magnetoplumbite structure. In view of the similarities between the layer

L. Ganapathi; J. Gopalakrishnan; C. N. R. Rao

1984-01-01

122

Barium Stars and Thermohaline Mixing  

SciTech Connect

Barium stars are formed in binary systems through mass transfer from the carbon and s-element rich primary in the AGB phase, to the secondary star which is in a less evolved evolutionary stage. The mixing of the accreted material from the AGB donor with the envelope of the secondary results in a dilution of the s-element abundances. Dilution in red giants is explained by the occurence of the first dredge up, while in case of dwarfs thermohaline mixing would determine it. A comparison between the theoretical predictions of the AGB stellar models and the spectroscopical observations of a large sample of barium stars has been made. Dilution due to thermohaline mixing was taken into account when searching for best fits of the observational data. The importance of thermohaline mixing in barium dwarfs is discussed.

Husti, Laura [Dipartimento di Fisica Generale, Universita di Torino, Via Pietro Giuria 1, 10125 Turin (Italy)

2008-01-24

123

Barium-induced skeletal muscle paralysis in the rat, and its relationship to human familial periodic paralysis  

PubMed Central

An in vivo study of skeletal muscle paralysis induced by intravenous barium chloride has been made in curarized and non-curarized rats. The influence of potassium and calcium chlorides, propranolol, ouabain, and prior adrenalectomy on the paralysis has also been studied. Paralysis is found to be due to a direct effect on skeletal muscle, and to correlate well with the development of hypokalaemia. Possible mechanisms of action of barium are discussed, and attention is drawn to the similarity between barium poisoning and hypokalaemic familial periodic paralysis.

Schott, G. D.; McArdle, B.

1974-01-01

124

The Calcium Economy  

Microsoft Academic Search

Calcium is the fifth most abundant element in the biosphere (after iron, aluminum, silicon, and oxygen). It is the stuff of\\u000a limestone and marble, coral and pearls, seashells and eggshells, antlers and bones. Because calcium salts exhibit intermediate\\u000a solubility, calcium is found both in solid form (rocks) and in solution. It was probably present in abundance in the watery\\u000a environment

Robert P. Heaney

125

Aluminum and Acid Effects on Calcium and Phosphorus Metabolism in Young Growing Chickens ( Gallus gallus domesticus ) and Mallard Ducks ( Anas platyrhynchos )  

Microsoft Academic Search

. Acidification is associated with increased mortality, reduced growth, and bone abnormalities in birds. Associated with acid\\u000a deposition is an increase in aluminum availability due to solubilization from soil and other sources. (Conversely, experimental\\u000a diets containing aluminum sulfate have much reduced pHs.) The present studies compare the effects of two levels of dietary\\u000a acid (sulfuric acid) (0.122 and 0.56 mol

M. C. Capdevielle; L. E. Hart; J. Goff; C. G. Scanes

1998-01-01

126

Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum  

SciTech Connect

Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as bath in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

2007-08-16

127

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

128

The Vapor Pressure of Barium.  

National Technical Information Service (NTIS)

The vapor pressure and the heat of vaporization of barium were measured using the Knudsen target technique. A recording microbalance was used to measure both the effusion rate and the recoil force exerted by the beam onto the target. The measured vapor pr...

P. D. Zavitsanos

1968-01-01

129

Aluminum Hydroxide  

MedlinePLUS

Aluminum hydroxide is used for the relief of heartburn, sour stomach, and peptic ulcer pain and to ... Aluminum hydroxide comes as a capsule, a tablet, and an oral liquid and suspension. The dose and ...

130

Quench Rate Studies of Aluminum Coordination and Oxygen Speciation in Calcium Aluminosilicate Glasses: Implications for Temperature Effects on the Structure of Aluminosilicate Melts  

Microsoft Academic Search

The atomic-scale structure of aluminosilicate glasses and melts is subject to temperature-induced rearrangement, which in turn controls variations in measurable thermodynamic properties. In order to investigate the effect of temperature on the structure of calcium aluminosilicate melts, we have used Al-27 MAS NMR, Al-27 3QMAS NMR, and O-17 MAS NMR to study fast- and slow-quenched calcium aluminosilicate glasses. Our previous

E. V. Dubinsky; J. F. Stebbins

2006-01-01

131

Formation of ettringite, Ca6Al2(SO4)3(OH)12.26H2O, AFt, and monosulfate, Ca4Al2O6(SO4).14H2O, AFm-14, in hydrothermal hydration of Portland cement and of calcium aluminum oxide-calcium sulfate dihydrate mixtures studied by in situ synchrotron X-ray powder diffraction  

NASA Astrophysics Data System (ADS)

In the hydration of calcium aluminum oxide-gypsum mixtures, i.e., Ca3Al2O6, Ca12Al14O33 and CaSO4.2H2O, the reaction products can be ettringite, Ca6Al2(SO4)3(OH)12.26H2O, monosulfate, Ca4Al2O6(SO4).14H2O, or the calcium aluminum oxide hydrate, Ca4Al2O7.19H2O. Ettringite is formed if sufficient CaSO4.2H2O is present in the mixture. Ettringite is converted to monosulfate when all CaSO4.2H2O is consumed in the synthesis of ettringite. The reactions were investigated in the temperature range 25-170C using in situ synchrotron X-ray powder diffraction. This technique allows the study of very fast chemical reactions that are observed here under hydrothermal conditions. A new experimental approach was developed to perform in situ mixing of the reactants during X-ray data collection.

Christensen, Axel Nrlund; Jensen, Torben R.; Hanson, Jonathan C.

2004-06-01

132

Bacteremia during barium enema study.  

PubMed

The occurrence of bacteremia was studied in patients undergoing barium enema. Blood cultures were done on 34 patients before, during, and after the procedure using two schedules. Cultures were obtained once during the procedure in the first schedule and four times in the second. None of the cultures were positive by the first schedule, while 23% of patients studied by the second schedule had one or more positive cultures. Organisms isolated were anaerobes. The bacteremia was transient and self-limited, without serious clinical sequelae. The incidence of bacteremia during barium enema examination was statistically indistinguishable from bacteremia previously reported during colonscopy. It is concluded that antibiotic prophylaxis is not indicated in most patients undergoing colonic diagnostic procedures. Prophylaxis in selected high-risk patients requires further study. PMID:416682

Butt, J; Hentges, D; Pelican, G; Henstorf, H; Haag, T; Rolfe, R; Hutcheson, D

1978-04-01

133

Yttrium and barium in open clusters  

NASA Astrophysics Data System (ADS)

Based on the VLT high-resolution spectra for stars of five open clusters: Ruprecht 4, Ruprecht 7, Berkeley 25, Berkeley 73, and Berkeley 75 (G. Carraro et al., 2007) we determined the yttrium and barium abundances using the synthetic-spectrum method. Barium abundance was calculated under a non-LTE approximation. We analyzed the correlation between yttrium and barium abundances and the ages of open clusters and stars of the Galactic thin disk.

Mishenina, T. V.; Korotin, S. A.; Yegorova, I. A.; Kovtukh, V. V.; Carraro, G.

2013-06-01

134

75 FR 20625 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013

...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

High-Temperature Strength of High-Purity Aluminum Alloyed with Various Elements  

Microsoft Academic Search

A derivatographic method is used to study the high-temperature strength of aluminum with a purity of 99.9999% and its alloys with magnesium, scandium, gadolinium, holmium, barium, and strontium. The degree of oxidation of high-purity aluminum and its alloys is determined depending on the temperature and the hold time. It is shown that the high-temperature strength of aluminum depends on its

A. V. Vakhobov; Yu. V. Shchevelev

2003-01-01

136

Novel Sulfated Glucomannan-Barium-Alginate Microcapsules in Islet Transplantation: Significantly Decreased the Secretion of Monocyte Chemotactic Protein 1 and Improved the Activity of Islet in Rats  

Microsoft Academic Search

The sulfated glucomannan can be used to filter the heparin-binding properties of cytokines. In this study, novel sulfated glucomannan-barium-alginate (SGA) microcapsules were prepared to encapsulate islets with barium-alginate (ABa) and calcium alginate-poly-l-lysine (APA) microcapsules as controls. SD rat islets were purified as donor cells to Lewis rats that had been treated with streptozotocin. Intraperitoneal transplantation was performed with about 3000

X. Chen; L. Zhang; Z. Qi; B. Guo; L. Zhong; B. Shen; Z. Yan; J. Zhang

2009-01-01

137

Heavy ion Rutherford backscattering spectrometry (HIRBS) study of barium diffusion in borosilicate glass  

NASA Astrophysics Data System (ADS)

Diffusion of barium in borosilicate glasses containing sodium and calcium has been studied using heavy ion Rutherford backscattering spectrometry (HIRBS) using 30 MeV 19F beam. A thin layer (25 ?g/cm2) of BaCl2 was vacuum evaporated on the polished surface of the glass samples which were then annealed at different temperatures (573 723 K) and subsequently subjected to HIRBS measurements. It was observed that introduction of 10 mole% of calcium in place of sodium results in increase in the activation energy of diffusion of barium by about 30%. This indicates that alkaline earth ions retard the diffusion process in borosilicate glass. The results corroborate the data obtained on diffusion of sodium by radiotracer method. The results have been explained in terms of the increasing rigidity of the glass network with introduction of alkaline earth ions.

Kumar, Sumit; Mishra, R. K.; Tomar, B. S.; Tyagi, A. K.; Kaushik, C. P.; Raj, Kanwar; Manchanda, V. K.

2008-02-01

138

Aluminum Boats  

NSDL National Science Digital Library

Test the buoyancy of an aluminum foil boat and an aluminum foil ball. Why does the same material in different shapes sink or float? This activity explores the fact that the amount of water pushed aside by an object equals the force of water pushing upward on the object.

Center, Reuben H.

1999-01-01

139

New barium ferrite particles: Spherical shape  

NASA Astrophysics Data System (ADS)

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

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

1999-04-01

140

Quantitative Analysis of the TWT Cathode Impregnants Using Flame Emission Spectroscopy.  

National Technical Information Service (NTIS)

Flame emission spectroscopy (FES) is demonstrated for the determination of barium, calcium, and aluminum concentrations in barium calcium aluminate dispenser cathode impregnants. The procedure consists of dissolving the impregnant in 0.5M to 2M hydrochlor...

R. A. Lipeles

1987-01-01

141

Calcium alloy as active material in secondary electrochemical cell  

DOEpatents

Calcium alloys such as calcium-aluminum and calcium-silicon, are employed as active material within a rechargeable negative electrode of an electrochemical cell. Such cells can use a molten salt electrolyte including calcium ions and a positive electrode having sulfur, sulfides, or oxides as active material. The calcium alloy is selected to prevent formation of molten calcium alloys resulting from reaction with the selected molten electrolytic salt at the cell operating temperatures.

Roche, Michael F. (Lombard, IL); Preto, Sandra K. (Stickney, IL); Martin, Allan E. (Woodridge, IL)

1976-01-01

142

Removal of Barium and Radium from Groundwater.  

National Technical Information Service (NTIS)

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 fr...

V. L. Snoeyink C. C. Chambers C. K. Schmidt R. F. Manner A. G. Myers

1987-01-01

143

Deflocculants for Tape Casting Barium Titanate Dielectrics.  

National Technical Information Service (NTIS)

The tape casting slip composition barium titanate powder, MEK-Ethanol solvent, phosphate ester dispersant, acrylic binder, PEG and butyl-benzyl-phthalate plasticizers and cyclohexanone was studied. The nature of the dispersion mechanism for the phosphate ...

W. R. Cannon

1985-01-01

144

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 -50C to +135C 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

145

Small barium rail gun for plasma injection.  

PubMed

A small rail gun with a barium electrode can be operated at higher than one shot per second to produce more than 2x10(16) barium ions with energy 10-20 eV. The operation of the gun takes advantage of the external magnetic field for cross-field plasma injection into a trap. Up to 7 kG of the magnetic field examined, the gun performance improves with the increased magnetic field strength. PMID:18647050

Kiwamoto, Y

1980-03-01

146

Aluminum Analysis.  

ERIC Educational Resources Information Center

Presents three problems based on the price of aluminum designed to encourage students to be cooperative and to use an investigative approach to learning. Students collect and synthesize information, analyze results, and draw conclusions. (AIM)

Sumrall, William J.

1998-01-01

147

The rise and phalli of barium stars  

NASA Astrophysics Data System (ADS)

Barium stars are thought to be formed by accretion of material from the wind of an s-process-rich asymptotic giant branch star onto a main sequence star in a binary system. The accretor then evolves up the giant branch and, as it cools, absorption lines of barium are prominent in its spectrum. This is the barium star we see today. Barium stars are excellent probes of binary-star physics because orbital periods and eccentricities are known for nearly all of them, i.e. the sample set is complete. Binary-star theory predicts that barium stars with periods shorter than a few thousand days should circularise by tidal interaction, but the observed stars are often highly eccentric. We investigate a potential source of their eccentricity: white dwarf kicks. We can reproduce the observed period-eccentricity distribution if we introduce a moderate kick speed of a few km/s together with efficient angular momentum loss in stellar winds and efficient common-envelope ejection. Many open questions remain which are key to the wind-accretion mechanism by which barium stars and other chemically-peculiar binaries such as CH and carbon-enhanced metal-poor (CEMP) stars form.

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

148

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

149

Effects of Different Fabrication Techniques on the Yttrium-Barium-Copper Oxide High Temperature Superconductor.  

National Technical Information Service (NTIS)

This study examines how several different parameters were changed in the yttrium-barium-copper oxide superconductor when the fabrication techniques were altered by using different barium precursors, including barium peroxide and barium carbonate; sinterin...

P. A. Rhea

1988-01-01

150

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

PubMed

Sulphate removal from sodium sulphate-rich brine using barium hydroxide and recovery of the barium salts has been investigated. The sodium sulphate-rich brine treated with different dosages of barium hydroxide to precipitate barium sulphate showed sulphate removal from 13.5 g/L to less than 400 mg/L over 60 min using a barium to sulphate molar ratio of 1.1. The thermal conversion of precipitated barium sulphate to barium sulphide achieved a conversion yield of 85% using coal as both a reducing agent and an energy source. The recovery of a pure mixture of barium salts from barium sulphide, which involved dissolution of barium sulphide and reaction with ammonium hydroxide resulted in recovery of a mixture of barium carbonate (62%) and barium hydroxide (38%), which is a critical input raw material for barium salts based acid mine drainage (AMD) desalination technologies. Under alkaline conditions of this barium salt mixture recovery process, ammonia gas is given off, while hydrogen sulfide is retained in solution as bisulfide species, and this provides basis for ammonium hydroxide separation and recovery for reuse, with hydrogen sulfide also recoverable for further industrial applications such as sulfur production by subsequent stripping. PMID:23485244

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

2013-01-01

151

A comparison of the calcium-free phosphate binder sevelamer hydrochloride with calcium acetate in the treatment of hyperphosphatemia in hemodialysis patients  

Microsoft Academic Search

Current phosphate binders used in hemodialysis patients include calcium-based binders that result in frequent hypercalcemia and aluminum-based binders that result in total body aluminum accumulation over time. This investigation describes the use of a calcium- and aluminum-free phosphate-binding polymer in hemodialysis patients and compares it with a standard calcium-based phosphate binder. An open-label, randomized, crossover study was performed to evaluate

Anthony J. Bleyer; Steven K. Burke; Maureen Dillon; Bruce Garrett; K. Shashi Kant; David Lynch; S. Noor Rahman; Patricia Schoenfeld; Isaac Teitelbaum; Steven Zeig; Eduardo Slatopolsky

1999-01-01

152

Recovery of aluminum and other metal values from fly ash  

DOEpatents

The invention relates to a method for improving the acid leachability of aluminum and other metal values found in fly ash which comprises sintering the fly ash, prior to acid leaching, with a calcium sulfate-containing composition at a temperature at which the calcium sulfate is retained in said composition during sintering and for a time sufficient to quantitatively convert the aluminum in said fly ash into an acid-leachable form.

McDowell, W.J.; Seeley, F.G.

1979-11-01

153

Recovery of aluminum and other metal values from fly ash  

DOEpatents

The invention described herein relates to a method for improving the acid leachability of aluminum and other metal values found in fly ash which comprises sintering the fly ash, prior to acid leaching, with a calcium sulfate-containing composition at a temperature at which the calcium sulfate is retained in said composition during sintering and for a time sufficient to quantitatively convert the aluminum in said fly ash into an acid-leachable form.

McDowell, William J. (Oak Ridge, TN); Seeley, Forest G. (Oak Ridge, TN)

1981-01-01

154

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

PubMed

Batch regeneration of barium carbonate (BaCO(3)) from barium sulphide (BaS) slurries by passing CO(2) gas into a pilot-scale bubbling column reactor under ambient conditions was used to assess the technical feasibility of BaCO(3) recovery in the Alkali Barium Calcium (ABC) desalination process and its use for sulphate removal from high sulphate Acid Mine Drainage (AMD). The effect of key process parameters, such as BaS slurry concentration and CO(2) flow rate on the carbonation, as well as the extent of sulphate removal from AMD using the recovered BaCO(3) were investigated. It was observed that the carbonation reaction rate for BaCO(3) regeneration in a bubbling column reactor significantly increased with increase in carbon dioxide (CO(2)) flow rate whereas the BaS slurry content within the range 5-10% slurry content did not significantly affect the carbonation rate. The CO(2) flow rate also had an impact on the BaCO(3) morphology. The BaCO(3) recovered from the pilot-scale bubbling column reactor demonstrated effective sulphate removal ability during AMD treatment compared with commercial BaCO(3). PMID:22233912

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

2012-01-01

155

Intramural extravasation of barium simulating carcinoma of the rectum  

Microsoft Academic Search

This report describes two patients found to have barium granuloma of the rectum. The lesions appeared as indurated, ulcerated\\u000a rectal masses that resembled carcinoma on endoscopic examination. Deep mucosal biopsy results demonstrated no malignancy and\\u000a barium sulfate crystals in tissue macrophages. Radiographs showed persistent soft-tissue barium in the rectum. Past reports\\u000a of barium granuloma have described ulcerated or polypoid masses

John E. Phelps; Robert A. Sanowski; Richard A. Kozarek

1981-01-01

156

Improved spectrophotometric analysis of barium styphnate  

SciTech Connect

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

Brown, N E; Blasi, J A

1983-01-01

157

Calcium Calculator  

MedlinePLUS

... Fun Stuff Fun Stuff Best for Bones Food Calcium Calculator How much calcium do you get every day? Remember, you need ... Deal with Vitamin D List of Foods with Calcium & Vitamin D Calcium Calculator Fooling Around with Food ...

158

Particulate barium fluxes and their relationships to biological productivity  

Microsoft Academic Search

To understand better the processes that control the transport of particulate barium through the water column and its preservation in marine sediments, we measured particulate barium fluxes along an equatorial transect at 140W using moored sediment traps. The fluxes of barium correlate strongly with the fluxes of organic carbon; however, this relationship is non-linearhigher carbon fluxes have proportionately less associated

Jack Dymond; Robert Collier

1996-01-01

159

Aluminum Pannier  

USGS Multimedia Gallery

This aluminum pannier was made for the storage of meat, vegetables and other food products. The pannier could be buried in the ground or placed in water in order to keep the contents cool. It was designed by Dr. J. D. Love and made for him in 1945. For transportation, this pannier, along with two re...

2009-07-22

160

Barium titanate fabricated from fur-fibres  

Microsoft Academic Search

Long-fibrous barium titanate (BaTiO3) particles were prepared by a hydrothermal reaction of potassium titanate hydrate (2K2O11TiO23H2O) and barium hydroxide (Ba(OH)2). Effects of preparation conditions on crystal structure and powder morphology were examined. Fur-fibres of K2O4TiO2, 110 mm long and 1100 ?m in diameter, were obtained by heating a mixture of K2CO3 and TiO2 powders at 1000 C for 100 h.

Yoshinobu Ohara; Masaru Miyayama; Tadao Shimizu; Hiroaki Yanagida

1996-01-01

161

Aluminum chlorohydrate III: Conversion to aluminum hydroxide.  

PubMed

Bayerite, an aluminum hydroxide polymorph, readily forms when the hydroxyl to aluminum ratio of aluminum chlorohydrate is raised to 3 by titration with sodium hydroxide. Dilution of aluminum chlorhydrate solutions with water leads to the formation of gibbsite, another aluminum hydroxide polymorph. The mechanism of conversion in each instance is related to the structure of the Al13O4(OH)24(H2O)7+(12) complex. PMID:7264935

Teagarden, D L; White, J L; Hem, S L

1981-07-01

162

Calcium Oscillations  

PubMed Central

Calcium signaling results from a complex interplay between activation and inactivation of intracellular and extracellular calcium permeable channels. This complexity is obvious from the pattern of calcium signals observed with modest, physiological concentrations of calcium-mobilizing agonists, which typically present as sequential regenerative discharges of stored calcium, a process referred to as calcium oscillations. In this review, we discuss recent advances in understanding the underlying mechanism of calcium oscillations through the power of mathematical modeling. We also summarize recent findings on the role of calcium entry through store-operated channels in sustaining calcium oscillations and in the mechanism by which calcium oscillations couple to downstream effectors.

Dupont, Genevieve; Combettes, Laurent; Bird, Gary S.; Putney, James W.

2011-01-01

163

Kinetic analysis of barium currents in chick cochlear hair cells.  

PubMed Central

Inward barium current (IBa) through voltage-gated calcium channels was recorded from chick cochlear hair cells using the whole-cell clamp technique. IBa was sensitive to dihydropyridines and insensitive to the peptide toxins omega-agatoxin IVa, omega-conotoxin GVIa, and omega-conotoxin MVIIC. Changing the holding potential over a -40 to -80 mV range had no effect on the time course or magnitude of IBa nor did it reveal any inactivating inward currents. The activation of IBa was modeled with Hodgkin-Huxley m2 kinetics. The time constant of activation, tau m, was 550 microseconds at -30 mV and gradually decreased to 100 microseconds at +50 mV. A Boltzmann fit to the activation curve, m infinity, yielded a half activation voltage of -15 mV and a steepness factor of 7.8 mV. Opening and closing rate constants, alpha m and beta m, were calculated from tau m and m infinity, then fit with modified exponential functions. The H-H model derived by evaluating the exponential functions for alpha m and beta m not only provided an excellent fit to the time course of IBa activation, but was predictive of the time course and magnitude of the IBa tail current. No differences in kinetics or voltage dependence of activation of IBa were found between tall and short hair cells. We conclude that both tall and short hair cells of the chick cochlea predominantly, if not exclusively, express noninactivating L-type calcium channels. These channels are therefore responsible for processes requiring voltage-dependent calcium entry through the basolateral cell membrane, such as transmitter release and activation of Ca(2+)-dependent K+ channels.

Zidanic, M; Fuchs, P A

1995-01-01

164

STABILIZED BARIUM TITANATE CERAMICS FOR CAPACITOR DIELECTRICS  

Microsoft Academic Search

The effects of additions of LaO and LaO--; 3TiO 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

165

Prospects for Barium Tagging in Gaseous Xenon  

Microsoft Academic Search

Tagging events with the coincident detection of a barium ion would greatly reduce the background for a neutrino-less double beta decay search in xenon. This paper describes progress towards realizing this goal. It outlines a source that can produce large quantities of Ba++ in gas, shows that this can be extracted to vacuum, and demonstrates a mechanism by which the

D. Sinclair; E. Rollin; J. Smith; A. Mommers; N. Ackerman; B. Aharmim; M. Auger; P. S. Barbeau; C. Benitez-Medina; M. Breidenbach; A. Burenkov; S. Cook; A. Coppens; T. Daniels; R. DeVoe; A. Dobi; M. J. Dolinski; K. Donato; Fairbank W. Jr; J. Farine; G. Giroux

2012-01-01

166

Low Temperature Thermal Expansion of Barium Ferrite.  

National Technical Information Service (NTIS)

The linear thermal expansion of polycrystalline barium ferrite, BaFe12O19, was measured from 76 to 293 K both parallel and perpendicular to the magnetization direction. An anisotropy of about 15-20% was observed. The results match well the available data ...

A. F. Clark W. M. Haynes V. A. Deason R. J. Trapani

1975-01-01

167

Deflocculants for Tape Casting Barium Titanate Dielectrics.  

National Technical Information Service (NTIS)

The first part of this study has been directed towards understanding the mechanisms of dispersion for barium titanate in a methylathyl ketone-ethanol system using a commercial phosphate ester dispersant. The dispersant was found to be very effective in lo...

W. R. Cannon

1986-01-01

168

Deflocculants for Tape Casting Barium Titanate Dielectrics.  

National Technical Information Service (NTIS)

A typical nonaqueous tape casting system based on a commercial acrylic binder was studied to understand the system in more depth. The following conclusions were drawn: The best surfactants for dispersing barium titanate in the MEK-ethanol solvent system a...

W. R. Cannon

1988-01-01

169

Recycling of automotive aluminum  

Microsoft Academic Search

With the global warming of concern, the secondary aluminum stream is becoming an even more important component of aluminum production and is attractive because of its economic and environmental benefits. In this work, recycling of automotive aluminum is reviewed to highlight environmental benefits of aluminum recycling, use of aluminum alloys in automotive applications, automotive recycling process, and new technologies in

Jirang CUI; Hans J. ROVEN

2010-01-01

170

ARE THERE ANY STARS LACKING NEUTRON-CAPTURE ELEMENTS? EVIDENCE FROM STRONTIUM AND BARIUM  

SciTech Connect

The cosmic dispersion in the abundances of the heavy elements strontium and barium in halo stars is well known. Strontium and barium are detected in most cool, metal-poor giants, but are these elements always detectable? To identify stars that could be considered probable candidates for lacking these elements, I examine the stellar abundance data available in the literature for 1148 field stars and 226 stars in dwarf galaxies, 776 of which have metallicities lower than [Fe/H] <-2.0. Strontium or barium have been detected in all field, globular cluster, and dwarf galaxy environments studied. All upper limits are consistent with the lowest detected ratios of [Sr/H] and [Ba/H]. The frequent appearance of these elements raises the intriguing prospect that at least one kind of neutron-capture reaction operates as often as the nucleosynthesis mechanisms that produce lighter elements, such as magnesium, calcium, or iron, although the yields of heavy elements may be more variable.

Roederer, Ian U., E-mail: iur@obs.carnegiescience.edu [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

2013-01-01

171

Aluminum extraction from aluminum industrial wastes  

NASA Astrophysics Data System (ADS)

Aluminum dross tailings, an industrial waste from the Egyptian Aluminum Company (Egyptalum), was used to produce two types of alums: aluminum sulfate alum (Al2(SO4)312H2O) and ammonium aluminum alum {(NH4)2SO4AL2 (SO4)324H2O}. This was carried out in two processes. The first involves leaching the impurities using diluted H2SO4 with different solid/liquid ratios at different temperatures to dissolve the impurities present in the starting material in the form of aluminum sulfates. The second process is the extraction of aluminum (as aluminum sulfate) from the purified aluminum dross tailings thus produced. This was carried out in an autoclave. The effects of temperature, time of reaction, and acid concentration on pressure leaching and extraction processes were studied in order to specify the optimum conditions to be applied in the bench scale production as well as the kinetics of leaching process.

Amer, A. M.

2010-05-01

172

Synthesis of aluminum isopropoxide from aluminum dross  

Microsoft Academic Search

Synthetic reaction of aluminum isopropoxide, which is used as a starting material for catalytic-grade alumina, has been studied\\u000a in the presence of a small amount of HgI2, HgCl2, I2 or FeCl3 from aluminum dross. It was synthesized by solid-liquid reaction between the aluminum metal and isopropyl alcohol, using\\u000a vacuum distillation process. The purity of the synthesized aluminum isopropoxide was obtained

Seung-Joon Yoo; Ho-Sung Yoon; Hee Dong Jang; Jung-Woon Lee; Seung-Tae Hong; Min-Jae Lee; Se-Il Lee; Ki-Won Jun

2006-01-01

173

High-field conduction in barium titanate  

NASA Astrophysics Data System (ADS)

We present current-voltage studies of very thin (~77 nm) barium titanate single crystals up to 1.3 GV/m applied field. These show that the mechanism of leakage current at high fields is that of space charge limited conduction (SCLC) in a regime with a continuous distribution of traps, according to the original model of Rose [Phys. Rev. 97, 1538 (1955)]. This study represents a factor of 5 in field compared with the early studies of BaTiO3 conduction [A. Branwood et al., Proc. Phys. Soc. London 79, 1161 (1962)]. Comparison is also given with ceramic multilayer barium titanate capacitors, and with variable range hopping [B. I. Shklovskii, Sov. Phys. Semicond. 6, 1964 (1973)], reported in SrTiO3 films [D. Fuchs, M. Adam, and R. Schneider, J. Phys. IV France 11, 71 (2001)].

Morrison, F. D.; Zubko, P.; Jung, D. J.; Scott, J. F.; Baxter, P.; Saad, M. M.; Bowman, R. M.; Gregg, J. M.

2005-04-01

174

Electrical properties of polycrystalline PTCR barium titanate  

Microsoft Academic Search

Semiconducting n-type barium titanate with a positive temperature coefficient of resistance (PTCR) has been made by doping BaTiO3 with 0.4 mol% Ho2O3. The d.c. resistivity, a.c. resistivity (1.2 kHz) and relative permittivity (1.2 kHz) at different temperatures between room temperature and 523 K have been measured. The high relative permittivity and the PTCR effect are attributed to the existence of

M. A. A. Issa

1992-01-01

175

Prospects for Barium Tagging in Gaseous Xenon  

NASA Astrophysics Data System (ADS)

Tagging events with the coincident detection of a barium ion would greatly reduce the background for a neutrino-less double beta decay search in xenon. This paper describes progress towards realizing this goal. It outlines a source that can produce large quantities of Ba++ in gas, shows that this can be extracted to vacuum, and demonstrates a mechanism by which the Ba++ can be efficiently converted to Ba+ as required for laser identification.

Sinclair, D.; Rollin, E.; Smith, J.; Mommers, A.; Ackeran, N.; Aharmin, B.; Auger, M.; Barbeau, P. S.; Benitez-Medina, C.; Breidenbach, M.; Burenkov, A.; Cook, S.; Coppens, A.; Daniels, T.; DeVoe, R.; Dobi, A.; Dolinski, M. J.; Donato, K.; Fairbank, W., Jr.; Farine, J.; Giroux, G.; Gornea, G.; Graham, K.; Gratta, G.; Green, M.; Hagemann, C.; Hall, C.; Hall, K.; Hallman, D.; Hargrove, C.; Herrin, S.; Kaufman, L. K.; Leonard, D. S.; LePort, F.; Mackay, D.; MacLennan, R.; Mong, B.; Montero Dez, M.; Mller, A. R.; Neilson, R.; Niner, E.; Odian, A.; O'Sullivan, K.; Ouellet, C.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Pushkin, K.; Rowson, P. C.; Slutsky, S.; Stekhanov, V.; Twelker, K.; Voskanian, N.; Vuilleumier, J.-L.; Wichoski, U.; Wodin, J.; Yang, L.; Yen, Y.-R.

2011-08-01

176

Electrical properties of barium-borosilicate glasses  

Microsoft Academic Search

Bulk and thin-blown films of barium-borosilicate glass were prepared and their electrical conduction properties at high and\\u000a low fields were measured as functions of temperature. The electrical conductivity is an exponential function of inverse temperature\\u000a at high temperatures with an activation energy in the range 1.0 to 1.4 eV, depending on composition. The conduction process\\u000a is believed to involve polarons

G. R. Moridi; A. Nouruzi; C. A. Hogarth

1991-01-01

177

Aqueous processing of barium titanate powders  

Microsoft Academic Search

In many modern electronic devices, multi-layer ceramic capacitors (MLCCs) are used in large quantities. For a greater volume efficiency of MLCCs, current efforts include thinner dielectric layers and a larger number of layers in a given volume, togethe r with embedded-capacitor design. All of these require a smaller particle size of the raw ceramic material, barium titanate (BaTiO3) powders, with

B. I. Lee; M. Wang; D. Yoon; M. Hu

2003-01-01

178

Microcapsules with intrinsic barium radiopacity for immunoprotection and X-ray/CT imaging of pancreatic islet cells.  

PubMed

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, Dian R; Manek, Sameer; Call, Emma; Arepally, Aravind; Bulte, Jeff W M

2012-03-22

179

Development of barium tagging technology for EXO  

NASA Astrophysics Data System (ADS)

The Enriched Xenon Observatory (EXO) is a series of experiments designed to search for the neutrinoless double beta decay of Xenon-136. The first experiment, known as EXO-200, is comprised of a liquid xenon TPC containing 200 kg of xenon enriched to 80% in Xenon-136 and is nearing completion. To suppress possible radioactive backgrounds, the EXO collaboration is also pursuing the development of a new technique to identify the production of the barium daughter ions produced by double beta decay. For this purpose, a linear radio-frequency ion trap has been constructed. Individual barium ions are trapped in this helium or argon buffer gas-filled trap and observed with a high signal-to-noise ratio by resonance fluorescence. Furthermore, two ion transfer methods are under parallel development, both involving the capture and transport of the ions on the surface of a specially designed tip. This talk will present the results obtained in the trapping of single buffer gas-cooled barium ions and the transfer of ions using a cryogenic tip, and our plans for an ion transfer tip using resonance ionization spectroscopy.

Montero Diez, Maria

2008-04-01

180

Rapid barium removal in the Delaware estuary  

SciTech Connect

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

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

1999-04-01

181

Aluminum applications expand  

Microsoft Academic Search

The transportation industry has increased its demands for extruded, cast, and sheet aluminum products, while the building and construction industries have demonstrated increased interest in new aluminum applications. The unique combination of properties provided by aluminum and its alloys make aluminum one of the most versatile, economical, and attractive materials for a wide range of applications. The low density and

Lichter

1996-01-01

182

The solubility and thermodynamic properties of ettringite, its chromium analogs, and calcium aluminum monochromate (3CaO*Al(2)O(3)*CaCrO(4)*nH(2)O)  

NASA Astrophysics Data System (ADS)

Ettringite (Ca6[(Al(OH)6)]2(SO 4)326H2O) is a naturally-occurring mineral and an important product of the hydration of Portland cements and fly ash. Substitution of Cr(III) for Al(III) and CrO4 for SO4 in the ettringite structure has been demonstrated and may be important with respect to the fate and transport of chromium in alkaline environments. Ettringite and its chromium analogs were synthesized and their solubilities measured via dissolution and precipitation experiments over a range of temperatures between 5 and 75C and pH values between 10 and 13. The log KSP,298 for the reaction Ca6AlOH 62SO 43?26H2O =6Ca2++2AlOH -4 +3SO 2-4 +4OH-+26H2O is -44.9 +/- 0.3. The enthalpy and entropy of reaction are 205 +/- 12 kJ mol-1 and 170 +/- 38 J mol -1 K-1, respectively. The free energy, enthalpy, and entropy of formation are -15211 +/- 20, -17550 +/- 16 kJ mol-1, and 1870 +/- 59 J mol -1 K-1, respectively, based on the reaction parameters and partial molar properties for the dissolved ions. The log KSP, free energy, and enthalpy of reaction for the Cr(III) ettringite analog, bentorite, are KSP,298 = -52.9 +/- 0.8, DeltaGr,298 = 302 +/- 10 and DeltaHr = 320 +/- 76 kJ mol-1 based on an equivalent dissolution reaction. Dissolution of bentorite is incongruent due to precipitation of another phase tentatively identified as Ca2Cr2O58H 2O. The log KSP, free energy and enthalpy of reaction for the dissolution of Ca6[(Al(OH)6)]2(CrO4 )326H2O are KSP,298 = -41.46 +/- 0.30, DeltaGr,298 = 236.6 +/- 3.9 and DeltaHr = 77.5 +/- 9.6 kJ mol-1. The log KSP varies with pH unless a CaCrO4(aq) complex is included in the speciation model. A log formation constant of K = 2.77 +/- 0.16 was obtained for the reaction Ca2+ + CrO42- = CaCrO 4(aq) by minimizing the variance of the IAP for Ca6[(Al(OH) 6)]2(CrO4)326H2O. A secondary precipitate, identified as calcium aluminum monochromate or (3CaOAl2O3CaCrO4nH 2O) was present in Cr(VI)-analog experimental residues. The log K SP for the reaction 3CaO?Al2O3?CaCrO4 ?15H2O=4Ca2++2AlOH -4 + CrO42-+4OH-+ 9H2O is -30.38 +/- 0.28. Ca6[(Al(OH)6)]2(SO4(1-x) , CrO4x)326H2O solids were synthesized and solid-solution aqueous-solution interactions were investigated through dissolution pathway studies. Although thermodynamic equilibrium was not achieved, dissolution pathways approximated stoichiometric saturation curves when plotted on Lippman diagrams.

Perkins, Robert Benjamin

183

Barium Granuloma of the Rectum: An Uncommon Complication of Barium Enema  

PubMed Central

Barium sulfate granuloma of the rectum may develop when this contrast material is forced through a discontinuity in the rectal mucosa. The ensuing mass may be confused with carcinoma. Preoperative biopsy and attention to plain films will prevent unnecessary inappropriate surgery. ImagesFig. 1.Fig. 2.Fig. 3a.Fig. 3b.

Lewis, Joseph W.; Kerstein, Morris D.; Koss, Neal

1975-01-01

184

Composition and structure measurements in an ionospheric barium cloud  

NASA Astrophysics Data System (ADS)

A 48 kg barium payload was launched from Eglin Air Force Base, Florida on 12 December 1980 at 2311 GMT and detonated at 183.7 km. At 2342:50.25 GMT, a second rocket, instrumented with an ion mass spectrometer and pulsed plasma probes, was fired to traverse the barium cloud. Composition, ion density, and structure measurements were acquired up to 241.2 km in both the natural and disturbed ionosphere. The rocket penetrated the barium cloud between 147 and 184 km. In addition to the Ba+, Ba++ produced by H Lyman alpha ionization, and Ca+, an impurity in the barium were detected in the cloud. A peak barium ion concentration of about 6,000,000 ions cu cm was measured at 161 km where the ionospheric NO+ and O2+ ions were essentially eliminated by large recombination loss. The bottom side of the barium cloud had a relatively smooth structure while the top side showed significant density fluctuations. The first experimental evidence of a theoretically predicted E region 'image cloud' was found in the form of an enhanced NO+ layer just below the barium cloud. Unexplained wave-like density variations in O+, NO+, and O2(+) also were seen above the barium cloud to 195 km. A quantitative estimate of the outgassing water vapor concentrations near the payload's surface was made using the fast change transfer rate coefficient for O+ + H2O yields H2O+ + O that created the observed water vapor ions.

Narcisi, R.; Tracinski, E.; Federico, G.; Wlodyka, L.; Bench, P.

1981-12-01

185

A study of positional disorder in strontium barium niobate  

Microsoft Academic Search

The first systematic examination of trends in the site occupancies of strontium and barium ions in strontium barium niobate (SBN) at three compositions across the phase range is presented. X-ray powder diffraction and Rietveld structure refinement were used to obtain refined structures for SBN. Some problems were encountered in the structure refinement due to the domain structure in the material.

M. P. Trubelja; E. Ryba; D. K. Smith

1996-01-01

186

Acute barium intoxication following ingestion of ceramic glaze.  

PubMed Central

A case of deliberate overdose of barium sulphide in a psychiatric setting is presented, with resulting flaccid paralysis, malignant arrhythmia, respiratory arrest and severe hypokalaemia, but ultimately with complete recovery. The degree of paralysis appears to be related directly to serum barium levels. The value of early haemodialysis, particularly with respiratory paralysis and hypokalaemia, is emphasised.

Thomas, M.; Bowie, D.; Walker, R.

1998-01-01

187

SEPARATION OF RADIUM AND BARIUM BY ION EXCHANGE ELUTION  

Microsoft Academic Search

Radium can be separated from barium-radium mixtures in ratios as high as ; 4440to 1 by a single elution from a cation exchange resin. Bariuim elution ; characteristics from Dowex 50 resin, position of elution maxima, and maximum ; barium loadings are correlated with citrate concentration and pH by the use of ; citrate complex equilibria, Ammonium citrate, 0.32M at

W. H. Power; H. W. Kirby; W. C. McCluggage; G. D. Nelson; J. H. Jr. Payne

1959-01-01

188

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

189

Barium in Teeth as Indicator of Body Burden.  

National Technical Information Service (NTIS)

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....

R. G. Miller J. D. B. Featherstone M. E. J. Curzon T. S. Mills C. P. Shields

1985-01-01

190

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

191

Barium silicate films for integrated optical circuits.  

PubMed

This paper describes the preparation and properties of rf sputtered barium silicate films that are suitable for use as transmission media in integrated optical circuits. It is shown that the films, which can be produced with a wide range of refractive indices by suitable selection of the ratio of the target constituents, exhibit low optical attenuation. The techniques used to deposit the films and the effect on loss of a number of parameters including pressure, film thickness, and substrate bias are discussed. PMID:20125380

Goell, J E

1973-04-01

192

Evaluation of barium hydroxide treatment efficacy on a dolomitic marble.  

PubMed

The Arch of Peace, by Luigi Cagnola, is one of the most famous neoclassical monuments in Milan. It has been subjected to conservative intervention in 1998. In the present paper the efficacy of the consolidation by means of barium hydroxide has been evaluated. The stone material showed severe degradation phenomena as: erosion, pulverisation, exfoliation. The analytical data acquired through X-ray diffraction (XRD), infrared spectrophotometry (FTIR) and scanning electron microscopy (SEM-EDX), allowed to compare the conditions of stone before and after the treatment with barium hydroxide. The presence of barium has been put in evidence mainly on the surface as barium sulphate, whereas barium is only sporadically present within the thickness of the decayed material. The treatment was judged not satisfying and its inefficacy is, most probably, due to a not suitable cleaning procedure carried out before the consolidation. PMID:11836959

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

193

How to Perform and Interpret Timed Barium Esophagogram  

PubMed Central

Timed barium esophagogram (TBE) is a simple and objective method for assessing the esophageal emptying. The technique of TBE is similar to usual barium swallow with some modifications, which include taking multiple sequential films at pre-decided time interval after a single swallow of a fixed volume of a specific density barium solution. While many authors have used height and width of the barium column to assess the esophageal emptying, others have used the area of the barium column. TBE is being used in patients with suspected or confirmed achalasia and to follow-up those who have been treated with pneumatic dilation or myotomy. This review discusses technique of performing TBE, interpretation and its utility in clinical practice.

Gupta, Mahesh; Ghoshal, Uday C

2013-01-01

194

Aluminum and renal osteodystrophy.  

PubMed

Evidence has emerged over the last several years indicating that aluminum accumulation in patients with chronic renal failure can cause certain forms of renal osteodystrophy, in particular osteomalacia and an aplastic lesion. The lines of evidence include epidemiological associations, chemical measurement and histological staining of bone aluminum, animal models of aluminum loading, and a favorable response to the removal of aluminum by chelation therapy. The primary sources of aluminum are dialysate solutions prepared from water with a high aluminum content and the oral ingestion of aluminum-containing phosphate binders. Desferrioxamine, a chelating agent with a high affinity for aluminum, can be used to remove aluminum during dialysis by increasing ultrafilterable plasma aluminum; preliminary results show that symptomatic patients markedly improve, both clinically and in their bone histology, after long-term chelation therapy with desferrioxamine. Treating water to ensure that aluminum levels are appropriately reduced in dialysate and the development of non-aluminum-containing phosphate binders are necessary to prevent aluminum-related osteodystrophy. PMID:3085581

Nebeker, H G; Coburn, J W

1986-01-01

195

21 CFR 82.2051 - Lakes (Ext. D&C).  

Code of Federal Regulations, 2013 CFR

...the basic radical sodium, potassium, barium, or calcium; or (ii) a salt prepared...radical sodium, potassium, aluminum, barium, calcium, strontium, or zirconium...and a lake prepared by extending the barium salt prepared from Ext. D&C Red No....

2013-04-01

196

Mupirocin Calcium  

Center for Drug Evaluation (CDER)

Text Version... Contains Nonbinding Recommendations Draft Guidance on Mupirocin Calcium ... Active ingredient: Mupirocin Calcium Form/Route: Cream/Topical ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

197

Calcium Calculator  

MedlinePLUS

... form Search - A + A You are here Home - Calcium Calculator Printer friendly Email Share Tweet Like Home ... Regional Audits Reports Facts and Statistics Popular content Calcium-rich foods The Board What is Osteoporosis? Treating ...

198

Formation of Al 2 O 3 BaTiO 3 nanocomposite oxide films on etched aluminum foil by solgel coating and anodizing  

Microsoft Academic Search

Barium titanate BaTiO3 (BT) sol was dip-coated on the etched aluminum foils by a solgel process. After annealed at 600C in air, the foils were\\u000a anodized in ammonium adipate solution. The voltagetime variations during anodizing were monitored. The structure, composition,\\u000a and electric properties of the anodic foils were investigated. The obtained foils were fabricated into aluminum electrolytic\\u000a capacitors and the

Xianfeng Du; Youlong Xu

2008-01-01

199

Electrorefining of Aluminum.  

National Technical Information Service (NTIS)

A novel inexpensive, energy-efficient approach to the electrorefining of contaminated aluminum scrap to a product suitable for recycle to wrought alloys has been investigated. The method uses a low temperature aluminum-chloride, sodium-chloride electrolyt...

J. P. Pemsler M. Dempsey

1981-01-01

200

The properties and uses of fluxes in molten aluminum processing  

NASA Astrophysics Data System (ADS)

Gaseous and solid fluxes play an important role in the degassing, demagging, and fluxing of aluminum and its alloys. Inert as well as reactive gases, or hexachloroethane, may be used to remove dissolved hydrogen and sodium. Magnesium may be removed by chlorine or an aluminum-fluoride-containing flux. Fluxes based on a KCl-NaCl mixture may be used to cover and protect the metal from oxidation. To recover aluminum from drosses, a more reactive flux containing cryolite or some other fluoride may be used. In this article, the thermodynamics of aluminum melting and refining are analyzed in terms of the behavior of sodium, magnesium, and calcium. The coalescence of aluminum drops in salt fluxes improves with fluoride additions. With increasing MgCl2 contents in the flux, the effects of NaF and KF additions become much less pronounced.

Utigard, T. A.

1998-11-01

201

ION CHROMATOGRAPHIC MEASUREMENT OF FLUORIDE AND SULFUR DIOXIDE IN SAMPLES COLLECTED AT ALUMINUM SMELTERS  

Microsoft Academic Search

Measurement of airborne fluoride and sulfur dioxide in aluminum smelting plants is important for both industrial hygiene and environmental reasons. The traditional analytical techniques employed have been ion-selective electrodes (ISE) for fluoride and barium\\/thorin titration for SO2. In this study, ion chromatography (IC) was evaluated as a substitute for these two techniques. Dust for particulate fluoride was collected on membrane

D. R. Balya

1991-01-01

202

Aluminum and Young Artists.  

ERIC Educational Resources Information Center

The author suggests a variety of ways in which aluminum and aluminum foil can be used in elementary and junior high art classes: relief drawing and rubbing; printing; repousse; sculpture; mobiles; foil sculpture; and three dimensional design. Sources of aluminum supplies are suggested. (SJL)

Anderson, Thomas

1980-01-01

203

Effect of B-site europium doping on the hydrogen transport properties of barium cerate  

NASA Astrophysics Data System (ADS)

Barium cerate doped with europium on the Ce-site (B-site of the ABO3 perovskite structure) has been investigated as a potential material for hydrogen separation. Barium cerate doped with 15 mol% europium (BaCe0.85Eu0.15O3-delta) demonstrated higher electrical conductivity in a hydrogen-containing gas stream than gadolinium-doped barium cerate (BaCe0.85Gd0.15O3-delta), which was known to have one of the highest conductivities (0.027 S/cm 2 compared to 0.021 S/cm2 at 800C). For europium dopant levels between 5 to 25 mol%, the sample doped with 15 mol% demonstrated higher electrical conductivities in dry forming gas (4% H2/96% N2) dry air, and wet nitrogen. The activation energies in dry air (0.60 eV) were indicative of p-type electronic conduction, and the activation energies in hydrogen-containing gases (0.35--0.45 eV) were indicative of protonic conduction. With BaCe0.85Eu0.15O3-delta , the onset of n-type electronic conductivity necessary for hydrogen separation was shown to occur at 600C. A gas-tight glass seal was developed to study the hydrogen permeation properties of BaCe0.85Eu0.15O3-delta. The glass seal was a composite of a glass containing strontium oxide, boron oxide, silicon oxide, aluminum oxide, and lanthanum oxide mixed with doped barium cerate powder. The seal would form at temperatures >875C, allowing for testing down to 650C. The effect of temperature, feed-side hydrogen partial pressure, and membrane thickness on hydrogen permeation flux of BaCe0.85Eu0.15O 3-delta was investigated. For the range of thicknesses studied (0.75 to 2.00 mm), the performance of BaCe0.85Eu0.15O 3-delta membranes is under mixed control of bulk diffusion and surface kinetics. This mixed control indicates that investigating BaCe 0.85Eu0.15O3-delta membranes thinner than 0.75 mm would result in a limited increase in hydrogen permeation flux unless measures were taken to improve surface kinetics. The need for improved surface kinetics was confirmed when surface modification using porous platinum on a 1.00 mm membrane resulted in an increase in permeation flux.

Rhodes, James Michael

204

Proton conductivity of potassium doped barium zirconates  

SciTech Connect

Potassium doped barium zirconates have been synthesized by solid state reactions. It was found that the solubility limit of potassium on A-sites is between 5% and 10%. Introducing extra potassium leads to the formation of second phase or YSZ impurities. The water uptake of barium zirconates was increased even with 5% doping of potassium at the A-site. The sintering conditions and conductivity can be improved significantly by adding 1 wt% ZnO during material synthesis. The maximum solubility for yttrium at B-sites is around 15 at% after introducing 1 wt% zinc. The conductivity of Ba{sub 0.95}K{sub 0.05}Zr{sub 0.85}Y{sub 0.11}Zn{sub 0.04}O{sub 3-{delta}} at 600 deg. C is 2.2x10{sup -3} S/cm in wet 5% H{sub 2}. The activation energies for bulk and grain boundary are 0.29(2), 0.79(2) eV in wet 5% H{sub 2} and 0.31(1), 0.74(3) eV in dry 5% H{sub 2}. A power density of 7.7 mW/cm{sup 2} at 718 deg. C was observed when a 1 mm thick Ba{sub 0.95}K{sub 0.05}Zr{sub 0.85}Y{sub 0.11}Zn{sub 0.04}O{sub 3-{delta}} pellet was used as electrolyte and platinum electrodes. - Graphical abstract: Potassium doped barium zirconates have been synthesized by solid state reactions. It was found that the solubility limit of potassium on A-sites is between 5% and 10 %. The sintering conditions and conductivity can be improved significantly by adding 1 wt% ZnO during material synthesis. Five percent doping of potassium at A-site can double the total conductivity.

Xu Xiaoxiang [School of Chemistry, University of St. Andrews, Fife KY16 9ST (United Kingdom); Tao Shanwen, E-mail: s.tao@hw.ac.u [School of Chemistry, University of St. Andrews, Fife KY16 9ST (United Kingdom); Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Irvine, John T.S. [School of Chemistry, University of St. Andrews, Fife KY16 9ST (United Kingdom)

2010-01-15

205

Migration and redistribution of oxygen vacancy in barium titanate ceramics  

NASA Astrophysics Data System (ADS)

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 C due to oxygen vacancy, and its relaxation strength differs greatly for specimen aged at 85 C for 120 h and at 150 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.

2006-08-01

206

A high-altitude barium radial injection experiment  

NASA Astrophysics Data System (ADS)

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

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

1980-12-01

207

Calcium Channels  

NASA Astrophysics Data System (ADS)

Ion channels underlie the electrical activity of cells. Calcium channels have a unique functional role, because not only do they participate in this activity, they form the means bywhich electrical signals are converted to responses within the cell. Calcium concentrations in the cytoplasm of cells are maintained at a low level, and calcium channels activate quickly such that the opening of ion channels can rapidly change the cytoplasmic environment. Once inside the cell, calcium acts as a "second messenger" prompting responses by binding to a variety of calcium sensitive proteins. Calcium channels are known to play an important role in stimulating muscle contraction, in neurotransmitter secretion, gene regulation, activating other ion channels, controlling the shape and duration of action potentials and many other processes. Since calcium plays an integral role in cell function, and since excessive quantities can be toxic, its movement is tightly regulated and controlled through a large variety of mechanisms.

Corry, Ben; Hool, Livia

208

Synthesis and characterization of barium hexagonal ferrite  

NASA Astrophysics Data System (ADS)

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

Manikandan, M.; Venkateswaran, C.

2013-02-01

209

Aluminum reference electrode  

DOEpatents

A stable reference electrode for use in monitoring and controlling the process of electrolytic reduction of a metal. In the case of Hall cell reduction of aluminum, the reference electrode comprises a pool of molten aluminum and a solution of molten cryolite, Na.sub.3 AlF.sub.6, wherein the electrical connection to the molten aluminum does not contact the highly corrosive molten salt solution. This is accomplished by altering the density of either the aluminum (decreasing the density) or the electrolyte (increasing the density) so that the aluminum floats on top of the molten salt solution.

Sadoway, Donald R. (Belmont, MA)

1988-01-01

210

Aluminum reference electrode  

DOEpatents

A stable reference electrode is described for use in monitoring and controlling the process of electrolytic reduction of a metal. In the case of Hall cell reduction of aluminum, the reference electrode comprises a pool of molten aluminum and a solution of molten cryolite, Na[sub 3]AlF[sub 6], wherein the electrical connection to the molten aluminum does not contact the highly corrosive molten salt solution. This is accomplished by altering the density of either the aluminum (decreasing the density) or the electrolyte (increasing the density) so that the aluminum floats on top of the molten salt solution. 1 fig.

Sadoway, D.R.

1988-08-16

211

Aluminum applications expand  

SciTech Connect

The transportation industry has increased its demands for extruded, cast, and sheet aluminum products, while the building and construction industries have demonstrated increased interest in new aluminum applications. The unique combination of properties provided by aluminum and its alloys make aluminum one of the most versatile, economical, and attractive materials for a wide range of applications. The low density and high strength of some alloys permit design and construction of strong, lightweight structures that are especially beneficial for bridges, buildings, and vehicles of all kinds. Aluminum is easily cast by all foundry processes, and can be readily worked into any needed form. Furthermore, increasing production efficiencies are making aluminum more cost-competitive with other materials. This article focuses on aluminum applications in automobiles, bridges, and housing.

Lichter, J. [Aluminum Association, Washington, DC (United States)

1996-10-01

212

Does calcium kill ESRD patientsthe skeptic's perspective  

Microsoft Academic Search

Recently, there has been intense interest in vascular calcification and the use of calcium-containing phos- phate binders for patients with end-stage renal disease (ESRD). A multi- centre trial evaluating the role of calcium-containing phosphate binders vs non-calcium, non-aluminum-containing binders and the progression of coronary calcification by electron beam computer- ized tomography (EBCT) has been underway for approximately 1 year. The

Joseph A. Coladonato; Lynda A. Szczech; Eli A. Friedman; William F. Owen Jr

2002-01-01

213

Microscopic Theory of the Phonon Frequencies in bcc Barium.  

National Technical Information Service (NTIS)

The phonon dispersion frequencies are calculated from first principles for bbc barium using a resonance pseudopotential model which incorporates the effect of s-d hybridization. It was also possible using this scheme to account for the anomalous feature o...

B. A. Oli

1988-01-01

214

Calculated emission rates for barium releases in space  

NASA Astrophysics Data System (ADS)

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.

1989-11-01

215

Long-term effects of calcium carbonate and 2.5 mEq\\/liter calcium dialysate on mineral metabolism  

Microsoft Academic Search

Long-term effects of calcium carbonate and 2.5 mEq\\/liter calcium dialysate on mineral metabolism. Many investigators have shown that calcium carbonate (CaCO3) is an effective phosphate binder which also prevents the potential disabling effects of aluminum (Al) accumulation. However, hypercalcemia may develop in a substantial numbers of patients. Thus, to control serum phosphate (PO4) and prevent hypercalcemia, we performed studies in

Eduardo Slatopolsky; Carol Weerts; Kathryn Norwood; Karla Giles; Patricia Fryer; Jane Finch; David Windus; James Delmez

1989-01-01

216

Composition and structure measurements in an ionospheric barium cloud  

Microsoft Academic Search

A 48 kg barium payload was launched from Eglin Air Force Base, Florida on 12 December 1980 at 2311 GMT and detonated at 183.7 km. At 2342:50.25 GMT, a second rocket, instrumented with an ion mass spectrometer and pulsed plasma probes, was fired to traverse the barium cloud. Composition, ion density, and structure measurements were acquired up to 241.2 km

R. Narcisi; E. Tracinski; G. Federico; L. Wlodyka; P. Bench

1981-01-01

217

Ultrafine Barium Titanate Powders via Microemulsion Processing Routes  

Microsoft Academic Search

Three processing routes have been used to prepare barium titanate powders, namely conventional coprecipitation, single-microemulsion coprecipitation using diether oxalate as the precipitant, and double-microemulsion coprecipita- tion using oxalic acid as the precipitant. A single-phase perovskite barium titanate was obtained when the double- microemulsion-derived oxalate precursor was calcined for 2 h at a temperature of as low as 550C, compared to

John Wang; Jiye Fang; Ser-Choon Ng; Leong-Ming Gan; Chwee-Har Chew; Xianbin Wang; Zexiang Shen

2004-01-01

218

The problem of heavy-element synthesis in barium stars  

NASA Astrophysics Data System (ADS)

An abundance analysis of the atmospheres of 33 stars, barium and normal G-K giants, is carried out using the differential model atmosphere method. Twenty barium stars which reveal a considerable enhancement of s-process elements exhibit slight depletions (about 0.2 dex) of Na, Mg, Mn, and Co; solar abundances for Si to Ni; and enhanced abundances (up to 1.5 dex) for Y to Eu. Mean parameters of the atmospheres are determined.

Zacs, L.

1991-07-01

219

Investigations on surface composition and microstructure of sintered barium titanate  

Microsoft Academic Search

The paper describes studies on surface atomic composition, microstructure and microarea elemental distribution in sintered\\u000a undoped as well as donor or acceptor doped polycrystalline barium titanate ceramics. The specimens examined are derived from\\u000a barium titanate powders synthesized by two different wet chemical procedures namely oxalate precursor route and gel-to-crystallite\\u000a conversion. The compositional analysis is carried out by backscattering spectrometry (BS)

Sanjiv Kumar; V. S. Raju; T. R. N. Kutty

2007-01-01

220

Synthesis of nanocomposites comprising iron and barium hexaferrites  

Microsoft Academic Search

Composites of nanometre-sized ?-iron and barium hexaferrite phases, respectively, have been synthesized by the ceramic processing route. Pure barium hexaferrite (BaO6Fe2O3) was first of all prepared by calcinations of the precursor oxides at a maximum temperature of 1200C for 4h. By subjecting the resulting powder having particle size of the order of 1?m to a reduction treatment in the temperature

M. Pal; S. Bid; S. K Pradhan; B. K Nath; D. Das; D. Chakravorty

2004-01-01

221

Coprecipitation of uranium and thorium with barium sulfate  

Microsoft Academic Search

The coprecipitation behaviour of uranium or thorium with barium sulfate is investigated from the variation of yields with uranium or thorium concentration, acid and acidity, and amount of sodium and\\/or potassium sulfate. Uranium or thorium in quantities less than 1.5 mg is quantitatively coprecipitated with barium (5.9 mg) sulfate when using an optimum conditions. The chemical form of uranium in

T. Kimura; Y. Kobayashi

1985-01-01

222

Aluminum: Recycling of Aluminum Dross/Saltcake  

SciTech Connect

As this NICE3 publication details, the objective of this project is to commercialize the process technology to eliminate all landfill waste associated with black dross and saltcake generated from aluminum recycling in the United States.

Blazek, S.

1999-01-29

223

Gastrointestinal tract labeling for MDCT of abdomen: Comparison of low density barium and low density barium in combination with water  

Microsoft Academic Search

The purpose of the study was to compare the quality of stomach and small bowel marking\\/labeling using 1,350ml of low-density\\u000a barium alone (VoLumen) with 900ml of low-density barium and 450ml of water for 16-MDCT scans of the abdomen and pelvis and\\u000a assess cost benefits with the two protocols. In this IRB approved study, 80 consecutive patients scheduled for routine CECT

Kavita Gulati; Zarine K. Shah; Nisha Sainani; Raul Uppot; Dushyant V. Sahani

2008-01-01

224

BONDING ALUMINUM METALS  

DOEpatents

A process is given for bonding aluminum to aluminum. Silicon powder is applied to at least one of the two surfaces of the two elements to be bonded, the two elements are assembled and rubbed against each other at room temperature whereby any oxide film is ruptured by the silicon crystals in the interface; thereafter heat and pressure are applied whereby an aluminum-silicon alloy is formed, squeezed out from the interface together with any oxide film, and the elements are bonded.

Noland, R.A.; Walker, D.E.

1961-06-13

225

Elimination of aluminum adjuvants.  

PubMed

In vitro dissolution experiments although perhaps not at typical body concentrations and temperatures demonstrated that the alpha-hydroxycarboxylic acids present in interstitial fluid (citric acid, lactic acid, and malic acid) are capable of dissolving aluminum-containing adjuvants. Amorphous aluminum phosphate adjuvant dissolved more rapidly than crystalline aluminum hydroxide adjuvant. Intramuscular administration in New Zealand White rabbits of aluminum phosphate and aluminum hydroxide adjuvants, which were labelled with 26Al, revealed that 26Al was present in the first blood sample (1 h) for both adjuvants. The area under the blood level curve for 28 days indicated that three times more aluminum was absorbed from aluminum phosphate adjuvant than aluminum hydroxide adjuvant. In vivo studies using 26Al-labelled adjuvants are relatively safe because accelerator mass spectrometry (AMS) can quantify quantities of 26Al as small as 10(-17) g. A similar study in humans would require a whole-body exposure of 0.7 microSv per year compared to the natural background exposure of 3000 microSv per year. The in vitro dissolution and in vivo absorption studies indicate that aluminum-containing adjuvants which are administered intramuscularly are dissolved by alpha-hydroxycarboxylic acids in interstitial fluid, absorbed into the blood, distributed to tissues, and eliminated in the urine. PMID:12184363

Hem, Stanley L

2002-05-31

226

Influence of addition of rare earth metals to aluminum on the effectiveness of absorption of impurity oxygen from argon in a closed system  

SciTech Connect

Removal of oxygen from closed systems plays a significant part in increasing the life of devices operating in absence of oxygen and other harmful impurities (e.g., in incandescent lamps, electronic tubes, etc.). Harmful gases are removed with the aid of gas absorbents. Magnesium, barium, aluminum, zirconium, titanium, rare earth metals (r.e.m.), and their compounds are used as gas absorbents. However, because of their high activity these substances are generally unsuitable for use in electric lamp production. Some of them, such as barium and magnesium, form deposits in the bulb dome which lower the luminous flux of the lamp, while others, e.g., zirconium, aluminum, and r.e.m., lose their initial activity during the technological assembly operations. In this communication results are reported of an investigation of the influence of rare earth metals added to aluminum on oxygen absorption in a closed space (incandescent lamp) when the oxygen content in the main gas is very low.

Glavatskii, Y.F.; Kozik, V.V.; Leshchev, S.V.; Serebrennikov, V.V.

1983-07-10

227

Carbothermic Aluminum Production Using Scrap Aluminum As A Coolant  

DOEpatents

A process for producing aluminum metal by carbothermic reduction of alumina ore. Alumina ore is heated in the presence of carbon at an elevated temperature to produce an aluminum metal body contaminated with about 10-30% by wt. aluminum carbide. Aluminum metal or aluminum alloy scrap then is added to bring the temperature to about 900-1000.degree. C. and precipitate out aluminum carbide. The precipitated aluminum carbide is filtered, decanted, or fluxed with salt to form a molten body having reduced aluminum carbide content.

LaCamera, Alfred F. (Trafford, PA)

2002-11-05

228

Barium studies for detecting esophagopharyngeal reflux events.  

PubMed

Esophagopharyngeal reflux (EPR) is among the factors involved in the supraesophageal complications of reflux disease, and is diagnosed by the regurgitation of barium from the upper third of the esophagus into the pharynx in the absence of swallow during a videofluoroscopic swallowing study. EPR is detected in approximately 20% of patients undergoing these studies, and occurs in different clinical groups without disease-specific associations. The vast majority of patients with EPR show esophageal motor abnormalities on swallowing studies. Notably, prolonged esophageal clearing time is independently and strongly associated with EPR. Our data suggest that the oropharyngeal phase of deglutition is impaired in >50% of patients with both gastroesophageal reflux disease and EPR. In the subset of patients with EPR, oral abnormalities are mostly related to tongue function. Based on the data emerging from our videofluoroscopic swallowing studies, it seems plausible that EPR occurs as a result of an underlying esophageal motor dysfunction facilitated by an impaired oral deglutition. As a consequence, when examining patients for EPR, both esophageal and oropharyngeal abnormalities should be sought. PMID:12928088

Torrico, Silvia; Corazziari, Enrico; Habib, Fortune Irene

2003-08-18

229

Fabrication of Lotus-Type Porous Aluminum through Thermal Decomposition Method  

NASA Astrophysics Data System (ADS)

Lotus-type porous aluminum with cylindrical pores was fabricated by unidirectional solidification through thermal decomposition of calcium hydroxide, sodium bicarbonate, or titanium hydride. The pore-forming gas decomposed from calcium hydroxide, sodium bicarbonate, and titanium hydride is identified as hydrogen. The elongated pores are evolved due to the solubility gap between liquid and solid when the melt dissolving hydrogen is solidified unidirectionally. The porosity of lotus aluminum is as high as 20 pct despite the type of the compounds. The pore size decreases and the pore density increases with increasing amount of calcium hydroxide, which is explained by an increase in the number of pore nucleation sites. The porosity and pore size in lotus aluminum fabricated using calcium hydroxide decrease with increasing argon pressure, which is explained by Boyles law. It is suggested that this fabrication method is simple and safe, which makes it superior to the conventional technique using high-pressure hydrogen gas.

Kim, S. Y.; Park, J. S.; Nakajima, H.

2009-04-01

230

Preparation of thick M-type barium hexaferrite films on double side of substrates by liquid-phase epitaxy deposition technique  

NASA Astrophysics Data System (ADS)

Liquid-phase epitaxy deposition has been investigated to obtain thick and high quality of barium hexaferrite films on (111) gadolinium gallium garnet (GGG) and m-plane (1100) aluminum oxide (Al2O3) substrates. For films deposited on (111) GGG substrate the c-axis was aligned perpendicular to the film plane, but in the plane for films deposited on Al2O3. The films were deposited on both sides of the substrates, where the total thickness of the films ranged between 70 and 190?m. The thickness and quality of these films meet the requirement for applications at high frequencies.

Yoon, S. D.; Vittoria, C.

2004-05-01

231

Calcium-dependent inactivation of calcium channels in cochlear hair cells of the chicken.  

PubMed

Voltage-gated calcium channels support both spontaneous and sound-evoked neurotransmitter release from ribbon synapses of cochlear hair cells. A variety of regulatory mechanisms must cooperate to ensure the appropriate level of activity in the restricted pool of synaptic calcium channels ( approximately 100) available to each synaptic ribbon. One potential feedback mechanism, calcium-dependent inactivation (CDI) of voltage-gated, L-type calcium channels, can be modulated by calmodulin-like calcium-binding proteins. CDI of voltage-gated calcium current was studied in hair cells of the chicken's basilar papilla (analogous to the mammalian cochlea) after blocking the predominant potassium conductances. For inactivating currents produced by 2.5 s steps to the peak of the current-voltage relation (1 mm EGTA internal calcium buffer), single exponential fits yielded an average decay time constant of 1.92 +/- 0.18 s (mean +/- s.e.m., n = 12) at 20-22 degrees C, while recovery occurred with a half-time of approximately 10 s. Inactivation produced no change in reversal potential, arguing that the observed relaxation did not result from alternative processes such as calcium accumulation or activation of residual potassium currents. Substitution of external calcium with barium greatly reduced inactivation, while inhibition of endoplasmic calcium pumps with t-benzohydroquinone (BHQ) or thapsigargin made inactivation occur faster and to a greater extent. Raising external calcium 10-fold (from 2 to 20 mm) increased peak current 3-fold, but did not alter the extent or time course of CDI. However, increasing levels of internal calcium buffer consistently reduced the rate and extent of inactivation. With 1 mm EGTA buffering and in 2 mm external calcium, the available pool of calcium channels was half-inactivated near the resting membrane potential (-50 mV). CDI may be further regulated by calmodulin-like calcium-binding proteins (CaBPs). mRNAs for several CaBPs are expressed in chicken cochlear tissue, and antibodies to CaBP4 label hair cells, but not supporting cells, equivalent to the pattern seen in mammalian cochlea. Thus, molecular mechanisms that underlie CDI appeared to be conserved across vertebrate species, may provide a means to adjust calcium channel open probability, and could serve to maintain the set-point for spontaneous release from the ribbon synapse. PMID:17656437

Lee, Seunghwan; Briklin, Olga; Hiel, Hakim; Fuchs, Paul

2007-07-26

232

Barium partitioning in coccoliths of Emiliania huxleyi  

NASA Astrophysics Data System (ADS)

The coccolithophore Emiliania huxleyi was grown in seawater under different Ba concentrations. The relationship of coccolith Ba/Ca ratio and seawater Ba/Ca ratio was found to be linear. The linear regression yields the apparent Ba exchange coefficient of 0.10. Our data support a recently proposed generic model (Langer G., Gussone N., Nehrke G., Riebesell U., Eisenhauer A., Kuhnert H., Rost B., Trimborn S., and Thoms S. (2006) Coccolith strontium to calcium ratios in Emiliania huxleyi: the dependence on seawater strontium and calcium concentrations. Limnol. Oceanogr.51, 310-320.) developed for explaining apparent exchange coefficients of metabolically inert divalent trace metals, such as Sr, in E. huxleyi. This model represents the first approach combining cell physiological processes and data from inorganic precipitation experiments, which quantitatively explains coccolith apparent Sr and Ba exchange coefficients.

Langer, Gerald; Nehrke, Gernot; Thoms, Silke; Stoll, Heather

2009-05-01

233

Single calcium channels on a cholinergic presynaptic nerve terminal.  

PubMed

The calyx-type synapse of the chick ciliary ganglion was used to examine single calcium channels in a vertebrate cholinergic presynaptic nerve terminal by means of the cell-attached, patch-clamp technique. Calcium channels were recorded on the internal, transmitter-release face of the nerve terminal, but were not detected on the external face. These channels were recruited at -30 mV, with maximum activation at about +30 mV, and were sometimes clustered at high densities. Single-channel conductance estimates with voltage-pulse or -ramp techniques gave values of 11-14 pS with 110 mM barium, which is in the intermediate, N-type range for calcium channels on a control neuron. This nerve terminal calcium channel, termed the NPT-type, may link action potentials to transmitter release at many vertebrate fast-transmitting synapses. PMID:1657055

Stanley, E F

1991-10-01

234

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

235

Acceleration of barium ions near 8000 km above an aurora  

NASA Astrophysics Data System (ADS)

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.

1984-12-01

236

Aluminum: Reducing chloride emissions from aluminum production  

SciTech Connect

Reynolds Metals Company (RMC), with assistance from a NICE{sup 3} grant, is developing for commercialization a closed-loop control process that greatly reduces chlorine emissions and increases plant efficiency while maintaining metal quality. The process still utilizes chlorine to remove impurities during aluminum processing, but is more effective than current methods. With the new technology chlorine in the stack is monitored and input chlorine is adjusted continuously. This optimization of chlorine use results in substantially less waste because less chlorine has to be bought or produced by aluminum manufacturers. This innovation is a significant improvement over conventional aluminum treatments, in which chlorine is injected in a more costly and wasteful manner. By the year 2010, the new technology has the potential to reduce the energy it takes to create chlorine by 8.4 billion Btu per year and to cut greenhouse gas emissions by 1,377 tons per year.

Simon, P.

1999-09-29

237

Chemistry of soil aluminum  

Microsoft Academic Search

Better understanding of soil aluminum has had dramatic effects on the interpretation of many aspects of soil chemistry. Aluminum is a Group III element, metallic in nature, and exhibits both ionic and cuvaient bonding. It is the most plentiful of all metallic cations of the earth's crust. It is released from octahedral coordination with oxygen in minerals by weathering processes.

E. O. McLean

1976-01-01

238

Aluminum-Air Battery.  

National Technical Information Service (NTIS)

An investigation of aluminum alloyed with small amounts (less than 0.1%) of In, Ga, and Tl in an aluminum-air battery with 2M NaCl as the electrolyte is reported. The tested laboratory model of the battery with a total weight of about 500 g operated at a ...

A. Despic D. Drazic S. Zecevic

1979-01-01

239

Anodizing Aluminum with Frills.  

ERIC Educational Resources Information Center

|"Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are also

Doeltz, Anne E.; And Others

1983-01-01

240

Anodizing Aluminum with Frills.  

ERIC Educational Resources Information Center

"Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are also

Doeltz, Anne E.; And Others

1983-01-01

241

Voluntary Aluminum Industrial Partnership  

Microsoft Academic Search

A very successful record of emissions reduction has been achieved through a voluntary program developed between U.S. primary aluminum producers and the U.S. Environmental Protection Agency (EPA). The program is currently in the final year of the first agreement period, and work is under way to develop a new memorandum of understanding to achieve future reductions. Primary aluminum producers working

Jerry Y. Marks

242

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

2011-08-17

243

Barium uptake and adsorption in diatoms  

NASA Astrophysics Data System (ADS)

Using trace metal-defined culture conditions, we measured the cellular barium concentration in cultures of the diatom Thalassiosira weissflogii. In cultures with low Fe concentration, at a typical surface seawater Ba concentration of 35 to 40 nmol/L, the cellular Ba was 0.5 ?mol/mol P (0.04 ?g/g dw), much below all previously published values for phytoplankton. When the Fe concentration in the growth medium was increased, the measured "cellular" Ba increased proportionally to the particulate Fe. Under conditions of ferric hydroxide precipitation, similar particulate Ba concentrations were measured in the absence and the presence of cells for a given concentration of particulate Fe. Thus, the bulk of the particulate Ba in such experiments was not truly intracellular but adsorbed on precipitated Fe hydroxides associated with the cell surface. A similar mechanism likely explains the high cellular Ba concentrations reported by previous investigators who utilized relatively high ratios of Fe to EDTA concentrations in the growth medium, resulting in Fe precipitation. On the basis of our results, it seems highly unlikely that intracellular uptake by living phytoplankton explains the vertical flux of Ba in oceanic waters. But the adsorption of Ba on Fe hydroxides that is seen in laboratory experiments must also occur in the oceans and contribute to Ba transport in the upper part of the water column. To be significant, however, such a mechanism would require that the particles that transport Ba out of the surface have a markedly lower Ba/Fe ratio than is measured in the average suspended material.

Sternberg, Erika; Tang, Degui; Ho, Tung-Yuan; Jeandel, Catherine; Morel, Franois M. M.

2005-06-01

244

The properties of barium stannate and aluminum oxide-based gas sensor  

Microsoft Academic Search

The properties of sensors manufactured by pressing BaSnO3 and BaSnO3 with Al2O3 were studied. An impact of Al2O3 on sensitivity and stability of sensors was established. The results show that an addition of Al2O3 to BaSnO3 improves the mechanical strength, stability and sensitivity of sensors. Moreover, the decrease in the temperature of maximum sensitivity is observed. There is a broad

I. Kocemba; M. Wrbel-J?drzejewska; A. Szychowska; J. Rynkowski; M. G?wka

2007-01-01

245

Phenotypic and Behavioral Defects Caused by Barium Exposure in Nematode Caenorhabditis elegans  

Microsoft Academic Search

To examine the possible phenotypic defects from barium exposure, a model organism, Caenorhabditis elegans, was chosen to analyze the multiple toxicities in barium-exposed animals. Endpoints of life span, body size, brood size,\\u000a generation time, head thrash, and body bend were selected for the assessment of barium toxicity. High concentrations (75?M\\u000a and 200?M) of barium exposure caused severe life-span defects. Body

D.-Y. Wang; Y. Wang

2008-01-01

246

Plasma etch chemistry of aluminum and aluminum alloy films  

Microsoft Academic Search

The chemistry occurring in glow discharges used to etch aluminum and aluminum alloy films is examined and is related to recurring problms such as initiation and reproducibility of etching, polymer or residue formation, photoresist degradation, aluminum corrosion, and safety aspects. The relative effects of different etch gases on these problems is discussed in light of aluminum surface chemistry and gas-phase

Dennis W. Hess

1982-01-01

247

Barium-borate-flyash glasses: As radiation shielding materials  

NASA Astrophysics Data System (ADS)

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

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

2008-01-01

248

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.

249

A high-altitude barium radial injection experiment  

NASA Astrophysics Data System (ADS)

On 16 March 1980 a rocket launched from Poker Flat, Alaska, carried a new type of high-explosive barium shaped charge to 571 km, where detonation injected a thin disk of barium vapor with high velocity nearly perpendicular to the magnetic field. The purpose of the experiment, named ``King Crab,'' was to advance knowledge of the instabilities, waves, and optical and magnetic effects produced. The TV images of the injection are spectacular, revealing three major regimes of expanding material which showed early instabilities in the neutral gas. The most unusual effect of the injection is a peculiar rayed barium-ion structure lying in the injection plane and centered on a 5 km ``black hole'' surrounding the injection point. Preliminary computer simulations show a similar rayed structure development due to an electrostatic instability.

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

250

Multiphoton laser ionization for energy conversion in barium vapor  

NASA Astrophysics Data System (ADS)

We have studied the ion detection of barium atoms in special heated ovens with a tungsten rod in the middle of the stainless steel tube. The tungsten rod was heated indirectly by the oven body heaters. A bias voltage between the cell body and the tungsten rod of 9 V was used to collect electrons, after the barium ions had been created. However, we could collect the electrons even without the bias voltage, although with ten times less efficiency. We studied the conditions for the successful bias-less thermionic signal detection using excimer/dye laser two-photon excitation of Rydberg states below and above the first ionization limit (two-photon wavelength at 475.79 nm). We employed a hot-pipe oven and heat-pipe oven (with inserted mesh) in order to generate different barium vapor distributions inside the oven. The thermionic signal increased by a factor of two under heat-pipe oven conditions.

Makdisi, Y.; Kokaj, J.; Afrousheh, K.; Mathew, J.; Nair, R.; Pichler, G.

2013-03-01

251

The use of antispasmodic drugs during barium enemas.  

PubMed

In 1958, Welin recommended the routine use of atropine before a barium enema to reduce mucus secretion and make the examination more comfortable. Currently, many radiologists believe that smooth-muscle spasmolysis is a useful adjunct during a barium enema and use such a spasmolytic agent. One survey found that spasmolytic agents were administered more frequently in 1987 than in 1976. The use of glucagon had increased 20% between 1976 and 1987. Among 34 foreign institutions responding to the survey, 37% used glucagon and 45% used scopolamine butylbromide (Buscopan). Nevertheless, it is still controversial whether spasmolytic agents play a significant role in the performance and interpretation of a barium enema. Some radiologists routinely use a spasmolytic agent; others do so only selectively. PMID:8191992

Skucas, J

1994-06-01

252

Radiation dose in mass screening for gastric cancer with high-concentration barium sulfate compared with moderate-concentration barium sulfate.  

PubMed

Recently, high-concentration barium sulfate has been developed and is used in many medical facilities. This study compared radiation dose using high-concentration and moderate-concentration barium sulfate. The dose was evaluated with an experimental method using a gastric phantom and with a clinical examination. In the former, the dose and X-ray tube load were measured on the phantom with two concentrations of barium sulfate. In the latter, the fluoroscopic dose-area product (DAP), the radiographic DAP and their sum, the total DAP, were investigated in 150 subjects (112 males, 38 females) treated with both concentrations of barium sulfate. The effective dose was calculated by the software of PCXMC in every case. The results of the experimental evaluation indicated that the effective dose and X-ray tube load were greater with high-concentration barium sulfate than with moderate-concentration barium sulfate (p < 0.05). The results of the clinical evaluation indicated that the fluoroscopic DAP was greater with moderate-concentration barium sulfate than with high-concentration barium sulfate (p < 0.05), but the radiographic DAP was quite the reverse, so the total DAP and effective dose were almost same with both concentrations of barium sulfate. We conclude that high-concentration barium sulfate does not increase radiation dose in mass screening for gastric cancer. PMID:19623859

Yamamoto, K; Azuma, M; Kuroda, C; Kubo, T; Yabunaka, K; Yamazaki, H; Katsuda, T; Takeda, Y

2009-06-01

253

Calcium Phosphate  

Microsoft Academic Search

Early childhood dental caries is defined by its complex etiology of intersecting causations. Diet in combination with good\\u000a oral hygiene, is the most prominently alterable component of this etiology.\\u000a \\u000a Providing enough calcium phosphate in the diet of the pregnant and nursing mother and eventually in the weaning infant ensures\\u000a that a prominent component (calcium phosphate deficiency) of the complex diagram

Rainy Dawn Warf; Ronald Ross Watson

254

Design of a vapor source for cesium-barium thermionic converters  

Microsoft Academic Search

A simple and reliable combined cesium-barium source containing pure barium and a multilayer cesium + pyrographite compound is designed for thermionic converters. The source can regulate the cesium and barium vapor pressures at a single point in the converter chamber; if necessary, the cesium concentration in the pyrographite can be changed so as to make the cesium vapor pressure P(Cs)

I. G. Gverdtsiteli; A. G. Kaladarishvili; V. G. Kashiia

1985-01-01

255

Characterization of dielectric barium titanate powders prepared by homogeneous precipitation chemical reaction for embedded capacitor applications  

Microsoft Academic Search

Various articles have reported that a highly pure and uniform form of barium titanate can be prepared by homogeneous precipitation. However, most of these works emphasize the mechanism of thermal decomposition of barium titanyl oxalate tetrahydrate, and only a few have discussed morphology or particle size. The morphology and particles size of barium titanyl oxalate tetrahydrate are governed by reaction

Jyh-Ming Hwu; Wen-Huai Yu; Wei-Chun Yang; Yu-Wen Chen; Yeh-Yu Chou

2005-01-01

256

Mass barium carbonate poisoning with fatal outcome, lessons learned: a case series  

Microsoft Academic Search

INTRODUCTION: Barium, a heavy divalent alkaline metal, has long been known to cause human toxicity. The common mode is accidental ingestion and the common compound is Barium carbonate. Here we report an incident of food poisoning in 27 law enforcement personnel with rapidly developing sequelae and a high mortality due to ingestion of Barium carbonate contaminated flour. CASE PRESENTATION: One

Aniruddha Ghose; Abdullah Abu Sayeed; Amir Hossain; Ridwanur Rahman; Abul Faiz; Gofranul Haque

2009-01-01

257

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Barium manganese oxide (BaMnO3). 721.10010...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3 ). (a...The chemical substance identified as barium manganese oxide (BaMnO3 )...

2009-07-01

258

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

259

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 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...

2010-04-01

260

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

261

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

262

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

263

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 azide50 percent or more water wet. Barium azide50 percent or more water wet,...

2010-10-01

264

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 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...

2009-04-01

265

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

Code of Federal Regulations, 2010 CFR

... 2009-10-01 2009-10-01 false Barium azide-50 percent or more water wet. 173...Other Than Class 1 and Class 7 § 173.182 Barium azide50 percent or more water wet. Barium azide50 percent or more water wet,...

2009-10-01

266

Predictive value of a diagnosis of colonic polyp on the double-contrast barium enema  

Microsoft Academic Search

The positive predictive value of a diagnosis of colonic polyp on the double-contrast barium enema was determined by analyzing 160 polypoid lesions reported in 105 patients. Of the 160 polyps, 139 were confirmed by endoscopy, surgery, or repeat barium enema for a positive predictive value of 87%. Twenty-one lesions were not confirmed despite repeat endoscopy, repeat barium enema, review of

David J. Ott; Deborah S. Ablin; David W. Gelfand; Isadore Meschan

1983-01-01

267

Modifications of Pt\\/alumina combustion catalysts by barium addition I. Properties of fresh catalysts  

Microsoft Academic Search

Platinum was deposited onto pure alumina as well as on alumina modified by addition of 7 and 15 wt.-% barium. The alumina hydroxyl groups were neutralized by barium addition and the surface of the modified support had a basic character. The introduction of barium decreased the accessible platinum area because of a sintering of the metal particles associated with a

Valrie Labalme; Nathalie Benhamou; Nolven Guilhaume; Edouard Garbowski; Michel Primet

1995-01-01

268

Determination of Barium in Bottled Drinking Water by Graphite Furnace Atomic Absorption Spectrometry  

Microsoft Academic Search

In relation to the wide environmental spread of barium and to its cardiovascular effects, barium levels were determined by graphite furnace atomic absorption spectrometry in 60 different brands of bottled water marketed in Italy.Matrix interferences were investigated in order to evaluate the use of an analytical calibration function rather than the much more time consuming addition technique.The barium content ranged

F. Fagioli; C. Locatelli; E. Lanciotti; G. Vallone; D. Mazzotta; A. Mugelli

1988-01-01

269

CoPrecipitation of Radium and Barium Salts as a Function of Temperature and Acidity  

Microsoft Academic Search

Co-precipitation of radium and barium salts which accompanies the cooling of a solution results in the deposition of a percentage of radium largely in excess of that of barium. Under similar conditions of cooling the relative amounts of radium and barium deposited have been determined at different temperatures throughout the cooling process and curves have been plotted. Determinations of the

W. B. Pietenpol

1942-01-01

270

The biological production of marine suspended barite and the barium cycle in the Western Mediterranean Sea  

Microsoft Academic Search

Suspended particulate barium was measured in the Western Mediterranean along 4 profiles sampled during the PHYCEMED 1 cruise in 1981. The non-terrigenous fraction of particulate barium (i.e. excess Ba; Baxs) can account for up to 96% of total barium. This fraction follows the barite settling and dissolution rate model we described earlier for the Atlantic Ocean, confirming barite as the

F. DEHAIRSI; C. E. Lambert; R. Chesselet; N. Risler

1987-01-01

271

Sorption of strontium-90 from fresh waters during sulfate modification of barium manganite  

Microsoft Academic Search

Recovery of strontium-90 with barium manganite from fresh waters (natural fresh waters of open basins) can be increased by adding agents that contain sulfate ions and thus modify the sorbent and chemically bind the sorbate. The treatment results in a heterogeneous anion-exchange transformation of barium manganite into barium sulfate-manganese dioxide and in simultaneous absorptive coprecipitation of strontium sulfate (microcomponent).

Yu. V. Egorov

1995-01-01

272

Sorption of strontium-90 from fresh waters during sulfate modification of barium manganite  

SciTech Connect

Recovery of strontium-90 with barium manganite from fresh waters (natural fresh waters of open basins) can be increased by adding agents that contain sulfate ions and thus modify the sorbent and chemically bind the sorbate. The treatment results in a heterogeneous anion-exchange transformation of barium manganite into barium sulfate-manganese dioxide and in simultaneous absorptive coprecipitation of strontium sulfate (microcomponent).

Ryzhen`kov, A.P.; Egorov, Yu.V. [Ural State Technical Univ., Ekaterinburg (Russian Federation)

1995-11-01

273

Environmental deterioration of aluminum-aluminum connections  

Microsoft Academic Search

Wire splice connections are investigated for deterioration due to environmental factors. The tested splices of solid aluminum and copper wires are made using twist-on connectors. Some specimen groups are exposed in a chamber at 35C and 90% relative humidity. Additional groups are exposed for ten years to a normal application environment. There is no current flow except when potential drop

Jesse Aronstein

1992-01-01

274

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

275

Calcium carbonate overdose  

MedlinePLUS

Tums overdose; Calcium overdose ... Calcium ... Products containing calcium carbonate, including Certain antacids (Tums, Chooz) Certain mineral supplements Certain hand lotions Certain vitamin and mineral supplements Note: ...

276

Minerals Yearbook 1991: Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

Calcium, is chemically very active and is found in a host of minerals that occur in nearly every geologic environment. Calcium fluoride is sold as fluorspar; calcium sulfate as gypsum or anhydrite; calcium oxide and hydroxide as lime; calcium phosphate as...

M. M. Miller

1992-01-01

277

Effects of different fabrication techniques on the Yttrium-Barium-Copper oxide high temperature superconductor  

NASA Astrophysics Data System (ADS)

This study examines how several different parameters were changed in the yttrium-barium-copper oxide superconductor when the fabrication techniques were altered by using different barium precursors, including barium peroxide and barium carbonate; sintering at different temperatures, including 850, 900, 950 C; and annealing in an above ambient oxygen environment. Twelve different pellets were fabricated, and measurements were taken on them which included density, X-ray diffraction, critical temperature, critical current density, and magnetic susceptibility. The results showed that the barium peroxide derived samples had higher densities, better critical current densities and lower resistivities in the normal state.

Rhea, Paul A.

1988-12-01

278

Separation of lanthanum, hafnium, barium and radiotracers yttrium-88 and barium-133 using crystalline zirconium phosphate and phosphonate compounds as prospective materials for a Ra223 radioisotope generator  

Microsoft Academic Search

Crystalline hybrid organic\\/inorganic ion exchangers based on zirconium phosphate and phosphonate compounds were evaluated for application in radium-223 generator for radiopharmaceutical applications. Various compositions were synthesized and the selectivity of these materials was determined for inactive lanthanum, hafnium and barium, and radiotracers yttrium-88 and barium-133. The hybrid materials show very efficient lanthanum\\/barium separation; the response for zirconium phosphate was even

Teresia Mller; Naima Bestaoui; Melissa Wierzbicki; Todd Adams; Abraham Clearfield

2011-01-01

279

Oxidation of Aluminum Nitride.  

National Technical Information Service (NTIS)

The oxidation characteristics of hot-pressed aluminum nitride were investigated. Three materials were studied in the temperature range 1100 to 1400 C in 15, 150, and 400 torr oxygen environments. The oxidation process was evaluated using thermogravimetric...

B. A. Rasmussen

1973-01-01

280

Fractography of Aluminum 7075.  

National Technical Information Service (NTIS)

The fractography of aluminum 7075, fractured in a 3% NaCl aqueous solution was characterized. Stress-corrosion cracking was found to occur through intermetallic precipitates present along the grain boundaries.

G. H. Koch

1977-01-01

281

Corrosion Inhibitors for Aluminum.  

ERIC Educational Resources Information Center

Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

Muller, Bodo

1995-01-01

282

Aluminum powder metallurgy processing.  

National Technical Information Service (NTIS)

The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from a...

J. F. Flumerfelt

1999-01-01

283

Aluminum-air battery  

Microsoft Academic Search

Aluminum alloyed with small amounts (less than 0.1%) of In, Ga, and Tl in an aluminum air battery with 2M NaCl as the electrolyte is reported. The tested laboratory model of the battery with a total weight of about 500 g operated at a total current of 8 A (j = 30 mA\\/cu cm) and a voltage of about 1

A. R. Despic; D. Drazic; S. Zecevic

1979-01-01

284

Aluminum Fluidity in Casting  

NASA Astrophysics Data System (ADS)

The understanding and control of fluidity is, and has been, a major aspect of foundry technology development. This paper reviews the progress made in this area over the years as it applies to aluminum castings. As a result of this development, thin-wall, high-integrity aluminum castings which were previously not thought possible have been produced. Further work in this area is expected to allow metal-matrix composites to fulfill their technical and economic promise.

Mollard, Francois R.; Flemings, Merton C.; Niyama, Eisuke F.

1987-11-01

285

CORROSION PROTECTION OF ALUMINUM  

DOEpatents

Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred.

Dalrymple, R.S.; Nelson, W.B.

1963-07-01

286

CORROSION PROTECTION OF ALUMINUM  

DOEpatents

Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred. (D.C.W.)

Dalrymple, R.S.; Nelson, W.B.

1963-07-01

287

Separation of barium and lantanium on aluminium oxide  

Microsoft Academic Search

Lanthanum 140 having a short period of half-decay is sufficient to be used as a radioactive indicator in chemistry investigations of lanthanides and actinides. Preparates based on lanthanum 140 allow one to carry out studies to determine rare-earth elements in technological products and raw materials. This work was devoted to the study of the separations of lanthanum 140 from barium

S. Khuzaev; N. A. Mirzaeva; A. Sultanov

1993-01-01

288

Geochemistry of Barium in Sediments of the Western Black Sea  

Microsoft Academic Search

During two cruises with RV POSEIDON and RV METEOR to the western Black Sea (west of Crimean Peninsula) in 2004 and 2007, respectively, sediment cores were taken along a transect from 500 to 1700 m water depth. Pore water and solid phase investigations aimed at unraveling the geochemical behaviour of barium in this anoxic water column and sedimentary environment. In

S. Kasten; K. Bogus; M. Jones; S. Henkel; C. Maerz; K. Pfeifer; R. Seifert

2008-01-01

289

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 ...

290

Barium Cloud Growth and Striation in a Conducting Background  

Microsoft Academic Search

Previous calculations of barium cloud growth did not give reasonable estimates of Striation scale size and onset time because they assumed either no ionospheric end shorting or no ion diffusion (all modes unstable) or strong shorting (all modes stable). We derive a set of equations that includes both finite end shorting and ion diffusion and solve by a new numerical

J. N. Shiau; A. Simon

1974-01-01

291

Dielectric Behavior of Nano Barium Titanate Filled Polymeric Composites  

NASA Astrophysics Data System (ADS)

Rapid growth of electronic industry requires development of new materials that combine the high dielectric constant intrinsic to ferroelectric ceramic materials with easy processing characteristics of polymers. Ceramic-polymeric composites possess interesting properties for a variety of electronic applications including passive electronic devices. In fact, polymer-ceramic materials have drawn lot attention for use in microelectronic packaging, because they can give higher performance with lower cost, size and weight. In this work, attempts are made to prepare ceramic polymer composites followed by characterization of dielectric properties. The Barium Titanate ceramic powders are synthesized using the hydrothermal process. Crystal structure and crystallite size of particles are determined using X-ray diffraction. Silane treatment is carried out on Barium Titanate powder to increase its compatibility with polymer, followed with preparation of ceramic polymer composites. Epoxy and polyvinyledene fluoride (PVDF) polymers are used as matrices for preparation of the composites. The proportion of nanopowder is varied from 60 to 90 wt%. Dielectric properties such as volume resistivity, dielectric constant, dissipation factor are evaluated. Results indicate that the dielectric constant and dissipation factor vary between 18 -140 and 0.01 to 0.09, respectively as the relative ratio of polymer and silane modified Barium Titanate is varied. Specifically, at 90 wt% of 0.1 wt% silane modified Barium Titanate, the highest dielectric constant of 140 along with dissipation factor of 0.07 is obtained in the epoxy based system.

Pratap, A.; Joshi, N. J.; Rakshit, P. B.; Grewal, G. S.; Shrinet, V.

292

Permittivity of Solid Solutions of Barium and Lead Titanate.  

National Technical Information Service (NTIS)

An investigation was made of the effect on the dielectric properties of barium titanate (BaTiO3) by the addition of small percentages (0 to 10 percent) of lead titanate (PbTiO3). Measurements were made at 1 kc/s within the temperature range 0 to 200C. Inc...

G. W. Marks L. A. Monson

1967-01-01

293

Study of Barium Strontium Titanate Thin Film Doped by Indium  

Microsoft Academic Search

We have developed Barium Strontium Tinanate (BST) doped by Indium as soft dopant on Pt\\/Si substrate using chemical solution deposition method followed by spin coating. The specimen is then examined by XRF to identify the chemical content, SEM to study the morphology of the films, XRD to calculate the grain size, and electrometer Keithley 6517A to obtain the hysteresis curves.

M. Hikam; B. Soegijono; Y. Iriani; I. Mudzakir; D. Fasquelle

2009-01-01

294

Minerals Yearbook, 1988. Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

The Bureau of Mines publishes reports for a variety of calcium-containing minerals and compounds because of their commercial significance and contribution to the quality of human life. The report includes calcium metal, calcium chloride, and various other...

D. E. Morse

1988-01-01

295

Cast Tenzaloy aluminum optics  

NASA Astrophysics Data System (ADS)

Since the early sixties, cast aluminum optics has held out a promise of low cost, durability, lightweight, ease of manufacture, the possibility of welding together sections to form large optics and a good match of some astronomical programs such as photometry. Needless to say, this rosy future has been fraught with difficulties. Poor short-term stability, sensitivity to temperature, porosity, bimetallic warping, soft optical surface, poor specularity, nickel adhesion problems, poor image quality, and the inability to generate aspherics, have all contributed to the bad name cast aluminum optics has acquired over the years. With the advent of improved aluminum alloys, long-term dimensional stability data, advances in adaptive optics and the need for very large monolithic mirrors with a relatively low handling risk, aluminum optics deserve another look. This paper is a collection of some of the early attempts to build cast aluminum mirrors using the stable alloy, Tenzaloy. The results of those efforts are discussed together with recommendations for future aluminum metal mirror work.

Forbes, Fred F.

1993-10-01

296

Origin of dynamical heterogeneities in calcium aluminosilicate liquids.  

PubMed

We investigate the heterogeneous dynamics of calcium aluminosilicate liquids across both the peraluminous and peralkaline regimes. Using the isoconfigurational ensemble method we find a clear correlation between dynamical heterogeneities and concentration fluctuations. Regions of high dynamic propensity have higher concentrations of both calcium and aluminum, whereas low propensity regions are silica rich. The isoconfigurational ensemble is found to be a powerful tool for studying the origin of heterogeneous dynamics of industrially relevant glass-forming liquids. PMID:20499973

Vargheese, K Deenamma; Tandia, Adama; Mauro, John C

2010-05-21

297

Origin of dynamical heterogeneities in calcium aluminosilicate liquids  

NASA Astrophysics Data System (ADS)

We investigate the heterogeneous dynamics of calcium aluminosilicate liquids across both the peraluminous and peralkaline regimes. Using the isoconfigurational ensemble method we find a clear correlation between dynamical heterogeneities and concentration fluctuations. Regions of high dynamic propensity have higher concentrations of both calcium and aluminum, whereas low propensity regions are silica rich. The isoconfigurational ensemble is found to be a powerful tool for studying the origin of heterogeneous dynamics of industrially relevant glass-forming liquids.

Vargheese, K. Deenamma; Tandia, Adama; Mauro, John C.

2010-05-01

298

Project Calcium  

SciTech Connect

Fouling problems in utility boilers have been classified into two principal types: high-temperature and low-temperature fouling. A multiclient-sponsored program was initiated at the Energy and Environmental Research Center (EERC) to better understand the causes of low-temperature fouling when burning high-calcium western US coals. The goals of Project Calcium were to define the low-temperature deposition problem, identify the calcium-based components that are responsible for the formation of the deposits, develop ways to predict their formation, and identify possible methods to mitigate the formation of these deposits. To achieve the goals of Project Calcium, detailed sampling of utility boilers and laboratory-scale studies coupled with state-of-the-art methods to determine the inorganic components in coals and coal ash-derived materials were conducted. Boiler Sampling was also performed. The work involved sampling coal, entrained ash, deposits and slags from five full-scale utility boilers combined with detailed advanced characterization of the materials. The results of this work aided in identifying the key phenomena to focus the laboratory studies and in model verification. Field testing was conducted at three utilities.

Hurley, J.P.; Benson, S.A.; Erickson, T.A.; Allan, S.E.; Bieber, J.

1992-09-01

299

The flame photometric determination of calcium in phosphate, carbonate, and silicate rocks  

USGS Publications Warehouse

A flame photometric method of determining calcium in phosphate, carbonate, and silicate locks has been developed Aluminum and phosphate interference was overcome by the addition of a large excess of magnesium. The method is rapid and suitable for routine analysis Results obtained are within ?? 2% of the calcium oxide content. ?? 1957.

Kramer, H.

1957-01-01

300

Releasing effects in flame photometry: Determination of calcium  

USGS Publications Warehouse

Strontium, lanthanum, neodymium, samarium, and yttrium completely release the flame emission of calcium from the depressive effects of sulfate, phosphate, and aluminate. Magnesium, beryllium, barium, and scandium release most of the calcium emission. These cations, when present in high concentration, preferentially form compounds with the depressing anions when the solution is evaporated rapidly in the flame. The mechanism of the interference and releasing effects is explained on the basis of the chemical equilibria in the evaporating droplets of solution and is shown to depend upon the nature of the compounds present in the aqueous phase of the solution. The need for background correction techniques is stressed. The releasing effect is used in the determination of calcium in silicate rocks without the need for separations.

Dinnin, J. I.

1960-01-01

301

Aluminum automotive space frames  

SciTech Connect

Design of aluminum structures is to a new topic. Aircraft makers have successfully solved difficult structural problems with a high degree of understanding and reliability. Other transportation modes such as trucks, trailers, and railcars have faced structural problems with some emphasis on high- and low-cycle fatigue of welded aluminum structures. However, the automotive market places stringent engineering demands on materials and superimposes demanding cost constraints. A project was instituted at Reynolds Metals Co. to investigate the opportunities for the cost-effective application of aluminum to automotive spaceframes. Several areas were recognized as key to the success of this application. They were: equivalent or superior structural stiffness of the assembly to existing steel unibody and/or steel spaceframe vehicles; effective joining of spaceframe members; equivalent or superior crashworthiness of the assembly; weight savings; flexibility; and low-cost approach aimed at effective manufacturing. To gain experience with the key aspects in a practical environment, the experience of current builders of steel tube frame chassis was explored. These chassis are typically used in low-volume vehicles requiring torsional stiffness, excellent crashworthiness, and exterior body-style flexibility. A model was developed using finite element methods that accurately predicts mass and stiffness of frames. An effective aluminum space frame was generated which was 7.5% stiffer and more than 20% lighter than the steel frame, with stresses kept below the fatigue limit for aluminum welds.

NONE

1995-08-01

302

Safety evaluation of dietary aluminum.  

PubMed

Aluminum is a nonessential metal to which humans are frequently exposed. Aluminum in the food supply comes from natural sources, water used in food preparation, food ingredients, and utensils used during food preparations. The amount of aluminum in the diet is small, compared with the amount of aluminum in antacids and some buffered analgesics. The healthy human body has effective barriers (skin, lungs, gastrointestinal tract) to reduce the systemic absorption of aluminum ingested from water, foods, drugs, and air. The small amount of aluminum (<1%) that is systemically absorbed is excreted principally in the urine and, to a lesser extent, in the feces. No reports of dietary aluminum toxicity to healthy individuals exist in the literature. Aluminum can be neurotoxic, when injected directly into the brains of animals and when accidentally introduced into human brains (by dialysis or shrapnel). A study from Canada reports cognitive and other neurological deficits among groups of workers occupationally exposed to dust containing high levels of aluminum. While the precise pathogenic role of aluminum in Alzheimer's disease (AD) remains to be defined, present data do not support a causative role for aluminum in AD. High intake of aluminum from antacid for gastrointestinal ailments has not been reported to cause any adverse effects and has not been correlated with neurotoxicity or AD. Foods and food ingredients are generally the major dietary sources of aluminum in the United States. Cooking in aluminum utensils often results in statistically significant, but relatively small, increases in aluminum content of food. Common aluminum-containing food ingredients are used mainly as preservatives, coloring agents, leavening agents, anticaking agents, etc. Safety evaluation and approval of these ingredients by the Food and Drug Administration indicate that these aluminum-containing compounds are safe for use in foods. PMID:11259180

Soni, M G; White, S M; Flamm, W G; Burdock, G A

2001-02-01

303

Preliminary assessment of potential health hazards associated with barium leached from glazed ceramicware.  

PubMed

Ceramic glazes contain several elements which have the potential to leach into food or beverages that are held or stored in ceramicware. Recently, barium salts have been investigated as one of the alternatives to lead in frit formulations for glazes. This preliminary evaluation addresses the potential health hazards associated with barium at levels that might leach from glazed ceramicware. A set of specialty ceramicware, consisting of five teacups and a pitcher, was examined for extractable barium. Exposure to barium that adults (18-44 years) might encounter using the vessels for coffee, tea, or orange juice was estimated. The exposure estimate was derived from values for intakes of the beverages and for the barium migration from glazed ceramicware test samples. An established reference dose (RfD) for barium exposure for the critical effect of hypertension was identified. The potential hazard associated with the leaching of barium from glazed ceramicware varied with the level of use. Consuming beverages in amounts up to the 95th percentile would not result in total barium intake in amounts that exceed the RfD; consuming large quantities (> 95th percentile) of beverages such as tea or coffee from glazed vessels might. This suggests that for a small portion of the population of users, intake of barium may be in quantities that warrant further consideration as a potential health hazard. Analyses of a broad sample of ceramicware and study of barium leaching behaviour under actual use conditions are needed to assess further the significance of these findings. PMID:9328533

Assimon, S A; Adams, M A; Jacobs, R M; Bolger, P M

1997-07-01

304

Calcium and bone disease  

PubMed Central

Calcium transport and calcium signaling are of basic importance in bone cells. Bone is the major store of calcium and a key regulatory organ for calcium homeostasis. Bone, in major part, responds to calcium-dependent signals from the parathyroids and via vitamin D metabolites, although bone retains direct response to extracellular calcium if parathyroid regulation is lost. Improved understanding of calcium transporters and calcium-regulated cellular processes has resulted from analysis of genetic defects, including several defects with low or high bone mass. Osteoblasts deposit calcium by mechanisms including phosphate and calcium transport with alkalinization to absorb acid created by mineral deposition; cartilage calcium mineralization occurs by passive diffusion and phosphate production. Calcium mobilization by osteoclasts is mediated by acid secretion. Both bone forming and bone resorbing cells use calcium signals as regulators of differentiation and activity. This has been studied in more detail in osteoclasts, where both osteoclast differentiation and motility are regulated by calcium.

Blair, Harry C.; Robinson, Lisa J.; Huang, Christopher L.-H.; Sun, Li; Friedman, Peter A.; Schlesinger, Paul H.; Zaidi, Mone

2013-01-01

305

Rabbit Neurobehavioral Toxicity from Aluminum.  

National Technical Information Service (NTIS)

A model for the production of neurobehavioral toxicity induced by systemic aluminum exposure was developed. Nictitating membrane extension conditioning was used to assess the influence of the aluminum treatment on learning (acquisition and conditioned res...

R. A. Yokel

1983-01-01

306

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

PubMed Central

Rectal bleeding often heralds serious colonic disease. The literature suggests that colonoscopy is superior to barium enema plus sigmoidoscopy, although no good comparative studies exist. Seventy one patients with overt rectal bleeding had prospectively flexible sigmoidoscopy, double contrast barium enema and colonoscopy completed independently. Against the gold standard, the sensitivity and specificity of colonoscopy were 0.69 and 0.78 respectively for a spectrum of colonic lesions, while for combined flexible sigmoidoscopy and double contrast barium enema these values were 0.80 and 0.56, respectively. When assessing adenoma or carcinoma, colonoscopy was more sensitive at 0.82 v 0.73, while flexible sigmoidoscopy plus double contrast barium enema was superior for detecting diverticular disease. The positive predictive value for colonoscopy was 0.87 against 0.81 for flexible sigmoidoscopy and double contrast barium enema. This study confirms that colonoscopy should be a first line investigation in subjects likely to require biopsy or therapeutic intervention.

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

1988-01-01

307

Particulates in aluminum sputtering discharges  

Microsoft Academic Search

Plasma-generated particulates are receiving increasing attention as a possible source of device yield reduction in plasma-assisted etching and deposition processes. We have investigated aluminum sputtering in argon discharges between parallel-plate aluminum electrodes under both direct current and radio frequency excitation. Pulsed laser-induced fluorescence experiments indicate that particulates containing aluminum form in these discharges under conditions in which aluminum sputtering takes

G. M. Jellum; D. B. Graves

1990-01-01

308

Molecular Structure of Aluminum Fluoride  

NSDL National Science Digital Library

Aluminum Fluoride is a solid, off-white, free-flowing granular material, insoluble in most organic and inorganic liquids at room temperatures. It is soluble in many fused salts. Aluminum Fluoride is used by aluminum producers to increase the conductivity of electrolytes in the smelting process. It is used as a flux ingredient for the removal of magnesium in refining aluminum scrap, by the ceramic industry for some body and glazing mixtures, and in the production of specialty refractory products.

2003-06-02

309

PROCESS FOR REMOVING ALUMINUM COATINGS  

DOEpatents

A process is presented for removing aluminum jackets or cans from uranium slugs. This is accomplished by immersing the aluminum coated uranium slugs in an aqueous solution of 9 to 20% sodium hydroxide and 35 to 12% sodium nitrate to selectively dissolve the aluminum coating, the amount of solution being such as to obtain a molar ratio of sodium hydroxide to aluminum of at least

Flox, J.

1959-07-01

310

Calcium Nephrolithiasis  

Microsoft Academic Search

Nephrolithiasis is a major cause of morbidity involving the urinary tract. The prevalence of this disease in the United States\\u000a increased from 3.8% in the 1970s to 5.2% in the 1990s. There were nearly 2 million physician office visits for nephrolithiasis\\u000a in 2000, and estimated annual costs totaled $2 billion. About 80% of stones are composed of calcium oxalate with

Zachary Z. BrenerJames; James F. Winchester; Michael Bergman

311

Influence of addition of rare earth metals to aluminum on the effectiveness of absorption of impurity oxygen from argon in a closed system  

Microsoft Academic Search

Removal of oxygen from closed systems plays a significant part in increasing the life of devices operating in absence of oxygen and other harmful impurities (e.g., in incandescent lamps, electronic tubes, etc.). Harmful gases are removed with the aid of gas absorbents. Magnesium, barium, aluminum, zirconium, titanium, rare earth metals (r.e.m.), and their compounds are used as gas absorbents. However,

Y. F. Glavatskii; V. V. Kozik; S. V. Leshchev; V. V. Serebrennikov

1983-01-01

312

Formation of yttrium barium cuprate powder at low temperatures  

SciTech Connect

Yttrium barium cuprate can be formed at temperatures below 800{degrees}C from mixed oxides and carbonate if a low-oxygen-pressure atmosphere is used. This eliminates the formation of a high-oxygen-content nonsuperconducting phase which has been previously shown to form at lower temperatures. Reaction of barium carbonate and the oxides of copper and yttrium at temperatures as low as 750{degrees}C in reducing atmospheres is shown to form tetragonal YBa{sub 2}Cu{sub 3}O{sub x} with x about 6. This compound can then be oxidized by cooling in an oxidizing atmosphere to obtain the desired x value of about 7.

Lay, K.W. (Research and Development Center, General Electric Co., Schenectady, NY (US))

1989-04-01

313

Oxygen tracer diffusion in donor doped barium titanate  

NASA Astrophysics Data System (ADS)

Oxygen exchange with the ambient atmosphere and oxygen diffusion are assumed to play a decisive role in the re-oxidation process of positive temperature coefficient (PTC) resistors based on donor doped barium titanate. 18O tracer experiments with subsequent time-of-flight secondary ion mass spectrometry (ToF-SIMS) measurements were thus carried out to investigate the oxygen diffusion properties of donor doped barium titanate. Fast grain boundary diffusion was found at temperatures between 750 C and 900 C. Moreover, evidence is given for a position dependent diffusion coefficient close to the surface. The secondary phase developing during the production process is shown to be Ti-rich and hardly any oxygen tracer exchange with this secondary phase could be observed. This suggests that grain boundary diffusion does not take place via such secondary phases. Rather, evidence of diffusion along an oxygen vacancy enriched space charge region is found.

Frmling, T.; Hou, J.; Preis, W.; Sitte, W.; Hutter, H.; Fleig, J.

2011-08-01

314

Photoionization and photoelectric loading of barium ion traps  

SciTech Connect

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 (6s{sup 2} {sup 1}S{sub 0}{r_reversible}6s6p {sup 3}P{sub 1}, {lambda}=791 nm) followed by excitation above the ionization threshold using a nitrogen gas laser ({lambda}=337 nm). Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation of the triplet 6s6p {sup 3}P{sub 1} state. Additionally, we report a particularly simple and efficient trap loading technique that employs an inexpensive uv epoxy curing lamp to generate photoelectrons.

Steele, A. V.; Churchill, L. R.; Griffin, P. F.; Chapman, M. S. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States)

2007-05-15

315

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.

316

Aluminum compounds as vaccine adjuvants.  

PubMed

Aluminum compounds are the only adjuvants used widely with routine human vaccines and are the most common adjuvants in veterinary vaccines also. Though there has been a search for alternate adjuvants, aluminum adjuvants will continue to be used for many years due to their good track record of safety, low cost and adjuvanticity with a variety of antigens. For infections that can be prevented by induction of serum antibodies, aluminum adjuvants formulated under optimal conditions are the adjuvants of choice. It is important to select carefully the type of aluminum adjuvant and optimize the conditions of adsorption for every antigen since this process is dependent upon the physico-chemical characteristics of both the antigens and aluminum adjuvants. Adsorption of antigens onto aluminum compounds depends heavily on electrostatic forces between adjuvant and antigen. Two commonly used aluminum adjuvants, aluminum hydroxide and aluminum phosphate have opposite charge at a neutral pH. The mechanism of adjuvanticity of aluminum compounds includes formation of a depot; efficient uptake of aluminum adsorbed antigen particles by antigen presenting cells due their particulate nature and optimal size (<10 m); and stimulation of immune competent cells of the body through activation of complement, induction of eosinophilia and activation of macrophages. Limitations of aluminum adjuvants include local reactions, augmentation of IgE antibody responses, ineffectiveness for some antigens and inability to augment cell-mediated immune responses, especially cytotoxic T-cell responses. PMID:10837642

Gupta

1998-07-01

317

RECLAMATION OF ALUMINUM FINISHING SLUDGES  

EPA Science Inventory

The research study of the reclamation of aluminum-anodizing sludges was conducted in two sequential phases focused on enhanced dewatering of aluminum-anodizing sludges to produce commercial-strength solutions of aluminum sulfate, i.e., liquid alum. The use of high-pressure (14 to...

318

Recycling of aluminum salt cake.  

National Technical Information Service (NTIS)

The secondary aluminum industry generates more than 110 (times) 10(sup 3) tons of salt-cake waste every year. This waste stream contains about 3--5% aluminum, 15--30% aluminum oxide, 30--40% sodium chloride, and 20--30% potassium chloride. As much as 50% ...

B. J. Jody E. J. Daniels P. V. Bonsignore D. E. Karvelas

1991-01-01

319

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

320

Separation of barium and lantanium on aluminium oxide  

SciTech Connect

Lanthanum 140 having a short period of half-decay is sufficient to be used as a radioactive indicator in chemistry investigations of lanthanides and actinides. Preparates based on lanthanum 140 allow one to carry out studies to determine rare-earth elements in technological products and raw materials. This work was devoted to the study of the separations of lanthanum 140 from barium 140 utilizing inorganic sorbents.

Khuzaev, S.; Mirzaeva, N.A.; Sultanov, A.

1993-12-31

321

Analysis of the sixth spectrum of barium: Ba VI  

Microsoft Academic Search

The spectrum of barium was photographed in the 300 -1240 wavelength region on a 3-m normal incidence spectrograph at the Antigonish laboratory. The source used was a triggered spark. All five levels of the ground configuration 5s25p3 and 42 of 44 levels of the 5s5p4 + 5s25p25d + 5s25p26s configurations of Ba VI have been established. One hundred and

A. Tauheed; Y. N. Joshi

1994-01-01

322

Substrate effects on the crystalline orientation of barium hexaferrite films  

Microsoft Academic Search

Insitu crystallized barium hexaferrite films have been deposited with a target-facing sputtering system under previously optimized conditions on four different substrates which are: SiO2, ZnO, Gd3Ga5O12, and Al2O3. By using several structural and magnetic characterizations different growth mechanisms were put forward according to the chosen substrate. On amorphous silica there is an important Ba affinity for SiO2, resulting in the

E. Lacroix; P. Gerard; G. Marest; M. Dupuy

1991-01-01

323

Texture and Microstructural Development in Gelcast Barium Hexaferrite  

SciTech Connect

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

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

2008-01-01

324

Elastic and Piezoelectric Coefficients of Single-Crystal Barium Titanate  

Microsoft Academic Search

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

Don Berlincourt; Hans Jaffe

1958-01-01

325

The positive temperature coefficient of resistivity in barium titanate  

Microsoft Academic Search

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

B. Huybrechts; K. Ishizaki; M. Takata

1995-01-01

326

Negative-U extended Hubbard model for doped barium bismuthates  

Microsoft Academic Search

We present detailed mean-field and random-phase-approximation studies of the negative-U, extended Hubbard model with a view to understanding the properties of the doped barium bismuthates. In particular, we obtain the phase diagram, the excitation spectrum, and the optical conductivity in the semiconducting phase of the bismuthates. We show by explicit calculations how this model leads to a natural explanation for

A. Taraphder; H. R. Krishnamurthy; Rahul Pandit; T. V. Ramakrishnan

1995-01-01

327

Preparation and microwave absorption properties of barium ferrite nanorods  

Microsoft Academic Search

Barium hexaferrite nanorods were successfully prepared using a solgel technique with polymethylmethacrylate as a template. The magnetic nanorods with diameters about 60nm and lengths about 300nm are visible from FESEM images. The electromagnetic parameters of BaFe12O19 with different shapes were measured with vector network analyzer at 515GHz. The results show that the microwave absorption properties of rod-shaped BaFe12O19 are better

Guohong Mu; Na Chen; Xifeng Pan; Haigen Shen; Mingyuan Gu

2008-01-01

328

AC Conducitivity in Bismuth-Substituted Barium Hexaferrites  

Microsoft Academic Search

Bismuth substituted barium hexaferrites in the composition series BaO(6-x) Fe2 O3x Bi2 O3 with 0

M. Pal; P. Brahma; D. Chakravorty

1994-01-01

329

Absolute ionisation functions for electron impact with barium  

Microsoft Academic Search

Absolute ionisation functions sigma n+(E)(n=1,2,3,4) and the total ionisation function sigma tot(E) for electron impact with barium have been determined for energies up to 600 eV. Modified crossed-beam techniques were applied using the excitation function of the light from the resonance transition as a reference standard for the cross sections. A time-of-flight device was used to separate ions with different

J.-M. Dettmann; F. Karstensen

1982-01-01

330

Acute barium intoxication following ingestion of soap water solution.  

PubMed

We present a rare case in which a young girl ingested a solution of a hair-removing soap. The ingestion resulted in profound hypokalemia and severe acidosis leading to flaccid paralysis, respiratory arrest and ventricular arrhythmias. Ultimately the patient made complete recovery. The soapwas found to contain barium sulfide. The degree of paralysis and acidosis appeared to be directly related to serum potassium levels. PMID:23559738

Joshi, Nandita; Sharma, Chhavi Sarabpreert; Sai; Sharma, Jai Prakash

2012-10-01

331

The Electrical Conductivity of Strontium-Barium Niobate  

NASA Astrophysics Data System (ADS)

We propose an explanation for the high electrical conductivity of the ferroelectric strontium-barium niobate. As the temperature T approaches the ferroelectric transition T c, the static dielectric constant \\varepsilon(0) diverges when a soft mode occurs. This divergence of \\varepsilon(0) reduces the donor binding energy, and increases the effective Bohr radius of the donor. The electrons bound to the donors become unbound, and the material becomes conductive.

Mahan, G. D.; Sofo, J. O.

2013-07-01

332

The distribution of rubidium, cesium and barium in the oceans  

Microsoft Academic Search

Rubidium, cesium and barium have been determined in several oceanic profiles by a neutron activation procedure based on the extraction of salt from 100 ml. samples by freeze-drying. Assuming a constant strontium-chlorinity ratio of 0.0425, strontium was used as an internal flux monitor. For 19.0% chlorinity the average concentrations of these three elements are 125 g Rb\\/1. (10 samples), 0.30

Ernst Bolter; Karl K. Turekian; Donald F. Schutz

1964-01-01

333

Light Scattering Investigations of Phase Transitions in Barium-Sodium  

Microsoft Academic Search

Barium sodium niobate, Ba_2NaNb _5O_{15} (BSN) possesses an incommensurate (IC) phase between an IC transition at T_1 = 300^circ C and a partial lock-in transition at T _{L} = 270^circ C. In addition, a few BSN crystals of the proper stoichiometry exhibit a reentrant phase transition at T_sp{1}{'} = 105 K to a phase with the same higher point group

William Franklin Oliver III

1988-01-01

334

Barium peritonitis: a rare complication of upper gastrointestinal contrast investigation.  

PubMed Central

Contrast examination of the gastrointestinal tract is rarely complicated by perforation. The colon and rectum are most commonly affected, with many perforations limited to the retroperitoneum. Generalised peritonitis is therefore rare, but is life-threatening and difficult to treat. We present two analogous cases in which extravasation of barium sulphate complicated contrast meal investigation. These cases illustrate important aspects in the management of this unusual occurrence. Images Figure

Karanikas, I. D.; Kakoulidis, D. D.; Gouvas, Z. T.; Hartley, J. E.; Koundourakis, S. S.

1997-01-01

335

Atoms in crossed fields: calculations for barium and hydrogen  

NASA Astrophysics Data System (ADS)

A method previously developed by Halley et al for non-hydrogenic atoms in laboratory strength static electric and magnetic fields (treated separately, and in a parallel geometry combination) has been extended to also handle crossed fields. Stimulated by results from recent experiments by Connerade et al at Imperial College, London, we have used the method to calculate the crossed field 0953-4075/30/16/004/img6 and 0953-4075/30/16/004/img7 barium photoabsorption spectra measured in these experiments. The calculated results are found to be in excellent agreement with those from experiment. Moreover, calculation complementing experiment has allowed the experimental magnetic field strength to be identified to better than 0.3% and barium field-free quantum defects to be determined to better than 0.01% (modulo unity). The corresponding photoabsorption spectra have also been calculated for hydrogen. Comparing calculated spectra and wavefunctions for the two atoms has identified the non-hydrogenic behaviour of barium, especially at longer wavelengths, to be due to the anomalous spectral locations, at near-zero electric field, of a small number of `seed' states. These `seed' states remain in their anomalous locations but grow in oscillator strength as the electric field strength is increased, thus giving rise to significant, localized, non-hydrogenic photoabsorption features. For progressively shorter wavelengths we reach a point where `seed' states can no longer be identified, and a much more uniform distribution of oscillator strength in the spectrum results.

Rao, Jianguo; Taylor, K. T.

1997-08-01

336

Orbital barium CRRES injection - effective source of ionospheric wavelike disturbances  

NASA Astrophysics Data System (ADS)

Spectral analysis of artificial wavelike disturbances (WD) in ionospheric parameters is presented. The sources of WD are barium clouds injections in Combined Release and Radiation Effects Satellite (CRRES) perigee experiments. Plasma concentration pulsations are found in the ionospheric F2 layer maximum over Havana (Cuba) at distances 1500-2500 km from the barium injection. It was found that for the spectral component with 10 min period, the delay (relative to injection moment) corresponded to WD propagation velocity in 323-390 m/s band and depended on the specific injection conditions. It was shown that in every experiment the WD effective propagation velocity in the terminator region correlated with the sunlit part of the trajectory from the injection point to Havana. When comparing this WD type with WD's of other origins (from earthquakes, high-altitude explosions and solar terminator), it was shown that purposeful injection in the ionosphere of even a small barium quantity with orbital velocity in terminator region might be the effective means for generation or amplification of natural WD.

Ruzhin, Yu. Ya.; Oraevsky, V. N.; Depueva, A. Kh.; Perez, H.; Palasio, L.

337

Barium thiolates and selenolates: syntheses and structural principles.  

PubMed

The synthesis and structural characterization of a family of barium thiolates and selenolates is described. The thiolates were synthesized by metallation of thiols, the selenolates by reductive insertion of the metal into the selenium-selenium bond of diorganodiselenides. Both reaction sequences were carried out by using barium metal dissolved in ammonia; this afforded barium thiolates and selenolates in good yield and purity. The structural principles displayed in the target compounds span a wide range of solid-state formulations, including monomeric and dimeric species, and separated ion triples, namely [Ba(thf)4(SMes*)2] (1; Mes* = 2,4,6-tBU3C6H2), [Ba(thf)4(SeMes*)2] (2), [Ba([18]crown-6)(hmpa)2][(SeMes*)2] (3), the dimeric [(Ba(py)3(thf)(SeTrip)2)2] (4; py = pyridine, Trip = 2,4.6-iPr3C6H2), and [Ba([18]crown-6)(SeTrip)2] (5). The full range of association modes is completed by [Ba([18]crown-6)(hmpa)SMes*][SMes*] (6) communicated earlier by this group. In the solid state, this compound displays an intermediate ion coordination mode: one anion is bound to the metal, while the second one is unassociated. Together these compounds provide structural information about all three different association modes for alkaline earth metal derivatives. This collection of structural data allows important conclusions about the influence of solvation and ligation on structural trends. PMID:11151839

Ruhlandt-Senge, K; Englich, U

2000-11-17

338

Synchronous barium peaks in high-resolution profiles of calcite and aragonite marine bivalve shells  

NASA Astrophysics Data System (ADS)

Barium/calcium profiles of bivalve shells are characterized by flat background signals periodically interrupted by sharp peaks, with the background signals correlated with water Ba/Ca. To test if the peaks are an environmental signal related to productivity, we analyzed high-resolution Ba/Ca profiles in bivalve shells that grew adjacent to one another. Two aragonitic Saxidomus giganteus show remarkable similarity over a decade of growth, clearly indicating an environmental forcing. Four calcitic Pecten maximus shells also record synchronous Ba/Ca peaks, again indicating an exogenous control. The Ba/Ca peaks, however, start ~40 days after the crash of a bloom, while sedimentation takes place immediately following the bloom. Barite formation in settling phytoplankton flocs, as has been previously proposed, is clearly not the cause of these peaks. Other possible causes, such as dissolved Ba in ambient water, spawning, shell organic matter content, and kinetic growth rate effects are also discussed, but none provide satisfactory explanations. Background shell Ba partition coefficients (Ba/Cacarbonate/Ba/Cawater) for both the calcitic shells (0.18) and aragonitic shells (0.16) are similar to that previously reported for the calcitic Mytilus edulis (~0.1). We suggest that Ba/Ca peaks in bivalve shells are caused by an as yet undetermined environmental forcing, while background Ba/Ca levels are a good indication of dissolved Ba/Ca in the water; both are independent of shell mineralogy.

Gillikin, David Paul; Lorrain, Anne; Paulet, Yves-Marie; Andr, Luc; Dehairs, Frank

2008-10-01

339

Synthesis of barium titanate films by plasma electrolytic oxidation at room electrolyte temperature  

Microsoft Academic Search

Crystalline barium titanate films were directly synthesized onto Ti plates by plasma electrolytic oxidation at room temperature using barium acetate and 2 M NaOH as electrolytes. The effect of the concentration of barium acetate ranging from 0.05 M to 0.5 M on the synthesis of BaTiO3 was investigated. XRD results showed that the formation of BaTiO3 required a minimum of

Chu-Tsun Wu; Fu-Hsing Lu

2005-01-01

340

Growth of calcium phosphate on poling treated ferroelectric BaTiO 3 ceramics  

Microsoft Academic Search

Barium titanate (BaTiO3; BTO) is ferroelectric and piezoelectric after poling treatment. In this study, the bioactivity of BTO was investigated after a poling treatment by examining the formation of crystal growth on specimen surfaces in vitro. Negatively charged BTO surfaces showed calcium phosphate (Ca-P) crystal growth, while deposition of sodium chloride was observed on the positively charged BTO surfaces. After

Yeong-Joon Park; Kyu-Seog Hwang; Jong-Eun Song; Joo L Ong; H Ralph Rawls

2002-01-01

341

Aluminum-ferricyanide battery  

NASA Astrophysics Data System (ADS)

A battery capable of producing high current densities with high charge capacity is described which includes an aluminum anode, a ferricyanide electrolyte and a second electrode capable of reducing ferricyanide electrolyte which is either dissolved in an alkaline solution or alkaline seawater solution. The performance of the battery is enhanced by high temperature and high electrolyte flow rates.

Marsh, Catherine; Licht, Stuart L.

1993-11-01

342

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

343

Aluminum Coatings for Steel  

Microsoft Academic Search

Aluminum coated steel possesses excellent oxidation and corrosion resistance in sulfur and marine: environments and can substitute for expensive alloy of steels. Hot dip aluminizing (HAD) and pack cementation calorizing (CAL) are dealt with in detail. IN HDA coats, some alloying action takes place, when the substrate is dipped in molten Al at 973 K for 1-2 minutes. The coat

Aruna Bahadur

1996-01-01

344

Foamed Aluminum Propellant Study.  

National Technical Information Service (NTIS)

This report summarizes the results of an AFRPL feasibility study on the use of a new experimental material, foam aluminum. The chief areas of interest center around the value of this material in high-burn-rate, pulse or end-burning motors and high acceler...

B. R. Warren C. G. Bacon

1968-01-01

345

Pitting corrosion of aluminum  

Microsoft Academic Search

This review describes the experiments performed during the last few decades which enhance knowledge of the pitting of aluminum. Specifically, metastable and stable pits, pit chemistry and the effect of intermetallics on pitting are discussed. The properties of metastable alloys and inhibition of Al are also discussed.

Z Szklarska-Smialowska

1999-01-01

346

REMOVAL OF ALUMINUM COATINGS  

DOEpatents

A process is presented for dissolving aluminum jackets from uranium fuel elements without attack of the uranium in a boiling nitric acid-mercuric nitrate solution containing up to 50% by weight of nitrtc acid and mercuric nitrate in a concentration of between 0.05 and 1% by weight.

Peterson, J.H.

1959-08-25

347

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

348

Serum Aluminum Transport and Aluminum Uptake in Chronic Renal Failure: Role of Iron and Aluminum Metabolism  

Microsoft Academic Search

Several factors have been blamed for increasing gastrointestinal absorption of aluminum. The likely role of iron metabolism was suggested some years ago. As iron and aluminum share many chemical properties, it is reasonable to think they also share biological pathways. The aim of this study was: (a) to evaluate serum aluminum transport and its relationship with iron-binding capacity, and (b)

Jorge B. Cannata; Ines R. Olaizola; Carlos Gomez-Alonso; Pilar Menndez-Fraga; Mario Alonso-Suarez; Bernardino Diaz-Lopez

1993-01-01

349

SOLDERING OF ALUMINUM BASE METALS  

DOEpatents

This patent deals with the soldering of aluminum to metals of different types, such as copper, brass, and iron. This is accomplished by heating the aluminum metal to be soldered to slightly above 30 deg C, rubbing a small amount of metallic gallium into the part of the surface to be soldered, whereby an aluminum--gallium alloy forms on the surface, and then heating the aluminum piece to the melting point of lead--tin soft solder, applying lead--tin soft solder to this alloyed surface, and combining the aluminum with the other metal to which it is to be soldered.

Erickson, G.F.

1958-02-25

350

Determination of silicon, barium, and titanium in fresnoite single crystals and raw materials for them  

SciTech Connect

Single crystals of fresnoite show good electroptic parameters and high resistance to laser radiation, and are being examined for use in acoustoelectronics and optoelectronics. This paper investigates simple and reliable methods of determining silicon, barium, and titanium without preliminary separation. The authors examined the effects of large amounts of titanium and barium on the determination of silicon; it was found that titanium interferes. Barium does not interfere with the determination of silicon. Barium and titanium were determined by EDTA titration. The relative standard deviation in determining each of the elements did not exceed 6 x 10/sup -3/.

Sizonenko, N.T.; Egorova, L.A.; Gaiduk, O.V.; Khukhryanskii, A.K.

1985-09-01

351

Mesoporous aluminum phosphite  

SciTech Connect

High surface area pure mesoporous aluminum-phosphorus oxide-based derivatives have been synthesized through an S{sup +}I{sup -} surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from aluminum atrane complexes and phosphoric and/or phosphorous acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from mesoporous aluminum phosphate (ALPO) up to total incorporation of phosphite entities (mesoporous aluminum phosphite), which results in a gradual evolution of the acidic properties of the final materials. While phosphate groups in ALPO act as network building blocks (bridging Al atoms), the phosphite entities become basically attached to the pore surface, what gives practically empty channels. The mesoporous nature of the final materials is confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and N{sub 2} adsorption-desorption isotherms. The materials present regular unimodal pore systems whose order decreases as the phosphite content increases. NMR spectroscopic results confirm the incorporation of oxo-phosphorus entities to the framework of these materials and also provide us useful information concerning the mechanism through which they are formed. - Abstract: TEM image of the mesoporous aluminum phosphite showing the hexagonal disordered pore array that is generated by using surfactant micelles as template. Also a scheme emphasizing the presence of an alumina-rich core and an ALPO-like pore surface is presented.

El Haskouri, Jamal, E-mail: haskouri@uv.e [Institut de Ciencia dels Materials de la Universitat de Valencia (ICMUV), P. O. Box 22085, 46071 Valencia (Spain); Perez-Cabero, Monica; Guillem, Carmen; Latorre, Julio; Beltran, Aurelio; Beltran, Daniel [Institut de Ciencia dels Materials de la Universitat de Valencia (ICMUV), P. O. Box 22085, 46071 Valencia (Spain); Amoros, Pedro, E-mail: pedro.amoros@uv.e [Institut de Ciencia dels Materials de la Universitat de Valencia (ICMUV), P. O. Box 22085, 46071 Valencia (Spain)

2009-08-15

352

Potassium blocks barium permeation through a calcium-activated potassium channel  

Microsoft Academic Search

Single high-conductance Ca2+-activated K + channels from rat skeletal muscle were inserted into planar lipid bilayers, and discrete blocking by the Ba 2+ ion was studied. Specifically, the ability of external K to reduce the Ba ~+ dissocia- tion rate was investigated. In the presence of 150 mM internal K +, 1-5 #M inter- nal Ba z+, and 150

JACQUES NEYTON; CHRISTOPHER MILLER

1988-01-01

353

Highly-textured thallium-barium-calcium-copper-oxide polycrystalline superconducting films on silver substrates  

SciTech Connect

Thick (8 to 10 {mu}m) Ba--Ca--Cu--O films have been rf magnetron sputtered onto Ag alloy (Consil 995) substrates. The films were given a post-deposition anneal in an over pressure of Tl in order to form the superconducting phases. Annealing protocols were done which result in predominantly the 1212 and 2212 phases. The substrate orientation was varied to determine its effect on film orientation. Material properties of the films were characterized by x-ray diffraction (XRD), ion beam backscattering spectroscopy, energy dispersive x-ray analysis (EDAX), and scanning electron microscopy (SEM). Electrical characterization of the films was done using dynamic impedance (DI) at 10 kHz and rf surface resistance (R{sub s}) at 18 GHz in a TE{sub 011} fundamental mode cavity. 19 refs., 7 figs.

Arendt, P.; Elliott, N.; Cooke, D.W.; Dye, R.; Gray, E.; Hubbard, K.; Martin, J.; Reeves, G.; Brown, D.; Klapetzky, A.

1990-01-01

354

Flame synthesis of calcium-, strontium-, barium fluoride nanoparticles and sodium chloride.  

PubMed

Non-oxidic salts such as NaCl, CaF2, SrF2 and BaF2 were synthesised using a flame spray method; optional doping of such fluorides with rare earth elements suggests possible applications in optics. PMID:15791326

Grass, Robert N; Stark, Wendelin J

2005-02-03

355

Straczekite, a new calcium barium potassium vanadate mineral from Wilson Springs, Arkansas.  

USGS Publications Warehouse

Straczekite occurs as a rare secondary mineral in fibrous seams, along with other V minerals (A.M. 64-713), in ore from the vanadium mine in Wilson Springs (formerly Potash Sulfur Springs), Garland County, Arkansas. It forms soft, thin laths of dark greenish black crystals up to 0.5 mm in length. Indexed XRD data are tabulated; strongest lines 3.486(100), 10.449(50), 1.8306(50), 1.9437(15) A; a 11.679, b 3.6608, c 10.636 A, beta 100.53o; space group C2/m, C2 or Cm. Chemical analysis gave V2O5 66.4, V2O4 15.3, Fe2O3 0.9, Na2O 0.4, K2O 1.8, CaO 2.5, BaO 5.5, H2O 7.2, = 100.0, leading to the formula (Ca0.39Ba0.31K0.33Na0.11)- 196(V4+1.59V5+6.31Fe3+0.10)O20.02(H2O)2.9; Dcalc. 3.21 g/cm3. A possible layer structure is discussed. The name is for J. A. Straczek, Chief Geologist at Union Carbide Corp.-R.A.H.

Evans, Jr, H. T.; Nord, G.; Marinenko, J.; Milton, C.

1984-01-01

356

Chemical interactions of bariumcalciumaluminosilicate-based sealing glasses with oxidation resistant alloys  

Microsoft Academic Search

In most planar solid oxide fuel cells (SOFC) stack designs, the interconnect, which is typically made from an oxidation resistant alloy, potentially including austenitic chromia-forming, ferritic chromia-forming, and alumina-forming alloys, has to be hermitically sealed to its adjacent components, usually by a sealing glass. To maintain the structural stability and minimize the degradation of stack performance, the sealing glass must

Zhenguo Yang; Jeffry W. Stevenson; Kerry D. Meinhardt

2003-01-01

357

Potassium blocks barium permeation through a calcium-activated potassium channel  

PubMed Central

Single high-conductance Ca2+-activated K+ channels from rat skeletal muscle were inserted into planar lipid bilayers, and discrete blocking by the Ba2+ ion was studied. Specifically, the ability of external K+ to reduce the Ba2+ dissociation rate was investigated. In the presence of 150 mM internal K+, 1-5 microM internal Ba2+, and 150 mM external Na+, Ba2+ dissociation is rapid (5 s-1) in external solutions that are kept rigorously K+ free. The addition of external K+ in the low millimolar range reduces the Ba2+ off-rate 20-fold. Other permeant ions, such as Tl+, Rb+, and NH4+ show a similar effect. The half- inhibition constants rise in the order: Tl+ (0.08 mM) less than Rb+ (0.1 mM) less than K+ (0.3 mM) less than Cs+ (0.5 mM) less than NH4+ (3 mM). When external Na+ is replaced by 150 mM N-methyl glucamine, the Ba2+ off-rate is even higher, 20 s-1. External K+ and other permeant ions reduce this rate by approximately 100-fold in the micromolar range of concentrations. Na+ also reduces the Ba2+ off-rate, but at much higher concentrations. The half-inhibition concentrations rise in the order: Rb+ (4 microM) less than K+ (19 microM) much less than Na+ (27 mM) less than Li+ (greater than 50 mM). The results require that the conduction pore of this channel contains at least three sites that may all be occupied simultaneously by conducting ions.

1988-01-01

358

The effects of calcium channel inhibitors and other procedures affecting calcium translocation on drug-induced rhythmic contractions in the rat vas deferens.  

PubMed Central

In the rat isolated vas deferens, methoxamine 8.1 microM produced an initial phasic response that declined towards baseline and was followed by rhythmic contractions that continued until wash-out. These responses were predominant in the epididymal half. BaCl2 1 mM produced a similar type of response which was not mediated by noradrenaline release or activation of alpha-adrenoceptors. The barium responses were similar in the epididymal and prostatic halves. Incubation in nominally Ca2+-free solution caused abolition or near abolition of rhythmic contractions produced by barium or methoxamine. The initial phasic response to methoxamine was abolished in Ca2+-free solution, whereas that produced by barium persisted. Rhythmic contractions produced by methoxamine or barium were inhibited by Mg2+ (2.4-20 mM) and by La3+ (1-5 mM). Mg2+ had selectivity for inhibition of the frequency of methoxamine- but not barium-induced rhythmic contractions. Despite their dependence on [Ca2+]o, barium- and methoxamine-induced rhythmic contractions were resistant to inhibition by calcium channel inhibitors. Verapamil, nifedipine and flunarazine inhibited the amplitude of rhythmic contractions more readily than the frequency (methoxamine IC50 for verapamil: amplitude = 29.8 +/- 5.40 microM, n = 6, frequency = 96.7 +/- 31.0 microM, n = 5, for nifedipine: amplitude = 2.42 +/- 0.34 microM, n = 7, frequency = 3.24 +/- 0.75 microM, n = 7, and for flunarizine: amplitude = 15.9 +/- 5.95 microM, n = 7, frequency = 153 +/- 28.6 microM, n = 7). There was no differentiation between inhibition of methoxamine and barium-induced responses. Like Mg2+, methoxyverapamil selectively inhibited the frequency of methoxamine-induced contractions (IC50: amplitude = 16.8 +/- 2.86 microM, n = 5, frequency = 2.07 +/- 0.81 microM, n = 5) but not barium-induced contractions (IC50: amplitude = 13.9 +/- 1.95 microM, n = 5, frequency = 48.5 +/- 8.98 microM, n = 5). Diazoxide (43.3-2167 microM) and nitroprusside (3.36-6712 microM) had only a small effect on barium contractions, but produced a dose-related reduction in the amplitude of methoxamine-induced responses. Diazoxide and nitroprusside caused methoxamine contractions to occur in groups, although they had no effect on their overall frequency. It is concluded that barium- and methoxamine-induced rhythmic contractions in the rat vas deferens are mediated by the entry of [Ca2+]o via membrane calcium channels that have a lower affinity (10-100 X) for calcium channel inhibitors than those mediating the KCl response.(ABSTRACT TRUNCATED AT 400 WORDS)

Hay, D. W.; Wadsworth, R. M.

1983-01-01

359

Coronary Calcium Scan  

MedlinePLUS

... the NHLBI on Twitter. What Is a Coronary Calcium Scan? A coronary calcium scan is a test ... you have calcifications in your coronary arteries. Coronary Calcium Scan Figure A shows the position of the ...

360

Get Enough Calcium  

MedlinePLUS

... Physical Activity > Nutrition > Get Enough Calcium Get Enough Calcium The Basics Take Action! Ver en espaol Content ... August 28, 2013 The Basics Your body needs calcium to build strong bones when you are young ...

361

Calcium and bones (image)  

MedlinePLUS

Calcium is one of the most important minerals for the growth, maintenance, and reproduction of the human ... body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the ...

362

Calcium and Bone Health  

MedlinePLUS

... to... Aadir en... Favorites Delicious Digg Google Bookmarks Calcium and Bone Health Bones play many roles in ... with osteoporosis, please visit the National Osteoporosis Foundation .* Calcium Calcium is a mineral needed by the body ...

363

Calcium source (image)  

MedlinePLUS

Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has ... as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the ...

364

Separation of lanthanum, hafnium, barium and radiotracers yttrium-88 and barium-133 using crystalline zirconium phosphate and phosphonate compounds as prospective materials for a Ra-223 radioisotope generator.  

PubMed

Crystalline hybrid organic/inorganic ion exchangers based on zirconium phosphate and phosphonate compounds were evaluated for application in radium-223 generator for radiopharmaceutical applications. Various compositions were synthesized and the selectivity of these materials was determined for inactive lanthanum, hafnium and barium, and radiotracers yttrium-88 and barium-133. The hybrid materials show very efficient lanthanum/barium separation; the response for zirconium phosphate was even better. A small-scale column loaded with pelletized zirconium phosphate compound demonstrated excellent retention of (88)Y and release of (133)Ba. PMID:21421323

Mller, Teresia; Bestaoui, Naima; Wierzbicki, Melissa; Adams, Todd; Clearfield, Abraham

2011-02-26

365

Amino acid residues outside of the pore region contribute to N-type calcium channel permeation.  

PubMed

It is widely believed that the selectivity of voltage-dependent calcium channels is mainly controlled by amino acid residues contained within four p-loop motifs forming the pore of the channel. An examination of the amino acid sequences of high voltage-activated calcium channels reveals that their domain III S5-H5 regions contain a highly conserved motif with homology to known EF hand calcium binding proteins, hinting that this region may contribute to channel permeation. To test this hypothesis, we used site-directed mutagenesis to replace three conserved negatively charged residues in the N-type calcium channel alpha1B subunit (Glu-1321, Asp-1323, and Glu-1332) with positively charged amino acids (lysine and arginine) and studied their effect on ion selectivity using whole cell and single channel patch clamp recordings. Whereas the wild type channels conducted barium much more effectively than calcium, the mutant displayed nearly equal permeabilities for these two ions. Individual replacement of residue 1332 or a double substitution of residues 1321 and 1323 with lysine and arginine, respectively, were equally effective. Disruption of the putative EF hand motif through replacement of the central glycine residue (1326) with proline resulted in a similar effect, indicating that the responses observed with the triple mutant were not due to changes in the net charge of the channel. Overall, our data indicate that residues outside of the narrow region of the pore have the propensity to contribute to calcium channel permeation. They also raise the possibility that interactions of calcium ions with a putative calcium binding domain at the extracellular side of the channel may underlie the differential permeabilities of the channel for barium and calcium ions. PMID:11120735

Feng, Z P; Hamid, J; Doering, C; Jarvis, S E; Bosey, G M; Bourinet, E; Snutch, T P; Zamponi, G W

2000-12-18

366

Chemistry of the Calsinter process for aluminum recovery from fly ash  

SciTech Connect

In 1977, 48.5 million tons of fly ash was produced in the United States from coal combustion. Based on an estimated average of 11.5% aluminum content in fly ash, this represent 5.58 million tons of aluminum. Similarly, for titanium, a fly ash content of 0.89% corresponds to 0.432 million tons of titanium. Both the Al and Ti quantities in flyash are close to US demand. One method for Al recovery from fly ash, the Calsinter method, is discussed. In this method fly ash is blended with gypsum and limestone. The mixture is pelletized and sintered at 1000 to 1250/sup 0/C. The sinter cake is ground and leached with dilute sulfuric acid. Waste solids are removed by filtration, and metal values are recovered from the filtrate. Aluminum can be recovered from the leach liquor by crystallization as ammonium alum or aluminum sulfate. Other metal values can be recovered by solvent extraction. Flue gas scrubber sludge, resulting from the limestone scrubbing of SO/sub 2/ from flue gas, contains calcium sulfate, calcium sulfite and unreacted calcium carbonate, and can be used instead of the gypsum and limestone. Thus, the Calsinter process becomes more attractive by combining two waste products to recover valuable resources. The characterization of fly ash and the Calsinter process material, and the effects of sintering temperature, composition, sintering time, and leach rate on the aluminum recovery are described.

Egan, B.Z.; Seeley, F.G.; Kelmers, A.D.

1980-01-01

367

Aluminum microstructures on anodic alumina for aluminum wiring boards.  

PubMed

The paper demonstrates simple methods for the fabrication of aluminum microstructures on the anodic oxide film of aluminum. The aluminum sheets were first engraved (patterned) either by laser beam or by embossing to form deep grooves on the surface. One side of the sheet was then anodized, blocking the other side by using polymer mask to form the anodic alumina. Because of the lower thickness at the bottom part of the grooves, the part was completely anodized before the complete oxidation of the other parts. Such selectively complete anodizing resulted in the patterns of metallic aluminum on anodic alumina. Using the technique, we fabricated microstructures such as line patterns and a simple wiring circuit-board-like structure on the anodic alumina. The aluminum microstructures fabricated by the techniques were embedded in anodic alumina/aluminum sheet, and this technique is promising for applications in electronic packaging and devices. PMID:20356280

Jha, Himendra; Kikuchi, Tatsuya; Sakairi, Masatoshi; Takahashi, Hideaki

2010-03-01

368

Mechanism and kinetics of aluminum and iron leaching from coal fly ash by sulfuric acid  

Microsoft Academic Search

The mechanism and kinetics of leaching of aluminum and iron from Coal Fly Ash (CFA), by sulfuric acid, involves a rate controlling step of mass transfer. It is shown that, in the leaching process, particles follow the shrinking core model with respect to formation of unreacted core that is encapsulated by a leached, porous, layer. Formation of diffusion resistant calcium

A. Seidel; Y. Zimmels

1998-01-01

369

Aluminum permanganate battery  

NASA Astrophysics Data System (ADS)

A battery is provided comprising an aluminum anode, an aqueous solution of permanganate as the cathodic species and a second electrode capable of reducing permanganate. Such a battery system is characterized by its high energy density and low polarization losses when operating at high temperatures in a strong caustic electrolyte, i.e., high concentration of hydroxyl ions. A variety of anode and electrocatalyst materials are suitable for the efficient oxidation-reduction process and are elucidated.

Marsh, Catherine; Licht, Stuart L.

1993-11-01

370

Mechanisms of Aluminum Tolerance  

Microsoft Academic Search

\\u000a Aluminum (Al) toxicity limits agricultural productivity over much of the worlds arable land by inhibiting root growth and\\u000a development. Affected plants have difficulty in acquiring adequate water and nutrition from their soil environments and thus\\u000a have stunted shoot development and diminished yield. Al toxicity is due to soil acidity and is largely a natural problem;\\u000a however, it can also result

Owen A. Hoekenga; Jurandir V. Magalhaes

371

Minerals Yearbook, 1989. Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

The Bureau of Mines publishes reports for a variety of calcium-containing minerals and compounds because of their commercial significance and contribution to the quality of human life. Calcium fluoride is sold as fluorspar; calcium sulfate as gypsum or an...

M. M. Miller

1990-01-01

372

Minerals Yearbook, 1990. Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

The U.S. Bureau of Mines publishes reports for a variety of calcium-containing minerals and compounds because of their commercial significance and contribution to the quality of human life. The 'Calcium and Calcium Compounds Annual Report' includes calciu...

M. M. Miller

1991-01-01

373

Calcium Depletion in Forest Soils of the Eastern US  

NSDL National Science Digital Library

This week's In the News focuses on calcium depletion in the forest soils of ten states in the Eastern US. Calcium depletion decreases the ability of trees to "ward off stresses such as temperature changes and insect defoliation". Scientists have noted that sugar maples and red spruce trees in ten different sites now have reduced resistance to "defoliation by insects and low winter temperatures". In a recent report, scientists Gregory Lawrence and Thomas Huntington of the US Geological Survey (USGS) claim that a cause of calcium depletion is acid rain. Lawrence and Huntington describe a mechanism whereby acid rain decreases calcium soil content: ". . . sulfuric and nitric acids from acid deposition . . . tend to remain in solution within the mineral soil where they lower the pH, thereby releasing aluminum to soil water and causing the leaching of calcium". In addition, timber harvesting may also contribute to the depletion of calcium in forest soils because, as trees are removed from the site, the calcium within them is removed as well. Due to the combined effects of acid rain and timber harvest, some areas have low calcium soil content and consequently low forest growth. The nine resources listed provide background information on acid rain and articles and research efforts on the relationship between calcium soil content and acid rain.

Nannapaneni, Sujani.

374

Crystal structure of complex natural aluminum magnesium calcium iron oxide  

NASA Astrophysics Data System (ADS)

The structure of a new natural oxide found near the Tashelga River (Eastern Siberia) was studied by X-ray diffraction. The pseudo-orthorhombic unit cell parameters are a = 5.6973(1) , b = 17.1823(4) , c = 23.5718(5) , ? = 90, sp. gr. Pc. The structure was refined to R = 0.0516 based on 4773 reflections with | F| > 7?( F) taking into account the twin plane perpendicular to the z axis (the twin components are 0.47 and 0.53). The crystal-chemical formula ( Z = 4) is Ca2Mg{2/IV}Fe{2/(2+)IV}[Al{14/VI}O31(OH)][Al{2/IV}O][AlIV]ALIV(OH)], where the Roman numerals designate the coordination of the atoms. The structure of the mineral is based on wide ribbons of edge-sharing Al octahedra (an integral part of the spinel layer). The ribbons run along the shortest x axis and are inclined to the y and z axes. The adjacent ribbons are shifted with respect to each other along the y axis, resulting in the formation of step-like layers in which the two-ribbon thickness alternates with the three-ribbon thickness. Additional Al octahedra and Mg and Fe2+ tetrahedra are located between the ribbons. The layers are linked together to form a three-dimensional framework by Al tetrahedra, Ca polyhedra, and hydrogen bonds with the participation of OH groups.

Rastsvetaeva, R. K.; Aksenov, S. M.; Verin, I. A.

2010-07-01

375

Crystal structure of complex natural aluminum magnesium calcium iron oxide  

SciTech Connect

The structure of a new natural oxide found near the Tashelga River (Eastern Siberia) was studied by X-ray diffraction. The pseudo-orthorhombic unit cell parameters are a = 5.6973(1) A, b = 17.1823(4) A, c = 23.5718(5) A, {beta} = 90{sup o}, sp. gr. Pc. The structure was refined to R = 0.0516 based on 4773 reflections with vertical bar F vertical bar > 7{sigma}(F) taking into account the twin plane perpendicular to the z axis (the twin components are 0.47 and 0.53). The crystal-chemical formula (Z = 4) is Ca{sub 2}Mg{sub 2}{sup IV}Fe{sub 2}{sup (2+)IV}[Al{sub 14}{sup VI}O{sub 31}(OH)][Al{sub 2}{sup IV}O][Al{sup IV}]AL{sup IV}(OH)], where the Roman numerals designate the coordination of the atoms. The structure of the mineral is based on wide ribbons of edge-sharing Al octahedra (an integral part of the spinel layer). The ribbons run along the shortest x axis and are inclined to the y and z axes. The adjacent ribbons are shifted with respect to each other along the y axis, resulting in the formation of step-like layers in which the two-ribbon thickness alternates with the three-ribbon thickness. Additional Al octahedra and Mg and Fe{sup 2+} tetrahedra are located between the ribbons. The layers are linked together to form a three-dimensional framework by Al tetrahedra, Ca polyhedra, and hydrogen bonds with the participation of OH groups.

Rastsvetaeva, R. K., E-mail: rast@ns.crys.ras.ru; Aksenov, S. M.; Verin, I. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2010-07-15

376

Composition and structure measurements in an ionospheric barium cloud. Final report  

SciTech Connect

A 48 kg barium payload was launched from Eglin Air Force Base, Florida on 12 December 1980 at 2311 GMT and detonated at 183.7 km. At 2342:50.25 GMT, a second rocket, instrumented with an ion mass spectrometer and pulsed plasma probes, was fired to traverse the barium cloud. Composition, ion density, and structure measurements were acquired up to 241.2 km in both the natural and disturbed ionosphere. The rocket penetrated the barium cloud between 147 and 184 km. In addition to the Ba+, Ba++ produced by H Lyman alpha ionization, and Ca+, an impurity in the barium were detected in the cloud. A peak barium ion concentration of about 6,000,000 ions cu cm was measured at 161 km where the ionospheric NO+ and O2+ ions were essentially eliminated by large recombination loss. The bottom side of the barium cloud had a relatively smooth structure while the top side showed significant density fluctuations. The first experimental evidence of a theoretically predicted E region 'image cloud' was found in the form of an enhanced NO+ layer just below the barium cloud. Unexplained wave-like density variations in O+, NO+, and O2(+) also were seen above the barium cloud to 195 km. A quantitative estimate of the outgassing water vapor concentrations near the payload's surface was made using the fast change transfer rate coefficient for O+ + H2O yields H2O+ + O that created the observed water vapor ions.

Narcisi, R.; Trzcinski, E.; Federico, G.; Wlodyka, L.; Bench, P.

1981-12-23

377

Primary lymphoma of the colon and rectum: CT and barium enema correlation  

Microsoft Academic Search

This paper presents the computed tomographic (CT) and barium enema (BE) findings in seven patients with proven primary lymphoma of the colon and rectum. CT and BE examination are complimentary studies in the evaluation of primary lymphoma of the colorectum, and certain relevant findings may be missed when radiographic evaluation does not include both modalities. Both CT and barium studies

Susan H. Wyatt; Elliot K. Fishman; Bronwyn Jones

1993-01-01

378

Rapid detection of myrosinase-producing fungi: a plate method based on opaque barium sulphate formation  

Microsoft Academic Search

A simple and rapid technique to assess the capability of fungi to produce myrosinase is reported. This was carried out by growing the tested fungi in sinigrinbarium agar plates. Strains capable of producing myrosinase were indicated by an opaque barium sulphate zone forming underneath and\\/or surrounding their colonies. This simple test has been confirmed by determination of myrosinase activity in

P. Sakorn; N. Rakariyatham; H. Niamsup; P. Nongkunsarn

2002-01-01

379

H? production in a small multicusp ion source with addition of barium  

Microsoft Academic Search

The effect on H? production by adding barium to a hydrogen discharge, in a small magnetically filtered multicusp ion source, has been investigated. It is found that the addition of barium can increase the H? output by a factor of 30. A strong dependence of H? output on the temperature of the ion source wall has also been observed.

S. R. Walther; K. N. Leung; W. B. Kunkel

1989-01-01

380

H - production in a small multicusp ion source with addition of barium  

Microsoft Academic Search

The effect on H⁻ production by adding barium to a hydrogen discharge, in a small magnetically filtered multicusp ion source, has been investigated. It is found that the addition of barium can increase the H⁻ output by a factor of 30. A strong dependence of H⁻ output on the temperature of the ion source wall has also been observed.

S. R. Walther; K. N. Leung; W. B. Kunkel

1989-01-01

381

Relative sensitivity of colonoscopy and barium enema for detection of colorectal cancer in clinical practice  

Microsoft Academic Search

BACKGROUND & AIMS: The relative sensitivities of barium enema and colonoscopy for colorectal cancer are still debated. The aim of this study was to determine the relative sensitivity of barium enema and colonoscopy in general clinical practice. METHODS: Medical records of 2193 consecutive colorectal cancer cases identified in 20 central Indiana hospitals were reviewed. All procedures performed within 3 years

DK Rex; EY Rahmani; JH Haseman; GT Lemmel; S Kaster; JS Buckley

1997-01-01

382

SHORT TERM TOXICITY (1 AND 10 DAY GAVAGE) OF BARIUM CHLORIDE IN MALE AND FEMALE RATS  

EPA Science Inventory

To assess adverse effects that might be caused by an event resulting in high levels of barium in drinking water, rats were gavaged with barium chloride (BaCl2 at dosage levels of 30,100, and 300 rng/kg in a 1-day study and at 100,145,209, and 300 rng/kg for 10 days, and the effec...

383

Epitaxial bismuth telluride layers grown on (111) barium fluoride substrates suitable for MQW-growth  

Microsoft Academic Search

Multi quantum wells and superlattices are discussed as suitable tools for increasing ZT. Best layer quality should be expected only for lattice matched growth. Therefore (111) barium fluoride should be most suitable compared to other common substrates like mica and sapphire, although up to now epitaxial growth of bismuth telluride on (111) barium fluoride with atomically flatness was not achieved.

J. Nurnus; H. Bottner; H. Beyer; A. Lambrecht

1999-01-01

384

Colonoscopy without premedication versus barium enema: a comparison of patient discomfort  

Microsoft Academic Search

Background: Colonoscopy is considered a painful procedure requiring routine intravenous sedation. We investigated whether unsedated colonoscopy causes more discomfort than barium enema. Methods: Procedure-related discomfort was determined in 100 consecutive patients undergoing colonoscopy without premedication and in an equal number of patients referred for sigmoidoscopy and barium enema. All patients underwent such examinations for the first time and had no

Volker F. Eckardt; Gerd Kanzler; Dieter Willems; Alexander J. Eckardt; Gudrun Bernhard

1996-01-01

385

Synthesis and properties of barium titanate solid solution thin films deposited on copper substrates  

Microsoft Academic Search

Barium titanate thin films were deposited via chemical solution deposition using a hybrid-chelate chemistry directly on copper foil substrates. A process was developed to crystallize and densify the ferroelectric films at 900C by using a reductive atmosphere containing nitrogen, hydrogen, water vapor, and oxygen impurities such that film constituents were oxidized to form barium titanate and the foil substrate remained

Jon Fredrick Ihlefeld

2006-01-01

386

LACK OF EFFECT OF DRINKING WATER BARIUM ON CARDIOVASCULAR RISK FACTORS  

EPA Science Inventory

Higher cardiovascular mortality has been associated in a single epidemiological study with higher levels of barium in drinking water. he purpose of this study was to determine whether drinking water barium at levels found in some U.S. communities alters the known risk factors for...

387

Nanocrystalline structure and magnetic properties of barium ferrite particles prepared via glycine as a fuel  

Microsoft Academic Search

The barium ferrite particles were prepared using a self-propagating combustion method with glycine as a fuel. The process was investigated with differential scanning calorimeter and thermogravimetric analysis. The effects of the pH value of the precursor solution, the glycine dosage and calcination temperature on the morphology, the crystalline structure and the magnetic properties of the barium ferrite particles were studied

Jianxun Qiu; Le Liang; Mingyuan Gu

2005-01-01

388

Observation and theory of the barium releases from the CRRES satellite  

Microsoft Academic Search

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

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

1992-01-01

389

Extracting aluminum from dross tailings  

NASA Astrophysics Data System (ADS)

Aluminum dross tailings, an industrial waste, from the Egyptian Aluminium Company (Egyptalum) was used to produce two types of alums: aluminum-sulfate alum [itAl2(SO4)3.12H2O] and ammonium-aluminum alum [ (NH 4)2SO4AL2(SO4)3.24H2O]. This was carried out in two processes. The first process is leaching the impurities using diluted H2SO4 with different solid/liquid ratios at different temperatures to dissolve the impurities present in the starting material in the form of solute sulfates. The second process is the extraction of aluminum (as aluminum sulfate) from the purifi ed aluminum dross tailings thus produced. The effects of temperature, time of reaction, and acid concentration on leaching and extraction processes were studied. The product alums were analyzed using x-ray diffraction and thermal analysis techniques.

Amer, A. M.

2002-11-01

390

Acute barium toxicity from ingestion of snake fireworks  

Microsoft Academic Search

IntroductionIngestion of fireworks has been infrequently reported in the medical literature. We describe a case of acute barium poisoning\\u000a following firework ingestion.\\u000a \\u000a \\u000a \\u000a Case ReportA 35-year-old male with a history of severe mental retardation presented with vomiting and diarrhea following ingestion of\\u000a 16 small fireworks (color snakes and black snakes). His condition rapidly deteriorated and he developed obtundation, wide\\u000a complex dysrhythmias,

Sean H. Rhyee; Kennon Heard

2009-01-01

391

Radium and barium in the Amazon River system  

SciTech Connect

Data for /sup 226/Ra and /sup 228/Ra in the Amazon River system show that the activity of each radium isotope is strongly correlated with barium concentrations. Two trends are apparent, one for rivers which drain shield areas and another for all other rivers. These data suggest that there has been extensive fractionation of U, Th, and Ba during weathering in the Amazon basin. The /sup 226/Ra data fit a flux model for the major ions indicating that /sup 226/Ra behaves conservatively along the main channel of the Amazon River.

Moore, W.S.; Edmond, J.M.

1984-03-20

392

Analysis of the sixth spectrum of barium: Ba VI  

NASA Astrophysics Data System (ADS)

The spectrum of barium was photographed in the 300 -1240 wavelength region on a 3-m normal incidence spectrograph at the Antigonish laboratory. The source used was a triggered spark. All five levels of the ground configuration 5s25p3 and 42 of 44 levels of the 5s5p4 + 5s25p25d + 5s25p26s configurations of Ba VI have been established. One hundred and twenty-seven lines have been classified. The parametric least-squaresfitted calculations involving configuration interaction amongst even parity configurations were carried out to interpret the observed spectrum satisfactorily.

Tauheed, A.; Joshi, Y. N.

1994-03-01

393

Agglomeration behavior of solid nickel on polycrystalline barium titanate  

SciTech Connect

This letter describes the phenomenon that takes place between nickel/barium titanate couples when heated under conditions employed in multilayer ceramic capacitor manufacturing practice: a 4hr, 1300C isothermal anneal in 1% H2 99% N2. Dense, sputtered nickel films were observed to dewet the titanate and agglomerate into discrete or interconnected islands via a solid-state process. Up to a critical film thickness value of ~1.4?m, the degree of agglomeration was found to display an exponential dependence on the thickness of the original nickel film.

Weil, K. Scott; Mast, Eric S.; Sprenkle, Vince

2007-11-01

394

Nanodielectric system for cryogenic applications: Barium titanate filled polyvinyl alcohol  

SciTech Connect

In the current study the focus is on dielectric properties (as a function of frequency and temperature) of a polymeric composite system composed of polyvinyl alcohol and barium titanate nano powder. In the investigations, the temperature range is between 50-295 K, and the frequency range is between $20\\ \\hertz-1\\ \\mega\\hertz$. Polarization and conduction processes are investigated in the linear regime. Dielectric breakdown strengths of samples are also reported. The materials presented have potential to be implemented in cryogenic capacitor or field grading applications.

Tuncer, Enis [ORNL; Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; Duckworth, Robert C [ORNL

2008-01-01

395

Coprecipitation of radium with barium sulfate from salt solutions  

Microsoft Academic Search

Coprecipitation of radium with barium sulfate from highly concentrated NaCl solutions is studied, including the effects of\\u000a the initial solution composition, alkaline reagent (CaO, NaOH), supporting electrolyte (NaCl) concentration, and pH. The process\\u000a is promoted by high NaCl concentration in the initial solution, which is due to structural transformation and change in the\\u000a sorption activity of the BaSO4 precipitate in

Yu. P. Kudryavskii; O. V. Rakhimova

2007-01-01

396

Radiation doses to children during modified barium swallow studies  

Microsoft Academic Search

BackgroundThere are minimal data on radiation doses to infants and children undergoing a modified barium swallow (MBS) study.\\u000a \\u000a \\u000a \\u000a ObjectiveTo document screening times, dose area product (DAP) and effective doses to children undergoing MBS and to determine factors\\u000a associated with increased screening times and effective dose.\\u000a \\u000a \\u000a \\u000a Materials and methodsFluoroscopic data (screening time, DAP, kVp) for 90 consecutive MBS studies using pulse

Kelly A. Weir; Sandra M. McMahon; Gillian Long; Judith A. Bunch; Nirmala Pandeya; Kerry S. Coakley; Anne B. Chang

2007-01-01

397

The barium ion jet experiments of the Porcupine project  

NASA Astrophysics Data System (ADS)

The injection of a barium plasma from a sounding rocket by the shaped charge technique offers several possibilities that cannot be achieved by conventional releases. This is due to high initial velocities of the atoms of up to 14 km/sec. Most of the the applications are related to the great heights that the ions can reach, but some depend directly on the initial momentum. Typical applications are: tracing at high altitudes, modifications, and alternate Ionization processes. Project Porcupine contributions in this field are summarized.

Haerendel, G.

1980-06-01

398

Aluminum Carbothermic Technology  

SciTech Connect

This report documents the non-proprietary research and development conducted on the Aluminum Carbothermic Technology (ACT) project from contract inception on July 01, 2000 to termination on December 31, 2004. The objectives of the program were to demonstrate the technical and economic feasibility of a new carbothermic process for producing commercial grade aluminum, designated as the ''Advanced Reactor Process'' (ARP). The scope of the program ranged from fundamental research through small scale laboratory experiments (65 kW power input) to larger scale test modules at up to 1600 kW power input. The tasks included work on four components of the process, Stages 1 and 2 of the reactor, vapor recovery and metal alloy decarbonization; development of computer models; and economic analyses of capital and operating costs. Justification for developing a new, carbothermic route to aluminum production is defined by the potential benefits in reduced energy, lower costs and more favorable environmental characteristics than the conventional Hall-Heroult process presently used by the industry. The estimated metrics for these advantages include energy rates at approximately 10 kWh/kg Al (versus over 13 kWh/kg Al for Hall-Heroult), capital costs as low as $1250 per MTY (versus 4,000 per MTY for Hall-Heroult), operating cost reductions of over 10%, and up to 37% reduction in CO2 emissions for fossil-fuel power plants. Realization of these benefits would be critical to sustaining the US aluminum industries position as a global leader in primary aluminum production. One very attractive incentive for ARP is its perceived ability to cost effectively produce metal over a range of smelter sizes, not feasible for Hall-Heroult plants which must be large, 240,000 TPY or more, to be economical. Lower capacity stand alone carbothermic smelters could be utilized to supply molten metal at fabrication facilities similar to the mini-mill concept employed by the steel industry. Major accomplishments for the program include definition of the system thermo-chemistry, demonstration of reactor stage 1, development of reactor stage 2 critical components in a 500 kW module, experimental determination of the vapor recovery reactor fundamentals, detailed design and installation of an advanced stage 1/vapor recovery reactor, feasibility of efficient separation of Al-C metal alloy product, updated capital and operating cost estimates, and development of computer models for all steps of the Advanced Reactor Process.

Bruno, Marshall J.

2005-03-31

399

Cathodic phenomena in aluminum electrowinning  

NASA Astrophysics Data System (ADS)

Although aluminum is one of the world's highest production-volume primary metals, it is particularly costly to produce for a variety of factors, not the least of which are the expenses associated with electrolytic reduction. Based on the scale of global aluminum processing, even minor improvements in the electrowinning technology can result in significant savings of resources. Thus, from this perspective, the following reviews recent studies of cathodic phenomena in aluminum electrowinning.

Bouteillon, J.; Poignet, J. C.; Rameau, J. J.

1993-02-01

400

Recycling of aluminum salt cake  

Microsoft Academic Search

The secondary aluminum industry generates more than 110 10³ tons of salt-cake waste every year. This waste stream contains about 3--5% aluminum, 15--30% aluminum oxide, 30--40% sodium chloride, and 20--30% potassium chloride. As much as 50% of the content of this waste is combined salt (sodium and potassium chlorides). Salt-cake waste is currently disposed of in conventional landfills. In

B. J. Jody; E. J. Daniels; P. V. Bonsignore; D. E. Karvelas

1991-01-01

401

Molecular aspects of aluminum toxicity  

Microsoft Academic Search

The focus in this review is directed to molecular aspects of aluminum toxicity in animal and plant cells. Unique thermodynamic features of Al(lII) ions impart biological specificity which may form the biochemical basis of aluminum interactions with cellular constituents. Current knowledge about aluminum?specific, molecular interactions is rather scanty. Al(III) ions may coordinate with nucleotides or complex to phospholipids resulting in

Alfred Haug; Charles E. Foy

1984-01-01

402

Evidence against Barium in the Mushroom Trogia venenata as a Cause of Sudden Unexpected Deaths in Yunnan, China  

PubMed Central

This study examined barium concentrations in the mushroom Trogia venenata, the leading culprit for sudden unexpected deaths in Yunnan, southwest China. We found that barium concentrations in T. venenata from Yunnan were low and comparable to other foods, inconsistent with barium concentrations in this mushroom as a significant contributor to these deaths.

Zhang, Ying; Li, Yanchun; Wu, Gang; Feng, Bang; Yoell, Shanze; Yu, Zefen; Zhang, Keqin

2012-01-01

403

High resolution imaging of barium ions and atoms near the sampling cone of an inductively coupled plasma mass spectrometer  

Microsoft Academic Search

Planar laser-induced fluorescence was used to map density distributions of ground state barium atoms, ground state barium ions, and excited-state barium ions in the region between the load coil and the sampling cone of an inductively coupled plasma mass spectrometer. The effects of power, nebulizer gas flow rate, and the addition of lithium to the sample on the distributions were

Andrew A. Mills; Jeffrey H. Macedone; Paul B. Farnsworth

2006-01-01

404

Jet-pump crystallizers in reaction-crystallization processes with solid reagentbarium sulphate precipitation study  

Microsoft Academic Search

The research results concerning barium sulphate precipitation from the concentrated water solutions of barium chloride by means of crystalline ammonium sulphate addition are presented. The experiments were carried out in a continuous laboratory DTM crystallizer with inner circulation of suspension. A liquid jet-pump device generating ascending\\/descending flow of medium in a mixing chamber was used. Influences of barium chloride concentration

K. Piotrowski; J. Koralewska; A. Matynia

2010-01-01

405

Fabrication of barium/strontium carbonate coated amorphous carbon nanotubes as an improved field emitter  

NASA Astrophysics Data System (ADS)

Amorphous carbon nanotubes (aCNTs) were synthesized by a chemical reaction between ferrocene and ammonium chloride at a temperature 250 ?C in an air furnace. As-synthesized aCNTs were coated with the barium/strontium carbonate through a simple chemical process. The coating of barium/strontium carbonate was confirmed by a high resolution transmission electron microscopy, X-ray diffraction, and Fourier transformed infrared spectroscopy. Morphology of the as-prepared samples was studied by field emission scanning electron microscopy. Thermal gravimetric analysis showed that barium/strontium carbonate coated aCNTs are more stable than the pristine aCNTs. As-prepared barium/strontium carbonate coated aCNTs showed significantly improved field emission properties with a turn-on field as low as 2.5 V/?m. The variation of field emission characteristics of the barium/strontium carbonate coated aCNTs with interelectrode distances was also studied.

Maity, S.; Jha, A.; Das, N. S.; Chattopadhyay, K. K.

2013-02-01

406

Temperature dependence dielectric properties of modified barium titanate-PVB composites  

NASA Astrophysics Data System (ADS)

In this work, attempts are made to prepare ceramic polymer-composite followed by characterization of dielectric properties. The Barium Titanate ceramic powders are synthesized using the hydrothermal process. Silane treatment is carried out on Barium Titanate powder to increase its compatibility with polymer, followed with preparation of ceramic-polymer composite. Polyvinyl Butyral (PVB) is used as matrix for preparation of the composites and the concentration of Barium Titanate is increased from 60 to 90 wt%. Dielectric properties such as volume resistivity, dielectric constant, dissipation factor are evaluated. Results indicate that the dielectric constant and dissipation factor vary between 52 to 120 and 0.01 to 0.07; respectively as the relative ratio of polymer and silane modified Barium Titanate is varied. Specifically, at 90 wt% of silane modified Barium Titanate, the highest dielectric constant of 123 along with dissipation factor of 0.07 is obtained.

Joshi, N. J.; Rakshit, P. B.; Grewal, G. S.; Shrinet, V.; Pratap, A.

2013-06-01

407

Effects of Different Barium Compounds on the Corrosion Resistance of Andalusite-Based Low-Cement Castables in Contact with Molten Al-Alloy  

NASA Astrophysics Data System (ADS)

An experimental study was conducted to investigate the interfacial phenomena between an Al alloy and andalusite low-cement castables (LCCs) containing fixed contents of barium compounds (BaO, BaSO4, and BaCO3) at 1123 K and 1433 K (850 C and 1160 C) using the Alcoa cup test. Interfacial reaction products and phases formed during heat treatment of the refractory samples were characterized using scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS) and X-ray diffraction analysis (XRD). The addition of both BaO and BaSO4 led to a significant reduction of alloy penetration into the refractory. Hexa-celsian formation was observed in both these refractories, which drastically increased their corrosion resistance. Barite decomposition was observed at 1373 K (1100 C) in the presence of alumina and silica, which was the precursor for hexa-celsian formation. Barium silicates were formed in all samples containing additives; however, this did not have any major influence on the corrosion resistance. Solidified eutectics of BaSi2 and ?-BaAl2Si2 formed in all these samples, which acted as an interfacial barrier that prevented additional molten aluminum penetration; however, the positive effect of intermetallic formation was offset by glassy phase formation in samples containing BaCO3 as the additive.

Adabifiroozjaei, Esmaeil; Koshy, Pramod; Rastkerdar, Ebad

2011-08-01

408

Aluminum-lithium for aerospace  

SciTech Connect

Aluminum-lithium alloys were developed primarily to reduce the weight of aircraft and aerospace structures. Lithium is the lightest metallic element, and each 1% of lithium added to aluminum reduces alloy density by about 3% and increases modulus by about 5%. Though lithium has a solubility limit of 4.2% in aluminum, the amount of lithium ranges between 1 and 3% in commercial alloys. Aluminum-lithium alloys are most often selected for aerospace components because of their low density, high strength, and high specific modulus. However, other applications now exploit their excellent fatigue resistance and cryogenic toughness.

Fielding, P.S.; Wolf, G.J. [Reynolds Metals Co., Richmond, VA (United States)

1996-10-01

409

Laser welding of aluminum alloys  

SciTech Connect

Recent interest in reducing the weight of automobiles to increase fuel mileage has focused attention on the use of aluminum and associated joining technologies. Laser beam welding is one of the more promising methods for high speed welding of aluminum. Consequently, substantial effort has been expended in attempting to develop a robust laser beam welding process. Early results have not been very consistent in the process requirements but more definitive data has been produced recently. This paper reviews the process parameters needed to obtain consistent laser welds on 5,000 series aluminum alloys and discusses the research necessary to make laser processing of aluminum a reality for automotive applications.

Leong, K.H.; Sabo, K.R.; Sanders, P.G. [Argonne National Lab., IL (United States). Technology Development Div.; Spawr, W.J.

1997-03-01

410

Mineral of the month: aluminum  

USGS Publications Warehouse

Aluminum is the second most abundant metallic element in Earths crust after silicon. Even so, it is a comparatively new industrial metal that has been produced in commercial quantities for little more than 100 years. Aluminum is lightweight, ductile, malleable and corrosion resistant, and is a good conductor of heat and electricity. Weighing about one-third as much as steel or copper per unit of volume, aluminum is used more than any other metal except iron. Aluminum can be fabricated into desired forms and shapes by every major metalworking technique to add to its versatility.

Plunkert, Patricia A.

2005-01-01

411

BLENDED CALCIUM ALUMINATE-CALCIUM SULFATE CEMENT-BASED GROUT FOR P-REACTOR VESSEL IN-SITU DECOMMISSIONING  

SciTech Connect

The objective of this report is to document laboratory testing of blended calcium aluminate - calcium hemihydrate grouts for P-Reactor vessel in-situ decommissioning. Blended calcium aluminate - calcium hemihydrate cement-based grout was identified as candidate material for filling (physically stabilizing) the 105-P Reactor vessel (RV) because it is less alkaline than portland cement-based grout which has a pH greater than 12.4. In addition, blended calcium aluminate - calcium hemihydrate cement compositions can be formulated such that the primary cementitious phase is a stable crystalline material. A less alkaline material (pH {<=} 10.5) was desired to address a potential materials compatibility issue caused by corrosion of aluminum metal in highly alkaline environments such as that encountered in portland cement grouts [Wiersma, 2009a and b, Wiersma, 2010, and Serrato and Langton, 2010]. Information concerning access points into the P-Reactor vessel and amount of aluminum metal in the vessel is provided elsewhere [Griffin, 2010, Stefanko, 2009 and Wiersma, 2009 and 2010, Bobbitt, 2010, respectively]. Radiolysis calculations are also provided in a separate document [Reyes-Jimenez, 2010].

Langton, C.; Stefanko, D.

2011-03-10

412

CALCIUM AND VITAMIN D  

Technology Transfer Automated Retrieval System (TEKTRAN)

Calcium is required for the bone formation phase of bone remodeling. An inadequate intake of calcium results in reduced calcium absorption. This stimulates hormone changes that induce bone remodeling. When the remodeling rate is high, bone loss occurs. With aging, calcium absorption efficiency d...

413

Barium Geochemistry of a Marginal Cold-seep Basin: Abundance and Provenance of Total Barium and Barite in the San Clemente Basin.  

NASA Astrophysics Data System (ADS)

Barium in marine sediments is found in various solid phases including barite, aluminosilicates, carbonates, organic material and oxyhydroxides. Barite, the dominant Ba-bearing solid phase in pelagic settings, is of particular interest as it has the potential for use as a tracer for paleoproductivity and past isotopic and rare earth element composition of seawater. Barite crystals form by abiotic precipitation in supersaturated microenvironments of decaying organic material in the water column and then settle as aggregates to the sediments. In areas of cold seep activity, discharge of barium-rich seep fluid also results in large in situ barite deposits at the seafloor. Transport of particles from these deposits leads to significantly increased barium concentrations in surrounding sediments. The San Clemente basin located about 100km off the coast of San Diego, is one such location where massive barite deposits have been observed in association with cold seep activity along the San Clemente fault that transects the basin. Analysis of surface sediments from the San Clemente basin has shown total barium enrichment of up to 140% higher than surface sediments from the neighboring Santa Catalina basin. Cold seeps are not present in the latter location, where the major source of barite is likely to be that associated with biogenic material. The significant input of barium from authigenic barite deposits to surrounding sediments affects global barium geochemistry and could possibly be used to provide a paleorecord for cold seep activity.

McQuay, E. L.; Torres, M. E.; Collier, R.; Huh, C.; Newell, S.

2004-12-01

414

Damping Studies of Ceramic Reinforced Aluminum.  

National Technical Information Service (NTIS)

Ceramic reinforced aluminum alloys exhibit a unique combination of mechanical properties not found in monolithic aluminum alloys. The addition of high modulus ceramic particles to conventional aluminum alloys results in increased strength, elastic modulus...

C. R. Wong S. Holcomb

1991-01-01

415

21 CFR 73.1645 - Aluminum powder.  

Code of Federal Regulations, 2012 CFR

...2013-04-01 2013-04-01 false Aluminum powder. 73.1645 Section 73.1645...CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely...

2013-04-01

416

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2012 CFR

...2013-04-01 2013-04-01 false Aluminum powder. 73.2645 Section 73...CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in...

2013-04-01

417

21 CFR 172.310 - Aluminum nicotinate.  

Code of Federal Regulations, 2012 CFR

... 3 2013-04-01 2013-04-01 false Aluminum nicotinate. 172.310 Section 172.310 ...Dietary and Nutritional Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be safely used as a source of...

2013-04-01

418

75 FR 80527 - Aluminum Extrusions From China  

Federal Register 2010, 2011, 2012, 2013

...Final) and 731-TA-1177 (Final)] Aluminum Extrusions From China AGENCY: United...less-than-fair-value imports from China of aluminum extrusions, primarily provided for in...these investigations is contained in Aluminum Extrusions From the People's...

2010-12-22

419

Wettability of carbon by aluminum and aluminum alloys  

Microsoft Academic Search

Wetting (both equilibrium contact angle and spreading kinetics) of aluminum and aluminum alloys with silicon and titanium on carbon substrates is investigated as a function of temperature and carbon microstructure. Experiments are carried out by the sessile drop technique under high vacuum, in the range from 1023 to 1250K. Three different types of carbon substrates are examined: vitreous carbon, pyrolytic

K. Landry; S. Kalogeropoulou; N. Eustathopoulos

1998-01-01

420

Thermoelastic ratcheting effect in bolted aluminum-to-aluminum connections  

Microsoft Academic Search

The effect of thermoelastic ratcheting on the mechanical integrity of bolted aluminum-to-aluminum connections using different mechanical contact devices was studied. Thermoelastic ratcheting was studied under current cycling conditions using currents 800 to 2000 A. The results show that the mechanical integrity of the connections is strongly affected by the joint configuration, which differs according to the mechanical devices used. To

MILENKO BRAUNOVIC; MILUTIN MARJANOV

1988-01-01

421

Some Fundamental Properties of Aluminum-Aluminum Electrical Contacts  

Microsoft Academic Search

The results of a fundamental Investigation of the properties of stationary aluminum-aluminum (AA1350) electrical contacts at room temperature both in an ultrahigh vacuum and in an oxygen atmosphere are reported. The contact couples consist of two polished spherical surfaces held together under constant load over a small area; the work was carried out in an environmental chamber which allows manipulation

R. S. TIMSIT

1980-01-01

422

Solid Aluminum Electrolytic Capacitors with Etched Aluminum Foil  

Microsoft Academic Search

Some suggestions are made for further developments in the field of electrolytic capacitors using etched aluminum foils and solid electrolytes. Various laboratory-tested construction procedures are discussed in detail. The behavior of capacity, dissipation factor, and leakage is illustrated as the function of temperature and frequency during storage with and without current. It is shown that the production of aluminum electrolytic

W. Post

1962-01-01

423

Production of aluminum metal by electrolysis of aluminum sulfide  

DOEpatents

Production of metallic aluminum by the electrolysis of Al.sub.2 S.sub.3 at 700.degree.-800.degree. C. in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

Minh, Nguyen Q. (Woodridge, IL); Loutfy, Raouf O. (Tucson, AZ); Yao, Neng-Ping (Clarendon Hills, IL)

1984-01-01

424

Can barium enema indicate when colonoscopy will be difficult?  

PubMed

The barium enemas of 48 consecutive patients, who were technically difficult to intubate at colonoscopy, were compared to those of 46 patients who were not. Measurements were taken of colonic length and mobility, and an assessment made of diverticular disease. Rectosigmoid length (mean difficult group = 61 cm, mean control = 54 cm, P = 0.01) and total colonic length (mean difficult group = 157 cm, mean control = 140 cm, P < 0.0001) were greater in the difficult colonoscopy group as were transverse colon mobility (mean difficult group = 10 cm, mean control = 7 cm, P = 0.003) or redundancy (transverse colon reaching the true pelvis on the erect film); 65% difficult group vs 17% control group, P < 0.0001. The presence of moderate or severe diverticular disease was also greater in the difficult (23%) compared to the control (4%) group, P = 0.02. When available, assessment of a previous barium enema is a useful guide to probable technical difficulty of colonscopy. It may allow appropriate allocation of potentially difficult cases to specialist endoscopy lists. PMID:7743720

Saunders, B P; Halligan, S; Jobling, C; Fukumoto, M; Moussa, M E; Williams, C B; Bartram, C I

1995-05-01

425

Indentation size effect in barium titanate with spherical tipped nanoindenters  

NASA Astrophysics Data System (ADS)

Nanoindentation tests in an 90-ac-domain area of an {001} orientated barium titanate single crystal were performed using four different indenters (two with cube corner and two with spherical shape) with tip radii from 61 nm to 1.9 ?m. Extensive calibrations of the tips on fused quartz and sapphire defined the penetration depth range for approximately spherical contact prior to indentation of barium titanate (BaTiO3). The measured elastic modulus is independent of the different indenters. The measurements showed plastic deformation after ``pop-in''. The calculated mean pressure remained constant for each indenter, but clearly depends upon the indenter radius. The indenter radius dependence of the hardness support the concept of ``geometrically necessary dislocations'', proposed by W. D. Nix and H. Gao [J. Mech. Phys. Sol., 46, 411 (1998)] and its extension to spherical tipped indenters [J. G. Swadener, E. P. George, G. M. Pharr, J. Mech. Phys. Solids, 50, 681 (2002)]. The results show this concept fits the data generated with indenter radii which are at least an order of magnitude lower than investigated by Swadener. Furthermore, the results agree with estimates of the statistically stored dislocation density determined for BaTiO3.

Scholz, T.; Muoz-Saldaa, J.; Swain, M. V.; Schneider, G. A.

2006-02-01

426

Proton trapping in yttrium-doped barium zirconate  

NASA Astrophysics Data System (ADS)

The environmental benefits of fuel cells have been increasingly appreciated in recent years. Among candidate electrolytes for solid-oxide fuel cells, yttrium-doped barium zirconate has garnered attention because of its high proton conductivity, particularly in the intermediate-temperature region targeted for cost-effective solid-oxide fuel cell operation, and its excellent chemical stability. However, fundamental questions surrounding the defect chemistry and macroscopic proton transport mechanism of this material remain, especially in regard to the possible role of proton trapping. Here we show, through a combined thermogravimetric and a.c. impedance study, that macroscopic proton transport in yttrium-doped barium zirconate is limited by protondopant association (proton trapping). Protons must overcome the association energy, 29?kJ?mol?1, as well as the general activation energy, 16?kJ?mol?1, to achieve long-range transport. Proton nuclear magnetic resonance studies show the presence of two types of proton environment above room temperature, reflecting differences in protondopant configurations. This insight motivates efforts to identify suitable alternative dopants with reduced association energies as a route to higher conductivities.

Yamazaki, Yoshihiro; Blanc, Frdric; Okuyama, Yuji; Buannic, Lucienne; Lucio-Vega, Juan C.; Grey, Clare P.; Haile, Sossina M.

2013-07-01

427

Barium titanate core--gold shell nanoparticles for hyperthermia treatments.  

PubMed

The development of new tools and devices to aid in treating cancer is a hot topic in biomedical research. The practice of using heat (hyperthermia) to treat cancerous lesions has a long history dating back to ancient Greece. With deeper knowledge of the factors that cause cancer and the transmissive window of cells and tissues in the near-infrared region of the electromagnetic spectrum, hyperthermia applications have been able to incorporate the use of lasers. Photothermal therapy has been introduced as a selective and noninvasive treatment for cancer, in which exogenous photothermal agents are exploited to achieve the selective destruction of cancer cells. In this manuscript, we propose applications of barium titanate core-gold shell nanoparticles for hyperthermia treatment against cancer cells. We explored the effect of increasing concentrations of these nanoshells (0-100 ?g/mL) on human neuroblastoma SH-SY5Y cells, testing the internalization and intrinsic toxicity and validating the hyperthermic functionality of the particles through near infrared (NIR) laser-induced thermoablation experiments. No significant changes were observed in cell viability up to nanoparticle concentrations of 50 ?g/mL. Experiments upon stimulation with an NIR laser revealed the ability of the nanoshells to destroy human neuroblastoma cells. On the basis of these findings, barium titanate core-gold shell nanoparticles resulted in being suitable for hyperthermia treatment, and our results represent a promising first step for subsequent investigations on their applicability in clinical practice. PMID:23847415

FarrokhTakin, Elmira; Ciofani, Gianni; Puleo, Gian Luigi; de Vito, Giuseppe; Filippeschi, Carlo; Mazzolai, Barbara; Piazza, Vincenzo; Mattoli, Virgilio

2013-06-28

428

Redox processes in highly yttrium-doped barium titanate  

NASA Astrophysics Data System (ADS)

The changes of microstructure occurring during oxidation of the reduced form of yttrium-doped barium titanate (Ba1-xYxTi1-x4+Tix3+O3) have been studied. Samples were sintered under reduction conditions at PO2=10-4Pa and oxidized by annealing at high temperatures (1150 and 1350 C) in air. Depending on yttrium concentration, the oxidation of the reduced form of the yttrium-doped BaTiO3 caused precipitation of the phase Ba6Ti17O40 or the phases Ba6Ti17O40 and Y2Ti2O7. 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 Ba1-xYxTi1-x/44+(VTi'''')x/4O3 responsible for increase in the resistance of outer grain layers, which lie between grain boundaries and grain.

Belous, Anatolii; v'Yunov, Oleg; Kovalenko, Leonid; Makovec, Darko

2005-05-01

429

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

430

Characterization of ultradispersed aluminum  

SciTech Connect

Samples of ultradispersed Al were received, which were produced by electrically exploding Al wires in argon. These samples comprised very small particles that were not significantly oxidized and that were stable in air. Particle morphology were studied with SE, micropycnometry, and gas adsorption surface area. Composition were determined using various techniques, as were thermal stability and reaction exotherms. The inexplicable reports of an Al-Ar compound and of an exothermic reaction were not confirmed. The material is a stable, nonoxidized, small-particle, highly reactive form of aluminum that is of interest in energetic materials formulations.

Simpson, R.L.; Maienschein, J.L.; Swansiger, R.W.; Garcia, F.; Darling, D.H.

1994-12-08

431

Effects of different fabrication techniques on the yttrium-barium-copper oxide high-temperature superconductor. Master's thesis  

SciTech Connect

This study examines how several different parameters were changed in the yttrium-barium-copper oxide superconductor when the fabrication techniques were altered by using different barium precursors, including barium peroxide and barium carbonate; sintering at different temperatures, including 850, 900, and 950 C; and annealing in an above ambient oxygen environment. Twelve different pellets were fabricated, and measurements were taken on them which included density, x-ray diffraction, critical temperature, critical current density, and magnetic susceptibility. Results showed that the barium perioxide derived samples had higher densities, better critical current densities and lower resistivities in the normal state.

Rhea, P.A.

1988-12-01

432

Aluminum-Lithium Alloy Research.  

National Technical Information Service (NTIS)

A recent Air Force program was focused on developing an isotropic aluminum-lithium alloy, having greater than two weight percent lithium. The addition of two weight percent lithium can reduce the density of aluminum by six percent and increase the modulus...

E. A. Starke A. A. Csontos

1997-01-01

433

Precipitation hardening of aluminum alloys  

Microsoft Academic Search

The author's charge was to discuss recent trends in research and development on precipitation hardened aluminum alloys and to indicate where research is needed. This will be done for three areas: fatigue, properties of grain boundaries and interfaces, and stability of precipitates at elevated temperatures. Present strong precipitation hardened aluminum alloys do not have high endurance limits. One problem is

Morris E. Fine

1975-01-01

434

Aluminum vehicle breaks new ground  

SciTech Connect

This article examines the efforts of automobile manufacturers and aluminum producers to develop a light weight crash resistant automobile. The topics of the article include alloys used, production techniques, fastening and bonding techniques, rigidity and crush resistance, weight reduction, die-casting and extruding of aluminum, design and construction of space frame.

Ashley, S.

1994-02-01

435

Laser welding of aluminum alloys  

Microsoft Academic Search

Recent interest in reducing the weight of automobiles to increase fuel milage has focused attention on the use of aluminum and associated joining technologies. Laser beam welding is one of the more promising methods for high speed welding of aluminum. Consequently, substantial effort has been expended in attempting to develop a robust laser beam welding process. Early results have not

Keng H. Leong; Kenneth R. Sabo; Paul G. Sanders; Walter J. Spawr

1997-01-01

436

Laser welding of aluminum alloys.  

National Technical Information Service (NTIS)

Recent interest in reducing the weight of automobiles to increase fuel mileage has focused attention on the use of aluminum and associated joining technologies. Laser beam welding is one of the more promising methods for high speed welding of aluminum. Co...

K. H. Leong K. R. Sabo P. G. Sanders W. J. Spawr

1997-01-01

437

Lost-Soap Aluminum Casting.  

ERIC Educational Resources Information Center

|Lost-wax casting in sterling silver is a costly experience for the average high school student. However, this jewelry process can be learned at no cost if scrap aluminum is used instead of silver, and soap bars are used instead of wax. This lost-soap aluminum casting process is described. (Author/KC)|

Mihalow, Paula

1980-01-01

438

Primary Aluminum Plants Worldwide - 1998  

USGS Publications Warehouse

The 1990 U.S. Bureau of Mines publication, Primary Aluminum Plants Worldwide, has been updated and is now available. The 1998 USGS edition of Primary Aluminum Plants Worldwide is published in two parts. Part IDetail contains information on individual primary smelter capacity, location, ownership, sources of energy, and other miscellaneous information. Part IISummary summarizes the capacity data by country

1999-01-01

439

The Benefits of Aluminum Windows.  

ERIC Educational Resources Information Center

Discusses benefits of aluminum windows for college construction and renovation projects, including that aluminum is the most successfully recycled material, that it meets architectural glass deflection standards, that it has positive thermal energy performance, and that it is a preferred exterior surface. (EV)

Goyal, R. C.

2002-01-01

440

Lost-Soap Aluminum Casting.  

ERIC Educational Resources Information Center

Lost-wax casting in sterling silver is a costly experience for the average high school student. However, this jewelry process can be learned at no cost if scrap aluminum is used instead of silver, and soap bars are used instead of wax. This lost-soap aluminum casting process is described. (Author/KC)

Mihalow, Paula

1980-01-01

441

The Benefits of Aluminum Windows.  

ERIC Educational Resources Information Center

|Discusses benefits of aluminum windows for college construction and renovation projects, including that aluminum is the most successfully recycled material, that it meets architectural glass deflection standards, that it has positive thermal energy performance, and that it is a preferred exterior surface. (EV)|

Goyal, R. C.

2002-01-01

442

ALUMINUM SOLUBILITY, CALCIUM-ALUMINUM EXCHANGE, AND PH IN ACID FOREST SOILS  

EPA Science Inventory

Important components in several models designed to describe the effects of acid deposition on soils and surface waters are the pH-A1 and Ca-A1 exchange relationships. f A1 solubility is controlled by A1 trihydroxide minerals, the theoretical pH-A1 relationship can be described by...

443

Aluminum solubility, calcium-aluminum exchange, and pH in acid forest soils  

Microsoft Academic Search

The pH-Al and Ca-Al exchange relationships are important components in several models designed to describe the effects of acid deposition on soils and surface waters. If Al solubility is controlled by Al trihydroxide minerals, the theoretical pH-Al relationship can be described by log(al{sup 3+}) = logK - 3pH. However, in practice it is often better described by log(Al{sup 3+}) =

J. O. Reuss; R. W. E. Hopper; P. M. Walthall; E. C. Roswall

2009-01-01

444

Minerals: Calcium, Phosphorus, and Magnesium  

MedlinePLUS

... Minerals: Calcium, Phosphorus, and Magnesium Healthy Living Listen Minerals: Calcium, Phosphorus, and Magnesium Article Body Three minerals calcium , phosphorus, and magnesiumaccount for 98% of ...

445

Aluminum inhibits erythropoiesis in vitro.  

PubMed Central

Anemia has been associated with aluminum intoxication in patients on chronic dialysis and in animals. In studies presented here, in vitro human erythroid culture was used to delineate the effects of aluminum on normal hematopoiesis. Aluminum by itself in routine culture, even at very high levels (1,035 ng/ml), did not significantly affect erythroid colony growth. The addition of human transferrin to the culture, however, resulted in a marked dose-dependent inhibition of erythroid, but not myeloid colony growth. At all doses, CFU-E progenitors showed greater inhibition than burst-forming units (BFU-E). Aluminum inhibition was not overcome by increasing the dose of erythropoietin or adding additional burst-promoting activity to the culture. Inhibition by aluminum was directly related to the number of binding sites on transferrin in the culture, and was not observed in the presence of fully iron-saturated transferrin. Images

Mladenovic, J

1988-01-01

446

Channeling of aluminum in silicon  

SciTech Connect

A systematic study of channeling of aluminum in the silicon crystal is reported. Depth distributions measured by secondary ion mass spectrometry are reported for 40-, 75-, and 150-keV aluminum channeled in the <100> and <110> directions of silicon. The profile dependence on alignment angle is shown for 150-keV aluminum in the <110> of silicon. Aluminum has low electronic stopping in silicon and corresponding deep channeled profiles are observed for aligned implants and deep channeling tails are observed on random implants. The maximum channeling range for 150-keV Al in <100> silicon is about 2.8 ..mu..m and is about 6.4 ..mu..m in <110> silicon. Some ions will reach the maximum channeling range even for 2/sup 0/ misalignment. Many of the deep channeling tails and ''supertails'' reported in earlier literature can be explained by the normal channeling of aluminum in silicon.

Wilson, R.G.; Hopkins, C.G.

1985-05-15

447

Recovering aluminum via plasma processing  

NASA Astrophysics Data System (ADS)

A process based on the use of a plasma system for recovering aluminum from dross, beverage cans, and aluminum scrap has been developed. The plasma process is clean, and there is no need for the addition of any compound, such as salt. In principle, a higher recovery rate of aluminum is attainable, since no oxidation of the aluminum occurs during the process. An economic analysis shows that the operating costs for the plasma system are at least 23% cheaper than for the traditional process using air/gas or ail/oil burners; the plasma process also does not generate either of the common residues produced by the burners. The maintenance costs of the plasma process are also lower than that of the traditional process. Overall, the plasma system is cheaper, cleaner, and easier than the oil/gas burner technology when recovering aluminum from dross, beverage cans, and scrap.

Szente, R. N.; Schroeter, R. A.; Garcia, M. G.; Bender, O. W.

1997-11-01

448

Anodic Aluminum Oxide Diodes  

NASA Astrophysics Data System (ADS)

During anodic oxidation of aluminum, the incorporated anion species from the electrolyte are drawn into the growing barrier layer at the pore base by the high electric field and, afterward, migrate inward. The barrier layer consists of acid anion-contaminated regions adjacent to the oxide/electrolyte interface and relatively pure alumina further away from it. It can be presumed that there is a depletion layer region in between the acid anion-contaminated material and the pure alumina material. This study investigates the diode characteristics of the anodic aluminum oxide (AAO) film based on the depletion layer region presumption. Different electrolyte acids are employed to fabricate AAO diodes which possess different electrical properties. The current--voltage (I--V) characteristic curves indicate that the AAO devices possess the electrical property of a diode, especially the sulfuric acid processed AAO. It was observed that the threshold voltages for the sulfuric acid, oxalic acid, and phosphoric acid are 3.3, 8, and 16 V, respectively. This fits in with the sequential order presumption of the p, n depletion layer thicknesses for these three electrolyte acids.

Chang, Cheng-Yao; Wang, Gou-Jen

2011-07-01

449

Fabrication and characterization of cerium-doped barium titanate inverse opal by sol-gel method  

SciTech Connect

Cerium-doped barium titanate inverted opal was synthesized from barium acetate contained cerous acetate and tetrabutyl titanate in the interstitial spaces of a polystyrene (PS) opal. This procedure involves infiltration of precursors into the interstices of the PS opal template followed by hydrolytic polycondensation of the precursors to amorphous barium titanate and removal of the PS opal by calcination. The morphologies of opal and inverse opal were characterized by scanning electron microscope (SEM). The pores were characterized by mercury intrusion porosimetry (MIP). X-ray photoelectron spectroscopy (XPS) investigation showed the doping structure of cerium, barium and titanium. And powder X-ray diffraction allows one to observe the influence of doping degree on the grain size. The lattice parameters, crystal size and lattice strain were calculated by the Rietveld refinement method. The synthesis of cerium-doped barium titanate inverted opals provides an opportunity to electrically and optically engineer the photonic band structure and the possibility of developing tunable three-dimensional photonic crystal devices. - Graphical abstract: Cerium-doped barium titanate inverted opal was synthesized from barium acetate acid contained cerous acetate and tetrabutyl titanate in the interstitial spaces of a PS opal, which involves infiltration of precursors into the interstices of the PS opal template and removal of the PS opal by calcination.

Jin Yi [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials, Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhu Yihua [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials, Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)], E-mail: yhzhu@ecust.edu.cn; Yang Xiaoling [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials, Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Li Chunzhong [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials, Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhou Jinghong [UNILAB, State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237 (China)

2007-01-15

450

Presynaptic calcium currents at voltage-clamped excitor and inhibitor nerve terminals of crayfish.  

PubMed Central

1. A two-electrode voltage clamp was used to record calcium currents from the excitatory and inhibitory nerve terminals that innervate the crayfish (Procambarus spp.) opener muscle. Other voltage-dependent currents were blocked with tetrodotoxin, 3,4-diaminopyridine, 4-aminopyridine and tetraethylammonium. 2. The presynaptic calcium current at both excitatory and inhibitory synapses was blocked by cadmium and omega-agatoxin IVA but was not affected by omega-conotoxin GVIA, omega-conotoxin MVIIC or nifedipine, suggesting that the calcium currents flow through P-type calcium channels. 3. Current-voltage (I-V) relations at both excitatory and inhibitory synapses are similar, with current activation near -40 mV, peak current near -10 mV and current reversal at membrane potentials greater than +25 mV. I-V relations were scaled along the current axis by partial calcium current blockade with cobalt, suggesting that series resistance and space-clamp errors were small. 4. A subset of terminals on one muscle fibre was locally superfused with a physiological saline containing barium; the rest of the preparation was superfused with a physiological saline containing calcium channel antagonists. Under such conditions the characteristics of the I-V relation were very similar to the I-V relations recorded when the entire preparation was bathed in physiological levels of calcium, suggesting that the space clamp was adequate. 5. Calcium channel activation, as determined from tail current analyses, was similar when the entire preparation was bathed in physiological levels of calcium or if terminals on one muscle fibre were locally superfused with barium. 6. During a 30 ms depolarization, calcium currents inactivated to a greater extent in inhibitory than in excitatory terminals. The inactivation was of small magnitude (< 20%) and was eliminated by intracellular injection of the calcium chelator BAPTA, suggesting that the inactivation was calcium dependent. 7. These data show that biophysical and pharmacological properties of calcium currents at crayfish neuromuscular junctions resemble those found at stellate synapses in squid. Images Figure 5

Wright, S N; Brodwick, M S; Bittner, G D

1996-01-01

451

Al 2O 3(Ba 0.5Sr 0.5)TiO 3 composite oxide films on etched aluminum foil by solgel coating and anodizing  

Microsoft Academic Search

(Ba0.5Sr0.5)TiO3 (BST) coating was applied to the etched aluminum foils by solgel dip-coating with (Ba0.5Sr0.5)TiO3 sol prepared by mixing tetrabutyl titanate, barium acetate, strontium acetate, diethylene glycol, acetic acid and distilled water. After annealing under 500600C in air, Al2O3BST composite oxide film was formed on the surface of the etched aluminum foil by anodizing galvanostatically in a neutral adipite and

Youlong Xu

2004-01-01

452

CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT WITH SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

453

Using Barium Ions for Heavy-Atom Derivatization and Phasing of Xylanse ll from Trichoderma longibrachiatum  

SciTech Connect

This paper describes the use of barium chloride to produce a heavy-atom derivative of xylanase II crystals from Trichoderma longibrachiatum, which was obtained either by cocrystallization or soaking. SAD phasing led to interpretable electron-density maps that allowed unambiguous chain tracing. In the best case, with a data set collected at 9.5 keV, 88% of the residues were built, with 83% of the side chains assigned. The barium ions are found to mainly interact with main-chain carbonyl groups and water molecules. It is suggested that barium ions could also be used as a potential anomalous scatterer in the quick cryosoaking procedure for phasing.

Moiseeva,N.; Allaire, M.

2007-01-01

454

Interactions between chloride and sulfate or silica removals from wastewater using an advanced lime-aluminum softening process: equilibrium modeling.  

PubMed

Interactions among chloride, sulfate, and silica removals from recycled industrial wastewater using an ultra-high lime with aluminum process (UHLA) were studied. An equilibrium model that is able to accurately predict the chemical behavior and interactions between chloride and sulfate or silica with UHLA at various initial conditions and chemical reagents was developed. X-ray diffraction (XRD) analysis was conducted to identify the precipitated solids formed in the UHLA process. Model predictions indicated that simultaneous removal of sulfate and chloride can be best described by the formation of a solid solution containing calcium chloroaluminate, calcium sulfoaluminate (ettringite), calcium monosulfate, tricalcium hydroxyaluminate, and tetracalcium hydroxyaluminate. However, simultaneous removal of silica and chloride can be best described by precipitation of calcium silicate and calcium aluminosilicate in addition to a solid solution containing calcium chloroaluminate, tricalcium hydroxyaluminate, and tetracalcium hydroxyaluminate. The XRD results indicated the presence of the same solids assumed by the equilibrium model. PMID:17571843

Abdel-Wahab, Ahmed; Batchelor, Bill

2007-05-01

455

On the nature of striae in strontium barium niobate  

SciTech Connect

Strontium barium niobate crystals were grown by the Czochralski technique. These crystals were 15--20 mm in diameter and 25 to 75 mm long. Two types stride, designated as coarse and fine, were characterized. The coarse stride are optically dense and are spaced by 100 to 500 {mu}m apart; the fine striae are optically less dense and spaced 5--50 {mu}m apart. The origins of the stride are attributed to thermal fluctuations in the melt related to the control system and to rotation of the growing crystal in non-isothermal radial gradients. Analysis of the crystals would indicated that the coarse striae may contain increased concentrations of sodium.

Monchamp, R.R.; Mihalik, G.B.; Franks, L.A.

1993-12-31

456

Interband two-photon absorption in strontium barium niobate crystals  

NASA Astrophysics Data System (ADS)

Interband two-photon absorption in photorefractive strontium barium niobate crystals SrxBa1-xNb2O6 (x = 0.61, 0.75), both pure and doped with Ni and La ions, is studied under excitation by trains of 523.5-nm picosecond laser pulses. The two-photon absorption coefficients are found to vary from 0.17 to 0.31 cm GW-1 depending on the azimuth of the linear polarisation of the pump radiation and on the chemical composition of samples. The dependences of the transmission of crystals on the pump radiation intensity show a hysteresis related to induced one-photon absorption from excited levels.

Zverev, Petr G.; Ivleva, Lyudmila I.; Karasik, Aleksandr Ya; Lukanin, V. I.; Chunaev, D. S.

2012-07-01

457

Barium titanate nanocomposite capacitor FY09 year end report.  

SciTech Connect

This late start RTBF project started the development of barium titanate (BTO)/glass nanocomposite capacitors for future and emerging energy storage applications. The long term goal of this work is to decrease the size, weight, and cost of ceramic capacitors while increasing their reliability. Ceramic-based nanocomposites have the potential to yield materials with enhanced permittivity, breakdown strength (BDS), and reduced strain, which can increase the energy density of capacitors and increase their shot life. Composites of BTO in glass will limit grain growth during device fabrication (preserving nanoparticle grain size and enhanced properties), resulting in devices with improved density, permittivity, BDS, and shot life. BTO will eliminate the issues associated with Pb toxicity and volatility as well as the variation in energy storage vs. temperature of PZT based devices. During the last six months of FY09 this work focused on developing syntheses for BTO nanoparticles and firing profiles for sintering BTO/glass composite capacitors.

Stevens, Tyler E.; DiAntonio, Christopher Brian; Yang, Pin; Chavez, Tom P.; Winter, Michael R.; Monson, Todd C.; Roesler, Alexander William; Fellows, Benjamin D.

2009-11-01

458

Polarization switching kinetics in ultrathin ferroelectric barium titanate film  

NASA Astrophysics Data System (ADS)

The investigation of polarization switching kinetics in an ultrathin barium titanate film reveals true threshold switching at a large coercive electric field, evidence that switching is of intrinsic thermodynamic nature, rather than of extrinsic nature initiated by thermal nucleation, which has no true threshold field. The switching speed of a 7 nm thick epitaxial film exhibits a critical slowing as the threshold is approached from above, a key characteristic of intrinsic switching. In contrast, a bulk crystal exhibits nucleation-initiated switching, which has no threshold, and proceeds even at fields well below the nominal coercive field, which was determined independently from the polarization-electric field hysteresis loop. Previously, this phenomenon was only reported for ultrathin ferroelectric polymer LangmuirBlodgett films. Since both the thermodynamic coercive field and the intrinsic switching kinetics are derived from the mean field theory of ferroelectricity, we expect that these phenomena will be found in other ferroelectric films at the nanoscale.

Gaynutdinov, R.; Minnekaev, M.; Mitko, S.; Tolstikhina, A.; Zenkevich, A.; Ducharme, S.; Fridkin, V.

2013-09-01

459

The Performance of Barium Sulfate Nanoparticles/polypropylene Hybrid Multifilament  

NASA Astrophysics Data System (ADS)

Nanosize barium sulfate (BaSO4) particles prepared with dodecyl benzene sulfonic acid (DBSA) in ethanol-water reaction system are used to prepare BaSO4/polypropylene (PP) nanocomposites by melt mixing method. It is then made into hybrid fibers by melt spinning and subsequent drawing with different ratios. The hybrid fibers are characterized by rheology, morphology, thermal stability and mechanical properties, respectively. The results indicate that the DBSA-modified BaSO4 can improve the spinnability of BaSO4/PP hybrid multifilament even at high BaSO4 nanoparticles concentration. DBSA can be used as compatibilizer to enhance the interface interaction of BaSO4/PP nanocomposites, because DBSA contains both hydrophobicity long alkyl chain and hydrophilic sulfonic group. Therefore, it can improve the performances of BaSO4/PP hybrid multifilament.

Li, Ying; Wang, Xuanjun; Mu, Xiaoxi; Zhang, Shujuan

2012-12-01

460

Syntheses and crystal structures of three barium uranium sulfides  

NASA Astrophysics Data System (ADS)

The barium uranium sulfides Ba3.69US6, BaUS3, and BaU2S5 have been synthesized at 1273, 1323, and 1323 K, respectively. The structures of these compounds have been determined by single-crystal X-ray diffraction methods. They crystallize in space groups D3d6-R3c, D2h16-Pnma, and C2h5-P21/c, respectively. Among these three ternaries and Ba2US6 the coordination geometries about the U atoms vary considerably. Ba3.69US6 is a mixed U4+/U5+compound whereas the others are U4+ compounds. The decreasing dimensionality of the four compounds with increasing Ba-to-U content shows the expected trend.

Mesbah, Adel; Ibers, James A.

2013-03-01

461

Properties of a nanocrystalline barium titanate on silicon humidity sensor  

NASA Astrophysics Data System (ADS)

A nanometric barium titanate (BaTiO3) film was fabricated on a silicon (SiO2/Si) substrate by the spin-coating method to make a resistive-type humidity sensor. The humidity sensing properties of the sensor were measured, including sensitivity, hysteresis, and response and recovery times. The sensing properties of the sensor did not change with the level of the applied voltage. The best linearity of the curve of impedance versus relative humidity (RH) appears at the frequency of 100 Hz. The capacitance of the sensor increases as RH increases, especially for low measurement frequency. The peaks of the dielectric loss of the humidity sensor move in the higher frequency direction as RH increases.

Wang, Jing; Wan, Hui; Lin, Qiuhua

2003-02-01

462

Assessment of patient exposure for barium enema examinations.  

PubMed

Methods are described for the assessment of patient exposure during clinical fluoroscopic procedures. Values of the roentgen-area-product (RAP) and their distribution throughout the examination are presented for both single-contrast and double-contrast barium enema studies. The double-contrast procedure was measured to give 50% more radiation to the patient than the single-contrast procedure when the same size optical aperture is used between the intensifier and TV pick-up tube. However, it was possible to decrease the fluoroscopic RAP value by over a factor of two for the double-contrast procedure without an adverse clinical effect by increasing the area of the aperture diaphragm. PMID:6642942

Bednarek, D R; Rudin, S; Wong, R

463

Calcium and acid rebound: a reappraisal.  

PubMed

We review acid rebound, the seemingly paradoxical increase in acid secretion resulting from administration of an antacid. Primarily a laboratory observation, the demonstration of the phenomenon was a major contributing factor to the swift, and possibly unjustified, fall from grace of calcium carbonate in the therapy of peptic ulcer disease despite years of apparently successful use. Calcium, as carbonate or other salts, causes an increase in gastric acid secretion owing, at least in part, to direct ionic stimulation. Another possible mode of action involves antral alkalinization with subsequent gastrin release. Other antacids, notably magnesium hydroxide and aluminum hydroxide, may therefore also cause rebound, but the data in this area are less convincing. Despite the demonstration that acid rebound occurs, no one has thoroughly investigated its clinical import. What limited data actually exist suggest no obvious clinically significant deleterious effect from use of calcium carbonate in peptic ulcer. Because of calcium carbonate's excellent acid-neutralizing capacity, its venerable past record in treating ulcer disease, and recent observations that low-dose antacids heal peptic ulcers, it is appropriate to reevaluate acid rebound, to focus on its clinical significance, if any. PMID:1500660

Hade, J E; Spiro, H M

1992-07-01

464

Aluminum: Industry of the future  

SciTech Connect

For over a century, the US aluminum industry has led the global market with advances in technology, product development, and marketing. Industry leaders recognize both the opportunities and challenges they face as they head into the 21st century, and that cooperative R and D is key to their success. In a unique partnership, aluminum industry leaders have teamed with the US Department of Energy`s Office of Industrial Technologies (OIT) to focus on innovative technologies that will help to strengthen the competitive position of the US aluminum industry and, at the same time, further important national goals. This industry-led partnership, the Aluminum Industry of the Future, promotes technologies that optimize the use of energy and materials in operations and reduce wastes and energy-related emissions. Led by The Aluminum Association, industry leaders began by developing a unified vision of future market, business, energy, and environmental goals. Their vision document, Partnerships for the Future, articulates a compelling vision for the next 20 years: to maintain and grow the aluminum industry through the manufacture and sale of competitively priced, socially desirable, and ecologically sustainable products. Continued global leadership in materials markets will require the combined resources of industry, universities, and government laboratories. By developing a unified vision, the aluminum industry has provided a framework for the next step in the Industries of the Future process, the development of a technology roadmap designed to facilitate cooperative R and D.

NONE

1998-11-01

465

Aluminum chlorohydrate II: Physicochemical properties.  

PubMed

Determination of the chloride content of aluminum chlorohydrate by a chloride-selective indicated that gamma Cl leads to 1. IR analysis demonstrated that chloride was exchanged readily by nitrate and that the IR bands of the anion were not perturbed significantly. Thus, chloride is believed to act as a counterion. A high positive charge is predicted based o the critical coagulation concentration of aluminum chlorohydrate and the stability of aluminum chlorohydrate to attack by protons, as demonstrated by pH-stat titration Potentiometric titration with sodium hydroxide showed adsorption of hydroxyl anions initially, but a higher pH than expected was observed at the end-point. This behavior is consistent with the Al13O4(OH)24(H2O)7+12 complex, which would adsorb hydroxyl anions initially and in which the central tetrahedral aluminum is shielded from the added hydroxyl anions. The reaction rate with ferron (8-hydroxy-7-iodo-5-quinolinesulfonic acid) suggests that the major species in aluminum chlorohydrate is a large aluminum poly-cation. A platey morphology for lyophilized, air-dried, and spray-dried aluminum chlorohydrate was observed by scanning electron microscopy. The platey appearance is consistent with the structure of Al13O4(OH)24(H2O)7+12 since the spherical nature and high uneven charge of the complex make stacking difficult. PMID:7264922

Teagarden, D L; Radavich, J F; White, J L; Hem, S L

1981-07-01

466

SBN60, strontium-barium niobate at 100?K.  

PubMed

The title compound, Sr0.6Ba0.4Nb2O6 (strontium barium niobium oxide), belongs to the group of strontium-barium niobates with varying composition of Sr and Ba. Their general formula can be written as Sr x Ba1 - x Nb2O6. Below the Curie temperature, T c , these materials indicate ferroelectric properties. The Curie temperature for SBN60 is equal to 3460.5?K so the structure is in the ferroelectric phase at the measurement temperature of 100?K. Characteristic for this family of compounds is the packing along the z-axis. The NbO6 corner-sharing octa-hedra surround three types of vacancy tunnels with penta-gonal, square and triangular shapes. The Sr(2+) ions partially occupy two unique sites, the first one located inside the penta-gon and the second one in the square tunnels. Consequently, they are situated on the mirror plane and the inter-section of two glide planes, respectively. The site inside the penta-gonal tunnel is additionally disordered so that the same position is shared by Ba(2+) and Sr(2+) ions whereas another part of the Ba(2+) ion occupies a different position (relative occupancies 0.43:0.41:0.16). One of the Nb(V) atoms and three of the O(2-) ions occupy general positions. The second Nb(V) atom is located on the inter-section of the mirror planes. Two remaining O(2-) ions are located on the same mirror plane. Only the Nb(V) atom and one of the O(2-) ions which is located on the mirror plane are not disordered. Each of the remaining O(2-) ions is split between two sites, with relative occupancies of 0.52:0.48 (O(2-) ions in general positions) and 0.64:0.36 (O(2-) ion on the mirror plane). PMID:24098159

Stachowicz, Marcin; Gawryszewska, Olga; Swirkowicz, Marek A; Lukasiewicz, Tadeusz

2013-09-28

467

SBN60, strontium-barium niobate at 100 K  

PubMed Central

The title compound, Sr0.6Ba0.4Nb2O6 (strontium barium niobium oxide), belongs to the group of strontiumbarium niobates with varying composition of Sr and Ba. Their general formula can be written as SrxBa1 - xNb2O6. Below the Curie temperature, T c, these materials indicate ferroelectric properties. The Curie temperature for SBN60 is equal to 3460.5?K so the structure is in the ferroelectric phase at the measurement temperature of 100?K. Characteristic for this family of compounds is the packing along the z-axis. The NbO6 corner-sharing octahedra surround three types of vacancy tunnels with pentagonal, square and triangular shapes. The Sr2+ ions partially occupy two unique sites, the first one located inside the pentagon and the second one in the square tunnels. Consequently, they are situated on the mirror plane and the intersection of two glide planes, respectively. The site inside the pentagonal tunnel is additionally disordered so that the same position is shared by Ba2+ and Sr2+ ions whereas another part of the Ba2+ ion occupies a different position (relative occupancies 0.43:0.41:0.16). One of the NbV atoms and three of the O2? ions occupy general positions. The second NbV atom is located on the intersection of the mirror planes. Two remaining O2? ions are located on the same mirror plane. Only the NbV atom and one of the O2? ions which is located on the mirror plane are not disordered. Each of the remaining O2? ions is split between two sites, with relative occupancies of 0.52:0.48 (O2? ions in general positions) and 0.64:0.36 (O2? ion on the mirror plane).

Stachowicz, Marcin; Gawryszewska, Olga; Swirkowicz, Marek A.; Lukasiewicz, Tadeusz

2013-01-01

468

Barium and carbon fluxes in the Canadian Arctic Archipelago  

NASA Astrophysics Data System (ADS)

The seasonal and spatial variability of dissolved Barium (Ba) in the Amundsen Gulf, southeastern Beaufort Sea, was monitored over a full year from September 2007 to September 2008. Dissolved Ba displays a nutrient-type behavior: the maximum water column concentration is located below the surface layer. The highest Ba concentrations are typically observed at river mouths, the lowest concentrations are found in water masses of Atlantic origin. Barium concentrations decrease eastward through the Canadian Arctic Archipelago. Barite (BaSO4) saturation is reached at the maximum dissolved Ba concentrations in the subsurface layer, whereas the rest of the water column is undersaturated. A three end-member mixing model comprising freshwater from sea-ice melt and rivers, as well as upper halocline water, is used to establish their relative contributions to the Ba concentrations in the upper water column of the Amundsen Gulf. Based on water column and riverine Ba contributions, we assess the depletion of dissolved Ba by formation and sinking of biologically bound Ba (bio-Ba), from which we derive an estimate of the carbon export production. In the upper 50 m of the water column of the Amundsen Gulf, riverine Ba accounts for up to 15% of the available dissolved Ba inventory, of which up to 20% is depleted by bio-Ba formation and export. Since riverine inputs and Ba export occur concurrently, the seasonal variability of dissolved Ba in the upper water column is moderate. Assuming a fixed organic carbon to bio-Ba flux ratio, carbon export out of the surface layer is estimated at 1.8 0.45 mol C m-2 yr-1. Finally, we propose a climatological carbon budget for the Amundsen Gulf based on recent literature data and our findings, the latter bridging the surface and subsurface water carbon cycles.

Thomas, Helmuth; Shadwick, Elizabeth; Dehairs, Frank; Lansard, Bruno; Mucci, Alfonso; Navez, Jacques; Gratton, Yves; Prowe, Friederike; Chierici, Melissa; Fransson, Agneta; Papakyriakou, Tim N.; Sternberg, Erika; Miller, Lisa A.; Tremblay, Jean-Ric; Monnin, Christophe

2011-09-01

469

Barium and Carbon fluxes in the Canadian Arctic Archipelago  

NASA Astrophysics Data System (ADS)

The seasonal and spatial variability of dissolved Barium (Ba) in the Amundsen Gulf, southeastern Beaufort Sea, was monitored over a full year from September 2007 to September 2008. Barium displays a nutrient-type behavior with the highest concentrations observed at river mouths. The water column maximum is located at the base of the surface layer with lower concentrations above and below. The lowest concentrations are found in water masses of Atlantic origin, and Ba concentrations decrease eastward through the Canadian Arctic Archipelago. A three end-member mixing model comprising fresh water from sea-ice melt and rivers, as well as upper halocline water, was used to establish their relative contributions to the surface waters of the Amundsen Gulf. Based on water column and riverine Ba contributions, we assess the Ba depletion by particle sinking and subsequently estimate the carbon export production. In the upper 50 m of the water column of Amundsen Gulf, riverine Ba accounts for up to 15% of the dissolved Ba inventory, whereas up to 20% of the dissolved Ba inventory is depleted by barite (BaSO4) formation and export. Since riverine inputs and Ba export occur concurrently, the seasonal variability of dissolved Ba is moderate. Assuming a fixed organic carbon to barite flux ratio, carbon export out of the surface layer is estimated at 2 mol C m-2 yr-1. Finally, we propose a climatological carbon budget for the Amundsen Gulf based on recent literature data and our findings, the latter bridging the surface and subsurface water carbon cycles. This work is a contribution to the Canadian IPY programs CFL and GEOTRACES, to ArcticNet as well as to the IGBP/IHDP core project LOICZ.

Thomas, H.; Shadwick, E. H.; Woule Ebongue, V.; Lansard, B.; Navez, J.; Gratton, Y.; Prowe, F.; Mucci, A.; Chierici, M.; Fransson, A.; Papakyriakou, T. N.; Sternberg, E.; Miller, L. A.

2010-12-01

470

Study of aluminum nitride formation by superfine aluminum powder combustion in air  

Microsoft Academic Search

An experimental study on the combustion of superfine aluminum powders (average particle diameter as?0.1 ?m) in air is reported. Formation of aluminum nitride during combustion of aluminum in air is focused in this study. Superfine aluminum powders were produced by wire electrical explosion (WEE) method. Such superfine aluminum powder is stable in air but, if ignited, it can burn in

Alexander Gromov; Vladimir Vereshchagin

2004-01-01

471

Stainable aluminum and not aluminum content reflects bone histology in dialyzed patients  

Microsoft Academic Search

Stainable aluminum and not aluminum content reflects bone histology in dialyzed patients. Quantitative evaluation of stainable bone aluminum and measurement of bone aluminum content were done in 55 patients on chronic maintenance dialysis. All patients underwent bone biopsies. Histomorphometry of static and dynamic parameters of bone structure, bone formation and resorption, and quantitation of stainable bone aluminum at the osteoidbone

Hartmut H Malluche

1986-01-01

472

PREPARATION OF URANIUM-ALUMINUM ALLOYS  

DOEpatents

A process is given for preparing uranium--aluminum alloys from a solution of uranium halide in an about equimolar molten alkali metal halide-- aluminum halide mixture and excess aluminum. The uranium halide is reduced and the uranium is alloyed with the excess aluminum. The alloy and salt are separated from each other. (AEC)

Moore, R.H.

1962-09-01

473

Aluminum Plasmonic Nanoantennas  

NASA Astrophysics Data System (ADS)

We have explored the plasmonic properties of individual Al nanorod antennas fabricated by planar lithography on lightly doped n-type silicon. Energy-resolved cathodoluminescence was used to image the local density of optical states with a spatial resolution of 20 nm and thereby identify the radiative modes of these nanostructures. Al nanoantenna emission exhibited highly tunable plasmonic resonances from the deep UV through the visible region of the spectrum. The dependence of the radiative dipolar and quadrupolar plasmon modes on antenna length and photon energy agreed well with finite difference time domain-based analysis of these nanostructures. The results herald nano-structured aluminum as a practical and highly promising material system for the design and implementation of UV and visible frequency plasmonics, broadening the range of potential applications of plasmonics into areas where complementary metal-oxide-semiconductor (CMOS) compatibility or low-cost, mass producibility are desired.

Everitt, Henry; Knight, Mark; Liu, Lifei; Yang, Yumin; Brown, Lisa; Mukherjee, Shaunak; King, Nicholas; Nordlander, Peter; Halas, Naomi

2013-03-01

474

Spray Rolling Aluminum Strip  

SciTech Connect

Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

2006-05-10

475

Calcium hydroxide poisoning  

MedlinePLUS

... powder produced by mixing calcium oxide ("lime") with water. Calcium hydroxide poisoning occurs when someone swallows this substance. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have ...

476

Plasmasynthesized nano-aluminum powders  

Microsoft Academic Search

The plasma electro-condensation\\u000a process was used to synthesize nano-sized aluminum powders. Adding different\\u000a chemicals modified the physical and chemical properties of these powders.\\u000a To characterize the nano-sized powders, X-ray diffraction, TEM, BET analyses,\\u000a and simultaneous TG\\/DSC analyses were performed. TG\\/DSC analyses revealed\\u000a a dramatic degradation of the aluminum oxide layer after storage of the aluminum\\u000a powder in air for a

Alla Pivkina; D. Ivanov; Yu. Frolov; Svetlana Mudretsova; Anna Nickolskaya; J. Schoonman

2006-01-01

477

Extracting aluminum from dross tailings  

Microsoft Academic Search

Aluminum dross tailings, an industrial waste, from the Egyptian Aluminium Company (Egyptalum) was used to produce two types\\u000a of alums: aluminum-sulfate alum [itAl2(SO4)3.12H2O]and ammonium-aluminum alum [(NH\\u000a 4)2SO4AL2(SO4)3.24H2O]. This was carried out in two processes. The first process is leaching the impurities using diluted H2SO4 with different solid\\/liquid ratios at different temperatures to dissolve the impurities present in the starting material

A. M. Amer

2002-01-01

478

Extracting aluminum from dross tailings  

Microsoft Academic Search

Aluminum dross tailings, an industrial waste, from the Egyptian Aluminium Company (Egyptalum) was used to produce two types of alums: aluminum-sulfate alum [itAl2(SO4)3.12H2O] and ammonium-aluminum alum [ (NH 4)2SO4AL2(SO4)3.24H2O]. This was carried out in two processes. The first process is leaching the impurities using diluted H2SO4 with different solid\\/liquid ratios at different temperatures to dissolve the impurities present in the

A. M. Amer

2002-01-01

479

Aluminum hydroxide issue closure package  

SciTech Connect

Aluminum hydroxide coatings on fuel elements stored in aluminum canisters in K West Basin were measured in July and August 1998. Good quality data was produced that enabled statistical analysis to determine a bounding value for aluminum hydroxide at a 99% confidence level. The updated bounding value is 10.6 kg per Multi-Canister Overpack (MCO), compared to the previously estimated bounding value of 8 kg/MCO. Thermal analysis using the updated bounding value, shows that the MCO generates oxygen concentrate that are below the lower flammability limits during the 40-year interim storage period and are, therefore, acceptable.

Bergman, T.B.

1998-08-26

480

Aluminum chlorohydrate I: Structure studies.  

PubMed

X-ray diffraction and IR and 27AI-NMR spectroscopy indicate that aluminum chlorohydrate is composed of a central aluminum in a tetrahedral configuration surrounded by 12 aluminum atoms in octahedral configuration. The complex, AI13O4(OH)24(H2O)7+12, is essentially spherical, with the +7 charge equally distributed on the surface. Seven chloride ions are associated with the complex as counterions. This structure is consistent with both the method of synthesis and the proposed mechanism of antiperspirant activity. PMID:7264921

Teagarden, D L; Kozlowski, J F; White, J L; Hem, S L

1981-07-01

481

Failure Properties of Aluminum and Aluminum Alloys under Impact Conditions.  

National Technical Information Service (NTIS)

Research under this grant was directed to two distinct tasks. First was study of the kinetics of shock-induced phase transitions in solids; second was measurement of precursor amplitudes in aluminum under carefully controlled conditions. Shock-induced str...

G. E. Duvall G. R. Fowles

1976-01-01

482

Calcium absorption and achlorhydria  

Microsoft Academic Search

Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium

Robert R. Recker

1985-01-01

483

Molecular cluster models of aluminum oxide and aluminum hydroxide surfaces  

Microsoft Academic Search

Ab initio, molecular orbital calculations for two different Hartree-Fock basis levels were performed on clusters in the system Al-O-H, and tested by comparing derived vibrational frequencies to the measured values for aluminum oxides and aluminum oxyhydroxide minerals. Models were chosen to reflect surface groups that may be present on aluminous minerals such as a-Al2O3 (corundum) and Al(OH)3 (gibbsite). Protonation and