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1

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

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

2014-07-01

2

Gaseous calcium, strontium, and barium phosphites  

Microsoft Academic Search

The authors investigated the composition of the vapor over calcium, strontium, and barium orthophosphates in the temperature range of 1900-2500°K. The study was carried out on an MS-1301 mass spectrometer; the vaporization was carried out from molybdenum Knudsen chambers. The heating was carried out by electron bombardment, and the temperature was measured with an EOP-66 optical pyrometer. The ions Me\\/sup

S. I. Lopatin; G. A. Semenov

1986-01-01

3

PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE  

E-print Network

PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE G.MALOVICHKO, V calcium titanate crystals, Ba0.77Ca0.23TiO3, in the temperature range between 4.2 K and 300 K are reported of crystals from barium titanate (BT) family make them promising candidates for various applications

Malovichko, Galina

4

Calcium barium niobate ridge waveguide on silicon substrate  

NASA Astrophysics Data System (ADS)

A novel optical ridge waveguide using calcium barium niobate (CBN) with a high electro-optic coefficient on silicon substrate is proposed for the design and realization of the next-generation hybrid modulators with short length and low driving voltage. To overcome the etching difficulty of CBN, the design of a waveguide, including an elevated CBN layer based on etched silicon dioxide, is presented. Fabrication of a thick 2.5-?m CBN layer is performed using pulsed laser deposition. Deposited silicon dioxide on the sides and top of the CBN reduces the waveguide loss as low as 3.44 dB/cm, measured using a cutback method. Good agreement between the mode profiles of the simulation and measurement is obtained.

Mortazy, Ebrahim; Stateikina, Irina; Tehranchi, Amirhossein; Delprat, Sébastien; Chaker, Mohamed; Wu, Ke

2010-07-01

5

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

6

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

7

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

8

Final Report on the Safety Assessment of Aluminum Silicate, Calcium Silicate, Magnesium Aluminum  

E-print Network

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

Ahmad, Sajjad

9

Structural study of a lead–barium–aluminum phosphate glass by MAS-NMR spectroscopy  

Microsoft Academic Search

The 31P- and 27Al-MAS-NMR spectra of a lead–barium–aluminum phosphate glass were measured and analyzed, and the short range structure of the glass are discussed. The 31P-MAS-NMR spectrum of the glass studied has a single isotropic peak at ?4.76 ppm, indicating that orthophosphate species are the dominant P-sites in the glass. The 27Al-MAS-NMR spectrum of the glass shows that the aluminum

Guo Gongyi

1998-01-01

10

21 CFR 182.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2010 CFR

...silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2 percent. (c) Limitations, restrictions, or explanation...substance is generally recognized as safe when used in table salt in accordance with good manufacturing...

2010-04-01

11

21 CFR 582.2122 - Aluminum calcium silicate.  

Code of Federal Regulations, 2010 CFR

...silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2 percent. (c) Limitations, restrictions, or explanation...substance is generally recognized as safe when used in table salt in accordance with good manufacturing or feeding...

2010-04-01

12

Aluminum Citrate Prevents Renal Injury from Calcium Oxalate Crystal Deposition  

PubMed Central

Calcium oxalate monohydrate crystals are responsible for the kidney injury associated with exposure to ethylene glycol or severe hyperoxaluria. Current treatment strategies target the formation of calcium oxalate but not its interaction with kidney tissue. Because aluminum citrate blocks calcium oxalate binding and toxicity in human kidney cells, it may provide a different therapeutic approach to calcium oxalate-induced injury. Here, we tested the effects of aluminum citrate and sodium citrate in a Wistar rat model of acute high-dose ethylene glycol exposure. Aluminum citrate, but not sodium citrate, attenuated increases in urea nitrogen, creatinine, and the ratio of kidney to body weight in ethylene glycol–treated rats. Compared with ethylene glycol alone, the addition of aluminum citrate significantly increased the urinary excretion of both crystalline calcium and crystalline oxalate and decreased the deposition of crystals in renal tissue. In vitro, aluminum citrate interacted directly with oxalate crystals to inhibit their uptake by proximal tubule cells. These results suggest that treating with aluminum citrate attenuates renal injury in rats with severe ethylene glycol toxicity, apparently by inhibiting calcium oxalate’s interaction with, and retention by, the kidney epithelium. PMID:23138489

Besenhofer, Lauren M.; Cain, Marie C.; Dunning, Cody

2012-01-01

13

Formation and properties of a lead-barium-aluminum phosphate glass  

SciTech Connect

A lead-barium-aluminum phosphate glass has been prepared by a wet chemical process. The phosphate glass exhibits high transmission in the visible region of the spectrum and into the mid-infrared and can strongly absorb in the ultraviolet at wavelengths of less than 344 nm. In addition, the glass has a relatively high index of refraction and a good chemical durability. Therefore, the phosphate glass can be used for general-purpose optical applications.

Gongyi, G. [Shanghai Jiao Tong Univ. (China). Dept. of Materials Science and Engineering; Yuli, C. [Shanghai Univ. (China). Dept. of Chemistry and Chemical Engineering

1995-02-01

14

Effect of chloride incorporation on the crystallization of zirconium-barium-lanthanum-aluminum fluoride glass  

NASA Technical Reports Server (NTRS)

One aspect of the influence of preparation procedure on the crystallization behavior of a zirconium-barium-lanthanum-aluminum fluoride glass was studied. The crystallization pattern of this glass may be affected by the chlorine concentration within it. In particular, when such glasses are heated at low temperatures, the alpha-Ba-Zr-F6 crystalline phase forms only in those glasses which contain chloride.

Neilson, G. F.; Smith, G. L.; Weinberg, M. C.

1985-01-01

15

The effect of calcium cations on the precipitation of barium sulfate 2: calcium ions in the presence of organic additives  

NASA Astrophysics Data System (ADS)

Calcium ions have been implicated in changing the precipitation of barium sulfate when organic additives are present, although whether it inhibits or promotes nucleation and/or growth has been disputed in the literature. We conducted a thorough investigation into the effect of calcium when additives are present and show that calcium cations do indeed promote nucleation of barium sulfate particles when compared to the appropriate control. This result is independent of the analytical method (conductivity or turbidity) used to assess precipitation. The nucleation promotion produces no change in the crystal morphology, thus morphology is not always a good indicator of nucleation or growth behavior. The extent of nucleation promotion depends on the functional group of the additive.

Jones, F.; Oliviera, A.; Parkinson, G. M.; Rohl, A. L.; Stanley, A.; Upson, T.

2004-10-01

16

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

PubMed Central

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

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

2012-01-01

17

Inhibition of barium-induced constriction of cerebral surface arterioles by blockers of calcium channels.  

PubMed

Barium ion, applied as BaCl2 to the cerebral surface, produces marked constriction of pial arterioles. The present data demonstrate that this constriction is inhibited by the calcium channel blockers verapamil and nimodipine. Verapamil in concentrations as low as 10)-7) M was effective in local administration. Verapamil in milligram per kilogram doses and nimodipine in microgram per kilogram doses were effective 30 min after intraperitoneal injection without producing dilation. The basis for the inhibitory action of the calcium channel blockers is not established by the data. However, in view of barium's known ability to depolarize membranes, it may be that the constriction which results is related to inward passage of ions and is facilitated by inward movements of calcium. PMID:4005434

Rosenblum, W I

1985-01-01

18

Effects of calcium, strontium, and barium ions on phosphorylation of hippocampal proteins in vitro.  

PubMed

Calcium ion alone or in the presence of added calmodulin stimulated in vitro transfer of 32P from [gamma 32P]ATP into several proteins of mitochondrial and synaptosomal particulate fractions from rat brain. Strontium ion was capable of substituting for calcium ion in this stimulation, but barium ion lacked this capacity. These results bring into question the hypothesis that calcium-dependent protein phosphorylation of synaptic proteins is intrinsic to neurotransmitter release during neurotransmission, but they do not rule out that possibility. PMID:6689699

Hoch, D B; Wilson, J E

1984-01-01

19

Calcium citrate without aluminum antacids does not cause aluminum retention in patients with functioning kidneys  

NASA Technical Reports Server (NTRS)

It has been suggested that calcium citrate might enhance aluminum absorption from food, posing a threat of aluminum toxicity even in patients with normal renal function. We therefore measured serum and urinary aluminum before and following calcium citrate therapy in patients with moderate renal failure and in normal subjects maintained on constant metabolic diets with known aluminum content (967-1034 mumol/day, or 26.1-27.9 mg/day, in patients and either 834 or 1579 mumol/day, or 22.5 and 42.6 mg/day, in normal subjects). Seven patients with moderate renal failure (endogenous creatinine clearance of 43 ml/min) took 50 mmol (2 g) calcium/day as effervescent calcium citrate with meals for 17 days. Eight normal women received 25 mmol (1 g) calcium/day as tricalcium dicitrate tablets with meals for 7 days. In patients with moderate renal failure, serum and urinary aluminum were normal before treatment at 489 +/- 293 SD nmol/l (13.2 +/- 7.9 micrograms/l) and 767 +/- 497 nmol/day (20.7 +/- 13.4 micrograms/day), respectively. They remained within normal limits and did not change significantly during calcium citrate treatment (400 +/- 148 nmol/l and 600 +/- 441 nmol/day, respectively). Similarly, no significant change in serum and urinary aluminum was detected in normal women during calcium citrate administration (271 +/- 59 vs 293 +/- 85 nmol/l and 515 +/- 138 vs 615 +/- 170 nmol/day, respectively). In addition, skeletal bone aluminum content did not change significantly in 14 osteoporotic patients (endogenous creatinine clearance of 68.5 ml/min) treated for 24 months with calcium citrate, 10 mmol calcium twice/day separately from meals (29.3 +/- 13.9 ng/mg ash bone to 27.9 +/0- 10.4, P = 0.727). In them, histomorphometric examination did not show any evidence of mineralization defect. Thus, calcium citrate given alone without aluminum-containing drugs does not pose a risk of aluminum toxicity in subjects with normal or functioning kidneys, when it is administered on an empty stomach at a recommended dose of 20 mmol calcium/day.

Sakhaee, K.; Wabner, C. L.; Zerwekh, J. E.; Copley, J. B.; Pak, L.; Poindexter, J. R.; Pak, C. Y.

1993-01-01

20

Pyroelectric and dielectric properties of calcium barium niobate single crystals  

NASA Astrophysics Data System (ADS)

The effect of the calcium concentration on the pyroelectric and dielectric properties of Ca x Ba1 - x Nb2O6 (CBN) crystals has been studied over a wide temperature range. It has been shown that the calcium concentration only influences the Curie point of crystals of this class. It insignificantly changes the absolute values of the permittivity, the coercive field, and the remanent polarization and does not influence their temperature dependences and the shape of the dielectric hysteresis loop. The possibility of the existence of relaxor properties in CBN crystals has been discussed.

Malyshkina, O. V.; Lisitsin, V. S.; Dec, J.; ?ukasiewicz, T.

2014-09-01

21

Calcium  

MedlinePLUS

... when taken with food. Some over-the-counter antacid products, such as Tums® and Rolaids®, contain calcium ... calcium excretion and thereby lower blood calcium levels. Antacids containing aluminum or magnesium increase calcium loss in ...

22

Calcium metal as a scavenger for antimony from aluminum alloys  

SciTech Connect

Previous work has shown that trace amounts of antimony (Sb) can affect the mechanical properties of strontium (Sr) modified aluminum castings. ANL has been investigating technology to remove or neutralize Sb to reduce its negative effect on the physical properties of those alloys. Review of past work on processing and recovery of scrap aluminum inferred that calcium (Ca) is an effective scavenger of Sb, bismuth, lead and cadmium. Following up on that lead, we have found that Ca is, indeed, effective for removing Sb from molten aluminum alloys although its effectiveness can be compromised by a wide range of processing conditions. A minimum ratio of about four to one, by weight, of Ca to Sb appears necessary to insure an effective scavenging of contained Sb.in 356 aluminum alloys.

Bonsignore, P.V.; Daniels, E.J.; Wu, C.T.

1994-10-04

23

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 5000-200 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 Fe-O and Ba-O bonds in M-type hexagonal ferrite (BaFe12O19) molecules. Also, the results explain the structural model, based on the effect of aluminum substitution “Al-O 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 293-493 K. The ac conductivity showed a linear relation with the frequency power law with an exponent s?0.69-0.14 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

24

Infrared determination of calcium or lithium nitrate in acetone solution determination of calcium or lithium in the presence of strontium or barium.  

PubMed

A method is proposed for the infrared determination of calcium or lithium in the presence of strontium or barium. A mixture of the nitrates is treated with acetone which dissolves only the calcium or lithium nitrate. The strontium or barium nitrate is filtered off. The nitrate is evaporated to about 2 ml with a stream of dry air and then diluted to 5 ml with acetone. The infrared spectrum is scanned from 860 to 800 cm(-1) and the nitrate peak at 824 cm(-1) for calcium and 827 cm(-1) for lithium is measured. The recommended range is 1-80 mg of calcium or lithium nitrate in the presence of up to about 200 mg of strontium or barium nitrate. PMID:18960539

Norwitz, G; Chasan, D E

1969-04-01

25

Synthesis, crystal structure and properties of calcium and barium hydroxyapatites containing copper ions in hexagonal channels  

Microsoft Academic Search

Coloured ceramic calcium and barium phosphate apatites containing copper ions were prepared by solid state reactions at 1100°C. Single crystals were grown by melting the ceramics in Bi?M?Cu?O (M=Ca, Ba) fluxes at 1300°C, and subsequent controlled cooling. The powders were characterised by X-ray diffraction, IR and UV–vis diffuse reflectance spectroscopy and SQUID magnetometry. The single crystals have empirical formulas Ca5(PO4)3Cu0.27O0.86Hy

Andrey S. Karpov; Jürgen Nuss; Martin Jansen; Pavel E. Kazin; Yury D. Tretyakov

2003-01-01

26

doi:10.1016/S0016-7037(03)00177-7 A thermodynamic investigation of barium and calcium sulfate stability in sediments at an  

E-print Network

doi:10.1016/S0016-7037(03)00177-7 A thermodynamic investigation of barium and calcium sulfate) Abstract--We have used a new thermodynamic model of barium and calcium sulfate solubilities- ters (Chang et al., 1996). Its occurrence is reported in altered sediments and mineral deposits forming

Paris-Sud XI, Université de

27

Experimental equations of state for calcium, strontium, and barium metals to 20 kbar from 4 to 295 K  

NASA Astrophysics Data System (ADS)

Piston-displacement measurements have been used to determine the equations of state of high-purity calcium and strontium (both fcc) and barium (bcc) metals to 20 kbar from 4 to 295 K. For each metal, the results have roughly 1% accuracy for the P=0 bulk modulus at 295 K and for the total volume change with pressure. The results also give the change with temperature of both the P=0 volume and the isothermal bulk modulus for these metals. While the bulk moduli for calcium and strontium are dependent only on the volume, those for barium show a significant temperature dependence with decreasing volume. Specifically, the bulk modulus for barium at 10 kbar is roughly 3% smaller at 295 K than would be predicted from the 0-K value at the same volume. Differences between the pressure-volume relations for bare samples and for those which were jacketed with indium metal are not understood.

Anderson, M. S.; Swenson, C. A.; Peterson, D. T.

1990-02-01

28

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

Microsoft Academic Search

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 β-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%

S. R. Jansen; J. M. Migchels; H. T. Hintzen; R. Metselaar

1999-01-01

29

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

NASA Technical Reports Server (NTRS)

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

Zaplatynsky, I.

1979-01-01

30

Role of barium nitrate on the sulfur fixation of calcium oxide.  

PubMed

In this paper, the effect of Ba(NO3)2 on the efficiency of sulfur fixation of calcium oxide during coal combustion was studied. The results showed that addition of barium nitrate to the CaO can enhance the sulfur removal rate of CaO significantly. The X-ray diffraction spectrum of residual ash of coal added some sulfur fixative expressed that Ba2+ can form a compound of Ba-Al-Si-O which encloses the CaSO4 to prevent it's decomposition, so Ba2+ can improve the action of sulfur fixation of CaO. The combustion character of the original coal and original coal added sulfur fixative was researched with thermal-gravity analyzer and the results expressed that adding some sulfur fixative to the coal will make the combustion character of coal change little. PMID:11590723

Liu, G G; Zheng, L Q; Lu, W Y

2001-01-01

31

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

Microsoft Academic Search

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

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

2003-01-01

32

Effects of low-molecular-weight aluminum complexes on brain tissue calcium homeostasis  

Microsoft Academic Search

The in vitro effects of low-molecular-weight aluminum complexes (citrate, lactate, and ATP complex) on the Ca2+ uptake and aluminum-induced lipid peroxidation of brain tissue show that the modification of the calcium homeostasis is determined\\u000a by the nature of the ligand and that there is no correlation between the aluminum-induced lipid peroxidation and the Ca2+ uptake. The same characteristics have been

Leopold J. Anghileri; Pierre Thouvenot; Alain Bertrand

1998-01-01

33

AN INTERSTELLAR ORIGIN FOR THE BERYLLIUM 10 IN CALCIUM-RICH, ALUMINUM-RICH INCLUSIONS S. J. Desch1  

E-print Network

AN INTERSTELLAR ORIGIN FOR THE BERYLLIUM 10 IN CALCIUM-RICH, ALUMINUM-RICH INCLUSIONS S. J. Desch1 October 15 ABSTRACT Beryllium 10 is a short-lived radionuclide (t1=2 ¼ 1:5 Myr) that was incorporated live into calcium-rich, aluminum-rich inclusions (CAIs) at the birth of our solar system. Beryllium 10 is unique

Connolly Jr, Harold C.

34

Accretion, partitioning and sequestration of calcium and aluminum in red spruce foliage: implications for tree health  

Microsoft Academic Search

Summary Calcium (Ca) is an essential macronutrient in plants and is an important component of many cellular struc- tures and physiological processes as well as overall forest func- tion. Aluminum (Al) in soil solution can inhibit Ca uptake by plants and disrupt many Ca-dependent metabolic and physio- logical processes of plants. The ratio of Ca to A1 in soil solution

CATHERINE H. BORER; PAUL G. SCHABERG; DONALD H. DEHAYES; GARY J. HAWLEY

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] [Eindhoven Univ. of Technology (Netherlands). Lab. of Solid State and Materials Chemistry

1999-02-01

36

Calcium-Aluminum-rich Inclusions in Chondritic Meteorites  

NASA Astrophysics Data System (ADS)

Calcium-aluminum-rich inclusions (CAIs) are submillimeter- to centimeter-sized clasts in chondritic meteorites, whose ceramic-like chemistry and mineralogy set them apart from other chondrite components. Since their first descriptions more than 30 years ago (e.g., Christophe Michel-Lévy, 1968), they have been the objects of a vast amount of study. At first, interest centered on the close similarity of their mineralogy to the first phases predicted by thermodynamic calculations to condense out of a gas of solar composition during cooling from very high temperatures (e.g., Lord, 1965; Grossman, 1972). Immediately thereafter, CAIs were found to be extremely old (4.56 Ga) and to possess unusual isotopic compositions (in particular, in magnesium and oxygen) suggestive of a presolar dust component. In short, they appear to be the oldest and most primitive objects formed in the infant solar system.In the late 1980s (e.g., MacPherson et al., 1988), the attention of most workers in the field was focused on understanding the petrogenesis and isotopic compositions of CAIs within a relatively restricted number of chondrite varieties. Much has changed since then. We now have extended our data sets beyond CV and CM chondrites to CAIs from ordinary, enstatite, and a wider range of carbonaceous chondrites. Out of this has emerged an ironic fact: the large centimeter-sized CAI "marbles" (the so-called type Bs; see below) that are so prominent in CV chondrites, and upon which so many of the original concepts were based owing to the abundance and availability of material from the Allende meteorite, turn out to be the exceptions rather than the norm. Indeed, we now know that the Allende parent body itself experienced so much postaccretion reprocessing that its CAIs reveal only a murky picture of the early solar nebula. Another profound change since 1988 has been the development of ion microprobe technology permitting microanalysis of oxygen isotopes within standard petrographic thin sections. One of the debates raging in 1988 centered on the difficulty of making CAIs at the distance of the asteroid belt where the host chondrites presumably accreted. Since then, a combination of isotopic (especially beryllium-boron and oxygen) evidence and theoretical modeling have suggested the interesting possibility that CAIs all formed very close to the infant sun and were later dispersed out to the respective chondrite accretion regions. Yet another difference from 1988 is that the science of meteoritics has matured past the point where workers study CAIs without consideration of other chondritic components, most notably chondrules. Bulk composition differences aside, CAIs and chondrules are both products of very high temperature events in the earliest solar system. Like chondrules, many CAIs apparently solidified from partially to completely molten droplets. Moreover, chondrules and CAIs both have far more complex histories than was generally recognized in the late 1980s: both may have experienced multiple melting episodes, followed by prolonged nebular and/or asteroidal modification due to gaseous or liquid interactions and reheating as a result of shock processes. In short, although CAIs are still recognized as being the oldest objects formed in our solar system and possessing isotopic traces of the presolar dust from which they ultimately formed, they are a long way from being the primitive condensates they were once thought to be. Rather than stressing the unusual isotopic characteristics of CAIs and the presolar implications, this chapter will instead treat CAIs as probes of the earliest solar system that reveal the nature of the high-temperature events, their chronology, and the likely locales where such events occurred.This chapter is not, and does not pretend to be, an exhaustive review of the sum of knowledge about CAIs. Indeed, so much new data have been generated since 1988, especially isotopic data from an ever-growing number of sophisticated ion microprobe labs, that it would far beyond the space limitations of this chapter to a

MacPherson, G. J.

2003-12-01

37

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

SciTech Connect

The deoxidation equilibrium of molten titanium and titanium-aluminum alloys saturated with solid CaO has been measured in the temperature range from 1,823 to 2,023 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 TiAl{sub 3}. The standard Gibbs energy of reaction for TiAl was obtained as follows: {Delta}G{degree} = 279,000 {minus} 103T J/mol. The possibilities for the deoxidation of titanium and titanium-aluminum alloys by using calcium-based fluxes are discussed.

Tsukihashi, Fumitaka; Tawara, Eiji; Hatta, Toshiyuki [Univ. of Tokyo (Japan). Dept. of Metallurgy

1996-12-01

38

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

39

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

40

Role of Accumulated Calcium in Alleviating Aluminum Injury in Wheat Plants  

PubMed Central

Aluminum (Al) sensitive wheat cultivar kalyansona was grown for 14?d in a range of Ca solution (125, 625, and 2500??M) plus other nutrients without Al. At 14?d after Ca treatment, half of these plants were harvested (H1), and the rest of the plants were exposed to 100??M Al for additional 6?d and harvested (H2). Severe Al injury was found only in the plants with the lowest supply of Ca before Al treatment. Aluminum concentration in the apoplastic fluid was very high at 125??M Ca probably because the plasma membrane of some of the cells was destroyed due to the attack of 100??M Al. Aluminum content in roots decreased with increasing supply of Ca before Al treatment. Calcium content decreased drastically at harvest (H2) in the plants with 100??M Al. Under Al stress conditions, the plant responded to Al in different ways due to not only the different Ca supply but also the variation of Ca content in the plant tissues. Actually, the plants having the largest Ca content in the roots before Al treatment can receive less Al injury during Al treatment. To substantiate this idea, a companion study was conducted to investigate the effects of 2500??M Ca supply during, before, and after 100??M Al treatment on root growth. The results indicated clearly that exogenous Ca supply before Al treatment is able to alleviate Al injury but less effective than Ca supply during Al treatment. PMID:24701169

Hossain, M. Alamgir; Ashrafuzzaman, M.; Hossain, A. K. M. Zakir; Ismail, Mohd. Razi; Koyama, H.

2014-01-01

41

Aluminum diffusion in Oxisols as influenced by soil water matric potential, ph, lime, gypsum, potassium chloride, and calcium phosphate  

Microsoft Academic Search

Plant root exposure to soil aluminum (Al) depends on the soil solution Al concentration and transport to the root by diffusion. Changes in Al diffusive flux for two Oxisols was measured under laboratory conditions as a function of pH, water matric potential, and applications of gypsum, potassium chloride, and calcium phosphate. Double?faced cation exchange resin sheets served as sinks for

F. H. T. Oliveira; R. F. Novais; T. J. Smyth; J. C. L. Neves

2000-01-01

42

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

43

Vapour pressure of water over saturated solutions of tartaric acid, sodium hydrogen tartrate, sodium tartrate, potassium tartrate, calcium tartrate, barium tartrate, citric acid, disodium hydrogen citrate, sodium citrate, and potassium citrate at temperatures from 277 K to 317 K  

Microsoft Academic Search

Vapour pressures of saturated aqueous solutions of tartaric acid, sodium hydrogen tartrate, sodium tartrate, potassium tartrate, calcium tartrate, barium tartrate, citric acid, disodium hydrogen citrate, sodium citrate, and potassium citrate were determined in the temperature range (277 to 317)K using an electronic hygrometer. Only for tartaric acid, sodium tartrate, potassium tartrate and citric acid was it possible to compare the

Emanuel Manzurola; Alexander Apelblat

2003-01-01

44

Hydration kinetics of modified calcium sulphoaluminate oxides studied by aluminum — 27 NMR spectroscopy and proton magnetic relaxation: Experimental data  

Microsoft Academic Search

Hydration kinetics of Na2O-, MgO-, BaO- and TiO2- doped calcium sulphoaluminate oxides, has been followed using 27Al NMR and proton magnetic relaxation measurements. Aluminum — 27 NMR spectra of hydrated pastes show a narrow peak at 80 ppm corresponding to the hydroxy-aluminate ions in a liquid phase. According to the changes of intensity of this lines during the induction period

A. B. Kudryavtsev; T. V. Kouznetsova

1997-01-01

45

Tree seedling growth and mortality responses to manipulations of calcium and aluminum in a northern hardwood forest1  

Microsoft Academic Search

To assess potential forest compositional responses to exchangeable soil calcium (CaeXch) and aluminum (Alex,,), we characterized light-dependent growth and mortality of tree seedlings under amendments of CaC1, and AlCl, at Hubbard Brook Experimental Forest (HBEF), New Hampshire, U.S.A. Seedlings of Acer saccharum Marsh., Fagus grandifolia Ehrh., Betula alleghaniensis Britton, Abies balsamea (L.) Mill., and Picea rubens Sarg. were transplanted into

Richard K. Kobe; Gene E. Likens; Christopher Eagar

2002-01-01

46

Early life stage brook trout (Salvelinus fontinalis) experiment to determine the effects of pH, calcium and aluminum in low conductivity water  

SciTech Connect

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 of fish; however, the exposures in these experiments have been of relatively short duration. The objective of the present study was to determine the chronic effects of elevated aluminum concentrations as a function of pH and calcium level on hatching success and subsequent fry survival of brook trout. Brook trout eyed eggs (25 per chamber) were exposed to a replicated matrix of four levels each of pH and calcium and five levels of aluminum totaling 64 different combinations in a 40-day test. The levels of pH, aluminum, and calcium were chosen to represent the chemistry of sensitive lakes and streams in eastern Canada, the northeastern United States, and Scandinavia. We exposed fish to higher aluminum concentrations at lower pH levels, based on the observation that in acidified natural waters, dissolved inorganic aluminum increases as pH decreases (e.g., Shofield 1982). The results presented are based on nominal pH, aluminum, and calcium levels. 9 refs., 12 figs., 4 tabs.

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

1984-01-01

47

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

48

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

SciTech Connect

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, or other processes contributing to acid soil infertility. Based on a critical review of literature on Al stress, we estimate that there is a 50:50 risk of adverse impacts on tree growth or nutrition when the soil solution Ca/Al ratio is as low as 1.0, a 75% risk when the soil solution ratio is as low as 0.5, and nearly a 100% risk when the soil solution Ca/Al molar ratio is as low as 0.2. The Ca/Al ratio of the soil solution can be corroborated with other complementary indices.

Cronan, C.S. [Univ. of Maine, Orono, ME (United States); Grigal, D.F. [Univ. of Minnesota, St. Paul, MN (United States)

1995-03-01

49

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

Microsoft Academic Search

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

Donald W. Sparling

1990-01-01

50

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

51

Calcium  

MedlinePLUS

... lead levels. Calcium carbonate is used as an antacid for “heartburn.” Calcium carbonate and calcium acetate are ... when given intravenously (by IV). Use as an antacid as calcium carbonate. Reducing phosphate levels in people ...

52

Inhibition of PCR-based assay for Bordetella pertussis by using calcium alginate fiber and aluminum shaft components of a nasopharyngeal swab.  

PubMed Central

A PCR-based assay for Bordetella pertussis was inhibited by using a calcium alginate fiber-tipped swab with an aluminum shaft but not by using a Dacron fiber-tipped swab with a plastic shaft. The calcium alginate fiber component inhibited the assay following storage for less than 1 min in a suspension of 10(3) CFU of B. pertussis per ml, whereas the aluminum shaft component required storage for at least 48 h in order to cause inhibition. We recommend the Dacron swab over the calcium alginate swab for collecting specimens for testing in PCR-based assays. Images PMID:8027309

Wadowsky, R M; Laus, S; Libert, T; States, S J; Ehrlich, G D

1994-01-01

53

Disturbance of Intracellular calcium homeostasis and CaMKII/CREB signaling is associated with learning and memory impairments induced by chronic aluminum exposure.  

PubMed

Aluminum-induced neuronal injury has been implicated in various neurodegenerative disorders. However, the underlying mechanism involved in this pathogenesis still remains unknown. Our present findings demonstrated that chronic aluminum exposure resulted in spatial learning impairment and significantly increased intracellular calcium level in the hippocampus of rats. Examination of the associated protein molecules essential for induction and maintenance of long-term potentiation revealed that aluminum exposure could increase the expression level of calmodulin (CaM), but the expression levels of CaM-dependent protein kinase II (CaMKII), and phosphorylated cAMP-responsive element binding protein (CREB) were significantly reduced, whereas the total protein levels of CaMKII and CREB did not change in the aluminum-treated hippocampus. Thus, we provide a previously unrecognized mechanism whereby chronic aluminum exposure impairs hippocampal learning and memory, at least in part, through disruption of intracellular calcium homeostasis and CaM/CaMKII/CREB signaling pathway. PMID:24366850

Wang, Biao; Zhao, Jiuhan; Yu, Meng; Meng, Xin; Cui, Xin; Zhao, Yan; Zhu, Yuyan; Xing, Wei; Guan, Yifu

2014-07-01

54

21 CFR 82.1051 - Lakes (D&C).  

Code of Federal Regulations, 2011 CFR

...talc, rosin, aluminum benzoate, calcium carbonate, or any combination of two...potassium, aluminum, barium, calcium, strontium, or zirconium...potassium, aluminum, barium, calcium, strontium, or zirconium....

2011-04-01

55

21 CFR 82.1051 - Lakes (D&C).  

Code of Federal Regulations, 2010 CFR

...talc, rosin, aluminum benzoate, calcium carbonate, or any combination of two...potassium, aluminum, barium, calcium, strontium, or zirconium...potassium, aluminum, barium, calcium, strontium, or zirconium....

2010-04-01

56

21 CFR 82.1051 - Lakes (D&C).  

Code of Federal Regulations, 2012 CFR

...talc, rosin, aluminum benzoate, calcium carbonate, or any combination of two...potassium, aluminum, barium, calcium, strontium, or zirconium...potassium, aluminum, barium, calcium, strontium, or zirconium....

2012-04-01

57

21 CFR 82.1051 - Lakes (D&C).  

Code of Federal Regulations, 2013 CFR

...talc, rosin, aluminum benzoate, calcium carbonate, or any combination of two...potassium, aluminum, barium, calcium, strontium, or zirconium...potassium, aluminum, barium, calcium, strontium, or zirconium....

2013-04-01

58

Effects of aluminum and acid on calcium uptake by the crayfish Orconectes virilis  

Microsoft Academic Search

Aluminum increases in concentration in acidified waters and is sometimes more toxic to aquatic organisms at acidic than at neutral pH. This paper examined the interaction of pH and Al in inhibiting uptake of Ca++ from lake water by postmolt crayfish,Orconectes virilis (Hagen). Aluminum at 200 µg\\/L in non-acidified media had no effect on45Ca uptake. Media at pH 5.5 without

D. F. Malley; P. S. S. Chang

1985-01-01

59

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

NASA Astrophysics Data System (ADS)

Very high temperature, Ca-rich alkaline magma intruded an argillite formation at Colle Fabbri, Central Italy, producing cordierite-tridymite metamorphism in the country rocks. An intense Ba-rich sulphate-carbonate-alkaline hydrothermal plume produced a zone of mineralization several meters thick around the igneous body. Reaction of hydrothermal fluids with country rocks formed calcium-silicate-hydrate (CSH), i.e., tobermorite-afwillite-jennite; calcium-aluminum-silicate-hydrate (CASH) — "cement" phases - i.e., thaumasite, strätlingite and an ettringite-like phase and several different species of zeolites: chabazite-Ca, willhendersonite, gismon-dine, three phases bearing Ca with the same or perhaps lower symmetry of phillipsite-Ca, levyne-Ca and the Ca-rich analogue of merlinoite. In addition, apophyllite-(KF) and/or apophyllite-(KOH), Ca-Ba-carbonates, portlandite and sulphates were present. A new polymorph from the pyrrhotite group, containing three layers of sphalerite-type structure in the unit cell, is reported for the first time. Such a complex association is unique. Most of these minerals are specifically related to hydration processes of: (1) pyrometamorphic metacarbonate/metapelitic rocks (natural analogues of cement clinkers); (2) mineralization between intrusive stocks and slates; and (3) high-calcium, alkaline igneous rocks such as melilitites and foidites as well as carbonatites. The Colle Fabbri outcrop offers an opportunity to study in situ complex crystalline overgrowth and specific crystal chemistry in mineral phases formed in igneous to hydrothermal conditions.

Stoppa, F.; Scordari, F.; Mesto, E.; Sharygin, V. V.; Bortolozzi, G.

2010-06-01

60

Physiological and toxicological effects of long-term exposure to acid, aluminum, and low calcium on adult brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri)  

SciTech Connect

Although the toxic effects of these three parameters were highly interactive, survival and growth of adult brook trout were reduced at elevated aluminum concentrations. Only 40 ug/L aluminum was necessary to produce similar responses in rainbow trout. Neither species was sensitive to pH alone in the range 4.5-6.5 except at very low calcium concentrations. Reductions in fecundity were observed, but only as a result of decreased growth. Progeny spawned from brook trout that had been exposed to 0.5 mg/L calcium were more sensitive to continued exposure to acid, aluminum and low calcium than were progeny of control fish. Physiologically, brook and rainbow trout responded similarly to sublethal acid, aluminum and low calcium stress. All fish exposed to depressed pH showed reductions in plasma sodium, but in most cases they were able to maintain normal plasma osmolality. But those fish stressed most severely displayed an entire suite of disturbances, including decreased survival, growth and feeding, as well as abnormal vitellogenesis and ionoregulatory failure.

Mount, D.R.

1987-01-01

61

SPATIAL AND TEMPORAL VARIATION IN CALCIUM AND ALUMINUM IN NORTHERN HARDWOOD FOREST FLOORS  

E-print Network

, soil acidification increases the availability of aluminum, which affects plants directly by decreasing and Grigal, 1995). Water, Air, and Soil Pollution 160: 109­118, 2005. C 2005 Springer. Printed water moves down through well drained soils after a rain event, the water potential gradient maintained

Phillips, Richard P.

62

Express Letter Oxygen isotopes in calcium^aluminum-rich inclusions from  

E-print Network

^aluminum-rich inclusions (CAIs) from primitive chondritic meteorites were among the ¢rst-formed solids in the solar nebula. One test of this model is to study CAIs from other chondrite varieties. E-chondrites are highly. These observations sug- gest that E-chondrite CAIs either formed during an earlier and more oxidized evolutionary

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

Associations of calcium and aluminum with the growth and health of sugar maple trees in Vermont  

Microsoft Academic Search

We compared tree growth and crown condition with soil and foliar elemental composition in 14 sugar maple (Acer saccharum Marsh.) stands in VT, USA, to evaluate if deficiencies or imbalances in cation nutrition were associated with growth and health reductions in native stands. The Till Source Model (TSM) was used to select study sites potentially high or low in calcium

Paul G. Schaberg; James W. Tilley; Gary J. Hawley; Donald H. DeHayes; Scott W. Bailey

2006-01-01

65

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

66

Barium Sulfate  

MedlinePLUS

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

67

Calcium  

MedlinePLUS

... it from: Dairy products. Low-fat milk, yogurt, cheese, and cottage cheese are good sources of calcium. Veggies. You'll ... burritos or wraps. Fill them with eggs and cheese for breakfast; turkey, cheese, lettuce, tomato, and light ...

68

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

Microsoft Academic Search

Many coarese-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

Gregory P. Meeker

1995-01-01

69

Programmed Cell Death-Involved Aluminum Toxicity in Yeast Alleviated by Antiapoptotic Members with Decreased Calcium Signals1  

PubMed Central

The molecular mechanisms of aluminum (Al) toxicity and tolerance in plants have been the focus of ongoing research in the area of stress phytophysiology. Recent studies have described Al-induced apoptosis-like cell death in plant and animal cells. In this study, we show that yeast (Saccharomyces cerevisiae) exposed to low effective concentrations of Al for short times undergoes enhanced cell division in a manner that is dose and cell density dependent. At higher concentrations of Al or longer exposure times, Al induces cell death and growth inhibition. Several apoptotic features appear during Al treatment, including cell shrinkage, vacuolation, chromatin marginalization, nuclear fragmentation, DNA degradation, and DNA strand breaks, as well as concomitant cell aggregation. Yeast strains expressing Ced-9, Bcl-2, and PpBI-1 (a plant Bax inhibitor-1 isolated from Phyllostachys praecox), respectively, display more resistance to Al toxicity compared with control cells. Data from flow cytometric studies show these three antiapoptotic members do not affect reactive oxygen species levels, but decrease calcium ion (Ca2+) signals in response to Al stress, although both intracellular reactive oxygen species and Ca2+ levels were increased. The data presented suggest that manipulation of the negative regulation process of programmed cell death may provide a novel mechanism for conferring Al tolerance. PMID:16861572

Zheng, Ke; Pan, Jian-Wei; Ye, Lan; Fu, Yu; Peng, Hua-Zheng; Wan, Bai-Yu; Gu, Qing; Bian, Hong-Wu; Han, Ning; Wang, Jun-Hui; Kang, Bo; Pan, Jun-Hang; Shao, Hong-Hong; Wang, Wen-Zhe; Zhu, Mu-Yuan

2007-01-01

70

Mechanism of action of barium ion on rat aortic smooth muscle.  

PubMed

The mechanism of action of barium ion on the aortic smooth muscle of the normal rat was investigated using in vitro calcium-depleted aortic strips. Aortic strips were depleted of calcium by repeated exposure to norepinephrine in a calcium-free bathing solution. Although calcium depletion abrogated the response of strips to catecholamines and depolarizing agents, the response to barium chloride remained quantitatively intact. The calcium influx blocker D 600 prevented the contractile response to barium but not to catecholamines, whereas phentolamine prevented the response to catecholamines but not barium. The strip response to barium was depressed by a twofold increase in extracellular magnesium concentration whether the strip was intact or calcium depleted. Although increased concentrations of calcium in the extracellular medium inhibited the contractile response to potassium ion, increases in barium merely potentiated the potassium contracture. These findings indicate that barium produces its contractile effect on vascular smooth muscle by a direct intracellular interaction with the contractile or regulatory proteins. Barium enters these cells via calcium influx channels and is probably not sequestered in a physiologically releasable pool. Unlike calcium, barium does not stabilize the smooth muscle sarcolemma when present in high concentration. PMID:6703038

Hansen, T R; Dineen, D X; Petrak, R

1984-03-01

71

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

72

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

USGS Publications Warehouse

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

Szabo, B. J.; Joensuu, O.

1967-01-01

73

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

NASA Astrophysics Data System (ADS)

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 thin films, the dominant conduction mechanism shows space-charge-limited current behavior at a low electric field, where the trap-filled limit field is determined as ETFL=10KV/cm, while at a high electric field the Poole-Frenkel emission is operative. In contrast, the conduction mechanism for 6 at. % Al-doped BSTA thin film is dominated by field-enhanced Schottky emission.

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

2005-03-01

74

Barium titanium glycolate: A new barium titanate powder precursor  

SciTech Connect

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

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

1996-02-01

75

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

76

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

PubMed

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. PMID:2353844

Sparling, D W

1990-01-01

77

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

78

Barium release system  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

79

Molecular Structure of Barium Chloride  

NSDL National Science Digital Library

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

2002-08-15

80

Reactions of 2-mercaptobenzoic acid with divalent alkaline earth metal ions: synthesis, spectral studies, and single-crystal X-ray structures of calcium, strontium, and barium complexes of 2,2'-dithiobis(benzoic acid).  

PubMed

The treatment of MCl(2).nH(2)O (M = Ca, Sr, or Ba) with 2-mercaptobenzoic acid (H-2-MBA) in a 1:2 ratio in an EtOH/H(2)O/NH(3) mixture leads to the formation of extended polymeric solids [[Ca(OOCC(6)H(4)SSC(6)H(4)COO)(H(2)O)(2)].0.5(C(2)H(5)OH)](n)(1), [[Sr(OOCC(6)H(4)SSC(6)H(4)COO)(H(2)O)(2)].0.5(C(2)H(5)OH)](n)(2), and [[Ba(2)(OOCC(6)H(4)SSC(6)H(4)COO)(2)(H(2)O)(2)].0.5H(2)O](n)(3), respectively. In all of the cases, under the reaction conditions employed, the H-2-MBA ligand undergoes thiol oxidation to form 2,2'-dithiobis(benzoic acid) (H(2)-DTBB). While the DTBB forms a 1:1 complex with heavier alkaline earth metals (1-3), only an ammonium salt, [(HOOCC(6)H(4)SSC(6)H(4)COOH)(HOOCC(6)H(4)SSC(6)H(4)COONH(4))] (4), was obtained as the final product in the reaction of H-2-MBA with MgCl(2).6H(2)O. Compounds 1-4 have been characterized with the aid of elemental analysis, thermal analysis, and infrared spectroscopic studies. All of the products are found to be thermally stable and do not melt on heating to 250 degrees C. Thermogravimetry on complexes 1-3 indicates the loss of coordinated and lattice water/solvent molecules below 200 degrees C (for complex 2) or 350 degrees C (for complexes 1 and 3). The solid-state structures of all of the derivatives 1-4 have been established by single-crystal X-ray diffraction studies. The calcium and strontium coordination polymers 1 and 2 are isomorphous. The DTBB ligands in 1 and 2 are hexadentate, and the compounds have a channel structure in which solvent ethanol molecules are included. In compound 3, barium ion forms a complex 3-dimensional coordination polymer where both the carboxylate and the sulfur centers of the DTBB ligands (which are hepta- and octadentate) coordinate to the metal. PMID:11754266

Murugavel, R; Baheti, K; Anantharaman, G

2001-12-31

81

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

82

An aluminum/calcium-rich, iron-poor, white dwarf star: evidence for an extrasolar planetary lithosphere?  

E-print Network

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. 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 Eart...

Zuckerman, B; Dufour, P; Melis, Carl; Klein, B; Jura, M

2011-01-01

83

Tailored Barium Swallow Study  

MedlinePLUS

Tailored Barium Swallow Study The TBS is a special study that is completed in radiology. The test evaluates the mouth and ... where foods and liquids go when a person swallows. It helps clinicians to identify the reasons for ...

84

Beta barium borate (BBO)  

Microsoft Academic Search

The paper contains a review of crystallographic, optical and nonlinear optical properties of beta barium borate (ß-BaB2O4 or BBO) crystal and presents a description of its typical applications in nonlinear optics and quantum electronics.

D. N. Nikogosyan

1991-01-01

85

Barium bright and heavy  

NASA Astrophysics Data System (ADS)

Katharina M. Fromm relates how barium and its ores went from a magical, glowing species that attracted witches and alchemists to components in a variety of compounds that are key parts of modern life.

Fromm, Katharina M.

2013-02-01

86

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

87

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

88

Aspiration of barium contrast.  

PubMed

The aspiration of barium contrast is a rare complication that may occur during studies of the digestive tract. Barium is an inert material that can cause anywhere from an asymptomatic mechanical obstruction to serious symptoms of respiratory distress that can result in patient death. We present the case of a 79-year-old male patient in whom we observed the presence of contrast medium residue in the lung parenchyma as an incidental finding during hospitalization. When the patient's medical file was reviewed, images were found of a barium swallow study that the patient had undergone months earlier, and we were able to observe the exact moment of the aspiration of the contrast material. The patient had been asymptomatic since the test. PMID:25309769

Fuentes Santos, Cristina; Steen, Bárbara

2014-01-01

89

Aspiration of Barium Contrast  

PubMed Central

The aspiration of barium contrast is a rare complication that may occur during studies of the digestive tract. Barium is an inert material that can cause anywhere from an asymptomatic mechanical obstruction to serious symptoms of respiratory distress that can result in patient death. We present the case of a 79-year-old male patient in whom we observed the presence of contrast medium residue in the lung parenchyma as an incidental finding during hospitalization. When the patient's medical file was reviewed, images were found of a barium swallow study that the patient had undergone months earlier, and we were able to observe the exact moment of the aspiration of the contrast material. The patient had been asymptomatic since the test. PMID:25309769

Fuentes Santos, Cristina; Steen, Barbara

2014-01-01

90

Observed Barium Emission Rates  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

91

Ultra-low temperature processing of barium tellurate dielectrics  

NASA Astrophysics Data System (ADS)

Ceramics, metals and polymers have unique electrical properties that are combined for electronic devices and systems. It necessitates lower processing temperatures for ceramics to be compatible with metal and polymer systems. In this thesis, the synthesis, crystal structure, and dielectric properties of barium tellurate are studied for temperatures between 500 and 900°C. Barium tellurate dielectric ceramics (BaTe4O9, BaTe 2O5, BaTe2O6, BaTeO3, BaTeO 4, and Ba2TeO5) are extensively investigated as new LTCC (Low-Temperature Cofired Ceramics) dielectric systems integrated with low resistivity metal electrodes such as silver and aluminum for microwave application. Studies on the phase formation and crystal structure through thermal analyses (Differential Scanning Calorimetry and Thermogravimetric Analysis, DSC-TGA) and X-ray diffraction phase analysis attest that barium tellurates are formed in the temperature range of 500 ˜ 900°C, through the sequential phase formations from Te-rich to Ba-rich phases. The oxygen coordination of the tellurium ion progresses from TeO4 to TeO6 via TeO 3+1 and TeO3 with increasing barium content as confirmed by structural analysis using infrared spectroscopy. High density barium tellurate ceramics are achieved at temperatures as low as 550°C, which provides the potential to be co-fired with low-melting aluminum metal electrodes in LTCC processing. Dielectric permittivity, loss, and temperature stability of barium tellurate dielectric ceramics were measured from 100 Hz to 13 GHz. Barium tellurate ceramics exhibit excellent microwave dielectric properties with intermediate dielectric permittivities and high quality factors (Q). The dielectric properties at microwave frequencies are epsilonr = 17.5, Qxf = 54700 GHz, TCf = -90 ppm/°C for BaTe4O9, epsilonr = 21, Qxf = 50300 GHz, TCf = -51 ppm/°C for BaTe2O6, epsilonr = 10, Qxf = 34000 GHz, TCf = -54 ppm/°C for BaTeO3, and epsilonr = 17, Qx f = 49600 GHz, TCf = -124 ppm/°C for Ba 2TeO5. Co-firing studies of barium tellurate ceramics with metal electrodes establish new LTCC systems for microwave devices. Chemical compatibility of barium tellurates with silver electrodes was achieved in the barium rich compositions. Ba2TeO5 was found to be covetable with silver electrodes at 850°C by adding CuO and B2O3 as fluxing agents. During the co-firing, a thin interfacial layer of AgTe is metastable according to the thermodynamic equilibrium between the Ba2TeO5-Ag/Ag 2O pseudo-binary system. A breakthrough LTCC technology with aluminum is based upon the ultra-low processing temperature and chemical compatibility of BaTe4O 9, which enables co-firing and fabrication of multilayer ceramic capacitors (MLCCs) with aluminum inner electrodes. The aluminum base metal electrode (BME) BaTe4O9 MLCCs provide good dielectric properties of epsilonr = 17.5, TCepsilon = 100 ppm/°C, and tan delta = 2.1 x 10-3 (Q ? 500) at 1 MHz, which are suitable for the class-1 MLCCs. Aluminum microstrip ring resonators on the BaTe4O9 substrates realized good electromagnetic performance of the new materials at microwave frequency exhibiting resonant frequency of 2.97 GHz and Q factor of 278.

Kwon, Do-Kyun

92

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

93

21 CFR 82.2051 - Lakes (Ext. D&C).  

Code of Federal Regulations, 2012 CFR

...talc, rosin, aluminum benzoate, calcium carbonate, or on any combination of...sodium, potassium, barium, or calcium; or (ii) a salt prepared from...potassium, aluminum, barium, calcium, strontium, or zirconium....

2012-04-01

94

21 CFR 82.2051 - Lakes (Ext. D&C).  

Code of Federal Regulations, 2011 CFR

...talc, rosin, aluminum benzoate, calcium carbonate, or on any combination of...sodium, potassium, barium, or calcium; or (ii) a salt prepared from...potassium, aluminum, barium, calcium, strontium, or zirconium....

2011-04-01

95

21 CFR 82.2051 - Lakes (Ext. D&C).  

Code of Federal Regulations, 2010 CFR

...talc, rosin, aluminum benzoate, calcium carbonate, or on any combination of...sodium, potassium, barium, or calcium; or (ii) a salt prepared from...potassium, aluminum, barium, calcium, strontium, or zirconium....

2010-04-01

96

21 CFR 82.2051 - Lakes (Ext. D&C).  

Code of Federal Regulations, 2013 CFR

...talc, rosin, aluminum benzoate, calcium carbonate, or on any combination of...sodium, potassium, barium, or calcium; or (ii) a salt prepared from...potassium, aluminum, barium, calcium, strontium, or zirconium....

2013-04-01

97

Samarium-neodymium chronology and rubidium-strontium systematics of an Allende calcium-aluminum-rich inclusion with implications for 146Sm half-life  

NASA Astrophysics Data System (ADS)

Calcium-aluminum-rich inclusions (CAIs) are primitive objects that formed within the protoplanetary disk surrounding the young Sun. Recent Pb-Pb chronologic studies have demonstrated that CAIs are the oldest solar system solids, crystallizing 4567 Ma ago (Amelin et al., 2002; Connelly et al., 2012). The isotope systematics of CAIs therefore provide critical insight into the earliest history of the Solar System. Although Sm-Nd and Rb-Sr geochronometers are highly effective tools for investigating cosmochemical evolution in the early Solar System, previous studies of CAIs have revealed evidence for isotopically disturbed systems. Here we report new age data for Allende CAI Al3S4 derived from both the long-lived (147Sm-143Nd) and short-lived (146Sm-142Nd) isotopic systems. The 147Sm-143Nd chronometer yields an age of 4560±34 Ma that is concordant with 207Pb-206Pb ages for CAIs and indicates that the Sm-Nd system was not significantly disturbed by secondary alteration or nucleosynthetic processes. The slope of the 146Sm-142Nd isochron defines the Solar System initial 146Sm/144Sm of 0.00828±0.00044. This value is significantly different from the value of 0.0094 determined by Kinoshita et al. (2012). Ages recalculated from all published 146Sm-142Nd isochron data using the traditional 103 Ma half-life and the initial 146Sm/144Sm value determined here closely match Pb-Pb and 147Sm-143Nd ages determined on the same samples. In contrast, ages recalculated using the 68 Ma half-life determined by Kinoshita et al. (2012) and either of the initial 146Sm/144Sm values are often anomalously old. This is particularly true for the youngest samples with 146Sm-142Nd isochron ages that are most sensitive to the choice of 146Sm half-life used in the age calculation. In contrast to the Sm-Nd isotope system, the Rb-Sr system is affected by alteration but yields an apparent isochron with a slope corresponding to a much younger age of 4247±110 Ma. Although the Rb-Sr system in CAIs appears to be disturbed, the initial 87Sr/86Sr value determined from the isochron is 0.698942±0.000008, and closely approximates estimates of the initial Solar System value. Although this isochron may be a mixing line, it might also record alteration on the Allende parent body in which Rb was added to the Al3S4 CAI that was initially largely devoid of Rb.

Marks, N. E.; Borg, L. E.; Hutcheon, I. D.; Jacobsen, B.; Clayton, R. N.

2014-11-01

98

Setting process of lime-based conservation mortars with barium hydroxide  

SciTech Connect

This paper presents the effect of barium hydroxide on the setting mechanism of lime-based conservation mortars, when used as an additive material. The study focuses on the monitoring of the setting process and the identification of the mineral phases formed, which are essential for furthering the study of the durability of barium mixtures against chemical degradation. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and thermal analysis (DTA-TG) were used to monitor the setting processes of these mixtures and identify new phases formed. The results suggest that barium hydroxide is evenly distributed within the lime and produces a homogeneous binding material, consisting of calcite (CaCO{sub 3}), witherite (BaCO{sub 3}) and barium-calcium carbonate [BaCa(CO{sub 3}){sub 2}]. Finally, it was found that barium carbonate can be directly bonded to calcitic aggregates and therefore increases its chemical compatibility with the binding material.

Karatasios, Ioannis [Institute of Materials Science, NCSR Demokritos, Aghia Paraskevi, 153 10 Athens (Greece)]. E-mail: ikarat@ims.demokritos.gr; Kilikoglou, Vassilis [Institute of Materials Science, NCSR Demokritos, Aghia Paraskevi, 153 10 Athens (Greece); Colston, Belinda [Department of Forensic and Biomedical Sciences, University of Lincoln, Lincoln, LN6 7TS (United Kingdom); Theoulakis, Panagiotis [Department of Conservation of Antiquities and Works of Art, TEI of Athens, Athens, 122 10 (Greece); Watt, David [Hutton and Rostron Environmental Investigations Limited/Centre for Sustainable Heritage, University College London (United Kingdom)

2007-06-15

99

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

100

Silicosis in barium miners.  

PubMed Central

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

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

1986-01-01

101

Calcium and olfactory transduction.  

PubMed

1. Inorganic cations, organic calcium antagonists, and calmodulin antagonists were applied to olfactory epithelia of frogs (Rana pipiens) while recording electroolfactogram (EOG) responses. 2. Inorganic cations inhibited EOGs in a rank order, reflecting their calcium channel blocking potency: La3+ greater than Zn2+ greater than Cd2+ greater than Al3+ greater than Ca2+ greater than Sr2+ greater than Co2+ greater than Ba2+ greater than Mg2+. Barium ion significantly enhanced EOGs immediately following application. 3. Diltiazem and verapamil produced dose-dependent EOG inhibition. 4. Calmodulin antagonists inhibited EOGs without correlation to their anti-calmodulin potency. PMID:2904344

Winegar, B D; Rosick, E R; Schafer, R

1988-01-01

102

Properties of Semiconductive Barium Titanates  

Microsoft Academic Search

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

Osamu Saburi

1959-01-01

103

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 80°C 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; Böttcher, Michael E.; Samankassou, Elias; Nägler, Thomas F.

2010-05-01

104

Barium uranyl diphosphonates  

SciTech Connect

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

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

2012-08-15

105

Barium uranyl diphosphonates  

NASA Astrophysics Data System (ADS)

Three Ba2+/UO22+ 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 °C. These compounds, Ba[UO2[CH2(PO3)2]·1.4H2O (Ba-1), Ba3[(UO2)4(CH2(PO3)2)2F6]·6H2O (Ba-2), and Ba2[(UO2)2(CH2(PO3)2)F4]·5.75H2O (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 UO5F2 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 [UO2[CH2(PO3)2]2- sheets. The interlayer space of the structures is occupied by Ba2+, which, along with the fluoride ion, mediates the structure formed and maintains overall charge balance.

Nelson, Anna-Gay D.; Alekseev, Evgeny V.; Ewing, Rodney C.; Albrecht-Schmitt, Thomas E.

2012-08-01

106

Barium as a productivity proxy in continental margin sediments: a study from the eastern Arabian Sea  

Microsoft Academic Search

Barium, aluminum, cadmium and uranium were analyzed in 112 surface sediment samples from the western continental margin of India. Excess Ba (Baxs) concentrations are high at the SW margin of India, an area of high productivity and lower at the central western continental margin, an area of lower productivity. High organic carbon export coupled with high sedimentation rates and a

C. Prakash Babu; H.-J. Brumsack; B. Schnetger; M. E. Böttcher

2002-01-01

107

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

108

Growth of highly oriented TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 9{minus}y} superconducting films on Ag substrates using a dip-coated barium calcium copper oxide sol-gel precursor  

SciTech Connect

Thin films of ba{sub 2}Ca{sub 2}Cu{sub 3}O{sub 7}, a precursor of TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 9{minus}y}, were prepared by sol-gel synthesis from an all-alkoxide solution. The barium and calcium precursors were the respective metals reacted with 2-methoxyethanol, and the copper precursor was copper methoxide complexed by triethanolamine. Silver substrates were coated using the sol-gel solution by dip-coating. Subsequent processing included a low-temperature drying step (600 C), repeated coating to provide the desired thickness, heat treatment at 850 C in oxygen to remove carbon, and reaction at 860 C in a two-zone thallination furnace to produce a TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 9{minus}y} superconducting film. These films were strongly c-axis-aligned, had a zero-resistance temperature (T{sub c}) of 110 K, and a critical-current density (J{sub c}) of 1.9 {times} 10{sup 4} A/cm{sup 2} at 77 K and zero magnetic field.

Paranthaman, M.; Beach, D.B. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

1995-09-01

109

Single atom barium sources for EXO barium tagging development  

NASA Astrophysics Data System (ADS)

Barium tagging, the extraction and identification of the ^136 Xe double beta decay daughter product, would allow the Enriched Xenon Observatory (EXO) experiment to eliminate almost all backgrounds. The collaboration has made much progress in developing an ion probe to extract a barium ion from either liquid or gas xenon and an ion trap to identify a single barium ion. Yet the true efficiencies of these methods cannot be known until a source of single barium ions is available. I will talk about the Ba source R&D efforts of the EXO collaboration; they include 1) using the alpha recoil of ^148Gd on a thin layer of BaF2, 2) using an electrostatic gate to select single atoms from a Ba ion beam, and 3) using chemistry to isolate ^ 137Cs which then beta decays to Ba^+. )

Yen, Yung-Ruey

2010-02-01

110

Discovery of the Barium Isotopes  

E-print Network

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

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

2009-08-13

111

Barium light source method and apparatus  

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

112

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. PMID:4813426

Schott, G. D.; McArdle, B.

1974-01-01

113

The Exotic Barium Bismuthates  

NASA Astrophysics Data System (ADS)

We review the remarkable properties, including superconductivity, charge-density-wave ordering and metal-insulator transitions, of lead- and potassium-doped barium bismuthate. We will discuss some of the early theoretical studies of these systems. Our recent theoretical work, on the negative-U, extended-Hubbard model for these systems, will also be described. Both the large- and intermediate-U regimes of this model were examined, using mean-field and random-phase approximations, particularly with a view to fitting various experimental properties of these bismuthates. On the basis of our studies, we point out possibilities for exotic physics in these systems. We also emphasize the different consequences of electronic and phonon-mediated mechanisms for the negative U. We show that, for an electronic mechanism, the semiconducting phases of these bismuthates must be unique, with their transport properties dominated by charge ±2e Cooperon bound states. This can explain the observed difference between the optical and transport gaps. We propose other experimental tests for this novel mechanism of charge transport and comment on the effects of disorder.

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

114

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 ...

115

Calcium supplements  

MedlinePLUS

... The two main forms of calcium pills are: Calcium carbonate: Over-the-counter antacid products, such as Tums and Rolaids contain calcium carbonate. These sources of calcium carbonate do not cost ...

116

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

117

Observations on the histochemistry of barium  

Microsoft Academic Search

The histochemistry of barium was investigated with particular reference to the use of sodium rhodizonate. It was found that not all batches of sodium rhodizonate were able to effect satisfactory visualisation of barium deposits. None of the other histological parameters considered gave a consistent indication of the presence of barium.

A. J. Chaplin; E. L. T. Turner

1983-01-01

118

Refractory concrete based on barium aluminate–barium zirconate cements for steel-making industries  

Microsoft Academic Search

Five refractory cement mixes were prepared from different proportions of barite, zirconia and calcined alumina by sintering at 1500–1550°C for 3h. The obtained cements were composed of barium aluminate and barium zirconate minerals in addition to comparable proportions of di-barium silicate.Cement mix prepared from 70wt.% barite, 10wt.% zirconia and 20wt.% alumina and containing comparable proportions of barium aluminate and barium

N. M. Khalil

2005-01-01

119

Fictive Temperature Effects on Non-Bridging Oxygen and Five-Coordinated Aluminum in Calcium Aluminosilicate Glasses: High Resolution 17O and 27Al NMR Spectroscopy  

NASA Astrophysics Data System (ADS)

Despite the importance of aluminosilicate melts to both the geological and technological communities, the configurational changes with temperature remain poorly understood. However, configurational changes with temperature play an important role in changes in thermodynamic and transport properties, as well as offering insight into potential relationships between minor structural species such as non-bridging oxygen (NBO) and VAl (AlO5). A previous study indicated changes in VAl with temperature in multiple calcium aluminosilicate glasses, while changes in NBO were only observed on the metaluminous join (Stebbins et al., 2008). Here we have expanded this to look at two series of calcium aluminosilicate glasses crossing the metaluminous join on a constant SiO2 isopleth at multiple fictive temperatures. In all cases, the amount of VAl present increased with increasing fictive temperature, although the magnitude of the increase varied with larger increases in the peraluminous regions versus the peralkaline earth regions. Increases in NBO are also observed with increasing fictive temperature in the metaluminous and peraluminous regions. Comparison of these results with those from the earlier study suggests that the changes may be most pronounced in the regions where the deviation from conventional wisdom are at their peak (e.g., in the metaluminous region of alkaline earth aluminosilicate glasses). Comparison of the increases in VAl and NBO with increasing fictive temperature support previous suggestions (Thompson and Stebbins 2011; Thompson and Stebbins 2012) that multiple mechanisms must exist to produce excess VAl and NBO and that at least some of these mechanisms must be decoupled from each other.

Thompson, L. M.; Stebbins, J. F.

2012-12-01

120

Incorporation of aluminum in the calcium silicate hydrate (C-S-H) of hydrated portland cements: a high-field 27Al and 29Si MAS NMR investigation.  

PubMed

The calcium silicate hydrate (C-S-H) phase resulting from hydration of a white Portland cement (wPc) in water and in a 0.3 M NaAlO(2) solution has been investigated at 14 and 11 hydration times, respectively, ranging from 6 h to 1 year by (27)Al and (29)Si MAS NMR spectroscopy. (27)Al MAS NMR spectra recorded at 7.05, 9.39, 14.09, and 21.15 T have allowed a determination of the (27)Al isotropic chemical shift (delta(iso)) and quadrupolar product parameter (P(Q) = C(Q)) for tetrahedrally coordinated Al incorporated in the C-S-H phase and for a pentacoordinated Al site. The latter site may originate from Al(3+) substituting for Ca(2+) ions situated in the interlayers of the C-S-H structure. The spectral region for octahedrally coordinated Al displays resonances from ettringite, monosulfate, and a third aluminate hydrate phase (delta(iso) = 5.0 ppm and P(Q) = 1.20 MHz). The latter phase is tentatively ascribed to a less-crystalline aluminate gel or calcium aluminate hydrate. The tetrahedral Al incorporated in the C-S-H phase has been quantitatively determined from (27)Al MAS spectra at 14.09 T and indirectly observed quantitatively in (29)Si MAS NMR spectra by the Q(2)(1Al) resonance at -81.0 ppm. A linear correlation is observed between the (29)Si MAS NMR intensity for the Q(2)(1Al) resonance and the quantity of Al incorporated in the C-S-H phase from (27)Al MAS NMR for the different samples of hydrated wPc. This correlation supports the assignment of the resonance at delta(iso)((29)Si) = -81.0 ppm to a Q(2)(1Al) site in the C-S-H phase and the assignment of the (27)Al resonance at delta(iso)((27)Al) = 74.6 ppm, characterized by P(Q)((27)Al) = 4.5 MHz, to tetrahedrally coordinated Al in the C-S-H. Finally, it is shown that hydration of wPc in a NaAlO(2) solution results in a C-S-H phase with a longer mean chain length of SiO(4) tetrahedra and an increased quantity of Al incorporated in the chain structure as compared to the C-S-H phase resulting from hydration of wPc in water. PMID:12665361

Andersen, Morten Daugaard; Jakobsen, Hans J; Skibsted, Jørgen

2003-04-01

121

Studies of aluminum in rat brain  

Microsoft Academic Search

The effects of high aluminum concentrations in rat brains were studied using ¹⁴C autoradiography to measure the uptake of ¹⁴C 2-deoxy-D-glucose (¹⁴C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-..mu..m resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate

J. J. Lipman; A. B. Brill; P. Som; K. W. Jones; S. Colowick; M. Cholewa

1985-01-01

122

Studies of aluminum in rat brain  

Microsoft Academic Search

The effects of high aluminum concentrations in rat brain were studied using14C autoradiography to measure the uptake of [14C]2deoxy-d-glucose ([14C]2dG) and microbeam proteon-induced X-ray emission (microPIXE) with a 20-?m resolution to measure concentrations of magnesium,\\u000a aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T), and\\u000a control animals were given sodium tartrate (Na-T). The14C

J. J. Lipman; A. B. Brill; P. Som; K. W. Jones; S. Colowick; M. Cholewa

1987-01-01

123

Calcium nutrition of Sphaerotilus growing in a continuous-flow apparatus.  

PubMed

Sphaerotilus natans required calcium for the production of sheaths and probably requires calcium for growth as well, though at a lower concentration. Neither strontium nor barium substituted for calcium. S. natans grew attached to the culture vessels of the continuous-flow apparatus even when no sheaths were produced. Tentative evidence showed that the requirement for calcium is shared by the manganese-oxidizing species S. discophorus. PMID:4970993

Dias, F F; Okrend, H; Dondero, N C

1968-09-01

124

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

125

Calcium-mediated inactivation of the calcium conductance in caesium-loaded giant neurones of Aplysia californica.  

PubMed Central

1. The intracellular potassium in giant neurones of Aplysia californica was replaced with caesium by a method utilizing the ionophore nystatin. Because caesium ions have low permeability through potassium channels outward currents during voltage-clamp depolarization were strongly curtailed after the caesium loading procedure and the subsequent wash-out of the ionophore. 2. The calcium current elicited by a test voltage-clamp depolarization (pulse 2) was depressed following the entry of calcium elicited by a prior depolarization (pulse 1). 3. The percentage depression of the test current was a linear function of the pulse 1 current-time integral, and thus appears to be related linearly to the amount of calcium carried into the cell during pulse 1. This linear relation was maintained when calcium entry was varied by changes in external calcium concentration, by altered pulse 1 amplitude and altered pulse 1 duration. Depression was substantially reduced by injection of EGTA, and by substitution of barium for extracellular calcium. 4. The calcium current was unaffected by prior hyperpolarization of the membrane or by prior depolarizations to about ECa. Depression of the current was not altered by addition of extracellular 50 mM-TEA or by a strong hyperpolarization between the conditioning and test pulses. 5. The rate relaxation of the inward current during a given depolarization depended on the rate of entry and accumulation of free calcium. Relaxation under a given command potential became slower when calcium was partially replaced with magnesium so as to produce a smaller calcium current, or when accumulation of intracellular free calcium was retarded by injected EGTA or by barium substitution for extracellular calcium. 6 Evidence is considered that accumulation of calcium ions at the cytoplasmic surface of the membrane leads to inactivation through an action upon the calcium conductance. Reduced driving force and intracellular surface-charge neutralization do not adequately account for the observed depression of the calcium current resulting from intracellular accumulation of calcium ions. PMID:6273532

Eckert, R; Tillotson, D L

1981-01-01

126

Improved spectrophotometric analysis of barium styphnate  

Microsoft Academic Search

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

N. E. Brown; J. A. Blasi

1983-01-01

127

Improved spectrophotometric analysis of barium styphnate  

Microsoft Academic Search

A spectrophotometric procedure to determine the purity of barium styphnate monohydrate based upon the absorbance of the styphnate ion at 326 and 413 nm has been developed. The purity is determined by comparing the absorbance of the styphnate ion in barium styphnate and styphnic acid at pH 6.8. Our investigation has shown that the molar absorptivities and maxima of the

Norman E. Brown; Jane A. Blasi

1985-01-01

128

Barium granuloma of the transverse colon.  

PubMed Central

A case of barium sulphate granuloma of the transverse colon following gunshot wounds to the abdomen has been described. Scanning electron microscopy with electron probe microanalysis was used to confirm the presence of barium sulphate and the absence of lead or other elements related to the gunshot wounds. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:740599

McKee, P. H.; Cameron, C. H.

1978-01-01

129

REMOVAL OF BARIUM AND RADIUM FROM GROUNDWATER  

EPA Science Inventory

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

130

Conversion of aluminum chlorohydrate to aluminum hydroxide  

Microsoft Academic Search

aluminum hydroxide. X-ray, IR, and 27A1 NMR spectroscopic data indicate that aluminum chlorohydrate is composed of a central aluminum in tetrahedral configuration surrounded by 12 aluminums each in octahedral configuration. This highly .charged complex is neutralized by 7 chloride counterions. In contrast, aluminum hydroxide has a polymer-like structure whose basic unit is a ring of six aluminums in octahedral configuration

DIRK L. TEAGARDEN; STANLEY L. HEM

131

Hepatic response to aluminum toxicity: Dyslipidemia and liver diseases  

Microsoft Academic Search

Aluminum (Al) is a metal toxin that has been implicated in the etiology of a number of diseases including Alzheimer's, Parkinson's, dialysis encephalopathy, and osteomalacia. Al has been shown to exert its effects by disrupting lipid membrane fluidity, perturbing iron (Fe), magnesium, and calcium homeostasis, and causing oxidative stress. However, the exact molecular targets of aluminum's toxicity have remained elusive.

Ryan J. Mailloux; Joseph Lemire; Vasu D. Appanna

2011-01-01

132

Effect of barium ion on p-aminohippurate transport in basolateral membrane vesicles isolated from rat kidney cortex.  

PubMed

To clarify the cause of the stimulation of p-aminohippurate (PAH) accumulation in rat kidney cortical slices by barium, an experiment was carried out with basolateral membrane vesicles isolated from rat kidney cortex. The effect of barium on PAH uptake by the membrane vesicles was compared with that of verapamil which also stimulated PAH accumulation in the slices. The enzyme marker for basolateral membrane, (Na+ + K+)- ATPase, was enriched 15-fold and the brushborder enzyme marker, alkaline phosphatase, was 1.3-fold in our membrane preparation. Contamination in this preparation by lysosomes, mitochondria and cytosol was also low but that by endoplasmic reticulum was slightly high as judged by the enzyme markers. PAH uptake by the membrane vesicles possessed the usual characteristics, i.e., sodium-dependence and probenecid-sensitivity. PAH uptake by the membrane vesicles was enhanced by barium, but not by verapamil. On the other hand, barium did not affect tetraethylammonium (TEA) uptake by the vesicles, and verapamil strongly inhibited it. Manganese also stimulated PAH uptake to the same extent as did barium, but calcium and strontium did not affect the uptake. Barium did not act on sodium transport in the membrane vesicles. An 'anion-sensitively transported lipophilic cation', triphenylmethylphosphonium iodide (TPMP), uptake was depressed by barium. These results suggest that barium stimulates selectively PAH uptake in basolateral membrane vesicles. Its stimulatory action may contribute at least partly to an increase in PAH accumulation in rat kidney cortical slices by this ion and may prove useful in an analysis of the mechanism of PAH transport system in renal basolateral membranes. PMID:2992405

Hori, M; Gemba, M

1985-06-01

133

Calcium Carbonate  

MedlinePLUS

... heart. Calcium carbonate also is used as an antacid to relieve heartburn, acid indigestion, and upset stomach. ... use.Do not take calcium carbonate as an antacid for more than 2 weeks unless your doctor ...

134

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

135

Acute barium nitrate intoxication treated by hemodialysis.  

PubMed

A 22-year-old male was admitted to hospital with diarrhea and vomiting, cardiac arrhythmias, severe hypokalemia and gradual onset of muscular weakness. A potassium infusion was started, but for several hours serum potassium remained low. Evidence of toxic ingestion was initially lacking. When it became clear -- after a considerable delay -- that the patient had ingested barium nitrate, hemodialysis was started. This resulted in rapid clinical improvement with correction of hypokalemia and restored muscular function. Intoxication with barium causes hypokalemia, arrhythmias, muscular weakness and paralysis, often requiring respiratory support. This patient presented with symptoms typical of severe barium intoxication, non-responsive to potassium supplementation. There are few published reports on the use of hemodialysis in barium poisoning. This case confirms the possible benefit of hemodialysis in severe cases, where potassium supplementation alone is insufficient. PMID:15675995

Bahlmann, H; Lindwall, R; Persson, H

2005-01-01

136

Barium Isotopes in Single Presolar Grains  

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

137

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)3·26H2O) 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 75°C 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, DeltaG°r,298 = 302 +/- 10 and DeltaH°r = 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 Ca2Cr2O5·8H 2O. The log KSP, free energy and enthalpy of reaction for the dissolution of Ca6[(Al(OH)6)]2(CrO4 )3·26H2O are KSP,298 = -41.46 +/- 0.30, DeltaG°r,298 = 236.6 +/- 3.9 and DeltaH°r = 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)3·26H2O. A secondary precipitate, identified as calcium aluminum monochromate or (3CaO·Al2O3·CaCrO4·nH 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)3·26H2O 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

138

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

139

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

140

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

NASA Technical Reports Server (NTRS)

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

Ota, K.; Conger, W. L.

1977-01-01

141

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

142

Relative bioavailability of calcium from calcium formate, calcium citrate, and calcium carbonate  

E-print Network

of calcium from calcium formate, a new experimental dietary calcium supplement, to that of calcium citrate and calcium carbonate. In a four-way crossover study, either a placebo or 1200 mg of calcium as calcium carbonate, calcium citrate, or calcium formate...

Hanzlik, Robert P.; Fowler, S. C.; Fisher, D. H.

2005-06-01

143

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

144

Expression and modulation of voltage-gated calcium channels after RNA injection in Xenopus oocytes.  

PubMed

Calcium ions flow into cells through several distinct classes of voltage-dependent calcium-selective channels. Such fluxes play important roles in electrical signaling at the cell membrane and in chemical signaling within cells. Further information about calcium channels was obtained by injecting RNA isolated from rat brain, heart and skeletal muscle into Xenopus oocytes. Macroscopic currents through voltage-operated calcium channels were resolved when the endogenous calcium-dependent chloride current was blocked by replacing external calcium with barium and chloride with methanesulfonate. The resulting barium current was insensitive to tetrodotoxin but was completely blocked by cadmium or cobalt. With both heart and brain RNA at least two distinct types of calcium ion conductance were found, distinguishable by their time course and inactivation properties. In oocytes injected with heart RNA, the slowly inactivating component was selectively blocked by the calcium-channel antagonist nifedipine. Barium ion currents induced by heart RNA were modulated by isoproterenol, cyclic adenosine monophosphate, and acetylcholine. PMID:2418503

Dascal, N; Snutch, T P; Lübbert, H; Davidson, N; Lester, H A

1986-03-01

145

Barium-Induced Exocytosis is Due to Internal Calcium Release and Block of Calcium Efflux  

Microsoft Academic Search

The concentration of cytosolic free Ca2+ ([Ca2+]_i) and the release of tritiated norepinephrine ([^3H]NE) were monitored during Ba2+ stimulation of sympathetic neurons cultured from chick embryos. Ba2+ (2.5 mM in Ca2+-free medium) caused a rise in [Ca2+]_i in all regions (cell bodies, neurites, and growth cones) of sympathetic neurons and evoked [^3H]NE release in the absence of other stimuli. The

Dennis A. Przywara; Pertha S. Chowdhury; Sanjiv V. Bhave; Taruna D. Wakade; Arun R. Wakade

1993-01-01

146

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

147

CARBONATION OF BARIUM SULFIDE IN A FOAM-BED REACTOR  

Microsoft Academic Search

Carbonation of barium sulfide to barium carbonate has been experimentally investigated in a foam-bed reactor. The variables studied are height of foam bed, initial concentration of barium sulfide in aqueous solution, gas flow rate, concentration of carbon dioxide in mixture with nitrogen, and surfactant concentration in the aqueous solution. The results indicate that the conversion in the reactor increases with

Amit A. Gaikwad; Niyantha Challapalli; Ashok N. Bhaskarwar

2010-01-01

148

Precipitation of Kraft Black Liquors by Alcohol-Calcium Solutions  

Microsoft Academic Search

Industrial and laboratory kraft black liquors were precipitated with a) water-soluble solvents (alcohols and acetone), b) calcium and aluminum salts, and c) alcohol-calcium solutions. Volume of solvent and the amount of Ca (or Al) were varied over wide intervals, and their effect on the amount and composition of precipitate was studied. Alcohol-calcium solutions were the best precipitating agent (90% of

J. C. Villar; A. Caperos; F. García-Ochoa

1996-01-01

149

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

Microsoft Academic Search

Objective  Spectral CT differs from dual-energy CT by using a conventional X-ray tube and a photon-counting detector. We wished to produce\\u000a 3D spectroscopic images of mice that distinguished calcium, iodine and barium.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  We developed a desktop spectral CT, dubbed MARS, based around the Medipix2 photon-counting energy-discriminating detector.\\u000a The single conventional X-ray tube operated at constant voltage (75 kVp) and constant current (150 µA).

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

2010-01-01

150

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

151

Production and isolation of endohedral strontium- and barium-based mono-metallofullerenes: Sr/Ba@C 82 and Sr/Ba@C 84  

NASA Astrophysics Data System (ADS)

We report the first isolation of strontium- and barium-based metallofullerenes and their characterisation by UV-vis-NIR absorption spectroscopy. The absorption spectra of the present samples (Sr/Ba@C 82 and Sr/Ba@C 84) show some similarity to their calcium-based analogues and are very different from those of yttrium- and lanthanum-based metallofullerenes. Assuming the barium atom to be in the 2 + state, which has an ionic radius of 1.34Å, the Ba-containing species represent the largest ionic radii-containing metallofullerenes so far isolated.

John, T.; Dennis, S.; Shinohara, Hisanori

1997-10-01

152

Calcium orthophosphates  

PubMed Central

The present overview is intended to point the readers’ attention to the important subject of calcium orthophosphates. This type of materials is of special significance for human beings, because they represent the inorganic part of major normal (bones, teeth and antlers) and pathological (i.e., those appearing due to various diseases) calcified tissues of mammals. For example, atherosclerosis results in blood vessel blockage caused by a solid composite of cholesterol with calcium orthophosphates, while dental caries and osteoporosis mean a partial decalcification of teeth and bones, respectively, that results in replacement of a less soluble and harder biological apatite by more soluble and softer calcium hydrogenphosphates. Therefore, the processes of both normal and pathological calcifications are just an in vivo crystallization of calcium orthophosphates. Similarly, dental caries and osteoporosis might be considered an in vivo dissolution of calcium orthophosphates. Thus, calcium orthophosphates hold a great significance for humankind, and in this paper, an overview on the current knowledge on this subject is provided. PMID:23507744

Dorozhkin, Sergey V.

2011-01-01

153

Improved Spectrophotometric Analysis of Barium Styphnate.  

National Technical Information Service (NTIS)

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 bari...

J. A. Blasi, N. E. Brown

1983-01-01

154

Barium Additives As Diesel Smoke Suppressants  

Microsoft Academic Search

The body of information presented in this paper is directed to those individuals concerned with the emission of smoke from diesel engines. A series of tests was performed on a Petter Type AA1 diesel engine using barium smoke suppressant additives. An Andersen cascade type sampler was used to collect samples and thus study the effect of the additive upon the

C. David Turley; David L. Brenchley; Robert R. Landolt

1973-01-01

155

Observations on a Fully Ionized Barium Plasma  

Microsoft Academic Search

A series of spectroscopic measurements in a fully ionized barium plasma column is described and discussed. The plasma was generated in the Q-1 device in a manner similar to that used to make alkali-metal plasmas. The observations show that the density contours and the temperature profiles in the body of the plasma were strongly influenced by conditions at the end

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

1965-01-01

156

Quantum manipulation on the Barium quadrupolar transition  

E-print Network

and stabilization of a new fiber laser system to ma- nipulate the Barium quadrupolar transition, with the aim . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 Trapped ion coupled to a laser field 18 3.1 Light-matter interaction . . . . . . . . . . . . . . . 55 6 Spectroscopy and sideband cooling on a single 138 Ba+ 58 6.1 Quantum jumps using the fiber laser . . . . . . . . . . . . .

Blatt, Rainer

157

Strength and toughness of barium titanate ceramics  

Microsoft Academic Search

The effect of processing variables on the mechanical and electrical properties of holmium-doped barium titanate ceramics with a positive temperature coefficient of resistance has been investigated. This paper contains details of the tests used to measure the mechanical properties of ceramics prepared using four compositional mixes. Two methods of measuring strength were used: diametral compression of disc samples and four-point

J. M. Blamey; T. V. Parry

1993-01-01

158

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

159

Studies of aluminum in rat brain  

SciTech Connect

The effects of high aluminum concentrations in rat brains were studied using /sup 14/C autoradiography to measure the uptake of /sup 14/C 2-deoxy-D-glucose (/sup 14/C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-..mu..m resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The /sup 14/C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of /sup 14/C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10/sup 9/ Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab.

Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

1985-01-01

160

The ultra-high lime with aluminum process for removing chloride from recirculating cooling water  

E-print Network

Chloride is a deleterious ionic species in cooling water systems because it is important in promoting corrosion. Chloride can be removed from cooling water by precipitation as calcium chloroaluminate using ultra-high lime with aluminum process (UHLA...

Abdel-wahab, Ahmed Ibraheem Ali

2004-09-30

161

Functional model for calcium mobilization in the depolarized isolated guinea-pig taenia coli.  

PubMed

The muscular response to pharmacological agents is directly dependent on intracellular ionic calcium (Ca2+) and is modulated by membrane permeability and cation-binding to subcellular organelles. The isometric contraction of the ventral guinea-pig taenia coli was registered in a bath with a Rich KCl-Ringer in the absence of Ca2+ and sodium (Na+) with or without EDTA or Sammarium (Sm3+). Our experimental sequence was based on alternate succession between the concentration-response-curves or decay-curves procedure to acetylcholine and barium (Ba2+) in the same preparation. It was found that a contracture elicited by barium ion was not significantly affected by inclusion of EDTA (.01 mM) or Sm3+ (.06 mM). Also, prior exposure of the depolarized muscle to acetylcholine did not affect the barium response. However, prior exposure of the muscle to acetylcholine sensitized the barium-induced contracture to the inhibitory actions of EDTA and Sm3+. Prior exposure of the muscle to barium ions strongly reduced the mechanical response to acetylcholine. In addition, tension recorded during an acetylcholine decay curve was observed to be reduced by EDTA and Sm3+, although some degree of tension could be elicited by acetylcholine even after the depolarized muscle had been exposed to EDTA or Sm3+ up to 70 min. The suggestion is put forward that barium ions mobilize intracellular stores of calcium which may be restored from calcium pools that are mobilized by acetylcholine, EDTA and Sm3+. Acetylcholine would be able to mobilize calcium ions from a firmly bound membrane store and additional less firmly bound membrane stores.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3129626

Pavan, C G; Turrin, M Q

1987-11-01

162

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

163

Rosuvastatin calcium  

Microsoft Academic Search

Rosuvastatin calcium (Crestor; AstraZeneca), the seventh drug in the statin class, was approved by the US FDA in August 2003 for the reduction of cholesterol levels in patients with hypercholesterolaemia. Billed as the most potent statin available, can it overcome initial setbacks and make a significant impact in the multi-billion-dollar market for cholesterol-lowering drugs?

Mark Thornton; Peter Kirkpatrick; Jeremy Quirk

2003-01-01

164

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 Díez, M.; Müller, 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

165

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

166

High-resolution ²⁷Al NMR study of calcium aluminate catalysts  

Microsoft Academic Search

The high-resolution ²⁷Al NMR spectra of calcium aluminates, calcium hydroaluminates, and calcium alumina supports and catalysts have been studied. The structures of the anhydrous calcium aluminates (CaAlâOâ, CaAlâOâ, 3CaO x AlâOâ, 12CaO x 7AlâOâ, talyum) consist of aluminum-oxygen tetrahedra and contain various types of aluminum atoms, the nonequivalence of which increases in going from strongly basic to weakly basic aluminates.

V. I. Yakerson; V. D. Nissenbaum; E. Z. Golosman; V. M. Mastikhin

1987-01-01

167

Prolonged Intraocular Pressure Reduction Following Intravitreal Barium Injection in Rabbits  

Microsoft Academic Search

The isolated ciliary epithelium contains barium-inhibitable potassium channels. The present study was aimed at testing the in vivo effects of barium on aqueous humor dynamics in rabbits. BaCl2was administered to one eye by topical delivery or intravitreal injection. Dynamic measurements included intraocular pressure, outflow facility, episcleral venous pressure and aqueous flow (fluorophotometry). Barium dynamics were studied using133Ba. Intraocular pressure was

THEODORE KRUPIN; ABBAS HYDERI; DIANE KARALEKAS; MARK J. FRITZ

1996-01-01

168

Creating unstable velocity-space distributions with barium injections  

NASA Technical Reports Server (NTRS)

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

Pongratz, M. B.

1983-01-01

169

Effects of barium concentration on oropharyngeal swallow timing measures.  

PubMed

Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between "thin" (40 % w/v concentration) and "ultrathin" (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; mean age = 31 years) each performed a series of three noncued 5-ml swallows each of ultrathin and thin liquid barium solutions in videofluoroscopy. Timing measures were compared between barium concentrations using a mixed-model ANOVA. The measures of interest were stage transition duration, pharyngeal transit time, and duration of upper esophageal sphincter opening. Significant differences were observed in the timing measures of swallowing with respect to barium concentration. In all cases, longer durations were seen with the higher barium concentration. Barium concentration influences timing parameters in healthy swallowing, even between ultrathin and thin concentrations. Clinicians need to understand and control for the impact of different barium stimuli on swallowing physiology. PMID:24045851

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

2014-02-01

170

Characterization of high-calcium fly ash and its influence on ettringite formation in portland cement pastes  

Microsoft Academic Search

High-calcium Class C fly ashes derived from Powder River Basin coal are currently used as supplementary cementing materials in portland cement concrete. These fly ashes tend to contain significant amounts of sulfur, calcium, and aluminum, thus they are potential sources of ettringite. Characterization of six high-calcium fly ashes originating from Powder River Basin coal have been carried out. The hydration

Jody Kathleen Tishmack

1999-01-01

171

Preliminary Study of a Lithium Aluminum Electrode for Thermal Batteries.  

National Technical Information Service (NTIS)

Laboratory tests have shown that a 25 weight percent alloy of lithium in aluminum should significantly outperform the calcium anode presently used in thermal batteries. The usable energy and power densities of this solid Li alloy are at least double those...

S. D. James

1973-01-01

172

External cadmium and internal calcium block of single calcium channels in smooth muscle cells from rabbit mesenteric artery.  

PubMed Central

The patch clamp technique was used to record unitary currents through single calcium channels from smooth muscle cells of rabbit mesenteric arteries. The effects of external cadmium and cobalt and internal calcium, barium, cadmium, and magnesium on single channel currents were investigated with 80 mM barium as the charge carrier and Bay K 8644 to prolong openings. External cadmium shortened the mean open time of single Ca channels. Cadmium blocking and unblocking rate constants of 16.5 mM-1 ms-1 and 0.6 ms-1, respectively, were determined, corresponding to dissociation constant Kd of 36 microM at -20 mV. These results are very similar to those reported for cardiac muscle Ca channels (Lansman, J. B., P. Hess, and R. W. Tsien. 1986. J. Gen. Physiol. 88:321-347). In contrast, Cd2+ (01-10 mM), when applied to the internal surface of Ca channels in inside-out patches, did not affect the mean open time, mean unitary current, or the variance of the open channel current. Internal calcium induced a flickery block, with a Kd of 5.8 mM. Mean blocking and unblocking rate constants for calcium of 0.56 mM-1 ms-1 and 3.22 ms-1, respectively, were determined. Internal barium (8 mM) reduced the mean unitary current by 36%. We conclude that under our experimental conditions, the Ca channel is not symmetrical with respect to inorganic ion block and that intracellular calcium can modulate Ca channel currents via a low-affinity binding site. PMID:2481511

Huang, Y; Quayle, J M; Worley, J F; Standen, N B; Nelson, M T

1989-01-01

173

Modifier cation (Ba, Ca, La, Y) field strength effects on aluminum and boron coordination in aluminoborosilicate glasses: the roles of fictive temperature and boron content  

NASA Astrophysics Data System (ADS)

The field strength of modifier cations has long been known to have important effects on oxide glass properties, but effects on network structure can be complex. For two series of barium, calcium, lanthanum and yttrium aluminoborosilicates with two different B/Si ratios, we report systematic variations in boron and aluminum coordination determined by NMR, and glass transition and heat capacities from differential scanning calorimetry. Data on glasses with different fictive temperatures allow B and Al speciation to be compared on an isothermal basis, rather than as conventionally done for as-quenched structures. Temperature and compositional effects can thus be isolated. These data and comparison to previous studies on glasses with lower B/Si ratios clearly show that higher modifier cation field strength increases the fraction of five- and six-coordinated Al in all compositions. In contrast, the previously documented trend towards more three-coordinated boron (and hence more non-bridging oxygens, NBO) in low B/Si glasses with higher field strength cations reverses in high B/Si and in high NBO compositions. Al and B coordination numbers both decrease with higher fictive temperature in the glasses studied here, suggesting a simple mechanism of coupled structural change.

Morin, Elizabeth I.; Wu, Jingshi; Stebbins, Jonathan F.

2014-08-01

174

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

175

External calcium ions are required for potassium channel gating in squid neurons.  

PubMed

The effects of calcium removal on the voltage-dependent potassium channels of isolated squid neurons were studied with whole cell patch-clamp techniques. When the calcium ion concentration was lowered from 10 to 0 millimolar (that is, no added calcium), potassium channel activity, identified from its characteristic time course, disappeared within a few seconds and there was a parallel increase in resting membrane conductance and in the holding current. The close temporal correlation of the changes in the three parameters suggests that potassium channels lose their ability to close in the absence of calcium and simultaneously lose their selectivity. If potassium channels were blocked by barium ion before calcium ion was removed, the increases in membrane conductance and holding current were delayed or prevented. Thus calcium is an essential cofactor in the gating of potassium channels in squid neurons. PMID:2437654

Armstrong, C M; Lopez-Barneo, J

1987-05-01

176

Migration and escape of barium atoms in a thermionic cathode  

Microsoft Academic Search

A quantitative study of the physical processes on a thermionic cathode that are crucial to both cathode life and noise are investigated. Of particular interest are the transport of the barium atoms from the cathode interior to the cathode surface and beyond. To investigate these physical processes, a model of barium migration to the surface and its subsequent removal by

Kevin L. Jensen; Y. Y. Lau; B. Levush

2000-01-01

177

Barium Tagging for the Enriched Xenon Observatory (EXO)  

NASA Astrophysics Data System (ADS)

The EXO experiment is designed to search for zero-neutrino double beta decay of the isotope Xe^136, in order to better understand the nature of neutrinos. Since the daughter of this decay is barium (Ba^136), detecting the presence of Ba^136 at a decay site (called ``barium tagging'') is the best way to reject backgrounds in the search for this decay. It is hopeful that barium tagging will be implemented in the next phase of EXO. One proposed barium tagging method is to trap the barium ion in a solid xenon matrix (by freezing the liquid xenon surrounding the decay), and move it to another location to do laser-induced fluorescence spectroscopy counting. Our group at CSU is researching the detection of single barium ions and atoms within a solid xenon matrix. A barium ion beam is used to implant the ions into freezing xenon, where laser spectroscopy is then performed. We demonstrate successful detection of very small numbers, and are nearing single-barium detection.

Walton, Timothy

2012-10-01

178

Cardiotoxic and bronchoconstrictor effects of industrial metal fumes containing barium.  

PubMed

For certain metal arc-welding and other metal processing operations, compounds of barium are used as flux components. Airborne fumes generated by welding with electrodes using barium fluoride or carbonate fluxes may contain 15-30% of barium in readily water-soluble form (Dare et al. 1984). Urine of welders inhaling such fumes was shown to contain elevated levels of barium ions (up to 234 micrograms/l). To assess the possible hazards of such exposure, the toxic potencies of fume samples, expressed in terms of their water-soluble barium ion contents, were compared with effects of solutions of barium salts in anaesthetised guinea-pigs. Dose-effect relationships were established and it was verified that acute toxic effects of inhaled aerosols or of intravenous bolus administration correlated with the barium contents of various forms of welding fumes. Bronchopulmonary reactivity to the barium was observed as marked increases in resistance to ventilatory air-flow, indicating bronchoconstriction. Simultaneously, marked pressor effects on blood pressure occurred. ECG abnormalities indicated myocardial hyperexcitability. Effects were modified by nifedipine and propranolol pretreatments. PMID:3468925

Hicks, R; Caldas, L Q; Dare, P R; Hewitt, P J

1986-01-01

179

Experiments with remote entanglement using single barium ions Nathan Kurz  

E-print Network

Experiments with remote entanglement using single barium ions Nathan Kurz A dissertation submitted This is to certify that I have examined this copy of a doctoral dissertation by Nathan Kurz and have found entanglement using single barium ions Nathan Kurz Chair of the Supervisory Committee: Dr. Boris B. Blinov

Blinov, Boris

180

Barium strontium titanate powder obtained by polymeric precursor method  

SciTech Connect

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

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

2003-03-15

181

Current-voltage characteristics of barium polymethacrylate  

SciTech Connect

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

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

1992-06-30

182

Barium dierbium(III) tetra-sulfide.  

PubMed

Barium dierbium(III) tetra-sulfide, BaEr2S4, crystallizes with four formula units in the ortho-rhom-bic space group Pnma in the CaFe2O4 structure type. The asymmetric unit contains two Er, one Ba, and four S atoms, each with .m. site symmetry. The structure consists of channels formed by corner- and edge-sharing ErS6 octa-hedra in which Ba atoms reside. The resultant coordination of Ba is that of a bicapped trigonal prism. PMID:23476480

Mesbah, Adel; Stojko, Wojciech; Ibers, James A

2013-03-01

183

Barium dierbium(III) tetra-sulfide  

PubMed Central

Barium dierbium(III) tetra­sulfide, BaEr2S4, crystallizes with four formula units in the ortho­rhom­bic space group Pnma in the CaFe2O4 structure type. The asymmetric unit contains two Er, one Ba, and four S atoms, each with .m. site symmetry. The structure consists of channels formed by corner- and edge-sharing ErS6 octa­hedra in which Ba atoms reside. The resultant coordination of Ba is that of a bicapped trigonal prism. PMID:23476480

Mesbah, Adel; Stojko, Wojciech; Ibers, James. A

2013-01-01

184

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

185

Dielectric properties of barium titanate supramolecular nanocomposites.  

PubMed

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

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

2014-04-01

186

Production of translationally cold barium monohalide ions  

NASA Astrophysics Data System (ADS)

We have produced sympathetically cooled barium monohalide ions BaX+ (X=F, Cl, Br) by reacting trapped, laser-cooled Ba+ ions with room-temperature gas-phase neutral halogen-containing molecules. Reaction rates for two of these (SF6 and CH3Cl) have been measured and were found to be in agreement with classical models. BaX+ ions are promising candidates for cooling to the rovibrational ground state, and our method presents a straightforward way to produce these polar molecular ions.

DePalatis, M. V.; Chapman, M. S.

2013-08-01

187

Short-cavity squeezing in barium  

NASA Technical Reports Server (NTRS)

Broadband phase sensitive noise and squeezing were experimentally observed in a system of barium atoms interacting with a single mode of a short optical cavity. Squeezing of 13 +/- 3 percent was observed. A maximum possible squeezing of 45 +/- 8 percent could be inferred for out experimental conditions, after correction for measured loss factors. Noise reductions below the quantum limit were found over a range of detection frequencies 60-170 MHz and were best for high cavity transmission and large optical depths. The amount of squeezing observed is consistent with theoretical predictions from a full quantum statistical model of the system.

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

1992-01-01

188

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 Boyle’s 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

189

Calcium and osteoporosis  

Microsoft Academic Search

Calcium is an essential nutrient that is involved in most metabolic processes and the phosphate salts of which provide mechanical rigidity to the bones and teeth, where 99% of the body's calcium resides. The calcium in the skeleton has the additional role of acting as a reserve supply of calcium to meet the body's metabolic needs in states of calcium

B. E. Christopher Nordin

1997-01-01

190

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

2001-01-01

191

Does peppermint oil relieve spasm during barium enema?  

PubMed

The effectiveness of topical peppermint oil added to barium sulphate suspension in relieving colonic muscle spasm during double contrast barium enema examination was assessed in a double blind study. 141 patients were randomized either to a control group (71 patients) examined with standard barium suspension or to the treatment group which received peppermint oil mixed with the barium preparation. No residual spasm was evident in a significant proportion of patients in the treated group (60%) compared with the control group (35%) (p < 0.001). The patients' acceptability of the procedure was good and there were no adverse effects on the overall quality of the examination. In conclusion, the addition of peppermint oil to the barium suspension seems to reduce the incidence of colonic spasm during the examination. The technique is simple, safe, cheap and it may lessen the need for intravenous administration of spasmolytic agents. PMID:7551780

Sparks, M J; O'Sullivan, P; Herrington, A A; Morcos, S K

1995-08-01

192

Aspects of aluminum toxicity  

SciTech Connect

Aluminum is the most abundant metal in the earth's crust. The widespread occurrence of aluminum, both in the environment and in foodstuffs, makes it virtually impossible for man to avoid exposure to this metal ion. Attention was first drawn to the potential role of aluminum as a toxic metal over 50 years ago, but was dismissed as a toxic agent as recently as 15 years ago. The accumulation of aluminum, in some patients with chronic renal failure, is associated with the development of toxic phenomena; dialysis encephalopathy, osteomalacic dialysis osteodystrophy, and an anemia. Aluminum accumulation also occurs in patients who are not on dialysis, predominantly infants and children with immature or impaired renal function. Aluminum has also been implicated as a toxic agent in the etiology of Alzheimer's disease, Guamiam amyotrophic lateral sclerosis, and parkinsonism-dementia. 119 references.

Hewitt, C.D.; Savory, J.; Wills, M.R. (Univ. of Virginia Health Sciences Center, Charlottesville (USA))

1990-06-01

193

Calcium Collage  

NSDL National Science Digital Library

In this activity (on pages 11-14 of PDF), learners cut out pictures from magazines of foods that help make bones strong and glue the pictures to a paper bone. The lesson plan includes information about various activities - including physical exercise as well as diet - that lead to healthy bones. It also includes a list of foods that provide calcium to strengthen bones, including dairy products, spinach, and tofu. The paper bones can be cut out of construction paper prior to the activity.

Omsi

2004-01-01

194

Crystal structure of Eu-doped magnetoplumbite-type lanthanum aluminum oxynitride with emission site splitting  

Microsoft Academic Search

Eu-doped lanthanum aluminum oxynitride (LaAl12(O,N)19) with magnetoplumbite structure was prepared by nitridation of the oxide precursor obtained from aluminum glycine gel and subsequent post-annealing. Eu-doped lanthanum aluminum oxynitride exhibited blue light emission at 440nm with a shoulder at 464nm under excitation at 254nm. Isostructural Eu-doped calcium aluminum oxide (CaAl12O19) exhibited a single emission peak at 415nm. Structural refinement using neutron

Yuji Masubuchi; Tomoyuki Hata; Teruki Motohashi; Shinichi Kikkawa

2011-01-01

195

Calcium source (image)  

MedlinePLUS

... kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the heart and circulatory system, as well as the secretion of essential hormones. There are many ways to supplement calcium, including a growing number of fortified foods.

196

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

197

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

198

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

199

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

200

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

201

Stabilized Aluminum Titanate  

NASA Technical Reports Server (NTRS)

Stable, potentially-inexpensive, cubic crystalline alpha aluminum titanate that shows no phase change to 1,700 K used in heat exchangers. Particular stabilizing species must be selected with careful attention to crystal dimensions and bond angles of alpha and beta phases of aluminum titanate.

Schroeder, J. E.

1985-01-01

202

Is the Aluminum Hypothesis Dead?  

PubMed Central

The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust. PMID:24806729

2014-01-01

203

Is the Aluminum Hypothesis dead?  

PubMed

The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust. PMID:24806729

Lidsky, Theodore I

2014-05-01

204

The aluminum smelting process.  

PubMed

This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development. PMID:24806722

Kvande, Halvor

2014-05-01

205

Effects on aqueous barium titanate tape properties of passivation of barium ion leaching by using dispersants  

Microsoft Academic Search

To passivate a barium titanate (BaTiO3) ceramic powder surface from Ba2+ ion leaching in water, passivation agent layer (PAL) was formed by drying the slurry after adding a commercial polymeric dispersant. By following the several characteristic steps of actual MLCC production process, slip and green properties were compared for two different polymer-adding modes; one is the PAL and the other

Dang-Hyok Yoon; Burtrand I. Lee

2004-01-01

206

Designed microstructures in textured barium hexaferrite  

NASA Astrophysics Data System (ADS)

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

Hovis, David Brian

207

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 120h and at 150°C for 5h. 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

208

Migration and redistribution of oxygen vacancy in barium titanate ceramics  

SciTech Connect

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

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

2006-08-14

209

A high-altitude barium radial injection experiment  

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

210

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

211

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

PubMed Central

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

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

2014-01-01

212

Compositional development of a plutonium surrogate glass without listed RCRA elements (lead and barium)  

SciTech Connect

A lanthanide borosilicate (LaBS) glass composition, being evaluated by Savannah River Technology Center (SRTC) or plutonium disposition as part of the U.S. Department of Energy`s (DOE) Office of the Fissile Materials Disposition (OFMD) program , has been processed with greater than 15 elemental weight percent thorium (a plutonium surrogate) without the presence of lead oxide in the glass. The glass composition is a result of several efforts to remove the lead by replacing it with strontium and sodium. The initial melts that included sodium and considerably lower aluminum resulted in visible phase separation. Two homogeneous lead free melts have been processed. The first one replaced one-fifth of the total lead with Sr on a mole percent basis. Other changes included slightly less aluminum with increases in boron and silica. The second glass composition was exactly the same as the first with an additional 1:1 replacement of barium with strontium on a mole percent basis. This last composition contains no elements considered to be hazardous as defined by the Resource and Conservation Recovery Act (RCRA elements). The Product Consistency Test (PCT) results of these two homogeneous glass composition show them to be slightly more durable than the original lanthanide borosilicate glasses (with lead) loaded with thorium

Meaker, T.F.

1996-09-24

213

Clinical biochemistry of aluminum  

SciTech Connect

Aluminum toxicity has been implicated in the pathogenesis of a number of clinical disorders in patients with chronic renal failure on long-term intermittent hemodialysis treatment. The predominant disorders have been those involving either bone (osteomalacic dialysis osteodystrophy) or brain (dialysis encephalopathy). In nonuremic patients, an increased brain aluminum concentration has been implicated as a neurotoxic agent in the pathogenesis of Alzheimer's disease and was associated with experimental neurofibrillary degeneration in animals. The brain aluminum concentrations of patients dying with the syndrome of dialysis encephalopathy (dialysis dementia) are significantly higher than in dialyzed patients without the syndrome and in nondialyzed patients. Two potential sources for the increased tissue content of aluminum in patients on hemodialysis have been proposed: (1) intestinal absorption from aluminum containing phosphate-binding gels, and (2) transfer across the dialysis membrane from aluminum in the water used to prepare the dialysate. These findings, coupled with our everyday exposure to the ubiquitous occurrence of aluminum in nature, have created concerns over the potential toxicity of this metal.

King, S.W.; Savory, J.; Wills, M.R.

1981-05-01

214

Study of the photovoltaic effect in thin film barium titanate  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

215

Calculated emission rates for barium releases in space  

NASA Technical Reports Server (NTRS)

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

Stenbaek-Nielsen, H. C.

1989-01-01

216

Solar eclipse sign of intussusception on barium enema.  

PubMed

The colographic appearance of intussusception is variously described as a claw sign, pincer defect, shouldering effect, and coiled-spring pattern. This report adds a new radiographic sign to the list. An end-on view of an intussusception on barium enema shows a ring of contrast resembling a solar eclipse. Familiarity with this bizarre appearance is desirable, lest it may be mistaken for spillage of barium due to a colonic perforation. PMID:11793074

Raveenthiran, V

2002-01-01

217

Thermal expansion of nitrates of lead, barium and strontium  

Microsoft Academic Search

The expansion coefficients of barium, strontium and lead nitrates have been studied above room temperatures. Lead nitrate\\u000a decomposes rapidly beyond 200° C. while crystals of barium nitrate crack above 270° C. Strontium nitrate exhibited no such\\u000a phenomena till 550° C.\\u000a \\u000a These crystals are isomorphous. The expansion coefficients of lead and strontium nitrates are nearly equal; they also possess\\u000a the same

R. Srinivasan

1955-01-01

218

'Skidding' of the CRRES G-9 barium release  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

219

Calcium channels of amphibian stomach and mammalian aorta smooth muscle cells.  

PubMed Central

Whole-cell and single-channel calcium currents were studied using single smooth muscle cells enzymatically-isolated from stomach of Amphiuma tridactylum and from guinea-pig aorta. These cells have a high specific resistance and can sustain calcium action potentials after suppression of potassium currents. Dialyzed Amphiuma smooth muscle cells had calcium currents which were stable for several hours whereas the calcium currents of aortic cells ran down quickly. Single channel calcium currents in cell-attached patches behaved similarly for the two cell types. Calcium channel conductance in 110 mM barium was 12 pS and the mean open time was 1.4 ms at a nominal membrane potential of +10 mV. Exposure of both cell types to BAY K8644 resulted in a dramatic prolongation of the calcium channel open times and a shift in the probability of opening to more negative potentials. Low-threshold calcium channels were not identified in the extensively studied amphibian cells. High-threshold calcium channels therefore appear to be the primary pathway for the calcium influx that produces contraction in these smooth muscle cells. Images FIGURE 1 PMID:2424518

Caffrey, J M; Josephson, I R; Brown, A M

1986-01-01

220

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

Microsoft Academic Search

The purpose of this study was to compare the patient tolerance and efficacy, as magnetic resonance imaging negative oral contrast agents, of a mixture of clay compound bentonite and low density barium sulfate suspension with that of higher density barium sulfate. Twenty patients were randomized into two groups: 10 patients receiving a mixture of low concentration 60% wv barium sulfate

Mark R. Paley; Ana I. Nicolas; Patricia J. Mergo; Gladys M. Torres; Sharon S. Burton; Pablo R. Ros

1997-01-01

221

The use of strontium and barium analyses for the reconstruction of the diet of the early medieval coastal population of Gda?sk (Poland): A preliminary study.  

PubMed

Barium and strontium analyses yield an important perspective on temporal shifts in diet in relation to social and environmental circumstances. This research focuses on reconstructing dietary strategies of individuals in the early medieval (12-13th century) population of Gda?sk on the coast of the Baltic Sea. To describe these strategies where seafood rich in minerals was included in the diet, levels of strontium, barium, calcium and phosphorus were measured in first permanent molars of adult men and women whose remains were excavated from the churchyard in the city centre. Faunal remains from the excavation were analysed as an environmental background with respect to the content of the above-mentioned elements. The impact of diagenesis on the odontological material under study was also determined by an analysis of the soil derived from the grave and non-grave surroundings. For verification of diagenetic processes, the calcium/phosphorus index was used. Strontium, calcium, phosphorus and barium levels were determined with the spectrophotometric method using the latest generation plasma spectrophotometer Elan 6100 ICP-MS. From the results of the analysis of taphonomic parameters such as the soil pH, potential ion exchange in the grave surroundings and the Ca/P ratio, it can be inferred that diagenetic factors had little impact on the studied material. From this pilot study we can conclude that in the early Middle Ages in the Baltic Sea basin, seafood was included in the diet from early childhood and at the same time the diet contained calcium-rich milk products (also rich in minerals). The lack of sex differences may indicate the absence of a sex-specific nutritional strategy in childhood and early adolescence. PMID:19476945

Szostek, Krzysztof; G?ab, Henryk; Pud?o, Aleksandra

2009-01-01

222

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

223

Walnut Hulls Clean Aluminum  

NASA Technical Reports Server (NTRS)

Hulls inflict minimal substrate damage. Walnut hulls found to be best abrasive for cleaning aluminum surfaces prior to painting. Samples blasted with walnut hulls showed no compressive stress of surface.

Colberg, W. R.; Gordon, G. H.; Jackson, C. H.

1984-01-01

224

Advances in aluminum anodizing  

NASA Technical Reports Server (NTRS)

White anodize is applied to aluminum alloy surfaces by specific surface preparation, anodizing, pigmentation, and sealing techniques. The development techniques resulted in alloys, which are used in space vehicles, with good reflectance values and excellent corrosive resistance.

Dale, K. H.

1969-01-01

225

Aequorin response facilitation and intracellular calcium accumulation in molluscan neurones  

PubMed Central

1. When molluscan neural somata are filled with the calcium-indicating photo-protein aequorin and subjected to a 1 Hz train of depolarizing pulses (0·3 sec duration to + 15 mV) under voltage clamp, the successive photo-emissions due to calcium influx facilitate. The origin of this phenomenon was investigated in identified neurones from the abdominal ganglion of Aplysia californica. 2. Since outward currents inactivate cumulatively in successive pulses, the effective depolarization increases due to a series resistance error. Elimination of this error by electronic compensation or pharmacological block of outward current reduced aequorin response facilitation by only about 30%, on the average. 3. When voltage-dependent sodium and potassium currents are blocked in tetraethylammonium (TEA)-substituted zero-sodium sea water, the remaining inward calcium currents display no facilitation. On the contrary, a slow decline during a pulse and a slight progressive depression in successive pulses are observed. Barium-substitution for calcium in the same medium eliminates a small residual potassium current insensitive to external TEA. The remaining inward barium currents also display depression instead of facilitation. 4. A non-pharmacological separation of calcium current was accomplished by measuring tail currents at the potassium equilibrium potential following depolarizing pulses. Calcium tail currents activate rapidly and then decline gradually and incompletely as depolarizing pulse duration is lengthened. Tail currents also show no evidence of facilitation; there is instead a slight depression of currents after successive pulses. 5. Increments of optical absorbance in neurones filled with the calcium-sensitive dye arsenazo III show a depression rather than facilitation to successive depolarizations in a train. The time course of these absorbance signals is consistent with the time-dependent depression of calcium current. 6. Calibration of arsenazo III response amplitude indicates that the dye reports only about 1% of the calcium concentration increment expected from knowledge of cell volume and the charge carried by calcium current during a depolarizing pulse. This suggests that cytoplasmic buffering of free calcium must occur rapidly, on a time scale comparable to the response time of arsenazo III (about 1 msec) or more rapidly. 7. The slow potassium tail current following a depolarizing pulse is calcium-dependent and probably provides an approximate index of the internal sub-membrane calcium concentration. Increments in this current after repetitive pulses display a slight progressive depression rather than facilitation. 8. Since neither calcium currents nor the concentration transients show facilitation, we conclude that aequorin response facilitation is due to the non-linear dependence of aequorin photo-emissions on calcium concentration. This conclusion is supported by a finding that the very different kinetics of arsenazo III responses and aequorin responses can be reconciled by a simple model representing calcium accumulation and known response properties of the two indicator substances. 9. In a train of impulses evoked by injecting depolarizing current into a neurone, the successive action potentials grow in duration. Nevertheless, a nearly constant calcium influx signalled by arsenazo III accompanies broadening action potentials. PMID:6247486

Smith, Stephen J.; Zucker, Robert S.

1980-01-01

226

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

227

Co-doped Barium Phosphate Glass  

NASA Astrophysics Data System (ADS)

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

Jiménez, J. A.

2014-09-01

228

High-resolution /sup 27/Al NMR study of calcium aluminate catalysts  

SciTech Connect

The high-resolution /sup 27/Al NMR spectra of calcium aluminates, calcium hydroaluminates, and calcium alumina supports and catalysts have been studied. The structures of the anhydrous calcium aluminates (CaAl/sub 2/O/sub 3/, CaAl/sub 4/O/sub 7/, 3CaO x Al/sub 2/O/sub 3/, 12CaO x 7Al/sub 2/O/sub 3/, talyum) consist of aluminum-oxygen tetrahedra and contain various types of aluminum atoms, the nonequivalence of which increases in going from strongly basic to weakly basic aluminates. In the NMR spectrum the signal of octahedrally coordinated aluminum is due to disordered aluminum-oxygen structures. During the forming of the calcium-alumina catalysts and supports the process (AlO/sub 4/) ..-->.. (AlO/sub 6/) takes place during hydration, and (AlO/sub 6/) ..-->.. (AlO/sub 4/) during thermolysis; the nonequivalence of the tetrahedrally coordinated aluminum atoms decreases, while the (AlO/sub 4/):(AlO/sub 6/) ratio decreases as the degree of hydration increases.

Yakerson, V.I.; Nissenbaum, V.D.; Golosman, E.Z.; Mastikhin, V.M.

1987-06-01

229

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

230

Aluminum, parathyroid hormone, and osteomalacia  

SciTech Connect

Aluminum exposure in man is unavoidable. The occurrence of dialysis dementia, vitamin D-resistant osteomalacia, and hypochromic microcytic anemia in dialysis patients underscores the potential for aluminum toxicity. Although exposure via dialysate and hyperalimentation leads to significant tissue aluminum accumulation, the ubiquitous occurrence of aluminum and the severe pathology associated with large aluminum burdens suggest that smaller exposures via the gastrointestinal tract and lungs could represent an important, though largely unrecognized, public health problem. It is clear that some aluminum absorption occurs with the ingestion of small amounts of aluminum in the diet and medicines, and even greater aluminum absorption is seen in individuals consuming large amounts of aluminum present in antacids. Aluminum absorption is enhanced in the presence of elevated circulating parathyroid hormone. In addition, elevated PTH leads to the preferential deposition of aluminum in brain and bone. Consequently, PTH is likely to be involved in the pathogenesis of toxicities in those organs. PTH excess also seems to lead to the deposition of aluminum in the parathyroid gland. The in vitro demonstration that aluminum inhibits parathyroid hormone release is consistent with the findings of a euparathyroid state in dialysis patients with aluminum related vitamin D-resistant osteomalacia. Nevertheless, it seems likely that hyperparathyroidism is at least initially involved in the pathogenesis of aluminum neurotoxicity and osteomalacia; the increases in tissue aluminum stores are followed by suppression of parathyroid hormone release, which is required for the evolution of osteomalacia. Impaired renal function is not a prerequisite for increased tissue aluminum burdens, nor for aluminum-related organ toxicity. Consequently, it is likely that these diseases will be observed in populations other than those with chronic renal disease.

Burnatowska-Hledin, M.A.; Kaiser, L.; Mayor, G.H.

1983-01-01

231

A Case of Recurrent Renal Aluminum Hydroxide Stone  

PubMed Central

Renal stone disease is characterized by the differences depending on the age, gender, and the geographic location of the patients. Seventy-five percent of the renal stone components is the calcium (Ca). The most common type of the stones is the Ca oxalate stones, while Ca phosphate, uric acid, struvite, and sistine stones are more rarely reported. Other than these types, triamterene, adenosine, silica, indinavir, and ephedrine stones are also reported in the literature as case reports. However, to the best of our knowledge, aluminum hydroxide stones was not reported reported before. Herein we will report a 38-years-old woman with the history of recurrent renal colic disease whose renal stone was determined as aluminum hydroxide stone in type. Aluminum mineral may be considered in the formation of kidney stones as it is widely used in the field of healthcare and cosmetics. PMID:25013740

Cak?roglu, Basri; Dogan, Akif Nuri; Tas, Tuncay; Gozukucuk, Ramazan; Uyanik, Bekir Sami

2014-01-01

232

Calcium carbonate overdose  

MedlinePLUS

... is an ingredient that is commonly found in antacids (for heartburn) and some dietary supplements. Calcium carbonate ... Products containing calcium carbonate, including Certain antacids ... mineral supplements Note: This list may not be all-inclusive.

233

82 2010 USDA Research Forum on Invasive Species GTR-NRS-P-75 MULTITROPHIC EFFECTS OF CALCIUM AVAILABILITY  

E-print Network

University of Delaware, Departments of Entomology and Wildlife Ecology, Newark, DE 19716 ABSTRACT Acid rain adsorbed to soil surfaces, and (2) aluminum is released to soil water by acid rain and displaces adsorbed, causing calcium to be more readily leached from the soil. The effects of acid rain on soil calcium

234

ALUMINUM RECLAMATION BY ACIDIC EXTRACTION OF ALUMINUM-ANODIZING SLUDGES  

EPA Science Inventory

Extraction of aluminum-anodizing sludges with sulfuric acid was examined to determine the potential for production of commercial-strength solutions of aluminum sulfate, that is liquid alum. The research established kinetic and stoichiometric relationships and evaluates product qu...

235

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

236

Acceleration of barium ions near 8000 km above an aurora  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

237

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

238

Calcium and Mitosis  

NASA Technical Reports Server (NTRS)

Although the mechanism of calcium regulation is not understood, there is evidence that calcium plays a role in mitosis. Experiments conducted show that: (1) the spindle apparatus contains a highly developed membrane system that has many characteristics of sarcoplasmic reticulum of muscle; (2) this membrane system contains calcium; and (3) there are ionic fluxes occurring during mitosis which can be seen by a variety of fluorescence probes. Whether the process of mitosis can be modulated by experimentally modulating calcium is discussed.

Hepler, P.

1983-01-01

239

Rocket having barium release system to create ion clouds in the upper atmosphere  

NASA Technical Reports Server (NTRS)

A chemical system for releasing a good yield of free barium atoms and barium ions to create ion clouds in the upper atmosphere and interplanetary space for the study of the geophysical properties of the medium is presented.

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

1974-01-01

240

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

E-print Network

Enhanced dielectric properties from barium strontium titanate films with strontium titanate buffer in their PE state. One of the leading material candidates for tunable materials is barium strontium titanate

Alpay, S. Pamir

241

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

242

Hyperuricosuric calcium oxalate nephrolithiasis  

Microsoft Academic Search

Many investigators have observed that renal calcium stones may be associated with uric acid disorders. Prien and Prien [1] noted that patients with gout who had stone disease frequently passed stones which contained or were composed of calcium oxalate. Gutman [2] also observed a high frequency of calcium oxalate stones in patients who had gout; and he called attention to

Fredric L Coe

1978-01-01

243

Contribution of calcium oxalate to soil-exchangeable calcium  

USGS Publications Warehouse

Acid deposition and repeated biomass harvest have decreased soil calcium (Ca) availability in many temperate forests worldwide, yet existing methods for assessing available soil Ca do not fully characterize soil Ca forms. To account for discrepancies in ecosystem Ca budgets, it has been hypothesized that the highly insoluble biomineral Ca oxalate might represent an additional soil Ca pool that is not detected in standard measures of soil-exchangeable Ca. We asked whether several standard method extractants for soil-exchangeable Ca could also access Ca held in Ca oxalate crystals using spike recovery tests in both pure solutions and soil extractions. In solutions of the extractants ammonium chloride, ammonium acetate, and barium chloride, we observed 2% to 104% dissolution of Ca oxalate crystals, with dissolution increasing with both solution molarity and ionic potential of cation extractant. In spike recovery tests using a low-Ca soil, we estimate that 1 M ammonium acetate extraction dissolved sufficient Ca oxalate to contribute an additional 52% to standard measurements of soil-exchangeable Ca. However, in a high-Ca soil, the amount of Ca oxalate spike that would dissolve in 1 M ammonium acetate extraction was difficult to detect against the large pool of exchangeable Ca. We conclude that Ca oxalate can contribute substantially to standard estimates of soil-exchangeable Ca in acid forest soils with low soil-exchangeable Ca. Consequently, measures of exchangeable Ca are unlikely to fully resolve discrepancies in ecosystem Ca mass balance unless the contribution of Ca oxalate to exchangeable Ca is also assessed.

Dauer, Jenny M.; Perakis, Steven S.

2013-01-01

244

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

245

Barium Levels in Soils and Centella asiatica  

PubMed Central

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

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

2013-01-01

246

Barium Levels in Soils and Centella asiatica.  

PubMed

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

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

2013-08-01

247

Recycled Aluminum Ornaments  

NSDL National Science Digital Library

This lesson plan from ATEEC will explain the principles of recycling. The activity would be most appropriate for technology studies or high school science classes. In all, it would require 2-5 hours of class time to complete. The purpose of the lesson is to demonstrate how aluminum is recycled. This laboratory activity does require some special equipment including a heat source capable of melting aluminum and an outdoor work area. Extension activities are also provided. The lesson plan is available for download as a PDF; users must create a free, quick login with ATEEC to access the materials.

Wishart, Ray

2013-06-14

248

Regeneration of aluminum hydride  

DOEpatents

The present invention provides methods and materials for the formation of hydrogen storage alanes, AlH.sub.x, where x is greater than 0 and less than or equal to 6 at reduced H.sub.2 pressures and temperatures. The methods rely upon reduction of the change in free energy of the reaction between aluminum and molecular H.sub.2. The change in free energy is reduced by lowering the entropy change during the reaction by providing aluminum in a state of high entropy, by increasing the magnitude of the change in enthalpy of the reaction or combinations thereof.

Graetz, Jason Allan (Mastic, NY); Reilly, James J. (Bellport, NY)

2009-04-21

249

Regeneration of aluminum hydride  

DOEpatents

The present invention provides methods and materials for the formation of hydrogen storage alanes, AlH.sub.x, where x is greater than 0 and less than or equal to 6 at reduced H.sub.2 pressures and temperatures. The methods rely upon reduction of the change in free energy of the reaction between aluminum and molecular H.sub.2. The change in free energy is reduced by lowering the entropy change during the reaction by providing aluminum in a state of high entropy, and by increasing the magnitude of the change in enthalpy of the reaction or combinations thereof.

Graetz, Jason Allan; Reilly, James J; Wegrzyn, James E

2012-09-18

250

Aluminum Hydroxide and Magnesium Hydroxide  

MedlinePLUS

Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

251

[The evaluation of the presumed mutagenic activity of barium nitrate].  

PubMed

Barium nitrate, which is used in industry in the production of green signal lights, to remove gases from vacuum tubes, and in the production of barium oxide, was assayed to assess the possible mutagenic effects using both the Ames test (S. typhimurium TA 1535, TA 1537, TA 1538, TA 97a, TA 98, TA 100, TA 102c), with and without metabolic activation with the plate incorporation assay and pre-incubation assay methods, and using the mitotic crossing over test, the mitotic genic conversion test, and the retromutation test in Saccharomyces cerevisiae, D7 strain, with and without metabolic activation. In the experimental conditions of the study, at various gradually increasing concentrations, barium nitrate gave negative results. PMID:1803207

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

1991-01-01

252

Electro-optical polycrystalline barium lanthanum titanium niobate  

SciTech Connect

This patent describes a transparent electro-optic article. It comprises: of a barium lanthanum titanium niobate wherein substantially all grains are of a grain size between about 2 and about 20 micron, the article has a pore volume of less than about 1 percent, and the article has a grain size of between about 2 and about 20 microns. This patent also describes a method of forming transparent electro-optical barium lanthanum titanium niobate. It comprises: providing particles of barium carbonate, lanthanum oxide, titanium oxide, and niobium oxide, calcining the particles, sintering the calcined particles at a temperature of between about 1200{degrees} C and 1300{degrees} C. and a vacuum of between about 10{sup {minus}3} and 10{sup {minus}4} torr while under pressure to form a sintered mass, cooling the sintered mass, slicing the mass to form wafers, heating the wafers in an oxidizing atmosphere.

Mehrotra, A.K.

1991-02-19

253

Appendicitis in children. Accuracy of the barium enema.  

PubMed

The barium enema (BE) may be useful in the diagnosis of atypical appendicitis in children. We analyzed our experience with 18 children in whom appendicitis was suspected and BE was performed. All of the children underwent surgical exploration. Nonfilling of the appendix with cecal indentation, extravasation of barium from the appendix, or both, were considered positive signs of an inflamed appendix on BE. Using these criteria, 12 of 14 cases of proved appendicitis were true positive and two were equivocal. Four children were proved not to have appendicitis; one of these patients had a true-negative BE, two had equivocal BEs, and there was one false-positive BE (Schönlein-Henoch purpura). Extravasation of barium into the peritoneal cavity was noted in one patient; this was a rare complication. PMID:3687874

Garcia, C; Rosenfield, N S; Markowitz, R I; Seashore, J H; Touloukian, R J; Cicchetti, D V

1987-12-01

254

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

255

The Contact Difference of Potential Between Barium and Zinc The External Work Function of Zinc  

Microsoft Academic Search

The methods of contact potential measurement described in previous reports of this series have been extended to zinc, for which the published work function data are discordant. Measurement was by the retarding potential method with variable anode, in tubes sealed from the pumps and gettered with vaporized barium. Barium was the reference metal and the measured surfaces of both barium

Paul A. Anderson

1940-01-01

256

Sputtering of a hydrogenated barium surface in a negative ion surface conversion source  

Microsoft Academic Search

Both the production of negative hydrogen ions on a barium surface and surface sputtering under low energy (~ 200 eV) intense particle bombardment is studied in the FOM Surface Conversion Experiment. We have observed a decrease in barium sputter-yield when a barium surface is exposed to an intense positive hydrogen or deuterium ion flux, extracted from a plasma. This effect

R. M. A. Heeren; D. Ciric; S. Yagura; H. J. Hopman; A. W. Kleyn

1992-01-01

257

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

E-print Network

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

Aksay, Ilhan A.

258

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

E-print Network

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

259

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

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

2014-07-01

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

2013-07-01

261

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

262

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

263

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

264

Compact pulse forming line using barium titanate ceramic material  

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

265

Electrically conductive anodized aluminum coatings  

NASA Technical Reports Server (NTRS)

A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

Alwitt, Robert S. (Inventor); Liu, Yanming (Inventor)

2001-01-01

266

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...

267

Study of the photovoltaic effect in thin film barium titanate  

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

268

Ionization and expansion of barium clouds in the ionosphere  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

269

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

270

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

271

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

272

Mesoporous aluminum phosphite  

NASA Astrophysics Data System (ADS)

High surface area pure mesoporous aluminum-phosphorus oxide-based derivatives have been synthesized through an S +I - 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 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.

El Haskouri, Jamal; Pérez-Cabero, Mónica; Guillem, Carmen; Latorre, Julio; Beltrán, Aurelio; Beltrán, Daniel; Amorós, Pedro

2009-08-01

273

Aluminum Corrosion and Turbidity  

SciTech Connect

Aluminum corrosion and turbidity formation in reactors correlate with fuel sheath temperature. To further substantiate this correlation, discharged fuel elements from R-3, P-2 and K-2 cycles were examined for extent of corrosion and evidence of breaking off of the oxide film. This report discusses this study.

Longtin, F.B.

2003-03-10

274

Aluminum battery alloys  

DOEpatents

Aluminum alloys suitable for use as anode structures in electrochemical cells are disclosed. These alloys include iron levels higher than previously felt possible, due to the presence of controlled amounts of manganese, with possible additions of magnesium and controlled amounts of gallium.

Thompson, D.S.; Scott, D.H.

1984-09-28

275

Voltage dependence of two inward currents carried by calcium and barium in the ciliate Stylonychia mytilus.  

PubMed Central

Two voltage-dependent inward currents in the fresh-water hypotrichous ciliate Stylonychia mytilus have been investigated, using two intracellular micro-electrodes, when either Ca ions or Ba ions are the charge carriers. In cells bathed in Ca-free Ba solution the two inward currents, named current I and current II, could be identified and studied in the absence of outward currents. The two inward currents could also be separated by addition of the plant lectin concanavalin A (0.5 microgram/ml) to the external medium, which resulted in the selective inhibition of current I. When the holding potential was set at values between -45 and -65 mV (normal resting potential is -50 mV), current I was shifted parallel to the holding potential along the voltage axis. This shift was 7.6 mV per 10 mV change in holding potential. The amplitude and voltage relationship of current II was not affected by these changes in the holding potential. The amplitude of current I in Ba solution was maximal when the membrane potential was held at -55 mV; it decreased with higher and lower holding potentials. The rate of activation of current I remained virtually unaffected at holding potentials between -45 and -60 mV, and was somewhat reduced at a holding potential of -65 mV. When the extracellular Ca concentration was varied between 0.1 and 5.0 mM, or when the cells were loaded with EGTA to reduce the intracellular level of ionized Ca, the resting membrane potential and the voltage relationships of both current I and II and of the outward current were shifted along the voltage axis according to the expected changes in membrane surface potential. Double-pulse experiments with varying interval potentials suggested voltage-dependent inactivation of current I and Ca-dependent inactivation of current II. Pre-hyperpolarizing steps of only 1 mV amplitude and 30 ms duration could result in the activation of current I, indicating that the activation voltage of current I closely followed the actual membrane potential. Hence, the same voltage steps elicited similar current I amplitudes with holding potentials between -45 and -60 mV. The results indicate that current II displays voltage properties described for Ca channels in other ciliates and many multicellular preparations, while current I shows an unusual voltage behaviour, which might be regarded as an 'adaptive type of excitation'.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2441038

Deitmer, J W

1986-01-01

276

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

277

Chemical interactions of barium–calcium–aluminosilicate-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

278

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

279

Electron Tunneling Studies of the Cuprate Superconductors Yttrium Barium Cuprate and Bismuth Strontium Calcium Cuprate  

NASA Astrophysics Data System (ADS)

Electron tunneling has long been regarded as one of the best techniques to study the energy gap, excitation spectrum, and ground state structure of superconductors. This thesis reports on the results of various efforts to fabricate single particle tunneling and Josephson proximity devices on the "high-T_{rm c}" cuprate superconductors YBa_2Cu _3O_7 and Bi_2Sr_2CaCu _2O_8 for the purpose of measuring the microscopic superconducting properties of these materials. It is well known that the cuprate superconductors have many undesirable chemical properties that can degrade the quality of the samples, particularly near the surface. For this reason, several methods of constructing tunnel junctions, each aimed at getting around some of the more obvious material problems, will be described, and the resulting data presented. Particular emphasis and attention will be paid to those major features of the data that are reproducible independent of the method of junction construction. Much of the data presented do not much resemble the classical norms given by the standard Bardeen-Cooper -Schrieffer theory of superconductivity. These differences from classical behavior include an anomalously large ratio of the energy gap to the transition temperature 2 Delta/kT_{rm c} ~ 6 to 7, a background tunneling conductance that is at least partially a linear function of voltage bias, the presence of a large normal electron contribution to the single-particle spectrum and the Josephson effect well below T_{rm c}, and a prominent anisotropy in the Josephson coupling to a standard superconductor like Pb. In addition, there is evidence that the classical proximity effect model of the coupling between a cuprate superconductor and a good normal metal must undergo some alterations in order to describe the proximity effect between YBa_2 Cu_3O_7 and an inert metal overlayer such as Ag.

Lee, Mark

280

Results of critical velocity experiments with barium, strontium, and calcium releases from CRRES satellite  

NASA Astrophysics Data System (ADS)

As part of the NASA Combined Release and Radiation Effects Satellite (CRRES) chemical release program in September 1990, two Ba and also one each Sr and Ca canisters of a boron-titanium thermite mixture, which vaporizes the element on ignition, were released near perigee after dusk in the South Pacific to study the critical velocity effect proposed by Alfven. The critical velocities of these three elements are 2.7, 3.5, and 5.4 km/s respectively, all well below the orbital velocity of 9.4 km/s. On September 10, 1990, a Sr and Ba pair (G-13, or critical ionization velocity (CIV) I) was released near Rarotonga at approximately 515 km altitude in a background electron density of 3.4 x 10(exp 6)/cu cm. On September 14, 1990, G-14 or CIV II released a Ca and Ba pair west of New Caledonia near 595 km at an electron density of 1.5 x 10(exp 6)/cu cm. Ions of all three elements were observed with low-light level imagers from two aircraft after they had transited up the magnetic field lines into the sunlight. Emissions from the spherically expanding neutral gas shells below the solar terminator, observed with cameras filtered for the Ba(+) ion line at 4554 A and also in unfiltered imagers for approximately 15 s after release, are probably due to excitation by hot electrons created in the CIV process. The ions created clearly lost much of their energy, which we now show can be explained by elastic collisions: Ba(+) + O. Inventories of the observed ions indicate yields of 0.15% and 1.84% for Ba in the first and second experiments, 0.02% for Sr and 0.27% for Ca. Ionization from all the releases continued along the satellite trajectory much longer (greater than 45 s) than expected for a CIV process. The ion production along the satellite track versus time typically shows a rapid rise to a peak in a few seconds followed by an exponential decrease to a level essentially constant rate. The characteristic distances for CIV I and II are 47 and 62 km, respectively. We interpret the early time rise and exponential fall to be due to CIV ionization, of 0.014% (CIV I) and 0.40% (CIV II) for the Ba releases. The later ions produced at a constant rate probably have origins from other such processes as stripping and associative ionization collisions with atmospheric constituents primarily O, and charge exchange with O(+), He(+), and H(+). We suggest that the much larger Ba ionization rate in CIV II than CIV I is due to the fact that the release occurred in the peak Ca density where hot electrons were already present.

Wescott, E. M.; Stenbaek-Nielsen, H. C.; Hampton, D. L.; Delamere, P. A.

1994-02-01

281

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

282

Atomic Transition Probabilities of Aluminum. A Critical Compilation D. E. Kellehera...  

E-print Network

Atomic Transition Probabilities of Aluminum. A Critical Compilation D. E. Kellehera... and L. I, published in 1969 by Wiese et al. Atomic Transition Probabilities, Vol. II, Vol. II: Sodium through Calcium, NSROS-NBS Vol. 2 U.S. GPO, Washington, D.C., 1969 . Atomic transition probabilities have been critically

Magee, Joseph W.

283

Original article Availability of calcium from skim milk, calcium sulfate  

E-print Network

Original article Availability of calcium from skim milk, calcium sulfate and calcium carbonate that the calcium in milk was more efficiently used than that from any other source. Carbonate, gluconate, citrate; accepted 19 November 1999) Abstract --Dairy products provide abundant, accessible calcium for humans, while

Paris-Sud XI, Université de

284

Calcium is incorporated into the calcium carbonate matrix of otoliths  

E-print Network

118 Calcium is incorporated into the calcium carbonate matrix of otoliths and into the calcium). In addition to calcium, trace elements, such as strontium, are also incorporated into the calcified components valence) allow strontium ions to act as replace- ments for calcium during the pro- cess of calcification

285

High average power generation in barium nitrate Raman laser  

NASA Astrophysics Data System (ADS)

The generation of low divergent ( M 2?1.5) first and third Stokes radiation in a barium nitrate Raman laser with average powers of 11 W and 5 W, respectively, was demonstrated. The quantum conversion efficiency was up to 21%. The possibility of thermal lens compensation in such Raman lasers was shown.

Lisinetskii, V. A.; Riesbeck, T.; Rhee, H.; Eichler, H. J.; Orlovich, V. A.

2010-04-01

286

Patient and occupational dosimetry in double contrast barium enema examinations  

Microsoft Academic Search

A new and relatively simple method is presented to distribute total dose-area product (DAP) over a number of projections that model exposure during double contrast barium enema (DCBE) examinations. In addition, hitherto unavailable entrance and effective doses to the physician performing the DCBE examination have been determined. DAP, fluoroscopy time, number of images as well as some patient data were

G J KEMERINK; A C W BORSTLAP; M J FRANTZEN; F W SCHULTZ; J ZOETELIEF; JMA VAN ENGELSHOVEN

287

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 ...

288

HEALTH EFFECTS OF HUMAN EXPOSURE TO BARIUM IN DRINKING WATER  

EPA Science Inventory

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

289

Barium strontium titanate powders prepared by spray pyrolysis  

Microsoft Academic Search

Ultasonic spray pyrolysis (SP) has been investigated for the production of the barium strontium titanate (BST) powders from the polymeric precursors. The processing parameters, such as flux of aerosol and temperature profile inside the furnace, were optimized to obtain single phase BST. The powders were characterized by the methods of X-ray diffraction analysis, SEM, EDS and TEM. The obtained powders

G. Brankovi?; Z. Brankovi?; M. S. Góes; C. O. Paiva-Santos; M. Cilense; J. A. Varela; E. Longo

2005-01-01

290

Dynamics of a barium release in the magnetospheric tail  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

291

BARIUM AND RADIUM IN WATER TREATMENT PLANT WASTES  

EPA Science Inventory

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

292

Barium-140 from irradiated uranium-233 without a carrier  

SciTech Connect

The optimum conditions for uranium-233 irradiation have been selected to obtain barium-140. The latter has been isolated without a carrier in a chromatographic column packed with KRS-8 cation-exchange resin (sulfocationite) with a yield of 83 +/- 6% and a radiochemical purity of 99.7% by its elutriation with ammonium acetate solution and subsequent sublimation.

Bulatenkov, Yu.V.; Gedeonov, A.D.; Mozzhukhin, A.V.

1987-09-01

293

Adsorption of oxygen on clean and barium covered copper surfaces: an XPS, UPS and AES study  

NASA Astrophysics Data System (ADS)

XPS studies of oxygen on barium covered copper surface show two types of dissociatively chemisorbed species, viz. O x- (529.5 eV) and Oy- (531.6 eV) ( x) < y < 2). This is supported by He II spectra which show two peaks at 6 and 9.2 eV below EF. While dissociatively chemisorbed oxygen on clean copper seen at 530 eV is strongly held even up to 700 K, the oxygen on barium covered surface starts desorbing at 450 K. The surface stoichiometry of oxygen to barium has been estimated both as functions of barium coverage and of temperature for a given barium concentration. The Cu(L 3VV)/Cu(L 3M 23M 23) Auger ratio technique has been employed to show charge transfer from barium to copper on the barium covered surface and from copper to oxygen on subsequent oxygen adsorption.

Ayyoob, M.; Hegde, M. S.

1984-11-01

294

Calcium-bismuth electrodes for large-scale energy storage (liquid metal batteries)  

NASA Astrophysics Data System (ADS)

Calcium is an attractive electrode material for use in grid-scale electrochemical energy storage due to its low electronegativity, earth abundance, and low cost. The feasibility of combining a liquid Ca-Bi positive electrode with a molten salt electrolyte for use in liquid metal batteries at 500-700 °C was investigated. Exhibiting excellent reversibility up to current densities of 200 mA cm-2, the calcium-bismuth liquid alloy system is a promising positive electrode candidate for liquid metal batteries. The measurement of low self-discharge current suggests that the solubility of calcium metal in molten salt electrolytes can be sufficiently suppressed to yield high coulombic efficiencies >98%. The mechanisms giving rise to Ca-Bi electrode overpotentials were investigated in terms of associated charge transfer and mass transport resistances. The formation of low density Ca11Bi10 intermetallics at the electrode-electrolyte interface limited the calcium deposition rate capability of the electrodes; however, the co-deposition of barium into bismuth from barium-containing molten salts suppressed Ca-Bi intermetallic formation thereby improving the discharge capacity.

Kim, Hojong; Boysen, Dane A.; Ouchi, Takanari; Sadoway, Donald R.

2013-11-01

295

Preliminary study of the CRRES magnetospheric barium releases  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

296

Mechanisms of Aluminum Tolerance  

Microsoft Academic Search

\\u000a Aluminum (Al) toxicity limits agricultural productivity over much of the world’s 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

297

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

298

Redox modulation of intracellular free calcium concentration in thyroid FRTL-5 cells: evidence for an enhanced extrusion of calcium.  

PubMed

Redox modulation is involved in the regulation of the intracellular free calcium concentration ([Ca2+]i) in several cell types. In thyroid cells, including thyroid FRTL-5 cells, changes in [Ca2+]i regulate important functions. In the present study we investigated the effects of the oxidizing compounds thimerosal and t-butyl hydroperoxide on [Ca2+]i in thyroid FRTL-5 cells. Thimerosal mobilized sequestered calcium, and evoked modest store-dependent calcium entry. Both compounds potently attenuated the increase in [Ca2+]i when store-operated calcium entry was evoked with thapsigargin. The entry of barium was not attenuated. Experiments performed with high extracellular pH, in sodium-free buffer and in the presence of vanadate suggested that thimerosal decreased [Ca2+]i by activating a calcium extrusion mechanism, probably a plasma membrane Ca2+-ATPase. All the observed effects were abrogated by the reducing agent beta-mercaptoethanol. The mechanism of action was apparently mediated via activation of protein kinase C, as thimerosal potently stimulated binding of [3H]phorbol 12, 13-dibutyrate, and was without effect on store-operated calcium entry in cells treated with staurosporine or in cells with down-regulated protein kinase C. Thimerosal did not depolarize the membrane potential, as evaluated using patch-clamp in the whole-cell mode. In immunoprecipitates obtained with an antibody against plasma membrane Ca2+-ATPase, we observed several phosphorylated bands in cells stimulated with thimerosal. In conclusion, we have shown that thimerosal attenuates an increase in [Ca2+]i, probably by activating a plasma membrane Ca2+-ATPase. PMID:10215601

Törnquist, K; Vainio, P; Titievsky, A; Dugué, B; Tuominen, R

1999-05-01

299

Micro Determination of Calcium  

Microsoft Academic Search

Hildebrand and Reilly1 have recently described a complexometric titration method for the determination of calcium: the indicator used, `Calcon', is superior to `Solochrome' black in that calcium can be determined independently of magnesium, and, unlike the murexide method, a sharp end-point is obtained. All three methods employ ethylenediamine tetraacetic acid. The purpose of the present communication is to direct attention

A. B. Gilbert

1959-01-01

300

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

301

Quasicrystalline particulate reinforced aluminum composite  

SciTech Connect

Particulate reinforced aluminum and aluminum alloy composites are rapidly emerging as new commercial materials for aerospace, automotive, electronic packaging and other high performance applications. However, their low processing ductility and difficulty in recyclability have been the key concern. In this study, two composite systems having the same aluminum alloy matrix, one reinforced with quasicrystals and the other reinforced with the conventional SiC reinforcements were produced with identical processing routes. Their processing characteristics and tensile mechanical properties were compared.

Anderson, I.E.; Biner, S.B.; Sordelet, D.J.; Unal, O.

1997-07-01

302

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

E-print Network

(23), 5697 (2004). 22. "Comparative Study of Lead Borate and Bismuth Lead Borate Glass Systems as RadiationBarium Titanate and Bismuth Oxide Nanocomposites Barium titanate, BaTiO3, and bismuth oxide Bi2O3, Condensed Matter, Vol. 15, 8927 (2003). 21. "Highly Nonlinear Bismuth-Oxide Fiber for Smooth Supercontinuun

Harmon, Julie P.

303

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

304

Mineral of the month: aluminum  

USGS Publications Warehouse

Aluminum is the second most abundant metallic element in Earth’s 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

305

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

306

Calcium current in molluscan neurones: measurement under conditions which maximize its visibility.  

PubMed Central

1. Membrane currents were studied in isolated somata of molluscan neurones from Archidoris monteryensis and Anisodoris nobilis. Under voltage clamp, inward current displayed a two phase time course, and in some cases a clear reversal potential difference could be shown for the fast and slow phases. The slower phase was carried predominantly by calcium ions. 2. The apparent magnitude of the slower phase was greatly influenced by conditions which altered potassium current flow. Blocking voltage-dependent potassium conductances, either by appropriate conditioning polarizations or by tetraethyl-ammonium (TEA) ion, enhanced the magnitude, while conditions which augmented potassium current made the slow phase disappear. 3. A fraction of the membrane potassium conductance was TEA insensitive. This fraction could be blocked by procedures which prevented internal levels of calcium from increasing during the voltage clamp pulse. Three such procedures were demonstrated; replacement of external calcium by magnesium, internal buffering by EGTA, and replacement of calcium by permeant barium. 4. Internal EGTA buffering or external barium in combination with external TEA produced an extreme change in membrane current as compared with the normal time course. Membrane current, when activated by pulses up to +50 mV, was net inward and showed only fractional inactivation over time courses running to several seconds. Pulses to voltages greater than +60 mV resulted in outward current. 5. It is concluded that under normal conditions the calcium conductance has the extended time course clearly evident under the modified conditions of paragraph 4 but that the calcium flux component is easily missed. 6. In agreement with several prior studies it is also concluded that a rise in internal calcium is causally related to a rise in potassium conductance. A transmembrane flux of calcium can be uncoupled from the gK increase by appropriate buffering of internal calcium. 7. The transient potassium current, IA, which bears a resemblance to calcium-dependent potassium transients in some muscle cells did not depend upon internal calcium but instead is a voltage-activated mechanism. PMID:439033

Connor, J A

1979-01-01

307

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

NASA Technical Reports Server (NTRS)

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

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

1972-01-01

308

Hydration of Portland cement with additions of calcium sulfoaluminates  

SciTech Connect

The effect of mineral additions based on calcium aluminates on the hydration mechanism of ordinary Portland cement (OPC) was investigated using isothermal calorimetry, thermal analysis, X-ray diffraction, scanning electron microscopy, solid state nuclear magnetic resonance and pore solution analysis. Results show that the addition of a calcium sulfoaluminate cement (CSA) to the OPC does not affect the hydration mechanism of alite but controls the aluminate dissolution. In the second blend investigated, a rapid setting cement, the amorphous calcium aluminate reacts very fast to ettringite. The release of aluminum ions strongly retards the hydration of alite but the C-S-H has a similar composition as in OPC with no additional Al to Si substitution. As in CSA-OPC, the aluminate hydration is controlled by the availability of sulfates. The coupling of thermodynamic modeling with the kinetic equations predicts the amount of hydrates and pore solution compositions as a function of time and validates the model in these systems.

Le Saout, Gwenn, E-mail: gwenn.le-saout@mines-ales.fr [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Lothenbach, Barbara [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland)] [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Hori, Akihiro [DENKA Chemicals GmbH, Wehrhahn-Center, Cantadorstr. 3, D-40211 Duesseldorf (Germany)] [DENKA Chemicals GmbH, Wehrhahn-Center, Cantadorstr. 3, D-40211 Duesseldorf (Germany); Higuchi, Takayuki [Denki Kagaku Kogyo Kabushiki Kaisha (DENKA), Omi, Itoigawa, Niigata, 949-0393 (Japan)] [Denki Kagaku Kogyo Kabushiki Kaisha (DENKA), Omi, Itoigawa, Niigata, 949-0393 (Japan); Winnefeld, Frank [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland)] [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland)

2013-01-15

309

Production of aluminum metal by electrolysis of aluminum sulfide  

DOEpatents

Metallic aluminum may be produced by the electrolysis of Al/sub 2/S/sub 3/ at 700 to 800/sup 0/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, N.Q.; Loutfy, R.O.; Yao, N.P.

1982-04-01

310

Aluminum monocarbonyl and aluminum isocarbonyl Steve S. Wesolowski,a)  

E-print Network

valence d electrons.2 One particularly useful experimental technique em- ployed in the study of metalAluminum monocarbonyl and aluminum isocarbonyl Steve S. Wesolowski,a) T. Daniel Crawford,b) Justin, configuration interaction, and coupled-cluster levels of theory with large basis sets. At the highest level

Crawford, T. Daniel

311

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

312

Aluminum nitride grating couplers.  

PubMed

Grating couplers in sputtered aluminum nitride, a piezoelectric material with low loss in the C band, are demonstrated. Gratings and a waveguide micromachined on a silicon wafer with 600 nm minimum feature size were defined in a single lithography step without partial etching. Silicon dioxide (SiO(2)) was used for cladding layers. Peak coupling efficiency of -6.6 dB and a 1 dB bandwidth of 60 nm have been measured. This demonstration of wire waveguides and wideband grating couplers in a material that also has piezoelectric and elasto-optic properties will enable new functions for integrated photonics and optomechanics. PMID:22695653

Ghosh, Siddhartha; Doerr, Christopher R; Piazza, Gianluca

2012-06-10

313

Target-Cell Contact Activates a Highly Selective Capacitative Calcium Entry Pathway in Cytotoxic T Lymphocytes  

PubMed Central

Calcium influx is critical for T cell activation. Evidence has been presented that T cell receptor–stimulated calcium influx in helper T lymphocytes occurs via channels activated as a consequence of depletion of intracellular calcium stores, a mechanism known as capacitative Ca2+ entry (CCE). However, two key questions have not been addressed. First, the mechanism of calcium influx in cytotoxic T cells has not been examined. While the T cell receptor–mediated early signals in helper and cytotoxic T cells are similar, the physiology of the cells is strikingly different, raising the possibility that the mechanism of calcium influx is also different. Second, contact of T cells with antigen-presenting cells or targets involves a host of intercellular interactions in addition to those between antigen–MHC and the T cell receptor. The possibility that calcium influx pathways in addition to those activated via the T cell receptor may be activated by contact with relevant cells has not been addressed. We have used imaging techniques to show that target-cell–stimulated calcium influx in CTLs occurs primarily through CCE. We investigated the permeability of the CTL influx pathway for divalent cations, and compared it to the permeability of CCE in Jurkat human leukemic T cells. CCE in CTLs shows a similar ability to discriminate between calcium, barium, and strontium as CCE in Jurkat human leukemic T lymphocytes, where CCE is likely to mediated by Ca2+ release–activated Ca2+ current (CRAC) channels, suggesting that CRAC channels also underlie CCE in CTLs. These results are the first determination of the mechanism of calcium influx in cytotoxic T cells and the first demonstration that cell contact–mediated calcium signals in T cells occur via depletion-activated channels. PMID:10662784

Zweifach, Adam

2000-01-01

314

Pyroelectricity in alternating ultrathin organized molecular films incorporating barium ions  

NASA Astrophysics Data System (ADS)

Pyroelectric properties in alternating DAEP/NC Langmuir-Blodgett (LB) films and effects of incorporating the barium cations on pyroelectric behaviors have been investigated. Its pyroelectric coefficient measured is found to be 58?C m-2 K-1at 300K. The dielectric properties have been measured and used to determine the figures of merit in thermal devices. Relative permittivity ?r and dielectric loss values tan? of pyroelectric films (in the range of 1KHz - 100KHz) are 2.34~1.96 and 0.08~0.04, respectively. These data give a maximum pyroelectric figure of merit of 150?C m-2 K-1 in the alternating LB films incorporating barium ions. The effects of different deposition on pyroelectric properties are also discussed in this paper. It is indicated that the alternating LB films is promising in the field of pyroelectricity and pyroelectric infrared detector.

Ma, Shihong; Li, Shuhong; Lu, Xingze; Wang, Wencheng; Wang, Genshui; Liu, Pulin; Guo, Shaoling; Chu, Junhao

2002-12-01

315

Numerical simulation of a radially injected barium cloud  

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

316

Observations and theory of the AMPTE magnetotail barium releases  

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

317

Study of the photovoltaic effect in thin film barium titanate  

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

318

The crystal growth of barium flouride in aqueous solution  

NASA Astrophysics Data System (ADS)

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

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

1983-06-01

319

NASA/Max Planck Institute Barium Ion Cloud Project.  

NASA Technical Reports Server (NTRS)

NASA and the Max Planck Institute for Extraterrestrial Physics (MPE), Munich, Germany, conducted a cooperative experiment involving the release and study of a barium cloud at 31,500 km altitude near the equatorial plane. The release was made near local magnetic midnight on Sept. 21, 1971. The MPE-built spacecraft contained a canister of 16 kg of Ba CuO mixture, a two-axis magnetometer, and other payload instrumentation. The objectives of the experiment were to investigate the interaction of the ionized barium cloud with the ambient medium and to deduce the properties of electric fields in the proximity of the release. An overview of the project is given to briefly summarize the organization, responsibilities, objectives, instrumentation, and operational aspects of the project.

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

1973-01-01

320

Relationship of pheasant occurrence to barium in Illinois soils.  

PubMed

Distribution of the ring-necked pheasant (Phasianus colchicus) is nearly co-extensive with the boundary of Wisconsinan glaciation; this is an area of base-rich soils that are mostly developed in calcareous tills. Anderson and Stewart (1973) speculated that barium in the diet might be a factor limiting the pheasant establishment in habitats adjacent to areas of long-term sustaining populations in Illinois. Total Ba was calculated for soils of 74 conterminous counties for which there were pheasant population data. Barium over the range of about 480 to 700 mg kg(-1) soil was unrelated to pheasant occurrence or to population indeces. The selective eating of iron-manganese concretions that are enriched in Ba might present a unique pathway for Ba loading. PMID:24197899

Jones, R L

1992-04-01

321

The Skylab barium plasma injection experiments. I - Convection observations  

NASA Technical Reports Server (NTRS)

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

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

1976-01-01

322

21 CFR 172.310 - Aluminum nicotinate.  

Code of Federal Regulations, 2012 CFR

... 3 2012-04-01 2012-04-01 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...

2012-04-01

323

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

324

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 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...

2012-04-01

325

21 CFR 73.1645 - Aluminum powder.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 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...

2012-04-01

326

21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.  

...Calcium pantothenate, calcium chloride double salt. 172.330 Section 172.330 Food and...Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may be safely...

2014-04-01

327

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

Microsoft Academic Search

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

Jay L. Benson; Walter H. Johnson

1966-01-01

328

Photoionization of the 4d subshell of barium  

Microsoft Academic Search

The photoionization cross section and angular distribution asymmetry parameter of the 4d10 subshell of atomic barium have been calculated using many-body perturbation theory and the relativistic random-phase approximation modified to include relaxation effects. Our main purpose is to determine whether relaxation and polarization effects can account for the large difference between recent 4d photoemission experiments and total absorption experiments. Polarization

M Kutzner; V Radojevi?; H P Kelly; Z Altun

1990-01-01

329

Photoionization of atomic barium including effects of relaxation and polarization  

Microsoft Academic Search

The photoionization cross sections of the 4d10, 5s2, 5p6, and 6s2 subshells of atomic barium and the angular distribution asymmetry parameters for the 4d10 and 5p6 subshells have been calculated using many-body perturbation theory. Our main purpose is to determine whether relaxation and polarization effects can account for the large difference between recent 4d photoemission experiments and total absorption experiments.

Mickey Kutzner; Zikri Altun; Hugh P. Kelly

1990-01-01

330

Domain Size Effect on Dielectric Properties of Barium Titanate Ceramics  

Microsoft Academic Search

Barium titanate (BaTiO3) ceramics with various grain sizes were prepared by a conventional sintering method and a two-step sintering method. The permittivity of the ceramics increased with decreasing the grain size down to 1.1 mum on average. The BaTiO3 ceramics with an average grain size of 1.1 mum had a high permittivity of 7,700. The transmission electron microscopy (TEM) observation

Takuya Hoshina; Kayo Takizawa; Jianyong Li; Takeshi Kasama; Hirofumi Kakemoto; Takaaki Tsurumi

2008-01-01

331

Ultrasonic Investigation on Nanocrystalline Barium Borate (BBO) Glass Ceramics  

Microsoft Academic Search

Barium Borate (BBO) glasses containing different compositions of BaO and B2O3 with BaF2, Cr2O3 and TiO2 have been prepared by normal melting and annealing technique. The prepared bulk BBO glasses have been subjected to heat?treatment. The heat?treated BBO glasses produce nanophase BBO crystals in its structure. The existence of nanophase structure of the BBO crystals have been studied through XRD

A. V. Gayathri Devi; V. Rajendran; K. Jeyasubramanian; N. Suresh Kumar

2006-01-01

332

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

333

Light yield and surface treatment of barium fluoride crystals  

Microsoft Academic Search

We report on a study of the light yield and surface treatment of barium fluoride (BaF2) scintillation crystals. Using a bialkali photocathode the photoelectron (p.e.) yield of BaF2 crystals was measured to be 130 p.e.\\/MeV for the fast components and 700 p.e.\\/MeV for the slow component. A somewhat hygroscopic nature for the BaF2 is found. Teflon film was found to

Z. Y. Wei; R. Y. Zhu; H. Newman; Z. W. Yin

1991-01-01

334

Elastic and Piezoelectric Coefficients of Single-Crystal Barium Titanate  

Microsoft Academic Search

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

Don Berlincourt; Hans Jaffe

1958-01-01

335

Adequacy of preparation for barium enema among elderly outpatients.  

PubMed Central

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

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

1991-01-01

336

Acute barium intoxication following ingestion of soap water solution  

PubMed Central

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

2012-01-01

337

Radium and barium in the Amazon River system  

Microsoft Academic Search

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

Willard S. Moore; John M. Edmond

1984-01-01

338

Relationship of pheasant occurrence to barium in Illinois soils  

Microsoft Academic Search

Distribution of the ring-necked pheasant (Phasianus colchicus) is nearly co-extensive with the boundary of Wisconsinan glaciation; this is an area of base-rich soils that are mostly developed in calcareous tills. Anderson and Stewart (1973) speculated that barium in the diet might be a factor limiting the pheasant establishment in habitats adjacent to areas of long-term sustaining populations in Illinois. Total

Robert L. Jones

1992-01-01

339

Internal hemorrhoids: diagnosis with double-contrast barium enema examinations.  

PubMed

The authors retrospectively studied 43 patients suspected of having internal hemorrhoids at double-contrast barium enema examination. At endoscopy, 24 patients (56%) had internal hemorrhoids, four (9%) had other pathologic lesions in the rectum without evidence of hemorrhoids, and 15 (35%) had no reported abnormalities in the rectum. Internal hemorrhoids were found at endoscopy in 10 of 20 patients (50%) with lobulated folds extending 3 cm or less from the anorectal junction and 10 of 13 patients (77%) with multiple submucosal nodules. However, no patients with these characteristic radiographic findings were found to have other pathologic lesions in the rectum that had been mistaken for hemorrhoids at barium enema examination. Conversely, three of four patients with lobulated folds extending more than 3 cm from the anorectal junction and one of six patients with solitary nodules had proctitis or rectal neoplasms. Thus, specific criteria are suggested for the diagnosis of internal hemorrhoids on double-contrast barium enema examinations. Suspected hemorrhoids that do not fulfill these criteria should be evaluated endoscopically to rule out other more serious pathologic lesions in the rectum. PMID:2399313

Levine, M S; Kam, L W; Rubesin, S E; Ekberg, O

1990-10-01

340

Dielectric properties of cobalt substituted M-type barium hexaferrite prepared by co-precipitation  

Microsoft Academic Search

Barium hexaferrite was synthesised via the co-precipitation method using high purity nitrates, oxides and carbonates of iron\\u000a (III), barium (II) and ammonium hydroxide. Once a phase pure sample of barium hexaferrite was obtained, it was doped, by weight,\\u000a with 1, 2, 3, 5, 10, 15, 20 and 30% cobalt oxide (Co3O4). The addition of cobalt to the BaM had the

Philip Shepherd; Kajal K. Mallick; Roger J. Green

2007-01-01

341

Absorbing properties and structural design of microwave absorbers based on carbonyl iron and barium ferrite  

Microsoft Academic Search

Carbonyl iron and barium ferrite powder (BaZn1.5Co0.5Fe16O27) were prepared in this work. The complex permittivity and permeability spectra for rubber radar absorbing materials employing carbonyl iron and barium ferrite powders were measured. A database describing the frequency dependence of the permittivities and permeabilities of the carbonyl iron and barium ferrite microwave absorbers with various powder percentage compositions in 2 18

Y. B. Feng; T. Qiu; C. Y. Shen

2007-01-01

342

Absorbing properties and structural design of microwave absorbers based on carbonyl iron and barium ferrite  

Microsoft Academic Search

Carbonyl iron and barium ferrite powder (BaZn1.5Co0.5Fe16O27) were prepared in this work. The complex permittivity and permeability spectra for rubber radar absorbing materials employing carbonyl iron and barium ferrite powders were measured. A database describing the frequency dependence of the permittivities and permeabilities of the carbonyl iron and barium ferrite microwave absorbers with various powder percentage compositions in 2–18GHz was

Y. B. Feng; T. Qiu; C. Y. Shen

2007-01-01

343

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

344

Aluminum frame motors: Environmental testing  

Microsoft Academic Search

The Civil Engineering Laboratory has conducted environmental tests to determine if aluminum frame motors instead of cast iron frame motors would be suitable for use in salt fog environments similar to those experienced at Naval Shore Facilities. The aluminum frame in the salt fog environment had minimal corrosion, indicating it is superior to cast iron for these applications. During the

D. E. Weems

1976-01-01

345

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 I—Detail contains information on individual primary smelter capacity, location, ownership, sources of energy, and other miscellaneous information. Part II—Summary summarizes the capacity data by country

1999-01-01

346

SOME PROPERTIES OF ALUMINUM NITRIDE  

Microsoft Academic Search

ABS>Aluminum nitride crystals in the form of bid-sided prismatic ; needles. up to 0.5 mm in diameter by 30 mm long, and thin plates, 2 to 3 mm in ; diameter, were prepared by vaporization of aluminum in a nitrogen atmosphere at ; temperatures ranging from 1800 to 2000 deg C, and the properties of the crystals ; determined. An

K. M. Taylor; Camille Lenie

1960-01-01

347

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

USGS Publications Warehouse

A method has been developed for the determination of calcium in phosphate, carbonate, and silicate rocks using the Beckman flame photometer, with photomultiplier attachement. The sample is dissolved in hydrofluoric, nitric, and perchloric acids, the hydrofluoric and nitric acids are expelled, a radiation buffer consisting of aluminum, magnesium, iron, sodium, potassium, phosphoric acid, and nitric acid is added, and the solution is atomized in an oxy-hydrogen flame with an instrument setting of 554 mµ. Measurements are made by comparison against calcium standards, prepared in the same manner, in the 0 to 50 ppm range. The suppression of calcium emission by aluminum and phosphate was overcome by the addition of a large excess of magnesium. This addition almost completely restores the standard curve obtained from a solution of calcium nitrate. Interference was noted when the iron concentration in the aspirated solution (including the iron from the buffer) exceeded 100 ppm iron. Other common rock-forming elements did not interfere. The results obtained by this procedure are within ± 2 percent of the calcium oxide values obtained by other methods in the range 1 to 95 percent calcium oxide. In the 0 to 1 percent calcium oxide range the method compares favorably with standard methods.

Kramer, Henry

1956-01-01

348

Barium sulfate suspension as a negative oral MRI contrast agent: in vitro and human optimization studies.  

PubMed

In vitro proton spectroscopy with line-width measurements and MR imaging were performed on various concentrations of commercially available single contrast (SC), double contrast, oral and rectal barium sulfate suspensions, as well as potassium sulfate, barium chloride, barium hydroxide, and 97% pure barium sulfate suspensions. Approximately 500 ml of 20%, 40%, 60%, and 70% w/w suspensions of SC oral barium sulfate suspensions were administered to four normal volunteers, respectively, and MR images were obtained at both 1.5 T and 0.15 T. Subsequently, 500 ml of 60% w/w suspensions of SC oral barium sulfate suspensions were administered to five normal volunteers and imaged at 1.5 T. All of the inert suspensions produced line-width broadening but the SC oral barium sulfate suspension at 50% and 70% stayed in suspension even after hours of standing undisturbed. As much as 80% of the small bowel and the entire colon were well visualized using the combination of 60% or 70% w/w SC barium sulfate suspensions with SE 550/22 and FISP pulse sequences. The effect was less at 0.15 T and also with the SE 2000/45/90 pulse sequences. We conclude that barium sulfate suspensions are useful as oral MRI contrast agents. PMID:2034046

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

1991-01-01

349

Hormonal Control of Calcium Homeostasis  

Microsoft Academic Search

Calcium homeostasis in the extracellular fluid is tightly controlled and defended physiologically. Hypercalce- mia always represents considerable underlying pathol- ogy and occurs when the hormonal control of calcium homeostasis is overwhelmed. The major hormones that are responsible for normal calcium homeostasis are parathyroid hormone and 1,25-dihydroxyvitamin D; these hormones control extracellular fluid calcium on a chronic basis. Over- or underproduction

Gregory R. Mundy; Theresa A. Guise

1999-01-01

350

Stoichiometry of Calcium Medicines  

ERIC Educational Resources Information Center

The topic of calcium supplement and its effects on human lives is presented in the way of questions to the students. It enables the students to realize the relevance of chemistry outside the classroom surrounding.

Pinto, Gabriel

2005-01-01

351

First principles pseudopotential calculations on aluminum and aluminum alloys  

SciTech Connect

Recent advances in computational techniques have led to the possibility of performing first principles calculations of the energetics of alloy formation on systems involving several hundred atoms. This includes impurity concentrations in the 1% range as well as realistic models of disordered materials (including liquids), vacancies, and grain boundaries. The new techniques involve the use of soft, fully nonlocal pseudopotentials, iterative diagonalization, and parallel computing algorithms. This approach has been pioneered by Car and Parrinello. Here the authors give a review of recent results using parallel and serial algorithms on metallic systems including liquid aluminum and liquid sodium, and also new results on vacancies in aluminum and on aluminum-magnesium alloys.

Davenport, J.W.; Chetty, N.; Marr, R.B.; Narasimhan, S.; Pasciak, J.E.; Peierls, R.F.; Weinert, M.

1993-12-31

352

Oxidation of aluminum nanoclusters  

SciTech Connect

The dynamics of oxidation of aluminum nanoclusters (20 nm diameter) is investigated using a parallel molecular dynamics approach based on variable charge interatomic interactions due to Streitz and Mintmire that include both ionic and covalent effects. Simulations are performed for both canonical ensembles for molecular oxygen (O{sub 2}) environments and microcanonical ensembles for molecular (O{sub 2}) and atomic (O{sub 1}) oxygen environments. Structural and dynamic correlations in the oxide region are calculated, as well as the evolution of charges, surface oxide thickness, diffusivities of atoms, and local stresses. In the microcanonical ensemble, the oxidizing reaction becomes explosive in both molecular and atomic oxygen environments due to the enormous energy release associated with Al-O bonding. Local stresses in the oxide scale cause rapid diffusion of aluminum and oxygen atoms. Analyses of the oxide scale reveal significant charge transfer and a variation of local structures from the metal-oxide interface to the oxide-environment interface. In the canonical ensemble, oxide depth grows linearly in time until {approx}30 ps, followed by saturation of oxide depth as a function of time. An amorphous oxide layer of thickness {approx}40 A is formed after 466 ps, in good agreement with experiments. The average mass density in the oxide scale is 75% of the bulk alumina density. Evolution of structural correlation in the oxide is analyzed through radial distribution and bond angles. Through detailed analyses of the trajectories of O atoms and their formation of OAl{sub n} structures, we propose a three-step process of oxidative percolation that explains deceleration of oxide growth in the canonical ensemble.

Campbell, Timothy J. [Collaboratory for Advanced Computing and Simulations, Department of Materials Science and Engineering, Department of Physics and Astronomy, Department of Computer Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Mississippi State University, Stennis Space Center, Mississippi 39529 (United States); Aral, Gurcan; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya [Collaboratory for Advanced Computing and Simulations, Department of Materials Science and Engineering, Department of Physics and Astronomy, Department of Computer Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Ogata, Shuji [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

2005-05-15

353

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

354

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

PubMed

There is an increasing public awareness of the relatively new and expanded industrial barium uses which are potential sources of human exposure (e.g., a shale gas development that causes an increased awareness of environmental exposures to barium). However, absorption of barium in exposed humans and a full spectrum of its health effects, especially among chronically exposed to moderate and low doses of barium populations, remain unclear. We suggest a systematic literature review (from 1875 to 2014) on environmental distribution of barium, its bioaccumulation, and potential and proven health impacts (in animal models and humans) to provide the information that can be used for optimization of future experimental and epidemiological studies and developing of mitigative and preventive strategies to minimize negative health effects in exposed populations. The potential health effects of barium exposure are largely based on animal studies, while epidemiological data for humans, specifically for chronic low-level exposures, are sparse. The reported health effects include cardiovascular and kidney diseases, metabolic, neurological, and mental disorders. Age, race, dietary patterns, behavioral risks (e.g., smoking), use of medications (those that interfere with absorbed barium in human organism), and specific physiological status (e.g., pregnancy) can modify barium effects on human health. Identifying, evaluating, and predicting the health effects of chronic low-level and moderate-level barium exposures in humans is challenging: Future research is needed to develop an understanding of barium bioaccumulation in order to mitigate its potential health impacts in various exposured populations. Further, while occupationally exposed at-risk populations exist, it is also important to identify potentially vulnerable subgroups among non-occupationally exposed populations (e.g., elderly, pregnant women, children) who are at higher risk of barium exposure from drinking water and food. PMID:24844320

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

2014-08-01

355

Thermodynamic investigation of the effect of alkali metal impuries on the processing of aluminum and magnesium alloys  

Microsoft Academic Search

Aluminum and magnesium alloys are widely used in the automobile and aerospace industries as structural materials due to their light weight, high specific strength and good formability. However, they suffer from the poor hot rolling characteristics due to undesired impurities like calcium, potassium, lithium and sodium. They increase the hydrogen solubility in the melt and promote the formation of porosity

Shengjun Zhang

2006-01-01

356

[Microbial geochemical calcium cycle].  

PubMed

The participation of microorganisms in the geochemical calcium cycle is the most important factor maintaining neutral conditions on the Earth. This cycle has profound influence on the fate of inorganic carbon, and, thereby, on the removal of CO2 from the atmosphere. The major part of calcium deposits was formed in the Precambrian, when prokaryotic biosphere predominated. After that, calcium recycling based on biogenic deposition by skeletal organisms became the main process. Among prokaryotes, only a few representatives, e.g., cyanobacteria, exhibit a special calcium function. The geochemical calcium cycle is made possible by the universal features of bacteria involved in biologically mediated reactions and is determined by the activities of microbial communities. In the prokaryotic system, the calcium cycle begins with the leaching of igneous rock predominantly through the action of the community of organotrophic organisms. The release of carbon dioxide to the soil air by organotrophic aerobes leads to leaching with carbonic acid and soda salinization. Under anoxic conditions, of major importance is the organic acid production by primary anaerobes (fermentative microorganisms). Calcium carbonate is precipitated by secondary anaerobes (sulfate reducers) and to a smaller degree by methanogens. The role of the cyanobacterial community in carbonate deposition is exposed by stromatolites, which are the most common organo-sedimentary Precambrian structures. Deposition of carbonates in cyanobacterial mats as a consequence of photoassimilation of CO2 does not appear to be a significant process. It is argued that carbonates were deposited at the boundary between the "soda continent", which emerged as a result of subaerial leaching with carbonic acid, and the ocean containing Ca2+. Such ecotones provided favorable conditions for the development of the benthic cyanobacterial community, which was a precursor of stromatolites. PMID:11910807

Zavarzin, G A

2002-01-01

357

Micro Joining of Aluminum Graphite Composites  

E-print Network

-doped Yttrium Aluminum Garnet laser OM Optical Microscopy RSW Resistance Spot Welding SEM Scanning Electron Microscopy UTM Universal Testing Machine YAG Yttrium Aluminum Garnet laser viii TABLE OF CONTENTS...-doped Yttrium Aluminum Garnet laser OM Optical Microscopy RSW Resistance Spot Welding SEM Scanning Electron Microscopy UTM Universal Testing Machine YAG Yttrium Aluminum Garnet laser viii TABLE OF CONTENTS...

Velamati, Manasa

2012-07-16

358

Depletion of calcium in the synaptic cleft of a calyx-type synapse in the rat brainstem  

PubMed Central

A new form of synaptic depression of excitatory synaptic transmission was observed when making voltage-clamp recordings from large presynaptic terminals, the calyces of Held and postsynaptic cells, the principal cells of the medial nucleus of the trapezoid body (MNTB), in slices of the rat auditory brainstem. A short (100 ms) depolarization of the postsynaptic cell to 0 mV reduced the amplitude of the EPSCs by 35 ± 5% (n = 7), measured at 10 ms following the depolarization. Recovery occurred within 0·5 s. The reduction of the EPSCs was most probably due to reduced presynaptic calcium influx, since postsynaptic depolarization reduced presynaptic calcium or barium currents. Conversely, presynaptic depolarization also reduced postsynaptic calcium or barium influx, under conditions where transmitter release was minimal. The calcium currents and the postsynaptic depolarization-induced suppression of synaptic transmission recovered with a similar time course, suggesting that this form of synaptic depression was, most probably, due to depletion of Ca2+ in the synaptic cleft. We conclude that when the Ca2+ influx into the pre- or postsynaptic cell is large, extracellular Ca2+ is depleted. Under these conditions, the Ca2+ concentration in the synaptic cleft is a sensitive indicator of the level of synaptic activity. However, the synaptic cleft is less sensitive to Ca2+ depletion than predicted from its estimated volume. PMID:10562339

Borst, J G G; Sakmann, B

1999-01-01

359

Venous intravasation of barium into the inferior mesenteric vein mimicking a coloureteral fistula: a case report and literature review.  

PubMed

Venous intravasation of barium following a barium enema is a rare event. We report a case of barium venous intravasation into the inferior mesenteric vein. Because of the close proximity to the course of the left ureter, this condition was interpreted initially as a coloureteral fistula. After further analysis of the original films, and left retrograde pyelography the true diagnosis was established. A literature review of barium intravasation is presented. PMID:2642308

Baer, H M; Siegelbaum, M H; Seidmon, E J; Kendall, A R

1989-01-01

360

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...

361

Influence of the nature of dopant oxides on the properties of semiconducting barium titanate  

SciTech Connect

This paper presents a thermochemical assessment of the process of doping barium titanate with yttrium, lanthanum, and cerium sesquioxides and their doing capabilities were compared. The thermochemical approach permits the chemical individuality of dopant oxides to be appraised. Yttrium doping of barium titanate is preferable to lanthanum or cerium doping.

Kostikov, Y.P.; Leikina, B.B.

1986-04-01

362

Effect of calcination on characteristics, surface texture and sinterability of chemically prepared barium titanate  

Microsoft Academic Search

Highly pure and finely divided barium titanate powders have been obtained by the pyrolysis of barium titanyl oxalate. The effect of time and temperature of calcination on the degree of crystallinity, fineness, and surface texture of the powders obtained have been demonstrated. The densification properties of the sintered bodies are discussed in relation to the characteristics of the calcined materials.

N. M. Ghoneim; S. Hanafi; Th. Salem

1990-01-01

363

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

E-print Network

.5 to 50.4 MS'2.At corresponding Ba2÷ concentrations, the resistance of cells in situ was somewhat lower). Barium, when applied to the retina, blocks the slow Pill potential3'2°, supporting a M~iller cell origin the effective- ness of Mfiller cells in regulating extracellular K÷ concentration ([K÷]o) in the retina. Barium

Newman, Eric A.

364

Underlayer and substrate effects in RF-magnetron sputtered barium ferrite thin film media  

Microsoft Academic Search

The effect of employing various sputtered underlayers and commercially available substrates in order to optimize the characteristics of barium ferrite (BaM) thin films for magnetic recording media have been studied. Our results show that the choice of underlayer or substrate controls the resultant surface morphology and magnetic properties of the BaM film. In particular, it was found that barium ferrite

A. T. A. Wee; J. P. Wang; A. C. H. Huan; L. P. Tan; R. Gopalakrishnan; K. L. Tan

1997-01-01

365

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

366

Charge and polarization distributions at the 90 domain wall in barium titanate ferroelectric  

E-print Network

Charge and polarization distributions at the 90° domain wall in barium titanate ferroelectric on quantum mechanics studies to provide a first-principles description of the 90° domain wall in barium in previous analyses, which have suggested domain walls ranging from 100 nm to 1 nm. These results should

Goddard III, William A.

367

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

E-print Network

with iron oxide and barium titanate nanoparticles Z. Guo a,*, S.-E. Lee a , H. Kim a , S. Park a , H.T. Hahn titanate nanoparticles fabricated by the surface-initiated-polymerization approach were investigated the introduction of the dielectric barium titanate nanoparticle into Fe2O3/PU nanocomposites. The permeability

Guo, John Zhanhu

368

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...

369

Aluminum-Air Battery Crystallizer.  

National Technical Information Service (NTIS)

A prototype crystallizer system for the aluminum-air battery operated reliably through simulated startup and shutdown cycles and met its design objectives. The crystallizer system allows for crystallization and removal of the aluminium hydroxide reaction ...

A. Maimoni

1987-01-01

370

Heated Aluminum Tanks Resist Corrosion  

NASA Technical Reports Server (NTRS)

Simple expedient of heating foam-insulated aluminum alloy tanks prevents corrosion by salt-laden moisture. Relatively-small temperature difference between such tank and surrounding air will ensure life of tank is extended by many years.

Johnson, L. E.

1983-01-01

371

Inhibitory Effect of C-Type Natriuretic Peptide on L-Type Calcium Channel Currents in Gastric Antral Myocytes of Guinea Pigs  

Microsoft Academic Search

The role of C-type natriuretic peptide (CNP) in the gastrointestinal tract is still unclear. This study was designed to investigate the effect of CNP on barium current (IBa) through the L-type calcium channel in gastric antral myocytes of guinea pigs. The whole-cell patch clamp technique was performed in gastric antral myocytes isolated by collagenase in guinea pigs. CNP significantly inhibited

J. B. Sun; X. Huang; H. Y. Xu; X. L. Li; L. Gao; Y. C. Kim; W. X. Xu

2006-01-01

372

Bis(chlorido)(dimethyl-sulfoxide-?O)barium(II)  

PubMed Central

The title compound, [BaCl2(C2H6SO)], forms a Ba6Cl9 cluster in which the BaCl2 units are connected via dimethyl­sulfoxide (DMSO) and chloride bridges. The central Cl atom of the Ba6Cl9 cluster is located on a threefold inversion axis and is coordinated octa­hedrally to six barium cations. In the crystal, the clusters are arranged in rows, which are inter­connected by the DMSO mol­ecules, forming a three-dimensional network. PMID:23284316

Gschwind, Fabienne; Jansen, Martin

2012-01-01

373

Atomic Mass and Nuclear Binding Energy for Ba-171 (Barium)  

NASA Astrophysics Data System (ADS)

This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Ba-171 (Barium, atomic number Z = 56, mass number A = 171).

Sukhoruchkin, S. I.; Soroko, Z. N.

374

Dielectric behavior of barium modified strontium bismuth titanate ceramic  

NASA Astrophysics Data System (ADS)

Barium Modified Strontium Bismuth Titanate(SBT) ceramic with general formula Sr1-xBaxBi4Ti4O15 is prepared by solid state reaction route. The structural analysis of the ceramics was done by X-ray diffraction technique. The X-ray patterns show that all the compositions are of single phase with orthorhombic structure. The temperature dependent dielectric behavior shows that the transition temperature decreases with Ba content but the maximum dielectric constant increases. The decreases of the transition with increase in Ba2+ ion, may be due to the decrease of orthorhombicity by the incorporation of Ba2+ ion in SBT lattice.

Nayak, P.; Badapanda, T.; Anwar, S.; Panigrahi, S.

2014-04-01

375

Radiation doses to children during modified barium swallow studies  

Microsoft Academic Search

Background  There are minimal data on radiation doses to infants and children undergoing a modified barium swallow (MBS) study.\\u000a \\u000a \\u000a \\u000a Objective  To 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 methods  Fluoroscopic 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

376

Development of an RIS probe for barium tagging for EXO  

NASA Astrophysics Data System (ADS)

Resonance Ionization Spectroscopy (RIS) has been shown to be a highly efficient method of selective ionization. We are investigating RIS as part of a high-efficiency single ion transport method to retrieve barium ions produced in double beta decay of xenon-136 and inject them in a ion trap where they are identified via optical spectroscopy. Highly efficient Ba-tagging would substantially reduce the background due to radioactive impurities in very large double-beta decay experiments, which limits the current generation of experiments. RIS is used to re-ionize the Ba atoms after they are desorbed from the substrate on which they had been captured.

Twelker, Karl

2010-11-01

377

Barium alginate cell-delivery systems: correlation between technological parameters.  

PubMed

The most recent trends for the development of several in vitro cell cultures have been oriented towards the cell immobilisation in 3-dimensional scaffolds and cell encapsulation. In fact, an important requirement of cell survival is self-assembly in functional communities, in the presence of an artificial extracellular matrix. In our research, a previously described technique for spermatozoa encapsulation was applied to obtain capsules loaded with an opaque agent as a model, and to perform a formulative study. A process variable, barium ion concentration, was correlated to some capsule properties, such as weight, gel thickness, total and core diameter. Ion concentration can be modified to obtain capsules with predictable characteristics. PMID:12176286

Torre, M L; Faustini, M; Norberti, R; Maggi, L; Maffeo, G; Conte, U; Vigo, D

2002-08-21

378

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

379

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. PMID:23042168

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

2012-01-01

380

Aluminum-air battery crystallizer  

Microsoft Academic Search

A prototype crystallizer system for the aluminum-air battery operated reliably through simulated startup and shutdown cycles and met its design objectives. The crystallizer system allows for crystallization and removal of the aluminium hydroxide reaction product; it is required to allow steady-state and long-term operation of the aluminum-air battery. The system has to minimize volume and maintain low turbulence and shear

A. Maimoni

1987-01-01

381

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

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

382

Gravimetric Determination of Calcium as Calcium Carbonate Hydrate.  

ERIC Educational Resources Information Center

The gravimetric determination of calcium as calcium carbonate is described. This experiment is suitable for undergraduate quantitative analysis laboratories. It is less expensive than determination of chloride as silver chloride. (BB)

Henrickson, Charles H.; Robinson, Paul R.

1979-01-01

383

Calcium revisited: part I  

PubMed Central

In February 2013, the US Preventive Services Task Force (see www.uspreventiveservicestaskforce.org) recommended ‘against daily supplementation with 400?IU or less of vitamin D3 and 1000, mg or less of calcium for the primary prevention of fractures in non institutionalized postmenopausal women', which illustrates the divergence of opinions. This review wants to shed an objective light on the importance of calcium for bone health. It cannot compete with an exhaustive analysis of the literature by an institute. It does not mention all significant references. But it highlights some pivotal studies from the past and it refers to recent studies that opened new views or added essential data to known facts. It also reflects the personal perception of the author. The first part deals mainly with intake, absorption, needs and recommendations; the second part will discuss the effects of calcium and its supplements on bone. PMID:24422133

Burckhardt, Peter

2013-01-01

384

Aluminum laser welding optimization  

NASA Astrophysics Data System (ADS)

Pulsed Nd:YAG laser with maximal power 150 W is used in our laboratory to cut, drill and weld metal and non-metal thin materials to thickness 2 mm. Welding is realized by fixed processing head or movable fiber one with beam diameter 0,6 mm in focus plane. Welding of stainless and low-carbon steel was tested before and results are publicized and used in practice. Now the goal of our experiment was optimization of process parameters for aluminum that has other physical properties than steels, lower density, higher heat conductivity and surface reflexivity. Pure alumina specimen 0,8 mm and Al-Mg-Si alloy 0,5 mm prepared for butt welds. Problem with surface layer of Al IIO 3 was overcome by sanding and chemical cleaning with grinding paste. Critical parameters for good weld shape are specimen position from beam focus plane, pulse length and energy, pulse frequency and the motion velocity that determines percentage of pulse overlap. Argon as protective gas was used with speed 6 liters per second. Thermal distribution in material can be modeled by numerical simulation. Software tool SYSWELD makes possible to fit laser as surface heat source, define weld geometry, and make meshing of specimen to finite elements and compute heat conduction during process. Color isotherms, vectors, mechanical deformations and others results can be study in post-processing.

Chmelí?ková, Hana; Halenka, Viktor; Lapšanská, Hana; Havelková, Martina

2007-04-01

385

75 FR 70689 - Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum-Greenwood Forge Division; Currently...  

Federal Register 2010, 2011, 2012, 2013

...Administration [TA-W-70,376] Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum- Greenwood Forge Division; Currently Known...2, 2009, applicable to workers of Kaiser Aluminum Fabricated Products, LLC, Kaiser...

2010-11-18

386

Calcium absorption from a new calcium delivery system (CCM)  

Microsoft Academic Search

Absorption of calcium from a highly soluble form of calcium, a mixed calcium citrate-malate* salt (CCM), was tested against calcium carbonate and milk in both rats and humans. The rat method estimated absorption from\\u000a the 6-day retention of an oral tracer, and the human method employed the standard double-isotope procedure. CCM was given\\u000a both as a dry powder and in

Kenneth T. Smith; Robert P. Heaney; Lawrence Flora; Sharilyn M. Hinders

1987-01-01

387

Nuclear calcium signaling.  

PubMed

Calcium is the major intracellular messenger linking synaptic activity in neurons to gene expression to control diverse functions including adaptive responses to synaptic activity as well as survival and death (Bading et al. 1993; Hardingham et al. 1997; Chawla and Bading 2001; West et al. 2001; Zhang et al. 2007; Flavell and Greenberg 2008; Mellstrom et al. 2008; Redmond 2008; Wayman et al. 2008; Bootman et al. 2009; Zhang et al. 2009; Hardingham and Bading 2010). Calcium entry at the synapse acts locally to activate signaling cascades which regulate posttranslational modifications essential for synaptic plasticity, such as the insertion of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) into the postsynaptic membrane (Soderling 2000; Malinow and Malenka 2002; Ehrlich and Malinow 2004). Synaptic activity can also evoke calcium signals in the nucleus which regulate gene pools largely through the phosphorylation of cAMP response element-binding protein (CREB) and its coactivator, CREB-binding protein (CBP) (Bading et al. 1993; Hardingham et al. 1997; Hardingham et al. 1999; Hu et al. 1999; Hardingham et al. 2001b; Impey et al. 2002; Zhang et al. 2009). Distinct mechanisms have been proposed to mediate synaptically generated calcium signals in subcompartments of pyramidal neurons; N-methyl-D -aspartate receptors (NMDARs) and ryanodine receptors have been implicated in the spine, inositol 3,4,5 triphosphate (IP3) receptors in the dendrites, and L-type voltage-gated calcium channels (VGCCs) at the soma and nucleus, although both NMDARs and IP3 receptors can also contribute to somatic and nuclear calcium signals under certain stimulation conditions (Nakamura et al. 1999; Bardo et al. 2006; Raymond and Redman 2006; Watanabe et al. 2006; Hong and Ross 2007; Hagenston et al. 2008; Bengtson et al. 2010). We review here the calcium signaling pathways underlying synaptically activated gene transcription leading to long-lasting changes in synaptic efficacy and memory as well as the physiological mechanisms by which synaptic activity evokes nuclear calcium signals. PMID:22351065

Bengtson, C Peter; Bading, Hilmar

2012-01-01

388

Plasma waves associated with the first AMPTE magnetotail barium release  

NASA Technical Reports Server (NTRS)

Plasma waves observed during the March 21, 1985, AMPTE magnetotail barium release are described. Electron plasma oscillations provided local measurements of the plasma density during both the expansion and decay phases. Immediately after the explosion, the electron density reached a peak of about 400,000/cu cm, and then started decreasing approximately as t to the -2.4 as the cloud expanded. About 6 minutes after the explosion, the electron density suddenly began to increase, reached a secondary peak of about 240/cu cm, and then slowly decayed down to the preevent level over a period of about 15 minutes. The density increase is believed to be caused by the collapse of the ion cloud into the diamagnetic cavity created by the initial expansion. The plasma wave intensities observed during the entire event were quite low. In the diamagnetic cavity, electrostatic emissions were observed near the barium ion plasma frequency, and in another band at lower frequencies. A broadband burst of electrostatic noise was also observed at the boundary of the diamagnetic cavity. Except for electron plasma oscillations, no significant wave activity was observed outside of the diamagnetic cavity.

Gurnett, D. A.; Anderson, R. R.; Bernhardt, P. A.; Luehr, H.; Haerendel, G.

1986-01-01

389

Results of magnetospheric barium ion cloud experiment of 1971  

NASA Technical Reports Server (NTRS)

The barium ion cloud experiment involved the release of about 2 kg of barium at an altitude of 31 482 km, a latitude of 6.926 N., and a longitude of 74.395 W. Significant erosion of plasma from the main ion core occurred during the initial phase of the ion cloud expansion. From the motion of the outermost striational filaments, the electric field components were determined to be 0.19 mV/m in the westerly direction and 0.68 mV/m in the inward direction. The differences between these components and those measured from balloons flown in the proximity of the extremity of the field line through the release point implied the existence of potential gradients along the magnetic field lines. The deceleration of the main core was greater than theoretically predicted. This was attributed to the formation of a polarization wake, resulting in an increase of the area of interaction and resistive dissipation at ionospheric levels. The actual orientation of the magnetic field line through the release point differed by about 10.5 deg from that predicted by magnetic field models that did not include the effect of ring current.

Adamson, D.; Fricke, C. L.; Long, S. A. T.

1975-01-01

390

Barium titanate core - gold shell nanoparticles for hyperthermia treatments  

PubMed Central

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

2013-01-01

391

Calcium carbonate with magnesium overdose  

MedlinePLUS

The combination of calcium carbonate and magnesium is commonly found in antacids, which are medicines that provide heartburn relief. Calcium carbonate with magnesium overdose occurs when someone accidentally or ...

392

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2011 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2011-04-01

393

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2010 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2010-04-01

394

21 CFR 184.1199 - Calcium gluconate.  

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2014-04-01

395

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2013 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2013-04-01

396

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2012 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2012-04-01

397

21 CFR 184.1191 - Calcium carbonate.  

...1) As a byproduct in the “Lime soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium...

2014-04-01

398

Stability and surface energies of wetted grain boundaries in aluminum oxide  

Microsoft Academic Search

The stability of a calcium-aluminum-silicate liquid film between two near-basal plane surfaces of sapphire at 1650 C was studied. Samples were prepared having an average basal misorientation across the interface of 6--7 [degree] about <10[bar 1]0>. The interfaces varied in orientation from 0[degree] to [approximately]38 to the [0001] direction. Three types of interfaces were observed: faceted, solid-liquid interfaces; low-angle grain

Doh-Yeon Kim; Sheldon M. Wiederhorn; Bernard J. Hockey; Carol A. Handwerker; John E. Blendell

1994-01-01

399

Lowering of Initial Anodizing Current Density due to Thin Aluminum Oxide Film on Evaporated Aluminum  

NASA Astrophysics Data System (ADS)

Initial current densities under constant voltage anodic oxidation are measured to estimate aluminum oxide film thickness on aluminum. It is shown that the logarithm of initial current density ratio with and without a thin aluminum oxide on aluminum is proportional to the logarithm of the exposure time to dry air. Auger electron spectroscopy measurements show that the surface of aluminum exposed to dry air is covered with a thicker aluminum oxide film than an aluminum surface just after aluminum oxide etching by an aqueous 5% sulfamic acid.

Kikuchi, Akira

1985-01-01

400

Commonwealth Aluminum: Manufacturer Conducts Plant-Wide Energy Assessments at Two Aluminum Sheet Production Operations;  

SciTech Connect

DOE Industrial Technologies Program case study describes the savings possible if Commonwealth Aluminum (now Aleris Rolled Products) makes improvements noted in energy assessments at two aluminum mills.

Not Available

2006-04-01

401

Calcium silicate insulation structure  

DOEpatents

An insulative structure including a powder-filled evacuated casing utilizes a quantity of finely divided synthetic calcium silicate having a relatively high surface area. The resultant structure-provides superior thermal insulating characteristics over a broad temperature range and is particularly well-suited as a panel for a refrigerator or freezer or the insulative barrier for a cooler or a insulated bottle.

Kollie, Thomas G. (Oak Ridge, TN); Lauf, Robert J. (Oak Ridge, TN)

1995-01-01

402

The Plasma Membrane Calcium Pump  

NASA Technical Reports Server (NTRS)

Three aspect of cellular calcium metabolism in animal cells was discussed including the importance of the plasma membrane in calcium homeostasis, experiments dealing with the actual mechanism of the calcium pump, and the function of the pump in relationship to the mitochondria and to the function of calmodulin in the intact cell.

Rasmussen, H.

1983-01-01

403

Defoaming effect of calcium soap  

Microsoft Academic Search

The effect of calcium oleate on foam stability was studied for aqueous solutions of two commonly used surfactants (anionic and nonionic) under alkaline conditions in the absence of oil. For the anionic surfactant, defoaming by calcium oleate appears to involve two mechanisms. One is that oleate and calcium ions are presumably incorporated into the surfactant monolayers with a resulting decrease

Hui Zhang; Clarence A. Miller; Peter R. Garrett; Kirk H. Raney

2004-01-01

404

Osteoinduction by calcium phosphate biomaterials  

Microsoft Academic Search

Different materials were implanted in muscles of dogs to study the osteoinduction of calcium phosphate biomaterials. Bone formation was only seen in calcium phosphate biomaterials with micropores, and could be found in hydroxyapatite (HA) ceramic, tricalcium phosphate\\/hydroxyapatite ceramic (BCP), ß-TCP ceramic and calcium phosphate cement. The osteoinductive potential was different in different materials. The results indicate that osteoinduction can be

Huipin Yuan; Zongjian Yang; Yubao Li; Xingdong Zhang; J. D. De Bruijn; K. De Groot

1998-01-01

405

Weld Repair of Thin Aluminum Sheet  

NASA Technical Reports Server (NTRS)

Weld repairing of thin aluminum sheets now possible, using niobium shield and copper heat sinks. Refractory niobium shield protects aluminum adjacent to hole, while copper heat sinks help conduct heat away from repair site. Technique limits tungsten/inert-gas (TIG) welding bombardment zone to melt area, leaving surrounding areas around weld unaffected. Used successfully to repair aluminum cold plates on Space Shuttle, Commercial applications, especially in sealing fractures, dents, and holes in thin aluminum face sheets or clad brazing sheet in cold plates, heat exchangers, coolers, and Solar panels. While particularly suited to thin aluminum sheet, this process also used in thicker aluminum material to prevent surface damage near weld area.

Beuyukian, C. S.; Mitchell, M. J.

1986-01-01

406

Intoxication by large amounts of barium nitrate overcome by early massive K supplementation and oral administration of magnesium sulphate.  

PubMed

Suicide by ingestion of barium is exceptionally rare. Adverse health effects depend on the solubility of the barium compound. Severe hypokalemia, which generally occurs within 2 hours after ingestion, is the predominating feature of acute barium toxicity, subsequently leading to adverse effects on muscular activity and cardiac automaticity. We report one case of acute poisoning with barium nitrate, a soluble barium compound. A 75-year-old woman was hospitalized after suicidal ingestion of a burrow mole fumigant containing 12.375 g of barium nitrate. About 1 hour post-ingestion, she was only complaining of abdominal pain. The ECG recording demonstrated polymorphic ventricular premature complexes (VPCs). Laboratory data revealed profound hypokalemia (2.1 mmol/L). She made a complete and uneventful recovery after early and massive potassium supplementation combined with oral magnesium sulphate to prevent barium nitrate absorption. PMID:20354061

Payen, Christine; Dellinger, Arnaud; Pulce, Corine; Cirimele, Vincent; Carbonnel, Vincent; Kintz, Pascal; Descotes, Jacques

2011-01-01

407

The Evolving Mixture of Barium Isotopes in Milky Way Halo Stars  

NASA Astrophysics Data System (ADS)

Heavy metals in stars form through one of two types of neutron capture processes: the rapid r-process or slower s-process. The fraction of odd and even barium isotopes in stars can indicate which process predominantly contributed to a star’s heavy metals, since odd barium isotopes predominantly form through the r-process and even barium isotopes through the s-process. The “stellar model” predicts that older stars contain comparable amounts of odd and even barium isotopes, while the “classical model” states that they almost exclusively contain odd isotopes. This study investigated these competing models by analyzing high-resolution spectra of twelve Milky Way stars. These spectra were analyzed for the first time in this study. To quantify r- and s-process enrichment, we measured the odd barium isotope fraction in the stars by fitting models to the stars’ spectra. Generating models involved measuring the stars’ Doppler shift, resolution, and barium abundance. To reduce error margins we optimized resolution and barium abundance measurements by enhancing existing techniques through several rounds of revisions. Our results support the stellar model of heavy metal enrichment, and our proposed optimizations will enable future researchers to obtain a deeper understanding of chemical enrichment in the Universe. This research was supported by the Science Internship Program at the University of California Santa Cruz, Lick Observatory, and the National Science Foundation.

Choudhury, Zareen; Kirby, E. N.; Guhathakurta, P.

2014-01-01

408

Induction in an Aluminum Can  

NSDL National Science Digital Library

This activity demonstrates Lenz's Law, which states that an induced electromotive force generates a current that induces a counter magnetic field that opposes the magnetic field generating the current. In the demonstration, an empty aluminum can floats on water in a tray, such as a Petri dish. Students spin a magnet just inside the can without touching the can. The can begins to spin. Understanding what happens can be explained in steps: first, the twirling magnet creates an alternating magnetic field. Students can use a nearby compass to observe that the magnetic field is really changing. Second, the changing magnetic field permeates most things around it, including the aluminum can itself. A changing magnetic field will cause an electric current to flow when there is a closed loop of an electrically conducting material. Even though the aluminum can is not magnetic, it is metal and will conduct electricity. So the twirling magnet causes an electrical current to flow in the aluminum can. This is called an "induced current." Third, all electric currents create magnetic fields. So, in essence, the induced electrical current running through the can creates its very own magnetic field, making the aluminum can magnetic. This is activity four of "Exploring Magnetism." The guide includes science background information, student worksheets, glossary and related resources.

409

Scaleable Clean Aluminum Melting Systems  

SciTech Connect

The project entitled 'Scaleable Clean Aluminum Melting Systems' was a Cooperative Research and Development Agreements (CRADAs) between Oak Ridge National Laboratory (ORNL) and Secat Inc. The three-year project was initially funded for the first year and was then canceled due to funding cuts at the DOE headquarters. The limited funds allowed the research team to visit industrial sites and investigate the status of using immersion heaters for aluminum melting applications. Primary concepts were proposed on the design of furnaces using immersion heaters for melting. The proposed project can continue if the funding agency resumes the funds to this research. The objective of this project was to develop and demonstrate integrated, retrofitable technologies for clean melting systems for aluminum in both the Metal Casting and integrated aluminum processing industries. The scope focused on immersion heating coupled with metal circulation systems that provide significant opportunity for energy savings as well as reduction of melt loss in the form of dross. The project aimed at the development and integration of technologies that would enable significant reduction in the energy consumption and environmental impacts of melting aluminum through substitution of immersion heating for the conventional radiant burner methods used in reverberatory furnaces. Specifically, the program would couple heater improvements with furnace modeling that would enable cost-effective retrofits to a range of existing furnace sizes, reducing the economic barrier to application.

Han, Q.; Das, S.K. (Secat, Inc.)

2008-02-15

410

A model of propagating calcium-induced calcium release mediated by calcium diffusion  

Microsoft Academic Search

The effect of sudden local fluctuations of the free sarcoplasmic (Ca++)i in cardiac cells on calcium release and calcium uptake by the sarcoplasmic reticulum (SR) was calculated with the aid of a simplified model of SR calcium handling. The model was used to evaluate whether propagation of calcium tran- sients and the range of propagation velocities observed experimentally (0.05-15 mm

PETER H. BACKX; PIETER P. DE TOMBE; JURJEN H. K. VAN DEEN

1989-01-01

411

Voltage-Gated Calcium Channels  

NASA Astrophysics Data System (ADS)

Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

Zamponi, Gerald Werner

412

Magnetic properties of Ni substituted Y-type barium ferrite  

NASA Astrophysics Data System (ADS)

Y-type barium hexaferrite is attractive material for various applications, such as high frequency antennas and RF devices, because of its interesting magnetic properties. Especially, Ni substituted Y- type hexaferrites have higher magnetic ordering temperature than other Y-type. We have investigated macroscopic and microscopic properties of Y-type barium hexaferrite. Ba2Co2-xNixFe12O22 (x = 0, 0.5, 1.0, 1.5, and 2.0) samples are prepared by solid-state reaction method and studied by X-ray diffraction (XRD), vibrating sample magnetometer, and Mössbauer spectroscopy, as well as a network analyzer for high frequency characteristics. The XRD pattern is analyzed by Rietveld refinement method and confirms the hexagonal structure with R-3m. The hysteresis curve shows ferrimagnetic behavior. Saturation magnetization (Ms) decreases with Ni contents. Ni2+, which preferentially occupies the octahedral site with up-spin sub-lattice, has smaller spin value S of 1 than Co2+ having S = 3/2. The zero-field-cooled (ZFC) measurement of Ba2Co1.5Ni0.5Fe12O22 shows that Curie and spin transition temperatures are found to be 718 K and 209 K, respectively. The Curie temperature TC is increased with Ni contents, while TS is decreased with Ni. The Mössbauer spectra were measured at various temperatures and fitted by using a least-squares method with six sextet of six Lorentzian lines for Fe sites, corresponding to the 3bVI, 6cIV*, 6cVI, 18hVI, 6cIV, and 3aIV sites at below TC. From Mössbauer measurements, we confirmed the spin state of Fe ion to be Fe3+ and obtained the isomer shift (?), magnetic hyperfine field (Hhf), and the occupancy ratio of Fe ions at six sub-lattices. The complex permeability and permittivity are measured between 100 MHz and 4 GHz, suggesting that Y-type barium hexaferrite is promising for antenna applications in UHF band.

Won, Mi Hee; Kim, Chul Sung

2014-05-01

413

Infrared determination of barium, strontium, sodium and potassium sulphates by the pellet technique.  

PubMed

Methods are proposed for the infrared determination of barium, strontium, sodium and potassium sulphates by the pellet technique. The semimicro sample is mixed with 300 mg of potassium bromide, the pellet is formed, and the peak heights are determined at the appropriate peak. Barium and strontium sulphates are measured at 983 and 993 cm(-1), respectively. Sodium and potassium sulphates are both measured at 619 cm(-1). Barium and strontium sulphates can be determined in the presence of each other in ratios from 1:20 to 20:1 from the measurements at 983 and 993 cm(-1). Carbonates or nitrates do not interfere with any of the procedures. PMID:18960911

Chasan, D E; Norwitz, G

1971-05-01

414

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

415

Improved methods to manufacture aluminum  

SciTech Connect

A low-temperature (750{degrees}C) process to produce aluminum, employing dimensionally-stable electrodes, was investigated under this contract. Tests were carried out at a 10-ampere scale to develop a nonconsumable anode and to evaluate certain cell operating parameters. The work was carried out in conjunction with a NSF SBIR research grant to study the fundamental science aspects of the process. A scaled up 300-ampere cell was built and a preliminary test run was made with encouraging results. The new technology has the promise of producing aluminum at 5.0 kWh/lb as compared to the US average of about 7.5 kWh/lb, and to produce it at lower cost. Preliminary technical discussions have been held with a major US aluminum company under secrecy agreement for eventual licensing.

Not Available

1992-06-15

416

Recycling of aluminum salt cake  

SciTech Connect

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% of the content of this waste is combined salt (sodium and potassium chlorides). Salt-cake waste is currently disposed of in conventional landfills. In addition, over 50 {times} 10{sup 3} tons of black dross that is not economical to reprocess a rotary furnace for aluminum recovery ends up in landfills. The composition of the dross is similar to that of salt cake, except that it contains higher concentrations of aluminum (up to 20%) and correspondingly lower amounts of salts. Because of the high solubility of the salts in water, these residues, when put in landfills, represent a potential source of pollution to surface-water and groundwater supplies. The increasing number of environmental regulations on the generation and disposal of industrial wastes are likely to restrict the disposal of these salt-containing wastes in conventional landfills. Processes exist that employ the dissolution and recovery of the salts from the waste stream. These wet-processing methods are economical only when the aluminum concentration in that waste exceeds about 10%. Argonne National Laboratory (ANL) conducted a study in which existing technologies were reviewed and new concepts that are potentially more cost-effective than existing processes were developed and evaluated. These include freeze crystallization, solvent/antisolvent extraction, common-ion effect, high-pressure/high-temperature process, and capillary-effect systems. This paper presents some of the technical and economic results of the aforementioned ANL study.

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

1991-12-01

417

Aluminum-air battery crystallizer  

NASA Astrophysics Data System (ADS)

A prototype crystallizer system for the aluminum-air battery operated reliably through simulated startup and shutdown cycles and met its design objectives. The crystallizer system allows for crystallization and removal of the aluminium hydroxide reaction product; it is required to allow steady-state and long-term operation of the aluminum-air battery. The system has to minimize volume and maintain low turbulence and shear to minimize secondary nucleation and energy consumption while enhancing agglomeration. A lamella crystallizer satisfies system constraints.

Maimoni, A.

1987-01-01

418

Aluminum-carbon composite electrode  

DOEpatents

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

Farahmandi, C. Joseph (Auburn, AL); Dispennette, John M. (Auburn, AL)

1998-07-07

419

Aluminum-carbon composite electrode  

DOEpatents

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg. 3 figs.

Farahmandi, C.J.; Dispennette, J.M.

1998-07-07

420

Hermetically sealed aluminum electrolytic capacitor  

NASA Technical Reports Server (NTRS)

Aluminum electrolytic capacitors are presently not allowed on NASA missions because they outgas water and organic vapors, as well as H2. As a consequence, much larger and heavier packages of tantalum capacitors are used. A hermetically sealed aluminum capacitor has been developed under NASA-MSFC SBIR contracts. This capacitor contains a nongassing electrolyte that was developed for this application so internal pressure would remain low. Capacitors rated at 250 to 540 V have been operated under full load for thousands of hours at 85 and 105 C with good electrical performance and low internal pressure. Electrolyte chemistry and seal engineering concepts will be discussed.

Alwitt, Robert S.; Liu, Yanming; Elias, William

1995-01-01

421

Advances in aluminum casting technology  

SciTech Connect

This symposium focuses on the improvements of aluminum casting quality and reliability through a better understanding of processes and process variables, and explores the latest innovations in casting-process design that allow increasing use of the castings to replace complex assemblies and heavy steel and cast-iron components in aerospace and automotive applications. Presented are 35 papers by international experts in the various aspects of the subject. The contents include: Semisolid casting; Computer-aided designing of molds and castings; Casting-process modeling; Aluminum-matrix composite castings; HIPing of castings; Progress in the US car project; Die casting and die design; and Solidification and properties.

Tiryakioglu, M.; Campbell, J. (eds.)

1998-01-01

422

Summary of Repair Techniques for Aluminum Bridging.  

National Technical Information Service (NTIS)

This report provides the results of an investigation designed to recommend joining processes which could be used in the field to repair aluminum bridging. A literature search was conducted to identify the various aluminum repair processes available. The m...

D. Brockman, R. A. Weber

1982-01-01

423

Current technologies and trends of aluminum design  

E-print Network

A literature review of current aluminum technology in the building and construction industry was carried out. Aluminum is an ideal material for building in corrosive environments and for building structures where small ...

Chen, Michael, 1981-

2004-01-01

424

Aluminum-Air Battery for Automotive Propulsion.  

National Technical Information Service (NTIS)

Research on the development of aluminum-air batteries which will be used in energy efficient, economical electric vehicles is reviewed with information on the research strategy, performance characteristics of aluminum-air cells, vehicle design, and the ne...

J. F. Cooper, E. Behrin

1980-01-01

425

BIOLOGICAL SPECIATION AND TOXICOKINETICS OF ALUMINUM  

EPA Science Inventory

This review discusses recent literature on the chemical and physiological factors that result in the absorption, distribution, and excretion of aluminum in mammals, with particular regard to gastrointestinal absorption and speciation in plasma. umans encounter aluminum, a ubiquit...

426

Aluminum: World market prospects for troubled times  

NASA Astrophysics Data System (ADS)

Aluminum and alumina prices and production volumes dropped significantly in 2008 due to the worldwide economic recession. This paper provides a comprehensive analysis of the current state of the aluminum industry and its outlook for the future.

Djukanovic, Goran

2009-02-01

427

Hydrogen peroxide attenuates store-operated calcium entry and enhances calcium extrusion in thyroid FRTL-5 cells.  

PubMed Central

Redox modulation participates in the regulation of intracellular free calcium concentration ([Ca(2+)](i)) in several cell types. In thyroid cells, including FRTL-5 cells, changes in [Ca(2+)](i) regulate several important functions, including the production of H(2)O(2) (hydrogen peroxide). As H(2)O(2) is of crucial importance for the production of thyroid hormones, we investigated the effects of H(2)O(2) on [Ca(2+)](i) in thyroid FRTL-5 cells. H(2)O(2) itself did not modulate basal [Ca(2+)](i). However, H(2)O(2) attenuated store-operated calcium entry evoked by thapsigargin, both in a sodium-containing buffer and in a sodium-free buffer. The effect of H(2)O(2) was abrogated by the reducing agent beta-mercaptoethanol. H(2)O(2) also attenuated the thapsigargin-evoked entry of barium and manganese. The effect of H(2)O(2) was, at least in part, mediated by activation of protein kinase C (PKC), as H(2)O(2) enhanced the binding of [(3)H]phorbol 12,13-dibutyrate. H(2)O(2) also stimulated the translocation of the isoenzyme PKCepsilon from the cytosolic fraction to the particulate fraction. Furthermore, H(2)O(2) did not attenuate store-operated calcium entry in cells treated with staurosporine or calphostin C, or in cells with down-regulated PKC. H(2)O(2) depolarized the membrane potential in bisoxonol-loaded cells and when patch-clamp in the whole-cell mode was used. The depolarization was attenuated in cells with down-regulated PKC. This depolarization, at least in part, explained the H(2)O(2)-evoked inhibition of calcium entry. In addition, H(2)O(2) enhanced the extrusion of calcium from cells stimulated with thapsigargin and this effect was abolished in cells with down-regulated PKC and after treatment of the cells with the reducing agent beta-mercaptoethanol. In conclusion H(2)O(2) attenuates an increase in [Ca(2+)](i). As H(2)O(2) is produced in thyroid cells in a calcium-dependent manner, our results suggest that H(2)O(2) may participate in the regulation of [Ca(2+)](i) in these cells via a negative-feedback mechanism involving activation of PKC. PMID:10998346

Tornquist, K; Vainio, P J; Bjorklund, S; Titievsky, A; Dugue, B; Tuominen, R K

2000-01-01

428

Raman study of barium titanate with oxygen vacancies  

NASA Astrophysics Data System (ADS)

Barium titanate (BaTiO 3) crystal samples with different distribution of oxygen vacancies were prepared through different thermal treatment processes. The influences of oxygen vacancies on the Raman spectra and X-ray photoelectron spectroscopy (XPS) spectra of BaTiO 3 single crystals were studied comparatively. Raman measurements of fast-cooled BaTiO 3, which annealed in vacuum and then cooled in air showed many different spectroscopic results comparing with as-received BaTiO 3 sample. Raman measurements of slow-cooled BaTiO 3, which annealed in vacuum and then cooled in tube furnace exhibited few spectroscopic differences. XPS measurements of as-received BaTiO 3 sample and fast-cooled BaTiO 3 sample confirmed that this discrepancy resulted from the surface phase of oxygen vacancy in BaTiO 3.

Zhang, W. H.; Chen, L.; Tao, Y. T.; Zhang, W. H.; Chen, J.; Zhang, J. X.

2011-12-01

429

Dynamics of the CRRES barium releases in the magnetosphere  

NASA Technical Reports Server (NTRS)

The Combined Release and Radiation Effects Satellite (CRRES) G-2, G-3, and G-4 ionized and neutral barium cloud positions are triangulated from ground-based optical data. From the time history of the ionized cloud motion perpendicular to the magnetic field, the late time coupling of the ionized cloud with the collisionless ambient plasma in the magnetosphere is investigated for each of the releases. The coupling of the ionized clouds with the ambient medium is quantitatively consistent with predictions from theory in that the coupling time increases with increasing distance from the Earth. Quantitative comparison with simple theory for the couping time also yields reasonable agreement. Other effects not predicted by the theory are discussed in the context of the observations.

Fuselier, S. A.; Mende, S. B.; Geller, S. P.; Miller, M.; Hoffman, R. A.; Wygant, J. R.; Pongratz, M.; Meredith, N. P.; Anderson, R. R.

1994-01-01

430

Nonlinear spectroscopy of barium in parallel electric and magnetic fields  

NASA Astrophysics Data System (ADS)

We report on the experimental spectral observations of barium in parallel electric and magnetic fields. The laser pulse is linearly polarized along or perpendicular to the fields, leading to the states m = 0 and the states m = ±1 populated, respectively, by one photon excitation. By sweeping the electric field, we observe the linear and nonlinear splitting of the diamagnetic spectrum as the electric field increases. The spectral anticrossing is induced by the atomic core effect. The Stark spectrum also shows an obvious nonlinear quadratic behavior when the applied magnetic field varies strongly. All spectra are well explained by the full quantum calculation after taking the quantum defect effects of the channel ns up to nf into account.

Yang, Hai-Feng; Gao, Wei; Cheng, Hong; Liu, Hong-Ping

2014-10-01

431

Negative-U extended Hubbard model for doped barium bismuthates  

NASA Astrophysics Data System (ADS)

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 the two, well-separated transport and optical gaps observed in the semiconducting phases of the bismuthates. We fix the parameters in our model by fitting these experimentally observed gaps; and with these parameter values we compute other properties of these systems. We also show how metallic screening and disorder can decrease the superconducting Tc dramatically. Our theory leads to an exotic charge-transport mechanism, dominated by charge +/-2e bosons (cooperons), in the semiconducting phases of these systems.

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

1995-07-01

432

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

433

Studies on immobilization of thorium in barium borosilicate glass  

NASA Astrophysics Data System (ADS)

The barium borosilicate glass (BBS) matrix has shown considerable solubility of ThO 2 at 1000 °C. As seen by X-ray diffractometry (XRD) and Electron probe micro analysis (EPMA) up to 15.86 wt% of ThO 2 could be dissolved in this matrix. The homogeneity of thoria loaded glass was convincingly ascertained by EPMA. Attempts to load more than 16 wt% ThO 2 led to the phase separation of crystalline phases identified as major phase of ThO 2 and minor percentage of ThSiO 4 phase with altogether different morphologies, as seen by XRD. Interestingly, the back scattered images of thorite crystals point towards the presence of chemical zoning. The results being reported in this paper are of interest especially with respect to immobilization of other actinides in borosilicate glass matrix.

Mishra, R. K.; Sengupta, Pranesh; Kaushik, C. P.; Tyagi, A. K.; Kale, G. B.; Raj, Kanwar

2007-02-01

434

A new type of microphone using flexoelectric barium strontium titnate  

NASA Astrophysics Data System (ADS)

A flexoelectric bridge-structured microphone using bulk barium strontium titanate (Ba0.65Sr0.35TiO3 or BST) ceramic was investigated in this study. The flexoelectric microphone was installed in an anechoic box and exposed to the sound pressure emitted from a loud speaker. Charge sensitivity of the flexoelectric microphone was measured and calibrated using a reference microphone. The 1.5 mm×768 ?m×50 ?m micro-machined bridge-structured flexoelectric microphone has a sensitivity of 0.92 pC/Pa, while its resonance frequency was calculated to be 98.67 kHz. The analytical and experimental results show that the flexoelectric microphone has both high sensitivity and broad bandwidth, indicating that flexoelectric microphones are potential candidates for many applications.

Kwon, Seol ryung; Huang, Wenbin; Zhang, Shujun; Yuan, Fuh-Gwo; Jiang, Xiaoning

2014-03-01

435

Pulsating aurora induced by upper atmospheric barium releases  

NASA Technical Reports Server (NTRS)

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

Deehr, C.; Romick, G.

1977-01-01

436

Communication: Barium ions and helium nanodroplets: Solvation and desolvation  

NASA Astrophysics Data System (ADS)

The solvation of Ba+ ions created by the photoionization of barium atoms located on the surface of helium nanodroplets has been investigated. The excitation spectra corresponding to the 6p 2P1/2 ? 6s 2S1/2 and 6p 2P3/2 ? 6s 2S1/2 transitions of Ba+ are found to be identical to those recorded in bulk He II [H. J. Reyher, H. Bauer, C. Huber, R. Mayer, A. Schafer, and A. Winnacker, Phys. Lett. A 115, 238 (1986)], indicating that the ions formed at the surface of the helium droplets become fully solvated by the helium. Time-of-flight mass spectra suggest that following the excitation of the solvated Ba+ ions, these are being ejected from the helium droplets either as bare Ba+ ions or as small Ba+Hen (n < 20) complexes.

Zhang, Xiaohang; Drabbels, Marcel

2012-08-01

437

Stochastic calcium mechanisms cause dendritic calcium spike variability.  

PubMed

Bursts of dendritic calcium spikes play an important role in excitability and synaptic plasticity in many types of neurons. In single Purkinje cells, spontaneous and synaptically evoked dendritic calcium bursts come in a variety of shapes with a variable number of spikes. The mechanisms causing this variability have never been investigated thoroughly. In this study, a detailed computational model using novel simulation routines is applied to identify the roles that stochastic ion channels, spatial arrangements of ion channels, and stochastic intracellular calcium have toward producing calcium burst variability. Consistent with experimental recordings from rats, strong variability in the burst shape is observed in simulations. This variability persists in large model sizes in contrast to models containing only voltage-gated channels, where variability reduces quickly with increase of system size. Phase plane analysis of Hodgkin-Huxley spikes and of calcium bursts identifies fluctuation in phase space around probabilistic phase boundaries as the mechanism determining the dependence of variability on model size. Stochastic calcium dynamics are the main cause of calcium burst fluctuations, specifically the calcium activation of mslo/BK-type and SK2 channels. Local variability of calcium concentration has a significant effect at larger model sizes. Simulations of both spontaneous and synaptically evoked calcium bursts in a reconstructed dendrite show, in addition, strong spatial and temporal variability of voltage and calcium, depending on morphological properties of the dendrite. Our findings suggest that stochastic intracellular calcium mechanisms play a crucial role in dendritic calcium spike generation and are therefore an essential consideration in studies of neuronal excitability and plasticity. PMID:24089492

Anwar, Haroon; Hepburn, Iain; Nedelescu, Hermina; Chen, Weiliang; De Schutter, Erik

2013-10-01

438

Calcium in Plants  

PubMed Central

Calcium is an essential plant nutrient. It is required for various structural roles in the cell wall and membranes, it is a counter?cation for inorganic and organic anions in the vacuole, and the cytosolic Ca2+ concentration ([Ca2+]cyt) is an obligate intracellular messenger coordinating responses to numerous developmental cues and environmental challenges. This article provides an overview of the nutritional requirements of different plants for Ca, and how this impacts on natural flora and the Ca content of crops. It also reviews recent work on (a) the mechanisms of Ca2+ transport across cellular membranes, (b) understanding the origins and specificity of [Ca2+]cyt signals and (c) characterizing the cellular [Ca2+]cyt?sensors (such as calmodulin, calcineurin B?like proteins and calcium?dependent protein kinases) that allow plant cells to respond appropriately to [Ca2+]cyt signals. PMID:12933363

WHITE, PHILIP J.; BROADLEY, MARTIN R.

2003-01-01

439

Complexometric Determination of Calcium  

NASA Astrophysics Data System (ADS)

Ethylenediaminetetraacetate (EDTA) complexes with numerous mineral ions, including calcium and magnesium. This reaction can be used to determine the amount of these minerals in a sample by a complexometric titration. Endpoints in the titration are detected using indicators that change color when they complex with mineral ions. Calmagite and eriochrome black T (EBT) are such indicators that change from blue to pink when they complex with calcium and magnesium. In the titration of a mineral-containing solution with EDTA, the solution turns from pink to blue at the endpoint with either indicator. The pH affects a complexometric EDTA titration in several ways, and must be carefully controlled. A major application of EDTA titration is testing the hardness of water, for which the method described is an official one (Standard Methods for the Examination of Water and Wastewater, Method 2340C; AOAC Method 920.196).

Nielsen, S. Suzanne

440

BD-21 3873: another yellow-symbiotic barium star.  

NASA Astrophysics Data System (ADS)

An abundance analysis of the yellow symbiotic system BD-21 3873 reveals it to be a metal-poor K-giant ([Fe/H]=-1.3) which is enriched in the heavy s-process elements. In that respect, this star appears to be a twin of AG Dra, another yellow symbiotic system analyzed in a previous paper (Smith et al., 1996A&A...315..179S). The heavy-element abundance distributions of AG Dra and BD-21 3873 are almost identical, and are best reproduced by a s-process with a neutron exposure parameter of 1.2-1.3mb^-1^ and a neutron density logN_n_=8.3 (as derived from the Rb/Zr ratio). These two systems thus link the symbiotic stars to the binary barium and CH stars which are also s-process enriched. These binary systems, which exhibit overabundances of the heavy elements, owe their abundance peculiarities to mass transfer from thermally-pulsing asymptotic giant branch stars, which have since evolved to become white-dwarf companions of the cool stars we now view as the chemically-peculiar primaries. The spectroscopic orbits of BD-21 3873 (derived from CORAVEL measurements) and AG Dra are similar to those of barium and CH stars. With an orbital period of 281.6d, BD-21 3873 is one of the closest systems in these families, and its light curve indeed suggests that variations due to reflection and ellipticity effects are present. The amplitude of the ellipsoidal variations indicates that the giant must be close to filling its Roche lobe. However, no acceptable solution simultaneously satisfies the constraints from the light curve, the orbital elements and the evolutionary tracks in the framework of the standard Roche lobe geometry. We suggest that this discrepancy may be resolved by taking into account the deformation of the Roche lobe caused by the force driving the large mass loss of the giant.

Smith, V. V.; Cunha, K.; Jorissen, A.; Boffin, H. M. J.

1997-08-01

441

SBN60, strontium-barium niobate at 100?K  

PubMed Central

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 SrxBa1 - xNb2O6. Below the Curie temperature, T c, these materials indicate ferroelectric properties. The Curie temperature for SBN60 is equal to 346±0.5?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). PMID:24098159

Stachowicz, Marcin; Gawryszewska, Olga; Swirkowicz, Marek A.; Lukasiewicz, Tadeusz

2013-01-01

442

The effect of zinc on the aluminum anode of the aluminum-air battery  

NASA Astrophysics Data System (ADS)

Aluminum is an ideal material for batteries, due to its excellent electrochemical performance. Herein, the effect of zinc on the aluminum anode of the aluminum-air battery, as an additive for aluminum alloy and electrolytes, has been studied. The results show that zinc can decrease the anodic polarization, restrain the hydrogen evolution and increase the anodic utilization rate.

Tang, Yougen; Lu, Lingbin; Roesky, Herbert W.; Wang, Laiwen; Huang, Baiyun

443

The effect of zinc on the aluminum anode of the aluminum–air battery  

Microsoft Academic Search

Aluminum is an ideal material for batteries, due to its excellent electrochemical performance. Herein, the effect of zinc on the aluminum anode of the aluminum–air battery, as an additive for aluminum alloy and electrolytes, has been studied. The results show that zinc can decrease the anodic polarization, restrain the hydrogen evolution and increase the anodic utilization rate.

Yougen Tang; Lingbin Lu; Herbert W. Roesky; Laiwen Wang; Baiyun Huang

2004-01-01

444

Epidemic aluminum intoxication in hemodialysis patients traced to use of an aluminum pump  

Microsoft Academic Search

Epidemic aluminum intoxication in hemodialysis patients traced to use of an aluminum pump. This study was designed to identify the source, risk factors, and clinical consequences of an outbreak of aluminum intoxication in hemodialysis patients using case-control and cohort studies. In 1991, a dialysis center in Pennsylvania [Dialysis Center A (DCA)] identified a number of patients with elevated serum aluminum

Dale R Burwen; Steven M Olsen; Lee A Bland; Matthew J Arduino; Marie H Reid; William R Jarvis

1995-01-01

445

THE SEPARATION AND DETERMINATION OF ALUMINUM IN PLUTONIUM-ALUMINUM ALLOYS  

Microsoft Academic Search

ABS>An anion-exchange method was given for the separation of aluminum ; from plutonium in a 1% aluminum-plutonium alloy. After separation, the aluminum ; is determined using oxine, either volumetrically or gravimetrically, or by a ; complexometric titration using EDTA. The volumetric methods are faster. On ; synthetic alloy samples containing 5.00 mg of aluminum and 500 mg of plutonium, ;

F. J. Miner; R. P. Degrazio; C. R. Jr. Forrey; T. C. Jones

1960-01-01

446

46 CFR 148.255 - Ferrosilicon, aluminum ferrosilicon, and aluminum silicon containing more than 30% but less than...  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Ferrosilicon, aluminum ferrosilicon, and aluminum silicon containing more than 30% but less than...Certain Materials § 148.255 Ferrosilicon, aluminum ferrosilicon, and aluminum silicon...

2012-10-01

447

40 CFR 180.1091 - Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a...  

Code of Federal Regulations, 2012 CFR

...25 2012-07-01 2012-07-01 false Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement... Exemptions From Tolerances § 180.1091 Aluminum isopropoxide and aluminum secondary...

2012-07-01

448

The phase composition of carbonized aluminum hydroxide  

Microsoft Academic Search

1.In the carbonization of aluminate solutions under conditions of pH 10–11.5 and 25–40°C, amorphous aluminum hydroxide precipitates.2.The gelatinous precipitates, which are products of aging of the amorphous aluminum hydroxide during the process of washing, are not any definite crystalline modification of aluminum hydroxide, but occupy an intermediate position between the amorphous and crystalline states. The molecules of aluminum hydroxide form

Ya. R. Katsobashvili; N. S. Kurkova; M. M. Getsiu

1969-01-01

449

Aluminum Compounds Used as Adjuvants in Vaccines  

Microsoft Academic Search

The structure of nine commercially manufactured aluminum-containing adjuvants was investigated by X-ray diffraction, infrared spectroscopy, transmission electron micrography, and energy dispersive spectrometry. Seven samples which were labeled as aluminum hydroxide were identified as boehmite, a crystalline aluminum oxyhydroxide [AIO(OH)]. However, the degree of crystallinity varied between the samples. Two samples which were labeled as aluminum phosphate were found to be

Suhag Shirodkar; Robert L. Hutchinson; Darold L. Perry; Joe L. White; Stanley L. Hem

1990-01-01

450

Mineral resource of the month: aluminum  

USGS Publications Warehouse

The article offers information on aluminum, a mineral resource which is described as the third-most abundant element in Earth's crust. According to the article, aluminum is the second-most used metal. Hans Christian Oersted, a Danish chemist, was the first to isolate aluminum in the laboratory. Aluminum is described as lightweight, corrosion-resistant and an excellent conductor of electricity and heat.

Bray, E. Lee

2012-01-01

451

Complexometric Determination of Calcium  

Microsoft Academic Search

\\u000a Ethylenediaminetetraacetate (EDTA) complexes with numerous mineral ions, including calcium and magnesium. This reaction can\\u000a be used to determine the amount of these minerals in a sample by a complexometric titration. Endpoints in the titration are\\u000a detected using indicators that change color when they complex with mineral ions. Calmagite and eriochrome black T (EBT) are\\u000a such indicators that change from blue

S. Suzanne Nielsen

2010-01-01

452

Calcium signaling in plants  

Microsoft Academic Search

.   Changes in the cytosolic concentration of calcium ions ([Ca2+]i) play a key second messenger role in signal transduction. These changes are visualized by making use of either Ca2+-sensitive fluorescent dyes or the Ca2+-sensitive photoprotein, aequorin. Here we describe the advances made over the last 10 years or so, which have conclusively\\u000a demonstrated a second messenger role for [Ca2+]i in

J. J. Rudd; V. E. Franklin-Tong

1999-01-01

453

Estimating Calcium Requirements  

Microsoft Academic Search

\\u000a Nutrient requirements are used by many groups to determine food choices and meal plans for feeding people across the lifespan.\\u000a They are used to evaluate sources of nutrients and for food labels to educate the consumer. Requirements also provide a guideline\\u000a to determine whether supplements are needed. If calcium requirements are underestimated, inadequate intakes are more likely,\\u000a which may compromise

Connie M. Weaver; Kathleen M. Hill

454

Blood aluminum levels as a function of aluminum intake from drinking water  

SciTech Connect

Questions regarding the health effects of aluminum are still unanswered. The speciation, pharmacokinetics, and toxicity of aluminum are not well understood. Furthermore, no animal or human studies of aluminum absorption have been reported using drinking water as the source of aluminum. The following experiment attempted to reach a better understanding of the bioavailability of aluminum from drinking water. Its objective was to determine whether or not increased aluminum ingestion from drinking water would be reflected in increased serum and whole blood aluminum levels in the baboon experimental model.

Turnquest, E.M.; Hallenbeck, W.H. (Univ. of Illinois, Chicago (United States))

1991-04-01

455

Aluminum-induced granulomas in a tattoo  

Microsoft Academic Search

A patient who developed localized, granulomatous reactions in a tattoo is described. With the use of scanning electron microscopy and energy dispersive x-ray microanalysis, both aluminum and titanium particles were found in the involved skin sections. Intradermal provocation testing with separate suspensions of aluminum and titanium induced a positive response only in the case of aluminum. Examination by scanning electron

N. McFadden; T. Lyberg; A. Hensten-Pettersen

1989-01-01

456

FRICTION AND WEAR OF ALUMINUM MATRIX COMPOSITES  

Microsoft Academic Search

Aluminum has some beneficial properties: low density, relatively low price, and corrosion resistance in many applications as well as availability in a large quantity. Mechanical properties of aluminum can be improved by alloying with metals as copper, magnesium, silicon etc. Soft metals as tin, lead, cadmium and silver alloyed in aluminum lower the friction and wear rate. At the same

Mihály Kozma

457

76 FR 23490 - Aluminum tris (O  

Federal Register 2010, 2011, 2012, 2013

...aluminum tris (O-ethylphosphonate) on pineapple fodder and forage because they are not...aluminum tris (O-ethylphosphonate) on pineapple fodder and forage because they are...aluminum tris (O-ethylphosphonate) on pineapple fodder and forage because they...

2011-04-27

458

Aluminum matrix composites and their superplasticity  

SciTech Connect

This paper introduces in simple terms manufacturing methods associated with aluminum matrix composite materials, superplasticity research as well as its applications, and probes structural faults during the manufacturing of aluminum matrix composite materials. In conjunction with this, it brings together a crossing of subjects to expound on trends in the development of research on aluminum matrix composite material superplasticity and its applications.

Tang, C.; Li, S.; Li, H.

1995-05-26

459

Fatigue crack propagation in aerospace aluminum alloys  

Microsoft Academic Search

This article reviews fracture mechanics-based, damage tolerant characterizations and predictions of fatigue crack growth in aerospace aluminum alloys. The results of laboratory experimentation and micromechanical modeling are summarized in the areas of 1) the wide range crack growth rate response of conventional aluminum alloys, 2) fatigue crack closure, 3) the fatigue behavior of advanced monolithic aluminum alloys and metal matrix

Richard P. Gangloff; Robert S. Piascik; Dennis L. Dicus; James C. Newman Jr.

1994-01-01

460

Design and Installation of Aluminum Conductor Systems  

Microsoft Academic Search

Fundamental similarities and differences between the two most widely used electrical conductor materials, copper and aluminum, are described, as well as how their differences must be taken into account in both design and installation. Detailed recommendations are given for aluminum bus and feeder conductor connections, as is information on a new group of aluminum conductor alloys, as well as new

Peter Pollak

1985-01-01

461

Aluminum in 2012 North American Light Vehicles  

NSDL National Science Digital Library

This study was carried out by Ducker Worldwide and funded by The Aluminum Association to evaluate the aluminum content in 2012 model year vehicles and the projected aluminum content growth through 2025. To gather data and form projections, Ducker surveyed original equipment manufactures (OEMs) and The Aluminum Association to create a metallic materials database with 32,000 cells per light vehicle. Using their database and other information from OEMs, Ducker concluded in the 2012 model year the average weight of aluminum on light vehicles will be approximately 348lbs, 30% of hoods will be aluminum, and 50% of cast aluminum wheels will be sourced from China. To meet corporate average fuel economy (CAFE) standards in 2025 Ducker speculates vehicle aluminum content will grow by 80% (671lbs avg. truck and 451lbs avg. for cars), milled aluminum components will increase, 50% of hoods will be aluminum, and manifolds will be made from magnesium rather than aluminum. Based on this studyâs conclusions, itâs clear that aluminum content in vehicles will continue to grow to meet CAFE standards by 2025. For more info on Ducker Worldwide, visit http://www.ducker.com/. Ducker has also performed studies for the Environmental Protection Agency (EPA) and the Department of Energy (DOE).

Association, The A.

462

Aluminum and bone disorders: with specific reference to aluminum contamination of infant nutrients.  

PubMed

Aluminum (Al) impairment of bone matrix formation and mineralization may be mediated by its direct effect on bone cells or indirectly by its effect on parathyroid hormone and calcium metabolism. Its toxic effects are proportional to tissue Al load. Al contamination of nutrients depends on the amount of Al present naturally in chemicals or from the manufacturing process. Intravenous calcium, phosphorus, and albumin solutions have high Al (greater than 500 micrograms/L), whereas crystalline amino acid, sterile water, and dextrose water have low Al (less than 50 micrograms/L) content. Enteral nutrients including human and whole cow milk have low Al, whereas highly processed infant formulas with multiple additives, such as soy formula, preterm infant formula, and formulas for specific disorders are heavily contaminated with Al. Healthy adults are in zero balance for Al. The gastrointestinal tract excludes greater than 95% of dietary Al, and kidney is the dominant organ for Al excretion. However, even with normal renal function, only 30-60% of an Al load from parenteral nutrition is excreted in the urine, resulting in tissue accumulation of Al. The risk for Al toxicity is greatest in infants with chronic renal insufficiency, recipients of long term parenteral nutrition, i.e., no gut barrier to Al loading, and preterm infants with low Al binding capacity. The rapid growth of the infant would theoretically potentiate Al toxicity in all infants, although the critical level of Al loading causing bone disorders is not known. To minimize tissue burden, Al content of infant nutrients should be similar to "background" levels, i.e., similar to whole milk (less than 50 micrograms/L). PMID:3292633

Koo, W W; Kaplan, L A

1988-06-01

463

Growth, Characterization and Applications of Beta-Barium Borate and Related Crystals.  

National Technical Information Service (NTIS)

Emphasis of our program during the past year has been on improving the size and quality of beta-barium borate (BBO) crystal, develop the growth recipe for lithium triborate crystal (LBO), characterization of LBO, develop BBO optical parametric oscillators...

C. L. Tang

1991-01-01

464

Barium Titanate Nanoparticles as Exogenous Contrast Agents in Second Harmonic Optical Coherence Tomography  

E-print Network

I propose and demonstrate a method by which barium titanate nanoparticle clusters can be used as exogenous contrast agents in Second Harmonic Optical Coherence Tomography imaging systems to localize and highlight desired regions of tissue. SH...

Pearson, Jeremy T

2013-05-06

465

Numberical simulation of the effects of radially injected barium plasma in the ionosphere  

NASA Technical Reports Server (NTRS)

The morphology of the ion cloud in the radial shaped charge barium injection was studied. The shape of the ion cloud that remains after the explosive products and neutral barium clears away was examined. The ion cloud which has the configuration of a rimless wagon wheel is shown. The major features are the 2.5 km radius black hole in the center of the cloud, the surrounding ring of barium ion and the spokes of barium ionization radiating away from the center. The cloud shows no evolution after it emerges from the neutral debris and it is concluded that it is formed within 5 seconds of the event. A numerical model is used to calculate the motion of ions and electrons subject to the electrostatic and lorenz forces.

Swift, D. W.

1985-01-01

466

Expression of N-type calcium channels in human adrenocortical cells and their contribution to corticosteroid synthesis.  

PubMed

The inhibition of aldosterone activity is a useful approach for preventing the progression of cardiovascular and renal diseases in hypertensive patients. Although the results of our previous in vivo study suggested that N-type calcium channels may have a role in regulating plasma aldosterone levels, the direct relationship between N-type calcium channels and aldosterone production in adrenocortical cells has not been examined. In this study, the analysis of quantitative reverse transcription-PCR, western blotting, and immunocytological staining indicated the possible presence of N-type calcium channels in human adrenocortical cells (H295R cell line). Patch clamp analysis indicated that omega-conotoxin GVIA (CnTX), an N-type calcium channel inhibitor, suppressed voltage-dependent barium currents. During steroidogenesis, CnTX significantly reduced the transient calcium signaling induced by angiotensin II (Ang II) and partially prevented Ang II-induced aldosterone and cortisol formation with no significant influence on CYP11B2 and CYP11B1 mRNA expression. In addition, in ?1B calcium channel subunits, knockdown significantly decreased Ang II-induced aldosterone formation with increments in CYP11B2 mRNA expression. We also investigated the inhibitory activities of some types of dihydropyridine calcium channel blockers (CCBs; cilnidipine: L-/N-type CCB, efonidipine: L-/T-type CCB, and nifedipine: L-type CCB), and these agents showed a dose-dependent inhibition effect on Ang II-induced aldosterone and cortisol production. Furthermore, only cilnidipine failed to suppress CYP11B1 expression in H295R cells. These results suggest that N-type calcium channels have a significant role in transducing the Ang II signal for aldosterone (and cortisol) biosynthesis, which may explain the mechanism by which N-type calcium channels regulate plasma aldosterone levels. PMID:20981032

Aritomi, Shizuka; Wagatsuma, Hirotaka; Numata, Tomohiro; Uriu, Yoshitsugu; Nogi, Yasuko; Mitsui, Akira; Konda, Tomoyuki; Mori, Yasuo; Yoshimura, Michihiro

2011-02-01

467

Recovering aluminum from aluminum dross in a DC electric-arc rotary furnace  

NASA Astrophysics Data System (ADS)

The recycling of aluminum scrap and dross yields significant economic and energy savings, as well environmental benefits. The recovery of aluminum depends on many factors. The aim of this work is to experimentally investigate aluminum recovery under different conditions. In this study, aluminum dross was processed in a direct-current electric-arc rotary furnace. The presence of crushing refractory bodies during processing was found to increase the degree of aluminum recovery by about ten percent.

Tzonev, Tz.; Lucheva, B.

2007-11-01

468

Aluminum-air battery development  

NASA Astrophysics Data System (ADS)

This paper presents the results of investigations of the performance of aluminum-air battery electrodes. Different electrodes were built and tested, and their performance measured. The authors conclude that the present component development has been successful, and that future research be aimed at system integration.

1987-11-01

469

Molecular Structure of Aluminum bromide  

NSDL National Science Digital Library

Aluminum bromide is hygroscopic and appears as white to yellow-red lumps. It is corrosive and causes severe burns. It should be stored in a cool, dry and well ventilated place. AlBr3 reacts violently with water and evolves HBr, and also reacts quickly with alcohols and acids.

2002-10-09

470

Generation of sub-100-fs Stokes pulses upon SRS in a barium nitrate crystal  

NASA Astrophysics Data System (ADS)

72-fs pulses are generated at the first Stokes component frequency upon stimulated Raman scattering in a barium nitrate crystal for the radiation of the Ti3+:Al2O3 laser with the pulse duration of 50 fs. The energy efficiency of conversion is 20%. The barium nitrate crystal was optically pumped by two consecutive orthogonally polarised chirped pulses with the following time compression of the Stokes radiation pulse.

Konyashchenko, Aleksandr V.; Losev, Leonid L.; Tenyakov, S. Yu

2010-10-01

471

Calculations of energy levels and lifetimes of low-lying states of barium and radium  

Microsoft Academic Search

We use the configuration-interaction method and many-body perturbation theory to perform accurate calculations of energy levels, transition amplitudes, and lifetimes of low-lying states of barium and radium. Calculations for radium are needed for the planning of measurements of parity- and time-invariance-violating effects which are strongly enhanced in this atom. Calculations for barium are used to control the accuracy of the

V. A. Dzuba; J. S. M. Ginges

2006-01-01

472

Calculations of energy levels and lifetimes of low-lying states of barium and radium  

Microsoft Academic Search

We use the configuration interaction method and many-body perturbation theory\\u000ato perform accurate calculations of energy levels, transition amplitudes, and\\u000alifetimes of low-lying states of barium and radium. Calculations for radium are\\u000aneeded for the planning of measurements of parity and time invariance violating\\u000aeffects which are strongly enhanced in this atom. Calculations for barium are\\u000aused to control the

V. A. Dzuba; J. S. M. Ginges

2006-01-01

473

Calculations of energy levels and lifetimes of low-lying states of barium and radium  

E-print Network

We use the configuration interaction method and many-body perturbation theory to perform accurate calculations of energy levels, transition amplitudes, and lifetimes of low-lying states of barium and radium. Calculations for radium are needed for the planning of measurements of parity and time invariance violating effects which are strongly enhanced in this atom. Calculations for barium are used to control the accuracy of the calculations.

Dzuba, V A

2006-01-01

474

VizieR Online Data Catalog: Chemical abundances in barium stars (Boyarchuk+, 2002)  

NASA Astrophysics Data System (ADS)

We used high-resolution spectra to compute model atmospheres to derive the atmospheric abundances of moderate barium stars. Comparing our results with analogous data for normal red giants, we find that the moderate barium stars appear to not differ systematically from normal red giants. Their chemical abundance anomalies show the same patterns and can be interpreted in terms of evolutionary effects: the evolutionary stage, mass, luminosity, and metallicity of the objects. (1 data file).

Boyarchuk, A. A.; Pakhomov, Yu. V.; Antipova, L. I.; Boyarchuk, M. E.

2003-03-01

475

Preparation and characterization of barium stannate: application as a liquefied petroleum gas sensor†  

Microsoft Academic Search

Barium stannate, BaSnO3, an n-type semiconducting oxide with cubic perovskite structure, has been prepared by the thermal decomposition of barium carbonate (BaCO3) and tin tetrahydroxide (Sn(OH)4). The material was characterized by various physical techniques such as differential thermal analysis (DTA\\/TG), X-ray diffraction (XRD), BET surface area, Fourier transform infra-red (FT-IR) spectroscopy and scanning electron microscopy (SEM). Of its several applications,

C. V. Gopal reddy; S. V. Manorama; V. J. Rao

2001-01-01

476

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

NASA Astrophysics Data System (ADS)

Carbon and chromite fractions from the Allende meteorite that contain isotopically anomalous xenon-131 to xenon-136 (carbonaceous chondrite fission or CCF xenon) at up to 5×1011 atoms per gram show no detectable isotopic anomalies in barium-130 to barium-138. This rules out the possibility that the CCF xenon was formed by in situ fission of an extinct superheavy element. Apparently the CCF xenon and its carbonaceous carrier are relics from stellar nucleosynthesis.

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

1983-12-01

477

Generation of sub-100-fs Stokes pulses upon SRS in a barium nitrate crystal  

SciTech Connect

72-fs pulses are generated at the first Stokes component frequency upon stimulated Raman scattering in a barium nitrate crystal for the radiation of the Ti{sup 3+}:Al{sub 2}O{sub 3} laser with the pulse duration of 50 fs. The energy efficiency of conversion is 20%. The barium nitrate crystal was optically pumped by two consecutive orthogonally polarised chirped pulses with the following time compression of the Stokes radiation pulse. (nonlinear optical phenomena)

Konyashchenko, Aleksandr V; Losev, Leonid L [P N Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation); Tenyakov, S Yu ['Avesta-project' Ltd., Troitsk, Moscow Region (Russian Federation)

2010-10-15

478

Removal of carbon dioxide by reactive crystallization in a scrubber—kinetics of barium carbonate crystals  

Microsoft Academic Search

A bubble column scrubber was utilized to remove simulated CO2 waste gas under a constant pH value. Using barium chloride solution as an absorbent reacting with CO2-gas in the scrubber under an alkaline solution condition, precipitates of barium carbonate were formed during the operation. Measured crystal size distributions at a given time were used to calculate the growth rate of

Pao-Chi Chen; K. L. Kou; H. K. Tai; S. L. Jin; C. L. Lye; C. Y. Lin

2002-01-01

479

Routine barium enema prior to closure of defunctioning ileostomy is not necessary  

PubMed Central

Purpose The use of barium enemas to confirm the anastomotic integrity prior to ileostomy closure is still controversial. The purpose of the study was to determine the utility of routine contrast enema prior to ileostomy closure and its impact on patient management in patients with a low pelvic anastomosis. Methods One hundred forty-five patients had a temporary loop ileostomy constructed to protect a low colorectal or coloanal anastomosis following low anterior resection for rectal cancer. All patients were evaluated by physical examination, proctoscopy, and barium enema prior to ileostomy closure. Results The median time from ileostomy creation to closure was 8 months. Five (3.5%) of the 144 patients were found to have clinically relevant strictures at the colorectal anastomosis on routine barium enema. One patient (0.7%) showed anastomotic leak on their barium enema. Overall, 141 patients (97.9%) had an uncomplicated postoperative course. Postoperative complication occurred in three patients (2.1%). None of them showed abnormal barium enema finding, which suggested that routine contrast enema examination did not predict postoperative complication. Conclusion Routine barium enema evaluation of low pelvic anastomoses before loop ileostomy closure did not provide any additional information for postoperative colorectal anastomotic complication. PMID:22880182

Hong, Sung Yeon; Kim, Do Yun; Suh, Kwang Wook

2012-01-01

480

[Calcium--essential for everybody].  

PubMed

Calcium regulates majority of metabolic processes within human organism and its optimal intake decreases risk of metabolic illnesses conditioned by diet. Deficiency of calcium results in higher body max index, increase risk of insulin resistance, diabetes type 2 and osteoporosis. Diet delivering full calcium load diminished impendency of hypertension; calcium regulates tension of smooth muscles of blood vessels, limits neurotransmitters activity and also diminish hazardous activity of sodium chloride. Anticancerogenic activity of calcium results from formation insoluble bile acids and fat acids salts, and most of all, from inhibition of intestine mucosa cells hyper proliferation. Due to presence of vitamin D3, CLA, proteins and bioactive peptides emerging from them, milk is more efficient in prophylaxis of diet conditioned illnesses than calcium supplements. Efficiency of milk and dairy products in treatment of obesity, sclerosis and hypertension has been proved by DASH diet. PMID:25095643

Cichosz, Grazyna; Czeczot, Hanna

2014-06-01