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Sample records for alkali substitutes technical

  1. 40 CFR 721.5278 - Substituted naphthalenesulfonic acid, alkali salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkali salt. 721.5278 Section 721.5278 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5278 Substituted naphthalenesulfonic acid, alkali salt. (a) Chemical... as a substituted naphthalenesulfonic acid, alkali salt (PMN P-95-85) is subject to reporting...

  2. 40 CFR 721.8900 - Substituted halogenated pyridinol, alkali salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkali salt. 721.8900 Section 721.8900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.8900 Substituted halogenated pyridinol, alkali salt. (a) Chemical... as substituted halogenated pyridinols, alkali salts (PMNs P-88-1271 and P-88-1272) are subject...

  3. 40 CFR 721.5278 - Substituted naphthalenesulfonic acid, alkali salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., alkali salt. 721.5278 Section 721.5278 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5278 Substituted naphthalenesulfonic acid, alkali salt. (a) Chemical... as a substituted naphthalenesulfonic acid, alkali salt (PMN P-95-85) is subject to reporting...

  4. 40 CFR 721.8900 - Substituted halogenated pyridinol, alkali salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkali salt. 721.8900 Section 721.8900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.8900 Substituted halogenated pyridinol, alkali salt. (a) Chemical... as substituted halogenated pyridinols, alkali salts (PMNs P-88-1271 and P-88-1272) are subject...

  5. 40 CFR 721.5278 - Substituted naphthalenesulfonic acid, alkali salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkali salt. 721.5278 Section 721.5278 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5278 Substituted naphthalenesulfonic acid, alkali salt. (a) Chemical... as a substituted naphthalenesulfonic acid, alkali salt (PMN P-95-85) is subject to reporting...

  6. 40 CFR 721.5278 - Substituted naphthalenesulfonic acid, alkali salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkali salt. 721.5278 Section 721.5278 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5278 Substituted naphthalenesulfonic acid, alkali salt. (a) Chemical... as a substituted naphthalenesulfonic acid, alkali salt (PMN P-95-85) is subject to reporting...

  7. 40 CFR 721.5278 - Substituted naphthalenesulfonic acid, alkali salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkali salt. 721.5278 Section 721.5278 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5278 Substituted naphthalenesulfonic acid, alkali salt. (a) Chemical... as a substituted naphthalenesulfonic acid, alkali salt (PMN P-95-85) is subject to reporting...

  8. 40 CFR 721.8900 - Substituted halogenated pyridinol, alkali salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkali salt. 721.8900 Section 721.8900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.8900 Substituted halogenated pyridinol, alkali salt. (a) Chemical..., chemical destruction and carbon adsorption. (iv) Release to water. Requirements as specified in § 721.90...

  9. 40 CFR 721.8900 - Substituted halogenated pyridinol, alkali salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted halogenated pyridinol, alkali salt. 721.8900 Section 721.8900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances §...

  10. Theoretical investigations on the stability of alkali metal substituted phenylpentazole.

    PubMed

    Zhang, Xueli; Gong, Xuedong

    2016-05-01

    The alkali metal (M=Li, Na, and K) para-substituted (M-1), meta-substituted (M-2) or ortho-substituted (M-3) derivatives of phenylpentazole (PhN5) were studied using density functional theory. The substituted metals improve the energy barrier for decomposition of the N5 ring of PhN5 by 19.3 ∼ 65.0 kJ/mol. M-3 has the ionic N-M bond, which is not found for M-1 and M-2. M-1 and M-2 have similar electrostatic potentials and dispersion interactions between metal and N5 ring. The comparable intramolecular interactions of M-1 and M-2 lead to similar N5 ring stability. Compared to M-1 and M-2, M-3 has a more negative charge on N5 ring and stronger dispersion interaction. The stronger intramolecular interactions of M-3 result in the higher N5 ring stability. For M-1 and M-2, different metals have slight affects on N5 ring stability. For M-3, N5 ring stability decreases in the order of Li > Na > K. The substituted metal lowers E g of PhN5. PMID:27083566

  11. Substitution mechanism of alkali metals for strontium in strontium hydroxyapatite

    SciTech Connect

    Naddari, Thouraya; Hamdi, Besma; Savariault, Jean Michel; El Feki, Hafed; Ben Salah, Abdelhamid

    2003-01-25

    Strontium hydroxyapatites substituted by alkali metals are synthesized by double decomposition method in basic medium. Structures of Sr{sub 9.50}Na{sub 0.30}(PO{sub 4}){sub 6}(OH){sub 1.30} (SrNaHAp) and Sr{sub 9.81}K{sub 0.12}(PO{sub 4}){sub 6}(OH){sub 1.74} (SrKHAp) are determined by X-ray powder diffraction. Both compounds are isotypic and crystallize in hexagonal system (space group P63/m) with the following cells: a=9.751(3) A and c=7.279(3) A for SrNaHAp and a=9.755(4) A and c=7.284(3) A for SrKHAp. Results are compared to those of Sr{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}. According to the site occupancy factors, in SrNaHAp sodium is localized in site (I) and in SrKHAp potassium in site (II). Both structures contain vacancies in hydroxyl and metal sites. The mechanism of alkali metals substitution for strontium proposed explains the vacancies formation.

  12. Heterovalent substitutions in garnet and their implications for diffusion of Y+REEs and alkalis (Invited)

    NASA Astrophysics Data System (ADS)

    Carlson, W. D.; Gale, J. D.; Wright, K.

    2013-12-01

    Lattice-dynamics calculations in the static limit suggest that large trivalent ions (Y+REEs) are incorporated into garnet primarily by means of substitutions that introduce menzerite and alkali components. The diffusion mechanisms implied by this finding explain otherwise puzzling aspects of recent determinations of diffusion rates for Y+REEs and Li in natural systems, bolstering confidence in the validity of those rates. Several substitution schemes have been proposed to provide the charge-balance required for incorporation of trivalent Y+REEs substituting for divalent cations in dodecahedral sites in aluminosilicate garnet: (1) YAG components, with tetrahedral Al; (2) vacancy components, with one unoccupied dodecahedral site for each two trivalent ions; (3) alkali components, with dodecahedral Na or Li; (4) menzerite components, with octahedral Mg or Fe; and (5) Y2Li components, with octahedral Li compensating for a pair of Y+REE ions. The relative energetic costs of these substitutions were evaluated in pyrope, almandine, spessartine and grossular by means of lattice-dynamics calculations at T = 0 K and P = 0 GPa, using well-established force-field potentials, and referencing exchange energies to the lattice energies of binary oxides as sources/sinks for the exchanged ions. Energies calculated for the incorporation of menzerite and alkali components are appreciably lower than those for the YAG component, and very substantially lower than those for the other components. Provided that the relative energetic costs are similar at elevated T and P to those in the static limit (testing of this assumption is currently underway), the menzerite and alkali substitutions should predominate in natural aluminosilicate garnets, the YAG substitution should play only a subordinate role, and the other substitutions should be near-negligible. As a result, diffusion mechanisms for Y+REEs in garnet require that motion of these elements must be coupled to transport of either

  13. A novel alkali metals/strontium co-substituted calcium polyphosphate scaffolds in bone tissue engineering.

    PubMed

    Song, Wei; Wang, Qiguang; Wan, Changxiu; Shi, Tong; Markel, David; Blaiser, Ralph; Ren, Weiping

    2011-08-01

    Our purpose of this study is to develop potassium or sodium/strontium co-substituted calcium polyphosphate (K/Sr-CPP or Na/Sr-CPP) bioceramics in application of bone repairing scaffold. The incorporation of K, Na, and Sr into CPP substrate via a calcining-sintering process was confirmed by X-ray diffractometry and inductively coupled plasma atomic emission spectroscopy. In vitro degradation study of co-substituted CPP indicated the incorporation of alkali metal elements promoted the degradability of CPP, and the scanning electron microscope showed the apatite-like minerals were precipitated on the surface of co-substituted CPP. The compress resistant strength of co-substituted CPP was elevated by dopants. The MTT assay and confocal laser-scanning microscope on osteoblasts culturing with co-substituted CPP showed no cytotoxicity. The cell proliferation on co-substituted CPP was even better than others. Thus, this co-substituted CPP bioceramics might have potential of applications in orthopedic field. PMID:21732528

  14. Ca(2+) function in photosynthetic oxygen evolution studied by alkali metal cations substitution.

    PubMed

    Ono, T; Rompel, A; Mino, H; Chiba, N

    2001-10-01

    Effects of adding monovalent alkali metal cations to Ca(2+)-depleted photosystem (PS)II membranes on the biochemical and spectroscopic properties of the oxygen-evolving complex were studied. The Ca(2+)-dependent oxygen evolution was competitively inhibited by K(+), Rb(+), and Cs(+), the ionic radii of which are larger than the radius of Ca(2+) but not inhibited significantly by Li(+) and Na(+), the ionic radii of which are smaller than that of Ca(2+). Ca(2+)-depleted membranes without metal cation supplementation showed normal S(2) multiline electron paramagnetic resonance (EPR) signal and an S(2)Q(A)(-) thermoluminescence (TL) band with a normal peak temperature after illumination under conditions for single turnover of PSII. Membranes supplemented with Li(+) or Na(+) showed properties similar to those of the Ca(2+)-depleted membranes, except for a small difference in the TL peak temperatures. The peak temperature of the TL band of membranes supplemented with K(+), Rb(+), or Cs(+) was elevated to approximately 38 degrees C which coincided with that of Y(D)(+)Q(A)(-) TL band, and no S(2) EPR signals were detected. The K(+)-induced high-temperature TL band and the S(2)Q(A)(-) TL band were interconvertible by the addition of K(+) or Ca(2+) in the dark. Both the Ca(2+)-depleted and the K(+)-substituted membranes showed the narrow EPR signal corresponding to the S(2)Y(Z)(+) state at g = 2 by illuminating the membranes under multiple turnover conditions. These results indicate that the ionic radii of the cations occupying Ca(2+)-binding site crucially affect the properties of the manganese cluster. PMID:11566758

  15. TECHNICAL REPORT FOR THE ALKALI LAKE ECOLOGICAL ASSESSMENT - PHASE I RECONNAISSANCE

    EPA Science Inventory

    This report summarizes the results of three field survey trips (June and September 1991, May 1992) taken to investigate the ecological effects associated with the release of over a million gallons of hazardous waste from herbicide production on the Alkali Lake playa. ampling of s...

  16. Technical report for the alkali lake ecological assessment, phase 1 reconnaissance (FY 91 and FY 92)

    SciTech Connect

    Linder, G.

    1993-03-01

    The report summarizes the results of three field survey trips (June and September 1991, May 1992) taken to investigate the ecological effects associated with the release of over a million gallons of hazardous waste from herbicide production on the Alkali Lake playa. Sampling of soil, sediment, groundwater, soil-dwelling invertebrates and vegetation confirmed that hazardous materials from the waste disposal area are migrating westerly within the shallow aquifer to West Alkali Lake. Two areas of dead vegetation were identified and permanently marked to determine if these areas are changing in size and location. Preliminary calculations using a linear food-chain model suggested that small mammalian herbivores would probably not display adverse effects due to dietary exposures to the contaminants. However, nestling shorebirds may be exposed to concentrations potentially associated with adverse biological effects.

  17. Alkali metal ionization detector

    DOEpatents

    Bauerle, James E.; Reed, William H.; Berkey, Edgar

    1978-01-01

    Variations in the conventional filament and collector electrodes of an alkali metal ionization detector, including the substitution of helical electrode configurations for either the conventional wire filament or flat plate collector; or, the substitution of a plurality of discrete filament electrodes providing an in situ capability for transferring from an operationally defective filament electrode to a previously unused filament electrode without removing the alkali metal ionization detector from the monitored environment. In particular, the helical collector arrangement which is coaxially disposed about the filament electrode, i.e. the thermal ionizer, provides an improved collection of positive ions developed by the filament electrode. The helical filament design, on the other hand, provides the advantage of an increased surface area for ionization of alkali metal-bearing species in a monitored gas environment as well as providing a relatively strong electric field for collecting the ions at the collector electrode about which the helical filament electrode is coaxially positioned. Alternatively, both the filament and collector electrodes can be helical. Furthermore, the operation of the conventional alkali metal ionization detector as a leak detector can be simplified as to cost and complexity, by operating the detector at a reduced collector potential while maintaining the sensitivity of the alkali metal ionization detector adequate for the relatively low concentration of alkali vapor and aerosol typically encountered in leak detection applications.

  18. Use of fluidized bed combustion by-products for liners and alkali substitutes. Technical report, March 1--May 31, 1995

    SciTech Connect

    Paul, B.C.; Esling, S.; Pisani, F.; Wells, T.

    1995-12-31

    Fluidized Bed Combustion of coal eliminates most emissions of S and N oxides but produces sizable volumes of a solid residue that EPA may require to be placed in capped and lined landfills. Fluidized Bed Combustors are one of the most promising growth markets for Illinois coal and imposing cap and liner requirements may make the technology uneconomic. Fluidized Bed residues are cementlike and when mixed with soil, produce a material as impermeable as the clay liners used at landfills. This project will demonstrate that the residues can be mixed with soils by regular construction equipment and used in place of clays as liner material. The demonstration cap will cover an area of 7 acres and will prevent water infiltration into acid producing material. Baseline studies of Briar Creek indicate that the water is now highly degraded by acid drainage. Construction delays have enhanced the data collected on Briar Creek by allowing monitoring to continue through major seasonal changes without any effects attributable to the FBC ash. Materials needed to place the wells and lysimeters have been obtained. A contractor will build and deliver a mobile foam generator and spray to the field to demonstrate fugitive dust control from FBC fly ash (dust problem is one key barrier to more widespread use of FBC ash).

  19. Simultaneous high-temperature removal of alkali and particulates in a pressurized gasification system. Final technical progress report, April 1981-July 1983

    SciTech Connect

    Mulik, P.R.; Alvin, M.A.; Bachovchin, D.M.

    1983-09-01

    This program is directed at performing experimental and analytical investigations, deriving system designs, and estimating costs to ascertain the feasibility of using aluminosilicate-based getters for controlling alkali in pressurized gasification systems. Its overall objective is to develop a plan for evaluating a scaled-up version of the gettering process as a unit operation or as an integral part of a particulate removal device. This report describes work completed on the four technical program tasks: Thermodynamic projections; Getter Selection and Qualification; System Performance Projections; and Program Definition for Concept Scale-up during the 27-month contract performance period. Work completed on the thermodynamic projections includes a data base update, development of alkali phase diagrams, and system performance projections. Getter selection and qualification efforts involved over 70 kinetic studies in which a leading candidate getter - emathlite - was selected and characterized. System performance projections identified a packed-bed configuration containing relatively large getter pellets as the preferred contacting device for a full-scale unit. For emathlite, we concluded that full-scale unit bed heights of 2 m or less would be required if we assume annual replacement on the basis of bed saturation capacity. Concept scale-up work involved defining the hardware and test program requirements for further development of the emathlite packed-bed system. 56 references, 80 figures, 74 tables.

  20. Desulfurization of Illinois coals with hydroperoxides of vegetable oils and alkali. Technical report, September 1--November 30, 1995

    SciTech Connect

    Smith, G.V.; Gaston, R.D.; Song, R.; Cheng, J.; Shi, F.; Wang, Y.

    1995-12-31

    Organic sulfur is removed from coals by treatment with aqueous base, air, and vegetable oils with minimal loss of BTU. Such results were revealed during exploratory experiments on an ICCI funded project to remove organic sulfur from Illinois coals with hydroperoxides of vegetable oils. In fact, prewashing IBC-108 coal with dilute alkali prior to treating with linseed oil and air results in 26% removal of sulfur. This new method will be investigated by treating coals with alkali, impregnating coals with polyunsaturated oils, converting the oils to their hydroperoxides, and heating. Since these oils are relatively inexpensive and easily applied, this project could lead to a cost effective method for removing organic sulfur from coals. Moreover the oils are environmentally safe; they will produce no noxious products and will improve burning qualities of the solid products. During this first quarter the selection of base for pretreatment and extraction (Task 1) has been completed. NaOH is better than NH{sub 4}OH for the pretreatment and Na{sub 2}CO{sub 3} is better than NaOH for the oil extraction. About 40% of sulfur is removed from IBC-108 coal using 5% NaOH for pretreatment followed by linseed oil oxidation in air and Na{sub 2}CO{sub 3} extraction.

  1. Materials compatibility and lubricants research on CFC-refrigerant substitutes. Technical progress report, 1 April 1995--30 June 1995

    SciTech Connect

    Szymurski, S.R.; Hourahan, G.C.; Godwin, D.S.; Amrane, K.

    1995-08-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory Committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. The AirConditioning and Refrigeration Technology Institute, Inc., (ARTI) manages and contracts multiple research projects and a data collection and dissemination effort. Detailed results from these projects are reported in technical reports prepared by each subcontractor.

  2. Complexation of Donor-Acceptor Substituted Aza-Crowns with Alkali and Alkaline Earth Metal Cations. Charge Transfer and Recoordination in Excited State.

    PubMed

    Volchkov, Valery V; Gostev, Fedor E; Shelaev, Ivan V; Nadtochenko, Viktor A; Dmitrieva, Svetlana N; Gromov, Sergey P; Alfimov, Mikhail V; Melnikov, Mikhail Ya

    2016-03-01

    Complexation between two aza-15-crown-5 ethers bearing electron donor and acceptor fragments and alkali and alkaline earth perchlorates has been studied using absorption, steady-state fluorescence and femtosecond transient absorption spectroscopy. The spectral-luminescent parameters, the stability and dissociation constants of the complexes were calculated. The intramolecular charge transfer reaction takes place both in the excited state of the crowns and their complexes 1:1; the latter is subjected to photorecoordination resulting in a weakening or a complete disruption of coordination bond between nitrogen atom and metal cation, disposed within a cavity of the crown. The compounds investigated can be viewed as novel optical molecular sensors for alkali and alkaline-earth metal cations. The photoejection of a metal cation into the bulk was not observed. PMID:26670689

  3. Alkali Bee

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The alkali bee, Nomia melanderi, is native to deserts and semi-arid desert basins of the western United States. It is a very effective and manageable pollinator for the production of seed in alfalfa (=lucerne) and some other crops, such as onion. It is the world’s only intensively managed ground-n...

  4. Substitutes for ozone depleting aerosol electrical contact cleaners and cleaner/lubricants. Technical report

    SciTech Connect

    Bevilacqua, P.; Clark, K.G.

    1996-01-24

    With the production of Class I Ozone Depleting Substances discontinued as of January 1996, it became necessary to identify suitable replacements for chlorofluorocarbon (CFC-113) and trichloroethane (TCA) based electrical contact cleaners and cleaner/lubricant products. Two hydrochlorofluorocarbon (HCFC-141b) blends were identified as substitutes and recommended for interim use.

  5. Influence of ZnO/MgO substitution on sintering, crystallisation, and bio-activity of alkali-free glass-ceramics.

    PubMed

    Kapoor, Saurabh; Goel, Ashutosh; Correia, Ana Filipa; Pascual, Maria J; Lee, Hye-Young; Kim, Hae-Won; Ferreira, José M F

    2015-08-01

    The present study reports on the influence of partial replacement of MgO by ZnO on the structure, crystallisation behaviour and bioactivity of alkali-free bioactive glass-ceramics (GCs). A series of glass compositions (mol%): 36.07 CaO-(19.24-x) MgO-x ZnO-5.61 P2O5-38.49 SiO2-0.59 CaF2 (x=2-10) have been synthesised by melt-quench technique. The structural changes were investigated by solid-state magic angle spinning nuclear magnetic resonance (MAS-NMR), X-ray diffraction and differential thermal analysis. The sintering and crystallisation behaviours of glass powders were studied by hot-stage microscopy and differential thermal analysis, respectively. All the glass compositions exhibited good densification ability resulting in well sintered and mechanically strong GCs. The crystallisation and mechanical behaviour were studied under non-isothermal heating conditions at 850 °C for 1h. Diopside was the primary crystalline phase in all the GCs followed by fluorapatite and rankinite as secondary phases. Another phase named petedunnite was identified in GCs with ZnO content >4 mol. The proliferation of mesenchymal stem cells (MSCs) and their alkaline phosphatase activity (ALP) on GCs was revealed to be Zn-dose dependent with the highest performance being observed for 4 mol% ZnO. PMID:26042713

  6. IDENTIFICATION OF TOXIC IMPURITIES IN TECHNICAL GRADES OF PESTICIDES DESIGNATED AS SUBSTITUTE CHEMICALS

    EPA Science Inventory

    Two different approaches were used to identify potentially harmful impurities present in technical grade pesticides. One approach was a theoretical approach that involved a literature search, study the manufacturing processes, identifying the main reactions and the numerous side ...

  7. Oxidation of substituted phenols in supercritical water. Final technical report, September 1992--August 1996

    SciTech Connect

    Savage, P.E.

    1996-11-01

    Wastewaters from coal-conversion processes contain phenolic compounds in appreciable concentrations. These compounds need to be removed so that the water can be discharged or reused. Oxidation in supercritical water is one potential means of treating coal-conversion wastewaters, and this project examined the reactions of model pollutants in supercritical water. The decomposition of cresols, hydroxybenzaidehydes, nitrophenols, and benzenediols was studied in dilute aqueous solutions in both the presence and absence of oxygen at 460{degrees}C and 250 atm. Experimental data from the oxidation of these compounds were fit to global, power-law rate expressions. The resulting rate laws showed that the reactivity of the different isomers at 460{degrees}C was in the order of ortho > para > meta for cresols and hydroxybenzaldehydes. Moreover, the CHO-substituted phenol was more reactive than the analogous CH{sub 3}-substituted phenol, and all of these substituted phenols were more reactive than phenol itself. Identifying and quantifying the reaction products of incomplete oxidation allowed us to assemble a general reaction network for the oxidation of cresols in supercritical water. This network comprises parallel primary paths to phenol, to a hydroxybenzaldehyde, and to ring-opening products. The hydroxybenzaldehyde reacts through parallel paths to phenol and to ring-opening products. Phenol also reacts via two parallel paths, but these lead to phenol dimers; and ring-opening products. The dimers are eventually converted to ring-opening products, and the ring-opening products are ultimately converted to CO{sub 2} The relative rates of the different paths in the reaction network are strong functions of the location of the substituent on the phenolic ring.

  8. Simultaneous high-temperature removal of alkali and particulates in a pressurized gasification system. Final technical progress report, October 1978-October 1980

    SciTech Connect

    Mulik, P.R.; Ciliberti, D.F.; Alvin, M.A.; Ahmed, M.M.; Bachovchin, D.M.; Keairns, D.L.

    1981-02-01

    This final project report summarizes the results of extensive thermodynamic and preliminary experimental studies that have identified the use of aluminosilicate materials for simultaneously removing volatile alkali and particulate released during pressurized gasification of coal. The gettering capacity of three selected materials has been evaluated in a bench-scale reactor operating at 1114 kPa total pressure and 1123 to 1173 K in alkali-laden inert and simulated fuel gas environments. At 1123 K alkali gettering results through insoluble complexes, while at 1173 K saturation of the insoluble complex is completed, with gettering occurring mainly through soluble complexes. The gettering mechanism will be delineated through future thermogravimetric studies in a proposed program extension.

  9. Alkali metal nitrate purification

    DOEpatents

    Fiorucci, Louis C.; Morgan, Michael J.

    1986-02-04

    A process is disclosed for removing contaminants from impure alkali metal nitrates containing them. The process comprises heating the impure alkali metal nitrates in solution form or molten form at a temperature and for a time sufficient to effect precipitation of solid impurities and separating the solid impurities from the resulting purified alkali metal nitrates. The resulting purified alkali metal nitrates in solution form may be heated to evaporate water therefrom to produce purified molten alkali metal nitrates suitable for use as a heat transfer medium. If desired, the purified molten form may be granulated and cooled to form discrete solid particles of purified alkali metal nitrates.

  10. Milk-alkali syndrome

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/000332.htm Milk-alkali syndrome To use the sharing features on this page, please enable JavaScript. Milk-alkali syndrome is a condition in which there ...

  11. Increasing Class C fly ash reduces alkali silica reactivity

    SciTech Connect

    Hicks, J.K.

    2007-07-01

    Contrary to earlier studies, it has been found that incremental additions of Class C fly ash do reduce alkali silica reactivity (ASR), in highly reactive, high alkali concrete mixes. AST can be further reduced by substituting 5% metakaolin or silica fume for the aggregate in concrete mixes with high (more than 30%) Class C fly ash substitution. The paper reports results of studies using Class C fly ash from the Labadie Station plant in Missouri which typically has between 1.3 and 1.45% available alkalis by ASTM C311. 7 figs.

  12. Materials Compatibility and Lubricants Research on CFC-refrigerant substitutes. Quarterly technical progress report, 1 July 1993--30 September 1993

    SciTech Connect

    Szymurski, S.R.; Hourahan, G.C.; Godwin, D.S.

    1993-10-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory Committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. The Air-Conditioning and Refrigeration Technology Institute, Inc., (ARTI) manages and contracts multiple research projects and a data collection and dissemination effort. Detailed results from these projects are reported in technical reports prepared by each subcontractor.

  13. Materials Compatibility and Lubricants Research on CFC-refrigerant substitutes; Quarterly MCLR program technical progress report, 1 October 1993--31 December 1993

    SciTech Connect

    Szymurski, S.R.; Hourahan, G.C.; Godwin, D.S.

    1994-01-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory Committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. The AirConditioning and Refrigeration Technology Institute, Inc., (ARTI) manages and contracts multiple research projects and a data collection and dissemination effort. Detailed results from these projects are reported in technical reports prepared by each subcontractor.

  14. Materials compatibility and lubricants research on CFC-refrigerant substitutes. Quarterly MCLR program technical progress report, January 1, 1995--March 31, 1995

    SciTech Connect

    Szymurski, S.R.; Hourahan, G.C.; Godwin, D.S.

    1995-04-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory Committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. The Air-Conditioning and Refrigeration Technology Institute, Inc., (ARTI) manages and contracts multiple research projects and a data collection and dissemination effort. Detailed results from these projects are reported in technical reports prepared by each subcontractor.

  15. Simultaneous high-temperature removal of alkali and particulates in a pressurized gasification system. Sixth quarterly technical progress report, July-September 1982. [Weight increase due to absorption

    SciTech Connect

    Alvin, M.A.; Bachovchin, D.M.

    1982-10-01

    This program is directed at performing experimental and analytical investigations, deriving system designs, and estimating costs to ascertain the feasibility of using aluminosilicate-based getters for controlling alkali in pressurized gasification systems. Its overall objective is to develop a comprehensive plan for evaluating a scaled-up version of the gettering process as a unit operation or as an integral part of a particulate removal device. This report briefly summarizes efforts previously completed on thermodynamic projections and system performance projections, together with current work on getter selection and qualification completed during the sixth quarter of the project. Work on the thermodynamic projections has been completed and includes an update of the data base, development of alkali phase diagrams, and projections for several gasification processes. Getter selection and qualification effforts involved six tests - five with Emathlite and activated bauxite on the thermogravimetric analysis (TGA) system and one with Emathlite on the bench-scale unit. Finally, system performance projections entailed examination of available kinetic data to ascertain the rate-controlling step, along with modeling efforts to determine the size requirements of a commercial-sized unit.

  16. Simultaneous high-temperature removal of alkali and particulates in a pressurized gasification system. Annual technical progress report, April 1981 through March 1982

    SciTech Connect

    Mulik, P.R.; Alvin, M.A.; Bachovchin, D.M.

    1982-05-01

    This program is directed at performing experimental and analytical investigations, deriving system designs, and estimating costs to ascertain the feasibility of using aluminosilicate-based getters for controlling alkali in pressurized gasification systems. Its overall objective is to develop a comprehensive plan for evaluating a scaled-up version of the gettering process as a unit operation or as an integral part of a particulate removal device. This report describes work completed on thermodynamic projections, getter selection and qualification, and system performance projections during the first year of the project. Work on the thermodynamic projections has been completed and includes an update of the data base, development of alkali phase diagrams, and projections for several gasification processes. Getter selection and qualification efforts involved 23 kinetic tests on our bench-scale reactor and 25 kinetic tests on our thermogravimetric analysis (TGA) system. A key series of tests on both units involved comprehensive getter screening tests in which 20 alternative getters were evaluated. System performance projections involved development of models using available kinetic data and subsequent projections of the size requirements for full-scale units.

  17. Materials Compatibility and Lubricants Research of CFC-refrigerant substitutes. Quarterly technical progress report, 1 April 1993--30 June 1993

    SciTech Connect

    Godwin, D.S.; Hourahan, G.C.; Szymurski, S.R.

    1993-07-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The DCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory Committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. Under the current MCLR program the Air-Conditioning and Refrigeration Technology Institute, Inc., (ARTI) is contracting and managing multiple research projects and a data collection and dissemination effort. Detailed results from these projects are reported in technical reports prepared by each researcher.

  18. Materials compatibility and lubricants research on CFC-refrigerant substitutes. Quarterly technical progress report, 1 October 1992--31 December 1992

    SciTech Connect

    Hourahan, G.C.; Szymurski, S.R.

    1993-01-01

    The materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC-refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. Under the current MCLR program the Air-Conditioning and Refrigeration Technology Institute, Inc., (ARTI) is contracting and managing multiple research projects and a data collection and dissemination effort. Preliminary results from these projects are reported in technical progress reports prepared by each researcher.

  19. Materials Compatibility and Lubricants Research on CFC-refrigerant substitutes. Quarterly technical progress report, 1 January 1993--31 March 1993

    SciTech Connect

    Godwin, D.A.; Hourahan, G.C.; Szymurski, S.R.

    1993-04-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC-refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory Committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. Under the current MCLR program the Air-Conditioning and Refrigeration Technology Institute, Inc., (ARTI) is contracting and managing multiple research projects and a data collection and dissemination effort. Detailed results from these projects are reported in technical reports prepared by each researcher.

  20. Energy retrofit of an office building by substitution of the generation system: performance evaluation via dynamic simulation versus current technical standards

    NASA Astrophysics Data System (ADS)

    Testi, D.; Schito, E.; Menchetti, E.; Grassi, W.

    2014-11-01

    Constructions built in Italy before 1945 (about 30% of the total built stock) feature low energy efficiency. Retrofit actions in this field can lead to valuable energetic and economic savings. In this work, we ran a dynamic simulation of a historical building of the University of Pisa during the heating season. We firstly evaluated the energy requirements of the building and the performance of the existing natural gas boiler, validated with past billings of natural gas. We also verified the energetic savings obtainable by the substitution of the boiler with an air-to-water electrically-driven modulating heat pump, simulated through a cycle-based model, evaluating the main economic metrics. The cycle-based model of the heat pump, validated with manufacturers' data available only at specified temperature and load conditions, can provide more accurate results than the simplified models adopted by current technical standards, thus increasing the effectiveness of energy audits.

  1. Apparatus enables accurate determination of alkali oxides in alkali metals

    NASA Technical Reports Server (NTRS)

    Dupraw, W. A.; Gahn, R. F.; Graab, J. W.; Maple, W. E.; Rosenblum, L.

    1966-01-01

    Evacuated apparatus determines the alkali oxide content of an alkali metal by separating the metal from the oxide by amalgamation with mercury. The apparatus prevents oxygen and moisture from inadvertently entering the system during the sampling and analytical procedure.

  2. Alkalis and Skin.

    PubMed

    Greenwood, John E; Tan, Jin Lin; Ming, Justin Choong Tzen; Abell, Andrew D

    2016-01-01

    The aim of this editorial is to provide an overview of the chemical interactions occurring in the skin of our patients on contact with alkaline agents. Strongly basic alkali is highly aggressive and will readily hydrolyze (or cleave) key biological molecules such as lipids and proteins. This phenomenon is known as saponification in the case of lipids and liquefactive denaturation for peptides and proteins. A short section on current first-aid concepts is included. A better understanding of the basic science behind alkali burns will make us better teachers and provide an insight into the urgency needed in treating these common and dangerous chemical injuries. PMID:26182072

  3. Alkali metal ion battery with bimetallic electrode

    SciTech Connect

    Boysen, Dane A; Bradwell, David J; Jiang, Kai; Kim, Hojong; Ortiz, Luis A; Sadoway, Donald R; Tomaszowska, Alina A; Wei, Weifeng; Wang, Kangli

    2015-04-07

    Electrochemical cells having molten electrodes having an alkali metal provide receipt and delivery of power by transporting atoms of the alkali metal between electrode environments of disparate chemical potentials through an electrochemical pathway comprising a salt of the alkali metal. The chemical potential of the alkali metal is decreased when combined with one or more non-alkali metals, thus producing a voltage between an electrode comprising the molten the alkali metal and the electrode comprising the combined alkali/non-alkali metals.

  4. Methods of recovering alkali metals

    DOEpatents

    Krumhansl, James L; Rigali, Mark J

    2014-03-04

    Approaches for alkali metal extraction, sequestration and recovery are described. For example, a method of recovering alkali metals includes providing a CST or CST-like (e.g., small pore zeolite) material. The alkali metal species is scavenged from the liquid mixture by the CST or CST-like material. The alkali metal species is extracted from the CST or CST-like material.

  5. Chlor-Alkali Technology.

    ERIC Educational Resources Information Center

    Venkatesh, S.; Tilak, B. V.

    1983-01-01

    Chlor-alkali technology is one of the largest electrochemical industries in the world, the main products being chlorine and caustic soda (sodium hydroxide) generated simultaneously by the electrolysis of sodium chloride. This technology is reviewed in terms of electrochemical principles and manufacturing processes involved. (Author/JN)

  6. Hydrothermal alkali metal recovery process

    DOEpatents

    Wolfs, Denise Y.; Clavenna, Le Roy R.; Eakman, James M.; Kalina, Theodore

    1980-01-01

    In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles by treating them with a calcium or magnesium-containing compound in the presence of water at a temperature between about 250.degree. F. and about 700.degree. F. and in the presence of an added base to establish a pH during the treatment step that is higher than would otherwise be possible without the addition of the base. During the treating process the relatively high pH facilitates the conversion of water-insoluble alkali metal compounds in the alkali metal residues into water-soluble alkali metal constituents. The resultant aqueous solution containing water-soluble alkali metal constituents is then separated from the residue solids, which consist of the treated particles and any insoluble materials formed during the treatment step, and recycled to the gasification process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. Preferably, the base that is added during the treatment step is an alkali metal hydroxide obtained by water washing the residue solids produced during the treatment step.

  7. Geopolymers and Related Alkali-Activated Materials

    NASA Astrophysics Data System (ADS)

    Provis, John L.; Bernal, Susan A.

    2014-07-01

    The development of new, sustainable, low-CO2 construction materials is essential if the global construction industry is to reduce the environmental footprint of its activities, which is incurred particularly through the production of Portland cement. One type of non-Portland cement that is attracting particular attention is based on alkali-aluminosilicate chemistry, including the class of binders that have become known as geopolymers. These materials offer technical properties comparable to those of Portland cement, but with a much lower CO2 footprint and with the potential for performance advantages over traditional cements in certain niche applications. This review discusses the synthesis of alkali-activated binders from blast furnace slag, calcined clay (metakaolin), and fly ash, including analysis of the chemical reaction mechanisms and binder phase assemblages that control the early-age and hardened properties of these materials, in particular initial setting and long-term durability. Perspectives for future research developments are also explored.

  8. Simple model potential and model wave functions for (H-alkali)+ and (alkali-alkali)+ ions

    NASA Astrophysics Data System (ADS)

    Patil, S. H.; Tang, K. T.

    2000-07-01

    A simple model potential is proposed to describe the interaction of a valence electron with the alkali core, which incorporates the correct asymptotic behavior in terms of dipolar polarizabilities, and the short-range exchange effects in terms of a hard core adjusted to give the correct energy for the valence electron. Based on this potential, simple wave functions are developed to describe the (H-alkali)+ and (alkali-alkali)+ ions. These wave functions exhibit some important structures of the ions, and provide a universal description of the properties of all (H-alkali)+ and (alkali-alkali)+ ions, in particular, the equilibrium separations of the nuclei and the corresponding dissociation energies. They also allow us to calculate the dipolar polarizabilities of Li2+, Na2+, K2+, Rb2+, and Cs2+.

  9. Alkali-vapor lasers

    NASA Astrophysics Data System (ADS)

    Zweiback, J.; Komashko, A.; Krupke, W. F.

    2010-02-01

    We report on the results from several of our alkali laser systems. We show highly efficient performance from an alexandrite-pumped rubidium laser. Using a laser diode stack as a pump source, we demonstrate up to 145 W of average power from a CW system. We present a design for a transversely pumped demonstration system that will show all of the required laser physics for a high power system.

  10. DEFINITIVE SOX CONTROL PROCESS EVALUATIONS: LIMESTONE, DOUBLE ALKALI, AND CITRATE FGD PROCESSES

    EPA Science Inventory

    The report gives results of a detailed comparative technical and economic evaluation of limestone slurry, generic double alkali, and citrate flue gas desulfurization (FGD) processes, assuming proven technology and using representative power plant, process design, and economic pre...

  11. Adsorption on Alkali Halides.

    NASA Astrophysics Data System (ADS)

    Urzua Duran, Gilberto Antonio

    1995-01-01

    Using a variety of interionic potentials, I have computed the configurations of adsorbed alkali halides monomers on the (001) surface of selected alkali halides crystals. In the majority of cases studied it is found that the monomer adsorbs perpendicular to the surface with the cation sitting nearly on top of the surface anion. In about ten percent of the cases though the monomer adsorbs tilted from the vertical. In these cases the ion that is closer to the surface can be the cation or the anion. The effect of polarization forces is found to be important. In order to discuss the effects of surface retaxation with adsorbates, I have evaluated the surface relaxation of the alkali halide crystals, using a shell model for the interionic forces. It is found that surface relaxation and rumpling are generally small, especially when the van der Waals forces are included. A theory of the effect of substrate vibrations on the binding of an adsorbed atom is developed. At T = 0 the binding energy is D_0-E, where D_0 is the surface well depth (classical binding energy) and E is the quantum correction. For several simple models, it is found that E is surprisingly model-independent. We compare D _0-E with the binding energies to a rigid substrate, D_0-E_{rs}, and to a vibrationally averaged substrate, D _0-E_{va}. We prove that E_{va}>=q E>=q E_ {rs} and that similar relations hold at finite temperature for the free energy of binding. In most cases E_{rs} is better than E_{va} as an approximation to E.

  12. PROCESS OF RECOVERING ALKALI METALS

    DOEpatents

    Wolkoff, J.

    1961-08-15

    A process is described of recovering alkali metal vapor by sorption on activated alumina, activated carbon, dehydrated zeolite, activated magnesia, or Fuller's earth preheated above the vaporization temperature of the alkali metal and subsequent desorption by heating the solvent under vacuum. (AEC)

  13. Preparation of alkali metal dispersions

    NASA Technical Reports Server (NTRS)

    Rembaum, A.; Landel, R. F. (Inventor)

    1968-01-01

    A method is described for producing alkali metal dispersions of high purity. The dispersions are prepared by varying the equilibrium solubility of the alkali metal in a suitable organic solvent in the presence of aromatic hydrocarbons. The equilibrium variation is produced by temperature change. The size of the particles is controlled by controlling the rate of temperature change.

  14. Purification of alkali metal nitrates

    DOEpatents

    Fiorucci, Louis C.; Gregory, Kevin M.

    1985-05-14

    A process is disclosed for removing heavy metal contaminants from impure alkali metal nitrates containing them. The process comprises mixing the impure nitrates with sufficient water to form a concentrated aqueous solution of the impure nitrates, adjusting the pH of the resulting solution to within the range of between about 2 and about 7, adding sufficient reducing agent to react with heavy metal contaminants within said solution, adjusting the pH of the solution containing reducing agent to effect precipitation of heavy metal impurities and separating the solid impurities from the resulting purified aqueous solution of alkali metal nitrates. The resulting purified solution of alkali metal nitrates may be heated to evaporate water therefrom to produce purified molten alkali metal nitrate suitable for use as a heat transfer medium. If desired, the purified molten form may be granulated and cooled to form discrete solid particles of alkali metal nitrates.

  15. Alkali metal and alkali earth metal gadolinium halide scintillators

    DOEpatents

    Bourret-Courchesne, Edith; Derenzo, Stephen E.; Parms, Shameka; Porter-Chapman, Yetta D.; Wiggins, Latoria K.

    2016-08-02

    The present invention provides for a composition comprising an inorganic scintillator comprising a gadolinium halide, optionally cerium-doped, having the formula A.sub.nGdX.sub.m:Ce; wherein A is nothing, an alkali metal, such as Li or Na, or an alkali earth metal, such as Ba; X is F, Br, Cl, or I; n is an integer from 1 to 2; m is an integer from 4 to 7; and the molar percent of cerium is 0% to 100%. The gadolinium halides or alkali earth metal gadolinium halides are scintillators and produce a bright luminescence upon irradiation by a suitable radiation.

  16. Decalcification resistance of alkali-activated slag.

    PubMed

    Komljenović, Miroslav M; Baščarević, Zvezdana; Marjanović, Nataša; Nikolić, Violeta

    2012-09-30

    This paper analyses the effects of decalcification in concentrated 6M NH(4)NO(3) solution on mechanical and microstructural properties of alkali-activated slag (AAS). Portland-slag cement (CEM II/A-S 42.5 N) was used as a benchmark material. Decalcification process led to a decrease in strength, both in AAS and in CEM II, and this effect was more pronounced in CEM II. The decrease in strength was explicitly related to the decrease in Ca/Si atomic ratio of C-S-H gel. A very low ratio of Ca/Si ~0.3 in AAS was the consequence of coexistence of C-S-H(I) gel and silica gel. During decalcification of AAS almost complete leaching of sodium and tetrahedral aluminum from C-S-H(I) gel also took place. AAS showed significantly higher resistance to decalcification in relation to the benchmark CEM II due to the absence of portlandite, high level of polymerization of silicate chains, low level of aluminum for silicon substitution in the structure of C-S-H(I), and the formation of protective layer of polymerized silica gel during decalcification process. In stabilization/solidification processes alkali-activated slag represents a more promising solution than Portland-slag cement due to significantly higher resistance to decalcification. PMID:22818592

  17. Upgrading platform using alkali metals

    SciTech Connect

    Gordon, John Howard

    2014-09-09

    A process for removing sulfur, nitrogen or metals from an oil feedstock (such as heavy oil, bitumen, shale oil, etc.) The method involves reacting the oil feedstock with an alkali metal and a radical capping substance. The alkali metal reacts with the metal, sulfur or nitrogen content to form one or more inorganic products and the radical capping substance reacts with the carbon and hydrogen content to form a hydrocarbon phase. The inorganic products may then be separated out from the hydrocarbon phase.

  18. 40 CFR 721.8900 - Substituted halogenated pyridinol, alkali salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... treatment will occur, or treatment in a lined, self-contained solar evaporation pond where UV light will degrade the substance, the number of kilograms per day per site is calculated after wastewater...

  19. Skin Substitutes

    PubMed Central

    Howe, Nicole; Cohen, George

    2014-01-01

    In a relatively short timespan, a wealth of new skin substitutes made of synthetic and biologically derived materials have arisen for the purpose of wound healing of various etiologies. This review article focuses on providing an overview of skin substitutes including their indications, contraindications, benefits, and limitations. The result of this overview was an appreciation of the vast array of options available for clinicians, many of which did not exist a short time ago. Yet, despite the rapid expansion this field has undergone, no ideal skin substitute is currently available. More research in the field of skin substitutes and wound healing is required not only for the development of new products made of increasingly complex biomolecular material, but also to compare the existing skin substitutes. PMID:25371771

  20. Hydrothermal alkali metal catalyst recovery process

    DOEpatents

    Eakman, James M.; Clavenna, LeRoy R.

    1979-01-01

    In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles primarily in the form of water soluble alkali metal formates by treating the particles with a calcium or magnesium-containing compound in the presence of water at a temperature between about 250.degree. F. and about 700.degree. F. and in the presence of added carbon monoxide. During the treating process the water insoluble alkali metal compounds comprising the insoluble alkali metal residues are converted into water soluble alkali metal formates. The resultant aqueous solution containing water soluble alkali metal formates is then separated from the treated particles and any insoluble materials formed during the treatment process, and recycled to the gasification process where the alkali metal formates serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. This process permits increased recovery of alkali metal constituents, thereby decreasing the overall cost of the gasification process by reducing the amount of makeup alkali metal compounds necessary.

  1. Electrolytic method to make alkali alcoholates using ion conducting alkali electrolyte/separator

    DOEpatents

    Joshi, Ashok V.; Balagopal, Shekar; Pendelton, Justin

    2011-12-13

    Alkali alcoholates, also called alkali alkoxides, are produced from alkali metal salt solutions and alcohol using a three-compartment electrolytic cell. The electrolytic cell includes an anolyte compartment configured with an anode, a buffer compartment, and a catholyte compartment configured with a cathode. An alkali ion conducting solid electrolyte configured to selectively transport alkali ions is positioned between the anolyte compartment and the buffer compartment. An alkali ion permeable separator is positioned between the buffer compartment and the catholyte compartment. The catholyte solution may include an alkali alcoholate and alcohol. The anolyte solution may include at least one alkali salt. The buffer compartment solution may include a soluble alkali salt and an alkali alcoholate in alcohol.

  2. The calcium-alkali syndrome.

    PubMed

    Arroyo, Mariangeli; Fenves, Andrew Z; Emmett, Michael

    2013-04-01

    The milk-alkali syndrome was a common cause of hypercalcemia, metabolic alkalosis, and renal failure in the early 20th century. It was caused by the ingestion of large quantities of milk and absorbable alkali to treat peptic ulcer disease. The syndrome virtually vanished after introduction of histamine-2 blockers and proton pump inhibitors. More recently, a similar condition called the calcium-alkali syndrome has emerged as a common cause of hypercalcemia and alkalosis. It is usually caused by the ingestion of large amounts of calcium carbonate salts to prevent or treat osteoporosis and dyspepsia. We describe a 78-year-old woman who presented with weakness, malaise, and confusion. She was found to have hypercalcemia, acute renal failure, and metabolic alkalosis. Upon further questioning, she reported use of large amounts of calcium carbonate tablets to treat recent heartburn symptoms. Calcium supplements were discontinued, and she was treated with intravenous normal saline. After 5 days, the calcium and bicarbonate levels normalized and renal function returned to baseline. In this article, we review the pathogenesis of the calcium-alkali syndrome as well as the differences between the traditional and modern syndromes. PMID:23543983

  3. Progress in Understanding Alkali-Alkali Spin Relaxation

    NASA Astrophysics Data System (ADS)

    Erickson, Christopher J.; Happer, William; Chann, Bien; Kadlecek, Stephen; Anderson, L. W.; Walker, Thad G.

    2000-06-01

    In extensive experiments we have shown that a spin interaction with a relatively long correlation time causes much of the spin relaxation in very dense alkali-metal vapors. The spin relaxation is affected by the pressure of the helium or nitrogen buffer gas, although there is little dependence at pressures above one atmosphere. There are substantial differences in the relaxation rates for different isotopes of the same element, for example ^87Rb and ^85Rb. We have completed extensive modeling of how singlet and triplet dimers and doublet trimers of the alkali-metal atoms could cause spin relaxation in dense alkali-metal vapors. In the case of doublet trimers or triplet dimers, we assume the main coupling to the nuclear spins is through the Fermi Contact interaction with the unpaired electrons. Spin loss to the rotation of the molecule is assumed to occur through the electronic spin-rotation and spin-axis (dipole-dipole) interactions for the triplet dimers. For the singlet dimers, we assume that the nuclear spins couple directly to the rotational angular momentum of the molecule through the electric quadrupole interaction. We account for all of the total nuclear spin states that occur for the dimers and trimers. We have also considered the possibility that the collisional breakup and formation rates of the dimers or trimers could saturate with increasing buffer gas pressure. Such saturation occurs in many other unimolecular reactions and is often ascribed to breakup through activated states.

  4. Chlor-alkali producers evaluate safer alternatives to asbestos

    SciTech Connect

    Stadig, W.

    1993-03-01

    Until recently, 75% of all US capacity for producing chlor-alkali - more than 40% of the world's capacity - has used asbestos diaphragm-cell technology. Although the Environmental Protection Agency continues to exempt asbestos use in diaphragms from restrictions, producers are considering alternatives. In Germany, stringent regulations will ban asbestos in chlor-alkali production after 1994. Heavy fines were levied recently against some chlor-alkali producers in the United States when EPA inspectors found asbestos fibers in cell renewal areas. Restrictions on the mining of asbestos raise the cost of obtaining adequate amounts of high-quality asbestos and gradually raise the cost of transporting and discarding spent diaphragms. Two alternatives are to use newly developed, non-asbestos diaphragms or to convert to existing ion-exchange membrane-cell technology. Only the former seems economical in the United States. The non-asbestos diaphragm is based on an inorganic polymer composite developed in 1988 as an asbestos substitute. The composite received Du Pont's Plunkett Award for Innovation with Teflon[trademark], landed on the National Development Association's 1991 Honor Roll and became a 1991 R D 100 Award winner. 6 figs.

  5. Alkali-deficient tourmaline from the Sullivan Pb-Zn-Ag deposit, British Columbia

    USGS Publications Warehouse

    Jiang, S.-Y.; Palmer, M.R.; Slack, J.F.

    1997-01-01

    Alkali-deficient tourmalines are found in albitized rocks from the hanging-wall of the Sullivan Pb-Zn-Ag deposit (British Columbia, Canada). They approximate the Mg-equivalent of foitite with an idealized formula D???(Mg2Al)Al6Si6O18(BO 3)3(OH)4. Major chemical substitutions in the tourmalines are the alkali-defect type [Na*(x) + Mg*(Y) = ???(X) + Al(Y)] and the uvite type [Na*(X) + Al(Y) = Ca(X) + Mg*(Y)], where Na* = Na + K, Mg* = Mg + Fe + Mn. The occurrence of these alkali-deficient tourmalines reflects a unique geochemical environment that is either alkali-depleted overall or one in which the alkalis preferentially partitioned into coexisting minerals (e.g. albite). Some of the alkali-deficient tourmalines have unusually high Mn contents (up to 1.5 wt.% MnO) compared to other Sullivan tourmalines. Manganese has a strong preference for incorporation into coexisting garnet and carbonate at Sullivan, thus many tourmalines in Mn-rich rocks are poor in Mn (<0.2 wt.% MnO). It appears that the dominant controls over the occurrence of Mn-rich tourmalines at Sullivan are the local availability of Mn and the lack of other coexisting minerals that may preferentially incorporate Mn into their structures.

  6. Technical note: Synergistic effect of iodide ions on inhibitive performance of substituted dithiobiurets during corrosion of mild steel in hot hydrochloric acid

    SciTech Connect

    Quraishi, M.A.; Rawat, J.; Ajmal, M.

    1999-10-01

    Four substituted dithiobiurets (i.e., 1,5-diphenyl-2,4-dithiobiuret [DPDTB]; 1-anisidyl-5-phenyl 2,4-dithiodiuret [APDTB]; 1-tolyl-5-phenyl 2,4-dithiobiuret [TPDTB]; and 1-chlorophenyl-5-phenyl 2,4-dithiobiuret [CPDTB]) were synthesized to study their inhibiting effect on mild steel (MS) corrosion in 5 N hot hydrochloric acid (HCl). The synergistic effect of these compounds with potassium iodide (KI) was studied at different concentrations, temperatures, and immersion periods by weight loss and potentiodynamic polarization methods. All compounds showed good inhibition efficiency (IE) at all temperatures and showed the enhancement in IE with the addition of small amounts of KI. Potentiodynamic polarization studies showed that APDTB and DPDTB are predominantly cathodic inhibitors, whereas TPDTB and CPDTB are mixed inhibitors. The adsorption of all these compounds followed Temkin's adsorption isotherm.

  7. Substitution in ce2tsi3 intermetallic compositions with t = (Cr, Mn, Fe, Co, or Ni) x (Pd or Au) 1-x. Technical report No. 30

    SciTech Connect

    1996-07-10

    Alloys of composition Ce2(3d/T)Si3, with `3d` one of Cr, Mn, Fe, Co or Ni and `T` being Pd or Au, were separated and examined by powder x-ray diffraction. Select single phase compositions were further examined by magnetic susceptibility, by resistivity for the Pd and Co end-members and by specific heat for Ce2CoSi3. For compounds not containing cobalt, effective cerium moments consistent with trivalent cerium were observed. A re-examination of the AlB2 related structure of Ce2CoSi3 by single crystal methods revealed ordering of cobalt within the CoSi3 hexagonal layer. Magnetic susceptibility, resistance and specific heat measurements suggest valence fluctuation behavior of the cerium in Ce2CoSi3. A return to trivalent cerium magnetic behavior occurs on increasing palladium or gold substitution for cobalt.

  8. Solvent substitution

    SciTech Connect

    Not Available

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  9. Positron-alkali atom scattering

    NASA Technical Reports Server (NTRS)

    Mceachran, R. P.; Horbatsch, M.; Stauffer, A. D.; Ward, S. J.

    1990-01-01

    Positron-alkali atom scattering was recently investigated both theoretically and experimentally in the energy range from a few eV up to 100 eV. On the theoretical side calculations of the integrated elastic and excitation cross sections as well as total cross sections for Li, Na and K were based upon either the close-coupling method or the modified Glauber approximation. These theoretical results are in good agreement with experimental measurements of the total cross section for both Na and K. Resonance structures were also found in the L = 0, 1 and 2 partial waves for positron scattering from the alkalis. The structure of these resonances appears to be quite complex and, as expected, they occur in conjunction with the atomic excitation thresholds. Currently both theoretical and experimental work is in progress on positron-Rb scattering in the same energy range.

  10. Alkali metal/sulfur battery

    DOEpatents

    Anand, Joginder N.

    1978-01-01

    Alkali metal/sulfur batteries in which the electrolyte-separator is a relatively fragile membrane are improved by providing means for separating the molten sulfur/sulfide catholyte from contact with the membrane prior to cooling the cell to temperatures at which the catholyte will solidify. If the catholyte is permitted to solidify while in contact with the membrane, the latter may be damaged. The improvement permits such batteries to be prefilled with catholyte and shipped, at ordinary temperatures.

  11. Superconductivity in alkali metal fullerides

    NASA Astrophysics Data System (ADS)

    Murphy, D. W.; Rosseinsky, M. J.; Haddon, R. C.; Ramirez, A. P.; Hebard, A. F.; Tycko, R.; Fleming, R. M.; Dabbagh, G.

    1991-12-01

    The recent synthesis of macroscopic quantities of spherical molecular carbon compounds, commonly called fullerenes, has stimulated a wide variety of studies of the chemical and physical properties of this novel class of compounds. We discovered that the smallest of the known fullerenes, C 60, could be made conducting and superconducting by reaction with alkali metals. In this paper, an overview of the motivation for these discoveries and some recent results are presented.

  12. Alkali metal sources for OLED devices

    NASA Astrophysics Data System (ADS)

    Cattaneo, Lorena; Longoni, Giorgio; Bonucci, Antonio; Tominetti, Stefano

    2005-07-01

    In OLED organic layers electron injection is improved by using alkali metals as cathodes, to lower work function or, as dopants of organic layer at cathode interface. The creation of an alkali metal layer can be accomplished through conventional physical vapor deposition from a heated dispenser. However alkali metals are very reactive and must be handled in inert atmosphere all through the entire process. If a contamination takes place, it reduces the lithium deposition rate and also the lithium total yield in a not controlled way. An innovative alkali metal dispensing technology has been developed to overcome these problems and ensure OLED alkali metal cathode reliability. The alkali Metal dispenser, called Alkamax, will be able to release up to a few grams of alkali metals (in particular Li and Cs) throughout the adoption of a very stable form of the alkali metal. Lithium, for example, can be evaporated "on demand": the evaporation could be stopped and re-activated without losing alkali metal yield because the metal not yet consumed remains in its stable form. A full characterization of dispensing material, dispenser configuration and dispensing process has been carried out in order to optimize the evaporation and deposition dynamics of alkali metals layers. The study has been performed applying also inside developed simulations tools.

  13. Sensory Substitution

    NASA Astrophysics Data System (ADS)

    Verrillo, Ronald T.

    The idea that the cutaneous surface may be employed as a substitute for the eyes and ears is by no means a modern notion. Although the sense of touch has long been considered as a surrogate for both the visual and auditory modalities, the focus of this chapter will be on the efforts to develop a tactile substitute for hearing, especially that of human speech. The visual system is our primary means of processing information about environmental space such as orientation, distance, direction and size. It is much less effective in making temporal discriminations. The auditory system is unparalleled in processing information that involves rapid sequences of temporal events, such as speech and music. The tactile sense is capable of processing both spatial and temporal information although not as effective in either domain as the eye or the ear.

  14. Regenerable activated bauxite adsorbent alkali monitor probe

    DOEpatents

    Lee, Sheldon H. D.

    1992-01-01

    A regenerable activated bauxite adsorber alkali monitor probe for field applications to provide reliable measurement of alkali-vapor concentration in combustion gas with special emphasis on pressurized fluidized-bed combustion (PFBC) off-gas. More particularly, the invention relates to the development of a easily regenerable bauxite adsorbent for use in a method to accurately determine the alkali-vapor content of PFBC exhaust gases.

  15. Regenerable activated bauxite adsorbent alkali monitor probe

    DOEpatents

    Lee, S.H.D.

    1992-12-22

    A regenerable activated bauxite adsorber alkali monitor probe for field applications to provide reliable measurement of alkali-vapor concentration in combustion gas with special emphasis on pressurized fluidized-bed combustion (PFBC) off-gas. More particularly, the invention relates to the development of a easily regenerable bauxite adsorbent for use in a method to accurately determine the alkali-vapor content of PFBC exhaust gases. 6 figs.

  16. Materials Compatibility and Lubricants Research on CFC-refrigerant substitutes. Quarterly MCLR Program technical progress report, July 1--September 30, 1995

    SciTech Connect

    Szymurski, S.R.; Hourahan, G.C.; Godwin, D.S.; Amrane, K.

    1995-10-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. This report summarizes the research conducted during the third quarter of calendar year 1995 on the following projects: Thermophysical properties of HCFC alternatives; Compatibility of manufacturing process fluids with HFC refrigerants and ester lubricants; Compatibility of motor materials used in air-conditioning for retrofits with alternative refrigerants and lubricants; Compatibility of lubricant additives with HFC refrigerants and synthetic lubricants; Products of motor burnouts; Accelerated test methods for predicting the life of motor materials exposed to refrigerant-lubricant mixtures; Investigation of flushing and clean-out methods; Investigation into the fractionation of refrigerant blends; Lean flammability limits as a fundamental refrigerant property; Effect of selected contaminants in AC and R equipment; Study of foaming characteristics; Study of lubricant circulation in systems; Evaluation of HFC-245ca for commercial use in low pressure chillers; Infrared analysis of refrigerant mixtures; Refrigerant database; Refrigerant toxicity survey; Thermophysical properties of HFC-32, HFC-123, HCFC-124 and HFC-125; Thermophysical properties of HFC-143a and HFC-152a; Theoretical evaluations of R-22 alternative fluids; Chemical and thermal stability of refrigerant-lubricant mixtures with metals; Miscibility of lubricants with refrigerants; Viscosity, solubility and density measurements of refrigerant-lubricant mixtures; Electrohydrodynamic enhancement of pool and in-tube boiling of alternative refrigerants; Accelerated screening methods; and more.

  17. EVALUATION OF THE LIMESTONE DUAL ALKALI PROTOTYPE SYSTEM AT PLANT SCHOLZ: FINAL REPORT

    EPA Science Inventory

    The report gives results of a 2-month test (February/March 1981) of the limestone dual alkali process at an existing 20 MW prototype facility at Gulf Power Company's Scholz Steam Plant. The project was intended to evaluate the technical feasibility of the process at a prototype s...

  18. Progress in High-Field Optical Pumping of Alkali Metal Nuclei

    NASA Astrophysics Data System (ADS)

    Patton, B.; Ishikawa, K.; Jau, Y.-Y.; Happer, W.

    2006-05-01

    We present preliminary results of an attempt to polarize alkali metal nuclei via optical pumping in a large (9.4-tesla) magnetic field. NMR measurements of ^87Rb and ^133Cs films in optical cells will be reported. Depopulation pumping of alkalis can easily produce electron polarizations of order unity, as measured during spin-exchange optical pumping of noble gases [1]. At low magnetic fields (< ˜1 kG), the strong hyperfine coupling between the alkali electron and nucleus allows angular momentum exchange from one to the other, resulting in nuclear polarization enhancement through optical pumping. In the high magnetic fields required for NMR, however, this interaction is largely decoupled and electron-nuclear spin exchange must rely upon the δA I .S interaction induced by buffer gas collisions (also called the ``Carver rate''). High-field optical pumping experiments may allow for a more precise measurement of this rate, as well as yielding insight into the transfer of angular momentum from the polarized alkali vapor to the bulk alkali metal on the cell walls. The technical challenges of high-resolution NMR of alkali metals at 9.4 tesla will be discussed. 1. E. Babcock, I. Nelson, S. Kadlecek, et al., Physical Review Letters 91, 123003 (2003).

  19. Alkali-Metal Spin Maser.

    PubMed

    Chalupczak, W; Josephs-Franks, P

    2015-07-17

    Quantum measurement is a combination of a read-out and a perturbation of the quantum system. We explore the nonlinear spin dynamics generated by a linearly polarized probe beam in a continuous measurement of the collective spin state in a thermal alkali-metal atomic sample. We demonstrate that the probe-beam-driven perturbation leads, in the presence of indirect pumping, to complete polarization of the sample and macroscopic coherent spin oscillations. As a consequence of the former we report observation of spectral profiles free from collisional broadening. Nonlinear dynamics is studied through exploring its effect on radio frequency as well as spin noise spectra. PMID:26230788

  20. Process for the disposal of alkali metals

    DOEpatents

    Lewis, Leroy C.

    1977-01-01

    Large quantities of alkali metals may be safely reacted for ultimate disposal by contact with a hot concentrated caustic solution. The alkali metals react with water in the caustic solution in a controlled reaction while steam dilutes the hydrogen formed by the reaction to a safe level.

  1. The alkali metals: 200 years of surprises.

    PubMed

    Dye, James L

    2015-03-13

    Alkali metal compounds have been known since antiquity. In 1807, Sir Humphry Davy surprised everyone by electrolytically preparing (and naming) potassium and sodium metals. In 1808, he noted their interaction with ammonia, which, 100 years later, was attributed to solvated electrons. After 1960, pulse radiolysis of nearly any solvent produced solvated electrons, which became one of the most studied species in chemistry. In 1968, alkali metal solutions in amines and ethers were shown to contain alkali metal anions in addition to solvated electrons. The advent of crown ethers and cryptands as complexants for alkali cations greatly enhanced alkali metal solubilities. This permitted us to prepare a crystalline salt of Na(-) in 1974, followed by 30 other alkalides with Na(-), K(-), Rb(-) and Cs(-) anions. This firmly established the -1 oxidation state of alkali metals. The synthesis of alkalides led to the crystallization of electrides, with trapped electrons as the anions. Electrides have a variety of electronic and magnetic properties, depending on the geometries and connectivities of the trapping sites. In 2009, the final surprise was the experimental demonstration that alkali metals under high pressure lose their metallic character as the electrons are localized in voids between the alkali cations to become high-pressure electrides! PMID:25666067

  2. Method of handling radioactive alkali metal waste

    DOEpatents

    Wolson, Raymond D.; McPheeters, Charles C.

    1980-01-01

    Radioactive alkali metal is mixed with particulate silica in a rotary drum reactor in which the alkali metal is converted to the monoxide during rotation of the reactor to produce particulate silica coated with the alkali metal monoxide suitable as a feed material to make a glass for storing radioactive material. Silica particles, the majority of which pass through a 95 mesh screen or preferably through a 200 mesh screen, are employed in this process, and the preferred weight ratio of silica to alkali metal is 7 to 1 in order to produce a feed material for the final glass product having a silica to alkali metal monoxide ratio of about 5 to 1.

  3. Method of handling radioactive alkali metal waste

    DOEpatents

    Wolson, R.D.; McPheeters, C.C.

    Radioactive alkali metal is mixed with particulate silica in a rotary drum reactor in which the alkali metal is converted to the monoxide during rotation of the reactor to produce particulate silica coated with the alkali metal monoxide suitable as a feed material to make a glass for storing radioactive material. Silica particles, the majority of which pass through a 95 mesh screen or preferably through a 200 mesh screen, are employed in this process, and the preferred weight ratio of silica to alkali metal is 7 to 1 in order to produce a feed material for the final glass product having a silica to alkali metal monoxide ratio of about 5 to 1.

  4. Vitreous Substitutes.

    PubMed

    Foster, William Joseph

    2008-04-01

    Modern vitreoretinal surgery is a young science. While tremendous developments have occurred in instrument design and technique since Machemer first described vitrectomy surgery in 1973[1], the application of advanced materials concepts to the development of intra-ocular compounds is a particularly exciting area of research. To date, the development of vitreous substitutes has played a significant role in enabling the dramatic and progressive improvement in surgical outcome, but perhaps no other area of research has the potential to further improve the treatment of retinal detachment and other retinal disorders. While prior research has focused solely upon the ability of a compound to re-attach the retina, future research should seek to enable the surgeon to inhibit the development of proliferative vitreoretinopathy and re-detachment, the integration of stem-cell therapies with surgical retina, long-term delivery of medications to the posterior segment, and the promotion of more rapid and complete visual rehabilitation. PMID:19343097

  5. Alkali burns from wet cement.

    PubMed Central

    Peters, W. J.

    1984-01-01

    When water is added to the dry materials of Portland cement calcium hydroxide is formed; the wet cement is caustic (with a pH as high as 12.9) and can produce third-degree alkali burns after 2 hours of contact. Unlike professional cement workers, amateurs are usually not aware of any danger and may stand or kneel in the cement for long periods. As illustrated in a case report, general physicians may recognize neither the seriousness of the injury in its early stages nor the significance of a history of prolonged contact with wet cement. All people working with cement should be warned about its dangers and advised to immediately wash and dry the skin if contact does occur. Images Fig. 1 PMID:6561052

  6. Integrating Sphere Alkali-Metal Vapor Cells

    NASA Astrophysics Data System (ADS)

    McGuyer, Bart; Ben-Kish, Amit; Jau, Yuan-Yu; Happer, William

    2010-03-01

    An integrating sphere is an optical multi-pass cavity that uses diffuse reflection to increase the optical path length. Typically applied in photometry and radiometry, integrating spheres have previously been used to detect trace gases and to cool and trap alkali-metal atoms. Here, we investigate the potential for integrating spheres to enhance optical absorption in optically thin alkali-metal vapor cells. In particular, we consider the importance of dielectric effects due to a glass container for the alkali-metal vapor. Potential applications include miniature atomic clocks and magnetometers, where multi-passing could reduce the operating temperature and power consumption.

  7. Alkali Silicate Vehicle Forms Durable, Fireproof Paint

    NASA Technical Reports Server (NTRS)

    Schutt, John B.; Seindenberg, Benjamin

    1964-01-01

    The problem: To develop a paint for use on satellites or space vehicles that exhibits high resistance to cracking, peeling, or flaking when subjected to a wide range of temperatures. Organic coatings will partially meet the required specifications but have the inherent disadvantage of combustibility. Alkali-silicate binders, used in some industrial coatings and adhesives, show evidence of forming a fireproof paint, but the problem of high surface-tension, a characteristic of alkali silicates, has not been resolved. The solution: Use of a suitable non-ionic wetting agent combined with a paint incorporating alkali silicate as the binder.

  8. Diode pumped alkali vapor fiber laser

    DOEpatents

    Payne, Stephen A.; Beach, Raymond J.; Dawson, Jay W.; Krupke, William F.

    2007-10-23

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

  9. Diode pumped alkali vapor fiber laser

    DOEpatents

    Payne, Stephen A.; Beach, Raymond J.; Dawson, Jay W.; Krupke, William F.

    2006-07-26

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

  10. Advancements in flowing diode pumped alkali lasers

    NASA Astrophysics Data System (ADS)

    Pitz, Greg A.; Stalnaker, Donald M.; Guild, Eric M.; Oliker, Benjamin Q.; Moran, Paul J.; Townsend, Steven W.; Hostutler, David A.

    2016-03-01

    Multiple variants of the Diode Pumped Alkali Laser (DPAL) have recently been demonstrated at the Air Force Research Laboratory (AFRL). Highlights of this ongoing research effort include: a) a 571W rubidium (Rb) based Master Oscillator Power Amplifier (MOPA) with a gain (2α) of 0.48 cm-1, b) a rubidium-cesium (Cs) Multi-Alkali Multi-Line (MAML) laser that simultaneously lases at both 795 nm and 895 nm, and c) a 1.5 kW resonantly pumped potassium (K) DPAL with a slope efficiency of 50%. The common factor among these experiments is the use of a flowing alkali test bed.

  11. Alkali metal for ultraviolet band-pass filter

    NASA Technical Reports Server (NTRS)

    Mardesich, Nick (Inventor); Fraschetti, George A. (Inventor); Mccann, Timothy A. (Inventor); Mayall, Sherwood D. (Inventor); Dunn, Donald E. (Inventor); Trauger, John T. (Inventor)

    1993-01-01

    An alkali metal filter having a layer of metallic bismuth deposited onto the alkali metal is provided. The metallic bismuth acts to stabilize the surface of the alkali metal to prevent substantial surface migration from occurring on the alkali metal, which may degrade optical characteristics of the filter. To this end, a layer of metallic bismuth is deposited by vapor deposition over the alkali metal to a depth of approximately 5 to 10 A. A complete alkali metal filter is described along with a method for fabricating the alkali metal filter.

  12. Alkali Metal Handling Practices at NASA MSFC

    NASA Technical Reports Server (NTRS)

    Salvail, Patrick G.; Carter, Robert R.

    2002-01-01

    NASA Marshall Space Flight Center (MSFC) is NASA s principle propulsion development center. Research and development is coordinated and carried out on not only the existing transportation systems, but also those that may be flown in the near future. Heat pipe cooled fast fission cores are among several concepts being considered for the Nuclear Systems Initiative. Marshall Space Flight Center has developed a capability to handle high-purity alkali metals for use in heat pipes or liquid metal heat transfer loops. This capability is a low budget prototype of an alkali metal handling system that would allow the production of flight qualified heat pipe modules or alkali metal loops. The processing approach used to introduce pure alkali metal into heat pipe modules and other test articles are described in this paper.

  13. Alkali-metal intercalation in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Béguin, F.; Duclaux, L.; Méténier, K.; Frackowiak, E.; Salvetat, J. P.; Conard, J.; Bonnamy, S.; Lauginie, P.

    1999-09-01

    We report on successful intercalation of multiwall (MWNT) and single wall (SWNT) carbon nanotubes with alkali metals by electrochemical and vapor phase reactions. A LiC10 compound was produced by full electrochemical reduction of MWNT. KC8 and CsC8-MWNT first stage derivatives were synthesized in conditions of alkali vapor saturation. Their identity periods and the 2×2 R 0° alkali superlattice are comparable to their parent graphite compounds. The dysonian shape of KC8 EPR line and the temperature-independent Pauli susceptibility are both characteristic of a metallic behavior, which was confirmed by 13C NMR anisotropic shifts. Exposure of SWNT bundles to alkali vapor led to an increase of the pristine triangular lattice from 1.67 nm to 1.85 nm and 1.87 nm for potassium and rubidium, respectively.

  14. Alkali metal intercalates of molybdenum disulfide.

    NASA Technical Reports Server (NTRS)

    Somoano, R. B.; Hadek, V.; Rembaum, A.

    1973-01-01

    Study of some of the physicochemical properties of compounds obtained by subjecting natural molybdenite and single crystals of molybdenum disulfide grown by chemical vapor transport to intercalation with the alkali group of metals (Li, Na, K, Rb, and Cs) by means of the liquid ammonia technique. Reported data and results include: (1) the intercalation of the entire alkali metal group, (2) stoichiometries and X-ray data on all of the compounds, and (3) superconductivity data for all the intercalation compounds.

  15. Superconductivity in alkali-doped C60

    NASA Astrophysics Data System (ADS)

    Ramirez, Arthur P.

    2015-07-01

    Superconductivity in alkali-doped C60 (A3C60, A = an alkali atom) is well described by an s-wave state produced by phonon mediated pairing. Moderate coupling of electrons to high-frequency shape-changing intra-molecular vibrational modes produces transition temperatures (Tc) up to 33 K in single-phase material. The good understanding of pairing in A3C60 offers a paradigm for the development of new superconducting materials.

  16. Desulfurizing Coal With an Alkali Treatment

    NASA Technical Reports Server (NTRS)

    Ravindram, M.; Kalvinskas, J. J.

    1987-01-01

    Experimental coal-desulfurization process uses alkalies and steam in fluidized-bed reactor. With highly volatile, high-sulfur bituminous coal, process removed 98 percent of pyritic sulfur and 47 percent of organic sulfur. Used in coal liquefaction and in production of clean solid fuels and synthetic liquid fuels. Nitrogen or steam flows through bed of coal in reactor. Alkalies react with sulfur, removing it from coal. Nitrogen flow fluidizes bed while heating or cooling; steam is fluidizing medium during reaction.

  17. Alkali metal crystalline polymer electrolytes.

    PubMed

    Zhang, Chuhong; Gamble, Stephen; Ainsworth, David; Slawin, Alexandra M Z; Andreev, Yuri G; Bruce, Peter G

    2009-07-01

    Polymer electrolytes have been studied extensively because uniquely they combine ionic conductivity with solid yet flexible mechanical properties, rendering them important for all-solid-state devices including batteries, electrochromic displays and smart windows. For some 30 years, ionic conductivity in polymers was considered to occur only in the amorphous state above Tg. Crystalline polymers were believed to be insulators. This changed with the discovery of Li(+) conductivity in crystalline poly(ethylene oxide)(6):LiAsF(6). However, new crystalline polymer electrolytes have proved elusive, questioning whether the 6:1 complex has particular structural features making it a unique exception to the rule that only amorphous polymers conduct. Here, we demonstrate that ionic conductivity in crystalline polymers is not unique to the 6:1 complex by reporting several new crystalline polymer electrolytes containing different alkali metal salts (Na(+), K(+) and Rb(+)), including the best conductor poly(ethylene oxide)(8):NaAsF(6) discovered so far, with a conductivity 1.5 orders of magnitude higher than poly(ethylene oxide)(6):LiAsF(6). These are the first crystalline polymer electrolytes with a different composition and structures to that of the 6:1 Li(+) complex. PMID:19543313

  18. Self-assembly of Alkali-uranyl-peroxide Clusters

    SciTech Connect

    Nyman, May; Rodriquez, Mark A.; Campana, Charles F.

    2010-08-11

    The hexavalent uranium specie, uranyl triperoxide, UO2(O2)34-, has been shown recently to behave like high oxidation-state d0 transition-metals, self-assembling into polyoxometalate-like clusters that contain up to 60 uranyl cations bridged by peroxide ligands. There has been much less focus on synthesis and structural characterization of salts of the monomeric UO2(O2)34- building block of these clusters. However, these could serve as water-soluble uranyl precursors for both clusters and materials, and also be used as simple models to study aqueous behavior by experiment and modeling. The countercation is of utmost importance to the assembly of these clusters, and Li+ has proven useful for the crystallization of many of the known cluster geometries to date. We present in this paper synthesis and structural characterization of two monomeric lithium uranyl-peroxide salts, Li4[UO2(O2)3]·10H2O (1) and [UO2(O2)3]12[(UO2(OH)4)Li16(H2O)28]3·Li6[H2O]26 (2). They were obtained from aqueous-alcohol solutions rather than the analogous aqueous solutions from which lithium uranyl-peroxide clusters are crystallized. Rapid introduction of the alcohol gives the structure of (1) whereas slow diffusion of alcohol results in crystallization of (2). (2) is an unusual structure featuring uranyl-centered alkali clusters that are linked into ring and spherical arrangements via [UO2(O2)3] anions. Furthermore, partial substitution of Rb or Cs into the synthesis results in formation of (2) with substitution of these larger alkalis into the uranyl-centered clusters. We surmise that the slow crystallization allows for direct bonding of alkali metals to the

  19. Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material

    DOEpatents

    Doeff, M.M.; Peng, M.Y.; Ma, Y.; Visco, S.J.; DeJonghe, L.C.

    1996-09-24

    An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M{sub x}Z{sub y}Mn{sub (1{minus}y)}O{sub 2}, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell. 11 figs.

  20. Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material

    DOEpatents

    Doeff, Marca M.; Peng, Marcus Y.; Ma, Yanping; Visco, Steven J.; DeJonghe, Lutgard C.

    1996-01-01

    An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M.sub.x Z.sub.y Mn.sub.(1-y) O.sub.2, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell.

  1. Second international conference on alkali-aggregate reactions in hydroelectric plants and dams

    SciTech Connect

    1995-12-31

    This document is the report of the Second International Conference on Alkali-Aggregate Reactions in Hydroelectric Plants and Dams. This conference was held in October 1995 in Chattanooga, TN and sponsored by the Tennessee Valley Authority. Thirty five papers were presented, with technical sessions covering: (1) The TVA experience, (2) AAR in Hydroelectric Powerplants, (3) AAR in Dams and Spillways, and (4) Long-term management of AAR. Additionally, there were several workshop sessions.

  2. On the Electron Paramagnetic Resonance Studies in Mixed Alkali Borate Glasses

    SciTech Connect

    Padmaja, G.; Reddy, T. Goverdhan; Kistaiah, P.

    2011-10-20

    Mixed alkali effect in oxide based glasses is one of the current research activity and studies on the behavior of spectroscopic parameters in these systems are quite important to understand the basic nature of this phenomenon. EPR studies of mixed alkali glasses Li{sub 2}O-K{sub 2}O-ZnO-B{sub 2}O{sub 3} doped with Fe{sup 3+} and Mn{sup 2+} were carried out at room temperature. The EPR spectra show typical resonances of d{sup 5} system (Fe{sup 3+} and Mn{sup 2+}) in all the measured glass specimens. Evaluated hyperfine constant, number of paramagnetic centers and paramagnetic susceptibility values show deviation from the linearity with the progressive substitution of the Li ion with K in glass network.

  3. Slow pyrolysis of prot, alkali and dealkaline lignins for production of chemicals.

    PubMed

    Biswas, Bijoy; Singh, Rawel; Kumar, Jitendra; Khan, Adnan Ali; Krishna, Bhavya B; Bhaskar, Thallada

    2016-08-01

    Effect of different lignins were studied during slow pyrolysis. Maximum bio-oil yield of 31.2, 34.1, and 29.5wt.% was obtained at 350, 450 and 350°C for prot lignin, alkali lignin and dealkaline lignin respectively. Maximum yield of phenolic compounds 78%, 80% and 92% from prot lignin, alkali and dealkaline lignin at 350, 450 and 350°C. The differences in the pyrolysis products indicated the source of lignins such as soft and hard wood lignins. The biochar characterisation revealed that the various ether linkages were broken during pyrolysis and lignin was converted into monomeric substituted phenols. Bio-oil showed that the relative contents of each phenolic compound changes significantly with pyrolysis temperature and also the relative contents of each compound changes with different samples. PMID:26873286

  4. Alkali Metal Carbenoids: A Case of Higher Stability of the Heavier Congeners.

    PubMed

    Molitor, Sebastian; Gessner, Viktoria H

    2016-06-27

    As a result of the increased polarity of the metal-carbon bond when going down the group of the periodic table, the heavier alkali metal organyl compounds are generally more reactive and less stable than their lithium congeners. We now report a reverse trend for alkali metal carbenoids. Simple substitution of lithium by the heavier metals (Na, K) results in a significant stabilization of these usually highly reactive compounds. This allows their isolation and handling at room temperature and the first structure elucidation of sodium and potassium carbenoids. The control of stability was used to control reactivity and selectivity. Hence, the Na and K carbenoids act as selective carbene-transfer reagents, whereas the more labile lithium systems give rise to product mixtures. Additional fine tuning of the M-C interaction by means of crown ether addition further allows for control of the stability and reactivity. PMID:27100278

  5. Alkali metal adsorption on Al(111)

    NASA Astrophysics Data System (ADS)

    Andersen, J. N.; Lundgren, E.; Nyholm, R.; Qvarford, M.

    1993-06-01

    The submonolayer adsorption of Na, K, Rb, and Cs on the Al(111) surface at 100 K and at room temperature is investigated by high resolution core level spectroscopy and low energy electron diffraction. It is found that the first alkali atoms on the surface adsorb at surface defects. At higher coverages, up to approximately one third of the maximum submonolayer coverage, alkali atoms adsorbed at defects coexist with a dispersed phase. At higher coverages island formation is found to occur for the majority of the systems. It is argued that all of the ordered structures formed at room temperature involve a disruption of the Al(111) surface in contrast to the situation at 100 K where the alkali atoms adsorb as adatoms.

  6. SAFE Alkali Metal Heat Pipe Reliability

    NASA Astrophysics Data System (ADS)

    Reid, Robert S.

    2003-01-01

    Alkali metal heat pipes are among the best understood and tested of components for first generation space fission reactors. A flight reactor will require production of a hundred or more heat pipes with assured reliability over a number of years. To date, alkali metal heat pipes have been built mostly in low budget development environments with little formal quality assurance. Despite this, heat pipe test samples suggest that high reliability can be achieved with the care justified for space flight qualification. Fabrication procedures have been established that, if consistently applied, ensure long-term trouble-free heat pipe operation. Alkali metal heat pipes have been successfully flight tested in micro gravity and also have been shown capable of multi-year operation with no evidence of sensitivity to fast neutron fluence up to 1023 n/cm2. This represents 50 times the fluence of the proposed Safe Affordable Fission Engine (SAFE-100) heat pipe reactor core.

  7. Diode pumped alkali lasers (DPALs): an overview

    NASA Astrophysics Data System (ADS)

    Krupke, William F.

    2008-05-01

    The concept of power-scalable, high beam-quality diode pumped alkali lasers was introduced in 2003 [Krupke, US Patent No. 6,643,311; Opt. Letters, 28, 2336 (2003)]. Since then several laboratory DPAL devices have been reported on, confirming many of the spectroscopic, kinetic, and laser characteristics projected from literature data. This talk will present an overview of the DPAL concept, summarize key relevant properties of the cesium, rubidium, and potassium alkali vapor gain media so-far examined, outline power scaling considerations, and highlight results of published DPAL laboratory experiments.

  8. Alkali metal vapors - Laser spectroscopy and applications

    NASA Technical Reports Server (NTRS)

    Stwalley, W. C.; Koch, M. E.

    1980-01-01

    The paper examines the rapidly expanding use of lasers for spectroscopic studies of alkali metal vapors. Since the alkali metals (lithium, sodium, potassium, rubidium and cesium) are theoretically simple ('visible hydrogen'), readily ionized, and strongly interacting with laser light, they represent ideal systems for quantitative understanding of microscopic interconversion mechanisms between photon (e.g., solar or laser), chemical, electrical and thermal energy. The possible implications of such understanding for a wide variety of practical applications (sodium lamps, thermionic converters, magnetohydrodynamic devices, new lasers, 'lithium waterfall' inertial confinement fusion reactors, etc.) are also discussed.

  9. Alkali-aggregate reaction in concrete containing high-alkali cement and granite aggregate

    SciTech Connect

    Owsiak, Z

    2004-01-01

    The paper discusses results of the research into the influence of high-alkali Portland cement on granite aggregate. The deformation of the concrete structure occurred after 18 months. The research was carried out by means of a scanning electron microscope equipped with a high-energy dispersive X-ray analyzer that allowed observation of unpolished sections of concrete bars exhibiting the cracking pattern typical of the alkali-silica reaction. Both the microscopic observation and the X-ray elemental analysis confirm the presence of alkali-silica gel and secondary ettringite in the cracks.

  10. Recovery of alkali metal constituents from catalytic coal conversion residues

    DOEpatents

    Soung, W.Y.

    In a coal gasification operation (32) or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles by contacting them with water or an aqueous solution to remove water-soluble alkali metal constituents and produce an aqueous solution enriched in said constituents. The aqueous solution thus produced is then contacted with carbon dioxide to precipitate silicon constituents, the pH of the resultant solution is increased, preferably to a value in the range between about 12.5 and about 15.0, and the solution of increased pH is evaporated to increase the alkali metal concentration. The concentrated aqueous solution is then recycled to the conversion process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.

  11. REVISITING CLASSICAL NUCLEOPHILIC SUBSTITUTIONS IN AQUEOUS MEDIUM: MICROWAVE-ASSISTED SYNTHESIS OF ALKYL AZIDES

    EPA Science Inventory

    An efficient and clean synthesis of alkyl azides using microwave (MW) radiation is described in aqueous medium by reacting alkyl halides or tosylates with alkali azides. This general and expeditious MW-enhanced approach to nucleophilic substitution reactions is applicable to the ...

  12. Salts of alkali metal anions and process of preparing same

    DOEpatents

    Dye, James L.; Ceraso, Joseph M.; Tehan, Frederick J.; Lok, Mei Tak

    1978-01-01

    Compounds of alkali metal anion salts of alkali metal cations in bicyclic polyoxadiamines are disclosed. The salts are prepared by contacting an excess of alkali metal with an alkali metal dissolving solution consisting of a bicyclic polyoxadiamine in a suitable solvent, and recovered by precipitation. The salts have a gold-color crystalline appearance and are stable in a vacuum at -10.degree. C. and below.

  13. Nucleophilic Aromatic Substitution.

    ERIC Educational Resources Information Center

    Avila, Walter B.; And Others

    1990-01-01

    Described is a microscale organic chemistry experiment which demonstrates one feasible route in preparing ortho-substituted benzoic acids and provides an example of nucleophilic aromatic substitution chemistry. Experimental procedures and instructor notes for this activity are provided. (CW)

  14. Faraday rotation density measurements of optically thick alkali metal vapors

    NASA Astrophysics Data System (ADS)

    Vliegen, E.; Kadlecek, S.; Anderson, L. W.; Walker, T. G.; Erickson, C. J.; Happer, William

    2001-03-01

    We investigate the measurement of alkali number densities using the Faraday rotation of linearly polarized light. We find that the alkali number density may be reliably extracted even in regimes of very high buffer gas pressure, and very high alkali number density. We have directly verified our results in potassium using absorption spectroscopy on the second resonance (4 2S→5 2P).

  15. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  16. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  17. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  18. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  19. 40 CFR 721.4660 - Alcohol, alkali metal salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alcohol, alkali metal salt. 721.4660... Substances § 721.4660 Alcohol, alkali metal salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as alcohol, alkali metal salt (PMN P-91-151)...

  20. 40 CFR 721.4660 - Alcohol, alkali metal salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alcohol, alkali metal salt. 721.4660... Substances § 721.4660 Alcohol, alkali metal salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as alcohol, alkali metal salt (PMN P-91-151)...

  1. 40 CFR 721.4660 - Alcohol, alkali metal salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alcohol, alkali metal salt. 721.4660... Substances § 721.4660 Alcohol, alkali metal salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as alcohol, alkali metal salt (PMN P-91-151)...

  2. 40 CFR 721.4660 - Alcohol, alkali metal salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alcohol, alkali metal salt. 721.4660... Substances § 721.4660 Alcohol, alkali metal salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as alcohol, alkali metal salt (PMN P-91-151)...

  3. 40 CFR 721.4660 - Alcohol, alkali metal salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alcohol, alkali metal salt. 721.4660... Substances § 721.4660 Alcohol, alkali metal salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as alcohol, alkali metal salt (PMN P-91-151)...

  4. Computational studies of solid-state alkali conduction in rechargeable alkali-ion batteries

    DOE PAGESBeta

    Deng, Zhi; Mo, Yifei; Ong, Shyue Ping

    2016-03-25

    The facile conduction of alkali ions in a crystal host is of crucial importance in rechargeable alkali-ion batteries, the dominant form of energy storage today. In this review, we provide a comprehensive survey of computational approaches to study solid-state alkali diffusion. We demonstrate how these methods have provided useful insights into the design of materials that form the main components of a rechargeable alkali-ion battery, namely the electrodes, superionic conductor solid electrolytes and interfaces. We will also provide a perspective on future challenges and directions. Here, the scope of this review includes the monovalent lithium- and sodium-ion chemistries that aremore » currently of the most commercial interest.« less

  5. Alkali resistant optical coatings for alkali lasers and methods of production thereof

    DOEpatents

    Soules, Thomas F; Beach, Raymond J; Mitchell, Scott C

    2014-11-18

    In one embodiment, a multilayer dielectric coating for use in an alkali laser includes two or more alternating layers of high and low refractive index materials, wherein an innermost layer includes a thicker, >500 nm, and dense, >97% of theoretical, layer of at least one of: alumina, zirconia, and hafnia for protecting subsequent layers of the two or more alternating layers of high and low index dielectric materials from alkali attack. In another embodiment, a method for forming an alkali resistant coating includes forming a first oxide material above a substrate and forming a second oxide material above the first oxide material to form a multilayer dielectric coating, wherein the second oxide material is on a side of the multilayer dielectric coating for contacting an alkali.

  6. Terahertz radiation in alkali vapor plasmas

    SciTech Connect

    Sun, Xuan; Zhang, X.-C.

    2014-05-12

    By taking advantage of low ionization potentials of alkali atoms, we demonstrate terahertz wave generation from cesium and rubidium vapor plasmas with an amplitude nearly one order of magnitude larger than that from nitrogen gas at low pressure (0.02–0.5 Torr). The observed phenomena are explained by the numerical modeling based upon electron tunneling ionization.

  7. The Additive Coloration of Alkali Halides

    ERIC Educational Resources Information Center

    Jirgal, G. H.; and others

    1969-01-01

    Describes the construction and use of an inexpensive, vacuum furnace designed to produce F-centers in alkali halide crystals by additive coloration. The method described avoids corrosion or contamination during the coloration process. Examination of the resultant crystals is discussed and several experiments using additively colored crystals are…

  8. Hyaline membrane disease, alkali, and intraventricular haemorrhage.

    PubMed Central

    Wigglesworth, J S; Keith, I H; Girling, D J; Slade, S A

    1976-01-01

    The relation between intraventricular haemorrhage (IVH) and hyaline membrane disease (HMD) was studied in singletons that came to necropsy at Hammersmith Hospital over the years 1966-73. The incidence of IVH in singleton live births was 3-22/1000 and of HMD 4-44/1000. Although the high figures were partily due to the large number of low birthweight infants born at this hospital, the incidence of IVH in babies weighing 1001-1500 g was three times as great as that reported in the 1658 British Perinatal Mortality Survey. Most IVH deaths were in babies with HMD, but the higher frequency of IVH was not associated with any prolongation of survival time of babies who died with HMD as compared with the 1958 survey. IVH was seen frequently at gestations of up to 36 weeks in babies with HMD but was rare above 30 weeks' gestation in babies without HMD. This indicated that factors associated with HMD must cause most cases of IVH seen at gestations above 30 weeks. Comparison of clinical details in infants with HMD who died with or without IVH (at gestations of 30-37 weeks) showed no significant differences between the groups other than a high incidence of fits and greater use of alkali therapy in the babies with IVH. During the 12 hours when most alkali therapy was given, babies dying with IVD received a mean total alkali dosage of 10-21 mmol/kg and those dying without IVH 6-34 mmol/kg (P less than 0-001).There was no difference in severity of hypoxia or of metabolic acidosis between the 2 groups. Babies who died with HMD and germinal layer haemorrhage (GLH) without IVH had received significantly more alkali than those who died with HMD alone, whereas survivors of severe respiratory distress syndrome had received lower alkali doses than other groups. It is suggested that the greatly increased death rate from IVH in babies with HMD indicates some alteration of management of HMD (since 1958) as a causative factor. Liberal use of hypertonic alkali solutions is the common factor

  9. Physics and chemistry of alkali-silica reactions

    SciTech Connect

    Diamond, S.; Barneyback, R.S. Jr.; Struble, L.J.

    1981-01-01

    The philosophy underlying recent research on alkali-silica reactions is reviewed and illustrations of recent results are provided. It has been possible to follow the kinetics of the chemical reaction between dissolved alkalis and opal in mortars by monitoring the rate at which alkalis are removed from the pore solutions of reacting mortars. Studies of the expansion behavior of synthetic alkali silica gels under controlled conditions were carried out and show no obvious correlation to chemical composition. The alkali reaction in mortars was found to produce changes in the appearance of opal grains documentable by the use of a scanning electron microscope.

  10. Calcium-Alkali Syndrome in the Modern Era

    PubMed Central

    Patel, Ami M.; Adeseun, Gbemisola A.; Goldfarb, Stanley

    2013-01-01

    The ingestion of calcium, along with alkali, results in a well-described triad of hypercalcemia, metabolic alkalosis, and renal insufficiency. Over time, the epidemiology and root cause of the syndrome have shifted, such that the disorder, originally called the milk-alkali syndrome, is now better described as the calcium-alkali syndrome. The calcium-alkali syndrome is an important cause of morbidity that may be on the rise, an unintended consequence of shifts in calcium and vitamin D intake in segments of the population. We review the pathophysiology of the calcium-alkali syndrome. PMID:24288027

  11. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted pyridine azo substituted... Specific Chemical Substances § 721.8780 Substituted pyridine azo substituted phenyl. (a) Chemical substance... substituted pyridine azo substituted phenyl (PMNs P-96-767 and P-96-773) are subject to reporting under...

  12. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted pyridine azo substituted... Specific Chemical Substances § 721.8780 Substituted pyridine azo substituted phenyl. (a) Chemical substance... substituted pyridine azo substituted phenyl (PMNs P-96-767 and P-96-773) are subject to reporting under...

  13. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted pyridine azo substituted... Specific Chemical Substances § 721.8780 Substituted pyridine azo substituted phenyl. (a) Chemical substance... substituted pyridine azo substituted phenyl (PMNs P-96-767 and P-96-773) are subject to reporting under...

  14. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted pyridine azo substituted... Specific Chemical Substances § 721.8780 Substituted pyridine azo substituted phenyl. (a) Chemical substance... substituted pyridine azo substituted phenyl (PMNs P-96-767 and P-96-773) are subject to reporting under...

  15. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted pyridine azo substituted... Specific Chemical Substances § 721.8780 Substituted pyridine azo substituted phenyl. (a) Chemical substance... substituted pyridine azo substituted phenyl (PMNs P-96-767 and P-96-773) are subject to reporting under...

  16. Alkali metal recovery from carbonaceous material conversion process

    DOEpatents

    Sharp, David W.; Clavenna, LeRoy R.; Gorbaty, Martin L.; Tsou, Joe M.

    1980-01-01

    In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced in the gasifier or similar reaction zone, alkali metal constitutents are recovered from the particles by withdrawing and passing the particles from the reaction zone to an alkali metal recovery zone in the substantial absence of molecular oxygen and treating the particles in the recovery zone with water or an aqueous solution in the substantial absence of molecular oxygen. The solution formed by treating the particles in the recovery zone will contain water-soluble alkali metal constituents and is recycled to the conversion process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. Preventing contact of the particles with oxygen as they are withdrawn from the reaction zone and during treatment in the recovery zone avoids the formation of undesirable alkali metal constituents in the aqueous solution produced in the recovery zone and insures maximum recovery of water-soluble alkali metal constituents from the alkali metal residues.

  17. Alkali element background reduction in laser ICP-MS

    NASA Astrophysics Data System (ADS)

    Magee, C. W., Jr.; Norris, C. A.

    2014-11-01

    Alkali backgrounds in laser ablation ICP-MS analyses can be enhanced by electron-induced ionization of alkali contamination on the skimmer cone, reducing effective detection limits for these elements. Traditionally, this problem is addressed by isolating analyses of high alkali materials onto a designated cone set, or by operating the ICP-MS in a "soft extraction" mode, which reduces the energy of electrons repelled into the potentially contaminated sampling cone by the extraction field. Here we present a novel approach, where we replace the traditional alkali glass tuning standards with synthetic low-alkali glass reference materials. Using this vitreous tuning solution, we find that this approach reduces the amount of alkali contamination produced, halving backgrounds for the heavy alkali elements without any change to analytical procedures. Using segregated cones is still the most effective method for reducing lithium backgrounds, but since the procedures are complimentary both can easily be applied to the routine operations of an analytical lab.

  18. Alkali element background reduction in laser ICP-MS

    NASA Astrophysics Data System (ADS)

    Magee, C. W., Jr.; Norris, C. A.

    2015-03-01

    Alkali backgrounds in laser ablation ICP-MS analyses can be enhanced by electron-induced ionisation of alkali contamination on the skimmer cone, reducing effective detection limits for these elements. Traditionally, this problem is addressed by isolating analyses of high-alkali materials onto a designated cone set, or by operating the ICP-MS in a "soft extraction" mode, which reduces the energy of electrons repelled into the potentially contaminated sampling cone by the extraction field. Here we present a novel approach, where we replace the traditional alkali glass tuning standards with synthetic low-alkali glass reference materials. Using this vitreous tuning solution, we find that this approach reduces the amount of alkali contamination produced, halving backgrounds for the heavy alkali elements without any change to analytical procedures. Using segregated cones is still the most effective method for reducing lithium backgrounds, but since the procedures are complimentary, both can easily be applied to the routine operations of an analytical lab.

  19. Developments in alkali-metal atomic magnetometry

    NASA Astrophysics Data System (ADS)

    Seltzer, Scott Jeffrey

    Alkali-metal magnetometers use the coherent precession of polarized atomic spins to detect and measure magnetic fields. Recent advances have enabled magnetometers to become competitive with SQUIDs as the most sensitive magnetic field detectors, and they now find use in a variety of areas ranging from medicine and NMR to explosives detection and fundamental physics research. In this thesis we discuss several developments in alkali-metal atomic magnetometry for both practical and fundamental applications. We present a new method of polarizing the alkali atoms by modulating the optical pumping rate at both the linear and quadratic Zeeman resonance frequencies. We demonstrate experimentally that this method enhances the sensitivity of a potassium magnetometer operating in the Earth's field by a factor of 4, and we calculate that it can reduce the orientation-dependent heading error to less than 0.1 nT. We discuss a radio-frequency magnetometer for detection of oscillating magnetic fields with sensitivity better than 0.2 fT/ Hz , which we apply to the observation of nuclear magnetic resonance (NMR) signals from polarized water, as well as nuclear quadrupole resonance (NQR) signals from ammonium nitrate. We demonstrate that a spin-exchange relaxation-free (SERF) magnetometer can measure all three vector components of the magnetic field in an unshielded environment with comparable sensitivity to other devices. We find that octadecyltrichlorosilane (OTS) acts as an anti-relaxation coating for alkali atoms at temperatures below 170°C, allowing them to collide with a glass surface up to 2,000 times before depolarizing, and we present the first demonstration of high-temperature magnetometry with a coated cell. We also describe a reusable alkali vapor cell intended for the study of interactions between alkali atoms and surface coatings. Finally, we explore the use of a cesium-xenon SERF comagnetometer for a proposed measurement of the permanent electric dipole moments (EDMs

  20. Strength and durability performance of alkali-activated rice husk ash geopolymer mortar.

    PubMed

    Kim, Yun Yong; Lee, Byung-Jae; Saraswathy, Velu; Kwon, Seung-Jun

    2014-01-01

    This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm(2) and 45 N/mm(2), respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4 environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete. PMID:25506063

  1. Strength and Durability Performance of Alkali-Activated Rice Husk Ash Geopolymer Mortar

    PubMed Central

    Kim, Yun Yong; Lee, Byung-Jae; Saraswathy, Velu

    2014-01-01

    This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm2 and 45 N/mm2, respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4 environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete. PMID:25506063

  2. The syntheses of phenol-containing azamacrocycles and liquid membrane transports of alkali cations

    NASA Astrophysics Data System (ADS)

    Ma, Shu-Lan; Qi, Chuan-Min; Zhu, Wen-Xiang; Guo, Qian-Ling; Liu, Ying-Chun; Zhang, Jing

    2005-01-01

    Two new tetra- N-substituted tetraazacrown ether derivatives, 4,7,13,16-tetra(2-hydroxy-3,4-dimethylbenzyl)-1,10-dioxa-4,7,13,16-tetraazacyclooctadecane (1) and 4,7,13,16-tetra(5- t-butyl-2-hydroxybenzyl)-1,10-dioxa-4,7,13,16-tetraazacyclooctadecane (2), have been synthesized via one-pot Mannich reaction. The compound 2 was structurally characterized. The liquid membrane transports of alkali metal cations using these two new macrocycles and the other two bisphenol-containing diaza-18-crown-6 ligands as ion-carriers were also studied. The results show that the rates of cation transport are closely related to the number of nitrogen donors and the steric effect of the substituted groups. Compared with some macrocyclic ligands, the two newly synthesized tetraazamacrocycles showed a good selectivity for Li +, and the two diazamacrocycles showed a good selectivity for Na +.

  3. Effect of alkali lignins with different molecular weights from alkali pretreated rice straw hydrolyzate on enzymatic hydrolysis.

    PubMed

    Li, Yun; Qi, Benkun; Luo, Jianquan; Wan, Yinhua

    2016-01-01

    This study investigated the effect of alkali lignins with different molecular weights on enzymatic hydrolysis of lignocellulose. Different alkali lignins fractions, which were obtained from cascade ultrafiltration, were added into the dilute acid pretreated (DAP) and alkali pretreated (AP) rice straws respectively during enzymatic hydrolysis. The results showed that the addition of alkali lignins enhanced the hydrolysis and the enhancement for hydrolysis increased with increasing molecular weights of alkali lignins, with maximum enhancement being 28.69% for DAP and 20.05% for AP, respectively. The enhancement was partly attributed to the improved cellulase activity, and filter paper activity increased by 18.03% when adding lignin with highest molecular weight. It was found that the enhancement of enzymatic hydrolysis was correlated with the adsorption affinity of cellulase on alkali lignins, and the difference in surface charge and hydrophobicity of alkali lignins were responsible for the difference in affinity between cellulase and lignins. PMID:26496216

  4. Removal of Retired Alkali Metal Test Systems

    SciTech Connect

    BREHM, W.F.

    2003-01-01

    This paper describes the successful effort to remove alkali metals, alkali metal residues, and piping and structures from retired non-radioactive test systems on the Hanford Site. These test systems were used between 1965 and 1982 to support the Fast Flux Test Facility and the Liquid Metal Fast Breeder Reactor Program. A considerable volume of sodium and sodium-potassium alloy (NaK) was successfully recycled to the commercial sector; structural material and electrical material such as wiring was also recycled. Innovative techniques were used to safely remove NaK and its residues from a test system that could not be gravity-drained. The work was done safely, with no environmental issues or significant schedule delays.

  5. Removal of Retired Alkali Metal Test Systems

    SciTech Connect

    Brehm, W. F.; Church, W. R.; Biglin, J. W.

    2003-02-26

    This paper describes the successful effort to remove alkali metals, alkali metal residues, and piping and structures from retired non-radioactive test systems on the Hanford Site. These test systems were used between 1965 and 1982 to support the Fast Flux Test Facility and the Liquid Metal Fast Breeder Reactor Program. A considerable volume of sodium and sodium-potassium alloy (NaK) was successfully recycled to the commercial sector; structural material and electrical material such as wiring was also recycled. Innovative techniques were used to safely remove NaK and its residues from a test system that could not be gravity-drained. The work was done safely, with no environmental issues or significant schedule delays.

  6. Quantum magnetism of alkali Rydberg atoms

    NASA Astrophysics Data System (ADS)

    Malinovskaya, Svetlana; Liu, Gengyuan

    2016-05-01

    We discuss a method to control dynamics in many-body spin states of 87Rb Rydberg atoms. The method permits excitation of cold gases and form ordered structures of alkali atoms. It makes use of a two-photon excitation scheme with circularly polarized and linearly chirped pulses. The method aims for controlled quantum state preparation in large ensembles. It is actual for experiments studding the spin hopping dynamics and realization of quantum random walks.

  7. Alkali Metal Heat Pipe Life Issues

    NASA Technical Reports Server (NTRS)

    Reid, Robert S.

    2004-01-01

    One approach to space fission power system design is predicated on the use of alkali metal heat pipes, either as radiator elements, thermal management components, or as part of the core primary heat-transfer system. This synopsis characterizes long-life core heat pipes. References are included where more detailed information can be found. Specifics shown here are for demonstrational purposes and do not necessarily reflect current Project Prometheus point designs.

  8. Alkali metal protective garment and composite material

    SciTech Connect

    Ballif, J.L.; Yuan, W.W.

    1980-09-16

    A protective garment and composite material providing satisfactory heat resistance and physical protection for articles and personnel exposed to hot molten alkali metals, such as sodium are described. Physical protection is provided by a continuous layer of nickel foil. Heat resistance is provided by an underlying backing layer of thermal insulation. Overlying outer layers of fireproof woven ceramic fibers are used to protect the foil during storage and handling.

  9. Alkali metal protective garment and composite material

    SciTech Connect

    Ballif, III, John L.; Yuan, Wei W.

    1980-01-01

    A protective garment and composite material providing satisfactory heat resistance and physical protection for articles and personnel exposed to hot molten alkali metals, such as sodium. Physical protection is provided by a continuous layer of nickel foil. Heat resistance is provided by an underlying backing layer of thermal insulation. Overlying outer layers of fireproof woven ceramic fibers are used to protect the foil during storage and handling.

  10. Study of superconducting state parameters of alkali alkali binary alloys by a pseudopotential

    NASA Astrophysics Data System (ADS)

    Vora, Aditya M.

    2006-12-01

    A detailed study of the superconducting state parameters (SSP) viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ∗, transition temperature TC, isotope effect exponent α and effective interaction strength N OV of ten alkali-alkali binary alloys i.e. Li 1- xNa x, Li 1- xK x, Li 1- xRb x, Li 1- xCs x, Na 1- xK x, Na 1- xRb x, Na 1- xCs x, K 1- xRb x, K 1- xCs x and Rb 1- xCs x are made within the framework of the model potential formalism and employing the pseudo-alloy-atom (PAA) model for the first time. We use the Ashcroft’s empty core (EMC) model potential for evaluating the superconducting properties of alkali alloys. Five different forms of local field correction functions viz. Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used to incorporate the exchange and correlation effects. A considerable influence of various exchange and correlation functions on λ and μ∗ is found from the present study. Reasonable agreement with the theoretical values of the SSP of pure components is found (corresponding to the concentration x = 0 or 1). It is also concluded that nature of the SSP strongly depends on the value of the atomic volume Ω0 of alkali-alkali binary alloys.

  11. Transport properties of alkali metal doped fullerides

    SciTech Connect

    Yadav, Daluram Yadav, Nishchhal

    2015-07-31

    We have studied the intercage interactions between the adjacent C{sub 60} cages and expansion of lattice due to the intercalation of alkali atoms based on the spring model to estimate phonon frequencies from the dynamical matrix for the intermolecular alkali-C{sub 60} phonons. We considered a two-peak model for the phonon density of states to investigate the nature of electron pairing mechanism for superconducting state in fullerides. Coulomb repulsive parameter and the electron phonon coupling strength are obtained within the random phase approximation. Transition temperature, T{sub c}, is obtained in a situation when the free electrons in lowest molecular orbital are coupled with alkali-C{sub 60} phonons as 5 K, which is much lower as compared to reported T{sub c} (20 K). The superconducting pairing is mainly driven by the high frequency intramolecular phonons and their effects enhance it to 22 K. The importance of the present study, the pressure effect and normal state transport properties are calculated within the same model leading superconductivity.

  12. Transport properties of alkali metal doped fullerides

    NASA Astrophysics Data System (ADS)

    Yadav, Daluram; Yadav, Nishchhal

    2015-07-01

    We have studied the intercage interactions between the adjacent C60 cages and expansion of lattice due to the intercalation of alkali atoms based on the spring model to estimate phonon frequencies from the dynamical matrix for the intermolecular alkali-C60 phonons. We considered a two-peak model for the phonon density of states to investigate the nature of electron pairing mechanism for superconducting state in fullerides. Coulomb repulsive parameter and the electron phonon coupling strength are obtained within the random phase approximation. Transition temperature, Tc, is obtained in a situation when the free electrons in lowest molecular orbital are coupled with alkali-C60 phonons as 5 K, which is much lower as compared to reported Tc (20 K). The superconducting pairing is mainly driven by the high frequency intramolecular phonons and their effects enhance it to 22 K. The importance of the present study, the pressure effect and normal state transport properties are calculated within the same model leading superconductivity.

  13. Ion Pairing in Alkali Nitrate Electrolyte Solutions.

    PubMed

    Xie, Wen Jun; Zhang, Zhen; Gao, Yi Qin

    2016-03-10

    In this study, we investigate the thermodynamics of alkali nitrate salt solutions, especially the formation of contact ion pairs between alkali cation and nitrate anion. The ion-pairing propensity shows an order of LiNO3 < NaNO3 < KNO3. Such results explain the salt activity coefficients and suggest that the empirical "law of matching water affinity" is followed by these alkali nitrate salt solutions. The spatial patterns of contact ion pairs are different in the three salt solutions studied here: Li(+) forms the contact ion pair with only one oxygen of the nitrate while Na(+) and K(+) can also be shared by two oxygens of the nitrate. In reproducing the salt activity coefficient using Kirkwood-Buff theory, we find that it is essential to include electronic polarization for Li(+) which has a high charge density. The electronic continuum correction for nonpolarizable force field significantly improves the agreement between the calculated activity coefficients and their experimental values. This approach also improves the performance of the force field on salt solubility. From these two aspects, this study suggests that electronic continuum correction can be a promising approach to force-field development for ions with high charge densities. PMID:26901167

  14. Contributions to the mixed-alkali effect in molecular dynamics simulations of alkali silicate glasses

    NASA Astrophysics Data System (ADS)

    Lammert, Heiko; Heuer, Andreas

    2005-12-01

    The mixed-alkali effect in the cation dynamics in silicate glasses is analyzed via molecular dynamics simulations. Observations suggest a description of the dynamics in terms of stable sites mostly specific to one ionic species. As main contributions to the mixed-alkali slow down longer residence times and an increased probability of correlated backjumps are identified. The slow down is related to the limited accessibility of foreign sites. The mismatch experienced in a foreign site is stronger and more retarding for the larger ions, the smaller ions can be temporarily accommodated. Also correlations between unlike as well as like cations are demonstrated that support cooperative behavior.

  15. Method for the safe disposal of alkali metal

    DOEpatents

    Johnson, Terry R.

    1977-01-01

    Alkali metals such as those employed in liquid metal coolant systems can be safely reacted to form hydroxides by first dissolving the alkali metal in relatively inert metals such as lead or bismuth. The alloy thus formed is contacted with a molten salt including the alkali metal hydroxide and possibly the alkali metal carbonate in the presence of oxygen. This oxidizes the alkali metal to an oxide which is soluble within the molten salt. The salt is separated and contacted with steam or steam-CO.sub.2 mixture to convert the alkali metal oxide to the hydroxide. These reactions can be conducted with minimal hydrogen evolution and with the heat of reaction distributed between the several reaction steps.

  16. Managing Substitute Teaching.

    ERIC Educational Resources Information Center

    Jones, Kevin R.

    1999-01-01

    This news brief presents information on managing substitute teaching. The information is based on issues discussed at a summit meeting which included public school administrators and personnel directors from around the nation. The main topics of concern focused around four core components related to the management of substitute teaching:…

  17. Determination of the common and rare alkalies in mineral analysis

    USGS Publications Warehouse

    Wells, R.C.; Stevens, R.E.

    1934-01-01

    Methods are described which afford a determination of each member of the alkali group and are successful in dealing with the quantities of the rare alkalies found in rocks and minerals. The procedures are relatively rapid and based chiefly on the use of chloroplatinic acid, absolute alcohol and ether, and ammonium sulfate. The percentages of all the alkalies found in a number of minerals are given.

  18. Environmental mercury contamination around a chlor-alkali plant

    SciTech Connect

    Lodenius, M.; Tulisalo, E.

    1984-04-01

    The chlor-alkali industry is one of the most important emitters of mercury. This metal is effectively spread from chlor-alkali plants into the atmosphere and it has been reported that only a few percent of the mercury emissions are deposited locally the major part spreading over very large areas. The purpose of this investigation was to study the spreading of mercury up to 100 km from a chlor-alkali plant using three different biological indicators.

  19. Electrochemical devices utilizing molten alkali metal electrode-reactant

    DOEpatents

    Hitchcock, D.C.; Mailhe, C.C.; De Jonghe, L.C.

    1985-07-10

    Electrochemical cells are provided with a reactive metal to reduce the oxide of the alkali metal electrode-reactant. Cells employing a molten alkali metal electrode, e.g., sodium, in contact with a ceramic electrolyte, which is a conductor of the ions of the alkali metal forming the electrode, exhibit a lower resistance when a reactive metal, e.g., vanadium, is allowed to react with and reduce the alkali metal oxide. Such cells exhibit less degradation of the electrolyte and of the glass seals often used to joining the electrolyte to the other components of the cell under cycling conditions.

  20. Electrochemical devices utilizing molten alkali metal electrode-reactant

    DOEpatents

    Hitchcock, David C.; Mailhe, Catherine C.; De Jonghe, Lutgard C.

    1986-01-01

    Electrochemical cells are provided with a reactive metal to reduce the oxide of the alkali metal electrode-reactant. Cells employing a molten alkali metal electrode, e.g., sodium, in contact with a ceramic electrolyte, which is a conductor of the ions of the alkali metal forming the electrode, exhibit a lower resistance when a reactive metal, e.g., vanadium, is allowed to react with and reduce the alkali metal oxide. Such cells exhibit less degradation of the electrolyte and of the glass seals often used to joining the electrolyte to the other components of the cell under cycling conditions.

  1. Measurement of Total Site Mercury Emissions from Chlor-Alkali Plant Using Ultraviolet Differential Optical Absorption Spectroscopy and Cell Room Roof-Vent Monitoring

    EPA Science Inventory

    This technical note describes a United States Environmental Protection Agency (U.S. EPA) measurement project to determine elemental mercury (Hg0) emissions from a mercury cell chlor-alkali (MCCA) facility in the southeastern U.S. during a 53-day monitoring campaign in the fall of...

  2. Ab Initio Molecular Dynamics of Dimerization and Clustering in Alkali Metal Vapors.

    PubMed

    Chaban, Vitaly V; Prezhdo, Oleg V

    2016-06-30

    Alkali metals are known to form dimers, trimers, and tetramers in their vapors. The mechanism and regularities of this phenomenon characterize the chemical behavior of the first group elements. We report ab initio molecular dynamics (AIMD) simulations of the alkali metal vapors and characterize their structural properties, including radial distribution functions and atomic cluster size distributions. AIMD confirms formation of Men, where n ranges from 2 to 4. High pressure sharply favors larger structures, whereas high temperature decreases their fraction. Heavier alkali metals maintain somewhat larger fractions of Me2, Me3, and Me4, relative to isolated atoms. A single atom is the most frequently observed structure in vapors, irrespective of the element and temperature. Due to technical difficulties of working with high temperatures and pressures in experiments, AIMD is the most affordable method of research. It provides valuable understanding of the chemical behavior of Li, Na, K, Rb, and Cs, which can lead to development of new chemical reactions involving these metals. PMID:27294399

  3. Electrodes For Alkali-Metal Thermoelectric Converters

    NASA Technical Reports Server (NTRS)

    Williams, Roger M.; Wheeler, Bob L.; Jeffries-Nakamura, Barbara; Lamb, James L.; Bankston, C. Perry; Cole, Terry

    1989-01-01

    Combination of thin, porous electrode and overlying collector grid reduces internal resistance of alkali-metal thermoelectric converter cell. Low resistance of new electrode and grid boosts power density nearly to 1 W/cm2 of electrode area at typical operating temperatures of 1,000 to 1,300 K. Conductive grid encircles electrode film on alumina tube. Bus wire runs along tube to collect electrical current from grid. Such converters used to transform solar, nuclear, and waste heat into electric power.

  4. High power diode pumped alkali vapor lasers

    NASA Astrophysics Data System (ADS)

    Zweiback, J.; Krupke, B.

    2008-05-01

    Diode pumped alkali lasers have developed rapidly since their first demonstration. These lasers offer a path to convert highly efficient, but relatively low brightness, laser diodes into a single high power, high brightness beam. General Atomics has been engaged in the development of DPALs with scalable architectures. We have examined different species and pump characteristics. We show that high absorption can be achieved even when the pump source bandwidth is several times the absorption bandwidth. In addition, we present experimental results for both potassium and rubidium systems pumped with a 0.2 nm bandwidth alexandrite laser. These data show slope efficiencies of 67% and 72% respectively.

  5. Cathode architectures for alkali metal / oxygen batteries

    SciTech Connect

    Visco, Steven J; Nimon, Vitaliy; De Jonghe, Lutgard C; Volfkovich, Yury; Bograchev, Daniil

    2015-01-13

    Electrochemical energy storage devices, such as alkali metal-oxygen battery cells (e.g., non-aqueous lithium-air cells), have a cathode architecture with a porous structure and pore composition that is tailored to improve cell performance, especially as it pertains to one or more of the discharge/charge rate, cycle life, and delivered ampere-hour capacity. A porous cathode architecture having a pore volume that is derived from pores of varying radii wherein the pore size distribution is tailored as a function of the architecture thickness is one way to achieve one or more of the aforementioned cell performance improvements.

  6. Elucidation of transport mechanism and enhanced alkali ion transference numbers in mixed alkali metal-organic ionic molten salts.

    PubMed

    Chen, Fangfang; Forsyth, Maria

    2016-07-28

    Mixed salts of Ionic Liquids (ILs) and alkali metal salts, developed as electrolytes for lithium and sodium batteries, have shown a remarkable ability to facilitate high rate capability for lithium and sodium electrochemical cycling. It has been suggested that this may be due to a high alkali metal ion transference number at concentrations approaching 50 mol% Li(+) or Na(+), relative to lower concentrations. Computational investigations for two IL systems illustrate the formation of extended alkali-anion aggregates as the alkali metal ion concentration increases. This tends to favor the diffusion of alkali metal ions compared with other ionic species in electrolyte solutions; behavior that has recently been reported for Li(+) in a phosphonium ionic liquid, thus an increasing alkali transference number. The mechanism of alkali metal ion diffusion via this extended coordination environment present at high concentrations is explained and compared to the dynamics at lower concentrations. Heterogeneous alkali metal ion dynamics are also evident and, somewhat counter-intuitively, it appears that the faster ions are those that are generally found clustered with the anions. Furthermore these fast alkali metal ions appear to correlate with fastest ionic liquid solvent ions. PMID:27375042

  7. (abstract) Fundamental Mechanisms of Electrode Kinetics and Alkali Metal Atom Transport at the Alkali Beta'-Alumina/Porous Electrode/Alkali Metal Vapor Three Phase Boundary

    NASA Technical Reports Server (NTRS)

    Williams, R. M.; Jeffries-Nakamura, B.; Ryan, M. A.; Underwood, M. L.; O'Connor, D.; Kisor, A.; Kikkert, S. K.

    1993-01-01

    The mechanisms of electrode kinetics and mass transport of alkali metal oxidation and alkali metal cation reduction at the solid electrolyte/porous electrode boundary as well as alkali metal transport through porous metal electrodes has important applications in optimizing device performance in alkali metal thermal to electric converter (AMTEC) cells which are high temperature, high current density electrochemical cells. Basic studies of these processes also affords the opportunity to investigate a very basic electrochemical reaction over a wide range of conditions; and a variety of mass transport modes at high temperatures via electrochemical techniques. The temperature range of these investigations covers 700K to 1240K; the alkali metal vapor pressures range from about 10(sup -2) to 10(sup 2) Pa; and electrodes studied have included Mo, W, Mo/Na(sub 2)MoO(sub 4), W/Na(sub 2)WO(sub 4), WPt(sub x), and WRh(sub x) (1.0 < x < 6.0 ) with Na at Na-beta'-alumina, and Mo with K at K-beta'-alumina. Both liquid metal/solid electrolyte/alkali metal vapor and alkali metal vapor/solid electrolyte/vapor cells have been used to characterize the reaction and transport processes. We have previously reported evidence of ionic, free molecular flow, and surface transport of sodium in several types of AMTEC electrodes.

  8. Characterization of Adsorbed Alkali Metal Ions in 2:1 Type Clay Minerals from First-Principles Metadynamics.

    PubMed

    Ikeda, Takashi; Suzuki, Shinichi; Yaita, Tsuyoshi

    2015-07-30

    Adsorption states of alkali metal ions in three kinds of 2:1 type clay minerals are systematically investigated via first-principles-based metadynamics. Our reconstructed free energy surfaces in a two-dimensional space of coordination numbers specifically employed as collective variables for describing the interlayer cations show that an inner-sphere (IS) complex is preferentially formed for Cs(+) in the 2:1 type trioctahedral clay minerals with saponite-like compositions, where lighter alkali metal ions show a tendency to form an outer-sphere one instead. The strong preference for an IS complex observed for Cs(+) is found to result partially from the capability of recognizing selectively Cs(+) ions at the basal O atoms with the Lewis basicity significantly enhanced by the isomorphic substitution in tetrahedral sheets. PMID:26151150

  9. 40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... naphthalenyl-substituted azonaphthol chromium complex. 721.981 Section 721.981 Protection of Environment...-substituted naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance and significant new... naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex (PMN P-93-1631) is subject...

  10. 40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... naphthalenyl-substituted azonaphthol chromium complex. 721.981 Section 721.981 Protection of Environment...-substituted naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance and significant new... naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex (PMN P-93-1631) is subject...

  11. 40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... naphthalenyl-substituted azonaphthol chromium complex. 721.981 Section 721.981 Protection of Environment...-substituted naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance and significant new... naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex (PMN P-93-1631) is subject...

  12. 40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... naphthalenyl-substituted azonaphthol chromium complex. 721.981 Section 721.981 Protection of Environment...-substituted naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance and significant new... naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex (PMN P-93-1631) is subject...

  13. 40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... naphthalenyl-substituted azonaphthol chromium complex. 721.981 Section 721.981 Protection of Environment...-substituted naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance and significant new... naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex (PMN P-93-1631) is subject...

  14. Alkali ash material: a novel fly ash-based cement.

    PubMed

    Rostami, Hossein; Brendley, William

    2003-08-01

    The United States generates 110 million t of coal ash annually. Approximately 70 million t of this coal ash is fly ash, of which 27% is recycled and the remaining 73% is landfilled. Disposal of such a huge quantity of ash poses a significant environmental problem. A new cementitious material has been developed, called alkali ash material (AAM), which is used to produce concrete for construction. AAM can be used to create a variety of concrete strengths and could revolutionize the concrete product manufacturing industry due to its economic advantage. AAM contains 40-95% Class F fly ash and is used as cement to bind sand, stone, and fibers creating concrete. AAM concrete has been tested for strength, durability, mechanical properties, and, most importantly, economic viability. AAM concrete is economically and technically viable for many construction applications. Some properties include rapid strength gain (90% of ultimate in 1 d), high ultimate strengths (110 MPa or 16,000 psi in 1 d), excellent acid resistance, and freeze-thaw durability. AAM's resistance to chemical attack, such as sulfuric (H2SO4), nitric (HNO3), hydrochloric (HCl), and organic acids, is far better than portland cement concrete. AAM is resistant to freeze-thaw attack based on ASTM C-666 specifications. Potential immediate applications of AAM are blocks, pipe, median barriers, sound barriers, and overlaying materials. Eventual markets are high strength construction products, bridge beams, prestressed members, concrete tanks, highway appurtenances, and other concrete products. PMID:12966995

  15. Sugar substitutes during pregnancy

    PubMed Central

    Pope, Eliza; Koren, Gideon; Bozzo, Pina

    2014-01-01

    Abstract Question I have a pregnant patient who regularly consumes sugar substitutes and she asked me if continuing their use would affect her pregnancy or child. What should I tell her, and are there certain options that are better for use during pregnancy? Answer Although more research is required to fully determine the effects of in utero exposure to sugar substitutes, the available data do not suggest adverse effects in pregnancy. However, it is recommended that sugar substitutes be consumed in moderate amounts, adhering to the acceptable daily intake standards set by regulatory agencies. PMID:25392440

  16. Superconductivity in alkali metal intercalated iron selenides.

    PubMed

    Krzton-Maziopa, A; Svitlyk, V; Pomjakushina, E; Puzniak, R; Conder, K

    2016-07-27

    Alkali metal intercalated iron selenide superconductors A x Fe2-y Se2 (where A  =  K, Rb, Cs, Tl/K, and Tl/Rb) are characterized by several unique properties, which were not revealed in other superconducting materials. The compounds crystallize in overall simple layered structure with FeSe layers intercalated with alkali metal. The structure turned out to be pretty complex as the existing Fe-vacancies order below ~550 K, which further leads to an antiferromagnetic ordering with Néel temperature fairly above room temperature. At even lower temperatures a phase separation is observed. While one of these phases stays magnetic down to the lowest temperatures the second is becoming superconducting below ~30 K. All these effects give rise to complex relationships between the structure, magnetism and superconductivity. In particular the iron vacancy ordering, linked with a long-range magnetic order and a mesoscopic phase separation, is assumed to be an intrinsic property of the system. Since the discovery of superconductivity in those compounds in 2010 they were investigated very extensively. Results of the studies conducted using a variety of experimental techniques and performed during the last five years were published in hundreds of reports. The present paper reviews scientific work concerning methods of synthesis and crystal growth, structural and superconducting properties as well as pressure investigations. PMID:27248118

  17. Durability of Alkali Activated Blast Furnace Slag

    NASA Astrophysics Data System (ADS)

    Ellis, K.; Alharbi, N.; Matheu, P. S.; Varela, B.; Hailstone, R.

    2015-11-01

    The alkali activation of blast furnace slag has the potential to reduce the environmental impact of cementitious materials and to be applied in geographic zones where weather is a factor that negatively affects performance of materials based on Ordinary Portland Cement. The scientific literature provides many examples of alkali activated slag with high compressive strengths; however research into the durability and resistance to aggressive environments is still necessary for applications in harsh weather conditions. In this study two design mixes of blast furnace slag with mine tailings were activated with a potassium based solution. The design mixes were characterized by scanning electron microscopy, BET analysis and compressive strength testing. Freeze-thaw testing up to 100 freeze-thaw cycles was performed in 10% road salt solution. Our findings included compressive strength of up to 100 MPa after 28 days of curing and 120 MPa after freeze-thaw testing. The relationship between pore size, compressive strength, and compressive strength after freeze-thaw was explored.

  18. Superconductivity in alkali metal intercalated iron selenides

    NASA Astrophysics Data System (ADS)

    Krzton-Maziopa, A.; Svitlyk, V.; Pomjakushina, E.; Puzniak, R.; Conder, K.

    2016-07-01

    Alkali metal intercalated iron selenide superconductors A x Fe2‑y Se2 (where A  =  K, Rb, Cs, Tl/K, and Tl/Rb) are characterized by several unique properties, which were not revealed in other superconducting materials. The compounds crystallize in overall simple layered structure with FeSe layers intercalated with alkali metal. The structure turned out to be pretty complex as the existing Fe-vacancies order below ~550 K, which further leads to an antiferromagnetic ordering with Néel temperature fairly above room temperature. At even lower temperatures a phase separation is observed. While one of these phases stays magnetic down to the lowest temperatures the second is becoming superconducting below ~30 K. All these effects give rise to complex relationships between the structure, magnetism and superconductivity. In particular the iron vacancy ordering, linked with a long-range magnetic order and a mesoscopic phase separation, is assumed to be an intrinsic property of the system. Since the discovery of superconductivity in those compounds in 2010 they were investigated very extensively. Results of the studies conducted using a variety of experimental techniques and performed during the last five years were published in hundreds of reports. The present paper reviews scientific work concerning methods of synthesis and crystal growth, structural and superconducting properties as well as pressure investigations.

  19. Unconventional Superconductivity of Alkali-doped Fullerenes

    NASA Astrophysics Data System (ADS)

    Potocnik, Anton; Krajnc, Andraz; Jeglic, Peter; Prassides, Kosmas; Rosseinsky, Matthew J.; Arcon, Denis

    2014-03-01

    The superconductivity of the alkali-doped fullerenes (A3C60, A = alkali metal) has been so far discussed within the standard theory of superconductivity developed by Bardeen, Cooper and Shrieffer (BCS), even thought, they exhibit relatively high critical temperatures (up to Tc = 32 K). However, after our recent high-pressure measurements on Cs3C60 such description became questionable. We have shown that the superconducting phase of A3C60, in fact, borders the antiferromagnetic insulating phase (AFI), commonly observed for high-temperature superconductors like cuprates or pnictides. In addition, we also increased the maximal Tc to 38 K. To investigate this peculiar superconductivity close to the border with AFI state we employed nuclear magnetic resonance technique on Cs3-xRbxC60 and on Cs3C60 at various high pressures. Our results could not be correctly explained either by the standard BCS or the extended BCS that includes electron-electron repulsion interaction - the Migdal-Eliashberg theory. Far better agreement is obtained by the Dynamical Mean Field Theory. Due to similarity with other unconventional superconductors these results could also be relevant to other unconventional high-temperature superconductors.

  20. Dynamics of reactive ultracold alkali polar molecules

    NASA Astrophysics Data System (ADS)

    Quéméner, Goulven; Bohn, John; Petrov, Alexander; Kotochigova, Svetlana

    2011-05-01

    Recently, ultracold polar molecules of KRb have been created. These molecules are chemically reactive and their lifetime in a trap is limited. However, their lifetime increases when they are loaded into a 1D optical lattice in the presence of an electric field. These results naturally raise the question of manipulating ultracold collisions of other species of alkali dimer molecules, with an eye toward both novel stereochemistry, as well as suppressing unwanted reactions, to enable condensed matter applications. In this talk, we report on a comparative study between the bi-alkali polar molecules of LiNa, LiK, LiRb, LiCs which have been predicted to be reactive. We compute the isotropic C6 coefficients of these systems and we predict the elastic and reactive rate coefficients when an electric field is applied in a 1D optical lattice. We will discuss the efficacy of evaporative cooling for each species. This work was supported by a MURI-AFOSR grant.

  1. Formation of lysinoalanine in egg white under alkali treatment.

    PubMed

    Zhao, Yan; Luo, Xuying; Li, Jianke; Xu, Mingsheng; Tu, Yonggang

    2016-03-01

    To investigate the formation mechanism of lysinoalanine (LAL) in eggs during the alkali treatment process, NaOH was used for the direct alkali treatment of egg white, ovalbumin, and amino acids; in addition, the amount of LAL formed during the alkali treatment process was measured. The results showed that the alkali treatment resulted in the formation of LAL in the egg white. The LAL content increased with increasing pH and temperature, with the LAL content first increasing and then leveling off with increasing time. The amount of LAL formed in the ovalbumin under the alkali treatment condition accounted for approximately 50.51% to 58.68% of the amount of LAL formed in the egg white. Thus, the LAL formed in the ovalbumin was the main source for the LAL in the egg white during the alkali treatment process. Under the alkali treatment condition, free L-serine, L-cysteine, and L-cystine reacted with L-lysine to form LAL; therefore, they are the precursor amino acids of LAL formed in eggs during the alkali treatment process. PMID:26772660

  2. Recovery of alkali metal constituents from catalytic coal conversion residues

    DOEpatents

    Soung, Wen Y.

    1984-01-01

    In a coal gasification operation (32) or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles by contacting them (46, 53, 61, 69) with water or an aqueous solution to remove water-soluble alkali metal constituents and produce an aqueous solution enriched in said constituents. The aqueous solution thus produced is then contacted with carbon dioxide (63) to precipitate silicon constituents, the pH of the resultant solution is increased (81), preferably to a value in the range between about 12.5 and about 15.0, and the solution of increased pH is evaporated (84) to increase the alkali metal concentration. The concentrated aqueous solution is then recycled to the conversion process (86, 18, 17) where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.

  3. 40 CFR 721.4740 - Alkali metal nitrites.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... defined in 40 CFR 721.3) containing amines. (b) ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkali metal nitrites. 721.4740... Substances § 721.4740 Alkali metal nitrites. (a) Chemical substances and significant new use subject...

  4. 40 CFR 721.4740 - Alkali metal nitrites.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... defined in 40 CFR 721.3) containing amines. (b) ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkali metal nitrites. 721.4740... Substances § 721.4740 Alkali metal nitrites. (a) Chemical substances and significant new use subject...

  5. 40 CFR 721.4740 - Alkali metal nitrites.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... defined in 40 CFR 721.3) containing amines. (b) ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkali metal nitrites. 721.4740... Substances § 721.4740 Alkali metal nitrites. (a) Chemical substances and significant new use subject...

  6. 40 CFR 721.4740 - Alkali metal nitrites.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... defined in 40 CFR 721.3) containing amines. (b) ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkali metal nitrites. 721.4740... Substances § 721.4740 Alkali metal nitrites. (a) Chemical substances and significant new use subject...

  7. Self-discharge in bimetallic cells containing alkali metal

    NASA Technical Reports Server (NTRS)

    Foster, M. S.; Hesson, J. C.; Shimotake, H.

    1969-01-01

    Theoretical analysis of thermally regenerative bimetallic cells with alkali metal anodes shows a relation between the current drawn and the rate of discharge under open-circuit conditions. The self-discharge rate of the cell is due to the dissolution and ionization of alkali metal atoms in the fused-salt electrolyte

  8. COMPLEX FLUORIDES OF PLUTONIUM AND AN ALKALI METAL

    DOEpatents

    Seaborg, G.T.

    1960-08-01

    A method is given for precipitating alkali metal plutonium fluorides. such as KPuF/sub 5/, KPu/sub 2/F/sub 9/, NaPuF/sub 5/, and RbPuF/sub 5/, from an aqueous plutonium(IV) solution by adding hydrogen fluoride and alkali-metal- fluoride.

  9. 40 CFR 721.4740 - Alkali metal nitrites.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4740 Alkali metal nitrites. (a) Chemical substances and significant new use subject to reporting. (1) The category of chemical substances which are nitrites of the alkali metals (Group IA in...

  10. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkali metal alkyl...

  11. Substitution of anticonvulsant drugs

    PubMed Central

    Steinhoff, Bernhard J; Runge, Uwe; Witte, Otto W; Stefan, Hermann; Hufnagel, Andreas; Mayer, Thomas; Krämer, Günter

    2009-01-01

    Changing from branded drugs to generic alternatives, or between different generic formulations, is common practice aiming at reducing health care costs. It has been suggested that antiepileptic drugs (AEDs) should be exempt from substitution because of the potential negative consequences of adverse events and breakthrough seizures. Controlled data are lacking on the risk of substitution. However, retrospective data from large medical claims databases suggest that switching might be associated with increased use of AED and non-AED medications, and health care resources (including hospitalization). In addition, some anecdotal evidence from patients and health care providers’ surveys suggest a potentially negative impact of substitution. Well-controlled data are needed to assess the real risk associated with substitution, allowing health care professionals involved in the care of patients with epilepsy to make informed decisions. This paper reviews currently available literature, based on which the authors suggest that the decision to substitute should be made on an individual basis by the physician and an informed patient. Unendorsed or undisclosed substitution at the pharmacy level should be discouraged. PMID:19707254

  12. Effects of alkali treatments on Ag nanowire transparent conductive films

    NASA Astrophysics Data System (ADS)

    Kim, Sunho; Kang, Jun-gu; Eom, Tae-yil; Moon, Bongjin; Lee, Hoo-Jeong

    2016-06-01

    In this study, we employ various alkali materials (alkali metals with different base strengths, and ammonia gas and solution) to improve the conductivity of silver nanowire (Ag NW)-networked films. The alkali treatment appears to remove the surface oxide and improve the conductivity. When applied with TiO2 nanoparticles, the treatment appears more effective as the alkalis gather around wire junctions and help them weld to each other via heat emitted from the reduction reaction. The ammonia solution treatment is found to be quick and aggressive, damaging the wires severely in the case of excessive treatment. On the other hand, the ammonia gas treatment seems much less aggressive and does not damage the wires even after a long exposure. The results of this study highlight the effectiveness of the alkali treatment in improving of the conductivity of Ag NW-networked transparent conductive films.

  13. Performance of Straight Steel Fibres Reinforced Alkali Activated Concrete

    NASA Astrophysics Data System (ADS)

    Faris, Meor Ahmad; Bakri Abdullah, Mohd Mustafa Al; Nizar Ismail, Khairul; Muniandy, Ratnasamy; Putra Jaya, Ramadhansyah

    2016-06-01

    This paper focus on the performance of alkali activated concrete produced by using fly ash activated by sodium silicate and sodium hydroxide solutions. These alkali activated concrete were reinforced with straight steel fibres with different weight percentage starting from 0 % up to 5 %. Chemical composition of raw material in the production alkali activated concrete which is fly ash was first identified by using X-ray fluorescence. Results reveal there have an effect of straight steel fibres inclusion to the alkali activated concrete. Highest compressive strength of alkali activated concrete which is 67.72 MPa was obtained when 3 % of straight fibres were added. As well as flexural strength, highest flexural strength which is 6.78 MPa was obtained at 3 % of straight steel fibres inclusions.

  14. Chemistry of alkali cation exchanged faujasite and mesoporous NaX using alkyl halides and phosphates

    NASA Astrophysics Data System (ADS)

    Lee, Min-Hong

    The purpose of this work was to increase the reactivity of Faujasite X (NaX) zeolite toward the reactive decontamination of materials subject to nucleophilic attack by means of zeolite cation optimization and by means of the synthesis of mesoporous Faujasite X. Primary alkyl halides and trialkyl phosphates have been the test materials on which the cation-optimized and mesoporous zeolites have been tested. In the alkali cation optimization work, reactions of methyl iodide and 1-chloropropane with alkali metal cation exchanged Faujasite zeolite X were investigated at room temperature. The reactivity of the framework and the product formation were shown to depend on zeolite framework counter-cation. A quantitative study of zeolite product formation has been carried out, primarily using solid-state NMR spectroscopy. Large alkali cations showed preference toward substitution chemistry. In contrast, alkyl halide exposed LiX and NaX zeolites underwent both substitution and elimination. Subsequently introduced water molecules led to hydrolysis of framework species that was sensitive to framework counter-cation. The mesoporous NaX zeolites work undertakes to test whether an improvement in surface chemical reactivity can be achieved by introducing mesopores into the already reactive nucleophilic microporous NaX zeolite. Incorporation of the polydiallyl dimethyl ammonium chloride (PDADMAC) template and the formation of mesopores in Faujasite X zeolite (NaX) were successful and well-characterized. The mesopores are proposed to have occurred from incorporation of the cationic PDADMAC polymer into the zeolite by compensating zeolite framework charge. Subsequent sodium cation exchange of calcined mesoporous NaX was shown to restore the chemical reactivity characteristic of as-synthesized NaX. Trialkyl organophosphorous compounds underwent substitution reactions. The reactivity of both microporous and mesoporous Faujasite zeolite X and the product formation was shown to depend on

  15. Diversity and Mechanisms of Alkali Tolerance in Lactobacilli▿

    PubMed Central

    Sawatari, Yuki; Yokota, Atsushi

    2007-01-01

    We determined the maximum pH that allows growth (pHmax) for 34 strains of lactobacilli. High alkali tolerance was exhibited by strains of Lactobacillus casei, L. paracasei subsp. tolerans, L. paracasei subsp. paracasei, L. curvatus, L. pentosus, and L. plantarum that originated from plant material, with pHmax values between 8.5 and 8.9. Among these, L. casei NRIC 1917 and L. paracasei subsp. tolerans NRIC 1940 showed the highest pHmax, at 8.9. Digestive tract isolates of L. gasseri, L. johnsonii, L. reuteri, L. salivarius subsp. salicinius, and L. salivarius subsp. salivarius exhibited moderate alkali tolerance, with pHmax values between 8.1 and 8.5. Dairy isolates of L. delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, and L. helveticus exhibited no alkali tolerance, with pHmax values between 6.7 and 7.1. Measurement of the internal pH of representative strains revealed the formation of transmembrane proton gradients (ΔpH) in a reversed direction (i.e., acidic interior) at alkaline external-pH ranges, regardless of their degrees of alkali tolerance. Thus, the reversed ΔpH did not determine alkali tolerance diversity. However, the ΔpH contributed to alkali tolerance, as the pHmax values of several strains decreased with the addition of nigericin, which dissipates ΔpH. Although neutral external-pH values resulted in the highest glycolysis activity in the presence of nigericin regardless of alkali tolerance, substantial glucose utilization was still detected in the alkali-tolerant strains, even in a pH range of between 8.0 and 8.5, at which the remaining strains lost most activity. Therefore, the alkali tolerance of glycolysis reactions contributes greatly to the determination of alkali tolerance diversity. PMID:17449704

  16. Synthesis and characterization of nitrogen substituted zeolites

    NASA Astrophysics Data System (ADS)

    Dogan, Fulya

    The interest in basic solid materials, particularly for basic zeolites has considerably increased in the last two decades because of their potential use in catalysis and separation. Basic zeolites have most often been obtained by ion-exchange or impregnation with alkali metal cations or grafting of organic bases onto zeolite pore walls. Such materials often suffer from instability and/or pore blockage, because none of these approaches places basic sites directly into the zeolite framework. Recently zeolitic materials have been made with some of the bridging oxygen atoms in Si--O--Si and/or Si--O--Al linkages replaced by NH groups, i.e. by substitution of framework oxygen by nitrogen. As a result, the basic strength of the framework increases due to the lower electronegativity of nitrogen with respect to oxygen. In this study, solid base catalysts are obtained by nitrogen substitution of the faujasite type of zeolites under ammonia flow at high temperatures. The efficiency of the reaction is tested by using zeolites with different aluminum contents and extraframework cations and varying the reaction conditions such as ammonia flow rate, reaction temperature and duration. The characterization studies show that high levels of nitrogen substitution can be achieved while maintaining porosity, particularly for NaY and low-aluminum HY zeolites, without a significant loss in the crystallinity. 27Al and 29 Si MAS NMR experiments performed on the nitrogen substituted zeolites show dealumination of the framework and preferential substitution for Si--OH--Al sites at the early stages of the reaction (temperatures at 750--800 °C). No preference is seen for reactions performed at higher temperatures and longer reaction times (e.g., 850 °C and 48 h). X-ray PDF analysis performed on the modified zeolites show that the Si-N distance in the 1st shell is longer than Si-O bond distance and Si-Si/Al bond distance of the Si-O/N-Si/Al linkage decreases, as an indication of a decrease in

  17. Elastic properties of alkali-feldspars

    NASA Astrophysics Data System (ADS)

    Waeselmann, N.; Brown, J.; Angel, R. J.; Ross, N.; Kaminsky, W.

    2013-12-01

    New measurements of single crystal elastic moduli for a suite of the alkali feldspars are reported. In order to interpret Earth's seismic structure, knowledge of the elastic properties of constituent minerals is essential. The elasticity of feldspar minerals, despite being the most abundant phase in Earth's crust (estimated to be more than 60%), were previously poorly characterized. All prior seismic and petrologic studies have utilized 50-year-old results, of questionable quality, based on 1-bar measurements on pseudo-single crystals. Alkali-feldspars present a large experimental challenge associated with their structural complexity. In the K-end member (KAlSi3O8) the symmetry is governed by Al/Si ordering, in the Na-end member (NaAlSi3O8) the symmetry is governed by whether or not there is a displacive collapse of the framework independent of the Al/Si ordering. K-feldspars exhibit monoclinic (C2/m) symmetry (necessitating determination of 13 elastic moduli) if disordered and triclinic (C-1) symmetry (21 elastic moduli) if ordered. Exsolution of Na-rich and K-rich phases is ubiquitous in natural samples, making it difficult to find suitable single phase and untwinned samples for study. The small single domain samples selected for this study were previously characterized by x-ray diffraction and microprobe analysis to ensure adequate sample quality. Surface wave velocities were measured on oriented surfaces of natural and synthetic single crystals using impulsively stimulated light scattering. A surface corrugation with a spacing of about 2 microns was impulsively created by the overlap of 100 ps infrared light pulses. The time evolution of the stimulated standing elastic waves was detected by measuring the intensity of diffraction from the surface corrugation of a variably delayed probe pulse. This method allows accurate (better than 0.2%) determination of velocities on samples smaller than 100 microns. The combination of measured surface wave velocities and

  18. Solvent-averaged potentials for alkali-, earth alkali-, and alkylammonium halide aqueous solutions

    NASA Astrophysics Data System (ADS)

    Hess, Berk; van der Vegt, Nico F. A.

    2007-12-01

    We derive effective, solvent-free ion-ion potentials for alkali-, earth alkali-, and alkylammonium halide aqueous solutions. The implicit solvent potentials are parametrized to reproduce experimental osmotic coefficients. The modeling approach minimizes the amount of input required from atomistic (force field) models, which usually predict large variations in the effective ion-ion potentials at short distances. For the smaller ion species, the reported potentials are composed of a Coulomb and a Weeks-Chandler-Andersen term. For larger ions, we find that an additional, attractive potential is required at the contact minimum, which is related to solvent degrees of freedom that are usually not accounted for in standard electrostatics models. The reported potentials provide a simple and accurate force field for use in molecular dynamics and Monte Carlo simulations of (poly-)electrolyte systems.

  19. Alkali oxide-tantalum oxide and alkali oxide-niobium oxide ionic conductors

    NASA Technical Reports Server (NTRS)

    Roth, R. S.; Parker, H. S.; Brower, W. S.; Minor, D.

    1974-01-01

    A search was made for new cationic conducting phases in alkali-tantalate and niobate systems. The phase equilibrium diagrams were constructed for the six binary systems Nb2O5-LiNbO3, Nb2O5-NaNbO3, Nb2O5-KNbO3, Ta2O5-NaTaO3, Ta2O5-LiTaO3, and Ta2O5-KTaO3. Various other binary and ternary systems were also examined. Pellets of nineteen phases were evaluated (by the sponsoring agency) by dielectric loss measurements. Attempts were made to grow large crystals of eight different phases. The system Ta2O5-KTaO3 contains at least three phases which showed peaks in dielectric loss vs. temperature. All three contain structures related to the tungsten bronzes with alkali ions in non-stoichiometric crystallographic positions.

  20. Volcanic Origin of Alkali Halides on Io

    NASA Technical Reports Server (NTRS)

    Schaefer, L.; Fegley, B., Jr.

    2003-01-01

    The recent observation of NaCl (gas) on Io confirms our earlier prediction that NaCl is produced volcanically. Here we extend our calculations by modeling thermochemical equilibrium of O, S, Li, Na, K, Rb, Cs, F, Cl, Br, and I as a function of temperature and pressure in a Pele-like volcanic gas with O/S/Na/Cl/K = 1.518/1/0.05/0.04/0.005 and CI chondritic ratios of the other (as yet unobserved) alkalis and halogens. For reference, the nominal temperature and pressure for Pele is 1760 plus or minus 210 K and 0.01 bars based on Galileo data and modeling.

  1. Alkali differentiation in LL-chondrites

    NASA Astrophysics Data System (ADS)

    Wlotzka, F.; Palme, H.; Spettel, B.; Wanke, H.; Fredriksson, K.; Noonan, A. F.

    1983-04-01

    The Kraehenberg and Bhola LL-group chondrites are heterogeneous agglomerates which contain a variety of lithic fragments and chondrules as well as crystal fragments. Both meteorites contain large, cm-sized fragments with high K enrichments. The K-rich inclusions are fragments of larger rock bodies which crystallized from melts of chondritic parent material that had previously been enriched in K and in heavier alkalies,while also being depleted in Na and metal. It is suggested that the K enrichment occurred as an exchange for Na in feldspars via a vapor phase, whose presence on the chondrite parent body (or bodies) is supported by the recent finding of fluid inclusions in chondritic silicates. Cooling rate considerations indicate that the K-rich rock units could not have been very large, implying that the K-rich materials were locally molten by, for example, impact.

  2. Heat pipes containing alkali metal working fluid

    NASA Technical Reports Server (NTRS)

    Morris, J. F. (Inventor)

    1981-01-01

    A technique for improving high temperature evaporation-condensation heat-transfer devices which have important and unique advantage in terrestrial and space energy processing is described. The device is in the form of a heat pipe comprising a sealed container or envelope which contains a capillary wick. The temperature of one end of the heat pipe is raised by the input of heat from an external heat source which is extremely hot and corrosive. A working fluid of a corrosive alkali metal, such as lithium, sodium, or potassium transfers this heat to a heat receiver remote from the heat source. The container and wick are fabricated from a superalloy containing a small percentage of a corrosion inhibiting or gettering element. Lanthanum, scandium, yttrium, thorium, and hafnium are utilized as the alloying metal.

  3. Comparative alkali washing of simulated radioactive sludge

    SciTech Connect

    Fugate, G.A.; Ensor, D.D.; Egan, B.Z.

    1996-10-01

    The treatment of large volumes of radioactive sludge generated from uranium and plutonium recovery processes is a pressing problem in the environmental restoration currently planned at various U.S. Department of Energy sites. This sludge, commonly stored in underground tanks, is mainly in the form of metal oxides or precipitated metal hydroxides and the bulk of this material is nonradioactive. One method being developed to pretreat this waste takes advantage of the amphoteric character of aluminum and other nonradioactive elements. Previous studies have reported on the dissolution of eleven elements from simulated sludge using NaOH solutions up to 6M. This work provides a comparative study using KOH. The effectiveness of the alkali washing as a treatment method to reduce the bulk of radioactive sludge requiring long term isolation will be discussed.

  4. The substitutability of reinforcers

    PubMed Central

    Green, Leonard; Freed, Debra E.

    1993-01-01

    Substitutability is a construct borrowed from microeconomics that describes a continuum of possible interactions among the reinforcers in a given situation. Highly substitutable reinforcers, which occupy one end of the continuum, are readily traded for each other due to their functional similarity. Complementary reinforcers, at the other end of the continuum, tend to be consumed jointly in fairly rigid proportion, and therefore cannot be traded for one another except to achieve that proportion. At the center of the continuum are reinforcers that are independent with respect to each other; consumption of one has no influence on consumption of another. Psychological research and analyses in terms of substitutability employ standard operant conditioning paradigms in which humans and nonhumans choose between alternative reinforcers. The range of reinforcer interactions found in these studies is more readily accommodated and predicted when behavior-analytic models of choice consider issues of substitutability. New insights are gained into such areas as eating and drinking, electrical brain stimulation, temporal separation of choice alternatives, behavior therapy, drug use, and addictions. Moreover, the generalized matching law (Baum, 1974) gains greater explanatory power and comprehensiveness when measures of substitutability are included. PMID:16812696

  5. The substitutability of reinforcers.

    PubMed

    Green, Leonard; Freed, Debra E

    1993-07-01

    Substitutability is a construct borrowed from microeconomics that describes a continuum of possible interactions among the reinforcers in a given situation. Highly substitutable reinforcers, which occupy one end of the continuum, are readily traded for each other due to their functional similarity. Complementary reinforcers, at the other end of the continuum, tend to be consumed jointly in fairly rigid proportion, and therefore cannot be traded for one another except to achieve that proportion. At the center of the continuum are reinforcers that are independent with respect to each other; consumption of one has no influence on consumption of another. Psychological research and analyses in terms of substitutability employ standard operant conditioning paradigms in which humans and nonhumans choose between alternative reinforcers. The range of reinforcer interactions found in these studies is more readily accommodated and predicted when behavior-analytic models of choice consider issues of substitutability. New insights are gained into such areas as eating and drinking, electrical brain stimulation, temporal separation of choice alternatives, behavior therapy, drug use, and addictions. Moreover, the generalized matching law (Baum, 1974) gains greater explanatory power and comprehensiveness when measures of substitutability are included. PMID:16812696

  6. Solid state cell with alkali metal halo-alkali thiocyanate electrolyte

    SciTech Connect

    Rao, B. M.; Silbernagel, B. G.

    1980-02-26

    A novel electrochemical cell is disclosed utilizing: (A) an anode which contains an alkali metal as an anode-active material; (B) a cathode and (C) an electrolyte comprising an electrolytically effective amount of one or more compounds having the formula: (Ax)ma'scn wherein a is an alkali metal, X is a halogen, a' is an alkali metal and 0.1 < or = N < or = 10. Preferred systems include lithium-containing anodes, lithium-containing electrolytes and cathodes which contain cathode-active material selected from the group consisting of cathode-active sulfurs, halogens, halides, chromates, phosphates, oxides and chalcogenides, especially those chalcogenides of the empirical formula mzm wherein M is one or more metals selected from the group consisting of iron, titanium, zirconium, hafnium, niobium, tantalum and vanadium, Z is one or more chalcogens selected from the group consisting of oxygen, sulfur, selenium and tellurium, and M is a numerical value between about 1.8 and about 3.2.

  7. Ionic alkali halide XUV laser feasibility study

    SciTech Connect

    Yang, T.T.; Gylys, V.T.; Bower, R.D.; Harris, D.G.; Blauer, J.A.; Turner, C.E.; Hindy, R.N.

    1989-11-10

    The objective of this work is to assess the feasibility of a select set of ionic alkali halide XUV laser concepts by obtaining the relevant kinetic and spectroscopic parameters required for a proof-of-principle and conceptual design. The proposed lasers operate in the 80--200 nm spectral region and do not require input from outside radiation sources for their operation. Frequency up-conversion and frequency mixing techniques and therefore not considered in the work to be described. An experimental and theoretical study of a new type of laser operating in the extreme ultraviolet wavelength region has been conducted. The lasing species are singly ionized alkali halide molecules such as Rb{sup 2+}F{sub {minus}}, Rb{sup 2+}Br{sup {minus}} and Cs{sup 2+}F{sup {minus}}. These species are similar in electronic structure to the rare gas halide excimers, such as XeF and Krf, except that the ionic molecules emit at wavelengths of 80--200 nm, much shorter than the conventional rare-gas halide excimer laser. The radiative lifetime of these molecules are typically near 1 ns, which is about an order of magnitude shorter than that for rare-gas halide systems. The values of the cross section for stimulated emission are on the order of 1 {times} 10{sup {minus}16}cm{sup 2}. Because of the fundamental similarity to existing UV lasers, these systems show promise as a high power, efficient XUV lasers. 55 refs., 50 figs., 5 tabs.

  8. Controlled in-situ dissolution of an alkali metal

    DOEpatents

    Jones, Jeffrey Donald; Dooley, Kirk John; Tolman, David Donald

    2012-09-11

    A method for the controllable dissolution of one or more alkali metals from a vessel containing a one or more alkali metals and/or one or more partially passivated alkali metals. The vessel preferably comprising a sodium, NaK or other alkali metal-cooled nuclear reactor that has been used. The alkali metal, preferably sodium, potassium or a combination thereof, in the vessel is exposed to a treatment liquid, preferably an acidic liquid, more preferably citric acid. Preferably, the treatment liquid is maintained in continuous motion relative to any surface of unreacted alkali metal with which the treatment liquid is in contact. The treatment liquid is preferably pumped into the vessel containing the one or more alkali metals and the resulting fluid is extracted and optionally further processed. Preferably, the resulting off-gases are processed by an off-gas treatment system and the resulting liquids are processed by a liquid disposal system. In one preferred embodiment, an inert gas is pumped into the vessel along with the treatment liquid.

  9. Ultrasonic coal washing to leach alkali elements from coals.

    PubMed

    Balakrishnan, S; Reddy, V Midhun; Nagarajan, R

    2015-11-01

    Deposition of fly ash particles onto heat-transfer surfaces is often one of the reasons for unscheduled shut-downs of coal-fired boilers. Fouling deposits encountered in convective sections of a boiler are characterized by arrival of ash particles in solidified (solid) state. Fouling is most frequently caused by condensation and chemical reaction of alkali vapors with the deposited ash particles creating a wet surface conducive to collect impacting ash particles. Hence, the amount of alkali elements present in coals, which, in turn, is available in the flue gas as condensable vapors, determines the formation and growth of fouling deposits. In this context, removal of alkali elements becomes vital when inferior coals having high-ash content are utilized for power generation. With the concept of reducing alkali elements present in a coal entering the combustor, whereby the fouling deposits can either be minimized or be weakened due to absence of alkali gluing effect, the ultrasonic leaching of alkali elements from coals is investigated in this study. Ultrasonic water-washing and chemical-washing, in comparison with agitation, are studied in order to estimate the intensification of the alkali removal process by sonication. PMID:26186840

  10. Alkali elemental and potassium isotopic compositions of Semarkona chondrules

    USGS Publications Warehouse

    Alexander, C.M. O'D.; Grossman, J.N.

    2005-01-01

    We report measurements of K isotope ratios in 28 Semarkona chondrules with a wide range of petrologic types and bulk compositions as well as the compositions of CPX-mesostasis pairs in 17 type I Semarkona chondrules, including two chondrules with radial alkali zonation and 19 type II chondrules. Despite the wide range in K/Al ratios, no systematic variations in K isotopic compositions were found. Semarkona chondrules do not record a simple history of Rayleigh-type loss of K. Experimentally determined evaporation rates suggest that considerable alkali evaporation would have occurred during chondrule formation. Nevertheless, based on Na CPX-mesostasis distribution coefficients, the alkali contents of the cores of most chondrules in Semarkona were probably established at the time of final crystallization. However, Na CPX-mesostasis distribution coefficients also show that alkali zonation in type I Semarkona chondrules was produced by entry of alkalis after solidification, probably during parent body alteration. This alkali metasomatism may have gone to completion in some chondrules. Our preferred explanation for the lack of systematic isotopic enrichments, even in alkali depleted type I chondrule cores, is that they exchanged with the ambient gas as they cooled. ?? The Meteoritical Society, 2005.

  11. Aryl substitution of pentacenes

    PubMed Central

    Waterloo, Andreas R; Sale, Anna-Chiara; Lehnherr, Dan; Hampel, Frank

    2014-01-01

    Summary A series of 11 new pentacene derivatives has been synthesized, with unsymmetrical substitution based on a trialkylsilylethynyl group at the 6-position and various aryl groups appended to the 13-position. The electronic and physical properties of the new pentacene chromophores have been analyzed by UV–vis spectroscopy (solution and thin films), thermoanalytical methods (DSC and TGA), cyclic voltammetry, as well as X-ray crystallography (for 8 derivatives). X-ray crystallography has been specifically used to study the influence of unsymmetrical substitution on the solid-state packing of the pentacene derivatives. The obtained results add to our ability to better predict substitution patterns that might be helpful for designing new semiconductors for use in solid-state devices. PMID:25161729

  12. [Delegation yes, substitution no!].

    PubMed

    Schroeder, A

    2014-08-01

    The aging of society leads on the one hand to increasing case numbers and on the other hand to a reduction in the number of physicians available for patient treatment. The delegation and substitution of medical duties as a tried and tested method is increasingly being recommended in order to compensate for the lack of physicians. The Berufsverband der Deutschen Urologen (BDU, Professional Association of German Urologists) supports the guiding principle of the Bundesärztekammer (Federal Medical Council) of "delegation yes, substitution no" and rejects a substitution of medical duties by non-medical academic health personnel. Against the background of the demographic changes, the increasing need for treatment and the current deficiency of junior physicians, a more extensive inclusion of well-qualified and experienced non-medical personnel by the delegation of medically responsible duties (medical scope of practice) can be an appropriate measure to maintain a good medical service in practices, hospitals and nursing homes. PMID:25047595

  13. [Substitution therapy with diamorphine].

    PubMed

    Roy, Mandy; Bleich, Stefan; Hillemacher, Thomas

    2016-03-01

    After a long lead time the substitution with diamorphine was taken into the German catalogue of statutory health insurance in 2010. Currently about 570 patients are treated this way in 9 ambulances in Germany. The study phase as well as the clinical practice are showing the success of this therapy concerning physical and mental health of patients and their circumstances of social life. Thereby substitution with diamorphine is underlying very strict admission criteria regarding patients on the one hand and particular organizational requirements of the medical institution on the other hand. This article explains these criteria in detail as well as neurobiological information and clinical workflow is presented. Improvement of mandatory requirements could lead to a better reaching of patients who benefit from substitution with diamorphine. PMID:27029045

  14. Life cycle assessment of solid waste management strategies in a chlor-alkali production facility.

    PubMed

    Muñoz, Edmundo; Navia, Rodrigo

    2011-06-01

    The waste management of a chlor-alkali and calcium chloride industrial facility from southern Chile was the object of this study. The main solid waste materials generated in these processes are brine sediments and calcium chloride sediments, respectively. Both residues are mixed in the liquid phase and filtered in a press filter, obtaining a final low humidity solid waste, called 'mixed sediments', which is disposed of in an industrial landfill as non-hazardous waste. The aim of the present study was to compare by means of LCA, the current waste management option of the studied chlor-alkali facility, namely landfill disposal, with two new possible options: the reuse of the mixed sediments as mineral additive in compost and the use of brine sediments as an unconventional sorbent for the removal of heavy metals from wastewater. The functional unit was defined as 1 tonne of waste being managed. To perform this evaluation, software SimaPro 7.0 was used, selecting the Ecoindicator 99 and CML 2000 methodologies for impact evaluation. The obtained results indicate that the use of brine sediments as a novel material for the removal of heavy metals from wastewater (scenario 3) presented environmental benefits when compared with the waste management option of sediments landfilling (scenario 1). The avoided environmental loads, generated by the substitution of activated granular carbon and the removal of Cu and Zn from wastewater in the treatment process generated positive environmental impacts, enhancing the environmental performance of scenario 3. PMID:20699293

  15. Use of ancient copper slags in Portland cement and alkali activated cement matrices.

    PubMed

    Nazer, Amin; Payá, Jordi; Borrachero, María Victoria; Monzó, José

    2016-02-01

    Some Chilean copper slag dumps from the nineteenth century still remain, without a proposed use that encourages recycling and reduces environmental impact. In this paper, the copper slag abandoned in landfills is proposed as a new building material. The slags studied were taken from Playa Negra and Púquios dumps, both located in the region of Atacama in northern Chile. Pozzolanic activity in lime and Portland cement systems, as well as the alkali activation in pastes with copper slag cured at different temperatures, was studied. The reactivity of the slag was measured using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), electrical conductivity and pH in aqueous suspension and Fourier Transform Infrared Spectroscopy (FTIR). Furthermore, copper slag-Portland cement mortars with the substitution of 25% (by weight) of cement by copper slag and alkali-activated slag mortars cured at 20 and 65 °C were made, to determine the compressive strength. The results indicate that the ancient copper slags studied have interesting binding properties for the construction sector. PMID:26615227

  16. Electrochemical cell utilizing molten alkali metal electrode-reactant

    DOEpatents

    Virkar, Anil V.; Miller, Gerald R.

    1983-11-04

    An improved electrochemical cell comprising an additive-modified molten alkali metal electrode-reactant and/or electrolyte is disclosed. Various electrochemical cells employing a molten alkali metal, e.g., sodium, electrode in contact with a cationically conductive ceramic membrane experience a lower resistance and a lower temperature coefficient of resistance whenever small amounts of selenium are present at the interface of the electrolyte and the molten alkali metal. Further, cells having small amounts of selenium present at the electrolyte-molten metal interface exhibit less degradation of the electrolyte under long term cycling conditions.

  17. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted methyl styrene, methyl methacrylate, and substituted silane. 721.6920 Section 721.6920 Protection... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  18. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted methyl styrene, methyl methacrylate, and substituted silane. 721.6920 Section 721.6920 Protection... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  19. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted methyl styrene, methyl methacrylate, and substituted silane. 721.6920 Section 721.6920 Protection... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  20. No cheap substitutes.

    PubMed

    Griffiths, Peter

    2016-06-15

    The Nuffield Trust report on reshaping the healthcare workforce was published last month. Its conclusions were widely reported as a recommendation to 'train up' nurses as a solution to junior doctor shortages, with support workers, in turn, substituting for registered nurses. PMID:27305238

  1. The Age of Substitutability

    ERIC Educational Resources Information Center

    Goeller, H. E.; Weinberg, Alvin M.

    1976-01-01

    Dwindling mineral resources might cause a shift from nonrenewable resources to renewable resources and inexhaustible elements such as iron and aluminum. Alternative energy sources such as breeder, fusion, solar, and geothermal power must be developed for production and recycling of materials. Substitution and, hence, living standards ultimately…

  2. Performing Substitute Teaching

    ERIC Educational Resources Information Center

    Bletzer, Keith V.

    2010-01-01

    Formal education is both a right and an obligation bestowed on young people in most all nations of the world. Teachers (adults) and students (youth) form a co-present dyadic contract that must be maintained within the classroom. Substitute teachers fill a role in sustaining the integrity of this teacher-student link, whenever teachers are absent.…

  3. Electric field-induced softening of alkali silicate glasses

    NASA Astrophysics Data System (ADS)

    McLaren, C.; Heffner, W.; Tessarollo, R.; Raj, R.; Jain, H.

    2015-11-01

    Motivated by the advantages of two-electrode flash sintering over normal sintering, we have investigated the effect of an external electric field on the viscosity of glass. The results show remarkable electric field-induced softening (EFIS), as application of DC field significantly lowers the softening temperature of glass. To establish the origin of EFIS, the effect is compared for single vs. mixed-alkali silicate glasses with fixed mole percentage of the alkali ions such that the mobility of alkali ions is greatly reduced while the basic network structure does not change much. The sodium silicate and lithium-sodium mixed alkali silicate glasses were tested mechanically in situ under compression in external electric field ranging from 0 to 250 V/cm in specially designed equipment. A comparison of data for different compositions indicates a complex mechanical response, which is observed as field-induced viscous flow due to a combination of Joule heating, electrolysis and dielectric breakdown.

  4. The 4843 Alkali Metal Storage Facility Closure Plan

    SciTech Connect

    Not Available

    1991-06-01

    The 4843 AMSF has been used primarily to provide a centralized building to receive and store dangerous and mixed alkali metal waste, including sodium and lithium, which has been generated at the Fast Flux Test Facility and at various other Hanford Site operations that used alkali metals. Most of the dangerous and mixed alkali metal waste received consists of retired equipment from liquid sodium processes. The unit continues to store material. In general, only solid alkali metal waste that is water reactive is stored at the 4843 AMSF. The 4843 AMSF will be closed in a manner consistent with Ecology guidelines and regulations (WAC 173-303-610). The general closure procedure is detailed as follows.

  5. Hall Determination of Atomic Radii of Alkali Metals

    ERIC Educational Resources Information Center

    Houari, Ahmed

    2008-01-01

    I will propose here an alternative method for determining atomic radii of alkali metals based on the Hall measurements of their free electron densities and the knowledge of their crystal structure. (Contains 2 figures.)

  6. Method for intercalating alkali metal ions into carbon electrodes

    DOEpatents

    Doeff, M.M.; Ma, Y.; Visco, S.J.; DeJonghe, L.

    1995-08-22

    A low cost, relatively flexible, carbon electrode for use in a secondary battery is described. A method is provided for producing same, including intercalating alkali metal salts such as sodium and lithium into carbon.

  7. Method for intercalating alkali metal ions into carbon electrodes

    DOEpatents

    Doeff, Marca M.; Ma, Yanping; Visco, Steven J.; DeJonghe, Lutgard

    1995-01-01

    A low cost, relatively flexible, carbon electrode for use in a secondary battery is described. A method is provided for producing same, including intercalating alkali metal salts such as sodium and lithium into carbon.

  8. Electric field-induced softening of alkali silicate glasses

    SciTech Connect

    McLaren, C.; Heffner, W.; Jain, H.; Tessarollo, R.; Raj, R.

    2015-11-02

    Motivated by the advantages of two-electrode flash sintering over normal sintering, we have investigated the effect of an external electric field on the viscosity of glass. The results show remarkable electric field-induced softening (EFIS), as application of DC field significantly lowers the softening temperature of glass. To establish the origin of EFIS, the effect is compared for single vs. mixed-alkali silicate glasses with fixed mole percentage of the alkali ions such that the mobility of alkali ions is greatly reduced while the basic network structure does not change much. The sodium silicate and lithium-sodium mixed alkali silicate glasses were tested mechanically in situ under compression in external electric field ranging from 0 to 250 V/cm in specially designed equipment. A comparison of data for different compositions indicates a complex mechanical response, which is observed as field-induced viscous flow due to a combination of Joule heating, electrolysis and dielectric breakdown.

  9. Effect of cavitation on removal of alkali elements from coal

    NASA Astrophysics Data System (ADS)

    Srivalli, H.; Nirmal, L.; Nagarajan, R.

    2015-12-01

    The main impurities in coal are sulphur, ash and alkali. On combustion, the volatile forms of these impurities are either condensed on the boilers, or emitted in the form of potentially hazardous gases. The alkali elements present in coal help the fly ash particles adhere to boiler surfaces by providing a wet surface on which collection of these particles can take place. Use of ultrasonic techniques in cleaning of coal has stirred interest among researchers in recent times. Extraction of alkali elements by cavitation effect using low-frequency ultrasound, in the presence of reagents (HNO3 and H2O2) is reported in this paper. Powdered coal was dissolved with the reagent and exposed to ultrasonic fields of various frequencies at different time intervals. The treated solution is filtered and tested for alkali levels.

  10. Alkali absorption and citrate excretion in calcium nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Sakhaee, K.; Williams, R. H.; Oh, M. S.; Padalino, P.; Adams-Huet, B.; Whitson, P.; Pak, C. Y.

    1993-01-01

    The role of net gastrointestinal (GI) alkali absorption in the development of hypocitraturia was investigated. The net GI absorption of alkali was estimated from the difference between simple urinary cations (Ca, Mg, Na, and K) and anions (Cl and P). In 131 normal subjects, the 24 h urinary citrate was positively correlated with the net GI absorption of alkali (r = 0.49, p < 0.001). In 11 patients with distal renal tubular acidosis (RTA), urinary citrate excretion was subnormal relative to net GI alkali absorption, with data from most patients residing outside the 95% confidence ellipse described for normal subjects. However, the normal relationship between urinary citrate and net absorbed alkali was maintained in 11 patients with chronic diarrheal syndrome (CDS) and in 124 stone-forming patients devoid of RTA or CDS, half of whom had "idiopathic" hypocitraturia. The 18 stone-forming patients without RTA or CDS received potassium citrate (30-60 mEq/day). Both urinary citrate and net GI alkali absorption increased, yielding a significantly positive correlation (r = 0.62, p < 0.0001), with the slope indistinguishable from that of normal subjects. Thus, urinary citrate was normally dependent on the net GI absorption of alkali. This dependence was less marked in RTA, confirming the renal origin of hypocitraturia. However, the normal dependence was maintained in CDS and in idiopathic hypocitraturia, suggesting that reduced citrate excretion was largely dietary in origin as a result of low net alkali absorption (from a probable relative deficiency of vegetables and fruits or a relative excess of animal proteins).

  11. Rock Degradation by Alkali Metals: A Possible Lunar Erosion Mechanism.

    PubMed

    Naughton, J J; Barnes, I L; Hammond, D A

    1965-08-01

    When rocks melt under ultrahigh-vacuum conditions, their alkali components volatilize as metals. These metal vapors act to comminute polycrystalline rocks to their component minerals. The resultant powder is porous and loosely packed and its characteristics may be compatible with the lunar surface as revealed by the Ranger photographs. If meteorite impact or lunar volcanism has produced vaporization or areas of molten lava, alkali erosion may have given dust of this character in adjacent solid areas. PMID:17747570

  12. Electrochemical cell having an alkali-metal-nitrate electrode

    DOEpatents

    Roche, M.F.; Preto, S.K.

    1982-06-04

    A power-producing secondary electrochemical cell includes a molten alkali metal as the negative-electrode material and a molten-nitrate salt as the positive-electrode material. The molten material in the respective electrodes are separated by a solid barrier of alkali-metal-ion conducting material. A typical cell includes active materials of molten sodium separated from molten sodium nitrate and other nitrates in mixture by a layer of sodium ..beta..'' alumina.

  13. Technical writing versus technical writing

    NASA Technical Reports Server (NTRS)

    Dillingham, J. W.

    1981-01-01

    Two terms, two job categories, 'technical writer' and 'technical author' are discussed in terms of industrial and business requirements and standards. A distinction between 'technical writing' and technical 'writing' is made. The term 'technical editor' is also considered. Problems inherent in the design of programs to prepare and train students for these jobs are discussed. A closer alliance between industry and academia is suggested as a means of preparing students with competent technical communication skills (especially writing and editing skills) and good technical skills.

  14. Alkali metal yttrium neo-pentoxide double alkoxide precursors to alkali metal yttrium oxide nanomaterials

    DOE PAGESBeta

    Boyle, Timothy J.; Neville, Michael L.; Sears, Jeremiah Matthew; Cramer, Roger

    2016-03-15

    In this study, a series of alkali metal yttrium neo-pentoxide ([AY(ONep)4]) compounds were developed as precursors to alkali yttrium oxide (AYO2) nanomaterials. The reaction of yttrium amide ([Y(NR2)3] where R=Si(CH3)3) with four equivalents of H-ONep followed by addition of [A(NR2)] (A=Li, Na, K) or Ao (Ao=Rb, Cs) led to the formation of a complex series of AnY(ONep)3+n species, crystallographically identified as [Y2Li3(μ3-ONep)(μ3-HONep)(μ-ONep)5(ONep)3(HONep)2] (1), [YNa2(μ3-ONep)4(ONep)]2 (2), {[Y2K3(μ3-ONep)3(μ-ONep)4(ONep)2(ηξ-tol)2][Y4K2(μ4-O)(μ3-ONep)8(ONep)4]•ηx-tol]} (3), [Y4K2(μ4-O)(μ3-ONep)8(ONep)4] (3a), [Y2Rb3(μ4-ONep)3(μ-ONep)6] (4), and [Y2Cs4(μ6-O)(μ3-ONep)6(μ3-HONep)2(ONep)2(ηx-tol)4]•tol (5). Compounds 1–5 were investigated as single source precursors to AYOx nanomaterials following solvothermal routes (pyridine, 185 °C for 24h). The final products after thermal processing weremore » found by powder X-ray diffraction experiments to be Y2O3 with variable sized particles based on transmission electron diffraction. Energy dispersive X-ray spectroscopy studies indicated that the heavier alkali metal species were present in the isolated nanomaterials.« less

  15. Alkali-slag cements for the immobilization of radioactive wastes

    SciTech Connect

    Shi, C.; Day, R.L.

    1996-12-31

    Alkali-slag cements consist of glassy slag and an alkaline activator and can show both higher early and later strengths than Type III Portland cement, if a proper alkaline activator is used. An examination of microstructure of hardened alkali-slag cement pastes with the help of XRD and SEM with EDAX shows that the main hydration product is C-S-H (B) with low C/S ratio and no crystalline substances exist such as Ca(OH){sub 2}, Al (OH){sub 3} and sulphoaluminates. Mercury intrusion tests indicate that hardened alkali-slag cement pastes have a lower porosity than ordinary Portland cement, and contain mainly gel pores. The fine pore structure of hardened alkali-slag cement pastes will restrict the ingress of deleterious substances and the leaching of harmful species such as radionuclides. The leachability of Cs{sup + } from hardened alkali-slag cement pastes is only half of that from hardened Portland cement. From all these aspects, it is concluded that alkali-slag cements are a better solidification matrix than Portland cement for radioactive wastes.

  16. Temperature dependence of elastic properties in alkali borate binary glasses

    NASA Astrophysics Data System (ADS)

    Kawashima, Mitsuru; Matsuda, Yu; Kojima, Seiji

    2011-05-01

    The elastic properties of alkali borate glasses, xM 2O·(100 - x)B 2O 3 (M = Li, Na, K, Rb, Cs, x = 14, 28), have been investigated by Brillouin scattering spectroscopy from room temperature up to 1100 °C. Above the glass transition temperature, Tg, the longitudinal sound velocity, VL, decreases markedly on heating. Such significant changes of the elastic properties result from the breakdown of the glass network above Tg. Alkali borate family with the same x shows the similar behavior in the temperature variations of VL up to around Tg. The absorption coefficient, αL, increases gradually above Tg. With the increase of the size of an alkali ion, the slope of VL just above Tg decreases. Since the fragility is related to the slope, the present results suggest that the fragility of alkali borate glasses increases as the size of alkali ion decreases. Such an alkali dependence of the fragility is discussed on the basis of the fluctuation of the boron coordination number.

  17. Two-phase alkali-metal experiments in reduced gravity

    SciTech Connect

    Antoniak, Z.I.

    1986-06-01

    Future space missions envision the use of large nuclear reactors utilizing either a single or a two-phase alkali-metal working fluid. The design and analysis of such reactors require state-of-the-art computer codes that can properly treat alkali-metal flow and heat transfer in a reduced-gravity environment. A literature search of relevant experiments in reduced gravity is reported on here, and reveals a paucity of data for such correlations. The few ongoing experiments in reduced gravity are noted. General plans are put forth for the reduced-gravity experiments which will have to be performed, at NASA facilities, with benign fluids. A similar situation exists regarding two-phase alkali-metal flow and heat transfer, even in normal gravity. Existing data are conflicting and indequate for the task of modeling a space reactor using a two-phase alkali-metal coolant. The major features of past experiments are described here. Data from the reduced-gravity experiments with innocuous fluids are to be combined with normal gravity data from the two-phase alkali-metal experiments. Analyses undertaken here give every expectation that the correlations developed from this data base will provide a valid representation of alkali-metal heat transfer and pressure drop in reduced gravity.

  18. Reduction of phosphorus and alkali levels in coking coals

    SciTech Connect

    Hoare, I.C.; Waugh, A.B.

    1995-12-31

    A number of coals, though exhibiting desirable coking properties, can have undesirable levels of alkalis and phosphorus. All the phosphorus in the coal will report to the coke, eventually to the iron and thence to the steel, with adverse effects on its metallurgical properties. Alkalis have damaging effects on the blast furnace operation and can be responsible for loss of heat, loss of production, efficiency loss and reduced furnace life. Buyers of coking coal commonly specify such parameters as phosphorus in coal and alkalis in ash, with penalties and rejection over certain limits. With the introduction of new direct reduction technologies such as COREX and HISMELT, and others such as PCI, it is anticipated that coal producers will have even tighter phosphorus and alkali specifications imposed on their products. Phosphorus is predominantly inorganic in origin occurring in a wide variety of minerals in coal, but its main source is apatite. It can be found mainly in the lower density fractions of the coal and intimately bound, so that conventional physical beneficiation techniques are relatively ineffective. CSIRO has developed a cost effective, selective chemical demineralization treatment, which can be applied to the problem of high alkali, high phosphorus coals. This particular technique makes use of unrefined organic acid, which also has the advantage of being low in cost and environmentally benign. In this paper, the effectiveness of acid demineralization of a number of coals is discussed, within the context of their phosphorus and alkali distributions throughout various size/density fractions.

  19. Alkali-metal azides interacting with metal-organic frameworks.

    PubMed

    Armata, Nerina; Cortese, Remedios; Duca, Dario; Triolo, Roberto

    2013-01-14

    Interactions between alkali-metal azides and metal-organic framework (MOF) derivatives, namely, the first and third members of the isoreticular MOF (IRMOF) family, IRMOF-1 and IRMOF-3, are studied within the density functional theory (DFT) paradigm. The investigations take into account different models of the selected IRMOFs. The mutual influence between the alkali-metal azides and the π rings or Zn centers of the involved MOF derivatives are studied by considering the interactions both of the alkali-metal cations with model aromatic centers and of the alkali-metal azides with distinct sites of differently sized models of IRMOF-1 and IRMOF-3. Several exchange and correlation functionals are employed to calculate the corresponding interaction energies. Remarkably, it is found that, with increasing alkali-metal atom size, the latter decrease for cations interacting with the π-ring systems and increase for the azides interacting with the MOF fragments. The opposite behavior is explained by stabilization effects on the azide moieties and determined by the Zn atoms, which constitute the inorganic vertices of the IRMOF species. Larger cations can, in fact, coordinate more efficiently to both the aromatic center and the azide anion, and thus stabilizing bridging arrangements of the azide between one alkali-metal and two Zn atoms in an η(2) coordination mode are more favored. PMID:23161861

  20. Small diatomic alkali molecules at ultracold temperatures

    NASA Astrophysics Data System (ADS)

    Wang, Tout Taotao

    This thesis describes experimental work done with two of the smallest diatomic alkali molecules, 6Li2 and 23Na 6Li, each formed out of its constituent atoms at ultracold temperatures. The 23Na6Li molecule was formed for the first time at ultracold temperatures, after previous attempts failed due to an incorrect assignment of Feshbach resonances in the 6Li+23Na system. The experiment represents successful molecule formation around the most difficult Feshbach resonance ever used, and opens up the possibility of transferring NaLi to its spin-triplet ground state, which has both magnetic and electric dipole moments and is expected to be long-lived. For 6Li2, the experimental efforts in this thesis have solved a long-standing puzzle of apparently long lifetimes of closed-channel fermion pairs around a narrow Feshbach resonance, finding that the lifetime is in fact short, as expected in the absence of Pauli suppression of collisions. Moreover, measurements of collisions of Li2 with free Li atoms demonstrates a striking first example of collisions involving molecules at ultracold temperatures described by physics beyond universal long-range van der Waals interactions.

  1. Superconductivity in alkali-doped fullerene nanowhiskers.

    PubMed

    Takeya, Hiroyuki; Konno, Toshio; Hirata, Chika; Wakahara, Takatsugu; Miyazawa, Kun'ichi; Yamaguchi, Takahide; Tanaka, Masashi; Takano, Yoshihiko

    2016-09-01

    Superconductivity in alkali metal-doped fullerene nanowhiskers (C60NWs) was observed in K3.3C60NWs, Rb3.0C60NWs and Cs2.0Rb1.0C60NWs with transition temperatures at 17, 25 and 26 K, respectively. Almost full shielding volume fraction (~80%) was observed in K3.3C60NWs when subjected to thermal treatment at 200 °C for a duration of 24 h. In contrast, the shielding fraction of Rb3.0C60NWs and Cs2.0Rb1.0C60NWs were calculated to be 8% and 6%, respectively. Here we report on an extensive investigation of the superconducting properties of these AC60NWs (A  =  K3.3, Rb3.0 and Cs2.0Rb1.0). These properties are compared to the ones reported on the corresponding conventional (single-crystal or powder) K-doped fullerene. We also evaluated the critical current densities of these C60NWs using the Bean model under an applied magnetic field up to 50 kOe. PMID:27385220

  2. The timing of alkali metasomatism in paleosols

    NASA Technical Reports Server (NTRS)

    MacFarlane, A. W.; Holland, H. D.

    1991-01-01

    We have measured the concentrations of rubidium and strontium and 87Sr/86Sr values of whole-rock samples from three paleosols of different ages. The oldest of the three weathering horizons, the 2,760 Ma Mt. Roe #1 paleosol in the Fortescue Group of Western Australia, experienced addition of Rb, and probably Sr, at 2,168 +/- 10 Ma. The intermediate paleosol, developed on the Hekpoort Basalt in South Africa, is estimated to have formed at 2,200 Ma, and yields a Rb-Sr isochron age of 1,925 +/- 32 Ma. The youngest of the three paleosols, developed on the Ongeluk basalt in Griqualand West, South Africa ca. 1,900 Ma, yielded a Rb-Sr age of 1,257 +/- 11 Ma. The Rb-Sr systematics of all three paleosols were reset during post-weathering metasomatism related to local or regional thermal disturbances. The Rb-Sr systematics of the paleosols were not subsequently disturbed. The near-complete removal of the alkali and alkaline earth elements from these paleosols during weathering made them particularly susceptible to resetting of their Rb-Sr systematics. Paleosols of this type are therefore sensitive indicators of the timing of thermal disturbances.

  3. Bioinorganic Chemistry of the Alkali Metal Ions.

    PubMed

    Kim, Youngsam; Nguyen, Thuy-Tien T; Churchill, David G

    2016-01-01

    The common Group 1 alkali metals are indeed ubiquitous on earth, in the oceans and in biological systems. In this introductory chapter, concepts involving aqueous chemistry and aspects of general coordination chemistry and oxygen atom donor chemistry are introduced. Also, there are nuclear isotopes of importance. A general discussion of Group 1 begins from the prevalence of the ions, and from a comparison of their ionic radii and ionization energies. While oxygen and water molecule binding have the most relevance to biology and in forming a detailed understanding between the elements, there is a wide range of basic chemistry that is potentially important, especially with respect to biological chelation and synthetic multi-dentate ligand design. The elements are widely distributed in life forms, in the terrestrial environment and in the oceans. The details about the workings in animal, as well as plant life are presented in this volume. Important biometallic aspects of human health and medicine are introduced as well. Seeing as the elements are widely present in biology, various particular endogenous molecules and enzymatic systems can be studied. Sodium and potassium are by far the most important and central elements for consideration. Aspects of lithium, rubidium, cesium and francium chemistry are also included; they help in making important comparisons related to the coordination chemistry of Na(+) and K(+). Physical methods are also introduced. PMID:26860297

  4. Superconductivity in alkali-doped fullerene nanowhiskers

    NASA Astrophysics Data System (ADS)

    Takeya, Hiroyuki; Konno, Toshio; Hirata, Chika; Wakahara, Takatsugu; Miyazawa, Kun’ichi; Yamaguchi, Takahide; Tanaka, Masashi; Takano, Yoshihiko

    2016-09-01

    Superconductivity in alkali metal-doped fullerene nanowhiskers (C60NWs) was observed in K3.3C60NWs, Rb3.0C60NWs and Cs2.0Rb1.0C60NWs with transition temperatures at 17, 25 and 26 K, respectively. Almost full shielding volume fraction (~80%) was observed in K3.3C60NWs when subjected to thermal treatment at 200 °C for a duration of 24 h. In contrast, the shielding fraction of Rb3.0C60NWs and Cs2.0Rb1.0C60NWs were calculated to be 8% and 6%, respectively. Here we report on an extensive investigation of the superconducting properties of these AC60NWs (A  =  K3.3, Rb3.0 and Cs2.0Rb1.0). These properties are compared to the ones reported on the corresponding conventional (single-crystal or powder) K-doped fullerene. We also evaluated the critical current densities of these C60NWs using the Bean model under an applied magnetic field up to 50 kOe.

  5. Relation between the electroforming voltage in alkali halide-polymer diodes and the bandgap of the alkali halide

    SciTech Connect

    Bory, Benjamin F.; Wang, Jingxin; Janssen, René A. J.; Meskers, Stefan C. J.; Gomes, Henrique L.; De Leeuw, Dago M.

    2014-12-08

    Electroforming of indium-tin-oxide/alkali halide/poly(spirofluorene)/Ba/Al diodes has been investigated by bias dependent reflectivity measurements. The threshold voltages for electrocoloration and electroforming are independent of layer thickness and correlate with the bandgap of the alkali halide. We argue that the origin is voltage induced defect formation. Frenkel defect pairs are formed by electron–hole recombination in the alkali halide. This self-accelerating process mitigates injection barriers. The dynamic junction formation is compared to that of a light emitting electrochemical cell. A critical defect density for electroforming is 10{sup 25}/m{sup 3}. The electroformed alkali halide layer can be considered as a highly doped semiconductor with metallic transport characteristics.

  6. Recovery of alumina and alkali in Bayer red mud by the formation of andradite-grossular hydrogarnet in hydrothermal process.

    PubMed

    Zhang, Ran; Zheng, Shili; Ma, Shuhua; Zhang, Yi

    2011-05-30

    Bayer red mud (RM) is an alumina refinery waste product rich in aluminum oxides and alkalis which are present primarily in the form of sodium hydro-aluminosilicate desilication product (DSP). A hydrothermal process was employed to recover alumina and alkali from "Fe-rich" and "Fe-lean" RM, the two representative species of RM produced in China. The hydrothermal process objective phase is andradite-grossular hydrogarnet characterized by the isomorphic substitution of Al and Fe. Batch experiments were used to evaluate the main factors influencing the recovery process, namely reaction temperature, caustic ratio (molar ratio of Na(2)O to Al(2)O(3) in sodium solution), sodium concentration and residence time. The results revealed that the Na(2)O content of 0.5 wt% and A/S of 0.3 (mass ratio of Al(2)O(3) to SiO(2)) in leached residue could be achieved with Fe-rich RM under optimal conditions. However, the hydrothermal treatment of Fe-lean RM proved less successful unless the reaction system was enriched with iron. Subsequent experiments examined the effects of the ferric compound's content and type on the substitution ratio. PMID:21444152

  7. LEAD SUBSTITUTION AND ELIMINATION STUDY, PART II

    SciTech Connect

    T. MARTINEZ; M. COURNOYER

    2001-01-01

    Within the Nuclear Materials Technology Division of Los Alamos National Laboratory, lead is used as shielding for a variety of operations, including actinide chemistry, weapons production, radiochemistry, and analytical chemistry. In this study, waste minimization issues associated with replacing lead shielding with non-hazardous materials are addressed. These include institutional program available to support this effort, the hazards and accompanying controls grouped with lead shielding, operations that use lead bricks and how this effects the selection of the substitute. Life cycle management issues are also examined. As a final step, an approach to get buy-in from both technical and budget minded employees is presented.

  8. Efficient destruction of CF4 through in situ generation of alkali metals from heated alkali halide reducing mixtures.

    PubMed

    Lee, Myung Churl; Choi, Wonyong

    2002-03-15

    Perfluorocarbons (PFCs) are the most potent green house gases that are very recalcitrant at destruction. An effective way of converting PFCs using hot solid reagents into safe products has been recently introduced. By investigating the thermal reductive destruction of tetrafluoromethane (CF4) we provided new insight and more physicochemical consideration on this novel process. The complete destruction of CF4was successfully achieved by flowing the gas through a heated reagent bed (400-950 degrees C) that contained powder mixtures of alkali halides, CaO, and Si. The silicon acted as a reducing agent of alkali halides for the in-situ production of alkali metals, and the calcium oxide played the role of a halide ion acceptor. The absence of any single component in this ternary mixture drastically reduced the destruction efficiency of CF4. The CF4 destruction efficiencies with the solid reagent containing the alkali halide, MX, increased in the order of Li approximately Na < K < Cs for alkali cations and I < Br < Cl < F for halide anions. This trend agreed with the endothermicity of the alkali metal generation reaction: the higher the endothermicity, the lower the destruction efficiency. Alkali metal generation was indirectly detected by monitoring H2 production from its reaction with water. The production of alkali metals increased with NaF, KF, and CsF in this order. The CsF/CaO/Si system exhibited the complete destruction of CF4 at as low as 600 degrees C. The solid product analysis by X-ray diffraction (XRD) showed the formation of CaF2 and the depletion of Si with black carbon particles formed in the solid reagent residue. No CO/CO2 and toxic HF and SiF4 formation were detected in the exhaust gas. PMID:11944694

  9. Alkali-aggregate reactivity of typical siliceious glass and carbonate rocks in alkali-activated fly ash based geopolymers

    NASA Astrophysics Data System (ADS)

    Lu, Duyou; Liu, Yongdao; Zheng, Yanzeng; Xu, Zhongzi; Shen, Xiaodong

    2013-08-01

    For exploring the behaviour of alkali-aggregate reactivity (AAR) in alkali-activated geopolymeric materials and assessing the procedures for testing AAR in geopolymers, the expansion behaviour of fly ash based geopolymer mortars with pure silica glass and typical carbonate rocks were studied respectively by curing at various conditions, i.e. 23°C and 38°C with relative humidity over 95%, immersed in 1M NaOH solution at 80°C. Results show that, at various curing conditions, neither harmful ASR nor harmful ACR was observed in geopolymers with the criteria specified for OPC system. However, with the change of curing conditions, the geopolymer binder and reactive aggregates may experience different reaction processes leading to quite different dimensional changes, especially with additional alkalis and elevated temperatures. It suggests that high temperature with additional alkali for accelerating AAR in traditional OPC system may not appropriate for assessing the alkali-aggregate reactivity behaviour in geopolymers designed for normal conditions. On the other hand, it is hopeful to control the dimensional change of geopolymer mortar or concrete by selecting the type of aggregates and the appropriate curing conditions, thus changing the harmful AAR in OPC into beneficial AAR in geopolymers and other alkali-activated cementitious systems.

  10. On-chip fabrication of alkali-metal vapor cells utilizing an alkali-metal source tablet

    NASA Astrophysics Data System (ADS)

    Tsujimoto, K.; Ban, K.; Hirai, Y.; Sugano, K.; Tsuchiya, T.; Mizutani, N.; Tabata, O.

    2013-11-01

    We describe a novel on-chip microfabrication technique for the alkali-metal vapor cell of an optically pumped atomic magnetometer (OPAM), utilizing an alkali-metal source tablet (AMST). The newly proposed AMST is a millimeter-sized piece of porous alumina whose considerable surface area holds deposited alkali-metal chloride (KCl) and barium azide (BaN6), source materials that effectively produce alkali-metal vapor at less than 400 °C. Our experiments indicated that the most effective pore size of the AMST is between 60 and 170 µm. The thickness of an insulating glass spacer holding the AMST was designed to confine generated alkali metal to the interior of the vapor cell during its production, and an integrated silicon heater was designed to seal the device using a glass frit, melted at an optimum temperature range of 460-490 °C that was determined by finite element method thermal simulation. The proposed design and AMST were used to successfully fabricate a K cell that was then operated as an OPAM with a measured sensitivity of 50 pT. These results demonstrate that the proposed concept for on-chip microfabrication of alkali-metal vapor cells may lead to effective replacement of conventional glassworking approaches.

  11. Mixed alkali effect on the spectroscopic properties of alkali-alkaline earth oxide borate glasses

    NASA Astrophysics Data System (ADS)

    Srinivas, G.; Ramesh, B.; Shareefuddin, Md.; Chary, M. N.; Sayanna, R.

    2016-05-01

    The mixed alkali and alkaline earth oxide borate glass with the composition xK2O - (25-x) Li2O-12.5BaO-12.5MgO-50B2O3 (x = 0, 5, 10, 15, 20 and 25mol %) and doped with 1mol% CuO were prepared by the melt quenching technique. From the optical absorption spectra the optical band gap, electronic polarizability(α02-), interaction parameter (A), theoretical and experimental optical basicity (Λ) values were evaluated. From the Electron Paramagnetic Resonance (EPR) spectral data the number of spins (N) and susceptibility (χ) were evaluated. The values of (α02-), and (Λ) increases with increasing of K2O content and electronic polarizability and interaction parameter show opposite behaviuor which may be due to the creation of non-bridging oxygens and expansion of borate network. The reciprocal of susceptibility (1/χ) and spin concentration (N) as a function of K2O content, varied nonlinearly which may be due to creation of non-bridging oxygens in the present glass system. This may be attributed to mixed alkali effect (MAE).

  12. The reaction dynamics of alkali dimer molecules and electronically excited alkali atoms with simple molecules

    SciTech Connect

    Hou, H.

    1995-12-01

    This dissertation presents the results from the crossed molecular beam studies on the dynamics of bimolecular collisions in the gas phase. The primary subjects include the interactions of alkali dimer molecules with simple molecules, and the inelastic scattering of electronically excited alkali atoms with O2. The reaction of the sodium dimers with oxygen molecules is described in Chapter 2. Two reaction pathways were observed for this four-center molecule-molecule reaction, i.e. the formations of NaO2 + Na and NaO + NaO. NaO2 products exhibit a very anisotropic angular distribution, indicating a direct spectator stripping mechanism for this reaction channel. The NaO formation follows the bond breaking of O2, which is likely a result of a charge transfer from Na2 to the excited state orbital of O2-. The scattering of sodium dimers from ammonium and methanol produced novel molecules, NaNH3 and Na(CH3OH), respectively. These experimental observations, as well as the discussions on the reaction dynamics and the chemical bonding within these molecules, will be presented in Chapter 3. The lower limits for the bond dissociation energies of these molecules are also obtained. Finally, Chapter 4 describes the energy transfer between oxygen molecules and electronically excited sodium atoms.

  13. Technical Shibboleths.

    ERIC Educational Resources Information Center

    Harris, John S.

    1998-01-01

    Focuses on technical sub-languages to reveal sociological functions of language that transcend mere transfer of substantive information. Finds one sociological feature, the shibboleth, acting widely throughout technical fields. (PA)

  14. Mechanisms of recovery from sublethal damage and potentially lethal damage induced by BrdUrd/313 nm light treatment: alkali-labile lesions.

    PubMed Central

    Hagan, M. P.; Han, A.; Smith, V. N.

    1984-01-01

    BrdUrd pulse labelling of synchronous Chinese hamster cell cultures was used to correlate repair of sublethal damage with removal of alkali-labile lesions. Both processes were modified in a quantitatively similar manner by cysteamine. In addition, the age responses for repair of sublethal damage and for cysteamine reduction of repair agreed. Through the use of thymidine as an S-phase-blocking agent it was further demonstrated that progression past the S-phase of the cell cycle was required for the loss of resistance to UVB light in BrdUrd-substituted cells. Similarly, a thymidine block administered before synthesis upon the BrdUrd-substituted template prevented the cell from acquiring the sensitivity to UVB light normally associated with synthesis on a lesioned template. The UVB-light-sensitive mutant V79-UC was shown to have reduced capacities both for the accumulation of sublethal injury and for the removal of alkali-labile lesions. These data support the notion that alkali-labile lesions are responsible for sublethal damage in BrdUrd pulse-labelled Chinese hamster cells. PMID:6582920

  15. Water Content of Lunar Alkali Fedlspar

    NASA Technical Reports Server (NTRS)

    Mills, R. D.; Simon, J. I.; Wang, J.; Alexander, C. M. O'D.; Hauri, E. H.

    2016-01-01

    Detection of indigenous hydrogen in a diversity of lunar materials, including volcanic glass, melt inclusions, apatite, and plagioclase suggests water may have played a role in the chemical differentiation of the Moon. Spectroscopic data from the Moon indicate a positive correlation between water and Th. Modeling of lunar magma ocean crystallization predicts a similar chemical differentiation with the highest levels of water in the K- and Th-rich melt residuum of the magma ocean (i.e. urKREEP). Until now, the only sample-based estimates of water content of KREEP-rich magmas come from measurements of OH, F, and Cl in lunar apatites, which suggest a water concentration of < 1 ppm in urKREEP. Using these data, predict that the bulk water content of the magma ocean would have <10 ppm. In contrast, estimate water contents of 320 ppm for the bulk Moon and 1.4 wt % for urKREEP from plagioclase in ferroan anorthosites. Results and interpretation: NanoSIMS data from granitic clasts from Apollo sample 15405,78 show that alkali feldspar, a common mineral in K-enriched rocks, can have approx. 20 ppm of water, which implies magmatic water contents of approx. 1 wt % in the high-silica magmas. This estimate is 2 to 3 orders of magnitude higher than that estimated from apatite in similar rocks. However, the Cl and F contents of apatite in chemically similar rocks suggest that these melts also had high Cl/F ratios, which leads to spuriously low water estimates from the apatite. We can only estimate the minimum water content of urKREEP (+ bulk Moon) from our alkali feldspar data because of the unknown amount of degassing that led to the formation of the granites. Assuming a reasonable 10 to 100 times enrichment of water from urKREEP into the granites produces an estimate of 100-1000 ppm of water for the urKREEP reservoir. Using the modeling of and the 100-1000 ppm of water in urKREEP suggests a minimum bulk silicate Moon water content between 2 and 20 ppm. However, hydrogen loss was

  16. Theory of Magnetotransport Anomalies in Alkali Metals

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaodong

    The galvanomagnetic properties of alkali metals, especially those of potassium, are studied taking into account the existence of an incommensurate change-density wave (CDW) structure. Occurrence of the CDW broken symmetry truncates the Fermi surface with a large number of energy gaps. Furthermore, any macroscopic crystal is likely divided into CDW (')Q-domains. An orientational (')Q-texture leads to a preferred direction in the crystal. For such an exotic system the effective magnetoresistivity tensor is anomalous and is derived for various magnetic fields. The residual (zero-field) resistance is also anisotropic. For fields 0.5 - 3T, Hall coefficients are found to be anisotropic, and a longitudinal-transverse mixing effect is discovered. The diagonal elements of the magnetoresistivity tensor are found to have a linear magnetoresistance. When the field is increased above 4T sharp open-orbit magnetoresistance spectrum develops. From the theoretical magnetoresistivity tensor, the induced-torque amplitude and phase patterns for potassium spheres are calculated. The theory quantitatively explains all of the induced-torque anomalies found experimentally in the last fourteen years. An interacting electron system, which is free of the CDW instabilities, is also studied by considering its spin response to a weak sinusoidal magnetic field. The many-body correction G(,-)((')q,(omega)) caused by exchange and correlation is introduced to describe the correct wave -vector- and frequency-dependent spin susceptibility. The exact behavior of G(,-)((')q,(omega)) in the large-q limit is shown to be related to the pair distribution function g((')r) at r = 0. G(,-)((')q,(omega)) (--->) 4g(0)-1 /3, as q (--->) (INFIN).At metallic densities this value is negative, opposite in sign to the limit at small wave vectors. Thus the spin susceptibility for large wave vectors is suppressed, rather than enhanced, by many-body effects.

  17. Alkali content of alpine ultramafic rocks

    USGS Publications Warehouse

    Hamilton, W.; Mountjoy, W.

    1965-01-01

    The lower limit of abundance of sodium and potassium in ultramafic rocks is less than the threshold amount detectable by conventional analytical methods. By a dilutionaddition modification of the flame-spectrophotometric method, sodium and potassium have been determined in 40 specimens of alpine ultramafic rocks. Samples represent six regions in the United States and one in Australia, and include dunite, peridotite, pyroxenite, and their variably serpentinized and metamorphosed derivatives. The median value found for Na2O is 0.004 per cent, and the range of Na2O is 0.001-0.19. The median value for K2O is 0.0034 per cent and the range is 0.001-0.031 per cent. Alkali concentrations are below 0.01 per cent Na2O in 28 samples and below 0.01 per cent K2O in 35. Derivation of basalt magma from upper-mantle material similar to such ultramafic rocks, as has been postulated, is precluded by the relative amounts of sodium and potassium, which are from 200 to 600 times more abundant in basalt than in the ultramafic rocks. Similar factors apply to a number of other elements. No reasonable process could produce such concentrations in, for example, tens of thousands of cubic miles of uniform tholeiitic basalt. The ultramafic rocks might have originated either as magmatic crystal precipitates or as mantle residues left after fusion and removal of basaltic magma. Injection of ultramafic rocks to exposed positions is tectonic rather than magmatic. ?? 1965.

  18. Clinical applications of skin substitutes.

    PubMed

    Nyame, Theodore T; Chiang, H Abraham; Orgill, Dennis P

    2014-08-01

    A unique understanding of the components of mammalian skin has led to the development of numerous skin substitutes. These skin substitutes attempt to compensate for functional and physiologic deficits present in damaged tissue. Skin substitutes, when appropriately applied in optimized settings, offer a promising solution to difficult wound management. The body of literature on skin substitutes increases as the understanding of tissue engineering and molecular biology expands. Given the high cost of these products, future randomized large prospective studies are needed to guide the clinical applications of skin substitutes. PMID:25085091

  19. Methodologies in creating skin substitutes.

    PubMed

    Nicholas, Mathew N; Jeschke, Marc G; Amini-Nik, Saeid

    2016-09-01

    The creation of skin substitutes has significantly decreased morbidity and mortality of skin wounds. Although there are still a number of disadvantages of currently available skin substitutes, there has been a significant decline in research advances over the past several years in improving these skin substitutes. Clinically most skin substitutes used are acellular and do not use growth factors to assist wound healing, key areas of potential in this field of research. This article discusses the five necessary attributes of an ideal skin substitute. It comprehensively discusses the three major basic components of currently available skin substitutes: scaffold materials, growth factors, and cells, comparing and contrasting what has been used so far. It then examines a variety of techniques in how to incorporate these basic components together to act as a guide for further research in the field to create cellular skin substitutes with better clinical results. PMID:27154041

  20. 40 CFR 721.10034 - Substituted pyridine coupled with diazotized substituted nitrobenzonitrile, diazotized...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted pyridine coupled with... Specific Chemical Substances § 721.10034 Substituted pyridine coupled with diazotized substituted... as substituted pyridine coupled with diazotized substituted nitrobenzonitrile, diazotized...

  1. 40 CFR 721.10034 - Substituted pyridine coupled with diazotized substituted nitrobenzonitrile, diazotized...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted pyridine coupled with... Specific Chemical Substances § 721.10034 Substituted pyridine coupled with diazotized substituted... as substituted pyridine coupled with diazotized substituted nitrobenzonitrile, diazotized...

  2. Optical properties and electronic structure of alkali doped SWNT

    NASA Astrophysics Data System (ADS)

    Nemes, Norbert M.; Fischer, John E.; Kamarás, Katalin; Borondics, Ferenc; Tanner, David B.; Rinzler, Andrew G.

    2003-03-01

    Alkali doped SWNT exhibit colors similar to alkali doped graphite (GIC). We study their electronic structure with IR reflectivity; the alkali dopants donate their valence electron to the SWNT host, so the free carrier concentration increases, shifting the Drude-edge into the visible spectral range. This is accompanied by a large shift of the Fermi-level, so the characteristic transitions between the 1D van Hove singularities of the undoped SWNT diminish. The presence of the alkali ions around the SWNT breaks the translational symmetry and increases coupling between parallel tubes within ropes. The momentum relaxation time shortens as the ropes become more three dimensional; alkali disorder contributes to the scattering. In p-type, HNO3 doped SWNT, the charge transfer is smaller; only the first subband of the semiconducting tubes gets depleted, shown by the disappearance of the first van Hove transition. This indicates a Fermi-level shift of ˜0.3 eV. The reflectivity has structure at low energy, which moves the Drude-peak to a sharp, intense peak at 0.1 eV in the optical conductivity, reminiscent of quasi-1D TTF-TCNQ.

  3. Multi-photon processes in alkali metal vapors

    NASA Astrophysics Data System (ADS)

    Gai, Baodong; Hu, Shu; Li, Hui; Shi, Zhe; Cai, Xianglong; Guo, Jingwei; Tan, Yannan; Liu, Wanfa; Jin, Yuqi; Sang, Fengting

    2015-02-01

    Achieving population inversion through multi-photon cascade pumping is almost always difficult, and most laser medium work under 1-photon excitation mechanism. But for alkali atoms such as cesium, relatively large absorption cross sections of several low, cascading energy levels enable them properties such as up conversion. Here we carried out research on two-photon excitation alkali fluorescence. Two photons of near infrared region are used to excite alkali atoms to n 2 D5/2, n 2 D3/2 or higher energy levels, then the blue fluorescence of (n+1) 2 P3/2,(n+1) 2 P1/2-->n 2 S1/2 are observed. Different pumping paths are tried and by the recorded spectra, transition routes of cesium are deducted and concluded. Finally the possibility of two-photon style DPALs (diode pumped alkali laser) are discussed, such alkali lasers can give output wavelengths in the shorter end of visual spectroscopy (400-460 nm) and are expected to get application in underwater communication and material laser processing.

  4. Polyimides comprising substituted benzidines

    NASA Technical Reports Server (NTRS)

    Harris, Frank W. (Inventor)

    1991-01-01

    A new class of polyimides and copolyimides made from substituted benzidines and aromatic dianhydrides and other aromatic diamines. The polyimides obtained with said diamines are distinguished by excellent thermal, excellent solubility, excellent electrical properties such as very low dielectric constants, excellent clarity and mechanical properties making the polyimides ideally suited as coating materials for microelectronic apparatii, as membranes for selective molecular or gas separation, as fibers in molecular composites, as high tensile strength, high compression strength fibers, as film castable coatings, or as fabric components.

  5. Trifluoromethyl-substituted polymers

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Current work sponsored by the grant at Southwest Texas State University is directed toward the synthesis and characterization of: (1) N-alkylated polyamides derived from o-fluorinated diacids; (2) highly fluorinated polyethers; (3) polyesters derived from 2-hydroxy-2-propyl substituted arenes and/or 2,5-difluoroterephthalic acid; and (4) silicon-containing fluoropolymers. Work during the period from 1 July to 31 Dec. 1993 focused primarily on items 3 and 4 and on the development of a phosphorus containing modification of '12F-PEK.'

  6. Energy conservation in the primary aluminum and chlor-alkali industries

    SciTech Connect

    Not Available

    1980-10-01

    The primary aluminum and chlor-alkali industries together use nearly 13% of the electrical energy consumed by US industry. As part of its mission to promote energy conservation in basic US industries, the DOE surveys the present technological status of the major electrochemical industries and evaluates promising technological innovations that may lead to reduced energy requirements. This study provides technical and economic analyses in support of a government program of research and development in advanced electrolytic technology. This program is intended to supplement the development efforts directed toward energy savings by private industry. Sections II and III of this report cover aluminum and chlorine production processes only, since these two industries represent over 90% of the electrical energy requirements of all electrolytic industries in the United States. Section IV examines barriers to accelerated research and development by the electrolytic industries, and makes suggestions for government actions to overcome these barriers.

  7. Maternal exposure to alkali, alkali earth, transition and other metals: Concentrations and predictors of exposure.

    PubMed

    Hinwood, A L; Stasinska, A; Callan, A C; Heyworth, J; Ramalingam, M; Boyce, M; McCafferty, P; Odland, J Ø

    2015-09-01

    Most studies of metals exposure focus on the heavy metals. There are many other metals (the transition, alkali and alkaline earth metals in particular) in common use in electronics, defense industries, emitted via combustion and which are naturally present in the environment, that have received limited attention in terms of human exposure. We analysed samples of whole blood (172), urine (173) and drinking water (172) for antimony, beryllium, bismuth, cesium, gallium, rubidium, silver, strontium, thallium, thorium and vanadium using ICPMS. In general most metals concentrations were low and below the analytical limit of detection with some high concentrations observed. Few factors examined in regression models were shown to influence biological metals concentrations and explained little of the variation. Further study is required to establish the source of metals exposures at the high end of the ranges of concentrations measured and the potential for any adverse health impacts in children. PMID:25984984

  8. Borate substituted ettringites

    SciTech Connect

    Csetenyi, L.J.; Glasser, F.P.

    1993-12-31

    The setting of cement is adversely affected by soluble borates. To reduce interference, the extent to which borate can be insolubilized has been investigated. One specific mechanism of insolubilization is by inclusion into ettringite. Ettringite, Ca{sub 6}Al{sub 2}(SO{sub 4}){sub 3}(OH){sub 12}{center_dot}26H{sub 2}O, is a normal and stable constituent of Portland cement. It has an open but non-zeolitic framework. Borate can substitute partially or fully for sulfate. Formation conditions, solubility and stability of borate ettringites, Ca{sub 6}Al{sub 2}(BO{sub 4}){sub 2-4}(OH,O){sub 12}{center_dot}26H{sub 2}O, are characterized using XRD, IR, DTA, and SEM. The potential durability of borate ettringites in a repository environment have been assessed by exposing it to Na-sulfate and Na-carbonate attack at different concentrations. Ion exchange occurs; back substitution of borate by sulfate is incomplete; high carbonate concentrations can, however, decompose borate ettringite. On heat treatment up to 85{degrees}C the crystalline morphology and the OH arrangement of the structure are altered, but the X-ray powder pattern, and hence its structural framework are largely unaffected. It is concluded that ettringite has potential to reduce the solubility of borate.

  9. Thermodynamics of Liquid Alkali Metals and Their Binary Alloys

    NASA Astrophysics Data System (ADS)

    Thakor, P. B.; Patel, Minal H.; Gajjar, P. N.; Jani, A. R.

    2009-07-01

    The theoretical investigation of thermodynamic properties like internal energy, entropy, Helmholtz free energy, heat of mixing (ΔE) and entropy of mixing (ΔS) of liquid alkali metals and their binary alloys are reported in the present paper. The effect of concentration on the thermodynamic properties of Ac1Bc2 alloy of the alkali-alkali elements is investigated and reported for the first time using our well established local pseudopotential. To investigate influence of exchange and correlation effects, we have used five different local field correction functions viz; Hartree(H), Taylor(T), Ichimaru and Utsumi(IU), Farid et al. (F) and Sarkar et al. (S). The increase of concentration C2, increases the internal energy and Helmholtz free energy of liquid alloy Ac1Bc2. The behavior of present computation is not showing any abnormality in the outcome and hence confirms the applicability of our model potential in explaining the thermodynamics of liquid binary alloys.

  10. Orbital Feshbach Resonance in Alkali-Earth Atoms.

    PubMed

    Zhang, Ren; Cheng, Yanting; Zhai, Hui; Zhang, Peng

    2015-09-25

    For a mixture of alkali-earth atomic gas in the long-lived excited state ^{3}P_{0} and the ground state ^{1}S_{0}, in addition to nuclear spin, another "orbital" index is introduced to distinguish these two internal states. In this Letter we propose a mechanism to induce Feshbach resonance between two atoms with different orbital and nuclear spin quantum numbers. Two essential ingredients are the interorbital spin-exchange process and orbital dependence of the Landé g factors. Here the orbital degrees of freedom plays a similar role as the electron spin degree of freedom in magnetic Feshbach resonance in alkali-metal atoms. This resonance is particularly accessible for the ^{173}Yb system. The BCS-BEC crossover in this system requires two fermion pairing order parameters, and displays a significant difference compared to that in an alkali-metal system. PMID:26451561

  11. Orbital Feshbach Resonance in Alkali-Earth Atoms

    NASA Astrophysics Data System (ADS)

    Zhang, Ren; Cheng, Yanting; Zhai, Hui; Zhang, Peng

    2015-09-01

    For a mixture of alkali-earth atomic gas in the long-lived excited state 3P0 and the ground state 1S0, in addition to nuclear spin, another "orbital" index is introduced to distinguish these two internal states. In this Letter we propose a mechanism to induce Feshbach resonance between two atoms with different orbital and nuclear spin quantum numbers. Two essential ingredients are the interorbital spin-exchange process and orbital dependence of the Landé g factors. Here the orbital degrees of freedom plays a similar role as the electron spin degree of freedom in magnetic Feshbach resonance in alkali-metal atoms. This resonance is particularly accessible for the 173Yb system. The BCS-BEC crossover in this system requires two fermion pairing order parameters, and displays a significant difference compared to that in an alkali-metal system.

  12. Release and sorption of alkali metals in coal conversion

    SciTech Connect

    Witthohn, A.; Oeltjen, L.; Hilpert, K.

    1998-07-01

    Released as gaseous species during coal combustion and gasification, alkali metal compounds cause high temperature corrosion especially at the gas turbine blading of coal-fired combined cycle power plants. Experimental and theoretical basic investigations are presented, which contribute to the understanding of the release and sorption of these contaminants. Knudsen effusion mass spectrometry was used to study the vaporization of coal ashes and slags at temperatures between 200 and 1,800 C and to determine the released alkali species and their partial pressures. The data base system FACT and the modified quasi-chemical model for non-ideal solutions were applied to model the thermodynamic behavior of coal slags and to determine material compositions of maximum alkali sorption capacity.

  13. The alkali-labile linkage between keratan sulphate and protein

    PubMed Central

    Hopwood, John J.; Robinson, H. Clem

    1974-01-01

    Keratan sulphate was isolated from adult intervertebral disc in 90% yield by sequential digestion of the whole tissue with papain, Pronase and Proteus vulgaris chondroitin sulphate lyase. Treatment of this preparation with alkali cleaved a glycosidic bond between N-acetylgalactosamine and threonine and produced, by an alkali-catalysed `peeling' reaction, an unsaturated derivative of N-acetylgalactosamine which reacted as a chromogen in the Morgan–Elson reaction, but remained covalently bonded to the keratan sulphate chain. This derivative was reduced and labelled by alkaline NaB3H4. The substituent at position 3 of N-acetylgalactosamine in the keratan sulphate–protein linkage was identified as a disaccharide, N-acetylneuraminylgalactose, which was isolated from the reaction mixture after alkali treatment. PMID:4281652

  14. Neuropsychiatric manifestations of alkali metal deficiency and excess.

    PubMed

    Yung, C Y

    1984-01-01

    The alkali metals from the Group IA of the periodic table (lithium, sodium, potassium, rubidium, cesium and francium) are reviewed. The neuropsychiatric aspects of alkali metal deficiencies and excesses (intoxications) are described. Emphasis was placed on lithium due to its clinical uses. The signs and symptoms of these conditions are characterized by features of an organic brain syndrome with delirium and encephalopathy prevailing. There are no clinically distinctive features that could be reliably used for diagnoses. Sodium and potassium are two essential alkali metals in man. Lithium is used as therapeutic agent in bipolar affective disorders. Rubidium has been investigated for its antidepressant effect in a group of psychiatric disorders. Cesium is under laboratory investigation for its role in carcinogenesis and in depressive illness. Very little is known of francium due to its great instability for experimental study. PMID:6395136

  15. Neuropsychiatric manifestations of alkali metal deficiency and excess

    SciTech Connect

    Yung, C.Y.

    1984-01-01

    The alkali metals from the Group IA of the periodic table (lithium, sodium, potassium, rubidium, cesium and francium) are reviewed. The neuropsychiatric aspects of alkali metal deficiencies and excesses (intoxications) are described. Emphasis was placed on lithium due to its clinical uses. The signs and symptoms of these conditions are characterized by features of an organic brain syndrome with delirium and encephalopathy prevailing. There are no clinically distinctive features that could be reliably used for diagnoses. Sodium and potassium are two essential alkali metals in man. Lithium is used as therapeutic agent in bipolar affective disorders. Rubidium has been investigated for its antidepressant effect in a group of psychiatric disorders. Cesium is under laboratory investigation for its role in carcinogenesis and in depressive illness. Very little is known of francium due to its great instability for experimental study.

  16. Theoretical study of the alkali and alkaline-earth monosulfides

    NASA Technical Reports Server (NTRS)

    Partridge, Harry; Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.

    1988-01-01

    Ab initio calculations have been used to obtain accurate spectroscopic constants for the X2Pi and A2Sigma(+) states of the alkali sulfides and the X1Sigma(+), a3Pi, and A1Pi states of the alkaline-earth sulfides. In contrast to the alkali oxides, the alkali sulfides are found to have X2Pi ground states, due to the larger electrostatic interaction. Dissociation energies of 3.27 eV for BeS, 2.32 eV for MgS, 3.29 eV for CaS, and 3.41 eV for SrS have been obtained for the X1Sigma(+) states of the alkaline-earth sulfides, in good agreement with experimental results. Core correlation is shown to increase the Te values for the a3Pi and A1Pi states of MgS, CaS, and SrS.

  17. Superconductivity above 30 K in alkali-metal-doped hydrocarbon

    PubMed Central

    Xue, Mianqi; Cao, Tingbing; Wang, Duming; Wu, Yue; Yang, Huaixin; Dong, Xiaoli; He, Junbao; Li, Fengwang; Chen, G. F.

    2012-01-01

    The recent discovery of superconductivity with a transition temperature (Tc) at 18 K in Kxpicene has extended the possibility of high-Tc superconductors in organic materials. Previous experience based on similar hydrocarbons, like alkali-metal doped phenanthrene, suggested that even higher transition temperatures might be achieved in alkali-metals or alkali-earth-metals doped such polycyclic-aromatic-hydrocarbons (PAHs), a large family of molecules composed of fused benzene rings. Here we report the discovery of high-Tc superconductivity at 33 K in K-doped 1,2:8,9-dibenzopentacene (C30H18). To our best knowledge, it is higher than any Tc reported previously for an organic superconductor under ambient pressure. This finding provides an indication that superconductivity at much higher temperature may be possible in such PAHs system and is worthy of further exploration. PMID:22548129

  18. Tissue engineering of cultured skin substitutes.

    PubMed

    Horch, Raymund E; Kopp, Jürgen; Kneser, Ulrich; Beier, Justus; Bach, Alexander D

    2005-01-01

    Skin replacement has been a challenging task for surgeons ever since the introduction of skin grafts by Reverdin in 1871. Recently, skin grafting has evolved from the initial autograft and allograft preparations to biosynthetic and tissue-engineered living skin replacements. This has been fostered by the dramatically improved survival rates of major burns where the availability of autologous normal skin for grafting has become one of the limiting factors. The ideal properties of a temporary and a permanent skin substitute have been well defined. Tissue-engineered skin replacements: cultured autologous keratinocyte grafts, cultured allogeneic keratinocyte grafts, autologous/allogeneic composites, acellular biological matrices, and cellular matrices including such biological substances as fibrin sealant and various types of collagen, hyaluronic acid etc. have opened new horizons to deal with such massive skin loss. In extensive burns it has been shown that skin substitution with cultured grafts can be a life-saving measure where few alternatives exist. Future research will aim to create skin substitutes with cultured epidermis that under appropriate circumstances may provide a wound cover that could be just as durable and esthetically acceptable as conventional split-thickness skin grafts. Genetic manipulation may in addition enhance the performance of such cultured skin substitutes. If cell science, molecular biology, genetic engineering, material science and clinical expertise join their efforts to develop optimized cell culture techniques and synthetic or biological matrices then further technical advances might well lead to the production of almost skin like new tissue-engineered human skin products resembling natural human skin. PMID:16202208

  19. Spill-Resistant Alkali-Metal-Vapor Dispenser

    NASA Technical Reports Server (NTRS)

    Klipstein, William

    2005-01-01

    A spill-resistant vessel has been developed for dispensing an alkali-metal vapor. Vapors of alkali metals (most commonly, cesium or rubidium, both of which melt at temperatures slightly above room temperature) are needed for atomic frequency standards, experiments in spectroscopy, and experiments in laser cooling. Although the present spill-resistant alkali-metal dispenser was originally intended for use in the low-gravity environment of outer space, it can also be used in normal Earth gravitation: indeed, its utility as a vapor source was confirmed by use of cesium in a ground apparatus. The vessel is made of copper. It consists of an assembly of cylinders and flanges, shown in the figure. The uppermost cylinder is a fill tube. Initially, the vessel is evacuated, the alkali metal charge is distilled into the bottom of the vessel, and then the fill tube is pinched closed to form a vacuum seal. The innermost cylinder serves as the outlet for the vapor, yet prevents spilling by protruding above the surface of the alkali metal, no matter which way or how far the vessel is tilted. In the event (unlikely in normal Earth gravitation) that any drops of molten alkali metal have been shaken loose by vibration and are floating freely, a mesh cap on top of the inner cylinder prevents the drops from drifting out with the vapor. Liquid containment of the equivalent of 1.2 grams of cesium was confirmed for all orientations with rubbing alcohol in one of the prototypes later used with cesium.

  20. Cation-pi interactions as a mechanism in technical lignin adsorption to cationic surfaces.

    PubMed

    Pillai, Karthik V; Renneckar, Scott

    2009-04-13

    The assembly of dissolved technical lignins in aqueous and organic medium has been studied at the solid-liquid interface. Adsorption of alkali lignin onto gold coated crystals treated with a cationic polymer was determined using a quartz crystal microbalance with dissipation monitoring. Complete coverage of the cationic surface with alkali lignin occurred at low solution concentration, revealing a high affinity coefficient under both alkali and neutral conditions. With additional adsorption studies from organosolv lignin in organic solvent and spectroscopic analysis of mixtures of cationic polymer and alkali lignin, a noncovalent interaction between lignin's aromatic rings and the cation of the quaternary ammonium group was shown to exist. The work underscores how polyphenolic biopolymers can strongly interact with cations through noncovalent interactions to control molecular architecture. PMID:19226174

  1. Interaction of alkali-metal overlayers with oxygen

    SciTech Connect

    Hrbek, J.; Xu, G.; Sham, T.K.; Shek, M.L.

    1989-05-01

    The interaction of oxygen with alkali metals (Li, Na, K, and Cs) was studied with valence and core-level photoemission (PE) using synchrotron radiation and by multiple mass thermal desorption (TDS). During a stepwise coadsorption of oxygen at 80 K, an increase in the emission intensity, a linewidth broadening, and a negative binding-energy shift of alkali-metal core levels is observed. Two stages of oxygen adsorption are identified in PE and TDS. In the low O/sub 2/ exposure range, an oxide species is formed; at higher exposures, peroxide and superoxide species are observed in Na, K, and Cs. The potassium--oxygen interaction is discussed in detail.

  2. Upgrading of petroleum oil feedstocks using alkali metals and hydrocarbons

    SciTech Connect

    Gordon, John Howard

    2014-09-09

    A method of upgrading an oil feedstock by removing heteroatoms and/or one or more heavy metals from the oil feedstock composition. This method reacts the oil feedstock with an alkali metal and an upgradant hydrocarbon. The alkali metal reacts with a portion of the heteroatoms and/or one or more heavy metals to form an inorganic phase separable from the organic oil feedstock material. The upgradant hydrocarbon bonds to the oil feedstock material and increases the number of carbon atoms in the product. This increase in the number of carbon atoms of the product increases the energy value of the resulting oil feedstock.

  3. Synergistic capture mechanisms for alkali and sulfur species from combustion

    SciTech Connect

    Peterson, T.W.; Shadman, F.; Wendt, J.O.L.; Wu, Baochun.

    1992-01-10

    Due to the generation of a wide variety of pollutants during coal combustion, research on the development of a multifunction sorbent for adsorbing SO{sub 2} and alkali compounds simultaneously is ongoing at the University of Arizona. The current work focuses on the thermodynamic behavior of the reacting system for alkali adsorption especially in gas phase. The temperature and pressure effects on sodium species and on the system are intensively investigated under the simulated flue gas composition condition. The interaction of sulfur dioxide with sodium chloride vapor and some other system elements is also explored.

  4. Interfacial tension in immiscible mixtures of alkali halides.

    PubMed

    Lockett, Vera; Rukavishnikova, Irina V; Stepanov, Victor P; Tkachev, Nikolai K

    2010-02-01

    The interfacial tension of the liquid-phase interface in seven immiscible reciprocal ternary mixtures of lithium fluoride with the following alkali halides: CsCl, KBr, RbBr, CsBr, KI, RbI, and CsI was measured using the cylinder weighing method over a wide temperature range. It was shown that for all mixtures the interfacial tension gradually decreases with growing temperature. The interfacial tension of the reciprocal ternary mixtures at a given temperature increases both with the alkali cation radius (K(+) < Rb(+) < Cs(+)) and with the radius of the halogen anion (Cl(-) < Br(-) < I(-)). PMID:20094678

  5. Feasibility of supersonic diode pumped alkali lasers: Model calculations

    SciTech Connect

    Barmashenko, B. D.; Rosenwaks, S.

    2013-04-08

    The feasibility of supersonic operation of diode pumped alkali lasers (DPALs) is studied for Cs and K atoms applying model calculations, based on a semi-analytical model previously used for studying static and subsonic flow DPALs. The operation of supersonic lasers is compared with that measured and modeled in subsonic lasers. The maximum power of supersonic Cs and K lasers is found to be higher than that of subsonic lasers with the same resonator and alkali density at the laser inlet by 25% and 70%, respectively. These results indicate that for scaling-up the power of DPALs, supersonic expansion should be considered.

  6. Shallow electron traps in alkali halide crystals: Mollwo-Ivey relations of the optical absorption bands

    NASA Astrophysics Data System (ADS)

    Ziraps, Valters

    2001-03-01

    Evidences are given that two classes of the transient IR- absorption bands: (a) with max. at 0.27-0.36 eV in NaCl, KCl, KBr, KI and RbCl (due to shallow electron traps according G. Jacobs or due to bound polarons according E.V. Korovkin and T.A. Lebedkina) and (b) with max. at 0.15-0.36 eV in NaI, NaBr, NaCl:I, KCl:I, RbCl:I and RbBr:I (due to on-center STE localized at iodine dimer according M. Hirai and collaborators) are caused by the same defect- atomic alkali impurity center [M+]c0e- (electron e- trapped by a substitutional smaller size alkali cation impurity [M+]c0). The Mollwo-Ivey plots (for the transient IR-absorption bands) of the zero-phonon line energy E0 (for NaCl, KCl, KBr, RbCl and NaBr, KCl:I) and/or the low-energy edge valued E0 (for NaI, RbCl:I, RbBr:I) versus anion-cation distance (d) evidence that two types of the [M+]c0e- centers are predominant: (a) [Na+]c0e- in the KX and RbX host crystals with the relation E0approximately equals 6.15/d2.74, (b) [Li+]c03- in the NaX host crystals - E0approximately equals 29.4/d4.72. The Mollwo-Ivey relation E0approximately equals 18.36/d(superscript 2.70 is fulfilled as well for the F' band in NaCl, KCl, KBr, KI, RbCl, RbI if we use the F' center optical binding energy values E0.

  7. Explicit Substitutions and All That

    NASA Technical Reports Server (NTRS)

    Ayala-Rincon, Mauricio; Munoz, Cesar; Busnell, Dennis M. (Technical Monitor)

    2000-01-01

    Explicit substitution calculi are extensions of the Lambda-calculus where the substitution mechanism is internalized into the theory. This feature makes them suitable for implementation and theoretical study of logic-based tools such as strongly typed programming languages and proof assistant systems. In this paper we explore new developments on two of the most successful styles of explicit substitution calculi: the lambda(sigma)- and lambda(s(e))-calculi.

  8. Explicit Substitutions and All That

    NASA Technical Reports Server (NTRS)

    Ayala-Rincon, Mauricio; Munoz, Cesar

    2000-01-01

    Explicit substitution calculi are extensions of the lambda-calculus where the substitution mechanism is internalized into the theory. This feature makes them suitable for implementation and theoretical study of logic-based tools such as strongly typed programming languages and proof assistant systems. In this paper we explore new developments on two of the most successful styles of explicit substitution calculi: the lambda sigma- and lambda S(e)-calculi.

  9. Trifluoromethyl-substituted tetrathiafulvalenes

    PubMed Central

    Jeannin, Olivier; Barrière, Frédéric

    2015-01-01

    Summary A series of tetrathiafulvalenes functionalized with one or two trifluoromethyl electron-withdrawing groups (EWG) is obtained by phosphite coupling involving CF3-substituted 1,3-dithiole-2-one derivatives. The relative effects of the EWG such as CF3, CO2Me and CN on the TTF core were investigated from a combination of structural, electrochemical, spectrochemical and theoretical investigations. Electrochemical data confirm the good correlations between the first oxidation potential of the TTF derivatives and the σmeta Hammet parameter, thus in the order CO2Me < CF3 < CN, indicating that, in any case, the mesomeric effect of the substituents is limited. Besides, crystal structure determinations show that the deformation of the unsymmetrically substituted dithiole rings, when bearing one, or two different EWG, and attributed to the mesomeric effect of ester or nitrile groups, is not notably modified or counter-balanced by the introduction of a neighboring trifluoromethyl group. DFT calculations confirm these observations and also show that the low energy HOMO–LUMO absorption band found in nitrile or ester-substituted TTFs is not found in TTF-CF3, where, as in TTF itself, the low energy absorption band is essentially attributable to a HOMO→LUMO + 1 transition. Despite relatively high oxidation potentials, these donor molecules with CF3 EWG can be involved in charge transfer complexes or cation radical salts, as reported here for the CF3-subsituted EDT-TTF donor molecule. A neutral charge transfer complex with TCNQ, (EDT-TTF-CF3)2(TCNQ) was isolated and characterized through alternated stacks of EDT-TTF-CF3 dimers and TCNQ in the solid state. A radical cation salt of EDT-TTF-CF3 is also obtained upon electrocrystallisation in the presence of the FeCl4 − anion. In this salt, formulated as (EDT-TTF-CF3)(FeCl4), the (EDT-TTF-CF3)+• radical cations are associated two-by-two into centrosymmetric dyads with a strong pairing of the radical species in a singlet

  10. Trifluoromethyl-substituted tetrathiafulvalenes.

    PubMed

    Jeannin, Olivier; Barrière, Frédéric; Fourmigué, Marc

    2015-01-01

    A series of tetrathiafulvalenes functionalized with one or two trifluoromethyl electron-withdrawing groups (EWG) is obtained by phosphite coupling involving CF3-substituted 1,3-dithiole-2-one derivatives. The relative effects of the EWG such as CF3, CO2Me and CN on the TTF core were investigated from a combination of structural, electrochemical, spectrochemical and theoretical investigations. Electrochemical data confirm the good correlations between the first oxidation potential of the TTF derivatives and the σmeta Hammet parameter, thus in the order CO2Me < CF3 < CN, indicating that, in any case, the mesomeric effect of the substituents is limited. Besides, crystal structure determinations show that the deformation of the unsymmetrically substituted dithiole rings, when bearing one, or two different EWG, and attributed to the mesomeric effect of ester or nitrile groups, is not notably modified or counter-balanced by the introduction of a neighboring trifluoromethyl group. DFT calculations confirm these observations and also show that the low energy HOMO-LUMO absorption band found in nitrile or ester-substituted TTFs is not found in TTF-CF3, where, as in TTF itself, the low energy absorption band is essentially attributable to a HOMO→LUMO + 1 transition. Despite relatively high oxidation potentials, these donor molecules with CF3 EWG can be involved in charge transfer complexes or cation radical salts, as reported here for the CF3-subsituted EDT-TTF donor molecule. A neutral charge transfer complex with TCNQ, (EDT-TTF-CF3)2(TCNQ) was isolated and characterized through alternated stacks of EDT-TTF-CF3 dimers and TCNQ in the solid state. A radical cation salt of EDT-TTF-CF3 is also obtained upon electrocrystallisation in the presence of the FeCl4 (-) anion. In this salt, formulated as (EDT-TTF-CF3)(FeCl4), the (EDT-TTF-CF3)(+•) radical cations are associated two-by-two into centrosymmetric dyads with a strong pairing of the radical species in a singlet state

  11. Ternary alkali-metal and transition metal or metalloid acetylides as alkali-metal intercalation electrodes for batteries

    DOEpatents

    Nemeth, Karoly; Srajer, George; Harkay, Katherine C; Terdik, Joseph Z

    2015-02-10

    Novel intercalation electrode materials including ternary acetylides of chemical formula: A.sub.nMC.sub.2 where A is alkali or alkaline-earth element; M is transition metal or metalloid element; C.sub.2 is reference to the acetylide ion; n is an integer that is 0, 1, 2, 3 or 4 when A is alkali element and 0, 1, or 2 when A is alkaline-earth element. The alkali elements are Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs) and Francium (Fr). The alkaline-earth elements are Berilium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra). M is a transition metal that is any element in groups 3 through 12 inclusive on the Periodic Table of Elements (elements 21 (Sc) to element 30 (Zn)). In another exemplary embodiment, M is a metalloid element.

  12. Isomer-specific analysis and toxic evaluation of polychlorinated naphthalenes in soil, sediment, and biota collected near the site of a former chlor-alkali plant

    SciTech Connect

    Kannan, K.; Blankenship, A.L.; Giesy, J.P.; Imagawa, T.

    1998-09-01

    Concentrations and composition of polychlorinated naphthalene (PCN) congeners were determined in soil, sediments, blue crab, striped mullet, and boat-tailed grackle collected near a chlor-alkali plant to determine their congener profile, bioaccumulation properties, and toxic potential. Concentrations of total PCNs as high as 23 {micro}g/g, dry wt, were found in sediments collected at the marsh contaminated by disposal of wastes from the chlor-alkali process. The spatial distribution of sediment-PCN concentrations was not related with those observed for polychlorinated biphenyls (PCBs). The PCN congener profile did not resemble those of any technical mixtures. Hepta- and octa-chloronaphthalenes were the most abundant congeners accounting for greater than 50% of the total PCN concentrations in soil and sediments. A characteristic profile of PCNs in samples collected at the chlor-alkali site suggests the formation of chloronaphthalene congeners during chlor-alkali process, as has been suggested for polychlorinated dibenzofurans (PCDFs). Concentrations of total PCNs in biota were 3--5 orders of magnitude less than in sediments. The profile of PCN congeners in biota was predominated by tetra- or penta-chloronaphthalenes, while hepta- and octa-chloronaphthalenes were not detected.

  13. 40 CFR 721.5452 - Alkali metal salt of halogenated organoborate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkali metal salt of halogenated... Specific Chemical Substances § 721.5452 Alkali metal salt of halogenated organoborate (generic). (a... generically as alkali metal salt of halogenated organoborate (PMN P-00-0638) is subject to reporting...

  14. 40 CFR 721.5985 - Fatty alkyl phosphate, alkali metal salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Fatty alkyl phosphate, alkali metal... Specific Chemical Substances § 721.5985 Fatty alkyl phosphate, alkali metal salt (generic). (a) Chemical... as a fatty alkyl phosphate, alkali metal salt (PMN P-99-0385) is subject to reporting under...

  15. 40 CFR 721.5452 - Alkali metal salt of halogenated organoborate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkali metal salt of halogenated... Specific Chemical Substances § 721.5452 Alkali metal salt of halogenated organoborate (generic). (a... generically as alkali metal salt of halogenated organoborate (PMN P-00-0638) is subject to reporting...

  16. 40 CFR 721.5452 - Alkali metal salt of halogenated organoborate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkali metal salt of halogenated... Specific Chemical Substances § 721.5452 Alkali metal salt of halogenated organoborate (generic). (a... generically as alkali metal salt of halogenated organoborate (PMN P-00-0638) is subject to reporting...

  17. 40 CFR 721.5452 - Alkali metal salt of halogenated organoborate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkali metal salt of halogenated... Specific Chemical Substances § 721.5452 Alkali metal salt of halogenated organoborate (generic). (a... generically as alkali metal salt of halogenated organoborate (PMN P-00-0638) is subject to reporting...

  18. The magnetic moments of vanadium impurities in alkali hosts and induced spin current in alkali films

    NASA Astrophysics Data System (ADS)

    Song, Funing

    Thin quench-condensed films of Na, K, Rb, and Cs are covered with 1/100 of a monolayer of Vanadium. Then the V impurities are covered with several atomic layers of the host. The magnetization of the sandwiches is measured by means of the anomalous Hall effect. For V impurities on the surface of Na and K, a magnetic moment of 7 Bohr magnetons is observed. After coverage with the host, the V moment became 6.5muB for the Na host. These results contradict the favored atomic model (predicting 0.6muB) and the resonance model. The V moment on the surface and in the bulk of Rb and Cs is about 4muB and considerably smaller than the measured moments of V in Na. Furthermore, the sign of the anomalous Hall resistance changes from negative for the Na host to positive for the Cs host. This indicates a change of the electronic structure of the impurity (plus host environment) when going from Na to Cs hosts. Sandwiches of FeK and FeCs are prepared at helium temperature and under ultra-high vacuum. The mean free path within these sandwiches can exceed the film thickness by a factor of five. This implies almost perfect specular reflection of the electrons at the interfaces. Therefore, the mean free path of the film is strongly dependent on the degree of the specular reflection. Furthermore, the experiments suggest that the specular reflections for spin-up and spin-down electrons are different at the Fe interface, resulting in a spin current in the alkali films. In order to detect this current, dilute Pb impurities are condensed on top of the free surface of the alkali films. Strong spin-orbit scatterers, such as Pb, introduce an anomalous Hall effect in the presence of a spin current, which can be detected through straightforward Hall measurements. The results of the AHE experiments clearly indicate the existence of a local spin current.

  19. Chlor-Alkali Industry: A Laboratory Scale Approach

    ERIC Educational Resources Information Center

    Sanchez-Sanchez, C. M.; Exposito, E.; Frias-Ferrer, A.; Gonzalez-Garaia, J.; Monthiel, V.; Aldaz, A.

    2004-01-01

    A laboratory experiment for students in the last year of degree program in chemical engineering, chemistry, or industrial chemistry is presented. It models the chlor-alkali process, one of the most important industrial applications of electrochemical technology and the second largest industrial consumer of electricity after aluminium industry.

  20. PVC waterproofing membranes and alkali-aggregated reaction in dams

    SciTech Connect

    Scuero, A.M.

    1995-12-31

    A waterproofing polyvinylchloride (PVC) based geocomposite was installed on two dams subject to alkali-aggregate reaction, to eliminate water intrusion and to protect the facing from further deterioration. The installation system allows drainage of the infiltrated water, thus accomplishing dehydration of the dam body. On one dam, the membrane also provided protection for future slot cutting.

  1. Influence of temperature on alkali stress adaptation in Listeria monocytogenes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Listeria monocytogenes cells may induce alkali stress adaptation when exposed to sublethal concentrations of alkaline cleaners and sanitizers that may be frequently used in the food processing environment. In the present study, the effect of temperature on the induction and the stability of such alk...

  2. Assesment of Alkali Resistance of Basalt Used as Concrete Aggregates

    NASA Astrophysics Data System (ADS)

    al-Swaidani, Aref M.; Baddoura, Mohammad K.; Aliyan, Samira D.; Choeb, Walid

    2015-11-01

    The objective of this paper is to report a part of an ongoing research on the influence of using crushed basalt as aggregates on one of durability-related properties of concrete (i.e. alkali-silica reaction which is the most common form of Alkali-Aggregate Reaction). Alkali resistance has been assessed through several methods specified in the American Standards. Results of petrographic examination, chemical test (ASTM C289) and accelerated mortar bar test (ASTM C1260) have particularly been reported. In addition, the weight change and compressive strength of 28 days cured concrete containing basaltic aggregates were also reported after 90 days of exposure to 10% NaOH solution. Dolomite aggregate were used in the latter test for comparison. The experimental results revealed that basaltic rocks quarried from As-Swaida'a region were suitable for production of aggregates for concrete. According to the test results, the studied basalt aggregates can be classified as innocuous with regard to alkali-silica reaction. Further, the 10% sodium hydroxide attack did not affect the compressive strength of concrete.

  3. DUAL ALKALI TEST AND EVALUATION PROGRAM. VOLUME I. EXECUTIVE SUMMARY

    EPA Science Inventory

    Volume I of the report is an executive summary of the results of a three-task program to investigate, characterize, and evaluate the basic process chemistry and the various operating modes of sodium-based dual alkali scrubbing processes. The tasks were: I, laboratory studies at b...

  4. Structural models for alkali-metal complexes of polyacetylene

    NASA Astrophysics Data System (ADS)

    Murthy, N. S.; Shacklette, L. W.; Baughman, R. H.

    1990-02-01

    Structural models for a stage-2 complex are proposed for polyacetylene doped with less than about 0.1 potassium or rubidium atoms per carbon. These structures utilize as a basic motif an alkali-metal column surrounded by four planar-zig-zag polyacetylene chains, a structure found at the highest dopant levels. In the new stage-2 structures, each polyacetylene chain neighbors only one alkali-metal column, so the phase contains four polymer chains per alkali-metal column. Basic structural aspects for stage-1 and stage-2 structures are now established for both potassium- and rubidium-doped polyacetylene. X-ray-diffraction and electrochemical data show that undoped and doped phases coexist at low dopant concentrations (<0.06 K atom per C). X-ray-diffraction data, down to a Bragg spacing of 1.3 Å, for polyacetylene heavily doped with potassium (0.125-0.167 K atom per C) is fully consistent with our previously proposed stage-1 tetragonal unit cell containing two polyacetylene chains per alkali-metal column. There is no evidence for our samples requiring a distortion to a monoclinic unit cell as reported by others for heavily doped samples. The nature of structural transformations and the relationship between structure and electronic properties are discussed for potassium-doped polyacetylene.

  5. Modeling of alkali aggregate reaction effects in concrete dams

    SciTech Connect

    Capra, B.; Bournazel, J.P.; Bourdarot, E.

    1995-12-31

    Alkali Aggregate Reactions (AAR) are difficult to model due to the random distribution of the reactive sites and the imperfect knowledge of these chemical reactions. A new approach, using fracture mechanics and probabilities, capable to describe the anisotropic swelling of a structure is presented.

  6. LABORATORY STUDY OF LIMESTONE REGENERATION IN DUAL ALKALI SYSTEMS

    EPA Science Inventory

    The report describes a series of open- and closed-loop laboratory bench scale experiments which were carried out to study parameters which affect the reaction of limestone with dual alkali flue gas desulfurization system process liquors. It gives details of several sets of operat...

  7. Method of assembling and sealing an alkali metal battery

    DOEpatents

    Elkins, P.E.; Bell, J.E.; Harlow, R.A.; Chase, G.G.

    1983-03-01

    A method of initially assembling and then subsequently hermetically sealing a container portion of an alkali metal battery to a ceramic portion of such a battery is disclosed. Sealing surfaces are formed respectively on a container portion and a ceramic portion of an alkali metal battery. These sealing surfaces are brought into juxtaposition and a material is interposed there between. This interposed material is one which will diffuse into sealing relationship with both the container portion and the ceramic portion of the alkali metal battery at operational temperatures of such a battery. A pressure is applied between these sealing surfaces to cause the interposed material to be brought into intimate physical contact with such juxtaposed surfaces. A temporary sealing material which will provide a seal against a flow of alkali metal battery reactants there through at room temperatures and is applied over the juxtaposed sealing surfaces and material interposed there between. The entire assembly is heated to an operational temperature so that the interposed material diffuses into the container portion and the ceramic portion to form a hermetic seal there between. The pressure applied to the juxtaposed sealing surfaces is maintained in order to ensure the continuation of the hermetic seal. 4 figs.

  8. High capacity nickel battery material doped with alkali metal cations

    DOEpatents

    Jackovitz, John F.; Pantier, Earl A.

    1982-05-18

    A high capacity battery material is made, consisting essentially of hydrated Ni(II) hydroxide, and about 5 wt. % to about 40 wt. % of Ni(IV) hydrated oxide interlayer doped with alkali metal cations selected from potassium, sodium and lithium cations.

  9. Method of assembling and sealing an alkali metal battery

    DOEpatents

    Elkins, Perry E.; Bell, Jerry E.; Harlow, Richard A.; Chase, Gordon G.

    1983-01-01

    A method of initially assembling and then subsequently hermetically sealing a container portion of an alkali metal battery to a ceramic portion of such a battery is disclosed. Sealing surfaces are formed respectively on a container portion and a ceramic portion of an alkali metal battery. These sealing surfaces are brought into juxtaposition and a material is interposed therebetween. This interposed material is one which will diffuse into sealing relationship with both the container portion and the ceramic portion of the alkali metal battery at operational temperatures of such a battery. A pressure is applied between these sealing surfaces to cause the interposed material to be brought into intimate physical contact with such juxtaposed surfaces. A temporary sealing material which will provide a seal against a flow of alkali metal battery reactants therethrough at room temperatures and is applied over the juxtaposed sealing surfaces and material interposed therebetween. The entire assembly is heated to an operational temperature so that the interposed material diffuses into the container portion and the ceramic portion to form a hermetic seal therebetween. The pressure applied to the juxtaposed sealing surfaces is maintained in order to ensure the continuation of the hermetic seal.

  10. ALKALI-ACTIVATED SLAG CEMENTS AS A SUSTAINABLE BUILDING MATERIAL

    EPA Science Inventory

    The overall goal of this project is to develop and characterize alkali-activated slag cements with minimal carbon footprints, as well as to answer scientific questions that have yet to be satisfactorily addressed by prior research. These questions include the final disposition...

  11. Electro-optic contribution to Raman scattering from alkali halides

    SciTech Connect

    Mahan, G.D.; Subbaswamy, K.R.

    1986-06-15

    The electro-optic contributions to second-order Raman scattering and field-induced first-order scattering from alkali halides are calculated explicitly in terms of the ionic hyperpolarizability coefficients. The relevant local-field corrections are evaluated. Illustrative numerical results are presented.

  12. Aqueous alkali metal hydroxide insoluble cellulose ether membrane

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1969-01-01

    A membrane that is insoluble in an aqueous alkali metal hydroxide medium is described. The membrane is a resin which is a water-soluble C2-C4 hydroxyalkyl cellulose ether polymer and an insolubilizing agent for controlled water sorption, a dialytic and electrodialytic membrane. It is particularly useful as a separator between electrodes or plates in an alkaline storage battery.

  13. Displacement, Substitution, Sublimation: A Bibliography.

    ERIC Educational Resources Information Center

    Pedrini, D. T.; Pedrini, Bonnie C.

    Sigmund Freund worked with the mechanisms of displacement, substitution, and sublimation. These mechanisms have many similarities and have been studied diagnostically and therapeutically. Displacement and substitution seem to fit in well with phobias, hysterias, somatiyations, prejudices, and scapegoating. Phobias, prejudices, and scapegoating…

  14. Gene Tree Discordance Causes Apparent Substitution Rate Variation.

    PubMed

    Mendes, Fábio K; Hahn, Matthew W

    2016-07-01

    Substitution rates are known to be variable among genes, chromosomes, species, and lineages due to multifarious biological processes. Here, we consider another source of substitution rate variation due to a technical bias associated with gene tree discordance. Discordance has been found to be rampant in genome-wide data sets, often due to incomplete lineage sorting (ILS). This apparent substitution rate variation is caused when substitutions that occur on discordant gene trees are analyzed in the context of a single, fixed species tree. Such substitutions have to be resolved by proposing multiple substitutions on the species tree, and we therefore refer to this phenomenon as Substitutions Produced by ILS (SPILS). We use simulations to demonstrate that SPILS has a larger effect with increasing levels of ILS, and on trees with larger numbers of taxa. Specific branches of the species trees are consistently, but erroneously, inferred to be longer or shorter, and we show that these branches can be predicted based on discordant tree topologies. Moreover, we observe that fixing a species tree topology when performing tests of positive selection increases the false positive rate, particularly for genes whose discordant topologies are most affected by SPILS. Finally, we use data from multiple Drosophila species to show that SPILS can be detected in nature. Although the effects of SPILS are modest per gene, it has the potential to affect substitution rate variation whenever high levels of ILS are present, particularly in rapid radiations. The problems outlined here have implications for character mapping of any type of trait, and for any biological process that causes discordance. We discuss possible solutions to these problems, and areas in which they are likely to have caused faulty inferences of convergence and accelerated evolution. PMID:26927960

  15. Alkali element constraints on Earth-Moon relations

    NASA Technical Reports Server (NTRS)

    Norman, M. D.; Drake, M. J.; Jones, J. H.

    1994-01-01

    Given their range of volatilities, alkali elements are potential tracers of temperature-dependent processes during planetary accretion and formation of the Earth-Moon system. Under the giant impact hypothesis, no direct connection between the composition of the Moon and the Earth is required, and proto-lunar material does not necessarily experience high temperatures. Models calling for multiple collisions with smaller planetesimals derive proto-lunar materials mainly from the Earth's mantle and explicitly invoke vaporization, shock melting and volatility-related fractionation. Na/K, K/Rb, and Rb/Cs should all increase in response to thermal volatization, so theories which derive the Moon substantially from Earth's mantle predict these ratios will be higher in the Moon than in the primitive mantle of the Earth. Despite the overall depletion of volatile elements in the Moon, its Na/K and K/Rb are equal to or less than those of Earth. A new model presented here for the composition of Earth's continental crust, a major repository of the alkali elements, suggests the Rb/Cs of the Moon is also less than that of Earth. Fractionation of the alkali elements between Earth and Moon are in the opposite sense to predictions based on the relative volatilities of these elements, if the Moon formed by high-T processing of Earth's mantle. Earth, rather than the Moon, appears to carry a signature of volatility-related fractionation in the alkali elements. This may reflect an early episode of intense heating on Earth with the Moon's alkali budget accreting from cooler material.

  16. Current situation of development of petroleum substituting energies (Canada)

    NASA Astrophysics Data System (ADS)

    1993-03-01

    Trends in development of petroleum substituting energies in Canada are described. Those fuels being put into practical use as substituting fuels in the transportation sector are natural gas, propane gas, methanol, hydrogen, and electric power. An architectural energy technology improving project was inaugurated on air conditioning, ventilation, and illumination in buildings that consume 34% of the entire energy. The IERD program was implemented by the bureau of efficient substituting energy technologies of CANMET on the research and development in industrial areas. Since having been introduced in 1977, this project has extended assistance to about 80 cases in industrial areas, of which 50% have achieved technical successes and were commercialized. With respect to bio energies, methods for effectively utilizing wastes that are difficult to treat are drawing attention. Research and development are being moved forward to put into practical use the solar energy, wind power, and small-scale regenerative energies.

  17. Interactions and low-energy collisions between an alkali ion and an alkali atom of a different nucleus

    NASA Astrophysics Data System (ADS)

    Rakshit, Arpita; Ghanmi, Chedli; Berriche, Hamid; Deb, Bimalendu

    2016-05-01

    We study theoretically interaction potentials and low-energy collisions between different alkali atoms and alkali ions. Specifically, we consider systems such as X + {{{Y}}}+, where X({{{Y}}}+) is either Li(Cs+) or Cs(Li+), Na(Cs+) or Cs(Na+) and Li(Rb+) or Rb(Li+). We calculate the molecular potentials of the ground and first two excited states of these three systems using a pseudopotential method and compare our results with those obtained by others. We derive ground-state scattering wave functions and analyze the cold collisional properties of these systems for a wide range of energies. We find that, in order to get convergent results for the total scattering cross sections for energies of the order 1 K, one needs to take into account at least 60 partial waves. The low-energy scattering properties calculated in this paper may serve as a precursor for experimental exploration of quantum collisions between an alkali atom and an alkali ion of a different nucleus.

  18. Materials compatibility and lubricants research on CFC-refrigerant substitutes

    NASA Astrophysics Data System (ADS)

    Szymurski, S. R.; Hawley, M.; Hourahan, G. C.; Godwin, D. S.

    1994-08-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory Committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. The Air-Conditioning and Refrigeration Technology Institute, Inc., (ARTI) manages and contracts multiple research projects and a data collection and dissemination effort. Detailed results from these projects are reported in technical reports prepared by each subcontractor.

  19. New aluminium-rich alkali slag matrix with clay minerals for immobilizing simulated radioactive Sr and Cs waste

    NASA Astrophysics Data System (ADS)

    Qian, Guangren; Sun, Darren Delai; Tay, Joo Hwa

    2001-12-01

    A new aluminium-rich alkali-activated slag matrix (M-AAS) with clay absorbents has been developed for immobilization of simulated radioactive Sr or Cs waste by introducing metakaolin, natural zeolite and NaOH-treated attapulgite clay minerals into alkali-activated slag matrix (AAS). The results revealed that the additions of metakaolin and clay absorbents into the cementitious matrixes would greatly enhance the distribution ratio, Rd, of selective adsorption whether the matrix was OPC matrix or AAS matrix. The new immobilizing matrix M-AAS not only exhibited the strongest selective adsorption for both Sr and Cs ions, but also was characterized by lower porosity and small pore diameter so that it exhibited the lowest leaching rate. Hydration product analyses also demonstrated that (Na+Al)-substituted C-S-H(I) and self-generated zeolite were major hydration products in the M-AAS matrix, which provided this new immobilizing matrix with better selective adsorption on Sr and Cs and lower leaching rate.

  20. How Do Substitute Teachers Substitute? An Empirical Study of Substitute-Teacher Labor Supply

    ERIC Educational Resources Information Center

    Gershenson, Seth

    2012-01-01

    This paper examines the daily labor supply of a potentially important, but often overlooked, source of instruction in U.S. public schools: substitute teachers. I estimate a sequential binary-choice model of substitute teachers' job-offer acceptance decisions using data on job offers made by a randomized automated calling system. Importantly, this…

  1. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10126 Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato...

  2. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10126 Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato...

  3. [Measurement of Mole Ratio for Alkali Metal Mixture by Using Spectral Absorption Method].

    PubMed

    Zou, Sheng; Zhang, Hong; Chen, Yao; Chen, Xi-yuan

    2015-08-01

    The ratio of alkali metal mixture is one of the most important parameters in gauge head belonging to the ultra-sensitivity inertial measurement equipment, which is required to detect precisely. According to the feature that ratio of alkali metal is related to alkali metal vapor density, the theory of optical depth is used to detect the ratio of alkali metal in the present article. The result shows that the data got by the theory of optical depth compared with empirical formula differs at three orders of magnitude, which can't ensure the accuracy. By changing the data processing method, model between spectral absorption rate and temperature in cell is established. The temperature in alkali metal cell is calibrated by spectral absorption rate. The ratio of alkali metal atoms in the cell is analyzed by calculating the alkali density with empirical formula. The computational error is less than 10%. PMID:26672309

  4. Technical Guid

    NASA Astrophysics Data System (ADS)

    Tanasescu, F. T.; Stanciu, V.; Nitu, V.; Nitu, C.

    The book contains the most important informations from Physics,Mechanics,Heat,Electromagnetism, Nuclear Physics as well as tables with values for physical and technical Quantities. The book is designed especially for engineers, but could be useful for physicists

  5. Synthesis and structural determination of alkali and alkaline earth metal containing bismuth vanadates

    NASA Astrophysics Data System (ADS)

    Bliesner, Rebecca Jean

    Exploratory synthesis plays an important role in the quest to discover new materials. There are very few structurally characterized alkali metal containing bismuth vanadates. Hybridization of the 6s and 6p orbitals of Bi 3+ and the resulting lone electron pair yields some very interesting stereochemistry and steric related properties. Some of those properties include ferroelectricity, ferroelasticity, electronic and ionic conduction, superconductivity, nonlinear optical capabilities and selective catalysis. Systematic exploration of the Na-Bi-V ternary system produced a new phase of NaBi3V2O10. This material crystallizes in the P1¯ space group and the reported oxygen ion conductivity is apparently due to the presence of interstitial oxygen rather than oxygen vacancies. Stabilization of the tetragonal scheelite phase of BiVO4 has been achieved by the substitution of a M2+ for Bi3+ . This has not been accomplished previously by a M2+ cation substitution. The compound Ca0.29Bi0.71VO 3.855 crystallizes in the P4¯ space group. An investigation of the K-Bi-V ternary system resulted in the discovery of a new potassium vanadate. K10Bi4V4O 21 crystallizes in the P6¯ space group with a equal to 10.205(2)A and c equal to 7.669(2)A. Other new compounds prepared, for which structures have not been determined are alpha-Na3BiV2O8, beta-Na3BiV 2O8, K8Bi5V5O24, Rb2BiVO5, a rubidium compound with a 3:3:2 stoichiometric ratio of Rb:Bi:V, a rubidium compound with 2:1:1, a sodium compound with 2:1:1 and a lithium compound with a 1:1:1 stoichiometric ratio of Li:Bi:V.

  6. 40 CFR 721.3063 - Substituted phenyl azo substituted phenyl esters (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted phenyl azo substituted... Significant New Uses for Specific Chemical Substances § 721.3063 Substituted phenyl azo substituted phenyl... chemical substances identified generically as substituted phenyl azo substituted phenyl esters (PMNs...

  7. 40 CFR 721.3063 - Substituted phenyl azo substituted phenyl esters (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted phenyl azo substituted... Significant New Uses for Specific Chemical Substances § 721.3063 Substituted phenyl azo substituted phenyl... as substituted phenyl azo substituted phenyl esters (PMNs P-95-655, P-95-782 and P-95-871)...

  8. 40 CFR 721.3063 - Substituted phenyl azo substituted phenyl esters (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted phenyl azo substituted... Significant New Uses for Specific Chemical Substances § 721.3063 Substituted phenyl azo substituted phenyl... chemical substances identified generically as substituted phenyl azo substituted phenyl esters (PMNs...

  9. Elucidating the magnetic and superconducting phases in the alkali metal intercalated iron chalcogenides

    NASA Astrophysics Data System (ADS)

    Wang, Meng; Yi, Ming; Tian, Wei; Bourret-Courchesne, Edith; Birgeneau, Robert J.

    2016-02-01

    The complex interdigitated phases have greatly frustrated attempts to document the basic features of the superconductivity in the alkali metal intercalated iron chalcogenides. Here, using elastic neutron scattering, energy-dispersive x-ray spectroscopy, and resistivity measurements, we elucidate the relations of these phases in RbxFeySe2 -zSz . We find (i) the iron content is crucial in stabilizing the stripe antiferromagnetic (AF) phase with rhombic iron vacancy order (y ≈1.5 ) , the block AF phase with √{5 }×√{5 } iron vacancy order (y ≈1.6 ) , and the iron vacancy-free phase (y ≈2 ) ; and (ii) the iron vacancy-free superconducting phase (z =0 ) evolves into an iron vacancy-free metallic phase with sulfur substitution (z >1.5 ) due to the progressive decrease of the electronic correlation strength. Both the stripe AF phase and the block AF phase are Mott insulators. The iron-rich compounds (y >1.6 ) undergo a first order transition from an iron vacancy disordered phase at high temperatures into the √{5 }×√{5 } iron vacancy ordered phase and the iron vacancy-free phase below Ts. Our data demonstrate that there are miscibility gaps between these three phases. The existence of the miscibility gaps in the iron content is a key to understanding the relationship between these complicated phases.

  10. Structural properties and adsorption capacity of holocellulose aerogels synthesized from an alkali hydroxide-urea solution

    NASA Astrophysics Data System (ADS)

    Kwon, Gu-Joong; Kim, Dae-Young; Hwang, Jae-Hyun; Kang, Joo-Hyon

    2014-05-01

    A tulip tree was used to synthesize a holocellulose aerogel from an aqueous alkali hydroxide-urea solution with the substitution of an organic solvent followed by freeze-drying. For comparison, the synthesized holocellulose aerogels were divided into two groups according to the source of the hydrogel, an upper suspended layer and a bottom concentrated layer of the centrifuged solution of cellulose and NaOH/urea solvents. We investigated the effects of the temperature of the pre-cooled NaOH/urea solution ( i.e., dissolution temperature) on the pore structure and the adsorption capacity of the holocellulose aerogel. A nano-fibrillar network structure of the holocellulose aerogel was observed, with little morphological difference in pore structure for different dissolution temperatures. Both micropores and mesopores were observed in the holocellulose aerogel. The specific surface area of the holocellulose aerogel was generally greater at lower dissolution temperatures. In a series of adsorption tests using methylene blue, the holocellulose aerogel showed the greatest adsorption capacity at the lowest dissolution temperature tested (-2°C). However, the dissolution temperature generally had little effect on the adsorption capacity. The holocellulose aerogel produced from the upper suspended layer of the centrifuged hydrogel solution showed a greater porosity and adsorption capacity than the one produced from the bottom concentrated layer. Overall, the aerogel made by utilizing a delignified tulip tree display a high surface area and a high adsorption property, indicating its possible application in eco-friendly adsorption materials.

  11. A New Alkali-Thermostable Azoreductase from Bacillus sp. Strain SF

    PubMed Central

    Maier, Jürgen; Kandelbauer, Andreas; Erlacher, Angelika; Cavaco-Paulo, Artur; Gübitz, Georg M.

    2004-01-01

    A screening for dye-decolorizing alkali-thermophilic microorganisms resulted in a Bacillus sp. strain isolated out of the wastewater drain of a textile finishing company. An NADH-dependent azoreductase of this strain, Bacillus sp. strain SF, was found to be responsible for the decolorization of azo dyes. This enzyme was purified by a combination of ammonium sulfate precipitation and anion-exchange and affinity chromatography and had a molecular mass of 61.6 kDa and an isoelectric point at pH 5.3. The pH optimum of the azoreductase depended on the substrate and was within the range of pHs 8 to 9, while the temperature maximum was reached at 80°C. Decolorization only took place in the absence of oxygen and was enhanced by FAD, which was not consumed during the reaction. A 26% similarity of this azoreductase to chaperonin Cpn60 from a Bacillus sp. was found by peptide mass mapping experiments. Substrate specificities of the azoreductase were studied by using synthesized model substrates based on di-sodium-(R)-benzyl-azo-2,7-dihydroxy-3,6-disulfonyl-naphthaline. Those dyes with NO2 substituents, especially in the ortho position, were degraded fastest, while analogues with a methyl substitution showed the lowest degradation rates. PMID:14766562

  12. Process for carbonaceous material conversion and recovery of alkali metal catalyst constituents held by ion exchange sites in conversion residue

    DOEpatents

    Sharp, David W.

    1980-01-01

    In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered for the particles by contacting or washing them with an aqueous solution containing calcium or magnesium ions in an alkali metal recovery zone at a low temperature, preferably below about 249.degree. F. During the washing or leaching process, the calcium or magnesium ions displace alkali metal ions held by ion exchange sites in the particles thereby liberating the ions and producing an aqueous effluent containing alkali metal constituents. The aqueous effluent from the alkali metal recovery zone is then recycled to the conversion process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.

  13. Nucleophilic Substitution by Benzodithioate Anions.

    ERIC Educational Resources Information Center

    Bonnans-Plaisance, Chantal; Gressier, Jean-Claude

    1988-01-01

    Describes a two-session experiment designed to provide a good illustration of, and to improve student knowledge of, the Grignard reaction and nucleophilic substitution. Discusses the procedure, experimental considerations, and conclusion of this experiment. (CW)

  14. DESIGNING ENVIRONMENTALLY BENIGN SOLVENT SUBSTITUTES

    EPA Science Inventory

    Since the signing of 1987 Montreal Protocol, reducing and eliminating the use of harmful solvents has become an internationally imminent environmental protection mission. Solvent substitution is an effective way to achieve this goal. The Program for Assisting the Replacement of...

  15. Structural implications of water dissolution in haplogranitic glasses from NMR spectroscopy: influence of total water content and mixed alkali effect

    NASA Astrophysics Data System (ADS)

    Schmidt, B. C.; Riemer, T.; Kohn, S. C.; Holtz, F.; Dupree, R.

    2001-09-01

    To study the effects of total water content and alkali substitution on the structure of aluminosilicate glasses, two series of glasses belonging to the ternary system Quartz (Qz)-Albite (Ab)-Orthoclase (Or) were synthesized and investigated with nuclear magnetic resonance (NMR) spectroscopy. Series I consisted of seven glasses with normative composition Ab 39Or 32Qz 29 (AOQ) and water contents ranging from 0 to 6 wt%. Series II consisted of dry and hydrous glasses (˜2.0 wt% H 2O) with five compositions along the join Qz 37Ab 63-Qz 34Or 66 (AQ-OQ) varying the alkali content (Na/K) at constant Si/Al ratio. All glasses were investigated with 1H, 23Na, 27Al and 29Si magic angle spinning (MAS) NMR. 29Si MAS spectra of AOQ glasses showed no change upon hydration, suggesting little variation of the Si environments although the large linewidth of the 29Si signal may hide the presence of some Si Q 3-OH. The isotropic chemical shift (δ iso) of 27Al showed no change upon hydration, regardless of the amount of dissolved water. The 27Al mean quadrupolar coupling constant (C q) decreased with increasing water content, indicating a general increase of symmetry of the charge distribution around Al, which suggests the absence of significant amounts of Al Q 3-OH. Nonetheless, the evolution of C q upon hydration suggests a correlation with OH concentration in the quenched glass. The evolution of 23Na isotropic chemical shifts upon hydration appears to be correlated with total water content or with the concentration of dissolved H 2O molecules. In general, the NMR data are consistent with the water solubility model of Kohn et al. (1989), involving the exchange of charge balancing cations by protons. However, in addition to the presence of molecular water, 1H-NMR results showed at least two types of OH groups of which one may be related to Al-OH. Although the small intensity of this signal indicates that only a minor fraction of OH groups is present in this species, it demonstrates

  16. Petrology and geochemistry of alkali gabbronorites from lunar breccia 67975

    NASA Technical Reports Server (NTRS)

    James, Odette B.; Flohr, Marta K.; Lindstrom, Marilyn M.

    1987-01-01

    Detailed results of petrologic and compositional studies of three clasts found in thin sections of the Apollo 16 lunar breccia 67975 and of four clasts extracted from the breccia (for instrumental neutron activation analysis) prior to thin sectioning are reported. The alkali gabbronorites of the breccia form two distinct subgroups, magnesian and ferroan. The magnesian gabbronorites are composed of bytownitic plagioclase, hypersthene, augite, a silica mineral, and trace Ba-rich K-feldspar. The ferroan gabbronorites are composed of ternary plagioclase, pigeonite, augite, Ba-rich K-feldspar, and a silica mineral. Trace minerals in both subgroups are apatite, REE-rich whitlockite, and zircon. The magnesian and ferroan alkali gabbronorites appear to have formed by progressive differentiation of the same, or closely related, parent REE-rich magmas.

  17. Alkali Halide Microstructured Optical Fiber for X-Ray Detection

    NASA Technical Reports Server (NTRS)

    DeHaven, S. L.; Wincheski, R. A.; Albin, S.

    2014-01-01

    Microstructured optical fibers containing alkali halide scintillation materials of CsI(Na), CsI(Tl), and NaI(Tl) are presented. The scintillation materials are grown inside the microstructured fibers using a modified Bridgman-Stockbarger technique. The x-ray photon counts of these fibers, with and without an aluminum film coating are compared to the output of a collimated CdTe solid state detector over an energy range from 10 to 40 keV. The photon count results show significant variations in the fiber output based on the materials. The alkali halide fiber output can exceed that of the CdTe detector, dependent upon photon counter efficiency and fiber configuration. The results and associated materials difference are discussed.

  18. Wetting Transitions of Inert Gases on Alkali Metal Surfaces

    NASA Astrophysics Data System (ADS)

    Bojan, M. J.; McDonald, I. A.; Cole, M. W.; Steele, W. A.

    1996-03-01

    Theoretical and experimental discoveries have been made recently of wetting and prewetting transitions of helium and hydrogen films on alkali metal surfaces [1,2]. New experiments show anomalous nonwetting behavior of Ne on Rb and Cs [3]. Building on earlier work [4], we have done and will describe results from the first Monte Carlo simulations showing wetting transitions for classical gases on alkali metal surfaces. * Research supported by an NSF Materials Research Group grant. 1. R. B.Hallock, J. Low Temp. Phys. 101, 31, 1995 2. M. W. Cole, J. Low Temp. Phys. 101, 25, 1995. 3. G. B. Hess, M. Sabatini, and M. H. W. Chan, unpublished 4. J. E. Finn and P. A. Monson, Phys. Rev. A 39, 6402, 1989.

  19. Properties and Performance of Alkali-Activated Concrete

    NASA Astrophysics Data System (ADS)

    Thomas, Robert J.

    Alkali-activated concrete (AAC) made with industrial byproducts as the sole binder is rapidly emerging as a sustainable alternative to ordinary portland cement concrete (PCC). Despite its exemplary mechanical performance and durability, there remain several barriers to widespread commercialization of AAC. This dissertation addresses several of these barriers. Mathematical models are proposed which efficiently and accurately predict the compressive strength of AAC as a function of activator composition, binder type, and curing condition. The relationships between compressive strength and other mechanical properties (i.e., tensile strength and modulus of elasticity) are discussed, as are stress-strain relationships. Several aspects related to the durability of AAC are also discussed, including dimensional stability under drying conditions, alkali-silica reactivity, and chloride permeability. The results of these experimental investigations are disseminated in the context of real-world applicability.

  20. Alkali halide microstructured optical fiber for X-ray detection

    SciTech Connect

    DeHaven, S. L. E-mail: russel.a.wincheski@nasa.gov; Wincheski, R. A. E-mail: russel.a.wincheski@nasa.gov; Albin, S.

    2015-03-31

    Microstructured optical fibers containing alkali halide scintillation materials of CsI(Na), CsI(Tl), and NaI(Tl) are presented. The scintillation materials are grown inside the microstructured fibers using a modified Bridgman-Stockbarger technique. The x-ray photon counts of these fibers, with and without an aluminum film coating are compared to the output of a collimated CdTe solid state detector over an energy range from 10 to 40 keV. The photon count results show significant variations in the fiber output based on the materials. The alkali halide fiber output can exceed that of the CdTe detector, dependent upon photon counter efficiency and fiber configuration. The results and associated materials difference are discussed.

  1. Alkali elements in the Earth's core: Evidence from enstatite meteorites

    NASA Technical Reports Server (NTRS)

    Lodders, K.

    1995-01-01

    The abundances of alkali elements in the Earth's core are predicted by assuming that accretion of the Earth started from material similar in composition to enstatite chondrites and that enstatite achondrites (aubrites) provide a natural laboratory to study core-mantle differentiation under extremely reducing conditions. If core formation on the aubrite parent body is comparable with core formation on the early Earth, it is found that 2600 (+/- 1000) ppm Na, 550 (+/- 260) ppm K, 3.4 (+/- 2.1) ppm Rb, and 0.31 (+/- 0.24) ppm Cs can reside in the Earth's core. The alkali-element abundances are consistent with those predicted by independent estimates based on nebula condensation calculations and heat flow data.

  2. Coherent coupling of alkali atoms by random collisions.

    PubMed

    Katz, Or; Peleg, Or; Firstenberg, Ofer

    2015-09-11

    Random spin-exchange collisions in warm alkali vapor cause rapid decoherence and act to equilibrate the spin state of the atoms in the vapor. In contrast, here we demonstrate experimentally and theoretically a coherent coupling of one alkali species to another species, mediated by these random collisions. We show that the minor species (potassium) inherits the magnetic properties of the dominant species (rubidium), including its lifetime (T_{1}), coherence time (T_{2}), gyromagnetic ratio, and spin-exchange relaxation-free magnetic-field threshold. We further show that this coupling can be completely controlled by varying the strength of the magnetic field. Finally, we explain these phenomena analytically by mode mixing of the two species via spin-exchange collisions. PMID:26406827

  3. Renal tubular acidosis due to the milk-alkali syndrome.

    PubMed

    Rochman, J; Better, O S; Winaver, J; Chaimowitz, C; Barzilai, A; Jacobs, R

    1977-06-01

    A 60-year-old man with a history of excessive ingestion of calcium carbonate presented with azotemia, hypercalcemia and hyperphosphatemia. His acid-base status was initially normal. Following the cessation of calcium carbonate treatment, the hypercalcemia and azotemia disappeared, and the patient was found to be in metabolic acidosis with blunted acid excretion and a urine pH of 6.1. Kidney biopsy showed focal tubular calcification; the tubular damage was apparently caused by hypercalcemia and had resulted in renal tubular acidosis. During the three months of observation since that time there has been a tendecy for spontaneous remission of the renal tubular acidosis. Impaired renal hydrogen ion excretion prevented the development of metabolic alkalosis despite ingestion of alkali initially, and was later responsible for the metabolic acidosis. Renal tubular acidosis occurring as a sequel to the milk-alkali syndrome may aggravate the danger of nephrocalcinosis in this syndrome. PMID:885714

  4. Operation and performance of a double-alkali scrubber

    SciTech Connect

    Sachtschale, J.R.; Dydo, J.F.

    1982-11-01

    Santa Fe Energy Co. (SFEC) installed a double-alkali sulfur dioxide absorber at its Kern River field near Bakersfield, CA. The flue gas desulfurization (FGD) system is designed to remove 95% of the sulfur dioxide from the exhaust of eight oil-fired steam generators when 1.5 wt% sulfur fuel oil is burned. The chemistry of the double-alkali process and the results of compliance and performance emissions testing are presented. Sulfur dioxide emission results are analyzed. Performance tests showed that total outlet sulfur dioxide emissions were 28.7 lbm/hr (0.00363 kg/s). If offset emissions are included, the net sulfur dioxide emissions were 0.22 lbm/hr (0.00003 kg/s).

  5. Polymerization reactivity of sulfomethylated alkali lignin modified with horseradish peroxidase.

    PubMed

    Yang, Dongjie; Wu, Xiaolei; Qiu, Xueqing; Chang, Yaqi; Lou, Hongming

    2014-03-01

    Alkali lignin (AL) was employed as raw materials in the present study. Sulfomethylation was conducted to improve the solubility of AL, while sulfomethylated alkali lignin (SAL) was further polymerized by horseradish peroxidase (HRP). HRP modification caused a significant increase in molecular weight of SAL which was over 20 times. It was also found to increase the amount of sulfonic and carboxyl groups while decrease the amount of phenolic and methoxyl groups in SAL. The adsorption quantity of self-assembled SAL film was improved after HRP modification. Sulfonation and HRP modification were mutually promoted. The polymerization reactivity of SAL in HRP modification was increased with its sulfonation degree. Meanwhile, HRP modification facilitated SAL's radical-sulfonation reaction. PMID:24534439

  6. Synthesis and studies on microhardness of alkali zinc borate glasses

    NASA Astrophysics Data System (ADS)

    Subhashini, Bhattacharya, Soumalya; Shashikala, H. D.; Udayashankar, N. K.

    2014-04-01

    The mixed alkali effect on zinc borate glasses have been reported. The glass systems of nominal composition 10Zn+xLi2O+yNa2O+80B2O3 (x = y = 0, 5, 10, 15 mol%) were prepared using standard melt quenching method. The structural, physical and mechanical properties of the samples have been studied using X-ray diffraction(XRD), density measurement and Vickers hardness measurement, respectively. A consistent increase in the density was observed, which explains the role of the modifiers (Li2O and Na2O) in the network modification of borate structure. The molar volume is decreasing linearly with the alkali concentration, which is attributed to the conversion of tetrahedral boron (BO4/2)- into (BO3/2)-. The microhardness studies reveals the anisotropy nature of the material. It further confirms that the samples belong to hard glass category.

  7. LLNL solvent substitution

    SciTech Connect

    Benkovitch, M.G.

    1992-12-01

    Allied-Signal Inc., Kansas City Division (KCD), manufactures the electrical, electromechanical, mechanical, and plastic components for nuclear weapons. The KCD has made a commitment to eliminate the use of chlorohydrocarbon (CHC) and chlorofluorocarbon (CFC) solvents to the greatest technical extent possible consistent with nuclear safety and stockpile reliability requirements by July 1993. Several non-halogenated solvents (Exxate 1000, Bioact EC-7, Bioact EC-7R, d-limonene, ACT-100, Kester 5769, and isopropyl alcohol) were evaluated to determine the most effective, non-chlorinated non-fluorinated, alternate solvent cleaning system for a particular electronic assembly in lieu of the current trichloroethylenefisopropyl alcohol baseline cleaning process. All of these solvents were evaluated using current manual spray cleaning processes. The solvents were evaluated for their effectiveness in removing a rosin based RMA solder flux, a particular silicone mold release, and a wide variety of general contaminants (oils, greases, mold releases, resins, etc.) normally found in production departments. A DI water/isopropyl alcohol spray cleaning process was also evaluated for removing two organic acid fluxes. Test samples were contaminated, spray cleaned with the appropriate solvent, and then analyzed for cleanliness. The Meseran Surface Analyzer was used to measure,, organic contamination on the samples before and after cleaning. An Omega Meter Model 600 was also used to detect solder flux residues.

  8. Optical Properties of Tm(3+) Ions in Alkali Germanate Glass

    NASA Technical Reports Server (NTRS)

    Walsh, Brian M.; Barnes, Norman P.; Reichle, Donald J.; Jiang, Shibin

    2006-01-01

    Tm-doped alkali germanate glass is investigated for use as a laser material. Spectroscopic investigations of bulk Tm-doped germanate glass are reported for the absorption, emission and luminescence decay. Tm:germanate shows promise as a fiber laser when pumped with 0.792 m diodes because of low phonon energies. Spectroscopic analysis indicates low nonradiative quenching and pulsed laser performance studies confirm this prediction by showing a quantum efficiency of 1.69.

  9. Lithological influence of aggregate in the alkali-carbonate reaction

    SciTech Connect

    Lopez-Buendia, A.M. . E-mail: angel.lopez@aidico.es; Climent, V. . E-mail: vcliment@grupogla.com; Verdu, P.

    2006-08-15

    The reactivity of carbonate rock with the alkali content of cement, commonly called alkali-carbonate reaction (ACR), has been investigated. Alkali-silica reaction (ASR) can also contribute in the alkali-aggregate reaction (AAR) in carbonate rock, mainly due to micro- and crypto-crystalline quartz or clay content in carbonate aggregate. Both ACR and ASR can occur in the same system, as has been also evidenced on this paper. Carbonate aggregate samples were selected using lithological reactivity criteria, taking into account the presence of dedolomitization, partial dolomitization, micro- and crypto-crystalline quartz. Selected rocks include calcitic dolostone with chert (CDX), calcitic dolostone with dedolomitization (CDD), limestone with chert (LX), marly calcitic dolostone with partial dolomitization (CD), high-porosity ferric dolostone with clays (FD). To evaluate the reactivity, aggregates were studied using expansion tests following RILEM AAR-2, AAR-5, a modification using LiOH AAR-5Li was also tested. A complementary study was done using petrographic monitoring with polarised light microscopy on aggregates immersed in NaOH and LiOH solutions after different ages. SEM-EDAX has been used to identify the presence of brucite as a product of dedolomitization. An ACR reaction showed shrinkage of the mortar bars in alkaline solutions explained by induced dedolomitization, while an ASR process typically displayed expansion. Neither shrinkage nor expansion was observed when mortar bars were immersed in solutions of lithium hydroxide. Carbonate aggregate classification with AAR pathology risk has been elaborated based on mechanical behaviours by expansion and shrinkage. It is proposed to be used as a petrographic method for AAR diagnosis to complement the RILEM AAR1 specifically for carbonate aggregate. Aggregate materials can be classified as I (non-reactive), II (potentially reactive), and III (probably reactive), considering induced dedolomitization ACR

  10. Precision optical metrology with alkali-atom isoclinic points

    NASA Astrophysics Data System (ADS)

    Wells, Nathan; Driskell, Travis; Camparo, James

    2016-06-01

    Vapour-phase spectroscopy rarely involves transitions between well-isolated atomic states. Routinely, the spectra comprise overlapped Doppler/pressure-broadened resonances, which leads to a “pulling” of the spectral peaks from their true atomic resonance frequencies. This pulling gives the absorption resonances a temperature sensitivity, which limits their utility for precision spectroscopy when sub-Doppler techniques are not viable. Here, we discuss the use of alkali isoclinic points as a solution to this problem.

  11. Resonances in low-energy positron-alkali scattering

    NASA Technical Reports Server (NTRS)

    Horbatsch, M.; Ward, S. J.; Mceachran, R. P.; Stauffer, A. D.

    1990-01-01

    Close-coupling calculations were performed with up to five target states at energies in the excitation threshold region for positron scattering from Li, Na and K. Resonances were discovered in the L = 0, 1 and 2 channels in the vicinity of the atomic excitation thresholds. The widths of these resonances vary between 0.2 and 130 MeV. Evidence was found for the existence of positron-alkali bound states in all cases.

  12. High-energy transversely pumped alkali vapor laser

    NASA Astrophysics Data System (ADS)

    Zweiback, J.; Komashko, A.

    2011-03-01

    We report on the results from our transversely pumped alkali laser. This system uses an Alexandrite laser to pump a stainless steel laser head. The system uses methane and helium as buffer gasses. Using rubidium, the system produced up to 40 mJ of output energy when pumped with 63 mJ. Slope efficiency was 75%. Using potassium as the lasing species the system produced 32 mJ and a 53% slope efficiency.

  13. Diode pumped alkali vapor lasers for high power applications

    NASA Astrophysics Data System (ADS)

    Zweiback, J.; Krupke, B.; Komashko, A.

    2008-02-01

    General Atomics has been engaged in the development of diode pumped alkali vapor lasers. We have been examining the design space looking for designs that are both efficient and easily scalable to high powers. Computationally, we have looked at the effect of pump bandwidth on laser performance. We have also looked at different lasing species. We have used an alexandrite laser to study the relative merits of different designs. We report on the results of our experimental and computational studies.

  14. (abstract) Experimental and Modeling Studies of the Exchange Current at the Alkali Beta'-Alumina/Porous Electrode/Alkali Metal Vapor Three Phase Boundary

    NASA Technical Reports Server (NTRS)

    Williams, R. M.; Jeffries-Nakamura, B.; Ryan, M. A.; Underwood, M. L.; O'Connor, D.; Kikkert, S.

    1993-01-01

    The microscopic mechanism of the alkali ion-electron recombination reaction at the three phase boundary zone formed by a porous metal electrode in the alkali vapor on the surface of an alkali beta'-alumina solid electrolyte (BASE) ceramic has been studied by comparison of the expected rates for the three simplest reaction mechanisms with known temperature dependent rate data; and the physical parameters of typical porous metal electrode/BASE/alkali metal vapor reaction zones. The three simplest reactions are tunneling of electrons from the alkali coated electrode to a surface bound alkali metal ion; emission of an electron from the electrode with subsequent capture by a surface bound alkali metal ion; and thermal emission of an alkali cation from the BASE and its capture on the porous metal electrode surface where it may recombine with an electron. Only the first reaction adequately accounts for both the high observed rate and its temperature dependence. New results include crude modeling of simple, one step, three phase, solid/solid/gas electrochemical reaction.

  15. Spatial Polarization Profile in an Optically Pumped Alkali Vapor

    NASA Astrophysics Data System (ADS)

    Olsen, Ben; Patton, Brian; Jau, Yuan-Yu; Happer, Will

    2009-05-01

    Spin-Exchange Optical Pumping (SEOP) is a technique used to polarize nuclei in gases, and more recently in solids, in excess of their equilibrium limit. SEOP is achieved by optically pumping an alkali vapor which subsequently transfers angular momentum to the nuclei of interest. The efficiency of SEOP is governed by optical pumping and relaxation of the alkali atoms, relaxation of the target nuclei, and interactions between the alkali and target substance. In this work we investigate the relationship between optical pumping and relaxation in cesium vapor with absorption spectroscopy at high magnetic field (2.7 T). Cesium vapor within a cylindrical glass vapor cell is optically pumped with a strong laser resonant with a D2 transition. The ground-state population of the vapor is measured at various positions along a diameter of the cell with a small, weak D1 laser beam which translates mechanically. The resulting polarization profile elucidates the interplay between optical pumping, diffusion in the buffer gas, and relaxation at the walls of the vapor cell. We report measurements of the spatial polarization profile in vapor cells with bare Pyrex walls and cells coated with paraffin (an anti-relaxation coating) or CsH salt (a target substance for SEOP), and compare them to numerical simulations. Further investigation might yield a new method for characterizing surface relaxation in vapor cells.

  16. Spin-Exchange Optical Pumping of Alkali Salts

    NASA Astrophysics Data System (ADS)

    Olsen, Ben; Patton, Brian; Jau, Yuan-Yu; Happer, Will; Ishikawa, Kiyoshi

    2008-05-01

    Spin-Exchange Optical Pumping (SEOP) is a technique used to polarize nuclei in excess of their equilibrium limit. SEOP is achieved by optically pumping an alkali vapor which then transfers angular momentum to the nuclei of interest. We have recently hyperpolarized ^133Cs nuclei in solid CsH using SEOP, achieving magnetizations more than an order of magnitude larger than the thermal equilibrium value.ootnotetextIshikawa et. al., Phys. Rev. Lett. 98, 183004 (2007) In subsequent work, we investigate the mechanisms underlying this transfer of angular momentum. By optically pumping Cs vapor with laser light resonant with several optical transitions, each yielding different nuclear and electronic spin currents to the solid, we attempt to determine the source of transferred angular momentum. Early evidence suggests both electronic and nuclear spin polarization in the vapor contribute to ^133Cs nuclear polarization in the salt. The ^1H polarization is also mildly affected by optical pumping. We compare these results to numerical simulations and to results from other alkali salts. Further studies are warranted to discover if polarization can be transferred to other nuclei (e.g., alkali salts) on the cell walls.

  17. The Interfacial Transition Zone in Alkali-Activated Slag Mortars

    NASA Astrophysics Data System (ADS)

    San Nicolas, Rackel; Provis, John

    2015-12-01

    The interfacial transition zone (ITZ) is known to strongly influence the mechanical and transport properties of mortars and concretes. This paper studies the ITZ between siliceous (quartz) aggregates and alkali activated slag binders in the context of mortar specimens. Backscattered electron images (BSE) generated in an environmental scanning electron microscope (ESEM) are used to identify unreacted binder components, reaction products and porosity in the zone surrounding aggregate particles, by composition and density contrast. X-ray mapping is used to exclude the regions corresponding to the aggregates from the BSE image of the ITZ, thus enabling analysis of only the binder phases, which are segmented into binary images by grey level discrimination. A distinct yet dense ITZ region is present in the alkali-activated slag mortars, containing a reduced content of unreacted slag particles compared to the bulk binder. The elemental analysis of this region shows that it contains a (C,N)-A-S-H gel which seems to have a higher content of Na (potentially deposited through desiccation of the pore solution) and a lower content of Ca than the bulk inner and outer products forming in the main binding region. These differences are potentially important in terms of long-term concrete performance, as the absence of a highly porous interfacial transition zone region is expected to provide a positive influence on the mechanical and transport properties of alkali-activated slag concretes.

  18. Electron Densities and Alkali Atoms in Exoplanet Atmospheres

    NASA Astrophysics Data System (ADS)

    Lavvas, P.; Koskinen, T.; Yelle, R. V.

    2014-11-01

    We describe a detailed study on the properties of alkali atoms in extrasolar giant planets, and specifically focus on their role in generating the atmospheric free electron densities, as well as their impact on the transit depth observations. We focus our study on the case of HD 209458b, and we show that photoionization produces a large electron density in the middle atmosphere that is about two orders of magnitude larger than the density anticipated from thermal ionization. Our purely photochemical calculations, though, result in a much larger transit depth for K than observed for this planet. This result does not change even if the roles of molecular chemistry and excited state chemistry are considered for the alkali atoms. In contrast, the model results for the case of exoplanet XO-2b are in good agreement with the available observations. Given these results we discuss other possible scenarios, such as changes in the elemental abundances, changes in the temperature profiles, and the possible presence of clouds, which could potentially explain the observed HD 209458b alkali properties. We find that most of these scenarios cannot explain the observations, with the exception of a heterogeneous source (i.e., clouds or aerosols) under specific conditions, but we also note the discrepancies among the available observations.

  19. The structure of metallic complexes of polyacetylene with alkali metals

    NASA Astrophysics Data System (ADS)

    Baughman, R. H.; Murthy, N. S.; Miller, G. G.

    1983-07-01

    The crystal structures of sodium, potassium, rubidium, and cesium doped polyacetylene have been determined using crystal packing and x-ray diffraction analyses. Each of these metallic complexes is tetragonal, with the polyacetylene chains forming a host lattice in which the alkali metal ions are present in channels. Lithium appears to be too small to stabilize the channel structure and an amorphous structure is observed. Predicted unit cell parameters and x-ray diffraction intensities are in agreement with observed values. Similarities with the alkali metal doped graphite suggest that hybridization between carbon pz orbitals and metal s orbitals occurs. Such hybridization is expected to result in a high conductivity component normal to the chain direction. On the other hand, direct overlap between polymer chains appears small, since alkali metal columns separate polymer chains. Compositions calculated for the channel structures (from meridional diffraction spacings, the intensity of equatorial diffraction lines, measured volume expansion, and distances in model complexes) all range from y=0.12 to 0.18 for (CHMy)x, where M is sodium, potassium, rubidium, or cesium.

  20. An accurate model potential for alkali neon systems.

    PubMed

    Zanuttini, D; Jacquet, E; Giglio, E; Douady, J; Gervais, B

    2009-12-01

    We present a detailed investigation of the ground and lowest excited states of M-Ne dimers, for M=Li, Na, and K. We show that the potential energy curves of these Van der Waals dimers can be obtained accurately by considering the alkali neon systems as one-electron systems. Following previous authors, the model describes the evolution of the alkali valence electron in the combined potentials of the alkali and neon cores by means of core polarization pseudopotentials. The key parameter for an accurate model is the M(+)-Ne potential energy curve, which was obtained by means of ab initio CCSD(T) calculation using a large basis set. For each MNe dimer, a systematic comparison with ab initio computation of the potential energy curve for the X, A, and B states shows the remarkable accuracy of the model. The vibrational analysis and the comparison with existing experimental data strengthens this conclusion and allows for a precise assignment of the vibrational levels. PMID:19968334

  1. Scattering of positrons and electrons by alkali atoms

    NASA Technical Reports Server (NTRS)

    Stein, T. S.; Kauppila, W. E.; Kwan, C. K.; Lukaszew, R. A.; Parikh, S. P.; Wan, Y. J.; Zhou, S.; Dababneh, M. S.

    1990-01-01

    Absolute total scattering cross sections (Q sub T's) were measured for positrons and electrons colliding with sodium, potassium, and rubidium in the 1 to 102 eV range, using the same apparatus and experimental approach (a beam transmission technique) for both projectiles. The present results for positron-sodium and -rubidium collisions represent the first Q sub T measurements reported for these collision systems. Features which distinguish the present comparisons between positron- and electron-alkali atom Q sub T's from those for other atoms and molecules (room-temperature gases) which have been used as targets for positrons and electrons are the proximity of the corresponding positron- and electron-alkali atom Q sub T's over the entire energy range of overlap, with an indication of a merging or near-merging of the corresponding positron and electron Q sub T's near (and above) the relatively low energy of about 40 eV, and a general tendency for the positron-alkali atom Q sub T's to be higher than the corresponding electron values as the projectile energy is decreased below about 40 eV.

  2. Insulin receptor-related receptor as an extracellular alkali sensor

    PubMed Central

    Deyev, Igor E.; Sohet, Fabien; Vassilenko, Konstantin P.; Serova, Oxana V.; Popova, Nadezhda V.; Zozulya, Sergey A.; Burova, Elena B.; Houillier, Pascal; Rzhevsky, Dmitry I.; Berchatova, Anastasiya A.; Murashev, Arkady N.; Chugunov, Anton O.; Efremov, Roman G.; Nikol’sky, Nikolai N.; Bertelli, Eugenio; Eladari, Dominique; Petrenko, Alexander G.

    2011-01-01

    SUMMARY The insulin receptor-related receptor (IRR), an orphan receptor tyrosine kinase of the insulin receptor family, can be activated by alkaline media both in vitro and in vivo at pH>7.9. The alkali-sensing property of IRR is conserved in frog, mouse and human. IRR activation is specific, dose-dependent, quickly reversible and demonstrates positive cooperativity. It also triggers receptor conformational changes and elicits intracellular signaling. The pH sensitivity of IRR is primarily defined by its L1F extracellular domains. IRR is predominantly expressed in organs that come in contact with mildly alkaline media. In particular, IRR is expressed in the cell subsets of the kidney that secrete bicarbonate into urine. Disruption of IRR in mice impairs the renal response to alkali loading attested by development of metabolic alkalosis and decreased urinary bicarbonate excretion in response to this challenge. We therefore postulate that IRR is an alkali sensor that functions in the kidney to manage metabolic bicarbonate excess. PMID:21641549

  3. Electron densities and alkali atoms in exoplanet atmospheres

    SciTech Connect

    Lavvas, P.; Koskinen, T.; Yelle, R. V.

    2014-11-20

    We describe a detailed study on the properties of alkali atoms in extrasolar giant planets, and specifically focus on their role in generating the atmospheric free electron densities, as well as their impact on the transit depth observations. We focus our study on the case of HD 209458b, and we show that photoionization produces a large electron density in the middle atmosphere that is about two orders of magnitude larger than the density anticipated from thermal ionization. Our purely photochemical calculations, though, result in a much larger transit depth for K than observed for this planet. This result does not change even if the roles of molecular chemistry and excited state chemistry are considered for the alkali atoms. In contrast, the model results for the case of exoplanet XO-2b are in good agreement with the available observations. Given these results we discuss other possible scenarios, such as changes in the elemental abundances, changes in the temperature profiles, and the possible presence of clouds, which could potentially explain the observed HD 209458b alkali properties. We find that most of these scenarios cannot explain the observations, with the exception of a heterogeneous source (i.e., clouds or aerosols) under specific conditions, but we also note the discrepancies among the available observations.

  4. Effect of alkali treatment on surface morphology of titanium

    SciTech Connect

    Tan, K. J. Wahab, M. A. A. Mahmod, S. Idris, M. I. Abdullah, H. Z.

    2015-07-22

    Alkali and heat treatments were first introduced by Kim et al. to prepare a bioactive surface on titanium. This method has been proven very effective and widely used in other studies to promote titanium osteointegration. This study aims to investigate further the effect of alkali treatment on surface morphology of high purity titanium. High purity titanium foils were immersed in NaOH aqueous solutions of 0.5 M, 5 M and 15 M at 60°C and 80 °C for 1, 3 and 7 days. The surface morphology was examined using Field Emission Scanning Electron Microscope (FESEM). The obtained phases were analysed using Fourier Transform Infrared Spectroscopy (FTIR) in the spectra range of 4000-600 cm{sup −1} at 4 cm{sup −1} resolution and 50 scans. At the same soaking temperature and soaking time, a thicker porous network was observed with increasing concentration of NaOH. At the same soaking temperature, a much porous structure was observed with increasing soaking time. At constant alkali concentration, more homogenously distributed porous surface structure was observed with increasing soaking temperature.

  5. Influence of substitution on the rheological properties and gelation of hydroxyethyl cellulose solution in NaOH-water solvent.

    PubMed

    Wang, Wencong; Li, Faxue; Yu, Jianyong; Navard, Patrick; Budtova, Tatiana

    2015-06-25

    The rheological properties of hydroxyethyl cellulose (HEC) with a low molar substitution (MS) dissolved in 8wt% NaOH-water were studied as a function of solution temperature, polymer concentration and molar substitution. Special attention was paid to gelation kinetics. Similar to cellulose dissolved in alkali or ionic liquids, the intrinsic viscosity of HEC decreased with temperature increase, indicating a decrease of solvent thermodynamic quality. The gelation time of HEC solutions decreased exponentially with temperature but the kinetics is much slower than the gelation of microcrystalline cellulose solutions in the same solvent. Higher molar substitution leads to slower gelation. The small amount of introduced hydroxyethyl groups prevented cellulose aggregation thus increasing solution stability. PMID:25839797

  6. Studies of Pressure-Broadening of Alkali Atom Resonance Lines for Modeling Atmospheres of Extrasolar Giant Planets and Brown Dwarfs

    NASA Technical Reports Server (NTRS)

    Kirby, Kate; Babb, J.; Yoshino, K.

    2004-01-01

    In L-dwarfs and T-dwarfs the resonance lines of sodium and potassium are so profoundly pressure-broadened that their wings extend several hundred nanometers from line center. With accurate knowledge of the line profiles as a function of temperature and pressure: such lines can prove to be valuable diagnostics of the atmospheres of such objects. We have initiated a joint program of theoretical and experimental research to study the line-broadening of alkali atom resonance lines due to collisions with species such as helium and molecular hydrogen. Although potassium and sodium are the alkali species of most interest in the atmospheres of cool brown dwarfs and extrasolar giant planets, some of our theoretical focus this year has involved the calculation of pressure-broadening of lithium resonance lines by He, as a test of a newly developed suite of computer codes. In addition, theoretical calculations have been carried out to determine the leading long range van der Waals coefficients for the interactions of ground and excited alkali metal atoms with helium atoms, to within a probable error of 2%. Such data is important in determining the behavior of the resonance line profiles in the far wings. Important progress has been made on the experimental aspects of the program since the arrival of a postdoctoral fellow in September. A new absorption cell has been designed, which incorporates a number of technical improvements over the previous cell, including a larger cell diameter to enhance the signal, and fittings which allow for easier cleaning, thereby significantly reducing the instrument down-time.

  7. Acid and alkali doped PBI electrolyte in electrochemical system

    NASA Astrophysics Data System (ADS)

    Xing, Baozhong

    In this work the conductivity of blank PBI membrane, acid doped PBI and alkaline doped PBI was systematically studied. A new methodology for sorption kinetics study in electrolyte solution has been established by monitoring the conductivity change during the sorption process. The model of the doping process and mechanism of conductivity are proposed. The performance of PBI (doped under optimum conditions) in fuel cell as PEM was evaluated. The experimental results show that the blank PBI in acid solution is an ionic insulator. It clarified the long time confusion in this area. The acid doped PBI membrane is an ionic conductor. The conductivity increases with the concentration of the acid solution. In high concentration acid solution, the conductivity increases with the type of acid in the order: H2SO 4 > H3PO4 > HClO4 > HNO3 > HCl. The kinetics of the doping process was studied, by a continuous method. The ionic conductivity mechanism was established. The PBI membranes doped with H2SO4 and H3PO4 exhibit better performance than NafionRTM. The doped FBI has more resistance to CO poison. 3% CO in H2 has little effect on the H3PO 4 doped PBI membrane at 185°C. The conductivity of the alkali doped PBI membrane changes with the concentration of the alkaline solution and the type of the alkalis. The conductivity has a maximum in KOH and NaOH solution. The maximum conductivity in KOH is higher than in NaOH and LiOH. It is about 5 times of that of NafionRTM in alkaline solution. The two-step sorption process in alkaline solution was observed. The first step is the permeation process of the alkalis in the PBI membrane. The permeation is the results of diffusion and interaction. It is concluded that the permeation process is controlled by the rate of interaction between the alkali and PBI molecule. The second step is the relaxation process in the membrane. This step contributes more to the conductivity for the membrane than the first step. The ionic conductivity mechanism

  8. Modifier interaction and mixed-alkali effect in bond constraint theory applied to ternary alkali metaphosphate glasses

    NASA Astrophysics Data System (ADS)

    Poletto Rodrigues, Bruno; Deubener, Joachim; Wondraczek, Lothar

    2016-05-01

    Introducing an interaction parameter γ, we implement modifier interaction and the mixed-alkali effect into bond constraint theory, and apply this extension for simplistic property prediction on ternary phosphate glasses. The severity of the mixed alkali effect results from the interplay of two simultaneous contributions: Bond constraints on the modifier species soften or stiffen with decreasing or increasing γ, respectively. When the modifier size is not too dissimilar the decrease in γ reflects that the alkali ions can easily migrate between different sites, forcing the network to continuously re-accommodate for any subsequent distortions. With increasing size difference, migration becomes increasingly difficult without considerable network deformation. This holds even for smaller ions, where the sluggish dynamics of the larger constituent result in blocking of the fast ion movement, leading to the subsequent increase in γ. Beyond a certain size difference in the modifier pair, a value of γ exceeding unity may indicate the presence of steric hindrance due to the large surrounding modifiers impeding the phosphate network to re-accommodate deformation.

  9. Technical Mathematics.

    ERIC Educational Resources Information Center

    Flannery, Carol A.

    This manuscript provides information and problems for teaching mathematics to vocational education students. Problems reflect applications of mathematical concepts to specific technical areas. The materials are organized into six chapters. Chapter 1 covers basic arithmetic, including fractions, decimals, ratio and proportions, percentages, and…

  10. Chlordane (Technical)

    Integrated Risk Information System (IRIS)

    Chlordane ( Technical ) ; CASRN 12789 - 03 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarc

  11. Experiment and simulation study on alkalis transfer characteristic during direct combustion utilization of bagasse.

    PubMed

    Liao, Yanfen; Cao, Yawen; Chen, Tuo; Ma, Xiaoqian

    2015-10-01

    Bagasse is utilized as fuel in the biggest biomass power plant of China, however, alkalis in the fuel created severe agglomeration and slagging problems. Alkalis transfer characteristic, agglomeration causes in engineering practice, additive improvement effects and mechanism during bagasse combustion were investigated via experiments and simulations. Only slight agglomeration occurs in ash higher than 800°C. Serious agglomeration in practical operation should be attributed to the gaseous alkalis evaporating at high temperature and condensing on the cooler grain surfaces in CFB. It can be speculated that ash caking can be avoided with temperature lower than 750°C and heating surface corrosion caused by alkali metal vapor can be alleviated with temperature lower than 850°C. Kaolin added into the bagasse has an apparent advantage over CaO additive both in enhancing ash fusion point and relieving alkali-chloride corrosion by locking alkalis in dystectic solid compounds over the whole temperature range. PMID:26196420

  12. Pretreatment of garden biomass by alkali-assisted ultrasonication: effects on enzymatic hydrolysis and ultrastructural changes

    PubMed Central

    2014-01-01

    The present investigation aims at studying the effectiveness of alkali-assisted ultrasonication on pretreatment of garden biomass (GB). Dry and powdered GB suspended in 1% NaOH was ultrasonicated for 15, 30 and 60 minutes at a frequency of 25 KHZ. The mode of action and effectiveness of alkali-assisted ultrasonication on GB was established through microscopic, scanning electron microscopic and X-ray diffraction studies. A perusal of results showed that alkali-assisted ultrasonication led to fibrillation of GB which ultimately facilitated enzymatic hydrolysis. The results also indicated that alkali-assisted ultrasonication is an efficient means of pretreatment of GB at moderate (45-50°C) working temperature and low (1%) concentration of alkali. The yield of reducing sugar after enzymatic hydrolysis increased almost six times as compared to control due to alkali-assisted ultrasonication. PMID:24843790

  13. Recent materials compatibility studies in refractory metal-alkali metal systems for space power applications.

    NASA Technical Reports Server (NTRS)

    Harrison, R. W.; Hoffman, E. E.; Davies, R. L.

    1972-01-01

    Advanced Rankine and other proposed space power systems utilize refractory metals in contact with both single-phase and two-phase alkali metals at elevated temperatures. A number of recent compatibility experiments are described which emphasize the excellent compatibility of refractory metals with the alkali metals, lithium, sodium, and potassium, under a variety of environmental conditions. The alkali metal compatibilities of tantalum-, columbium-, molybdenum-, and tungsten-base alloys are discussed.

  14. Systematics of Alkali and PB Abundances in Meteoritic and Lunar Samples

    NASA Astrophysics Data System (ADS)

    Kita, N. T.

    1996-03-01

    The alkali depletion is not a unique characteristic of the moon, but is common to eucrites, angrites, and the earth. Because the moon and the earth are depleted in more volatile Pb in a similar degree to both chondrites and achondrites, it is hard to assume that alkali depletion was caused by vaporization loss during the giant impact event. Alkali and volatile depletion might have originated from their source material which accreted to the planets.

  15. Identifying alkali metal inhibitors of crystal growth: a selection criterion based on ion pair hydration energy.

    PubMed

    Farmanesh, Sahar; Alamani, Bryan G; Rimer, Jeffrey D

    2015-09-21

    We show that alkali metals function as effective modifiers of calcium oxalate monohydrate (COM) crystallization wherein alkali-oxalate ion parings reduce the rate of crystal growth by as much as 60%. Our findings reveal a distinct trend in alkali metal efficacy that cannot be explained by colloidal theories or simple descriptors, such as ion size, but is consistent with a theoretical model that accounts for the ion pair's affinity for water. PMID:26242310

  16. Calculation of Radiative Corrections to E1 matrix elements in the Neutral Alkalis

    SciTech Connect

    Sapirstein, J; Cheng, K T

    2004-09-28

    Radiative corrections to E1 matrix elements for ns-np transitions in the alkali metal atoms lithium through francium are evaluated. They are found to be small for the lighter alkalis but significantly larger for the heavier alkalis, and in the case of cesium much larger than the experimental accuracy. The relation of the matrix element calculation to a recent decay rate calculation for hydrogenic ions is discussed, and application of the method to parity nonconservation in cesium is described.

  17. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted benzenesulfonic acid copper compound (generic). 721.10126 Section 721.10126 Protection of... substituted phenyl azo substituted benzenesulfonic acid copper compound (generic). (a) Chemical substance and... substituted phenyl azo substituted benzenesulfonic acid copper compound (PMN P-06-689) is subject to...

  18. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted benzenesulfonic acid copper compound (generic). 721.10126 Section 721.10126 Protection of... substituted phenyl azo substituted benzenesulfonic acid copper compound (generic). (a) Chemical substance and... substituted phenyl azo substituted benzenesulfonic acid copper compound (PMN P-06-689) is subject to...

  19. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted benzenesulfonic acid copper compound (generic). 721.10126 Section 721.10126 Protection of... substituted phenyl azo substituted benzenesulfonic acid copper compound (generic). (a) Chemical substance and... substituted phenyl azo substituted benzenesulfonic acid copper compound (PMN P-06-689) is subject to...

  20. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted...

  1. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted...

  2. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted...

  3. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted...

  4. Bone grafts and their substitutes.

    PubMed

    Fillingham, Y; Jacobs, J

    2016-01-01

    The continual cycle of bone formation and resorption is carried out by osteoblasts, osteocytes, and osteoclasts under the direction of the bone-signaling pathway. In certain situations the host cycle of bone repair is insufficient and requires the assistance of bone grafts and their substitutes. The fundamental properties of a bone graft are osteoconduction, osteoinduction, osteogenesis, and structural support. Options for bone grafting include autogenous and allograft bone and the various isolated or combined substitutes of calcium sulphate, calcium phosphate, tricalcium phosphate, and coralline hydroxyapatite. Not all bone grafts will have the same properties. As a result, understanding the requirements of the clinical situation and specific properties of the various types of bone grafts is necessary to identify the ideal graft. We present a review of the bone repair process and properties of bone grafts and their substitutes to help guide the clinician in the decision making process. PMID:26733632

  5. Magnesium substitution in brushite cements.

    PubMed

    Alkhraisat, Mohammad Hamdan; Cabrejos-Azama, Jatsue; Rodríguez, Carmen Rueda; Jerez, Luis Blanco; Cabarcos, Enrique López

    2013-01-01

    The use of magnesium-doped ceramics has been described to modify brushite cements and improve their biological behavior. However, few studies have analyzed the efficiency of this approach to induce magnesium substitution in brushite crystals. Mg-doped ceramics composed of Mg-substituted β-TCP, stanfieldite and/or farringtonite were reacted with primary monocalcium phosphate (MCP) in the presence of water. The cement setting reaction has resulted in the formation of brushite and newberyite within the cement matrix. Interestingly, the combination of SAED and EDX analyses of single crystal has indicated the occurrence of magnesium substitution within brushite crystals. Moreover, the effect of magnesium ions on the structure, and mechanical and setting properties of the new cements was characterized as well as the release of Ca(2+) and Mg(2+) ions. Further research would enhance the efficiency of the system to incorporate larger amounts of magnesium ions within brushite crystals. PMID:25428098

  6. Resistance-induced antibiotic substitution.

    PubMed

    Howard, David H

    2004-06-01

    In many cases, physicians prescribe antibiotics without knowing whether an individual patient is infected with a susceptible or resistant pathogen. As the proportion of resistant organisms in a community increases, physicians substitute away from older-inexpensive drugs to newer, more expensive agents as first line therapy. This paper explores the implications of resistance-induced antibiotic substitution for epidemiological models to predict future resistance levels, efforts to measure the health care costs associated with resistance, and policies to improve physicians' antibiotic prescribing decisions. The extent of resistance-induced substitution in outpatient settings is documented using a data set consisting of observations on initial physician office visits for otitis media in the US controlling for new product introductions and price increases, per prescription antibiotic spending increased by 22% between 1980 and 1996, corresponding to a steep increase in resistance levels over the same period. PMID:15185388

  7. Substitution systems and nonextensive statistics

    NASA Astrophysics Data System (ADS)

    García-Morales, V.

    2015-12-01

    Substitution systems evolve in time by generating sequences of symbols from a finite alphabet: At a certain iteration step, the existing symbols are systematically replaced by blocks of Nk symbols also within the alphabet (with Nk, a natural number, being the length of the kth block of the substitution). The dynamics of these systems leads naturally to fractals and self-similarity. By using B-calculus (García-Morales, 2012) universal maps for deterministic substitution systems both of constant and non-constant length, are formulated in 1D. It is then shown how these systems can be put in direct correspondence with Tsallis entropy. A 'Second Law of Thermodynamics' is also proved for these systems in the asymptotic limit of large words.

  8. Unified optical symbolic substitution processor

    NASA Astrophysics Data System (ADS)

    Casasent, David P.

    1990-07-01

    Symbolic substitution operations can be realized optically on a correlator. This is a very attractive and efficient architecture for symbolic substitution. It allows parallel multichannel realization with a fixed set of filters (on film or easily realized on low space bandwidth product spatial light modulators) using space and frequency-multiplexing or sequential filters. All basic logic, numeric and morphological image processing functions can be achieved by symbolic substitution. Moreover, all operations are possible on one multifunctional optical processor. Morphological operations are felt to be essential for ATR and pattern recognition preprocessing in clutter. They greatly improve the role for optics by allowing the same optical architecture to be used for low, medium and high level vision.

  9. Crystallized alkali-silica gel in concrete from the late 1890s

    SciTech Connect

    Peterson, Karl . E-mail: cee@mtu.edu; Gress, David . E-mail: dlgress@unh.edu; Van Dam, Tom . E-mail: cee@mtu.edu; Sutter, Lawrence . E-mail: cee@mtu.edu

    2006-08-15

    The Elon Farnsworth Battery, a concrete structure completed in 1898, is in an advanced state of disrepair. To investigate the potential for rehabilitation, cores were extracted from the battery. Petrographic examination revealed abundant deposits of alkali silica reaction products in cracks associated with the quartz rich metasedimentary coarse aggregate. The products of the alkali silica reaction are variable in composition and morphology, including both amorphous and crystalline phases. The crystalline alkali silica reaction products are characterized by quantitative X-ray energy dispersive spectrometry (EDX) and X-ray diffraction (XRD). The broad extent of the reactivity is likely due to elevated alkali levels in the cements used.

  10. [Using a modified remote sensing imagery for interpreting changes in cultivated saline-alkali land].

    PubMed

    Gao, Hui; Liu, Hui-tao; Liu, Hong-juan; Liu, Jin-tong

    2015-04-01

    This paper developed a new interpretation symbol system for grading and classifying saline-alkali land, using Huanghua, a cosatal city in Hebei Province as a case. The system was developed by inverting remote sensing images from 1992 to 2011 based on site investigation, plant cover characteristics and features of remote sensing images. Combining this interpretation symbol system with supervising classification method, the information on arable land was obtained for the coastal saline-alkali ecosystem of Huanghua City, and the saline-alkali land area, changes in intensity of salinity-alkalinity and spatial distribution from 1992 to 2011 were analyzed. The results showed that salinization of arable land in Huanghua City alleviated from 1992 to 2011. The severely and moderately saline-alkali land area decreased in 2011 compared with 1992, while the non/slightly saline land area increased. The moderately saline-alkali land in southeast transformed to non/slightly saline-alkaline, while the severely saline-alkali land in west of the city far from the coastal zone became moderately saline-alkaline. The center of gravity (CG) of severely and non/slightly saline-alkali land moved closer the coastline, while that of the moderately saline-alkali land moved from southwest coastal line to northwest. Factors influencing changes in arable land within the saline-alkali ecosystem of Huanghua City were climate, hydrology and human activities. PMID:26259441

  11. High-temperature interactions of alkali vapors with solids during coal combustion and gasification

    SciTech Connect

    Punjak, W.A.

    1988-01-01

    A temperature and concentration programmed reaction method is used to investigate the mechanism by which organically bound alkali is released from carbonaceous substrates. Vaporization of the alkali is preceded by reduction of oxygen-bearing groups during which CO is generated. A residual amount of alkali remains after complete reduction. This residual level is greater for potassium, indicating that potassium has stronger interactions with graphitic substrates that sodium. Other mineral substrates were exposed to high temperature alkali chloride vapors under both nitrogen and simulated flue gas atmospheres to investigate their potential application as sorbents for the removal of alkali from coal conversion flue gases. The compounds containing alumina and silica are found to readily adsorb alkali vapors and the minerals kaolinite, bauxite and emathlite are identified as promising alkali sorbents. The fundamentals of alkali adsorption on kaolinite, bauxite and emathlite are compared and analyzed both experimentally and through theoretical modeling. The experiments were performed in a microgravimetric reactor system; the sorbents were characterized before and after alkali adsorption using scanning Auger microscopy, X-ray diffraction analysis, mercury porosimetry and atomic emission spectrophotometry. The results show that the process is not a simple physical condensation, but a complex combination of several diffusion steps and reactions.

  12. Spectroscopic (FT-IR, FT-Raman, UV) and microbiological studies of di-substituted benzoates of alkali metals

    NASA Astrophysics Data System (ADS)

    Kalinowska, M.; Świsłocka, R.; Borawska, M.; Piekut, J.; Lewandowski, W.

    2008-06-01

    The FT-IR, FT-Raman and UV spectra of 3,5-dihydroxybenzoic and 3,5-dichlorobenzoic acids as well as lithium, sodium, potassium, rubidium, caesium 3,5-dihydroxy- and 3,5-dichlorobenzoates were recorded, assigned and compared. The theoretical geometries, Mulliken atomic charges, IR wavenumbers were obtained in B3LYP/6-311++G** level. On the basis of the gathered experimental and theoretical data the effect of metals and substituents on the electronic system of studied compounds were investigated. Moreover, the antimicrobiological activity of studied compounds against two species of bacteria: Bacillus subtilis, Staphylococus aureus and one species of yeast: Candida albicans were studied after 24 and 48 h of incubation. The attempt was made, to find out whether there is any correlation between the first principal component and the degree of growth inhibition exhibited by studied compounds in relation to selected microorganisms.

  13. Symplectites in garnet megacrysts captured by alkali mafic magma

    NASA Astrophysics Data System (ADS)

    Aseeva, Anna; Vysotskiy, Sergey; Karabtsov, Alexander; Alexandrov, Igor; Chashchin, Alexander

    2014-05-01

    Megacrysts are widespread in Cenozoic alkali-basalts of many volcanic provinces of the world. Garnet megacrysts containing symplectites are the most interesting, as can be used for reconstruction of physical and chemical conditions in liquid basalt at the moment of garnet crystal capture. The collection of garnet megacrysts and garnet-pyroxene aggregates from Shavaryn-Tsaram (Hangaj plateau, Mongolia) and Bartoj (Dzhida basaltic field, Russia) paleovolcanoes has studied. Cenozoic alkali basaltic volcanism of these two spatially separated areas is considered to be related to a uniform process of lithosphere spreading in Baikal and related Central Asian rift systems. The studying of garnet-pyroxene aggregate and fragments of garnet megacrysts from these two paleovolcanoes revealed two mineral associations: primary and secondary. The former includes garnet and clinopyroxene, the letter (symplectite) is presented by products of garnet disintegration (clinopyroxene remain unaltered). At least two paragenesis can be allocated: 1) shpinel - plagioclase-olivine sometimes with gedrite and orthopyroxene; 2) olivine (with glass). Experimental modeling of decomposition process in garnet megacryst has been carried out with the help of 'Selector' softwear at various P-T parameters. Physical and chemical conditions of this paragenesis occurrence have also been estimated by up-to-date geothermometers and geobarometers (T 950-1000 C, P 4-4.5 kbar. Conclusions: 1. Garnet megacrysts are apparently in non-equilibrium with alkali-basalts. They were formed in conditions corresponding to zones of mantle plums at the bottom of crust, in magmatic chambers at constant infiltration of fluid. Subsequently megacrysts were captured by alkali-basalt magma and taken out to the surface. 2. Kelyphitic rims on garnet megacrysts is a result of partial melting of megacrysts on interaction with the hosting alkali basaltic rock. During melting garnet transforms with the formation of Na-K glass and Mg

  14. Technical considerations.

    PubMed

    Fugazzotto, P A

    1999-01-01

    Appropriately applied, guided tissue regeneration (GTR) therapy is an important addition to the clinician's treatment armamentarium. However, GTR therapy is highly technique-sensitive, and failure to understand and manage the subtleties of treatment will significantly diminish therapeutic results. This article discusses the technical prerequisites for successful application of GTR therapy to infrabony defects and periodontally involved furcations for maximization of treatment results. PMID:11360324

  15. Exotic s-wave superconductivity in alkali-doped fullerides

    NASA Astrophysics Data System (ADS)

    Nomura, Yusuke; Sakai, Shiro; Capone, Massimo; Arita, Ryotaro

    2016-04-01

    Alkali-doped fullerides ({{A}3}{{\\text{C}}60} with A  =  K, Rb, Cs) show a surprising phase diagram, in which a high transition-temperature ({{T}\\text{c}} ) s-wave superconducting state emerges next to a Mott insulating phase as a function of the lattice spacing. This is in contrast with the common belief that Mott physics and phonon-driven s-wave superconductivity are incompatible, raising a fundamental question on the mechanism of the high-{{T}\\text{c}} superconductivity. This article reviews recent ab initio calculations, which have succeeded in reproducing comprehensively the experimental phase diagram with high accuracy and elucidated an unusual cooperation between the electron-phonon coupling and the electron-electron interactions leading to Mott localization to realize an unconventional s-wave superconductivity in the alkali-doped fullerides. A driving force behind the exotic physics is unusual intramolecular interactions, characterized by the coexistence of a strongly repulsive Coulomb interaction and a small effectively negative exchange interaction. This is realized by a subtle energy balance between the coupling with the Jahn-Teller phonons and Hund’s coupling within the {{\\text{C}}60} molecule. The unusual form of the interaction leads to a formation of pairs of up- and down-spin electrons on the molecules, which enables the s-wave pairing. The emergent superconductivity crucially relies on the presence of the Jahn-Teller phonons, but surprisingly benefits from the strong correlations because the correlations suppress the kinetic energy of the electrons and help the formation of the electron pairs, in agreement with previous model calculations. This confirms that the alkali-doped fullerides are a new type of unconventional superconductors, where the unusual synergy between the phonons and Coulomb interactions drives the high-{{T}\\text{c}} superconductivity.

  16. Research on mouse model of grade II corneal alkali burn

    PubMed Central

    Bai, Jun-Qiang; Qin, Hai-Feng; Zhao, Shi-Hong

    2016-01-01

    AIM To choose appropriate concentration of sodium hydroxide (NaOH) solution to establish a stable and consistent corneal alkali burn mouse model in grade II. METHODS The mice (n=60) were randomly divided into four groups and 15 mice each group. Corneal alkali burns were induced by placing circle filter paper soaked with NaOH solutions on the right central cornea for 30s. The concentrations of NaOH solutions of groups A, B, C, and D were 0.1 mol/L, 0.15 mol/L, 0.2 mol/L, and 1.0 mol/L respectively. Then these corneas were irrigated with 20 mL physiological saline (0.9% NaCl). On day 7 postburn, slit lamp microscope was used to observe corneal opacity, corneal epithelial sodium fluorescein staining positive rate, incidence of corneal ulcer and corneal neovascularization, meanwhile pictures of the anterior eyes were taken. Cirrus spectral domain optical coherence tomography was used to scan cornea to observe corneal epithelial defect and corneal ulcer. RESULTS Corneal opacity scores (x±s) were not significantly different between the group A and group B (P=0.097). Incidence of corneal ulcer in group B was significantly higher than that in group A (P=0.035). Incidence of corneal ulcer and perforation rate in group B was lower than that in group C. Group C and D had corneal neovascularization, and incidence of corneal neovascularization in group D was significantly higher than that in group C (P=0.000). CONCLUSION Using 0.15 mol/L NaOH can establish grade II mouse model of corneal alkali burns. PMID:27162717

  17. Exotic s-wave superconductivity in alkali-doped fullerides.

    PubMed

    Nomura, Yusuke; Sakai, Shiro; Capone, Massimo; Arita, Ryotaro

    2016-04-20

    Alkali-doped fullerides (A3C60 with A = K, Rb, Cs) show a surprising phase diagram, in which a high transition-temperature (Tc) s-wave superconducting state emerges next to a Mott insulating phase as a function of the lattice spacing. This is in contrast with the common belief that Mott physics and phonon-driven s-wave superconductivity are incompatible, raising a fundamental question on the mechanism of the high-Tc superconductivity. This article reviews recent ab initio calculations, which have succeeded in reproducing comprehensively the experimental phase diagram with high accuracy and elucidated an unusual cooperation between the electron-phonon coupling and the electron-electron interactions leading to Mott localization to realize an unconventional s-wave superconductivity in the alkali-doped fullerides. A driving force behind the exotic physics is unusual intramolecular interactions, characterized by the coexistence of a strongly repulsive Coulomb interaction and a small effectively negative exchange interaction. This is realized by a subtle energy balance between the coupling with the Jahn-Teller phonons and Hund's coupling within the C60 molecule. The unusual form of the interaction leads to a formation of pairs of up- and down-spin electrons on the molecules, which enables the s-wave pairing. The emergent superconductivity crucially relies on the presence of the Jahn-Teller phonons, but surprisingly benefits from the strong correlations because the correlations suppress the kinetic energy of the electrons and help the formation of the electron pairs, in agreement with previous model calculations. This confirms that the alkali-doped fullerides are a new type of unconventional superconductors, where the unusual synergy between the phonons and Coulomb interactions drives the high-Tc superconductivity. PMID:26974650

  18. Magnetic Resonance Reversals in Optically Pumped Alkali-Metal Vapor

    NASA Astrophysics Data System (ADS)

    Gong, Fei; Jau, Yuan-Yu; Happer, William

    2007-06-01

    We report an unusual new phenomenon, peculiar sign reversals of the ground-state magnetic resonances and of the ``zero-dip" resonance (Zeeman resonance at zero field) of optically-pumped, alkali-metal vapors. These anomalies occur when a ``weak" circular polarized D1 laser light is tuned to pump atoms predominantly from the lower ground-state hyperfine multiplet. One can understand the signal reversals in simple, semi-quantitative way with reference to this distribution. uantitative computer simulations are in excellent greement with observations.

  19. Intrinsic Impurities in Glass Alkali-Vapor Cells

    NASA Astrophysics Data System (ADS)

    Patton, B.; Ishikawa, K.; Jau, Y.-Y.; Happer, W.

    2007-07-01

    We report NMR measurements of metallic Cs133 in glass cells. The solid-liquid phase transition was studied by observing the NMR peaks arising from these two phases; surprisingly, many cells yielded two additional NMR peaks below the melting point. We attribute these signals to two distinct impurities which can dissolve in the liquid alkali metal and affect its chemical shift. Intentional contamination of cesium cells with O2 confirms this hypothesis for one peak. The other contaminant remains unknown but can appear in evacuated cells. Similar effects have been seen in Rb87 cells.

  20. Magnetic resonance reversals in optically pumped alkali-metal vapor

    NASA Astrophysics Data System (ADS)

    Gong, F.; Jau, Y.-Y.; Happer, W.

    2007-05-01

    We report an unusual phenomenon, peculiar sign reversals of the ground-state magnetic resonances and of the zero-dip resonance (Zeeman resonance at zero field) of optically pumped, alkali-metal vapors. These anomalies occur when a weak circularly polarized D1 laser light is tuned to pump atoms predominantly from the lower ground-state hyperfine multiplet. One can understand the signal reversals in a simple, semiquantitative way with reference to the spin-temperature distribution. Quantitative computer simulations are in excellent agreement with observations.

  1. Determination of Alkali Ions in Biological and Environmental Samples.

    PubMed

    Hauser, Peter C

    2016-01-01

    An overview of the common methods for the determination of the alkali metals is given. These are drawn from all of the three principle branches of quantitative analysis and consist mainly of optical atomic spectrometric methods, ion-selective electrodes, and the separation methods of ion-chromatography and capillary electrophoresis. Their main characteristics and performance parameters are discussed. Important specific applications are also examined, namely clinical analysis, single cell analysis, the analysis of soil samples and hydroponic nutrient solutions, as well as the detection of the radioactive (137)Cs isotope. PMID:26860298

  2. Wave optics simulation of diode pumped alkali laser (DPAL)

    NASA Astrophysics Data System (ADS)

    Endo, Masamori; Nagaoka, Ryuji; Nagaoka, Hiroki; Nagai, Toru; Wani, Fumio

    2016-03-01

    A numerical simulation code for a diode pumped alkali laser (DPAL) was developed. The code employs the Fresnel- Kirchhoff diffraction integral for both laser mode and pump light propagations. A three-dimensional rate equation set was developed to determine the local gain. The spectral divergence of the pump beam was represented by a series of monochromatic beams with different wavelengths. The calculated results showed an excellent agreements with relevant experimental results. It was found that the main channel of the pump power drain is the spontaneous emission from the upper level of the lasing transition.

  3. Alkali metal/halide thermal energy storage systems performance evaluation

    NASA Technical Reports Server (NTRS)

    Phillips, W. M.; Stearns, J. W.

    1986-01-01

    A pseudoheat-pipe heat transfer mechanism has been demonstrated effective in terms of both total heat removal efficiency and rate, on the one hand, and system isothermal characteristics, on the other, for solar thermal energy storage systems of the kind being contemplated for spacecraft. The selection of appropriate salt and alkali metal substances for the system renders it applicable to a wide temperature range. The rapid heat transfer rate obtainable makes possible the placing of the thermal energy storage system around the solar receiver canister, and the immersing of heat transfer fluid tubes in the phase change salt to obtain an isothermal heat source.

  4. Alkali-silica reaction resistant concrete using pumice blended cement

    NASA Astrophysics Data System (ADS)

    Ramasamy, Uma

    Durability of structures is a major challenge for the building industry. One of the many types of concrete deterioration that can affect durability is alkali-silica reaction (ASR). ASR has been found in most types of concrete structures, including dams, bridges, pavements, and other structures that are 20 to 50 years old. The degradation mechanism of ASR produces a gel that significantly expands in the presence of water as supplied from the surrounding environment. This expansion gel product can create high stresses and cracking of the concrete, which can lead to other forms of degradation and expensive structural replacement costs. The four essential factors that produce an expansive ASR gel in concrete are the presence of alkalis, siliceous aggregate, moisture, and free calcium hydroxide (CH). If concrete is starved of any one of these essential components, the expansion can be prevented. Reducing CH through the use of a supplementary cementitious material (SCM) such as natural pozzolan pumice is the focus of this research. By using a pozzolan, the amount of CH is reduced with time based on the effectiveness of the pozzolan. Many pozzolans exist, but one such naturally occurring pozzolanic material is pumice. This research focuses on determining the effect of a finely ground pumice as a SCM in terms of its resistance to ASR expansion, as well as improving resistance to other potential concrete durability mechanisms. In spite of having high alkali contents in the pumice, mixtures containing the SCM pumice more effectively mitigated the ASR expansion reaction than other degradation mechanisms. Depending on the reactivity of the aggregates and fineness of the pumice, 10-15% replacement of cement with the pumice was found to reduce the ASR expansion to the acceptable limits. The amount of CH remaining in the concrete was compared to the ASR expansion in order to improve understanding of the role of CH in the ASR reaction. Thermo-gravimetric analysis (TGA) and X

  5. Hypercalcemic encephalopathy due to milk alkali syndrome and injection teriparatide.

    PubMed

    Kharb, Sandeep; Gundgurthi, Abhay; Pandit, Aditi; Brar, Karninder S; Garg, M K

    2012-11-01

    An 82-year-old male, a known case of severe osteoporosis with vertebral fracture and prostatic carcinoma, was treated with gonadotropin releasing hormone analogue, calcium carbonate, cholecalciferol sachet and injection teriparatide. His diet consisted of milk and curd. He developed altered behavior and generalized weakness, and on investigation, hypercalcemia, hypokalemia, and metabolic alkalosis with low parathyroid hormone levels were detected. Injection teriparatide was stopped and he was managed with forced saline diuresis and injection zoledronic acid. He was diagnosed as a case of milk alkali syndrome in whom teriparatide and prolonged immobilization played a permissive role in the development of hypercalcemic encephalopathy. PMID:23226658

  6. Optical response of alkali metal atoms confined in nanoporous glass

    SciTech Connect

    Burchianti, A; Marinelli, C; Mariotti, E; Bogi, A; Marmugi, L; Giomi, S; Maccari, M; Veronesi, S; Moi, L

    2014-03-28

    We study the influence of optical radiation on adsorption and desorption processes of alkali metal atoms confined in nanoporous glass matrices. Exposure of the sample to near-IR or visible light changes the atomic distribution inside the glass nanopores, forcing the entire system to evolve towards a different state. This effect, due to both atomic photodesorption and confinement, causes the growth and evaporation of metastable nanoparticles. It is shown that, by a proper choice of light characteristics and pore size, these processes can be controlled and tailored, thus opening new perspectives for fabrication of nanostructured surfaces. (nanoobjects)

  7. A new mechanism for radiation damage processes in alkali halides

    NASA Astrophysics Data System (ADS)

    Dubinko, V. I.; Turkin, A. A.; Vainshtein, D. I.; den Hartog, H. W.

    1999-12-01

    We present a theory of radiation damage formation in alkali halides based on a new mechanism of dislocation climb, which involves the production of VF centers (self-trapped hole neighboring a cation vacancy) as a result of the absorption of H centers of dislocation lines. We consider the evolution of all experimentally observed extended defects: metal colloids, gas bubbles, and vacancy voids. Voids are shown to arise and grow large due to the reaction between F and VF centers at the surface of halogen bubbles. Voids can ignite a back reaction between the radiolytic products resulting in decomposition of the irradiated material.

  8. Chemical compatibility of structural materials in alkali metals

    SciTech Connect

    Natesan, K.; Rink, D.L.; Haglund, R.

    1995-04-01

    The objectives of this task are to (a) evaluate the chemical compatibility of structural alloys such as V-5 wt.%Cr-5 wt.%Ti alloy and Type 316 stainless steel for application in liquid alkali metals such as lithium and sodium-78 wt.% potassium (NaK) at temperatures in the range that are of interest for International Thermonuclear Experimental Reactor (ITER); (b) evaluate the transfer of nonmetallic elements such as oxygen, nitrogen, carbon, and hydrogen between structural materials and liquid metals; and (c) evaluate the effects of such transfers on the mechanical and microstructural characteristics of the materials for long-term service in liquid-metal-environments.

  9. Ground state properties of alkali and alkaline-earth hydrides

    NASA Astrophysics Data System (ADS)

    Fuentealba, P.; Reyes, O.; Stoll, H.; Preuss, H.

    1987-11-01

    The ground state potential energy curves of alkali (LiH to CsH) and alkaline-earth monohydrides (BeH to BaH) have been calculated. A pseudopotential formalism including a core-polarization potential has been used. For the valence correlation energy, two different methods, the local spin-density functional and the configuration interaction with single and double excitations, have been employed. Dissociation energies, bond lengths, vibrational frequencies, anharmonicity constants, and dipole moments are reported. The agreement with experimental values, where available, is very good. A discussion and a comparison with other theoretical values, at different levels of approximation, are also included.

  10. Polarizability measurements of the alkalis using an atom interferometer

    NASA Astrophysics Data System (ADS)

    Hromada, Ivan; Holmgren, William; Trubko, Raisa; Ronan, Joseph; Cronin, Alexander

    2011-10-01

    We discuss our latest static DC polarizability measurements of the alkalis: Li through Cs. Our Mach-Zehnder atom interferometer uses nanogratings to diffract and recombine any atom or molecular beam. Because we use the same machine to measure polarizability of different atoms, we are able to report polarizability ratios (e.g., αNa/αLi) with 0.1% precision. To achieve this precision, we also describe a novel technique called phase chopping to measure the atom beam velocity with 0.05% precision.

  11. Nuclear alkali metal Rankine power systems for space applications

    SciTech Connect

    Moyers, J.C.; Holcomb, R.S.

    1986-08-01

    Nucler power systems utilizing alkali metal Rankine power conversion cycles offer the potential for high efficiency, lightweight space power plants. Conceptual design studies are being carried out for both direct and indirect cycle systems for steady state space power applications. A computational model has been developed for calculating the performance, size, and weight of these systems over a wide range of design parameters. The model is described briefly and results from parametric design studies, with descriptions of typical point designs, are presented in this paper.

  12. Alkali-lead-iron phosphate glass and associated method

    DOEpatents

    Boatner, L.A.; Sales, B.C.; Franco, S.C.S.

    1994-03-29

    A glass composition and method of preparation utilizes a mixture consisting of phosphorus oxide within the range of about 40 to 49 molar percent, lead oxide within the range of about 10 to 25 molar percent, iron oxide within the range of about 10 to 17 molar percent and an alkali oxide within the range of about 23 to 30 molar percent. The glass resulting from the melting and subsequent solidifying of the mixture possesses a high degree of durability and a coefficient of thermal expansion as high as that of any of a number of metals. Such features render this glass highly desirable in glass-to-metal seal applications. 6 figures.

  13. Alkali-lead-iron phosphate glass and associated method

    DOEpatents

    Boatner, Lynn A.; Sales, Brian C.; Franco, Sofia C. S.

    1994-01-01

    A glass composition and method of preparation utilizes a mixture consisting of phosphorus oxide within the range of about 40 to 49 molar percent, lead oxide within the range of about 10 to 25 molar percent, iron oxide within the range of about 10 to 17 molar percent and an alkali oxide within the range of about 23 to 30 molar percent. The glass resulting from the melting and subsequent solidifying of the mixture possesses a high degree of durability and a coefficient of thermal expansion as high as that of any of a number of metals. Such features render this glass highly desirable in glass-to-metal seal applications.

  14. Workability and mechanical properties of alkali activated slag concrete

    SciTech Connect

    Collins, F.G.; Sanjayan, J.G.

    1999-03-01

    This paper reports the results of an investigation on concrete containing alkali activated slag (AAS) as the binder, with emphasis on achievement of reasonable workability and equivalent one-day strength to portland cement concrete at normal curing temperatures. Two types of activators were used: sodium hydroxide in combination with sodium carbonate and sodium silicate in combination with hydrated lime. The fresh concrete properties reported include slump and slump loss, air content, and bleed. Mechanical properties of AAS concrete, including compressive strength, elastic modulus, flexural strength, drying shrinkage, and creep are contrasted with those of portland cement concrete.

  15. Theoretical determination of the alkali-metal superoxide bond energies

    NASA Technical Reports Server (NTRS)

    Partridge, Harry; Bauschlicher, Charles W., Jr.; Sodupe, Mariona; Langhoff, Stephen R.

    1992-01-01

    The bond dissociation energies for the alkali-metal superoxides have been computed using extensive Gaussian basis sets and treating electron correlation at the modified coupled-pair functional level. Our computed D0 values are 61.4, 37.2, 40.6, and 38.4 kcal/mol for LiO2, NaO2, KO2, and RbO2, respectively. These values, which are expected to be lower bounds and accurate to 2 kcal/mol, agree well with some of the older flame data, but rule out several recent experimental measurements.

  16. Laser synthesis of ultracold alkali metal dimers: optimization and control

    NASA Astrophysics Data System (ADS)

    Pazyuk, E. A.; Zaitsevskii, A. V.; Stolyarov, A. V.; Tamanis, M.; Ferber, R.

    2015-10-01

    The review concerns the potential of modern high-resolution laser spectroscopy and state-of-the-art ab initio electronic structure calculations used to obtain comprehensive information on the energy and radiative properties of strongly coupled rovibronic diatomic states. The possibility of deperturbation treatment of the intermediate electronically excited states at the experimental (spectroscopic) level of accuracy is demonstrated taking alkali metal dimers as examples. The deperturbation analysis is of crucial importance to optimize multistep laser synthesis and stabilization of ultracold molecular ensembles in their absolute ground level. The bibliography includes 227 references.

  17. Alkali-metal silicate binders and methods of manufacture

    NASA Technical Reports Server (NTRS)

    Schutt, J. B. (Inventor)

    1979-01-01

    A paint binder is described which uses a potassium or sodium silicate dispersion having a silicon dioxide to alkali-metal oxide mol ratio of from 4.8:1 to 6.0:1. The binder exhibits stability during both manufacture and storage. The process of making the binder is predictable and repeatable and the binder may be made with inexpensive components. The high mol ratio is achieved with the inclusion of a silicon dioxide hydrogel. The binder, which also employs a silicone, is in the final form of a hydrogel sol.

  18. An electron diffraction study of alkali chloride vapors

    NASA Technical Reports Server (NTRS)

    Mawhorter, R. J.; Fink, M.; Hartley, J. G.

    1985-01-01

    A study of monomers and dimers of the four alkali chlorides NaCl, KCl, RbCl, and CsCl in the vapor phase using the counting method of high energy electron diffraction is reported. Nozzle temperatures from 850-960 K were required to achieve the necessary vapor pressures of approximately 0.01 torr. Using harmonic calculations for the monomer and dimer 1 values, a consistent set of structures for all four molecules was obained. The corrected monomer distances reproduce the microwave values very well. The experiment yields information on the amount of dimer present in the vapor, and these results are compared with thermodynamic values.

  19. Crystal growth of sulfide materials from alkali polysulfide liquids

    NASA Technical Reports Server (NTRS)

    White, W. B.

    1979-01-01

    The fluids experiment system was designed for low temperature solution growth, nominally aqueous solution growth. The alkali polysulfides, compositions in the systems Na2S-S and K2S-S form liquids in the temperature range of 190 C to 400 C. These can be used as solvents for other important classes of materials such as transition metal and other sulfides which are not soluble in aqueous media. Among these materials are luminescent and electroluminescent crystals whose physical properties are sensitive functions of crystal perfection and which could, therefore, serve as test materials for perfection improvement under microgravity conditions.

  20. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Poly(oxyalkylenediyl),.alpha... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...

  1. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Poly(oxyalkylenediyl),.alpha... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...

  2. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Poly(oxyalkylenediyl),.alpha... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...

  3. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Poly(oxyalkylenediyl),.alpha... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...

  4. 'Vegetable' substitutes for diesel fuel

    SciTech Connect

    Not Available

    1981-07-22

    Research programs in the US, Brazil, South Africa and the Philippines on efforts to find a vegetable oil substitute for diesel fuel are reported. A narrowing price gap with diesel fuel and a favourable energy balance improve the prospects for such fuels. Much of the current work is centered on blends, rather than the use of the pure oil.

  5. Physiological Evaluation of Alkali-Salt Tolerance of Thirty Switchgrass (Panicum virgatum) Lines.

    PubMed

    Hu, Guofu; Liu, Yiming; Zhang, Xunzhong; Yao, Fengjiao; Huang, Yan; Ervin, Erik H; Zhao, Bingyu

    2015-01-01

    Soil salt-alkalization is a major limiting factor for crop production in many regions. Switchgrass (Panicum virgatum L.) is a warm-season C4 perennial rhizomatous bunchgrass and a target lignocellulosic biofuel species. The objective of this study was to evaluate relative alkali-salt tolerance among 30 switchgrass lines. Tillers of each switchgrass line were transplanted into pots filled with fine sand. Two months after transplanting, plants at E5 developmental stage were grown in either half strength Hoagland's nutrient solution with 0 mM Na+ (control) or half strength Hoagland's nutrient solution with 150 mM Na+ and pH of 9.5 (alkali-salt stress treatment) for 20 d. Alkali-salt stress damaged cell membranes [higher electrolyte leakage (EL)], reduced leaf relative water content (RWC), net photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr). An alkali-salt stress tolerance trait index (ASTTI) for each parameter was calculated based on the ratio of the value under alkali-salt stress and the value under non-stress conditions for each parameter of each line. Relative alkali-salt tolerance was determined based on principal components analysis and cluster analysis of the physiological parameters and their ASTTI values. Significant differences in alkali-salt stress tolerance were found among the 30 lines. Lowland lines TEM-SEC, Alamo, TEM-SLC and Kanlow were classified as alkali-salt tolerant. In contrast, three lowland lines (AM-314/MS-155, BN-13645-64) and two upland lines (Caddo and Blackwell-1) were classified as alkali-salt sensitive. The results suggest wide variations exist in alkali-salt stress tolerance among the 30 switchgrass lines. The approach of using a combination of principal components and cluster analysis of the physiological parameters and related ASTTI is feasible for evaluating alkali-salt tolerance in switchgrass. PMID:26146987

  6. Nonlinear pressure shifts of alkali-metal atoms in xenon

    NASA Astrophysics Data System (ADS)

    McGuyer, Bart; Xia, Tian; Jau, Yuan-Yu; Happer, William

    2011-05-01

    Compact, portable atomic frequency standards are based on the microwave resonance frequencies of alkali-metal atoms in inert buffer gases. The frequency shift of these resonances due to collisions with the buffer gas is known as the pressure shift. We demonstrate that the microwave resonance frequencies of ground-state 87Rb and 133Cs atoms have a nonlinear dependence on the pressure of the buffer gas Xe. Previous work has demonstrated a nonlinear dependence in Ar and Kr, but not He and N2, which is thought to be due to the loosely-bound van der Waals molecules that are known to form between alkali-metal and buffer-gas atoms in Ar, Kr, and Xe, but not He and N2. Surprisingly, we find that the nonlinearities in Xe are of the opposite sign to those in Ar and Kr, even though the overall shifts for each of these gases are negative. This discrepancy suggests that though the shifts due to the molecules in Ar and Kr are positive, the shifts due to the molecules in Xe are negative. No nonlinearities were observed in the buffer gas Ne to within our experimental accuracy, which suggests that molecules do not form in Ne. Additionally, we present improved measurements of the shifts of Rb and Cs in He and N2 and of Rb in Ar and Kr. This work was supported by the Air Force Office of Scientific Research and the Department of Defense through the NDSEG program.

  7. Synthesis and studies on microhardness of alkali zinc borate glasses

    SciTech Connect

    Subhashini, Bhattacharya, Soumalya Shashikala, H. D. Udayashankar, N. K.

    2014-04-24

    The mixed alkali effect on zinc borate glasses have been reported. The glass systems of nominal composition 10Zn+xLi{sub 2}O+yNa{sub 2}O+80B{sub 2}O{sub 3} (x = y = 0, 5, 10, 15 mol%) were prepared using standard melt quenching method. The structural, physical and mechanical properties of the samples have been studied using X-ray diffraction(XRD), density measurement and Vickers hardness measurement, respectively. A consistent increase in the density was observed, which explains the role of the modifiers (Li{sub 2}O and Na{sub 2}O) in the network modification of borate structure. The molar volume is decreasing linearly with the alkali concentration, which is attributed to the conversion of tetrahedral boron (BO{sub 4/2}){sup −} into (BO{sub 3/2}){sup −}. The microhardness studies reveals the anisotropy nature of the material. It further confirms that the samples belong to hard glass category.

  8. Laser cooling of nuclear spin 0 alkali 78Rb

    NASA Astrophysics Data System (ADS)

    Behr, J. A.; Gorelov, A.; Anholm, M.

    2015-05-01

    The textbook example for sub-Doppler cooling is a J = 1/2 I = 0 alkali atom in lin ⊥ lin molasses. In the σ+ σ- configuration of a standard MOT, the main sub-Doppler cooling mechanism relies on changing alignment (MF2 population) with the summed linear polarization orientation, but there is no such variation in AC Stark shift for F = 1/2. We have nevertheless looked for signs of sub-Doppler cooling by trapping I = 0 78Rb in a standard MOT and measuring the cloud size as a function of laser detuning and intensity. The 78Rb cloud size does not change significantly with lowered intensity, and expands slightly with detuning, consistent with minimal to no sub-Doppler cooling. Our geometry does show the well-known substantially smaller cloud size with detuning and intensity for I = 3/2 87Rb. Maintaining an I = 0 alkali cloud size with lowered intensity will help our planned β- ν correlation experiments in 38mK decay by suppressing possible production of photoassisted dimers. Supported by NSERC and NRC Canada through TRIUMF.

  9. Alkali oxide-tantalum, niobium and antimony oxide ionic conductors

    NASA Technical Reports Server (NTRS)

    Roth, R. S.; Brower, W. S.; Parker, H. S.; Minor, D. B.; Waring, J. L.

    1975-01-01

    The phase equilibrium relations of four systems were investigated in detail. These consisted of sodium and potassium antimonates with antimony oxide and tantalum and niobium oxide with rubidium oxide as far as the ratio 4Rb2O:llB2O5 (B=Nb, Ta). The ternary system NaSbO3-Sb2O4-NaF was investigated extensively to determine the actual composition of the body centered cubic sodium antimonate. Various other binary and ternary oxide systems involving alkali oxides were examined in lesser detail. The phases synthesized were screened by ion exchange methods to determine mobility of the mobility of the alkali ion within the niobium, tantalum or antimony oxide (fluoride) structural framework. Five structure types warranted further investigation; these structure types are (1) hexagonal tungsten bronze (HTB), (2) pyrochlore, (3) the hybrid HTB-pyrochlore hexagonal ordered phases, (4) body centered cubic antimonates and (5) 2K2O:3Nb2O5. Although all of these phases exhibit good ion exchange properties only the pyrochlore was prepared with Na(+) ions as an equilibrium phase and as a low porosity ceramic. Sb(+3) in the channel interferes with ionic conductivity in this case, although relatively good ionic conductivity was found for the metastable Na(+) ion exchanged analogs of RbTa2O5F and KTaWO6 pyrochlore phases.

  10. Crystal chemistry of hydrothermally grown ternary alkali rare earth fluorides.

    PubMed

    McMillen, Colin D; Comer, Sara; Fulle, Kyle; Sanjeewa, Liurukara D; Kolis, Joseph W

    2015-12-01

    The structural variations of several alkali metal rare earth fluoride single crystals are summarized. Two different stoichiometric formulations are considered, namely those of ARE2F7 and ARE3F10 (A = K, Rb, Cs; RE = Y, La-Lu), over a wide range of ionic radii of both the alkali and rare earth (RE) ions. Previously reported and several new single-crystal structures are considered. The new single crystals are grown using hydrothermal methods and the structures are compared with literature reports of structures grown from both melts and hydrothermal fluids. The data reported here are combined with the literature data to gain a greater understanding of structural subtleties surrounding these systems. The work underscores the importance of the size of the cations to the observed structure type and also introduces synthetic technique as a contributor to the same. New insights based on single-crystal structure analysis in the work introduce a new disordered structure type in the case of ARE2F7, and examine the trends and boundaries of the ARE3F10 stoichiometry. Such fundamental structural information is useful in understanding the potential applications of these compounds as optical materials. PMID:26634734

  11. Formation of Alkali Hydrides via Two-photon Excitation

    NASA Astrophysics Data System (ADS)

    Juarros, Elizabeth; Kirby, Kate; Coté, Robin

    2006-05-01

    Alkali hydride molecules are very polar, exhibiting large ground-state dipole moments. Ultracold sources of alkali atoms and hydrogen have been created in the laboratory. We explore theoretically the feasibility of forming such molecules from a mixture of the ultracold atomic gases, employing a two-photon stimulated radiative association process -- Raman excitation. The triplet ground state for lithium hydride is of particular interest since it supports only one bound ro-vibrational level. Using accurate molecular potential energy curves and dipole transition moments, we have calculated the rate coefficients for populating the bound ro-vibrational level of the a^3&+circ; state of LiH via the excited b^3π state. We have found that significant molecule formation rates can be realized with laser intensities and atomic densities that are attainable experimentally. Also, we have calculated the rate coefficients for populating all the vibrational levels of the X^1&+circ; state of LiH via the excited B^1π state. In this case, we have found that significant formation rates into the upper vibrational levels can be realized. We examine the spontaneous emission cascade which takes place from these upper vibrational levels on a timescale of milliseconds, and calculate the resulting rotational populations in v=0. We show that photon emission in the cascade process does not contribute to trap loss.

  12. OSL studies of alkali fluoroperovskite single crystals for radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Daniel, D. Joseph; Raja, A.; Madhusoodanan, U.; Annalakshmi, O.; Ramasamy, P.

    2016-08-01

    This paper presents a preliminary investigation of the optically stimulated luminescence (OSL) of alkali fluoroperovskite single crystals for radiation dosimetry. The perovskite-like KMgF3, NaMgF3 and LiBaF3 polycrystalline compounds doped with rare earths (Eu2+ and Ce3+) were synthesized by standard solid state reaction technique. Phase purity of the synthesized compounds was analyzed by powder X-ray diffraction technique. Single crystals of these compounds have been grown from melt by using vertical Bridgman-Stockbarger method. The Linearly Modulated OSL and Continuous Wave OSL measurements were performed in these alkali fluorides using blue light stimulation. Thermal bleaching experiments have shown that OSL signals originate from traps which are unstable near 200 °C, thus proving the suitability of the signals for dosimetric purposes. Optical bleaching measurements were also performed for these fluoride samples. OSL dose response was studied as a function of dose which was found to increase with beta dose.

  13. Interpretation of the IR spectra of alkali borate glasses

    SciTech Connect

    Chekhovskii, V.G.

    1985-11-01

    This paper describes methods of interpretation of the IR spectra of alkali borate glasses. In view of the difficulties which are encountered in a strict interpretation of the IR spectra of crystalline oxygen-containing compounds with complex anions, semiempirical methods of interpretation are commonly used. The existence of glasses of groups with an atomic (ionic) arrangement close to that in the crystalline compounds makes it possible to a certain extent to use the spectra of crystalline compounds in the interpretation of the IR spectra of glasses. The alkali borate glass systems were chosen for this study because the information on their structure is the most detailed by comparison with other borate glasses. IR spectrospcopy showed that the spectral regions in which fundamental asymmetrical stretching vibrations in BO/sub 3/ and BO/sub 4/ polyhedra occur, in most cases, are fairly clearly defined independently of the combined or separate presence of these polyhedra. It is proposed that the bands in the IR spectra of sodium and lithium borate glasses be assigned to vibrations mostly localized on specific fragments of polyborate groups present in the glasses. The data from IR spectroscopy confirms that tetraborate groups are present in lithium borate glasses.

  14. Alkali-Doped Lithium Orthosilicate Sorbents for Carbon Dioxide Capture.

    PubMed

    Yang, Xinwei; Liu, Wenqiang; Sun, Jian; Hu, Yingchao; Wang, Wenyu; Chen, Hongqiang; Zhang, Yang; Li, Xian; Xu, Minghou

    2016-09-01

    New alkali-doped (Na2 CO3 and K2 CO3 ) Li4 SiO4 sorbents with excellent performance at low CO2 concentrations were synthesized. We speculate that alkali doping breaks the orderly arrangement of the Li4 SiO4 crystals, hence increasing its specific surface area and the number of pores. It was shown that 10 wt % Na2 CO3 and 5 wt % K2 CO3 are the optimal additive ratios for doped sorbents to attain the highest conversions. Moreover, under 15 vol % CO2 , the doped sorbents present clearly faster absorption rates and exhibit stable cyclic durability with impressive conversions of about 90 %, at least 20 % higher than that of non-doped Li4 SiO4 . The attained conversions are also 10 % higher than the reported highest conversion of 80 % on doped Li4 SiO4 . The performance of Li4 SiO4 is believed to be enhanced by the eutectic melt, and it is the first time that the existence of eutectic Li/Na or Li/K carbonate on doped sorbents when absorbing CO2 at high temperature is confirmed; this was done using systematical analysis combining differential scanning calorimetry with in situ powder X-ray diffraction. PMID:27531239

  15. Biological neutralization of chlor-alkali industry wastewater.

    PubMed

    Jain, Rakeshkumar M; Mody, Kalpana H; Keshri, Jitendra; Jha, Bhavanath

    2011-11-01

    The present work reports biological neutralization of chlor-alkali industrial effluent by an alkaliphilic bacterium, isolated from the Gujarat coast, which was identified as Enterococcus faecium strain R-5 on the basis of morphological, biochemical and partial 16S rRNA gene sequencing. The isolate was capable of bringing down the pH of waste water from 12.0 to 7.0 within 3 h in the presence of carbon and nitrogen sources, with simultaneous reduction in total dissolved solutes (TDS) up to 19-22%. This bacterium produced carboxylic acid, as revealed by FT-IR analysis, which facilitated neutralization of alkaline effluent. The presence of unconventional raw materials viz. Madhuca indica flowers or sugar cane bagasse as carbon and nitrogen sources could effectively neutralize alkaline effluent and thus making the bioremediation process economically viable. The time required for neutralization varied with size of inoculum. To the best of our knowledge, this is the first report on biological neutralization of a chlor-alkali industrial effluent. PMID:21944194

  16. High and rapid alkali cation storage in ultramicroporous carbonaceous materials

    NASA Astrophysics Data System (ADS)

    Yun, Young Soo; Lee, Seulbee; Kim, Na Rae; Kang, Minjee; Leal, Cecilia; Park, Kyu-Young; Kang, Kisuk; Jin, Hyoung-Joon

    2016-05-01

    To achieve better supercapacitor performance, efforts have focused on increasing the specific surface area of electrode materials to obtain higher energy and power density. The control of pores in these materials is one of the most effective ways to increase the surface area. However, when the size of pores decreases to a sub-nanometer regime, it becomes difficult to apply the conventional parallel-plate capacitor model because the charge separation distance (d-value) of the electrical double layer has a similar length scale. In this study, ultramicroporous carbonaceous materials (UCMs) containing sub-nanometer-scale pores are fabricated using a simple in situ carbonization/activation of cellulose-based compounds containing potassium. The results show that alkali cations act as charge carriers in the ultramicropores (<0.7 nm), and these materials can deliver high capacitances of ∼300 F g-1 at 0.5 A g-1 and 130 F g-1, even at a high current rate of 65 A g-1 in an aqueous medium. In addition, the UCM-based symmetric supercapacitors are stable over 10,000 cycles and have a high energy and power densities of 8.4 Wh kg-1 and 15,000 W kg-1, respectively. This study provides a better understanding of the effects of ultramicropores in alkali cation storage.

  17. A Three Level Analytic Model for Alkali Vapor Lasers

    SciTech Connect

    Hager, Gordon D.; Perram, Glen P.

    2010-10-08

    A three level analytic model for optically pumped alkali metal vapor lasers is developed considering the steady-state rate equations for the longitudinally averaged number densities of the ground {sup 2}S{sub 1/2} and first excited {sup 2}P{sub 1/2} and {sup 2}P{sub 3/2} states. The threshold pump intensity includes both the requirements to fully bleach the pump transition and exceed optical losses, typically about 200 W/cm{sup 2}. Slope efficiency depends critically on the fraction of incident photons absorbed and the overlap of pump and resonator modes, approaching the quantum efficiency of 0.95-0.98, depending on alkali atom. For efficient operation, the collisional relaxation between the two upper levels should be fast relative to stimulated emission. By assuming a statistical distribution between the upper levels, the limiting analytic solution for the quasi-two level system is achieved. Application of the model and comparisons to recent laser demonstrations is presented.

  18. A new polarizable force field for alkali and halide ions

    SciTech Connect

    Kiss, Péter T.; Baranyai, András

    2014-09-21

    We developed transferable potentials for alkali and halide ions which are consistent with our recent model of water [P. T. Kiss and A. Baranyai, J. Chem. Phys. 138, 204507 (2013)]. Following the approach used for the water potential, we applied Gaussian charge distributions, exponential repulsion, and r{sup −6} attraction. One of the two charges of the ions is fixed to the center of the particle, while the other is connected to this charge by a harmonic spring to express polarization. Polarizability is taken from quantum chemical calculations. The repulsion between different species is expressed by the combining rule of Kong [J. Chem. Phys. 59, 2464 (1972)]. Our primary target was the hydration free energy of ions which is correct within the error of calculations. We calculated water-ion clusters up to 6 water molecules, and, as a crosscheck, we determined the density and internal energy of alkali-halide crystals at ambient conditions with acceptable accuracy. The structure of hydrated ions was also discussed.

  19. Universalities in ultracold reactions of alkali-metal polar molecules

    NASA Astrophysics Data System (ADS)

    Quéméner, Goulven; Bohn, John L.; Petrov, Alexander; Kotochigova, Svetlana

    2011-12-01

    We consider ultracold collisions of ground-state heteronuclear alkali-metal dimers that are susceptible to four-center chemical reactions 2AB→A2+B2 even at submicrokelvin temperatures. These reactions depend strongly on species, temperature, electric field, and confinement in an optical lattice. We calculate ab initio van der Waals coefficients for these interactions and use a quantum formalism to study the scattering properties of such molecules under an external electric field and optical lattice. We also apply a quantum threshold model to explore the dependence of reaction rates on the various parameters. We find that, among the heteronuclear alkali-metal fermionic species, LiNa is the least reactive, whereas LiCs is the most reactive. For the bosonic species, LiK is the most reactive in zero field, but all species considered, LiNa, LiK, LiRb, LiCs, and KRb, share a universal reaction rate once a sufficiently high electric field is applied. For indistinguishable bosons, the inelastic/reactive rate increases as d2 in the quantum regime, where d is the dipole moment induced by the electric field. This is a weaker power-law dependence than for indistinguishable fermions, for which the rate behaves as d6.

  20. A new polarizable force field for alkali and halide ions

    NASA Astrophysics Data System (ADS)

    Kiss, Péter T.; Baranyai, András

    2014-09-01

    We developed transferable potentials for alkali and halide ions which are consistent with our recent model of water [P. T. Kiss and A. Baranyai, J. Chem. Phys. 138, 204507 (2013)]. Following the approach used for the water potential, we applied Gaussian charge distributions, exponential repulsion, and r-6 attraction. One of the two charges of the ions is fixed to the center of the particle, while the other is connected to this charge by a harmonic spring to express polarization. Polarizability is taken from quantum chemical calculations. The repulsion between different species is expressed by the combining rule of Kong [J. Chem. Phys. 59, 2464 (1972)]. Our primary target was the hydration free energy of ions which is correct within the error of calculations. We calculated water-ion clusters up to 6 water molecules, and, as a crosscheck, we determined the density and internal energy of alkali-halide crystals at ambient conditions with acceptable accuracy. The structure of hydrated ions was also discussed.

  1. Dirac Node Lines in Pure Alkali Earth Metals.

    PubMed

    Li, Ronghan; Ma, Hui; Cheng, Xiyue; Wang, Shoulong; Li, Dianzhong; Zhang, Zhengyu; Li, Yiyi; Chen, Xing-Qiu

    2016-08-26

    Beryllium is a simple alkali earth metal, but has been the target of intensive studies for decades because of its unusual electron behavior at surfaces. The puzzling aspects include (i) severe deviations from the description of the nearly free-electron picture, (ii) an anomalously large electron-phonon coupling effect, and (iii) giant Friedel oscillations. The underlying origins for such anomalous surface electron behavior have been under active debate, but with no consensus. Here, by means of first-principles calculations, we discover that this pure metal system, surprisingly, harbors the Dirac node line (DNL) that in turn helps to rationalize many of the existing puzzles. The DNL is featured by a closed line consisting of linear band crossings, and its induced topological surface band agrees well with previous photoemission spectroscopy observations on the Be (0001) surface. We further reveal that each of the elemental alkali earth metals of Mg, Ca, and Sr also harbors the DNL and speculate that the fascinating topological property of the DNL might naturally exist in other elemental metals as well. PMID:27610865

  2. [Socio-medical significance of alkalie resistance, alkalie neutralization and skin-surface lipid content in atopic neurodermatitis and ichthyosis vulgaris (author's transl)].

    PubMed

    Schnyder, U W; Gloor, M; Taugner, M

    1977-01-01

    In individuals free from skin diseases, the resistance and the neutralisation to alkali, and the quantity of lipids at the surface of the skin, are constitltional factors; these idiotypically (genetically) controlled factors are subject to paratypical (environmental) variations. The frequency of a reduced alkali neutralisation and of sebostasis in case of neurodermitis atopica and of ichthyosis vulgaris is not dealt with in the literature, but it results from literature findings that a pathologic alkali resistance is a facultative feature in neurodermitis atopica, while it is an obligatory one in ichthyosis vulgaris. The difference seems to be conditioned genetically. In neurodermitis atopica, the genotype is in itself of no pathogenic importance since the disease is induced exclusively by exogenous and endogenous, non hereditary agents. In ichthyosis vulgaris, the reduced alkali resistance falls into the pleiotropic character of the disease. PMID:907654

  3. EVALUATION OF THE LIMESTONE DUAL ALKALI PROTOTYPE SYSTEM PLANT SCHOLZ: SYSTEM DESIGN AND PROGRAM PLAN

    EPA Science Inventory

    The report describes the (Phase I) design of both a limestone dual alkali system at Gulf Power Co.'s Scholz steam plant and a related test program. The limestone dual alkali process will be tested at an existing 20 MWe prototype facility at the Scholz plant. The intent of the pro...

  4. 40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated sulfonated diphenyl oxide... New Uses for Specific Chemical Substances § 721.2565 Alkylated sulfonated diphenyl oxide, alkali and... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and...

  5. In situ alkali-silica reaction observed by x-ray microscopy

    SciTech Connect

    Kurtis, K.E.; Monteiro, P.J.M.; Brown, J.T.; Meyer-Ilse, W.

    1997-04-01

    In concrete, alkali metal ions and hydroxyl ions contributed by the cement and reactive silicates present in aggregate can participate in a destructive alkali-silica reaction (ASR). This reaction of the alkalis with the silicates produces a gel that tends to imbibe water found in the concrete pores, leading to swelling of the gel and eventual cracking of the affected concrete member. Over 104 cases of alkali-aggregate reaction in dams and spillways have been reported around the world. At present, no method exists to arrest the expansive chemical reaction which generates significant distress in the affected structures. Most existing techniques available for the examination of concrete microstructure, including ASR products, demand that samples be dried and exposed to high pressure during the observation period. These sample preparation requirements present a major disadvantage for the study of alkali-silica reaction. Given the nature of the reaction and the affect of water on its products, it is likely that the removal of water will affect the morphology, creating artifacts in the sample. The purpose of this research is to observe and characterize the alkali-silica reaction, including each of the specific reactions identified previously, in situ without introducing sample artifacts. For observation of unconditioned samples, x-ray microscopy offers an opportunity for such an examination of the alkali-silica reaction. Currently, this investigation is focusing on the effect of calcium ions on the alkali-silica reaction.

  6. Difficulties in Interpreting Alkali Metal Trends at the Senior Chemistry Level.

    ERIC Educational Resources Information Center

    de Berg, Kevin

    2001-01-01

    Explores the reasons for the differences in alkali metal reactivity in water in terms of thermodynamics rather than ionization trends. Shows that differences in alkali metal reactivity with water are more appropriately explained in terms of the kinetics of the reactions. (MM)

  7. Molecular dynamics simulation of alkali borate glass using coordination dependent potential

    SciTech Connect

    Park, B.; Cormack, A.N.

    1997-12-31

    The structure of sodium borate glass was investigated by molecular dynamics simulation using coordination dependent potential model. The simulated alkali borate glass consists of basic units, BO{sub 3} triangle, BO{sub 4} tetrahedra and structural groups such as boroxol ring and triborate units. The coordination of boron is converted from 3 to 4 by adding alkali oxide.

  8. 40 CFR 721.5985 - Fatty alkyl phosphate, alkali metal salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.5985 Fatty alkyl phosphate, alkali metal salt (generic). (a) Chemical... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty alkyl phosphate, alkali...

  9. 40 CFR 721.5452 - Alkali metal salt of halogenated organoborate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.5452 Alkali metal salt of halogenated organoborate (generic). (a... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkali metal salt of...

  10. Structural Investigation of Alkali Activated Clay Minerals for Application in Water Treatment Systems

    NASA Astrophysics Data System (ADS)

    Bumanis, G.; Bajare, D.; Dembovska, L.

    2015-11-01

    Alkali activation technology can be applied for a wide range of alumo-silicates to produce innovative materials with various areas of application. Most researches focuse on the application of alumo-silicate materials in building industry as cement binder replacement to produce mortar and concrete [1]. However, alkali activation technology offers high potential also in biotechnologies [2]. In the processes where certain pH level, especially alkaline environment, must be ensured, alkali activated materials can be applied. One of such fields is water treatment systems where high level pH (up to pH 10.5) ensures efficient removal of water pollutants such as manganese [3]. Previous investigations had shown that alkali activation technology can be applied to calcined clay powder and aluminium scrap recycling waste as a foam forming agent to create porous alkali activated materials. This investigation focuses on the structural investigation of calcined kaolin and illite clay alkali activation processes. Chemical and mineralogical composition of both clays were determined and structural investigation of alkali activated materials was made by using XRD, DTA, FTIR analysis; the microstructure of hardened specimens was observed by SEM. Physical properties of the obtained material were determined. Investigation indicates the essential role of chemical composition of the clay used in the alkali activation process, and potential use of the obtained material in water treatment systems.

  11. Thermodynamic Properties Of Alkali Species In Coal Based Combined Cycle Power Systems

    SciTech Connect

    Willenborg, W.; Wolf, K.J.; Fricke, C.; Moeller, M.; Prikhodovsky, A.; Hilpert, K.; Singheiser, L.

    2002-09-20

    The aim of this project is to support the development of a concept for a successful alkali removal. Two strategies are possible: optimizing the alkali retention potential of the coal ash slag in the combustion chamber and the liquid slag separators and separate alkali removal with solid sorbents (getters) at temperatures below 1450 C. Therefore in a first step the alkali partial pressure over coal ash slag should be determined in order to get information about the retention potential of the slag. The influence of additives on the retention potential of the slag should be investigated. The measurements should show if the alkali partial pressure over the slag is generally low enough in case of thermodynamic equilibrium. In case of too high alkali partial pressures a separate alkali removal is needed. Therefore in a second step commercial sorbent materials should be investigated concerning their sorption potential for alkalis. To get information about the influence of getter components on the sorption potential some mixtures of pure components, predicted by thermodynamic modeling to be most effective, should be investigated.

  12. SUMMARY REPORT: SULFUR OXIDES CONTROL TECHNOLOGY SERIES: FLUE GAS DESULFURIZATION - DUAL ALKALI PROCESS

    EPA Science Inventory

    Describes dual alkali (or double alkali) flue gas desulfurization (FGD) which is a throwaway process in which sulfur dioxide (SO2) is removed from the flue gas by a soluble sodium-based scrubbing liquor. he collected SO2 is precipitated as calcium sulfite (CaSO3), calcium sulfate...

  13. CHARACTERIZATION OF MERCURY EMISSIONS AT A CHLOR-ALKALI PLANT, VOLUME II. APPENDICES F-J

    EPA Science Inventory

    The report gives results of a characterization of mercury (Hg) emissions at a chlor-alkali plant. Up to 160 short tons (146 Mg) of Hg is consumed by the chlor-alkali industry each year. Very little quantitative information is currently available however, on the actual Hg losses f...

  14. 40 CFR 721.4663 - Fluorinated carboxylic acid alkali metal salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... metal salts. 721.4663 Section 721.4663 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4663 Fluorinated carboxylic acid alkali metal salts. (a) Chemical... fluorinated carboxylic acid alkali metal salts (PMNs P-95-979/980/981) are subject to reporting under...

  15. 40 CFR 721.5985 - Fatty alkyl phosphate, alkali metal salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... salt (generic). 721.5985 Section 721.5985 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5985 Fatty alkyl phosphate, alkali metal salt (generic). (a) Chemical... as a fatty alkyl phosphate, alkali metal salt (PMN P-99-0385) is subject to reporting under...

  16. 40 CFR 721.5985 - Fatty alkyl phosphate, alkali metal salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... salt (generic). 721.5985 Section 721.5985 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5985 Fatty alkyl phosphate, alkali metal salt (generic). (a) Chemical... as a fatty alkyl phosphate, alkali metal salt (PMN P-99-0385) is subject to reporting under...

  17. 40 CFR 721.10097 - Disubstituted benzenesulfonic acid, alkali metal salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkali metal salt (generic). 721.10097 Section 721.10097 Protection of Environment ENVIRONMENTAL... metal salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as disubstituted benzenesulfonic acid, alkali metal salt (PMN...

  18. 40 CFR 721.10097 - Disubstituted benzenesulfonic acid, alkali metal salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkali metal salt (generic). 721.10097 Section 721.10097 Protection of Environment ENVIRONMENTAL... metal salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as disubstituted benzenesulfonic acid, alkali metal salt (PMN...

  19. 40 CFR 721.4663 - Fluorinated carboxylic acid alkali metal salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... metal salts. 721.4663 Section 721.4663 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4663 Fluorinated carboxylic acid alkali metal salts. (a) Chemical... fluorinated carboxylic acid alkali metal salts (PMNs P-95-979/980/981) are subject to reporting under...

  20. 40 CFR 721.10098 - Disubstituted benzoic acid, alkali metal salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... metal salt (generic). 721.10098 Section 721.10098 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10098 Disubstituted benzoic acid, alkali metal salt... identified generically as disubstituted benzoic acid, alkali metal salt (PMN P-03-643) is subject...

  1. 40 CFR 721.5985 - Fatty alkyl phosphate, alkali metal salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... salt (generic). 721.5985 Section 721.5985 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5985 Fatty alkyl phosphate, alkali metal salt (generic). (a) Chemical... as a fatty alkyl phosphate, alkali metal salt (PMN P-99-0385) is subject to reporting under...

  2. 40 CFR 721.10098 - Disubstituted benzoic acid, alkali metal salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... metal salt (generic). 721.10098 Section 721.10098 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10098 Disubstituted benzoic acid, alkali metal salt... identified generically as disubstituted benzoic acid, alkali metal salt (PMN P-03-643) is subject...

  3. 40 CFR 721.10098 - Disubstituted benzoic acid, alkali metal salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... metal salt (generic). 721.10098 Section 721.10098 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10098 Disubstituted benzoic acid, alkali metal salt... identified generically as disubstituted benzoic acid, alkali metal salt (PMN P-03-643) is subject...

  4. 40 CFR 721.4663 - Fluorinated carboxylic acid alkali metal salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... metal salts. 721.4663 Section 721.4663 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4663 Fluorinated carboxylic acid alkali metal salts. (a) Chemical... fluorinated carboxylic acid alkali metal salts (PMNs P-95-979/980/981) are subject to reporting under...

  5. 40 CFR 721.10098 - Disubstituted benzoic acid, alkali metal salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... metal salt (generic). 721.10098 Section 721.10098 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10098 Disubstituted benzoic acid, alkali metal salt... identified generically as disubstituted benzoic acid, alkali metal salt (PMN P-03-643) is subject...

  6. 40 CFR 721.4663 - Fluorinated carboxylic acid alkali metal salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... metal salts. 721.4663 Section 721.4663 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4663 Fluorinated carboxylic acid alkali metal salts. (a) Chemical... fluorinated carboxylic acid alkali metal salts (PMNs P-95-979/980/981) are subject to reporting under...

  7. 40 CFR 721.10097 - Disubstituted benzenesulfonic acid, alkali metal salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkali metal salt (generic). 721.10097 Section 721.10097 Protection of Environment ENVIRONMENTAL... metal salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as disubstituted benzenesulfonic acid, alkali metal salt (PMN...

  8. 40 CFR 721.10097 - Disubstituted benzenesulfonic acid, alkali metal salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkali metal salt (generic). 721.10097 Section 721.10097 Protection of Environment ENVIRONMENTAL... metal salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as disubstituted benzenesulfonic acid, alkali metal salt (PMN...

  9. First-principles study of ternary graphite compounds cointercalated with alkali atoms (Li, Na, and K) and alkylamines towards alkali ion battery applications

    NASA Astrophysics Data System (ADS)

    Ri, Gum-Chol; Yu, Chol-Jun; Kim, Jin-Song; Hong, Song-Nam; Jong, Un-Gi; Ri, Mun-Hyok

    2016-08-01

    First-principles calculations were carried out to investigate the structural, energetic, and electronic properties of ternary graphite compounds cointercalated with alkali atoms (AM = Li, Na, and K) and normal alkylamine molecules (nCx; x = 1, 2, 3, 4), denoted as AM-nCx-GICs. From the optimization of the orthorhombic unit cells for the crystalline compounds, it was found that, with the increase in the atomic number of alkali atoms, the layer separations decrease in contrast to AM-GICs, while the bond lengths between alkali atoms and graphene layer, and nitrogen atom of alkylamine increase. The calculated formation energies and interlayer binding energies of AM-nC3-GICs indicate that the compounds is increasingly stabilized from Li to K, and the energy barriers for migration of alkali atoms suggest that alkali cation with larger ionic radius diffuses more smoothly in graphite, being similar to AM-GICs. Through the analysis of electronic properties, it was established that more extent of electronic charge is transferred from more electropositive alkali atom to the carbon ring of graphene layer, and the hybridization of valence electron orbitals between alkylamine molecules and graphene layer is occurred.

  10. Communication: Dimensionality of the ionic conduction pathways in glass and the mixed-alkali effect.

    PubMed

    Novy, Melissa; Avila-Paredes, Hugo; Kim, Sangtae; Sen, Sabyasachi

    2015-12-28

    A revised empirical relationship between the power law exponent of ac conductivity dispersion and the dimensionality of the ionic conduction pathway is established on the basis of electrical impedance spectroscopic (EIS) measurements on crystalline ionic conductors. These results imply that the "universal" ac conductivity dispersion observed in glassy solids is associated with ionic transport along fractal pathways. EIS measurements on single-alkali glasses indicate that the dimensionality of this pathway D is ∼2.5, while in mixed-alkali glasses, D is lower and goes through a minimum value of ∼2.2 when the concentrations of the two alkalis become equal. D and σ display similar variation with alkali composition, thus suggesting a topological origin of the mixed-alkali effect. PMID:26723583

  11. Recovery of Ga(III) by Raw and Alkali Treated Citrus limetta Peels

    PubMed Central

    2014-01-01

    Alkali treated Citrus limetta peels were used for recovery of Ga(III) from its aqueous solution. The raw and alkali treated peels were characterized for functional groups. The efficiency of adsorption increased from 47.62 mg/g for raw peels to 83.33 mg/g for alkali treated peels. Between pH 1 and 3, the adsorption increased and thereafter decreased drastically. The adsorption followed pseudosecond order kinetics and Langmuir isotherm gave the best fit for the experimental data. Desorption studies showed 95.28% desorption after 3 cycles for raw peels while it was 89.51% for alkali treated peels. Simulated Bayer liquor showed 39.57% adsorption for gallium ions on raw peels which was enhanced to 41.13% for alkali treated peels.

  12. PEP-1-FK506BP inhibits alkali burn-induced corneal inflammation on the rat model of corneal alkali injury.

    PubMed

    Kim, Dae Won; Lee, Sung Ho; Shin, Min Jea; Kim, Kibom; Ku, Sae Kwang; Youn, Jong Kyu; Cho, Su Bin; Park, Jung Hwan; Lee, Chi Hern; Son, Ora; Sohn, Eun Jeong; Cho, Sung-Woo; Park, Jong Hoon; Kim, Hyun Ah; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2015-11-01

    FK506 binding protein 12 (FK506BP) is a small peptide with a single FK506BP domain that is involved in suppression of immune response and reactive oxygen species. FK506BP has emerged as a potential drug target for several inflammatory diseases. Here, we examined the protective effects of directly applied cell permeable FK506BP (PEP-1-FK506BP) on corneal alkali burn injury (CAI). In the cornea, there was a significant decrease in the number of cells expressing pro-inflammation, apoptotic, and angiogenic factors such as TNF-α, COX-2, and VEGF. Both corneal opacity and corneal neovascularization (CNV) were significantly decreased in the PEP-1-FK506BP treated group. Our results showed that PEP-1-FK506BP can significantly inhibit alkali burn-induced corneal inflammation in rats, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors and inflammatory cytokines. These results suggest that PEP-1-FK506BP may be a potential therapeutic agent for CAI. PMID:25817214

  13. PEP-1-FK506BP inhibits alkali burn-induced corneal inflammation on the rat model of corneal alkali injury

    PubMed Central

    Kim, Dae Won; Lee, Sung Ho; Shin, Min Jea; Kim, Kibom; Ku, Sae Kwang; Youn, Jong Kyu; Cho, Su Bin; Park, Jung Hwan; Lee, Chi Hern; Son, Ora; Sohn, Eun Jeong; Cho, Sung-Woo; Park, Jong Hoon; Kim, Hyun Ah; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2015-01-01

    FK506 binding protein 12 (FK506BP) is a small peptide with a single FK506BP domain that is involved in suppression of immune response and reactive oxygen species. FK506BP has emerged as a potential drug target for several inflammatory diseases. Here, we examined the protective effects of directly applied cell permeable FK506BP (PEP-1-FK506BP) on corneal alkali burn injury (CAI). In the cornea, there was a significant decrease in the number of cells expressing pro-inflammation, apoptotic, and angiogenic factors such as TNF-α, COX-2, and VEGF. Both corneal opacity and corneal neovascularization (CNV) were significantly decreased in the PEP-1-FK506BP treated group. Our results showed that PEP-1-FK506BP can significantly inhibit alkali burn-induced corneal inflammation in rats, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors and inflammatory cytokines. These results suggest that PEP-1-FK506BP may be a potential therapeutic agent for CAI. [BMB Reports 2015; 48(11): 618-623] PMID:25817214

  14. 40 CFR 721.4280 - Substituted hydrazine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted hydrazine. 721.4280... Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted hydrazine (PMN P-90-594)...

  15. 40 CFR 721.4280 - Substituted hydrazine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted hydrazine. 721.4280... Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted hydrazine (PMN P-90-594)...

  16. 40 CFR 721.4280 - Substituted hydrazine.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted hydrazine. 721.4280... Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted hydrazine (PMN P-90-594)...

  17. 40 CFR 721.4280 - Substituted hydrazine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted hydrazine. 721.4280... Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted hydrazine (PMN P-90-594)...

  18. 40 CFR 721.4280 - Substituted hydrazine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted hydrazine. 721.4280... Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted hydrazine (PMN P-90-594)...

  19. 40 CFR 721.9100 - Substituted quinoline.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted quinoline. 721.9100... Substances § 721.9100 Substituted quinoline. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted quinoline (PMN P-93-1183)...

  20. 40 CFR 721.9100 - Substituted quinoline.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted quinoline. 721.9100... Substances § 721.9100 Substituted quinoline. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted quinoline (PMN P-93-1183)...

  1. 40 CFR 721.3360 - Substituted ethanolamine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted ethanolamine. 721.3360... Substances § 721.3360 Substituted ethanolamine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted ethanolamine (PMN P-91-490)...

  2. Ethynyl and substituted ethynyl-terminated polysulfones

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M. (Inventor)

    1984-01-01

    Ethynyl and substituted ethynyl-terminated polysulfones and a process for preparing the same are disclosed. These polysulfones are thermally cured to induce cross-linking and chain extension, producing a polymer system with improved solvent resistance and use temperature. Also disclosed are substituted 4-ethynylbenzoyl chlorides as precursors to the substituted ethynyl-terminated polysulfones and a process for preparing the same.

  3. Ethynyl and substituted ethynyl-terminated polysulfones

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M. (Inventor)

    1986-01-01

    Ethynyl and substituted ethynyl-terminated polysulfones and their synthesis are disclosed. These polysulfones are thermally cured to induce cross-linking and chain extension, producing a polymer system with improved solvent resistance and use temperatures. Also disclosed are substituted 4-ethynylbenzoyl chlorides as precursors to the substituted ethynyl-terminated polysulfones and a process for preparing the same.

  4. Permanent Teacher Preparation for Substitute Teachers.

    ERIC Educational Resources Information Center

    Hardman, Steve; Tippetts, Zachary

    2001-01-01

    Presents information about what should be communicated to substitute teachers and why it is important, focusing on the substitute teacher's role, classroom management tools, curriculum management, and preparing students for the substitute teacher by creating bridges that will help minimize the sense of separation students feel when they have a…

  5. Substitutes for School Nurses in Illinois

    ERIC Educational Resources Information Center

    Vollinger, Linda Jeno; Bergren, Martha Dewey; Belmonte-Mann, Frances

    2011-01-01

    The purpose of this descriptive study was to explore utilization of nurse substitutes in the school setting in Illinois. The literature described personnel who staff the school health office in the absence of the school nurse and the barriers to obtaining nurse substitutes. There were no empirical studies conducted on school nurse substitutes in…

  6. 40 CFR 721.9820 - Substituted triazole.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted triazole. 721.9820 Section... Substances § 721.9820 Substituted triazole. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as a substituted triazole (PMN P-90-1731)...

  7. 40 CFR 721.9820 - Substituted triazole.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted triazole. 721.9820 Section... Substances § 721.9820 Substituted triazole. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as a substituted triazole (PMN P-90-1731)...

  8. 40 CFR 721.9820 - Substituted triazole.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted triazole. 721.9820 Section... Substances § 721.9820 Substituted triazole. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as a substituted triazole (PMN P-90-1731)...

  9. 40 CFR 721.9820 - Substituted triazole.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted triazole. 721.9820 Section... Substances § 721.9820 Substituted triazole. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as a substituted triazole (PMN P-90-1731)...

  10. 40 CFR 721.9820 - Substituted triazole.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted triazole. 721.9820 Section... Substances § 721.9820 Substituted triazole. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as a substituted triazole (PMN P-90-1731)...

  11. 24 CFR 221.252 - Substitute mortgagors.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Substitute mortgagors. 221.252... Cost Homes § 221.252 Substitute mortgagors. (a) Selling mortgagor. The mortgagee may effect the release... approval of a substitute mortgagor, as provided by this section. (b) Purchasing mortgagor. The...

  12. 40 CFR 721.5867 - Substituted phenol.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted phenol. 721.5867 Section... Substances § 721.5867 Substituted phenol. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as substituted phenol (PMNs P-89-1125,...

  13. 40 CFR 721.5867 - Substituted phenol.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted phenol. 721.5867 Section... Substances § 721.5867 Substituted phenol. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as substituted phenol (PMNs P-89-1125,...

  14. 40 CFR 721.5867 - Substituted phenol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted phenol. 721.5867 Section... Substances § 721.5867 Substituted phenol. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as substituted phenol (PMNs P-89-1125,...

  15. 40 CFR 721.5867 - Substituted phenol.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted phenol. 721.5867 Section... Substances § 721.5867 Substituted phenol. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as substituted phenol (PMNs P-89-1125,...

  16. 40 CFR 721.5867 - Substituted phenol.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted phenol. 721.5867 Section... Substances § 721.5867 Substituted phenol. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as substituted phenol (PMNs P-89-1125,...

  17. Iridium-Catalyzed Allylic Substitution

    NASA Astrophysics Data System (ADS)

    Hartwig, John F.; Pouy, Mark J.

    Iridium-catalyzed asymmetric allylic substitution has become a valuable method to prepare products from the addition of nucleophiles at the more substituted carbon of an allyl unit. The most active and selective catalysts contain a phosphoramidite ligand possessing at least one arylethyl substituent on the nitrogen atom of the ligand. In these systems, the active catalyst is generated by a base-induced cyclometalation at the methyl group of this substituent to generate an iridium metalacycle bound by the COD ligand of the [Ir(COD)Cl]2 precursor and one additional labile dative ligand. Such complexes catalyze the reactions of linear allylic esters with alkylamines, arylamines, phenols, alcohols, imides, carbamates, ammonia, enolates and enolate equivalents, as well as typical stabilized carbon nucleophiles generated from malonates and cyanoesters. Iridium catalysts for enantioselective allylic substitution have also been generated from phosphorus ligands with substituents bound by heteroatoms, and an account of the studies of such systems, along with a description of the development of iridium catalysts is included.

  18. Resonant photodissociation in substituted benzenes

    NASA Astrophysics Data System (ADS)

    Scarborough, Tim; McAcy, Collin; Foote, David; Uiterwaal, Cornelis

    2011-05-01

    Cyclic aromatic molecules are abundant in organic chemistry, with a wide variety of applications, including pharmacology, pollution studies and genetic research. Among the simplest of these molecules is benzene (C6H6) , with many relevant molecules being benzene-like with a single atomic substitution. In such a substitution, the substituent determines a characteristic perturbation of the electronic structure of the molecule. We discuss the substitution of halogens into the ring (C6H5X), and its effects on the dynamics of ionization and dissociation of the molecule without the focal volume effect. In particular, using 800-nm, 50-fs laser pulses, we present results in the dissociation of fluorobenzene, chlorobenzene, bromobenzene and iodobenzene into the phenyl ring (C6H5) and the atomic halogen, and the subsequent ionization of these fragments. The impact of the ``heavy atom effect'' on a 1 (π , π*) -->3 (n , σ*) singlet-triplet intersystem crossing will be emphasized. Currently under investigation is whether such a dissociation can be treated as an effective source of the neutral substituent. This material is based upon work supported by the National Science Foundation under Grant No. PHY-0355235.

  19. Crystal Structures of Three Framework Alkali Metal Uranyl Phosphate Hydrates

    NASA Astrophysics Data System (ADS)

    Locock, Andrew J.; Burns, Peter C.

    2002-08-01

    Three homeotypic hydrated alkali metal uranyl phosphates, A2(UO 2)[(UO 2)(PO 4)] 4(H 2O) 2, A=Cs ( CsUP), Rb ( RbUP), K ( KUP), were synthesized by hydrothermal methods. Intensity data were collected at room temperature using Mo Kα radiation and a CCD-based area detector. Their crystal structures were solved by Patterson ( CsUP) and direct ( RbUP, KUP) methods and refined by full-matrix least-squares techniques to agreement indices ( CsUP, RbUP, KUP) w R2=0.048, 0.230, 0.072 for all data, and R1=0.023, 0.078, 0.038 calculated for 5338, 4738, 4514 unique observed reflections (∣ Fo∣≥4 σF), respectively. The compound CsUP is orthorhombic, space group Cmc2 1, Z=4, a=14.854(1), b=13.879(1), c=12.987(1) Å, V=2677.5(3) Å 3. Both RbUP and KUP are monoclinic, space group Cm, but are presented in the unconventional pseudo-orthorhombic space group Fm11 to facilitate comparison with CsUP and to allow a model for RbUP that includes the effects of pseudo-merohedral twinning. RbUP is monoclinic, space group Fm11, Z=4, a=15.72(2), b=13.84(1), c=13.05(1) Å, α=90.39°(2), V=2839(5) Å 3; KUP is monoclinic, space group Fm11, Z=4, a=15.257(1), b=13.831(1), c=13.007(1) Å, α=91.760°(1), V=2743.4(3) Å 3. The structures consist of sheets of phosphate tetrahedra and uranyl pentagonal bipyramids, with composition [(UO 2)(PO 4)] -, that are topologically identical to the uranyl silicate sheets in uranophane-beta. These sheets are connected by a uranyl pentagonal bipyramid in the interlayer that shares corners with two phosphate tetrahedra on each of two adjacent sheets and whose fifth equatorial vertex is an H 2O group, resulting in an open framework with alkali metal cations in the larger cavities of the structures. Where CsUP and RbUP have two alkali metal positions and a H 2O group in these cavities, KUP has four K atoms and two H 2O groups, all of which are partially occupied, in the interstitial sites.

  20. Materials compatibility and lubricants research on CFC-refrigerant substitutes

    SciTech Connect

    Hourahan, G.C.; Szymurski, S.R.

    1993-01-01

    The materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC-refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. Under the current MCLR program the Air-Conditioning and Refrigeration Technology Institute, Inc., (ARTI) is contracting and managing multiple research projects and a data collection and dissemination effort. Preliminary results from these projects are reported in technical progress reports prepared by each researcher.