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Sample records for oxygenates substituted

  1. Oxygen defects in Fe-substituted Tl-system superconductors

    Institute of Scientific and Technical Information of China (English)

    李阳; 曹国辉; 王耘波; 马庆珠; 熊小涛; 陈宁; 马如璋; 郭应焕; 许祝安; 王劲松; 张小俊; 焦正宽; 彭获田; 周思海

    1996-01-01

    For Fe-doped T1-1223 phase,the excess oxygen defects induced by Fe dopants are studied by means of Hall coefficient,thermogravimetric measurements,Mossbauer spectroscopy,and the model calculation of the effective bond valence.The extra oxygen defects have effects on carrier density and microstructure of the superconductors.In the light doping level of Fe (x=0-0.05),the superconducting transition and carrier density have significant corresponding relation--the zero resistance temperature Tco and carrier densities decrease linearly with Fe dopants increasing.The thermogravimetric measurements show that the Fe3+ ions’ substituting for Cu2+ ions can bring the extra oxygen into the lattice to form extra oxygen defects.The calculation of the effective bond valence shows that the decrease of carrier density originates the strongly localized binding of the extra oxygen defects.The distortion of Cu-O layer induced by the extra oxygen defects decreases the superconductive transition temperature.The microstructure

  2. Photoinduced intramolecular substitution reaction of aryl halide with carbonyl oxygen of amide group

    CERN Document Server

    Park, Y T; Kim, M S; Kwon, J H

    2002-01-01

    Photoreaction of N-(o-halophenyl)acetamide in basic acetonitrile produces an intramolecular substituted product, 2-methylbenzoxazole in addition to reduced product, acetanilide, whereas photoreaction of N-(o-halobenzyl)acetamide affords a reduced product, N-benzylacetamide only. On the basis of preparative reaction, kinetics, and UV/vis absorption behavior, an electrophilic aromatic substitution of aryl halide with oxygen of its amide bond are proposed.

  3. Photoinduced intramolecular substitution reaction of aryl halide with carbonyl oxygen of amide group

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Tae; Song, Myong Geun; Kim, Moon Sub; Kwon, Jeong Hee [Kyungpook National Univ., Daegu (Korea, Republic of)

    2002-09-01

    Photoreaction of N-(o-halophenyl)acetamide in basic acetonitrile produces an intramolecular substituted product, 2-methylbenzoxazole in addition to reduced product, acetanilide, whereas photoreaction of N-(o-halobenzyl)acetamide affords a reduced product, N-benzylacetamide only. On the basis of preparative reaction, kinetics, and UV/vis absorption behavior, an electrophilic aromatic substitution of aryl halide with oxygen of its amide bond are proposed.

  4. Photoinduced intramolecular substitution reaction of aryl halide with carbonyl oxygen of amide group

    International Nuclear Information System (INIS)

    Park, Yong Tae; Song, Myong Geun; Kim, Moon Sub; Kwon, Jeong Hee

    2002-01-01

    Photoreaction of N-(o-halophenyl)acetamide in basic acetonitrile produces an intramolecular substituted product, 2-methylbenzoxazole in addition to reduced product, acetanilide, whereas photoreaction of N-(o-halobenzyl)acetamide affords a reduced product, N-benzylacetamide only. On the basis of preparative reaction, kinetics, and UV/vis absorption behavior, an electrophilic aromatic substitution of aryl halide with oxygen of its amide bond are proposed

  5. Oxygen pumping characteristics of Cu-Ti double substituted bismuth vanadate

    Energy Technology Data Exchange (ETDEWEB)

    Paydar, M.H. [Shiraz Univ. (Iran). Dept. of Metallurgy and Material Sciences; Hadian, A.M. [Teheran Univ. (Iran). Dept. of Metallurgy and Material Sciences; Fafilek, G. [Technische Univ., Vienna (Austria). Inst. fuer Technische Elektrochemie

    2002-07-01

    In the present paper, we are going to report on a detailed study of the characteristics of an electrochemical oxygen pump for an open system using Cu-Ti double substituted bismuth vanadate as the electrolyte. The major objectives are to show a correlation between oxygen pumping current, cell voltage, Faradic efficiency and oxygen production rate. The maximum current density that can be applied without significant structural modification has been determined and the effect of working temperature on the mentioned parameters have been investigated. The results show that there is an Ohmic relationship between current and voltage at low current densities and a deviation towards lower voltages than expected from Ohm's law with increasing current density. The oxygen production rate increased in a linear fashion by increasing the current density while at high current densities, corresponding to the non linear current voltage section, its gradient decline. Under constant current load, at very high current density (I > 800 mAcm{sup -2}), instability in cell potential was observed, which was reversible and supposed to be the effect of electronic percolation. (orig.)

  6. BLOOD SUBSTITUTES: EVOLUTION FROM NON-CARRYING TO OXYGEN AND GAS CARRYING FLUIDS

    Science.gov (United States)

    Cabrales, Pedro; Intaglietta, Marcos

    2013-01-01

    The development of oxygen (O2) carrying blood substitutes has evolved from the goal of replicating blood O2 transports properties to that of preserving microvascular and organ function, reducing the inherent or potential toxicity of the material used to carry O2, and treating pathologies initiated by anemia and hypoxia. Furthermore, the emphasis has shifted from blood replacement fluid to “O2 therapeutics” that restore tissue oxygenation to specific tissues regions. This review covers the different alternatives, potential and limitations of hemoglobin based O2 carriers (HBOCs) and perfluorocarbon based O2 carriers (PFCOCs), with emphasis on the physiological conditions disturbed in the situation that they will be used. It describes how concepts learned from plasma expanders without O2 carrying capacity can be applied to maintain O2 delivery and summarizes the microvascular responses due to HBOCs and PFCOCs. This review also presents alternative applications of HBOCs and PFCOCs namely: 1) How HBOC O2 affinity can be engineered to target O2 delivery to hypoxic tissues; and 2) How the high gas solubility of PFCOCs provides new opportunities for carrying, dissolving and delivering gases with biological activity. It is concluded that current blood substitutes development has amplified their applications horizon by devising therapeutic functions for oxygen carriers requiring limited O2 delivery capacity restoration. Conversely, full, blood-like O2 carrying capacity re-establishment awaits control of O2 carrier toxicity. PMID:23820271

  7. Effect of Sr substituted La 2−x Sr x NiO 4+δ (x = 0, 0.2, 0.4, 0.6, and 0.8) on oxygen stoichiometry and oxygen transport properties

    KAUST Repository

    Inprasit, T.; Wongkasemjit, S.; Skinner, S. J.; Burriel, M.; Limthongkul, P.

    2015-01-01

    © The Royal Society of Chemistry 2015. Stoichiometry and oxygen diffusion properties of La2-xSrxNiO4±δ with x = 0.2, 0.4, 0.6, and 0.8 prepared via a sol-gel method were investigated in this study. Iodometric titration and thermogravimetric analysis were used to determine the oxygen non-stoichiometry. Over the entire compositional range, the samples exhibit oxygen hyperstoichiometry with the minimum value δ = 0.14 at x = 0.4. Mixed effects of reduction of oxygen excess and increasing valence of Ni were found to serve as charge compensation mechanisms; the former dominated at a low level of substitution, x < 0.4, while the latter dominated at higher levels of Sr (0.4 < x < 0.8). The highest oxygen diffusion coefficient was found for the minimum amount of Sr substitution, x = 0.2, continuously decreasing with x until x = 0.6. An unusual increase in D∗ was observed when the Sr content increased up to x = 0.8.

  8. High impact of uranyl ions on carrying-releasing oxygen capability of hemoglobin-based blood substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Li; Du, Lili; Liu, Wenyuan; Liu, Zhichao [Northwest Institute of Nuclear Technology, Xi' an, Shaanxi (China); Jia, Yi; Li, Junbai [Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing (China)

    2015-01-07

    The effect of radioactive UO{sub 2}{sup 2+} on the oxygen-transporting capability of hemoglobin-based oxygen carriers has been investigated in vitro. The hemoglobin (Hb) microspheres fabricated by the porous template covalent layer-by-layer (LbL) assembly were utilized as artificial oxygen carriers and blood substitutes. Magnetic nanoparticles of iron oxide (Fe{sub 3}O{sub 4}) were loaded in porous CaCO{sub 3} particles for magnetically assisted chemical separation (MACS). Through the adsorption spectrum of magnetic Hb microspheres after adsorbing UO{sub 2}{sup 2+}, it was found that UO{sub 2}{sup 2+} was highly loaded in the magnetic Hb microspheres, and it shows that the presence of UO{sub 2}{sup 2+} in vivo destroys the structure and oxygen-transporting capability of Hb microspheres. In view of the high adsorption capacity of UO{sub 2}{sup 2+}, the as-assembled magnetic Hb microspheres can be considered as a novel, highly effective adsorbent for removing metal toxins from radiation-contaminated bodies, or from nuclear-power reactor effluent before discharge into the environment. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Characterization of the Sr(2+)- and Cd(2+)-Substituted Oxygen-Evolving Complex of Photosystem II by Quantum Mechanics/Molecular Mechanics Calculations.

    Science.gov (United States)

    Pitari, Fabio; Bovi, Daniele; Narzi, Daniele; Guidoni, Leonardo

    2015-09-29

    The Mn4CaO5 cluster in the oxygen-evolving complex is the catalytic core of the Photosystem II (PSII) enzyme, responsible for the water splitting reaction in oxygenic photosynthesis. The role of the redox-inactive ion in the cluster has not yet been fully clarified, although several experimental data are available on Ca2+-depleted and Ca2+-substituted PSII complexes, indicating Sr2+-substituted PSII as the only modification that preserves oxygen evolution. In this work, we investigated the structural and electronic properties of the PSII catalytic core with Ca2+ replaced with Sr2+ and Cd2+ in the S2 state of the Kok−Joliot cycle by means of density functional theory and ab initio molecular dynamics based on a quantum mechanics/ molecular mechanics approach. Our calculations do not reveal significant differences between the substituted and wild-type systems in terms of geometries, thermodynamics, and kinetics of two previously identified intermediate states along the S2 to S3 transition, namely, the open cubane S2 A and closed cubane S2 B conformers. Conversely, our calculations show different pKa values for the water molecule bound to the three investigated heterocations. Specifically, for Cd-substituted PSII, the pKa value is 5.3 units smaller than the respective value in wild type Ca-PSII. On the basis of our results, we conclude that, assuming all the cations sharing the same binding site, the induced difference in the acidity of the binding pocket might influence the hydrogen bonding network and the redox levels to prevent the further evolution of the cycle toward the S3 state.

  10. Oxygen-storage behavior and local structure in Ti-substituted YMnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Levin, I., E-mail: igor.levin@nist.gov [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Krayzman, V.; Vanderah, T.A. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Tomczyk, M. [Department of Ceramics and Glass Engineering, University of Aveiro, Aveiro 3810-193 (Portugal); Wu, H. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Tucker, M.G. [Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Playford, H.Y. [ISIS Facility, Rutherford Appleton Laboratory, Didcot, Oxford (United Kingdom); Woicik, J.C.; Dennis, C.L. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Vilarinho, P.M. [Department of Ceramics and Glass Engineering, University of Aveiro, Aveiro 3810-193 (Portugal)

    2017-02-15

    Hexagonal manganates RMnO{sub 3} (R=Y, Ho, Dy) have been recently shown to exhibit oxygen-storage capacities promising for three-way catalysts, air-separation, and related technologies. Here, we demonstrate that Ti substitution for Mn can be used to chemically tune the oxygen-breathing properties of these materials towards practical applications. Specifically, Y(Mn{sub 1−x}Ti{sub x})O{sub 3} solid solutions exhibit facile oxygen absorption/desorption via reversible Ti{sup 3+}↔Ti{sup 4+} and Mn{sup 3+}↔Mn{sup 4+} reactions already in ambient air at ≈400 °C and ≈250 °C, respectively. On cooling, the oxidation of both cations is accompanied by oxygen uptake yielding a formula YMn{sup 3+}{sub 1−x-y}Mn{sup 4+}{sub y}Ti{sup 4+}{sub x}O{sub 3+δ}. The presence of Ti promotes the oxidation of Mn{sup 3+} to Mn{sup 4+}, which is almost negligible for YMnO{sub 3} in air, thereby increasing the uptake of oxygen beyond that required for a given Ti{sup 4+} concentration. The reversibility of the redox reactions is limited by sluggish kinetics; however, the oxidation process continues, if slowly, even at room temperature. The extra oxygen atoms are accommodated by the large interstices within a triangular lattice formed by the [MnO{sub 5}] trigonal bipyramids. According to bond distances from Rietveld refinements using the neutron diffraction data, the YMnO{sub 3} structure features under-bonded Mn and even more severely under-bonded oxygen atoms that form the trigonal bases of the [MnO{sub 5}] bipyramids. The tensile bond strain around the 5-fold coordinated Mn site and the strong preference of Ti{sup 4+}(and Mn{sup 4+}) for higher coordination numbers likely provide driving forces for the oxidation reaction. Reverse Monte Carlo refinements of the local atomic displacements using neutron total scattering revealed how the excess oxygen atoms are accommodated in the structure by correlated local displacements of the host atoms. Large displacements of the under

  11. A Singlet Oxygen Photogeneration and Luminescence Study of Unsymmetrically Substituted Mesoporphyrinic Compounds

    Directory of Open Access Journals (Sweden)

    Anabela Sousa Oliveira

    2009-01-01

    Full Text Available This paper deals with a series of new unsymmetrically substituted mesoporphyrins: 5-(2-hydroxyphenyl-10,15,20-tris-phenyl-21,23-H-porphyrin (TPPOHO, 5-(3-hydroxyphenyl-10,15,20-tris-phenyl-21,23-H-porphyrin (TPPOHM, 5-(4-hydroxyphenyl-10,15,20-tris-phenyl-21,23-H-porphyrin (TPPOHP, 5-(2-hydroxyphenyl-10,15,20-tris-butyl-21,23-H-porphyrin (TBPOHO, and their parent nonsubstituted compounds, respectively, 5,10,15,20-tetrakis-phenyl-21,23-H-porphyrin (TPP and 5,10,15,20-tetrakis-butyl-21,23-H-porphyrin (TBP. Several photophysical studies were carried out to access the influence of the unsymmetrical substitution at the porphyrinic macrocycle on porthyrin's photophysical properties, especially porthyrin's efficiency as singlet oxygen sensitizers. The quantum yields of singlet oxygen generation were determined in benzene (ΦΔ(TPP = 0.66 ± 0.05; ΦΔ(TPPOHO = 0.69 ± 0.04; ΦΔ(TPPOHM = 0.62 ± 0.04; ΦΔ(TPPOHP = 0.73 ± 0.03; ΦΔ(TBP = 0.76 ± 0.03; ΦΔ(TBPOHO = 0.73 ± 0.02 using the 5,10,15,20-tetraphenyl-21,23-H-porphine (ΦΔ(TPP = 0.66 and Phenazine (ΦΔ(Phz = 0.83 as reference compounds. Their fluorescence quantum yields were found to be (Φf(TPPOHO = 0.10 ± 0.04; Φf(TPPOHM = 0.09 ± 0.03; Φf(TPPOHP = 0.13 ± 0.02; Φf(TBP = 0.08 ± 0.03 and Φf(TBPOHO = 0.08 ± 0.02 using 5,10,15,20-tetraphenyl-21,23-H-porphine as reference Φf(TPP = 0.13. Singlet state lifetimes were also determined in the same solvent. All the porphyrins presented very similar fluorescence lifetimes (mean values of τS (with O2, air equilibrated = 9.6 ± 0.3 nanoseconds and (without O2, argon purged = 10.1 ± 0.6 nanoseconds, resp.. The phosphorescence emission was found to be negligible for this series of unsymmetrically substituted mesoporphyrins, but an E-type, thermally activated, delayed fluorescence process was proved to occur at room temperature.

  12. Copper-substituted perovskite compositions for solid oxide fuel cell cathodes and oxygen reduction electrodes in other electrochemical devices

    Science.gov (United States)

    Rieke, Peter C [Pasco, WA; Coffey, Gregory W [Richland, WA; Pederson, Larry R [Kennewick, WA; Marina, Olga A [Richland, WA; Hardy, John S [Richland, WA; Singh, Prabhaker [Richland, WA; Thomsen, Edwin C [Richland, WA

    2010-07-20

    The present invention provides novel compositions that find advantageous use in making electrodes for electrochemical cells. Also provided are electrochemical devices that include active oxygen reduction electrodes, such as solid oxide fuel cells, sensors, pumps and the like. The compositions comprises a copper-substituted ferrite perovskite material. The invention also provides novel methods for making and using the electrode compositions and solid oxide fuel cells and solid oxide fuel cell assemblies having cathodes comprising the compositions.

  13. Relationship between Al content and substitution mechanism of Al-bearing anhydrous bridgmanites

    Science.gov (United States)

    Noda, M.; Inoue, T.; Kakizawa, S.

    2017-12-01

    It is considered that two substitution mechanisms, Tschermak substitution and oxygen vacancy substitution, exist in MgSiO3 bridgmanite for the incorporation of Al in anhydrous condition. Kubo and Akaogi (2000) has conducted the phase equilibrium experiment in the system MgSiO3-Al2O3, and established the phase diagram up to 28 GPa. However the careful observation in the bridgmanite shows that the chemical compositions are slightly deviated from Tschermak substitution join. The same tendency can be also observed in the run products by Irifune et al. (1996). This result indicates that pure Tschermak substitution bridgmanite cannot be stable even in the MgSiO3-Al2O3 join experiment. However, the previous studies used powder samples as the starting materials, so the absorbed water may affect the results. Therefore, we tried to conduct the experiment in the join MgSiO3-Al2O3 in extremely anhydrous condition to clarify whether the pure Tschermak substitution bridgmanite can be stable or not. In addition, we also examined the stability of oxygen vacancy bridgmanite in the extremely anhydrous condition for the comparison. The high pressure synthesis experiments were conducted at 28 GPa and 1600-1700° for 1hour using a Kawai-type multi-anvil apparatus. Four different Al content samples were prepared as the starting materials along the ideal substitution line of Tschermak (Al=0.025, 0.05, 0.1, 0.15 mol) and oxygen-vacancy (Al=0.025, 0.05, 0.075, 0.1 mol) substitutions, respectively (when total cation of 2). The glass rods were used as the starting materials to eliminate the absorbed water on the sample surface. The chemical compositions of the synthesized bridgmanite could not be measured by EPMA because of small grain size less than submicron. Therefore the chemical compositions were estimated from the result of the XRD pattern by subtracting the amount of the other phases. The estimated chemical compositions of Tschermak substitution bridgmanites were consistent with the

  14. Influence of higher sodium substitutions on magnetic entropy ...

    Indian Academy of Sciences (India)

    The change in entropy also decreases with increase in substitution of sodium. A notable change ... of substituting elements for A and B ions, valence states of. Mn and the oxygen ... applied external magnetic field of 7 T.17 Sodium substitu- ..... Bohigas X, Tejada J, Del Barco E, Zhang X X and Sales M. 1998 Appl. Phys. Lett.

  15. Carbon substituting for oxygen in silicates: A novel mechanism for carbon incorporation in the deep Earth

    Science.gov (United States)

    Armentrout, M. M.; Tavakoli, A.; Ionescu, E.; Mera, G.; Riedel, R.; Navrotsky, A.

    2013-12-01

    Traditionally, carbon in the deep Earth has been thought of in terms of either carbonate at high oxygen fugacities or graphite or diamond under more reducing conditions. However, material science studies of amorphous Si-O-C polymer derived ceramics have demonstrated that carbon can be accommodated as an anion substituting for oxygen in mixed silica tetrahedra. Furthermore these structures are energetically favorable relative to a mixture of crystalline silica, silicon carbide, and graphite by ten or more kJ/g.atom. Thermodynamic stability suggests that these nano-structured composites are a potentially important storage mechanism for carbon under moderately reducing conditions. Here we expand the scope of the previous work by examining the compositional effect of geologically relevant cations (calcium and magnesium) on the thermodynamic stability, nanostructure, and ability to accommodate carbon of these composites. Silicon oxy-carbides doped with magnesium, magnesium and calcium or undoped resisted crystallization at 1100 C under inert atmosphere. 29Si NMR of the samples shows a similar distribution of silicon between end-member and mixed sites (Table 1). Results are presented from studies utilizing NMR, high temperature solution calorimetry, and microprobe. Table 1. Percentages of Si species in each material as determined by 29Si NMR.

  16. EPR-study of reversible oxygenation process of coordination compounds of cobalt(II) with S-substituted N1,N4-di(salicylidene)-isothiosemicarbazides

    International Nuclear Information System (INIS)

    Gerbeleu, N.V.; Revenko, M.D.; Rusu, V.G.; Shames, A.T.

    1987-01-01

    The reaction between molecular oxygen and coordination compounds of cobalt(II) with S-substituted N 1 ,N 4 -di(salicylidene)isothiosemicarbazides in dimethyl sulfoxide solution was studied by the EPR method. It was found that paramagnetic monomeric adducts and diamagnetic μ-peroxo-dimers are formed. The spin-Hamiltonian parameters of the EPR spectra of the initial cobalt complexes, as well as of the paramagnetic adducts were determined. The nature of the Co-O 2 bond is discussed

  17. Selective oxidation of glycerol to formic acid in highly concentrated aqueous solutions with molecular oxygen using V-substituted phosphomolybdic acids

    KAUST Repository

    Zhang, Jizhe

    2014-01-01

    Formic acid is an important commodity chemical as well as a promising medium for hydrogen storage and hydrogen production. In this paper, we report that formic acid can be produced through selective oxidation of glycerol, a low-cost by-product of biodiesel, by using vanadium-substituted phosphomolybdic acids as catalysts and molecular oxygen as the oxidant. Significantly, this catalytic system allows for high-concentration conversions and thus leads to exceptional efficiency. Specifically, 3.64 g of formic acid was produced from 10 g of glycerol/water (50/50 in weight) solution. © 2014 the Partner Organisations.

  18. Oxygen nonstoichiometry and transport properties of strontium substituted lanthanum cobaltite

    DEFF Research Database (Denmark)

    Søgaard, Martin; Hendriksen, Peter Vang; Mogensen, Mogens Bjerg

    2006-01-01

    Oxygen nonstoichiometry, structure and transport properties of the two compositions (La-0.6 Sr-0.4)(0.99)CoO3-delta (LSC40) and La0.85Sr0.15CoO3-delta (LSC15) were measured. It was found that the oxygen nonstoichiometry as a function of the temperature and oxygen partial pressure could be described...... using the itinerant electron model. The electrical conductivity, sigma, of the materials is high (sigma > 500 S cm(-1)) in the measured temperature range (650 - 1000 degrees C) and oxygen partial pressure range (0.209-10(-4) atm). At 900 degrees C the electrical conductivity is 1365 and 1491 S cm(-1......) in air for LSC40 and LSC15, respectively. A linear correlation between the electrical conductivity and the oxygen vacancy concentration was found for both samples. The mobility of the electron-holes was inversely proportional with the absolute temperature indicating a metallic type conductivity for LSC40...

  19. Laser ablation of Bi-substituted gadolinium iron garnet films

    International Nuclear Information System (INIS)

    Watanabe, N.; Hayashida, K.; Kawano, K.; Higuchi, K.; Ohkoshi, M.; Tsushima, K.

    1995-01-01

    Bi-substituted gadolinium iron garnet films were deposited by laser ablation. The composition, the structure and the magnetic properties of the films were found to be strongly dependent both on the compositions of the targets and on the pressure of oxygen. The highest values of Bi-substitution up to x=1.44 with uniform composition were obtained, after annealing in air. ((orig.))

  20. Enantioconvergent synthesis by sequential asymmetric Horner-Wadsworth-Emmons and palladium-catalyzed allylic substitution reactions

    DEFF Research Database (Denmark)

    Pedersen, Torben Møller; Hansen, E. Louise; Kane, John

    2001-01-01

    A new method for enantioconvergent synthesis has been developed. The strategy relies on the combination of an asymmetric Horner-Wadsworth-Emmons (HWE) reaction and a palladium-catalyzed allylic substitution. Different $alpha@-oxygen-substituted, racemic aldehydes were initially transformed by asy...... the allylic stereocenter and the alkene geometry. Thus, a single $gamma@-substituted ester was obtained as the overall product, in high isomeric purity. The method was applied to a synthesis of a subunit of the iejimalides, a group of cytotoxic macrolides.......A new method for enantioconvergent synthesis has been developed. The strategy relies on the combination of an asymmetric Horner-Wadsworth-Emmons (HWE) reaction and a palladium-catalyzed allylic substitution. Different $alpha@-oxygen-substituted, racemic aldehydes were initially transformed...... by asymmetric HWE reactions into mixtures of two major $alpha@,$beta@-unsaturated esters, possessing opposite configurations at their allylic stereocenters as well as opposite alkene geometry. Subsequently, these isomeric mixtures of alkenes could be subjected to palladium-catalyzed allylic substitution...

  1. Cation Radical Accelerated Nucleophilic Aromatic Substitution via Organic Photoredox Catalysis.

    Science.gov (United States)

    Tay, Nicholas E S; Nicewicz, David A

    2017-11-15

    Nucleophilic aromatic substitution (S N Ar) is a direct method for arene functionalization; however, it can be hampered by low reactivity of arene substrates and their availability. Herein we describe a cation radical-accelerated nucleophilic aromatic substitution using methoxy- and benzyloxy-groups as nucleofuges. In particular, lignin-derived aromatics containing guaiacol and veratrole motifs were competent substrates for functionalization. We also demonstrate an example of site-selective substitutive oxygenation with trifluoroethanol to afford the desired trifluoromethylaryl ether.

  2. AB initio energetics of lanthanum substitution in ferroelectric bismuth titanate

    International Nuclear Information System (INIS)

    Shah, S.H.

    2012-01-01

    Density functional theory based electronic structure calculations play a vital role in understanding, controlling and optimizing physical properties of materials at microscopic level. In present study system of interest is bismuth titanate (Bi/sub 4/Ti/sub 3/O/sub 12/)/(BIT) which has wide range of applications such as a high temperature piezoelectric and one of the best material for memory devices. However, it also suffers from serious issues such as oxygen vacancies which degrade its performance as a memory element and piezoelectric material. In this context, the bulk and defect properties of orthorhombic bismuth titanate (Bi/sub 4/Ti/sub 3/O/sub 12/) and bismuth lanthanum titanate (Bi/sub 3.25/La/sub 0.75/Ti/sub 3/O/sub 12/)/(BLT, x=0.75) were investigated by using first principles calculations and atomistic thermodynamics. Heats of formation, valid chemical conditions for synthesis, lanthanum substitution energies and oxygen and bismuth vacancy formation energies were computed. The study improves understanding of how native point defects and substitutional impurities influence the ferroelectric properties of these layered perovskite materials. It was found that lanthanum incorporation could occur on either of the two distinct bismuth sites in the structure and that the effect of substitution is to increase the formation energy of nearby native oxygen vacancies. The results provide direct atomistic evidence over a range of chemical conditions for the suggestion that lanthanum incorporation reduces the oxygen vacancy concentration. Oxygen vacancies contribute to ferroelectric fatigue by interacting strongly with domain walls and therefore a decrease in their concentration is beneficial. (orig./A.B.)

  3. In vivo EPR oximetry using an isotopically-substituted nitroxide: Potential for quantitative measurement of tissue oxygen

    Science.gov (United States)

    Weaver, John; Burks, Scott R.; Liu, Ke Jian; Kao, Joseph P.Y.; Rosen, Gerald M.

    2017-01-01

    Variations in brain oxygen (O2) concentration can have profound effects on brain physiology. Thus, the ability to quantitate local O2 concentrations noninvasively in vivo could significantly enhance understanding of several brain pathologies. However, quantitative O2 mapping in the brain has proven difficult. The electron paramagnetic resonance (EPR) spectra of nitroxides are sensitive to molecular O2 and can be used to estimate O2 concentrations in aqueous media. We recently synthesized labile-ester-containing nitroxides, such as 3-acetoxymethoxycarbonyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl (nitroxide 4), which accumulate in cerebral tissue after in situ hydrolysis, and thus enable spatial mapping of O2 concentrations in the mouse brain by EPR imaging. In an effort to improve O2 quantitation, we prepared 3-acetoxymethox ycarbonyl-2,2,5,5-tetra(2H3)methyl-1-(3,4,4-2H3,1-15N)pyrrolidinyloxyl (nitroxide 2), which proved to be a more sensitive probe than its normo-isotopic version for quantifying O2 in aqueous solutions of various O2 concentrations. We now demonstrate that this isotopically substituted nitroxide is ~2-fold more sensitive in vivo than the normo-isotopic nitroxide 4. Moreover, in vitro and in vivo EPR spectral-spatial imaging results with nitroxide 2 demonstrate significant improvement in resolution, reconstruction and spectral response to local O2 concentrations in cerebral tissue. Thus, isotopic-substituted nitroxides, such as 2, are excellent sensors for in vivo O2 quantitation in tissues, such as the brain. PMID:27567323

  4. EPR-study of reversible oxygenation process of coordination compounds of cobalt(II) with S-substituted N/sup 1/,N/sup 4/-di(salicylidene)-isothiosemicarbazides

    Energy Technology Data Exchange (ETDEWEB)

    Gerbeleu, N.V.; Revenko, M.D.; Rusu, V.G.; Shames, A.T.

    1987-09-01

    The reaction between molecular oxygen and coordination compounds of cobalt(II) with S-substituted N/sup 1/,N/sup 4/-di(salicylidene)isothiosemicarbazides in dimethyl sulfoxide solution was studied by the EPR method. It was found that paramagnetic monomeric adducts and diamagnetic ..mu..-peroxo-dimers are formed. The spin-Hamiltonian parameters of the EPR spectra of the initial cobalt complexes, as well as of the paramagnetic adducts were determined. The nature of the Co-O/sub 2/ bond is discussed.

  5. Radiation chemistry of alternative fuel oxygenates - substituted ethers

    International Nuclear Information System (INIS)

    Mezyk, S. P.; Cooper, W. J.; Bartels, D. M.; Tobien, T.; O'Shea, K. E.

    1999-01-01

    The electron beam process, an advanced oxidation and reduction technology, is based in the field of radiation chemistry. Fundamental to the development of treatment processes is an understanding of the underlying chemistry. The authors have previously evaluated the bimolecular rate constants for the reactions of methyl tert-butyl ether (MTBE) and with this study have extended their studies to include ethyl tert-butyl ether (ETBE), di-isopropyl ether (DIPE) and tert-amyl methyl ether (TAME) with the hydroxyl radical, hydrogen atom and solvated electron using pulse radiolysis. For all of the oxygenates the reaction with the hydroxyl radical appears to be of primary interest in the destruction of the compounds in water. The rates with the solvated electron are limiting values as the rates appear to be relatively low. The hydrogen atom rate constants are relatively low, coupled with the low yield in radiolysis, they concluded that these are of little significance in the destruction of the alternative fuel oxygenates (and MTBE)

  6. Effect of the oxygen isoelectronic substitution in Cu2ZnSnS4 and its photovoltaic application

    International Nuclear Information System (INIS)

    Tablero, C.

    2012-01-01

    The optoelectronic properties of Cu 2 ZnSnS 4 and environmental considerations have attracted significant interest for photovoltaics. Using first-principles, we analyze the possible improvement of this material as a photovoltaic absorber via the isoelectronic substitution of S with O atoms. The evolution of the acceptor level is analyzed with respect to the atomic position of the nearest neighbors of the O atom. We estimate the maximum efficiency of this compound when used as a light absorber. The presence of the sub-band gap level below the conduction band could increases the solar-energy conversion with respect to the host. - Highlights: ► Cu 2 ZnSnS 4 is a promising material for low cost thin film solar cell technology. ► Its optoelectronic properties could be improved by states in the band gap. ► The oxygen to give rise to deep traps. ► Maximum efficiency can be larger than the host semiconductor.

  7. Growth and Properties of Oxygen and Ion Doped BISMUTH(2) STRONTIUM(2) Calcium COPPER(2) Oxygen (8+DELTA) Single Crystals

    Science.gov (United States)

    Mitzi, David Brian

    1990-01-01

    A directional solidification method for growing large single crystals in the Bi_2Sr _2CaCu_2O _{8+delta} system is reported. Ion substitutions, with replacement of La for Sr and Y for Ca, as well as oxygen doping in these crystals has been explored. Ion doping results in little change of the superconducting transition for substitution levels below 20-25% (as a result of simultaneous oxygen intercalation), while beyond this level, the Meissner signal broadens and the low temperature Meissner signal decreases. Microprobe analysis and x-ray diffraction performed on these more highly substituted single crystals, provides evidence for inhomogeneity and phase segregation into regions of distinct composition. Annealing unsubstituted crystals in increasing partial pressures of oxygen reversibly depresses the superconducting transition temperature from 90K (as made) to 77K (oxygen pressure annealed) while the Hall concentrations increase from n = 3.1(3) times 10 ^{21} cm^{ -3} (0.34 holes/Cu site) to 4.6(3) times 10^{21} cm^{-3} (0.50 holes/Cu site). Further suppression of T_{c} to 72K is possible by annealing in oxygen pressures up to 100atm. No degradation of the Meissner transition or other indications of inhomogeneity or phase segregation with doping are noted, suggesting that oxygen doped Bi_2Sr _2CaCu_2O _{8+delta} is a suitable system for pursuing doping studies. The decrease in T _{c} with concentration for 0.34 <=q n <=q 0.50 indicates that a high carrier concentration regime exists where T_{c} decreases with n and suggests that this decrease does not arise from material inhomogeneity or other materials problems. The physical properties of these Bi _2Sr_2CaCu _2O_{8+delta} crystals, in this high carrier concentration regime, will be discussed.

  8. System and method for producing substitute natural gas from coal

    Science.gov (United States)

    Hobbs, Raymond [Avondale, AZ

    2012-08-07

    The present invention provides a system and method for producing substitute natural gas and electricity, while mitigating production of any greenhouse gasses. The system includes a hydrogasification reactor, to form a gas stream including natural gas and a char stream, and an oxygen burner to combust the char material to form carbon oxides. The system also includes an algae farm to convert the carbon oxides to hydrocarbon material and oxygen.

  9. Crystal structure details of La- and Bi-substituted hydroxyapatites: Evidence for LaO+ and BiO+ with a very short metal–oxygen bond

    International Nuclear Information System (INIS)

    Kazin, Pavel E.; Pogosova, Mariam A.; Trusov, Lev A.; Kolesnik, Irina V.; Magdysyuk, Oxana V.; Dinnebier, Robert E.

    2016-01-01

    Crystal structures of substituted apatites with general formula Ca 10−x M x (PO 4 ) 6 (OH 1−δ ) 2−x O x , where M=La, Bi, 0≤x<2, were refined using high-resolution X-ray powder diffraction patterns. Individual positions for Ca 2+ and M 3+ -ions localized near Ca2-site were determined. The M 3+ -ion was found shifted toward the hexagonal channel center with respect to the Ca 2+ -ion, forming very short bond with the intrachannel O 2− , while leaving considerably longer distances to other oxygen atoms, which suggested the existence of a MO + ion. Distinct bands of stretching M–O modes were observed in the Raman and FT-IR spectra of the compounds. The bond lengths for BiO + and LaO + were estimated to be 2.05(1) and 2.09(1) Å correspondingly. The latter was almost 0.3 Å lower than the shortest La–O bond in La 2 O 3 . The realization of such a strong lanthanide–oxygen bond in a crystal lattice could provide a very high axial ligand field and might be implemented to develop high-energy-barrier single-molecule magnets as well as to tune properties of lanthanide-based luminophores. - Graphical abstract: A fragment of the La-for-Ca substituted apatite crystal structure focusing on the La–O bond. - Highlights: • Individual positions in the apatite crystal lattice for a doping atom (La, Bi) and Ca. • The doping atom shifts toward the center of the hexagonal channel. • BiO + and LaO + with estimated short bond lengths of 2.05 and 2.09 Å respectively.

  10. Oxygen chain disorder and compensation by Ca in Y(1-2-3) cuprates

    International Nuclear Information System (INIS)

    Suryanarayanan, R.; Ouhammou, L.; Das, A.; Leelaprute, S.

    1994-01-01

    Several M dopants such as Al, Fe, and Co at the Cu site destroy the superconductivity of YBa 2 Cu 3 O 6+z . However, superconductivity is restored by substituting Ca at the Y site. Arguments are developed to show that the oxygen chain disorder is not the only cause for destroying the superconductivity. A universal relation seems to exist between the net hole density as a result of Ca substitution and Tc. To stabilize the perovskite structure of YSr 2 Cu 3 O 6+z , it is necessary to substitute Cu by certain elements. Examples are given on Ti and Re substitution. Again, Ca cosubstitution increases Tc. Further, the irreversibility line is enhanced by Ca, indicating improved pinning in these materials in spite of the oxygen disorder. 16 refs., 4 figs., 1 tab

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

    Science.gov (United States)

    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 to...

  12. In Situ Spectroscopy and Mechanistic Insights into CO Oxidation on Transition-Metal-Substituted Ceria Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Joseph S.; Stoerzinger, Kelsey A.; Hong, Wesley T.; Risch, Marcel; Giordano, Livia [Dipartimento; Mansour, Azzam N. [Naval; Shao-Horn, Yang

    2017-09-12

    Herein we investigate the reaction intermediates formed during CO oxidation on copper-substituted ceria nanoparticles (Cu0.1Ce0.9O2–x) by means of in situ spectroscopic techniques and identify an activity descriptor that rationalizes a trend with other metal substitutes (M0.1Ce0.9O2–x, M = Mn, Fe, Co, Ni). In situ X-ray absorption spectroscopy (XAS) performed under catalytic conditions demonstrates that O2– transfer occurs at dispersed copper centers, which are redox active during catalysis. In situ XAS reveals a dramatic reduction at the copper centers that is fully reversible under catalytic conditions, which rationalizes the high catalytic activity of Cu0.1Ce0.9O2–x. Ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) show that CO can be oxidized to CO32– in the absence of O2. We find that CO32– desorbs as CO2 only under oxygen-rich conditions when the oxygen vacancy is filled by the dissociative adsorption of O2. These data, along with kinetic analyses, lend support to a mechanism in which the breaking of copper–oxygen bonds is rate-determining under oxygen-rich conditions, while refilling the resulting oxygen vacancy is rate-determining under oxygen-lean conditions. On the basis of these observations and density functional calculations, we introduce the computed oxygen vacancy formation energy (Evac) as an activity descriptor for substituted ceria materials and demonstrate that Evac successfully rationalizes the trend in the activities of M0.1Ce0.9O2–x catalysts that spans three orders of magnitude. The applicability of Evac as a useful design descriptor is demonstrated by the catalytic performance of the ternary oxide Cu0.1La0.1Ce0.8O2–x, which has an apparent activation energy rivaling those of state-of-the-art Au/TiO2 materials. Thus, we suggest that cost-effective catalysts for CO oxidation can be rationally designed by judicious choice of substituting

  13. Single amino acid substitution in important hemoglobinopathies does not disturb molecular function and biological process

    Directory of Open Access Journals (Sweden)

    Viroj Wiwanitkit

    2008-06-01

    Full Text Available Viroj WiwanitkitDepartment of Laboratory Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, ThailandAbstract: Hemoglobin is an important protein found in the red cells of many animals. In humans, the hemoglobin is mainly distributed in the red blood cell. Single amino acid substitution is the main pathogenesis of most hemoglobin disorders. Here, the author used a new gene ontology technology to predict the molecular function and biological process of four important hemoglobin disorders with single substitution. The four studied important abnormal hemoglobins (Hb with single substitution included Hb S, Hb E, Hb C, and Hb J-Baltimore. Using the GoFigure server, the molecular function and biological process in normal and abnormal hemoglobins was predicted. Compared with normal hemoglobin, all studied abnormal hemoglobins had the same function and biological process. This indicated that the overall function of oxygen transportation is not disturbed in the studied hemoglobin disorders. Clinical findings of oxygen depletion in abnormal hemoglobin should therefore be due to the other processes rather than genomics, proteomics, and expression levels.Keywords: hemoglobin, amino acid, substitution, function

  14. Ionic Liquids: An Environmentally Friendly Media for Nucleophilic Substitution Reactions

    International Nuclear Information System (INIS)

    Jorapur, Yogesh R.; Chi, Dae Yoon

    2006-01-01

    Ionic liquids are alternative reaction media of increasing interest and are regarded as an eco-friendly alternatives, of potential use in place of the volatile organic solvents typically used in current chemical processing methods. They are emerging as the smart and excellent solvents, which are made of positive and negative ions that they are liquids near room temperature. The nucleophilic substitution reaction is one of the important method for inserting functional groups into a carbon skeleton. Many nucleophilic substitution reactions have been found with enhanced reactivity and selectivity in ionic liquid. In this review, some recent interesting results of nucleophilic substitution reactions such as hydroxylations, ether cleavages, carbon-X (X = carbon, oxygen, nitrogen, fluorine) bond forming reactions, and ring opening of epoxides in ionic liquids are discussed

  15. Critical hematocrit and oxygen partial pressure in the beating heart of pigs.

    Science.gov (United States)

    Hiebl, B; Mrowietz, C; Ploetze, K; Matschke, K; Jung, F

    2010-12-01

    In cardiac surgery the substitution of lost blood volume by plasma substitutes is a common therapeutical approach. None of the currently available blood substitutes has a sufficient oxygen transport capacity. This can limit the functional integrity of the myocardium known as highly oxygen consumptive. The study was aimed to get information about the minimal hematocrit, also known as critical hematocrit (cHct), which guarantees a stable and adequate oxygen partial pressure in the myocardium (pO2). In adult female pigs (n=7) the hematocrit was reduced by isovolemic blood dilution with an intravenous infusion of isotonic 4% gelatine polysuccinate solution, The substituted blood volume ranged between 3000ml and 7780ml (mean: 5254±1672ml). In all animals the pO2 of the myocardium of the beating heart and of the resting skeletal muscle increased until blood dilution resulted in a Hct decrease down to 15%. Further blood dilution resulted in a decrease of the pO2. Only after the Hct was <10% the pO2 was lower than before blood dilution and accompanied by a lethal ischemia of the myocardium. These data indicate a cHct of about 10% in the pig animal model. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Eosin-sensitized photooxidation of substituted phenylalanines and tyrosines

    Energy Technology Data Exchange (ETDEWEB)

    Rizzuto, F.; Spikes, J.D.

    1977-01-01

    The cosin-sensitized photooxidation of tyrosine and a number of compounds related to tyrosine (substituted phenylalanines) was studied by steady-state kinetic and flash photolysis techniques. In particular, the role of the phenolic group and the amino and carboxyl groups of the alanyl side chain in the photooxidation mechanism was investigated in detail. Several relationships between substrate structure and susceptibility to photooxidation as well as effects of substrate structure on photooxidation mechanisms were found. For example, phenylalanine is not photooxidizable, but substitution of electron-donating (activating) groups such as -OH (as in tyrosine) or -NH/sub 2/ (as in p-aminophenylalanine) results in rapidly photooxidized derivatives. However, substituting deactivating groups such as -Cl (as in p-chlorophenylalanine) or weakly activating groups such as -OCH/sub 3/ (as in 4-methoxyphenylalanine) result in non-photooxidizable derivatives. Substitution of additional activating groups to the ring of hydroxy-substituted phenylalanines results in increased rates of photooxidation, whereas additional deactivating groups result in decreased photooxidation rates. The rate-determining step in the photooxidation mechanism is shown to be dependent on the presence and position of an electron-donating substituent on the benzenoid ring. Only minor involvement of the side chain amino and carboxyl groups was found. Both singlet oxygen and hydrogen abstraction mechanisms are involved in the eosin-sensitized photooxidation of hydroxy-substituted phenylalanines (e.g., tyrosine). The hydrogen abstraction mechanism probably predominates at both pH 8 and 11.

  17. Synthesis of Heteroaromatic Compounds by Oxidative Aromatization Using an Activated Carbon/Molecular Oxygen System

    Directory of Open Access Journals (Sweden)

    Masahiko Hayashi

    2009-08-01

    Full Text Available A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in the synthesis of 2-arylbenzazoles is also discussed. In the final section, we will disclose the efficient synthesis of substituted 9,10-anthracenes via oxidative aromatization.

  18. Effect of argon addition into oxygen atmosphere on YBCO thin films deposition

    International Nuclear Information System (INIS)

    Mozhaev, P. B.; Borisenko, I. V.; Ovsyannikov, G. A.; Kuehle, A.; Bindslev-Hansen, J.; Johannes, L.; Skov, J. L.

    2002-01-01

    Multicomponent nature of the YBa 2 Cu 3 O x (YBCO) high-temperature superconductor makes difficult fabrication of smooth thin films: every local deviation from stoichiometry can result in seeding of a non-superconducting oxide particle. High density of such particles on typical YBCO thin film surface, however, presumes overall non-stoichiometry of the film. Such an effect can result from (i) non-uniform material transport from target to substrate, and (ii) re-evaporation or re-sputtering from the growing film surface. The first reason is more usual for laser ablation deposition technique, the second is typical for long sputtering deposition processes. Substitution of oxygen with argon in the deposition atmosphere improves surface quality of YBCO thin films deposited both by laser ablation and DC-sputtering at high pressure techniques. In the first case, the ablated species are scattered different ways in the oxygen atmosphere. Addition of argon decreases the inelastic scattering of barium; the proper part of Ar in the deposition atmosphere makes scattering and, hence, transport of all atoms uniform. The YBCO films deposited by DC-sputtering at high pressure technique are Ba-deficient also, but the reason is re-sputtering of Ba from the growing film as a result of negative oxygen ions bombardment. Such bombardment can lead also to chemical interaction of the deposited material with the substrate, as in the case of deposition of YBCO thin film on the CeO 2 buffer layer on sapphire. Substitution of oxygen with argon not only suppresses ion bombardment of the film, but also increases discharge stability due to presence of positive Ar + ions. The limiting factor of argon substitution is sufficient oxygenation of the growing oxide film. When oxygen partial pressure is too small, the superconducting quality of the YBCO thin film decreases and such a decrease cannot be overcome by prolonged oxygenation after deposition. (Authors)

  19. Electrochemical behavior of meso-substituted iron porphyrins in alkaline aqueous media

    Science.gov (United States)

    Berezina, N. M.; Bazanov, M. I.; Maksimova, A. A.; Semeikin, A. S.

    2017-12-01

    The effect meso-substitution in iron porphyrin complexes has on their redox behavior in alkaline aqueous solutions is studied via cyclic voltammetry. The voltammetric features of the reduction of iron pyridylporphyrins suggest that the sites of electron transfer lie at the ligand, the metal ion, and the pyridyl moieties. The electron transfer reactions between the different forms of these compounds, including the oxygen reduction reaction they mediate, are outlined to show the sequence and potential ranges in which they occur in alkaline aqueous media. Under our experimental conditions, the iron porphyrins exist as μ-oxo dimmers whose activity for the electrocatalytic reduction of oxygen displays a considerable dependence on the nature of the substitutents and nitrogen isomerization (for pyridylporphyrins) and grows in the order (Fe( ms-Ph)4P)2O, (Fe[ ms-(Py-3)Ph3]P)2O, (Fe[ ms-(Py-4)4]P)2O, and (Fe[ ms-(Py-3)4]P)2O.

  20. Crystal structure details of La- and Bi-substituted hydroxyapatites: Evidence for LaO{sup +} and BiO{sup +} with a very short metal–oxygen bond

    Energy Technology Data Exchange (ETDEWEB)

    Kazin, Pavel E., E-mail: kazin@inorg.chem.msu.ru [Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation); Pogosova, Mariam A.; Trusov, Lev A.; Kolesnik, Irina V. [Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation); Magdysyuk, Oxana V.; Dinnebier, Robert E. [Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart (Germany)

    2016-05-15

    Crystal structures of substituted apatites with general formula Ca{sub 10−x}M{sub x}(PO{sub 4}){sub 6}(OH{sub 1−δ}){sub 2−x}O{sub x}, where M=La, Bi, 0≤x<2, were refined using high-resolution X-ray powder diffraction patterns. Individual positions for Ca{sup 2+} and M{sup 3+}-ions localized near Ca2-site were determined. The M{sup 3+}-ion was found shifted toward the hexagonal channel center with respect to the Ca{sup 2+}-ion, forming very short bond with the intrachannel O{sup 2−}, while leaving considerably longer distances to other oxygen atoms, which suggested the existence of a MO{sup +} ion. Distinct bands of stretching M–O modes were observed in the Raman and FT-IR spectra of the compounds. The bond lengths for BiO{sup +} and LaO{sup +} were estimated to be 2.05(1) and 2.09(1) Å correspondingly. The latter was almost 0.3 Å lower than the shortest La–O bond in La{sub 2}O{sub 3}. The realization of such a strong lanthanide–oxygen bond in a crystal lattice could provide a very high axial ligand field and might be implemented to develop high-energy-barrier single-molecule magnets as well as to tune properties of lanthanide-based luminophores. - Graphical abstract: A fragment of the La-for-Ca substituted apatite crystal structure focusing on the La–O bond. - Highlights: • Individual positions in the apatite crystal lattice for a doping atom (La, Bi) and Ca. • The doping atom shifts toward the center of the hexagonal channel. • BiO{sup +} and LaO{sup +} with estimated short bond lengths of 2.05 and 2.09 Å respectively.

  1. Hyperfine interactions associated with iron substitute superconducting oxides

    International Nuclear Information System (INIS)

    Ellis, D.E.; Dunlap, B.D.; Saitovitch, E.B.; Azevedo, I.S.; Scorzelli, R.B.; Kimball, C.W.

    1988-01-01

    Theoretical and experimental Moessbauer spectroscopy studies have been made concerning charge and spin densities and magnetic hyperfine fields (H hf in iron-substituted superconducting oxides. Calculations were carried out in the self-consistent-field embedded cluster model using local density theory (SCF-Xα) with a variational atomic orbital basis. Spectral densities and changes in charge and spin density were monitored around neighboring Cu sites, as well as Fe impurity site, in La 2 Cu 1-x Fe x O 4 and YBa 2 Cu 3-x Fe x O 7-y compounds. Moessbauer isomer shifts (IS), quadrupole splittings (QS) and H hf are obtained by fitting multiline models to the observed spectra and are compared with SCF-Xα results for specific lattice sites. The influence of oxygen vacancies and partial oxygen disorder is modelled and compared with the experimental data on variable oxygen content and disorder. (author)

  2. Synthesis, in vitro and in vivo antimalarial assessment of sulfide, sulfone and vinyl amide-substituted 1,2,4-trioxanes prepared via thiol-olefin co-oxygenation (TOCO) of allylic alcohols.

    Science.gov (United States)

    Amewu, Richard; Gibbons, Peter; Mukhtar, Amira; Stachulski, Andrew V; Ward, Stephen A; Hall, Charlotte; Rimmer, Karen; Davies, Jill; Vivas, Livia; Bacsa, John; Mercer, Amy E; Nixon, Gemma; Stocks, Paul A; O'Neill, Paul M

    2010-05-07

    Thiol-Olefin Co-Oxygenation (TOCO) methodology has been applied to the synthesis of a small library of weak base and polar 1,2,4-trioxanes. The 1,2,4-trioxane units synthesised exhibit remarkable stability as they survive base catalysed hydrolysis and mixed anhydride/amine coupling reactions. This unique stability feature has enabled a range of novel substitution patterns to be incorporated within the spiro 1,2,4-trioxane unit. Selected analogues express potent in vitro nM antimalarial activity, low cytotoxicity and oral activity in the Plasmodium berghei mouse model of malaria.

  3. Tailoring the Selectivity for Electrocatalytic Oxygen Evolution on Ruthenium Oxides by Zinc Substitution

    Czech Academy of Sciences Publication Activity Database

    Petrykin, Valery; Macounová, Kateřina; Shlyakhtin, O. A.; Krtil, Petr

    2010-01-01

    Roč. 49, č. 28 (2010), s. 4813-4815 ISSN 1433-7851 R&D Projects: GA AV ČR IAA400400906 Institutional research plan: CEZ:AV0Z40400503 Keywords : electrocatalysis * ruthenium oxides * zinc substitution Subject RIV: CG - Electrochemistry Impact factor: 12.730, year: 2010

  4. Anelastic relaxation peaks in single crystals of zirconium-oxygen alloys

    International Nuclear Information System (INIS)

    Ritchie, I.G.; Sprungmann, K.W.; Atrens, A.; Rosinger, H.E.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

    1977-01-01

    Relaxations of the compliances S 11 -S 12 and S 44 have been observed in single crystals of zirconium-oxygen alloys tested in flexure and in torsion respectively. The relaxations are attributed to the stress-induced reorientation of substitutional impurity atoms (s) paired with interstitial oxygen atoms (i). The results demonstrate that the jump of the interstitial parallel to the basal plane dominates in the reorientation of the s-i pair

  5. Oxygen nonstoichiometry and defects in Mn-doped Gd2Ti2O7+x

    International Nuclear Information System (INIS)

    Porat, O.; Tuller, H.L.

    1996-01-01

    The oxygen nonstoichiometry in Mn-doped Gd 2 Ti 2 O 7 , Gd 2 (Ti 0.975 Mn 0.025 ) 2 O 7+x , was measured electrochemically, as a function of temperature and oxygen partial pressure, with the aid of an oxygen titration cell. The analysis of the data shows that the defect equilibrium can be described by considering the dominant point defects to be neutral oxygen interstitials, doubly charged oxygen vacancies, and trivalent and quadrivalent Mn ions substituted in the Ti sites. The enthalpies for the formation of neutral oxygen interstitials and trivalent Mn are determined

  6. The nursing perspective on monitoring hemodynamics and oxygen transport.

    Science.gov (United States)

    Tucker, Dawn; Hazinski, Mary Fran

    2011-07-01

    Maintenance of adequate systemic oxygen delivery requires careful clinical assessment integrated with hemodynamic measurements and calculations to detect and treat conditions that may compromise oxygen delivery and lead to life-threatening shock, respiratory failure, or cardiac arrest. The bedside nurse constantly performs such assessments and measurements to detect subtle changes and trends in patient condition. The purpose of this editorial is to highlight nursing perspectives about the hemodynamic and oxygen transport monitoring systems summarized in the Pediatric Cardiac Intensive Care Society Evidence- Based Review and Consensus Statement on Monitoring of Hemodynamics and Oxygen Transport Balance. There is no substitute for the observations of a knowledgeable and experienced clinician who understands the patient's condition and potential causes of deterioration and is able to evaluate response to therapy.

  7. Molecular controls of the oxygenation and redox reactions of hemoglobin.

    Science.gov (United States)

    Bonaventura, Celia; Henkens, Robert; Alayash, Abdu I; Banerjee, Sambuddha; Crumbliss, Alvin L

    2013-06-10

    The broad classes of O(2)-binding proteins known as hemoglobins (Hbs) carry out oxygenation and redox functions that allow organisms with significantly different physiological demands to exist in a wide range of environments. This is aided by allosteric controls that modulate the protein's redox reactions as well as its O(2)-binding functions. The controls of Hb's redox reactions can differ appreciably from the molecular controls for Hb oxygenation and come into play in elegant mechanisms for dealing with nitrosative stress, in the malarial resistance conferred by sickle cell Hb, and in the as-yet unsuccessful designs for safe and effective blood substitutes. An important basic principle in consideration of Hb's redox reactions is the distinction between kinetic and thermodynamic reaction control. Clarification of these modes of control is critical to gaining an increased understanding of Hb-mediated oxidative processes and oxidative toxicity in vivo. This review addresses emerging concepts and some unresolved questions regarding the interplay between the oxygenation and oxidation reactions of structurally diverse Hbs, both within red blood cells and under acellular conditions. Developing methods that control Hb-mediated oxidative toxicity will be critical to the future development of Hb-based blood substitutes.

  8. Radiation sensitive polymers of oxygen-substituted maleimides and elements containing same

    International Nuclear Information System (INIS)

    Wilson, J.C.

    1977-01-01

    Radiation sensitive polymers comprising from about 1 to 100 mole % of a polymerized maleimide monomer consisting of a hydrocarbon group having from 2 to 20 carbon atoms, preferably a bridged hydrocarbon group having from 6 to 10 carbon atoms and from 0 to about 99 mole % of at least one additional polymerized ethylenically unsaturated monomer are described. The polymers are soluble in organic solvents, possess desirably high glass transition temperatures and are capable of undergoing a photochemical reaction to yield polymers having isocyanate and oxy-substituted cyclopropane moieties which are capable of crosslinking in the presence of active hydrogen-containing compounds. The polymers are useful in radiation sensitive compositions and elements containing same

  9. Perovskite-related oxide materials for oxygen-permeable electrochemical membrans

    OpenAIRE

    Naumovich, E. N.; Yaremchenko, A. A.; Viskup, A. P.; Kharton, V. V.

    2003-01-01

    This brief review is focused on the studies of mixed ionic-electronic conductors on the basis of lanthanum gallate doped with transition metal cations in the В sublattice. The substitution of gallium with iron, cobalt or nickel results in greater electronic conductivity, simultaneously keeping high level of the oxy-gen ionic transport. In particular, La0 90Sr0 10Ga0 65Ni0 20Mg0 1503d perovskite exhib-its attractive oxygen permeability, which is quite similar to that of La2Ni04- and (...

  10. Bulk manufacture of concentrated oxygen gas-filled microparticles for intravenous oxygen delivery.

    Science.gov (United States)

    Kheir, John N; Polizzotti, Brian D; Thomson, Lindsay M; O'Connell, Daniel W; Black, Katherine J; Lee, Robert W; Wilking, James N; Graham, Adam C; Bell, David C; McGowan, Francis X

    2013-08-01

    Self-assembling, concentrated, lipid-based oxygen microparticles (LOMs) have been developed to administer oxygen gas when injected intravenously, preventing organ injury and death from systemic hypoxemia in animal models. Distinct from blood substitutes, LOMs are a one-way oxygen carrier designed to rescue patients who experience life-threatening hypoxemia, as caused by airway obstruction or severe lung injury. Here, we describe methods to manufacture large quantities of LOMs using an in-line, recycling, high-shear homogenizer, which can create up to 4 liters of microparticle emulsion in 10 minutes, with particles containing a median diameter of 0.93 microns and 60 volume% of gas phase. Using this process, we screen 30 combinations of commonly used excipients for their ability to form stable LOMs. LOMs composed of DSPC and cholesterol in a 1:1 molar ratio are stable for a 100 day observation period, and the number of particles exceeding 10 microns in diameter does not increase over time. When mixed with blood in vitro, LOMs fully oxygenate blood within 3.95 seconds of contact, and do not cause hemolysis or complement activation. LOMs can be manufactured in bulk by high shear homogenization, and appear to have a stability and size profile which merit further testing. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Deuterium isotope fractionation between ortho-alkyl substituted phenols and t-butylthiol in oxygen bases

    International Nuclear Information System (INIS)

    Wawer, A.; Jelenska-Kazimierczuk, M.; Szydlowski, J.

    1998-01-01

    Equilibrium isotope effect in the exchange reaction of deuterium between phenol(P), 2-isopropyl phenol (IPP), 2,6-diisopropyl phenol (DIPP), 2,6-diterbutyl phenol (DTBP) and tertbutylthiol (TBT) has been studied in 296 K. The fractionation factors (α) have been measured in cyclohexane and carbon tetrachloride solutions and in a few oxygen bases: acetone, 1,4-dioxane, ethyl formate, ethyl ether, tetrahydrofurane, N,N-dimethylformamide, dimethylsulfoxide and hexamethylphosphoramide. Using chemical shifts of phenol OH protons, the thermodynamic parameters of complex formation with the oxygen bases have been determined. The experimental data show that lnα correlates with the formation enthalpy of the phenol-oxygen base complex in DIPP-TBT-base system but there is no simple correlation in IPP-TBT-base system. Furthermore, it was found that in DTBT-TBT-base system lnα depends linearly on the basicity of the solvent (DN parameters). On the other hand, lnα correlates with acidic parameters of the solvents (AN) in IPP-TBT-base and P-TBT-base systems. All above correlations are explained by taking into account two competition processes: self association of phenol molecules and their solvation by oxygen bases. (author)

  12. Carbon-hydrogen defects with a neighboring oxygen atom in n-type Si

    Science.gov (United States)

    Gwozdz, K.; Stübner, R.; Kolkovsky, Vl.; Weber, J.

    2017-07-01

    We report on the electrical activation of neutral carbon-oxygen complexes in Si by wet-chemical etching at room temperature. Two deep levels, E65 and E75, are observed by deep level transient spectroscopy in n-type Czochralski Si. The activation enthalpies of E65 and E75 are obtained as EC-0.11 eV (E65) and EC-0.13 eV (E75). The electric field dependence of their emission rates relates both levels to single acceptor states. From the analysis of the depth profiles, we conclude that the levels belong to two different defects, which contain only one hydrogen atom. A configuration is proposed, where the CH1BC defect, with hydrogen in the bond-centered position between neighboring C and Si atoms, is disturbed by interstitial oxygen in the second nearest neighbor position to substitutional carbon. The significant reduction of the CH1BC concentration in samples with high oxygen concentrations limits the use of this defect for the determination of low concentrations of substitutional carbon in Si samples.

  13. Fine structure study on low concentration zinc substituted hydroxyapatite nanoparticles

    International Nuclear Information System (INIS)

    Hu, Wei; Ma, Jun; Wang, Jianglin; Zhang, Shengmin

    2012-01-01

    The fine structure of zinc substituted hydroxyapatite was studied using experimental analysis and first-principles calculations. The synthetic hydroxyapatite nanoparticles containing low Zn concentration show rod-like morphology. The crystallite sizes and unit-cell volumes tended to decrease with the increased Zn concentration according to X-ray diffraction patterns. The Zn K-edge X-ray absorption spectra and fitting results suggest that the hydroxyapatite doped with 0.1 mole% zinc is different in the zinc coordination environments compared with that containing more zinc. The density function theory calculations were performed on zinc substituted hydroxyapatite. Two mechanisms included replacing calcium by zinc and inserting zinc along the hydroxyl column and were investigated, and the related substitution energies were calculated separately. It is found that the substitution energies are negative and lowest for inserting zinc between the two oxygen atoms along the hydroxyl column (c-axis). Combined with the spectral analysis, it is suggested that the inserting mechanism is favored for low concentration zinc substituted hydroxyapatite. Highlights: ► We investigate the fine structure of hydroxyapatite with low content of Zn. ► XANES spectra are similar but a little different at low zinc content. ► Zinc ions influence hydroxyapatite crystal formation and lattice parameters. ► Formation energies are calculated according to plane-wave density function theory. ► Low content of zinc prefers to locate at hydroxyl column in hydroxyapatite lattice.

  14. Ability of bacterial biphenyl dioxygenases from Burkholderia sp. LB400 and Comamonas testosteroni B-356 to catalyse oxygenation of ortho-hydroxychlorobiphenyls formed from PCBs by plants

    International Nuclear Information System (INIS)

    Francova, K.; Mackova, M.; Macek, T.; Sylvestre, M.

    2004-01-01

    Bacterial dioxygenases are useful in breakdown of PCB products associated with plants. - Capacity of enzymes of the biphenyl/chlorobiphenyl pathway, especially biphenyl dioxygenase (BPDO) of two polychlorinated biphenyls (PCB) degrading bacteria, Burkholderia sp. LB400 and Comamonas testosteroni B-356, to metabolize ortho-substituted hydroxybiphenyls was tested.,These compounds found among plant products of PCB metabolism, are carrying chlorine atoms on the hydroxyl-substituted ring. The abilities of His-tagged purified LB400 and B-356 BPDOs to catalyze the oxygenation of 2-hydroxy-3-chlorobiphenyl, 2-hydroxy-5-chlorobiphenyl and 2-hydroxy-3,5-dichlorobiphenyl were compared. Both enzyme preparations catalyzed the hydroxylation of the three chloro-hydroxybiphenyls on the non-substituted ring. Neither LB400 BPDO nor B-356 BPDO oxygenated the substituted ring of the ortho-hydroxylated biphenyl. The fact that metabolites generated by both enzymes were identical for all three hydroxychlorobiphenyls tested; exclude any other mode of attack of these compounds by LB400 BPDOs than the ortho-meta oxygenation

  15. Functional analysis of protein N-myristoylation: Metabolic labeling studies using three oxygen-substituted analogs of myristic acid and cultured mammalian cells provide evidence for protein-sequence-specific incorporation and analog-specific redistribution

    International Nuclear Information System (INIS)

    Johnson, D.R.; Heuckeroth, R.O.; Gordon, J.I.; Cox, A.D.; Solski, P.A.; Buss, J.E.; Devadas, B.; Adams, S.P.; Leimgruber, R.M.

    1990-01-01

    Covalent attachment of myristic acid (C14:0) to the NH 2 -terminal glycine residue of a number of cellular, viral, and oncogene-encoded proteins is essential for full expression of their biological function. Substitution of oxygen for methylene groups in this fatty acid does not produce a significant change in chain length or stereochemistry but does result in a reduction in hydrophobicity. These heteroatom-containing analogs serve as alternative substrates for mammalian myristoyl-CoA: protein N-myristoyltransferase and offer the opportunity to explore structure/function relationships of myristate in N-myristoyltransferase proteins. The authors have synthesized three tritiated analogs of myristate with oxygen substituted for methylene groups at C6, C11, and C13. Metabolic labeling studies were performed with these compounds and (i) a murine myocyte cell line (BC 3 H1), (ii) a rat fibroblast cell that produces p60 v-src (3Xsrc), or (iii) NIH 3T3 cells that have been engineered to express a fusion protein consisting of an 11-residue myristoylation signal from the Rasheed sarcoma virus (RaSV) gag protein linked to c-Ha-ras with a Cys → Ser-186 mutation. Two-dimensional gel electrophoresis of membrane and soluble fractions prepared from cell lysates revealed different patterns of incorporation of the analogs into cellular N-myristoyl proteins. The demonstration that these analogs differ in the extent to which they are incorporated and in their ability to cause redistribution of any single protein suggests that they may also have sufficient selectivity to be of potential therapeutic value

  16. Molecular Controls of the Oxygenation and Redox Reactions of Hemoglobin

    Science.gov (United States)

    Henkens, Robert; Alayash, Abdu I.; Banerjee, Sambuddha; Crumbliss, Alvin L.

    2013-01-01

    Abstract Significance: The broad classes of O2-binding proteins known as hemoglobins (Hbs) carry out oxygenation and redox functions that allow organisms with significantly different physiological demands to exist in a wide range of environments. This is aided by allosteric controls that modulate the protein's redox reactions as well as its O2-binding functions. Recent Advances: The controls of Hb's redox reactions can differ appreciably from the molecular controls for Hb oxygenation and come into play in elegant mechanisms for dealing with nitrosative stress, in the malarial resistance conferred by sickle cell Hb, and in the as-yet unsuccessful designs for safe and effective blood substitutes. Critical Issues: An important basic principle in consideration of Hb's redox reactions is the distinction between kinetic and thermodynamic reaction control. Clarification of these modes of control is critical to gaining an increased understanding of Hb-mediated oxidative processes and oxidative toxicity in vivo. Future Directions: This review addresses emerging concepts and some unresolved questions regarding the interplay between the oxygenation and oxidation reactions of structurally diverse Hbs, both within red blood cells and under acellular conditions. Developing methods that control Hb-mediated oxidative toxicity will be critical to the future development of Hb-based blood substitutes. Antioxid. Redox Signal. 18, 2298–2313. PMID:23198874

  17. Strontium influence on the oxygen electrocatalysis of La2−xSrxNiO4±δ (0.0 ≤ xSr ≤ 1.0) thin films

    KAUST Repository

    Lee, Dongkyu; Lee, Yueh-Lin; Grimaud, Alexis; Hong, Wesley T.; Biegalski, Michael D.; Morgan, Dane; Shao-Horn, Yang

    2014-01-01

    Substitution of lanthanum by strontium (Sr) in the A-site of cobalt-containing perovskites can greatly promote oxygen surface exchange kinetics at elevated temperatures. Little is known about the effect of A-site substitution on the oxygen electrocatalysis of Ruddlesden-Popper (RP) oxides. In this study, we report, for the first time, the growth and oxygen surface exchange kinetics of La2-xSrxNiO 4±δ (LSNO, 0.0 ≤ xSr ≤ 1.0) thin films grown on (001)cubic-Y2O3-stabilized ZrO 2 (YSZ) by pulsed laser deposition. High-resolution X-ray diffraction analysis revealed that the LSNO film orientation was changed gradually from the (100)tetra. (in-plane) to the (001)tetra. (out-of-plane) orientation in the RP structure with increasing Sr from La2NiO 4+δ (xSr = 0) to LaSrNiO4±δ (xSr = 1.0). Such a change in the LSNO film orientation was accompanied by reduction in the oxygen surface exchange kinetics by two orders of magnitude as shown from electrochemical impedance spectroscopy results. Density functional theory (DFT) calculations showed that Sr substitution could stabilize the (001)tetra. surface relative to the (100) tetra. surface and both Sr substitution and increasing (001) tetra. surface could greatly weaken adsorption of molecular oxygen in the La-La bridge sites in the RP structure, which can reduce oxygen surface exchange kinetics. This journal is © the Partner Organisations 2014.

  18. Oxygen Measurements in Liposome Encapsulated Hemoglobin

    Science.gov (United States)

    Phiri, Joshua Benjamin

    Liposome encapsulated hemoglobins (LEH's) are of current interest as blood substitutes. An analytical methodology for rapid non-invasive measurements of oxygen in artificial oxygen carriers is examined. High resolution optical absorption spectra are calculated by means of a one dimensional diffusion approximation. The encapsulated hemoglobin is prepared from fresh defibrinated bovine blood. Liposomes are prepared from hydrogenated soy phosphatidylcholine (HSPC), cholesterol and dicetylphosphate using a bath sonication method. An integrating sphere spectrophotometer is employed for diffuse optics measurements. Data is collected using an automated data acquisition system employing lock-in -amplifiers. The concentrations of hemoglobin derivatives are evaluated from the corresponding extinction coefficients using a numerical technique of singular value decomposition, and verification of the results is done using Monte Carlo simulations. In situ measurements are required for the determination of hemoglobin derivatives because most encapsulation methods invariably lead to the formation of methemoglobin, a nonfunctional form of hemoglobin. The methods employed in this work lead to high resolution absorption spectra of oxyhemoglobin and other derivatives in red blood cells and liposome encapsulated hemoglobin (LEH). The analysis using singular value decomposition method offers a quantitative means of calculating the fractions of oxyhemoglobin and other hemoglobin derivatives in LEH samples. The analytical methods developed in this work will become even more useful when production of LEH as a blood substitute is scaled up to large volumes.

  19. Quadruple labelled dual oxygen and pH-sensitive ratiometric nanosensors

    Directory of Open Access Journals (Sweden)

    Veeren M. Chauhan

    2016-05-01

    Full Text Available Nanosensors capable of simultaneously measuring dissolved oxygen concentrations from 0 to 100% saturation and pH over the full physiological range, from pH 3.5 to 7.5, that advance the methods towards understanding of key biological gradients, were synthesised. A library of water soluble oxygen-sensitive porphyrins, with three substituted charged functional groups and a chemically flexible carboxylate functional group were spectroscopically analysed to assess their sensitivity to changes in dissolved oxygen concentrations as free species in solution and in suspension as nanoparticle conjugates. A platinum cationic porphyrin was taken forward to fabricate ratiometric oxygen-sensitive nanosensors, using 5-(and-6-carboxytetramethylrhodamine (TAMRA as internal standard. In addition, quadruple labelled dual oxygen and pH-sensitive nanosensors were synthesised using the cationic Pt porphyrin, pH-sensitive fluorescein dyes, carboxyfluorescein (FAM and Oregon Green (OG, in a 1:1 ratio, and TAMRA. We envisage the dual oxygen and pH nanosensors will find broad utility in the characterisation of diverse microenvironments, where there are complex interactions between molecular oxygen and pH. Keywords: Fluorescent, Phosphorescent, Nanosensor, Oxygen, pH, Ratiometric, Platinum metalloporphyrin

  20. Maleimido substituted cyclotriphosphazene resins for fire and heat resistant composites

    Science.gov (United States)

    Kumar, D.; Fohlen, G. M.; Parker, J. A.

    1983-01-01

    A new class of fire- and heat-resistant matrix resins have been synthesized by the thermal polymerization of maleimido substituted phenoxycyclotriphosphazenes. The resins have exhibited a char yield of 82 percent at 800 C in nitrogen and 81 percent at 700 C in air. Graphite-fabric laminates based on a resin of this class have shown a limiting oxygen index of 100 percent even at 300 C. Details of the fabrication of the resins and the composites and testing procedures are discussed.

  1. Simple, heart-smart substitutions

    Science.gov (United States)

    Coronary artery disease - heart smart substitutions; Atherosclerosis - heart smart substitutions; Cholesterol - heart smart substitutions; Coronary heart disease - heart smart substitutions; Healthy diet - heart ...

  2. β-diketones containing oxygen atom in fluorinated radical

    International Nuclear Information System (INIS)

    Shivanyuk, A.F.; Kudryavtseva, L.S.; Lozinskij, M.O.; Neplyuev, V.M.; Fialkov, Yu.A.; Bratolyubova, A.G.

    1981-01-01

    The synthesis of a number of new aliphatic fluorinated β- diketones containing oxygen atom in fluorinated radical of linear or cyclic structure is described. The reaction of combination with aryldiazonium salts resulting in the formation of corresponding arylhydrazones of fluorinated triketones is studied. It is shown that as a result of arylhydrazone condensation with hydroxylamine, hydrazine and its substituted derivatives the fluorine-containing derivatives of isoxazol and pyrazol are formed [ru

  3. beta. -diketones containing oxygen atom in fluorinated radical

    Energy Technology Data Exchange (ETDEWEB)

    Shivanyuk, A.F.; Kudryavtseva, L.S.; Lozinskij, M.O.; Neplyuev, V.M.; Fialkov, Yu.A.; Bratolyubova, A.G. (AN Ukrainskoj SSR, Kiev. Inst. Organicheskoj Khimii)

    1981-10-01

    The synthesis of a number of new aliphatic fluorinated ..beta..-diketones containing oxygen atom in fluorinated radical of linear or cyclic structure is described. The reaction of combination with aryldiazonium salts resulting in the formation of corresponding arylhydrazones of fluorinated triketones is studied. It is shown that as a result of arylhydrazone condensation with hydroxylamine, hydrazine and its substituted derivatives the fluorine-containing derivatives of isoxazol and pyrazol are formed.

  4. Structural and electronic transformations in substituted La-Sr manganites depending on cations and oxygen content

    Science.gov (United States)

    Karpasyuk, Vladimir; Badelin, Alexey; Merkulov, Denis; Derzhavin, Igor; Estemirova, Svetlana

    2018-05-01

    In the present research experimental data are obtained for the Jahn-Teller O‧ phase formation, phase transformation "orthorhombic-rhombohedral structure" and the change of the conductance type in the systems of manganites La3+1-c+xSr2+c-xMn3+1-c-x-2γMn4+c+2γZn2+xO3+γ, La3+1-c-xSr2+c+xMn3+1-c-x-2γMn4+c+2γGe4+xO3+γ, La3+1-cSr2+cMn3+1-x-c-2γMn4+c+2γ(Zn2+0.5Ge4+0.5)xO3+γ, where Mn4+ ions concentration is independent of "x". Ceramic samples were sintered in air at 1473 K. As-sintered samples had an excess of oxygen content. In order to provide stoichiometric oxygen content, the samples were annealed at 1223 K and partial pressure of oxygen PO2 = 10-1 Pа. Structural characteristics of the O‧ phase were obtained. The position of the phase boundary "orthorhombic-rhombohedral structure" and the temperature of the conductance type change depending on the cation composition of manganites and oxygen content were determined. Possible approaches to the interpretation of experimental results were suggested.

  5. Growth, structural and magnetic characterization of Al-substituted barium hexaferrite single crystals

    International Nuclear Information System (INIS)

    Vinnik, D.A.; Zherebtsov, D.A.; Mashkovtseva, L.S.; Nemrava, S.; Bischoff, M.; Perov, N.S.; Semisalova, A.S.; Krivtsov, I.V.; Isaenko, L.I.; Mikhailov, G.G.; Niewa, R.

    2014-01-01

    Highlights: • Growth of large Al-substituted crystals BaFe 12−x Al x O 19. • Al-content controllable by flux composition. • Crystallographic site preference of Al unraveled. • Magnetic characterization depending on Al-content. - Abstract: Large single crystals of aluminum-substituted M-type barium hexaferrite BaFe 12−x Al x O 19 were obtained from carbonate flux. The Al content in the crystals can be controlled via the Al content of the flux up to x = 1.1 according to single crystal X-ray structure refinements. Al shows a distinct preference to substitute Fe on crystallographic sites with high coordination numbers by oxygen atoms, whereas no significant amounts of Al can be found on a tetrahedrally coordinated site. An increasing amount of the aluminum dopant results in a monotonous reduction of the Curie temperature from 440 to 415 °C and the saturation magnetization at room temperature from 68 to 57 emu/g for single crystal and from 61 to 53 emu/g for powder samples

  6. Replacement of Oxygen by Sulfur in Small Organic Molecules. 3. Theoretical Studies on the Tautomeric Equilibria of the 2OH and 4OH-Substituted Oxazole and Thiazole and the 3OH and 4OH-Substituted Isoxazole and Isothiazole in the Isolated State and in Solution

    Directory of Open Access Journals (Sweden)

    Peter I. Nagy

    2016-07-01

    Full Text Available This follow-up paper completes the author’s investigations to explore the in-solution structural preferences and relative free energies of all OH-substituted oxazole, thiazole, isoxazole, and isothiazole systems. The polarizable continuum dielectric solvent method calculations in the integral-equation formalism (IEF-PCM were performed at the DFT/B97D/aug-cc-pv(q+(dz level for the stable neutral tautomers with geometries optimized in dichloromethane and aqueous solution. With the exception of the predictions for the predominant tautomers of the 3OH isoxazole and isothiazole, the results of the IEF-PCM calculations for identifying the most stable tautomer of the given species in the two selected solvents agreed with those from experimental investigations. The calculations predict that the hydroxy proton, with the exception for the 4OH isoxazole and 4OH isothiazole, moves preferentially to the ring nitrogen or to a ring carbon atom in parallel with the development of a C=O group. The remaining, low-fraction OH tautomers will not be observable in the equilibrium compositions. Relative solvation free energies obtained by the free energy perturbation method implemented in Monte Carlo simulations are in moderate accord with the IEF-PCM results, but consideration of the ΔGsolv/MC values in calculating ΔGstot maintains the tautomeric preferences. It was revealed from the Monte Carlo solution structure analyses that the S atom is not a hydrogen-bond acceptor in any OH-substituted thiazole or isothiazole, and the OH-substituted isoxazole and oxazole ring oxygens may act as a weak hydrogen-bond acceptor at most. The molecules form 1.0−3.4 solute−water hydrogen bonds in generally unexplored numbers at some specific solute sites. Nonetheless, hydrogen-bond formation is favorable with the NH, C=O and OH groups.

  7. Influences of alloying elements and oxygen on the stability and elastic properties of Mg17Al12

    International Nuclear Information System (INIS)

    Dai, Jianhong; Song, Yan; Yang, Rui

    2014-01-01

    Highlights: • Most alloying elements stabilize Mg 17 Al 12 with negative occupation energy. • The alloying element and oxygen co-existed Mg 17 Al 12 are stable. • Strong bonding interactions existed between alloying element and host atoms. - Abstract: Influence of alloying elements (Ca, Mn, Ni, Cu, Zn, Zr, Sn, and La) and oxygen on stability and elastic properties of Mg 17 Al 12 has been studied by first principles total energy calculations. The occupation preferences of oxygen and alloying elements in Mg 17 Al 12 are identified. Ca, Zr, and La tend to substitute for Mg atoms, Zn, Cu, and Ni prefer to occupy Al site, and Mn and Sn show positive occupation energy for substituting both Mg and Al atoms. The impurity oxygen prefers to occupy interstitial sites surrounded by four Mg atoms regardless the presence of alloying elements in this system. Elastic constants were estimated to evaluate the mechanical stability of alloyed systems. The results show that alloys which own negative occupation energy also satisfy the mechanical stability criteria. Electronic structures were analyzed to clarify the intrinsic mechanisms of how alloying elements and oxygen influence the stability of Mg 17 Al 12 . The stabilization effect of alloying elements and oxygen was found to originate from the strong bonding interaction with the matrix

  8. Stability and electronic properties of oxygen-doped ZnS polytypes: DFTB study

    Science.gov (United States)

    Popov, Ilya S.; Vorokh, Andrey S.; Enyashin, Andrey N.

    2018-06-01

    Synthesis from aqueous solutions is an affordable method for fabrication of II-VI semiconductors. However, application of this method often imposes a disorder of crystal lattice, manifesting as a rich variety of polytypes arising from wurtzite and zinc blende phases. The origin of this disordering still remains debatable. Here, the influence of the most likely impurity at water environment - substitutional oxygen - on the polytypic equilibrium of zinc sulphide is studied by means of density-functional tight-binding method. According to calculations, the inclusion of such oxygen does not affect the polytypic equilibrium. Apart of thermodynamic stability, the electronic and elastic properties of ZnS polytypes are studied as the function of oxygen distribution.

  9. Study of Ti4+ substitution in ZrW2O8 negative thermal expansion materials

    International Nuclear Information System (INIS)

    Buysser, Klaartje de; Driessche, Isabel van; Putte, Bart van de; Schaubroeck, Joseph; Hoste, Serge

    2007-01-01

    Powder XRD-analysis and thermo-mechanical analysis on sintered TiO 2 -WO 3 -ZrO 2 mixtures revealed the formation of Zr 1-x Ti x W 2 O 8 solid solutions. A noticeable decrease in unit cell parameter 'a' and in the order-disorder transition temperature could be seen in the case of Zr 1-x Ti x W 2 O 8 solid solutions. Studies performed on other ZrW 2 O 8 solid solutions have attributed an increase in phase transition temperature to a decrease in free lattice volume, whereas a decrease in phase transition temperature was suggested to be due to the presence of a more disordered state. Our studies indicate that the phase transition temperature in our materials is strongly influenced by the bond dissociation energy of the substituting ion-oxygen bond. A decrease in bond strength may compensate for the effect of a decrease in lattice free volume, lowering the phase transition temperature as the degree of substitution by Ti 4+ increases. This hypothesis is proved by differential scanning calorimetry. - Graphical abstract: This study indicates that the phase transition temperature in our materials Zr 1-x Ti x W 2 O 8 is strongly influenced by the bond dissociation energy of the substituting ion-oxygen bond. A decrease in bond strength may compensate for the effect of a decrease in lattice-free volume, lowering the phase transition temperature

  10. Substituted Pyrazinecarboxamides: Synthesis and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Katarina Kralova

    2006-03-01

    Full Text Available Condensation of the corresponding chlorides of some substituted pyrazine-2-carboxylic acids (pyrazine-2-carboxylic acid, 6-chloropyrazine-2-carboxylic acid, 5-tert-butylpyrazine-2-carboxylic acid or 5-tert-butyl-6-chloropyrazine-2-carboxylic acid withvarious ring-substituted aminothiazoles or anilines yielded a series of amides. Thesyntheses, analytical and spectroscopic data of thirty newly prepared compounds arepresented. Structure-activity relationships between the chemical structures and the anti-mycobacterial, antifungal and photosynthesis-inhibiting activity of the evaluatedcompounds are discussed. 3,5-Bromo-4-hydroxyphenyl derivatives of substitutedpyrazinecarboxylic acid, 16-18, have shown the highest activity against Mycobacteriumtuberculosis H37Rv (54-72% inhibition. The highest antifungal effect againstTrichophyton mentagrophytes, the most susceptible fungal strain tested, was found for5-tert-butyl-6-chloro-N-(4-methyl-1,3-thiazol-2-ylpyrazine-2-carboxamide (8, MIC =31.25 μmol·mL-1. The most active inhibitors of oxygen evolution rate in spinachMolecules 2006, 11 243 chloroplasts were the compounds 5-tert-butyl-6-chloro-N-(5-bromo-2-hydroxyphenyl- pyrazine-2-carboxamide (27, IC50 = 41.9 μmol·L-1 and 5-tert-butyl-6-chloro-N-(1,3- thiazol-2-yl-pyrazine-2-carboxamide (4, IC50 = 49.5 μmol·L-1.

  11. Neutron diffraction study of Fe-substituted YBa2Cu3O7

    International Nuclear Information System (INIS)

    Balagurov, A.M.; Mironova, G.M.; Pajaczkowska, A.; Piechota, J.; Shimchak, Kh.

    1989-01-01

    Neutron diffraction spectra of YBa 2 (Cu 1-x Fe x )O 7-δ (0 2 planes were determined. It is significant that the doped iron atoms occupy both of the copper site. The substitution of Fe for Cu in (2q) site is proportional to the concentration of iron in the sample. For small x there are a considerable amount of vacancies (10%) in the Cu1 site, which disappear quickly if x increases. Therefore, a joint effect of Cu substitution and the filling in vacancies by Fe occures for the Cu1 site. The amount of oxygen in samples increases with x up to 7.06 for x=0.12. Any visible effect of location of Fe at the Ba site is absent, but we can not exclude it completely. 20 refs.; 4 figs.; 1 tab

  12. Atomic substitution in selected high-temperature superconductors: Elucidating the nature of Raman spectra excitations

    Science.gov (United States)

    Hewitt, Kevin Cecil

    2000-10-01

    In this thesis, the effects of atomic substitution on the vibrational and electronic excitations found in the Raman spectra of selected high-temperature superconductors (HTS) are studied. In particular, atomic and isotopic substitution methods have been used to determine the character of features observed in the Raman spectra of Bi2Sr2Ca n-1CunO2 n+4+delta (n = 1 - Bi2201, n = 2 - Bi2212) and YBa2Cu3O7-delta (Y123). In Bi2201, Pb substitution for Bi (and Sr) has led to the reduction and eventual removal of the structural modulation, characteristic of all members of the Bi-family of HTS. The high quality single crystals and our sensitive triple spectrometer enabled identification of a pair of low frequency modes. The modes are determined to arise from shear and compressional rigid-layer vibrations. The normal state of underdoped cuprates is characterized by a pseudogap of unknown origin. In crystals of underdoped Bi2212 a spectral peak found at 590 cm-1, previously attributed to the pairing of quasiparticles (above Tc) and hence to the formation of a normal state pseudogap, has been found to soften by 3.8% with oxygen isotope exchange. In addition, the feature is absent in fully oxygenated and yttrium underdoped crystals. In this study, the first of its kind on underdoped and isotope substituted Bi2212, the feature has been assigned to stretching vibrations of oxygen in the a-b plane. Bi2212 crystals with varying hole concentrations (0.07 Raman scattering experiments that sample the diagonal (B 2g) and principal axes (B1 g) of the BZ have led us to conclude that the superconducting gap possesses dx2-y2 symmetry, in the underdoped and overdoped regimes. It is found that the magnitude of the superconducting gap (Delta(k)) is sensitive to changes in p. Studies of the pair-breaking peak found in the B1g spectra allow us to conclude that the magnitude of the maximum gap (Deltamax) decreases monotonically with increasing hole doping, for p > 0.13. The pair

  13. Cost reduction in the cold: heat generated by terrestrial locomotion partly substitutes for thermoregulation costs in Knot Calidris canutus

    NARCIS (Netherlands)

    Bruinzeel, L.W.; Piersma, T.

    1998-01-01

    To test whether heat generated during locomotion substitutes for the thermoregulation cost, oxygen consumption of four post-absorptive temperate-wintering Knot Calidris canutus was measured at air temperatures of 25 degrees C (thermoneutral) and 10 degrees C (c. 10 degrees below the lower critical

  14. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Science.gov (United States)

    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 phenyl...

  15. Oxygen Non-Stoichiometry and Electrical Conductivity of La0.2Sr0.8Fe0.8B0.2O3 − δ, B = Fe, Ti, Ta

    DEFF Research Database (Denmark)

    Lohne, Ørjan Fossmark; Phung, Tan Nhut; Grande, Tor

    2014-01-01

    The oxygen non-stoichiometry was determined by coulometric titration for the perovskite oxides La0.2Sr0.8FeO3 − δ and La0.2Sr0.8Fe0.8B0.2O3 − δ (B = Ti4+ and Ta5+) in the temperature range 600 °C ⩽ T ⩽ 900 °C and the oxygen partial pressure range: 1⋅10-15≤po2≤0.209 atm. The non-stoichiometry (δ...... for the substituted materials. The electrical conductivity was measured at T = 900 °C in the oxygen partial pressure range: 1⋅10-17≤po2≤0.209 atm. The electrical conductivity and charge carrier mobility decrease upon 20% substitution of Fe roughly by a factor of 2, but do not show a significant dependence......) is observed to decrease with B-site substitution of Fe. The data can be well fitted with simple defect chemistry models. At low oxygen non-stoichiometry all compositions show a deviation from a localized electrons defect model. The standard and partial molar thermodynamic quantities were obtained...

  16. Band gap modification and ferroelectric properties of Bi0.5(Na,K0.5TiO3-based by Li substitution

    Directory of Open Access Journals (Sweden)

    Ngo Duc Quan

    2014-01-01

    Full Text Available We report on the reduction of band gap in Bi0.5(Na0.82-xLixK0.180.5(Ti0.95Sn0.05O3 from 2.99 eV to 2.84 eV due to the substitutions of Li+ ions to Na+ sites. In addition, the lithium substitution samples exhibit an increasing of the maximal polarizations from 21.8 to 25.7 μC/cm2. The polarization enhancement of ferroelectric and reduction of the band gaps are strongly related to the Li substitution concentration as evaluated via the electronegative between A-site and oxygen and tolerance factor. The results are promising for photovoltaic and photocatalytic applications.

  17. The effect of Ce ion substituted OMS-2 nanostructure in catalytic activity for benzene oxidation

    Science.gov (United States)

    Hou, Jingtao; Li, Yuanzhi; Mao, Mingyang; Zhao, Xiujian; Yue, Yuanzheng

    2014-11-01

    The nanostructure of Ce doped OMS-2 plays a very important role in its catalytic property. We demonstrate by density functional theory (DFT) calculations that the unique nanostructure of the Ce ion substituted OMS-2 with Mn vacancy in the framework is beneficial for the improvement of catalytic activity, while the nanostructure of the Ce ion substituted OMS-2 without defects are detrimental to the catalytic activity. We establish a novel and facile strategy of synthesizing these unique Ce ion substituted OMS-2 nanostructure with Mn vacancies in the framework by hydrothermal redox reaction between Ce(NO3)3 and KMnO4 with KMnO4/Ce(NO3)3 at a molar ratio of 3 : 1 at 120 °C. Compared to pure OMS-2, the produced catalyst of Ce ion substituted OMS-2 ultrathin nanorods exhibits an enormous enhancement in the catalytic activity for benzene oxidation, which is evidenced by a significant decrease (ΔT50 = 100 °C, ΔT90 = 129 °C) in the reaction temperature of T50 and T90 (corresponding to the benzene conversion = 50% and 90%), which is considerably more efficient than the expensive supported noble metal catalyst (Pt/Al2O3). We combine both theoretical and experimental evidence to provide a new physical insight into the significant effect due to the defects induced by the Ce ion substitution on the catalytic activity of OMS-2. The formation of unique Ce ion substituted OMS-2 nanostructure with Mn vacancies in the framework leads to a significant enhancement of the lattice oxygen activity, thus tremendously increasing the catalytic activity.The nanostructure of Ce doped OMS-2 plays a very important role in its catalytic property. We demonstrate by density functional theory (DFT) calculations that the unique nanostructure of the Ce ion substituted OMS-2 with Mn vacancy in the framework is beneficial for the improvement of catalytic activity, while the nanostructure of the Ce ion substituted OMS-2 without defects are detrimental to the catalytic activity. We establish a novel

  18. Thin Bioactive Zn Substituted Hydroxyapatite Coating Deposited on Ultrafine Grained Titanium Substrate: Structure Analysis

    Science.gov (United States)

    Prosolov, Konstantin A.; Belyavskaya, Olga A.; Muehle, Uwe; Sharkeev, Yurii P.

    2018-02-01

    Nanocrystalline Zn substituted hydroxyapatite coatings were deposited by radiofrequency magnetron sputtering on the surface of ultrafine-grained titanium substrates. Cross section transmission electron microscopy provided information about the morphology and texture of the thin film while in-column energy dispersive X-ray analysis confirmed the presence of Zn in the coating. The Zn substituted hydroxyapatite coating was formed by an equiaxed polycrystalline grain structure. Effect of substrate crystallinity on the structure of deposited coating is discussed. An amorphous TiO2 sublayer of 8 nm thickness was detected in the interface between the polycrystalline coating and the Ti substrate. Its appearance in the amorphous state is attributed to prior to deposition etching of the substrate and subsequent condensation of oxygen-containing species sputtered from the target. This layer contributes to the high coating-to-substrate adhesion. The major P-O vibrational modes of high intensity were detected by Raman spectroscopy. The Zn substituted hydroxyapatite could be a material of choice when antibacterial osteoconductive coating with a possibility of withstanding mechanical stress during implantation and service is needed.

  19. Substituted N-Phenylpyrazine-2-carboxamides, Their Synthesis and Evaluation as Herbicides and Abiotic Elicitors

    Directory of Open Access Journals (Sweden)

    Katarína Kráľová

    2007-12-01

    Full Text Available The condensation of substituted pyrazine-2-carboxylic acid chlorides with ring-substituted anilines yielded five substituted pyrazine-2-carboxylic acid amides. Thesynthesis, and analytical, lipophilicity and biological data of the newly synthesizedcompounds are presented in this paper. The photosynthesis inhibition, antialgal activityand the effect of a series of pyrazine derivatives as abiotic elicitors on the accumulation offlavonoids in a callus culture of Ononis arvensis (L. were investigated. The most activeinhibitor of the oxygen evolution rate in spinach chloroplasts was 6-chloro-pyrazine-2-carboxylic acid (3-iodo-4-methylphenyl-amide (2, IC50 = 51.0 μmol·L-1. The highestreduction of chlorophyll content in Chlorella vulgaris was found for 5-tert-butyl-N-(4-chloro-3-methylphenyl-pyrazine-2-carboxamide (3, IC50 = 44.0 μmol·L-1. The maximalflavonoid production (about 900% was reached after a twelve-hour elicitation processwith 6-chloropyrazine-2-carboxylic acid (3-iodo-4-methylphenyl-amide (2.

  20. Thin Bioactive Zn Substituted Hydroxyapatite Coating Deposited on Ultrafine-Grained Titanium Substrate: Structure Analysis

    Directory of Open Access Journals (Sweden)

    Konstantin A. Prosolov

    2018-02-01

    Full Text Available Nanocrystalline Zn-substituted hydroxyapatite coatings were deposited by radiofrequency magnetron sputtering on the surface of ultrafine-grained titanium substrates. Cross-section transmission electron microscopy provided information about the morphology and texture of the thin film while in-column energy dispersive X-ray analysis confirmed the presence of Zn in the coating. The Zn-substituted hydroxyapatite coating was formed by an equiaxed polycrystalline grain structure. Effect of substrate crystallinity on the structure of deposited coating is discussed. An amorphous TiO2 sublayer of 8-nm thickness was detected in the interface between the polycrystalline coating and the Ti substrate. Its appearance in the amorphous state is attributed to prior to deposition etching of the substrate and subsequent condensation of oxygen-containing species sputtered from the target. This layer contributes to the high coating-to-substrate adhesion. The major P–O vibrational modes of high intensity were detected by Raman spectroscopy. The Zn-substituted hydroxyapatite could be a material of choice when antibacterial osteoconductive coating with a possibility of withstanding mechanical stress during implantation and service is needed.

  1. Effects on artificial blood substitute (Fluosol-DA) by 60Co gamma-ray irradiation

    International Nuclear Information System (INIS)

    Hishikawa-Itoh, Youko; Ayakawa, Yoshio; Miyata, Nobuki

    1982-01-01

    It had been demonstrated the high oxygen solubility of perfluorochemical emulsion (Fluosol-DA), and Fluosol-DA is going to apply as an oxygen carrier, namely artificial blood substitutes for clinical application. There have been many reports on physical, chemical and biological aspects of Fluosol-DA, but not have been reported on irradiation effects. In this paper, we investigated the effects on Fluosol-DA by 60 Co γ-ray irradiation. 1. pH of Fluosol-DA was increased apparently, this effect was not by irradiation, but by thermal effect. 2. Optical density of Fluosol-DA at 620 nm which meaned an effect on particles of Fluosol-DA was not changed by γ-irradiation. 3. F - ion concentration of Fluosol-DA which meaned an effect on structure of perfluorochemical was not changed merkedly. 4. The solubility of oxygen of Fluosol-DA was slightly increased by γ-irradiation at 25 0 C and 11 0 C, but this effect was disregarded. These results suggested that 60 Co γ-irradiation did not effect on pH, size or aggregation of particles, release of F - ion from Fluosol-DA and solubility of oxygen of Fluosol-DA. (author)

  2. Mechanisms of Base Substitution Mutagenesis in Cancer Genomes

    Directory of Open Access Journals (Sweden)

    Albino Bacolla

    2014-03-01

    Full Text Available Cancer genome sequence data provide an invaluable resource for inferring the key mechanisms by which mutations arise in cancer cells, favoring their survival, proliferation and invasiveness. Here we examine recent advances in understanding the molecular mechanisms responsible for the predominant type of genetic alteration found in cancer cells, somatic single base substitutions (SBSs. Cytosine methylation, demethylation and deamination, charge transfer reactions in DNA, DNA replication timing, chromatin status and altered DNA proofreading activities are all now known to contribute to the mechanisms leading to base substitution mutagenesis. We review current hypotheses as to the major processes that give rise to SBSs and evaluate their relative relevance in the light of knowledge acquired from cancer genome sequencing projects and the study of base modifications, DNA repair and lesion bypass. Although gene expression data on APOBEC3B enzymes provide support for a role in cancer mutagenesis through U:G mismatch intermediates, the enzyme preference for single-stranded DNA may limit its activity genome-wide. For SBSs at both CG:CG and YC:GR sites, we outline evidence for a prominent role of damage by charge transfer reactions that follow interactions of the DNA with reactive oxygen species (ROS and other endogenous or exogenous electron-abstracting molecules.

  3. Mechanisms of base substitution mutagenesis in cancer genomes.

    Science.gov (United States)

    Bacolla, Albino; Cooper, David N; Vasquez, Karen M

    2014-03-05

    Cancer genome sequence data provide an invaluable resource for inferring the key mechanisms by which mutations arise in cancer cells, favoring their survival, proliferation and invasiveness. Here we examine recent advances in understanding the molecular mechanisms responsible for the predominant type of genetic alteration found in cancer cells, somatic single base substitutions (SBSs). Cytosine methylation, demethylation and deamination, charge transfer reactions in DNA, DNA replication timing, chromatin status and altered DNA proofreading activities are all now known to contribute to the mechanisms leading to base substitution mutagenesis. We review current hypotheses as to the major processes that give rise to SBSs and evaluate their relative relevance in the light of knowledge acquired from cancer genome sequencing projects and the study of base modifications, DNA repair and lesion bypass. Although gene expression data on APOBEC3B enzymes provide support for a role in cancer mutagenesis through U:G mismatch intermediates, the enzyme preference for single-stranded DNA may limit its activity genome-wide. For SBSs at both CG:CG and YC:GR sites, we outline evidence for a prominent role of damage by charge transfer reactions that follow interactions of the DNA with reactive oxygen species (ROS) and other endogenous or exogenous electron-abstracting molecules.

  4. [The substitution effect of leadership substitutes for transformational leadership in nursing organization].

    Science.gov (United States)

    Kim, Jeong-Hee

    2006-04-01

    This paper was conducted to examine the effects of transformational leadership behaviors, within the substitutes for leadership model (Kerr & Jermier, 1978). Data was collected from 181 staff nurses in 3 general hospitals, with self-reporting questionnaires (MLQ developed by Bass, rd-SLS developed by Podsakoff, et al., and MSQ developed by Weiss, et al.). Descriptive statistics, factor analysis, Cronbach's alpha and moderated regression analysis were used. 1) The transformational leader behaviors and substitutes for leadership each had correlations with job satisfaction. 2) The total amount of variance accounted for by the substitutes for leadership was substantially greater than by the transformational leadership behaviors. 3) Few of the substitutes variables moderated the relationships between the transformational leader behaviors and job satisfaction in a manner consistent with that specified by Howell, Dorfman, and Kerr (1986). The finding of this study suggest that leaders need to have a better understanding of those contextual variables that influence job satisfaction. Thus future research should focus attention on the moderating effects of substitutes, as well as the things that leaders can do to influence them. In addition, it may be good to examine the effects of substitutes on other criterion variables.

  5. Ultrasound Promoted Synthesis of Bis(substituted pyrazol-4-ylcarbonyl-Substituted Thioureas

    Directory of Open Access Journals (Sweden)

    Li Xiao

    2009-03-01

    Full Text Available A series of novel bis(substituted pyrazol-4-ylcarbonyl-substituted thioureas have been synthesized by the reactions of substituted pyrazol-4-ylcarbonyl isothiocyanates with different diamines under ultrasound irradiation and classical heating method at 20-25 °C. In general, substantial improvement in rates and modest yields increases were observed when reactions were carried out under sonication, compared with the classical heating method. The structures of these compounds have been elucidated by elemental and spectral (IR, 1H-NMR analysis.

  6. Density functional theory investigation of oxygen interaction with boron-doped graphite

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juan; Wang, Chen [State Key Lab of New Ceramic and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Liang, Tongxiang, E-mail: txliang@tsinghua.edu.cn [State Key Lab of New Ceramic and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Lai, Wensheng [Advanced Material Laboratory, School of Materials Science & Engineering, Tsinghua University, Beijing, 100084 (China)

    2016-12-30

    Highlights: • Density-functional approach is applied to study the interaction of oxygen with boron-doped graphite. • Adsorption and diffusion of oxygen atoms on boron doped graphite surfaces are studied. • Recombination of oxygen is investigated by ER and LH mechanisms. • Low boron concentration facilitates O{sub 2} formation while high boron loading inhibits the recombination. • The presence of B−B bonds due to boron accumulation makes it impossible for oxygen recombination. - Abstract: Boron inserted as impurity by substitution of carbon atoms in graphite is known to change (improve or deteriorate) oxidation resistance of nuclear graphite, but the reason for both catalytic and inhibiting oxidation is still uncertain. As a first step, this work is more specially devoted to the adsorption and diffusion of oxygen atoms on the surface and related to the problem of oxygen retention on the pure and boron-containing graphite surfaces. Adsorption energies and energy barriers associated to the diffusion for molecular oxygen recombination are calculated in the density functional theory framework. The existence of boron modifies the electronic structure of the surface, which results in an increase of the adsorption energy for O. However, low boron loading makes it easier for the recombination into molecular oxygen. For high boron concentration, it induces a better O retention capability in graphite because the presence of B-B bonds decreases recombination of the adsorbed oxygen atoms. A possible explanation for both catalytic and inhibiting effects of boron in graphite is proposed.

  7. Quantum design and synthesis of a boron-oxygen-yttrium phase

    International Nuclear Information System (INIS)

    Music, Denis; Chirita, Valeriu; Kreissig, Ulrich; Czigany, Zsolt; Schneider, Jochen M.; Helmersson, Ulf

    2003-01-01

    Ab initio calculations are used to design a crystalline boron-oxygen-yttrium (BOY) phase. The essential constituent is yttrium substituting for oxygen in the boron suboxide structure (BO 0.17 ) with Y/B and O/B ratios of 0.07. The calculations predict that the BOY phase is 0.36 eV/atom more stable than crystalline BO 0.17 and experiments confirm the formation of crystalline thin films. The BOY phase was synthesized with reactive rf magnetron sputtering and identified with x-ray and selected area electron diffraction. Films with Y/B ratios ranging from 0.10 to 0.32, as determined via elastic recoil detection analysis, were grown over a wide range of temperatures (300-600 deg. C) and found to withstand 1000 deg. C

  8. Substitution determination of Fmoc‐substituted resins at different wavelengths

    Science.gov (United States)

    Kley, Markus; Bächle, Dirk; Loidl, Günther; Meier, Thomas; Samson, Daniel

    2017-01-01

    In solid‐phase peptide synthesis, the nominal batch size is calculated using the starting resin substitution and the mass of the starting resin. The starting resin substitution constitutes the basis for the calculation of a whole set of important process parameters, such as the number of amino acid derivative equivalents. For Fmoc‐substituted resins, substitution determination is often performed by suspending the Fmoc‐protected starting resin in 20% (v/v) piperidine in DMF to generate the dibenzofulvene–piperidine adduct that is quantified by ultraviolet–visible spectroscopy. The spectrometric measurement is performed at the maximum absorption wavelength of the dibenzofulvene–piperidine adduct, that is, at 301.0 nm. The recorded absorption value, the resin weight and the volume are entered into an equation derived from Lambert–Beer's law, together with the substance‐specific molar absorption coefficient at 301.0 nm, in order to calculate the nominal substitution. To our knowledge, molar absorption coefficients between 7100 l mol−1 cm−1 and 8100 l mol−1 cm−1 have been reported for the dibenzofulvene–piperidine adduct at 301.0 nm. Depending on the applied value, the nominal batch size may differ up to 14%. In this publication, a determination of the molar absorption coefficients at 301.0 and 289.8 nm is reported. Furthermore, proof is given that by measuring the absorption at 289.8 nm the impact of wavelength accuracy is reduced. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. PMID:28635051

  9. Near-Infrared Phosphorus-Substituted Rhodamine with Emission Wavelength above 700 nm for Bioimaging.

    Science.gov (United States)

    Chai, Xiaoyun; Cui, Xiaoyan; Wang, Baogang; Yang, Fan; Cai, Yi; Wu, Qiuye; Wang, Ting

    2015-11-16

    Phosphorus has been successfully fused into a classic rhodamine framework, in which it replaces the bridging oxygen atom to give a series of phosphorus-substituted rhodamines (PRs). Because of the electron-accepting properties of the phosphorus moiety, which is due to effective σ*-π* interactions and strengthened by the inductivity of phosphine oxide, PR exhibits extraordinary long-wavelength fluorescence emission, elongating to the region above 700 nm, with bathochromic shifts of 140 and 40 nm relative to rhodamine and silicon-substituted rhodamine, respectively. Other advantageous properties of the rhodamine family, including high molar extinction coefficient, considerable quantum efficiency, high water solubility, pH-independent emission, great tolerance to photobleaching, and low cytotoxicity, stay intact in PR. Given these excellent properties, PR is desirable for NIR-fluorescence imaging in vivo. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Oxygen stabilized zirconium-vanadium-iron alloy

    International Nuclear Information System (INIS)

    Gruen, D.M.; Mendelsohn, M.H.

    1982-01-01

    An oxygen stabilized intermetallic compound having the formula (Zrsub(1-x)Tisub(x))sub(2-u)(Vsub(1-y)Fesub(y))Osub(z) where x = 0.0 to 0.9, y = 0.01 to 0.9, z = 0.25 to 0.5 and u = 0 to 1. The compound is capable of reversibly sorbing hydrogen at temperatures from -196 deg C to 200 deg C at pressures down to 10 - 6 torr. The compound is suitable for use as a hydrogen getter in low pressure, high temperature applications such as magnetic confinement fusion devices, and the iron content may be substituted by nickel, cobalt or manganese. (author)

  11. Oxygen stabilized zirconium-vanadium-iron alloy

    International Nuclear Information System (INIS)

    Gruen, D.M.; Mendelsohn, M.H.

    1982-01-01

    An oxygen stabilized intermetallic compound having the formula (Zrsub(1-x)Tisub(x))sub(2-u)(Vsub(1-y)Fesub(y))Osub(z) where x=0.0 to 0.9, y=0.01 to 0.9, z=0.25 to 0.5 and u=0 to 1. The compound is capable of reversibly sorbing hydrogen at temperatures from -196 0 C to 200 0 C at pressures down to 10 - 6 torr. The compound is suitable for use as a hydrogen getter in low pressure, high temperature applications such as magnetic confinement fusion devices, and the iron content may be substituted by nickel, cobalt or manganese. (author)

  12. The structural studies of vanadium substituted lithium-bismuth-boro-tellurite glass

    Science.gov (United States)

    Madhu, A.; Eraiah, B.

    2018-05-01

    The structural studies of vanadium substituted lithium-bismuth-boro-tellurite glass is successfully prepared and certain analysis like XRD,FTIR,DTA/TGA with density, molar volume are done. The amorphous phase has been identified based on X-ray diffraction analysis. The vanadium oxide plays the role as a glass-modifier and influences on BO3 ↔ BO4 conversion. The observed nonlinear variation in Tg with vanadium oxide increase, it reflects structural changes. The nonlinear variation of density and molar volume can be attributed to vanadium oxide incorporation have increased the number of Non-bridging oxygen (NBO'S).

  13. Substitution determination of Fmoc-substituted resins at different wavelengths.

    Science.gov (United States)

    Eissler, Stefan; Kley, Markus; Bächle, Dirk; Loidl, Günther; Meier, Thomas; Samson, Daniel

    2017-10-01

    In solid-phase peptide synthesis, the nominal batch size is calculated using the starting resin substitution and the mass of the starting resin. The starting resin substitution constitutes the basis for the calculation of a whole set of important process parameters, such as the number of amino acid derivative equivalents. For Fmoc-substituted resins, substitution determination is often performed by suspending the Fmoc-protected starting resin in 20% (v/v) piperidine in DMF to generate the dibenzofulvene-piperidine adduct that is quantified by ultraviolet-visible spectroscopy. The spectrometric measurement is performed at the maximum absorption wavelength of the dibenzofulvene-piperidine adduct, that is, at 301.0 nm. The recorded absorption value, the resin weight and the volume are entered into an equation derived from Lambert-Beer's law, together with the substance-specific molar absorption coefficient at 301.0 nm, in order to calculate the nominal substitution. To our knowledge, molar absorption coefficients between 7100 l mol -1  cm -1 and 8100 l mol -1  cm -1 have been reported for the dibenzofulvene-piperidine adduct at 301.0 nm. Depending on the applied value, the nominal batch size may differ up to 14%. In this publication, a determination of the molar absorption coefficients at 301.0 and 289.8 nm is reported. Furthermore, proof is given that by measuring the absorption at 289.8 nm the impact of wavelength accuracy is reduced. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd.

  14. Electricity/oil substitution

    International Nuclear Information System (INIS)

    Melvin, J.G.

    1980-09-01

    The extent to which electricity could substitute for imported oil in Canada is assessed and it is concluded that the bulk of projected oil imports could be displaced. This substitution of electricity for oil could be largely completed within two decades, with existing technology, using Canadian resources. The substitution of electricity for imported oil would result in relatively low energy costs and would stimulate economic growth. Energy self-sufficiency through the substitution of electricity for oil is uniquely a Canadian option; it is not open to other industrial countries. The option exists because of Canada's resources of oil sands for essential liquid fuels, hydraulic and nuclear electrical potential, and natural gas as an interim source of energy. While other countries face an energy crisis due to declining supplies of oil, Canada faces opportunities. The policies of Federal and Provincial governments, as perceived by individual decision makers, will have a major influence on Canada's ability to realize opportunities. (auth)

  15. Investigation of Structural, Morphological, Magnetic Properties and Biomedical applications of Cu2+ Substituted Uncoated Cobalt Ferrite Nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Margabandhu

    Full Text Available ABSTRACT In the present work, Cu2+ substituted cobalt ferrite (Co1-xCuxFe2O4, x = 0, 0.3, 0.5, 0.7 and 1 magnetic nanopowders were synthesized via chemical co-precipitation method. The prepared powders were investigated by various characterization methods such as X-ray diffraction analysis (XRD, scanning electron microscope analysis (SEM, vibrating sample magnetometer analysis (VSM and fourier transform infrared spectroscopy analysis (FTIR. The XRD analysis reveals that the synthesized nanopowders possess single phase centred cubic spinel structure. The average crystallite size of the particles ranging from 27-49 nm was calculated by using Debye-scherrer formula. Magnetic properties of the synthesized magnetic nanoparticles are studied by using VSM. The VSM results shows the magnetic properties such as coercivity, magnetic retentivity decreases with increase in copper substitution whereas the saturation magnetization shows increment and decrement in accordance with Cu2+ substitution in cobalt ferrite nanoparticles. SEM analysis reveals the morphology of synthesized magnetic nanoparticles. FTIR spectra of Cu2+ substituted cobalt ferrite magnetic nanoparticles were recorded in the frequency range 4000-400cm-1. The spectrum shows the presence of water adsorption and metal oxygen bonds. The adhesion nature of Cu2+ substituted cobalt ferrite magnetic nanoparticles with bacteria in reviewed results indicates that the synthesized nanoparticles could be used in biotechnology and biomedical applications.

  16. Reaction mechanism of oxygen atoms with unsaturated hydrocarbons by the crossed molecular beams method

    Energy Technology Data Exchange (ETDEWEB)

    Buss, R.J.; Baseman, R.J.; Guozhong, H.; Lee, Y.T.

    1982-04-01

    From a series of studies of the reaction of oxygen atoms with unsaturated hydrocarbons using the crossed molecular beam method, the dominant reaction mechanisms were found to be the simple substitution reactions with oxygen atoms replacing H, Cl, Br atom or alkyl groups. Complication due to secondary reaction was avoided by carrying out experiments under single collisions and observing primary products directly. Primary products were identified by measuring the angular and velocity distributions of products at all the mass numbers which could be detected by the mass spectrometer, and from comparison of these distributions, applying the requirement of energy and momentum conservation.

  17. Reaction Mechanism of Oxygen Atoms with Unsaturated Hydrocarbons by the Crossed-Molecular-Beams Method

    Science.gov (United States)

    Buss, R. J.; Baseman, R. J.; Guozhong, H.; Lee, Y. T.

    1982-04-01

    From a series of studies of the reaction of oxygen atoms with unsaturated hydrocarbons using the crossed molecular beam method, the dominant reaction mechanisms were found to be the simple substitution reactions with oxygen atoms replacing H, Cl, Br atom or alkyl groups. Complication due to secondary reaction was avoided by carrying out experiments under single collisions and observing primary products directly. Primary products were identified by measuring the angular and velocity distributions of products at all the mass numbers which could be detected by the mass spectrometer, and from comparison of these distributions, applying the requirement of energy and momentum conservation.

  18. Radiation effects on the behavior of carbon and oxygen impurities and the role of Ge in Czochralski grown Si upon annealing

    International Nuclear Information System (INIS)

    Londos, C. A.; Andrianakis, A.; Emtsev, V.; Ohyama, H.

    2009-01-01

    The annealing behavior of the oxygen and carbon impurities in Czochralski grown silicon (Cz-Si) was investigated in electron- and neutron-irradiated materials. The irradiated samples were subjected to isochronal anneals of up to ∼1000 deg. C, and the evolution of oxygen and carbon concentrations was monitored by means of infrared spectroscopy from the amplitudes of the 1106 and 605 cm -1 bands of the two impurities correspondingly. It was found that the electron irradiation does not affect the temperature of annealing of oxygen, although in the neutron-irradiated samples the oxygen band begins to decay in the spectra at a lower temperature than that in the nonirradiated samples. This behavior could be determined by supersaturation of vacancies mainly liberated from disordered regions in the latter material. This assists the oxygen aggregation process. Regarding carbon evolution, it was found that in the irradiated samples the annealing out of the 605 cm -1 band occurs at a lower temperature than that of the nonirradiated samples. Prior to the onset of decay of the 605 cm -1 band an inverse annealing stage was observed in the irradiated samples, indicating partial restoration of substitutional carbon. The general behavior was discussed with respect to the supersaturation of intrinsic defects, mainly self-interstitials. As a result, large C N (Si I ) M complexes are formed. There are two processes running in parallel: the recovery of substitutional carbon from carbon-related defects and C N (Si I ) M complexes and the transformation of C N (Si I ) M complexes to SiC-based precipitates. Noticeably, in electron-irradiated Ge-doped Si the inverse annealing stage of substitutional carbon is suppressed. Furthermore, our results showed that the Ge doping of Cz-Si of up to 2x10 20 cm -3 does not practically affect the temperature at which oxygen and carbon are completely lost in irradiated Cz-Si:Ge.

  19. Native Alanine Substitution in the Glycine Hinge Modulates Conformational Flexibility of Heme Nitric Oxide/Oxygen (H-NOX) Sensing Proteins.

    Science.gov (United States)

    Hespen, Charles W; Bruegger, Joel J; Guo, Yirui; Marletta, Michael A

    2018-06-15

    Heme nitric oxide/oxygen sensing (H-NOX) domains are direct NO sensors that regulate a variety of biological functions in both bacteria and eukaryotes. Previous work on H-NOX proteins has shown that upon NO binding, a conformational change occurs along two glycine residues on adjacent helices (termed the glycine hinge). Despite the apparent importance of the glycine hinge, it is not fully conserved in all H-NOX domains. Several H-NOX sensors from the family Flavobacteriaceae contain a native alanine substitution in one of the hinge residues. In this work, the effect of the increased steric bulk within the Ala-Gly hinge on H-NOX function was investigated. The hinge in Kordia algicida OT-1 ( Ka H-NOX) is composed of A71 and G145. Ligand-binding properties and signaling function for this H-NOX were characterized. The variant A71G was designed to convert the hinge region of Ka H-NOX to the typical Gly-Gly motif. In activity assays with its cognate histidine kinase (HnoK), the wild type displayed increased signal specificity compared to A71G. Increasing titrations of unliganded A71G gradually inhibits HnoK autophosphorylation, while increasing titrations of unliganded wild type H-NOX does not inhibit HnoK. Crystal structures of both wild type and A71G Ka H-NOX were solved to 1.9 and 1.6 Å, respectively. Regions of H-NOX domains previously identified as involved in protein-protein interactions with HnoK display significantly higher b-factors in A71G compared to wild-type H-NOX. Both biochemical and structural data indicate that the hinge region controls overall conformational flexibility of the H-NOX, affecting NO complex formation and regulation of its HnoK.

  20. Preparation of a calcium-substituted copper-rich yttrium barium copper oxide superconductor from a spray-dried nitrate precursor

    International Nuclear Information System (INIS)

    Gyurov, G.; Khristova, I.; Peshev, P.; Abrashev, M.V.

    1993-01-01

    A calcium-substituted YBa 2 Cu 4 O 8 (1-2-4) high-temperature superconductor is synthesized from a precursor obtained by spray-drying of a nitrate solution containing the corresponding metals in a stoichiometric ratio. The synthesis takes place during one-stage heat-treatment of the precursor at 800 C in an oxygen flow under a pressure of 1 atm within a relatively short period of time, additives as well as intermediate grinding and pressing of the products being not needed. Measurements of the a.c. susceptibility have revealed a very sharp superconducting transition which is comparable with that of samples prepared under a high pressure. The transition in Ca-substituted YBa 2 Cu 4 O 8 occurs at a temperature by about 8 K higher than T c of the Ca-free phase. Raman spectra suggest that during the substitution calcium does not occupy barium positions in the YBa 2 Cu 4 O 8 lattice

  1. Hydroxylation of p-substituted phenols by tyrosinase: Further insight into the mechanism of tyrosinase activity

    International Nuclear Information System (INIS)

    Muñoz-Muñoz, Jose Luis; Berna, Jose; García-Molina, María del Mar; Garcia-Molina, Francisco; Garcia-Ruiz, Pedro Antonio; Varon, Ramon

    2012-01-01

    Highlights: ► The action the copper complexes and tyrosinase on phenols is equivalent. ► Isotope effect showed that nucleophilic attack to copper atom may be the slower step. ► The value of ρ (Hammett constant) supports an electrophilic aromatic substitution. ► Data obtained in steady state pH 7 conditions support the mechanism of Scheme 1SM. -- Abstract: A study of the monophenolase activity of tyrosinase by measuring the steady state rate with a group of p-substituted monophenols provides the following kinetic information: k cat m and the Michaelis constant, K M m . Analysis of these data taking into account chemical shifts of the carbon atom supporting the hydroxyl group (δ) and σ p + , enables a mechanism to be proposed for the transformation of monophenols into o-diphenols, in which the first step is a nucleophilic attack on the copper atom on the form E ox (attack of the oxygen of the hydroxyl group of C-1 on the copper atom) followed by an electrophilic attack (attack of the hydroperoxide group on the ortho position with respect to the hydroxyl group of the benzene ring, electrophilic aromatic substitution with a reaction constant ρ of −1.75). These steps show the same dependency on the electronic effect of the substituent groups in C-4. Furthermore, a study of a solvent deuterium isotope effect on the oxidation of monophenols by tyrosinase points to an appreciable isotopic effect. In a proton inventory study with a series of p-substituted phenols, the representation of k cat f n /k cat f 0 against n (atom fractions of deuterium), where k cat f n is the catalytic constant for a molar fraction of deuterium (n) and k cat f 0 is the corresponding kinetic parameter in a water solution, was linear for all substrates. These results indicate that only one of the proton transfer processes from the hydroxyl groups involved the catalytic cycle is responsible for the isotope effects. We suggest that this step is the proton transfer from the hydroxyl group

  2. Approaches in Substitution of Organic Solvents

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    2000-01-01

    In substitution of harmful chemicals or products with less harmful or harmless ones, there are different approaches according to the different situations, the technical requirements to the substitutes, and the goals for the substitution. Three different cases are presented. The substitution process...

  3. Crystallographic and electrical properties of Pr substituted Gd-123 nanometre sized high temperature superconductors

    International Nuclear Information System (INIS)

    Huse, V.R.; Mote, V.D.; Shah, S.S.; Dole, B.N.; Purushotham, Y.; Dhar, S.K.

    2011-01-01

    The samples of Gd 1-x Pr x Ba 2 Cu 3 O 7-δ with compositions x = 0.0, 0.1 and 0.3 were prepared by ceramic route. The XRD study of all samples is carried out. The XRD studies of the samples prepared by ceramic route show GdPr-123 system have an orthorhombic perovskite structure. The lattice parameters, oxygen content, volume of unit cell, orthorhombic perovskite structure. The lattice parameters, oxygen content, volume of unit cell, orthorhombic distortion, hole concentration in CuO 2 plane and charge on Cu-O plane were evaluated using XRD data. It is found that the lattice parameters, volume of unit cell increase while oxygen content orthorhombic distortion, hole concentration (Psh) and average charge (p) decrease as doping percentage of Pr increases. The resistivity measurement shows the transition temperature decreases while transition width increases with increasing Pr concentration. The suppression of superconductivity may be due to reduction in hole concentration or magnetic pair breaking. We report such qualitative results of Pr substituted Gd-123 in this paper quantitatively. (author)

  4. Structure, stability, and thermomechanical properties of Ca-substituted Pr2NiO4 + δ

    Science.gov (United States)

    Pikalova, E. Yu.; Medvedev, D. A.; Khasanov, A. F.

    2017-04-01

    Ca-substituted layered nickelates with a general Pr2- x Ca x NiO4 + δ composition ( x = 0-0.7, Δ x = 0.1) were prepared in the present work and their structural and physic-chemical properties were investigated in order to select the most optimal materials, which can be used as cathodes for solid oxide fuel cells. With an increase in Ca content in Pr2- x Ca x NiO4 + δ the following tendencies were observed: (i) a decrease in the concentration of nonstoichiometric oxygen (δ), (ii) a decrease in the unit cell parameters and volume, (iii) stabilization of the tetragonal structure, (iv) a decrease of the thermal expansion coefficients, and (v) enchancement of thermodynamic stability and compatibility with selected oxygen- and proton-conducting electrolytes. The Pr1.9Ca0.1NiO4 + δ material, having highest δ value, departs from the general "properties-composition" dependences ascertained. This indicates that oxygen non-stoichiometry has determining influence on the functional properties of layered nickelates.

  5. Medicineringsfejl ved generisk substitution

    DEFF Research Database (Denmark)

    Rölfing, Jan

    2012-01-01

    Generic substitution is a major cause of medical mistakes in the general population. Danish legislation obligates pharmacies to substitute prescribed medicine with the cheapest equivalent formulation, despite variations in product name, packaging, shape and colour. Consequently, medical mistakes...... occur. Scientific evidence on the consequences of generic substitution is sparse. Call upon fellow health workers to report medical mistakes to the national entities and scientific peers, in order to increase awareness and scientific evidence about the problem....

  6. Solvent substitution

    International Nuclear Information System (INIS)

    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

  7. Band gap modification and ferroelectric properties of Bi{sub 0.5}(Na,K){sub 0.5}TiO{sub 3}-based by Li substitution

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Ngo Duc [Department of General Physics, School of Engineering Physics, Ha Noi University of Science and Technology, 1 Dai Co Viet road, Ha Noi (Viet Nam); International Training Institute for Materials Science, Hanoi University of Science and Technology, 1 Dai Co Viet road, Hanoi (Viet Nam); Hung, Vu Ngoc [International Training Institute for Materials Science, Hanoi University of Science and Technology, 1 Dai Co Viet road, Hanoi (Viet Nam); Quyet, Nguyen Van [Hanautech Co., Ltd., 832, Tamnip-dong, Yuseong-gu, Daejeon (Korea, Republic of); Chung, Hoang Vu [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet street, Hanoi (Viet Nam); Dung, Dang Duc, E-mail: dung.dangduc@hust.edu.vn [Department of General Physics, School of Engineering Physics, Ha Noi University of Science and Technology, 1 Dai Co Viet road, Ha Noi (Viet Nam)

    2014-01-15

    We report on the reduction of band gap in Bi{sub 0.5}(Na{sub 0.82-x}Li{sub x}K{sub 0.18}){sub 0.5}(Ti{sub 0.95}Sn{sub 0.05})O{sub 3} from 2.99 eV to 2.84 eV due to the substitutions of Li{sup +} ions to Na{sup +} sites. In addition, the lithium substitution samples exhibit an increasing of the maximal polarizations from 21.8 to 25.7 μC/cm{sup 2}. The polarization enhancement of ferroelectric and reduction of the band gaps are strongly related to the Li substitution concentration as evaluated via the electronegative between A-site and oxygen and tolerance factor. The results are promising for photovoltaic and photocatalytic applications.

  8. A determination of the oxygen non-stoichiometry of the oxygen storage materials LnBaMn2O5+δ (Ln=Gd, Pr)

    Science.gov (United States)

    Jeamjumnunja, Kannika; Gong, Wenquan; Makarenko, Tatyana; Jacobson, Allan J.

    2016-07-01

    The A-site ordered double-perovskite oxides, LnBaMn2O5+δ (Ln=Gd, Pr), were synthesized and investigated to understand the effect of A site cation substitution on the oxygen storage properties of these materials. The present results are compared with our previous data for YBaMn2O5+δ. The results clearly reveal that changing the Ln cation strongly influences the oxidation/reduction behavior of LnBaMn2O5+δ. Based on thermogravimetric analysis data, oxygen uptake begins at lower temperatures in both air and oxygen in compounds with Ln3+ ions larger than Y3+. These oxides exhibit almost complete and reversible oxygen uptake/release between fully-reduced LnBaMn2O5 and fully-oxidized LnBaMn2O6 during changes of the oxygen partial pressure between air and 1.99% H2/Ar. In addition, the oxygen non-stoichiometries of GdBaMn2O5+δ and PrBaMn2O5+δ were determined as a function of pO2 at 600, 650, 700 and 750 °C by Coulometric titration at near-equilibrium conditions. The results confirm that these materials have two distinct phases on oxidation/reduction with δ≈0, 0.5 and a third phase with a range of composition with an oxygen content (5+δ) approaching 6. The stabilities of the LnBaMn2O5+δ phases extend over a wide range of oxygen partial pressures (∼10-25≤pO2 (atm)≤∼1) depending on temperature. Isothermal experiments show that the larger the Ln3+ cation the lower pO2 for phase conversion. At some temperatures and pO2 conditions, the LnBaMn2O5+δ compounds are unstable with respect to decomposition to BaMnO3-δ and LnMnO3. This instability is more apparent in Coulometric titration experiments than in thermogravimetric analysis. The Coulometric titration experiments are necessarily slow in order to achieve equilibrium oxygen compositions.

  9. Effet de la substitution du cuivre par du lithium sur les proprietes de l'oxyde spinelle lithium(x)cuivre(y-x)cobalt(3-y)oxygen(4) etudie pour l'electrocatalyse de la reaction de degagement de l'oxygene en milieu alcalin

    Science.gov (United States)

    Fatih, Khalid

    L'electrolyse de l'eau demeure la seule technologie industrielle de generation de l'hydrogene et de l'oxygene tres purs sans rejet de CO2 dans l'atmosphere, ce qui le rend tres attrayant par rapport a la combustion de carburants fossiles qui provoque presentement de serieux problemes environnementaux. Dans le but d'ameliorer le rendement de ce procede, nous avons developpe de nouveaux materiaux d'anode peu couteux, a base de l'oxyde mixte CuyCo3-yO 4, qui possedent une cinetique rapide pour la reaction de degagement de l'oxygene (RDO). Cette reaction suscite un interet particulier en raison de la surtension d'activation relativement elevee a l'anode qui cause la principale perte de rendement du procede. Une etude systematique a ete effectuee sur la substitution du Cu par du Li (0 a 40%), afin d'elucider les proprietes electrocatalytiques des oxydes LixCuy-xCo3-yO4. Ces oxydes, prepares sous forme de poudres par decomposition thermique des nitrates precurseurs entre 300 et 500°C, ont montre (DRX et FTIR) une structure spinelle inverse non-stcechiometrique avec une diminution du volume de la maille cristalline. La surface specifique par BET est d'environ 6 m2 g-1. Le pcn, obtenu par titrage acido-basique, a indique une diminution de la force du lien M-OH avec le taux du Li dans l'oxyde. Les analyses par XPS, realisees sur des films d'oxyde prepares par nebulisation reactive sur un substrat lisse de nickel, revelent un enrichissement de la surface en Cu a partir de 30% Li, et la presence des cations de surface Co2+, Co3+, Cu +, Cu2+ et Cu3+. La concentration de ce dernier montre un maximum a 10 et 20% Li. Suite a la substitution du Cu par du Li, la compensation de la charge serait assuree principalement par la formation d'especes Cu3+ pour les oxydes contenant jusqu'a 20% Li, et par la formation d'especes Co3+ aux taux de substitution superieurs. Les micrographies MEB montrent une morphologie hemispherique des particules d'oxyde reparties uniformement sur le substrat

  10. 40 CFR Appendix D to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes

    Science.gov (United States)

    2010-07-01

    ... the following criteria, derived from Society of Automotive Engineers (SAE) standards and recommended... Substitutes] Application Substitute Decision Conditions Comments Electronics Cleaning w/CFC-113 and MCF HFC... Sector [Acceptable Subject to Narrowed Use Limits] Application Substitute Decision Comments Electronics...

  11. Optimal ordering quantities for substitutable deteriorating items under joint replenishment with cost of substitution

    Science.gov (United States)

    Mishra, Vinod Kumar

    2017-09-01

    In this paper we develop an inventory model, to determine the optimal ordering quantities, for a set of two substitutable deteriorating items. In this inventory model the inventory level of both items depleted due to demands and deterioration and when an item is out of stock, its demands are partially fulfilled by the other item and all unsatisfied demand is lost. Each substituted item incurs a cost of substitution and the demands and deterioration is considered to be deterministic and constant. Items are order jointly in each ordering cycle, to take the advantages of joint replenishment. The problem is formulated and a solution procedure is developed to determine the optimal ordering quantities that minimize the total inventory cost. We provide an extensive numerical and sensitivity analysis to illustrate the effect of different parameter on the model. The key observation on the basis of numerical analysis, there is substantial improvement in the optimal total cost of the inventory model with substitution over without substitution.

  12. Impact of arsenic/phosphorus substitution on the intrinsic conformational properties of the phosphodiester backbone of DNA investigated using ab initio quantum mechanical calculations.

    Science.gov (United States)

    Denning, Elizabeth J; Mackerell, Alexander D

    2011-04-20

    Deoxyribonucleic acid (DNA) is composed of five major elements carbon, hydrogen, nitrogen, oxygen, and phosphorus. The substitution of any of these elements in DNA would be anticipated to have major biological implications. However, recent studies have suggested that the substitution of arsenic into DNA (As-DNA) in bacteria may be possible. To help evaluate this possibility, ab initio quantum mechanical calculations are used to show that arsenodiester and phosphodiester linkages have similar geometric and conformational properties. Based on these results, it is suggested that the As-DNA will have similar conformational properties to phosphorus-based DNA, including the maintenance of base stacking.

  13. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Engineering glucose oxidase to minimize the influence of oxygen on sensor response

    International Nuclear Information System (INIS)

    Horaguchi, Yohei; Saito, Shoko; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

    2014-01-01

    Glucose oxidase (GOx) is an important industrial enzyme and is recognized as the gold standard for monitoring blood glucose. However, due to its inherent oxidase property, the presence of oxygen affects electrochemical measurements of venous blood glucose employing artificial electron mediators. We therefore attempted to engineer Penicillium amagasakiense-derived GOx into a dehydrogenase by focusing on the amino acid residues predicted to interact with oxygen. Our rational amino acid substitution approach resulted in the construction of the Ser114Ala/Phe355Leu mutant, which has an 11-fold decrease in oxidase activity and 2.8-fold increase in dehydrogenase activity compared with wild-type GOx. As a result, the dehydrogenase/oxidase activity ratio of the engineered enzyme was 32-fold greater than that of the wild-type enzyme. The enzyme sensor constructed with Ser114Ala/Phe355Leu was considerably less affected by oxygen than the wild-type GOx-based sensor at lower glucose concentrations

  15. Statistical Physics of Complex Substitutive Systems

    Science.gov (United States)

    Jin, Qing

    Diffusion processes are central to human interactions. Despite extensive studies that span multiple disciplines, our knowledge is limited to spreading processes in non-substitutive systems. Yet, a considerable number of ideas, products, and behaviors spread by substitution; to adopt a new one, agents must give up an existing one. This captures the spread of scientific constructs--forcing scientists to choose, for example, a deterministic or probabilistic worldview, as well as the adoption of durable items, such as mobile phones, cars, or homes. In this dissertation, I develop a statistical physics framework to describe, quantify, and understand substitutive systems. By empirically exploring three collected high-resolution datasets pertaining to such systems, I build a mechanistic model describing substitutions, which not only analytically predicts the universal macroscopic phenomenon discovered in the collected datasets, but also accurately captures the trajectories of individual items in a complex substitutive system, demonstrating a high degree of regularity and universality in substitutive systems. I also discuss the origins and insights of the parameters in the substitution model and possible generalization form of the mathematical framework. The systematical study of substitutive systems presented in this dissertation could potentially guide the understanding and prediction of all spreading phenomena driven by substitutions, from electric cars to scientific paradigms, and from renewable energy to new healthy habits.

  16. Atomic substitutions in synthetic apatite; Insights from solid-state NMR spectroscopy

    Science.gov (United States)

    Vaughn, John S.

    Apatite, Ca5(PO4)3X (where X = F, Cl, or OH), is a unique mineral group capable of atomic substitutions for cations and anions of varied size and charge. Accommodation of differing substituents requires some kind of structural adaptation, e.g. new atomic positions, vacancies, or coupled substitutions. These structural adaptations often give rise to important physicochemical properties relevant to a range of scientific disciplines. Examples include volatile trapping during apatite crystallization, substitution for large radionuclides for long-term storage of nuclear fission waste, substitution for fluoride to improve acid resistivity in dental enamel composed dominantly of hydroxylapatite, and the development of novel biomaterials with enhanced biocompatibility. Despite the importance and ubiquity of atomic substitutions in apatite materials, many of the mechanisms by which these reactions occur are poorly understood. Presence of substituents at dilute concentration and occupancy of disordered atomic positions hinder detection by bulk characterization methods such as X-ray diffraction (XRD) and infrared (IR) spectroscopy. Solid-state nuclear magnetic resonance (NMR) spectroscopy is an isotope-specific structural characterization technique that does not require ordered atomic arrangements, and is therefore well suited to investigate atomic substitutions and structural adaptations in apatite. In the present work, solid-state NMR is utilized to investigate structural adaptations in three different types of apatite materials; a series of near-binary F, Cl apatite, carbonate-hydroxylapatite compositions prepared under various synthesis conditions, and a heat-treated hydroxylapatite enriched in 17O. The results indicate that hydroxyl groups in low-H, near binary F,Cl apatite facilitate solid-solution between F and Cl via column reversals, which result in average hexagonal symmetry despite very dilute OH concentration ( 2 mol percent). In addition, 19F NMR spectra indicate

  17. Distorted chain sites for Co- and Fe-substituted YBa2Cu3O/sub 7-δ/

    International Nuclear Information System (INIS)

    Bridges, F.; Boyce, J.B.; Claeson, T.; Geballe, T.H.; Tarascon, J.M.; Xerox Palo Alto Research Center, Palo Alto, California 94304; Physics Department, Chalmers University of Technology, S-41296 Gothenburg, Sweden; Department of Applied Physics, Stanford University, Stanford, California 94305; Bell Communications Research Laboratory, Red Bank, New Jersey 07701)

    1989-01-01

    We present x-ray-absorption fine-structure (XAFS) measurements for a series of Co- and Fe-substituted samples of YBa 2 Cu 3 O/sub 7-δ/(Y-Ba-Cu-O). Our analysis of the first- and second-neighbor environments indicates that the Co atoms primarily replace the Cu in the chain sites, the Cu(1) atoms, in Y-Ba-Cu-O, but many of these Co(1) sites and their neighboring oxygen sites are highly distorted. The first-neighbor Co-O peak consists of approximately 3.5 oxygen at 1.8 A and approximately 1.3 oxygen at 2.4 A, while the second-neighbor multipeak in the XAFS data is unexpectedly low in amplitude. Structure in this peak is inconsistent with a simple Gaussian broadening and indicates that several Co(1)-Ba distances exist. We propose an aggregation of the Co atoms into distorted, zigzag chains along the directions, with some of the Co displaced off center by approximately 0.4 A along a perpendicular direction. This model is consistent with the second-neighbor XAFS data, provides an explanation for the tetragonal structure via twinning on a microscopic scale, and accommodates excess oxygen within the Co chains. The Fe data suggest that similar chains also exist in the Fe-substituted samples. There are, however, some differences between the local environments of the Fe and Co. The primary difference is that a small but significant number of Fe atoms occupy the Cu(2) plane sites while no appreciable number of Co atoms are found on the Cu(2) sites in the more dilute samples. Finally, near-edge measurements on the Co and Fe K-absorption edges indicate that the valence is primarily +3, but a mixture of valences exists. For Co the edge position corresponds to a mixture of +2 and +3 valences, while Fe exists in a mixture of +2, +3, and +4 states

  18. Growth and properties of oxygen- and ion-doped Bi2Sr2CaCu2O8+δ single crystals

    International Nuclear Information System (INIS)

    Mitzi, D.B.; Lombardo, L.W.; Kapitulnik, A.; Laderman, S.S.; Jacowitz, R.D.

    1990-01-01

    A directional solidification method for growing large single crystals in the Bi 2 Sr 2 CaCu 2 O 8+δ system is reported. Ion doping, with replacement of La for Sr and Y for Ca, as well as oxygen doping in these crystals has been explored. Doped and undoped crystals have been characterized using microprobe analysis, x-ray diffraction, thermogravimetric analysis, and magnetic and Hall measurements. Ion doping results in little change of the superconducting transition for substitution levels below 20--25%, while beyond this level the Meissner signal broadens and the low-temperature Meissner signal decreases. Microprobe analysis and x-ray diffraction performed on these more highly substituted single crystals provide evidence for inhomogeneity and phase segregation into regions of distinct composition. Annealing unsubstituted crystals in increasing partial pressures of oxygen reversibly depresses the superconducting transition temperature from 90 (as made) to 77 K (oxygen pressure annealed), while the carrier concentrations, as determined from Hall effect measurements, increase from n=3.1(3)x10 21 cm -3 (0.34 holes per Cu site) to 4.6(3)x10 21 cm -3 (0.50 holes per Cu site)

  19. Hydroxylamine as an oxygen nucleophile: substitution of sulfonamide by a hydroxyl group in benzothiazole-2-sulfonamides

    NARCIS (Netherlands)

    Kamps, J.A.G.; Belle, R.; Mecinovic, J.

    2013-01-01

    Benzothiazole-2-sulfonamides react with an excess of hydroxylamine in aqueous solutions to form 2-hydroxybenzothiazole, sulfur dioxide, and the corresponding amine. Mechanistic studies that employ a combination of structure-reactivity relationships, oxygen labeling experiments, and (in)direct

  20. Pair Distribution Function Analysis of Structural Disorder by Nb5+ Inclusion in Ceria: Evidence for Enhanced Oxygen Storage Capacity from Under-Coordinated Oxide.

    Science.gov (United States)

    Hiley, Craig I; Playford, Helen Y; Fisher, Janet M; Felix, Noelia Cortes; Thompsett, David; Kashtiban, Reza J; Walton, Richard I

    2018-02-07

    Partial substitution of Ce 4+ by Nb 5+ is possible in CeO 2 by coinclusion of Na + to balance the charge, via hydrothermal synthesis in sodium hydroxide solution. Pair distribution function analysis using reverse Monte Carlo refinement reveals that the small pentavalent substituent resides in irregular coordination positions in an average fluorite lattice, displaced away from the ideal cubic coordination toward four oxygens. This results in under-coordinated oxygen, which explains significantly enhanced oxygen storage capacity of the materials of relevance to redox catalysis used in energy and environmental applications.

  1. Anaerobic biotransformation of roxarsone and related N-substituted phenylarsonic acids

    Science.gov (United States)

    Cortinas, I.; Field, J.A.; Kopplin, M.; Garbarino, J.R.; Gandolfi, A.J.; Sierra-Alvarez, R.

    2006-01-01

    Large quantities of arsenic are introduced into the environment through land application of poultry litter containing the organoarsenical feed additive roxarsone (3-nitro-4-hydroxyphenylarsonic acid). The objective of this study was to evaluate the bioconversion of roxarsone and related N-substituted phenylarsonic acid derivatives under anaerobic conditions. The results demonstrate that roxarsone is rapidly transformed in the absence of oxygen to the corresponding aromatic amine, 4-hydroxy-3-aminophenylarsonic acid (HAPA). The formation of HAPA is attributable to the facile reduction of the nitro group. Electron-donating substrates, such as hydrogen gas, glucose, and lactate, stimulated the rate of nitro group reduction, indicating a microbial role. During long-term incubations, HAPA and the closely related 4-aminophenylarsonic acid (4-APA) were slowly biologically eliminated by up to 99% under methanogenic and sulfate-reducing conditions, whereas little or no removal occurred in heat-killed inoculum controls. Arsenite and, to a lesser extent, arsenate were observed as products of the degradation. Freely soluble forms of the inorganic arsenical species accounted for 19-28% of the amino-substituted phenylarsonic acids removed. This constitutes the first report of a biologically catalyzed rupture of the phenylarsonic group under anaerobic conditions. ?? 2006 American Chemical Society.

  2. Biologic and synthetic skin substitutes: An overview.

    Science.gov (United States)

    Halim, Ahmad Sukari; Khoo, Teng Lye; Mohd Yussof, Shah Jumaat

    2010-09-01

    The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. Skin substitutes have important roles in the treatment of deep dermal and full thickness wounds of various aetiologies. At present, there is no ideal substitute in the market. Skin substitutes can be divided into two main classes, namely, biological and synthetic substitutes. The biological skin substitutes have a more intact extracellular matrix structure, while the synthetic skin substitutes can be synthesised on demand and can be modulated for specific purposes. Each class has its advantages and disadvantages. The biological skin substitutes may allow the construction of a more natural new dermis and allow excellent re-epithelialisation characteristics due to the presence of a basement membrane. Synthetic skin substitutes demonstrate the advantages of increase control over scaffold composition. The ultimate goal is to achieve an ideal skin substitute that provides an effective and scar-free wound healing.

  3. Biologic and synthetic skin substitutes: An overview

    Directory of Open Access Journals (Sweden)

    Halim Ahmad

    2010-10-01

    Full Text Available The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. Skin substitutes have important roles in the treatment of deep dermal and full thickness wounds of various aetiologies. At present, there is no ideal substitute in the market. Skin substitutes can be divided into two main classes, namely, biological and synthetic substitutes. The biological skin substitutes have a more intact extracellular matrix structure, while the synthetic skin substitutes can be synthesised on demand and can be modulated for specific purposes. Each class has its advantages and disadvantages. The biological skin substitutes may allow the construction of a more natural new dermis and allow excellent re-epithelialisation characteristics due to the presence of a basement membrane. Synthetic skin substitutes demonstrate the advantages of increase control over scaffold composition. The ultimate goal is to achieve an ideal skin substitute that provides an effective and scar-free wound healing.

  4. The effect of carbon and boron on the accumulation of vacancy-oxygen complexes in silicon

    International Nuclear Information System (INIS)

    Akhmetov, V.D.; Bolotov, V.V.

    1980-01-01

    By means of IR-absorption measurements the dose dependencies of the concentrations of vacancy-oxygen complexes (VO), interstitial oxygen atoms (Osub(I)), substitutional carbon atoms (Csub(S)) and interstitial carbon-oxygen complexes (Csub(I)Osub(I)) in n- and p-type silicon irradiated with 1.1 MeV electrons have been investigated. The observed increase of the production rate of VO-complexes with the rise of carbon and boron atoms concentrations (these impurities act as sinks for silicon interstitial atoms) has been explained in terms of annihilation of the vacancies and interstitials on the oxygen atoms. The results obtained show that boron atoms are more effective sinks than carbon atoms for the interstitial silicon atoms. That seems to be connected not only with the higher probability of boron injection into interstitial position but also with the further capture of interstitial silicon atoms on the interstitial boron, i.e. with the interstitial cluster formation. (author)

  5. Bone substitute biomaterials

    CERN Document Server

    Mallick, K

    2014-01-01

    Bone substitute biomaterials are fundamental to the biomedical sector, and have recently benefitted from extensive research and technological advances aimed at minimizing failure rates and reducing the need for further surgery. This book reviews these developments, with a particular focus on the desirable properties for bone substitute materials and their potential to encourage bone repair and regeneration. Part I covers the principles of bone substitute biomaterials for medical applications. One chapter reviews the quantification of bone mechanics at the whole-bone, micro-scale, and non-scale levels, while others discuss biomineralization, osteoductivization, materials to fill bone defects, and bioresorbable materials. Part II focuses on biomaterials as scaffolds and implants, including multi-functional scaffolds, bioceramics, and titanium-based foams. Finally, Part III reviews further materials with the potential to encourage bone repair and regeneration, including cartilage grafts, chitosan, inorganic poly...

  6. Influence of oxygen incorporation on the defect structure of GaN microrods and nanowires. An XPS and CL study

    International Nuclear Information System (INIS)

    Guzmán, G; Herrera, M; Silva, R; Vásquez, G C; Maestre, D

    2016-01-01

    We report a cathodoluminescence (CL) and x-ray photoelectron spectroscopy (XPS) study of the influence of oxygen incorporation on the defect structure of GaN microrods and nanowires. The micro- and nanostructures were synthesized by a thermal evaporation method, which enables us to incorporate oxygen at different concentrations by varying the growth temperature. HR-TEM measurements revealed that oxygen generates stacking fault defects and edge dislocations along the GaN nanowires. Amorphous GaO x N y compounds were segregated on the surface of the nanowires. XPS, XRD and CL measurements suggests that the microrods and nanowires were composed of amorphous oxynitride compounds at their surface and GaN at their inner region. CL measurements revealed that the nanostructures generated an emission of 2.68 eV that increased in intensity proportionally to their oxygen content. We have attributed this emission to electronic transitions between donor substitutional-oxygen (O N ) and acceptor interstitial-oxygen (O i ) state levels. (paper)

  7. Hydroxylation of p-substituted phenols by tyrosinase: Further insight into the mechanism of tyrosinase activity

    Energy Technology Data Exchange (ETDEWEB)

    Munoz-Munoz, Jose Luis [GENZ - Grupo de Investigacion Enzimologia, Departamento de Bioquimica y Biologia Molecular-A, Facultad de Biologia, Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain); Berna, Jose [Grupo de Quimica Organica Sintetica, Departamento de Quimica Organica, Facultad de Quimica Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia (Spain); Garcia-Molina, Maria del Mar; Garcia-Molina, Francisco [GENZ - Grupo de Investigacion Enzimologia, Departamento de Bioquimica y Biologia Molecular-A, Facultad de Biologia, Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain); Garcia-Ruiz, Pedro Antonio [QCPAI - Grupo de Quimica de Carbohidratos, Polimeros y Aditivos Industriales, Departamento de Quimica Organica, Facultad de Quimica Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia (Spain); Varon, Ramon [Departamento de Quimica-Fisica, Escuela de Ingenieros Industriales de Albacete, Universidad de Castilla la Mancha, Avda. Espana s/n. Campus Universitario, E-02071 Albacete (Spain); and others

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer The action the copper complexes and tyrosinase on phenols is equivalent. Black-Right-Pointing-Pointer Isotope effect showed that nucleophilic attack to copper atom may be the slower step. Black-Right-Pointing-Pointer The value of {rho} (Hammett constant) supports an electrophilic aromatic substitution. Black-Right-Pointing-Pointer Data obtained in steady state pH 7 conditions support the mechanism of Scheme 1SM. -- Abstract: A study of the monophenolase activity of tyrosinase by measuring the steady state rate with a group of p-substituted monophenols provides the following kinetic information: k{sub cat}{sup m} and the Michaelis constant, K{sub M}{sup m}. Analysis of these data taking into account chemical shifts of the carbon atom supporting the hydroxyl group ({delta}) and {sigma}{sub p}{sup +}, enables a mechanism to be proposed for the transformation of monophenols into o-diphenols, in which the first step is a nucleophilic attack on the copper atom on the form E{sub ox} (attack of the oxygen of the hydroxyl group of C-1 on the copper atom) followed by an electrophilic attack (attack of the hydroperoxide group on the ortho position with respect to the hydroxyl group of the benzene ring, electrophilic aromatic substitution with a reaction constant {rho} of -1.75). These steps show the same dependency on the electronic effect of the substituent groups in C-4. Furthermore, a study of a solvent deuterium isotope effect on the oxidation of monophenols by tyrosinase points to an appreciable isotopic effect. In a proton inventory study with a series of p-substituted phenols, the representation of k{sub cat}{sup f{sub n}}/k{sub cat}{sup f{sub 0}} against n (atom fractions of deuterium), where k{sub cat}{sup f{sub n}} is the catalytic constant for a molar fraction of deuterium (n) and k{sub cat}{sup f{sub 0}} is the corresponding kinetic parameter in a water solution, was linear for all substrates. These results indicate that

  8. XPS Analysis of Ni and Oxygen in Single-Sintered SrTiO3 Multifunction Ceramic

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    XPS analyses have been performed to investigate the chemical conditions of Ni and oxygen on grain surfaces in single-sintered SrTiO3 capacitor-varistor ceramic doped with Nb2O5 and NiO. It is ascertained that Ni is in form of Ni2+ ions, which substitute for Ti4+ ions on grain surfaces during the oxidizing annealing. Moreover, it is confirmed that three kinds of chemically adsorbed oxygen such as O2-, O- and O~ are formed on grain surfaces. It is proposed that these behaviors contribute greatly to the generation of multiple types of grain boundary acceptor states in the ceramic.

  9. Electrochemical transformations of oxygen and the defect structure of solid solutions on the basis of alkaline earth metal ortho-vanadates

    International Nuclear Information System (INIS)

    Khodos, M.Ya.; Belysheva, G.M.; Brajnina, Kh.Z.

    1986-01-01

    Effect of iso- and heterovalent substitution in the structure of alkaline earth metal ortho-vanadates and synthesis conditions, simulating the definite type of their crystal lattice disordering, on the character of potentiodynamic anodic-cathodic curves has been investigated by the method of cyclic voltammetry. Correlation between signals observed and the defect structure of oxide compounds is refined. Oxygen chemisorption is shown to be determined by concentration of nonequilibrium oxygen vacancies, which formation is accompanied by appearance of quasi-free electrons

  10. Substituting freshwater: Can ocean desalination and water recycling capacities substitute for groundwater depletion in California?

    Science.gov (United States)

    Badiuzzaman, Pierre; McLaughlin, Eoin; McCauley, Darren

    2017-12-01

    While the sustainability of resource depletion is a longstanding environmental concern, wider attention has recently been given to growing water scarcity and groundwater depletion. This study seeks to test the substitutability assumption embedded in weak sustainability indicators using a case study of Californian water supply. The volume of groundwater depletion is used as a proxy for unsustainable water consumption, and defined by synthesising existing research estimates into low, medium and high depletion baselines. These are compared against projected water supply increases from ocean desalination and water recycling by 2035, to determine whether new, drought-proof water sources can substitute for currently unsustainable groundwater consumption. Results show that the maximum projected supply of new water, 2.47 million acre-feet per year (MAF/yr), is sufficient to meet low depletion estimates of 2.02 MAF/yr, but fails to come near the high depletion estimate of 3.44 MAF/yr. This does not necessarily indicate physical limitations of substitutability, but more so socio-economic limitations influenced by high comparative costs. By including capacities in demand-substitutability via urban water conservation, maximum predicted capacities reach 5.57 MAF/yr, indicating wide room for substitution. Based on these results, investment in social and institutional capital is an important factor to enhance demand-side substitutability of water and other natural resources, which has been somewhat neglected by the literature on the substitutability of natural resources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Extending the basic function of lattice oxygen in lepidocrocite titanate - The conversion of intercalated fatty acid to liquid hydrocarbon fuels

    Science.gov (United States)

    Maluangnont, Tosapol; Arsa, Pornanan; Sooknoi, Tawan

    2017-12-01

    We report herein the basicity of the external and internal lattice oxygen (OL) in lepidocrocite titanates with respect to CO2 and palmitic acid, respectively. Several compositions have been tested with different types of the metal M aliovalently (co)substituted for Ti, K0.8[MyTi2-y]O4 (M = Li, Mg, Fe, Co, Ni, Cu, Zn, Cu/Ni and Cu/Zn). The low CO2 desorption peak temperature (70-100 °C) suggests that the external OL sites are weakly basic similar to TiO2. However, the internal OL sites are sufficiently basic to deprotonate palmitic acid, forming the intercalated potassium palmitate at the interlayer spaces. The latter serves as a two-dimensional (2D) molecular reactor for the production of liquid hydrocarbon fuels via deoxygenation under atmospheric N2. A relationship has been observed between the yield of the liquid products vs the partial charge of the lattice oxygen (δO). Since the deoxygenation pathway is highly dependent on the metal substitution, the redox-active sites might also play some roles. The co-substituted K0.8[Cu0.2Ni0.2]Ti1.6O4 produced 68.0% yield of the liquid products, with 51% saturated and 15% unsaturated C15 hydrocarbons at 350 °C.

  12. 40 CFR 721.4420 - Substituted hydroxylamine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted hydroxylamine. 721.4420... Substances § 721.4420 Substituted hydroxylamine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted hydroxylamine (PMN P-84-492) is...

  13. Isothermal gas chromatography of short-lived Hf isotopes and element 104 in chlorinating, oxygen containing carrier gas

    Energy Technology Data Exchange (ETDEWEB)

    Jost, D.T.; Dressler, R.; Eichler, B.; Piguet, D.; Tuerler, A.; Gaeggeler, H.W.; Gaertner, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Grantz, M.; Huebener, S. [FZR (Germany); Buklanov, G.; Lebedev, V.; Timkhin, S.; Vedeneev, M.V.; Yakushev, A.; Zvara, I. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)

    1997-09-01

    Based on thermodynamic state functions retention times of Hf and element 104 were calculated in the case of the simple adsorption of the tetrachlorides and the case of a complex adsorption involving a substitution process with oxygen in the chlorinating gas. Preliminary results for {sup 261}104 and Hf are shown. (author) 1 fig., 1 tab., 3 refs.

  14. Lack of conventional oxygen-linked proton and anion binding sites does not impair allosteric regulation of oxygen binding in dwarf caiman hemoglobin

    Science.gov (United States)

    Fago, Angela; Malte, Hans; Storz, Jay F.; Gorr, Thomas A.

    2013-01-01

    In contrast to other vertebrate hemoglobins (Hbs) whose high intrinsic O2 affinities are reduced by red cell allosteric effectors (mainly protons, CO2, organic phosphates, and chloride ions), crocodilian Hbs exhibit low sensitivity to organic phosphates and high sensitivity to bicarbonate (HCO3−), which is believed to augment Hb-O2 unloading during diving and postprandial alkaline tides when blood HCO3− levels and metabolic rates increase. Examination of α- and β-globin amino acid sequences of dwarf caiman (Paleosuchus palpebrosus) revealed a unique combination of substitutions at key effector binding sites compared with other vertebrate and crocodilian Hbs: β82Lys→Gln, β143His→Val, and β146His→Tyr. These substitutions delete positive charges and, along with other distinctive changes in residue charge and polarity, may be expected to disrupt allosteric regulation of Hb-O2 affinity. Strikingly, however, P. palpebrosus Hb shows a strong Bohr effect, and marked deoxygenation-linked binding of organic phosphates (ATP and DPG) and CO2 as carbamate (contrasting with HCO3− binding in other crocodilians). Unlike other Hbs, it polymerizes to large complexes in the oxygenated state. The highly unusual properties of P. palpebrosus Hb align with a high content of His residues (potential sites for oxygenation-linked proton binding) and distinctive surface Cys residues that may form intermolecular disulfide bridges upon polymerization. On the basis of its singular properties, P. palpebrosus Hb provides a unique opportunity for studies on structure-function coupling and the evolution of compensatory mechanisms for maintaining tissue O2 delivery in Hbs that lack conventional effector-binding residues. PMID:23720132

  15. Substitutes for School Nurses in Illinois

    Science.gov (United States)

    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…

  16. Modeling competitive substitution in a polyelectrolyte complex

    International Nuclear Information System (INIS)

    Peng, B.; Muthukumar, M.

    2015-01-01

    We have simulated the invasion of a polyelectrolyte complex made of a polycation chain and a polyanion chain, by another longer polyanion chain, using the coarse-grained united atom model for the chains and the Langevin dynamics methodology. Our simulations reveal many intricate details of the substitution reaction in terms of conformational changes of the chains and competition between the invading chain and the chain being displaced for the common complementary chain. We show that the invading chain is required to be sufficiently longer than the chain being displaced for effecting the substitution. Yet, having the invading chain to be longer than a certain threshold value does not reduce the substitution time much further. While most of the simulations were carried out in salt-free conditions, we show that presence of salt facilitates the substitution reaction and reduces the substitution time. Analysis of our data shows that the dominant driving force for the substitution process involving polyelectrolytes lies in the release of counterions during the substitution

  17. Comparing the physical properties of Pr/Gd and Pr/Ce substitutions in Ru(Gd1.5Ce0.5)Sr2Cu2O10- δ

    Science.gov (United States)

    Khajehnezhad, A.; Nikseresht, N.; Hadipour, H.; Akhavan, M.

    2008-06-01

    We have compared the electrical and magnetic properties of Ru(Gd1.5- x Pr x )Ce0.5Sr2Cu2O10- δ (Pr/Gd samples) with x = 0.0, 0.01, 0.03, 0.033, 0.035, 0.04, 0.05, 0.06, 0.1 and RuGd1.5(Ce0.5- x Pr x ) Sr2 Cu2O10- δ (Pr/Ce samples) with x = 0.0, 0.01, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2 prepared by the standard solid-state reaction technique. We obtained the XRD patterns for different samples with various x. The lattice parameters versus x for different substitutions have been obtained from Rietveld analysis. To determine how the magnetic and superconducting properties of these layered cuprate systems can be affected by Pr substitution, the resistivity, and magnetoresistivity, with H ext varying from 0.0 to 15 kOe, have been measured at various temperatures. Superconducting transition temperature T c and magnetic transition T irr , have been obtained through resistivity and ac susceptibility measurements. The T c suppression due to Pr/Gd and Pr/Ce substitutions show competition between pair breaking by magnetic impurities, hole doping due to different valances of ions, difference in ionic radii, and oxygen stoichiometry. Pr/Gd substitution suppresses superconductivity more rapidly than for Pr/Ce, showing that the effect of hole doping and magnetic impurity pair breaking is stronger than the difference in ionic radii. In Pr/Gd substitution, the small difference between the ionic radii of Pr3+,4+ and Gd3+, and absorption of more oxygen due to the higher valence of Pr with respect to Gd, decreases the mean Ru-Ru distance, and as a result, the magnetic exchange interaction becomes stronger with the increase of x. However, Pr/Ce substitution has the opposite effect. The magnetic parameters such as H c , obtained through magnetization measurements versus applied magnetic field isotherm at 77 K and room temperatures, become stronger with x in Pr/Gd and weaker with x in Pr/Ce substitution.

  18. Synthesis, characterization, and subcellular localization studies of amino acid-substituted porphyrinic pigments

    Science.gov (United States)

    van Diggelen, Lisa; Khin, Hnin; Conner, Kip; Shao, Jenny; Sweezy, Margaretta; Jung, Anna H.; Isaac, Meden; Simonis, Ursula

    2009-06-01

    Stopping cancer in its path occurs when photosensitizers (PSs) induce apoptotic cell death after their exposure to light and the subsequent formation of reactive oxygen species. In pursuit of our hypothesis that mitochondrial localizing PSs will enhance the efficacy of the photosensitizing process in photodynamic therapy, since they provoke cell death by inducing apoptosis, we synthesized and characterized tetraphenylporphyrins (TPPs) that are substituted at the paraphenyl positions by two amino acids and two fluoro or hydroxyl groups, respectively. They were prepared according to the Lindsey-modified Adler-Longo methodology using trifluoromethanesulfonylchloride (CF3SO2Cl) as a catalyst instead of trifluoroacetic acid. The use of CF3SO2Cl yielded cleaner products in significantly higher yields. During the synthesis, not only the yields and work-up procedure of the TPPs were improved by using CF3SO2Cl as a catalyst, but also a better means of synthesizing the precursor dipyrromethanes was tested by using indium(III) chloride. Column chromatography, HPLC, and NMR spectroscopy were used to separate and characterize the di-amino acid-dihydroxy, or difluoro-substituted porphyrins and to ascertain their purity before subcellular localization studies were carried out. Studies using androgen-sensitive human prostate adenocarcinoma cells LNCaP revealed that certain amino acid substituted porphyrins that are positively charged in the slightly acidic medium of cancer cells are very useful in shedding light on the targets of TPPs in subcellular organelles of cancer cells. Although some of these compounds have properties of promising photosensitizers by revealing increased water solubility, acidic properties, and innate ability to provoke cell death by apoptosis, the cell killing efficacy of these TPPs is low. This correlates with their subcellular localization. The di-amino acid, di-hydroxy substituted TPPs localize mainly to the lysosomes, whereas the di-fluoro-substituted

  19. Substitutional analysis

    CERN Document Server

    Rutherford, Daniel Edwin

    2013-01-01

    Classic monograph, suitable for advanced undergraduates and graduate students. Topics include calculus of permutations and tableaux, semi-normal representation, orthogonal and natural representations, group characters, and substitutional equations. 1968 edition.

  20. Aryl substitution of pentacenes

    Directory of Open Access Journals (Sweden)

    Andreas R. Waterloo

    2014-07-01

    Full Text Available 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.

  1. Aryl substitution of pentacenes

    Science.gov (United States)

    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

  2. Computational study of cation substitutions in apatites

    International Nuclear Information System (INIS)

    Tamm, Toomas; Peld, Merike

    2006-01-01

    Density-functional theory plane-wave modeling of fluor- and hydroxyapatites has been performed, where one or two calcium ions per unit cell were replaced with cadmium or zinc cations. It was found that cadmium ions favor Ca(1) positions in fluorapatites and Ca(2) positions in hydroxyapatites, in agreement with experiment. A similar pattern is predicted for zinc substitutions. In the doubly substituted cases, where only hydroxyapatites were modeled, a preference for the substituting ions to be located in Ca(2) position was also observed. Displacement of the hydroxide ions from their symmetrical positions on the hexagonal axis can be used to explain the preferred configurations of substituting ions around the axis. -- Deformation of the hydroxide ion chain due to substitutions around the ion channel in substituted hydroxyapatites

  3. Optimal time for initiating extracorporeal membrane oxygenation.

    Science.gov (United States)

    Haile, Dawit T; Schears, Gregory J

    2009-09-01

    The technical evolution of extracorporeal membrane oxygenation (ECMO) coincides with the vast improvement in intensive care medicine of the past 4 decades. Extracorporeal circulatory technology substitutes for acutely failed cardiac or pulmonary function until these organs regain sustainable function through goal-oriented intensive care practice. The technology has been validated to improve survival in select patients who would otherwise have 100% mortality. This is by far the most complex life-sustaining technology employed and thus can contribute significant risks such that the decision to institute ECMO requires prompt risk and benefit analysis. Delaying the institution of ECMO may cause irreversible pulmonary and cardiac injuries in addition to other organs. Therefore, the optimal time of initiating ECMO support is crucial to the survival of a critically ill patient.

  4. Currency substitution in Eastern Europe

    NARCIS (Netherlands)

    van Aarle, B.; Budina, N.

    1995-01-01

    Monetary instability during the transition process from a command economy to a market economy has induced a considerable increase in currency substitution in Eastern Europe. Currency substitution itself affects monetary stability since it reduces the stability of velocity. This paper investigates

  5. Density functional study the interaction of oxygen molecule with defect sites of graphene

    Energy Technology Data Exchange (ETDEWEB)

    Qi Xuejun [State Key Laboratory of Coal Combustion, Wuhan 430074 (China); Guo Xin, E-mail: guoxin@mail.hust.edu.cn [State Key Laboratory of Coal Combustion, Wuhan 430074 (China); Zheng Chuguang [State Key Laboratory of Coal Combustion, Wuhan 430074 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer The defect sites existed on the graphite surface create active sites and enhance the reactivity of carbonaceous material. Black-Right-Pointing-Pointer Oxygen molecule more favor chemisorbed on the graphene surface contains defect sites than the perfect surface. Black-Right-Pointing-Pointer The single active oxygen atom adsorbed on the defect surfaces, it completely insert into the surface. - Abstract: The present article reports a theoretical study of oxygen interacted with graphene surface containing defect sites on the atomic level by employing the density functional theory combined with the graphene cluster model. It was founded that oxygen molecule prefers to be chemisorbed on the graphene surface containing defect sites compared to the perfect surface. The adsorption energy of O{sub 2} on the double defect site is about 2.5 times as large as that on the perfect graphene surface. Moreover, the oxygen molecule interacts with S-W defect site gives rise to stable epoxy structure, which pulling the carbon atom outward from the original site in the direction perpendicular to the surface. If the oxygen molecule is adsorbed on the single vacancy site, two C-O bonds are formed on the graphene surface. However, when the oxygen molecule is chemisorbed on the double vacancy site, the oxygen atoms substitute the missing carbon atom's position in the carbon plane and form a hexagonal structure on the graphene network. The results indicate that single active oxygen atom approaches the defect site, it's completely adsorbed in the plane and high energy is released. In all cases, the interaction of an oxygen atom with defect surface involves an exothermic process. The defect site creates active sites on the surface of graphene and produces catalytic effects during the process of oxidation of carbonaceous materials.

  6. Chitosan Dermal Substitute and Chitosan Skin Substitute Contribute to Accelerated Full-Thickness Wound Healing in Irradiated Rats

    Directory of Open Access Journals (Sweden)

    Abu Bakar Mohd Hilmi

    2013-01-01

    Full Text Available Wounds with full-thickness skin loss are commonly managed by skin grafting. In the absence of a graft, reepithelialization is imperfect and leads to increased scar formation. Biomaterials can alter wound healing so that it produces more regenerative tissue and fewer scars. This current study use the new chitosan based biomaterial in full-thickness wound with impaired healing on rat model. Wounds were evaluated after being treated with a chitosan dermal substitute, a chitosan skin substitute, or duoderm CGF. Wounds treated with the chitosan skin substitute showed the most re-epithelialization (33.2 ± 2.8%, longest epithelial tongue (1.62 ± 0.13 mm, and shortest migratory tongue distance (7.11 ± 0.25 mm. The scar size of wounds treated with the chitosan dermal substitute (0.13 ± 0.02 cm and chitosan skin substitute (0.16 ± 0.05 cm were significantly decreased (P<0.05 compared with duoderm (0.45 ± 0.11 cm. Human leukocyte antigen (HLA expression on days 7, 14, and 21 revealed the presence of human hair follicle stem cells and fibroblasts that were incorporated into and surviving in the irradiated wound. We have proven that a chitosan dermal substitute and chitosan skin substitute are suitable for wound healing in full-thickness wounds that are impaired due to radiation.

  7. Substitution between cars within the household

    DEFF Research Database (Denmark)

    De Borger, Bruno; Mulalic, Ismir; Rouwendal, Jan

    2016-01-01

    In this paper we study the demand for car kilometres in two-car households, focusing on the substitution between cars of different fuel efficiency in response to fuel price changes. We use a large sample of detailed Danish data on two-car households to estimate – for each car owned by the household...... – own and cross-price effects of increases in fuel costs per kilometre. The empirical results show that failure to capture substitution between cars within the household can result in substantial misspecification biases. Ignoring substitution, the basic model yielded fuel price elasticities of 0.......98 and 1.41 for the primary and secondary cars, respectively. Accounting for substitution effects, these figures reduce to, respectively, 0.32 and 0.45. Consistent with substitution behaviour, we find that the fuel price elasticity of fuel demand exceeds the elasticity of kilometre demands with respect...

  8. Elasticity of Substitution and Antidumping Measures

    DEFF Research Database (Denmark)

    Drud Hansen, Jørgen; Meinen, Philipp; Nielsen, Jørgen Ulff-Møller

    Abstract This paper analyzes the role of the elasticity of substitution for anti-dumping decisions across countries. In monopolistic competition models with cost heterogeneous firms across countries, price differences vary inversely with the elasticity of substitution. Anti-dumping duties should...... therefore also vary inversely with the elasticity of substitution at least for countries which have a strong focus on prices in the determination of their anti-dumping measures. We test this for ten countries from 1990 to 2009 using data on anti-dumping from Chad Bown (2010) and US-data at 8-digit level...... in our empirical investigation support the predicted role of the elasticity of substitution as we find a significant negative relation between the elasticity of substitution and the final anti-dumping duties for the ‘lesser duty rule’ group of countries. The countries which do not follow the ‘lesser duty...

  9. Oxygenated fixation demonstrates novel and improved ultrastructural features of the human endolymphatic sac

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Caye-Thomasen, Per; Qvortrup, Klaus

    2013-01-01

    OBJECTIVES/HYPOTHESIS: The purpose of the present study is to describe in detail the ultrastructure of the human endolymphatic sac using a new and improved method of fixation as well as a refined surgical approach in obtaining specimens. STUDY DESIGN: Transmission electron microscopy of the human...... epithelial cell lining in all 18 specimens. In general, we found very well-preserved specimens with well-defined intracellular structures. In contrast to the results in former studies, a minimum of fixation artifacts was observed in the present study. Three different cell types were observed...... endolymphatic sac, employing an oxygenated fixative. METHODS: Eighteen tissue samples of the human endolymphatic sac were obtained during surgery for vestibular schwannoma using the translabyrinthine approach. The specimens were fixed in 2% glutaraldehyde in an oxygenated fluorocarbon blood substitute vehicle...

  10. Biological background of dermal substitutes

    NARCIS (Netherlands)

    van der Veen, V. C.; van der Wal, M.B.; van Leeuwen, M.C.; Ulrich, M.; Middelkoop, E.

    2010-01-01

    Dermal substitutes are of major importance in treating full thickness skin defects, both in acute and chronic wounds. In this review we will outline specific requirements of three classes of dermal substitutes:-natural biological materials, with a more or less intact extracellular matrix

  11. Structure and Electrical Properties of NdBa2Cu3Oy Thin Films by Laser Ablation at Low Oxygen Partial Pressure

    DEFF Research Database (Denmark)

    Mozhaev, Peter B.; Mozhaeva, Julia; Khoryushin, Alexey

    2017-01-01

    in the film can be suppressed by an increase of the deposition temperature or by a decrease of the oxygen partial pressure during deposition. The presence of Nd/Ba disorder during deposition stimulates the introduction of oxygen into the growing film. A simple model is proposed for estimation of oxygen......A deposition process for NdBa2Cu3Oy thin films by laser ablation at decreased deposition temperature was developed using substitution of oxygen with argon in the chamber during deposition. A low deposition rate is the crucial factor to obtain high-quality NBCO films. The Nd/Ba cation disorder...... contents in the film using structural parameters measured with XRD techniques. Studies of the post-deposition annealing process showed ordering of the Nd/Ba sub-lattice and intense oxygen in- and out-diffusion. The temperature of the post-deposition annealing step should be chosen low enough (∼400 °C...

  12. Partial substitution of Zn Effects on the Structural and Electrical Properties of High Temperature Hg0.95Ag0.05Ba2Ca2Cu3O8+δ Superconductors

    Science.gov (United States)

    Abed, Noor S.; Fathi, Sabah J.; Jassim, Kareem A.; Mahdi, Shatha H.

    2018-05-01

    The effect of the Ag partial substitution at Hg site in HgOδ layer and Zn partial substitution at Ca site in CaO layer on the structure,Tc,electrical properties, and oxygen content for Hg-1223 have been studied. Bulk polycrystalline Hg1-xAgxBa2Ca2-yZnyCu3O8+δ compound samples with x=0.05 and y=0.0, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3, are synthesized by a solid state reaction process. Structural properties are studied by using X-ray powder pattern, the high temperature phase superconductor (Hg-1223) of the tetragonal structure didn't change with the partial substitution of Zn and Ag ions, lattice parameters c,c/a are established to vary with Ag and Zn- substitution. The surface morphology has been studied by using atomic force microscopes (AFM), showed that all specimens have good crystalline and homogeneous surface. Also give a best nano size value is 75.72 nm at x=0.05 and y=0.3. Four probe technique is used to measure Tc. The Tc were found to be increases from 129 K to 147 K and oxygen content were found to be increases with increasing Zn. In addition, dielectric properties (dielectric constant, dielectric loss factor, and the alternating electrical conductivity) are characterized directly by relating with Ag and Zn concentration.

  13. The effect of S-substitution at the O6-guanine site on the structure and dynamics of a DNA oligomer containing a G:T mismatch.

    Directory of Open Access Journals (Sweden)

    Elaine Ann Moore

    Full Text Available The effect of S-substitution on the O6 guanine site of a 13-mer DNA duplex containing a G:T mismatch is studied using molecular dynamics. The structure, dynamic evolution and hydration of the S-substituted duplex are compared with those of a normal duplex, a duplex with S-substitution on guanine, but no mismatch and a duplex with just a G:T mismatch. The S-substituted mismatch leads to cell death rather than repair. One suggestion is that the G:T mismatch recognition protein recognises the S-substituted mismatch (GS:T as G:T. This leads to a cycle of futile repair ending in DNA breakage and cell death. We find that some structural features of the helix are similar for the duplex with the G:T mismatch and that with the S-substituted mismatch, but differ from the normal duplex, notably the helical twist. These differences arise from the change in the hydrogen-bonding pattern of the base pair. However a marked feature of the S-substituted G:T mismatch duplex is a very large opening. This showed considerable variability. It is suggested that this enlarged opening would lend support to an alternative model of cell death in which the mismatch protein attaches to thioguanine and activates downstream damage-response pathways. Attack on the sulphur by reactive oxygen species, also leading to cell death, would also be aided by the large, variable opening.

  14. Substitution in recreation choice behavior

    Science.gov (United States)

    George L. Peterson; Daniel J. Stynes; Donald H. Rosenthal; John F. Dwyer

    1985-01-01

    This review discusses concepts and theories of substitution in recreation choice. It brings together the literature of recreation research, psychology, geography, economics, and transportation. Parallel and complementary developments need integration into an improved theory of substitution. Recreation decision behavior is characterized as a nested or sequential choice...

  15. Why Does Trigonometric Substitution Work?

    Science.gov (United States)

    Cunningham, Daniel W.

    2018-01-01

    Modern calculus textbooks carefully illustrate how to perform integration by trigonometric substitution. Unfortunately, most of these books do not adequately justify this powerful technique of integration. In this article, we present an accessible proof that establishes the validity of integration by trigonometric substitution. The proof offers…

  16. Analysis of γ-ray irradiated pasteurized agaricus (Agaricus blazei Murill) by ESR in oxygen-free atmosphere

    International Nuclear Information System (INIS)

    Kemeya, Hiromi; Ukai, Mitsuko

    2007-01-01

    Agaricus (Agaricus blazei Murill) is one of a popular crude drug in Japan and East Asia countries. The crude drugs originating from natural raw products are easy to be contaminated by microorganism. Radiation method has been introduced as the sterilization technology for crude drugs. ESR has been used for the detection of radicals in irradiated drugs. Using ESR, we detected radical species in Agaricus before and after the gamma ray pasteurization. The ESR spectrum consists of a broad sextet centered at g=2.0, a singlet at same g-value and a singlet at g=4.0. We found that relaxation times of radicals in Agaricus varied by the presence of oxygen. Upon substitution of air by Ar, i.e., the absent of oxygen in the ESR sample tube, the T 1 value became 10 times larger than the presence of oxygen. Accordingly, the progressive saturation curve indicates more immediate saturation under the Ar than air atmosphere. Radicals, produced by the γ-ray irradiation to Agaricus, are very sensitive to oxygen. We concluded that ESR spectrum of irradiated Agaricus sample in the absence of oxygen is useful for the detection of dose level of γ-ray irradiation. (author)

  17. Substituted Indoleacetic Acids Tested in Tissue Cultures

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1978-01-01

    Monochloro substituted IAA inhibited shoot induction in tobacco tissue cultures about as much as IAA. Dichloro substituted IAA inhibited shoot formation less. Other substituted IAA except 5-fluoro- and 5-bromoindole-3-acetic acid were less active than IAA. Callus growth was quite variable...

  18. Structure, nonstoichiometry, sintering and oxygen permeability of perovskite SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jin Na [College of Chemistry and Materials Science, Liaoning University of Petroleum and Chemical Technology, Fushun 113001 (China); State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Lu, Hui, E-mail: huilu@dicp.ac.cn [Greenhouse Gas Research Center, Climate Change Technology Research Division, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of); State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Gui, Jian Zhou [College of Chemistry and Materials Science, Liaoning University of Petroleum and Chemical Technology, Fushun 113001 (China); Kim, Jong Pyo; Son, Sou Hwan [Greenhouse Gas Research Center, Climate Change Technology Research Division, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of); Park, Jung Hoon, E-mail: pjhoon@kier.re.kr [Greenhouse Gas Research Center, Climate Change Technology Research Division, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of)

    2013-04-20

    Highlights: ► The novel Fe/Nb co-substituted SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides were characterized by the XRD, DSC, TG and SEM–EDS. ► The high structural stability of the co-substituted SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides. ► The excellent oxygen permeation performance of the co-substituted SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.10) membrane. -- Abstract: The novel Fe/Nb co-substituted SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides have been synthesized and characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG), and scanning electron microscopy (SEM). The XRD and DSC results demonstrate that the structural stability of the Fe/Nb co-substituted samples x = 0.05, 0.10 is improved greatly compared to the sample x = 0.00. The Fe/Nb co-doping in the SrCoO{sub 3−δ} oxide results in the improved structural stability of the SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides. The nonstoichiometric and sintering properties were investigated by TG and SEM, and the oxygen permeation fluxes were measured at 800–950 °C for the sample x = 0.10. The improved oxygen permeability of the ceramic SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.10) membrane compared to the (Ba{sub 0.5}Sr{sub 0.5})(Co{sub 0.8}Fe{sub 0.2})O{sub 3−δ} and SrCo{sub 0.8}Fe{sub 0.2}O{sub 3–δ} membranes, was observed under an air/He oxygen partial pressure gradient at 800–950 °C.

  19. Photophysical properties and localization of chlorins substituted with methoxy groups, hydroxyl groups and alkyl chains in liposome-like cellular membrane

    Energy Technology Data Exchange (ETDEWEB)

    Al-Omari, S [Department of Physics, Hashemite University, Zarqa 13115 (Jordan)

    2007-06-01

    Some of the photophysical properties (stationary absorbance and fluorescence, fluorescence decay times and singlet oxygen quantum yields) of chlorins substituted with methoxy groups, hydroxyl groups and hydrocarbonic chains were studied in ethanol and dipalmitoyl-phosphatidylcholine (DPPC) liposomes using steady-state and time-resolved fluorescence spectroscopies. The photophysical behaviors of the chlorins in liposomes like cellular membrane were compared with those obtained from chlorin-liposome systems delivered to Jurkat cells in order to select potent photosensitizers for the photodynamic treatment of cancer. The localization of the studied chlorins inside liposomes was found to depend strongly on the substituents of chlorins. Absorption spectra of chlorins embedded in DPPC-liposomes have been recorded in the temperature range of 20-70 deg. C. It is demonstrated that the location of the chlorin molecules depends on the phase state of the phospholipids. These observations are confirmed by the fluorescence lifetimes, singlet oxygen lifetimes and singlet oxygen quantum yields results.

  20. Currency Substitution and Inflation in Peru Currency Substitution and Inflation in Peru

    OpenAIRE

    Liliana Rojas-Suarez

    1992-01-01

    This paper shows that there is a long-run relationship between the expected rate of depreciation in the black-market-exchange rate and the ratio of domestic to foreign money in Peru: that is, the hypothesis of currency substitution can explain the behavior of real holdings of money in Peru. The paper also shows that, while, the importance of currency substitution as a transmission mechanism through which domestic policies affected the dynamics of inflation was relatively small during a period...

  1. The Morishima Gross elasticity of substitution

    OpenAIRE

    Blackorby, Charles; Primont, Daniel; Russell, R. Robert

    2007-01-01

    We show that the Hotelling-Lau elasticity of substitution, an extension of the Allen-Uzawa elasticity to allow for optimal output-quantity (or utility) responses to changes in factor prices, inherits all of the failings of the Allen-Uzawa elasticity identified by Blackorby and Russell [1989 AER]. An analogous extension of the Morishima elasticity of substitution to allow for output quantity changes preserves the salient properties of the original Hicksian notion of elasticity of substitution.

  2. Vanadium substitution: A simple and economic way to improve UV sensing in ZnO

    Science.gov (United States)

    Srivastava, Tulika; Bajpai, Gaurav; Rathore, Gyanendra; Liu, Shun Wei; Biring, Sajal; Sen, Somaditya

    2018-04-01

    The UV sensing in pure ZnO is due to oxygen adsorption/desorption process from the ZnO surface. Vanadium doping improves the UV sensitivity of ZnO. The enhancement in UV sensitivity in vanadium-substituted ZnO is attributed to trapping and de-trapping of electrons at V4+ and V5+-related defect states. The V4+ state has an extra electron than the V5+ state. A V4+ to V5+ transformation happens with excitation of this electron to the conduction band, while a reverse trapping process liberates a visible light. An analytic study of response phenomenon reveals this trapping and de-trapping process.

  3. Engineering the oxygen sensing regulation results in an enhanced recombinant human hemoglobin production by Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Martinez Ruiz, José Luis; Liu, Lifang; Petranovic, Dina

    2015-01-01

    Efficient production of appropriate oxygen carriers for transfusions (blood substitutes or artificial blood) has been pursued for many decades, and to date several strategies have been used, from synthetic polymers to cell-free hemoglobin carriers. The recent advances in the field of metabolic en...... the transcription factor HAP1, which resulted in an increase of the final recombinant active hemoglobin titer exceeding 7% of the total cellular protein....

  4. Nitrogen diffusion in hafnia and the impact of nitridation on oxygen and hydrogen diffusion: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Sathiyanarayanan, Rajesh, E-mail: rajessat@in.ibm.com, E-mail: rajesh.sathiyanarayanan@gmail.com; Pandey, R. K.; Murali, K. V. R. M. [IBM Semiconductor Research and Development Center, Bangalore 560045 (India)

    2015-01-21

    Using first-principles simulations, we have computed incorporation energies and diffusion barriers of ammonia, the nitrogen molecule and atomic nitrogen in monoclinic hafnia (m-HfO{sub 2}). Our calculations show that ammonia is likely to dissociate into an NH{sub 2} molecular unit, whereas the nitrogen molecule remains as a molecule either in the interstitial space or at an oxygen lattice site. The lowest energy pathway for the diffusion of atomic nitrogen interstitials consists of the hopping of the nitrogen interstitial between neighboring three-coordinated lattice oxygen atoms that share a single Hf atom, and the barrier for such hops is determined by a switching mechanism. The substitutional nitrogen atom shows a preference for diffusion through the doubly positive oxygen vacancy-mediated mechanism. Furthermore, we have investigated the impact of nitrogen atoms on the diffusion barriers of oxygen and hydrogen interstitials in m-HfO{sub 2}. Our results show that nitrogen incorporation has a significant impact on the barriers for oxygen and hydrogen diffusion: nitrogen atoms attract oxygen and hydrogen interstitials diffusing in the vicinity, thereby slowing down (reducing) their diffusion (diffusion length)

  5. Theoretical study of physical properties and oxygen incorporation effect in nanolaminated ternary carbides 211-MAX phases

    KAUST Repository

    Kanoun, Mohammed

    2012-01-01

    In this chapter, we employ ab initio approaches to review some important physical properties of nanolaminated ternary carbides MAX phases. We fi rstly use an all electron full-potential linearized augmented plane-wave method within the generalized gradient approximation and the density functional theory approaches, to explore the existence of a steric effect on the M site in these compounds. The elastic properties are also reported in order to assess the mechanical stability. The substitution of oxygen for carbon in Ti 2 SnC M n +1 AX n, forming Ti 2 SnC 1- x O x, is examined next, where we simulated the effect of oxygen incorporation on mechanical and electronic properties using projector augmented wave method. We show that oxygen has interesting effects on both of elastic and electronic properties, that the bulk modulus decreases when oxygen concentration increases. The bonding in Ti 2 SnC 1- x O x has a tendency to a covalent-ionic nature with the presence of metallic character. © 2012 Woodhead Publishing Limited.

  6. Photocatalytic CO2 reduction by Cr-substituted Ba2 (In2-xCrx)O5·(H2O)δ (0.04 ≤ x ≤ 0.60)

    KAUST Repository

    Yoon, Songhak; Gaul, Michael; Sharma, Sitansh; Son, Kwanghyo; Hagemann, Hans; Ziegenbalg, Dirk; Schwingenschlö gl, Udo; Widenmeyer, Marc; Weidenkaff, Anke

    2018-01-01

    Cr-substituted polycrystalline Ba2(In2-xCrx)O5·(H2O)δ powders (0.04 ≤ x ≤ 0.60) were synthesized by solid state reaction to investigate the relation of crystal structure, thermochemical, magnetic, and optical properties. The Cr-substitution results in an unit cell expansion and formation of the higher-symmetric tetragonal phase together with increased oxygen and hydrogen contents. Magnetic property measurements reveal that the diamagnetic pristine Ba2In2O5·(H2O)δ becomes magnetically ordered upon Cr-substitution. By UV–vis spectroscopy a gradual shift of the absorption-edge energy to lower values was observed. Numerical calculations showed that the observed bandgap narrowing was ascribed to the Cr induced states near the Fermi level. The correlation between the changes of crystal chemistry, magnetic, and optical properties of Cr-substituted Ba2(In2-xCrx)O5·(H2O)δ can be explained by the replacement of In by Cr. Consequently, an enhanced photocatalytic CO2 reduction activity was observed with increasing Cr substitution, compatible with the state-of-the-art high surface area TiO2 photocatalyst (P-25).

  7. Photocatalytic CO2 reduction by Cr-substituted Ba2 (In2-xCrx)O5·(H2O)δ (0.04 ≤ x ≤ 0.60)

    KAUST Repository

    Yoon, Songhak

    2018-02-09

    Cr-substituted polycrystalline Ba2(In2-xCrx)O5·(H2O)δ powders (0.04 ≤ x ≤ 0.60) were synthesized by solid state reaction to investigate the relation of crystal structure, thermochemical, magnetic, and optical properties. The Cr-substitution results in an unit cell expansion and formation of the higher-symmetric tetragonal phase together with increased oxygen and hydrogen contents. Magnetic property measurements reveal that the diamagnetic pristine Ba2In2O5·(H2O)δ becomes magnetically ordered upon Cr-substitution. By UV–vis spectroscopy a gradual shift of the absorption-edge energy to lower values was observed. Numerical calculations showed that the observed bandgap narrowing was ascribed to the Cr induced states near the Fermi level. The correlation between the changes of crystal chemistry, magnetic, and optical properties of Cr-substituted Ba2(In2-xCrx)O5·(H2O)δ can be explained by the replacement of In by Cr. Consequently, an enhanced photocatalytic CO2 reduction activity was observed with increasing Cr substitution, compatible with the state-of-the-art high surface area TiO2 photocatalyst (P-25).

  8. Photocatalytic CO2 reduction by Cr-substituted Ba2(In2-xCrx)O5·(H2O)δ (0.04 ≤ x ≤ 0.60)

    Science.gov (United States)

    Yoon, Songhak; Gaul, Michael; Sharma, Sitansh; Son, Kwanghyo; Hagemann, Hans; Ziegenbalg, Dirk; Schwingenschlogl, Udo; Widenmeyer, Marc; Weidenkaff, Anke

    2018-04-01

    Cr-substituted polycrystalline Ba2(In2-xCrx)O5·(H2O)δ powders (0.04 ≤ x ≤ 0.60) were synthesized by solid state reaction to investigate the relation of crystal structure, thermochemical, magnetic, and optical properties. The Cr-substitution results in an unit cell expansion and formation of the higher-symmetric tetragonal phase together with increased oxygen and hydrogen contents. Magnetic property measurements reveal that the diamagnetic pristine Ba2In2O5·(H2O)δ becomes magnetically ordered upon Cr-substitution. By UV-vis spectroscopy a gradual shift of the absorption-edge energy to lower values was observed. Numerical calculations showed that the observed bandgap narrowing was ascribed to the Cr induced states near the Fermi level. The correlation between the changes of crystal chemistry, magnetic, and optical properties of Cr-substituted Ba2(In2-xCrx)O5·(H2O)δ can be explained by the replacement of In by Cr. Consequently, an enhanced photocatalytic CO2 reduction activity was observed with increasing Cr substitution, compatible with the state-of-the-art high surface area TiO2 photocatalyst (P-25).

  9. Substitution of matrices over rings

    NARCIS (Netherlands)

    Hautus, M.L.J.

    1995-01-01

    For a given commutative ring with an identity element, we define and study the substitution of a matrix with entries in into a matrix polynomial or rational function over . A Bezout-type remainder theorem and a "partial-substitution rule" are derived and used to obtain a number of results. The

  10. Zinc and Carbonate Co-Substituted Nano-Hydroxyapatite

    Science.gov (United States)

    Girija, E. K.; Kumar, G. Suresh; Thamizhavel, A.

    2011-07-01

    Synthesis of Zn or CO32- substituted nano-hydroxyapatite (HA) and its physico-chemical properties have been well documented. However, the effects of the simultaneous substitution of Zn and CO32- in nano-HA have not been reported. In the present study, Zn and CO32- substitutions in nano HA independently and concurrently have been done by wet precipitation method and characterized by XRD and FT-IR for its phase purity and chemical homogeneity. Further modulations of the bioactivity and thermal stability of HA due to the substitutions have been studied.

  11. Substituting missing data in compositional analysis

    Energy Technology Data Exchange (ETDEWEB)

    Real, Carlos, E-mail: carlos.real@usc.es [Area de Ecologia, Departamento de Biologia Celular y Ecologia, Escuela Politecnica Superior, Universidad de Santiago de Compostela, 27002 Lugo (Spain); Angel Fernandez, J.; Aboal, Jesus R.; Carballeira, Alejo [Area de Ecologia, Departamento de Biologia Celular y Ecologia, Facultad de Biologia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2011-10-15

    Multivariate analysis of environmental data sets requires the absence of missing values or their substitution by small values. However, if the data is transformed logarithmically prior to the analysis, this solution cannot be applied because the logarithm of a small value might become an outlier. Several methods for substituting the missing values can be found in the literature although none of them guarantees that no distortion of the structure of the data set is produced. We propose a method for the assessment of these distortions which can be used for deciding whether to retain or not the samples or variables containing missing values and for the investigation of the performance of different substitution techniques. The method analyzes the structure of the distances among samples using Mantel tests. We present an application of the method to PCDD/F data measured in samples of terrestrial moss as part of a biomonitoring study. - Highlights: > Missing values in multivariate data sets must be substituted prior to analysis. > The substituted values can modify the structure of the data set. > We developed a method to estimate the magnitude of the alterations. > The method is simple and based on the Mantel test. > The method allowed the identification of problematic variables in a sample data set. - A method is presented for the assessment of the possible distortions in multivariate analysis caused by the substitution of missing values.

  12. Substitution effect and effect of axle’s flexibility at (pseudo-rotaxanes

    Directory of Open Access Journals (Sweden)

    Friedrich Malberg

    2014-06-01

    Full Text Available This study investigates the effect of substitution with different functional groups and of molecular flexibility by changing within the axle from a single C–C bond to a double C=C bond. Therefore, we present static quantum chemical calculations at the dispersion-corrected density functional level (DFT-D3 for several Leigh-type rotaxanes. The calculated crystal structure is in close agreement with the experimental X-ray data. Compared to a stiffer axle, a more flexible one results in a stronger binding by 1–3 kcal/mol. Alterations of the binding energy in the range of 5 kcal/mol could be achieved by substitution with different functional groups. The hydrogen bond geometry between the isophtalic unit and the carbonyl oxygen atoms of the axle exhibited distances in the range of 2.1 to 2.4 Å for six contact points, which shows that not solely but to a large amount the circumstances in the investigated rotaxanes are governed by hydrogen bonding. Moreover, the complex with the more flexible axle is usually more unsymmetrical than the one with the stiff axle. The opposite is observed for the experimentally investigated axle with the four phenyl stoppers. Furthermore, we considered an implicit continuum solvation model and found that the complex binding is weakened by approximately 10 kcal/mol, and hydrogen bonds are slightly shortened (by up to 0.2 Å.

  13. Nanocrystallinity effects on osteoblast and osteoclast response to silicon substituted hydroxyapatite.

    Science.gov (United States)

    Casarrubios, Laura; Matesanz, María Concepción; Sánchez-Salcedo, Sandra; Arcos, Daniel; Vallet-Regí, María; Portolés, María Teresa

    2016-11-15

    Silicon substituted hydroxyapatites (SiHA) are highly crystalline bioceramics treated at high temperatures (about 1200°C) which have been approved for clinical use with spinal, orthopedic, periodontal, oral and craniomaxillofacial applications. The preparation of SiHA with lower temperature methods (about 700°C) provides nanocrystalline SiHA (nano-SiHA) with enhanced bioreactivity due to higher surface area and smaller crystal size. The aim of this study has been to know the nanocrystallinity effects on the response of both osteoblasts and osteoclasts (the two main cell types involved in bone remodelling) to silicon substituted hydroxyapatite. Saos-2 osteoblasts and osteoclast-like cells (differentiated from RAW-264.7 macrophages) have been cultured on the surface of nano-SiHA and SiHA disks and different cell parameters have been evaluated: cell adhesion, proliferation, viability, intracellular content of reactive oxygen species, cell cycle phases, apoptosis, cell morphology, osteoclast-like cell differentiation and resorptive activity. This comparative in vitro study evidences that nanocrystallinity of SiHA affects the cell/biomaterial interface inducing bone cell apoptosis by loss of cell anchorage (anoikis), delaying osteoclast-like cell differentiation and decreasing the resorptive activity of this cell type. These results suggest the potential use of nano-SiHA biomaterial for preventing bone resorption in treatment of osteoporotic bone. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Effects of Hemopure on maximal oxygen uptake and endurance performance in healthy humans.

    Science.gov (United States)

    Ashenden, M J; Schumacher, Y O; Sharpe, K; Varlet-Marie, E; Audran, M

    2007-05-01

    Haemoglobin-based oxygen carriers (HBOCs) such as Hemopure are touted as a tenable substitute for red blood cells and therefore potential doping agents, although the mechanisms of oxygen transport of HBOCs are incompletely understood. We investigated whether infusion of Hemopure increased maximal oxygen uptake (V.O 2max) and endurance performance in healthy subjects. Twelve male subjects performed two 4-minute submaximal exercise bouts equivalent to 60 % and 75 % of V.O (2max) on a cycle ergometer, followed by a ramped incremental protocol to elicit V.O (2max). A crossover design tested the effect of infusing either 30 g (6 subjects) or 45 g (6 subjects) of Hemopure versus a placebo. Under our study conditions, Hemopure did not increase V.O (2max) nor endurance performance. However, the infusion of Hemopure caused a decrease in heart rate of approximately 10 bpm (p=0.009) and an average increase in mean ( approximately 7 mmHg) and diastolic blood pressure ( approximately 8 mmHg) (p=0.046) at submaximal and maximal exercise intensities. Infusion of Hemopure did not bestow the same physiological advantages generally associated with infusion of red blood cells. It is conceivable that under exercise conditions, the hypertensive effects of Hemopure counter the performance-enhancing effect of improved blood oxygen carrying capacity.

  15. Determinants of generic drug substitution in Switzerland

    Directory of Open Access Journals (Sweden)

    Lufkin Thomas M

    2011-01-01

    Full Text Available Abstract Background Since generic drugs have the same therapeutic effect as the original formulation but at generally lower costs, their use should be more heavily promoted. However, a considerable number of barriers to their wider use have been observed in many countries. The present study examines the influence of patients, physicians and certain characteristics of the generics' market on generic substitution in Switzerland. Methods We used reimbursement claims' data submitted to a large health insurer by insured individuals living in one of Switzerland's three linguistic regions during 2003. All dispensed drugs studied here were substitutable. The outcome (use of a generic or not was modelled by logistic regression, adjusted for patients' characteristics (gender, age, treatment complexity, substitution groups and with several variables describing reimbursement incentives (deductible, co-payments and the generics' market (prices, packaging, co-branded original, number of available generics, etc.. Results The overall generics' substitution rate for 173,212 dispensed prescriptions was 31%, though this varied considerably across cantons. Poor health status (older patients, complex treatments was associated with lower generic use. Higher rates were associated with higher out-of-pocket costs, greater price differences between the original and the generic, and with the number of generics on the market, while reformulation and repackaging were associated with lower rates. The substitution rate was 13% lower among hospital physicians. The adoption of the prescribing practices of the canton with the highest substitution rate would increase substitution in other cantons to as much as 26%. Conclusions Patient health status explained a part of the reluctance to substitute an original formulation by a generic. Economic incentives were efficient, but with a moderate global effect. The huge interregional differences indicated that prescribing behaviours and

  16. Substitution within the Danish printing industry

    DEFF Research Database (Denmark)

    Larsen, Henrik Fred; Bøg, Carsten

    2009-01-01

    are running a substitution project. A major part of the work has been mapping the presence of chemicals which are potential candidates for substitution (e.g. PBT, CMR, vPvB, EDS) within the Danish printing industry and this work was recently finished. The mapping comprises a combination of a literature study......The implementation of the EU REACH regulation will most probably promote substitution within sectors handling a lot of different chemicals like the printing industry. With the aim of being at the cutting edge of this development the Danish EPA together with the Danish printing industry and IPU...... total 15 substances) were found in the Danish printing industry. This paper presents the results of the mapping of chemical candidates and the first results on preparing for actual substitutions....

  17. Technological substitution options for controlling greenhouse gas emissions

    International Nuclear Information System (INIS)

    Barbier, E.B.; Burgess, J.C.; Pearce, D.W.

    1991-01-01

    This chapter is concerned with technological options for greenhouse gas substitution. The authors interpret the term substitution to exclude energy conservation/efficiency measures, investments in afforestation (sinks), and greenhouse gas removal or abatement technologies. Their working definition of greenhouse gas substitution includes (1) replacement technologies, for example, substituting a greenhouse gas technology with a nongreenhouse gas technology; and (2) reduction technologies, for example, substituting a greenhouse gas technology with an alternative technology that reduces greenhouse gas emissions. Essentially, replacement technologies involve 100 percent reduction in CO 2 ; reduction technologies involve a partial reduction in CO 2 . Of the man-made sources of greenhouse gases, energy is the most important and is expected to contribute to at least half of the global warming effect in the near future. The majority of this impact is from fossil fuel combustion as a source of carbon dioxide (CO 2 ), although fossil fuels also contribute significantly to methane (CH 4 ), to nitrous oxide (N 2 O), and to low-level ozone (O 3 ) through production of various nitrogen gases (NO x ) and carbon monoxide (CO). This study analyzes the available greenhouse gas substitutions and their costs. The authors concentrate particularly on substitutions for fossil-fuel combustion and CFC production and consumption. They conclude by summarizing the potential for greenhouse gas substitution, the cost-effectiveness of the various options and the design of incentives for substitution

  18. Noval 1-substituted-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazole derivatives: Synthesis and pharmacological activity

    Directory of Open Access Journals (Sweden)

    Sabir Hussain

    2015-05-01

    Full Text Available Several-1-carbothioamide-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 2a–d, 1-(pyridine-4-ylcarbonyl-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 3a–d, 1-(5-chloro-6-fluoro-1,3-benzothiazole-2-ylthiocarbamoyl-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 4a–d and 1-[(1,2,4-triazole-4-yl carbothioamide]-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 5a–d were synthesized. The structures of the newly synthesized compounds were supported by IR, 1H NMR and mass spectral data. These compounds were investigated for their, anti-inflammatory, analgesic, ulcerogenic, lipid peroxidation, antibacterial and antifungal activities. Some of the synthesized compounds showed potent anti-inflammatory activity along with minimal ulcerogenic effect and lipid peroxidation, compared to ibuprofen and flurbiprofen. Some of the tested compounds also showed moderate antimicrobial activity against tested bacterial and fungal strains.

  19. Antimony substitution in SmFeAsO

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Daniel; Braun, Hans F. [Universitaet Bayreuth (Germany)

    2015-07-01

    In the iron based compounds structural and magnetic phase transitions can be suppressed by applying external hydrostatic pressure and superconductivity emerges. Beside hydrostatic pressure, it is possible to apply chemical pressure by the substitution of atoms in the compounds with smaller ones. Such a substitution was successful for example in LaFeAs{sub 1-x}P{sub x}O, where the parent compound shows a structural and a spin-density-wave transition and the P doped samples become superconducting. We are interested in the opposite way and substitute the As by the bigger Sb. In literature, the substitution in the La-1111 compounds was possible up to a substitution level of 40 %. With Sm, instead of La, we used a smaller rare-earth metal. We present the results obtained on polycrystalline samples characterized by Xray powder diffraction and resistivity measurements.

  20. Oxygen Transport Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay

    2008-08-30

    small polaron conduction mechanism. Scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) were used to develop strategies to detect and characterize vacancy creation, dopant segregations and defect association in the oxygen conducting membrane material. The pO{sub 2} and temperature dependence of the conductivity, non-stoichiometry and thermal-expansion behavior of compositions with increasing complexity of substitution on the perovskite A and B sites were studied. Studies with the perovskite structure show anomalous behavior at low oxygen partial pressures (<10{sup -5} atm). The anomalies are due to non-equilibrium effects and can be avoided by using very strict criteria for the attainment of equilibrium. The slowness of the oxygen equilibration kinetics arises from two different mechanisms. In the first, a two phase region occurs between an oxygen vacancy ordered phase such as brownmillerite SrFeO{sub 2.5} and perovskite SrFeO{sub 3-x}. The slow kinetics is associated with crossing the two phase region. The width of the miscibility gap decreases with increasing temperature and consequently the effect is less pronounced at higher temperature. The preferred kinetic pathway to reduction of perovskite ferrites when the vacancy concentration corresponds to the formation of significant concentrations of Fe{sup 2+} is via the formation of a Ruddlesden-Popper (RP) phases as clearly observed in the case of La{sub 0.5}Sr{sub 0.5}FeO{sub 3-x} where LaSrFeO{sub 4} is found together with Fe. In more complex compositions, such as LSFTO, iron or iron rich phases are observed locally with no evidence for the presence of discrete RP phase. Fracture strength of tubular perovskite membranes was determined in air and in reducing atmospheric conditions. The strength of the membrane decreased with temperature and severity of reducing conditions although the strength distribution (Weibull parameter, m) was relatively unaltered. Surface and volume

  1. [Delegation yes, substitution no!].

    Science.gov (United States)

    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.

  2. Substituting missing data in compositional analysis

    International Nuclear Information System (INIS)

    Real, Carlos; Angel Fernandez, J.; Aboal, Jesus R.; Carballeira, Alejo

    2011-01-01

    Multivariate analysis of environmental data sets requires the absence of missing values or their substitution by small values. However, if the data is transformed logarithmically prior to the analysis, this solution cannot be applied because the logarithm of a small value might become an outlier. Several methods for substituting the missing values can be found in the literature although none of them guarantees that no distortion of the structure of the data set is produced. We propose a method for the assessment of these distortions which can be used for deciding whether to retain or not the samples or variables containing missing values and for the investigation of the performance of different substitution techniques. The method analyzes the structure of the distances among samples using Mantel tests. We present an application of the method to PCDD/F data measured in samples of terrestrial moss as part of a biomonitoring study. - Highlights: → Missing values in multivariate data sets must be substituted prior to analysis. → The substituted values can modify the structure of the data set. → We developed a method to estimate the magnitude of the alterations. → The method is simple and based on the Mantel test. → The method allowed the identification of problematic variables in a sample data set. - A method is presented for the assessment of the possible distortions in multivariate analysis caused by the substitution of missing values.

  3. Oxygen nonstoichiometry and thermodynamic quantities in solid solution SrFe1-xSnxO3-δ

    Science.gov (United States)

    Merkulov, O. V.; Markov, A. A.; Leonidov, I. A.; Patrakeev, M. V.; Kozhevnikov, V. L.

    2018-06-01

    The oxygen content (3-δ) variations in tin substituted derivatives SrFe1-xSnxO3-δ, where x = 0.05, 0.1, 0.17 and 0.25, of perovskite-like strontium ferrite, have been studied by coulometric titration measurements within oxygen partial pressure (pO2) range 10-19-10-2 atm at 800-950 °С. The obtained dependencies of (3-δ) from pO2 and temperature are used for calculations of partial molar thermodynamic functions of oxygen in the oxide structure. It is found that a satisfactory explanation of the experimental results can be attained within frameworks of the ideal solution model with ion and electron defects appearing in the result of oxidation and disproportionation of iron cations. The increase of the oxidation reaction enthalpy with tin content is consistent with the increase of the unit cell parameter, i.e., the stretch and relaxation of Fe-O chemical bonds.

  4. Development of a diesel substitute fuel

    Energy Technology Data Exchange (ETDEWEB)

    Reiter, Anton; Mair-Zelenka, Philipp [Graz Univ. of Technology (Austria). Inst. of Chemical Engineering and Environmental Technology; Zeymer, Marc [OMV Refining and Marketing GmbH, Vienna (Austria). MRDI-D Product Development and Innovation

    2013-06-01

    Substitute fuels composed of few real chemical compounds are an alternative characterisation approach for conventional fuels as opposed to the traditional pseudo-component method. With the algorithm proposed in this paper the generation of such substitutes will be facilitated and well-established thermodynamic methods can be applied for physical property-data prediction. Based on some quality criteria like true boiling-point curve, liquid density, C/H ratio, or cloud point of a target fuel a surrogate which meets these properties is determined by fitting its composition. The application and capabilities of the algorithm developed are demonstrated by means of an exemplary diesel substitute fuel. The substitute mixture obtained can be generated and used for evaluation of property-prediction methods. Furthermore this approach can help to understand the effects of mixing fossil fuels with biogenic compounds. (orig.)

  5. 2-Bromo-1,4-naphthoquinone: a potentially improved substitute of menadione in Apatone™ therapy

    Directory of Open Access Journals (Sweden)

    F.S. Graciani

    2012-08-01

    Full Text Available Apatone™, a combination of menadione (2-methyl-1,4-naphthoquinone, VK3 and ascorbic acid (vitamin C, VC is a new strategy for cancer treatment. Part of its effect on tumor cells is related to the cellular pro-oxidative imbalance provoked by the generation of hydrogen peroxide (H2O2 through naphthoquinone redox cycling. In this study, we attempted to find new naphthoquinone derivatives that would increase the efficiency of H2O2 production, thereby potentially increasing its efficacy for cancer treatment. The presence of an electron-withdrawing group in the naphthoquinone moiety had a direct effect on the efficiency of H2O2 production. The compound 2-bromo-1,4-naphthoquinone (BrQ, in which the bromine atom substituted the methyl group in VK3, was approximately 10- and 19-fold more efficient than VK3 in terms of oxygen consumption and H2O2 production, respectively. The ratio [H2O2]produced / [naphthoquinone]consumed was 68 ± 11 and 5.8 ± 0.2 (µM/µM for BrQ and VK3, respectively, indicating a higher efficacy of BrQ as a catalyst for the autoxidation of ascorbic acid. Both VK3 and BrQ reacted with glutathione (GSH, but BrQ was the more effective substrate. Part of GSH was incorporated into the naphthoquinone, producing a nucleophilic substitution product (Q-SG. The depletion of BrQ by GSH did not prevent its redox capacity since Q-SG was also able to catalyze the production of reactive oxygen species. VK3/VC has already been submitted to clinical trials for the treatment of prostate cancer and has demonstrated promising results. However, replacement of VK3 with BrQ will open new lines of investigation regarding this approach to cancer treatment.

  6. 2-Bromo-1,4-naphthoquinone: a potentially improved substitute of menadione in Apatone™ therapy

    International Nuclear Information System (INIS)

    Graciani, F.S.; Ximenes, V.F.

    2012-01-01

    Apatone™, a combination of menadione (2-methyl-1,4-naphthoquinone, VK 3 ) and ascorbic acid (vitamin C, VC) is a new strategy for cancer treatment. Part of its effect on tumor cells is related to the cellular pro-oxidative imbalance provoked by the generation of hydrogen peroxide (H 2 O 2 ) through naphthoquinone redox cycling. In this study, we attempted to find new naphthoquinone derivatives that would increase the efficiency of H 2 O 2 production, thereby potentially increasing its efficacy for cancer treatment. The presence of an electron-withdrawing group in the naphthoquinone moiety had a direct effect on the efficiency of H 2 O 2 production. The compound 2-bromo-1,4-naphthoquinone (BrQ), in which the bromine atom substituted the methyl group in VK 3 , was approximately 10- and 19-fold more efficient than VK 3 in terms of oxygen consumption and H 2 O 2 production, respectively. The ratio [H 2 O 2 ] produced / [naphthoquinone] consumed was 68 ± 11 and 5.8 ± 0.2 (µM/µM) for BrQ and VK 3 , respectively, indicating a higher efficacy of BrQ as a catalyst for the autoxidation of ascorbic acid. Both VK 3 and BrQ reacted with glutathione (GSH), but BrQ was the more effective substrate. Part of GSH was incorporated into the naphthoquinone, producing a nucleophilic substitution product (Q-SG). The depletion of BrQ by GSH did not prevent its redox capacity since Q-SG was also able to catalyze the production of reactive oxygen species. VK 3 /VC has already been submitted to clinical trials for the treatment of prostate cancer and has demonstrated promising results. However, replacement of VK 3 with BrQ will open new lines of investigation regarding this approach to cancer treatment

  7. The characterisation of vapour-phase alkali metal-tellurium-oxygen species

    International Nuclear Information System (INIS)

    Gomme, R.A.; Ogden, J.S.; Bowsher, B.R.

    1986-10-01

    Detailed assessments of hypothetical severe accidents in light water reactors require the identification of the chemical forms of the radionuclides in order to determine their transport characteristics. Caesium and tellurium are important volatile fission products in accident scenarios. This report describes detailed studies to characterise the chemical species that vaporise from heated mixtures of various alkali metal-tellurium-oxygen systems. The molecular species were characterised by a combination of quadrupole mass spectrometry and matrix isolation-infrared spectroscopy undertaken in conjunction with experiments involving oxygen-18 substitution. The resulting spectra were interpreted in terms of a vapour-phase molecule with the stoichiometry M 2 TeO 3 (M = K,Rb,Cs) for M/Te molecular ratios of ∼ 2, and polymeric species for ratios < 2. This work has demonstrated the stability of caesium tellurite. The formation of this relatively low-volatility, water-soluble species could significantly modify the transport and release of caesium and tellurium. The data presented in this report should allow more comprehensive thermodynamic calculations to be undertaken that assist in the quantification of fission product behaviour during severe reactor accidents. (author)

  8. Singlet oxygen quenching by oxygen in tetraphenyl-porphyrin solutions

    International Nuclear Information System (INIS)

    Dedic, Roman; Korinek, Miloslav; Molnar, Alexander; Svoboda, Antonin; Hala, Jan

    2006-01-01

    Time-resolved measurement of singlet oxygen infrared phosphorescence is a powerful tool for determination of quantum yields and kinetics of its photosensitization. This technique was employed to investigate in detail the previously observed effect of singlet oxygen quenching by oxygen. The question whether the singlet oxygen is quenched by oxygen in ground or in excited state was addressed by study of two complementary dependencies of singlet oxygen lifetimes: on dissolved oxygen concentration and on excitation intensity. Oxygen concentration dependence study of meso-tetra(4-sulphonato)phenylporphyrin (TPPS 4 ) phosphorescence kinetics showed linearity of the dependence of TPPS 4 triplet state rate-constant. Corresponding bimolecular quenching constant of (1.5±0.1)x10 9 l/mol s was obtained. On the other hand, rate constants of singlet oxygen depopulation exhibit nonlinear dependence on oxygen concentration. Comparison of zero oxygen concentration-extrapolated value of singlet oxygen lifetime of (6.5±0.4) μs to (3.7±0.1) μs observed under air-saturated conditions indicates importance of the effect of quenching of singlet oxygen by oxygen. Upward-sloping dependencies of singlet oxygen depopulation rate-constant on excitation intensity evidence that singlet oxygen is predominantly quenched by oxygen in excited singlet state

  9. Tonemic Substitution

    African Journals Online (AJOL)

    Ezenwafor

    grammatical constructions. The choice of substitutable tonemes as observed from the analyzed data is highly. Ezenwafordependent on the intuitive judgement of the native speaker. This work shows with adequate data, that regular tonemic changes are not always meaningful in Ekwulobia lect. Such tonemic alternations are ...

  10. Preparation and characterization of structures of oxygen-ion-conductive thin-film membranes; Herstellung und Charakterisierung von sauerstoffionenleitenden Duennschichtmembranstrukturen

    Energy Technology Data Exchange (ETDEWEB)

    Betz, Michael

    2010-07-01

    In power plants using Oxyfuel technology, fossil fuels are combusted with pure oxygen. This leads to carbon dioxide of high purity, which is necessary for its transport and storage. Oxygen separation by means of perovskitic membranes have great potential to decrease the efficiency losses caused by the allocation of the enormous amounts of oxygen. The aim of this work is the preparation and characterisation of thin film membranes on porous substrates and the analysis of their oxygen permeation properties. Therefore the material system A{sub 0,68}Sr{sub 0,3}Fe{sub 0,8}Co{sub 0,2}O{sub 3-{delta}} (A68SFC) was analysed, where the A-site was substituted with Lanthanides (La, Pr, Nd, Eu, Sm, Gd, Dy, Er) or alkaline earth metals (Ba, Ca). After an extensive characterisation, the selection was reduced to the substitutions with La, Pr and Nd. Other compounds could not meet the demands with regard to phase purity, chemical stability or extension behaviour. All analyses were conducted in comparison to Ba{sub 0,5}Sr{sub 0,5}Co{sub 0,8}Fe{sub 0,2}O{sub 3-{delta}} (BSCF) which is known to exhibit higher permeation rates, but is more sensitive to stability issues. The dependency of permeation rates on membrane thickness or oxygen partial pressures on both membrane surfaces is discussed by means of permeation measurements conducted on bulk BSCF membranes. These cannot be described completely by the Wagner equation. This is due to changes of the driving force originating from influences of the surface reaction kinetics and concentration polarisation on the membrane surface, which are not considered. Porous substrates for asymmetric membranes were manufactured by tape casting and warm pressing. The application of the functional layer was performed via screen printing. Permeation measurements show that the asymmetric structures exhibit higher permeation rates in comparison to bulk membranes with L=1 mm. The moderate increase can be attributed to the low gas permeability of the

  11. 40 CFR Appendix B to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes

    Science.gov (United States)

    2010-07-01

    ... demonstrate it can be used safely in this end-use. CFC-12 Motor Vehicle Air Conditioners (Retrofit and New... Conditions Application Substitute Decision Conditions Comments CFC-12 Automobile Motor Vehicle Air... refrigerant. CFC-12 Automobile Motor Vehicle Air Conditioning (New equipment only) R-152a as a substitute for...

  12. Crystal chemical substitutions and doping of YBa2Cu3Ox and related superconductors

    International Nuclear Information System (INIS)

    Skakle, J.M.S.

    1998-01-01

    This review covers the literature on cationic and anionic substitutions and their effect on the properties of YBCO. Reported solubility limits are given, together with crystal symmetry and trends in unit cell parameters with dopant concentration. The dopant site is considered; this is additionally complex in the case of copper substitution because of the two distinct copper sites in the crystal structure. The effect of the dopant on the critical temperature, T c , is reviewed; the literature is often contradictory due to the dual effects of variable oxygen content and the nature of the dopant. Preparation methods appear to have an effect on solubility limits, crystal symmetry and T c . Also, the methods used to determine solubility limits are often imprecise which can lead to contradictions. The magnetic properties of doped materials are reviewed; for some dopants, particularly the magnetic lanthanides, antiferromagnetism and superconductivity co-exist. The related RBa 2 Cu 3 O δ phases (R=lanthanide), their structure, properties and behaviour on doping are reviewed in a similar way. For the larger rare earths, the related systems R 1+x Ba 2-x Cu 3 O δ are reviewed; as x increases, the transition temperature decreases and compositions R 1.5 Ba 1.5 Cu 3 O δ are semiconducting. The upper and lower solubility limit changes with R, and for R=Dy, the upper limit is 2 Cu 3 O δ , cannot be prepared in air since substitution of La onto the Ba site occurs, forming the Ba-deficient solid solutions. (orig.)

  13. Biofuels in West Africa: prospective analysis of substitution for petroleum products

    International Nuclear Information System (INIS)

    Tonato, A.

    1993-01-01

    Is it viable and realistic to believe that biofuels can relieve the energy bill for certain countries in West Africa, restimulate whole areas often cut off from the development process, and diversify the outlets of the agricultural sector, hard struck as it is by the price drop in raw materials. The answer here is drawn from a micro-economic analysis of Benin, Burkina Faso, the Ivory Coast, and Niger, concerning the competitiveness of the three main products considered: - ethanol, produced from cane sugar; - methanol, obtained from eucalyptus by cryogenic oxygen gasification process; methyl ester, from palm oil. The result of this study is a forecast, for the year 2010, of conditions under which methyl alcohols and ester might be substituted for refined gasoline and fuel oil, and a hierarchical classification of the various biofuels in West Africa. (author). 15 refs., 8 tabs

  14. The substitution bias of the consumer price index

    OpenAIRE

    Frenger, Petter

    2006-01-01

    Abstract: The paper uses elementary consumer theory to propose an inflation independent ratio definition of the substitution bias of the Laspeyres consumer price index, and derives an approximate substitution bias which depends on the size of the price change as measured by a norm in the Laspeyres plane and on the elasticity of substitution in the direction of the price change. This norm or distance measure can be interpreted as a price substitution index which yields useful in...

  15. Operator substitution

    NARCIS (Netherlands)

    Hautus, M.L.J.

    1994-01-01

    Substitution of an operator into an operator-valued map is defined and studied. A Bezout-type remainder theorem is used to derive a number of results. The tensor map is used to formulate solvability conditions for linear matrix equations. Some applications to system theory are given, in particular

  16. Substitution reactions of technetium complexes

    International Nuclear Information System (INIS)

    Omori, T.

    1997-01-01

    Substitution reactions of a series of technetium complexes are considered in comparison with corresponding reactions of rhenium. Rhenium and technetium complexes are rather inert in substitution reactions, the latter are characterized by greater rate constants when they proceed according to dissociative mechanism. In rare cases when k Tc /k Re id little it is assumed that the reaction proceeds according to the associative mechanism. (author)

  17. Maximum parsimony, substitution model, and probability phylogenetic trees.

    Science.gov (United States)

    Weng, J F; Thomas, D A; Mareels, I

    2011-01-01

    The problem of inferring phylogenies (phylogenetic trees) is one of the main problems in computational biology. There are three main methods for inferring phylogenies-Maximum Parsimony (MP), Distance Matrix (DM) and Maximum Likelihood (ML), of which the MP method is the most well-studied and popular method. In the MP method the optimization criterion is the number of substitutions of the nucleotides computed by the differences in the investigated nucleotide sequences. However, the MP method is often criticized as it only counts the substitutions observable at the current time and all the unobservable substitutions that really occur in the evolutionary history are omitted. In order to take into account the unobservable substitutions, some substitution models have been established and they are now widely used in the DM and ML methods but these substitution models cannot be used within the classical MP method. Recently the authors proposed a probability representation model for phylogenetic trees and the reconstructed trees in this model are called probability phylogenetic trees. One of the advantages of the probability representation model is that it can include a substitution model to infer phylogenetic trees based on the MP principle. In this paper we explain how to use a substitution model in the reconstruction of probability phylogenetic trees and show the advantage of this approach with examples.

  18. Type Substitution for Object-Oriented Programming

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Palsberg, Jens

    1990-01-01

    Genericity allows the substitution of types in a class. This is usually obtained through parameterized classes, although they are inflexible since any class can be inherited but is not in itself parameterized. We suggest a new genericity mechanism, type substitution, which is a subclassing concep...

  19. 40 CFR 721.5350 - Substituted nitrile (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted nitrile (generic name... Substances § 721.5350 Substituted nitrile (generic name). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted nitrile (PMN P-83...

  20. Application of thiol-olefin co-oxygenation methodology to a new synthesis of the 1,2,4-trioxane pharmacophore.

    Science.gov (United States)

    O'Neill, Paul M; Mukhtar, Amira; Ward, Stephen A; Bickley, Jamie F; Davies, Jill; Bachi, Mario D; Stocks, Paul A

    2004-09-02

    [reaction: see text] Thiol-olefin co-oxygenation (TOCO) of substituted allylic alcohols generates alpha-hydroxyperoxides that can be condensed in situ with various ketones to afford a series of functionalized 1,2,4-trioxanes in good yields. Manipulation of the phenylsulfenyl group in 4a allows for convenient modification to the spiro-trioxane substituents, and we describe, for the first time, the preparation of a new class of antimalarial prodrug.

  1. On the effect of heterovalent substitutions in ruthenocuprates

    Energy Technology Data Exchange (ETDEWEB)

    Klamut, P.W.; Dabrowski, B.; Mini, S.M.; Maxwell, M.; Mais, J.; Felner, I.; Asaf, U.; Ritter, F.; Shengelaya, A.; Khasanov, R.; Savic, I.M.; Keller, H.; Wisniewski, A.; Puzniak, R.; Fita, I.M.; Sulkowski, C.; Matusiak, M

    2003-05-01

    We discuss the properties of superconducting derivatives of the RuSr{sub 2}GdCu{sub 2}O{sub 8} (1212-type) ruthenocuprate, for which heterovalent doping has been achieved through partial substitution of Cu ions into the RuO{sub 2} planes (Ru{sub 1-x}Sr{sub 2}GdCu{sub 2+x}O{sub 8-{delta}}, 0{<=}x{<=}0.75, T{sub c}{sup max}=72 K for x=0.3-0.4) and Ce ions into the Gd sites (RuSr{sub 2}Gd{sub 1-y}Ce{sub y}Cu{sub 2}O{sub 8}, 0{<=}y{<=}0.1). The measurements of XANES, thermopower, and magnetization under external pressure reveal an underdoped character of all compounds. Muon spin rotation experiments indicate the presence of magnetic order at low temperatures (T{sub m}=14-2 K for x=0.1-0.4). Properties of these two series lead us to the qualitative phase diagram for differently doped 1212-type ruthenocuprates. The difference in temperature of magnetic ordering found for superconducting and non-superconducting RuSr{sub 2}GdCu{sub 2}O{sub 8} is discussed in the context of the properties of substituted compounds. The high pressure oxygen conditions required for synthesis of Ru{sub 1-x}Sr{sub 2}RECu{sub 2+x}O{sub 8-{delta}}, have been extended to synthesis of a Ru{sub 1-x}Sr{sub 2}Eu{sub 2-y}Ce{sub y}Cu{sub 2+x}O{sub 10-{delta}} series. The Cu {yields} Ru doping achieved in these phases is found to decrease the temperature for magnetic ordering as well the volume fraction of the magnetic phase.

  2. Sodium-carbonate co-substituted hydroxyapatite ceramics

    Directory of Open Access Journals (Sweden)

    Zoltan Z. Zyman

    2013-12-01

    Full Text Available Powders of sodium-carbonate co-substituted hydroxyapatite, having sodium content in the range of 0.25–1.5 wt.% with a 0.25 wt.% step, were prepared by a precipitation-solid state reaction route. Compacts of the powders were sintered in a CO2 flow (4 mL/min at 1100 °C for 2 h. The sintered ceramics contained sodium and carbonate ions in the ranges of 0–1.5 wt.% and 1.3–6 wt.%, respectively, which are typical impurity concentrations in biological apatite. A relationship between sodium and carbonate contents and the type of carbonate substitution was found. The total carbonate content progressively increased with the sodium content. The obtained ceramics showed an AB-type carbonate substitution. However, the substitution became more B-type as the sodium content increased. As a result, the carbonation was almost B-type (94 % for the highest sodium content (1.5 wt.%.

  3. Relationship between symmetry of porphyrinic pi-conjugated systems and singlet oxygen (1Delta g) yields: low-symmetry tetraazaporphyrin derivatives.

    Science.gov (United States)

    Ishii, Kazuyuki; Itoya, Hatsumi; Miwa, Hideya; Fujitsuka, Mamoru; Ito, Osamu; Kobayashi, Nagao

    2005-07-07

    We have investigated the excited-state properties and singlet oxygen ((1)Delta(g)) generation mechanism in phthalocyanines (4M; M = H(2), Mg, or Zn) and in low-symmetry metal-free, magnesium, and zinc tetraazaporphyrins (TAPs), that is, monobenzo-substituted (1M), adjacently dibenzo-substituted (2AdM), oppositely dibenzo-substituted (2OpM), and tribenzo-substituted (3M) TAP derivatives, whose pi conjugated systems were altered by fusing benzo rings. The S(1)(x) and S(1)(y) states (these lowest excited singlet states are degenerate in D(4)(h) symmetry) split in the low-symmetry TAP derivatives. The excited-state energies were quantitatively determined from the electronic absorption spectra. The lowest excited triplet (T(1)(x)) energies were also determined from phosphorescence spectra, while the second lowest excited triplet (T(1)(y)) states were evaluated by using the energy splitting between the T(1)(x) and T(1)(y) states previously reported (Miwa, H.; Ishii, K.; Kobayashi, N. Chem. Eur. J. 2004, 10, 4422-4435). The singlet oxygen quantum yields (Phi(Delta)) are strongly dependent on the pi conjugated system. In particular, while the Phi(Delta) value of 2AdH(2) is smallest in our system, that of 2OpH(2), an isomer of 2AdH(2), is larger than that of 4Zn, in contrast to the heavy atom effect. The relationship between the molecular structure and Phi(Delta) values can be transformed into a relationship between the S(1)(x) --> T(1)(y) intersystem crossing rate constant (k(ISC)) and the energy difference between the S(1)(x) and T(1)(y) states (DeltaE(S)(x)(T)(y)). In each of the Zn, Mg, and metal-free compounds, the Phi(Delta)/tau(F) values (tau(F): fluorescence lifetime), which are related to the k(ISC) values, are proportional to exp(-DeltaE(S)(x)(T)(y)), indicating that singlet oxygen ((1)Delta(g)) is produced via the T(1)(y) state and that the S(1)(x) --> T(1)(y) ISC process follows the energy-gap law. From the viewpoint of photodynamic therapy, our methodology

  4. Educators Take Another Look at Substitutes

    Science.gov (United States)

    Zubrzycki, Jaclyn

    2012-01-01

    The mythology surrounding the substitute teacher is not a pretty one: Paper airplanes, lost learning, bullying. But as schools collect more information about teacher absenteeism and its consequences, districts and schools are exploring ways to professionalize substitute teaching--or experiment with alternative ways of coping with teacher absences.…

  5. On magnetic ordering in heavily sodium substituted hole doped lanthanum manganites

    Energy Technology Data Exchange (ETDEWEB)

    Sethulakshmi, N. [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Unnimaya, A.N. [Centre for Materials for Electronic Technology (CMET), Thrissur 680581, Kerala (India); Al-Omari, I.A.; Al-Harthi, Salim [Department of Physics, Sultan Qaboos University, PC 123 Muscat (Oman); Sagar, S. [Government College for Women, Thiruvananthapuram 695014, Kerala (India); Thomas, Senoy [Materials Science and Technology Division, National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, Kerala (India); Srinivasan, G. [Department of Physics, Oakland University, Rochester (United States); Anantharaman, M.R., E-mail: mraiyer@yahoo.com [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India)

    2015-10-01

    Mixed valence manganite system with monovalent sodium substituted lanthanum manganites form the basis of the present work. Lanthanum manganites belonging to the series La{sub 1−x}Na{sub x}MnO{sub 3} with x=0.5–0.9 were synthesized using modified citrate gel method. Variation of lattice parameters and unit cell volume with Na concentration were analyzed and the magnetization measurements indicated ferromagnetic ordering in all samples at room temperature. Low temperature magnetization behavior indicated that all samples exhibit antiferromagnetism along with ferromagnetism and it has also been observed that antiferromagnetic ordering dominates ferromagnetic ordering as concentration is increased. Evidence for such a magnetic inhomogeneity in these samples has been confirmed from the variation in Mn{sup 3+}/Mn{sup 4+} ion ratio from X-ray Photoelectron Spectroscopy and from the absorption peak studies using Ferromagnetic Resonance Spectroscopy. - Highlights: • Higher substitution of more than 50 percent of monovalent ion, sodium for La sites in lanthanum manganites scarce in literature. • Structural studies using XRD and further structure refinement by Rietveld refinement confirmed orthorhombic pbnm spacegroup. • Ferromagnetic behavior at room temperature with saturation magnetization decreasing with increase in sodium concentration. • M vs T measurements using FC ZFC proved coexisting FM/AFM behavior arising from exchange interactions between different valence states of Mn ions. • Disparity in ratio of Mn valence ions indicated presence of vacancies providing the role of vacancies and oxygen stoichiometry in deciding magnetic inhomogeneity.

  6. Sensory Substitution and Multimodal Mental Imagery.

    Science.gov (United States)

    Nanay, Bence

    2017-09-01

    Many philosophers use findings about sensory substitution devices in the grand debate about how we should individuate the senses. The big question is this: Is "vision" assisted by (tactile) sensory substitution really vision? Or is it tactile perception? Or some sui generis novel form of perception? My claim is that sensory substitution assisted "vision" is neither vision nor tactile perception, because it is not perception at all. It is mental imagery: visual mental imagery triggered by tactile sensory stimulation. But it is a special form of mental imagery that is triggered by corresponding sensory stimulation in a different sense modality, which I call "multimodal mental imagery."

  7. Substitution effect of pentavalent bismuth ions on the electronic structure and physicochemical properties of perovskite-structured Ba(In0.5Ta0.5-xBix)O3 semiconductors

    International Nuclear Information System (INIS)

    Kim, Tae Woo; Hur, Su Gil; Hwang, Seong-Ju; Park, Hyunwoong; Park, Yiseul; Choi, Wonyong; Choy, Jin-Ho

    2007-01-01

    We have investigated the substitution effect of pentavalent bismuth ions on the electronic structure and physicochemical properties of barium indium tantalate. X-ray diffraction, X-ray absorption spectroscopic, and energy dispersive spectroscopic microprobe analyses reveal that, under oxygen atmosphere of 1 atm, pentavalent Bi ions are successfully stabilized in the octahedral site of the perovskite tantalate lattice. According to diffuse reflectance UV-vis spectroscopic analysis, the Bi substitution gives rise to the significant narrowing of band gap of barium indium tantalate even at a low Bi content of ∼5%, underscoring a high efficiency of Bi substitution in the band gap engineering. Such an effective narrowing of the band gap upon the Bi substitution would be attributable to the lowering of conduction band position due to the high electronegativity of Bi V substituent. As a result of band gap engineering, the Ba(In 0.5 Ta 0.5-x Bi x )O 3 compounds with x ≥ 0.03 can generate photocurrents under visible light irradiation (λ > 420 nm). Based on the present experimental findings, it becomes clear that the substitution of highly electronegative p-block element like Bi V ion can provide a very powerful tool for tailoring the electronic structure and physicochemical properties of wide band gap semiconductors

  8. Stores, Prices, and Currency Substitution

    OpenAIRE

    Gabriele, Camera; Winkler, Johannes

    1999-01-01

    We study endogenous currency substitution in a decentralized trade environment. Sellers maximize profits from sales of imperfectly substitutable goods by posting prices in either one of two currencies. A unique symmetric equilibrium exists where goods are priced only in the local currency. This occurs if foreign trade is sporadic, there is sufficient but not excessive liquidity, and discounting is low. Excess or scarcity of liquidity, however, induces sellers to extract all surplus from bu...

  9. Commercial formalin substitutes for histopathology

    DEFF Research Database (Denmark)

    Prentø, P; Lyon, H

    1997-01-01

    We compared the performance of six commercial fixatives proposed to be formalin substitutes with the performance of buffered formalin, Clarke's ethanol-acetic acid, and ethanol, using rat liver, small intestine, and kidney. We investigated the rate of penetration, mode of fixation, extent of prot...... was obtained by combining formalin fixation with antigen retrieval. We conclude that none of the proposed commercial substitutes for buffered formalin are adequate for critical histology or histopathology....

  10. Study on Characteristics of Co-firing Ammonia/Methane Fuels under Oxygen Enriched Combustion Conditions

    Science.gov (United States)

    Xiao, Hua; Wang, Zhaolin; Valera-Medina, Agustin; Bowen, Philip J.

    2018-06-01

    Having a background of utilising ammonia as an alternative fuel for power generation, exploring the feasibility of co-firing ammonia with methane is proposed to use ammonia to substitute conventional natural gas. However, improvement of the combustion of such fuels can be achieved using conditions that enable an increase of oxygenation, thus fomenting the combustion process of a slower reactive molecule as ammonia. Therefore, the present study looks at oxygen enriched combustion technologies, a proposed concept to improve the performance of ammonia/methane combustion. To investigate the characteristics of ammonia/methane combustion under oxygen enriched conditions, adiabatic burning velocity and burner stabilized laminar flame emissions were studied. Simulation results show that the oxygen enriched method can help to significantly enhance the propagation of ammonia/methane combustion without changing the emission level, which would be quite promising for the design of systems using this fuel for practical applications. Furthermore, to produce low computational-cost flame chemistry for detailed numerical analyses for future combustion studies, three reduced combustion mechanisms of the well-known Konnov's mechanism were compared in ammonia/methane flame simulations under practical gas turbine combustor conditions. Results show that the reduced reaction mechanisms can provide good results for further analyses of oxygen enriched combustion of ammonia/methane. The results obtained in this study also allow gas turbine designers and modellers to choose the most suitable mechanism for further combustion studies and development.

  11. Biologic and synthetic skin substitutes: An overview

    OpenAIRE

    Halim, Ahmad Sukari; Khoo, Teng Lye; Mohd. Yussof, Shah Jumaat

    2010-01-01

    The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. Skin substitutes have important roles in the treatment of deep dermal and full thickness wounds of various aetiologies. At present, there is no ideal substitute in the market. Skin substit...

  12. Different diffusion mechanisms of oxygen in ReBa{sub 2}Cu{sub 3}O{sub 7−x} (Re = Y, Ho) single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vovk, R.V.; Boiko, Y.I.; Bogdanov, V.V.; Kamchatnaya, S.N.; Goulatis, I.L. [V. N. Karazin Kharkiv National University, 4 Svobody sq., 61077 Kharkiv (Ukraine); Chroneos, A. [Faculty of Engineering, Environment and Computing, Coventry University, Priory Street, Coventry CV1 5FB (United Kingdom); Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom)

    2017-05-15

    Highlights: • Single file diffusion mechanism of oxygen ions. • Ho modifies the diffusion mechanism in the oxygen sublattice. • Ho changes the efficient interaction of ions in CuO-planes. - Abstract: In the present study, the time dependencies of the resistivity of ReBa{sub 2}Cu{sub 3}O{sub 7−x} (Re=Y, Ho) single crystals with varying degree of deviation from oxygen stoichiometry was investigated. It was shown that the accelerated transport of oxygen ions in the initial stage of the process can be carried out along the one-dimensional non-stoichiometric vacancies’ accumulation by the single file diffusion mechanism. The final phase redistribution of oxygen ions in ReBa{sub 2}Cu{sub 3}O{sub 7−x} (Re = Y, Ho) is described by the classical mechanism of volume diffusion. The substitution of yttrium by holmium significantly affects the charge redistribution and changes the efficient interaction of ions in CuO-planes, thereby modifying the mass transfer diffusion mechanisms in the oxygen sublattice. Thus, a significant length change of the time intervals occurs, corresponding to the oxygen ions’ single file and volume diffusion mechanisms.

  13. [Guidelines for substitution treatments in prison populations].

    Science.gov (United States)

    Michel, L; Maguet, O

    2005-01-01

    Care access for the drug addict patients in prison (in particular for the treatments of substitution) in France is very unequal from one establishment to another. This reflects the great variability of the practices of substitution and especially the absence of consensus on the methods of adaptation of these practices to the prison environment. Because of difficulties expressed by prisoners and medical staff on this subject and of stakes (let us recall that approximately 30% of the prisoners are dependent or abusers of one or more psychoactive substances), the formulation of recommendations or of a good practices guide of substitution in prison appeared necessary. Work that we detail here answers a ordering of the Advisory Commission of the Treatments of Substitution (September 2001) whose authors are members. It was presented at the session April 2003. It results from the confrontation of a review of the literature (including legal texts and official reports concerning substitution, the organization of the care in prison environment and the lawful framework), with a vast investigation. The latter was carried out near medical staff (22 prisons), penitentiary staff (3 prisons, 27 people met including directors of these establishments) and prisoners (7 establishments, 28 prisoners met) in the form of individual talks (semi-directing interviews with evaluation of the type of existing device and its knowledge by the penitentiary staff and the prisoners; statement of the suggestions, needs and requests of the medical, penitentiary staffs and of the prisoners). In the whole visited prisons, 7.8% (870) of the prisoners received substitution treatments (6.35% by buprenorphine, 1.44% by methadone), representing a proportion of substituted drug addicts (870 substituted for an evaluation of 3,350 prisoners drug addicts among the 11,168 prisoners of the 22 visited prisons) notably lower than that in free environment (56%, ie 96,000 substituted for an evaluated population of

  14. REACH-related substitution within the Danish printing industry

    DEFF Research Database (Denmark)

    Larsen, Henrik Fred; Bøg, Carsten; Markussen, Helene

    are running a substitution project. A major part of the work has been mapping the presence of chemicals which are potential candidates for substitution (e.g. PBT, CMR, vPvB, EDS) within the Danish printing industry. The mapping comprises a combination of a literature study and an investigation of the actual......The accomplishment of the EU REACH regulation will most probably promote substitution within sectors handling a lot of different chemicals like the printing industry. With the aim of being at the cutting edge of this development the Danish EPA together with the Danish printing industry and IPU...... fulfil one or more of the criteria (e.g. CMR, EDS) for the REACH Annex XIV candidate list (authorisation). The paper presents the results of the mapping of chemical candidates and the first results of the actual substitutions. Keywords: REACH, chemicals, substitution, printing industry....

  15. Protein substitute for children and adults with phenylketonuria.

    Science.gov (United States)

    Yi, Sarah H L; Singh, Rani H

    2015-02-27

    Phenylketonuria is an inherited metabolic disorder characterised by an absence or deficiency of the enzyme phenylalanine hydroxylase. The aim of treatment is to lower blood phenylalanine concentrations to the recommended therapeutic range to prevent developmental delay and support normal growth. Current treatment consists of a low-phenylalanine diet in combination with a protein substitute which is free from or low in phenylalanine. Guidance regarding the use, dosage, and distribution of dosage of the protein substitute over a 24-hour period is unclear, and there is variation in recommendations among treatment centres. This is an update of a Cochrane review first published in 2005, and previously updated in 2008. To assess the benefits and adverse effects of protein substitute, its dosage, and distribution of dose in children and adults with phenylketonuria who are adhering to a low-phenylalanine diet. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which consists of references identified from comprehensive electronic database searches and hand searches of relevant journals and abstract books of conference proceedings. We also contacted manufacturers of the phenylalanine-free and low-phenylalanine protein substitutes for any data from published and unpublished randomised controlled trials.Date of the most recent search of the Group's Inborn Errors of Metabolism Trials Register: 03 April 2014. All randomised or quasi-randomised controlled trials comparing: any dose of protein substitute with no protein substitute; an alternative dosage; or the same dose, but given as frequent small doses throughout the day compared with the same total daily dose given as larger boluses less frequently. Both authors independently extracted data and assessed trial quality. Three trials (69 participants) are included in this review. One trial investigated the use of protein substitute in 16 participants, while a further two trials investigated the

  16. Nitrogen ligation to manganese in the photosynthetic oxygen-evolving complex: Continuous-wave and pulsed EPR studies of Photosystem II particles containing 14N or 15N

    International Nuclear Information System (INIS)

    DeRose, V.J.; Yachandra, V.K.; McDermott, A.E.; Britt, R.D.; Sauer, K.; Klein, M.P.

    1991-01-01

    The possibility of nitrogen ligation to the Mn in the oxygen-evolving complex from photosystem II was investigated with electron paramagnetic resonance (EPR) and electron spin echo envelope modulation (ESEEM) spectroscopies using 14 N- and 15 N-labeled preparations. Oxygen-evolving preparations were isolated from a thermophilic cyanobacterium, Synechococcus sp., grown on a medium containing either 14 NO 3 - or 15 NO - 3 as the sole source of nitrogen. The substructure on the multiline EPR signal, which arises from Mn in the S 2 state of the enzyme, was measured with continuous-wave EPR. No changes were detected in the substructure peak positions upon substitution of 15 N for 14 N, indicating that this substructure is not due to superhyperfine coupling from nitrogen ligands. To detect potential nitrogen ligands with superhyperfine couplings of lesser magnitude than could be observed with conventional EPR methods, electron spin-echo envelope modulation experiments were also performed on the multiline EPR signal. The Fourier transform of the light-minus-dark time domain ESEEM data shows a peak at 4.8 MHz in 14 N samples which is absent upon substitution with 15 N. This gives unambiguous evidence for weak hyperfine coupling of nitrogen to the Mn of the oxygen-evolving complex. Possible origins of this nitrogen interaction are discussed

  17. Muon substituted free radicals

    International Nuclear Information System (INIS)

    Burkhard, P.; Fischer, H.; Roduner, E.; Strub, W.; Gygax, F.N.; Brinkman, G.A.; Louwrier, P.W.F.; McKenna, D.; Ramos, M.; Webster, B.C.

    1984-01-01

    Spin polarized energetic positive muons are injected as magnetic probes into unsaturated organic liquids. They are implemented via fast chemical processes ( -10 s) in various molecules. Of particular interest among these are muonium substituted free radicals. The technique allows determination of accurate rate coefficients for fast chemical reactions of radicals. Furthermore, radiochemical processes occuring in picoseconds after injection of the muon are studied. Of fundamental interest are also the structural and dynamical implications of substituting a proton by a muon, or in other terms, a hydrogen atom by a muonium atom. Selected examples for each of these three types of experiments are given. (Auth.)

  18. 99 Tc NMR determination of the oxygen isotope content in 18 O-enriched water.

    Science.gov (United States)

    Tarasov, Valerii P; Kirakosyan, Gayana А; German, Konstantin E

    2018-03-01

    99 Tc NMR has been suggested as an original method of evaluating the content of oxygen isotopes in oxygen-18-enriched water, a precursor for the production of radioisotope fluorine-18 used in positron emission tomography. To this end, solutions of NH 4 TcO 4 or NaTcO 4 (up to 0.28 mol/L) with natural abundance of oxygen isotopes in virgin or recycled 18 O-enriched water have been studied by 99 Tc NMR. The method is based on 16 O/ 17 O/ 18 O intrinsic isotope effects in the 99 Tc NMR chemical shifts, and the statistical distribution of oxygen isotopes in the coordination sphere of TcO 4 - and makes it possible to quantify the composition of enriched water by measuring the relative intensities of the 99 Tc NMR signals of the Tc 16 O 4-n 18 O n - isotopologues. Because the oxygen exchange between TcO 4 - and enriched water in neutral and alkaline solutions is characterized by slow kinetics, gaseous HCl was bubbled through a solution for a few seconds to achieve the equilibrium distribution of oxygen isotopes in the Tc coordination sphere without distortion of the oxygen composition of the water. Pertechnetate ion was selected as a probe due to its high stability in solutions and the significant 99 Tc NMR shift induced by a single 16 O→ 18 O substitution (-0.43 ± 0.01 ppm) in TcO 4 - and spin coupling constant 1 J( 99 Tc- 17 O) (131.46 Hz) favourable for the observation of individual signals of Tc 16 O 4-n 18 O n - isotopologues. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Are Synonymous Substitutions in Flowering Plant Mitochondria Neutral?

    Science.gov (United States)

    Wynn, Emily L; Christensen, Alan C

    2015-10-01

    Angiosperm mitochondrial genes appear to have very low mutation rates, while non-gene regions expand, diverge, and rearrange quickly. One possible explanation for this disparity is that synonymous substitutions in plant mitochondrial genes are not truly neutral and selection keeps their occurrence low. If this were true, the explanation for the disparity in mutation rates in genes and non-genes needs to consider selection as well as mechanisms of DNA repair. Rps14 is co-transcribed with cob and rpl5 in most plant mitochondrial genomes, but in some genomes, rps14 has been duplicated to the nucleus leaving a pseudogene in the mitochondria. This provides an opportunity to compare neutral substitution rates in pseudogenes with synonymous substitution rates in the orthologs. Genes and pseudogenes of rps14 have been aligned among different species and the mutation rates have been calculated. Neutral substitution rates in pseudogenes and synonymous substitution rates in genes are significantly different, providing evidence that synonymous substitutions in plant mitochondrial genes are not completely neutral. The non-neutrality is not sufficient to completely explain the exceptionally low mutation rates in land plant mitochondrial genomes, but selective forces appear to play a small role.

  20. Potential radiosensitizing agents. 5. 2-Substituted benzimidazole derivatives

    International Nuclear Information System (INIS)

    Gupta, R.P.; Larroquette, C.A.; Agrawal, K.C.

    1982-01-01

    A series of 2-substituted benzimidazoles and their derivatives have been synthesized and tested for their ability to selectively sensitize hypoxic Chinese hamster cells (V-79) toward the lethal effect of ionizing radiation. These compounds were prepared by reacting the 2-substituted benzimidazoles with 1,2-epoxy-3-methoxypropane in the presence of potassium carbonate. Reaction of the 2-nitro and 2-methylfonyl analogue with the epoxide also yielded a cyclized material, which was confirmed to be a benzimidazo[2,1-b]oxazole. In an attempt to increase the electron affinity, 5- or 6-nitro-2-substituted-benzimidazoles were also synthesized and then reacted with the epoxide to yield the corresponding 1-substituted derivatives. The results of the biological tests for the radiosensitizing activity of these agents against Chinese hamster cells (V-79) in culture indicated that the 2-nitro-substituted analogues were the most effective sensitizers in this series

  1. Effect of oxygen defects on transport properties and Tc of YBa2Cu3O6+x: Displacement energy for plane and chain oxygen and implications for irradiation-induced resistivity and Tc suppression

    International Nuclear Information System (INIS)

    Tolpygo, S.K.; Lin, J.; Gurvitch, M.; Hou, S.Y.; Phillips, J.M.

    1996-01-01

    The effect of electron irradiation with energy from 20 to 120 keV on the resistivity, Hall coefficient, and superconducting critical temperature T c of YBa 2 Cu 3 O 6+x thin films has been studied. The threshold energy of incident electrons for T c suppression has been found, and the displacement energy for oxygen in CuO 2 planes has been evaluated as 8.4 eV for irradiation along the c axis. The kinetics of production of the in-plane oxygen vacancies has been studied and found to be governed by athermal recombination of vacancy-interstitial pairs. The evaluated recombination volume constitutes about 21 unit cells. The increase in the T-linear resistivity slope and Hall coefficient at unchanged T c was observed in irradiations with subthreshold incident energies and was ascribed to the effect of chain oxygen displacements. The upper limit on the displacement energy for chain oxygen has been estimated as 2.8 eV. In x=0.9 samples the T c suppression by in-plane oxygen defects and increase in residual resistivity have been found to be, respectively, -280 K and 1.5 mΩcm per defect in the unit cell. It is shown that T c suppression by in-plane oxygen defects is a universal function of the transport impurity scattering rate and can be described qualitatively by pair-breaking theory for d-wave superconductors with nonmagnetic potential scatterers. Evaluation of scattering and pair-breaking rates as well as the scattering cross section and potential is given. A comparison of the influence of in-plane oxygen defects on transport properties with that of other in-plane defects, such as Zn and Ni substitutions for Cu, is also made. copyright 1996 The American Physical Society

  2. Arylazoindazole Photoswitches : Facile Synthesis and Functionalization via SNAr Substitution

    NARCIS (Netherlands)

    Travieso-Puente, Raquel; Budzak, Simon; Chen, Juan; Stacko, Peter; Jastrzebski, Johann T B H; Jacquemin, Denis; Otten, Edwin

    2017-01-01

    A straightforward synthetic route to arylazoindazoles via nucleophilic aromatic substitution is presented. Upon deprotonation of the NH group, a C6F5-substituted formazan undergoes facile cyclization as a result of intermolecular nucleophilic substitution (SNAr). This new class of azo photoswitches

  3. Goods-Time Elasticity of Substitution in Health Production.

    Science.gov (United States)

    Du, Juan; Yagihashi, Takeshi

    2017-11-01

    We examine how inputs for health production, in particular, medical care and health-enhancing time, are combined to improve health. The estimated elasticity of substitution from a constant elasticity of substitution production function is significantly less than one for the working-age population, rejecting the unit elasticity of substitution used in previous studies. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Enhanced osteoconductivity of sodium-substituted hydroxyapatite by system instability.

    Science.gov (United States)

    Sang Cho, Jung; Um, Seung-Hoon; Su Yoo, Dong; Chung, Yong-Chae; Hye Chung, Shin; Lee, Jeong-Cheol; Rhee, Sang-Hoon

    2014-07-01

    The effect of substituting sodium for calcium on enhanced osteoconductivity of hydroxyapatite was newly investigated. Sodium-substituted hydroxyapatite was synthesized by reacting calcium hydroxide and phosphoric acid with sodium nitrate followed by sintering. As a control, pure hydroxyapatite was prepared under identical conditions, but without the addition of sodium nitrate. Substitution of calcium with sodium in hydroxyapatite produced the structural vacancies for carbonate ion from phosphate site and hydrogen ion from hydroxide site of hydroxyapatite after sintering. The total system energy of sodium-substituted hydroxyapatite with structural defects calculated by ab initio methods based on quantum mechanics was much higher than that of hydroxyapatite, suggesting that the sodium-substituted hydroxyapatite was energetically less stable compared with hydroxyapatite. Indeed, sodium-substituted hydroxyapatite exhibited higher dissolution behavior of constituent elements of hydroxyapatite in simulated body fluid (SBF) and Tris-buffered deionized water compared with hydroxyapatite, which directly affected low-crystalline hydroxyl-carbonate apatite forming capacity by increasing the degree of apatite supersaturation in SBF. Actually, sodium-substituted hydroxyapatite exhibited markedly improved low-crystalline hydroxyl-carbonate apatite forming capacity in SBF and noticeably higher osteoconductivity 4 weeks after implantation in calvarial defects of New Zealand white rabbits compared with hydroxyapatite. In addition, there were no statistically significant differences between hydroxyapatite and sodium-substituted hydroxyapatite on cytotoxicity as determined by BCA assay. Taken together, these results indicate that sodium-substituted hydroxyapatite with structural defects has promising potential for use as a bone grafting material due to its enhanced osteoconductivity compared with hydroxyapatite. © 2013 Wiley Periodicals, Inc.

  5. Oxygen toxicity

    Directory of Open Access Journals (Sweden)

    C. A. van der Westhuizen

    1990-07-01

    Full Text Available Oxygen has been discovered about 200 years ago. Since then the vital physiological involvement of oxygen in various biologi­cal processes, mainly energy production, has been established. However, in the body molecular oxygen can be converted to toxic oxygen metabolites such as superoxide anion, hydrogen peroxide, the hydroxyl radical and singlet oxygen. These toxic metabolites are produced mainly in the mitochondria, plasma membranes and endoplasmic reticulum.

  6. 40 CFR 721.4596 - Diazo substituted carbomonocyclic metal complex.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Diazo substituted carbomonocyclic... Specific Chemical Substances § 721.4596 Diazo substituted carbomonocyclic metal complex. (a) Chemical... as a diazo substituted carbomonocyclic metal complex (PMN P-94-1039) is subject to reporting under...

  7. Electrochemical Water Oxidation and Stereoselective Oxygen Atom Transfer Mediated by a Copper Complex.

    Science.gov (United States)

    Kafentzi, Maria-Chrysanthi; Papadakis, Raffaello; Gennarini, Federica; Kochem, Amélie; Iranzo, Olga; Le Mest, Yves; Le Poul, Nicolas; Tron, Thierry; Faure, Bruno; Simaan, A Jalila; Réglier, Marius

    2018-04-06

    Water oxidation by copper-based complexes to form dioxygen has attracted attention in recent years, with the aim of developing efficient and cheap catalysts for chemical energy storage. In addition, high-valent metal-oxo species produced by the oxidation of metal complexes in the presence of water can be used to achieve substrate oxygenation with the use of H 2 O as an oxygen source. To date, this strategy has not been reported for copper complexes. Herein, a copper(II) complex, [(RPY2)Cu(OTf) 2 ] (RPY2=N-substituted bis[2-pyridyl(ethylamine)] ligands; R=indane; OTf=triflate), is used. This complex, which contains an oxidizable substrate moiety (indane), is used as a tool to monitor an intramolecular oxygen atom transfer reaction. Electrochemical properties were investigated and, upon electrolysis at 1.30 V versus a normal hydrogen electrode (NHE), both dioxygen production and oxygenation of the indane moiety were observed. The ligand was oxidized in a highly diastereoselective manner, which indicated that the observed reactivity was mediated by metal-centered reactive species. The pH dependence of the reactivity was monitored and correlated with speciation deduced from different techniques, ranging from potentiometric titrations to spectroscopic studies and DFT calculations. Water oxidation for dioxygen production occurs at neutral pH and is probably mediated by the oxidation of a mononuclear copper(II) precursor. It is achieved with a rather low overpotential (280 mV at pH 7), although with limited efficiency. On the other hand, oxygenation is maximum at pH 8-8.5 and is probably mediated by the electrochemical oxidation of an antiferromagnetically coupled dinuclear bis(μ-hydroxo) copper(II) precursor. This constitutes the first example of copper-centered oxidative water activation for a selective oxygenation reaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Questioning nuclear waste substitution: a case study.

    Science.gov (United States)

    Marshall, Alan

    2007-03-01

    This article looks at the ethical quandaries, and their social and political context, which emerge as a result of international nuclear waste substitution. In particular it addresses the dilemmas inherent within the proposed return of nuclear waste owned by Japanese nuclear companies and currently stored in the United Kingdom. The UK company responsible for this waste, British Nuclear Fuels Limited (BNFL), wish to substitute this high volume intermediate-level Japanese-owned radioactive waste for a much lower volume of much more highly radioactive waste. Special focus is given to ethical problems that they, and the UK government, have not wished to address as they move forward with waste substitution. The conclusion is that waste substitution can only be considered an ethical practice if a set of moderating conditions are observed by all parties. These conditions are listed and, as of yet, they are not being observed.

  9. 40 CFR 721.10043 - Dineopentyl-4-substituted phthalate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dineopentyl-4-substituted phthalate... Specific Chemical Substances § 721.10043 Dineopentyl-4-substituted phthalate (generic). (a) Chemical... as dineopentyl-4-substituted phthalate (PMN P-02-697) is subject to reporting under this section for...

  10. Mixed oxygen ion/electron-conducting ceramics for oxygen separation

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, J.W.; Armstrong, T.R.; Armstrong, B.L. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-08-01

    Mixed oxygen ion and electron-conducting ceramics are unique materials that can passively separate high purity oxygen from air. Oxygen ions move through a fully dense ceramic in response to an oxygen concentration gradient, charge-compensated by an electron flux in the opposite direction. Compositions in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, perovskites where M=Sr, Ca, and Ba, and N=Mn, Ni, Cu, Ti, and Al, have been prepared and their electrical, oxygen permeation, oxygen vacancy equilibria, and catalytic properties evaluated. Tubular forms, disks, and asymmetric membrane structures, a thin dense layer on a porous support of the same composition, have been fabricated for testing purposes. In an oxygen partial gradient, the passive oxygen flux through fully dense structures was highly dependent on composition. An increase in oxygen permeation with increased temperature is attributed to both enhanced oxygen vacancy mobility and higher vacancy populations. Highly acceptor-doped compositions resulted in oxygen ion mobilities more than an order of magnitude higher than yttria-stabilized zirconia. The mixed conducting ceramics have been utilized in a membrane reactor configuration to upgrade methane to ethane and ethylene. Conditions were established to balance selectivity and throughput in a catalytic membrane reactor constructed from mixed conducting ceramics.

  11. Import Substitution in Regional Industrial Production: Theoretical and Practical Aspects

    Directory of Open Access Journals (Sweden)

    Yevgeniy Georgievich Animitsa

    2015-09-01

    Full Text Available The article proves the important role of import substitution in the economic security protection of state and its regions, especially in times of crisis, geopolitical and economical instability. The authors argue that the problem of import substitution is not modern, trendy scientific stream. The issue of displacement of import goods by domestic ones was brought up in famous classic theories of mercantilists. The particular emphasis is placed on the analysis and systematization of different scientific approaches, which are utilized by native and foreign scientists to bring out the matter of “import substitution,” to determine its essential characteristics. The authors suggest their own interpretation of the import substitution notion. In the article, the most significant pro and contra arguments in import substitution policy are defined. The regional aspects in the import substitution are approved: case study — organization of industrial import substitution in the Sverdlovsk region. In the article, the authors analyze the subject matter of the Program “Development of Intraregional Industrial Cooperation and Implementation of an Import Substitution in Branches of Industry in the Sverdlovsk Region.” It is resumed, that active policy of import substitution in the industry may become the driver of regional economic development.

  12. Educating T-Shaped professionals to meet substitution challenges and developing business models for substitution and recycling

    Science.gov (United States)

    Arroyo, Ana; Mendibil Eguiluz, Javier; Sánchez Cupido, Laura

    2018-03-01

    One strategy to overcome the challenges related to critical raw materials (CRMs) is their substitution and recycling. However, the bright scientific idea, proof of concept or laboratory demonstration need to cross the valley of death in order to become stated as ‘a substitute’ instead of ‘a potential substitute’. Most PhD students and Post Docs specialize within a given thematic area; for example on specific materials or on substitution in a certain application. This specialization could limit the ability to generate innovations and profitable business models if there are not enough tools and skills to transform new knowledge and research results into an appealing value proposition towards customers and to a business opportunity for the current markets. The project proposes a framework for developing substitution and recycling related cross-sectorial skills and tools. These are applied for training business-related competences e.g. teamwork, management, communication, value proposition and business models design, especially within RTOs and industries. The proposed learning itinerary can radically improve the path from scientific proof of concept into innovation and lean start up or industrial market launch. The developed framework is tested by a pilot group having several topics within the areas of substitution and recycling of critical raw materials.

  13. Synthesis of Novel Benzimidazolyl-substituted Acrylonitriles and Amidino-substituted Benzimidazo[1,2-a]Quinolines

    Directory of Open Access Journals (Sweden)

    Grace Karminski-Zamola

    2006-08-01

    Full Text Available A series of novel benzimidazole derivatives 3-10 were synthesized. Benzimidazolyl-substituted acrylonitriles 3 and 4 underwent a photochemical dehydrocyclization reaction to give the corresponding mono- and dicyano-substituted benzimidazo[1,2-a] quinolines 5 and 6. Pinner reaction of these compounds did not give the expected mono- and diamidines, but rather only compounds 7-10, with amido groups at 6-position were isolated. A mechanism for the reaction is proposed. Acyclic compounds 3 and 4, as well as cyclic benzimidazo[1,2-a]quinolines 5-8, exhibit interesting spectroscopic properties and are potential biologically active compounds.

  14. Effect of tin doping on oxygen- and carbon-related defects in Czochralski silicon

    International Nuclear Information System (INIS)

    Chroneos, A.; Londos, C. A.; Sgourou, E. N.

    2011-01-01

    Experimental and theoretical techniques are used to investigate the impact of tin doping on the formation and the thermal stability of oxygen- and carbon-related defects in electron-irradiated Czochralski silicon. The results verify previous reports that Sn doping reduces the formation of the VO defect and suppresses its conversion to the VO 2 defect. Within experimental accuracy, a small delay in the growth of the VO 2 defect is observed. Regarding carbon-related defects, it is determined that Sn doping leads to a reduction in the formation of the C i O i , C i C s , and C i O i (Si I ) defects although an increase in their thermal stability is observed. The impact of strain induced in the lattice by the larger tin substitutional atoms, as well as their association with intrinsic defects and carbon impurities, can be considered as an explanation to account for the above observations. The density functional theory calculations are used to study the interaction of tin with lattice vacancies and oxygen- and carbon-related clusters. Both experimental and theoretical results demonstrate that tin co-doping is an efficient defect engineering strategy to suppress detrimental effects because of the presence of oxygen- and carbon-related defect clusters in devices.

  15. Trace maps of general substitutional sequences

    International Nuclear Information System (INIS)

    Kolar, M.; Nori, F.

    1990-01-01

    It is shown that for arbitrary n, there exists a trace map for any n-letter substitutional sequence. Trace maps are explicitly obtained for the well-known circle and Rudin-Shapiro sequences which can be defined by means of substitution rules on three and four letters, respectively. The properties of the two trace maps and their consequences for various spectral properties are briefly discussed

  16. Substituted decision making: elder guardianship.

    Science.gov (United States)

    Leatherman, Martha E; Goethe, Katherine E

    2009-11-01

    The goal of this column is to help experienced clinicians navigate the judicial system when they are confronted with requests for capacity evaluations that involve guardianship (conservatorship). The interface between the growing elderly medical population and increasing requests for substituted decision making is becoming more complex. This column will help practicing psychiatrists understand the medical, legal, and societal factors involved in adult guardianship. Such understanding is necessary in order to effectively perform guardianship evaluations and adequately inform courts, patients, and families about the psychiatric diagnoses central to substituted decision making.

  17. Boomerang-type substitution reaction: reactivity of fullerene epoxides and a halofullerenol.

    Science.gov (United States)

    Jia, Zhenshan; Zhang, Xiang; Zhang, Gaihong; Huang, Shaohua; Fang, Hao; Hu, Xiangqing; Li, Yuliang; Gan, Liangbing; Zhang, Shiwei; Zhu, Daoben

    2007-02-05

    The C(s)-symmetric fullerene chlorohydrin C60(Cl)(OH)(OOtBu)4 reacts with 4-dimethylaminopyridine (DMAP) and 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield two isomers with the formula C60(O)(OOtBu)4 in good yields. These isomers differ with respect to the location of the epoxy functionality. The one from DMAP is C(s) symmetric, whereas that from DABCO is C1 symmetric with the epoxy group on the central pentagon. Two different mechanisms are proposed to explain the chemoselectivity of these reactions. The reaction with DMAP involves single-electron transfer as the key step; DMAP acts as the electron donor. A combination of an oxygen-atom shift and S(N)2'' processes (boomerang substitution) are responsible for the formation of isomer with DACBO. Various related reactions support the proposed mechanisms. The structures of new fullerene derivatives were determined by spectroscopy, single-crystal X-ray analysis, and chemical correlation experiments.

  18. Substitute energy resource policy in Japan

    International Nuclear Information System (INIS)

    Umehara, Katsuhiko

    1980-01-01

    Japan depends 88% of energy resources and 99.8% of petroleum on imports. The solution of energy problems is now made internationally. As the means for Japan, there are the substitution of other resources for petroleum and its promotion. However, this involves the considerable funds for the development and utilization, which must be borne by the people in the form of tax. For governmental financing, a special account must be set up for the particular purpose. In the research and development of new energy resources, new institution is required. The following matters are described: petroleum shortage coming even in 1980s, the international need of substitute energy development, the need for establishing measures for substitute energy resources, acquisition of the funds, special-account governmental financing, and an institute of new energy development. (author)

  19. Multisensory integration, sensory substitution and visual rehabilitation

    DEFF Research Database (Denmark)

    Proulx, Michael J; Ptito, Maurice; Amedi, Amir

    2014-01-01

    Sensory substitution has advanced remarkably over the past 35 years since first introduced to the scientific literature by Paul Bach-y-Rita. In this issue dedicated to his memory, we describe a collection of reviews that assess the current state of neuroscience research on sensory substitution...

  20. Atom interaction propensities of oxygenated chemical functions in crystal packings

    Directory of Open Access Journals (Sweden)

    Christian Jelsch

    2017-03-01

    Full Text Available The crystal contacts of several families of hydrocarbon compounds substituted with one or several types of oxygenated chemical groups were analyzed statistically using the Hirshfeld surface methodology. The propensity of contacts to occur between two chemical types is described with the contact enrichment descriptor. The systematic large enrichment ratios of some interactions like the O—H...O hydrogen bonds suggests that these contacts are a driving force in the crystal packing formation. The same statement holds for the weaker C—H...O hydrogen bonds in ethers, esters and ketones, in the absence of polar H atoms. The over-represented contacts in crystals of oxygenated hydrocarbons are generally of two types: electrostatic attractions (hydrogen bonds and hydrophobic interactions. While Cl...O interactions are generally avoided, in a minority of chloro-oxygenated hydrocarbons, significant halogen bonding does occur. General tendencies can often be derived for many contact types, but outlier compounds are instructive as they display peculiar or rare features. The methodology also allows the detection of outliers which can be structures with errors. For instance, a significant number of hydroxylated molecules displaying over-represented non-favorable oxygen–oxygen contacts turned out to have wrongly oriented hydroxyl groups. Beyond crystal packings with a single molecule in the asymmetric unit, the behavior of water in monohydrate compounds and of crystals with Z′ = 2 (dimers are also investigated. It was found in several cases that, in the presence of several oxygenated chemical groups, cross-interactions between different chemical groups (e.g. water/alcohols; alcohols/phenols are often favored in the crystal packings. While some trends in accordance with common chemical principles are retrieved, some unexpected results can however appear. For example, in crystals of alcohol–phenol compounds, the strong O—H...O hydrogen bonds between

  1. 2-Bromo-1,4-naphthoquinone: a potentially improved substitute of menadione in Apatone™ therapy

    Energy Technology Data Exchange (ETDEWEB)

    Graciani, F.S.; Ximenes, V.F. [Departamento de Química, Faculdade de Ciências, Universidade Estadual Paulista, Bauru SP (Brazil); Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara SP (Brazil)

    2012-05-18

    Apatone™, a combination of menadione (2-methyl-1,4-naphthoquinone, VK{sub 3}) and ascorbic acid (vitamin C, VC) is a new strategy for cancer treatment. Part of its effect on tumor cells is related to the cellular pro-oxidative imbalance provoked by the generation of hydrogen peroxide (H{sub 2}O{sub 2}) through naphthoquinone redox cycling. In this study, we attempted to find new naphthoquinone derivatives that would increase the efficiency of H{sub 2}O{sub 2} production, thereby potentially increasing its efficacy for cancer treatment. The presence of an electron-withdrawing group in the naphthoquinone moiety had a direct effect on the efficiency of H{sub 2}O{sub 2} production. The compound 2-bromo-1,4-naphthoquinone (BrQ), in which the bromine atom substituted the methyl group in VK{sub 3}, was approximately 10- and 19-fold more efficient than VK{sub 3} in terms of oxygen consumption and H{sub 2}O{sub 2} production, respectively. The ratio [H{sub 2}O{sub 2}]{sub produced} / [naphthoquinone]{sub consumed} was 68 ± 11 and 5.8 ± 0.2 (µM/µM) for BrQ and VK{sub 3}, respectively, indicating a higher efficacy of BrQ as a catalyst for the autoxidation of ascorbic acid. Both VK{sub 3} and BrQ reacted with glutathione (GSH), but BrQ was the more effective substrate. Part of GSH was incorporated into the naphthoquinone, producing a nucleophilic substitution product (Q-SG). The depletion of BrQ by GSH did not prevent its redox capacity since Q-SG was also able to catalyze the production of reactive oxygen species. VK{sub 3}/VC has already been submitted to clinical trials for the treatment of prostate cancer and has demonstrated promising results. However, replacement of VK{sub 3} with BrQ will open new lines of investigation regarding this approach to cancer treatment.

  2. Constructing HVS-Based Optimal Substitution Matrix Using Enhanced Differential Evolution

    Directory of Open Access Journals (Sweden)

    Shu-Fen Tu

    2013-01-01

    Full Text Available Least significant bit (LSB substitution is a method of information hiding. The secret message is embedded into the last k bits of a cover-image in order to evade the notice of hackers. The security and stego-image quality are two main limitations of the LSB substitution method. Therefore, some researchers have proposed an LSB substitution matrix to address these two issues. Finding the optimal LSB substitution matrix can be conceptualized as a problem of combinatorial optimization. In this paper, we adopt a different heuristic method based on other researchers’ method, called enhanced differential evolution (EDE, to construct an optimal LSB substitution matrix. Differing from other researchers, we adopt an HVS-based measurement as a fitness function and embed the secret by modifying the pixel to a closest value rather than simply substituting the LSBs. Our scheme extracts the secret by modular operations as simple LSB substitution does. The experimental results show that the proposed embedding algorithm indeed improves imperceptibility of stego-images substantially.

  3. DOES CURRENCY SUBSTITUTION AFFECT EXCHANGE RATE VOLATILITY?

    Directory of Open Access Journals (Sweden)

    Hisao Kumamoto

    2014-10-01

    Full Text Available This study investigates the impacts of the degree of currency substitution on nominal exchange rate volatility in seven countries (Indonesia, the Philippines, the Czech Republic, Hungary, Poland, Argentina, and Peru. We use the Threshold ARCH model to consider the ratchet effect of currency substitution and sample periods in the 2000s, during which time the economies of the sample countries stabilized, while the U.S. dollar and euro depreciated against other major currencies following the recent global financial crisis. The presented empirical analyses show that the degree of currency substitution has significant positive effects on the conditional variance of the depreciation rate of the nominal exchange rate in most sample countries. Moreover, a shock to the depreciation rate of the nominal exchange rate has asymmetric effects on the conditional variance, depending on the sign. One possible explanation for these differential effects is the existence of the ratchet effect of currency substitution.

  4. The role of biomass in US industrial interfuel substitution

    International Nuclear Information System (INIS)

    Jones, Clifton T.

    2014-01-01

    The role of biomass in US industrial interfuel substitution in the industrial sector has typically been analyzed using data for the four traditional fuels of coal, oil, electricity and natural gas. However, the use of biomass as an industrial fuel in the US has grown, and now exceeds that of coal. Using data from 1960 to 2011, interfuel substitution in the US industrial sector is modeled with a dynamic linear logit model which includes biomass alongside the other four traditional fuels. Adding biomass to the model reduces somewhat the estimated own-price and cross-price elasticities for the other four fuels, while revealing that biomass and natural gas are substitute fuels. This implies that previous studies excluding biomass may have overestimated the potential for interfuel substitution, giving policy makers an inaccurate impression of the ability of carbon taxes or other environmental regulation to reduce greenhouse gas (GHG) emissions. - Highlights: • Biomass usage by the US industrial sector now exceeds coal usage. • Previous interfuel substitution studies have not included biomass as a fuel. • Linear logit model is used to examine role of biomass in interfuel substitution. • Including biomass in the model lowers estimated price elasticities for traditional fuels. • Biomass is found to be a substitute for natural gas for industrial users

  5. Closed Loop Control of Oxygen Delivery and Oxygen Generation

    Science.gov (United States)

    2017-08-01

    were used for this study and were connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen...connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen based on the oxygen saturation...2017-4119, 28 Aug 2017. oximetry (SpO2) and intermittent arterial blood sampling for arterial oxygen tension (partial pressure of oxygen [PaO2]) and

  6. Carburants de substitution : orientations et recherches françaises Synthetic Fuels: French Orientation and Research

    Directory of Open Access Journals (Sweden)

    Guibet J. C.

    2006-11-01

    Full Text Available Le programme d'études et de recherches entrepris en France, depuis 1981, dans le domaine des carburants de substitution, porte à la fois sur l'examen des techniques d'obtention et sur les modalités d'utilisation de ces produits. Les travaux concernent essentiellement le méthanol, le système acétono-butylique et, pour les moteurs Diesel, les dérivés d'huiles végétales. On prévoit, dans une première phase, l'incorporation de faibles proportions - moins de 10 % - de produits organiques oxygénés dans le supercarburant sans modifier les spécifications du produit ni les conditions de réglage des véhicules. D'autres études sont effectuées sur des mélanges à teneur moyenne ou élevée en méthanol (30, 50 ou 90 % afin d'examiner les meilleures voies possibles pour une substitution plus importante. The research undertaken in France since 1981 in the field of alternative fuels includes both the ways of producing and the ways of using such products. These research projects mainly concern methanol, butanol-acetone system and, for diesel engines, vegetable-oil derivatives. In the first phase, plans are being made to incorporate small proportions (less then 10% of oxygenated organic products in premium gasoline without modifying either the specifications of the product or vehicle tuning conditions. Other research is being done on mixtures with a moderate or high methanol content (30, 50 or 90% so as to examine the best possible methods for substituting larger amounts.

  7. High-Energy-Density Metal-Oxygen Batteries: Lithium-Oxygen Batteries vs Sodium-Oxygen Batteries.

    Science.gov (United States)

    Song, Kyeongse; Agyeman, Daniel Adjei; Park, Mihui; Yang, Junghoon; Kang, Yong-Mook

    2017-12-01

    The development of next-generation energy-storage devices with high power, high energy density, and safety is critical for the success of large-scale energy-storage systems (ESSs), such as electric vehicles. Rechargeable sodium-oxygen (Na-O 2 ) batteries offer a new and promising opportunity for low-cost, high-energy-density, and relatively efficient electrochemical systems. Although the specific energy density of the Na-O 2 battery is lower than that of the lithium-oxygen (Li-O 2 ) battery, the abundance and low cost of sodium resources offer major advantages for its practical application in the near future. However, little has so far been reported regarding the cell chemistry, to explain the rate-limiting parameters and the corresponding low round-trip efficiency and cycle degradation. Consequently, an elucidation of the reaction mechanism is needed for both lithium-oxygen and sodium-oxygen cells. An in-depth understanding of the differences and similarities between Li-O 2 and Na-O 2 battery systems, in terms of thermodynamics and a structural viewpoint, will be meaningful to promote the development of advanced metal-oxygen batteries. State-of-the-art battery design principles for high-energy-density lithium-oxygen and sodium-oxygen batteries are thus reviewed in depth here. Major drawbacks, reaction mechanisms, and recent strategies to improve performance are also summarized. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Moessbauer studies of 57Fe substitution of Cu ions in superconducting oxides

    International Nuclear Information System (INIS)

    Saitovitch, E.B.

    1988-01-01

    Since the discovery of high-T c superconductivity in YBa 2 Cu 3 O 7 oxides several studies of metal ions substitutions were reported. The observed depression on T c without a systematic correlation with the charge and magnetic moment of Cu substituents claims for more detailed information about its local properties as can be revealed by 57 Fe Moessbauer spectroscopy. The results for different iron concentrations combined with modifications of the superconducting transition are discussed concerning the presence of magnetic moments on the Fe ions and the preferential occupation of Cu(1) sites, recently confirmed by neutron and electron diffraction experiments. The oxygen coordination for the different iron species are proposed on the basis of their dependence on Fe concentration, their behavior at high temperatures as well as the electron diffraction and electron microscopy measurements reported for Fe: YBa 2 Cu 3 O 7 samples. (author) [pt

  9. Oxygen Therapy

    Directory of Open Access Journals (Sweden)

    Bonnie Solmes

    2000-01-01

    Full Text Available LTOT is prescribed for people with chronic lung disease in whom there is a decrease in the ability of the lungs to supply enough oxygen to the body. The heart is obliged to pump faster to meet the body's oxygen requirements. This may place undue stress on the heart, resulting in palpitations, dizziness and fatigue. A low oxygen level in arterial blood is also harmful to the heart, the brain and the pulmonary blood vessels. Oxygen therapy is used to break this cycle. A person with low blood oxygen will often be able to accomplish more with less fatigue with the help of supplemental oxygen therapy. Shortness of breath is a mechanical problem resulting from the effects of chronic obstructive pulmonary disease. Oxygen therapy may or may not reduce shortness of breath, but it will help the lungs and heart to function with less stress.

  10. [Domiciliary oxygen therapy].

    Science.gov (United States)

    Abdel Kafi, S

    2010-09-01

    In Belgium, oxygen therapy is becoming more and more accessible. When oxygen is needed for short periods or for special indications as palliative care, an agreement between mutual insurance companies and pharmacists allows the practitioner the home installation of gazeous oxygen cylinder or of oxygen concentrator. When long term oxygen therapy (LTOT) is indicated for patients with respiratory insufficiency, the pneumologist must first ask the INAMI the authorization to install one of the following modalities: oxygen concentrator with or without demand oxygen delivery cylinder and liquid oxygen. The goal of LTOT is to increase survival and quality of life. The principal and well accepted indication for LTOT is severe hypoxemia. The beneficial effects of oxygen therapy limited at night or on exertion are controversial. In order to increase patient's autonomy, oxygen can be prescribed for ambulation, respecting prescription's rules. At each step of oxygen therapy implementing (indication, choice of the device and follow-up) the patient under oxygen may benefit from a joint approach between the general practitioner and the chest specialist.

  11. Effect of substitution groups in carbon-13 NMR of tri-substituted camphors; Efeitos de substituintes em RMN de carbono-13 de canforas 3-substituidas

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Carlos R; Rittner, Roberto [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica; Basso, Ernani A [Universidade Estadual de Maringa, PR (Brazil). Dept. de Quimica Inorganica

    1994-12-31

    This work presents and discusses the empirical effects of substitution groups in the carbon-13 NMR spectra of tri-substituted camphors and their correlation with the chemical properties of such substitution groups such as electronegativity. The obtained results are presented and discussed

  12. 21 CFR 184.1259 - Cocoa butter substitute.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cocoa butter substitute. 184.1259 Section 184.1259... FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1259 Cocoa butter substitute. (a) The common or...

  13. 40 CFR 721.562 - Substituted alkylamine salt.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted alkylamine salt. 721.562 Section 721.562 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.562 Substituted alkylamine salt...

  14. Oxygen therapy - infants

    Science.gov (United States)

    ... breathe increased amounts of oxygen to get normal levels of oxygen in their blood. Oxygen therapy provides babies with the extra oxygen. Information Oxygen is a gas that the cells in your body need to work properly. The ...

  15. Structural and chemical reactivity modifications of a cobalt perovskite induced by Sr-substitution. An in situ XAS study

    International Nuclear Information System (INIS)

    Hueso, Jose L.; Holgado, Juan P.; Pereñíguez, Rosa; Gonzalez-DelaCruz, V.M.; Caballero, Alfonso

    2015-01-01

    LaCoO 3 and La 0.5 Sr 0.5 CoO 3−δ perovskites have been studied by in situ Co K-edge XAS. Although the partial substitution of La(III) by Sr(II) species induces an important increase in the catalytic oxidation activity and modifies the electronic state of the perovskite, no changes could be detected in the oxidation state of cobalt atoms. So, maintaining the electroneutrality of the perovskite requires the generation of oxygen vacancies in the network. The presence of these vacancies explains that the substituted perovskite is now much more reducible than the original LaCoO 3 perovskite. As detected by in situ XAS, after a consecutive reduction and oxidation treatment, the original crystalline structure of the LaCoO 3 perovskite is maintained, although in a more disordered state, which is not the case for the Sr doped perovskite. So, the La 0.5 Sr 0.5 CoO 3−δ perovskite submitted to the same hydrogen reduction treatment produces metallic cobalt, while as determined by in situ XAS spectroscopy the subsequent oxidation treatment yields a Co(III) oxide phase with spinel structure. Surprisingly, no Co(II) species are detected in this new spinel phase. - Highlights: • A Sr-substituted lanthanum cobalt perovskite has been prepared by spray pyrolysis. • It has been established that Co(III) cations are present in both perovskites. • LaCoO 3 is a less reducible phase than the substituted La 0.5 Sr 0.5 CoO 3−δ . • After reoxidation of reduced La 0.5 Sr 0.5 CoO 3−δ , a 100% Co(III) spinel is obtained

  16. Law of substitution for mixed arrays

    International Nuclear Information System (INIS)

    Koudelka, A.J.

    1987-01-01

    The nuclear safety justification of a mixed array of dissimilar fissile units of metal units and dilute solution units, according to Clayton, has been a persistent and nagging problem. Dissimilar uranium metal or dissimilar uranium solution units in a mixed array can also create a modeling nightmare for the nuclear criticality safety engineer. Now, a calculational method known as the Law of Substitution has been developed to ensure that the k/sub eff/ of an array of uranium metal and uranium solution units will satisfy any k/sub eff/ limit set by the nuclear safety engineer. The nuclear criticality safety engineer can utilize the Law of Substitution to safely mix or substitute different uranium metal units, different uranium solution units, and more importantly, uranium metal and dilute UO 2 solution units in an array. The Law of Substitution is as follows: (1) calculate the k/sub eff/ of each unit type in its own infinite planar array. (2) Determine the edge-to-edge spacing of the infinite planar array of each type of unit to satisfy a desired k/sub eff/. (3) Select the largest edge-to-edge spacing from among the similar units in their infinite planar arrays and use that spacing for the finite or infinite planar array of mixed units

  17. Influence of substitution on the proton donor and proton acceptor abilities of molecules. III. Study of chlorine and ftorine substitution alcohol

    International Nuclear Information System (INIS)

    Nurulloev, M.; Narziev, B.N.; Islomov, Z.; Fayzieva, M.

    2006-01-01

    This work gives the study of influence of chlorine and ftorine atoms as substitutions to proton donor and proton acceptor ability of primary, secondary and tertiary alifatic alcohol. In accordance to developed method the proton donor ability of studied substances are determined. It is shown that the quantity of proton donor ability of reactionary center of the molecules depend on substitution nature and its proton acceptor quantity. Proposed that substitution influence of these molecule mainly transferred by inductive effect

  18. [Contingency management in opioid substitution treatment].

    Science.gov (United States)

    Specka, M; Böning, A; Scherbaum, N

    2011-07-01

    The majority of opiate-dependent patients in substitution treatment show additional substance-related disorders. Concomitant use of heroin, alcohol, benzodiazepines or cocaine compromises treatment success. Concomitant drug use may be treated by using contingency management (CM) which is based on learning theory. In CM, abstinence from drugs, as verified by drug screenings, is reinforced directly and contingently. Reinforcers used in CM studies with substituted patients were, amongst others, vouchers and take-home privileges. Studies in the USA show a medium average effect of CM on drug consumption rates and abstinence. The effects decrease markedly after the end of the intervention. We discuss whether CM is applicable within the German substitution treatment system and how it can be combined with other interventions such as selective detoxification treatments or cognitive-behavioural programmes. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Substitution between Cars within the Household

    DEFF Research Database (Denmark)

    de Borger, Bruno; Mulalic, Ismir; Rouwendal, Jan

    In this paper we study the demand for car kilometres in two-car households, focusing on the substitution between cars in response to fuel price changes. We use a large sample of detailed Danish data on two-car households to estimate—for each car owned by the household—own and cross-price effects...... of increases in fuel costs per kilometre. The empirical results show that failure to capture substitution between cars within the household can result in substantial misspecification biases. Ignoring substitution, we estimate fuel price elasticities of –0.81 and -0.65 for the primary and secondary cars...... efficient car, finding partial support for the underlying hypothesis. More importantly, the results of this extended model emphasize the importance of behavioural differences related to the position of the most fuel efficient car in the household, suggesting that households’ fuel efficiency choices...

  20. Substitution as a Device of Grammatical Cohesion in English Contexts

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Hasannejad

    2012-05-01

    Full Text Available The present study set out to investigate the effect of teaching substitution as a kind of grammatical cohesion on the true identification of confusing substitution elements with cohesive or non-cohesive roles in different contexts and also the production of modal, reporting and conditional contexts through clausal substitution acquaintance. To this end, the following procedures were taken. First 120 male and female EFL students were selected from Iranshahr Azad University. Having administered the language proficiency test, researchers selected 80 students as intermediate subjects according to their TOEFL band scores. First, pretests of cohesion identification (substitution and production of modal, reporting and conditional environments were administered to both control and experimental groups. Then, the experimental group was exposed to the teaching of the above-said above-mentioned cohesive device. Finally, post-tests of substitution elements’ identification and modal, reporting and conditional contexts’ production through clausal substitution familiarity were administered. The results showed that cohesive device treatment helped students on the true identification of substitution elements. Another finding proved that EFL students might have no difficulty in learning certain rules or classification of rules and application of their clausal substitution knowledge in creating modal, reporting and conditional contexts. Our findings can have implications for the field of language learning and teaching.

  1. Associations between generic substitution and patient-related factors

    DEFF Research Database (Denmark)

    Østergaard Rathe, Jette

    Associations between generic substitution and patient-related factors Jette Østergaard Rathe1, Pia V. Larsen1, Morten Andersen2, Janus L. Thomsen3, Maja S. Paulsen1, Jens Søndergaard1 1. Research Unit of General Practice, Institute of Public Health, University of Southern Denmark 2. Centre...... for Pharmacoepidemiology, Karolinska Institutet, Department of Medicine Solna, Stockholm, Sweden 3. Danish Quality Unit of General Practice, Odense, Denmark Background Generic substitution means that chemically equivalent but less expensive drugs are dispensed in place of a brand name product. Although generic medicines...... by definition are bioequivalent to their brand name counterparts there are concerns about whether generic substitution is always accompanied by clinical equivalence in terms of effectiveness and that it may cause concerns and thereby causing some skepticism towards generic substitution. There is, however...

  2. Long term substitution treatment (maintenance treatment of opioid dependent persons

    Directory of Open Access Journals (Sweden)

    Wirl, Charlotte

    2007-03-01

    Full Text Available Health political background: Methadone substitution treatment in Germany is introduced in 1988 in the framework of a scientific pilot study in North Rhein Westphalia. Recent statistics show that by now a broad offer of substitution treatment exists. From 1 June 2002 to 31 December 2003 113,000 substitution treatments have been recorded as being started of which around 56,000 have been recorded as ongoing treatments by 1 December 2003. Scientific background: Substitution treatment (treatment of opioid-dependent persons using substitution substances is one part of addiction treatment. Its goals are harm reduction and the stabilisation of opioid dependent persons. Integration of opioid-dependent persons in a treatment-setting, reduction of consumption of psychoactive substances, reduction of risk behaviour (primarily related to infectious diseases, decrease of mortality and improvements concerning the social, psychic and physic situation are seen as a success of substitution treatment as maintenance therapy. Research questions: The aim of this HTA report is to investigate which indicators can be used to evaluate the effectiveness of substitution treatment. Based on these indicators an evaluation of the medical, social and economical benefit of substitution treatment - also in relation to abstinence oriented treatment - is carried out. Methods: A systematic literature search was performed in 31 international databases which yielded 2451 articles with publication date between 1995 and February 2005. Results: After a twofold selection process 32 publications were included for assessment and 276 publications were used as background literature. Despite serious restrictions due to selection bias and dropout in most studies focusing on substitution treatment, reduction of consumption of illegal opioids, reduction of risk behaviour, criminal behaviour, mortality and incidence of HIV can be seen as an empirically proven success of substitution treatment

  3. Oxygen diffusion and oxygen effect in tumor tissue

    International Nuclear Information System (INIS)

    Eissa, H.M.; Hehn, G.

    1979-06-01

    The diffusion of oxygen in tumor cords of bronchus carcinoma of the lung have been studied with refined computer methods for solving the diffusion equation in axis symmetric tumor structures. In this tumor configuration we may find three different regions consisting of euoxic cells, hypoxic tumor cells and necrotic parts. In the case of oxygen supply from a capillary inside a cylinder of tumor tissue with radius 200 μm or in a tumor cord of radius 300 μm with oxygen supply by capillaries outside, we get a relation of well oxygenated cells to hypoxic cells approximately as 1:8 or as 1:1.1 respectively. Of course most of the tumor cords observed in histological slices have smaller diameters, so that an average of approximately 20% hypoxic cells can be assumed. Based on the work of Ardenne, the diffusion of oxygen and glucose in a tumor of type DS-carcinosarcom has been investigated in both intact tumor and tumor treated with ionizing radiation. We can show that a strong reoxygenation effect takes place in that the well supplied regions may increase in some tumor configurations up to a factor of four by volume. The biological consequences of the oxygen pressure determined in tumor cells are discussed in detail. The investigation of oxygen diffusion in the intercapillary tumor region should give a quantitative physical basis for considering the oxygen effect with the aim to explain the advantages of neutron therapy against conventional radiotherapy. (orig./MG) [de

  4. X-ray sensitization of chromatids with unifilarly and bifilarly substituted DNA

    International Nuclear Information System (INIS)

    Wolff, S.

    1981-01-01

    When cells are grown for two rounds of DNA replication in the presence of the thymidine analogue 5-bromodeoxyuridine, chromosomes containing one chromatid with unifilarly substituted DNA and one with bifilarly substituted DNA are found. These can be distinguished by harlequin staining techniques that stain one chromatid dark and one light. When the degree of substitution is 60% or greater, 3 times as many X-ray-induced chromatid breaks are produced as in unsubstituted chromatids. This represents maximal sensitization. The unifilarly substituted (dark) chromatid is as sensitive as its bifilarly substituted (light) sister chromatid. If cells are grown in low concentrations of 5-bromodeoxyuridine (BrdUrd), then the amount of substitution is less and the bifilarly substituted chromatic is more sensitive than the unifilarly substituted one. When large numbers of cells are grown in very low concentrations of BrdUrd, the analogue is almost completely depleted during the first round of replication leading to harlequin chromosomes containing one unsubstituted (dark) and one unifilarly substituted (light) chromatid. Under these conditions a maximal sensitization between light-staining and dark-staining chromatids can occur. This can be confused with the differential sensitivity between unifilarly and bifilarly substituted chromatids. The apparent discrepant results obtained by different investigators are most likely caused by the use of very low levels of BrdUrd in some of the experiments. (orig.)

  5. [Currently available skin substitutes].

    Science.gov (United States)

    Oravcová, Darina; Koller, Ján

    2014-01-01

    The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. Autologous split or full-thickness skin graft are the best definitive burn wound coverage, but it is constrained by the limited available sources, especially in major burns. Donor site morbidities in term of additional wounds and scarring are also of concern of the autograft application. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. This paper reviews currently available skin substitutes, produced in not for-profit skin banks as well as commercially available. They are divided according to type of material included, as biological, biosynthetic and synthetic and named respectively.

  6. Evaluating rare amino acid substitutions (RGC_CAMs in a yeast model clade.

    Directory of Open Access Journals (Sweden)

    Kenneth Polzin

    Full Text Available When inferring phylogenetic relationships, not all sites in a sequence alignment are equally informative. One recently proposed approach that takes advantage of this inequality relies on sites that contain amino acids whose replacement requires multiple substitutions. Identifying these so-called RGC_CAM substitutions (after Rare Genomic Changes as Conserved Amino acids-Multiple substitutions requires that, first, at any given site in the amino acid sequence alignment, there must be a minimum of two different amino acids; second, each amino acid must be present in at least two taxa; and third, the amino acids must require a minimum of two nucleotide substitutions to replace each other. Although theory suggests that RGC_CAM substitutions are expected to be rare and less likely to be homoplastic, the informativeness of RGC_CAM substitutions has not been extensively evaluated in biological data sets. We investigated the quality of RGC_CAM substitutions by examining their degree of homoplasy and internode certainty in nearly 2.7 million aligned amino acid sites from 5,261 proteins from five species belonging to the yeast Saccharomyces sensu stricto clade whose phylogeny is well-established. We identified 2,647 sites containing RGC_CAM substitutions, a number that contrasts sharply with the 100,887 sites containing RGC_non-CAM substitutions (i.e., changes between amino acids that require only a single nucleotide substitution. We found that RGC_CAM substitutions had significantly lower homoplasy than RGC_non-CAM ones; specifically RGC_CAM substitutions showed a per-site average homoplasy index of 0.100, whereas RGC_non-CAM substitutions had a homoplasy index of 0.215. Internode certainty values were also higher for sites containing RGC_CAM substitutions than for RGC_non-CAM ones. These results suggest that RGC_CAM substitutions possess a strong phylogenetic signal and are useful markers for phylogenetic inference despite their rarity.

  7. Anthropogenic areas as incidental substitutes for original habitat.

    Science.gov (United States)

    Martínez-Abraín, Alejandro; Jiménez, Juan

    2016-06-01

    One speaks of ecological substitutes when an introduced species performs, to some extent, the ecosystem function of an extirpated native species. We suggest that a similar case exists for habitats. Species evolve within ecosystems, but habitats can be destroyed or modified by natural and human-made causes. Sometimes habitat alteration forces animals to move to or remain in a suboptimal habitat type. In that case, the habitat is considered a refuge, and the species is called a refugee. Typically refugee species have lower population growth rates than in their original habitats. Human action may lead to the unintended generation of artificial or semiartificial habitat types that functionally resemble the essential features of the original habitat and thus allow a population growth rate of the same magnitude or higher than in the original habitat. We call such areas substitution habitats and define them as human-made habitats within the focal species range that by chance are partial substitutes for the species' original habitat. We call species occupying a substitution habitat adopted species. These are 2 new terms in conservation biology. Examples of substitution habitats are dams for European otters, wheat and rice fields for many steppeland and aquatic birds, and urban areas for storks, falcons, and swifts. Although substitution habitats can bring about increased resilience against the agents of global change, the conservation of original habitat types remains a conservation priority. © 2016 Society for Conservation Biology.

  8. N-substituted iminodiacetic acids

    International Nuclear Information System (INIS)

    Nunn, A.; Loberg, M.

    1982-01-01

    The chemical preparation of several new N-substituted iminodiacetic acid derivatives are described. These compounds when complexed with sup(99m)Tc provide useful radiopharmaceuticals for the external imaging of the hepatobiliary system. (U.K.)

  9. Photophysical investigation of cyano-substituted terrylenediimide derivatives.

    Science.gov (United States)

    Kennes, Koen; Baeten, Yannick; Vosch, Tom; Sempels, Wouter; Yordanov, Stoyan; Stappert, Sebastian; Chen, Long; Müllen, Klaus; Hofkens, Johan; Van der Auweraer, Mark; Fron, Eduard

    2014-12-18

    Two new terrylenediimide (TDI) chromophores with cyano substituents in the bay and core area (BCN-TDI and OCN-TDI, respectively) have been characterized by a wide range of techniques, and their applicability for stimulated emission depletion (STED) microscopy has been tested. By cyano substitution an increase of the fluorescence quantum yield and a decrease of the nonradiative rate constant is achieved and attributed to a reduced charge-transfer character of the excited state due to a lower electron density of the TDI core. For BCN-TDI, the substitution in the bay area induces a strong torsional twist in the molecule which, similar to phenoxy bay-perylenediimide (PDI), has a strong effect on the fluorescence lifetime but appears to prevent the aggregation that is observed for OCN-TDI. The single-molecule photobleaching stability of BCN- and OCN-TDI is lower than that of a reference TDI without cyano substitution (C7-TDI), although less so for OCN-TDI. The photophysical properties of the excited singlet state are only slightly influenced by the cyano groups. The observed intense stimulated emission, the pump-dump-probe experiments, and STED single-molecule imaging indicate that STED experiments with the cyano-substituted TDIs are possible. However, because of aggregation and more efficient photobleaching, the performance of BCN- and OCN-TDI is worse than that of the reference compound without cyano groups (C7-TDI). Bay-substituted TDIs are less suitable for STED microscopy.

  10. Substitute fluid examinations for liquid manure

    Directory of Open Access Journals (Sweden)

    Schrader Kevin

    2017-01-01

    Full Text Available For the farming industry it is essential to use liquid manure as natural fertilizer. Through new agricultural regulation 2015 in Germany the industry must develop new liquid manure spreader systems because the ammonia and methane emission are limited. In a research project the University of Applied Sciences Zwickau and some other industry partners will develop such a new innovative liquid manure spreader. The new liquid manure spreader should use pulsating air to distribute the liquid manure exactly. The pulsating air, which flows through the pipelines, should be analysed at a test station. For examinations at this test station it is important to find another substitute fluid because liquid manure smells strong, is not transparent and is also not homogeneous enough for scientific investigations. Furthermore it is important to ensure that the substitute fluid is, like liquid manure, a non-Newtonian fluid. The substitute fluid must be a shear-thinning substance - this means the viscosity decrease at higher shear rate. Many different samples like soap-water-farragoes, jelly-water-farragoes, agar-water-farragoes, soap-ethanol-farragoes and more are, for the project, examined in regard of their physical properties to find the best substitute fluid. The samples are examined at the rotational viscometer for viscosity at various shear rates and then compared with the viscosity values of liquid manure.

  11. Substitute fluid examinations for liquid manure

    Science.gov (United States)

    Schrader, Kevin; Riedel, Marco; Eichert, Helmut

    For the farming industry it is essential to use liquid manure as natural fertilizer. Through new agricultural regulation 2015 in Germany the industry must develop new liquid manure spreader systems because the ammonia and methane emission are limited. In a research project the University of Applied Sciences Zwickau and some other industry partners will develop such a new innovative liquid manure spreader. The new liquid manure spreader should use pulsating air to distribute the liquid manure exactly. The pulsating air, which flows through the pipelines, should be analysed at a test station. For examinations at this test station it is important to find another substitute fluid because liquid manure smells strong, is not transparent and is also not homogeneous enough for scientific investigations. Furthermore it is important to ensure that the substitute fluid is, like liquid manure, a non-Newtonian fluid. The substitute fluid must be a shear-thinning substance - this means the viscosity decrease at higher shear rate. Many different samples like soap-water-farragoes, jelly-water-farragoes, agar-water-farragoes, soap-ethanol-farragoes and more are, for the project, examined in regard of their physical properties to find the best substitute fluid. The samples are examined at the rotational viscometer for viscosity at various shear rates and then compared with the viscosity values of liquid manure.

  12. Endogenous cueing attenuates object substitution masking.

    Science.gov (United States)

    Germeys, Filip; Pomianowska, I; De Graef, P; Zaenen, P; Verfaillie, K

    2010-07-01

    Object substitution masking (OSM) is a form of visual masking in which a briefly presented target surrounded by four small dots is masked by the continuing presence of the four dots after target offset. A major parameter in the prediction of OSM is the time required for attention to be directed to the target following its onset. Object substitution theory (Di Lollo et al. in J Exp Psychol Gen 129:481-507, 2000) predicts that the sooner attention can be focused at the target's location, the less masking will ensue. However, recently Luiga and Bachmann (Psychol Res 71:634-640, 2007) presented evidence that precueing of attention to the target location prior to target-plus-mask onset by means of a central (endogenous) arrow cue does not reduce OSM. When attention was cued exogenously, OSM was attenuated. Based on these results, Luiga and Bachmann argued that object substitution theory should be adapted by differentiating the ways of directing attention to the target location. The goal of the present study was to further examine the dissociation between the effects of endogenous and exogenous precueing on OSM. Contrary to Luiga and Bachmann, our results show that prior shifts of attention to the target location initiated by both exogenous and endogenous cues reduce OSM as predicted by object substitution theory and its computational model CMOS.

  13. Structural change of NaO1/2-WO3-NbO5/2-LaO3/2-PO5/2 glass induced by electrochemical substitution of sodium ions with protons.

    Science.gov (United States)

    Ishiyama, Tomohiro; Yamaguchi, Takuya; Nishii, Junji; Yamashita, Toshiharu; Kawazoe, Hiroshi; Kuwata, Naoaki; Kawamura, Junichi; Omata, Takahisa

    2015-05-28

    Structural changes of 35NaO1/2-1WO3-8NbO5/2-5LaO3/2-51PO5/2 glass (1W-glass) before and after the electrochemical substitution of sodium ions with protons by alkali-proton substitution (APS) are studied by Raman and (31)P magic-angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopies. The glass before APS consists of (PO3(-))8.6(P2O7(4-)) chains on average and the terminal Q(1) units (-O-PO3(3-)) are bound to MO6 octahedra (M denotes niobium or tungsten) through P-O-M bonds. Some non-bridging oxygens (NBOs) in the MO6 octahedra are present in addition to the bridging oxygens (BOs) in P-O-M bonds. APS induces fragmentation of the phosphate chains because the average chain length decreases to (PO3(-))3.7(P2O7(4-)) after APS, despite the total number of modifier cations of sodium and lanthanum ions and protons being unaffected by APS. This fragmentation is induced by some of the NBOs in the MO6 octahedra before APS, changing to BOs of the newly formed M-O-P bonds after APS, because of the preferential formation of P-OH bonds over M-OH ones in the present glass. We show that APS under the conditions used here is not a simple substitution of sodium ions with protons, but it is accompanied by the structural relaxation of the glass to stabilize the injected protons.

  14. Zinc-Substituted Myoglobin Is a Naturally Occurring Photo-antimicrobial Agent with Potential Applications in Food Decontamination.

    Science.gov (United States)

    Delcanale, Pietro; Montali, Chiara; Rodríguez-Amigo, Beatriz; Abbruzzetti, Stefania; Bruno, Stefano; Bianchini, Paolo; Diaspro, Alberto; Agut, Montserrat; Nonell, Santi; Viappiani, Cristiano

    2016-11-16

    Zinc-substituted myoglobin (ZnMb) is a naturally occurring photosensitizer that generates singlet oxygen with a high quantum yield. Using a combination of photophysical and fluorescence imaging techniques, we demonstrate the interaction of ZnMb with Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. An efficient antibacterial action against S. aureus was observed, with a reduction up to 99.9999% in the number of colony-forming units, whereas no sizable effect was detected against E. coli. Because ZnMb is known to form during the maturation of additive-free not-cooked cured ham, the use of this protein as a built-in photodynamic agent may constitute a viable method for the decontamination of these food products from Gram-positive bacteria.

  15. Hazardous solvent substitution

    International Nuclear Information System (INIS)

    Twitchell, K.E.

    1995-01-01

    This article is an overview of efforts at INEL to reduce the generation of hazardous wastes through the elimination of hazardous solvents. To aid in their efforts, a number of databases have been developed and will become a part of an Integrated Solvent Substitution Data System. This latter data system will be accessible through Internet

  16. Oxygen effect and intracellular oxygen content (adaptation hypothesis)

    Energy Technology Data Exchange (ETDEWEB)

    Yarmonenko, S P; Ehpshtejn, I M [Akademiya Meditsinskikh Nauk SSSR, Moscow. Onkologicheskij Tsentr

    1977-01-01

    Experimental data indicating that a radiomodifying action of hypoxia is dependent on the ''prehistory'' of the irradiated object are considered. This dependence manifests itself in a decreased protective action of acute hypoxia on the hypoxia-adapted objects. To explain this a hypothesis is proposed connecting a degree of cell radiosensitivity modification, determined by the oxygen effect, with the intracellular oxygen content. The latter, in accord with current ideas, is regulated by variations in the diffusion resistance to oxygen shown by the cytoplasmic membranes depending on the energy level of the cell and the degree of its oxygenation.

  17. Oxygen effect and intracellular oxygen content (adaptation hypothesis)

    International Nuclear Information System (INIS)

    Yarmonenko, S.P.; Ehpshtejn, I.M.

    1977-01-01

    Experimental data indicating that a radiomodifying action of hypoxia is dependent on the ''prehistory'' of the irradiated object are considered. This dependence manifests itself in a decreased protective action of acute hypoxia on the hypoxia-adapted objects. To explain this a hypothesis is proposed connecting a degree of cell radiosensitivity modification, determined by the oxygen effect, with the intracellular oxygen content. The latter, in accord with current ideas, is regulated by variations in the diffusion resistance to oxygen shown by the cytoplasmic membranes depending on the energy level of the cell and the degree of its oxygenation

  18. Fat substitutes in processing of sausages using piramutaba waste.

    Science.gov (United States)

    de Fátima Henriques Lourenço, Lúcia; Dos Santos Galvão, Giane Célia; da Conceição Amaral Ribeiro, Suezilde; de Fátima Amaral Ribeiro, Carmelita; Park, Kil Jin

    2014-07-01

    The aim of this study was to evaluate fat substitute in processing of sausages prepared with surimi of waste from piramutaba filleting. The formulation ingredients were mixed with the fat substitutes added according to a fractional planning 2(4-1), where the independent variables, manioc starch (Ms), hydrogenated soy fat (F), texturized soybean protein (Tsp) and carrageenan (Cg) were evaluated on the responses of pH, texture (Tx), raw batter stability (RBS) and water holding capacity (WHC) of the sausage. Fat substitutes were evaluated in 11 formulations and the results showed that the greatest effects on the responses were found to Ms, F and Cg, being eliminated from the formulation Tsp. To find the best formulation for processing piramutaba sausage was made a complete factorial planning of 2(3) to evaluate the concentrations of fat substitutes in an enlarged range. The optimum condition found for fat substitutes in the sausages formulation were carrageenan (0.51%), manioc starch (1.45%) and fat (1.2%).

  19. Substitution treatment for opioid addicts in Germany

    Directory of Open Access Journals (Sweden)

    Gerlach Ralf

    2007-02-01

    Full Text Available Abstract Background After a long and controversial debate methadone maintenance treatment (MMT was first introduced in Germany in 1987. The number of patients in MMT – first low because of strict admission criteria – increased considerably since the 1990s up to some 65,000 at the end of 2006. In Germany each general practitioner (GP, who has completed an additional training in addiction medicine, is allowed to prescribe substitution drugs to opioid dependent patients. Currently 2,700 GPs prescribe substitution drugs. Psychosocial care should be made available to all MMT patients. Results The results of research studies and practical experiences clearly indicate that patients benefit substantially from MMT with improvements in physical and psychological health. MMT proves successful in attaining high retention rates (65 % to 85 % in the first years, up to 50 % after more than seven years and plays a major role in accessing and maintaining ongoing medical treatment for HIV and hepatitis. MMT is also seen as a vital factor in the process of social re-integration and it contributes to the reduction of drug related harms such as mortality and morbidity and to the prevention of infectious diseases. Some 10 % of MMT patients become drug-free in the long run. Methadone is the most commonly prescribed substitution medication in Germany, although buprenorphine is attaining rising importance. Access to MMT in rural areas is very patchy and still constitutes a problem. There are only few employment opportunities for patients participating in MMT, although regular employment is considered unanimously as a positive factor of treatment success. Substitution treatment in German prisons is heterogeneous in access and treatment modalities. Access is very patchy and the number of inmates in treatment is limited. Nevertheless, substitution treatment plays a substantial part in the health care system provided to drug users in Germany. Conclusion In Germany, a

  20. Substitution treatment for opioid addicts in Germany.

    Science.gov (United States)

    Michels, Ingo Ilja; Stöver, Heino; Gerlach, Ralf

    2007-02-02

    After a long and controversial debate methadone maintenance treatment (MMT) was first introduced in Germany in 1987. The number of patients in MMT--first low because of strict admission criteria--increased considerably since the 1990s up to some 65,000 at the end of 2006. In Germany each general practitioner (GP), who has completed an additional training in addiction medicine, is allowed to prescribe substitution drugs to opioid dependent patients. Currently 2,700 GPs prescribe substitution drugs. Psychosocial care should be made available to all MMT patients. The results of research studies and practical experiences clearly indicate that patients benefit substantially from MMT with improvements in physical and psychological health. MMT proves successful in attaining high retention rates (65% to 85% in the first years, up to 50% after more than seven years) and plays a major role in accessing and maintaining ongoing medical treatment for HIV and hepatitis. MMT is also seen as a vital factor in the process of social re-integration and it contributes to the reduction of drug related harms such as mortality and morbidity and to the prevention of infectious diseases. Some 10% of MMT patients become drug-free in the long run. Methadone is the most commonly prescribed substitution medication in Germany, although buprenorphine is attaining rising importance. Access to MMT in rural areas is very patchy and still constitutes a problem. There are only few employment opportunities for patients participating in MMT, although regular employment is considered unanimously as a positive factor of treatment success. Substitution treatment in German prisons is heterogeneous in access and treatment modalities. Access is very patchy and the number of inmates in treatment is limited. Nevertheless, substitution treatment plays a substantial part in the health care system provided to drug users in Germany. In Germany, a history of substitution treatment spanning 20 years has meanwhile

  1. Perron-Frobenius theory and frequency convergence for reducible substitutions

    OpenAIRE

    Lustig, Martin; Uyanik, Caglar

    2016-01-01

    We prove a general version of the classical Perron-Frobenius convergence property for reducible matrices. We then apply this result to reducible substitutions and use it to produce limit frequencies for factors and hence invariant measures on the associated subshift. The analogous results are well known for primitive substitutions and have found many applications, but for reducible substitutions the tools provided here were so far missing from the theory.

  2. Product portfolio optimization based on substitution

    DEFF Research Database (Denmark)

    Myrodia, Anna; Moseley, A.; Hvam, Lars

    2017-01-01

    The development of production capabilities has led to proliferation of the product variety offered to the customer. Yet this fact does not directly imply increase of manufacturers' profitability, nor customers' satisfaction. Consequently, recent research focuses on portfolio optimization through...... substitution and standardization techniques. However when re-defining the strategic market decisions are characterized by uncertainty due to several parameters. In this study, by using a GAMS optimization model we present a method for supporting strategic decisions on substitution, by quantifying the impact...

  3. Currency Substitution and Inflation in Peru

    OpenAIRE

    Liliana Rojas-Suárez

    1992-01-01

    This paper shows that there is a long-run relationship between the expected rate of depreciation in the black-market-exchange rate and the ratio of domestic to foreign money in Peru; that is, the hypothesis of currency substitution can explain the behavior of real holdings of money in Peru. The paper also shows that, while the importance of currency substitution as a transmission mechanism through which domestic policies affected the dynamics of inflation was relatively small during a period ...

  4. Secretion of wound healing mediators by single and bi-layer skin substitutes.

    Science.gov (United States)

    Maarof, Manira; Law, Jia Xian; Chowdhury, Shiplu Roy; Khairoji, Khairul Anuar; Saim, Aminuddin Bin; Idrus, Ruszymah Bt Hj

    2016-10-01

    Limitations of current treatments for skin loss caused by major injuries leads to the use of skin substitutes. It is assumed that secretion of wound healing mediators by these skin substitutes plays a role in treating skin loss. In our previous study, single layer keratinocytes (SK), single layer fibroblast (SF) and bilayer (BL; containing keratinocytes and fibroblasts layers) skin substitutes were fabricated using fibrin that had shown potential to heal wounds in preclinical studies. This study aimed to quantify the secretion of wound healing mediators, and compare between single and bi-layer skin substitutes. Skin samples were digested to harvest fibroblasts and keratinocytes, and expanded to obtain sufficient cells for the construction of skin substitutes. Acellular fibrin (AF) construct was used as control. Substitutes i.e. AF, SK, SF and BL were cultured for 2 days, and culture supernatant was collected to analyze secretion of wound healing mediators via multiplex ELISA. Among 19 wound healing mediators tested, BL substitute secreted significantly higher amounts of CXCL1 and GCSF compared to SF and AF substitute but this was not significant with respect to SK substitute. The BL substitute also secreted significantly higher amounts of CXCL5 and IL-6 compared to other substitutes. In contrast, the SK substitute secreted significantly higher amounts of VCAM-1 compared to other substitutes. However, all three skin substitutes also secreted CCL2, CCL5, CCL11, GM-CSF, IL8, IL-1α, TNF-α, ICAM-1, FGF-β, TGF-β, HGF, VEGF-α and PDGF-BB factors, but no significant difference was seen. Secretion of these mediators after transplantation may play a significant role in promoting wound healing process for the treatment of skin loss.

  5. Benefits of oxygen in CuInSe{sub 2} and CuGaSe{sub 2} containing Se-rich grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Chunbao, E-mail: chunbaofeng@126.com [Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China); Luo, Min; Li, Bolin; Li, Dengfeng [Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China); Nie, Jinlan [Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Dong, Huining [Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China)

    2014-05-01

    Using density functional theory calculation, we show that oxygen (O) exhibits an interesting effect in CuInSe{sub 2} and CuGaSe{sub 2}. The Se atoms with dangling bonds in a Se-rich Σ3 (114) grain boundary (GB) create deep gap states due to strong interaction between Se atoms. However, when such a Se atom is substituted by an O atom, the deep gap states can be shifted into valence band, making the site no longer a harmful non-radiative recombination center. We find that O atoms prefer energetically to substitute these Se atoms and induce significant lattice relaxation due to their smaller atomic size and stronger electronegativity, which effectively reduces the anion–anion interaction. Consequently, the deep gap states are shifted to lower energy regions close or even below the top of the valence band.

  6. Chemical ordering in substituted fluorite oxides: a computational investigation of Ho2Zr2O7 and RE2Th2O7 (RE=Ho, Y, Gd, Nd, La)

    OpenAIRE

    Jonathan M. Solomon; Jacob Shamblin; Maik Lang; Alexandra Navrotsky; Mark Asta

    2016-01-01

    Fluorite-structured oxides find widespread use for applications spanning nuclear energy and waste containment, energy conversion, and sensing. In such applications the host tetravalent cation is often partially substituted by trivalent cations, with an associated formation of charge-compensating oxygen vacancies. The stability and properties of such materials are known to be influenced strongly by chemical ordering of the cations and vacancies, and the nature of such ordering and associated e...

  7. Theory and development of fluorescence-based optochemical oxygen sensors: oxygen optodes.

    Science.gov (United States)

    Opitz, N; Lübbers, D W

    1987-01-01

    As the preceding considerations concerning the physical and technical features of oxygen optodes have demonstrated, fluorescence-based optochemical oxygen sensors possess certain advantages and peculiarities compared to conventionally applied electrochemical sensors such as polarographic oxygen electrodes. First, in contrast to oxygen electrodes, oxygen measurements with oxygen optodes do not suffer from distortions caused by the reference electrodes. In addition, because of the polarographic process, platinum electrodes continuously consume oxygen, which falsifies the results, especially when small sample volumes or long-term measurements, or both, are involved, whereas the sensor layer of oxygen optodes must only be equilibrated. Moreover, the surface of the platinum wire has to be catalytically clean in order to obtain a plateau of the polarogram and, consequently, to achieve a low rest current at zero PO2. Unfortunately, the demand for catalytically clean platinum surfaces turns out to be rather critical, since surface contamination occurs even with membranized electrodes, resulting in the well-known phenomenon of "electrode poisoning." The question of the specificity of oxygen electrodes also must be considered. In this context, CO2 and halothane may interfere with oxygen measurements, whereas fluorescence quenching is unaffected by CO2 and halothane affects the measurements only slightly, depending on the special indicator used. Furthermore, because of the flow dependence, oxygen measurements with the oxygen electrode show a distinct "stirring effect" caused by the turbulence in front of the electrode, which disturbs the diffusion field. Because of the completely different physical principle of fluorescence optical sensors, such influences are not observed with oxygen optodes. In addition, isolation and shielding of electrical circuits found in electrodes are not necessary for optodes. Furthermore, the sensitivity of oxygen optodes can be tuned to the desired

  8. A new β chain hemoglobin variant with increased oxygen affinity: Hb Santa Giusta Sardegna [β93(F9)Cys→Trp; HBB c.282T>G].

    Science.gov (United States)

    Fais, Antonella; Sollaino, Maria Carla; Barella, Susanna; Perseu, Lucia; Era, Benedetta; Corda, Marcella

    2012-01-01

    During a screening program for the identification of β-thalassemia (β-thal) carriers in Sardinia, Italy, we identified two subjects with increased hemoglobin (Hb) levels and an abnormal Hb variant. The same variant was detected in a family member. DNA sequencing revealed a TGT > TGG mutation at codon 93 of the β-globin gene. Structural analysis demonstrated that the cystine residue at position 93 of the β chain was substituted by tryptophan. Since this amino acid substitution had not yet been reported, we designated this variant Hb Santa Giusta Sardegna for the place of birth of the subjects. This amino acid substitution occurs at the tyrosine pocket of the β chain as well as at the α1β2/α2β1 contact of the quaternary structure of the molecule. The presence of this Hb in the hemolysate causes an increased oxygen affinity, a slightly reduced Bohr effect and a reduced heme-heme interaction (n(50), Hill's constant) in comparison with those of Hb A.

  9. Substitute equations for index reduction and discontinuity handling

    NARCIS (Netherlands)

    Fabian, G.; Beek, van D.A.; Rooda, J.E.

    2000-01-01

    Several techniques exist for index reduction and consistent initialization of higher index DAEs. Many such techniques change the original set of equations by differentiation, substitution, and/or introduction of new variables. This paper introduces substitute equations as a new language element. By

  10. Thermal stability of substitutional ag in CdTe

    NARCIS (Netherlands)

    Jahn, SG; Hofsass, H; Restle, M; Ronning, C; Quintel, H; BharuthRam, K; Wahl, U

    The thermal stability of substitutional Ag in CdTe was deduced from lattice location measurements at different temperatures. Substitutional Ag probe atoms were generated via transmutation doping from radioactive Cd isotopes. The lattice sites of Ag isotopes were determined by measuring the

  11. MOLECULAR THERMODYNAMICS IN THE DESIGN OF SUBSTITUTE SOLVENTS

    Science.gov (United States)

    The use of physical properties and fluid behavior from molecular thermodynamics can lead to better decision making in the design of substitute solvents and can greatly reduce the expense and time required to find substitutes compared to designing solvents by experiment. this pape...

  12. Oxygen Therapy

    Science.gov (United States)

    ... their breathing to dangerously low levels. Will I need oxygen when I sleep? Usually if you use supplemental oxygen during the ... your health care provider tells you you only need to use oxygen for exercise or sleep. Even if you feel “fine” off of your ...

  13. Interfuel substitution in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Serletis, Apostolos; Vasetsky, Olexandr [Department of Economics, University of Calgary, Calgary, Alberta (Canada); Timilsina, Govinda R. [Development Research Group, The World Bank, 1818 H Street N.W., Washington, DC 20433 (United States)

    2010-05-15

    In this paper, we use the locally flexible translog functional form to investigate the demand for energy and interfuel substitution in the United States and to provide a comparison of our results with most of the existing empirical energy demand literature. Motivated by the widespread practice of ignoring theoretical regularity, we follow Barnett's (2002) suggestions and estimate the model subject to theoretical regularity, using methods developed by Diewert and Wales (1987) and Ryan and Wales (2000), in an attempt to produce inference consistent with neoclassical microeconomic theory. Moreover, we use the most recent data, published by the U.S. Energy Information Administration (EIA), and in addition to investigating interfuel substitution possibilities in total U.S. energy demand, we follow Serletis et al. (2009) and also examine interfuel substitution possibilities in energy demand by sector. Moreover, we test for weak separability, with the objective of discovering the structure of the functional form in total energy demand as well as energy demand by sector. (author)

  14. Retinal Vessel Oxygen Saturation during 100% Oxygen Breathing in Healthy Individuals.

    Directory of Open Access Journals (Sweden)

    Olof Birna Olafsdottir

    Full Text Available To detect how systemic hyperoxia affects oxygen saturation in retinal arterioles and venules in healthy individuals.Retinal vessel oxygen saturation was measured in 30 healthy individuals with a spectrophotometric retinal oximeter (Oxymap T1. Oximetry was performed during breathing of room air, 100% oxygen (10 minutes, 6L/min and then again room air (10 minutes recovery.Mean oxygen saturation rises modestly in retinal arterioles during 100% oxygen breathing (94.5%±3.8 vs. 92.0%±3.7% at baseline, p<0.0001 and dramatically in retinal venules (76.2%±8.0% vs. 51.3%±5.6%, p<0.0001. The arteriovenous difference decreased during 100% oxygen breathing (18.3%±9.0% vs. 40.7%±5.7%, p<0.0001. The mean diameter of arterioles decreased during 100% oxygen breathing compared to baseline (9.7±1.4 pixels vs. 10.3±1.3 pixels, p<0.0001 and the same applies to the mean venular diameter (11.4±1.2 pixels vs. 13.3±1.5 pixels, p<0.0001.Breathing 100% oxygen increases oxygen saturation in retinal arterioles and more so in venules and constricts them compared to baseline levels. The dramatic increase in oxygen saturation in venules reflects oxygen flow from the choroid and the unusual vascular anatomy and oxygen physiology of the eye.

  15. 40 CFR Appendix H to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes, Effective May 28, 1999

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Substitutes Subject to Use Restrictions and Unacceptable Substitutes, Effective May 28, 1999 H Appendix H to Subpart G of Part 82... STRATOSPHERIC OZONE Significant New Alternatives Policy Program Pt. 82, Subpt. G, App. H Appendix H to Subpart G...

  16. Growth and properties of oxygen- and ion-doped Bi2Sr2CaCu2O8+δ single crystals

    Science.gov (United States)

    Mitzi, D. B.; Lombardo, L. W.; Kapitulnik, A.; Laderman, S. S.; Jacowitz, R. D.

    1990-04-01

    A directional solidification method for growing large single crystals in the Bi2Sr2CaCu2O8+δ system is reported. Ion doping, with replacement of La for Sr and Y for Ca, as well as oxygen doping in these crystals has been explored. Doped and undoped crystals have been characterized using microprobe analysis, x-ray diffraction, thermogravimetric analysis, and magnetic and Hall measurements. Ion doping results in little change of the superconducting transition for substitution levels below 20-25%, while beyond this level the Meissner signal broadens and the low-temperature Meissner signal decreases. Microprobe analysis and x-ray diffraction performed on these more highly substituted single crystals provide evidence for inhomogeneity and phase segregation into regions of distinct composition. Annealing unsubstituted crystals in increasing partial pressures of oxygen reversibly depresses the superconducting transition temperature from 90 (as made) to 77 K (oxygen pressure annealed), while the carrier concentrations, as determined from Hall effect measurements, increase from n=3.1(3)×1021 cm-3 (0.34 holes per Cu site) to 4.6(3)×1021 cm-3 (0.50 holes per Cu site). No degradation of the Meissner transition or other indications of inhomogeneity or phase segregation with doping are noted, suggesting that oxygen-doped Bi2Sr2CaCu2O8+δ is a suitable system for pursuing doping studies. The decrease in Tc with concentration for 0.34<=n<=0.50 indicates that a high-carrier-concentration regime exists in which Tc decreases with n and suggests that this decrease does not arise from material inhomogeneity or other materials problems. An examination of the variation of Tc with the density of states and lattice constants for all of the doped and undoped superconducting samples considered here indicates that changes in Tc with doping are primarily affected by changes in the density of states (or carrier concentration) rather than by structural variation induced by the doping.

  17. Multifaceted Material Substitution: The Case of NdFeB Magnets, 2010-2015

    Science.gov (United States)

    Smith, Braeton J.; Eggert, Roderick G.

    2016-07-01

    Substitution is an important response for material users when faced with disruption to the availability or price of an essential material. In economic terms, substitution refers to the ability of firms to alter their patterns of material use in response to exogenous market shocks. Substitution comes in different forms which vary from situation to situation. This paper uses expert opinion to identify the specific forms of substitution that occurred in permanent magnets, specifically neodymium-iron-boron magnets, following the significant increase in rare earth prices in 2010-2011. The paper provides a framework for understanding the multifaceted nature of substitution and assesses the relative importance of five different types of substitution. Technology-for-element, grade-for-grade, and system-for-system substitution appear to have been more important than element-for-element and magnet-for-magnet substitution. Cost pass-through and absorption were also important responses.

  18. Fluorescence behavior and singlet oxygen generating abilities of aluminum phthalocyanine in the presence of anisotropic gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Mthethwa, Thandekile; Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za

    2015-01-15

    Gold nanoparticles (spheres, rods and bipyramids) were synthesized. The nanocrystals were characterized by UV–visible spectrometry, transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The as prepared gold nanoparticles were then conjugated to a quaternized 2,(3)-tetra [2-(dimethylamino) ethanethio] substituted Al(OH) phthalocyanine (complex 1). The conjugation of phthalocyanines with gold nanoparticles resulted in a decrease in the fluorescence quantum yields and lifetimes. Conversely, an increase in the singlet oxygen quantum yields was observed for the conjugated complex 1 in the presence of AuNPs. - Highlights: • Gold nanoparticles (spheres, rods and bipyramids) were synthesized. • Gold nanoparticles were then conjugated to a quaternized ClAl phthalocyanine. • Conjugation of phthalocyanines with gold nanoparticles resulted in a decrease in the fluorescence quantum yields. • An increase in the singlet oxygen quantum yields was observed for the phthalocyanine in the presence of nanoparticles.

  19. Cannabis as a substitute for alcohol and other drugs

    Directory of Open Access Journals (Sweden)

    Reiman Amanda

    2009-12-01

    Full Text Available Abstract Background Substitution can be operationalized as the conscious choice to use one drug (legal or illicit instead of, or in conjunction with, another due to issues such as: perceived safety; level of addiction potential; effectiveness in relieving symptoms; access and level of acceptance. This practice of substitution has been observed among individuals using cannabis for medical purposes. This study examined drug and alcohol use, and the occurrence of substitution among medical cannabis patients. Methods Anonymous survey data were collected at the Berkeley Patient's Group (BPG, a medical cannabis dispensary in Berkeley, CA. (N = 350 The sample was 68% male, 54% single, 66% White, mean age was 39; 74% have health insurance (including MediCal, 41% work full time, 81% have completed at least some college, 55% make less than $40,000 a year. Seventy one percent report having a chronic medical condition, 52% use cannabis for a pain related condition, 75% use cannabis for a mental health issue. Results Fifty three percent of the sample currently drinks alcohol, 2.6 was the average number of drinking days per week, 2.9 was the average number of drinks on a drinking occasion. One quarter currently uses tobacco, 9.5 is the average number of cigarettes smoked daily. Eleven percent have used a non-prescribed, non OTC drug in the past 30 days with cocaine, MDMA and Vicodin reported most frequently. Twenty five percent reported growing up in an abusive or addictive household. Sixteen percent reported previous alcohol and/or drug treatment, and 2% are currently in a 12-step or other recovery program. Forty percent have used cannabis as a substitute for alcohol, 26% as a substitute for illicit drugs and 66% as a substitute for prescription drugs. The most common reasons given for substituting were: less adverse side effects (65%, better symptom management (57%, and less withdrawal potential (34% with cannabis. Conclusion The substitution of one

  20. Neutron kerma factors, and water equivalence of some tissue substitutes

    International Nuclear Information System (INIS)

    Singh, V. P.; Badiger, N. M.; Vega C, H. R.

    2014-08-01

    The kerma factors and kerma relative to air and water of 24 compounds used as tissue substitutes were calculated for neutron energy from 2.53 x 10 -8 up to 29 MeV. The kerma ratio of the tissue substitutes relative to air and water were calculated by the ratio of kerma factors of the tissue substitute to air and water respectively. The water equivalence of the selected tissue substitutes was observed above neutron energies 100 eV. Kerma ratio relative to the air for Poly-vinylidene fluoride and Teflon are found to be nearest to unity in very low energy (up to 1 eV) and above 63 eV respectively. It was found that the natural rubber as a water equivalent tissue substitute compound. The results of the kerma factors in our investigation shows a very good agreement with those published in ICRU-44. We found that at higher neutron energies, the kerma factors and kerma ratios of the selected tissue substitute compounds are approximately same, but differences are large for energies below 100 eV. (Author)

  1. Experimental evidence of six-fold oxygen coordination for phosphorus and XANES calculations

    Energy Technology Data Exchange (ETDEWEB)

    Flank, A-M; Trcera, N; Itie, J-P; Lagarde, P [Synchrotron Soleil, L' Orme des Merisiers, BP 48, 91192 Gif sur Yvette (France); Brunet, F [Laboratoire de Geologie, CNRS-ENS-UMR8538, 24 rue Lhommond, 75005 Paris (France); Irifune, T [Geodynamics Research Center, Ehime University, Matsuyama 790-8577 (Japan)

    2009-11-15

    Phosphorus, a group V element, has always been found so far in minerals, biological systems and synthetic compounds with an oxygen coordination number of four (i.e, PO{sub 4} groups). We demonstrate here using phosphorus K-edge XANES spectroscopy that this element can also adopt a six-fold oxygen coordination (i.e, PO{sub 6} groups). This new coordination was achieved in AlPO{sub 4} doped SiO{sub 2} stishovite synthesized at 18 GPa and 1873 K and quenched down to ambient conditions. The well-crystallized P-bearing stishovite grains (up to 100{mu}m diameter) were embedded in the back-transformation products of high pressure form of AlPO{sub 4} matrix. They were identified by elemental mapping ({mu}-XRF). {mu}-XANES spectra collected at the Si and P K edges in the Si rich region with a very low concentration of P present striking resemblance, Si itself being characteristic of pure stishovite. We can therefore infer that phosphorus in the corresponding stishovite crystal is involved in an octahedral coordination made of six oxygen atoms. First principle XANES calculations using a plane-wave density functional formalism with core-hole effects treated in a supercell approach at the P K edge for a P atom substituting an Si one in the stishovite structure confirm this assertion. This result shows that in the lower-mantle where all silicon is six-fold coordinated, phosphorus has the crystal-chemical ability to remain incorporated into silicate structures.

  2. Experimental evidence of six-fold oxygen coordination for phosphorus and XANES calculations

    Science.gov (United States)

    Flank, A.-M.; Trcera, N.; Brunet, F.; Itié, J.-P.; Irifune, T.; Lagarde, P.

    2009-11-01

    Phosphorus, a group V element, has always been found so far in minerals, biological systems and synthetic compounds with an oxygen coordination number of four (i.e, PO4 groups). We demonstrate here using phosphorus K-edge XANES spectroscopy that this element can also adopt a six-fold oxygen coordination (i.e, PO6 groups). This new coordination was achieved in AlPO4 doped SiO2 stishovite synthesized at 18 GPa and 1873 K and quenched down to ambient conditions. The well-crystallized P-bearing stishovite grains (up to 100μm diameter) were embedded in the back-transformation products of high pressure form of AlPO4 matrix. They were identified by elemental mapping (μ-XRF). μ-XANES spectra collected at the Si and P K edges in the Si rich region with a very low concentration of P present striking resemblance, Si itself being characteristic of pure stishovite. We can therefore infer that phosphorus in the corresponding stishovite crystal is involved in an octahedral coordination made of six oxygen atoms. First principle XANES calculations using a plane-wave density functional formalism with core-hole effects treated in a supercell approach at the P K edge for a P atom substituting an Si one in the stishovite structure confirm this assertion. This result shows that in the lower-mantle where all silicon is six-fold coordinated, phosphorus has the crystal-chemical ability to remain incorporated into silicate structures.

  3. Experimental evidence of six-fold oxygen coordination for phosphorus and XANES calculations

    International Nuclear Information System (INIS)

    Flank, A-M; Trcera, N; Itie, J-P; Lagarde, P; Brunet, F; Irifune, T

    2009-01-01

    Phosphorus, a group V element, has always been found so far in minerals, biological systems and synthetic compounds with an oxygen coordination number of four (i.e, PO 4 groups). We demonstrate here using phosphorus K-edge XANES spectroscopy that this element can also adopt a six-fold oxygen coordination (i.e, PO 6 groups). This new coordination was achieved in AlPO 4 doped SiO 2 stishovite synthesized at 18 GPa and 1873 K and quenched down to ambient conditions. The well-crystallized P-bearing stishovite grains (up to 100μm diameter) were embedded in the back-transformation products of high pressure form of AlPO 4 matrix. They were identified by elemental mapping (μ-XRF). μ-XANES spectra collected at the Si and P K edges in the Si rich region with a very low concentration of P present striking resemblance, Si itself being characteristic of pure stishovite. We can therefore infer that phosphorus in the corresponding stishovite crystal is involved in an octahedral coordination made of six oxygen atoms. First principle XANES calculations using a plane-wave density functional formalism with core-hole effects treated in a supercell approach at the P K edge for a P atom substituting an Si one in the stishovite structure confirm this assertion. This result shows that in the lower-mantle where all silicon is six-fold coordinated, phosphorus has the crystal-chemical ability to remain incorporated into silicate structures.

  4. Smart Phones and their Substitutes

    DEFF Research Database (Denmark)

    Bødker, Mads; Gimpel, Gregory; Hedman, Jonas

    2009-01-01

    Drawing on data from a longitudinal field study, this paper investigates the influence of existing, better and stand-alone technology substitutes on the use of smart phones. By applying prospect theory, media richness theory, and business model literature, the purpose of this paper is to improve...... our understanding of the role of substitutes, device content fit issues, and implications for business models by asking the question: What is an effective business model to address the relationship between user preference and the fit of the smart phone and everyday task? The field study data suggest...... the need for business models to recognize that adoption decisions are reference-dependent and strongly influenced by the fit between task and smart phone....

  5. Labour migration and substitution (updated) : Second, revised version

    NARCIS (Netherlands)

    Cremers, Jan

    2017-01-01

    This (revised) paper compares the outcomes of several national and international studies on substitution as a consequence of migrants entering the labour market. Substitution appears if finding a job by one person results in the job loss (or non-obtaining of a job) of another person. The recruitment

  6. US veterans use vitamins and supplements as substitutes for prescription medication.

    Science.gov (United States)

    Goldstein, Jennifer N; Long, Judith A; Arevalo, Doris; Ibrahim, Said A; Mao, Jun J

    2014-12-01

    Vitamins and supplements are the most commonly used form of complementary and alternative medicine in the United States. Growing research suggests that patients substitute vitamins and supplements for their prescription medications. The reasons might include cost of prescription medications and discordant patient and doctor health belief systems. To investigate the prevalence of substitution of vitamins and supplements for prescription medications among veterans who receive care in the VA health care system and whether substitution is associated with prescription rationing due to cost, treatment beliefs, or distrust of the health system. Cross-sectional observational survey. Primary care patients (n=275) at the Philadelphia VA Medical Center. Medication substitution, prescription medication rationing, treatment beliefs, and health system distrust were measured with structured instruments. Multivariate logistic regression was performed with substitution as the dependent variable. A significant number of primary care patients in the VA system use vitamins and supplements 206 (75%). The prevalence of medication substitution is high 48 (18%). Medication substitution is strongly associated with prescription rationing due to cost (adjusted odds ratio 6.3, 95% confidence interval: 2.0-19.5, P=0.001). Similarly, greater belief in complementary and alternative approaches to care positively predicts medication substitution (adjusted odds ratio 1.08, 95% confidence interval: 1.01-1.15, P=0.011). There is no significant association between health system distrust and likelihood of medication substitution. Medication substitution is prevalent in this sample of inner city primary care patients who receive care in the VA system. Cost of prescriptions and belief in the value of complementary and alternative approaches to care appear to be associated with this patient-driven treatment decision.

  7. Electrochemical Reduction of Oxygen and Nitric Oxide at Low Temperature on La1−xSrxFeO3−δ Cathodes

    DEFF Research Database (Denmark)

    Kammer Hansen, Kent

    2014-01-01

    A series of six strontium-substituted lanthanum ferrites (La1-xSrxFeO3-delta, x = 0.00, 0.05, 0.15, 0.25, 0.35, and 0.50) were synthesized using the glycine-nitrate process and evaluated as cathodes for the electrochemical reduction of oxygen and nitric oxide in the temperature range 200 to 400...... degrees C, using cone-shaped electrodes and cyclic voltammetry. It was shown that the ferrites had a higher activity towards the electrochemical reduction of nitric oxide than towards the electrochemical reduction of oxygen, in the investigated temperature range. The highest activity towards...... the electrochemical reduction of nitric oxide was found for La0.95Sr0.05FeO3-delta at 400 degrees C. This compound also showed the highest activity towards the electrochemical reduction of oxygen at 400 degrees C. The highest apparent selectivity was found for the compound LaFeO3 at 200 degrees C. The materials...

  8. Tailoring the Activity for Oxygen Evolution Electrocatalysis on Rutile TiO2(110) by Transition-Metal Substitution

    DEFF Research Database (Denmark)

    Garcia-Mota, Monica; Vojvodic, Aleksandra; Metiu, Horia

    2011-01-01

    The oxygen evolution reaction (OER) on the rutile M-TiO2(110) (M = V, Nb, Ta, Cr, Mo, W, Mn, Fe, Ru, Ir, Ni) surfaces was investigated by using density functional theory calculations. The stability of different doped TiO2 systems was analyzed. The scaling relationship between the binding energies...... of OER intermediates (HOO* versus HO*) is found to follow essentially the same trend as for undoped oxides. Our theoretical analysis shows a lower overpotential associated with OER on the doped M-TiO2(110) than on the undoped TiO2(110). The theoretical activity of Cr-, Mo-, Mn-, and Ir-doped TiO2...

  9. Si-substituted hydroxyapatite nanopowders: Synthesis, thermal stability and sinterability

    International Nuclear Information System (INIS)

    Bianco, Alessandra; Cacciotti, Ilaria; Lombardi, Mariangela; Montanaro, Laura

    2009-01-01

    Synthetic hydroxyapatites incorporating small amounts of Si have shown improved biological performances in terms of enhanced bone apposition, bone in-growth and cell-mediated degradation. This paper reports a systematic investigation on Si-substituted hydroxyapatite (Si 1.40 wt%) nanopowders produced following two different conventional wet methodologies: (a) precipitation of Ca(NO 3 ) 2 .4H 2 O and (b) titration of Ca(OH) 2 . The influence of the synthesis process on composition, thermal behaviour and sinterability of the resulting nanopowders is studied. Samples were characterised by electron microscopy, induced coupled plasma atomic emission spectroscopy, thermal analysis, infrared spectroscopy, N 2 adsorption measurements, X-ray diffraction and dilatometry. Semicrystalline Si-substituted hydroxyapatite powders made up of needle-like nanoparticles were obtained, the specific surface area ranged between 84 and 110 m 2 /g. Pure and Si-substituted hydroxyapatite nanopowders derived from Ca(NO 3 ) 2 .4H 2 O decomposed around 1000 deg. C. Si-substituted hydroxyapatite nanopowders obtained from Ca(OH) 2 were thermally stable up to 1200 deg. C and showed a distinct decreased thermal stability with respect to the homologous pure sample. Si-substituted hydroxyapatites exhibited higher sintering temperature and increased total shrinkage with respect to pure powders. Nanostructured dense ceramics were obtained by sintering at 1100 deg. C Si-substituted hydroxyapatites derived from Ca(OH) 2

  10. Substituted Amides of Pyrazine-2-carboxylic acids: Synthesis and Biological Activity

    Directory of Open Access Journals (Sweden)

    Katarina Kralova

    2002-03-01

    Full Text Available Condensation of 6-chloro-, 5-tert-butyl- or 6-chloro-5-tert-butylpyrazine-2-carboxylic acid chloride with ring substituted anilines yielded a series of amides, which were tested for their in vitro antimycobacterial, antifungal and photosynthesis-inhibiting activities. The highest antituberculotic activity (72% inhibition against Mycobacterium tuberculosis and the highest lipophilicity (log P = 6.85 were shown by the 3,5-bistrifluoromethylphenyl amide of 5-tert-butyl-6-chloropyrazine-2-carboxylic acid (2o. The 3-methylphenyl amides of 6-chloro- and 5-tert-butyl-6-chloro-pyrazine-2-carboxylic acid (2d and 2f exhibited only a poor in vitro antifungal effect (MIC = 31.25-500 μmol·dm-3 against all strains tested, although the latter was the most active antialgal compound (IC50 = 0.063 mmol·dm-3. The most active inhibitor of oxygen evolution rate in spinach chloroplasts was the (3,5-bis-trifluoromethylphenylamide of 6-chloropyrazine-2-carboxylic acid (2m, IC50 = 0.026 mmol·dm-3.

  11. Enhanced activity and stability of La-doped CeO2 monolithic catalysts for lean-oxygen methane combustion.

    Science.gov (United States)

    Zhu, Wenjun; Jin, Jianhui; Chen, Xiao; Li, Chuang; Wang, Tonghua; Tsang, Chi-Wing; Liang, Changhai

    2018-02-01

    Effective utilization of coal bed methane is very significant for energy utilization and environment protection. Catalytic combustion of methane is a promising way to eliminate trace amounts of oxygen in the coal bed methane and the key to this technology is the development of high-efficiency catalysts. Herein, we report a series of Ce 1-x La x O 2-δ (x = 0-0.8) monolithic catalysts for the catalytic combustion of methane, which are prepared by citric acid method. The structural characterization shows that the substitution of La enhance the oxygen vacancy concentration and reducibility of the supports and promote the migration of the surface oxygen, as a result improve the catalytic activity of CeO 2 . M-Ce 0.8 La 0.2 O 2-δ (monolithic catalyst, Ce 0.8 La 0.2 O 2-δ coated on cordierite honeycomb) exhibits outstanding activity for methane combustion, and the temperature for 10 and 90% methane conversion are 495 and 580 °C, respectively. Additionally, Ce 0.8 La 0.2 O 2-δ monolithic catalyst presents excellent stability at high temperature. These Ce 1-x La x O 2-δ monolithic materials with a small amount of La incorporation therefore show promises as highly efficient solid solution catalysts for lean-oxygen methane combustion. Graphical abstract ᅟ.

  12. From incremental to fundamental substitution in chemical alternatives assessment

    DEFF Research Database (Denmark)

    Fantke, Peter; Weber, Roland; Scheringer, Martin

    2015-01-01

    to similarity in chemical structures and, hence, similar hazard profiles between phase-out and substitute chemicals, leading to a rather incremental than fundamental substitution. A hampered phase-out process, the lack of implementing Green Chemistry principles in chemicals design, and lack of Sustainable...... an integrated approach of all stakeholders involved toward more fundamental and function-based substitution by greener and more sustainable alternatives. Our recommendations finally constitute a starting point for identifying further research needs and for improving current alternatives assessment practice....

  13. Oxygen vacancy-induced room-temperature ferromagnetism in D—D neutron irradiated single-crystal TiO2 (001) rutile

    Science.gov (United States)

    Xu, Nan-Nan; Li, Gong-Ping; Pan, Xiao-Dong; Wang, Yun-Bo; Chen, Jing-Sheng; Bao, Liang-Man

    2014-10-01

    Remarkable room temperature ferromagnetism in pure single-crystal rutile TiO2 (001) samples irradiated by D—D neutron has been investigated. By combining X-ray diffraction and positron annihilation lifetime, the contracted lattice has been clearly identified in irradiated TiO2, where Ti4+ ions can be easily reduced to the state of Ti3+. As there were no magnetic impurities that could contaminate the samples during the whole procedure, some Ti3+ ions reside on interstitial or substituted sites accompanied by oxygen vacancies should be responsible for the ferromagnetism.

  14. Computational Modeling of Degradation of Substituted Benzyltrimethyl Ammonium: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Long, H.; Pivovar, B. S.

    2014-09-01

    The degradation of cations on the alkaline exchange membranes is the major challenge for alkaline membrane fuel cells. In this paper, we investigated the degradation barriers by density functional theory for substituted benzyltrimethyl ammonium (BTMA+) cations, which is one of the most commonly used cations for alkaline exchange membranes. We found that substituted cations with electron-releasing substituent groups at meta-position of the benzyl ring could result in improved degradation barriers. However, after investigating more than thirty substituted BTMA+ cations with ten different substituent groups, the largest improvement of degradation barriers is only 1.6 kcal/mol. This implies that the lifetime of alkaline membrane fuel cells could increase from a few months to a few years by using substituted BTMA+ cations, an encouraging but still limited improvement for real-world applications.

  15. Industrialization in Sub-Saharan Africa and import substitution policy

    Directory of Open Access Journals (Sweden)

    Ana Paula F. Mendes

    2014-03-01

    Full Text Available This article aims to contribute to the understanding of the process of import substitution in Sub-Saharan Africa. The process of industrialization in Sub-Saharan Africa occurred in two phases: a first step, even very early during the colonial regime began around the 1920s and ended in the late forties; a second phase of industrialization began in the late fifties and gained momentum in the sixties, when import substitution was implemented more widely. Although these countries were the last to embark on the strategy of import substitution, they followed the same steps of Latin American countries, and as the structural domestic and external constraints were too strong, the failure of the policy of import substitution arrived early and the negative impact on these economies had a greater magnitude.

  16. The structural features of hemicelluloses dissolved out at different cooking stages of active oxygen cooking process.

    Science.gov (United States)

    Shi, Jianbin; Yang, Qiulin; Lin, Lu

    2014-04-15

    This work described the morphologic changes of corn stalk and the structural characterization of its hemicelluloses dissolved in yellow liquor at different cooking stages. The results showed that active oxygen cooking process was an efficient method to depolymerize the corn stalk into cellulose, hemicelluloses, and lignin as a pretreatment of biomass conversion. This cooking process can also be divided into three phases: bulk delignification, extended delignification, and residual delignification. During the heating-up period 57.67% of hemicelluloses and 62.31% of lignin were removed from the raw material. However, only 15% of hemicelluloses and 23.21% of lignin were removed during at temperature' period. The hemicelluloses from the corn stalk and yellow liquor were composed of (1→4)-β-D-xylopyranose backbones substituted with α-l-arabinofuranosyl, 4-O-methyl-α-D-glucuronic acid, and some methoxyl residues. The backbones of hemicelluloses were gradually cleaved during the cooking process. The acetyl groups substituted with xylopyranosyl residues were completely cleaved during the cooking process. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Substitution and diffusion of Cr 2+ and Cr 3+ in synthetic forsterite and natural olivine at 1200–1500 °C and 1 bar

    Energy Technology Data Exchange (ETDEWEB)

    Jollands, M. C.; O' Neill, H. St. C.; Van Orman, J.; Berry, A. J.; Hermann, J.; Newville, M.; Lanzirotti, A.

    2018-01-01

    The diffusion and substitution mechanisms of Cr in forsterite were studied as a function of crystallographic orientation and the chemical potentials of all four components in the system MgO-SiO2-Cr-O. Oxygen fugacity (fO2) was varied over 15.4 log units at 1400 °C and was fixed at the iron-wüstite equilibrium for a temperature series (1200–1500 °C). The valence state changes of Cr along some diffusion profiles was also investigated using X-ray absorption near edge structure spectroscopy.

  18. Substitution Effects and Linear Free Energy Relationships During Reduction of 4- Benzoyl-n-(4-substituted Benzyl)pyridinium Cations

    Science.gov (United States)

    Leventis, Nicholas; Zhang, Guo-Hui; Rawashdeh, Abdel-Monem M.; Sotiriou-Leventis, Chariklia; Gray, Hugh R. (Technical Monitor)

    2003-01-01

    In analogy to 4-(para-substituted benzoyl)-N-methylpyridinium cations (1-X's), the title species (2-X's, -X = -OCH3, -CH3, -H, -Br, -COCH3, -NO2) undergo two reversible, well-separated (E(sub 1/2) greater than or equal to 650 mV) one-electron reductions. The effect of substitution on the reduction potentials of 2-X's is much weaker than the effect of the same substituents on 1-X's: the Hammett rho-values are 0.80 and 0.93 for the 1st- and 2nd-e reduction of 2-X's vs. 2.3 and 3.3 for the same reductions of 1-X's, respectively. Importantly, the nitro group of 2-NO2 undergoes reduction before the 2nd-e reduction of the 4-benzoylpyridinium system. These results suggest that the redox potentials of the 4-benzoylpyridinium system can be course-tuned via p-benzoyl substitution and fine-tuned via para-benzyl substitution. Introducing the recently derived substituent constant of the -NO2(sup)- group (sigma para-NO2(sup)- = -0.97) yields an excellent correlation for the 3rd-e reduction of 2- NO2 (corresponding to the reduction of the carbonyl group) with the 2nd-e reduction of the other 2-X's, and confirms the electron donating properties of -NO2(sup)-.

  19. Luminescence enhancement of (Sr1-x Mx )2 SiO4 :Eu2+ phosphors with M (Ca2+ /Zn2+ ) partial substitution for white light-emitting diodes.

    Science.gov (United States)

    Wang, Yulong; Zhang, Wentao; Gao, Yang; Long, Jianping; Li, Junfeng

    2017-02-01

    Eu 2 + -doped Sr 2 SiO 4 phosphor with Ca 2 + /Zn 2 + substitution, (Sr 1-x M x ) 2 SiO 4 :Eu 2 + (M = Ca, Zn), was prepared using a high-temperature solid-state reaction method. The structure and luminescence properties of Ca 2 + /Zn 2 + partially substituted Sr 2 SiO 4 :Eu 2 + phosphors were investigated in detail. With Ca 2 + or Zn 2 + added to the silicate host, the crystal phase could be transformed between the α-form and the β-form of the Sr 2 SiO 4 structure. Under UV excitation at 367 nm, all samples exhibit a broad band emission from 420 to 680 nm due to the 4f 6 5d 1  → 4f 7 transition of Eu 2 + ions. The broad emission band consists of two peaks at 482 and 547 nm, which correspond to Eu 2 + ions occupying the ten-fold oxygen-coordinated Sr.(I) site and the nine-fold oxygen-coordinated Sr.(II) site, respectively. The luminescence properties, including the intensity and lifetime of Sr 2 SiO 4 :Eu 2 + phosphors, improved remarkably on Ca 2 + /Zn 2 + addition, and promote its application in white light-emitting diodes. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  20. A first-principles study of light non-metallic atom substituted blue phosphorene

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Minglei [School of Mechanical Engineering, Southeast University, Nanjing 211189, Jiangsu (China); Tang, Wencheng, E-mail: 101000185@seu.edu.cn [School of Mechanical Engineering, Southeast University, Nanjing 211189, Jiangsu (China); Ren, Qingqiang [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, Hunan (China); Wang, Sa-ke [Department of Physics, Southeast University, Nanjing 210096, Jiangsu (China); Yu, Jin [School of Materials Science and Engineering, Southeast University, Nanjing 211189, Jiangsu (China); Jiangsu Key Laboratory of Advanced Metallic Materials, Southeast University, Nanjing 211189, Jiangsu (China); Du, Yanhui [School of Mechanical Engineering, Southeast University, Nanjing 211189, Jiangsu (China)

    2015-11-30

    Graphical abstract: - Highlights: • All the impurities are covalently bonded to blue phosphorene (with a single vacancy). • All the substituted systems are semiconductors. • B-substituted system exhibits direct bandgap semiconductor behavior. • The band gaps with spin polarization are found in C and O-substituted systems. • Our works can paves a new route at nanoscale for novel functionalities of optical and spintronics devices. - Abstract: First-principles calculations are implemented to study the geometric, electronic and magnetic properties of light non-metallic atom (B, C, N, O and F) substituted blue phosphorene. All the substituted systems are highly stable. The B-substituted system is a direct bandgap semiconductor with a bandgap size about 1.5 eV. The C, O-substituted systems are promising systems to explore two-dimensional diluted magnetic semiconductors. Magnetism is observed for C and O substitution, while for the other impurities no magnetic moment is detected. Our works paves a new route at nanoscale for novel functionalities of optical and spintronics devices.

  1. SUBSTITUTION OF CADMIUM CYANIDE ELECTROPLATING WITH ZINC CHLORIDE ELECTROPLATING

    Science.gov (United States)

    The study evaluated the zinc chloride electroplating process as a substitute for cadmium cyanide electroplating in the manufacture of industrial connectors and fittings at Aeroquip Corporation. The process substitution eliminates certain wastes, specifically cadmium and cyanide, ...

  2. Contribution to the study of the substitution of the thiol group of cysteine in presence of pyridoxal or pyridoxal phosphate; Contribution a l'etude de la substitution du groupe thiol de la cysteine en presence de pyridoxal ou de phosphate de pyridoxal

    Energy Technology Data Exchange (ETDEWEB)

    Ratsisalovanina-Rajaonarivelo, Olga

    1960-11-15

    This academic work shows that the detachment of SH{sup -}, OH{sup -} and OPO{sub 3}H{sub 2}{sup -}, respectively from cysteine, serine and phosphoserine can occur with its substitution by a sulphur-containing group. The author first shows the ability of pyridoxal and of pyridoxal phosphate to catalyse the exchange between the sulphur of the cysteine thiol group and the sulphur of the mineral sulphide, and to catalyse the cysteine synthesis from serine or phosphoserine in presence of mineral sulphur. Then, she studied various parameters of the synthesis reaction: influence of concentrations, of temperature, of reaction time, of metal nature, of oxygen presence, and of pH on efficiency in terms of cysteic acid.

  3. A Group Action Method for Construction of Strong Substitution Box

    Science.gov (United States)

    Jamal, Sajjad Shaukat; Shah, Tariq; Attaullah, Atta

    2017-06-01

    In this paper, the method to develop cryptographically strong substitution box is presented which can be used in multimedia security and data hiding techniques. The algorithm of construction depends on the action of a projective general linear group over the set of units of the finite commutative ring. The strength of substitution box and ability to create confusion is assessed with different available analyses. Moreover, the ability of resistance against malicious attacks is also evaluated. The substitution box is examined by bit independent criterion, strict avalanche criterion, nonlinearity test, linear approximation probability test and differential approximation probability test. This substitution box is equated with well-recognized substitution boxes such as AES, Gray, APA, S8, prime of residue, Xyi and Skipjack. The comparison shows encouraging results about the strength of the proposed box. The majority logic criterion is also calculated to analyze the strength and its practical implementation.

  4. Substitution of wastes for fuels and raw materials in high-temperature processes; Substitution von Brennstoffen und Rohstoffen durch Abfaelle in Hochtemperaturprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, R. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Energieverfahrenstechnik; Beckmann, M. [Clausthaler Umwelttechnik-Institut GmbH (CUTEC), Clausthal-Zellerfeld (Germany)

    1998-09-01

    The physical recycling and energy conversion of wastes has for a long time been a topic of discussion. Some of the most interesting questions in this connection concern specific applications such as the co-combustion of sewage sludge in power plants, substitution of plastic wastes for primary fuels in burning processes in the cement industry etc. This paper also undertakes a comparative study of different applications, giving additional consideration to the state of the art in thermal waste treatment. Different processes can of course only be compared by taking the entirety of expenditures on additives and auxiliary energy into account and assuming equal side constraints for all processes. A further requirement is that the waste materials` specific properties that are relevant to the application in question have to be taken into account. This concerns in particular the effects of the substitution of waste-derived fuels (secondary fuels) for primary fuels on, for example, heat transfer conditions during the combustion process, flow conditions, and the resultant temperature distribution, transport of feedstock, and specific energy expenditure. Secondary fuels must be suited for substitution in various respects, e.g. in their material properties, and their combustion and thermal behaviour. The present paper deals in particular with the requirements on wastes as substitutes for primary fuels with regard to combustion and thermal behaviour. For this purpose it briefly discusses some important aspects of heat transfer in firing plants and industrial furnaces. An important criterion in assessing fuel substitution is the energy exchange ratio, which expresses value of the substitute fuel relative to that of the primary fuel and should be duly considered when making comparative studies. Focussing on aspects of process engineering the paper also deals exemplarily with the influence of fuel substitution on, e.g. furnace temperature, exhaust gas quantities etc. in clinker

  5. Carbolanthanation of substituted alkynes

    International Nuclear Information System (INIS)

    Kalinin, V.N.; Kazimirchuk, E.I.; Vitt, S.V.; Khandozhko, V.N.; Beletskaya, I.P.

    1993-01-01

    Using the reaction between CH 3 YbI and substituted alkynes as an example, agents can enter into carbolanthanation reaction via transfer of a methyl group to carbon atom of acetylene bond with the production of a new olefin carbanion. 5 refs.; 1 fig.; 3 tabs

  6. Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite.

    Science.gov (United States)

    Friederichs, Robert J; Chappell, Helen F; Shepherd, David V; Best, Serena M

    2015-07-06

    Experimental chemistry and atomic modelling studies were performed here to investigate a novel ionic co-substitution in hydroxyapatite (HA). Zinc, silicate co-substituted HA (ZnSiHA) remained phase pure after heating to 1100 °C with Zn and Si amounts of 0.6 wt% and 1.2 wt%, respectively. Unique lattice expansions in ZnSiHA, silicate Fourier transform infrared peaks and changes to the hydroxyl IR stretching region suggested Zn and silicate co-substitution in ZnSiHA. Zn and silicate insertion into HA was modelled using density functional theory (DFT). Different scenarios were considered where Zn substituted for different calcium sites or at a 2b site along the c-axis, which was suspected in singly substituted ZnHA. The most energetically favourable site in ZnSiHA was Zn positioned at a previously unreported interstitial site just off the c-axis near a silicate tetrahedron sitting on a phosphate site. A combination of experimental chemistry and DFT modelling provided insight into these complex co-substituted calcium phosphates that could find biomedical application as a synthetic bone mineral substitute. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  7. Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite

    Science.gov (United States)

    Friederichs, Robert J.; Chappell, Helen F.; Shepherd, David V.; Best, Serena M.

    2015-01-01

    Experimental chemistry and atomic modelling studies were performed here to investigate a novel ionic co-substitution in hydroxyapatite (HA). Zinc, silicate co-substituted HA (ZnSiHA) remained phase pure after heating to 1100°C with Zn and Si amounts of 0.6 wt% and 1.2 wt%, respectively. Unique lattice expansions in ZnSiHA, silicate Fourier transform infrared peaks and changes to the hydroxyl IR stretching region suggested Zn and silicate co-substitution in ZnSiHA. Zn and silicate insertion into HA was modelled using density functional theory (DFT). Different scenarios were considered where Zn substituted for different calcium sites or at a 2b site along the c-axis, which was suspected in singly substituted ZnHA. The most energetically favourable site in ZnSiHA was Zn positioned at a previously unreported interstitial site just off the c-axis near a silicate tetrahedron sitting on a phosphate site. A combination of experimental chemistry and DFT modelling provided insight into these complex co-substituted calcium phosphates that could find biomedical application as a synthetic bone mineral substitute. PMID:26040597

  8. Modelling energy and non-energy substitution: A brief survey of elasticities

    International Nuclear Information System (INIS)

    Frondel, Manuel

    2011-01-01

    Estimating the degree of substitution between energy and non-energy inputs is the key for any evaluation of environmental and energy policies. Yet, given the variety of substitution elasticities, the central question arises as to which measure would be most appropriate. Apparently, Allen's elasticities of substitution have been the most-used measures in applied production analysis. In line with , this paper argues that cross-price elasticities are preferable for many practical purposes. This conclusion is based on a survey of classical substitution measures, such as those from Allen, Morishima, and McFadden. The survey highlights the fact that cross-price elasticities are their essential ingredients. - Highlights: → Given the large variety of substitution elasticities, the central question arises as to which measure would be most appropriate. Apparently, Allen's elasticities of substitution have been the most-used measures in applied production analysis. → In line with , this paper argues that cross-price elasticities are preferable for many practical purposes. → This conclusion is based on a survey of classical substitution measures, such as those from Allen, Morishima, and McFadden. → The survey also highlights the fact that cross-price elasticities are their essential ingredients.

  9. Sublattice imbalance of substitutionally doped nitrogen in graphene

    DEFF Research Database (Denmark)

    Lawlor, James A.; Gorman, Paul D.; Power, Stephen

    2014-01-01

    Motivated by the recently observed sublattice asymmetry of substitutional nitrogen impurities in CVD grown graphene, we show, in a mathematically transparent manner, that oscillations in the local density of states driven by the presence of substitutional impurities are responsible for breaking......, but should be present in other impurities. (C) 2014 Elsevier Ltd. All rights reserved....

  10. Hydrothermal synthesis and characterizations of Ti substituted Mn-ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, Nasser Y., E-mail: nmost69@yahoo.com [Faculty of Science, Taif University, P.O. Box 888 Al-Haweiah, Taif (Saudi Arabia); Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt); Hessien, M.M. [Faculty of Science, Taif University, P.O. Box 888 Al-Haweiah, Taif (Saudi Arabia); Advanced materials Division-Central metallurgical R and D Institute (CMRDI), P.O. Box 87 Helwan, Cairo (Egypt); Shaltout, Abdallah A. [Faculty of Science, Taif University, P.O. Box 888 Al-Haweiah, Taif (Saudi Arabia); Spectroscopy Department, Physics Division, National Research Center, El Behooth Str., 12622 Dokki, Cairo (Egypt)

    2012-07-15

    Highlights: Black-Right-Pointing-Pointer Hydrothermal synthesized of well-crystallized Ti-substituted MnFe{sub 2}O{sub 4} nanoparticles at 180 Degree-Sign C without any calcination step. The chemical composition was represented by Mn{sub 1-2x}Ti{sub x}Fe{sub 2}O{sub 4} with x having values 0.0, 0.1, 0.2, 0.3 and 0.4. Black-Right-Pointing-Pointer The change in lattice parameter and saturation magnetization with increasing Ti-substitution was investigated and explained. Black-Right-Pointing-Pointer The change in microstructure due to Ti{sup 4+} ions substitutions was investigated using TEM analysis. - Abstarct: A series of well-crystallized Mn{sub 1-2x}Ti{sub x}Fe{sub 2}O{sub 4} nanoparticles with x values of 0.0, 0.1, 0.2, 0.3 and 0.4 have been synthesized by hydrothermal route at 180 Degree-Sign C in the presence of NaOH as mineralizer. The obtained ferrite samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The XRD analysis showed that pure single phases of cubic ferrites were obtained with x up to 0.2. However, samples with x > 0.2 showed traces of unreacted anatase. The increase in Ti-substitution up to x = 0.2 leads to an increase in the lattice parameter of the prepared ferrites. On the other hand, the increase in Ti-substitution over x = 0.2 leads to a decrease in the lattice parameter. The average crystallite size was in the range of 39-57 nm, where it is increased by increasing the Ti-substitution up to x = 0.3, then decreased for x = 0.4. According to VSM results, the saturation magnetization increased with Ti ion substitution of x = 0.1 and decreased for x > 0.1.

  11. Hydrophobic core substitutions in calbindin D9k

    DEFF Research Database (Denmark)

    Kragelund, B B; Jönsson, M; Bifulco, G

    1998-01-01

    Hydrophobic core residues have a marked influence on the Ca2+-binding properties of calbindin D9k, even though there are no direct contacts between these residues and the bound Ca2+ ions. Eleven different mutants with substitutions in the hydrophobic core were produced, and their equilibrium Ca2+...... that the hydrophobic core residues promote Ca2+ binding both by contributing to the preformation of the Ca2+ sites in the apo state and by preferentially stabilizing the Ca2+-bound state.......Hydrophobic core residues have a marked influence on the Ca2+-binding properties of calbindin D9k, even though there are no direct contacts between these residues and the bound Ca2+ ions. Eleven different mutants with substitutions in the hydrophobic core were produced, and their equilibrium Ca2...... that the mutation causes only very minimal perturbations in the immediate vicinity of residue 61. Substitutions of alanines or glycines for bulky residues in the center of the core were found to have significant effects on both Ca2+ affinity and dissociation rates. These substitutions caused a reduction in affinity...

  12. 39 CFR 762.43 - Issuance of substitute disbursement postal money order.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Issuance of substitute disbursement postal money...; DISBURSEMENT POSTAL MONEY ORDERS DISBURSEMENT POSTAL MONEY ORDERS Issuance of Substitutes for Lost, Destroyed, Mutilated, and Defaced Disbursement Postal Money Orders § 762.43 Issuance of substitute disbursement postal...

  13. Oxygen-Partial-Pressure Sensor for Aircraft Oxygen Mask

    Science.gov (United States)

    Kelly, Mark; Pettit, Donald

    2003-01-01

    A device that generates an alarm when the partial pressure of oxygen decreases to less than a preset level has been developed to help prevent hypoxia in a pilot or other crewmember of a military or other high-performance aircraft. Loss of oxygen partial pressure can be caused by poor fit of the mask or failure of a hose or other component of an oxygen distribution system. The deleterious physical and mental effects of hypoxia cause the loss of a military aircraft and crew every few years. The device is installed in the crewmember s oxygen mask and is powered via communication wiring already present in all such oxygen masks. The device (see figure) includes an electrochemical sensor, the output potential of which is proportional to the partial pressure of oxygen. The output of the sensor is amplified and fed to the input of a comparator circuit. A reference potential that corresponds to the amplified sensor output at the alarm oxygen-partial-pressure level is fed to the second input of the comparator. When the sensed partial pressure of oxygen falls below the minimum acceptable level, the output of the comparator goes from the low state (a few millivolts) to the high state (near the supply potential, which is typically 6.8 V for microphone power). The switching of the comparator output to the high state triggers a tactile alarm in the form of a vibration in the mask, generated by a small 1.3-Vdc pager motor spinning an eccentric mass at a rate between 8,000 and 10,000 rpm. The sensation of the mask vibrating against the crewmember s nose is very effective at alerting the crewmember, who may already be groggy from hypoxia and is immersed in an environment that is saturated with visual cues and sounds. Indeed, the sensation is one of rudeness, but such rudeness could be what is needed to stimulate the crewmember to take corrective action in a life-threatening situation.

  14. Control of Chemical Risks by Substitution of Harmful Substances

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    1997-01-01

    Substitution of volatile, organic solvents with non-volatile, low-toxic esters of fatty acids for cleaning purposes in offset printing has successfully been implemented in several European countries. Similar substitutions in other industrial cleaning processes seem possible, especially regarding...

  15. Consumer acceptance and appropriateness of meat substitutes in a meal context

    NARCIS (Netherlands)

    Elzerman, J.E.; Hoek, A.C.; Boekel, van M.A.J.S.; Luning, P.A.

    2011-01-01

    The replacement of meat by meat substitutes could help to reduce the environmental burden of our food production systems. However, the acceptance of most meat substitutes is still low. This study investigated the role of meal context on the acceptance of meat substitutes. In a central location test

  16. A close correlation between induced ferromagnetism and oxygen deficiency in Fe doped In2O3

    International Nuclear Information System (INIS)

    Singhal, R.K.; Samariya, A.; Kumar, Sudhish; Sharma, S.C.; Xing, Y.T.; Deshpande, U.P.; Shripathi, T.; Saitovitch, E.

    2010-01-01

    We report on the reversible manipulation of room temperature ferromagnetism in Fe (5%) doped In 2 O 3 polycrystalline magnetic semiconductor. The X-ray diffraction and photoemission measurements confirm that the Fe ions are well incorporated into the lattice, substituting the In 3+ ions. The magnetization measurements show that the host In 2 O 3 has a diamagnetic ground state, while it shows weak ferromagnetism at 300 K upon Fe doping. The as-prepared sample was then sequentially annealed in hydrogen, air, vacuum and finally in air. The ferromagnetic signal shoots up by hydrogenation as well as vacuum annealing and bounces back upon re-annealing the samples in air. The sequence of ferromagnetism shows a close inter-relationship with the behavior of oxygen vacancies (V o ). The Fe ions tend to a transform from 3+ to 2+ state during the giant ferromagnetic induction, as revealed by photoemission spectroscopy. A careful characterization of the structure, purity, magnetic, and transport properties confirms that the ferromagnetism is due to neither impurities nor clusters but directly related to the oxygen vacancies. The ferromagnetism can be reversibly controlled by these vacancies while a parallel variation of carrier concentration, as revealed by resistance measurements, appears to be a side effect of the oxygen vacancy variation.

  17. Photochemical reaction of Si-substituted ethynylsilanes with 1,2-ethanedithiol

    Energy Technology Data Exchange (ETDEWEB)

    Voronkov, M.G.; Brodskaya, E.I.; Kalabin, G.A.; Vlasova, N.N.; Yarosh, O.G.; Zhila, G.Y.

    1985-12-01

    The authors investigate the chief products of the photochemical reactions of Si-substituted ethynylsilanes with 1,2,-ethanedithiol at 60-70 C. It is found that the chief products are 2-triorganylsilyl-substituted 1,4-dithiacyclopentanes and 1,4-dithiacyclohexanes. On lowering the temperature to -30 C, formation of bis (triorganylsilyl)-substituted 1,4,7,10-tetrathiacyclododecanes occurs along with the abo ve-mentioned five- and six-membered heterocycles.

  18. Hyperfine magnetic fields in substituted Finemet alloys

    Energy Technology Data Exchange (ETDEWEB)

    Brzózka, K., E-mail: k.brzozka@uthrad.pl [University of Technology and Humanities in Radom, Department of Physics (Poland); Sovák, P. [P.J. Šafárik University, Institute of Physics (Slovakia); Szumiata, T.; Gawroński, M.; Górka, B. [University of Technology and Humanities in Radom, Department of Physics (Poland)

    2016-12-15

    Transmission Mössbauer spectroscopy was used to determine the hyperfine fields of Finemet-type alloys in form of ribbons, substituted alternatively by Mn, Ni, Co, Al, Zn, V or Ge of various concentration. The comparative analysis of magnetic hyperfine fields was carried out which enabled to understand the role of added elements in as-quenched as well as annealed samples. Moreover, the influence of the substitution on the mean direction of the local hyperfine magnetic field was examined.

  19. Substituting telecommunications for travel - Feasible or desirable

    Science.gov (United States)

    Van Vleck, E. M.

    1974-01-01

    This paper reviews recent advances in telecommunications and examines the detailed structure of travel to estimate the feasibility of substituting telecommunications for various travel objectives. The impact of travel is analyzed from a social, economic, energy, and pollution standpoint to assess the desirability of substitution. Perhaps 35-50% of the nation's travel could, in theory, be replaced by very advanced telecommunications (such as a much improved large-screen teleconferencing network), but public resistance would be massive. Much economic dislocation would result since, for example, over 25% of retail sales are travel-related. The energy savings would be modest since only 25% of the nation's energy is consumed by transportation. However, all pollution would be reduced substantially since transportation accounts for 75% of the carbon monoxide, 60% of the hydrocarbon, and 55% of the nitrogen oxide pollution in the nation. Problems related to the implementation of large-scale substitution are discussed.

  20. Nanostructured Mn{sub x}O{sub y} for oxygen reduction reaction (ORR) catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Delmondo, Luisa, E-mail: luisa.delmondo@polito.it [Department of Applied Science and Technology—DISAT, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Salvador, Gian Paolo; Muñoz-Tabares, José Alejandro; Sacco, Adriano; Garino, Nadia; Castellino, Micaela [Center for Space Human Robotics @PoliTo, Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Torino (Italy); Gerosa, Matteo; Massaglia, Giulia [Department of Applied Science and Technology—DISAT, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Center for Space Human Robotics @PoliTo, Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Torino (Italy); Chiodoni, Angelica; Quaglio, Marzia [Center for Space Human Robotics @PoliTo, Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Torino (Italy)

    2016-12-01

    Highlights: • Good performance catalysts for oxygen reduction reaction. • Nanostructured low-cost catalysts respect to platinum ones. • Synthesis using environmental benign chemical reagents. - Abstract: In the field of fuel cells, oxygen plays a key role as the final electron acceptor. To facilitate its reduction (Oxygen Reduction Reaction—ORR), a proper catalyst is needed and platinum is considered the best one due to its low overpotential for this reaction. By considering the high price of platinum, alternative catalysts are needed and manganese oxides (Mn{sub x}O{sub y}) can be considered promising substitutes. They are inexpensive, environmental friendly and can be obtained into several forms; most of them show significant electro-catalytic performance, even if strategies are needed to increase their efficiency. In particular, by developing light and high-surface area materials and by optimizing the presence of catalytic sites, we can obtain a cathode with improved electro-catalytic performance. In this case, nanofibers and xerogels are two of the most promising nanostructures that can be used in the field of catalysis. In this work, a study of the morphological and catalytic behavior of Mn{sub x}O{sub y} nanofibers and xerogels is proposed. Nanofibers were obtained by electrospinning, while xerogels were prepared by sol-gel and freeze drying techniques. Despite of the different preparation approaches, the obtained nanostructured manganese oxides exhibited similar catalytic performance for the ORR, comparable to those obtained from Pt catalysts.

  1. Density functional theory study the effects of oxygen-containing functional groups on oxygen molecules and oxygen atoms adsorbed on carbonaceous materials.

    Science.gov (United States)

    Qi, Xuejun; Song, Wenwu; Shi, Jianwei

    2017-01-01

    Density functional theory was used to study the effects of different types of oxygen-containing functional groups on the adsorption of oxygen molecules and single active oxygen atoms on carbonaceous materials. During gasification or combustion reactions of carbonaceous materials, oxygen-containing functional groups such as hydroxyl(-OH), carbonyl(-CO), quinone(-O), and carboxyl(-COOH) are often present on the edge of graphite and can affect graphite's chemical properties. When oxygen-containing functional groups appear on a graphite surface, the oxygen molecules are strongly adsorbed onto the surface to form a four-member ring structure. At the same time, the O-O bond is greatly weakened and easily broken. The adsorption energy value indicates that the adsorption of oxygen molecules changes from physisorption to chemisorption for oxygen-containing functional groups on the edge of a graphite surface. In addition, our results indicate that the adsorption energy depends on the type of oxygen-containing functional group. When a single active oxygen atom is adsorbed on the bridge site of graphite, it gives rise to a stable epoxy structure. Epoxy can cause deformation of the graphite lattice due to the transition of graphite from sp2 to sp3 after the addition of an oxygen atom. For quinone group on the edge of graphite, oxygen atoms react with carbon atoms to form the precursor of CO2. Similarly, the single active oxygen atoms of carbonyl groups can interact with edge carbon atoms to form the precursor of CO2. The results show that oxygen-containing functional groups on graphite surfaces enhance the activity of graphite, which promotes adsorption on the graphite surface.

  2. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi_0_._9_8B_0_._0_2

    International Nuclear Information System (INIS)

    Sun, Hui; Lu, Xu; Morelli, Donald T.

    2016-01-01

    Boron-added CoSi, CoSi_0_._9_8B_0_._0_2, possesses a very high thermoelectric power factor of 60 μW cm"−"1 K"−"2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms is intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi_0_._9_8B_0_._0_2 has been studied. Here, we present a study of the substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands, while Ge substitution only shifts the Fermi level upward into the conduction band. Our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.

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

    Science.gov (United States)

    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 under...

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

    Science.gov (United States)

    2010-07-01

    ..., 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 to...

  5. Substitution possibilities and determinants of energy intensity for China

    International Nuclear Information System (INIS)

    Ma, Hengyun; Oxley, Les; Gibson, John

    2009-01-01

    This paper measures technological change, factor demand and inter-factor and inter-fuel substitutability measures for China. We use individual fuel price data and a two-stage approach to estimate total factor cost functions and fuel share equations. Both inter-factor and inter-fuel substitution elasticities are calculated and the change in energy intensity is decomposed into its driving forces. The results suggest that energy is substitutable for capital regionally and for labor nationally. Capital substitutes for energy more easily than labor does. Energy intensity changes vary by region but the major drivers seem to be 'budget effect' and the adoption of energy-intensive technologies, which might be embodied in high-level energy-using exports and sectors, capital investment and even old technique and equipment imports. Whether the trend in rising energy intensity continues will be significant for China and the rest of the world. (author)

  6. Substitution possibilities and determinants of energy intensity for China

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hengyun [College of Economics and Management, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002 (China); Department of Economics, University of Canterbury, Private bag 4800, Christchurch 8140 (New Zealand); Oxley, Les [Department of Economics, University of Canterbury, Private bag 4800, Christchurch 8140 (New Zealand); Gibson, John [Department of Economics, University of Waikato, Private Bag 3105, Hamilton (New Zealand)

    2009-05-15

    This paper measures technological change, factor demand and inter-factor and inter-fuel substitutability measures for China. We use individual fuel price data and a two-stage approach to estimate total factor cost functions and fuel share equations. Both inter-factor and inter-fuel substitution elasticities are calculated and the change in energy intensity is decomposed into its driving forces. The results suggest that energy is substitutable for capital regionally and for labor nationally. Capital substitutes for energy more easily than labor does. Energy intensity changes vary by region but the major drivers seem to be 'budget effect' and the adoption of energy-intensive technologies, which might be embodied in high-level energy-using exports and sectors, capital investment and even old technique and equipment imports. Whether the trend in rising energy intensity continues will be significant for China and the rest of the world. (author)

  7. Pesticide Substitution: Combining Food Safety with Environmental Quality

    DEFF Research Database (Denmark)

    Fantke, Peter

    2015-01-01

    Various pesticides are authorized for use on agricultural food crops. Despite regulatory risk assessments aiming at ensuring consumer and environmental safety, pesticides contribute to human and environmental impacts. Guidance is needed to optimize pesticide use practice and minimize human...... and environmental exposure. Comparative pesticide substitution scenarios are presented to address this need. In a case study on wheat, different pesticides have been compared with respect to their substitution potential with focus on human health. Results demonstrate that health impacts can be reduced up to 99......% by defining adequate substitution scenarios. Comprehensive scenarios need to also consider worker and environmental burden, and information on crop rotation, pest pressure, environmental conditions, application costs and efficacy. Such scenarios help to increase food safety and more sustainable use...

  8. Generic medicines and generic substitution: contrasting perspectives of stakeholders in Ireland.

    Science.gov (United States)

    O'Leary, A; Usher, C; Lynch, M; Hall, M; Hemeryk, L; Spillane, S; Gallagher, P; Barry, M

    2015-12-15

    The Health (Pricing and Supply of Medical Goods) Act 2013 passed into law in July 2013 and legislated for generic substitution in Ireland. The aim of the study was to ascertain the knowledge and perceptions of stakeholders i.e. patients, pharmacists and prescribers, of generic medicines and to generic substitution with the passing of legislation. Three stakeholder specific questionnaires were developed to assess knowledge of and perceptions to generic medicines and generic substitution. Purposive samples of patients, prescribers and pharmacists were analysed. Descriptive quantitative and qualitative analyses were undertaken. A total of 762 healthcare professionals and 353 patients were recruited. The study highlighted that over 84% of patients were familiar with generic medicines and are supportive of the concept of generic substitution. Approximately 74% of prescribers and 84% of pharmacists were supportive of generic substitution in most cases. The main areas of concern highlighted by the healthcare professionals that might impact on the successful implementation of the policy, were the issue of bioequivalence with generic medicines, the computer software systems used at present in general practitioner (GP) surgeries and the availability of branded generics. The findings from this study identify a high baseline rate of acceptance to generic medicines and generic substitution among patients, prescribers and pharmacists in the Irish setting. The concerns of the main stakeholders provide a valuable insight into the potential difficulties that may arise in its implementation, and the need for on-going reassurance and proactive dissemination of the impact of the generic substitution policy. The existing positive attitude to generic medicines and generic substitution among key stakeholders in Ireland to generic substitution, combined with appropriate support and collaboration should result in the desired increase in rates of prescribing, dispensing and use of generic

  9. Testing of currency substitution effect on exchange rate volatility in Serbia

    Directory of Open Access Journals (Sweden)

    Petrović Predrag

    2016-01-01

    Full Text Available Despite numerous different definitions existing in the literature, currency substitution is generally understood as a phenomenon when domestic residents prefer to use foreign currency rather than domestic currency. The main reasons for such phenomenon include high and volatile inflation, strong depreciation of national currency and high interest rate differential in favour of foreign currency. Currency substitution, as a monetary phenomenon, is widely spread in Latin American, Eastern European and some Asian countries. This paper is dedicated to the influence of currency substitution on exchange rate volatility in Serbia. The research included testing of three hypotheses: (i currency substitution positively affects depreciation rate volatility, (ii depreciation rate volatility has stronger responses to the past negative than to the past positive depreciation shocks, and (iii currency substitution positively affects expected depreciation rate. The analysis was implemented for the period 2002:m1-2015:m12 (2004:m1- 2015:m12, applying modified EGARCH-M model. Based on the obtained results, all three hypotheses have been supremely rejected regardless of the manner of quantification of currency substitution.

  10. A test of the substitution-habitat hypothesis in amphibians.

    Science.gov (United States)

    Martínez-Abraín, Alejandro; Galán, Pedro

    2017-12-08

    Most examples that support the substitution-habitat hypothesis (human-made habitats act as substitutes of original habitat) deal with birds and mammals. We tested this hypothesis in 14 amphibians by using percentage occupancy as a proxy of habitat quality (i.e., higher occupancy percentages indicate higher quality). We classified water body types as original habitat (no or little human influence) depending on anatomical, behavioral, or physiological adaptations of each amphibian species. Ten species had relatively high probabilities (0.16-0.28) of occurrence in original habitat, moderate probability of occurrence in substitution habitats (0.11-0.14), and low probability of occurrence in refuge habitats (0.05-0.08). Thus, the substitution-habitat hypothesis only partially applies to amphibians because the low occupancy of refuges could be due to the negligible human persecution of this group (indicating good conservation status). However, low occupancy of refuges could also be due to low tolerance of refuge conditions, which could have led to selective extinction or colonization problems due to poor dispersal capabilities. That original habitats had the highest probabilities of occupancy suggests amphibians have a good conservation status in the region. They also appeared highly adaptable to anthropogenic substitution habitats. © 2017 Society for Conservation Biology.

  11. An evaluation of Substitute natural gas production from different coal gasification processes based on modeling

    International Nuclear Information System (INIS)

    Karellas, S.; Panopoulos, K.D.; Panousis, G.; Rigas, A.; Karl, J.; Kakaras, E.

    2012-01-01

    Coal and lignite will play a significant role in the future energy production. However, the technical options for the reduction of CO 2 emissions will define the extent of their share in the future energy mix. The production of synthetic or substitute natural gas (SNG) from solid fossil fuels seems to be a very attractive process: coal and lignite can be upgraded into a methane rich gas which can be transported and further used in high efficient power systems coupled with CO 2 sequestration technologies. The aim of this paper is to present a modeling analysis comparison between substitute natural gas production from coal by means of allothermal steam gasification and autothermal oxygen gasification. In order to produce SNG from syngas several unit operations are required such as syngas cooling, cleaning, potential compression and, of course, methanation reactors. Finally the gas which is produced has to be conditioned i.e. removal of unwanted species, such as CO 2 etc. The heat recovered from the overall process is utilized by a steam cycle, producing power. These processes were modeled with the computer software IPSEpro™. An energetic and exergetic analysis of the coal to SNG processes have been realized and compared. -- Highlights: ► The production of SNG from coal is examined. ► The components of the process were simulated for integrated autothermal or allothermal coal gasification to SNG. ► The energetic and exergetic evaluation of the two processes is presented.

  12. The C21-formyl group in chlorophyll f originates from molecular oxygen.

    Science.gov (United States)

    Garg, Harsh; Loughlin, Patrick C; Willows, Robert D; Chen, Min

    2017-11-24

    Chlorophylls (Chls) are the most important cofactors for capturing solar energy to drive photosynthetic reactions. Five spectral types of Chls have been identified to date, with Chl f having the most red-shifted absorption maximum because of a C2 1 -formyl group substitution of Chl f However, the biochemical provenance of this formyl group is unknown. Here, we used a stable isotope labeling technique ( 18 O and 2 H) to determine the origin of the C2 1 -formyl group of Chl f and to verify whether Chl f is synthesized from Chl a in the cyanobacterial species Halomicronema hongdechloris. In the presence of either H 2 18 O or 18 O 2 , the origin of oxygen atoms in the newly synthesized chlorophylls was investigated. The pigments were isolated with HPLC, followed by MS analysis. We found that the oxygen atom of the C2 1 -formyl group originates from molecular oxygen and not from H 2 O. Moreover, we examined the kinetics of the labeling of Chl a and Chl f from H. hongdechloris grown in 50% D 2 O-seawater medium under different light conditions. When cells were shifted from white light D 2 O-seawater medium to far-red light H 2 O-seawater medium, the observed deuteration in Chl f indicated that Chl(ide) a is the precursor of Chl f Taken together, our results advance our understanding of the biosynthesis pathway of the chlorophylls and the formation of the formyl group in Chl f . © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. A New Substitution Cipher - Random-X

    Directory of Open Access Journals (Sweden)

    Falguni Patel

    2015-08-01

    Full Text Available Ciphers are the encryption methods to prepare the algorithm for encryption and decryption. The currently known ciphers are not strong enough to protect the data. A new substitution cipher Random-X that we introduce in this paper can be used for password encryption and data encryption. Random-X cipher is a unique substitution cipher which replaces the units of plaintext with triplets of letters. The beauty of this cipher is that the encrypted string of the same plain text is not always same. This makes it strong and difficult to crack. This paper covers the principle the implementation ideas and testing of Random-X cipher.

  14. Substitution between cars within the household

    DEFF Research Database (Denmark)

    De Borger, Bruno; Mulalic, Ismir; Rouwendal, Jan

    The purpose of this paper is to study to what extent two-car households substitute the use of their less fuel efficient car by the use of their more fuel efficient car after an increase in fuel prices. Based on a simple theoretical framework we use a large sample of detailed Danish data on two-car...... households to estimate, for each car owned by the household, own and cross-price effects of increases in fuel costs per kilometer. The empirical results point at important substitution effects, so that models that estimate responses to fuel prices on the implicit or explicit assumption of one car per...

  15. Biomaterials in search of a meniscus substitute.

    Science.gov (United States)

    Rongen, Jan J; van Tienen, Tony G; van Bochove, Bas; Grijpma, Dirk W; Buma, Pieter

    2014-04-01

    The menisci fulfill key biomechanical functions in the tibiofemoral (knee) joint. Unfortunately meniscal injuries are quite common and most often treated by (partial) meniscectomy. However, some patients experience enduring symptoms, and, more importantly, it leads to an increased risk for symptomatic osteoarthritis. Over the past decades, researchers have put effort in developing a meniscal substitute able to prevent osteoarthritis and treat enduring clinical symptoms. Grossly, two categories of substitutes are observed: First, a resorbable scaffold mimicking biomechanical function which slowly degrades while tissue regeneration and organization is promoted. Second, a non resorbable, permanent implant which mimics the biomechanical function of the native meniscus. Numerous biomaterials with different (material) properties have been used in order to provide such a substitute. Nevertheless, a clinically applicable cartilage protecting material is not yet emerged. In the current review we provide an overview, and discuss, these different materials and extract recommendations regarding material properties for future developmental research. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Thermodynamic studies on charge-coupled substituted synthetic monazite

    Energy Technology Data Exchange (ETDEWEB)

    Rawat, D. [Product Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Phapale, S. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Mishra, R., E-mail: mishrar@barc.gov.in [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Dash, S. [Product Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2017-04-15

    Phosphate-based monazite ceramic is considered worldwide as a potential crystalline host matrix for immobilization of long-lived tri- and tetra-valent actinides present in high-level nuclear waste. Monazite is chemically stable with respect to the leaching processes and has high radiation stability. The present paper describes the influence of charged coupled (Ca{sup 2+}, Th{sup 4+}) substitution in place of La{sup 3+} on thermodynamic stability of synthetic monazite ceramics. XRD-analysis of Ca, Th substituted LaPO{sub 4} viz., La{sub 1-x}Ca{sub x/2}Th{sub x/2}PO{sub 4} (0 ≤ x ≤ 1) points to the formation of ideal solid-solution in the entire range of composition. However, thermodynamic analysis indicates deviation from ideal solid-solution with a minima at x = 0.25. The substituted La{sub 1-x}Ca{sub x/2}Th{sub x/2}PO{sub 4} system is found to be iso-entropic and stabilized mainly by enthalpy. Enthalpies of formation as a function of Ca{sup 2+}, Th{sup 4+} substitution were analysed to provide insights into the development of thermodynamically stable nuclear waste matrix.

  17. Implementing opioid substitution in Lebanon: Inception and challenges.

    Science.gov (United States)

    El-Khoury, Joseph; Abbas, Zeinab; Nakhle, Pascale E; Matar, Marie-Therese

    2016-05-01

    Opioid Substitution Treatment (OST) is a firmly established method of treating and managing dependence to opioids in Europe, the US and rest of the developed world. It has a solid evidence base and a positive safety track record. Dissemination of its practice, in parallel to the acceptance of harm reduction as an effective approach, is still timid in low and middle Income countries. After years of advocacy on the parts of clinicians and the voluntary sector, the government of Lebanon launched a national opioid substitution program in 2011 using buprenorphine as the substance of substitution. Lebanon is one of the first countries in the MENA region to establish such a program despite a difficult socio-political context. This paper provides the background of harm reduction efforts in the region and presents the outline of the program from inception to present date. Challenges and recommendations for the future are also discussed. The Lebanese experience with opioid substitution is encouraging so far and can be used as a template for others in the region who might be contemplating broadening the range of services available to tackle addiction to heroin and related substances. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Sequential Use of Hyperbaric Oxygen, Synthetic Skin Substitute and Skin Grafting in the Treatment of a Refractory Vasculitic Ulcer.

    Science.gov (United States)

    Akcali, Gökhan; Uzun, Günalp; Yapici, Abdül Kerim; Yildiz, Şenol

    2013-12-01

    Cutaneous leukocytoclastic vasculitis (CLCV) is a disorder characterized by the inflammation of the small vessels of the skin. CLCV may cause recurrent, drug-resistant, non-healing ulcers. Herein, we present a patient with a recalcitrant ulcer caused by CLCV, who was successfully treated with hyperbaric oxygen therapy and skin grafting. There is not any particular therapy/product that will heal all type of wounds. We can achieve better results provided that wound care products and advanced treatments are used at the right time.

  19. Oxygen permeation through oxygen ion oxide-noble metal dual phase composites

    NARCIS (Netherlands)

    Chen, C.S.; Chen, C.S.; Kruidhof, H.; Bouwmeester, Henricus J.M.; Verweij, H.; Burggraaf, Anthonie; Burggraaf, A.J.

    1996-01-01

    Oxygen permeation behaviour of three composites, yttria-stabilized zirconia-palladium, erbia-stabilized bismuth oxidenoble metal (silver, gold) was studied. Oxygen permeation measurements were performed under controlled oxygen pressure gradients at elevated temperatures. Air was supplied at one side

  20. Structural transformations, water incorporation and transport properties of tin-substituted barium indate

    Science.gov (United States)

    Cichy, Kacper; Skubida, Wojciech; Świerczek, Konrad

    2018-06-01

    Incorporation of water into tin-substituted BaIn1-xSnxO3-δ (x = 0.1-0.3) is shown to influence crystal structure at room temperature, structural transformations at high temperatures and ionic transport properties of the materials. Increasing tin content stabilizes oxygen vacancy-disordered perovskite-type phase, which together with large changes of the unit cell volume occurring during hydration and dehydration processes, result in a complex structural behavior, as documented by high-temperature X-ray diffraction and thermogravimetric studies. Impedance spectroscopy measurements at elevated temperatures (350-800 °C) revealed very high proton conductivity in BaIn.8Sn.2O3-δ, exceeding 1.1·10-3 S cm-1 at 500 °C, with high values of the transference number in wet air. At the same time, relaxation kinetics of the electrical conductivity showed a monotonous nature, which indicates negligible component of the electronic hole conductivity in the hydrated material. The oxides are extremely moisture-sensitive, which results in a significant mechanical stability problems, affecting possibility to prepare electrolyte membranes.

  1. SO2 policy and input substitution under spatial monopoly

    International Nuclear Information System (INIS)

    Gerking, Shelby; Hamilton, Stephen F.

    2010-01-01

    Following the U.S. Clean Air Act Amendments of 1990, electric utilities dramatically increased their utilization of low-sulfur coal from the Powder River Basin (PRB). Recent studies indicate that railroads hauling PRB coal exercise a substantial degree of market power and that relative price changes in the mining and transportation sectors were contributing factors to the observed pattern of input substitution. This paper asks the related question: To what extent does more stringent SO 2 policy stimulate input substitution from high-sulfur coal to low-sulfur coal when railroads hauling low-sulfur coal exercise spatial monopoly power? The question underpins the effectiveness of incentive-based environmental policies given the essential role of market performance in input, output, and abatement markets in determining the social cost of regulation. Our analysis indicates that environmental regulation leads to negligible input substitution effects when clean and dirty inputs are highly substitutable and the clean input market is mediated by a spatial monopolist. (author)

  2. Modified broken rice starch as fat substitute in sausages

    Directory of Open Access Journals (Sweden)

    Valéria Maria Limberger

    2011-09-01

    Full Text Available The demand for low-fat beef products has led the food industry to use fat substitutes such as modified starch. About 14% of broken rice is generated during processing. Nevertheless, this by-product contains high levels of starch; being therefore, great raw material for fat substitution. This study evaluated the applicability of chemically and physically modified broken rice starch as fat substitute in sausages. Extruded and phosphorylated broken rice was used in low-fat sausage formulation. All low-fat sausages presented about 55% reduction in the fat content and around 28% reduction in the total caloric value. Fat replacement with phosphorylated and extruded broken rice starch increased the texture acceptability of low-fat sausages, when compared to low-fat sausages with no modified broken rice. Results suggest that modified broken rice can be used as fat substitute in sausage formulations, yielding lower caloric value products with acceptable sensory characteristics.

  3. The applied theory of energy substitution in production

    International Nuclear Information System (INIS)

    Thompson, Henry

    2006-01-01

    This paper reviews the applied theory of energy cross price partial elasticities of substitution, and presents it in a transparent fashion. It uses log linear and translog production and cost functions due to their economic properties and convenient estimating forms, but the theory applies other functional forms. The objective is to encourage increased empirical research that would deepen understanding and appreciation of energy substitution. (author)

  4. A determination of the oxygen non-stoichiometry of the oxygen storage materials LnBaMn{sub 2}O{sub 5+δ} (Ln=Gd, Pr)

    Energy Technology Data Exchange (ETDEWEB)

    Jeamjumnunja, Kannika; Gong, Wenquan; Makarenko, Tatyana; Jacobson, Allan J., E-mail: ajjacob@uh.edu

    2016-07-15

    The A-site ordered double-perovskite oxides, LnBaMn{sub 2}O{sub 5+δ} (Ln=Gd, Pr), were synthesized and investigated to understand the effect of A site cation substitution on the oxygen storage properties of these materials. The present results are compared with our previous data for YBaMn{sub 2}O{sub 5+δ}. The results clearly reveal that changing the Ln cation strongly influences the oxidation/reduction behavior of LnBaMn{sub 2}O{sub 5+δ}. Based on thermogravimetric analysis data, oxygen uptake begins at lower temperatures in both air and oxygen in compounds with Ln{sup 3+} ions larger than Y{sup 3+}. These oxides exhibit almost complete and reversible oxygen uptake/release between fully-reduced LnBaMn{sub 2}O{sub 5} and fully-oxidized LnBaMn{sub 2}O{sub 6} during changes of the oxygen partial pressure between air and 1.99% H{sub 2}/Ar. In addition, the oxygen non-stoichiometries of GdBaMn{sub 2}O{sub 5+δ} and PrBaMn{sub 2}O{sub 5+δ} were determined as a function of pO{sub 2} at 600, 650, 700 and 750 °C by Coulometric titration at near-equilibrium conditions. The results confirm that these materials have two distinct phases on oxidation/reduction with δ≈0, 0.5 and a third phase with a range of composition with an oxygen content (5+δ) approaching ~6. The stabilities of the LnBaMn{sub 2}O{sub 5+δ} phases extend over a wide range of oxygen partial pressures (∼10{sup −25}≤pO{sub 2} (atm)≤∼1) depending on temperature. Isothermal experiments show that the larger the Ln{sup 3+} cation the lower pO{sub 2} for phase conversion. At some temperatures and pO{sub 2} conditions, the LnBaMn{sub 2}O{sub 5+δ} compounds are unstable with respect to decomposition to BaMnO{sub 3−δ} and LnMnO{sub 3}. This instability is more apparent in Coulometric titration experiments than in thermogravimetric analysis. The Coulometric titration experiments are necessarily slow in order to achieve equilibrium oxygen compositions. - Graphical abstract: Structure of Ln

  5. Enhancement in magnetic and dielectric properties of La and Pr co substituted BiFeO3

    International Nuclear Information System (INIS)

    Srivastava, Amit; Singh, H.K.; Awana, V.P.S.; Srivastava, O.N.

    2013-01-01

    diminished from 0.960 for x = 0.0, y = 0.0, 0.321 for x = 0.2, y = 0.0 and to 0.20 for x = 0.2, y = 0.05 at 100 Hz. This improvement in dielectric properties is likely due to the changes of lattice parameters and suppression of oxygen vacancies caused by La and Pr co substitution

  6. The oxygen effect and adaptive response of cells. Report 3. Simulation of respiratory oxygenation and oxygen permeability of cells

    International Nuclear Information System (INIS)

    Ehpshtejn, I.M.

    1978-01-01

    Variations in the oxygen concentration in extracellural [O 2 ] 0 and intracellular [Osub(2)]sub(i) media of cells small in size (d = 2 ] 0 - t-curves). It is shown that the Value of [Osub(2)]sub(i) may be expressed by four variants of its functional dependence: (a) on enzymic reaction of oxygen consumption, (b) on the order of reaction with respect to oxygen, (c) on physiological parameters of cells, and (d) on characteristic oxygen concentrations in the system. Items (c) and (d) are based on the postulated diffusion-kinetic model of oxygen consumption by an idealized cell of small size that consists of a drop of homogenous solution of the respiratory enzyme which is characterized by an equivalent Michaelis constant. The drop is enveloped in a uniform membrane that possesses a definite diffuse resistance to oxygen

  7. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi{sub 0.98}B{sub 0.02}

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hui, E-mail: huisun3@iflytek.com [Department of Basic Teaching, Anhui Institute of Information Technology, Wuhu, Anhui 241000 (China); Lu, Xu [College of Physics, Chongqing University, Chongqing 401331 (China); Morelli, Donald T. [Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824 (United States)

    2016-07-21

    Boron-added CoSi, CoSi{sub 0.98}B{sub 0.02}, possesses a very high thermoelectric power factor of 60 μW cm{sup −1} K{sup −2} at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms is intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi{sub 0.98}B{sub 0.02} has been studied. Here, we present a study of the substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands, while Ge substitution only shifts the Fermi level upward into the conduction band. Our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.

  8. Nonsynonymous substitution in abalone sperm fertilization genes exceeds substitution in introns and mitochondrial DNA

    Science.gov (United States)

    Metz, Edward C.; Robles-Sikisaka, Refugio; Vacquier, Victor D.

    1998-01-01

    Strong positive Darwinian selection acts on two sperm fertilization proteins, lysin and 18-kDa protein, from abalone (Haliotis). To understand the phylogenetic context for this dramatic molecular evolution, we obtained sequences of mitochondrial cytochrome c oxidase subunit I (mtCOI), and genomic sequences of lysin, 18-kDa, and a G protein subunit. Based on mtDNA differentiation, four north Pacific abalone species diverged within the past 2 million years (Myr), and remaining north Pacific species diverged over a period of 4–20 Myr. Between-species nonsynonymous differences in lysin and 18-kDa exons exceed nucleotide differences in introns by 3.5- to 24-fold. Remarkably, in some comparisons nonsynonymous substitutions in lysin and 18-kDa genes exceed synonymous substitutions in mtCOI. Lysin and 18-kDa intron/exon segments were sequenced from multiple red abalone individuals collected over a 1,200-km range. Only two nucleotide changes and two sites of slippage variation were detected in a total of >29,000 nucleotides surveyed. However, polymorphism in mtCOI and a G protein intron was found in this species. This finding suggests that positive selection swept one lysin allele and one 18-kDa allele to fixation. Similarities between mtCOI and lysin gene trees indicate that rapid adaptive evolution of lysin has occurred consistently through the history of the group. Comparisons with mtCOI molecular clock calibrations suggest that nonsynonymous substitutions accumulate 2–50 times faster in lysin and 18-kDa genes than in rapidly evolving mammalian genes. PMID:9724763

  9. Replacing the Transfusion of 1–2 Units of Blood with Plasma Expanders that Increase Oxygen Delivery Capacity: Evidence from Experimental Studies

    Directory of Open Access Journals (Sweden)

    Amy G. Tsai

    2014-10-01

    Full Text Available At least a third of the blood supply in the world is used to transfuse 1–2 units of packed red blood cells for each intervention and most clinical trials of blood substitutes have been carried out at this level of oxygen carrying capacity (OCC restoration. However, the increase of oxygenation achieved is marginal or none at all for molecular hemoglobin (Hb products, due to their lingering vasoactivity. This has provided the impetus for the development of “oxygen therapeutics” using Hb-based molecules that have high oxygen affinity and target delivery of oxygen to anoxic areas. However it is still unclear how these oxygen carriers counteract or mitigate the functional effects of anemia due to obstruction, vasoconstriction and under-perfusion. Indeed, they are administered as a low dosage/low volume therapeutic Hb (subsequently further diluted in the circulatory pool and hence induce extremely small OCC changes. Hyperviscous plasma expanders provide an alternative to oxygen therapeutics by increasing the oxygen delivery capacity (ODC; in anemia they induce supra-perfusion and increase tissue perfusion (flow by as much as 50%. Polyethylene glycol conjugate albumin (PEG-Alb accomplishes this by enhancing the shear thinning behavior of diluted blood, which increases microvascular endothelial shear stress, causes vasodilation and lowering peripheral vascular resistance thus facilitating cardiac function. Induction of supra-perfusion takes advantage of the fact that ODC is the product of OCC and blood flow and hence can be maintained by increasing either or both. Animal studies suggest that this approach may save a considerable fraction of the blood supply. It has an additional benefit of enhancing tissue clearance of toxic metabolites.

  10. Near-ambient X-ray photoemission spectroscopy and kinetic approach to the mechanism of carbon monoxide oxidation over lanthanum substituted cobaltites

    Energy Technology Data Exchange (ETDEWEB)

    Hueso, J. L.; Martinez-Martinez, D.; Cabalerro, Alfonso; Gonzalez-Elipe, Agustin Rodriguez; Mun, Bongjin Simon; Salmeron, Miquel

    2009-07-31

    We have studied the oxidation of carbon monoxide over a lanthanum substituted perovskite (La0.5Sr0.5CoO3-d) catalyst prepared by spray pyrolysis. Under the assumption of a first-order kinetics mechanism for CO, it has been found that the activation energy barrier of the reaction changes from 80 to 40 kJ mol-1 at a threshold temperature of ca. 320 oC. In situ XPS near-ambient pressure ( 0.2 torr) shows that the gas phase oxygen concentration over the sample decreases sharply at ca. 300 oC. These two observations suggest that the oxidation of CO undergoes a change of mechanism at temperatures higher than 300 oC.

  11. Mass spectrometric investigation of vinyl-substituted organic boron compounds

    International Nuclear Information System (INIS)

    Tarielashvili, V.O.; Ordzhonikidze, K.G.; Parulava, L.P.; Vakhaniya, G.V.

    1992-01-01

    Mass spectrometric investigation of vinyl-substituted organic compounds was conducted. Ionization was performed by electron shock. Possibility of determining boron isotope content is all analyzed organic boron vinyl-substituted compounds by direct method is shown. This simplifies sufficiently and lowers the price of analysis, improves its accuracy and rapidity

  12. CodonTest: modeling amino acid substitution preferences in coding sequences.

    Directory of Open Access Journals (Sweden)

    Wayne Delport

    2010-08-01

    Full Text Available Codon models of evolution have facilitated the interpretation of selective forces operating on genomes. These models, however, assume a single rate of non-synonymous substitution irrespective of the nature of amino acids being exchanged. Recent developments have shown that models which allow for amino acid pairs to have independent rates of substitution offer improved fit over single rate models. However, these approaches have been limited by the necessity for large alignments in their estimation. An alternative approach is to assume that substitution rates between amino acid pairs can be subdivided into rate classes, dependent on the information content of the alignment. However, given the combinatorially large number of such models, an efficient model search strategy is needed. Here we develop a Genetic Algorithm (GA method for the estimation of such models. A GA is used to assign amino acid substitution pairs to a series of rate classes, where is estimated from the alignment. Other parameters of the phylogenetic Markov model, including substitution rates, character frequencies and branch lengths are estimated using standard maximum likelihood optimization procedures. We apply the GA to empirical alignments and show improved model fit over existing models of codon evolution. Our results suggest that current models are poor approximations of protein evolution and thus gene and organism specific multi-rate models that incorporate amino acid substitution biases are preferred. We further anticipate that the clustering of amino acid substitution rates into classes will be biologically informative, such that genes with similar functions exhibit similar clustering, and hence this clustering will be useful for the evolutionary fingerprinting of genes.

  13. Factor substitution and rebound effect in China’s food industry

    International Nuclear Information System (INIS)

    Lin, Boqiang; Xie, Xuan

    2015-01-01

    Highlights: • The basic information of China’s food industry is introduced in detail. • Inter-factor substitution relationship in China’s food industry is analyzed. • Direct rebound effect in the industry is measured. • Several relevant policy suggestions about energy conservation are provided. - Abstract: Energy efficiency improvement can reduce the energy consumption of an industry, and thus promote energy conservation. However, the reduction of effective energy prices caused by energy efficiency improvement will lower energy costs for enterprises, making them substitute energy for other input factors. Therefore, energy conservation brought about by efficiency improvement will be partly offset. This offset is called the energy rebound effect of an industry. This paper estimates the system of cost share equations in China’s food industry, analyzes the substitution relationship between each input factor, and calculates the direct rebound effect. The results show that: there exist substitution relationships between energy and other input factors, among which the substitution elasticity between energy and labor is the biggest, and the substitution of energy for capital dominates that of capital for energy. The direct rebound effect is approximately 34.39%, which means that about 34.39% of energy conservation caused by energy efficiency enhancement in the industry has been offset by the rebound effect. The paper proposes some policy suggestions on energy conservation according to the results of substitution relationship among input factors and the rebound effect of the industry. The policy suggestions include reducing the capital and labor costs of the food industry by decreasing financing costs of small businesses, optimizing personnel management, and rationalizing the energy pricing mechanism to form a reasonable energy price.

  14. Influences of oxygen incorporation on the structural and optoelectronic properties of Cu_2ZnSnS_4 thin films

    International Nuclear Information System (INIS)

    Yu, Ruei-Sung; Hung, Ta-Chun

    2016-01-01

    Highlights: • Oxygen incorporation in Cu_2ZnSnS_4 changes the energy band structure. • The material has a comparatively high-absorptive capacity for short wavelength. • Absorption coefficients of the film increase from 10"4 to 10"5 cm"−"1. • The oxygen-containing CZTS film has a mixture of crystallite and crystalline states. • The material could be a candidate as an absorber layer in multi-junction solar cells. - Abstract: This study used the sol–gel method to prepare Cu_2ZnSnS_4 thin films containing oxygen and explored the composition, structural, and optoelectronic properties of the films. The non-vacuum process enabled the oxygen content of the Cu_2ZnSnS_4 films to be 8.89 at% and 10.30 at% for two different annealing conditions. In the crystal structure, oxygen was substituted at the positions of sulfur and appeared in the interstitial sites of the lattice. The compositions of the thin films deviated from the stoichiometric ratio. Both films had kesterite structures with no secondary phase structure. The kesterite CZTS film possessed a composite microstructure of crystallite and crystalline states. The microstructure of the Cu_2ZnSnS_4 film with higher oxygen content was denser and the average grain size was smaller. Incorporating oxygen atoms into crystalline Cu_2ZnSnS_4 changed the energy band structure: the direct energy band gaps were, respectively, 2.75 eV and 2.84 eV; the thin films mainly adsorbed photons with wavelengths less than 500 nm; and the absorption coefficients increased from 10"4 cm"−"1 to 10"5 cm"−"1. The films had a comparatively high absorptive capacity for photons less than 350 nm. Increasing the oxygen content of the film lowered the resistivity. Thus, the oxygen-containing Cu_2ZnSnS_4 thin film could be a candidate for the p-type absorber layer material required in multi-junction solar cells.

  15. Proterozoic atmospheric oxygen

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    2014-01-01

    This article is concerned with the evolution of atmospheric oxygen concentrations through the Proterozoic Eon. In particular, this article will seek to place the history of atmospheric oxygenation through the Proterozoic Eon in the context of the evolving physical environment including the history...... of continental growth and volcanic outgassing, as well as biogeochemical processing of elements within the oceans. The author will seek to explore constraints on the history of oxygenation and understand which processes have regulated oxygen through this eon....

  16. Resources, recycle, and substitution

    International Nuclear Information System (INIS)

    Wymer, R.G.

    A two-fold strategy appears necessary to ensure that the resource needs of the developed and developing nations are met. First, recycle and substitution must be encouraged in those instances where they do find application. Although these measures have limited applicability, they may be of vital importance in those instances where they do apply; in any event, they buy time. Second, practical and economical technologies must be developed to exploit the lower-grade and marginal ores and the oftentimes abundant but highly refractory ores, as well as to greatly increase the recovery of secondary elements present in the ores - elements whose form and amounts in the ores make them economically unrecoverable by themselves, but which are economically recoverable as by-products. It is often the case that if these elements are not recovered during the initial mining and milling operations, they are rendered unrecoverable, in a practical sense, forever. Furthermore, they may even become environmental pollutants. Specific examples of recovery from refractory ores, by-product recovery, and recycle are given. Also, some suggestions of substitutes for important resources are tabulated

  17. Convergent synthesis of 6-substituted phenanthridines via anionic ring closure

    DEFF Research Database (Denmark)

    Lysén, M.; Kristensen, Jesper Langgaard; Vedsø, P.

    2002-01-01

    Chemical equation presented The addition of organometallic derivatives to the cyano group of 2-(2-fluorophenyl)benzonitrile followed by intramolecular nucleophilic substitution produces 6-substituted phenanthridines. Alkyllithiums, aryllithiums, and sterically nondemanding lithium amides reacted ...

  18. Oxygen respiration rates of benthic foraminifera as measured with oxygen microsensors

    DEFF Research Database (Denmark)

    Geslin, E.; Risgaard-Petersen, N.; Lombard, Fabien

    2011-01-01

    of the foraminiferal specimens. The results show a wide range of oxygen respiration rates for the different species (from 0.09 to 5.27 nl cell−1 h−1) and a clear correlation with foraminiferal biovolume showed by the power law relationship: R = 3.98 10−3 BioVol0.88 where the oxygen respiration rate (R) is expressed......Oxygen respiration rates of benthic foraminifera are still badly known, mainly because they are difficult to measure. Oxygen respiration rates of seventeen species of benthic foraminifera were measured using microelectrodes and calculated on the basis of the oxygen fluxes measured in the vicinity...... groups (nematodes, copepods, ostracods, ciliates and flagellates) suggests that benthic foraminifera have a lower oxygen respiration rates per unit biovolume. The total contribution of benthic foraminifera to the aerobic mineralisation of organic matter is estimated for the studied areas. The results...

  19. A Web service substitution method based on service cluster nets

    Science.gov (United States)

    Du, YuYue; Gai, JunJing; Zhou, MengChu

    2017-11-01

    Service substitution is an important research topic in the fields of Web services and service-oriented computing. This work presents a novel method to analyse and substitute Web services. A new concept, called a Service Cluster Net Unit, is proposed based on Web service clusters. A service cluster is converted into a Service Cluster Net Unit. Then it is used to analyse whether the services in the cluster can satisfy some service requests. Meanwhile, the substitution methods of an atomic service and a composite service are proposed. The correctness of the proposed method is proved, and the effectiveness is shown and compared with the state-of-the-art method via an experiment. It can be readily applied to e-commerce service substitution to meet the business automation needs.

  20. 1-Hydroxyethyl-2-Substituted Phenoxymethyl Benzimidazoles: Synthesis and Crystal Structures

    International Nuclear Information System (INIS)

    Wu, J.; Wang, Z.; Gu, H.; Chen, W.; Zhao, L.; Zhao, C.

    2016-01-01

    Five novel 1-hydroxyethyl-2-substituted phenoxymethyl benzimidazoles c1-c5 were successfully synthesized by a three-step route. Firstly, five substituted phenoxymethyl acids a1-a5 were prepared by the O-carboxymethylation reaction of the starting substituted phenols under microwave irradiation. Then, these compounds reacted with o-phenylendiamine to get the key intermediates 2-substituted phenoxymethyl benzimidazoles b1-b5. At last, the target compounds were synthesized by the N-hydroxyethylation reaction of b1-b5 with 2-chloroethyl alcohol through the solid-liquid phase transfer catalysis method, where tetrabutyl ammonium bromide (TBAB) was used as the catalyst. The structures of the target compounds were well characterized and verified by elemental analysis, MS, IR, 1H NMR, 13C NMR and single crystal X-ray diffraction analysis. (author)

  1. A model for oxygen conservation associated with titration during pediatric oxygen therapy.

    Directory of Open Access Journals (Sweden)

    Grace Wu

    Full Text Available Continuous oxygen treatment is essential for managing children with hypoxemia, but access to oxygen in low-resource countries remains problematic. Given the high burden of pneumonia in these countries and the fact that flow can be gradually reduced as therapy progresses, oxygen conservation through routine titration warrants exploration.To determine the amount of oxygen saved via titration during oxygen therapy for children with hypoxemic pneumonia.Based on published clinical data, we developed a model of oxygen flow rates needed to manage hypoxemia, assuming recommended flow rate at start of therapy, and comparing total oxygen used with routine titration every 3 minutes or once every 24 hours versus no titration.Titration every 3 minutes or every 24 hours provided oxygen savings estimated at 11.7% ± 5.1% and 8.1% ± 5.1% (average ± standard error of the mean, n = 3, respectively. For every 100 patients, 44 or 30 kiloliters would be saved-equivalent to 733 or 500 hours at 1 liter per minute.Ongoing titration can conserve oxygen, even performed once-daily. While clinical validation is necessary, these findings could provide incentive for the routine use of pulse oximeters for patient management, as well as further development of automated systems.

  2. Story of skeletally substituted benzenes

    Indian Academy of Sciences (India)

    Unknown

    values are extensively used to define aromaticity quantitatively.3 In a recent study on ... studies were directed to unravel the subtle ways in which the stability, reactivity, and ..... The singlet–triplet gaps of all the skeletally substituted benzenes ...

  3. 49 CFR 383.77 - Substitute for driving skills tests.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Substitute for driving skills tests. 383.77... Substitute for driving skills tests. At the discretion of a State, the driving skill test as specified in... acceptable skills test, or an applicant's driving record in combination with certain driving experience. The...

  4. Managing demand uncertainty: probabilistic selling versus inventory substitution

    OpenAIRE

    Zhang, Y.; Hua, Guowei; Wang, Shouyang; Zhang, Juliang; Fernández Alarcón, Vicenç

    2018-01-01

    Demand variability is prevailing in the current rapidly changing business environment, which makes it difficult for a retailer that sells multiple substitutable products to determine the optimal inventory. To combat demand uncertainty, both strategies of inventory substitution and probabilistic selling can be used. Although the two strategies differ in operation, we believe that they share a common feature in combating demand uncertainty by encouraging some customers to give up some specific ...

  5. Artificial oxygen transport protein

    Science.gov (United States)

    Dutton, P. Leslie

    2014-09-30

    This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

  6. Cation substitution induced blue-shift of optical band gap

    Indian Academy of Sciences (India)

    Cation substitution induced blue-shift of optical band gap in nanocrystalline Zn ( 1 − x ) Ca x O thin films deposited by sol–gel dip coating technique ... thin films giving 13.03% enhancement in theenergy gap value due to the electronic perturbation caused by cation substitution as well as deterioration in crystallinity.

  7. Dehydroepiandrosterone substitution in female adrenal failure: no impact on endothelial function and cardiovascular parameters despite normalization of androgen status

    DEFF Research Database (Denmark)

    Christiansen, Jens Juel; Andersen, Niels Holmark; Sørensen, Keld E

    2007-01-01

    because of skin side effects and anxiety, respectively. All patients had low circulating androgens baseline and normal range androgens during DHEA treatment. We examined patients with noninvasive endothelial cell function, magnetic resonance imaging (MRI)-based cardiac output, echocardiography, ambulatory...... 24-h blood pressure and maximal oxygen consumption. RESULTS: DHEA treatment normalized androgen status to levels seen in healthy women. DHEA and placebo treatment had no effect on echocardiographic parameters of myocardial dimensions or systolic and diastolic function, noninvasive endothelial cell...... in vascular endothelium has been described and in vitro studies have shown involvement of DHEA in NO dependent pathways. AIM: To evaluate effects of DHEA substitution on cardiovascular parameters. DESIGN: Six months randomized, double-blind, placebo-controlled crossover study. Treatment consisted of DHEA 50...

  8. Aircraft Oxygen Generation

    Science.gov (United States)

    2012-02-01

    An Oxygen Enriched Air System for the AV-8A Harrier (NADC-81198-60).” 70 Horch , T., et. al. “The F-16 Onboard Oxygen Generating System: Performance...Only and Safety Privileged). Horch , T., Miller, R., Bomar, J., Tedor, J., Holden, R., Ikels, K., & Lozano, P. (1983). The F-16 Onboard Oxygen

  9. Osseointegration of subperiosteal implants using bovine bone substitute and various membranes

    DEFF Research Database (Denmark)

    Aaboe, Merete; Schou, S.; Hjørting-Hansen, E.

    2000-01-01

    Osseointegration, subperiosteal implant, bone substitute, bovine bone, guided bone, regeneration, histology, rabbits......Osseointegration, subperiosteal implant, bone substitute, bovine bone, guided bone, regeneration, histology, rabbits...

  10. Novel synthesis and characterization of an AB-type carbonate-substituted hydroxyapatite.

    Science.gov (United States)

    Gibson, Iain R; Bonfield, William

    2002-03-15

    A novel synthesis route has been developed to produce a high-purity mixed AB-type carbonate-substituted hydroxyapatite (CHA) with a carbonate content that is comparable to the type and level observed in bone mineral. This method involves the aqueous precipitation in the presence of carbonate ions in solution of a calcium phosphate apatite with a Ca/P molar ratio greater than the stoichiometric value of 1.67 for hydroxyapatite (HA). The resulting calcium-rich carbonate-apatite is sintered/heat-treated in a carbon dioxide atmosphere to produce a single-phase, crystalline carbonate-substituted hydroxyapatite. In contrast to previous methods for producing B- or AB-type carbonate-substituted hydroxyapatites, no sodium or ammonium ions, which would be present in the reaction mixture from the sodium or ammonium carbonates commonly used as a source of carbonate ions, were present in the final product. The chemical and phase compositions of the carbonate-substituted hydroxyapatite was characterized by X-ray fluorescence and X-ray diffraction, respectively, and the level and nature of the carbonate substitution were studied using C-H-N analysis and Fourier transform infrared spectroscopy, respectively. The carbonate substitution improves the densification of hydroxyapatite and reduces the sintering temperature required to achieve near-full density by approximately 200 degrees C compared to stoichiometric HA. Initial studies have shown that these carbonate-substituted hydroxyapatites have improved mechanical and biologic properties compared to stoichiometric hydroxyapatite. Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 59: 697-708, 2002

  11. Oxygen enrichment incineration

    International Nuclear Information System (INIS)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

  12. Oxygen enrichment incineration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

  13. Amino acid substitutions in random mutagenesis libraries: lessons from analyzing 3000 mutations.

    Science.gov (United States)

    Zhao, Jing; Frauenkron-Machedjou, Victorine Josiane; Kardashliev, Tsvetan; Ruff, Anna Joëlle; Zhu, Leilei; Bocola, Marco; Schwaneberg, Ulrich

    2017-04-01

    The quality of amino acid substitution patterns in random mutagenesis libraries is decisive for the success in directed evolution campaigns. In this manuscript, we provide a detailed analysis of the amino acid substitutions by analyzing 3000 mutations of three random mutagenesis libraries (1000 mutations each; epPCR with a low-mutation and a high-mutation frequency and SeSaM-Tv P/P) employing lipase A from Bacillus subtilis (bsla). A comparison of the obtained numbers of beneficial variants in the mentioned three random mutagenesis libraries with a site saturation mutagenesis (SSM) (covering the natural diversity at each amino acid position of BSLA) concludes the diversity analysis. Seventy-six percent of the SeSaM-Tv P/P-generated substitutions yield chemically different amino acid substitutions compared to 64% (epPCR-low) and 69% (epPCR-high). Unique substitutions from one amino acid to others are termed distinct amino acid substitutions. In the SeSaM-Tv P/P library, 35% of all theoretical distinct amino acid substitutions were found in the 1000 mutation library compared to 25% (epPCR-low) and 26% (epPCR-high). Thirty-six percent of distinct amino acid substitutions found in SeSaM-Tv P/P were unobtainable by epPCR-low. Comparison with the SSM library showed that epPCR-low covers 15%, epPCR-high 18%, and SeSaM-Tv P/P 21% of obtainable beneficial amino acid positions. In essence, this study provides first insights on the quality of epPCR and SeSaM-Tv P/P libraries in terms of amino acid substitutions, their chemical differences, and the number of obtainable beneficial amino acid positions.

  14. 26 CFR 601.505 - Revocation, change in representation and substitution or delegation of representative.

    Science.gov (United States)

    2010-04-01

    ... authorizes the substitution or delegation. An employee of a recognized representative may not be substituted... substitution or delegation of representative. 601.505 Section 601.505 Internal Revenue INTERNAL REVENUE SERVICE... Practice Requirements § 601.505 Revocation, change in representation and substitution or delegation of...

  15. Effects of oxygen concentration on atmospheric pressure dielectric barrier discharge in Argon-Oxygen Mixture

    Science.gov (United States)

    Li, Xuechun; Li, Dian; Wang, Younian

    2016-09-01

    A dielectric barrier discharge (DBD) can generate a low-temperature plasma easily at atmospheric pressure and has been investigated for applications in trials in cancer therapy, sterilization, air pollution control, etc. It has been confirmed that reactive oxygen species (ROS) play a key role in the processes. In this work, we use a fluid model to simulate the plasma characteristics for DBD in argon-oxygen mixture. The effects of oxygen concentration on the plasma characteristics have been discussed. The evolution mechanism of ROS has been systematically analyzed. It was found that the ground state oxygen atoms and oxygen molecular ions are the dominated oxygen species under the considered oxygen concentrations. With the oxygen concentration increasing, the densities of electrons, argon atomic ions, resonance state argon atoms, metastable state argon atoms and excited state argon atoms all show a trend of decline. The oxygen molecular ions density is high and little influenced by the oxygen concentration. Ground state oxygen atoms density tends to increase before falling. The ozone density increases significantly. Increasing the oxygen concentration, the discharge mode begins to change gradually from the glow discharge mode to Townsend discharge mode. Project supported by the National Natural Science Foundation of China (Grant No. 11175034).

  16. Generation time, life history and the substitution rate of neutral mutations.

    Science.gov (United States)

    Lehtonen, Jussi; Lanfear, Robert

    2014-11-01

    Our understanding of molecular evolution is hampered by a lack of quantitative predictions about how life-history (LH) traits should correlate with substitution rates. Comparative studies have shown that neutral substitution rates vary substantially between species, and evidence shows that much of this diversity is associated with variation in LH traits. However, while these studies often agree, some unexplained and contradictory results have emerged. Explaining these results is difficult without a clear theoretical understanding of the problem. In this study, we derive predictions for the relationships between LH traits and substitution rates in iteroparous species by using demographic theory to relate commonly measured life-history traits to genetic generation time, and by implication to neutral substitution rates. This provides some surprisingly simple explanations for otherwise confusing patterns, such as the association between fecundity and substitution rates. The same framework can be applied to more complex life histories if full life-tables are available. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  17. Limitations of potentiometric oxygen sensors operating at low oxygen levels

    DEFF Research Database (Denmark)

    Lund, Anders; Jacobsen, Torben; Hansen, Karin Vels

    2011-01-01

    The electrochemical processes that limit the range of oxygen partial pressures in which potentiometric oxygen sensors can be used, were analysed using a theoretical and an experimental approach. Electrochemical impedance spectroscopy was performed on porous Pt/yttria stabilised zirconia (YSZ......) electrodes between 10−6 and 0.2 bar and at temperatures between 500 and 950 °C. The flow of oxide ions and electron holes through a sensor cell, with a YSZ electrolyte, were calculated under similar conditions. The oxygen permeation of the sensor cell was insignificant at an oxygen partial pressure of 10......−6 bar for an inlet flow rate higher than 2 L h−1 between 600 and 800 °C. The polarisation resistance measured between 10−6 and 10−4 bar was found to be inversely proportional to the oxygen partial pressure, nearly temperature independent and inversely proportional to the inlet gas flow rate, which shows...

  18. Currency Substitution and The Law of One Price

    OpenAIRE

    Gabriele Camera; Johannes Winkler

    2000-01-01

    We study endogenous currency substitution in a decentralized trade environment. Sellers maximize profits from sales of imperfectly substitutable goods by posting prices in either one of two currencies. A unique symmetric equilibrium exists where goods are priced only in the local currency. This occurs if foreign trade is sporadic, there is sufficient but not excessive liquidity, and discounting is low. Excess or scarcity of liquidity, however, induces sellers to extract all surplus from buyer...

  19. Bone healing and bone substitutes.

    Science.gov (United States)

    Costantino, Peter D; Hiltzik, David; Govindaraj, Satish; Moche, Jason

    2002-02-01

    With the advent of new biomaterials and surgical techniques, the reconstructive surgeon has a wider range of treatment modalities for the rehabilitation and reconstruction of craniofacial skeletal deformities than ever before. These innovative substances act as true bone graft substitutes, thereby allowing the surgeon to avoid the use of autogenous bone grafts and their associated donor site morbidity. Surgeons have long been interested in producing a composite graft that can heal faster by induction, incorporate with surrounding tissues, and be remodeled to resemble native bone. Currently, there are a host of bone graft substitutes available that vary in both their composition and properties. Craniomaxillofacial surgeons must therefore become comfortable with numerous biomaterials to best tailor the treatment for each patient individually. Ongoing investigations into the next phase of tissue engineering will continue to bring us closer to the ability to regenerate or replace bone.

  20. Substituting oil by electric power

    International Nuclear Information System (INIS)

    Lichtenberg, H.

    1981-01-01

    Parting from the development of primary energy use the author refers to the latest investigations and results presented on the 1980 World Energy Conference and with special regard to oil points out the threatening exhaustion of fossil energy resources. Maintaining the economic structure of the Federal Republic of Germany implies an orientation away from oil. Due to its flexible application technology and quasi-inexhaustible energy resources electric power may substantially contribute to oil substitution which as a matter of fact is of particular interest in connection with the heat market. Coal alone cannot substitute both oil and nuclear energy. Thus, the above postulates the use of the latter. Leaving nuclear energy inactive today will effect an increase in the demand for oil the negative consequences of which would weight heavily upon the anyhow unbalanced import/export ratio of the Federal Republic of Germany. (orig.) [de

  1. Stochastic demography and the neutral substitution rate in class-structured populations.

    Science.gov (United States)

    Lehmann, Laurent

    2014-05-01

    The neutral rate of allelic substitution is analyzed for a class-structured population subject to a stationary stochastic demographic process. The substitution rate is shown to be generally equal to the effective mutation rate, and under overlapping generations it can be expressed as the effective mutation rate in newborns when measured in units of average generation time. With uniform mutation rate across classes the substitution rate reduces to the mutation rate.

  2. Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

    Directory of Open Access Journals (Sweden)

    Satoru Mori

    2017-10-01

    Full Text Available Phthalocyanines and subphthalocyanines are attracting attention as functional dyes that are applicable to organic solar cells, photodynamic therapy, organic electronic devices, and other applications. However, phthalocyanines are generally difficult to handle due to their strong ability to aggregate, so this property must be controlled for further applications of phthalocyanines. On the other hand, trifluoroethoxy-substituted phthalocyanines are known to suppress aggregation due to repulsion of the trifluoroethoxy group. Furthermore, the electronic characteristics of phthalocyanines are significantly changed by the strong electronegativity of fluorine. Therefore, it is expected that trifluoroethoxy-substituted phthalocyanines can be applied to new industrial fields. This review summarizes the synthesis and application of trifluoroethoxy-substituted phthalocyanine and subphthalocyanine derivatives.

  3. Nature of oxygen donors and radiation defects in oxygen-doped germanium

    International Nuclear Information System (INIS)

    Fukuoka, Noboru; Atobe, Kozo; Honda, Makoto; Matsuda, Koji.

    1991-01-01

    The nature of oxygen donors and radiation defects in oxygen-doped germanium were studied through measurements of the infrared absorption spectrum, deep level transient spectroscopy spectrum and carrier concentration. It is revealed that a new donor is not formed in oxygen-doped germanium. An A-center (interstitial oxygen-vacancy pair) forms a complex with a thermal donor in its annealing stage at 60degC-140degC. The introduction rate of defects by 1.5 MeV electron irradiation was enhanced in thermal-donor-doped samples. (author)

  4. Association of Dietary Proportions of Macronutrients with Visceral Adiposity Index: Non-Substitution and Iso-Energetic Substitution Models in a Prospective Study.

    Science.gov (United States)

    Moslehi, Nazanin; Ehsani, Behnaz; Mirmiran, Parvin; Hojjat, Parvane; Azizi, Fereidoun

    2015-10-26

    We aimed to investigate associations between dietary macronutrient proportions and prospective visceral adiposity index changes (ΔVAI). The study included 1254 adults (18-74 years), from the Tehran Lipid and Glucose Study (TLGS), who were followed for three years. Dietary intakes were assessed twice using food frequency questionnaires. Associations of dietary macronutrient with ΔVAI and risk of visceral adiposity dysfunction (VAD) after three years were investigated. The percentage of energy intake from protein in the total population, and from fat in women, were associated with higher increases in VAI. A 5% higher energy intake from protein substituted for carbohydrate, monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) was associated with higher ΔVAI. Higher energy intake from animal protein substituted for PUFAs was positively associated with ΔVAI. Substituting protein and PUFAs with MUFAs were related to higher ΔVAI. The associations were similar in men and women, but reached significance mostly among women. Risk of VAD was increased when 1% of energy from protein was replaced with MUFAs. Substituting protein for carbohydrate and fat, and fat for carbohydrate, resulted in increased risk of VAD in women. Higher dietary proportions of protein and animal-derived MUFA may be positively associated with ΔVAI and risk of VAD.

  5. Intraportal islet oxygenation.

    Science.gov (United States)

    Suszynski, Thomas M; Avgoustiniatos, Efstathios S; Papas, Klearchos K

    2014-05-01

    Islet transplantation (IT) is a promising therapy for the treatment of diabetes. The large number of islets required to achieve insulin independence limit its cost-effectiveness and the number of patients who can be treated. It is believed that >50% of islets are lost in the immediate post-IT period. Poor oxygenation in the early post-IT period is recognized as a possible reason for islet loss and dysfunction but has not been extensively studied. Several key variables affect oxygenation in this setting, including (1) local oxygen partial pressure (pO(2)), (2) islet oxygen consumption, (3) islet size (diameter, D), and (4) presence or absence of thrombosis on the islet surface. We discuss implications of oxygen-limiting conditions on intraportal islet viability and function. Of the 4 key variables, the islet size appears to be the most important determinant of the anoxic and nonfunctional islet volume fractions. Similarly, the effect of thrombus formation on the islet surface may be substantial. At the University of Minnesota, average size distribution data from clinical alloislet preparations (n = 10) indicate that >150-µm D islets account for only ~30% of the total islet number, but >85% of the total islet volume. This suggests that improved oxygen supply to the islets may have a profound impact on islet survivability and function since most of the β-cell volume is within large islets which are most susceptible to oxygen-limiting conditions. The assumption that the liver is a suitable islet transplant site from the standpoint of oxygenation should be reconsidered. © 2014 Diabetes Technology Society.

  6. [Correlation between the inspired fraction of oxygen, maternal partial oxygen pressure, and fetal partial oxygen pressure during cesarean section of normal pregnancies].

    Science.gov (United States)

    Castro, Carlos Henrique Viana de; Cruvinel, Marcos Guilherme Cunha; Carneiro, Fabiano Soares; Silva, Yerkes Pereira; Cabral, Antônio Carlos Vieira; Bessa, Roberto Cardoso

    2009-01-01

    Despite changes in pulmonary function, maternal oxygenation is maintained during obstetric regional blocks. But in those situations, the administration of supplementary oxygen to parturients is a common practice. Good fetal oxygenation is the main justification; however, this has not been proven. The objective of this randomized, prospective study was to test the hypothesis of whether maternal hyperoxia is correlated with an increase in fetal gasometric parameters in elective cesarean sections. Arterial blood gases of 20 parturients undergoing spinal block with different inspired fractions of oxygen were evaluated and correlated with fetal arterial blood gases. An increase in maternal inspired fraction of oxygen did not show any correlation with an increase of fetal partial oxygen pressure. Induction of maternal hyperoxia by the administration of supplementary oxygen did not increase fetal partial oxygen pressure. Fetal gasometric parameters did not change even when maternal parameters changed, induced by hyperoxia, during cesarean section under spinal block.

  7. Capital-Energy Substitution and Shifts in Factor Demand. A Meta-Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koetse, M.J. [Department of Spatial Economics, Vrije Universiteit Amsterdam (Netherlands); De Groot, Henri L.F. [Tinbergen Institute, Amsterdam (Netherlands); Florax, R.J.G.M. [Department of Agricultural Economics, Purdue University, West Lafayette (United States)

    2006-07-01

    This paper presents results of a meta-regression analysis on empirical estimates of capital-energy substitution. Theoretically it is clear that a distinction should be made between Morishima substitution elasticities and cross-price elasticities. The former represent purely technical substitution possibilities while the latter include an income effect and therefore represent economic substitution potential. We estimate a meta-regression model with separate coefficients for the two elasticity samples. Our findings suggest that primary model assumptions on returns to scale, technological change and separability of input factors matter for the outcome of a primary study. Aggregation of variables and the type of data used in empirical research are also relevant sources of systematic effect-size variation. Taking these factors into consideration, we compute ideal-typical elasticities for the short, medium and long run. The resulting figures clearly show that substitution elasticities are substantially higher than cross price elasticities. Therefore, despite considerable technical opportunities for capital-energy substitution, they are almost entirely outweighed by the negative income effect brought about by energy price increases; the short and medium run cross price elasticities are not statistically different from zero. In the long run this pattern does not hold. Our findings therefore suggest that actual changes in the demand for capital due to energy price increases take time.

  8. Yeast alter micro-oxygenation of wine: oxygen consumption and aldehyde production.

    Science.gov (United States)

    Han, Guomin; Webb, Michael R; Richter, Chandra; Parsons, Jessica; Waterhouse, Andrew L

    2017-08-01

    Micro-oxygenation (MOx) is a common winemaking treatment used to improve red wine color development and diminish vegetal aroma, amongst other effects. It is commonly applied to wine immediately after yeast fermentation (phase 1) or later, during aging (phase 2). Although most winemakers avoid MOx during malolactic (ML) fermentation, it is often not possible to avoid because ML bacteria are often present during phase 1 MOx treatment. We investigated the effect of common yeast and bacteria on the outcome of micro-oxygenation. Compared to sterile filtered wine, Saccharomyces cerevisiae inoculation significantly increased oxygen consumption, keeping dissolved oxygen in wine below 30 µg L -1 during micro-oxygenation, whereas Oenococcus oeni inoculation was not associated with a significant impact on the concentration of dissolved oxygen. The unfiltered baseline wine also had both present, although with much higher populations of bacteria and consumed oxygen. The yeast-treated wine yielded much higher levels of acetaldehyde, rising from 4.3 to 29 mg L -1 during micro-oxygenation, whereas no significant difference was found between the bacteria-treated wine and the filtered control. The unfiltered wine exhibited rapid oxygen consumption but no additional acetaldehyde, as well as reduced pyruvate. Analysis of the acetaldehyde-glycerol acetal levels showed a good correlation with acetaldehyde concentrations. The production of acetaldehyde is a key outcome of MOx and it is dramatically increased in the presence of yeast, although it is possibly counteracted by the metabolism of O. oeni bacteria. Additional controlled experiments are necessary to clarify the interaction of yeast and bacteria during MOx treatments. Analysis of the glycerol acetals may be useful as a proxy for acetaldehyde levels. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Oxygen configurations in silica

    International Nuclear Information System (INIS)

    Chelikowsky, James R.; Chadi, D. J.; Binggeli, N.

    2000-01-01

    We propose a transition state for oxygen in silica. This state is produced by the insertion of an oxygen molecule into the Si-O-Si bond, i.e., it consists of producing a Si-O-O-O-Si bond. This state allows molecular oxygen diffusion in silica without breaking the molecular O 2 bond and it is energetically more stable than a peroxy configuration. This configuration may allow for exchange of molecular oxygen with the oxygen in the silica framework. (c) 2000 The American Physical Society

  10. Oxygen transport by oxygen potential gradient in dense ceramic oxide membranes

    Energy Technology Data Exchange (ETDEWEB)

    Maiya, P.S.; Balachandran, U.; Dusek, J.T.; Mieville, R.L. [Argonne National Lab., IL (United States). Energy Technology Div.; Kleefisch, M.S.; Udovich, C.A. [Amoco Exploration/Production, Naperville, IL (United States)

    1996-05-01

    Numerous studies have been conducted in recent years on the partial oxidation of methane to synthesis gas (syngas: CO + H{sub 2}) with air as the oxidant. In partial oxidation, a mixed-oxide ceramic membrane selectively transports oxygen from the air; this transport is driven by the oxygen potential gradient. Of the several ceramic materials the authors have tested, a mixed oxide based on the Sr-Fe-Co-O system has been found to be very attractive. Extensive oxygen permeability data have been obtained for this material in methane conversion experiments carried out in a reactor. The data have been analyzed by a transport equation based on the phenomenological theory of diffusion under oxygen potential gradients. Thermodynamic calculations were used to estimate the driving force for the transport of oxygen ions. The results show that the transport equation deduced from the literature describes the permeability data reasonably well and can be used to determine the diffusion coefficients and the associated activation energy of oxygen ions in the ceramic membrane material.

  11. 40 CFR 721.10063 - Halo substituted hydroxy nitrophenyl amide (generic).

    Science.gov (United States)

    2010-07-01

    ... amide (generic). 721.10063 Section 721.10063 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10063 Halo substituted hydroxy nitrophenyl amide (generic). (a) Chemical... as halo substituted hydroxy nitrophenyl amide (PMN P-04-792) is subject to reporting under this...

  12. Carbonate hydroxyapatite and silicon-substituted carbonate hydroxyapatite

    DEFF Research Database (Denmark)

    Bang, L T; Long, B D; Othman, R

    2014-01-01

    The present study investigates the chemical composition, solubility, and physical and mechanical properties of carbonate hydroxyapatite (CO3Ap) and silicon-substituted carbonate hydroxyapatite (Si-CO3Ap) which have been prepared by a simple precipitation method. X-ray diffraction (XRD), Fourier......(3-)) site and also entered simultaneously into the hydroxyapatite structure. The Si-substituted CO3Ap reduced the powder crystallinity and promoted ion release which resulted in a better solubility compared to that of Si-free CO3Ap. The mean particle size of Si-CO3Ap was much finer than that of CO3Ap...

  13. Characterization of hydroxyapatite substituted with silicon

    International Nuclear Information System (INIS)

    Silva, H.M. da; Soares, G.A.; Mateescu, M.; Anselme, K.; Palard, M.; Champion, E.

    2009-01-01

    Incorporation of silicon (Si) ions into hydroxyapatite structure (HA) influences on physical, chemical and physiological properties. Some studies reported the improved bioactivity Si substitution, and it also accelerates the biomineralization process. The main objective of this work is to characterize stoichiometric hydroxyapatite and hydroxyapatite substituted with 1.13% in weight of Si (SiHA) using a wet precipitation method followed by a heat treatment. SEM/EDS, AFM, DRX and FTIR analyses were used to characterize the samples. EDS and FTIR results confirmed the presence of Si. Silicon induces small changes on crystal structure of HA, not detected on X-ray diffraction patterns of sintered tablets of SiHA and HA. No secondary phases were observed, that indicates the Si had entered the HA lattice. (author)

  14. Alloys of Pt and Rare Earths for the Oxygen Electroreduction Reaction

    DEFF Research Database (Denmark)

    Malacrida, Paolo

    This thesis presents the development and characterization of a new class of Pt alloys for catalyzing the Oxygen Reduction Reaction (ORR), in perspective of a future substitution of traditional Pt-based catalysts at the cathode of Polymer Electrolyte Membrane Fuel Cells (PEMFCs). Focused on spectr....... A number of bimetallic alloys based on Pt and a rare earth, like the Pt-Y system or more recently proposed Pt-lanthanide phases, have been tested and characterized. Polycrystalline Pt5La and Pt5Ce exhibited more than a factor of 3 enhancement in specific activity relative to state......-Y nanoparticles are among the most active ORR catalysts ever reported, although they lose 37 % of this activity after stability test. Similar to the case of polycrystals, after immersion in the acidic electrolyte and testing the active phase consists of a Pt shell surrounding an alloyed core. Also in this case...

  15. Intermediate-Valence Tautomerism in Decamethylytterbocene Complexes of Methyl-Substituted Bipyridines

    Energy Technology Data Exchange (ETDEWEB)

    Booth, Corwin H.; Kazhdan, Daniel; Werkema, Evan L.; Walter, Marc D.; Lukens, Wayne W.; Bauer, Eric D.; Hu, Yung-Jin; Maron, Laurent; Eisenstein, Odile; Head-Gordon, Martin; Andersen, Richard A.

    2011-01-25

    Multiconfigurational, intermediate valent ground states are established in several methyl-substituted bipyridine complexes of bispentamethylcyclopentadienylytterbium, Cp*{sub 2} Yb(Me{sub x}-bipy). In contrast to Cp*{sub 2} Yb(bipy) and other substituted-bipy complexes, the nature of both the ground state and the first excited state are altered by changing the position of the methyl or dimethyl substitutions on the bipyridine rings. In particular, certain substitutions result in multiconfigurational, intermediate valent open-shell singlet states in both the ground state and the first excited state. These conclusions are reached after consideration of single-crystal x-ray diffraction (XRD), the temperature dependence of x-ray absorption near-edge structure (XANES), extended x-ray absorption fine-structure (EXAFS), and magnetic susceptibility data, and are supported by CASSCF-MP2 calculations. These results place the various Cp*{sub 2}Yb(bipy) complexes in a new tautomeric class, that is, intermediate-valence tautomers.

  16. The elasticity of substitution of superlative price indices

    OpenAIRE

    Petter Frenger

    2005-01-01

    Abstract: The paper presents a method for computing the curvature implicit in the use of superlative price indices. It extends the quadratic lemma and allows us to compute the elasticity of substitution of the underlying preferences in the direction of the observed price change for the Törnqvist and the quadratic mean of order r indices. It derives the expressions for the directional shadow elasticity of substitution and applies the results to the Norwegian CPI data base. Ke...

  17. Tunable ferromagnetic resonance in La-Co substituted barium hexaferrites at millimeter wave frequencies

    Science.gov (United States)

    Korolev, Konstantin A.; Wu, Chuanjian; Yu, Zhong; Sun, Ke; Afsar, Mohammed N.; Harris, Vincent G.

    2018-05-01

    Transmittance measurements have been performed on La-Co substituted barium hexaferrites in millimeter waves. Broadband millimeter-wave measurements have been carried out using the free space quasi-optical spectrometer, equipped with a set of high power backward wave oscillators covering the frequency range of 30 - 120 GHz. Strong absorption zones have been observed in the millimeter-wave transmittance spectra of all La-Co substituted barium hexaferrites due to the ferromagnetic resonance. Linear shift of ferromagnetic resonance frequency as functions of La-Co substitutions have been found. Real and imaginary parts of dielectric permittivity of La-Co substituted barium hexaferrites have been calculated using the analysis of recorded high precision transmittance spectra. Frequency dependences of magnetic permeability of La-Co substituted barium hexaferrites, as well as saturation magnetization and anisotropy field have been determined based on Schlömann's theory for partially magnetized ferrites. La-Co substituted barium hexaferrites have been further investigated by DC magnetization to assess magnetic behavior and compare with millimeter wave data. Consistency of saturation magnetization determined independently by both millimeter wave absorption and DC magnetization have been found for all La-Co substituted barium hexaferrites. These materials seem to be quite promising as tunable millimeter wave absorbers, filters, circulators, based on the adjusting of their substitution parameters.

  18. Comparison of domiciliary oxygen using liquid oxygen and concentrator in northern Taiwan

    Directory of Open Access Journals (Sweden)

    Chien-Ling Su

    2014-01-01

    Conclusion: Patients in the LOG used oxygen for longer hours, went on more outings, and were more likely to travel with oxygen than patients in the OCG. Being ambulatory with liquid oxygen might enable patients with COPD to walk more effectively.

  19. Simultaneous Monitoring of Vascular Oxygenation and Tissue Oxygen Tension of Breast Tumors Under Hyperbaric Oxygen Exposure

    Science.gov (United States)

    2008-04-01

    28. Alagoz, T., R. Buller, B. Anderson, K. Terrell , R...and oxygenation Ann . New Acad. Sci. 838 29–45 Chapman J D, Stobbe C C, Arnfield M R, Santus R, Lee J and McPhee M S 1991 Oxygen dependency of tumor

  20. The Use of Substitutes - Continuity and the-Group-as-a-Whole

    DEFF Research Database (Denmark)

    Nielsen, Jan; Thygesen, Bente; Aagaard, Søren

    2009-01-01

    of continuity, i.e. the self- sustaining power of the group and the limits of this is illustrated and discussed in connection with planned versus unplanned substitute periods, showing the importance of preparation when the therapist has to be away, and a substitute is used. Key words: substitute, locum......, continuity, conductor, leadership, group-as-a-whole...

  1. Muonium substituted molecules

    International Nuclear Information System (INIS)

    Cox, S.F.J.

    1990-12-01

    The manner in which Muon Spin Rotation and Level Crossing Resonance are used to characterise muonium substituted organic radicals is described, and illustrated with spectra for the ethyl radical and related species. Comparison with electron spin resonance data for the unsubstituted radicals reveals significant structural and hyperfine isotope effects which can be traced to the effects of zero point motion. The first comparable results for a diamagnetic species, exhibiting a quadrupole isotope effect by comparison with conventional nuclear quadrupole resonance data, are presented and discussed. (author)

  2. 40 CFR 721.3810 - Formaldehyde, polymers with substituted phenols (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymers with... New Uses for Specific Chemical Substances § 721.3810 Formaldehyde, polymers with substituted phenols... identified generically as Formaldehyde, polymers with substituted phenols (PMN P-99-0558) is subject to...

  3. Behavioral service substitution (Chapter 9)

    NARCIS (Netherlands)

    Stahl, C.; Aalst, van der W.M.P.; Bouguettaya, A.; Sheng, Q.Z.; Daniel, F.

    2014-01-01

    Service-oriented design supports system evolution and encourages reuse and modularization. A key ingredient of service orientation is the ability to substitute one service by another without reconfiguring the overall system. This chapter aims to give an overview of the state of the art and open

  4. Tissue reaction and material characteristics of four bone substitutes

    DEFF Research Database (Denmark)

    Jensen, S S; Aaboe, M; Pinholt, E M

    1996-01-01

    and Interpore 500 HA/CC) were implanted into 5-mm bur holes in rabbit tibiae. There was no difference in the amount of newly formed bone around the four biomaterials. Interpore 500 HA/CC resorbed completely, whereas the other three biomaterials did not undergo any detectable biodegradation. Bio......The aim of the present study was to qualitatively and quantitatively compare the tissue reactions around four different bone substitutes used in orthopedic and craniofacial surgery. Cylinders of two bovine bone substitutes (Endobon and Bio-Oss) and two coral-derived bone substitutes (Pro Osteon 500......-Oss was osseointegrated to a higher degree than the other biomaterials. Material characteristics obtained by diffuse reflectance infrared Fourier transform spectrometry analysis and energy-dispersive spectrometry did not explain the differences in biologic behavior....

  5. How Firms Substitute for Authority in Strategic Decision-Making

    DEFF Research Database (Denmark)

    Dobrajska, Magdalena; Billinger, Stephan; Becker, Markus C.

    Strategic decisions are often made by multiple organizational members who form decision-making structures specialized for a given strategic decision. We study a series of strategic decisions in a business unit of a global Fortune 500 firm, identifying for each decision the hierarchical...... takes place in response to changes in decision characteristics, including decision complexity, decision importance, CEO proximity, and the degree to which a decision is routine. We show various manifestations of the substitution mechanism and discuss implications for strategic decision-making....... and departmental positions of all participating organizational members. We find that firms substitute between different structural components in decision-making structures to combine hierarchical authority with cross-departmental coordination and redundant knowledge. This substitution between structural components...

  6. Structural disorder and electronic hybridization in NicMg1-cO solid solutions probed by XANES at the oxygen K edge

    International Nuclear Information System (INIS)

    Chen Dongliang; Zhong Jun; Chu Wangsheng; Wu Ziyu; Kuzmin, Alexei; Mironova-Ulmane, Nina; Marcelli, Augusto

    2007-01-01

    A series of Ni c Mg 1-c O solid solutions has been studied for the first time looking at the structural disorder by means of x-ray absorption near-edge-structure (XANES) spectroscopy at the oxygen K edge. The experimental XANES signals were analysed within the full multiple scattering formalism and were interpreted taking into account clusters of up to 15 coordination shells around an absorbing oxygen atom. The substitution of nickel atoms by magnesium atoms results in a dramatic decrease of the empty density of states in the conduction band close to the Fermi level due to an exchange of the 3d(Ni)-2p(O) interaction with 3p(Mg)-2p(O). Besides, a simultaneous small decrease of the 3d(Ni)-2p(O) hybridization is also induced by the lattice expansion, determined by the difference in ionic radii between nickel and magnesium ions

  7. Recombination and detachment in oxygen discharges: the role of metastable oxygen molecules

    International Nuclear Information System (INIS)

    Gudmundsson, J T

    2004-01-01

    A global (volume averaged) model of oxygen discharges is used to study the transition from a recombination dominated discharge to a detachment dominated discharge. The model includes the metastable oxygen molecules O 2 (a 1 Δ g ) and O 2 (b 1 Σ g + ) and the three Herzberg states O 2 (A 3 Σ u + , A' 3 Δ u , c 1 Σ u - ). Dissociative attachment of the oxygen molecule in the ground state O 2 ( 3 Σ g - ) and the metastable oxygen molecule O 2 (a 1 Δ g ) are the dominating channels for creation of the negative oxygen ion O - . At high pressures, dissociative attachment of the Herzberg states contributes significantly to the creation of the negative oxygen ion, O - . The detachment by a collision of the metastable oxygen molecule O 2 (b 1 Σ g + ) with the oxygen ion, O - , is a significant loss process for the O - at pressures above 10 mTorr. Its contribution to the loss is more significant at a lower applied power, but at the higher pressures it is always significant. Detachment by collision with O( 3 P) is also an important loss mechanism for O - . We find that ion-ion recombination is the dominating loss process for negative ions in oxygen discharges at low pressures and calculate the critical pressure where the contributions of recombination reactions and detachment reactions are equal. This critical pressure depends on the applied power, increases with applied power and is in the range 5-14 mTorr in the pressure and power range investigated

  8. Effect of hypolimnetic oxygenation on oxygen depletion rates in two water-supply reservoirs.

    Science.gov (United States)

    Gantzer, Paul A; Bryant, Lee D; Little, John C

    2009-04-01

    Oxygenation systems, such as bubble-plume diffusers, are used to improve water quality by replenishing dissolved oxygen (DO) in the hypolimnia of water-supply reservoirs. The diffusers induce circulation and mixing, which helps distribute DO throughout the hypolimnion. Mixing, however, has also been observed to increase hypolimnetic oxygen demand (HOD) during system operation, thus accelerating oxygen depletion. Two water-supply reservoirs (Spring Hollow Reservoir (SHR) and Carvins Cove Reservoir (CCR)) that employ linear bubble-plume diffusers were studied to quantify diffuser effects on HOD. A recently validated plume model was used to predict oxygen addition rates. The results were used together with observed oxygen accumulation rates to evaluate HOD over a wide range of applied gas flow rates. Plume-induced mixing correlated well with applied gas flow rate and was observed to increase HOD. Linear relationships between applied gas flow rate and HOD were found for both SHR and CCR. HOD was also observed to be independent of bulk hypolimnion oxygen concentration, indicating that HOD is controlled by induced mixing. Despite transient increases in HOD, oxygenation caused an overall decrease in background HOD, as well as a decrease in induced HOD during diffuser operation, over several years. This suggests that the residual or background oxygen demand decreases from one year to the next. Despite diffuser-induced increases in HOD, hypolimnetic oxygenation remains a viable method for replenishing DO in thermally-stratified water-supply reservoirs such as SHR and CCR.

  9. Spray generator of singlet oxygen for a chemical oxygen-iodine laser

    Czech Academy of Sciences Publication Activity Database

    Jirásek, Vít; Hrubý, Jan; Špalek, Otomar; Čenský, Miroslav; Kodymová, Jarmila

    2010-01-01

    Roč. 100, č. 4 (2010), s. 779-791 ISSN 0946-2171 Grant - others:European Office of Aerospace R&D(US) FA8655-09-1-3091 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20760514 Keywords : spray generator of singlet oxygen * singlet oxygen * chemical oxygen-iodine laser Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.239, year: 2010

  10. Enantioselective epoxidation with chiral MN(III)(salen) catalysts: kinetic resolution of aryl-substituted allylic alcohols.

    Science.gov (United States)

    Adam, W; Humpf, H U; Roschmann, K J; Saha-Möller, C R

    2001-08-24

    A set of aryl-substituted allylic alcohols rac-2 has been epoxidized by chiral Mn(salen*) complexes 1 as the catalyst and iodosyl benzene (PhIO) as the oxygen source. Whereas one enantiomer of the allylic alcohol 2 is preferentially epoxidized to give the threo- or cis-epoxy alcohol 3 (up to 80% ee) as the main product (dr up to >95:5), the other enantiomer of 2 is enriched (up to 53% ee). In the case of 1,1-dimethyl-1,2-dihydronaphthalen-2-ol (2c), the CH oxidation to the enone 4c proceeds enantioselectively and competes with the epoxidation. The absolute configurations of the allylic alcohols 2 and their epoxides 3 have been determined by chemical correlation or CD spectroscopy. The observed diastereo- and enantioselectivities in the epoxidation reactions are rationalized in terms of a beneficial interplay between the hydroxy-directing effect and the attack along the Katsuki trajectory.

  11. Substitution and Complementarity of Alcohol and Cannabis: A Review of the Literature.

    Science.gov (United States)

    Subbaraman, Meenakshi Sabina

    2016-09-18

    Whether alcohol and cannabis are used as substitutes or complements remains debated, and findings across various disciplines have not been synthesized to date. This article is a first step towards organizing the interdisciplinary literature on alcohol and cannabis substitution and complementarity. Electronic searches were performed using PubMed and ISI Web of Knowledge. Behavioral studies of humans with "alcohol" (or "ethanol") and "cannabis" (or "marijuana") and "complement(*)" (or "substitut(*)") in the title or as a keyword were considered. Studies were organized according to sample characteristics (youth, general population, clinical and community-based). These groups were not set a priori, but were informed by the literature review process. Of the 39 studies reviewed, 16 support substitution, ten support complementarity, 12 support neither and one supports both. Results from studies of youth suggest that youth may reduce alcohol in more liberal cannabis environments (substitute), but reduce cannabis in more stringent alcohol environments (complement). Results from the general population suggest that substitution of cannabis for alcohol may occur under more lenient cannabis policies, though cannabis-related laws may affect alcohol use differently across genders and racial groups. Alcohol and cannabis act as both substitutes and complements. Policies aimed at one substance may inadvertently affect consumption of other substances. Future studies should collect fine-grained longitudinal, prospective data from the general population and subgroups of interest, especially in locations likely to legalize cannabis.

  12. Effects of the oxygenation level on formation of different reactive oxygen species during photodynamic therapy.

    Science.gov (United States)

    Price, Michael; Heilbrun, Lance; Kessel, David

    2013-01-01

    We examined the effect of the oxygenation level on efficacy of two photosensitizing agents, both of which target lysosomes for photodamage, but via different photochemical pathways. Upon irradiation, the chlorin termed NPe6 forms singlet oxygen in high yield while the bacteriopheophorbide WST11 forms only oxygen radicals (in an aqueous environment). Photokilling efficacy by WST11 in cell culture was impaired when the atmospheric oxygen concentration was reduced from 20% to 1%, while photokilling by NPe6 was unaffected. Studies in a cell-free system revealed that the rates of photobleaching of these agents, as a function of the oxygenation level, were correlated with results described above. Moreover, the rate of formation of oxygen radicals by either agent was more sensitive to the level of oxygenation than was singlet oxygen formation by NPe6. These data indicate that the photochemical process that leads to oxygen radical formation is more dependent on the oxygenation level than is the pathway leading to formation of singlet oxygen. © 2013 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2013 The American Society of Photobiology.

  13. Advanced Oxygen Systems for Aircraft (Systemes d’Oxygene Avances)

    Science.gov (United States)

    1996-04-01

    Oxygen Generating System (NAOGS), SAM-TR-80-12, Brooks AFB TX 78235, 1980. 11. Horch TC, Miller RL, Bomar JB, Tedor JB, Holden RD, Ikels KG, and...sieve oxygen generation sys- tem. Data from Horch et al (15). cabin altitude. The minimum and maximum oxygen concen- tration lines depict the...an AV-8A Aircraft; Naval Air Test Center Report No. SY-136R-81, 1981. 15. Horch TC, Miller RL, Bomar JB Jr, Tedor JB, Holden RD, Ikels KG, and

  14. Orbital-selective Mott phase of Cu-substituted iron-based superconductors

    International Nuclear Information System (INIS)

    Liu, Yang; Zhao, Yang-Yang; Song, Yun

    2016-01-01

    We study the phase transition in Cu-substituted iron-based superconductors with a new developed real-space Green’s function method. We find that Cu substitution has strong effect on the orbital-selective Mott transition introduced by the Hund’s rule coupling. The redistribution of the orbital occupancy which is caused by the increase of the Hund’s rule coupling, gives rise to the Mott–Hubbard metal-insulator transition in the half-filled d xy orbital. We also find that more and more electronic states appear inside that Mott gap of the d xy orbital with the increase of Cu substitution, and the in-gap states around the Fermi level are strongly localized at some specific lattice sites. Further, a distinctive phase diagram, obtained for the Cu-substituted Fe-based superconductors, displays an orbital-selective insulating phase, as a result of the cooperative effect of the Hund’s rule coupling and the impurity-induced disorder. (paper)

  15. The Doubting System 1: Evidence for automatic substitution sensitivity.

    Science.gov (United States)

    Johnson, Eric D; Tubau, Elisabet; De Neys, Wim

    2016-02-01

    A long prevailing view of human reasoning suggests severe limits on our ability to adhere to simple logical or mathematical prescriptions. A key position assumes these failures arise from insufficient monitoring of rapidly produced intuitions. These faulty intuitions are thought to arise from a proposed substitution process, by which reasoners unknowingly interpret more difficult questions as easier ones. Recent work, however, suggests that reasoners are not blind to this substitution process, but in fact detect that their erroneous responses are not warranted. Using the popular bat-and-ball problem, we investigated whether this substitution sensitivity arises out of an automatic System 1 process or whether it depends on the operation of an executive resource demanding System 2 process. Results showed that accuracy on the bat-and-ball problem clearly declined under cognitive load. However, both reduced response confidence and increased response latencies indicated that biased reasoners remained sensitive to their faulty responses under load. Results suggest that a crucial substitution monitoring process is not only successfully engaged, but that it automatically operates as an autonomous System 1 process. By signaling its doubt along with a biased intuition, it appears System 1 is "smarter" than traditionally assumed.

  16. Substitution rate and natural selection in parvovirus B19

    Science.gov (United States)

    Stamenković, Gorana G.; Ćirković, Valentina S.; Šiljić, Marina M.; Blagojević, Jelena V.; Knežević, Aleksandra M.; Joksić, Ivana D.; Stanojević, Maja P.

    2016-01-01

    The aim of this study was to estimate substitution rate and imprints of natural selection on parvovirus B19 genotype 1. Studied datasets included 137 near complete coding B19 genomes (positions 665 to 4851) for phylogenetic and substitution rate analysis and 146 and 214 partial genomes for selection analyses in open reading frames ORF1 and ORF2, respectively, collected 1973–2012 and including 9 newly sequenced isolates from Serbia. Phylogenetic clustering assigned majority of studied isolates to G1A. Nucleotide substitution rate for total coding DNA was 1.03 (0.6–1.27) x 10−4 substitutions/site/year, with higher values for analyzed genome partitions. In spite of the highest evolutionary rate, VP2 codons were found to be under purifying selection with rare episodic positive selection, whereas codons under diversifying selection were found in the unique part of VP1, known to contain B19 immune epitopes important in persistent infection. Analyses of overlapping gene regions identified nucleotide positions under opposite selective pressure in different ORFs, suggesting complex evolutionary mechanisms of nucleotide changes in B19 viral genomes. PMID:27775080

  17. Kinetics of oxygen species in an electrically driven singlet oxygen generator

    Science.gov (United States)

    Azyazov, V. N.; Torbin, A. P.; Pershin, A. A.; Mikheyev, P. A.; Heaven, M. C.

    2015-12-01

    The kinetics of oxygen species in the gaseous medium of a discharge singlet oxygen generator has been revisited. Vibrationally excited ozone O3(υ) formed in O + O2 recombination is thought to be a significant agent in the deactivation of singlet oxygen O2(a1Δ), oxygen atom removal and ozone formation. It is shown that the process O3(υ ⩾ 2) + O2(a1Δ) → 2O2 + O is the main O2(a1Δ) deactivation channel in the post-discharge zone. If no measures are taken to decrease the oxygen atom concentration, the contribution of this process to the overall O2(a1Δ) removal is significant, even in the discharge zone. A simplified model for the kinetics of vibrationally excited ozone is proposed. Calculations based on this model yield results that are in good agreement with the experimental data.

  18. Oxygen therapy reduces postoperative tachycardia

    DEFF Research Database (Denmark)

    Stausholm, K; Kehlet, H; Rosenberg, J

    1995-01-01

    Concomitant hypoxaemia and tachycardia in the postoperative period is unfavourable for the myocardium. Since hypoxaemia per se may be involved in the pathogenesis of postoperative tachycardia, we have studied the effect of oxygen therapy on tachycardia in 12 patients randomly allocated to blinded...... air or oxygen by facemask on the second or third day after major surgery. Inclusion criteria were arterial hypoxaemia (oxygen saturation 90 beat.min-1). Each patient responded similarly to oxygen therapy: an increase in arterial oxygen saturation and a decrease...... in heart rate (p oxygen has a positive effect on the cardiac oxygen delivery and demand balance....

  19. Dependence of nitrite oxidation on nitrite and oxygen in low-oxygen seawater

    Science.gov (United States)

    Sun, Xin; Ji, Qixing; Jayakumar, Amal; Ward, Bess B.

    2017-08-01

    Nitrite oxidation is an essential step in transformations of fixed nitrogen. The physiology of nitrite oxidizing bacteria (NOB) implies that the rates of nitrite oxidation should be controlled by concentration of their substrate, nitrite, and the terminal electron acceptor, oxygen. The sensitivities of nitrite oxidation to oxygen and nitrite concentrations were investigated using 15N tracer incubations in the Eastern Tropical North Pacific. Nitrite stimulated nitrite oxidation under low in situ nitrite conditions, following Michaelis-Menten kinetics, indicating that nitrite was the limiting substrate. The nitrite half-saturation constant (Ks = 0.254 ± 0.161 μM) was 1-3 orders of magnitude lower than in cultivated NOB, indicating higher affinity of marine NOB for nitrite. The highest rates of nitrite oxidation were measured in the oxygen depleted zone (ODZ), and were partially inhibited by additions of oxygen. This oxygen sensitivity suggests that ODZ specialist NOB, adapted to low-oxygen conditions, are responsible for apparently anaerobic nitrite oxidation.

  20. 40 CFR 721.7220 - Polymer of substituted phenol, formaldehyde, epichlorohydrin, and disubstituted benzene.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of substituted phenol... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7220 Polymer of substituted phenol... subject to reporting. (1) The chemical substance identified generically as polymer of substituted phenol...

  1. Selected polyethylene glycols as DOP substitutes. Addendum 1

    International Nuclear Information System (INIS)

    Gerber, B.V.

    1981-01-01

    The recommendation is made that Polyethylene glycol (PEG) 400 be considered as a substitute for DOP in aerosol generators producing a polydisperse distribution for testing the integrity of filters and for testing respirator fit. Further, the recommendation is made that pentaethylene glycol (PTAEG) and possibly hexaethylene glycol be considered as a substitute for DOP in aerosol generators thermally producing monodisperse aerosol for quality acceptance tests according tu US federal specifications and standards. The toxicology data base available on the polyethylene glycol family of chemical compounds is discussed and the conclusion is drawn that the probability of approval and acceptance as a non-hazardous substance in the filter and filter media test role is high. Data and analysis supporting PTAEG performance equivalent to DOP in the filter and filter media test role are given or referenced. Cost and availability of the substitute materials is discussed. Conclusions based on the present data and information are given and recommendations for further work are made

  2. Electrophoretic deposition of zinc-substituted hydroxyapatite coatings.

    Science.gov (United States)

    Sun, Guangfei; Ma, Jun; Zhang, Shengmin

    2014-06-01

    Zinc-substituted hydroxyapatite nanoparticles synthesized by the co-precipitation method were used to coat stainless steel plates by electrophoretic deposition in n-butanol with triethanolamine as a dispersant. The effect of zinc concentration in the synthesis on the morphology and microstructure of coatings was investigated. It is found that the deposition current densities significantly increase with the increasing zinc concentration. The zinc-substituted hydroxyapatite coatings were analyzed by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. It is inferred that hydroxyapatite and triethanolamine predominate in the chemical composition of coatings. With the increasing Zn/Ca ratios, the contents of triethanolamine decrease in the final products. The triethanolamine can be burnt out by heat treatment. The tests of adhesive strength have confirmed good adhesion between the coatings and substrates. The formation of new apatite layer on the coatings has been observed after 7days of immersion in a simulated body fluid. In summary, the results show that dense, uniform zinc-substituted hydroxyapatite coatings are obtained by electrophoretic deposition when the Zn/Ca ratio reaches 5%. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Transport properties and Raman spectra of impurity substituted MgB2

    International Nuclear Information System (INIS)

    Masui, T.

    2007-01-01

    Recent advances in the study of MgB 2 are reviewed, with focus on the transport properties and Raman scattering measurements for impurity substituted crystals. Carbon and Aluminium substitution change band filling, introduce intraband and interband scattering. These effects are seen in the temperature dependence of resistivity, Hall coefficients, and phonon peak of Raman spectra. Manganese substitution introduces magnetic scattering, that increases resistivity but gives little change in Raman spectra. The effect of disorder in neutron irradiated samples is also discussed

  4. Substitute natural gas from biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Tunaa, Per (Lund Inst. of Technology, Lund (SE))

    2008-03-15

    Biomass is by many considered as the only alternative to phase-out the usage of fossil fuels such as natural gas and oil especially for the transportation sector where alternative solutions, such as hydrogen fuel cells and batteries, are not yet fully developed. Thermal gasification or other methods such as pyrolysis of the biomass must be applied in order to produce an intermediate product suitable for further upgrading to either gaseous or liquid products. This thesis will evaluate the possibilities of producing, substitute natural gas, (SNG) from biomass gasification by using computer simulation. Three different gasification techniques were evaluated; entrained-flow, fluidized-bed and indirect gasification coupled with two different desulphurisation systems and two methanation processes. The desulphurisation systems were a zinc oxide bed and a Rectisol wash system. Methanation were performed by a series of adiabatic reactors with gas recycling and by an isothermal reactor. The impact on SNG efficiency from system pressure, isothermal methanation temperature and PSA methane recovery were evaluated as well. The results show that the fluidized-bed and the indirect gasifier have the highest SNG efficiency. Furthermore there are little to no difference between the methanation processes and small differences for the gas cleanup systems. SNG efficiencies in excess of 50 % were possible for all gasifiers. SNG efficiency is defined as the energy in the SNG product divided by the total input to the system from biomass, drying and oxygen. Increasing system pressure has a negative impact on SNG efficiency as well as increasing operating costs due to increased power for compression. Isothermal methanation temperature has no significant impact on SNG efficiency. Recovering as much methane as possible in the PSA is the most important parameter. Recovering methane that has been dissolved in condensed process water increases the SNG efficiency by 2-10% depending on system.

  5. Size effects on cation heats of formation. I. Methyl substitutions in nitrogenous compounds

    International Nuclear Information System (INIS)

    Leach, Sydney

    2012-01-01

    Graphical abstract: Heat of formation of cations as a function of ln(n) where n is the number of atoms in the ion: methyl substituted immonium cations. N = substitution at nitrogen sites, C = substitution at carbon sites. Highlights: ► Heats of formation of nitrogenous cations by graphical method relating to ion size. ► Methyl substitution in formamides, acetamides, immonium, amine, and imine cations. ► Methyl substitution in ammonium and amino cations. ► New studies ionization energies and heats of formation required in several cases. - Abstract: The heats of formation of molecular ions are often not known to better than 10 or 20 kJ/mol. The present study on nitrogenous compounds adopts the graphical approach of Holmes and Lossing which relates cation heats of formation to cation size. A study of methyl substitution in formamides and acetamides is followed by an examination of heat of formation data on carbon-site and nitrogen-site methyl substitution in immonium, amine, imine, ammonium and amino cations. The results provide tests of the validity of this graphical method and also suggest investigating or re-investigating the ionization energies and the heats of formation of several of the molecules studied.

  6. Hyperbaric Oxygen Therapy and Oxygen Compatibility of Skin and Wound Care Products.

    Science.gov (United States)

    Bernatchez, Stéphanie F; Tucker, Joseph; Chiffoleau, Gwenael

    2017-11-01

    Objective: Use test methods to assess the oxygen compatibility of various wound care products. Approach: There are currently no standard test methods specifically for evaluating the oxygen compatibility and safety of materials under hyperbaric oxygen (HBO) conditions. However, tests such as the oxygen index (OI), oxygen exposure (OE), and autogenous ignition temperature (AIT) can provide useful information. Results: The OI test measures the minimum oxygen concentration that will support candle-like burning, and it was used to test 44 materials. All but two exhibited an OI equal to or greater (safer) than a control material commonly used in HBO. The OE test exposes each material to an oxygen-enriched atmosphere (>99.5% oxygen) to monitor temperature and pressure for an extended duration. The results of the OE testing indicated that none of the 44 articles tested with this method self-ignited within the 60°C, 3 atm pressurized oxygen atmosphere. The AIT test exposes materials to a rapid ramp up in temperature in HBO conditions at 3 atm until ignition occurs. Ten wound care materials and seven materials usually avoided in HBO chambers were tested. The AIT ranged from 138°C to 384°C for wound care products and from 146°C to 420°C for the other materials. Innovation: This work provides useful data and recommendations to help develop a new standard approach for evaluating the HBO compatibility of wound care products to ensure safety for patients and clinicians. Conclusion: The development of an additional test to measure the risk of electrostatic discharge of materials in HBO conditions is needed.

  7. Hydrophosphorylation of substituted alkynes by phosphonic acids

    International Nuclear Information System (INIS)

    Nifant'ev, E.F.; Solovetskaya, L.A.; Maslennikova, V.I.; Sergeev, N.M.

    1987-01-01

    Hydrophosphorylation of functionally substituted alkynes by phosphonic acids can be a convenient method for synthesis of functionally substituted mono- and diphosphine oxides. The ease of hydrophosphorylation is determined by the strength of the negative inductive effect of the substituents on the triple bond and the steric factor. The structure of the bis-adducts was confirmed by elementary analysis and the 31 P and 13 C NMR spectra. The 31 P NMR spectrum is an AB two-spin system. The values of the chemical shifts and spin-spin interaction constants 3 J/sub PP/ are in agreement with the data in the literature for similar compounds

  8. Srtucture and properties of intracomplexes of 2-substituted 8-mercaptoquinoline derivatives

    International Nuclear Information System (INIS)

    Sturis, A.P.; Bankovskij, Yu.A.; Pech, L.Ya.

    1990-01-01

    The results of investigation of the molecular and crystal structure of 2-substituted 8-mercaptoquinoline internal complexes (in particular complexes of cadmium and indium) have been reviewed. Substitution of hydrogen atom in o-position in relation to the nitrogen atom in the ligand molecule causes the steric hindrance in the molecules of complexes. Due to it the changes in structure of the central atom coordination center in the MR 2 complexes from the planar (8-mercaptoquinolinates) to the distored tetrahedral (2-substituted 8-mercaptoquinolinates) occur. The ascertainment of such effect allows to explain the changes in physicochemical properties of 2-substituted 8-mercaptoquinolinates (hypsochromic shift of absorption maxima, decrease of the amount of ligands connected to the central atom, decrease of stability, increase of solubility in organic solvents) in comparison with 8-mercaptoquinolinates

  9. Petroleum, alcohol, and energy substitution in Brazil: Theoretical and empirical issues

    International Nuclear Information System (INIS)

    Biller, D.

    1991-01-01

    As in other Latin American nations, the petroleum industry has always been surrounded by controversy in Brazil. Issues related to exploration, exploitation, and import of crude have received special attention by Brazilian decision makers. In the past decade, an additional relevant issue was brought into play by the oil crisis. An import substitution program for energy was implemented by the development of alternative indigenous energy sources. Among these sources, sugarcane was viewed as a reliable renewable resource for the production of fuel alcohol and, very recently, of electricity. Brazil engaged in a gigantic program of fuel substitution, which is now facing severe problems due to the fall of petroleum prices. This study analyzes the recent energy import substitution program in Brazil, specifically concentrating on microeconomic and environmental aspects of fuel substitution

  10. Solvent Effects on Oxygen-17 Chemical Shifts in Amides. Quantitative Linear Solvation Shift Relationships

    Science.gov (United States)

    Díez, Ernesto; Fabián, Jesús San; Gerothanassis, Ioannis P.; Esteban, Angel L.; Abboud, José-Luis M.; Contreras, Ruben H.; de Kowalewski, Dora G.

    1997-01-01

    A multiple-linear-regression analysis (MLRA) has been carried out using the Kamlet-Abboud-Taft (KAT) solvatochromic parameters in order to elucidate and quantify the solvent effects on the17O chemical shifts ofN-methylformamide (NMF),N,N-dimethylformamide (DMF),N-methylacetamide (NMA), andN,N-dimethylacetamide (DMA). The chemical shifts of the four molecules show the same dependence (in ppm) on the solvent polarity-polarizability, i.e., -22π*. The influence of the solvent hydrogen-bond-donor (HBD) acidities is slightly larger for the acetamides NMA and DMA, i.e., -48α, than for the formamides NMF and DMF, i.e., -42α. The influence of the solvent hydrogen-bond-acceptor (HBA) basicities is negligible for the nonprotic molecules DMF and DMA but significant for the protic molecules NMF and NMA, i.e., -9β. The effect of substituting the N-H hydrogen by a methyl group amounts to -5.9 ppm in NMF and 5.4 ppm in NMA. The effect of substituting the O=C-H hydrogen amounts to 5.5 ppm in NMF and 16.8 ppm in DMF. The model of specific hydration sites of amides by I. P. Gerothanassis and C. Vakka [J. Org. Chem.59,2341 (1994)] is settled in a more quantitative basis and the model by M. I. Burgar, T. E. St. Amour, and D. Fiat [J. Phys. Chem.85,502 (1981)] is critically evaluated.17O hydration shifts have been calculated for formamide (FOR) by the ab initio LORG method at the 6-31G* level. For a formamide surrounded by the four in-plane molecules of water in the first hydration shell, the calculated17O shift change due to the four hydrogen bonds, -83.2 ppm, is smaller than the empirical hydration shift, -100 ppm. The17O shift change from each out-of-plane water molecule hydrogen-bonded to the amide oxygen is -18.0 ppm. These LORG results support the conclusion that no more than four water molecules are hydrogen-bonded to the amide oxygen in formamide.

  11. Oxygen transfer rate during the production of alginate by Azotobacter vinelandii under oxygen-limited and non oxygen-limited conditions

    Directory of Open Access Journals (Sweden)

    Peña Carlos F

    2011-02-01

    Full Text Available Abstract Background The oxygen transfer rate (OTR and dissolved oxygen tension (DOT play an important role in determining alginate production and its composition; however, no systematic study has been reported about the independent influence of the OTR and DOT. In this paper, we report a study about alginate production and the evolution of the molecular mass of the polymer produced by a wild-type A. vinelandii strain ATCC 9046, in terms of the maximum oxygen transfer rate (OTRmax in cultures where the dissolved oxygen tension (DOT was kept constant. Results The results revealed that in the two dissolved oxygen conditions evaluated, strictly controlled by gas blending at 0.5 and 5% DOT, an increase in the agitation rate (from 300 to 700 rpm caused a significant increase in the OTRmax (from 17 to 100 mmol L-1 h-1 for DOT of 5% and from 6 to 70 mmol L-1 h-1 for DOT of 0.5%. This increase in the OTRmax improved alginate production, as well as the specific alginate production rate (SAPR, reaching a maximal alginate concentration of 3.1 g L-1 and a SAPR of 0.031 g alg g biom-1 h-1 in the cultures at OTRmax of 100 mmol L-1 h-1. In contrast, the mean molecular mass (MMM of the alginate isolated from cultures developed under non-oxygen limited conditions increased by decreasing the OTRmax, reaching a maximal of 550 kDa at an OTRmax of 17 mmol L-1 h-1 . However, in the cultures developed under oxygen limitation (0.5% DOT, the MMM of the polymer was practically the same (around 200 kDa at 300 and 700 rpm, and this remained constant throughout the cultivation. Conclusions Overall, our results showed that under oxygen-limited and non oxygen-limited conditions, alginate production and its molecular mass are linked to the OTRmax, independently of the DOT of the culture.

  12. Experimental investigation on performance characteristics of a diesel engine using diesel-water emulsion with oxygen enriched air

    Directory of Open Access Journals (Sweden)

    P. Baskar

    2017-03-01

    Full Text Available Diesel engines occupy a crucial position in automobile industry due to their high thermal efficiency and high power to weight ratio. However, they lag behind in controlling air polluting components coming out of the engine exhaust. Therefore, diesel consumption should be analyzed for future energy consumption and this can be primarily controlled by the petroleum fuel substitution techniques for existing diesel engines, which include biodiesel, alcohol-diesel emulsions and diesel water emulsions. Among them the diesel water emulsion is found to be most suitable fuel due to reduction in particulate matter and NOx emission, besides that it also improves the brake thermal efficiency. But the major problem associated with emulsions is the ignition delay, since this is responsible for the power and torque loss. A reduction in NOx emission was observed due to reduction in combustion chamber temperature as the water concentration increases. However the side effect of emulsified diesel is a reduction in power which can be compensated by oxygen enrichment. The present study investigates the effects of oxygen concentration on the performance characteristics of a diesel engine when the intake air is enriched to 27% of oxygen and fueled by 10% of water diesel emulsion. It was found that the brake thermal efficiency was enhanced, combustion characteristics improved and there is also a reduction in HC emissions.

  13. Asymmetric syntheses of 3,4-disubstituted tetrahydroquinoline derivatives using (+)- sparteine-mediated electrophilic substitution

    International Nuclear Information System (INIS)

    Choi, Yun Soo; Kang, Kyoung Hee; Park, Yong Sun

    2015-01-01

    Tetrahydroquinolines bearing substituents are frequently found as a substructure in a number of alkaloids and natural products. Since their individual stereoisomers displays different biological activities, it is desirable to develop a highly stereoselective synthetic method for tetrahydroquinolines. While some progress has recently been made toward the development of asymmetric synthetic methods for tetrahydroquinolines, it is still a challenging topic in organic synthesis. In order to investigate the source of diastereoselection attained in the substitution reaction with a racemic epoxide, we examined the substitution of 2 with an excess amount of racemic p-chlorophenyl-substituted oxirane. We have developed a novel method for the asymmetric synthesis of trans-3,4-diaryl-substituted tetrahy- droquinolines from ortho-substituted N-pivaloyl anilines. The enantioselective process includes (+)-sparteine-mediated stereoselective lithiati on, kinetic resolution of epoxides in substitution, and stereospecific Mitsu nobu cyclization as the key reactions. The simple protocol can provide highly functionalized tetrahydroqu inoline rings and would allow their further functionalization to access more complex target molecules

  14. Cross-Cultural Comparison between German, French and Dutch Consumer Preferences for Meat Substitutes

    Directory of Open Access Journals (Sweden)

    Ramona Weinrich

    2018-05-01

    Full Text Available Sustainability is becoming an increasingly important consideration for consumers when purchasing food. As meat production has a significant impact on the environment, meat substitutes are becoming more and more popular in Europe. However, consumers who regularly buy meat substitutes are still the exception. Although there are some initial results indicating why this proportion is still low, most research has been concentrated in the Netherlands. This paper aims to compare reasons for consuming or not consuming meat substitutes in three European countries—Germany, the Netherlands and France. As very little is known about the underlying reasons, an explorative approach was chosen. Focus group discussions were carried out in all three countries, six altogether. The results show that all participants can enumerate meat substitutes. The main reason for not consuming meat substitutes is the taste of meat. Further, eating habits seem to be fixed and convenience might also be an impediment to reducing meat consumption in favour of meat substitutes, as is confusion regarding healthy eating.

  15. Asymmetric syntheses of 3,4-disubstituted tetrahydroquinoline derivatives using (+)- sparteine-mediated electrophilic substitution

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yun Soo; Kang, Kyoung Hee; Park, Yong Sun [Dept. of Chemistry, Konkuk University, Seoul (Korea, Republic of)

    2015-05-15

    Tetrahydroquinolines bearing substituents are frequently found as a substructure in a number of alkaloids and natural products. Since their individual stereoisomers displays different biological activities, it is desirable to develop a highly stereoselective synthetic method for tetrahydroquinolines. While some progress has recently been made toward the development of asymmetric synthetic methods for tetrahydroquinolines, it is still a challenging topic in organic synthesis. In order to investigate the source of diastereoselection attained in the substitution reaction with a racemic epoxide, we examined the substitution of 2 with an excess amount of racemic p-chlorophenyl-substituted oxirane. We have developed a novel method for the asymmetric synthesis of trans-3,4-diaryl-substituted tetrahy- droquinolines from ortho-substituted N-pivaloyl anilines. The enantioselective process includes (+)-sparteine-mediated stereoselective lithiati on, kinetic resolution of epoxides in substitution, and stereospecific Mitsu nobu cyclization as the key reactions. The simple protocol can provide highly functionalized tetrahydroqu inoline rings and would allow their further functionalization to access more complex target molecules.

  16. Substitution Relationship Between The Agency Problem Control Mechanisms in Malaysia: Simultaneous Equation Analysis

    Directory of Open Access Journals (Sweden)

    D. Agus Harjito

    2009-05-01

    Full Text Available This study investigates the substitution relationship (substitutability between debt policy, insider ownership, and dividend policy as the agency problem control mechanism in Malaysia. If the substitution relationship exists between the agency control mechanisms, the agency problem can be reduced through this relationship. Reducing the agency problem as a result can increase the firm value proxied by Tobin’s Q. This study employs 396 firms sample listed on Malaysian Bourse from 2001 to 2004. To achieves the objectives, this study uses two-stage least square method. The results of this study indicate that the substitutability between debt policy, insider ownership, and dividend policy as agency problem control mechanism does not fully exist in Malaysia. Apparently the substitutability only exists for debt policy and dividend. There is no substitution between debt policy and insider ownership as well as between dividend policy and insider ownership. Key words: debt policy, insider ownership, dividend policy, agency problem, firm value

  17. Substitution of sugar-sweetened beverages with other beverage alternatives

    DEFF Research Database (Denmark)

    Zheng, Miaobing; Allman-Farinelli, Margaret; Heitmann, Berit Lilienthal

    2015-01-01

    alternatives on long-term health outcomes. METHOD: We systematically retrieved studies from six electronic databases from inception to November 2013. Prospective cohort studies and randomized controlled trials (RCTs) examining the effects of substituting beverage alternatives for SSBs on long-term health...... to high. Evidence from both cohort studies and RCTs showed substitution of SSBs by various beverage alternatives was associated with long-term lower energy intake and lower weight gain. However, evidence was insufficient to draw conclusions regarding the effect of beverage substitution on other health...... outcomes, and which beverage alternative is the best choice. CONCLUSIONS: Although studies on this topic are sparse, the available evidence suggests a potential beneficial effect on body weight outcomes when SSBs are replaced by water or low-calorie beverages. Further studies in this area are warranted...

  18. Antimalarial Activity of C-10 Substituted Triazolyl Artemisinin.

    Science.gov (United States)

    Park, Gab-Man; Park, Hyun; Oh, Sangtae; Lee, Seokjoon

    2017-12-01

    We synthesized C-10 substituted triazolyl artemisinins by the Huisgen cycloaddition reaction between dihydroartemisinins (2) and variously substituted 1, 2, 3-triazoles (8a-8h). The antimalarial activities of 32 novel artemisinin derivatives were screened against a chloroquine-resistant parasite. Among them, triazolyl artemisinins with electron-withdrawing groups showed stronger antimalarial activities than those shown by the derivatives having electron-donating groups. In particularly, m-chlorotriazolyl artemisinin (9d-12d) showed antimalarial activity equivalent to that of artemisinin and could be a strong drug candidate.

  19. Gamma-ray decontamination of a milk substitute for calf feeding

    International Nuclear Information System (INIS)

    Blasco, M. I.; Roberti, A.; Horak, Celina I.; Narvaiz, Patricia; Kairiyama, Eulogia

    1999-01-01

    A contaminated milk substitute for calf feeding has been irradiated to reduce the content of bacteria and fungi. The results of microbiological, chemical and physico-chemical studies demonstrate that an irradiation doses of 7 kGy reduce to an acceptable level the content of contaminants without damaging the milk substitute. (author)

  20. 31 CFR 370.14 - Can substitute payment procedures be used?

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Can substitute payment procedures be used? 370.14 Section 370.14 Money and Finance: Treasury Regulations Relating to Money and Finance... FUNDS TRANSFERS RELATING TO UNITED STATES SECURITIES Credit ACH Entries § 370.14 Can substitute payment...

  1. 76 FR 8666 - Substitution in Case of Death of Claimant

    Science.gov (United States)

    2011-02-15

    ... DEPARTMENT OF VETERANS AFFAIRS 38 CFR Parts 3, 14, 20 RIN 2900-AN91 Substitution in Case of Death... Veterans Affairs (VA) proposes to amend its regulations concerning adjudication of claims, representation..., not later than one year after the death of the claimant, request to be substituted for the claimant...

  2. Cannabis as a substitute for prescription drugs – a cross-sectional study

    Science.gov (United States)

    Corroon, James M; Mischley, Laurie K; Sexton, Michelle

    2017-01-01

    Background The use of medical cannabis is increasing, most commonly for pain, anxiety and depression. Emerging data suggest that use and abuse of prescription drugs may be decreasing in states where medical cannabis is legal. The aim of this study was to survey cannabis users to determine whether they had intentionally substituted cannabis for prescription drugs. Methods A total of 2,774 individuals were a self-selected convenience sample who reported having used cannabis at least once in the previous 90 days. Subjects were surveyed via an online anonymous questionnaire on cannabis substitution effects. Participants were recruited through social media and cannabis dispensaries in Washington State. Results A total of 1,248 (46%) respondents reported using cannabis as a substitute for prescription drugs. The most common classes of drugs substituted were narcotics/opioids (35.8%), anxiolytics/benzodiazepines (13.6%) and antidepressants (12.7%). A total of 2,473 substitutions were reported or approximately two drug substitutions per affirmative respondent. The odds of reporting substituting were 4.59 (95% confidence interval [CI], 3.87–5.43) greater among medical cannabis users compared with non-medical users and 1.66 (95% CI, 1.27–2.16) greater among those reporting use for managing the comorbidities of pain, anxiety and depression. A slightly higher percentage of those who reported substituting resided in states where medical cannabis was legal at the time of the survey (47% vs. 45%, p=0.58), but this difference was not statistically significant. Discussion These patient-reported outcomes support prior research that individuals are using cannabis as a substitute for prescription drugs, particularly, narcotics/opioids, and independent of whether they identify themselves as medical or non-medical users. This is especially true if they suffer from pain, anxiety and depression. Additionally, this study suggests that state laws allowing access to, and use of, medical

  3. Dodecatungstocobaltate and Sn (IV)-Substituted Polyoxometalate ...

    African Journals Online (AJOL)

    NICO

    work metals, or substituting different cations for the protons to make their acidic or neutral ... corrosive materials in comparison with traditional Lewis acids. The importance of .... salt by treatment with potassium chloride. Finally, the cobalt (II).

  4. A theoretical model for oxygen transport in skeletal muscle under conditions of high oxygen demand.

    Science.gov (United States)

    McGuire, B J; Secomb, T W

    2001-11-01

    Oxygen transport from capillaries to exercising skeletal muscle is studied by use of a Krogh-type cylinder model. The goal is to predict oxygen consumption under conditions of high demand, on the basis of a consideration of transport processes occurring at the microvascular level. Effects of the decline in oxygen content of blood flowing along capillaries, intravascular resistance to oxygen diffusion, and myoglobin-facilitated diffusion are included. Parameter values are based on human skeletal muscle. The dependence of oxygen consumption on oxygen demand, perfusion, and capillary density are examined. When demand is moderate, the tissue is well oxygenated and consumption is slightly less than demand. When demand is high, capillary oxygen content declines rapidly with axial distance and radial oxygen transport is limited by diffusion resistance within the capillary and the tissue. Under these conditions, much of the tissue is hypoxic, consumption is substantially less than demand, and consumption is strongly dependent on capillary density. Predicted consumption rates are comparable with experimentally observed maximal rates of oxygen consumption.

  5. Synthesis of 3-substituted 5-arylidene-1-methyl-2-thiohydantoins under microwave irradiation

    DEFF Research Database (Denmark)

    Khodari, A.I.; Nielsen, John

    2002-01-01

    A mono-modal microwave oven was used to expedite the synthesis of small libraries of 3-substituted 1-methyl-2-thiohydantoins and 3-substituted 5-arylidene-1-methyl-2-thiohydantoins. In comparison with the traditional reflux methods, similar or higher yields were obtained.......A mono-modal microwave oven was used to expedite the synthesis of small libraries of 3-substituted 1-methyl-2-thiohydantoins and 3-substituted 5-arylidene-1-methyl-2-thiohydantoins. In comparison with the traditional reflux methods, similar or higher yields were obtained....

  6. Hydrogen bonding in (substituted benzene)·(water)n clusters with n≤4

    International Nuclear Information System (INIS)

    Barth, H.-D.; Buchhold, K.; Djafari, S.; Reimann, B.; Lommatzsch, U.; Brutschy, B.

    1998-01-01

    Infrared ion-depletion spectroscopy, a double resonance method combining vibrational predissociation with resonant two-photon ionization (R2PI) spectroscopy, has been applied to study mixed clusters of the type (substituted benzene)·(H 2 O) n with n≤4. The UV chromophores were p-difluorobenzene, fluorobenzene, benzene, toluene, p-xylene and anisole. From the IR depletion spectra in the region of the OH stretching vibrations it could be shown that the water molecules are attached as subclusters to the chromophores. Size and configuration of the subclusters could be deduced from the IR depletion spectra. In the anisole·(H 2 O) 1 a nd 2 complexes the water clusters form an ordinary hydrogen bond to the oxygen atom of the methoxy group. In all other mixed complexes a π-hydrogen bond is formed between one of the free OH groups of a water subcluster and the π-system of the chromophore. According to the strength of this interaction the frequency of the respective absorption band exhibits a characteristic red-shift which could be related to the total atomic charges in the aromatic ring. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Oxygen-transfer performance of a newly designed, very low-volume membrane oxygenator.

    Science.gov (United States)

    Burn, Felice; Ciocan, Sorin; Carmona, Natalia Mendez; Berner, Marion; Sourdon, Joevin; Carrel, Thierry P; Tevaearai Stahel, Hendrik T; Longnus, Sarah L

    2015-09-01

    Oxygenation of blood and other physiological solutions are routinely required in fundamental research for both in vitro and in vivo experimentation. However, very few oxygenators with suitable priming volumes (parallel-oriented microporous polypropylene hollow fibres, placed inside a hollow shell with a lateral-luer outlet, and sealed at both extremities. With this design, perfusate is delivered via the core-tube to the centre of the mini-oxygenator, and exits via the luer port. A series of mini-oxygenators were constructed and tested in an in vitro perfusion circuit by monitoring oxygen transfer using modified Krebs-Henseleit buffer or whole porcine blood. Effects of perfusion pressure and temperature over flows of 5-60 ml × min(-1) were assessed. Twelve mini-oxygenators with a mean priming volume of 1.5 ± 0.3 ml were evaluated. With buffer, oxygen transfer reached a maximum of 14.8 ± 1.0 ml O2 × l(-1) (pO2: 450 ± 32 mmHg) at perfusate flow rates of 5 ml × min(-1) and decreased with an increase in perfusate flow to 7.8 ± 0.7 ml ml O2 × l(-1) (pO2: 219 ± 24 mmHg) at 60 ml × min(-1). Similarly, with blood perfusate, oxygen transfer also decreased as perfusate flow increased, ranging from 33 ± 5 ml O2 × l(-1) at 5 ml × min(-1) to 11 ± 2 ml O2 × l(-1) at 60 ml × min(-1). Furthermore, oxygen transfer capacity remained stable with blood perfusion over a period of at least 2 h. We have developed a new miniaturized membrane oxygenator with an ultra-low priming volume (circuits, such as small animal extracorporeal circulation and ex vivo organ perfusion. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  8. Substitution and complementarity of alcohol and cannabis: A review of the literature

    Science.gov (United States)

    2016-01-01

    Background Whether alcohol and cannabis are used as substitutes or complements remains debated, and findings across various disciplines have not been synthesized to date. Objective This paper is a first step towards organizing the interdisciplinary literature on alcohol and cannabis substitution and complementarity. Method Electronic searches were performed using PubMed and ISI Web of Knowledge. Behavioral studies of humans with ‘alcohol’ (or ‘ethanol’) and ‘cannabis’ (or ‘marijuana”) and ‘complement*’ (or ‘substitut*’) in the title or as a keyword were considered. Studies were organized according to sample characteristics (youth, general population, clinical and community-based). These groups were not set a priori, but were informed by the literature review process. Results Of the 39 studies reviewed, 16 support substitution, ten support complementarity, 12 support neither and one supports both. Results from studies of youth suggest that youth may reduce alcohol in more liberal cannabis environments (substitute), but reduce cannabis in more stringent alcohol environments (complement). Results from the general population suggest that substitution of cannabis for alcohol may occur under more lenient cannabis policies, though cannabis-related laws may affect alcohol use differently across genders and racial groups. Conclusions Alcohol and cannabis act as both substitutes and complements. Policies aimed at one substance may inadvertently affect consumption of other substances. Future studies should collect fine-grained longitudinal, prospective data from the general population and subgroups of interest, especially in locations likely to legalize cannabis. PMID:27249324

  9. Physicochemical and sensory characteristics of soy sauce substituted with pigeon pea (Cajanus cajan (Linn.))

    Science.gov (United States)

    Retnaningsih, C.; Sumardi; Meiliana; Surya, A.

    2018-01-01

    The objective of this study wasto investigate the physicochemical and sensory properties of the soy sauce substituted with pigeon pea. Soybean was substituted by 20%, 50%, 75%, and 100% of pigeon pea. The observation included viscosity, total solids, protein levels, antioxidant activity, and sensory characteristics. The results showed that the more substitution of pigeon pea, the less the protein content of soy sauce and the more the antioxidant activity as well as total solids. The most favored group was 25% pigeon pea substitution. It is suggested that soy sauce could be prepared using 25% to 75% pigeon pea substitution.

  10. Carbon mineralization and oxygen dynamics in sediments with deep oxygen penetration, Lake Superior

    DEFF Research Database (Denmark)

    Li, Jiying; Crowe, Sean Andrew; Miklesh, David

    2012-01-01

    To understand carbon and oxygen dynamics in sediments with deep oxygen penetration, we investigated eight locations (160–318-m depth) throughout Lake Superior. Despite the 2–4 weight percent organic carbon content, oxygen penetrated into the sediment by 3.5 to > 12 cm at all locations. Such deep ...... volume-specific carbon degradation rates were 0.3–1.5 µmol cm−3 d−1; bioturbation coefficient near the sediment surface was 3–8 cm2 yr−1. These results indicate that carbon cycling in large freshwater systems conforms to many of the same trends as in marine systems.......To understand carbon and oxygen dynamics in sediments with deep oxygen penetration, we investigated eight locations (160–318-m depth) throughout Lake Superior. Despite the 2–4 weight percent organic carbon content, oxygen penetrated into the sediment by 3.5 to > 12 cm at all locations. Such deep......, suggesting that temporal variability in deeply oxygenated sediments may be greater than previously acknowledged. The oxygen uptake rates (4.4–7.7 mmol m−2 d−1, average 6.1 mmol m−2 d−1) and carbon mineralization efficiency (∼ 90% of deposited carbon) were similar to those in marine hemipelagic and pelagic...

  11. Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads.

    Science.gov (United States)

    Wang, Lin; Acosta, Miguel A; Leach, Jennie B; Carrier, Rebecca L

    2013-04-21

    Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and oxygen insensitive Nile blue reference dye, and a poly-dimethylsiloxane (PDMS) shell rendering biocompatibility. Human intestinal epithelial Caco-2 cells were cultivated on a series of PDMS and type I collagen based substrates patterned with micro-well arrays for 3 or 7 days, and then brought into contact with oxygen sensing beads. Using an image analysis algorithm to convert florescence intensity of beads to partial oxygen pressure in the culture system, tens of microns-size oxygen sensing beads enabled the spatial measurement of local oxygen concentration in the microfabricated system. Results generally indicated lower oxygen level inside wells than on top of wells, and local oxygen level dependence on structural features of cell culture surfaces. Interestingly, chemical composition of cell culture substrates also appeared to affect oxygen level, with type-I collagen based cell culture systems having lower oxygen concentration compared to PDMS based cell culture systems. In general, results suggest that oxygen sensing beads can be utilized to achieve real-time and local monitoring of micro-environment oxygen level in 3D microfabricated cell culture systems.

  12. Oxygen evolution reaction catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  13. Relating oxygen partial pressure, saturation and content: the haemoglobin-oxygen dissociation curve.

    Science.gov (United States)

    Collins, Julie-Ann; Rudenski, Aram; Gibson, John; Howard, Luke; O'Driscoll, Ronan

    2015-09-01

    The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content), saturation (S O2 ) and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin-oxygen dissociation curve, a graphical representation of the relationship between oxygen satur-ation and oxygen partial pressure helps us to understand some of the principles underpinning this process. Historically this curve was derived from very limited data based on blood samples from small numbers of healthy subjects which were manipulated in vitro and ultimately determined by equations such as those described by Severinghaus in 1979. In a study of 3524 clinical specimens, we found that this equation estimated the S O2 in blood from patients with normal pH and S O2 >70% with remarkable accuracy and, to our knowledge, this is the first large-scale validation of this equation using clinical samples. Oxygen saturation by pulse oximetry (S pO2 ) is nowadays the standard clinical method for assessing arterial oxygen saturation, providing a convenient, pain-free means of continuously assessing oxygenation, provided the interpreting clinician is aware of important limitations. The use of pulse oximetry reduces the need for arterial blood gas analysis (S aO2 ) as many patients who are not at risk of hypercapnic respiratory failure or metabolic acidosis and have acceptable S pO2 do not necessarily require blood gas analysis. While arterial sampling remains the gold-standard method of assessing ventilation and oxygenation, in those patients in whom blood gas analysis is indicated, arterialised capillary samples also have a valuable role in patient care. The clinical role of venous blood gases however remains less well defined.

  14. Relating oxygen partial pressure, saturation and content: the haemoglobin–oxygen dissociation curve

    Directory of Open Access Journals (Sweden)

    Julie-Ann Collins

    2015-09-01

    The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content, saturation (SO2 and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin–oxygen dissociation curve, a graphical representation of the relationship between oxygen satur­ation and oxygen partial pressure helps us to understand some of the principles underpinning this process. Historically this curve was derived from very limited data based on blood samples from small numbers of healthy subjects which were manipulated in vitro and ultimately determined by equations such as those described by Severinghaus in 1979. In a study of 3524 clinical specimens, we found that this equation estimated the SO2 in blood from patients with normal pH and SO2 >70% with remarkable accuracy and, to our knowledge, this is the first large-scale validation of this equation using clinical samples. Oxygen saturation by pulse oximetry (SpO2 is nowadays the standard clinical method for assessing arterial oxygen saturation, providing a convenient, pain-free means of continuously assessing oxygenation, provided the interpreting clinician is aware of important limitations. The use of pulse oximetry reduces the need for arterial blood gas analysis (SaO2 as many patients who are not at risk of hypercapnic respiratory failure or metabolic acidosis and have acceptable SpO2 do not necessarily require blood gas analysis. While arterial sampling remains the gold-standard method of assessing ventilation and oxygenation, in those patients in whom blood gas analysis is indicated, arterialised capillary samples also have a valuable role in patient care. The clinical role of venous blood gases however remains less well defined.

  15. Integrated turbomachine oxygen plant

    Science.gov (United States)

    Anand, Ashok Kumar; DePuy, Richard Anthony; Muthaiah, Veerappan

    2014-06-17

    An integrated turbomachine oxygen plant includes a turbomachine and an air separation unit. One or more compressor pathways flow compressed air from a compressor through one or more of a combustor and a turbine expander to cool the combustor and/or the turbine expander. An air separation unit is operably connected to the one or more compressor pathways and is configured to separate the compressed air into oxygen and oxygen-depleted air. A method of air separation in an integrated turbomachine oxygen plant includes compressing a flow of air in a compressor of a turbomachine. The compressed flow of air is flowed through one or more of a combustor and a turbine expander of the turbomachine to cool the combustor and/or the turbine expander. The compressed flow of air is directed to an air separation unit and is separated into oxygen and oxygen-depleted air.

  16. Structural and magnetic properties of Co-substituted NiCu ferrite nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Li, Le-Zhong, E-mail: lezhongli@cuit.edu.cn; Zhong, Xiao-Xi; Wang, Rui; Tu, Xiao-Qiang; Peng, Long

    2017-07-01

    Highlights: • There are Fe{sub 2}O{sub 3} and CuO impurity phases when x ≤ 0.10. • The saturation magnetization and coercivity monotonically increase with the increase of Co substitution. • The anisotropy constant increases with the increase of Co substitution. • The calculated and observed values of magneton number are in close agreement with each other. - Abstract: Co-substituted NiCu ferrite nanopowders with the chemical formula Ni{sub 0.5−x}Cu{sub 0.5−x}Co{sub 2x}Fe{sub 2}O{sub 4} (0 ≤ x ≤ 0.50) were synthesized by sol-gel auto-combustion method. The effects of Co substitution on the cation distribution, structural and magnetic properties of the NiCu ferrite nanopowders have been investigated. Differential thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM) measurements were used to characterize the chemical, structural and magnetic properties of the ferrite nanopowders, respectively. The DTA-TG results indicate that there are three steps of the combustion process. XRD results indicate that there are Fe{sub 2}O{sub 3} and CuO impurity phases when x ≤ 0.10. Furthermore, the lattice parameter increases, and the X-ray density and the average crystallite size decrease with increasing Co substitution. And the obtained particle size from TEM image is in very good agreement with the average crystallite size estimated by XRD measurements. The saturation magnetization and coercivity monotonically increase with the increase of Co substitution. The increase of the saturation magnetization is due to the substitution of Ni{sup 2+} and Cu{sup 2+} ions with lower magnetic moment by Co{sup 2+} ions with higher magnetic moment on the octahedral sites. And the increase of the coercivity is mainly due to the increase of magnetocrystalline anisotropy energy.

  17. Oxygen sensitive polymeric nanocapsules for optical dissolved oxygen sensors

    Science.gov (United States)

    Sun, Zhijuan; Cai, Chenxin; Guo, Fei; Ye, Changhuai; Luo, Yingwu; Ye, Shuming; Luo, Jianchao; Zhu, Fan; Jiang, Chunyue

    2018-04-01

    Immobilization of the oxygen-sensitive probes (OSPs) in the host matrix greatly impacts the performance and long-term usage of the optical dissolved oxygen (DO) sensors. In this work, fluorescent dyes, as the OSPs, were encapsulated with a crosslinked fluorinated polymer shell by interfacial confined reversible addition fragmentation chain transfer miniemulsion polymerization to fabricate oxygen sensitive polymeric nanocapsules (NCs). The location of fluorescent dyes and the fluorescent properties of the NCs were fully characterized by fourier transform infrared spectrometer, x-ray photoelectron spectrometer and fluorescent spectrum. Dye-encapsulated capacity can be precisely tuned from 0 to 1.3 wt% without self-quenching of the fluorescent dye. The crosslinked fluorinated polymer shell is not only extremely high gas permeability, but also prevents the fluorescent dyes from leakage in aqueous as well as in various organic solvents, such as ethanol, acetone and tetrahydrofuran (THF). An optical DO sensor based on the oxygen sensitive NCs was fabricated, showing high sensitivity, short response time, full reversibility, and long-term operational stability of online monitoring DO. The sensitivity of the optical DO sensor is 7.02 (the ratio of the response value in fully deoxygenated and saturated oxygenated water) in the range 0.96-14.16 mg l-1 and the response time is about 14.3 s. The sensor’s work curve was fit well using the modified Stern-Volmer equation by two-site model, and its response values are hardly affected by pH ranging from 2 to 12 and keep constant during continuous measurement for 3 months. It is believed that the oxygen sensitive polymeric NCs-based optical DO sensor could be particularly useful in long-term online DO monitoring in both aqueous and organic solvent systems.

  18. Accounting for product substitution in the analysis of food taxes targeting obesity.

    Science.gov (United States)

    Miao, Zhen; Beghin, John C; Jensen, Helen H

    2013-11-01

    We extend the existing literature on food taxes targeting obesity. We systematically incorporate the implicit substitution between added sugars and solid fats into a comprehensive food demand system and evaluate the effect of taxes on sugars and fats. The approach conditions how food and obesity taxes affect total calorie intake. The proposed methodology accounts for the ability of consumers to substitute leaner low-fat and low-sugar items for rich food items within the same food group. We calibrate this demand system approach using recent food intake data and existing estimates of price and income elasticities of demand. The demand system accounts for both the within-food group substitution and the substitution across these groups. Simulations of taxes on added sugars and solid fat show that the tax impact on consumption patterns is understated and the induced welfare loss is overstated when not allowing for the substitution possibilities within food groups. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Substitution between energy and classical factor inputs in the Chinese steel sector

    International Nuclear Information System (INIS)

    Smyth, Russell; Narayan, Paresh Kumar; Shi, Hongliang

    2011-01-01

    China's steel sector is the largest in the world and has been a major driving force behind China's high rate of economic growth. This sector, however, is also a major consumer of energy and, in particular, coal. As a result, the iron and steel sector in China is a major contributor to greenhouse gas emissions and other pollutants. In this article we examine the potential for inter-factor substitution between capital, energy and labor in the Chinese steel sector and find that capital and energy and energy and labor are substitutes. This result suggests that removal of price ceilings on energy would tend to reduce energy use and increase capital intensiveness. While the potential for substitution between energy and labor is less than that between energy and capital, the elasticity of substitution between energy and labor is high compared with previous findings for other countries. This fact suggests that there may be potential for substituting labor for energy, given China's abundance of labor.

  20. Effects of motexafin gadolinium on tumor oxygenation and cellular oxygen consumption

    International Nuclear Information System (INIS)

    Donnelly, E.T.; Liu, Y.; Rockwell, S.; Magda, D.

    2003-01-01

    Full text: Recent work in our laboratory showed that motexafin gadolinium (MGd, Xcytrin), a drug currently in Phase III clinical trials as an adjuvant to radiation therapy, modulates the oxygen tensions in EMT6 tumors. The median pO 2 increased from the control value of 1.5±0.4 mmHg to 7.4 ± 3.8 mmHg six hours after treatment with 40 μmol/kg MGd and the percentage of severely hypoxic readings in the tumors ( 7 plateau phase EMT6 cells in 3 mL Dulbecco's Modified Eagle's Medium supplemented with 10% dialyzed fetal bovine serum, which contains no ascorbic acid. In the absence of ascorbic acid, 100 μM MGd did not alter the cellular oxygen consumption rate for EMT6 cells significantly. Marked inhibition of cellular oxygen consumption was observed when cells were incubated with 100 μM MGd in medium supplemented with equimolar ascorbic acid (a 31.5% decrease in consumption was observed after 6 hours of treatment). The 5% mannitol vehicle solution with equimolar ascorbic acid had no discernible effect on cellular oxygen consumption. Ascorbic acid may facilitate cellular uptake of MGd via the intermediate formation of a MGd-oxalate complex. These studies suggest that changes in cellular oxygen consumption could contribute to the changes in tumor oxygenation seen after administration of MGd. These experiments were supported by Pharmacyclics and training grant T32CA09085 from the NIH (E.T.D.). We thank Dr. Raymond Russell for allowing us to use his oxygen electrode apparatus

  1. XPS and DFT study of pulsed Bi-implantation of bulk and thin-films of ZnO—The role of oxygen imperfections

    Energy Technology Data Exchange (ETDEWEB)

    Zatsepin, D.A. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620990 Yekaterinburg (Russian Federation); Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg (Russian Federation); Boukhvalov, D.W., E-mail: danil@hanyang.ac.kr [Department of Chemistry, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 04763 (Korea, Republic of); Theoretical Physics and Applied Mathematics Department, Ural Federal University, Mira Street 19, 620002 Yekaterinburg (Russian Federation); Gavrilov, N.V. [Institute of Electrophysics, Russian Academy of Sciences, Ural Branch, 620990 Yekaterinburg (Russian Federation); Kurmaev, E.Z. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620990 Yekaterinburg (Russian Federation); Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg (Russian Federation); Zhidkov, I.S. [Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg (Russian Federation)

    2016-11-30

    Highlights: • Both theory and experiment evidence similarity of patterns of Bi-implantation in surface and bulk ZnO. • In the bulk morphology of ZnO both experiment and theory demonstrate preferability of substitutional defects. • Experiment and theory also evidence the formation of bismuth nano-clustes from substitutional and interstitial defects without formation of secondary metallic phase. • Oxygen vacancies is crucial to formation of these nano-clusters. - Abstract: An atomic and electronic structure of the bulk and thin-film morphologies of ZnO were modified using pulsed Bi-ion implantation (1 × 10{sup 17} cm{sup −2} fluence, 70 min exposure under Bi-ion beam, E{sub Bi}{sup +} = 30 keV, pulsed ion-current density of not more than 0.8 mA/cm{sup 2} with a repetition rate of 12.5 Hz). The final samples were qualified by X-ray photoelectron core-level and valence band mapping spectroscopy applying ASTM materials science standard. The spectroscopy data obtained was discussed on the basis of DFT-models for Bi-embedding into ZnO host-matrices. It was established that in the case of direct Bi-impurities insertion into the employed ZnO-host for both studied morphologies neither the only “pure” Bi{sub 2}O{sub 3}-like phase nor the only “pure” Bi-metal will be preferable to appear as a secondary phase. An unfavorability of the large cluster agglomeration of Bi-impurities in ZnO-hosts has been shown and an oxygen 2s electronic states pleomorphizm was surely established.

  2. Structural and light up-conversion luminescence properties of Er3+-Yb3+-W6+ substituted Bi4Ti3O12

    Science.gov (United States)

    Bokolia, Renuka; Rai, Vineet K.; Chauhan, Lalita; Sreenivas, K.

    2016-05-01

    The structural and light up-conversion (UC) luminescence properties of W6+ substituted Bi3.79Er0.03Yb0.18Ti3-xWxO12 (0 ≤ x ≤ 0.10) ceramics prepared by solid state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of single phase material with orthorhombic structure. A decrease in the lattice parameters and unit cell volume is observed with increasing W content. Strong UC luminescence at 527, 548 and 662 nm is seen under an excitation of 980 nm for an optimum W content (x = 0.06) and is attributed to the transitions 2H11/2 →4I15/2, 4S3/2 →4I15/2 and 4F9/2 →4I15/2 respectively. The improved UC luminescence is ascribed to the reduced defects such as oxygen vacancies and change in the crystal field around Er3+ ions due to B-site (Ti4+) substitution with W6+ ions. Enhanced UC emission is observed for an optimum content of w6+ in the prepared composition Bi3.79Er0.03Yb0.18Ti3-xWxO12 for x = 0.06.

  3. Minority anion substitution by Ni in ZnO

    CERN Document Server

    Pereira, Lino Miguel da Costa; Correia, João Guilherme; Amorim, Lígia Marina; Silva, Daniel José; David-Bosne, Eric; Decoster, Stefan; da Silva, Manuel Ribeiro; Temst, Kristiaan; Vantomme, André

    2013-01-01

    We report on the lattice location of implanted Ni in ZnO using the $\\beta$− emission channeling technique. In addition to the majority substituting for the cation (Zn), a significant fraction of the Ni atoms occupy anion (O) sites. Since Ni is chemically more similar to Zn than it is to O, the observed O substitution is rather puzzling. We discuss these findings with respect to the general understanding of lattice location of dopants in compound semiconductors. In particular, we discuss potential implications on the magnetic behavior of transition metal doped dilute magnetic semiconductors.

  4. Preparation and Reaction Chemistry of Novel Silicon-Substituted 1,3-Dienes

    Directory of Open Access Journals (Sweden)

    Partha P. Choudhury

    2015-09-01

    Full Text Available 2-Silicon-substituted 1,3-dienes containing non transferrable groups known to promote transmetallation were prepared by Grignard chemistry and enyne metathesis. These dienes participated in one pot metathesis/Diels-Alder reactions in regio- and diastereoselective fashions. Electron-rich alkenes showed the fastest rates in metathesis reactions, and ethylene, a commonly used metathesis promoter slowed enyne metathesis. 2-Pyridyldimethylsilyl and 2-thienyldimethylsilyl substituted Diels-Alder cycloadducts participated in cross-coupling chemistry and the 2-thienyldimethylsilyl substituted cycloadducts underwent cross-coupling under very mild reaction conditions.

  5. Eight Ways to Make Sure Substitute Teachers Aren't Baby-Sitters.

    Science.gov (United States)

    Drury, William R.

    1988-01-01

    Substitutes might never be as good as regular teachers, but they still can provide high-quality instruction. Suggestions include meeting with them as a group twice a year, principal and peer support, and development workshops specifically for substitutes. (TE)

  6. Effect of Ca substitution on the electrochemical properties of the Ruddlesden-Popper oxides Sr3.2-xCaxLn0.8Fe1.5Co1.5O10-δ

    Science.gov (United States)

    Padmasree, K. P.; Lai, Ke-Yu; Kaveevivitchai, Watchareeya; Manthiram, Arumugam

    2018-01-01

    The Ruddlesden-Popper (R-P) oxides Sr3.2-xCaxLn0.8Fe1.5Co1.5O10-δ with x = 0 and 0.4 and Ln = La, Pr, and Nd, have been synthesized and the effect of Ca on their electrochemical properties as cathodes in solid oxide fuel cells (SOFC) has been investigated. The substitution of Ca for Sr in Sr3.2-xCaxLn0.8Fe1.5Co1.5O10-δ decreases the amount of oxygen loss on heating and the thermal expansion coefficient (TEC). The phase instability of these materials at high temperature is a significant issue that restricts their application as SOFC cathodes, and the substitution of Ca effectively stabilizes the Sr3.2-xCaxLn0.8Fe1.5Co1.5O10-δ phase at 800 °C. Among the different lanthanides with and without Ca in Sr3.2-xCaxLn0.8Fe1.5Co1.5O10-δ, the Ln = Nd samples exhibit an enhancement in cathode performance in SOFC compared to Ln = La and Pr samples, which may be attributed to the higher concentration of oxygen vacancies in the Ln = Nd samples. Comparing the various compositions studied, the Sr2.8Ca0.4Nd0.8Fe1.5Co1.5O10-δ cathode material exhibits superior performance in SOFC with good phase stability.

  7. Conceptual approach to the development of an active process of import substitution

    Directory of Open Access Journals (Sweden)

    Yu. A. Salikov

    2018-01-01

    Full Text Available In the current political and economic situation, the process of import substitution is of particular importance. Modern processes of social globalization involve the expansion of cooperation and integration of all levels and types of social production. However, there is a risk of increasing risks in the areas of economic and defense security, openness of new technologies, consumer (food and commodity dependence, that is, increasing the risk of loss of stability of the socio-economic system. It is obvious that the main strategic objectives for socio-economic systems are different for each hierarchical level. At the macroeconomic level, these tasks are related not only to the formation of a system of priorities and incentives for the reorientation of the national reproductive complex to the production of import-substituting products, but also to the development of an institutional framework for initiating and launching import-substitution processes.. Import substitution is an active process of replacing imported goods with domestic analogues. It is important to note that for the Russian Federation import substitution is forced, because the beginning of the policy of substitution of foreign goods for goods produced domestically against Russia was introduced a number of trade and economic sanctions imposed by the countries of Europe and the United States. In addition, it should be emphasized that the process of import substitution in the domestic economy should a priori have realistic and objectively marked borders, as the the task of ensuring that excessive (as a limit – one hundred percent of replacement itself is not only achievable in principle, but requiring undue effort and material costs, can cause considerable damage to the national economy. The analysis of the theories of foreign direct investment. The scheme of construction of production on the basis of active import substitution was built. Thus, it is necessary to note the importance of

  8. Mutations of different molecular origins exhibit contrasting patterns of regional substitution rate variation.

    Directory of Open Access Journals (Sweden)

    Navin Elango

    2008-02-01

    Full Text Available Transitions at CpG dinucleotides, referred to as "CpG substitutions", are a major mutational input into vertebrate genomes and a leading cause of human genetic disease. The prevalence of CpG substitutions is due to their mutational origin, which is dependent on DNA methylation. In comparison, other single nucleotide substitutions (for example those occurring at GpC dinucleotides mainly arise from errors during DNA replication. Here we analyzed high quality BAC-based data from human, chimpanzee, and baboon to investigate regional variation of CpG substitution rates. We show that CpG substitutions occur approximately 15 times more frequently than other single nucleotide substitutions in primate genomes, and that they exhibit substantial regional variation. Patterns of CpG rate variation are consistent with differences in methylation level and susceptibility to subsequent deamination. In particular, we propose a "distance-decaying" hypothesis, positing that due to the molecular mechanism of a CpG substitution, rates are correlated with the stability of double-stranded DNA surrounding each CpG dinucleotide, and the effect of local DNA stability may decrease with distance from the CpG dinucleotide.Consistent with our "distance-decaying" hypothesis, rates of CpG substitution are strongly (negatively correlated with regional G+C content. The influence of G+C content decays as the distance from the target CpG site increases. We estimate that the influence of local G+C content extends up to 1,500 approximately 2,000 bps centered on each CpG site. We also show that the distance-decaying relationship persisted when we controlled for the effect of long-range homogeneity of nucleotide composition. GpC sites, in contrast, do not exhibit such "distance-decaying" relationship. Our results highlight an example of the distinctive properties of methylation-dependent substitutions versus substitutions mostly arising from errors during DNA replication. Furthermore

  9. Oxygen Association-Dissociation and Stability Analysis on Mouse Hemoglobins with Mutant α- and β-Globins

    Science.gov (United States)

    D'Surney, S. J.; Popp, R. A.

    1992-01-01

    Oxygen association-dissociation and hemoglobin stability analysis were performed on mouse hemoglobins with amino acid substitutions in an α-globin (α89, His to Leu) and a β-globin (β59, Lys to Ile). The variant α-globin, designated chain 5(m) in the Hba(g2) haplotype, had a high oxygen affinity and was stable. The variant β-globin, (β(s2)) of the Hbb(s2) haplotype, also had an elevated oxygen affinity and in addition was moderately unstable in 19% isopropanol. Hemoglobins from the expected nine (Hba(g2)/Hba(g2);Hbb(s)/Hbb(s) X Hba(a)/Hba(a);Hbb(s2)/Hbb(s2)) F(2) genotypes can be grouped into five classes of P(50) values characterized by strict additivity and dependency on mutant globin gene dosage; physiologically, both globin variants gave indistinguishable effects on oxygen affinity. The hemoglobin of normal mice (Hba(a)/Hba(a);Hbb(s)/Hbb(s)) had a P(50) = 40 mm Hg and the hemoglobin of Hba(g2)/Hba(g2);Hbb(s2)/Hbb(s2) F(2) mice had a P(50) = 25 mm Hg (human P(50) = 26 mm Hg). Peripheral blood from Hba(g2)/Hba(g2);Hbb(s)/Hbb(s), Hba(a)/Hba(a);Hbb(s2)/Hbb(s2) and Hba(g2)/Hba(g2);Hbb(s2)/Hbb(s2) mice exhibited normal hematological values except for a slightly higher hematocrit for Hba(g2)/Hba(g2);Hbb(s)/Hbb(s) and Hba(g2)/Hba(g2);Hbb(s2)/Hbb(s2) mice, slightly elevated red cell counts for mice of the three mutant genotypes, and significantly lower values for the mean corpuscular volume and mean corpuscular hemoglobin for Hba(g2)/Hba(g2);Hbb(s2)/Hbb(s2) mice. PMID:1427042

  10. Internal-reference solid-electrolyte oxygen sensor

    International Nuclear Information System (INIS)

    Haaland, D.M.

    1977-01-01

    A new solid-electrolyte oxygen sensor has been developed that eliminates the conventional oxygen reference in previous solid-electrolyte oxygen sensor designs and is, therefore, ideally suited as an insertion device for remote oxygen monitoring applications. It is constructed with two cells of stabilized zirconia sealed into a small unit using a new high-temperature platinum-zirconia seal. One electrochemical cell monitors the ratio of oxygen partial pressures inside and outside the sensor while the other solid-electrolyte cell is used for quantitative electrochemical pumping of oxygen. The internal oxygen reference is generated by initially pumping all oxygen out of the known internal volume of the sensor and then quantitatively pumping oxygen back in until oxygen partial pressures are equal inside and out. This information is used with the ideal gas law to calculate oxygen partial pressures. Tests were conducted from 400 to 1000 0 C in mixtures of oxygen and nitrogen spanning approximately 0.2 to 21 percent oxygen concentration range. Sensors with sputtered platinum and porous platinum paste electrodes were compared

  11. Alkyl Substitution Effect on Oxidation Stability of Sulfone-Based Electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Su, Chi-Cheung [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; He, Meinan [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Redfern, Paul [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Curtiss, Larry A. [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Liao, Chen [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Zhang, Lu [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Burrell, Anthony K. [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA; Zhang, Zhengcheng [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Argonne IL 60439 USA

    2016-02-16

    Organic sulfone compounds have been widely used as high-voltage electrolytes for lithium-ion batteries for decades. However, owing to the complexity of the synthesis of new sulfones, only a few commercially available sulfones have been studied. In this paper, we report the synthesis of new sulfone compounds with various substituent groups and the impact of the substituent group on the oxidation stability of sulfones. Electrochemical floating tests using a 5 V LiNi0.5Mn1.5O4 spinel cathode and density functional theory calculations showed that the cyclopentyl-substituted sulfone McPS suffered from oxidation instability, starting from 4.9 V versus Li+/Li, as observed by the large leakage currents. On the other hand, the isopropyl-substituted sulfone MiPS and tetramethylene substituted sulfone TMS showed much improved oxidation stability under identical testing conditions. The substitution structure of the sulfone plays a significant role in the determination of its oxidative stability and should first be considered for the development of new sulfone-based electrolytes for high-voltage, high-energy lithium-ion batteries.

  12. Effect of oxygen incorporation on the structure and elasticity of Ti-Al-O-N coatings synthesized by cathodic arc and high power pulsed magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Hans, M., E-mail: hans@mch.rwth-aachen.de; Baben, M. to; Music, D.; Ebenhöch, J.; Schneider, J. M. [Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Primetzhofer, D. [Department of Physics and Astronomy, Uppsala University, Lägerhyddsvägen 1, S-75120 Uppsala (Sweden); Kurapov, D.; Arndt, M.; Rudigier, H. [Oerlikon Balzers Coating AG, Iramali 18, LI-9496 Balzers, Principality of Liechtenstein (Liechtenstein)

    2014-09-07

    Ti-Al-O-N coatings were synthesized by cathodic arc and high power pulsed magnetron sputtering. The chemical composition of the coatings was determined by means of elastic recoil detection analysis and energy dispersive X-ray spectroscopy. The effect of oxygen incorporation on the stress-free lattice parameters and Young's moduli of Ti-Al-O-N coatings was investigated by X-ray diffraction and nanoindentation, respectively. As nitrogen is substituted by oxygen, implications for the charge balance may be expected. A reduction in equilibrium volume with increasing O concentration is identified by X-ray diffraction and density functional theory calculations of Ti-Al-O-N supercells reveal the concomitant formation of metal vacancies. Hence, the oxygen incorporation-induced formation of metal vacancies enables charge balancing. Furthermore, nanoindentation experiments reveal a decrease in elastic modulus with increasing O concentration. Based on ab initio data, two causes can be identified for this: First, the metal vacancy-induced reduction in elasticity; and second, the formation of, compared to the corresponding metal nitride bonds, relatively weak Ti-O and Al-O bonds.

  13. Effect of oxygen incorporation on the structure and elasticity of Ti-Al-O-N coatings synthesized by cathodic arc and high power pulsed magnetron sputtering

    International Nuclear Information System (INIS)

    Hans, M.; Baben, M. to; Music, D.; Ebenhöch, J.; Schneider, J. M.; Primetzhofer, D.; Kurapov, D.; Arndt, M.; Rudigier, H.

    2014-01-01

    Ti-Al-O-N coatings were synthesized by cathodic arc and high power pulsed magnetron sputtering. The chemical composition of the coatings was determined by means of elastic recoil detection analysis and energy dispersive X-ray spectroscopy. The effect of oxygen incorporation on the stress-free lattice parameters and Young's moduli of Ti-Al-O-N coatings was investigated by X-ray diffraction and nanoindentation, respectively. As nitrogen is substituted by oxygen, implications for the charge balance may be expected. A reduction in equilibrium volume with increasing O concentration is identified by X-ray diffraction and density functional theory calculations of Ti-Al-O-N supercells reveal the concomitant formation of metal vacancies. Hence, the oxygen incorporation-induced formation of metal vacancies enables charge balancing. Furthermore, nanoindentation experiments reveal a decrease in elastic modulus with increasing O concentration. Based on ab initio data, two causes can be identified for this: First, the metal vacancy-induced reduction in elasticity; and second, the formation of, compared to the corresponding metal nitride bonds, relatively weak Ti-O and Al-O bonds

  14. Non-self-sustained electric discharge in oxygen gas mixtures: singlet delta oxygen production

    CERN Document Server

    Ionin, A A; Kotkov, A A; Kochetov, I V; Napartovich, A P; Seleznev, L V; Sinitsyn, D V; Hager, G D

    2003-01-01

    The possibility of obtaining a high specific input energy in an electron-beam sustained discharge ignited in oxygen gas mixtures O sub 2 : Ar : CO (or H sub 2) at the total gas pressures of 10-100 Torr was experimentally demonstrated. The specific input energy per molecular component exceeded approx 6 kJ l sup - sup 1 atm sup - sup 1 (150 kJ mol sup - sup 1) as a small amount of carbon monoxide was added into a gas mixture of oxygen and argon. It was theoretically demonstrated that one might expect to obtain a singlet delta oxygen yield of 25% exceeding its threshold value needed for an oxygen-iodine laser operation at room temperature, when maintaining a non-self-sustained discharge in oxygen gas mixtures with molecular additives CO, H sub 2 or D sub 2. The efficiency of singlet delta oxygen production can be as high as 40%.

  15. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    2011-05-01

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  16. Oxygen Tension in the Aqueous Humor of Human Eyes under Different Oxygenation Conditions

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    Farideh Sharifipour

    2013-01-01

    Full Text Available Purpose: To measure oxygen tension in the aqueous humor of human eyes under different oxygenation conditions. Methods: This prospective comparative interventional case series consisted of two parts. In the first part, 120 consecutive patients scheduled for cataract surgery were randomized into group I (control group in which surgery was performed under local anesthesia inhaling 21% oxygen; group II in whom general anesthesia using 50% oxygen was employed; and group III receiving general anesthesia with 100% oxygen. After aspirating 0.2 ml aqueous humor under sterile conditions, the aqueous sample and a simultaneously drawn arterial blood sample were immediately analyzed using a blood gas analyzer. In part II the same procedures were performed in 10 patients after fitting a contact lens and patching the eye for 20 minutes (group IV and in 10 patients after transcorneal delivery of oxygen at a flow rate of 5 L/min (group V. Results: Mean aqueous PO2 in groups I, II and III was 112.3±6.2, 141.1±20.4, and 170.1±27 mmHg, respectively (P values <0.001 and mean arterial PO2 was 85.7±7.9, 184.6±46, and 379.1±75.9 mmHg, respectively (P values <0.001. Aqueous PO2 was 77.2±9.2 mmHg in group IV and 152.3±10.9 mmHg in group V (P values <0.001. There was a significant correlation between aqueous and blood PO2 (r=0.537, P<0.001. The contribution of atmospheric oxygen to aqueous PO2 was 23.7%. Conclusion: Aqueous oxygen tension is mostly dependent on the systemic circulation and in part on the atmosphere. Increasing inspiratory oxygen and transcorneal oxygen delivery both increase aqueous PO2 levels.

  17. Impacts of Vehicle Weight Reduction via Material Substitution on Life-Cycle Greenhouse Gas Emissions.

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    Kelly, Jarod C; Sullivan, John L; Burnham, Andrew; Elgowainy, Amgad

    2015-10-20

    This study examines the vehicle-cycle and vehicle total life-cycle impacts of substituting lightweight materials into vehicles. We determine part-based greenhouse gas (GHG) emission ratios by collecting material substitution data and evaluating that alongside known mass-based GHG ratios (using and updating Argonne National Laboratory's GREET model) associated with material pair substitutions. Several vehicle parts are lightweighted via material substitution, using substitution ratios from a U.S. Department of Energy report, to determine GHG emissions. We then examine fuel-cycle GHG reductions from lightweighting. The fuel reduction value methodology is applied using FRV estimates of 0.15-0.25, and 0.25-0.5 L/(100km·100 kg), with and without powertrain adjustments, respectively. GHG breakeven values are derived for both driving distance and material substitution ratio. While material substitution can reduce vehicle weight, it often increases vehicle-cycle GHGs. It is likely that replacing steel (the dominant vehicle material) with wrought aluminum, carbon fiber reinforced plastic (CRFP), or magnesium will increase vehicle-cycle GHGs. However, lifetime fuel economy benefits often outweigh the vehicle-cycle, resulting in a net total life-cycle GHG benefit. This is the case for steel replaced by wrought aluminum in all assumed cases, and for CFRP and magnesium except for high substitution ratio and low FRV.

  18. Application of queuing theory in inventory systems with substitution flexibility

    Science.gov (United States)

    Seyedhoseini, S. M.; Rashid, Reza; Kamalpour, Iman; Zangeneh, Erfan

    2015-03-01

    Considering the competition in today's business environment, tactical planning of a supply chain becomes more complex than before. In many multi-product inventory systems, substitution flexibility can improve profits. This paper aims to prepare a comprehensive substitution inventory model, where an inventory system with two substitute products with ignorable lead time has been considered, and effects of simultaneous ordering have been examined. In this paper, demands of customers for both of the products have been regarded as stochastic parameters, and queuing theory has been used to construct a mathematical model. The model has been coded by C++, and it has been analyzed due to a real example, where the results indicate efficiency of proposed model.

  19. Challenges of therapeutic substitution of drugs for economic reasons: focus on CVD prevention.

    Science.gov (United States)

    Johnston, Atholl

    2010-04-01

    Healthcare systems throughout the world are under increasing pressure to control and minimise costs. The substitution of initially-prescribed drugs with cheaper equivalents is an obvious option which presents a rapid and visible means to reduce these costs. Whether the substitution improves patient and/or population outcomes must be appraised and this paper highlights the conditions under which therapeutic substitution may require additional thought and consideration. In this paper, some of the medical evidence and the regulatory environment for and against the three types of therapeutic substitution - generic, within-class and between-class - are discussed. This article is not an exhaustive review of the literature, but captures some of the key clinical, pharmacological, economic, policy and ethical issues regarding generic and therapeutic substitution. Search criteria of the most commonly used terms, i.e. therapeutic substitution, switching, interchange, and bioequivalence, were applied to Embase, PubMed and Google Scholar to identify relevant publications. Although population studies support therapeutic substitution in principle, there is evidence that substitution may not always result in therapeutic equivalence in individual patients, with the consequent potential for greater risks of decreased efficacy and/or increased safety concerns. Factors such as patient choice and therapeutic equivalence also play an important role in the effectiveness of the treatment and overall management of the patient. The pan-European regulatory environment provides another contradiction, encouraging widespread cost containment through reduction in drug acquisition costs, while simultaneously promoting an increased role for patients in defining and managing their own treatment. There is a strong rationale for careful management in some patients with cardiovascular disease. Treatment decisions should be transparent and based on strong clinical evidence. If not, drug substitution on

  20. A Low-Pressure Oxygen Storage System for Oxygen Supply in Low-Resource Settings.

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    Rassool, Roger P; Sobott, Bryn A; Peake, David J; Mutetire, Bagayana S; Moschovis, Peter P; Black, Jim Fp

    2017-12-01

    Widespread access to medical oxygen would reduce global pneumonia mortality. Oxygen concentrators are one proposed solution, but they have limitations, in particular vulnerability to electricity fluctuations and failure during blackouts. The low-pressure oxygen storage system addresses these limitations in low-resource settings. This study reports testing of the system in Melbourne, Australia, and nonclinical field testing in Mbarara, Uganda. The system included a power-conditioning unit, a standard oxygen concentrator, and an oxygen store. In Melbourne, pressure and flows were monitored during cycles of filling/emptying, with forced voltage fluctuations. The bladders were tested by increasing pressure until they ruptured. In Mbarara, the system was tested by accelerated cycles of filling/emptying and then run on grid power for 30 d. The low-pressure oxygen storage system performed well, including sustaining a pressure approximately twice the standard working pressure before rupture of the outer bag. Flow of 1.2 L/min was continuously maintained to a simulated patient during 30 d on grid power, despite power failures totaling 2.9% of the total time, with durations of 1-176 min (mean 36.2, median 18.5). The low-pressure oxygen storage system was robust and durable, with accelerated testing equivalent to at least 2 y of operation revealing no visible signs of imminent failure. Despite power cuts, the system continuously provided oxygen, equivalent to the treatment of one child, for 30 d under typical power conditions for sub-Saharan Africa. The low-pressure oxygen storage system is ready for clinical field trials. Copyright © 2017 by Daedalus Enterprises.