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Sample records for cubic nacl type

  1. DO3-type cubic structure of nonstoichiometric vanadium monoxide

    NASA Astrophysics Data System (ADS)

    Davydov, D. A.; Gusev, A. I.

    2010-03-01

    An X-ray diffraction study indicates that nonstoichiometric vanadium monoxide VO y ≡ V x O z ( y = z/x) has a cubic structure of the DO3 type (space group Fm bar 3 m), where vanadium atoms are not only at the 4( a) sites of the metal fcc sublattice, but also at the tetrahedral 8( c) sites. This circumstance fundamentally distinguishes monoxide VO y from strongly nonstoichiometric MX y compounds with the B1 structure and the same space group, where atoms M and X and structural vacancies ▪ and ▭ of the metal and nonmetal sublattices, respectively, are distributed over the 4( a) and 4( b) sites. The dependence of the filling factor q of the tetrahedral interstices by vanadium atoms on the relative content y of oxygen in VO y has been obtained. It has been shown that the composition of cubic vanadium monoxide should be represented as VO y ≡ V x O z ≡ V x - 2 q V{2/q ( t)}▪1 - x + 2 q O z ▭1 - z , taking into account the structure.

  2. Bonding in scandium monosulfide a NaCl crystal type

    SciTech Connect

    Merrick, J.A.

    1980-08-01

    The transition temperature of an order-disorder transition in Sc/sub 0/ /sub 81/S (R anti 3m to Fm3m) occurs at 700/sup 0/C. A group of ordered sublattices on the NaCl-type lattice (Fm3m) was generated and a Madelung energy and configurational entropy were calculated for each sublattice assuming the ions to be Sc/sup 2/ /sup 48 +/ and S/sup 2 -/. Mean field and pair interaction approximations were used to model long-range and short-range orderings, respectively. The electrostatic model fails to predict the observed short-range and long-range orderings. The high temperature vaporization of ScP was investigated by mass spectrometry and target collection Knudsen effusion at 1767 to 2209K. The composition ScP/sub 1/ /sub 00/ vaporizes congruently to the gaseous species Sc, P, and P/sub 2/. A temperature independent third law enthalpy of atomization (..delta..H/sup 0//sub atom,298/ = 252.2 +- 2.8 kcal mole/sup -1/) has a value approx. 12 kcal larger than that reported for ScS. Nonrelativistic, nonself-consistent LAPW band structure calculations are reported for ScS. XPS and UPS measurements are reported for Sc/sub 2/S/sub 3/ and several compositions Sc/sub 1-x/S (0.0 less than or equal to x less than or equal to 0.2). The Sc and S 2p binding energies (XPS) obtained for the defect scandium monosulfides are very close to those found in the pure elements, suggesting covalent bonding. The Sc 2p energy region has an interesting satellite structure.

  3. Antisolvent crystallization of NaCl using the minute-bubble technique - Effects of different antisolvent types

    NASA Astrophysics Data System (ADS)

    Wada, Yoshinari; Matsumoto, Masakazu; Onoe, Kaoru

    2016-08-01

    To develop a crystallization technique that enables the control of the crystal size distribution, antisolvent crystallization of sodium chloride (NaCl) under a continuous supply of N2 minute-bubbles was performed. The effects of the additive volume ratio of ethanol (EtOH) on the molar yield and size distribution of the NaCl crystals and the effects of the antisolvent type on crystallization phenomena of NaCl were examined. The initial concentration of NaCl in the saturated solution was set at 5.54 mol/l, and EtOH was added as an antisolvent to the saturated NaCl solution, where the added volume ratio of EtOH was in the range of 5 to 50 vol% (as EtOH/NaCl system). As a comparison, the antisolvent crystallization phenomenon of NaCl in a MeOH/NaCl system was also investigated. N2 minute-bubbles with an average bubble size of 40 μm were continuously supplied to the NaCl supersaturated solution using a self-supporting bubble generator, and NaCl was crystallized. Consequently, the production enhancement and crystal size minimization of NaCl were caused by the residence of minute-bubbles because of the acceleration of nucleation and the inhibition of crystal coalescence. Moreover, the results indicated that the enhancement effect of NaCl crystal production and the minimizing effect of average crystal size depended on the additive volume and the type of alcohol as antisolvent.

  4. Radium geochemistry in Na-Cl type groundwater in Niigata Prefecture, Japan.

    PubMed

    Tomita, Junpei; Satake, Hiroshi; Fukuyama, Taijiro; Sasaki, Keiichi; Sakaguchi, Aya; Yamamoto, Masayoshi

    2010-03-01

    Radium isotopes in 23 Na-Cl type groundwater sampled mainly from deep wells in Niigata Prefecture, which is the site of the largest oil- and gas-fields in Japan, were measured along with U isotopes, chemical components and hydrogen and oxygen isotope ratios to elucidate the distribution and behavior of Ra in a brackish environment underground. Also analyzed were U and Th isotopes in 38 rock samples collected from outcrops at 17 locations. Ra-226 concentrations (8.86-1637 mBq kg(-1)) of groundwater samples roughly correlated with total dissolved solid (TDS) concentrations and other alkaline earth contents. Their (228)Ra/(226)Ra activity ratios (0.32-5.2) were similar to or higher than the (232)Th/(238)U activity ratios (0.6-1.7) in the rocks. The most likely transport mechanism of Ra isotopes into groundwater was due to their alpha-recoil from the solid phase, probably from the water-rock interface where Th isotopes had accumulated, and adsorption/desorption reaction based on the increase in (226)Ra contents with TDS.

  5. Modeling of type-2 fuzzy cubic B-spline surface for flood data problem in Malaysia

    NASA Astrophysics Data System (ADS)

    Bidin, Mohd Syafiq; Wahab, Abd. Fatah

    2017-08-01

    Malaysia possesses a low and sloping land areas which may cause flood. The flood phenomenon can be analyzed if the surface data of the study area can be modeled by geometric modeling. Type-2 fuzzy data for the flood data is defined using type-2 fuzzy set theory in order to solve the uncertainty of complex data. Then, cubic B-spline surface function is used to produce a smooth surface. Three main processes are carried out to find a solution to crisp type-2 fuzzy data which is fuzzification (α-cut operation), type-reduction and defuzzification. Upon conducting these processes, Type-2 Fuzzy Cubic B-Spline Surface Model is applied to visualize the surface data of the flood areas that are complex uncertainty.

  6. Phytantriol-based inverted type bicontinuous cubic phase for vascular embolization and drug sustained release.

    PubMed

    Han, Ke; Pan, Xin; Chen, Meiwan; Wang, Rongchang; Xu, Yuehong; Feng, Min; Li, Ge; Huang, Min; Wu, Chuanbin

    2010-12-23

    The potential feasibility of using phytantriol-based inverted type bicontinuous cubic phase as an embolization agent and sustained release system was evaluated in this study. In the ternary phytantriol-water-ethanol system, when water content was less than 30% (w/w), the injectable isotropic solution was formed and could transform into the bicontinuous cubic phase upon contacting the dissolution/body fluids. The transformation of the isotropic solution was confirmed by polarized light microscopy (PLM), small angle X-ray scattering (SAXS), resonance Raman spectroscopy, and rheological measurements. The in vitro dissolution results showed that the release was sustained for up to 30 days and was affected by drug loading and the initial compositions of isotropic solutions. In vivo, the embolization study was performed with normal rabbits using transcatheter arterial embolization technique and was monitored under digital subtraction angiography (DSA). The angiographical results showed that the hepatic artery was successfully embolized with phytantriol cubic phase. Therefore, with the vascular embolization and sustained release characteristics, the phytantriol-based inverted type bicontinuous cubic phase could be used for arterial transcatheter chemoembolization on hepatocellular carcinoma. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Magnetic and structural transitions in crystals with a structure of the NaCl type

    NASA Astrophysics Data System (ADS)

    Kassan-Ogly, F. A.; Filippov, B. N.

    2009-04-01

    A model of simultaneous magnetic and structural first-order transitions in antiferromagnets with a strong cubic magnetic anisotropy has been constructed on the basis of a synthesis of magnetic modified 6-state and 8-state Potts models and the theoretical model of structural phase transitions in cubic crystals. A revised scheme has been suggested for the derivation of possible magnetic structures in the fcc lattice with allowance for competing interactions between the nearest and next-nearest neighbors. A calculation of the temperature evolution of high-temperature diffuse magnetic scattering of neutrons has been carried out to show that the mechanism of a magnetic transition at the Néel point is caused by the transformation of diffuse magnetic scattering into magnetic Bragg peaks.

  8. Generating Erler-Schnabl-type solution for the tachyon vacuum in cubic superstring field theory

    NASA Astrophysics Data System (ADS)

    Aldo Arroyo, E.

    2010-11-01

    We study a new set of identity-based solutions to analyze the problem of tachyon condensation in open bosonic string field theory and cubic superstring field theory. Even though these identity-based solutions seem to be trivial, it turns out that after performing a suitable gauge transformation, we are left with the known Erler-Schnabl-type solutions which correctly reproduce the value of the D-brane tension. This result shows explicitly that a seemingly trivial solution can generate a non-trivial configuration which precisely represents the tachyon vacuum.

  9. Low pH-Induced Pore Formation by the T Domain of Botulinum Toxin Type A is Dependent upon NaCl Concentration

    SciTech Connect

    Lai, B.; Swaminathan, S.; Agarwal, R.; Nelson, L. D.; London, E.

    2010-07-19

    Botulinum neurotoxins (BoNTs) undergo low pH-triggered membrane insertion, resulting in the translocation of their light (catalytic) chains into the cytoplasm. The T (translocation) domain of the BoNT heavy chain is believed to carry out translocation. Here, the behavior of isolated T domain from BoNT type A has been characterized, both in solution and when associated with model membranes. When BoNT T domain prepared in the detergent dodecylmaltoside was diluted into aqueous solution, it exhibited a low pH-dependent conformational change below pH 6. At low pH the T domain associated with, and formed pores within, model membrane vesicles composed of 30 mol% dioleoylphosphatidylglycerol/70 mol% dioleoylphosphatidylcholine. Although T domain interacted with vesicles at low (50 mM) and high (400 mM) NaCl concentrations, the interaction required much less lipid at low salt. However, even at high lipid concentrations pore formation was much more pronounced at low NaCl concentrations than at high NaCl concentration. Increasing salt concentration after insertion in the presence of 50 mM NaCl did not decrease pore formation. A similar effect of NaCl concentration upon pore formation was observed in vesicles composed solely of dioleoylphosphatidylcholine, showing that the effect of NaCl did not solely involve modulation of electrostatic interactions between protein and anionic lipids. These results indicate that some feature of membrane-bound T domain tertiary structure critical for pore formation is highly dependent upon salt concentration.

  10. Effects of low NaNO2 and NaCl concentrations on Listeria monocytogenes growth in emulsion-type sausage

    PubMed Central

    Lee, Jeeyeon; Gwak, Eunji; Lee, Heeyoung; Ha, Jimyeong; Lee, Soomin; Kim, Sejeong; Oh, Mi-Hwa; Park, Beom-Young; Choi, Kyoung-Hee; Yoon, Yohan

    2017-01-01

    Objective The objective of this study was to evaluate the effect of combinations of NaNO2 and NaCl concentrations on Listeria monocytogenes (L. monocytogenes) growth in emulsion-type sausage. Methods Emulsion-type sausages formulated with different combinations of NaNO2 (0 and 10 ppm) and NaCl (1.00%, 1.25%, and 1.50%) were inoculated with a five-strain L. monocytogenes mixture, and stored at 4°C, 10°C, and 15°C, under aerobic or vacuum conditions. L. monocytogenes cell counts were measured at appropriate intervals, and kinetic parameters such as growth rate and lag phase duration (LPD) were calculated using the modified Gompertz model. Results Growth rates increased (0.004 to 0.079 Log colony-forming unit [CFU]/g/h) as storage temperature increased, but LPD decreased (445.11 to 8.35 h) as storage temperature and NaCl concentration increased. The effect of combinations of NaCl and low-NaNO2 on L. monocytogenes growth was not observed at 4°C and 10°C, but it was observed at 15°C, regardless of atmospheric conditions. Conclusion These results indicate that low concentrations of NaNO2 and NaCl in emulsion-type sausage may not be sufficient to prevent L. monocytogenes growth, regardless of whether they are vacuum-packaged and stored at low temperatures. Therefore, additional techniques are necessary for L. monocytogenes control in the product. PMID:27739291

  11. Multiharmonic cubic-nonlinear theory of plasma-beam superheterodyne free-electron lasers of the dopplertron type

    SciTech Connect

    Kulish, V. V.; Lysenko, A. V.; Koval, V. V.

    2010-12-15

    A multiharmonic cubic-nonlinear theory of a plasma-beam superheterodyne free-electron laser of the dopplertron type is constructed. A retarded electromagnetic wave propagating in the magnetized plasma-beam system toward the electron beam is used for pumping. The multiharmonic interaction of waves which plays an important role is taken into account. Saturation levels and mechanisms are analyzed. The promising application of such systems for generating high-power electromagnetic radiation in the millimeter wavelength range is demonstrated.

  12. Effect of the introduction of oxide ion vacancies into cubic fluorite-type rare earth oxides on the NO decomposition catalysis

    SciTech Connect

    Masui, Toshiyuki; Nagai, Ryosuke; Imanaka, Nobuhito

    2014-12-15

    Cubic fluorite-type solid solutions based on Pr{sub 6}O{sub 11} and CeO{sub 2} were synthesized and oxide anion vacancies were intentionally introduced into the cubic fluorite-type lattice through the charge compensating mechanism by Mg{sup 2+} and/or Ca{sup 2+} doping into their lattices. The oxide anion vacancies bring about positive effect on NO decomposition catalysis. The reason for the increase in the catalytic activity was attributed to defect fluorite-type structures close to the C-type cubic one, because C-type cubic rare earth oxides, in which one-quarter of the oxygen atoms in the fluorite-type structure are removed, show high NO decomposition activity. In particular, the positive effect of the formation of oxide anion vacancies was significant for Pr{sub 6}O{sub 11} and its solid solutions, because the molar volume of Pr{sub 6}O{sub 11} is larger than that of CeO{sub 2}, and Pr{sub 6}O{sub 11} contains Pr{sup 3+} as well as Pr{sup 4+} and thereby a small amount of oxide anion vacancies exist inherently in the lattice. - Graphical abstract: Oxide anion vacancies intentionally introduced into the cubic fluorite-type lattice bring about positive effect on NO decomposition catalysis. - Highlights: • Cubic fluorite-type solid solutions were synthesized. • Oxide anion vacancies were intentionally introduced into the cubic fluorite-type lattice. • The oxide anion vacancies bring about positive effect on NO decomposition catalysis. • The activity was enhanced by making the structure close to the C-type cubic one.

  13. Non-hamiltonian 3-connected cubic planar graphs with only two types of faces besides 4-gons

    NASA Astrophysics Data System (ADS)

    Ong, Siew-Hui; Abidin, Nornadia Zainal

    2015-10-01

    Let G(p,q,r) denote the class of all 3-connected cubic planar graphs whose faces are of only three types, namely p-gon, q-gon and r-gon. Here, we show that there exist non-hamiltonian members for the following classes of graphs: (i) G(3,4,r) for r ≥ 7, (ii) G(4,5,r) for r ≥ 8, (iii) G(4,q,r) for q ∈ {7,9,11} and r ≥ 6 and (iv) G(4,q,q + 5) and G(4,q,q + 2,q + 5) for q ≥ 5.

  14. Two cubic phases in kimzeyite garnet from the type locality Magnet Cove, Arkansas

    SciTech Connect

    Antao, Sytle M.; Cruickshank, Laura A.

    2016-11-08

    The crystal structure of an optically anisotropic kimzeyite garnet from Magnet Cove, Arkansas, USA, where it was first discovered, was refined with the Rietveld method, cubic space group, Ia\\overline 3 d, and monochromatic [λ = 0.41422 (2) Å] synchrotron high-resolution powder X-ray diffraction (HRPXRD) data. The Rietveld refinement reduced χ2and overallR(F2) values are 1.840 and 0.0647, respectively. The sample, with the general garnet formula[8]X3[6]Y2[4]Z3[4]O12, contains an intergrowth of two cubic phases that occur initially as oscillatory growth zoning, and patchy intergrowths arise later from fluid-enhanced dissolution and re-precipitation. The two compositions obtained with electron-probe microanalyses (EPMA) are Ca3.00(Zr1.31Ti4+0.46Fe3+0.22Mn3+0.01)Σ2[Al0.76Fe3+1.01Si1.23]Σ3O12for phase 1aand Ca2.99(Zr1.48Ti4+0.37Fe3+0.15)Σ2[Al0.87Fe3+0.98Si1.15]Σ3O12for phase 1b. The weight percentage, unit-cell parameter (Å), distances (Å), and site occupancy factors (s.o.f.s) for phase 1aare as follows: 42.6 (2)%,a= 12.46553 (3) Å, average <X—O> = 2.482,Y—O = 2.059 (2),Z—O = 1.761 (2) Å, Ca (Xs.o.f.) = 0.960 (4), Zr (Ys.o.f.) = 0.809 (3), and Fe (Zs.o.f.) = 0.623 (2). The corresponding values for phase 1bare 57.4 (2)%,a= 12.47691 (2) Å, average <

  15. A thermochemical explanation for the stability of NaCl3 and NaCl7

    NASA Astrophysics Data System (ADS)

    Fernandes de Farias, Robson

    2017-03-01

    Thermodynamically stable cubic and orthorhombic NaCl3 as well as NaCl7 have been synthesized (Zhang et al., 2013). In the present work, a thermochemical explanation for the stability of such unusual sodium chlorides is provided, based on lattice energy values. Using the Glasser-Jenkins generalized equation (Glasser and Jenkins, 2000) lattice energies (kJ mol-1) of -162.5, -168.9 and -113.1 are calculated for Pm3n NaCl3, Pnma NaCl3 and NaCl7, respectively. It is postulated that any NaxCly compound could be synthesized, if the ionic character of the Nasbnd Cl bond in the prepared compound remains around 80%, and the sodium charge below unit.

  16. Cubic-Structured HfLaO for the Blocking Layer of a Charge-Trap Type Flash Memory Device

    NASA Astrophysics Data System (ADS)

    Park, Jong Kyung; Park, Youngmin; Song, Myeong Ho; Lim, Sung Kyu; Oh, Jae Sub; Sig Joo, Moon; Hong, Kwon; Cho, Byung Jin

    2010-09-01

    Cubic-structured HfLaO with a high κ-value of 30-40 is used for the blocking layer in a charge-trap type memory device. Compared to an Al2O3 blocking layer, the single HfLaO blocking layer shows lower leakage current, faster program speed, larger memory window, and greater robustness at high voltage, but inferior charge retention due to lower conduction band offset (CBO). When an Al2O3 layer is inserted between the HfLaO and the charge trap layers, good charge retention, even at 150 °C, is achieved, maintaining the advantages of HfLaO.

  17. Susceptibility of dry-cured tuna to oxidative deterioration and biogenic amines generation: I. Effect of NaCl content, antioxidant type and ageing.

    PubMed

    Roseiro, L C; Santos, C; Gonçalves, H; Serrano, C; Aleixo, C; Partidário, A; Lourenço, A R; Dias, M Abreu; da Ponte, D J B

    2017-08-01

    This study aimed to assess lipid oxidation and biogenic amine (BA) development in "muxama", a dry-cured tuna muscle product, as affected by salt content, antioxidant type and ageing time. Overall, BA contents decreased with NaCl level (2785.1mgkg(-1), 1148.1mgkg(-1) and 307.7mgkg(-1)) and increased with ageing time (366.2mgkg(-1), 1711.8mgkg(-1) and 2959.2mgkg(-1) in the final product (T0), and after 1 (T1) and 3 (T3) months of ageing, respectively). Regardless of the test conditions, the most concentrated BA was always tyramine. For the ageing periods considered in the present study, malondialdehyde formation was affected by the NaCl level, with the saltiest samples exhibiting lower content. Rosemary and sage extracts represented promising technological options for preserving muxama from oxidation and to minimize the presence of a fishy flavour and odour, but this treatment may cause the colour to lose some of its redness and become less appealing.

  18. Effect of the introduction of oxide ion vacancies into cubic fluorite-type rare earth oxides on the NO decomposition catalysis

    NASA Astrophysics Data System (ADS)

    Masui, Toshiyuki; Nagai, Ryosuke; Imanaka, Nobuhito

    2014-12-01

    Cubic fluorite-type solid solutions based on Pr6O11 and CeO2 were synthesized and oxide anion vacancies were intentionally introduced into the cubic fluorite-type lattice through the charge compensating mechanism by Mg2+ and/or Ca2+ doping into their lattices. The oxide anion vacancies bring about positive effect on NO decomposition catalysis. The reason for the increase in the catalytic activity was attributed to defect fluorite-type structures close to the C-type cubic one, because C-type cubic rare earth oxides, in which one-quarter of the oxygen atoms in the fluorite-type structure are removed, show high NO decomposition activity. In particular, the positive effect of the formation of oxide anion vacancies was significant for Pr6O11 and its solid solutions, because the molar volume of Pr6O11 is larger than that of CeO2, and Pr6O11 contains Pr3+ as well as Pr4+ and thereby a small amount of oxide anion vacancies exist inherently in the lattice.

  19. Thermal stability and thermal expansion studies of cubic fluorite-type MgF{sub 2} up to 135 GPa

    SciTech Connect

    Sun, X.W.; Song, T.; Wei, X.P.; Quan, W.L.; Liu, X.B.; Su, W.F.

    2014-04-01

    Highlights: • The thermal expansion of MgF{sub 2} with a fluorite-type structure has been investigated. • The quasi-harmonic Debye model is applied to take into account the thermal effect. • Particular attention is paid to the prediction of thermal expansion for the first time. - Abstract: The thermal expansion of MgF{sub 2} with a fluorite structure has been investigated at high pressures using plane-wave pseudopotential scheme within the local density approximation correction in the frame of density functional theory based on the analysis of thermal stability using classical molecular dynamics simulations up to 6500 K. To investigate the thermodynamic properties like as the P–V–T equation of state and volumetric thermal expansion coefficient α{sub V} of cubic fluorite-type MgF{sub 2} at extended pressure and temperature ranges, we apply the quasi-harmonic Debye model in which the phononic effects are considered. The P–V relationship and α{sub V} dependence of the pressure up to 135 GPa at different temperatures, and the V–T relationship and α{sub V} dependence of the temperature up to the melting temperature 1500 K at different pressures have been obtained.

  20. Abnormal thermal expansion properties of cubic NaZn13-type La(Fe,Al)13 compounds.

    PubMed

    Li, Wen; Huang, Rongjin; Wang, Wei; Zhao, Yuqiang; Li, Shaopeng; Huang, Chuanjun; Li, Laifeng

    2015-02-28

    The cubic NaZn13-type La(Fe,Al)13 compounds were synthesized, and their linear thermal expansion properties were investigated in the temperature range of 4.2-300 K. It was found that these compounds exhibit abnormal thermal expansion behavior, i.e., pronounced negative thermal expansion (NTE) or zero thermal expansion (ZTE) behavior, below the Curie temperature due to the magnetovolume effect (MVE). Moreover, in the La(Fe,Al)13 compounds, the modification of the coefficient of thermal expansion (CTE) as well as the abnormal thermal expansion (ATE) temperature-window is achieved through optimizing the proportion of Fe and Al. Typically, the average CTE of the LaFe13-xAlx compounds with x = 1.8 reaches as large as -10.47 × 10(-6) K(-1) between 100 and 225 K (ΔT = 125 K). Also, the ZTE temperature-window of the LaFe13-xAlx compounds with x = 2.5 and x = 2.7 could be broadened to 245 K (from 5 to 250 K). Besides, the magnetic properties of these compounds were measured and correlated with the abnormal thermal expansion behavior. The present results highlight the potential application of such La(Fe,Al)13 compounds with abnormal thermal expansion properties in cryogenic engineering.

  1. Interaction of macroparticles localized in Wigner-Seitz cells of various types of cubic lattices in an equilibrium plasma

    NASA Astrophysics Data System (ADS)

    Filippov, A. V.

    2016-10-01

    The interaction of two charged point macroparticles located in Wigner-Seitz cells of simple cubic (SC), body-centered cubic (BCC), or face-centered cubic (FCC) lattices in an equilibrium plasma has been studied within the Debye approximation or, more specifically, based on the linearized Poisson-Boltzmann model. The shape of the outer boundary is shown to exert a strong influence on the pattern of electrostatic interaction between the two macroparticles, which transforms from repulsion at small interparticle distances to attraction as the interparticle distance approaches half the length of the computational cell. The macroparticle pair interaction potential in an equilibrium plasma is shown to be nevertheless the Debye one and purely repulsive for likely charged macroparticles.

  2. Interaction of macroparticles localized in Wigner–Seitz cells of various types of cubic lattices in an equilibrium plasma

    SciTech Connect

    Filippov, A. V.

    2016-10-15

    The interaction of two charged point macroparticles located in Wigner–Seitz cells of simple cubic (SC), body-centered cubic (BCC), or face-centered cubic (FCC) lattices in an equilibrium plasma has been studied within the Debye approximation or, more specifically, based on the linearized Poisson–Boltzmann model. The shape of the outer boundary is shown to exert a strong influence on the pattern of electrostatic interaction between the two macroparticles, which transforms from repulsion at small interparticle distances to attraction as the interparticle distance approaches half the length of the computational cell. The macroparticle pair interaction potential in an equilibrium plasma is shown to be nevertheless the Debye one and purely repulsive for likely charged macroparticles.

  3. Thermal expansivity and bulk modulus of ZnO with NaCl-type cubic structure at high pressures and temperatures

    NASA Astrophysics Data System (ADS)

    Sun, Xiaowei; Liu, Zijiang; Chen, Qifeng; Chu, Yandong; Wang, Chengwei

    2006-12-01

    The thermal expansivity and bulk modulus of ZnO with NaCl-type cubic structure were estimated by using the constant temperature and pressure molecular dynamics technique with effective pair potentials which consist of the Coulomb, dispersion, and repulsion interaction at high pressures and temperatures. It is shown that the calculated thermodynamic parameters including linear thermal expansion coefficient, isothermal bulk modulus and its pressure derivative are in good agreement with the available experimental data and the latest theoretical results. At an extended pressure and temperature ranges, linear thermal expansion coefficient and isothermal bulk modus have also been predicted. The thermodynamic properties of ZnO with NaCl-type cubic structure are summarized in the pressure 0 150 GPa ranges and the temperature up to 3000 K.

  4. Higher Dimensional Gaussian-Type Solitons of Nonlinear Schrödinger Equation with Cubic and Power-Law Nonlinearities in PT-Symmetric Potentials

    PubMed Central

    Chen, Yi-Xiang; Xu, Fang-Qian

    2014-01-01

    Two families of Gaussian-type soliton solutions of the (n+1)-dimensional Schrödinger equation with cubic and power-law nonlinearities in -symmetric potentials are analytically derived. As an example, we discuss some dynamical behaviors of two dimensional soliton solutions. Their phase switches, powers and transverse power-flow densities are discussed. Results imply that the powers flow and exchange from the gain toward the loss regions in the cell. Moreover, the linear stability analysis and the direct numerical simulation are carried out, which indicates that spatial Gaussian-type soliton solutions are stable below some thresholds for the imaginary part of -symmetric potentials in the defocusing cubic and focusing power-law nonlinear medium, while they are always unstable for all parameters in other media. PMID:25542020

  5. Radium isotopes ((226)Ra and (228)Ra) in Na-Cl type groundwaters from Tohoku District (Aomori, Akita and Yamagata Prefectures) in Japan.

    PubMed

    Tomita, Jumpei; Zhang, Jing; Yamamoto, Masayoshi

    2014-11-01

    A total of 28 Na-Cl type groundwater samples were collected from Aomori, Akita and Yamagata Prefectures, in the Tohoku District of Japan, and their radium isotope ((226)Ra and (228)Ra) concentrations were measured along with their chemical components and stable isotope ratios (δ(2)H and δ(18)Os). The (226)Ra concentrations in groundwater samples varied widely, ranging from 8.8 to 1587 mBq kg(-1). These concentrations showed an increasing tendency with the increase of the total dissolved solid (TDS) contents. The (228)Ra/(226)Ra activity ratios were in the range from 0.3 to 4.2, with most data being around 0.5-2. These ratios were within those of (232)Th/(238)U found in granitic and related rocks and so on in Japan, indicating that Ra isotopes mainly ejected into the groundwater by the alpha-recoil process. The relationship between (226)Ra and other parameters suggested that Ra isotopes in groundwater samples in this study were mainly constrained by adsorption-desorption reactions depending on salinity with wide variation. Clear correlation between (226)Ra-Ca, (226)Ra-Sr, (226)Ra-Ba and (226)Ra-TDS observed in sulfate-free groundwater samples indicated that Ra isotopes of them were constrained by adsorption-desorption reactions depending on salinity under reducing condition. In contrast, relationship of (226)Ra-Ca, (226)Ra-Sr, (226)Ra-Ba and (226)Ra-TDS in sulfate-containing groundwater samples varied widely, and then, removal or enhanced mobility of Ra isotopes of them were observed.

  6. Gaussian-type light bullet solutions of the (3 + 1)-dimensional Schrödinger equation with cubic and power-law nonlinearities in PT-symmetric potentials

    NASA Astrophysics Data System (ADS)

    Zhu, Hai-Ping; Dai, Chao-Qing

    2014-12-01

    Two kinds of Gaussian-type light bullet (LB) solutions of the (3 + 1)-dimensional Schrödinger equation with cubic and power-law nonlinearities in PT-symmetric potentials are analytically obtained. The phase switches, powers and transverse power-flow densities of these solutions in homogeneous media are studied. The linear stability analysis of these LB solutions and the direct numerical simulation indicate that LB solutions are stable below some thresholds for the imaginary part of PT-symmetric potentials in the defocusing cubic and focusing power-law nonlinear medium, while they are always unstable for all parameters in other media. Moreover, the broadened and compressed behaviors of LBs in the exponential periodic amplification system and diffraction decreasing system are discussed. Results indicate that LB is more stable for the sign-changing nonlinearity in the exponential periodic amplification system than for the non-sign-changing nonlinearity in the diffraction decreasing system at the same propagation distances.

  7. Cubic Icosahedra? A Problem in Assigning Symmetry

    ERIC Educational Resources Information Center

    Lloyd, D. R.

    2010-01-01

    There is a standard convention that the icosahedral groups are classified separately from the cubic groups, but these two symmetry types have been conflated as "cubic" in some chemistry textbooks. In this note, the connection between cubic and icosahedral symmetries is examined, using a simple pictorial model. It is shown that octahedral and…

  8. Cubic Icosahedra? A Problem in Assigning Symmetry

    ERIC Educational Resources Information Center

    Lloyd, D. R.

    2010-01-01

    There is a standard convention that the icosahedral groups are classified separately from the cubic groups, but these two symmetry types have been conflated as "cubic" in some chemistry textbooks. In this note, the connection between cubic and icosahedral symmetries is examined, using a simple pictorial model. It is shown that octahedral and…

  9. Effects of fibre type and structure of longissimus lumborum (Ll), biceps femoris (Bf) and semimembranosus (Sm) deer muscles salting with different Nacl addition on proteolysis index and texture of dry-cured meats.

    PubMed

    Żochowska-Kujawska, J

    2016-11-01

    The aim of the present study was to describe the effect of fibre type and structure as well as NaCl level on the proteolysis index and texture parameters observed in dry-cured meats produced from individual deer muscles. The biceps femoris, semimembranosus and longissimus lumborum muscles were cut from deer main elements, shaped into blocks by trimming off the edges, cured by adding 4, 6 and 8% of salt (w/w) and dried in a ripening chamber for 29days. The results indicated that deer dry-cured muscles with higher percentage of red fibres (type I) showed higher texture parameters, proteolysis index as well as lower moisture losses than muscles with higher amount of white fibres (type IIB). Dry-cured deer muscles with lower NaCl content showed higher values of proteolysis index and lower hardness, cohesiveness, springiness, and chewiness, as well as lower changes in structure elements. Copyright © 2016. Published by Elsevier Ltd.

  10. Phase transitions in antiferromagnets with a NaCl structure

    NASA Astrophysics Data System (ADS)

    Kassan-Ogly, F. A.; Filippov, B. N.

    2006-05-01

    A revised derivation scheme of possible magnetic structures in an FCC lattice with the nearest- and next-nearest-neighbor interactions taken into account is proposed. A model of simultaneous magnetic and structural phase transitions of the first order is developed for antiferromagnets with a NaCl structure and with a strong cubic magnetic anisotropy on the base of synthesis of magnetic modified 6-state Potts model and theoretical models of structural phase transitions in cubic crystals. It is shown that the high-temperature diffuse magnetic scattering of neutrons transforms into magnetic Bragg reflections below Néel point.

  11. Infrared thermography monitoring of the NaCl crystallisation process

    NASA Astrophysics Data System (ADS)

    Vázquez, Patricia; Thomachot-Schneider, Céline; Mouhoubi, Kamel; Fronteau, Gilles; Gommeaux, Maxime; Benavente, David; Barbin, Vincent; Bodnar, Jean-Luc

    2015-07-01

    In this work, we describe the growth of NaCl crystals by evaporating droplets of aqueous solution while monitoring them with infrared thermography. Over the course of the evaporation experiments, variations in the recorded signal were observed and interpreted as being the result of evaporation and crystallisation. In particular, we observed sharp and transient decreases in the thermosignal during the later stages of high-concentration drop evaporation. The number of such events per experiment, referred to as "pop-cold events", varied from 1 to over 100 and had durations from 1 to 15 s. These events are interpreted as a consequence from the top-supplied creeping (TSC) of the solution feeding the growth of efflorescence-like crystals. This phenomenon occurred when the solution was no longer macroscopically visible. In this case, efflorescence-like crystals with a spherulite shape grew around previously formed cubic crystals. Other crystal morphologies were also observed but were likely fed by mass diffusion or bottom-supplied creeping (BSC) and were not associated with "pop-cold events"; these morphologies included the cubic crystals at the centre, ring-shaped at the edge of droplets and fan-shaped crystals. After complete evaporation, an analysis of the numbers and sizes of the different types of crystals was performed using image processing. Clear differences in their sizes and distribution were observed in relation to the salt concentration. Infrared thermography permitted a level of quantification that previously was only possible using other techniques. As example, the intermittent efflorescence growth process was clearly observed and measured for the first time using infrared thermography.

  12. NaCl effect on the distribution of wall ingrowth polymers and arabinogalactan proteins in type A transfer cells of Medicago sativa Gabès leaves.

    PubMed

    Boughanmi, Néziha; Thibault, Florence; Decou, Raphael; Fleurat-Lessard, Pierrette; Béré, Emile; Costa, Guy; Lhernould, Sabine

    2010-06-01

    We studied the distribution of wall ingrowth (WI) polymers by probing thin sections of companion cells specialized as transfer cells in minor veins of Medicago sativa cv Gabès blade with affinity probes and antibodies specific to polysaccharides and glycoproteins. The wall polymers in the controls were similar in WIs and in the primary wall but differently distributed. The extent of labeling in these papillate WIs differed for JIM5 and JIM7 homogalacturonans but was in the same range for LM5 and LM6 rhamnogalacturonans and xyloglucans. These data show that WI enhancement probably requires arabinogalactan proteins (JIM8) mainly localized on the outer part of the primary wall and WIs. By comparison, NaCl-treated plants exhibited cell wall polysaccharide modifications indicating (1) an increase in unesterified homogalacturonans (JIM5), probably implicated in Na(+) binding and/or polysaccharide network interaction for limiting turgor variations in mesophyll cells; (2) enhancement of the xyloglucan network with an accumulation of fucosylated xyloglucans (CCRC-M1) known to increase the capacity of cellulose binding; and (3) specific recognition of JIM8 arabinogalactan proteins that could participate in both wall enlargement and cohesion by increasing the number of molecular interactions with the other polymers. In conclusion, the cell wall polysaccharide distribution in enlarged WIs might (1) participate in wall resistance to sequestration of Na(+), allowing a better control of hydric homeostasis in mesophyll cells to maintain metabolic activity in source leaves, and (2) maintain tolerance of M. sativa to NaCl.

  13. Melting curve of NaCl determined using synchrotron x-ray radiography

    NASA Astrophysics Data System (ADS)

    Chen, J.; Yu, T.; Long, H.; Wang, L.; Garai, J.

    2009-12-01

    NaCl has been widely used as a pressure calibrant in in-situ high pressure synchrotron x-ray study. The applicable pressure and temperature range of this calibrant is from ambient condition up to B1-B2 transition in pressure and to melting in temperature. Melting data of NaCl at high pressures are still very limited. We have conducted comparative experiments to study melting of NaCl using energy dispersive x-ray diffraction and radiographic imaging at high pressure up to 8.8GPa. The experiments were carried out using the cubic-type multi-anvil pressure (SAM85) at the X17B2 beamline of the National Synchrotron Light Source (NSLS). In the x-ray diffraction experiments, melting is inferred when disappearance of diffraction peak of NaCl from a mixture of NaCl+BN (to reduce possible grain growth) is observed. In the x-ray radiography experiment, a WC sphere is place in the top portion of pure NaCl sample; melting is inferred when the WC sphere start to drop in the sample. The experimental result indicates that the melting temperatures determined from the two types of observations may differ by 60°C at 5 GPa. Due to unavoidable grain growth near melting, x-ray diffraction signals may disappear from the point solid state detector even though the melting is not achieved. Therefore the radiography method may reflect more accurate measurement of melting temperature. Melting curve of NaCl was measured up to 1.8 GPa by Clark et al (1), and between 2 and 4 GPa by Pistorius (2). The new melting data are consistent with the previous results. All the experimental are in good agreement with theoretical prediction using Simon fusion equation (2) and the relation between melting temperature and Debye temperature (3). References: (1) Clark, Jr. Effect of Pressure on the Melting Points of Eight Alkali Halides, Journal of Chemical Physics 31 (6) 1526-1531 (1959). (2) Kraut and Kennedy, New Melting Law at High Pressures, Physical Review 151 (2) 668-675 (1966) (3) J. Garai, and J. Chen

  14. Surface chemistry of BORAZON: I, Analysis of the three cubic boron nitride materials: Type 1, 510, and 550

    SciTech Connect

    Moddeman, W.E.; Foose, D.S.; Bowling, W.C.; Burke, A.R.; Kasten, L.S.; Cassidy, R.T.

    1992-03-25

    Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface chemistry of three BORAZON* materials: Type I, 510, and 550. Samples were examined in the ``as-received`` condition and following heat treatments in air. Boron oxides were found on the Type I and 550 BORAZON crystals; oxide thicknesses were estimated to be 15A. The titanium-coated product, 510, was found to have a discontinuous titanium coating with a TiO{sub 2} layer that was approximately 20A thick. Following heat treatment at 800{degrees}C for 1 hr in air, the boron oxide layer on the Type I crystals was found to increase in thickness to approximately 30A. The same heat treatment on the 510 crystals yielded a multi-layered structure consisting of an enriched outer layer of B{sub 2}O{sub 3} over a predominantly TiO{sub 2} one. The entire initial titanium coating was oxidized, and segregated patches of B{sub 2}O{sub 3} (``islands``) were observed. The segregated patches can be explained in terms of the coalescence of liquid B{sub 2}O{sub 3} (melting point = 450{degrees}C). The 550 crystals were oxidized at 500{degrees}C. The oxide formed at this temperature was B{sub x}O (x > 0.67). These results were interpreted in terms of their potential use in sealing BORAZON to glass in vitreous bonding.

  15. Surface chemistry of BORAZON: I, Analysis of the three cubic boron nitride materials: Type 1, 510, and 550

    SciTech Connect

    Moddeman, W.E.; Foose, D.S.; Bowling, W.C.; Burke, A.R.; Kasten, L.S.; Cassidy, R.T.

    1992-03-25

    Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface chemistry of three BORAZON* materials: Type I, 510, and 550. Samples were examined in the as-received'' condition and following heat treatments in air. Boron oxides were found on the Type I and 550 BORAZON crystals; oxide thicknesses were estimated to be 15A. The titanium-coated product, 510, was found to have a discontinuous titanium coating with a TiO{sub 2} layer that was approximately 20A thick. Following heat treatment at 800{degrees}C for 1 hr in air, the boron oxide layer on the Type I crystals was found to increase in thickness to approximately 30A. The same heat treatment on the 510 crystals yielded a multi-layered structure consisting of an enriched outer layer of B{sub 2}O{sub 3} over a predominantly TiO{sub 2} one. The entire initial titanium coating was oxidized, and segregated patches of B{sub 2}O{sub 3} ( islands'') were observed. The segregated patches can be explained in terms of the coalescence of liquid B{sub 2}O{sub 3} (melting point = 450{degrees}C). The 550 crystals were oxidized at 500{degrees}C. The oxide formed at this temperature was B{sub x}O (x > 0.67). These results were interpreted in terms of their potential use in sealing BORAZON to glass in vitreous bonding.

  16. Piecewise Cubic Interpolation Package

    SciTech Connect

    Fritsch, F. N.; LLNL,

    1982-04-23

    PCHIP (Piecewise Cubic Interpolation Package) is a set of subroutines for piecewise cubic Hermite interpolation of data. It features software to produce a monotone and "visually pleasing" interpolant to monotone data. Such an interpolant may be more reasonable than a cubic spline if the data contain both 'steep' and 'flat' sections. Interpolation of cumulative probability distribution functions is another application. In PCHIP, all piecewise cubic functions are represented in cubic Hermite form; that is, f(x) is determined by its values f(i) and derivatives d(i) at the breakpoints x(i), i=1(1)N. PCHIP contains three routines - PCHIM, PCHIC, and PCHSP to determine derivative values, six routines - CHFEV, PCHFE, CHFDV, PCHFD, PCHID, and PCHIA to evaluate, differentiate, or integrate the resulting cubic Hermite function, and one routine to check for monotonicity. A FORTRAN 77 version and SLATEC version of PCHIP are included.

  17. β-Mn-type Co(8+x)Zn(12-x) as a defect cubic Laves phase: site preferences, magnetism, and electronic structure.

    PubMed

    Xie, Weiwei; Thimmaiah, Srinivasa; Lamsal, Jagat; Liu, Jing; Heitmann, Thomas W; Quirinale, Dante; Goldman, Alan I; Pecharsky, Vitalij; Miller, Gordon J

    2013-08-19

    The results of crystallographic analysis, magnetic characterization, and theoretical assessment of β-Mn-type Co-Zn intermetallics prepared using high-temperature methods are presented. These β-Mn Co-Zn phases crystallize in the space group P4(1)32 [Pearson symbol cP20; a = 6.3555(7)-6.3220(7)], and their stoichiometry may be expressed as Co(8+x)Zn(12-x) [1.7(2) < x < 2.2(2)]. According to a combination of single-crystal X-ray diffraction, neutron powder diffraction, and scanning electron microscopy, atomic site occupancies establish clear preferences for Co atoms in the 8c sites and Zn atoms in the 12d sites, with all additional Co atoms replacing some Zn atoms, a result that can be rationalized by electronic structure calculations. Magnetic measurements and neutron powder diffraction of an equimolar Co:Zn sample confirm ferromagnetism in this phase with a Curie temperature of ∼420 K. Neutron powder diffraction and electronic structure calculations using the local spin density approximation indicate that the spontaneous magnetization of this phase arises exclusively from local moments at the Co atoms. Inspection of the atomic arrangements of Co(8+x)Zn(12-x) reveals that the β-Mn aristotype may be derived from an ordered defect, cubic Laves phase (MgCu2-type) structure. Structural optimization procedures using the Vienna ab initio simulation package (VASP) and starting from the undistorted, defect Laves phase structure achieved energy minimization at the observed β-Mn structure type, a result that offers greater insight into the β-Mn structure type and establishes a closer relationship with the corresponding α-Mn structure (cI58).

  18. Fermi Surface Properties Based on the Relativistic Effect in SrBi3 with AuCu3-Type Cubic Structure

    NASA Astrophysics Data System (ADS)

    Kakihana, Masashi; Akamine, Hiromu; Yara, Tomoyuki; Teruya, Atsushi; Nakamura, Ai; Takeuchi, Tetsuya; Hedo, Masato; Nakama, Takao; Ōnuki, Yoshichika; Harima, Hisatomo

    2015-12-01

    Bi-6p electrons are well known to possess a strong spin-orbit interaction, but a mass correction based on the relativistic effect is scarcely discussed in the electronic state. To clarify the relativistic properties of Bi-6p electrons, we grew single crystals of SrBi3 with the AuCu3-type cubic structure by the Bi self-flux method and carried out electrical resistivity, specific heat, and de Haas-van Alphen (dHvA) experiments. Several kinds of closed Fermi surfaces are observed from the dHvA effect. Among them, three kinds of main Fermi surfaces are compared with the results of full-potential linearized augmented plane wave (FLAPW) energy band calculations under two considerations. One corresponds to the mass correction in the spin-orbit interaction for Bi-6p electrons. The other is without the mass correction. Detected two kinds of the main Fermi surfaces are well explained with and without the mass correction, but a remaining Fermi surface is explained only with the mass correction. The relativistic effects of the spin-orbit interaction and mass correction are essentially important for Bi-6p electrons in SrBi3.

  19. Low-temperature abnormal thermal expansion property of Mn doped cubic NaZn13-type La(Fe, Al)13 compounds

    NASA Astrophysics Data System (ADS)

    Zhao, Yuqiang; Huang, Rongjin; Shan, Yi; Wang, Wei; Li, Jiangtao; Li, Laifeng

    2017-09-01

    Low-temperature abnormal thermal expansion (ATE) materials have been recently developed because of their significant applications for cryogenic engineering. However, the challenge still remains for the control of ATE effect at cryogenic temperature and adjustable ATE is of fundamental interest. In this paper, we report the isotropic ATE in La(Fe, Al)13 compounds over a wide adjusting temperature range by partially substituting Fe by Mn. It is found that all samples crystallize in the cubic NaZn13-type structure with the Fm\\bar{3}c space group. The introduction of nonmagnetic Mn atoms reduces the Fe-Fe exchange interaction, therefore, the itinerant electron system needs less energy to break the magnetic order in ferromagnetic (FM) state at low temperature. The negative thermal expansion (NTE) operation-temperature window moves towards lower temperatures accompanied with the decrease of Curie temperature (T C) by increasing Mn elements. Moreover, the composite combining Mn 0 and Mn 57 broadens the zero thermal expansion (ZTE) behavior occurring in the whole tested temperature range. The present studies could be useful to control the thermal expansion, and indicate the potential applications of ATE materials in cryogenic engineering.

  20. Cubic topological Kondo insulators.

    PubMed

    Alexandrov, Victor; Dzero, Maxim; Coleman, Piers

    2013-11-27

    Current theories of Kondo insulators employ the interaction of conduction electrons with localized Kramers doublets originating from a tetragonal crystalline environment, yet all Kondo insulators are cubic. Here we develop a theory of cubic topological Kondo insulators involving the interaction of Γ(8) spin quartets with a conduction sea. The spin quartets greatly increase the potential for strong topological insulators, entirely eliminating the weak topological phases from the diagram. We show that the relevant topological behavior in cubic Kondo insulators can only reside at the lower symmetry X or M points in the Brillouin zone, leading to three Dirac cones with heavy quasiparticles.

  1. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  2. Electron scattering in graphene with adsorbed NaCl nanoparticles

    SciTech Connect

    Drabińska, Aneta Kaźmierczak, Piotr; Bożek, Rafał; Karpierz, Ewelina; Wysmołek, Andrzej; Kamińska, Maria; Wołoś, Agnieszka; Krajewska, Aleksandra

    2015-01-07

    In this work, the results of contactless magnetoconductance and Raman spectroscopy measurements performed for a graphene sample after its immersion in NaCl solution were presented. The properties of the immersed sample were compared with those of a non-immersed reference sample. Atomic force microscopy and electron spin resonance experiments confirmed the deposition of NaCl nanoparticles on the graphene surface. A weak localization signal observed using contactless magnetoconductance showed the reduction of the coherence length after NaCl treatment of graphene. Temperature dependence of the coherence length indicated a change from ballistic to diffusive regime in electron transport after NaCl treatment. The main inelastic scattering process was of the electron-electron type but the major reason for the reduction of the coherence length at low temperatures was additional, temperature independent, inelastic scattering. We associate it with spin flip scattering, caused by NaCl nanoparticles present on the graphene surface. Raman spectroscopy showed an increase in the D and D′ bands intensities for graphene after its immersion in NaCl solution. An analysis of the D, D′, and G bands intensities proved that this additional scattering is related to the decoration of vacancies and grain boundaries with NaCl nanoparticles, as well as generation of new on-site defects as a result of the decoration of the graphene surface with NaCl nanoparticles. The observed energy shifts of 2D and G bands indicated that NaCl deposition on the graphene surface did not change carrier concentration, but reduced compressive biaxial strain in the graphene layer.

  3. Design and synthesis of new type I bicontinuous cubic lyotropic liquid crystal monomers based on the gemini framework for molecular-size separation applications

    NASA Astrophysics Data System (ADS)

    Wiesenauer, Brian R.

    The overall objective of this thesis research was the design and synthesis of new type I bicontinuous cubic (QI) phase-forming, gemini-shaped lyotropic liquid crystal (LLC) monomers for the preparation of nanoporous polymer membrane materials. These new QI-phase LLC monomers were designed to overcome several shortcomings of previously developed QI-phase LLC monomers in the Gin research group that include expensive and difficult synthesis, poor film processibility, and limited blendability with additives. The first method for obtaining this objective was the synthesis of six homologues of a new gemini ammonium LLC monomer, two of which exhibit a QI phase with water. Both of these LLCs form a robust Q I phase such that a gel of these materials can be fully infused into a microporous support membrane and then cross-linked to maintain the LLC phase structure. The resulting QI-phase polymer film showed a uniform pore size of 0.86 nm in water nanofiltration and desalination experiments. This QI monomer platform is less costly and less rigorous to synthesize than previously synthesized phosphonium-based gemini QI LLC monomers. These new LLC monomers also have the ability to blend with the hydrophobic, commercially available cross-linkable elastomer vinyl-EPDM (v-EPDM) to form breathable composite barrier materials. In the appropriate composition, melt-infused gemini ammonium monomer/v-EPDM polymer membranes exhibit extremely high pure water vapor fluxes, and high rejection of toxic industrial chemical vapors. A new cross-linkable gemini LLC monomer based on charged imidazolium units was also developed that forms a QI phase with glycerol. This new LLC monomer can be solution-cast from MeOH and UV-irradiated to form cross-linked thin-film composite QI membranes with slightly larger effective pore size (0.96 nm) than the previous systems. A related goal of this thesis research was to develop methods for systematically tuning the effective pore size of nanoporous QI polymer

  4. Cubic nitride templates

    DOEpatents

    Burrell, Anthony K; McCleskey, Thomas Mark; Jia, Quanxi; Mueller, Alexander H; Luo, Hongmei

    2013-04-30

    A polymer-assisted deposition process for deposition of epitaxial cubic metal nitride films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures under a suitable atmosphere to yield metal nitride films and the like. Such films can be used as templates for the development of high quality cubic GaN based electronic devices.

  5. Facile hydrothermal synthesis of cubic spinel AB2O4 type MnFe2O4 nanocrystallites and their electrochemical performance

    NASA Astrophysics Data System (ADS)

    Kwon, JongMyeong; Kim, Jae-Hong; Kang, Soon-Hyung; Choi, Cheol-Jong; Rajesh, John Anthuvan; Ahn, Kwang-Soon

    2017-08-01

    Cubic spinel MnFe2O4 nanoparticles were synthesized using a simple hydrothermal method followed by post-annealing. The effects of the reaction temperature on the crystallinity, morphology, and electrochemical performance were studied. The reaction temperature played an important role in the synthesis of highly crystalline MnFe2O4 nanoparticles. At low reaction temperatures (<160 °C), the synthesized product contained a secondary inactive Fe2O3 phase as well as MnFe2O4 nanoparticles. In contrast, pure MnFe2O4 nanoparticles were obtained at temperatures above 180 °C. Furthermore, the crystallinity of the MnFe2O4 nanoparticles was enhanced significantly by increasing the reaction temperature to 200 °C. The cubic spinel MnFe2O4 nanoparticles synthesized at 200 °C delivered a maximum specific capacitance of 282.4 F g-1 at a current density of 0.5 A g-1 in a 2 M aqueous KOH solution, and exhibited long-term cyclic stability of 85.8% capacitance retention after 2000 cycles. This was attributed to the cubic spinel ferrite nanocrystallite particles not only providing the more active sites for OH- ion diffusion but also reducing the path lengths for OH- ion diffusion. These results show that the synthesized MnFe2O4 nanoparticles are promising candidates for pseudocapacitors and other electrochemical applications.

  6. Variable-temperature single-crystal X-ray diffraction study of tetragonal and cubic perovskite-type barium titanate phases.

    PubMed

    Nakatani, Tomotaka; Yoshiasa, Akira; Nakatsuka, Akihiko; Hiratoko, Tatsuya; Mashimo, Tsutomu; Okube, Maki; Sasaki, Satoshi

    2016-02-01

    A variable-temperature single-crystal X-ray diffraction study of a synthetic BaTiO3 perovskite has been performed over the temperature range 298-778 K. A transition from a tetragonal (P4mm) to a cubic (Pm3m) phase has been revealed near 413 K. In the non-centrosymmetric P4mm symmetry group, both Ti and O atoms are displaced along the c-axis in opposite directions with regard to the Ba position fixed at the origin, so that Ti(4+) and Ba(2+) cations occupy off-center positions in the TiO6 and BaO12 polyhedra, respectively. Smooth temperature-dependent changes of the atomic coordinates become discontinuous with the phase transition. Our observations imply that the cations remain off-center even in the high-temperature cubic phase. The temperature dependence of the mean-square displacements of Ti in the cubic phase includes a significant static component which means that Ti atoms are statistically distributed in the off-center positions.

  7. Cubic colloidal platinum nanoparticles

    SciTech Connect

    Ahmadi, T.S.; Wang, Z.L.; Henglein, A.; El-Sayed, M.A.

    1996-06-01

    Cubic platinum nanoparticles (4-18 nm) have been synthesized for the first time in solution by the controlled reduction of K{sub 2}PtCl{sub 4} with hydrogen gas in the presence of sodium polyacrylate as a capping material. The nanoparticles are found to have fcc structures, similar to the bulk metal with (100) facets.

  8. BF into cubic meters

    Treesearch

    Henry Spelter

    2002-01-01

    Noted forest products industry researcher and writer says the conversion factor traditionally used to convert logs measured in board feet to cubic meters has risen. In the U.S., most timber is measured in terms of board feet. The log scales currently in use to estimate lumber recovery from roundwood, however, were created in the 19th century according to sawmill...

  9. Why is Polonium simple cubic?

    NASA Astrophysics Data System (ADS)

    Roundy, David; Kraig, Robert E.; Cohen, Marvin L.

    2002-03-01

    Scientists have long pondered why the simple cubic structure is so rarely seen in nature. Only one element forms the simple cubic structure: polonium. There are `proofs' dating back to 1954 that the simple cubic lattice should be unstable. We will attempt to address the question of why polonium takes the simple cubic structure by means of ab initio calculations using the pseudopotential density functional method. We will discuss the electronic structure of polonium in relation to its crystal structure.

  10. Cubic membranes: a structure-based design for DNA uptake.

    PubMed

    Almsherqi, Zakaria; Hyde, Stephen; Ramachandran, Malarmathy; Deng, Yuru

    2008-09-06

    Cubic membranes are soft three-dimensional crystals found within cell organelles in a variety of living systems, despite the aphorism of Fedorov: 'crystallization is death'. They consist of multi-bilayer lipid-protein stacks, folded onto anticlastic surfaces that resemble triply periodic minimal surfaces, forming highly swollen crystalline sponges. Although cubic membranes have been observed in numerous cell types and under different pathophysiological conditions, knowledge about the formation and potential function(s) of non-lamellar, cubic structures in biological systems is scarce. We report that mitochondria with this cubic membrane organization isolated from starved amoeba Chaos carolinense interact sufficiently with short segments of phosphorothioate oligonucleotides (PS-ODNs) to give significant ODNs uptake. ODNs condensed within the convoluted channels of cubic membrane by an unknown passive targeting mechanism. Moreover, the interaction between ODNs and cubic membrane is sufficient to retard electrophoretic mobility of the ODN component in the gel matrix. These ODN-cubic membrane complexes are readily internalized within the cytoplasm of cultured mammalian cells. Transmission electron microscopic analysis confirms ODNs uptake by cubic membranes and internalization of ODN-cubic membrane complexes into the culture cells. Cubic membranes thus may offer a new, potentially benign medium for gene transfection.

  11. Kinetin Reversal of NaCl Effects

    PubMed Central

    Katz, Adriana; Dehan, Klara; Itai, Chanan

    1978-01-01

    Leaf discs of Nicotiana rustica L. were floated on NaCl in the presence of kinetin or abscisic acid. On the 5th day 14CO2 fixation, [3H]leucine incorporation, stomatal conductance, and chlorophyll content were determined. Kinetin either partially or completely reversed the inhibitory effects of NaCl while ABA had no effect. PMID:16660618

  12. Lithium ion micrometer diffusion in a garnet-type cubic Li7La3Zr2O12 (LLZO) studied using 7Li NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Hayamizu, Kikuko; Seki, Shiro; Haishi, Tomoyuki

    2017-01-01

    Mobile lithium ions in a cubic garnet Li7La3Zr2O12 (Al-stabilized) were studied using 7Li NMR spectroscopy for membrane and powder samples, the latter of which was ground from the membrane. Lithium diffusion in a micrometer space was measured using the pulsed-gradient spin-echo 7Li NMR method between 70 and 130 °C. When the observation time (Δ ) was shorter than 20 ms, the echo attenuation showed diffusive diffraction patterns, indicating that the Li+ diffusing space is not free but restricted. For longer Δ, the values of apparent diffusion constant (Dapparent) became gradually smaller to approach an equilibrated value (close to a tracer diffusion constant). In addition, the Dapparent depends on the pulse field gradient strength (g) and became smaller as g became larger. These experimental results suggest that the lithium ions diffuse through Li+ pathways surrounded by stationary anions and lithium ions, and are affected by collisions and diffractions. One-dimensional profiles of the membrane sample of thickness 0.5 mm were observed from 65 to 110 °C and the area intensity, as well as the lithium occurrence near the surface, increased with the increase in temperature. The temperature-dependent area intensity showed a correspondence to the number of Li+ carrier ions estimated from the ionic conductivity and the equilibrated diffusion constant through the Nernst-Einstein relationship.

  13. Lithium ion micrometer diffusion in a garnet-type cubic Li7La3Zr2O12 (LLZO) studied using (7)Li NMR spectroscopy.

    PubMed

    Hayamizu, Kikuko; Seki, Shiro; Haishi, Tomoyuki

    2017-01-14

    Mobile lithium ions in a cubic garnet Li7La3Zr2O12 (Al-stabilized) were studied using (7)Li NMR spectroscopy for membrane and powder samples, the latter of which was ground from the membrane. Lithium diffusion in a micrometer space was measured using the pulsed-gradient spin-echo (7)Li NMR method between 70 and 130 °C. When the observation time (Δ) was shorter than 20 ms, the echo attenuation showed diffusive diffraction patterns, indicating that the Li(+) diffusing space is not free but restricted. For longer Δ, the values of apparent diffusion constant (Dapparent) became gradually smaller to approach an equilibrated value (close to a tracer diffusion constant). In addition, the Dapparent depends on the pulse field gradient strength (g) and became smaller as g became larger. These experimental results suggest that the lithium ions diffuse through Li(+) pathways surrounded by stationary anions and lithium ions, and are affected by collisions and diffractions. One-dimensional profiles of the membrane sample of thickness 0.5 mm were observed from 65 to 110 °C and the area intensity, as well as the lithium occurrence near the surface, increased with the increase in temperature. The temperature-dependent area intensity showed a correspondence to the number of Li(+) carrier ions estimated from the ionic conductivity and the equilibrated diffusion constant through the Nernst-Einstein relationship.

  14. Molecular dynamics simulation of NaCl dissolution.

    PubMed

    Lanaro, Gabriele; Patey, G N

    2015-03-19

    Molecular dynamics simulations are used to investigate the dissolution of NaCl nanocrystals (containing ∼2400 ions) in water. We focus on systems under sink conditions at 300 K, but the influences of concentration and temperature are also investigated. Cubical, spherical, tablet-shaped, and rod-shaped nanocrystals are considered, and it is shown that the initial shape can influence the dissolution process. Dissolution is observed to occur in three stages: an initial period where the most exposed ions are removed from the crystal surface, and the crystal takes on a solution-annealed shape which persists throughout the second stage of dissolution; a second long intermediate stage where dissolution roughly follows a fixed rate law; and a final stage where the small residual crystal (≲200 ions) dissolves at an ever increasing rate until it disappears. The second stage of dissolution which applies for most of the dissolution process is well described by classical rate equations which simply assume that the dissolution rate is proportional to an active surface area from which ions are most easily detached from the crystal. The active area depends on the initial crystal shape. We show that for our model NaCl nanocrystals the rate-determining step for dissolution under sink conditions is ion detachment from the crystal, and that diffusion layers do not exist for these systems.

  15. Synthesis of epitaxial ternary Co1-xFexSi2 silicides with CsCl- and CaF2-type cubic structures on Si(111) by codeposition techniques

    NASA Astrophysics Data System (ADS)

    Hong, S.; Pirri, C.; Wetzel, P.; Gewinner, G.

    1997-05-01

    We have grown ternary Co1-xFexSi2 silicide films, about 100 Å thick, by codeposition onto Si(111) held at room temperature in the whole composition range 0<=x<=1. Low-energy electron diffraction, inelastic medium-energy electron diffraction, x-ray diffraction, x-ray photoelectron diffraction, and photoemission spectroscopy techniques are used to investigate the atomic and electronic structure of these ternary silicides. It is found that the as-deposited films are metallic and adopt an ordered cubic structure of CsCl type with essentially random vacancies, except in Co-rich films (x<=0.25) where a tendency toward an ordered vacancy arrangement of the CaF2 type is already visible. Upon annealing at 650 °C, these silicides are found to be metastable, but phase separation does not take place. Fe-rich (x>=0.85) films invariably convert into a semiconducting phase with a structure similar to the orthorhombic Β-FeSi2 one. Yet, most interestingly, the cubic structure is preserved for x<=0.85, i.e., stabilized when the Co content exceeds about 15%. X-ray diffraction reveals that these phases exhibit partial CaF2 long-range order. The order parameter is close to zero for x=0.85 and increases rapidly with increasing Co content. The data indicate that Fe does not merely substitute for Co atoms in a perfect CaF2-type CoSi2 structure. Several of the Fe and possibly Co atoms preferentially occupy the interstitial octahedral sites of this latter structure even for x<=0.50, while for x>=0.75 a local environment essentially similar to that in defected CsCl-type structure is observed for both Fe and Co sites.

  16. Gaussian-type light bullet solutions of the (3+1)-dimensional Schrödinger equation with cubic and power-law nonlinearities in PT-symmetric potentials

    SciTech Connect

    Zhu, Hai-Ping; Dai, Chao-Qing

    2014-12-15

    Two kinds of Gaussian-type light bullet (LB) solutions of the (3+1)-dimensional Schrödinger equation with cubic and power-law nonlinearities in PT-symmetric potentials are analytically obtained. The phase switches, powers and transverse power-flow densities of these solutions in homogeneous media are studied. The linear stability analysis of these LB solutions and the direct numerical simulation indicate that LB solutions are stable below some thresholds for the imaginary part of PT-symmetric potentials in the defocusing cubic and focusing power-law nonlinear medium, while they are always unstable for all parameters in other media. Moreover, the broadened and compressed behaviors of LBs in the exponential periodic amplification system and diffraction decreasing system are discussed. Results indicate that LB is more stable for the sign-changing nonlinearity in the exponential periodic amplification system than for the non-sign-changing nonlinearity in the diffraction decreasing system at the same propagation distances.

  17. Growth and characterization of cubic and non-cubic Ge nanocrystals

    SciTech Connect

    Mukherjee, S.; Pradhan, A.; Bhunia, S.; Mukherjee, S.; Maitra, T.; Nayak, A.

    2016-05-06

    Germanium nanocrystals with tetragonal (ST-12) and diamond like cubic (Ge-I) phases have been selectively grown by controlling the ionization and electrostatic potential of Ge clusters in an ion cluster beam deposition system. Predominantly tetragonal nanocrystals were obtained when grown using neutral clusters. The percentage of cubic phase increased when grown by ionizing the clusters and accelerating them towards substrates by applying electrostatic bias in the range of 1.5 –2.5 kV. Raman spectroscopic measurement showed strong peak at 275 cm{sup −1} and 300 cm{sup −1} for tetragonal and cubic Ge nanocrystals, respectively. TEM measurements showed crystalline lattice fringes of both type of the nanocrystals. The selected area electron diffraction patterns showed (111) and (210) as the dominating lattice planes for tetragonal nanocrystals while the cubic phases had (111), (311) and (331) as the prominent lattice planes. The optical absorption edge redshifted from 1.75 to 1.55 eV as the percentage of the cubic phases increased in the NC composition in the composite film.

  18. Expanded halogen-bonded anion organic networks with star-shaped iodoethynyl-substituted molecules: from corrugated 2D hexagonal lattices to pyrite-type 2-fold interpenetrated cubic lattices.

    PubMed

    Lieffrig, Julien; Jeannin, Olivier; Fourmigué, Marc

    2013-04-24

    Halogen bonding interactions between halide anions and neutral polyiodinated linkers are used for the elaboration of anion organic frameworks, by analogy with well-known MOF derivatives. The extended, 3-fold symmetry, 1,3,5-tris(iodoethynyl)-2,4,6-trifluorobenzene (1) cocrystallizes with a variety of halide salts, namely, Et3S(+)I(-), Et3MeN(+)I(-), Et4N(+)Br(-), Et3BuN(+)Br(-), Me-DABCO(+)I(-), Bu3S(+)I(-), Bu4N(+)Br(-), Ph3S(+)Br(-), Ph4P(+)Br(-), and PPN(+)Br(-). Salts with 1:1 stoichiometry formulated as (1)·(C(+),X(-)) show recurrent formation of corrugated (6,3) networks, with the large cavities thus generated, filled either by the cations and solvent (CHCl3) molecules and/or by interpenetration (up to 4-fold interpenetration). The 2:1 salt formulated as (1)2·(Et3BuN(+)Br(-)) crystallizes in the cubic Ia3 space group (a = 22.573(5) Å, V = 11502(4) Å(3)), with the Br(-) ion located on 3 site and molecule 1 on a 3-fold axis. The 6-fold, unprecedented octahedral coordination of the bromide anion generates an hexagonal three-dimensional network of Pa3 symmetry, as observed in the pyrite model structure, at variance with the usual, but lower-symmetry, rutile-type topology. In this complex system, the I centering gives rise to a 2-fold interpenetration of class Ia, while the cations and solvent molecules are found disordered within interconnected cavities. Another related cubic structure of comparable unit cell volume (space group Pa3̅, a = 22.4310(15) Å, V = 11286.2(13) Å(3)) is found with (1)2·(Et3S(+)I(-)).

  19. Infrared cubic dielectric resonator metamaterial.

    SciTech Connect

    Sinclair, Michael B.; Brener, Igal; Peters, David William; Ginn, James Cleveland, III; Ten Eyck, Gregory A.

    2010-06-01

    Dielectric resonators are an effective means to realize isotropic, low-loss optical metamaterials. As proof of this concept, a cubic resonator is analytically designed and then tested in the long-wave infrared.

  20. Nontrivial topology of cubic alkali bismuthides

    NASA Astrophysics Data System (ADS)

    Rusinov, I. P.; Sklyadneva, I. Yu.; Heid, R.; Bohnen, K.-P.; Petrov, E. K.; Koroteev, Yu. M.; Echenique, P. M.; Chulkov, E. V.

    2017-06-01

    We report an ab initio study of the effect of pressure on vibrational and electronic properties of K3Bi and Rb3Bi in the cubic F m 3 ¯m structure. It is shown that the high-temperature cubic phase of K3Bi and Rb3Bi is dynamically unstable at T =0 but can be stabilized by pressure. The electronic spectra of alkali bismuthides are found to possess the bulk band touching at the Brillouin zone center and an inverted spin-orbit bulk band structure. Upon hydrostatic compression the compounds transform from the topologically nontrivial semimetal (K3Bi )/metal (Rb3Bi ) into a trivial semiconductor (metal) with a conical Dirac-type dispersion of electronic bands at the point of the topological transition. In K3Bi the dynamical stabilization occurs before the system undergoes the topological phase transition.

  1. Vacancy-induced mechanical stabilization of cubic tungsten nitride

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Karthik; Khare, Sanjay; Gall, Daniel

    2016-11-01

    First-principles methods are employed to determine the structural, mechanical, and thermodynamic reasons for the experimentally reported cubic WN phase. The defect-free rocksalt phase is both mechanically and thermodynamically unstable, with a negative single crystal shear modulus C44=-86 GPa and a positive enthalpy of formation per formula unit Hf=0.623 eV with respect to molecular nitrogen and metallic W. In contrast, WN in the NbO phase is stable, with C44=175 GPa and Hf=-0.839 eV . A charge distribution analysis reveals that the application of shear strain along [100] in rocksalt WN results in an increased overlap of the t2 g orbitals which causes electron migration from the expanded to the shortened W-W <110 > bond axes, yielding a negative shear modulus due to an energy reduction associated with new bonding states 8.1-8.7 eV below the Fermi level. A corresponding shear strain in WN in the NbO phase results in an energy increase and a positive shear modulus. The mechanical stability transition from the NaCl to the NbO phase is explored using supercell calculations of the NaCl structure containing Cv=0 %-25 % cation and anion vacancies, while keeping the N-to-W ratio constant at unity. The structure is mechanically unstable for Cv<5 % . At this critical vacancy concentration, the isotropic elastic modulus E of cubic WN is zero, but increases steeply to E =445 GPa for Cv=10 % , and then less steeply to E =561 GPa for Cv=25 % . Correspondingly, the hardness estimated using Tian's model increases from 0 to 15 to 26 GPa as Cv increases from 5% to 10% to 25%, indicating that a relatively small vacancy concentration stabilizes the cubic WN phase and that the large variations in reported mechanical properties of WN can be attributed to relatively small changes in Cv.

  2. A Multifunctional Sensor for Concentrations of Ternary Solution with NaCl and Sucrose Employed in Osmotic Dehydration Process

    NASA Astrophysics Data System (ADS)

    Wei, Guo; Shida, Katsunori

    2003-08-01

    Ternary solution with NaCl and sucrose is widely employed in the osmotic dehydration process of food. In this paper we present a multifunctional sensor capable of directly sensing temperature and two physical parameters of solutions, namely ultrasonic velocity and electrical conductivity. By combination measurement of these three measurable parameters, the concentrations of various components in ternary solution with NaCl and sucrose can be simultaneously determined. A regression algorithm based on natural cubic spline interpolation and the least squares method is developed to estimate the concentrations of NaCl and sucrose, which considers the temperature influence on the multifunctional sensor and then enables decoupling of the reconstruction of concentrations in 4D space into 3D space. This sensor could prove valuable as a process control sensor in food industry.

  3. How Cubic Can Ice Be?

    DOE PAGES

    Amaya, Andrew J.; Pathak, Harshad; Modak, Viraj P.; ...

    2017-06-28

    Using an X-ray laser, we investigated the crystal structure of ice formed by homogeneous ice nucleation in deeply supercooled water nanodrops (r ≈ 10 nm) at ~225 K. The nanodrops were formed by condensation of vapor in a supersonic nozzle, and the ice was probed within 100 μs of freezing using femtosecond wide-angle X-ray scattering at the Linac Coherent Light Source free-electron X-ray laser. The X-ray diffraction spectra indicate that this ice has a metastable, predominantly cubic structure; the shape of the first ice diffraction peak suggests stacking-disordered ice with a cubicity value, χ, in the range of 0.78 ±more » 0.05. The cubicity value determined here is higher than those determined in experiments with micron-sized drops but comparable to those found in molecular dynamics simulations. Lastly, the high cubicity is most likely caused by the extremely low freezing temperatures and by the rapid freezing, which occurs on a ~1 μs time scale in single nanodroplets.« less

  4. Multiple CubicBezier Curves.

    ERIC Educational Resources Information Center

    Khonsari, Michael M.; Horn, Douglas

    1990-01-01

    An algorithm is described for generating smooth curves of first-order continuity. The algorithm is composed of several cubic Bezier curves joined together at the user defined control points. Introduced is a tension control parameter which can be set thus providing additional flexibility in the design of free-form curves. (KR)

  5. Cubication of Conservative Nonlinear Oscillators

    ERIC Educational Resources Information Center

    Belendez, Augusto; Alvarez, Mariela L.; Fernandez, Elena; Pascual, Immaculada

    2009-01-01

    A cubication procedure of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force, and this allows us to approximate the original nonlinear differential equation by a Duffing equation in which the coefficients for the linear…

  6. Cubication of Conservative Nonlinear Oscillators

    ERIC Educational Resources Information Center

    Belendez, Augusto; Alvarez, Mariela L.; Fernandez, Elena; Pascual, Immaculada

    2009-01-01

    A cubication procedure of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force, and this allows us to approximate the original nonlinear differential equation by a Duffing equation in which the coefficients for the linear…

  7. Cubic Unit Cell Construction Kit.

    ERIC Educational Resources Information Center

    Mattson, Bruce

    2000-01-01

    Presents instructions for building a simple interactive unit-cell construction kit that allows for the construction of simple, body-centered, and face-centered cubic lattices. The lit is built from inexpensive and readily available materials and can be built in any number of sizes. (WRM)

  8. TRPM5-dependent amiloride- and benzamil-insensitive NaCl chorda tympani taste nerve response.

    PubMed

    Ren, ZuoJun; Rhyu, Mee-Ra; Phan, Tam-Hao T; Mummalaneni, Shobha; Murthy, Karnam S; Grider, John R; DeSimone, John A; Lyall, Vijay

    2013-07-01

    Transient receptor potential (TRP) subfamily M member 5 (TRPM5) cation channel is involved in sensing sweet, bitter, umami, and fat taste stimuli, complex-tasting divalent salts, and temperature-induced changes in sweet taste. To investigate if the amiloride- and benzamil (Bz)-insensitive NaCl chorda tympani (CT) taste nerve response is also regulated in part by TRPM5, CT responses to 100 mM NaCl + 5 μM Bz (NaCl + Bz) were monitored in Sprague-Dawley rats, wild-type (WT) mice, and TRP vanilloid subfamily member 1 (TRPV1) and TRPM5 knockout (KO) mice in the presence of resiniferatoxin (RTX), a TRPV1 agonist. In rats, NaCl + Bz + RTX CT responses were also monitored in the presence of triphenylphosphine oxide, a specific TRPM5 blocker, and capsazepine and N-(3-methoxyphenyl)-4-chlorocinnamid (SB-366791), specific TRPV1 blockers. In rats and WT mice, RTX produced biphasic effects on the NaCl + Bz CT response, enhancing the response at 0.5-1 μM and inhibiting it at >1 μM. The NaCl + Bz + SB-366791 CT response in rats and WT mice and the NaCl + Bz CT response in TRPV1 KO mice were inhibited to baseline level and were RTX-insensitive. In rats, blocking TRPV1 by capsazepine or TRPM5 by triphenylphosphine oxide inhibited the tonic NaCl + Bz CT response and shifted the relationship between RTX concentration and the magnitude of the tonic CT response to higher RTX concentrations. TRPM5 KO mice elicited no constitutive NaCl + Bz tonic CT response. The relationship between RTX concentration and the magnitude of the tonic NaCl + Bz CT response was significantly attenuated and shifted to higher RTX concentrations. The results suggest that pharmacological or genetic alteration of TRPM5 activity modulates the Bz-insensitive NaCl CT response and its modulation by TRPV1 agonists.

  9. Solving Cubic Equations by Polynomial Decomposition

    ERIC Educational Resources Information Center

    Kulkarni, Raghavendra G.

    2011-01-01

    Several mathematicians struggled to solve cubic equations, and in 1515 Scipione del Ferro reportedly solved the cubic while participating in a local mathematical contest, but did not bother to publish his method. Then it was Cardano (1539) who first published the solution to the general cubic equation in his book "The Great Art, or, The Rules of…

  10. Glycerol prevents dehydration in lipid cubic phases.

    PubMed

    Richardson, S J; Staniec, P A; Newby, G E; Rawle, J L; Slaughter, A R; Terrill, N J; Elliott, J M; Squires, A M

    2015-07-21

    Lipid cubic phase samples dry out and undergo phase transitions when exposed to air. We demonstrate experimentally and theoretically that adding glycerol controllably lowers the humidity at which cubic phases form. These results broaden the potential applications of cubic phases and open up the potential of a new humidity-responsive nanomaterial.

  11. Superconductivity in cubic noncentrosymmetric PdBiSe Crystal

    NASA Astrophysics Data System (ADS)

    Joshi, B.; Thamizhavel, A.; Ramakrishnan, S.

    2015-03-01

    Mixing of spin singlet and spin triplet superconducting pairing state is expected in noncentrosymmetric superconductors (NCS) due to the inherent presence of Rashba-type antisymmetric spin-orbit coupling. Unlike low symmetry (tetragonal or monoclinic) NCS, parity is isotropicaly broken in space for cubic NCS and can additionally lead to the coexistence of magnetic and superconducting state under certain conditions. Motivated with such enriched possibility of unconventional superconducting phases in cubic NCS we are reporting successful formation of single crystalline cubic noncentrosymmetric PdBiSe with lattice parameter a = 6.4316 Å and space group P21 3 (space group no. 198) which undergoes to superconducting transition state below 1.8 K as measured by electrical transport and AC susceptibility measurements. Significant strength of Rashba-type antisymmetric spin-orbit coupling can be expected for PdBiSe due to the presence of high Z (atomic number) elements consequently making it potential candidate for unconventional superconductivity.

  12. Effects of stacking disorder on thermal conductivity of cubic ice

    NASA Astrophysics Data System (ADS)

    Johari, G. P.; Andersson, Ove

    2015-08-01

    Cubic ice is said to have stacking disorder when the H2O sequences in its structure (space group F d 3 ¯ m ) are interlaced with hexagonal ice (space group P63/mmc) sequences, known as stacking faults. Diffraction methods have shown that the extent of this disorder varies in samples made by different methods, thermal history, and the temperature T, but other physical properties of cubic and hexagonal ices barely differ. We had found that at 160 K, the thermal conductivity, κ, of cubic ice is ˜20% less than that of hexagonal ice, and this difference varies for cubic ice samples prepared by different methods and/or subjected to different thermal history. After reviewing the methods of forming cubic ice, we report an investigation of the effects of stacking disorder and other features by using new data, and by analyzing our previous data on the dependence of κ on T and on the pressure. We conclude that the lower κ of cubic ice and its weaker T-dependence is due mainly to stacking disorder and small crystal sizes. On in situ heating at 20-50 MPa pressure, κ increases and cubic ice irreversibly transforms more sharply to ice Ih, and at a higher T of ˜220 K, than it does in ex situ studies. Cooling and heating between 115 and 130 K at 0.1 K min-1 rate yield the same κ value, indicating that the state of cubic ice in these conditions does not change with time and T. The increase in κ of cubic ice observed on heat-annealing before its conversion to hexagonal ice is attributed to the loss of stacking faults and other types of disorders, and to grain growth. After discussing the consequences of our findings on other properties, we suggest that detailed studies of variation of a given property of cubic ice with the fraction of stacking faults in its structure may reveal more about the effect of this disorder. A similar disorder may occur in the mono-layers of H2O adsorbed on a substrate, in bulk materials comprised of two dimensional layers, in diamond and in

  13. Effects of stacking disorder on thermal conductivity of cubic ice.

    PubMed

    Johari, G P; Andersson, Ove

    2015-08-07

    Cubic ice is said to have stacking disorder when the H2O sequences in its structure (space group Fd3̄m) are interlaced with hexagonal ice (space group P6(3)/mmc) sequences, known as stacking faults. Diffraction methods have shown that the extent of this disorder varies in samples made by different methods, thermal history, and the temperature T, but other physical properties of cubic and hexagonal ices barely differ. We had found that at 160 K, the thermal conductivity, κ, of cubic ice is ∼20% less than that of hexagonal ice, and this difference varies for cubic ice samples prepared by different methods and/or subjected to different thermal history. After reviewing the methods of forming cubic ice, we report an investigation of the effects of stacking disorder and other features by using new data, and by analyzing our previous data on the dependence of κ on T and on the pressure. We conclude that the lower κ of cubic ice and its weaker T-dependence is due mainly to stacking disorder and small crystal sizes. On in situ heating at 20-50 MPa pressure, κ increases and cubic ice irreversibly transforms more sharply to ice Ih, and at a higher T of ∼220 K, than it does in ex situ studies. Cooling and heating between 115 and 130 K at 0.1 K min(-1) rate yield the same κ value, indicating that the state of cubic ice in these conditions does not change with time and T. The increase in κ of cubic ice observed on heat-annealing before its conversion to hexagonal ice is attributed to the loss of stacking faults and other types of disorders, and to grain growth. After discussing the consequences of our findings on other properties, we suggest that detailed studies of variation of a given property of cubic ice with the fraction of stacking faults in its structure may reveal more about the effect of this disorder. A similar disorder may occur in the mono-layers of H2O adsorbed on a substrate, in bulk materials comprised of two dimensional layers, in diamond and in

  14. WNK kinases regulate thiazide-sensitive Na-Cl cotransport.

    PubMed

    Yang, Chao-Ling; Angell, Jordan; Mitchell, Rose; Ellison, David H

    2003-04-01

    Pseudohypoaldosteronism type II (PHAII) is an autosomal dominant disorder of hyperkalemia and hypertension. Mutations in two members of the WNK kinase family, WNK1 and WNK4, cause the disease. WNK1 mutations are believed to increase WNK1 expression; the effect of WNK4 mutations remains unknown. The clinical phenotype of PHAII is opposite to Gitelman syndrome, a disease caused by dysfunction of the thiazide-sensitive Na-Cl cotransporter. We tested the hypothesis that WNK kinases regulate the mammalian thiazide-sensitive Na-Cl cotransporter (NCC). Mouse WNK4 was cloned and expressed in Xenopus oocytes with or without NCC. Coexpression with WNK4 suppressed NCC activity by more than 85%. This effect did not result from defects in NCC synthesis or processing, but was associated with an 85% reduction in NCC abundance at the plasma membrane. Unlike WNK4, WNK1 did not affect NCC activity directly. WNK1, however, completely prevented WNK4 inhibition of NCC. Some WNK4 mutations that cause PHAII retained NCC-inhibiting activity, but the Q562E WNK4 demonstrated diminished activity, suggesting that some PHAII mutations lead to loss of NCC inhibition. Gain-of-function WNK1 mutations would be expected to inhibit WNK4 activity, thereby activating NCC, contributing to the PHAII phenotype. Together, these results identify WNK kinases as a previously unrecognized sodium regulatory pathway of the distal nephron. This pathway likely contributes to normal and pathological blood pressure homeostasis.

  15. Weighted cubic and biharmonic splines

    NASA Astrophysics Data System (ADS)

    Kvasov, Boris; Kim, Tae-Wan

    2017-01-01

    In this paper we discuss the design of algorithms for interpolating discrete data by using weighted cubic and biharmonic splines in such a way that the monotonicity and convexity of the data are preserved. We formulate the problem as a differential multipoint boundary value problem and consider its finite-difference approximation. Two algorithms for automatic selection of shape control parameters (weights) are presented. For weighted biharmonic splines the resulting system of linear equations can be efficiently solved by combining Gaussian elimination with successive over-relaxation method or finite-difference schemes in fractional steps. We consider basic computational aspects and illustrate main features of this original approach.

  16. Transparent polycrystalline cubic silicon nitride

    NASA Astrophysics Data System (ADS)

    Nishiyama, Norimasa; Ishikawa, Ryo; Ohfuji, Hiroaki; Marquardt, Hauke; Kurnosov, Alexander; Taniguchi, Takashi; Kim, Byung-Nam; Yoshida, Hidehiro; Masuno, Atsunobu; Bednarcik, Jozef; Kulik, Eleonora; Ikuhara, Yuichi; Wakai, Fumihiro; Irifune, Tetsuo

    2017-03-01

    Glasses and single crystals have traditionally been used as optical windows. Recently, there has been a high demand for harder and tougher optical windows that are able to endure severe conditions. Transparent polycrystalline ceramics can fulfill this demand because of their superior mechanical properties. It is known that polycrystalline ceramics with a spinel structure in compositions of MgAl2O4 and aluminum oxynitride (γ-AlON) show high optical transparency. Here we report the synthesis of the hardest transparent spinel ceramic, i.e. polycrystalline cubic silicon nitride (c-Si3N4). This material shows an intrinsic optical transparency over a wide range of wavelengths below its band-gap energy (258 nm) and is categorized as one of the third hardest materials next to diamond and cubic boron nitride (cBN). Since the high temperature metastability of c-Si3N4 in air is superior to those of diamond and cBN, the transparent c-Si3N4 ceramic can potentially be used as a window under extremely severe conditions.

  17. Hardness of cubic solid solutions

    PubMed Central

    Gao, Faming

    2017-01-01

    We demonstrate that a hardening rule exists in cubic solid solutions with various combinations of ionic, covalent and metallic bonding. It is revealed that the hardening stress ∆τFcg is determined by three factors: shear modulus G, the volume fraction of solute atoms fv, and the size misfit degree δb. A simple hardening correlation in KCl-KBr solid-solution is proposed as ∆τFcg = 0.27 G. It is applied to calculate the hardening behavior of the Ag-Au, KCl-KBr, InP-GaP, TiN-TiC, HfN-HfC, TiC-NbC and ZrC-NbC solid-solution systems. The composition dependence of hardness is elucidated quantitatively. The BN-BP solid-solution system is quantitatively predicted. We find a hardening plateau region around the x = 0.55–0.85 in BNxP1−x, where BNxP1−x solid solutions are far harder than cubic BN. Because the prediction is quantitative, it sets the stage for a broad range of applications. PMID:28054659

  18. Transparent polycrystalline cubic silicon nitride.

    PubMed

    Nishiyama, Norimasa; Ishikawa, Ryo; Ohfuji, Hiroaki; Marquardt, Hauke; Kurnosov, Alexander; Taniguchi, Takashi; Kim, Byung-Nam; Yoshida, Hidehiro; Masuno, Atsunobu; Bednarcik, Jozef; Kulik, Eleonora; Ikuhara, Yuichi; Wakai, Fumihiro; Irifune, Tetsuo

    2017-03-17

    Glasses and single crystals have traditionally been used as optical windows. Recently, there has been a high demand for harder and tougher optical windows that are able to endure severe conditions. Transparent polycrystalline ceramics can fulfill this demand because of their superior mechanical properties. It is known that polycrystalline ceramics with a spinel structure in compositions of MgAl2O4 and aluminum oxynitride (γ-AlON) show high optical transparency. Here we report the synthesis of the hardest transparent spinel ceramic, i.e. polycrystalline cubic silicon nitride (c-Si3N4). This material shows an intrinsic optical transparency over a wide range of wavelengths below its band-gap energy (258 nm) and is categorized as one of the third hardest materials next to diamond and cubic boron nitride (cBN). Since the high temperature metastability of c-Si3N4 in air is superior to those of diamond and cBN, the transparent c-Si3N4 ceramic can potentially be used as a window under extremely severe conditions.

  19. Vacancy Relaxation in Cubic Crystals

    NASA Technical Reports Server (NTRS)

    Girifalco, L. A.; Weizer, V. G.

    1960-01-01

    The configuration of the atoms surrounding a vacancy in four face-centered cubic and three body-centered cubic metals has been computed, using a pairwise, central-force model in which the energy of interaction between two atoms was taken to have the form of a Morse function. Only radial relaxations were considered. The first and second nearest-neighbor relaxations for the face-centered systems were found to be: Pb (1.42,-0.43), Ni (2.14,-0.39), Cu(2.24,-0.40) and Ca (2.73,-0.41, expressed in percentages of normal distances. For the body-centered systems the relaxations out to the fourth nearest neighbors to the vacancy were: Fe (6.07,-2.12, -0.25, -), Ba (7.85, -2.70, 0.70, -0.33) and Na (10.80, -3.14, 3.43, -0.20). The positive signs indicate relaxation toward the vacancy and the negative signs indicate relaxation away from the vacancy. The energies of relaxation (eV) are: Pb (0.162), Ni (0.626), Cu (0.560), Ca (0.400), Fe (1.410), Ba (0.950) and Na (0.172).

  20. Transparent polycrystalline cubic silicon nitride

    PubMed Central

    Nishiyama, Norimasa; Ishikawa, Ryo; Ohfuji, Hiroaki; Marquardt, Hauke; Kurnosov, Alexander; Taniguchi, Takashi; Kim, Byung-Nam; Yoshida, Hidehiro; Masuno, Atsunobu; Bednarcik, Jozef; Kulik, Eleonora; Ikuhara, Yuichi; Wakai, Fumihiro; Irifune, Tetsuo

    2017-01-01

    Glasses and single crystals have traditionally been used as optical windows. Recently, there has been a high demand for harder and tougher optical windows that are able to endure severe conditions. Transparent polycrystalline ceramics can fulfill this demand because of their superior mechanical properties. It is known that polycrystalline ceramics with a spinel structure in compositions of MgAl2O4 and aluminum oxynitride (γ-AlON) show high optical transparency. Here we report the synthesis of the hardest transparent spinel ceramic, i.e. polycrystalline cubic silicon nitride (c-Si3N4). This material shows an intrinsic optical transparency over a wide range of wavelengths below its band-gap energy (258 nm) and is categorized as one of the third hardest materials next to diamond and cubic boron nitride (cBN). Since the high temperature metastability of c-Si3N4 in air is superior to those of diamond and cBN, the transparent c-Si3N4 ceramic can potentially be used as a window under extremely severe conditions. PMID:28303948

  1. Hardness of cubic solid solutions

    NASA Astrophysics Data System (ADS)

    Gao, Faming

    2017-01-01

    We demonstrate that a hardening rule exists in cubic solid solutions with various combinations of ionic, covalent and metallic bonding. It is revealed that the hardening stress ∆τFcg is determined by three factors: shear modulus G, the volume fraction of solute atoms fv, and the size misfit degree δb. A simple hardening correlation in KCl-KBr solid-solution is proposed as ∆τFcg = 0.27 G. It is applied to calculate the hardening behavior of the Ag-Au, KCl-KBr, InP-GaP, TiN-TiC, HfN-HfC, TiC-NbC and ZrC-NbC solid-solution systems. The composition dependence of hardness is elucidated quantitatively. The BN-BP solid-solution system is quantitatively predicted. We find a hardening plateau region around the x = 0.55-0.85 in BNxP1-x, where BNxP1-x solid solutions are far harder than cubic BN. Because the prediction is quantitative, it sets the stage for a broad range of applications.

  2. Compensation in epitaxial cubic SiC films

    NASA Technical Reports Server (NTRS)

    Segall, B.; Alterovitz, S. A.; Haugland, E. J.; Matus, L. G.

    1986-01-01

    Hall measurements on four n-type cubic SiC films epitaxially grown by chemical vapor deposition on SiC substrates are reported. The temperature dependent carrier concentrations indicate that the samples are highly compensated. Donor ionization energies, E sub D, are less than one half the values previously reported. The values for E sub D and the donor concentration N sub D, combined with results for small bulk platelets with nitrogen donors, suggest the relation E sub D (N sub D) = E sub D(O) - alpha N sub N sup 1/3 for cubic SiC. A curve fit gives alpha is approx 2.6x10/5 meV cm and E sub D (O) approx 48 meV, which is the generally accepted value of E sub D(O) for nitrogen donors in cubic SiC.

  3. Large Negative Thermal Expansion and Anomalous Behavior on Compression in Cubic ReO3-type AIIBIVF6: CaZrF6 and CaHfF6

    SciTech Connect

    Hancock, Justin C.; Chapman, Karena W.; Halder, Gregory J.; Morelock, Cody R.; Karlan, Benjamin S.; Gallington, Leighanne C.; Bongiorno, Angelo; Han, Chu; Zhou, Si; Wilkinson, Angus P.

    2015-06-09

    CaZrF6 and CaHfF6 display much stronger negative thermal expansion (NTE) (alpha(L100 K) similar to -18 and -22 ppm K-1, respectively) than ZrW2O8 and other corner-shared framework structures. Their NTE is comparable to that reported for framework solids containing multiatom bridges, such as metal cyanides and metal-organic frameworks. However, they are formable as ceramics, transparent over a wide wavelength range and can be handled in air; these characteristics can be beneficial for applications. The NTE of CaZrF6 is strongly temperature-dependent, and first-principles calculations show that it is largely driven by vibrational modes below similar to 150 cm(-1). CaZrF6 is elastically soft with a bulk modulus (K-300K) of 37 GPa and, upon compression, starts to disorder at similar to 400 MPa. The strong NTE of CaZrF6, which remains cubic to <10 K, contrasts with cubic CoZrF6, which only displays modest NTE above its rhombohedral to cubic phase transition at similar to 270 K. CaZrF6 and CaHfF6 belong to a large and compositionally diverse family of materials, A(II)B(IV)F(6), providing for a detailed exploration of the chemical and structural factors controlling NTE and many opportunities for the design of controlled thermal expansion materials.

  4. Nonlinear surface acoustic waves in cubic crystals

    NASA Astrophysics Data System (ADS)

    Kumon, Ronald Edward

    Model equations developed by Hamilton, Il'inskii, and Zabolotskaya [J. Acoust. Soc. Am. 105, 639-651 (1999)] are used to perform theoretical and numerical studies of nonlinear surface acoustic waves in a variety of nonpiezoelectric cubic crystals. The basic theory underlying the model equations is outlined, quasilinear solutions of the equations are derived, and expressions are developed for the shock formation distance and nonlinearity coefficient. A time-domain equation corresponding to the frequency-domain model equations is derived and shown to reduce to a time-domain equation introduced previously for Rayleigh waves [E. A. Zabolotskaya, J. Acoust. Soc. Am. 91, 2569-2575 (1992)]. Numerical calculations are performed to predict the evolution of initially monofrequency surface waves in the (001), (110), and (111) planes of the crystals RbCl, KCl, NaCl, CaF2, SrF2, BaF2, C (diamond), Si, Ge, Al, Ni, Cu in the moverline 3m point group, and the crystals Cs-alum, NH4- alum, and K-alum in the moverline 3 point group. The calculations are based on measured second- and third- order elastic constants taken from the literature. Nonlinearity matrix elements which describe the coupling strength of harmonic interactions are shown to provide a powerful tool for characterizing waveform distortion. Simulations in the (001) and (110) planes show that in certain directions the velocity waveform distortion may change in sign, generation of one or more harmonies may be suppressed and shock formation postponed, or energy may be transferred rapidly to the highest harmonics and shock formation enhanced. Simulations in the (111) plane show that the nonlinearity matrix elements are generally complex-valued, which may lead to asymmetric distortion and the appearance of low frequency oscillations near the peaks and shocks in the velocity waveforms. A simple transformation based on the phase of the nonlinearity matrix is shown to provide a reasonable approximation of asymmetric waveform

  5. Polarization conversion in cubic Raman crystals

    NASA Astrophysics Data System (ADS)

    McKay, Aaron; Sabella, Alexander; Mildren, Richard P.

    2017-02-01

    Nonlinear conversion of unpolarized beams to lower frequencies is generally inefficient in c(2) materials, as it is challenging to achieve phase-matching for input ordinary and extraordinary beams simultaneously in the normal dispersion regime. Here, we show that cubic Raman crystals having doubly and triply degenerate (E and F type) modes provide a method for efficient nonlinear frequency downconversion of an unpolarized beam and yield a linearly polarized output state. Using Mueller calculus, optimal crystal directions for such polarization conversion are determined. Using diamond, an example of an F-class Raman crystal, we have verified that such conversion is possible with near quantum-defect-limited slope efficiency and a linear polarization contrast of more than 23.9 dB.

  6. Polarization conversion in cubic Raman crystals

    PubMed Central

    McKay, Aaron; Sabella, Alexander; Mildren, Richard P.

    2017-01-01

    Nonlinear conversion of unpolarized beams to lower frequencies is generally inefficient in c(2) materials, as it is challenging to achieve phase-matching for input ordinary and extraordinary beams simultaneously in the normal dispersion regime. Here, we show that cubic Raman crystals having doubly and triply degenerate (E and F type) modes provide a method for efficient nonlinear frequency downconversion of an unpolarized beam and yield a linearly polarized output state. Using Mueller calculus, optimal crystal directions for such polarization conversion are determined. Using diamond, an example of an F-class Raman crystal, we have verified that such conversion is possible with near quantum-defect-limited slope efficiency and a linear polarization contrast of more than 23.9 dB. PMID:28169327

  7. Integral representations for products of Airy functions Part 2. Cubic products

    NASA Astrophysics Data System (ADS)

    Reid, W. H.

    Integral representations are obtained for some cubic products of the Airy functions Ai(z) and Bi(z). These integral representations are of the Laplace contour type but they involve the modified Bessel functions of order 16. From these results it is then possible to evaluate a number of definite integrals involving such cubic products.

  8. Angiotensin II stimulates water and NaCl intake through separate cell signalling pathways in rats.

    PubMed

    Daniels, Derek; Mietlicki, Elizabeth G; Nowak, Erica L; Fluharty, Steven J

    2009-01-01

    Angiotensin II (AngII) stimulation of water and NaCl intake is a classic model of the behavioural effects of hormones. In vitro studies indicate that the AngII type 1 (AT(1)) receptor stimulates intracellular pathways that include protein kinase C (PKC) and mitogen-activated protein (MAP) kinase activation. Previous studies support the hypotheses that PKC is involved in AngII-induced water, but not NaCl intake and that MAP kinase plays a role in NaCl consumption, but not water intake, after injection of AngII. The present experiments test these hypotheses in rats using central injections of AngII in the presence or absence of a PKC inhibitor or a MAP kinase inhibitor. Pretreatment with the PKC inhibitor chelerythrine attenuated AngII-induced water intake, but NaCl intake was unaffected. In contrast, pretreatment with U0126, a MAP kinase inhibitor, had no effect on AngII-induced water intake, but attenuated NaCl intake. These data support the working hypotheses and significantly extend our earlier findings and those of others. Perhaps more importantly, these experiments demonstrate the remarkable diversity of peptide receptor systems and add support for the surprising finding that intracellular signalling pathways can have divergent behavioural relevance.

  9. Silver nanoparticles and silver ions stabilized in NaCl nanocrystals

    NASA Astrophysics Data System (ADS)

    Flores-López, N. S.; Cortez-Valadez, M.; Moreno-Ibarra, G. M.; Larios-Rodríguez, E.; Torres-Flores, E. I.; Delgado-Beleño, Y.; Martinez-Nuñez, C. E.; Ramírez-Rodríguez, L. P.; Arizpe-Chávez, H.; Castro-Rosas, J.; Ramirez-Bon, R.; Flores-Acosta, M.

    2016-10-01

    This study presents a two-step synthesis of nanoparticles and the stabilization process of Ag ions in the matrix of NaCl nanocrystals. Ag+ ions are incorporated to NaCl with a new and attractive method that can be easily used for the different types of alkaline halides. The nanoparticles with predominant size found between 10 and 15 nm were stabilized on the surface and/or interior of NaCl nanocrystals using, in the first stages, the ionic-exchange property of zeolite A4. The optical properties of the materials were characterized through optical absorption, leading to well defined absorption bands located in the wave length values between 217-275 nm and 350-770 nm approximately, for Ag+ and AgNp, respectively. The antibacterial property of Ag ions and nanoparticles stabilized in NaCl was analyzed against gram-negative Escherichia Coli and Klebsiella bacteria. In order to quantify the antibacterial effect of Ag ions and nanoparticles the inhibition ratio was used as a parameter on the bacteria colonies grown in culture medium by conventional methods. Ag+ ions that were stabilized in NaCl nanocrystals show a mayor inhibition ratio in contact with Klebsiella bacteria, conversely Ag nanoparticles showed better results in contact with E. coli.

  10. Angiotensin II stimulates water and NaCl intake through separate cell signalling pathways

    PubMed Central

    Daniels, Derek; Mietlicki, Elizabeth G.; Nowak, Erica L.; Fluharty, Steven J.

    2010-01-01

    Angiotensin II (AngII) stimulation of water and NaCl intake is a classic model of the behavioural effects of hormones. In vitro studies indicate that the AngII type 1 (AT1) receptor stimulates intracellular pathways that include PKC and MAP kinase activation. Previous studies support the hypotheses that PKC is involved in AngII-induced water, but not NaCl intake and that MAP kinase plays a role in NaCl consumption, but not water intake, after injection of AngII. The present experiments test these hypotheses using central injections of AngII in the presence or absence of a PKC inhibitor or a MAP kinase inhibitor. Pre-treatment with the PKC inhibitor chelerythrine attenuated AngII-induced water intake, but NaCl intake was unaffected. In contrast, pre-treatment with U0126, a MAP kinase inhibitor, had no effect on AngII-induced water intake, but attenuated NaCl intake. These data support the working hypotheses and significantly extend our earlier findings and those of others. Perhaps more importantly, these experiments demonstrate the remarkable diversity of peptide receptor systems and add support for the surprising finding that intracellular signalling pathways can have divergent behavioural relevance. PMID:18723579

  11. Regulation of aquaporin-mediated water transport in Arabidopsis roots exposed to NaCl.

    PubMed

    Lee, Seong H; Zwiazek, Janusz J

    2015-04-01

    The effects of Ca(NO3)2, KF and okadaic acid (OA) on cell hydraulic responses to NaCl were examined in roots of Arabidopsis thaliana wild-type plants and compared with plants overexpressing plasma membrane intrinsic protein PIP2;5. Root treatment with 10 mM NaCl rapidly and sharply reduced cell hydraulic conductivity (L(p)) in the wild-type Arabidopsis plants, but had no effect on L(p) in Arabidopsis plants overexpressing PIP2;5, suggesting that changes in protein and aquaporin gene expression were among the initial targets responsible for the inhibition of L(p) by NaCl. The down-regulation of PIP transcripts after 1 h exposure to 10 mM NaCl was likely a significant factor in the reduction of L(p). The effect of NaCl on L(p) in the wild-type plants was abolished when the NaCl-treated roots were subsequently exposed to 5 mM KF, 5 mM Ca(NO3)2 and 5 µM OA. The reduction of L(p) by 5 mM KF could not be prevented by treatment with 5 mM Ca(NO3)2 in both wild-type and PIP2;5-overexpressing plants. However, 5 µM OA, which was added following NaCl or KF treatment, completely reversed L(p) within several minutes. The results provide evidence for high sensitivity of aquaporin-mediated water transport to relatively low NaCl concentrations and point to the phosphorylation and/or dephosphorylation processes as those that are likely responsible for the protection of L(p) by fluoride and calcium treatments against the effects of NaCl. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. An Application of Specific Sensors For The Monitoring of NaCl in Soft Cheeses

    NASA Astrophysics Data System (ADS)

    Lvova, Larisa; Mielle, Patrick; Salles, Christian; Denis, Sylvain; Vergoignan, Catherine; Barra, Aurélien; Di Natale, Corrado; Paolesse, Roberto; Temple-Boyer, Pierre; Feron, Gilles

    2011-09-01

    The commercial sensors and prototype ISEs array (Ion Selective Electrodes array) were utilized for NaCl concentration measurements in soft cheeses, in particular in vitro gut process and in commercial Italian mozzarella cheeses. The values obtained from the sensors were compared with HPLC analysis. The results showed the feasibility of the ISE array application to monitor NaCl in soft cheese during the breakdown in the digester. The best results were obtained with the use of ISEs array combining, in particular, Cl- and Na+ detections. The salinity of commercial mozzarella cheese samples and the originally utilized milk type (cow or buffalo) were also satisfactory determined with the developed ISE array.

  13. Automated reasoning about cubic curves.

    SciTech Connect

    Padmanabhan, R.; McCune, W.; Mathematics and Computer Science; Univ. of Manitoba

    1995-01-01

    It is well known that the n-ary morphisms defined on projective algebraic curves satisfy some strong local-to-global equational rules of derivation not satisfied in general by universal algebras. For example, every rationally defined group law on a cubic curve must be commutative. Here we extract from the geometry of curves a first order property (gL) satisfied by all morphisms defined on these curves such that the equational consequences known for projective curves can be derived automatically from a set of six rules (stated within the first-order logic with equality). First, the rule (gL) is implemented in the theorem-proving program Otter. Then we use Otter to automatically prove some incidence theorems on projective curves without any further reference to the underlying geometry or topology of the curves.

  14. Two-dimensional cubic convolution.

    PubMed

    Reichenbach, Stephen E; Geng, Frank

    2003-01-01

    The paper develops two-dimensional (2D), nonseparable, piecewise cubic convolution (PCC) for image interpolation. Traditionally, PCC has been implemented based on a one-dimensional (1D) derivation with a separable generalization to two dimensions. However, typical scenes and imaging systems are not separable, so the traditional approach is suboptimal. We develop a closed-form derivation for a two-parameter, 2D PCC kernel with support [-2,2] x [-2,2] that is constrained for continuity, smoothness, symmetry, and flat-field response. Our analyses, using several image models, including Markov random fields, demonstrate that the 2D PCC yields small improvements in interpolation fidelity over the traditional, separable approach. The constraints on the derivation can be relaxed to provide greater flexibility and performance.

  15. Temperature-dependent formation of NaCl dihydrate in levitated NaCl and sea salt aerosol particles.

    PubMed

    Peckhaus, Andreas; Kiselev, Alexei; Wagner, Robert; Duft, Denis; Leisner, Thomas

    2016-12-28

    Recent laboratory studies indicate that the hydrated form of crystalline NaCl is potentially important for atmospheric processes involving depositional ice nucleation on NaCl dihydrate particles under cirrus cloud conditions. However, recent experimental studies reported a strong discrepancy between the temperature intervals where the efflorescence of NaCl dihydrate has been observed. Here we report the measurements of the volume specific nucleation rate of crystalline NaCl in the aqueous solution droplets of pure NaCl suspended in an electrodynamic balance at constant temperature and humidity in the range from 250 K to 241 K. Based on these measurements, we derive the interfacial energy of crystalline NaCl dihydrate in a supersaturated NaCl solution and determined its temperature dependence. Taking into account both temperature and concentration dependence of nucleation rate coefficients, we explain the difference in the observed fractions of NaCl dihydrate reported in the previous studies. Applying the heterogeneous classical nucleation theory model, we have been able to reproduce the 5 K shift of the NaCl dihydrate efflorescence curve observed for the sea salt aerosol particles, assuming the presence of super-micron solid inclusions (hypothetically gypsum or hemihydrate of CaSO4). These results support the notion that the phase transitions in microscopic droplets of supersaturated solution should be interpreted by accounting for the stochastic nature of homogeneous and heterogeneous nucleation and cannot be understood on the ground of bulk phase diagrams alone.

  16. Temperature-dependent formation of NaCl dihydrate in levitated NaCl and sea salt aerosol particles

    NASA Astrophysics Data System (ADS)

    Peckhaus, Andreas; Kiselev, Alexei; Wagner, Robert; Duft, Denis; Leisner, Thomas

    2016-12-01

    Recent laboratory studies indicate that the hydrated form of crystalline NaCl is potentially important for atmospheric processes involving depositional ice nucleation on NaCl dihydrate particles under cirrus cloud conditions. However, recent experimental studies reported a strong discrepancy between the temperature intervals where the efflorescence of NaCl dihydrate has been observed. Here we report the measurements of the volume specific nucleation rate of crystalline NaCl in the aqueous solution droplets of pure NaCl suspended in an electrodynamic balance at constant temperature and humidity in the range from 250 K to 241 K. Based on these measurements, we derive the interfacial energy of crystalline NaCl dihydrate in a supersaturated NaCl solution and determined its temperature dependence. Taking into account both temperature and concentration dependence of nucleation rate coefficients, we explain the difference in the observed fractions of NaCl dihydrate reported in the previous studies. Applying the heterogeneous classical nucleation theory model, we have been able to reproduce the 5 K shift of the NaCl dihydrate efflorescence curve observed for the sea salt aerosol particles, assuming the presence of super-micron solid inclusions (hypothetically gypsum or hemihydrate of CaSO4). These results support the notion that the phase transitions in microscopic droplets of supersaturated solution should be interpreted by accounting for the stochastic nature of homogeneous and heterogeneous nucleation and cannot be understood on the ground of bulk phase diagrams alone.

  17. Cubic spline functions for curve fitting

    NASA Technical Reports Server (NTRS)

    Young, J. D.

    1972-01-01

    FORTRAN cubic spline routine mathematically fits curve through given ordered set of points so that fitted curve nearly approximates curve generated by passing infinite thin spline through set of points. Generalized formulation includes trigonometric, hyperbolic, and damped cubic spline fits of third order.

  18. Modified cubic convolution resampling for Landsat

    NASA Technical Reports Server (NTRS)

    Prakash, A.; Mckee, B.

    1985-01-01

    An overview is given of Landsat Thematic Mapper resampling technique, including a modification of the well-known cubic convolution interpolator (nearest neighbor interpolation) used to provide geometric correction for TM data. Post launch study has shown that the modified cubic convolution interpolator can selectively enhance or suppress frequency bands in the output image. This selectivity is demonstrated on TM Band 3 imagery.

  19. Cubic spline functions for curve fitting

    NASA Technical Reports Server (NTRS)

    Young, J. D.

    1972-01-01

    FORTRAN cubic spline routine mathematically fits curve through given ordered set of points so that fitted curve nearly approximates curve generated by passing infinite thin spline through set of points. Generalized formulation includes trigonometric, hyperbolic, and damped cubic spline fits of third order.

  20. Dissociation of methane hydrate in aqueous NaCl solutions.

    PubMed

    Yagasaki, Takuma; Matsumoto, Masakazu; Andoh, Yoshimichi; Okazaki, Susumu; Tanaka, Hideki

    2014-10-09

    Molecular dynamics simulations of the dissociation of methane hydrate in aqueous NaCl solutions are performed. It is shown that the dissociation of the hydrate is accelerated by the formation of methane bubbles both in NaCl solutions and in pure water. We find two significant effects on the kinetics of the hydrate dissociation by NaCl. One is slowing down in an early stage before bubble formation, and another is swift bubble formation that enhances the dissociation. These effects arise from the low solubility of methane in NaCl solution, which gives rise to a nonuniform spatial distribution of solvated methane in the aqueous phase. We also demonstrate that bubbles form near the hydrate interface in dense NaCl solutions and that the hydrate dissociation proceeds inhomogeneously due to the bubbles.

  1. Dynamic and static interactions in CO overlayers on sintered NaCl films

    NASA Astrophysics Data System (ADS)

    Zecchina, A.; Scarano, D.; Garrone, E.

    1985-09-01

    Sublimation of NaCl onto a cold (77 K) NaCl plate followed by sintering at 300 K gives an IR transparent film formed by individual crystallites having cubic shape. CO adsorbed on {100} faces of the crystallites gives an IR peak at 2161-2156 cm -1, while CO adsorbed on edges (steps) gives a weaker peak at ˜2175 cm -1. The CO molecules are adsorbed on Na + ions and form a bidimensional array of parallel oscillators. Lateral adsorbate-adsorbate interactions (dynamic and static) are responsible for the shift of the IR frequency. The relative weight of the static and dynamic effects is estimated by using 12CO- 13CO mixtures. The dynamic effect is well described by the modified Hammaker equation, with α v=0.0235 Å-3. The unusually low value of the dynamic polarizability agrees very well with literature data concerning the intensity of the stretching band of CO adsorbed on ions. The static effect, causing a consistent negative shift of the CO frequency, is related to through-solid interactions of inductive nature.

  2. A look through ‘lens’ cubic mitochondria

    PubMed Central

    Almsherqi, Zakaria; Margadant, Felix; Deng, Yuru

    2012-01-01

    Cell membranes may fold up into three-dimensional nanoperiodic cubic structures in biological systems. Similar geometries are well studied in other disciplines such as mathematics, physics and polymer chemistry. The fundamental function of cubic membranes in biological systems has not been uncovered yet; however, their appearance in specialized cell types indicates a role as structural templates or perhaps direct physical entities with specialized biophysical properties. The mitochondria located at the inner segment of the retinal cones of tree shrew (Tupaia glis and Tupaia belangeri) contain unique patterns of concentric cristae with a highly ordered membrane arrangement in three dimensions similar to the photonic nanostructures observed in butterfly wing scales. Using a direct template matching method, we show that the inner mitochondrial membrane folds into multi-layered (8 to 12 layers) gyroid cubic membrane arrangements in the photoreceptor cells. Three-dimensional simulation data demonstrate that such multi-layer gyroid membrane arrangements in the retinal cones of a tree shrew's eye can potentially function as: (i) multi-focal lens; (ii) angle-independent interference filters to block UV light; and (iii) a waveguide photonic crystal. These theoretical results highlight for the first time the significance of multi-layer cubic membrane arrangements to achieve near-quasi-photonic crystal properties through the simple and reversible biological process of continuous membrane folding. PMID:24098837

  3. Ultrahard nanotwinned cubic boron nitride.

    PubMed

    Tian, Yongjun; Xu, Bo; Yu, Dongli; Ma, Yanming; Wang, Yanbin; Jiang, Yingbing; Hu, Wentao; Tang, Chengchun; Gao, Yufei; Luo, Kun; Zhao, Zhisheng; Wang, Li-Min; Wen, Bin; He, Julong; Liu, Zhongyuan

    2013-01-17

    Cubic boron nitride (cBN) is a well known superhard material that has a wide range of industrial applications. Nanostructuring of cBN is an effective way to improve its hardness by virtue of the Hall-Petch effect--the tendency for hardness to increase with decreasing grain size. Polycrystalline cBN materials are often synthesized by using the martensitic transformation of a graphite-like BN precursor, in which high pressures and temperatures lead to puckering of the BN layers. Such approaches have led to synthetic polycrystalline cBN having grain sizes as small as ∼14 nm (refs 1, 2, 4, 5). Here we report the formation of cBN with a nanostructure dominated by fine twin domains of average thickness ∼3.8 nm. This nanotwinned cBN was synthesized from specially prepared BN precursor nanoparticles possessing onion-like nested structures with intrinsically puckered BN layers and numerous stacking faults. The resulting nanotwinned cBN bulk samples are optically transparent with a striking combination of physical properties: an extremely high Vickers hardness (exceeding 100 GPa, the optimal hardness of synthetic diamond), a high oxidization temperature (∼1,294 °C) and a large fracture toughness (>12 MPa m(1/2), well beyond the toughness of commercial cemented tungsten carbide, ∼10 MPa m(1/2)). We show that hardening of cBN is continuous with decreasing twin thickness down to the smallest sizes investigated, contrasting with the expected reverse Hall-Petch effect below a critical grain size or the twin thickness of ∼10-15 nm found in metals and alloys.

  4. Cubical Sets and Trace Monoid Actions

    PubMed Central

    Husainov, Ahmet A.

    2013-01-01

    This paper is devoted to connections between trace monoids and cubical sets. We prove that the category of trace monoids is isomorphic to the category of generalized tori and it is a reflective subcategory of the category of cubical sets. Adjoint functors between the categories of cubical sets and trace monoid actions are constructed. These functors carry independence preserving morphisms in the independence preserving morphisms. This allows us to build adjoint functors between the category of weak asynchronous systems and the category of higher dimensional automata. PMID:24453827

  5. Biomechanical Analysis with Cubic Spline Functions

    ERIC Educational Resources Information Center

    McLaughlin, Thomas M.; And Others

    1977-01-01

    Results of experimentation suggest that the cubic spline is a convenient and consistent method for providing an accurate description of displacement-time data and for obtaining the corresponding time derivatives. (MJB)

  6. Biomechanical Analysis with Cubic Spline Functions

    ERIC Educational Resources Information Center

    McLaughlin, Thomas M.; And Others

    1977-01-01

    Results of experimentation suggest that the cubic spline is a convenient and consistent method for providing an accurate description of displacement-time data and for obtaining the corresponding time derivatives. (MJB)

  7. Smooth cubic commensurate oxides on gallium nitride

    SciTech Connect

    Paisley, Elizabeth A.; Gaddy, Benjamin E.; LeBeau, James M.; Shelton, Christopher T.; Losego, Mark D.; Mita, Seiji; Collazo, Ramón; Sitar, Zlatko; Irving, Douglas L.; Maria, Jon-Paul; Biegalski, Michael D.; Christen, Hans M.

    2014-02-14

    Smooth, commensurate alloys of 〈111〉-oriented Mg{sub 0.52}Ca{sub 0.48}O (MCO) thin films are demonstrated on Ga-polar, c+ [0001]-oriented GaN by surfactant-assisted molecular beam epitaxy and pulsed laser deposition. These are unique examples of coherent cubic oxide|nitride interfaces with structural and morphological perfection. Metal-insulator-semiconductor capacitor structures were fabricated on n-type GaN. A comparison of leakage current density for conventional and surfactant-assisted growth reveals a nearly 100× reduction in leakage current density for the surfactant-assisted samples. HAADF-STEM images of the MCO|GaN interface show commensurate alignment of atomic planes with minimal defects due to lattice mismatch. STEM and DFT calculations show that GaN c/2 steps create incoherent boundaries in MCO over layers which manifest as two in-plane rotations and determine consequently the density of structural defects in otherwise coherent MCO. This new understanding of interfacial steps between HCP and FCC crystals identifies the steps needed to create globally defect-free heterostructures.

  8. Radiation damage in cubic-stabilized zirconia

    NASA Astrophysics Data System (ADS)

    Costantini, Jean-Marc; Beuneu, François; Weber, William J.

    2013-09-01

    Cubic yttria-stabilized zirconia (YSZ) can be used for nuclear applications as an inert matrix for actinide immobilization or transmutation. Indeed, the large amount of native oxygen vacancies leads to a high radiation tolerance of this material owing to defect recombination occurring in the atomic displacement cascades induced by fast neutron irradiation or ion implantations, as showed by molecular dynamics (MD) simulations. Amorphization cannot be obtained in YSZ either by nuclear-collision or electronic-excitation damage, just like in urania. A kind of polygonization structure with slightly disoriented crystalline domains is obtained in both cases. In the first steps of damage, specific isolated point defects (like F+-type color centers) and point-defect clusters are produced by nuclear collisions with charged particles or neutrons. Further increase of damage leads to dislocation-loop formation then to collapse of the dislocation network into a polygonization structure. For swift heavy ion irradiations, a similar polygonization structure is obtained above a threshold stopping power value of about 20-30 keV nm-1.

  9. Smooth cubic commensurate oxides on gallium nitride

    NASA Astrophysics Data System (ADS)

    Paisley, Elizabeth A.; Gaddy, Benjamin E.; LeBeau, James M.; Shelton, Christopher T.; Biegalski, Michael D.; Christen, Hans M.; Losego, Mark D.; Mita, Seiji; Collazo, Ramón; Sitar, Zlatko; Irving, Douglas L.; Maria, Jon-Paul

    2014-02-01

    Smooth, commensurate alloys of ⟨111⟩-oriented Mg0.52Ca0.48O (MCO) thin films are demonstrated on Ga-polar, c+ [0001]-oriented GaN by surfactant-assisted molecular beam epitaxy and pulsed laser deposition. These are unique examples of coherent cubic oxide|nitride interfaces with structural and morphological perfection. Metal-insulator-semiconductor capacitor structures were fabricated on n-type GaN. A comparison of leakage current density for conventional and surfactant-assisted growth reveals a nearly 100× reduction in leakage current density for the surfactant-assisted samples. HAADF-STEM images of the MCO|GaN interface show commensurate alignment of atomic planes with minimal defects due to lattice mismatch. STEM and DFT calculations show that GaN c/2 steps create incoherent boundaries in MCO over layers which manifest as two in-plane rotations and determine consequently the density of structural defects in otherwise coherent MCO. This new understanding of interfacial steps between HCP and FCC crystals identifies the steps needed to create globally defect-free heterostructures.

  10. Radiation damage in cubic-stabilized zirconia

    SciTech Connect

    Costantini, Jean-Marc; Beuneu, Francois; Weber, William J

    2013-01-01

    Cubic yttria-stabilized zirconia (YSZ) can be used for nuclear applications as an inert matrix for actinide immobilization or transmutation. Indeed, the large amount of native oxygen vacancies leads to a high radiation tolerance of this material owing to defect recombination occurring in the atomic displacements cascades induced by fast neutron irradiation or ion implantations, as showed by Molecular dynamics (MD) simulations. Amorphization cannot be obtained in YSZ either by nuclear-collision or electronic-excitation damage, just like in urania. A kind of polygonization structure with slightly disoriented crystalline domains is obtained in both cases. In the first steps of damage, specific isolated point defects (like F+-type color centers) and point-defect clusters are produced by nuclear collisions with charged particles or neutrons. Further increase of damage leads to dislocation-loop formation, then to collapse of the dislocation network into a polygonization structure. For swift heavy ion irradiations, a similar polygonization structure is obtained above a threshold stopping power value of about 20-30 keV nm-1.

  11. A note on cubic convolution interpolation.

    PubMed

    Meijering, Erik; Unser, Michael

    2003-01-01

    We establish a link between classical osculatory interpolation and modern convolution-based interpolation and use it to show that two well-known cubic convolution schemes are formally equivalent to two osculatory interpolation schemes proposed in the actuarial literature about a century ago. We also discuss computational differences and give examples of other cubic interpolation schemes not previously studied in signal and image processing.

  12. Great Plains makes 100 billion cubic feet

    SciTech Connect

    Not Available

    1987-03-01

    The Great Plains coal gasification plant on January 18, 1987 produced its 100 billionth cubic foot of gas since start-up July 28, 1984. Owned by the Department of Energy and operated by ANG Coal Gasification Company, the plant uses the Lurgi process to produce about 50 billion cubic feet per year of gas from five million tons per year of lignite. The plant has been performing at well above design capacity.

  13. Electrostatic swelling of bicontinuous cubic lipid phases.

    PubMed

    Tyler, Arwen I I; Barriga, Hanna M G; Parsons, Edward S; McCarthy, Nicola L C; Ces, Oscar; Law, Robert V; Seddon, John M; Brooks, Nicholas J

    2015-04-28

    Lipid bicontinuous cubic phases have attracted enormous interest as bio-compatible scaffolds for use in a wide range of applications including membrane protein crystallisation, drug delivery and biosensing. One of the major bottlenecks that has hindered exploitation of these structures is an inability to create targeted highly swollen bicontinuous cubic structures with large and tunable pore sizes. In contrast, cubic structures found in vivo have periodicities approaching the micron scale. We have been able to engineer and control highly swollen bicontinuous cubic phases of spacegroup Im3m containing only lipids by (a) increasing the bilayer stiffness by adding cholesterol and (b) inducing electrostatic repulsion across the water channels by addition of anionic lipids to monoolein. By controlling the composition of the ternary mixtures we have been able to achieve lattice parameters up to 470 Å, which is 5 times that observed in pure monoolein and nearly twice the size of any lipidic cubic phase reported previously. These lattice parameters significantly exceed the predicted maximum swelling for bicontinuous cubic lipid structures, which suggest that thermal fluctuations should destroy such phases for lattice parameters larger than 300 Å.

  14. M3(Au,Ge)19 and M(3.25)(Au,Ge)18 (M = Ca, Yb): distinctive phase separations driven by configurational disorder in cubic YCd6-type derivatives.

    PubMed

    Lin, Qisheng; Corbett, John D

    2010-05-17

    Exploratory syntheses in the M-Au-Ge (M = Ca, Yb) systems have led to the discovery of two cleanly separated non-stoichiometric phases M(3)Au(approximately 14.4)Ge(approximately 4.6) (I) and M(3.25)Au(approximately 12.7)Ge(approximately 5.3) (II). Single crystal X-ray studies reveal that both (space group Im3) feature body-centered-cubic packing of five-shell multiply endohedral clusters that resemble those in the parent YCd(6) (= Y(3)Cd(18)) and are akin to approximate phases in other quasicrystal systems. However, differences resulting from various disorders in these are distinctive. The innermost cluster in the M(3)Au(approximately 14.4)Ge(approximately 4.6) phase (I) remains a disordered tetrahedron, as in the YCd(6) parent. In contrast, its counterpart in the electron-richer M(3.25)Au(approximately 12.7)Ge(approximately 5.3) phase (II) is a "rattling" M atom. The structural differentiations between I and II exhibit strong correlations between lattice parameters, cluster sizes, particular site occupancies, and valence electron counts.

  15. Accurate thermoelastic tensor and acoustic velocities of NaCl

    SciTech Connect

    Marcondes, Michel L.; Shukla, Gaurav; Silveira, Pedro da; Wentzcovitch, Renata M.

    2015-12-15

    Despite the importance of thermoelastic properties of minerals in geology and geophysics, their measurement at high pressures and temperatures are still challenging. Thus, ab initio calculations are an essential tool for predicting these properties at extreme conditions. Owing to the approximate description of the exchange-correlation energy, approximations used in calculations of vibrational effects, and numerical/methodological approximations, these methods produce systematic deviations. Hybrid schemes combining experimental data and theoretical results have emerged as a way to reconcile available information and offer more reliable predictions at experimentally inaccessible thermodynamics conditions. Here we introduce a method to improve the calculated thermoelastic tensor by using highly accurate thermal equation of state (EoS). The corrective scheme is general, applicable to crystalline solids with any symmetry, and can produce accurate results at conditions where experimental data may not exist. We apply it to rock-salt-type NaCl, a material whose structural properties have been challenging to describe accurately by standard ab initio methods and whose acoustic/seismic properties are important for the gas and oil industry.

  16. Accurate thermoelastic tensor and acoustic velocities of NaCl

    NASA Astrophysics Data System (ADS)

    Marcondes, Michel L.; Shukla, Gaurav; da Silveira, Pedro; Wentzcovitch, Renata M.

    2015-12-01

    Despite the importance of thermoelastic properties of minerals in geology and geophysics, their measurement at high pressures and temperatures are still challenging. Thus, ab initio calculations are an essential tool for predicting these properties at extreme conditions. Owing to the approximate description of the exchange-correlation energy, approximations used in calculations of vibrational effects, and numerical/methodological approximations, these methods produce systematic deviations. Hybrid schemes combining experimental data and theoretical results have emerged as a way to reconcile available information and offer more reliable predictions at experimentally inaccessible thermodynamics conditions. Here we introduce a method to improve the calculated thermoelastic tensor by using highly accurate thermal equation of state (EoS). The corrective scheme is general, applicable to crystalline solids with any symmetry, and can produce accurate results at conditions where experimental data may not exist. We apply it to rock-salt-type NaCl, a material whose structural properties have been challenging to describe accurately by standard ab initio methods and whose acoustic/seismic properties are important for the gas and oil industry.

  17. Stomatal and Nonstomatal Components to Inhibition of Photosynthesis in Leaves of Capsicum annuum during Progressive Exposure to NaCl Salinity.

    PubMed

    Bethke, P C; Drew, M C

    1992-05-01

    Young bell pepper (Capsicum annuum L.) plants grown in nutrient solution were gradually acclimated to 50, 100, or 150 moles per cubic meter NaCl, and photosynthetic rates of individual attached leaves were measured on several occasions during the salinization period at external CO(2) concentrations ranging from approximately 70 to 1900 micromoles per mole air. Net CO(2) assimilation (A) was plotted against computed leaf internal CO(2) concentration (C(i)), and the initial slope of this A-C(i) curve was used as a measure of photosynthetic ability. During the 10 to 14 days after salinization began, leaves from plants exposed to 50 moles per cubic meter NaCl showed little change in photosynthetic ability, whereas those treated to 100 or 150 moles per cubic meter NaCl had up to 85% inhibition, with increase in CO(2) compensation point. Leaves appeared healthy, and leaf chlorophyll content showed only a 14% reduction at the highest salinity levels. Partial stomatal closure occurred with salinization, but reductions in photosynthesis were primarily nonstomatal in origin. Photosynthetic ability was inversely related to the concentration of either Na(+) or Cl(-) in the leaf laminas sampled at the end of the experimental period. However, the concentration of Cl(-) expressed on a tissue water basis was greater, exceeding 300 moles per cubic meter, and Cl(-) was more closely associated (R(2) = 0.926) with the inhibition of photosynthetic ability. Leaf turgor was not reduced by salinization and leaf osmotic potential decreased to a slightly greater extent than the osmotic potential decreases of the nutrient solutions. Concentration of accumulated Na(+) and Cl(-) (on a tissue water basis) accounted quantitatively for maintenance of leaf osmotic balance, assuming that these ions were sequestered in the vacuoles.

  18. Infinite geometric frustration in a cubic dipole cluster

    NASA Astrophysics Data System (ADS)

    Schönke, Johannes; Schneider, Tobias M.; Rehberg, Ingo

    2015-01-01

    The geometric arrangement of interacting (magnetic) dipoles is a question of fundamental importance in physics, chemistry, and engineering. Motivated by recent progress concerning the self-assembly of magnetic structures, the equilibrium orientation of eight interacting dipoles in a cubic cluster is investigated in detail. Instead of discrete equilibria we find a type of ground state consisting of infinitely many orientations. This continuum of energetically degenerate states represents a yet unknown form of magnetic frustration. The corresponding dipole rotations in the flat potential valley of this Goldstone mode enable the construction of frictionless magnetic couplings. Using computer-assisted algebraic geometry methods, we moreover completely enumerate all equilibrium configurations. The seemingly simple cubic system allows for exactly 9536 unstable discrete equilibria falling into 183 distinct energy families.

  19. NaCl Taste Thresholds in 13 Inbred Mouse Strains

    PubMed Central

    Ishiwatari, Yutaka

    2012-01-01

    Molecular mechanisms of salty taste in mammals are not completely understood. We use genetic approaches to study these mechanisms. Previously, we developed a high-throughput procedure to measure NaCl taste thresholds, which involves conditioning mice to avoid LiCl and then examining avoidance of NaCl solutions presented in 48-h 2-bottle preference tests. Using this procedure, we measured NaCl taste thresholds of mice from 13 genealogically divergent inbred stains: 129P3/J, A/J, BALB/cByJ, C3H/HeJ, C57BL/6ByJ, C57BL/6J, CBA/J, CE/J, DBA/2J, FVB/NJ, NZB/BlNJ, PWK/PhJ, and SJL/J. We found substantial strain variation in NaCl taste thresholds: mice from the A/J and 129P3/J strains had high thresholds (were less sensitive), whereas mice from the BALB/cByJ, C57BL/6J, C57BL/6ByJ, CE/J, DBA/2J, NZB/BINJ, and SJL/J had low thresholds (were more sensitive). NaCl taste thresholds measured in this study did not significantly correlate with NaCl preferences or amiloride sensitivity of chorda tympani nerve responses to NaCl determined in the same strains in other studies. To examine whether strain differences in NaCl taste thresholds could have been affected by variation in learning ability or sensitivity to toxic effects of LiCl, we used the same method to measure citric acid taste thresholds in 4 inbred strains with large differences in NaCl taste thresholds but similar acid sensitivity in preference tests (129P3/J, A/J, C57BL/6J, and DBA/2J). Citric acid taste thresholds were similar in these 4 strains. This suggests that our technique measures taste quality–specific thresholds that are likely to represent differences in peripheral taste responsiveness. The strain differences in NaCl taste sensitivity found in this study provide a basis for genetic analysis of this phenotype. PMID:22293936

  20. Cubic mesoporous titanium phosphonates with multifunctionality.

    PubMed

    Ma, Tian-Yi; Lin, Xiu-Zhen; Yuan, Zhong-Yong

    2010-07-26

    Cubic mesoporous titanium phosphonate materials with bridged organic groups inside the framework were synthesized by means of a one-pot hydrothermal autoclaving process, with the assistance of cationic surfactant cetyltrimethylammonium bromide. 1-Hydroxyethylidene-1,1-diphosphonic acid was used as the coupling molecule. A typical cubic mesophase with surface area of 1052 m(2) g(-1) and pore size of 2.6 nm was confirmed by XRD, TEM, and N(2) sorption analysis. The organophosphonate groups were homogeneously incorporated in the network of the mesoporous solids, as revealed by FTIR and magic-angle spinning (MAS) NMR spectroscopy, and thermogravimetry and differential scanning calorimetry (TG-DSC) measurements. The synthesized hydroxyethylidene-bridged cubic mesoporous titanium phosphonates proved to be thermally stable up to 350 degrees C, with a well-preserved hybrid framework and cubic mesoporous architecture. The obtained cubic mesophase could be transformed into a hexagonal mesophase by simply adjusting the molar ratios of the added raw materials, namely, a Ti/P molar ratio of 1:4 and a CTAB/Ti molar ratio of 1.9-2.3 for the cubic phase and Ti/P molar ratio of 3:4 and CTAB/Ti molar ratio of 0.1-0.4 for the hexagonal phase. The cubic hybrid materials could be used as efficient photocatalysts for the photodegradation of rhodamine B. Moreover, they were also used for adsorption of CO(2) and heavy metal ions and exhibited a significant capture amount of around 1.0 mmol g(-1) for CO(2) molecules at 35 degrees C and high adsorption capacity of 28.5 micromol g(-1) for Cu(2+) ions with good reusability, which demonstrated their promising potential in environmental remediation.

  1. Predictions of the Electronic Structure and Related Properties of Cubic Calcium Hexaboride (CaB6)

    DTIC Science & Technology

    2010-06-01

    suggest that CaB6 may be a semi-metal or a semiconductor. The simple cubic structure of CaB6 is comprised of metal Ca atoms (Ca) located at the corners...simple cubic structure with a Cesium Chloride (CsCl) type lattice arrangement. It is a member of the )3(1 mPmOh space group. Our calculations utilized

  2. Interpolation by two-dimensional cubic convolution

    NASA Astrophysics Data System (ADS)

    Shi, Jiazheng; Reichenbach, Stephen E.

    2003-08-01

    This paper presents results of image interpolation with an improved method for two-dimensional cubic convolution. Convolution with a piecewise cubic is one of the most popular methods for image reconstruction, but the traditional approach uses a separable two-dimensional convolution kernel that is based on a one-dimensional derivation. The traditional, separable method is sub-optimal for the usual case of non-separable images. The improved method in this paper implements the most general non-separable, two-dimensional, piecewise-cubic interpolator with constraints for symmetry, continuity, and smoothness. The improved method of two-dimensional cubic convolution has three parameters that can be tuned to yield maximal fidelity for specific scene ensembles characterized by autocorrelation or power-spectrum. This paper illustrates examples for several scene models (a circular disk of parametric size, a square pulse with parametric rotation, and a Markov random field with parametric spatial detail) and actual images -- presenting the optimal parameters and the resulting fidelity for each model. In these examples, improved two-dimensional cubic convolution is superior to several other popular small-kernel interpolation methods.

  3. Effect of NaCl Addition on Rheological Behaviors of Commercial Gum-Based Food Thickener Used for Dysphagia Diets

    PubMed Central

    Cho, Hyun-Moon; Yoo, Whachun; Yoo, Byoungseung

    2015-01-01

    Rheological properties of thickened fluids used for consumption by people with dysphagia (swallowing difficulty) are very sensitive to several factors, such as thickener type, temperature, pH, sugar, protein, and NaCl. In this study, steady and dynamic rheological properties of thickened water samples mixed with five commercial xanthan gum-based food thickeners (A~E) were studied in the presence of NaCl at different concentrations (0.3%, 0.6%, 0.9%, and 1.2%). The magnitudes of apparent viscosity (ηa,50), consistency index (K), yield stress (σoc), and dynamic moduli (G′ and G″) showed significant differences in rheological behaviors between thickened samples with various NaCl concentrations. Dynamic moduli values of all thickened samples, except for samples with thickener C, were much higher than those of the control (0% NaCl). All rheological parameter values (K, G′, and G″) in a thickener A were much higher than those in other thickeners. These results suggest that rheological properties of thickened samples containing NaCl are strongly affected by xanthan gum-NaCl interaction and depended on the type of thickener. PMID:26176002

  4. Reversible wetting of NaCl nanoparticles at relative humidities below deliquescence observed by environmental non-contact AFM

    SciTech Connect

    Bruzewicz, D.A.; Lewis, E.; Ocko, B. M.; McGraw, R. L.; Schwartz, S. E.

    2009-12-14

    The behavior of NaCl nanoparticles as a function of relative humidity (RH) was characterized by depositing particles on a prepared hydrophobic surface and measuring their height via non-contact environmental atomic force microscopy (AFM). Non-contact AFM allows greater sensitivity to changes in the size of particles than does contact AFM or scanning electron microscopy, and greater sensitivity to changes in shape than do mass-based techniques. Crystalline cubic NaCl nanoparticles with sides of 35 to 150 nm were found to reversibly take up water with increasing RH, and to form a liquid-like surface layer of thickness 2 to 4 nm at humidities well below the deliquescence point of 75.0% at 20°C. Measurable uptake begins at 70% RH. The maximum thickness of the layer increases with increasing RH for a given particle size and, for a given RH, increases with increasing particle size over the range studied. The liquid-like behavior of the layer is indicated by a reversible “rounding” at the tops of the particles, where the ratio of particle height to radius of curvature increases from zero (flat top) at 68% RH to 0.7 at 74% RH. These observations suggest that a reorganization of mass occurs on the solid NaCl nanoparticle, and hence that the behavior of NaCl aerosol nanoparticles at RH between 70 and 75% RH is more complex than an abrupt first-order phase transition. Theoretical treatments of the phase transition should therefore account for both the presence of a liquid-like layer prior to deliquescence, and the RH-dependent thickness of the layer.

  5. Packing of nonoverlapping cubic particles: Computational algorithms and microstructural characteristics

    NASA Astrophysics Data System (ADS)

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

    2016-12-01

    Packing of cubic particles arises in a variety of problems, ranging from biological materials to colloids and the fabrication of new types of porous materials with controlled morphology. The properties of such packings may also be relevant to problems involving suspensions of cubic zeolites, precipitation of salt crystals during CO2 sequestration in rock, and intrusion of fresh water in aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We present a detailed simulation and microstructural characterization of packings of nonoverlapping monodisperse cubic particles, following up on our preliminary results [H. Malmir et al., Sci. Rep. 6, 35024 (2016), 10.1038/srep35024]. A modification of the random sequential addition (RSA) algorithm has been developed to generate such packings, and a variety of microstructural descriptors, including the radial distribution function, the face-normal correlation function, two-point probability and cluster functions, the lineal-path function, the pore-size distribution function, and surface-surface and surface-void correlation functions, have been computed, along with the specific surface and mean chord length of the packings. The results indicate the existence of both spatial and orientational long-range order as the the packing density increases. The maximum packing fraction achievable with the RSA method is about 0.57, which represents the limit for a structure similar to liquid crystals.

  6. Dry Powder Precursors of Cubic Liquid Crystalline Nanoparticles (cubosomes)

    NASA Astrophysics Data System (ADS)

    Spicer, Patrick T.; Small, William B.; Small, William B.; Lynch, Matthew L.; Burns, Janet L.

    2002-08-01

    Cubosomes are dispersed nanostructured particles of cubic phase liquid crystal that have stimulated significant research interest because of their potential for application in controlled-release and drug delivery. Despite the interest, cubosomes can be difficult to fabricate and stabilize with current methods. Most of the current work is limited to liquid phase processes involving high shear dispersion of bulk cubic liquid crystalline material into sub-micron particles, limiting application flexibility. In this work, two types of dry powder cubosome precursors are produced by spray-drying: (1) starch-encapsulated monoolein is produced by spray-drying a dispersion of cubic liquid crystalline particles in an aqueous starch solution and (2) dextran-encapsulated monoolein is produced by spray-drying an emulsion formed by the ethanol-dextran-monoolein-water system. The encapsulants are used to decrease powder cohesion during drying and to act as a soluble colloidal stabilizer upon hydration of the powders. Both powders are shown to form (on average) 0.6 μm colloidally-stable cubosomes upon addition to water. However, the starch powders have a broader particle size distribution than the dextran powders because of the relative ease of spraying emulsions versus dispersions. The developed processes enable the production of nanostructured cubosomes by end-users rather than just specialized researchers and allow tailoring of the surface state of the cubosomes for broader application.

  7. Packing of nonoverlapping cubic particles: Computational algorithms and microstructural characteristics.

    PubMed

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M Reza Rahimi

    2016-12-01

    Packing of cubic particles arises in a variety of problems, ranging from biological materials to colloids and the fabrication of new types of porous materials with controlled morphology. The properties of such packings may also be relevant to problems involving suspensions of cubic zeolites, precipitation of salt crystals during CO_{2} sequestration in rock, and intrusion of fresh water in aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We present a detailed simulation and microstructural characterization of packings of nonoverlapping monodisperse cubic particles, following up on our preliminary results [H. Malmir et al., Sci. Rep. 6, 35024 (2016)2045-232210.1038/srep35024]. A modification of the random sequential addition (RSA) algorithm has been developed to generate such packings, and a variety of microstructural descriptors, including the radial distribution function, the face-normal correlation function, two-point probability and cluster functions, the lineal-path function, the pore-size distribution function, and surface-surface and surface-void correlation functions, have been computed, along with the specific surface and mean chord length of the packings. The results indicate the existence of both spatial and orientational long-range order as the the packing density increases. The maximum packing fraction achievable with the RSA method is about 0.57, which represents the limit for a structure similar to liquid crystals.

  8. Genetics Home Reference: pseudohypoaldosteronism type 2

    MedlinePlus

    ... cascade revisited: WNK1 stimulates the activity of the Na-Cl cotransporter via SPAK, an effect antagonized by ... Molecular pathogenesis of inherited hypertension with hyperkalemia: the Na-Cl cotransporter is inhibited by wild-type but ...

  9. Superhard BC3 in cubic diamond structure

    DOE PAGES

    Zhang, Miao; Liu, Hanyu; Li, Quan; ...

    2015-01-06

    We solve the crystal structure of recently synthesized cubic BC3 using an unbiased swarm structure search, which identifies a highly symmetric BC3 phase in the cubic diamond structure (d–BC3) that contains a distinct B-B bonding network along the body diagonals of a large 64-atom unit cell. Simulated x-ray diffraction and Raman peaks of d–BC3 are in excellent agreement with experimental data. Calculated stress-strain relations of d–BC3 demonstrate its intrinsic superhard nature and reveal intriguing sequential bond-breaking modes that produce superior ductility and extended elasticity, which are unique among superhard solids. Here, the present results establish the first boron carbide inmore » the cubic diamond structure with remarkable properties, and these new findings also provide insights for exploring other covalent solids with complex bonding configurations.« less

  10. Image reconstruction by parametric cubic convolution

    NASA Technical Reports Server (NTRS)

    Park, S. K.; Schowengerdt, R. A.

    1983-01-01

    Cubic convolution, which has been discussed by Rifman and McKinnon (1974), was originally developed for the reconstruction of Landsat digital images. In the present investigation, the reconstruction properties of the one-parameter family of cubic convolution interpolation functions are considered and thee image degradation associated with reasonable choices of this parameter is analyzed. With the aid of an analysis in the frequency domain it is demonstrated that in an image-independent sense there is an optimal value for this parameter. The optimal value is not the standard value commonly referenced in the literature. It is also demonstrated that in an image-dependent sense, cubic convolution can be adapted to any class of images characterized by a common energy spectrum.

  11. Electrochemical Behavior of Al-B₄C Metal Matrix Composites in NaCl Solution.

    PubMed

    Han, Yu-Mei; Chen, X-Grant

    2015-09-21

    Aluminum based metal matrix composites (MMCs) have received considerable attention in the automotive, aerospace and nuclear industries. One of the main challenges using Al-based MMCs is the influence of the reinforcement particles on the corrosion resistance. In the present study, the corrosion behavior of Al-B₄C MMCs in a 3.5 wt.% NaCl solution were investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. Results indicated that the corrosion resistance of the composites decreased when increasing the B₄C volume fraction. Al-B₄C composite was susceptible to pitting corrosion and two types of pits were observed on the composite surface. The corrosion mechanism of the composite in the NaCl solution was primarily controlled by oxygen diffusion in the solution. In addition, the galvanic couples that formed between Al matrix and B₄C particles could also be responsible for the lower corrosion resistance of the composites.

  12. Purely cubic action for string field theory

    NASA Technical Reports Server (NTRS)

    Horowitz, G. T.; Lykken, J.; Rohm, R.; Strominger, A.

    1986-01-01

    It is shown that Witten's (1986) open-bosonic-string field-theory action and a closed-string analog can be written as a purely cubic interaction term. The conventional form of the action arises by expansion around particular solutions of the classical equations of motion. The explicit background dependence of the conventional action via the Becchi-Rouet-Stora-Tyutin operator is eliminated in the cubic formulation. A closed-form expression is found for the full nonlinear gauge-transformation law.

  13. Diffuse reflectivity measurement using cubic cavity.

    PubMed

    Yu, Jia; Zhang, Y G; Gao, Qiang; Hu, Gang; Zhang, Z G; Wu, S H

    2014-04-01

    A method for measuring diffuse reflectivity using cubic cavity based on the variable port fraction method was developed by measuring oxygen P11 line at 762 nm using tunable diode laser absorption spectroscopy. An experimental method to determine the additional path length l0 was presented. We measured the diffuse reflectivity of a cubic cavity with scattering coatings of different thickness. The error of diffuse reflectivity was reduced from 0.004 to 0.0003 when the diffuse reflectivity increased from 0.867(4) to 0.9887(3). A simulation result manifests that the error of diffuse reflectivity has the potential to be further reduced at higher diffuse reflectivity.

  14. High Pressure Strength Study on NaCl

    NASA Astrophysics Data System (ADS)

    Mi, Z.; Shieh, S. R.; High Pressure Mineral Physics Group

    2010-12-01

    Yield strength is regarded as one important property related to rheological characteristics of minerals in the Earth’s interior. The strength study of NaCl, a popular pressure medium in static high pressure experiments, has been carried out under non-hydrostatic conditions in a diamond anvil cell up to 43 GPa at room temperature using radial energy dispersive X-ray diffraction technique. Phase transformation from B1 (rock salt structure) to B2 (CsCl structure) starts at 29.4 GPa, and is complete at 32.1 GPa. Bulk modulus obtained by third order Birch-Manurgham equation of state is 25.5 GPa with pressure derivative 4.6 for B1 phase, and 30.78 GPa with pressure derivative 4.32 GPa for B2 phase, which are in a good agreement with previous studies. The differential stress of NaCl B1 phase shows very gentle increase with pressure, which indicates that NaCl is a very good pressure-transmitting medium at pressure below 30 GPa. However, the differential stress increases more abruptly for B2 phase and this may imply that NaCl can no longer be regarded as a “soft” pressure medium at very high pressures. For B1 phase, (111) is the strongest plane and (200) is the weakest plane, while (200) becomes the strongest plane in B2 phase. Pure NaCl is weaker than mixture MgO and NaCl, which indicates that soft material become stronger when mixed with hard material. The yield strength of B2 obtained through energy dispersive X-ray diffraction technique increase linearly, while the value derived by pressure gradient method shows jagged trend.

  15. Cubic membranes: a legend beyond the Flatland* of cell membrane organization

    PubMed Central

    Almsherqi, Zakaria A.; Kohlwein, Sepp D.; Deng, Yuru

    2006-01-01

    Cubic membranes represent highly curved, three-dimensional nanoperiodic structures that correspond to mathematically well defined triply periodic minimal surfaces. Although they have been observed in numerous cell types and under different conditions, particularly in stressed, diseased, or virally infected cells, knowledge about the formation and function of nonlamellar, cubic structures in biological systems is scarce, and research so far is restricted to the descriptive level. We show that the “organized smooth endoplasmic reticulum” (OSER; Snapp, E.L., R.S. Hegde, M. Francolini, F. Lombardo, S. Colombo, E. Pedrazzini, N. Borgese, and J. Lippincott-Schwartz. 2003. J. Cell Biol. 163:257–269), which is formed in response to elevated levels of specific membrane-resident proteins, is actually the two-dimensional representation of two subtypes of cubic membrane morphology. Controlled OSER induction may thus provide, for the first time, a valuable tool to study cubic membrane formation and function at the molecular level. PMID:16785319

  16. Reversible uptake of water on NaCl nanoparticles at relative humidity below deliquescence point observed by noncontact environmental atomic force microscopy.

    PubMed

    Bruzewicz, Derek A; Checco, Antonio; Ocko, Benjamin M; Lewis, Ernie R; McGraw, Robert L; Schwartz, Stephen E

    2011-01-28

    The behavior of NaCl nanoparticles as a function of relative humidity (RH) has been characterized using non-contact environmental atomic force microscopy (e-AFM) to measure the heights of particles deposited on a prepared hydrophobic surface. Cubic NaCl nanoparticles with sides of 35 and 80 nm were found to take up water reversibly with increasing RH well below the bulk deliquescence relative humidity (DRH) of 75% at 23(∘)C, and to form a liquid-like surface layer of thickness 2 to 5 nm, with measurable uptake (>2 nm increase in particle height) beginning at 70% RH. The maximum thickness of the layer increased with increasing RH and increasing particle size over the range studied. The liquid-like behavior of the layer was indicated by a reversible rounding at the upper surface of the particles, fit to a parabolic cross-section, where the ratio of particle height to maximum radius of curvature increases from zero (flat top) at 68% RH to 0.7 ± 0.3 at 74% RH. These observations, which are consistent with a reorganization of mass on the solid NaCl nanocrystal at RH below the DRH, suggest that the deliquescence of NaCl nanoparticles is more complex than an abrupt first-order phase transition. The height measurements are consistent with a phenomenological model that assumes favorable contributions to the free energy of formation of a liquid layer on solid NaCl due both to van der Waals interactions, which depend partly upon the Hamaker constant, A(film), of the interaction between the thin liquid film and the solid NaCl, and to a longer-range electrostatic interaction over a characteristic length of persistence, ξ; the best fit to the data corresponded to A(film)= 1 kT and ξ = 2.33 nm.

  17. Exogenously applied ascorbic acid ameliorates detrimental effects of NaCl and mannitol stress in Vicia faba seedlings.

    PubMed

    Younis, Mahmoud E; Hasaneen, Mohammed N A; Kazamel, Amany M S

    2010-03-01

    The adverse effects of either NaCl or mannitol on growth, nitrogen content, and antioxidant system in Vicia faba seedlings were investigated. The role of exogenous ascorbic acid in increasing resistance to these stressors was also evaluated. Thus, with an increase in concentration of either NaCl or mannitol in culture media, a progressively greater significant decrease in percentage germination, in growth parameters, and in nitrogen constituents of the germinating beans, was observed. On the other hand, amide-, nitrate-, and total soluble-N contents appeared to show a progressive significant increase. Exogenous addition of ascorbic acid (4 mM) to the stressful media induced a pronounced significantly increased percentage germination and the growth attributes, whereas nitrogen constituents were variably changed in relation to values maintained in beans treated with either NaCl or mannitol. Furthermore, exogenous addition of ascorbic acid to NaCl or mannitol media induced a significant increase in the contents of ascorbate and glutathione and enzymatic antioxidant activities, in particular, in beans treated with the three highest concentrations of NaCl or mannitol, throughout the period of the experiments (12 days). Thus, ascorbic acid ameliorates the adverse effects of the stressful media; the magnitude of amelioration being a function of the type and the concentration of the stressful agent as well as of the duration of treatment. The importance of the above-mentioned changes in growth and metabolism to stress tolerance in broad bean is discussed.

  18. Natural non poisonous green inhibitor of Glycyrrhiza glabra for mild steel in 3.5% NaCl

    NASA Astrophysics Data System (ADS)

    Koundal, Vishal; Haldhar, Rajesh; Saxena, Akhil; Prasad, Dwarika

    2017-07-01

    Leaves extracts of Glycyrrhiza glabra was investigated as sustainable corrosion resister of mild steel in 3.5% NaCl by using polarization measurements, UV, IR and SEM study. This plant shows good corrosion inhibition efficiency at lower concentration of inhibitor. This plant extract act as a mixed type of inhibitor and form a defensive coat on the surface of mild steel and decreases the corrosion rate. Here, our main goal to find out the corrosion barricade characters of the plant extract saturated with 3.5% NaCl.

  19. A monotonicity conjecture for real cubic maps

    SciTech Connect

    Dawson, S.P.; Galeeva, R.; Milnor, J.; Tresser, C.

    1993-12-01

    This will be an outline of work in progress. We study the conjecture that the topological entropy of a real cubic map depends ``monotonely`` on its parameters, in the sense that each locus of constant entropy in parameter space is a connected set. This material will be presented in more detail in a later paper.

  20. Sound velocity anisotropy in cubic crystals

    NASA Technical Reports Server (NTRS)

    Tsang, T.; Park, H. Y.

    1983-01-01

    Simple analytical expressions may be derived for sound velocities in cubic crystals by using lattice harmonics or functions which are invariant under the crystal symmetry operations. These expressions are in good agreement with the exact results for typical crystals such as metallic iron and potassium fluoride.

  1. Bistable Helmholtz solitons in cubic-quintic materials

    SciTech Connect

    Christian, J. M.; McDonald, G. S.; Chamorro-Posada, P.

    2007-09-15

    We propose a nonlinear Helmholtz equation for modeling the evolution of broad optical beams in media with a cubic-quintic intensity-dependent refractive index. This type of nonlinearity is appropriate for some semiconductor materials, glasses, and polymers. Exact analytical soliton solutions are presented that describe self-trapped nonparaxial beams propagating at any angle with respect to the reference direction. These spatially symmetric solutions are, to the best of our knowledge, the first bistable Helmholtz solitons to be derived. Accompanying conservation laws (both integral and particular forms) are also reported. Numerical simulations investigate the stability of the solitons, which appear to be remarkably robust against perturbations.

  2. Supercooling of aqueous NaCl and KCl solutions under acoustic levitation.

    PubMed

    Lü, Y J; Wei, B

    2006-10-14

    The supercooling capability of aqueous NaCl and KCl solutions is investigated at containerless state by using acoustic levitation method. The supercooling of water is obviously enhanced by the alkali metal ions and increases linearly with the augmentation of concentrations. Furthermore, the supercooling depends on the nature of ions and is 2-3 K larger for NaCl solution than that for KCl solution in the present concentration range: Molecular dynamics simulations are performed to reveal the intrinsic correlation between supercoolability and microstructure. The translational and orientational order parameters are applied to quantitatively demonstrate the effect of ionic concentration on the hydrogen-bond network and ice melting point. The disrupted hydrogen-bond structure determines essentially the concentration dependence of supercooling. On the other hand, the introduced acoustic pressure suppresses the increase of supercooling by promoting the growth and coalescence of microbubbles, the effective nucleation catalysts, in water. However, the dissolved ions can weaken this effect, and moreover the degree varies with the ion type. This results in the different supercoolability for NaCl and KCl solutions under the acoustic levitation conditions.

  3. Bulk liquid pertraction of NaCl from aqueous solution using carrier-mediated transport.

    PubMed

    Naim, M M; El-Shafei, A A; Moneer, A A; Elewa, M M; Kandeel, W G

    2015-10-06

    In the present work, removal of NaCl using the bulk liquid membrane (BLM) technique has been investigated, using a simple apparatus for conducting the experiments. Variables investigated were volume ratio of donor phase (DP) to receptor phase (RP), presence of sequestering agent (SA) in RP, type of organic liquid membrane (LM), quantity of mobile carrier (MC) in the LM. Stirring speed and volume of LM were kept constant at 100 rpm and 130 ml, respectively. The mass transfer of NaCl was analysed based on kinetic laws of two consecutive irreversible first-order reactions, and kinetic parameters (k1d, k2m, k2r, [Formula: see text], tmax, [Formula: see text], and [Formula: see text]) for the transport of NaCl were investigated. The values obtained demonstrate that the process is diffusionally controlled. Results indicate that the membrane entrance and exit rate constants (k1, k2) increase with decreasing DP:RP ratio and with decrease in quantity of MC, and quantity of SA, and the presence of dichloroethane (DCE) is preferred to chloroform (CF) as LM.

  4. Substituting KCl for NaCl in fresh Queso Fresco

    USDA-ARS?s Scientific Manuscript database

    Reducing the sodium level in cheese is challenging when a signature salty flavor is expected, such as in high-moisture Queso Fresco (QF). Fresh starter-free QF was fine milled and dry salted at different levels of NaCl and KCl to obtain total salt levels of 1.5 to 2.0%. The treatments contained 1....

  5. Ultraweak bioluminescence of maize under NaCl stress

    NASA Astrophysics Data System (ADS)

    Xie, Zhaohui

    2009-11-01

    In this paper, the delayed ultra-weak luminescence (UWL), leaf dry/fresh weight and reactive oxygen species (ROS) of the maize (Jundan 20) were investigated under various NaCl concentration. The results showed that following with the increase of NaCl, ROS contents increased obviously, but the UWL intensity decreased, and the decrease speed increased following with the increase of NaCl concentration, the decrease extent of delayed luminescence ranged from 10.4% to 27.2%. It was also found that both dry and fresh weight of seedling leaves decreased, but the ratio of dry/fresh weight increased. According to these results, we speculated that the decrease of UWL was mainly closely associated with the destruction of seedling normal physiological activities and metabolic disorder which were caused by NaCl stress, rather than ROS only. This study revealed that the spectral analysis of UWL is a useful tool for studying plant response to salt stress.

  6. New tetragonal derivatives of cubic NaZn{sub 13}-type structure: RNi{sub 6}Si{sub 6} compounds, crystal structure and magnetic ordering (R=Y, La, Ce, Sm, Gd–Yb)

    SciTech Connect

    Pani, M.; Manfrinetti, P.; Provino, A.; Yuan, Fang; Mozharivskyj, Y.; Morozkin, A.V.; Knotko, A.V.; Garshev, A.V.; Yapaskurt, V.O.; Isnard, O.

    2014-02-15

    Novel RNi{sub 6}Si{sub 6} compounds adopt the new CeNi{sub 6}Si{sub 6}-type structure for R=La–Ce (tP52, space group P4/nbm N 125-1) and new YNi{sub 6}Si{sub 6}-type structure for R=Y, Sm, Gd–Yb (tP52, space group P4{sup ¯}b2N 117) that are tetragonal derivative of NaZn{sub 13}-type structure, like LaCo{sub 9}Si{sub 4}-type. The CeNi{sub 6}Si{sub 6}, GdNi{sub 6}Si{sub 6}, TbNi{sub 6}Si{sub 6}, DyNi{sub 6}Si{sub 6} and HoNi{sub 6}Si{sub 6} compounds are Curie–Weiss paramagnets down to ∼30 K, and do not order magnetically down to 5 K. However, the inverse paramagnetic susceptibility of LaNi{sub 6}Si{sub 6} does not follow Curie–Weiss law. The DyNi{sub 6}Si{sub 6} shows ferromagnetic-like saturation behaviour at 5 K in applied fields of 50 kOe, giving rise to a magnetic moment value of 6.5 μ{sub B}/f.u. in 50 kOe. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi{sub 6}Si{sub 6} with K=[±1/4, ±1/4, 0] wave vector below ∼10 K. - Graphical abstract: Novel (La, Ce)Ni{sub 6}Si{sub 6} compounds adopt the new CeNi{sub 6}Si{sub 6}-type structure and (Y, Sm, Gd–Yb) adopt the new YNi{sub 6}Si{sub 6}-type structure that are tetragonal derivative of NaZn{sub 13}-type structure, like LaCo{sub 9}Si{sub 4}-type. The CeNi{sub 6}Si{sub 6}, GdNi{sub 6}Si{sub 6}, TbNi{sub 6}Si{sub 6}, DyNi{sub 6}Si{sub 6} and HoNi{sub 6}Si{sub 6} compounds are Curie–Weiss paramagnets down to ∼30 K, and do not order magnetically down to 4.2 K. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi{sub 6}Si{sub 6} with K=[±1/4, ±1/4, 0] wave vector below ∼10 K. Display Omitted - Highlights: • The new (La, Ce)Ni{sub 6}Si{sub 6} compounds adopt the new CeNi{sub 6}Si{sub 6}-type structure. • The new (Y, Sm, Gd–Yb)Ni{sub 6}Si{sub 6} compounds adopt the new YNi{sub 6}Si{sub 6}-type structure. • TbNi{sub 6}Si

  7. Ytterbium: Transition at High Pressure from Face-Centered Cubic to Body-Centered Cubic Structure.

    PubMed

    Hall, H T; Barnett, J D; Merrill, L

    1963-01-11

    Pressure of 40,000 atmospheres at 25 degrees C induces a phase transformation in ytterbium metal; the face-centered cubic structure changes to body-centered cubic. The radius of the atom changes from 1.82 to 1.75 A. At the same time the atom's volume decreases by 11 percent and the volume, observed macroscopically, decreases 3.2 percent.

  8. Interfacial free energy of the NaCl crystal-melt interface from capillary wave fluctuations.

    PubMed

    Benet, Jorge; MacDowell, Luis G; Sanz, Eduardo

    2015-04-07

    In this work we study, by means of molecular dynamics simulations, the solid-liquid interface of NaCl under coexistence conditions. By analysing capillary waves, we obtain the stiffness for different orientations of the solid and calculate the interfacial free energy by expanding the dependency of the interfacial free energy with the solid orientation in terms of cubic harmonics. We obtain an average value for the solid-fluid interfacial free energy of 89 ± 6 mN m(-1) that is consistent with previous results based on the measure of nucleation free energy barriers [Valeriani et al., J. Chem. Phys. 122, 194501 (2005)]. We analyse the influence of the simulation setup on interfacial properties and find that facets prepared as an elongated rectangular stripe give the same results as those prepared as squares for all cases but the 111 face. For some crystal orientations, we observe at small wave-vectors a behaviour not consistent with capillary wave theory and show that this behavior does not depend on the simulation setup.

  9. Face-Centered-Cubic Nanostructured Polymer Foams

    NASA Astrophysics Data System (ADS)

    Cui, C.; Baughman, R. H.; Liu, L. M.; Zakhidov, A. A.; Khayrullin, I. I.

    1998-03-01

    Beautifully iridescent polymer foams having Fm-3m cubic symmetry and periodicities on the scale of the wavelength of light have been synthesized by the templating of porous synthetic opals. These fabrication processes involve the filling of porous SiO2 opals (with typical cubic lattice parameters of 250 nm) with either polymers or polymer precursors, polymerization of the precursors if necessary, and removal of the fcc array of SiO2 balls to provide an all-polymer structure. The structures of these foams are similar to periodic minimal surfaces, although the Gaussian curvature can have both positive and negative values. Depending upon whether the internal surfaces of the opal are polymer filled or polymer coated, the polymer replica has either one or two sets of independent channels. We fill these channels with semiconductors, metals, or superconductors to provide electronic and optical materials with novel properties dependent on the nanoscale periodicity.

  10. Wavelets based on Hermite cubic splines

    NASA Astrophysics Data System (ADS)

    Cvejnová, Daniela; Černá, Dana; Finěk, Václav

    2016-06-01

    In 2000, W. Dahmen et al. designed biorthogonal multi-wavelets adapted to the interval [0,1] on the basis of Hermite cubic splines. In recent years, several more simple constructions of wavelet bases based on Hermite cubic splines were proposed. We focus here on wavelet bases with respect to which both the mass and stiffness matrices are sparse in the sense that the number of nonzero elements in any column is bounded by a constant. Then, a matrix-vector multiplication in adaptive wavelet methods can be performed exactly with linear complexity for any second order differential equation with constant coefficients. In this contribution, we shortly review these constructions and propose a new wavelet which leads to improved Riesz constants. Wavelets have four vanishing wavelet moments.

  11. Use of Pom Pons to Illustrate Cubic Crystal Structures.

    ERIC Educational Resources Information Center

    Cady, Susan G.

    1997-01-01

    Describes a method that uses olefin pom pons to illustrate cubic crystal structure. Facilitates hands-on examination of different packing arrangements such as hexagonal close-packed and cubic close-packed structures. (JRH)

  12. Use of Pom Pons to Illustrate Cubic Crystal Structures.

    ERIC Educational Resources Information Center

    Cady, Susan G.

    1997-01-01

    Describes a method that uses olefin pom pons to illustrate cubic crystal structure. Facilitates hands-on examination of different packing arrangements such as hexagonal close-packed and cubic close-packed structures. (JRH)

  13. Cubic Polynomials with Rational Roots and Critical Points

    ERIC Educational Resources Information Center

    Gupta, Shiv K.; Szymanski, Waclaw

    2010-01-01

    If you want your students to graph a cubic polynomial, it is best to give them one with rational roots and critical points. In this paper, we describe completely all such cubics and explain how to generate them.

  14. Cubic Polynomials with Rational Roots and Critical Points

    ERIC Educational Resources Information Center

    Gupta, Shiv K.; Szymanski, Waclaw

    2010-01-01

    If you want your students to graph a cubic polynomial, it is best to give them one with rational roots and critical points. In this paper, we describe completely all such cubics and explain how to generate them.

  15. Effect of cubic aeroelastic nonlinearities on flutter

    NASA Astrophysics Data System (ADS)

    Berci, M.

    2017-07-01

    The effect of cubic aero-structural nonlinearities on aeroelastic flutter instability is here investigated. Focusing on the unstable flutter mode, the exact amplitude and frequency of the arising limit cycle oscillations are determined analytically. Both harmonic balance and multiple scales methods are adopted and perfect agreement of the explicit results is demonstrated, for the case of small perturbations of the aircraft speed in the neighborhood of the flutter instability.

  16. Quasiparticle Interference on Cubic Perovskite Oxide Surfaces

    NASA Astrophysics Data System (ADS)

    Okada, Yoshinori; Shiau, Shiue-Yuan; Chang, Tay-Rong; Chang, Guoqing; Kobayashi, Masaki; Shimizu, Ryota; Jeng, Horng-Tay; Shiraki, Susumu; Kumigashira, Hiroshi; Bansil, Arun; Lin, Hsin; Hitosugi, Taro

    2017-08-01

    We report the observation of coherent surface states on cubic perovskite oxide SrVO3(001 ) thin films through spectroscopic-imaging scanning tunneling microscopy. A direct link between the observed quasiparticle interference patterns and the formation of a dx y -derived surface state is supported by first-principles calculations. We show that the apical oxygens on the topmost VO2 plane play a critical role in controlling the coherent surface state via modulating orbital state.

  17. Deposition Of Cubic BN On Diamond Interlayers

    NASA Technical Reports Server (NTRS)

    Ong, Tiong P.; Shing, Yuh-Han

    1994-01-01

    Thin films of polycrystalline, pure, cubic boron nitride (c-BN) formed on various substrates, according to proposal, by chemical vapor deposition onto interlayers of polycrystalline diamond. Substrate materials include metals, semiconductors, and insulators. Typical substrates include metal-cutting tools: polycrystalline c-BN coats advantageous for cutting ferrous materials and for use in highly oxidizing environments-applications in which diamond coats tend to dissolve in iron or be oxidized, respectively.

  18. Deposition Of Cubic BN On Diamond Interlayers

    NASA Technical Reports Server (NTRS)

    Ong, Tiong P.; Shing, Yuh-Han

    1994-01-01

    Thin films of polycrystalline, pure, cubic boron nitride (c-BN) formed on various substrates, according to proposal, by chemical vapor deposition onto interlayers of polycrystalline diamond. Substrate materials include metals, semiconductors, and insulators. Typical substrates include metal-cutting tools: polycrystalline c-BN coats advantageous for cutting ferrous materials and for use in highly oxidizing environments-applications in which diamond coats tend to dissolve in iron or be oxidized, respectively.

  19. Cubic pencils of lines and bivariate interpolation

    NASA Astrophysics Data System (ADS)

    Carnicer, J. M.; Gasca, M.

    2008-10-01

    Cubic pencils of lines are classified up to projectivities. Explicit formulae for the addition of lines on the set of nonsingular lines of the pencils are given. These formulae can be used for constructing planar generalized principal lattices, which are sets of points giving rise to simple Lagrange formulae in bivariate interpolation. Special attention is paid to the irreducible nonsingular case, where elliptic functions are used in order to express the addition in a natural form.

  20. 46 CFR 160.035-9 - Cubic capacity of lifeboats.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Cubic capacity of lifeboats. 160.035-9 Section 160.035-9...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Lifeboats for Merchant Vessels § 160.035-9 Cubic capacity of... its cubic capacity. (1) Length (L). The length is the distance in feet from the inside of the...

  1. 46 CFR 160.035-9 - Cubic capacity of lifeboats.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Cubic capacity of lifeboats. 160.035-9 Section 160.035-9...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Lifeboats for Merchant Vessels § 160.035-9 Cubic capacity of... its cubic capacity. (1) Length (L). The length is the distance in feet from the inside of the...

  2. Northeastern forest survey revised cubic-foot volume equations

    Treesearch

    Charles T. Scott

    1981-01-01

    Cubic-foot volume equations are presented for the 17 species groups used in the forest survey of the 14 northeastern states. The previous cubic- foot volume equations were simple linear in form; the revised cubic-foot volume equations are nonlinear.

  3. Critical behavior of dilute NaCl in H2O

    USGS Publications Warehouse

    Pitzer, Kenneth S.; Bischoff, J.L.; Rosenbauer, R.J.

    1987-01-01

    The compositions of the saturated vapor and liquid phases are measured for the system NaCl-H2O at 380??C, which is close to the critical point of pure water. The shape of the phase equilibrium curve is classical, which confirms a conclusion reached earlier on the basis of less accurate data. This implies that the long-range forces introduced by the NaCl suppress the non-classical effects present in pure H2O. An empirical equation of a classical type fits these data. ?? 1987.

  4. Degree of disorder in cubic mesophases in thermotropics: thermodynamic study of a liquid crystal showing two cubic mesophases.

    PubMed

    Saito, Kazuya; Shinhara, Takashi; Nakamoto, Tadahiro; Kutsumizu, Shoichi; Yano, S; Sorai, Michio

    2002-03-01

    Heat capacity of a thermotropic mesogen ANBC(22) (4(')-alkoxy-3(')-nitrobiphenyl-4-carboxylic acid with 22 carbon atoms in alkyl chain) showing two cubic mesophases was measured by adiabatic calorimetry between 13 and 480 K. Excess enthalpies and entropies due to phase transitions were determined. A small thermal anomaly due to the cubic Im3m-->cubic Ia3d phase transition was successfully detected. Through an analysis of chain-length dependence of the entropy of transition, the sequence of two cubic mesophases (with space groups Ia3d and Im3m) is deduced for thermotropic mesogens ANBC(n). It is shown that the disorder of the core arrangement decreases in the order of Sm-C-->cubic (Im3m)-->cubic (Ia3d) while that of the chain in the reverse order cubic (Ia3d)-->cubic (Im3m)-->Sm C.

  5. Pronounced negative thermal expansion from a simple structure: cubic ScF(3).

    PubMed

    Greve, Benjamin K; Martin, Kenneth L; Lee, Peter L; Chupas, Peter J; Chapman, Karena W; Wilkinson, Angus P

    2010-11-10

    Scandium trifluoride maintains a cubic ReO(3) type structure down to at least 10 K, although the pressure at which its cubic to rhombohedral phase transition occurs drops from >0.5 GPa at ∼300 K to 0.1-0.2 GPa at 50 K. At low temperatures it shows strong negative thermal expansion (NTE) (60-110 K, α(l) ≈ -14 ppm K(-1)). On heating, its coefficient of thermal expansion (CTE) smoothly increases, leading to a room temperature CTE that is similar to that of ZrW(2)O(8) and positive thermal expansion above ∼1100 K. While the cubic ReO(3) structure type is often used as a simple illustration of how negative thermal expansion can arise from the thermally induced rocking of rigid structural units, ScF(3) is the first material with this structure to provide a clear experimental illustration of this mechanism for NTE.

  6. Spontaneous Graphitization of Ultrathin Cubic Structures: A Computational Study

    NASA Astrophysics Data System (ADS)

    Sorokin, Pavel B.; Kvashnin, Alexander G.; Zhu, Zhen; Tománek, David

    2014-12-01

    Results based on {\\em ab initio} density functional calculations indicate a general graphitization tendency in ultrathin slabs of cubic diamond, boron nitride, and many other cubic structures including rocksalt. Whereas such compounds often show an energy preference for cubic rather than layered atomic arrangements in the bulk, the surface energy of layered systems is commonly lower than that of their cubic counterparts. We determine the critical slab thickness for a range of systems, below which a spontaneous conversion from a cubic to a layered graphitic structure occurs, driven by surface energy reduction in surface-dominated structures.

  7. Nano-Engineered Cubic Zirconia for Orthopaedic Implant Applications

    NASA Astrophysics Data System (ADS)

    Namavar, F.; Rubinstein, A.; Sabirianov, R.; Thiele, G.; Sharp, J.; Pokharel, U.; Namavar, R.; Garvin, K.

    2012-02-01

    Osseointegration failure of the prosthesis prevents long-term stability, which contributes to pain, implant loosening, and infection that usually necessitates revision surgery. Cell attachment and spreading in vitro is generally mediated by adhesive proteins such as fibronectin and vitronectin. We designed and produced pure cubic zirconia (ZrO2) ceramic coatings by ion beam assisted deposition (IBAD) with nanostructures comparable to the size of proteins. Our ceramic coatings exhibit high hardness and a zero contact angle with serum. In contrast to Hydroxyapatite (HA), nano-engineered zirconia films possess excellent adhesion to all orthopaedic materials. Adhesion and proliferation experiments were performed with a bona fide mesenchymal stromal cells cell line (OMA-AD). Our experimental results indicated that nano-engineered cubic zirconia is superior in supporting growth, adhesion, and proliferation. We performed a comparative analysis of adsorption energies of the FN fragment using quantum mechanical calculations and Monte Carlo simulation on both types of surfaces: smooth and nanostructured. We have found that the initial FN fragment adsorbs significantly stronger on the nanostructured surface than on the smooth surface.

  8. Charge compensation at the interface between the polar NaCl(111) surface and a NaCl aqueous solution.

    PubMed

    Sayer, Thomas; Zhang, Chao; Sprik, Michiel

    2017-09-14

    Periodic supercell models of electric double layers formed at the interface between a charged surface and an electrolyte are subject to serious finite size errors and require certain adjustments in the treatment of the long-range electrostatic interactions. In a previous publication Zhang and Sprik [Phys. Rev. B 94, 245309 (2016)], we have shown how this can be achieved using finite field methods. The test system was the familiar simple point charge model of a NaCl aqueous solution confined between two oppositely charged walls. Here this method is extended to the interface between the (111) polar surface of a NaCl crystal and a high concentration NaCl aqueous solution. The crystal is kept completely rigid and the compensating charge screening the polarization can only be provided by the electrolyte. We verify that the excess electrolyte ionic charge at the interface conforms to the Tasker 1/2 rule for compensating charge in the theory of polar rock salt (111) surfaces. The interface can be viewed as an electric double layer with a net charge. We define a generalized Helmholtz capacitance CH which can be computed by varying the applied electric field. We find CH=8.23 μF cm(-2), which should be compared to the 4.23 μF cm(-2) for the (100) non-polar surface of the same NaCl crystal. This is rationalized by the observation that compensating ions shed their first solvation shell adsorbing as contact ions pairs on the polar surface.

  9. Charge compensation at the interface between the polar NaCl(111) surface and a NaCl aqueous solution

    NASA Astrophysics Data System (ADS)

    Sayer, Thomas; Zhang, Chao; Sprik, Michiel

    2017-09-01

    Periodic supercell models of electric double layers formed at the interface between a charged surface and an electrolyte are subject to serious finite size errors and require certain adjustments in the treatment of the long-range electrostatic interactions. In a previous publication Zhang and Sprik [Phys. Rev. B 94, 245309 (2016)], we have shown how this can be achieved using finite field methods. The test system was the familiar simple point charge model of a NaCl aqueous solution confined between two oppositely charged walls. Here this method is extended to the interface between the (111) polar surface of a NaCl crystal and a high concentration NaCl aqueous solution. The crystal is kept completely rigid and the compensating charge screening the polarization can only be provided by the electrolyte. We verify that the excess electrolyte ionic charge at the interface conforms to the Tasker 1/2 rule for compensating charge in the theory of polar rock salt (111) surfaces. The interface can be viewed as an electric double layer with a net charge. We define a generalized Helmholtz capacitance CH which can be computed by varying the applied electric field. We find CH=8.23 μ F cm-2, which should be compared to the 4.23 μ F cm-2 for the (100) non-polar surface of the same NaCl crystal. This is rationalized by the observation that compensating ions shed their first solvation shell adsorbing as contact ions pairs on the polar surface.

  10. Cherenkov and Scintillation Properties of Cubic Zirconium

    NASA Technical Reports Server (NTRS)

    Christl, M.J.; Adams, J.H.; Parnell, T.A.; Kuznetsov, E.N.

    2008-01-01

    Cubic zirconium (CZ) is a high index of refraction (n =2.17) material that we have investigated for Cherenkov counter applications. Laboratory and proton accelerator tests of an 18cc sample of CZ show that the expected fast Cherenkov response is accompanied by a longer scintillation component that can be separated by pulse shaping. This presents the possibility of novel particle spectrometers which exploits both properties of CZ. Other high index materials being examined for Cherenkov applications will be discussed. Results from laboratory tests and an accelerator exposure will be presented and a potential application in solar energetic particle instruments will be discussed

  11. Craniofacial Reconstruction Using Rational Cubic Ball Curves

    PubMed Central

    Majeed, Abdul; Mt Piah, Abd Rahni; Gobithaasan, R. U.; Yahya, Zainor Ridzuan

    2015-01-01

    This paper proposes the reconstruction of craniofacial fracture using rational cubic Ball curve. The idea of choosing Ball curve is based on its robustness of computing efficiency over Bezier curve. The main steps are conversion of Digital Imaging and Communications in Medicine (Dicom) images to binary images, boundary extraction and corner point detection, Ball curve fitting with genetic algorithm and final solution conversion to Dicom format. The last section illustrates a real case of craniofacial reconstruction using the proposed method which clearly indicates the applicability of this method. A Graphical User Interface (GUI) has also been developed for practical application. PMID:25880632

  12. Two-layer tubes from cubic crystals

    NASA Astrophysics Data System (ADS)

    Goldstein, R. V.; Gorodtsov, V. A.; Lisovenko, D. S.; Volkov, M. A.

    2016-12-01

    Effective Young's moduli and Poisson's ratios of two-layer tubes from cubic crystals have been analyzed theoretically. It is shown (using derived formulas for numerical estimates) that the mechanical properties of two-layer tube composites from auxetics and nonauxetics are not described by the mixture rule. It is demonstrated that the deviation of the effective modulus from the mixture rule predictions rapidly increases with an increase in Young's modulus of the nonauxetic components of a composite. It is established that, combining auxetics and nonauxetics in layered tubes, one can obtain, depending on the packing order in layers, either a strong increase or a decrease in auxeticity.

  13. Cherenkov and Scintillation Properties of Cubic Zirconium

    NASA Technical Reports Server (NTRS)

    Christl, M.J.; Adams, J.H.; Parnell, T.A.; Kuznetsov, E.N.

    2008-01-01

    Cubic zirconium (CZ) is a high index of refraction (n =2.17) material that we have investigated for Cherenkov counter applications. Laboratory and proton accelerator tests of an 18cc sample of CZ show that the expected fast Cherenkov response is accompanied by a longer scintillation component that can be separated by pulse shaping. This presents the possibility of novel particle spectrometers which exploits both properties of CZ. Other high index materials being examined for Cherenkov applications will be discussed. Results from laboratory tests and an accelerator exposure will be presented and a potential application in solar energetic particle instruments will be discussed

  14. Electronic structure of nonstoichiometric cubic hydrides

    SciTech Connect

    Switendick, A.C.

    1980-01-01

    Using the supercell approach we have calculated the electronic structure of Y/sub 4/H/sub 8/, Y/sub 4/H/sub 9/, Y/sub 4/H/sub 11/, and Y/sub 4/H/sub 12/ as prototypic of nonstoichiometric cubic di- and trihydrides. The nature of the interaction between the yttrium and the octahedral and tetrahedral hydrogens is shown by the relative amount of charge contained in the crystal spheres. Each added hydrogen lowers one band which was already partially filled. The charge on both the octahedral and tetrahedral sites is very similar and significantly more than is contained in a comparable atomic sphere.

  15. Inhibition of nitrate reduction by NaCl adsorption on a nano-zero-valent iron surface during a concentrate treatment for water reuse.

    PubMed

    Hwang, Yuhoon; Kim, Dogun; Shin, Hang-Sik

    2015-01-01

    Nanoscale zero-valent iron (NZVI) has been considered as a possible material to treat water and wastewater. However, it is necessary to verify the effect of the matrix components in different types of target water. In this study, different effects depending on the sodium chloride (NaCl) concentration on reductions of nitrates and on the characteristics of NZVI were investigated. Although NaCl is known as a promoter of iron corrosion, a high concentration of NaCl (>3 g/L) has a significant inhibition effect on the degree of NZVI reactivity towards nitrate. The experimental results were interpreted by a Langmuir-Hinshelwood-Hougen-Watson reaction in terms of inhibition, and the decreased NZVI reactivity could be explained by the increase in the inhibition constant. As a result of a chloride concentration analysis, it was verified that 7.7-26.5% of chloride was adsorbed onto the surface of NZVI. Moreover, the change of the iron corrosion product under different NaCl concentrations was investigated by a surface analysis of spent NZVI. Magnetite was the main product, with a low NaCl concentration (0.5 g/L), whereas amorphous iron hydroxide was observed at a high concentration (12 g/L). Though the surface was changed to permeable iron hydroxide, the Fe(0) in the core was not completely oxidized. Therefore, the inhibition effect of NaCl could be explained as the competitive adsorption of chloride and nitrate.

  16. Expression and phosphorylation of the Na+-Cl- cotransporter NCC in vivo is regulated by dietary salt, potassium, and SGK1.

    PubMed

    Vallon, Volker; Schroth, Jana; Lang, Florian; Kuhl, Dietmar; Uchida, Shinichi

    2009-09-01

    The Na-Cl cotransporter NCC is expressed in the distal convoluted tubule, activated by phosphorylation, and has been implicated in renal NaCl and K(+) homeostasis. The serum and glucocorticoid inducible kinase 1 (SGK1) contributes to renal NaCl retention and K(+) excretion, at least in part, by stimulating the epithelial Na(+) channel and Na(+)-K(+)-ATPase in the downstream segments of aldosterone-sensitive Na(+)/K(+) exchange. In this study we confirmed in wild-type mice (WT) that dietary NaCl restriction increases renal NCC expression and its phosphorylation at Thr(53), Thr(58), and Ser(71), respectively. This response, however, was attenuated in mice lacking SGK1 (Sgk1(-/-)), which may contribute to impaired NaCl retention in those mice. Total renal NCC expression and phosphorylation at Thr(53), Thr(58), and Ser(71) in WT were greater under low- compared with high-K(+) diet. This finding is consistent with a regulation of NCC to modulate Na(+) delivery to downstream segments of Na(+)/K(+) exchange, thereby modulating K(+) excretion. Dietary K(+)-dependent variation in renal expression of total NCC and phosphorylated NCC were not attenuated in Sgk1(-/-) mice. In fact, high-K(+) diet-induced NCC suppression was enhanced in Sgk1(-/-) mice. The hyperkalemia induced in Sgk1(-/-) mice by a high-K(+) diet may have augmented NCC suppression, thereby increasing Na(+) delivery and facilitating K(+) excretion in downstream segments of impaired Na(+)/K(+) exchange. In summary, changes in NaCl and K(+) intake altered NCC expression and phosphorylation, an observation consistent with a role of NCC in NaCl and K(+) homeostasis. The two maneuvers dissociated plasma aldosterone levels from NCC expression and phosphorylation, implicating additional regulators. Regulation of NCC expression and phosphorylation by dietary NaCl restriction appears to involve SGK1.

  17. Elliptically polarised cnoidal waves in a medium with spatial dispersion of cubic nonlinearity

    SciTech Connect

    Makarov, Vladimir A; Perezhogin, I A; Petnikova, V M; Potravkin, N N; Shuvalov, Vladimir V

    2012-02-28

    We present new specific analytic solutions of a system of nonlinear Schroedinger equations, corresponding to elliptically polarised cnoidal waves in an isotropic gyrotropic medium with spatial dispersion of cubic nonlinearity and second-order frequency dispersion under the conditions of formation of the waveguides of the same type for each of the circularly polarised components of the light field.

  18. Rheological properties of Cubic colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Boromand, Arman; Maia, Joao

    2016-11-01

    Colloidal and non-colloidal suspensions are ubiquitous in many industrial application. There are numerous studies on these systems to understand and relate their complex rheological properties to their microstructural evolution under deformation. Although most of the experimental and simulation studies are centered on spherical particles, in most of the industrial applications the geometry of the colloidal particles deviate from the simple hard sphere and more complex geometries exist. Recent advances in microfabrication paved the way to fabricate colloidal particles with complex geometries for applications in different areas such as drug delivery where the fundamental understanding of their dynamics has remained unexplored. In this study, using dissipative particle dynamics, we investigate the rheological properties of cubic (superball) particles which are modeled as the cluster of core-modified DPD particles. Explicit representation of solvent particles in the DPD scheme will conserve the full hydrodynamic interactions between colloidal particles. Rheological properties of these cubic suspensions are investigated in the dilute and semi-dilute regimes. The Einstein and Huggins coefficients for these particles with different superball exponent will be calculate which represent the effect of single particle's geometry and multibody interactions on viscosity, respectively. The response of these suspensions is investigated under simple shear and oscillatory shear where it is shown that under oscillation these particles tend to form crystalline structure giving rise to stronger shear-thinning behavior recently measured experimentally.

  19. Multiply charged monopoles in cubic dimer model

    NASA Astrophysics Data System (ADS)

    Ganesh Jaya, Sreejith; Powell, Stephen

    2015-03-01

    The classical cubic dimer model is a 3D statistical mechanical system whose degrees of freedom are dimers that occupy the edges between nearest neighbour vertices of a cubic lattice. Dimer occupancies are subject to the local constraint that every vertex is associated with exactly one dimer. In the presence of an aligning interaction, it is known that the system exhibits an unconventional continuous thermal phase transition from a symmetry broken columnar phase to a Coulomb-phase. The transition is in the NCCP1 universality class, which also describes the Neel-VBS transition in the JQ model and the S =1/2 Heisenberg model with suppression of hedgehog defects. Using Monte-Carlo simulations of a pair of defects in a background of fluctuating dimers, we calculate the scaling exponents for fugacities of monopole defects of charge Q = 2 and 3 at this critical point. Our estimates suggest that Q = 3 monopoles are relevant and could therefore drive the JQ model away from the NCCP1 critical point on a hexagonal lattice.

  20. Relationship between NaCl- and H2O2-Induced Cytosolic Ca2+ Increases in Response to Stress in Arabidopsis

    PubMed Central

    Ye, Rui; Xue, Yan; Chen, Amelia; An, Lizhe; Pei, Zhen-Ming

    2013-01-01

    Salinity is among the environmental factors that affect plant growth and development and constrain agricultural productivity. Salinity stress triggers increases in cytosolic free Ca2+ concentration ([Ca2+]i) via Ca2+ influx across the plasma membrane. Salinity stress, as well as other stresses, induces the production of reactive oxygen species (ROS). It is well established that ROS also triggers increases in [Ca2+]i. However, the relationship and interaction between salinity stress-induced [Ca2+]i increases and ROS-induced [Ca2+]i increases remain poorly understood. Using an aequorin-based Ca2+ imaging assay we have analyzed [Ca2+]i changes in response to NaCl and H2O2 treatments in Arabidopsis thaliana. We found that NaCl and H2O2 together induced larger increases in [Ca2+]i in Arabidopsis seedlings than either NaCl or H2O2 alone, suggesting an additive effect on [Ca2+]i increases. Following a pre-treatment with either NaCl or H2O2, the subsequent elevation of [Ca2+]i in response to a second treatment with either NaCl or H2O2 was significantly reduced. Furthermore, the NaCl pre-treatment suppressed the elevation of [Ca2+]i seen with a second NaCl treatment more than that seen with a second treatment of H2O2. A similar response was seen when the initial treatment was with H2O2; subsequent addition of H2O2 led to less of an increase in [Ca2+]i than did addition of NaCl. These results imply that NaCl-gated Ca2+ channels and H2O2-gated Ca2+ channels may differ, and also suggest that NaCl- and H2O2-evoked [Ca2+]i may reduce the potency of both NaCl and H2O2 in triggering [Ca2+]i increases, highlighting a feedback mechanism. Alternatively, NaCl and H2O2 may activate the same Ca2+ permeable channel, which is expressed in different types of cells and/or activated via different signaling pathways. PMID:24124535

  1. Pressure-induced phase transformations in cubic Gd[subscript 2]O[subscript 3

    SciTech Connect

    Bai, Ligang; Liu, Jing; Li, Xiaodong; Jiang, Sheng; Xiao, Wansheng; Li, Yanchun; Tang, Lingyun; Zhang, Yufeng; Zhang, Dechun

    2009-10-21

    High-pressure transformation and compression behavior of Gd{sub 2}O{sub 3} were investigated using synchrotron radiation x-ray diffraction in a diamond anvil cell up to 44 GPa at room temperature. The structural transformation from a cubic to a monoclinic phase occurred during the sample precompression process. Phase transitions from both the cubic and the monoclinic polymorphs to a hexagonal structure were observed. The hexagonal phase was stable up to the highest pressure in this study and was not quenchable and transformed to a monoclinic phase after pressure release. The bulk moduli of Gd{sub 2}O{sub 3} for the cubic, monoclinic, and hexagonal phases were obtained by fitting the compression data to the Birch-Murnaghan equation of state. Moreover, an anomaly of the hexagonal type Gd{sub 2}O{sub 3} was observed.

  2. Cubic TiO2 as a potential light absorber in solar-energy conversion

    NASA Astrophysics Data System (ADS)

    Mattesini, M.; de Almeida, J. S.; Dubrovinsky, L.; Dubrovinskaia, N.; Johansson, B.; Ahuja, R.

    2004-09-01

    Materials are currently sought for use in the photo-induced decomposition of water on crystalline electrodes. Titanium dioxide is valuable in this respect. The electronic structural properties of cubic TiO2 polymorphs were investigated by means of first-principles methods. We demonstrate that both fluorite- and pyrite-type TiO2 have important optical absorptive transitions in the region of the visible light. A cubic TiO2 phase that can efficiently absorb the sunlight would be an important candidate material for the development of the solar cells. Also, we present results on the Ti L edges for the two different titania forms. We predict that a qualitative spectroscopic discrimination of the cubic polymorphs can be achieved by following the Ti 2p→3d x-ray transitions.

  3. La 4[(C 2) 1- xGe x] 3, Lanthanum(III) Dicarbide(4-) Germanide(4-) Mixed Crystals: A Continuous Transition between the Cubic Structure Types cI40 (Rb 4O 6/Pu 2C 3) and cI28 (Th 3P 4)

    NASA Astrophysics Data System (ADS)

    Carrillo-Cabrera, Wilder; Curda, Jan; Peters, Karl; von Schnering, Hans Georg

    1999-10-01

    La4(C2)2Ge was obtained as a minor component from the reaction of the elements in corundum crucibles enclosed in stainless steel ampoules at 1360 K. The compound is gray with metallic luster. The crystal structure (space group Ioverline43d (No. 220); a=8.995(1) Å; Z=4; R(F)=0.033, Rw(F2)=0.061 for 106 reflections (all data) with 2θmax=50° measured on four-circle diffractometer) may be described as a 3D framework of condensed La8 dodecahedra (bisdisphenoids) centered by Ge atoms and C2 dumbbells (d(C-C)=1.22 Å). La4(C2)2Ge and the previous reported cubic compounds La2C3≙La4(C2)3, "La5C1.5Ge3" ≙La4(C2)0.60Ge2.40, and La4Ge3 demonstrate the existence of a large range of homogeneity La4[(C2)1-xGex]3 between the yellow transparent ethenide (4-) La2C3 and La4Ge3. In the series, the C2 dumbbells are replaced by Ge atoms, corresponding with the formal charges C4-2, Ge4-, and La3+. These mixed crystals (Pearson symbol cI28⇔40) represent a continuous transition between the structure types cI40 (Rb4O6/Pu2C3) and cI28 (Th3P4). The results are discussed together with the general trends in the members of both structures types.

  4. Analysis of diffraction from (001) twist boundaries in cubic metals

    SciTech Connect

    Brokman, A.; Balluffi, R.W.

    1983-02-01

    An analysis of the diffraction from (001) twist boundaries in cubic metals has been made using analytical methods. A relatively simple model for boundary structure involving rotational relaxations around O lattice elements in the boundary core was employed. The results yielded grain boundary diffracted intensity on a grain boundary diffraction lattice in reciprocal space. This lattice consisted of an array of line elements running parallel to the twist axis in a square pattern corresponding to the reciprocal lattice of the Coincidence Site Lattice lying parallel to the grain boundary plane. The analytical model predicted the presently available main features of experimentally observed diffracted intensities and also those obtained by computer simulation calculations and clearly revealed the physical origins of the diffraction effects. The generalization of the analytical model to include any type of boundary was indicated. 9 figures.

  5. Analysis of diffraction from (001) twist boundaries in cubic metals

    SciTech Connect

    Brokman, A.; Balluffi, R.W.

    1983-10-01

    An analysis of the diffraction from (001) twist boundaries in cubic metals has been made using analytical methods. A simple model for boundary structure involving rotational relaxations around O lattice elements in the boundary core was employed. The results yielded grain boundary diffracted intensity on a grain boundary diffraction lattice in reciprocal space. This lattice consisted of an array of line elements running parallel to the twist axis in a square pattern corresponding to the reciprocal lattice of the coincidence site lattice lying parallel to the grain boundary plane. The analytical model predicted the main features of experimentally observed diffracted intensities and also those obtained by computer simulation and revealed the physical origins of the diffraction effects. The generalization of the analytical model to include any type of boundary was indicated.

  6. P2Y2 receptor knock-out mice display normal NaCl absorption in medullary thick ascending limb.

    PubMed

    Marques, Rita D; Praetorius, Helle A; Leipziger, Jens

    2013-01-01

    Local purinergic signals modulate renal tubular transport. Acute activation of renal epithelial P2 receptors causes inhibition of epithelial transport and thus, should favor increased water and salt excretion by the kidney. So far only a few studies have addressed the effects of extracellular nucleotides on ion transport in the thick ascending limb (TAL). In the medullary thick ascending limb (mTAL), basolateral P2X receptors markedly (~25%) inhibit NaCl absorption. Although this segment does express both apical and basolateral P2Y2 receptors, acute activation of the basolateral P2Y2 receptors had no apparent effect on transepithelial ion transport. Here we studied, if the absence of the P2Y2 receptor causes chronic alterations in mTAL NaCl absorption by comparing basal and AVP-stimulated transepithelial transport rates. We used perfused mouse mTALs to electrically measure NaCl absorption in juvenile (<35 days) and adult (>35 days) male mice. Using microelectrodes, we determined the transepithelial voltage (Vte) and the transepithelial resistance (Rte) and thus, transepithelial NaCl absorption (equivalent short circuit current, I'sc). We find that mTALs from adult wild type (WT) mice have significantly lower NaCl absorption rates when compared to mTALs from juvenile WT mice. This could be attributed to significantly higher Rtevalues in mTALs from adult WT mice. This pattern was not observed in mTALs from P2Y2 receptor knockout (KO) mice. In addition, adult P2Y2 receptor KO mTALs have significantly lower Vtevalues compared to the juvenile. No difference in absolute I'sc was observed when comparing mTALs from WT and KO mice. AVP stimulated the mTALs to similar increases of NaCl absorption irrespective of the absence of the P2Y2 receptor. No difference was observed in the medullary expression level of NKCC2 in between the genotypes. These data indicate that the lack of P2Y2 receptors does not cause substantial differences in resting and AVP-stimulated NaCl absorption

  7. P2Y2 receptor knock-out mice display normal NaCl absorption in medullary thick ascending limb

    PubMed Central

    Marques, Rita D.; Praetorius, Helle A.; Leipziger, Jens

    2013-01-01

    Local purinergic signals modulate renal tubular transport. Acute activation of renal epithelial P2 receptors causes inhibition of epithelial transport and thus, should favor increased water and salt excretion by the kidney. So far only a few studies have addressed the effects of extracellular nucleotides on ion transport in the thick ascending limb (TAL). In the medullary thick ascending limb (mTAL), basolateral P2X receptors markedly (~25%) inhibit NaCl absorption. Although this segment does express both apical and basolateral P2Y2 receptors, acute activation of the basolateral P2Y2 receptors had no apparent effect on transepithelial ion transport. Here we studied, if the absence of the P2Y2 receptor causes chronic alterations in mTAL NaCl absorption by comparing basal and AVP-stimulated transepithelial transport rates. We used perfused mouse mTALs to electrically measure NaCl absorption in juvenile (<35 days) and adult (>35 days) male mice. Using microelectrodes, we determined the transepithelial voltage (Vte) and the transepithelial resistance (Rte) and thus, transepithelial NaCl absorption (equivalent short circuit current, I'sc). We find that mTALs from adult wild type (WT) mice have significantly lower NaCl absorption rates when compared to mTALs from juvenile WT mice. This could be attributed to significantly higher Rtevalues in mTALs from adult WT mice. This pattern was not observed in mTALs from P2Y2 receptor knockout (KO) mice. In addition, adult P2Y2 receptor KO mTALs have significantly lower Vtevalues compared to the juvenile. No difference in absolute I'sc was observed when comparing mTALs from WT and KO mice. AVP stimulated the mTALs to similar increases of NaCl absorption irrespective of the absence of the P2Y2 receptor. No difference was observed in the medullary expression level of NKCC2 in between the genotypes. These data indicate that the lack of P2Y2 receptors does not cause substantial differences in resting and AVP-stimulated NaCl absorption

  8. Sodium reduction in margarine using NaCl substitutes.

    PubMed

    Gonçalves, Carla; Rodrigues, Jéssica; Júnior, Heraldo; Carneiro, João; Freire, Tassyana; Freire, Luísa

    2017-08-17

    Sodium chloride is traditionally used as a food additive in food processing. However, because of its high sodium content, NaCl has been associated with chronic diseases. Margarine is a popular product that is used in several preparations, but it includes high sodium content; therefore, it is among the products whose sodium content should be reduced. Thus, the objective of this study was to produce margarines with reduced sodium content prepared using a salt mixture. The following 4 margarine formulations were prepared: Formulation A (control - 0% sodium reduction), Formulation B (20.8% less sodium), Formulation C (33.0% less sodium) and Formulation D (47.4% less sodium). The low sodium formulations were produced using a salt mixture consisting of NaCl, KCl, and monosodium glutamate at different concentrations. The margarines were evaluated using an acceptance test and descriptive tests: time-intensity and temporal dominance of sensations. The mixture used is a good alternative for preparing low sodium margarine because the low sodium formulations feature equal salinity and do not produce a strange or bad taste. Furthermore, it may be possible to prepare margarines with up to 47.4% less sodium and that are acceptable to consumers.

  9. Curvature and Tangency Handles for Control of Convex Cubic Shapes

    DTIC Science & Technology

    2000-01-01

    looked at A-splines constructed with segments of singular al- gebraic cubics, which are just rational cubics, with new, geometrically more meaningful...contact interpolation , and curvatures at three prescribed points, see Figures 1-4. Curve and Surface Design: Saint-Malo 1999 91 Pierre-Jean Laurent...curvature at one contact point. §2. Barycentric Coordinates and Curvature at the Endpoints The general algebraic cubic in cartesian coordinates x, y is

  10. Cubic meter volume optical coherence tomography

    PubMed Central

    WANG, ZHAO; POTSAID, BENJAMIN; CHEN, LONG; DOERR, CHRIS; LEE, HSIANG-CHIEH; NIELSON, TORBEN; JAYARAMAN, VIJAYSEKHAR; CABLE, ALEX E.; SWANSON, ERIC; FUJIMOTO, JAMES G.

    2017-01-01

    Optical coherence tomography (OCT) is a powerful three-dimensional (3D) imaging modality with micrometer-scale axial resolution and up to multi-GigaVoxel/s imaging speed. However, the imaging range of high-speed OCT has been limited. Here, we report 3D OCT over cubic meter volumes using a long coherence length, 1310 nm vertical-cavity surface-emitting laser and silicon photonic integrated circuit dual-quadrature receiver technology combined with enhanced signal processing. We achieved 15 µm depth resolution for tomographic imaging at a 100 kHz axial scan rate over a 1.5 m range. We show 3D macroscopic imaging examples of a human mannequin, bicycle, machine shop gauge blocks, and a human skull/brain model. High-bandwidth, meter-range OCT demonstrates new capabilities that promise to enable a wide range of biomedical, scientific, industrial, and research applications. PMID:28239628

  11. On the stability of cubic galileon accretion

    NASA Astrophysics Data System (ADS)

    Bergliaffa, Santiago Esteban Perez; Maier, Rodrigo

    2017-09-01

    We examine the linear stability of the nongravitating steady-state galileon accretion for the case of a Schwarzcshild black hole. Considering the galileon action up to the cubic term in a static and spherically symmetric background we obtain the general solution for the equation of motion which is divided into two branches. By perturbing this solution we define an effective metric which determines the propagation of fluctuations. In this general picture we establish the position of the sonic horizon together with the matching condition of the two branches on it. Restricting to the case of a Schwarzschild background, we show, via the analysis of the energy of the perturbations and its time derivative, that the accreting field is linearly stable.

  12. Cubic meter volume optical coherence tomography.

    PubMed

    Wang, Zhao; Potsaid, Benjamin; Chen, Long; Doerr, Chris; Lee, Hsiang-Chieh; Nielson, Torben; Jayaraman, Vijaysekhar; Cable, Alex E; Swanson, Eric; Fujimoto, James G

    2016-12-01

    Optical coherence tomography (OCT) is a powerful three-dimensional (3D) imaging modality with micrometer-scale axial resolution and up to multi-GigaVoxel/s imaging speed. However, the imaging range of high-speed OCT has been limited. Here, we report 3D OCT over cubic meter volumes using a long coherence length, 1310 nm vertical-cavity surface-emitting laser and silicon photonic integrated circuit dual-quadrature receiver technology combined with enhanced signal processing. We achieved 15 µm depth resolution for tomographic imaging at a 100 kHz axial scan rate over a 1.5 m range. We show 3D macroscopic imaging examples of a human mannequin, bicycle, machine shop gauge blocks, and a human skull/brain model. High-bandwidth, meter-range OCT demonstrates new capabilities that promise to enable a wide range of biomedical, scientific, industrial, and research applications.

  13. Triangulation of cubic panorama for view synthesis.

    PubMed

    Zhang, Chunxiao; Zhao, Yan; Wu, Falin

    2011-08-01

    An unstructured triangulation approach, new to our knowledge, is proposed to apply triangular meshes for representing and rendering a scene on a cubic panorama (CP). It sophisticatedly converts a complicated three-dimensional triangulation into a simple three-step triangulation. First, a two-dimensional Delaunay triangulation is individually carried out on each face. Second, an improved polygonal triangulation is implemented in the intermediate regions of each of two faces. Third, a cobweblike triangulation is designed for the remaining intermediate regions after unfolding four faces to the top/bottom face. Since the last two steps well solve the boundary problem arising from cube edges, the triangulation with irregular-distribution feature points is implemented in a CP as a whole. The triangular meshes can be warped from multiple reference CPs onto an arbitrary viewpoint by face-to-face homography transformations. The experiments indicate that the proposed triangulation approach provides a good modeling for the scene with photorealistic rendered CPs.

  14. A smoothing algorithm using cubic spline functions

    NASA Technical Reports Server (NTRS)

    Smith, R. E., Jr.; Price, J. M.; Howser, L. M.

    1974-01-01

    Two algorithms are presented for smoothing arbitrary sets of data. They are the explicit variable algorithm and the parametric variable algorithm. The former would be used where large gradients are not encountered because of the smaller amount of calculation required. The latter would be used if the data being smoothed were double valued or experienced large gradients. Both algorithms use a least-squares technique to obtain a cubic spline fit to the data. The advantage of the spline fit is that the first and second derivatives are continuous. This method is best used in an interactive graphics environment so that the junction values for the spline curve can be manipulated to improve the fit.

  15. Activation energy of the low-load NaCl transition from nanoindentation loading curves.

    PubMed

    Kaupp, Gerd

    2014-01-01

    Access to activation energies E(a) of phase transitions is opened by unprecedented analyses of temperature dependent nanoindentation loading curves. It is based on kinks in linearized loading curves, with additional support by coincidence of kink and electrical conductivity of silicon loading curves. Physical properties of B1, B2, NaCl and further phases are discussed. The normalized low-load transition energy of NaCl (Wtrans/µN) increases with temperature and slightly decreases with load. Its semi-logarithmic plot versus T obtains activation energy E(a)/µN for calculation of the transition work for all interesting temperatures and pressures. Arrhenius-type activation energy (kJ/mol) is unavailable for indentation phase transitions. The E(a) per load normalization proves insensitive to creep-on-load, which excludes normalization to depth or volume for large temperature ranges. Such phase transition E(a)/µN is unprecedented material's property and will be of practical importance for the compatibility of composite materials under impact and further shearing interactions at elevated temperatures.

  16. Electrochemical Behavior of Al-B4C Metal Matrix Composites in NaCl Solution

    PubMed Central

    Han, Yu-Mei; Chen, X.-Grant

    2015-01-01

    Aluminum based metal matrix composites (MMCs) have received considerable attention in the automotive, aerospace and nuclear industries. One of the main challenges using Al-based MMCs is the influence of the reinforcement particles on the corrosion resistance. In the present study, the corrosion behavior of Al-B4C MMCs in a 3.5 wt.% NaCl solution were investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. Results indicated that the corrosion resistance of the composites decreased when increasing the B4C volume fraction. Al-B4C composite was susceptible to pitting corrosion and two types of pits were observed on the composite surface. The corrosion mechanism of the composite in the NaCl solution was primarily controlled by oxygen diffusion in the solution. In addition, the galvanic couples that formed between Al matrix and B4C particles could also be responsible for the lower corrosion resistance of the composites. PMID:28793574

  17. Low pressure growth of cubic boron nitride films

    NASA Technical Reports Server (NTRS)

    Ong, Tiong P. (Inventor); Shing, Yuh-Han (Inventor)

    1997-01-01

    A method for forming thin films of cubic boron nitride on substrates at low pressures and temperatures. A substrate is first coated with polycrystalline diamond to provide a uniform surface upon which cubic boron nitride can be deposited by chemical vapor deposition. The cubic boron nitride film is useful as a substitute for diamond coatings for a variety of applications in which diamond is not suitable. any tetragonal or hexagonal boron nitride. The cubic boron nitride produced in accordance with the preceding example is particularly well-suited for use as a coating for ultra hard tool bits and abrasives, especially those intended to use in cutting or otherwise fabricating iron.

  18. Vibration analysis of cubic rotary-linear piezoelectric actuator.

    PubMed

    Mashimo, Tomoaki; Toyama, Shigeki

    2011-04-01

    Cubic design of a stator in a rotary-linear piezoelectric actuator is sophisticated and interesting, but the vibration theory of the cubic stator remains unclear when using the finite element method (FEM). In this paper, we analyze the vibration behavior of the cubic stator by applying the energy method, which distinguishes the component of mechanical energy. By changing the design of the stator (especially the length in the direction of the through-hole axis), we clarify how the vibration modes are in accordance at one equal frequency in cubic shape. The behavior of the vibration modes is discussed using conventional vibration theory of a beam and a plate. © 2011 IEEE

  19. Monoolein Cubic Phase Gels and Cubosomes Doped with Magnetic Nanoparticles-Hybrid Materials for Controlled Drug Release.

    PubMed

    Szlezak, Monika; Nieciecka, Dorota; Joniec, Aleksandra; Pękała, Marek; Gorecka, Ewa; Emo, Mélanie; Stébé, Marie J; Krysiński, Paweł; Bilewicz, Renata

    2017-01-25

    Hybrid materials consisting of a monoolein lipidic cubic phase (LCP) incorporating two types of magnetic nanoparticles (NP) were designed as addressable drug delivery systems. The materials, prepared in the form of a gel, were subsequently used as a macroscopic layer modifying an electrode and, after dispersion to nanoscale, as magnetocubosomes. These two LCPs were characterized by small-angle X-ray scattering (SAXS), cross-polarized microscopy, magnetic measurements, and phase diagrams. The magnetic dopants were hydrophobic NPoleic and hydrophilic NPcitric, characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM), and their influence on the properties of the cubic phases was investigated. The removal of the anticancer drug, Doxorubicin (Dox) from the hybrid cubic phase gels was studied by electrochemical methods. The advantages of incorporating magnetic nanoparticles into the self-assembled lipid liquid crystalline phases include the ability to address the cubic phase nanoparticle containing large amounts of drug and to control the kinetics of the drug release.

  20. Solving Buckmaster equation using cubic B-spline and cubic trigonometric B-spline collocation methods

    NASA Astrophysics Data System (ADS)

    Chanthrasuwan, Maveeka; Asri, Nur Asreenawaty Mohd; Hamid, Nur Nadiah Abd; Majid, Ahmad Abd.; Azmi, Amirah

    2017-08-01

    The cubic B-spline and cubic trigonometric B-spline functions are used to set up the collocation in finding solutions for the Buckmaster equation. These splines are applied as interpolating functions in the spatial dimension while the finite difference method (FDM) is used to discretize the time derivative. The Buckmaster equation is linearized using Taylor's expansion and solved using two schemes, namely Crank-Nicolson and fully implicit. The von Neumann stability analysis is carried out on the two schemes and they are shown to be conditionally stable. In order to demonstrate the capability of the schemes, some problems are solved and compared with analytical and FDM solutions. The proposed methods are found to generate more accurate results than the FDM.

  1. The three dimensionality of cell membranes: lamellar to cubic membrane transition as investigated by electron microscopy.

    PubMed

    Chong, Ketpin; Deng, Yuru

    2012-01-01

    Biological membranes are generally perceived as phospholipid bilayer structures that delineate in a lamellar form the cell surface and intracellular organelles. However, much more complex and highly convoluted membrane organizations are ubiquitously present in many cell types under certain types of stress, states of disease, or in the course of viral infections. Their occurrence under pathological conditions make such three-dimensionally (3D) folded and highly ordered membranes attractive biomarkers. They have also stimulated great biomedical interest in understanding the molecular basis of their formation. Currently, the analysis of such membrane arrangements, which include tubulo-reticular structures (TRS) or cubic membranes of various subtypes, is restricted to electron microscopic methods, including tomography. Preservation of membrane structures during sample preparation is the key to understand their true 3D nature. This chapter discusses methods for appropriate sample preparations to successfully examine and analyze well-preserved highly ordered membranes by electron microscopy. Processing methods and analysis conditions for green algae (Zygnema sp.) and amoeba (Chaos carolinense), mammalian cells in culture and primary tissue cells are described. We also discuss methods to identify cubic membranes by transmission electron microscopy (TEM) with the aid of a direct template matching method and by computer simulation. A 3D analysis of cubic cell membrane topology by electron tomography is described as well as scanning electron microscopy (SEM) to investigate surface contours of isolated mitochondria with cubic membrane arrangement.

  2. Cubic phases for studies of drug partition into lipid bilayers.

    PubMed

    Engström, S; Nordén, T P; Nyquist, H

    1999-08-01

    Drug partition into lipid bilayers in a cubic liquid-crystalline phase was investigated. Glyceryl monooleate was used to form the lipid bilayer in a reversed bicontinuous cubic liquid-crystalline phase. The reason for using the cubic phase is that it may coexist with an external aqueous phase, and that the phase boundary (cubic phase/aqueous bulk) is well-defined due to the stiffness of the cubic phase. This makes the cubic phase a potential candidate for high throughput screening (HTS) of the lipophilicity and the dissociation constant (if any) of drug compounds. Clomethiazole (CMZ), lidocaine, prilocaine and 4-phenylbutylamine (4-PBA) were chosen as model drug compounds. It was shown that it is possible to determine a pH-dependent apparent partition coefficient, Kbl/w, of a drug compound using a lipid bilayer expressed as a cubic liquid-crystalline structure. Good agreement was found when the resulting Kbl/w vs. pH curves for CMZ, lidocaine and prilocaine were fitted to a mathematical expression. This included the bilayer/water partition coefficient for the unionised and ionised drug respectively and the pKa of the drug. The effect of different experimental conditions; such as amount of cubic phase, temperature, agitation, sample preparation and interfacial area between the cubic phase and the aqueous bulk on the partition kinetics were investigated as well. The studies reveal that the time needed to reach partition equilibrium was, as expected, substantially reduced (from days to hours) by decreasing the amount of cubic phase, increasing the interfacial area between the cubic phase and the aqueous phase, and increasing the temperature and the agitation of the sample. It was also shown that the bilayer affinity of 4-PBA was increased when a zwitterionic lipid (i.e. dioleoyl phosphatidylcholine, DOPC) was incorporated in the bilayer.

  3. Impaired NaCl taste thresholds in Zn deprived rats

    SciTech Connect

    Brosvic, G.M.; Slotnick, B.M.; Nelson, N.; Henkin, R.I.

    1986-03-05

    Zn deficiency is a relatively common cause of loss of taste acuity in humans. In some patients replacement with exogenous Zn results in rapid reversal of the loss whereas in others prolonged treatment is needed to restore normal taste function. To study this 300 gm outbred Sprague Dawley rats were given Zn deficient diet (< 1 ppm Zn) supplemented with Zn in drinking water (0.1 gm Zn/100 gm body weight). Rats were trained in an automated operant conditions procedure and NaCl taste thresholds determined. During an initial training period and over two replications mean thresholds were 0.006% and mean plasma Zn was 90 +/- 2 ..mu..g/dl (M +/- SEM) determined by flame atomic absorption spectrophotometry. Rats were then divided into two groups; in one (3 rats) Zn supplement was removed, in the other (4 rats), pair-fed with the former group, Zn supplement was continued. In 10 days NaCl thresholds in Zn deprived rats increased significantly (0.07%, p < 0.01) and in 17 days increased 13 fold (0.08%) but thresholds for pair fed, supplemented rats remained constant (0.006%). There was no overlap in response between any rat in the two groups. Plasma Zn at 17 days in Zn-deprived rats was significantly below pair-fed rats (52 +/- 13 vs 89 +/- 6 ..mu..g/dl, respectively, P < 0.01). At this time Zn-deprived rats were supplemented with Zn for 27 days without any reduction in taste thresholds. These preliminary results are consistent with previous observations in Zn deficient patients.

  4. The biosynthesis of ochratoxin A by Penicillium as one mechanism for adaptation to NaCl rich foods.

    PubMed

    Schmidt-Heydt, Markus; Graf, Eva; Stoll, Dominic; Geisen, Rolf

    2012-04-01

    Penicillium.nordicum is an ochratoxin A producing filamentous fungus, which is adapted to sodium chloride and protein rich food environments like certain cheeses or dry cured meats. Penicillium.verrucosum usually occurs on cereals but can also be isolated from brined olives. It could be shown that sodium chloride has a profound influence on the regulation of ochratoxin A biosynthesis in both Penicillium species. High amounts of ochratoxin A are produced by P. nordicum over a wide concentration range of NaCl (5-100 g/l) with a weak optimum at about 20 g/l after growth on YES medium. P. verrucosum shifts secondary metabolite biosynthesis after growth on YES medium from citrinin at low to ochratoxin at elevated NaCl concentrations. The ochratoxin A biosynthesis of P. nordicum is accompanied by an induction of the otapksPN gene, the gene of the ochratoxin A polyketide synthase. A mutant strain unable to produce ochratoxin showed a drastic growth reduction under high NaCl conditions. Determination of the dry weight and the chloride content in the mycelium of the P. nordicum wild type strain and a non-ochratoxin A producing mutant strain showed a much higher increase of both parameters in the mutant compared to the wild type. These results suggest, that the constant biosynthesis and excretion of ochratoxin A, which itself contains a chloride atom, ensures a partial chloride homeostasis in the fungal cell. This mechanism may support the adaptation of ochratoxin A producing Penicillia to NaCl rich foods.

  5. Laser Deposition of Cubic Boron Nitride on Electronic Materials.

    DTIC Science & Technology

    1991-08-12

    wurtzite or cubic structure of BN (see Figures 4 and 5). It is clear that the films grown via laser processing were amorphous rather than crystalline... cubic structure of BN can be obtained. It appears from our work and Dr. Doll’s work that excimer laser ablated species do not have sufficient energy

  6. Cubic Polynomials with Real or Complex Coefficients: The Full Picture

    ERIC Educational Resources Information Center

    Bardell, Nicholas S.

    2016-01-01

    The cubic polynomial with real coefficients has a rich and interesting history primarily associated with the endeavours of great mathematicians like del Ferro, Tartaglia, Cardano or Vieta who sought a solution for the roots (Katz, 1998; see Chapter 12.3: The Solution of the Cubic Equation). Suffice it to say that since the times of renaissance…

  7. Cubic Polynomials with Real or Complex Coefficients: The Full Picture

    ERIC Educational Resources Information Center

    Bardell, Nicholas S.

    2016-01-01

    The cubic polynomial with real coefficients has a rich and interesting history primarily associated with the endeavours of great mathematicians like del Ferro, Tartaglia, Cardano or Vieta who sought a solution for the roots (Katz, 1998; see Chapter 12.3: The Solution of the Cubic Equation). Suffice it to say that since the times of renaissance…

  8. Estimating the hydrogen ion concentration in concentrated NaCl and Na{sub 2}SO{sub 4} electrolytes

    SciTech Connect

    Rai, D.; Felmy, A.R.; Juracich, S.P.; Rao, F.

    1995-06-01

    Combination glass electrodes were tested for determining H{sup +} concentrations in concentrated pure and mixed NaCl and Na{sub 2}SO{sub 4} solutions, as well as natural brine systems. NaCl, Na{sub 2}SO{sub 4}, and mixtures of NaCl and Na{sub 2}SO{sub 4} solutions were analyzed. Correction factors for estimating pC{sub H}{sup +} (negative logarithm of H{sup +} concentration) were determined from measured/observed pH values. Required Gran-type titrations were done with HCl and/or NaOH. The titration method is described and a step-by-step procedure provided; it has been used previously for determining pC{sub H}{sup +} values of synthetic chloride-dominated brines. Precautions are required to determine correction factors for electrolytes that react with H{sup +} or OH{sup {minus}} [sulfate brines for titration with acid; magnesium brines for titration with base because of precipitation of Mg(OH)2]. Correction factors A (pC{sub H}{sup +} = pH{sub ob} + A) from HCl titrations were similar to those from NaOH titrations where the concentration of free H{sup +} was calculated using a thermodynamic model. These values should be applicable to solns with a very large range in measured pH values (2 to 12). Because a large number of solns were titrated with HCl and the A values are similar for HCl and NaOH titrations, the A values for NaCl and Na2SO4 solns were fit as a function of molality to allow extrapolation. For NaCl solns 0 to 6.0 M, A can be obtained by multiplying the molality by 0.159. For Na2SO4 solns 0 to 2.0 M, the values of A can be obtained from (0.221 {minus} 0.549X + 0.201X{sup 2}), where X is the molality of Na{sub 2}SO{sub 4}. Orion-Ross electrode evaluations indicated that the A values did not differ significantly for different electrodes. Results suggest that the data in this report can be used to estimate A values for different NaCl and Na{sub 2}SO{sub 4} solns even for noncalibrated electrodes.

  9. [Physiological responses of different cucumber cultivars seedlings to iso-osmotic Mg (NO3) 2 and NaCl stress].

    PubMed

    Cao, Qi-wei; Li, Li-bin; Kong, Su-ping; Qiu, An; Chen, Wei; Zhang, Yun-nan; Sun, Xiao-lei

    2015-04-01

    In this study, the effects of iso-osmotic solution of Mg (NO3) 2 and NaCl on seedling growth, leaf lipid peroxidation, antioxidant enzyme activities, and osmotic adjustment substance accumulation were investigated using three cucumber cultivars with different ecotypes. Then salt tolerance was evaluated by membership function method. The results revealed that under the stress of 60 and 80 mmol x L(-1) Mg(NO3) 2 solution and its isotonic 90 and 120 mmol x L(-1) NaCl solution, the seedling traits such as height, stem diameter, leaf area, fresh and dry mass of aerial part and underground parts, and antioxidant enzymes activity were obviously decreased with the increasing concentration of Mg( NO3)2 and its isotonic NaCl in the three cucumber cultivars. Moreover, the inhibitory effects became more obvious with the increasing concentration of either Mg(NO3)2 or NaCl solution. MDA content and membrane lipid peroxidation were enhanced in cucumber seedlings. Among the three cultivars, SJ31-1 changed less than the other two cultivars regarding the reduced amplitudes of biomass, and activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the increased amplitude of MDA. In addition, Mg (NO3)2 solution inhibited seedling growth more strongly than isotonic NaCl solution did, such difference was relatively significant with increasing the concentration of solution. The contents of proline, soluble amino acids, and soluble sugars varied depending on the cucumber genotype and salt type. The increased amplitude of proline content was the largest in SJ31-1, and that of soluble sugars was the largest in Lubai 19 when growing under salt treatment. The change of these parameters in Xintaimici was in between. Soluble sugars and soluble proteins were predominant osmolytes unde NaCl stress, whereas proline and soluble proteins were main osmolytes under Mg (NO3) 2 stress. Comprehensive evaluation showed that salt tolerance of the three cucumber cultivars was in order

  10. Testing the Tube Super-Dielectric Material Hypothesis: Increased Energy Density Using NaCl

    NASA Astrophysics Data System (ADS)

    Gandy, Jonathan; Cortes, Francisco Javier Quintero; Phillips, Jonathan

    2016-11-01

    The focus of the present work is the evaluation of the low-frequency dielectric performance of titanium dioxide nanotube arrays, created by anodization, filled with aqueous NaCl solutions. At low frequency (ca. <10-2 Hz), capacitors made up of this so-called tube super-dielectric material were found to have extreme dielectric constants, greater than 1 billion. The same capacitors also registered unprecedented energy densities, nearly 400 J/cm3, better than that observed (<250 J/cm3) for the same type of anodized titania filled with an aqueous solution of NaNO3, and about an order of magnitude better than commercial supercapacitors. Sufficient data were collected to propose a correlation relating dielectric thickness and salt concentration to overall energy density.

  11. Electrolytic lesions of the pedunculopontine nucleus disrupt concurrent learned aversion induced by NaCl.

    PubMed

    Mediavilla, C; Molina, F; Puerto, A

    2000-09-01

    Bilateral electrolytic lesions in the pedunculopontine nucleus (PPN) impair acquisition of short-term, or concurrent, Taste Aversion Learning (TAL) in rats. This type of TAL is characterized by the daily presentation of two different flavor stimuli at the same time, one associated with simultaneous intragastric administration of an aversive product (hypertonic NaCl) and the other with physiological saline. Sham-lesioned control animals learn this taste discrimination task, but both lesioned animals and control animals learn a long-term, or delayed, TAL task in which each gustatory stimulus is presented individually every other day and the intragastric products, LiCl (0.15 M) and physiological saline, are administered after a 15-min delay. These results are analyzed in the context of the cerebellar circuits involved in learning and in relation to the two TAL modalities described above.

  12. Two New Cubic Structures of Mercury Arsenidehalides

    NASA Astrophysics Data System (ADS)

    Shevelkov, Andrei V.; Dikarev, Evgeny V.; Popovkin, Boris A.

    1996-11-01

    Crystal structures of Hg4As2Br3(I) and Hg7.4As4Cl6(II), which was prepared for the first time, have been refined based on the X-ray single crystal experiments. Both phases crystallize in the cubic space groupPa3. Crystal data: I,a= 12.610(1),Z= 8,R1= 0.0602; II,a= 12.178(1),Z= 4,R1= 0.0584. Characteristic of both structures are the As2Hg6octahedra having an As-As separation of ca. 2.38 Å. Such octahedra share vertices with AsHg4tetrahedra in I, while in II they compose a perovskite-like three-dimensional network by sharing all vertices. Part of the mercury atoms in II have no neighbors up to 3.53 Å and are considered to possess a zero oxidation state. An idealized path for the I to II structure transformation, which is based on the difference of halogen radii, is suggested.

  13. Topological oxide insulator in cubic perovskite structure.

    PubMed

    Jin, Hosub; Rhim, Sonny H; Im, Jino; Freeman, Arthur J

    2013-01-01

    The emergence of topologically protected conducting states with the chiral spin texture is the most prominent feature at the surface of topological insulators. On the application side, large band gap and high resistivity to distinguish surface from bulk degrees of freedom should be guaranteed for the full usage of the surface states. Here, we suggest that the oxide cubic perovskite YBiO3, more than just an oxide, defines itself as a new three-dimensional topological insulator exhibiting both a large bulk band gap and a high resistivity. Based on first-principles calculations varying the spin-orbit coupling strength, the non-trivial band topology of YBiO3 is investigated, where the spin-orbit coupling of the Bi 6p orbital plays a crucial role. Taking the exquisite synthesis techniques in oxide electronics into account, YBiO3 can also be used to provide various interface configurations hosting exotic topological phenomena combined with other quantum phases.

  14. Topological Oxide Insulator in Cubic Perovskite Structure

    PubMed Central

    Jin, Hosub; Rhim, Sonny H.; Im, Jino; Freeman, Arthur J.

    2013-01-01

    The emergence of topologically protected conducting states with the chiral spin texture is the most prominent feature at the surface of topological insulators. On the application side, large band gap and high resistivity to distinguish surface from bulk degrees of freedom should be guaranteed for the full usage of the surface states. Here, we suggest that the oxide cubic perovskite YBiO3, more than just an oxide, defines itself as a new three-dimensional topological insulator exhibiting both a large bulk band gap and a high resistivity. Based on first-principles calculations varying the spin-orbit coupling strength, the non-trivial band topology of YBiO3 is investigated, where the spin-orbit coupling of the Bi 6p orbital plays a crucial role. Taking the exquisite synthesis techniques in oxide electronics into account, YBiO3 can also be used to provide various interface configurations hosting exotic topological phenomena combined with other quantum phases. PMID:23575973

  15. Why Do Membranes of Some Unhealthy Cells Adopt a Cubic Architecture?

    PubMed Central

    2016-01-01

    Nonlamellar lipid arrangements, including cubosomes, appear in unhealthy cells, e.g., when they are subject to stress, starvation, or viral infection. The bioactivity of cubosomes—nanoscale particles exhibiting bicontinuous cubic structures—versus more common vesicles is an unexplored area due to lack of suitable model systems. Here, glycodendrimercubosomes (GDCs)—sugar-presenting cubosomes assembled from Janus glycodendrimers by simple injection into buffer—are proposed as mimics of biological cubic membranes. The bicontinuous cubic GDC architecture has been demonstrated by electron tomography. The stability of these GDCs in buffer enabled studies on lectin-dependent agglutination, revealing significant differences compared with the vesicular glycodendrimersome (GDS) counterpart. In particular, GDCs showed an increased activity toward concanavalin A, as well as an increased sensitivity and selectivity toward two variants of banana lectins, a wild-type and a genetically modified variant, which is not exhibited by GDSs. These results suggest that cells may adapt under unhealthy conditions by undergoing a transformation from lamellar to cubic membranes as a method of defense. PMID:28058284

  16. Non--Cubic Symmetry of the Electronic Response in AFM Late Transition--Metal Oxides.

    NASA Astrophysics Data System (ADS)

    Posternak, M.; Baldereschi, A.; Massidda, S.; Resta, R.

    1998-03-01

    The late transition--metal monoxides (MnO, FeO, CoO, NiO) have the rocksalt structure in their paramagnetic phase, while below the Neel temperature a weak structural distortion accompanies an AFM ordering of type II. Therefore, it is generally assumed that most nonmagnetic (i.e. spin--integrated) crystalline properties are essentially cubic: we give here convincing evidence of the contrary. We focus on the half--filled d shell oxide MnO as the most suitable case study, on which we perform accurate ab--initio, all--electron calculations, within different one--particle schemes. In order to study the symmetry lowering due to AFM ordering, we assume an ideal cubic geometry throughout. The calculated TO frequencies and Born effective charge tensor do not have cubic symmetry. The standard LSD severely exaggerates the deviations from cubic symmetry, confirming its unreliability for calculating properties of insulating AFM oxides, while a model self--energy correction scheme(S. Massidda et al.), Phys. Rev. B 55, 13494 (1997). reduces considerably the anisotropy. We also explain the origin and the magnitude of this effect in terms of the mixed charge--transfer/Mott--Hubbard character of MnO.

  17. Effect of NaCl, Gum Arabic and Microbial Transglutaminase on the Gel and Emulsion Characteristics of Porcine Myofibrillar Proteins

    PubMed Central

    Davaatseren, Munkhtugs

    2014-01-01

    This study investigated the effect of gum arabic (GA) combined with microbial transglutaminase (TG) on the functional properties of porcine myofibrillar protein (MP). As an indicator of functional property, heat-set gel and emulsion characteristics of MP treated with GA and/or TG were explored under varying NaCl concentrations (0.1-0.6 M). The GA improved thermal gelling ability of MP during thermal processing and after cooling, and concomitantly added TG assisted the formation of viscoelastic MP gel formation. Meanwhile, the addition of GA decreased cooking yield of MP gel at 0.6 M NaCl concentration, and the yield was further decreased by TG addition, mainly attributed by enhancement of protein-protein interactions. Emulsion characteristics indicated that GA had emulsifying ability and the addition of GA increased the emulsification activity index (EAI) of MP-stabilized emulsion. However, GA showed a negative effect on emulsion stability, particularly great drop in the emulsion stability index (ESI) was found in GA treatment at 0.6 M NaCl. Consequently, the results indicated that GA had a potential advantage to form a viscoelastic MP gel. For the practical aspect, the application of GA in meat processing had to be limited to the purposes of texture enhancer such as restructured products, but not low-salt products and emulsion-type meat products. PMID:26761678

  18. Comparing van der Waals DFT methods for water on NaCl(001) and MgO(001).

    PubMed

    Kebede, Getachew G; Spångberg, Daniel; Mitev, Pavlin D; Broqvist, Peter; Hermansson, Kersti

    2017-02-14

    In this work, a range of van der Waals type density functionals are applied to the H2O/NaCl(001) and H2O/MgO(001) interface systems to explore the effect of an explicit dispersion treatment. The functionals we use are the self-consistent vdW functionals vdW-DF, vdW-DF2, optPBE-vdW, optB88-vdW, optB86b-vdW, and vdW-DF-cx, as well as the dispersion-corrected PBE-TS and PBE-D2 methods; they are all compared with the standard PBE functional. For both NaCl(001) and MgO(001), we find that the dispersion-flavoured functionals stabilize the water-surface interface by approximately 20%-40% compared to the PBE results. For NaCl(001), where the water molecules remain intact for all overlayers, the dominant contribution to the adsorption energy from "density functional theory dispersion" stems from the water-surface interactions rather than the water-water interactions. The optPBE-vdW and vdW-DF-cx functionals yield adsorption energies in good agreement with available experimental values for both NaCl and MgO. To probe the strengths of the perturbations of the adsorbed water molecules, we also calculated water dipole moments and found an increase up to 85% for water at the MgO(001) surface and 70% at the NaCl(001) surface, compared to the gas-phase dipole moment.

  19. Comparing van der Waals DFT methods for water on NaCl(001) and MgO(001)

    NASA Astrophysics Data System (ADS)

    Kebede, Getachew G.; Spângberg, Daniel; Mitev, Pavlin D.; Broqvist, Peter; Hermansson, Kersti

    2017-02-01

    In this work, a range of van der Waals type density functionals are applied to the H2O/NaCl(001) and H2O/MgO(001) interface systems to explore the effect of an explicit dispersion treatment. The functionals we use are the self-consistent vdW functionals vdW-DF, vdW-DF2, optPBE-vdW, optB88-vdW, optB86b-vdW, and vdW-DF-cx, as well as the dispersion-corrected PBE-TS and PBE-D2 methods; they are all compared with the standard PBE functional. For both NaCl(001) and MgO(001), we find that the dispersion-flavoured functionals stabilize the water-surface interface by approximately 20%-40% compared to the PBE results. For NaCl(001), where the water molecules remain intact for all overlayers, the dominant contribution to the adsorption energy from "density functional theory dispersion" stems from the water-surface interactions rather than the water-water interactions. The optPBE-vdW and vdW-DF-cx functionals yield adsorption energies in good agreement with available experimental values for both NaCl and MgO. To probe the strengths of the perturbations of the adsorbed water molecules, we also calculated water dipole moments and found an increase up to 85% for water at the MgO(001) surface and 70% at the NaCl(001) surface, compared to the gas-phase dipole moment.

  20. Arbuscular mycorrhizal symbiosis and osmotic adjustment in response to NaCl stress: a meta-analysis

    PubMed Central

    Augé, Robert M.; Toler, Heather D.; Saxton, Arnold M.

    2014-01-01

    Arbuscular mycorrhizal (AM) symbiosis can enhance plant resistance to NaCl stress in several ways. Two fundamental roles involve osmotic and ionic adjustment. By stimulating accumulation of solutes, the symbiosis can help plants sustain optimal water balance and diminish Na+ toxicity. The size of the AM effect on osmolytes has varied widely and is unpredictable. We conducted a meta-analysis to determine the size of the AM effect on 22 plant solute characteristics after exposure to NaCl and to examine how experimental conditions have influenced the AM effect. Viewed across studies, AM symbioses have had marked effects on plant K+, increasing root and shoot K+ concentrations by an average of 47 and 42%, respectively, and root and shoot K+/Na+ ratios by 47 and 58%, respectively. Among organic solutes, soluble carbohydrates have been most impacted, with AM-induced increases of 28 and 19% in shoots and roots. The symbiosis has had no consistent effect on several characteristics, including root glycine betaine concentration, root or shoot Cl− concentrations, leaf Ψπ, or shoot proline or polyamine concentrations. The AM effect has been very small for shoot Ca++ concentration and root concentrations of Na+, Mg++ and proline. Interpretations about AM-conferred benefits regarding these compounds may be best gauged within the context of the individual studies. Shoot and root K+/Na+ ratios and root proline concentration showed significant between-study heterogeneity, and we examined nine moderator variables to explore what might explain the differences in mycorrhizal effects on these parameters. Moderators with significant impacts included AM taxa, host type, presence or absence of AM growth promotion, stress severity, and whether NaCl constituted part or all of the experimental saline stress treatment. Meta-regression of shoot K+/Na+ ratio showed a positive response to root colonization, and root K+/Na+ ratio a negative response to time of exposure to NaCl. PMID:25368626

  1. On the shock response of cubic metals

    NASA Astrophysics Data System (ADS)

    Bourne, N. K.; Gray, G. T.; Millett, J. C. F.

    2009-11-01

    The response of four cubic metals to shock loading is reviewed in order to understand the effects of microstructure on continuum response. Experiments are described that link defect generation and storage mechanisms at the mesoscale to observations in the bulk. Four materials were reviewed; these were fcc nickel, the ordered fcc intermetallic Ni3Al, the bcc metal tantalum, and two alloys based on the intermetallic phase TiAl; Ti-46.5Al-2Cr-2Nb and Ti-48Al-2Cr-2Nb-1B. The experiments described are in two groups: first, equation of state and shear strength measurements using Manganin stress gauges and, second, postshock microstructural examinations and measurement of changes in mechanical properties. The behaviors described are linked through the description of time dependent plasticity mechanisms to the final states achieved. Recovered targets displayed dislocation microstructures illustrating processes active during the shock-loading process. Reloading of previously shock-prestrained samples illustrated shock strengthening for the fcc metals Ni and Ni3Al while showing no such effect for bcc Ta and for the intermetallic TiAl. This difference in effective shock hardening has been related, on the one hand, to the fact that bcc metals have fewer available slip systems that can operate than fcc crystals and to the observation that the lower symmetry materials (Ta and TiAl) both possess high Peierls stress and thus have higher resistances to defect motion in the lattice under shock-loading conditions. These behaviors, compared between these four materials, illustrate the role of defect generation, transport, storage, and interaction in determining the response of materials to shock prestraining.

  2. Determining the Incorporation of NaCl into Ice VII by Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Runge, C. E.; Frank, M. R.

    2003-12-01

    High-pressure H2O polymorphs have been thought to comprise the interior of some planetary bodies. Ice VII, a polymorph of H2O with a large range of pressure stability above 2 GPa and room temperature is thought to compose a portion of some Galilean satellites, e.g. Callisto. It has also been hypothesized that these satellites may contain internal salt-water "oceans" (Khurana et al., 1998) that, if present, may affect the distribution of Ice VII at depth. The OH bond in Ice VII has been studied by Raman spectroscopy (Pruzan et al., 1990; Walrafen et al., 1982), however, no data exist on how the bonding structure of Ice VII changes with the incorporation of trace amounts of salt. This study sought to measure the Raman shift in Ice VII formed from NaCl-H2O solutions to 20 GPa. Samples of pure H2O, and 5 wt% NaCl were loaded into a Mao-Bell type Diamond Anvil Cell and Raman spectroscopy was used to analyze the samples at pressure increments of 1-2 GPa. The relative OH stretching frequency was measured to observe the bond structure in Ice VII samples formed from the H2O and NaCl-H2O solutions as pressure increases. OH shifts from the NaCl-H2O solutions were compared to pure H2O measurements observed in this study and also compared to previous studies in the pure H2O system. All results show a negative linear decrease in OH stretching frequency as pressure increases. OH stretching frequency in Ice VII formed from pure water can be represented by the best-fit line: v = 3322.8353 - 23.9857P where P is pressure in GPa and v is the OH stretching frequency in rel cm-1. OH stretching frequencies in Ice VII formed from the 5 wt% NaCl solution was modeled with a linear equation: v = 3338.2502 - 22.6019P. Ice VII formed from 5 wt% data shows a systematic increase of approximately 15 rel cm-1 for any given pressure. From Raman spectra, we hypothesize that NaCl is being incorporated into the bond structure of Ice VII formed from low salinity solutions. Future experiments will be

  3. Polyimide nanocomposites based on cubic zirconium tungstate

    NASA Astrophysics Data System (ADS)

    Ramasubramanian Sharma, Gayathri

    2009-12-01

    In this research, cubic zirconium tungstate (ZrW2O8) was used as a filler to reduce the CTE of polyimides (PI), and the effect of ZrW2O8 nanoparticles on the bulk polymer properties was studied. Polyimides are high performance polymers with exceptional thermal stability, and there is a need for PIs with low CTEs for high temperature applications. The nanofiller, cubic ZrW2O8, is well known for its isotropic negative thermal expansion (NTE) over a wide temperature range from -272.7 to 777°C. The preparation of nanocomposites involved the synthesis of ZrW 2O8 nanofiller, engineering the polymer-filler interface using linker groups and optimization of processing strategies to prepare free-standing PI nanocomposite films. A hydrothermal method was used to synthesize ZrW 2O8 nanoparticles. Polyimide-ZrW2O8 interface interaction was enhanced by covalently bonding linker moieties to the surface of ZrW2O8 nanoparticles. Specifically, ZrW 2O8 nanoparticles were functionalized with two different linker groups: (1) a short aliphatic silane, and (2) low molecular weight PI. The surface functionalization was confirmed using X-ray photoelectron spectroscopy and thermal gravimetric analysis (TGA). Reprecipitation blending was used to prepare the freestanding PI-ZrW2O8 nanocomposite films with up to 15 volume% filler loading. SEM images showed the improvements in polymer-filler wetting behavior achieved using interface engineering. SEM images indicated that there was better filler dispersion in the PI matrix using reprecipitation blending, compared to the filler dispersion achieved in the nanocomposites prepared using conventional blending technique. The structure-property relationships in PI-ZrW2O8 nanocomposites were investigated by studying the thermal degradation, glass transition, tensile and thermal expansion properties of the nanocomposites. The properties were studied as a function of filler loading and interface linker groups. Addition of ZrW2O8 nanoparticles did not

  4. Heat capacity of ZnO with cubic structure at high temperatures

    NASA Astrophysics Data System (ADS)

    Sun, X. W.; Liu, Z. J.; Chen, Q. F.; Lu, H. W.; Song, T.; Wang, C. W.

    2006-11-01

    The heat capacities at constant pressure and constant volume, and thermal expansivity are calculated for ZnO with rocksalt-type and zinc-blende-type cubic structures over a wide range of temperatures using molecular dynamics simulations with interactions due to effective pair-wise potentials which consist of the Coulomb, dispersion, and repulsion interaction. It is shown that the calculated structural and thermodynamic parameters including lattice constant, thermal-expansion coefficient, isothermal bulk modulus and its pressure derivative at ambient condition are in good agreement with the available experimental data and the latest theoretical results. At extended pressure and temperature ranges, lattice constant and heat capacity have also been predicted. The structural and thermodynamic properties of ZnO with cubic structure are summarized in the 300-1500 K temperature ranges and up to 100 kbar pressure.

  5. Electrically evoked cubic distortion product otoacoustic emissions from gerbil cochlea.

    PubMed

    Ren, T; Nuttall, A L; Miller, J M

    1996-12-01

    It has been demonstrated that electrical stimulation of the cochlear partition results in basilar membrane vibration and otoacoustic emissions. Electromotility of stimulated outer hair cells (OHCs) elicits the electrically evoked otoacoustic emissions (EEOAEs). Although electrically evoked upper and lower sideband distortion products (DPs) have been reported, electrically evoked cubic DP has not been investigated. Since the acoustically evoked cubic DP is the most commonly used otoacoustic measure of cochlear nonlinearity, this study tested whether electrical stimuli evoke a cubic DP otoacoustic emission. An electrical current containing the frequency component f1 and f2 (f1 < f2) was delivered to the round window niche of the gerbil, and electrically induced sound pressure change in the external ear canal was measured with a microphone. It was found that, in addition to f1 and f2 EEOAEs, cubic DP (2f1-f2) and other emissions at 3f1-2f2, 2f2-f1 and f2-f1 frequencies are electrically evoked. The electrically evoked cubic DP growth is similar to that of an acoustically evoked cubic DP. An electrical stimulus at f1 or f2 and an acoustic stimulus at f2 or f1 produce an identical cubic DP to that evoked by two electrical stimuli and/or two acoustic stimuli at f1 and f2 frequencies. An acoustic suppressor at a frequency near f2 can completely suppress an electrically evoked cubic DP emission. These data demonstrate that DPs can be provoked by a complex two frequency electrical current delivered to the round window niche. These stimuli elicit mechanical vibrations, from stimulated OHCs near the round window, which propagate apically toward their characteristic frequency places on the basilar membrane, and produce combination DPs. Electrically evoked cubic DPs appear to be produced by the same nonlinear mechanism that generates acoustically evoked DPs.

  6. Formation and stability of cubic ice in water droplets.

    PubMed

    Murray, Benjamin J; Bertram, Allan K

    2006-01-07

    There is growing evidence that a metastable phase of ice, cubic ice, plays an important role in the Earth's troposphere and stratosphere. Cubic ice may also be important in diverse fields such as cryobiology and planetary sciences. Using X-ray diffraction, we studied the formation of cubic ice in pure water droplets suspended in an oil matrix as a function of droplet size. The results show that droplets of volume median diameter 5.6 microm froze dominantly to cubic ice with stacking faults. These results support previous suggestions that cubic ice is the crystalline phase that nucleates when pure water droplets freeze homogeneously at approximately 235 K. It is also shown that as the size of the water droplets increased from 5.6 to 17.0 microm, the formation of the stable phase of ice, hexagonal ice, was favoured. This size dependence can be rationalised with heat transfer calculations. We also investigated the stability of cubic ice that forms in water droplets suspended in an oil matrix. We observe cubic ice up to 243 K, much higher in temperature than observed in many previous studies. This result adds to the existing literature that shows bulk ice I(c) can persist up to approximately 240 K. The transformation of cubic ice to hexagonal ice also showed a complex time and temperature dependence, proceeding rapidly at first and then slowing down and coming to a halt. These combined results help explain why cubic ice forms in some experiments described in the literature and not others.

  7. Characterization of NaCl tolerance in Desulfovibrio vulgaris Hildenborough through experimental evolution.

    PubMed

    Zhou, Aifen; Baidoo, Edward; He, Zhili; Mukhopadhyay, Aindrila; Baumohl, Jason K; Benke, Peter; Joachimiak, Marcin P; Xie, Ming; Song, Rong; Arkin, Adam P; Hazen, Terry C; Keasling, Jay D; Wall, Judy D; Stahl, David A; Zhou, Jizhong

    2013-09-01

    Desulfovibrio vulgaris Hildenborough strains with significantly increased tolerance to NaCl were obtained via experimental evolution. A NaCl-evolved strain, ES9-11, isolated from a population cultured for 1200 generations in medium amended with 100 mM NaCl, showed better tolerance to NaCl than a control strain, EC3-10, cultured for 1200 generations in parallel but without NaCl amendment in medium. To understand the NaCl adaptation mechanism in ES9-11, we analyzed the transcriptional, metabolite and phospholipid fatty acid (PLFA) profiles of strain ES9-11 with 0, 100- or 250 mM-added NaCl in medium compared with the ancestral strain and EC3-10 as controls. In all the culture conditions, increased expressions of genes involved in amino-acid synthesis and transport, energy production, cation efflux and decreased expression of flagellar assembly genes were detected in ES9-11. Consistently, increased abundances of organic solutes and decreased cell motility were observed in ES9-11. Glutamate appears to be the most important osmoprotectant in D. vulgaris under NaCl stress, whereas, other organic solutes such as glutamine, glycine and glycine betaine might contribute to NaCl tolerance under low NaCl concentration only. Unsaturation indices of PLFA significantly increased in ES9-11. Branched unsaturated PLFAs i17:1 ω9c, a17:1 ω9c and branched saturated i15:0 might have important roles in maintaining proper membrane fluidity under NaCl stress. Taken together, these data suggest that the accumulation of osmolytes, increased membrane fluidity, decreased cell motility and possibly an increased exclusion of Na(+) contribute to increased NaCl tolerance in NaCl-evolved D. vulgaris.

  8. Characterization of NaCl tolerance in Desulfovibrio vulgaris Hildenborough through experimental evolution

    PubMed Central

    Zhou, Aifen; Baidoo, Edward; He, Zhili; Mukhopadhyay, Aindrila; Baumohl, Jason K; Benke, Peter; Joachimiak, Marcin P; Xie, Ming; Song, Rong; Arkin, Adam P; Hazen, Terry C; Keasling, Jay D; Wall, Judy D; Stahl, David A; Zhou, Jizhong

    2013-01-01

    Desulfovibrio vulgaris Hildenborough strains with significantly increased tolerance to NaCl were obtained via experimental evolution. A NaCl-evolved strain, ES9-11, isolated from a population cultured for 1200 generations in medium amended with 100 mM NaCl, showed better tolerance to NaCl than a control strain, EC3-10, cultured for 1200 generations in parallel but without NaCl amendment in medium. To understand the NaCl adaptation mechanism in ES9-11, we analyzed the transcriptional, metabolite and phospholipid fatty acid (PLFA) profiles of strain ES9-11 with 0, 100- or 250 mM-added NaCl in medium compared with the ancestral strain and EC3-10 as controls. In all the culture conditions, increased expressions of genes involved in amino-acid synthesis and transport, energy production, cation efflux and decreased expression of flagellar assembly genes were detected in ES9-11. Consistently, increased abundances of organic solutes and decreased cell motility were observed in ES9-11. Glutamate appears to be the most important osmoprotectant in D. vulgaris under NaCl stress, whereas, other organic solutes such as glutamine, glycine and glycine betaine might contribute to NaCl tolerance under low NaCl concentration only. Unsaturation indices of PLFA significantly increased in ES9-11. Branched unsaturated PLFAs i17:1 ω9c, a17:1 ω9c and branched saturated i15:0 might have important roles in maintaining proper membrane fluidity under NaCl stress. Taken together, these data suggest that the accumulation of osmolytes, increased membrane fluidity, decreased cell motility and possibly an increased exclusion of Na+ contribute to increased NaCl tolerance in NaCl-evolved D. vulgaris. PMID:23575373

  9. Genetic variability of NaCl tolerance in tomato.

    PubMed

    Saeed, A; Saleem, M F; Zakria, M; Anjum, S A; Shakeel, A; Saeed, N

    2011-07-12

    Cultivation of crops in soils with high salt (NaCl) content can affect plant development. We examined the morphological and physiological mechanisms of salt tolerance in tomato. The responses of 72 accessions of tomato (Solanum lycopersicum) to salinity were compared by measuring shoot and root lengths, and fresh shoot and root weights relative to those of controls (plants grown in normal salt levels). All traits were reduced at the seedling stage when salinity levels were increased. The accession x salinity interaction was significant for all traits. Root length had higher heritability than other traits and was used as a selection criterion to identify salt-tolerant and -non-tolerant accessions. On the basis of root length, accessions LA2661, CLN2498A, CLN1621L, BL1176, 6233, and 17870 were considered to be more tolerant than accessions 17902, LO2875 and LO4360. The degree of salt tolerance was checked by analyzing K+ and Na+ concentrations and K+/Na+ ratio in tissues of plants treated with 10 and 15 dS/m salinity levels. Tolerance of these accessions to salinity was most associated with low accumulation of Na+ and higher K+/Na+ ratios.

  10. Electrochemical Properties of Al-Cu Alloys in Nacl Solutions

    NASA Astrophysics Data System (ADS)

    Roman, Alejandra Silvina; Méndez, Claudia Marcela; Schvezov, Carlos Enrique; Ares, Alicia Esther

    In this paper the structure of aluminum based alloys and their corrosion behavior by using different electrochemical techniques as characterization methods are considered. Currently, it becomes imperative to know the role of the Al2Cu against the susceptibility to corrosion of these alloys. The present work aims to studying the electrochemical behavior of aluminum base alloys with the following compositions: Al-1wt.%Cu, Al-4.5wt.%Cu and Al-15wt.%Cu (with different grain structures), in 1M NaCl solutions, at room temperature. Cyclic potentiodynamic polarization tests were performed and were found that the alloys with more than 1wt.%Cu in the matrix have an unstable behavior and without tendency to reach passivity. The equivalent circuits derived from electrochemical impedance spectroscopy technique (EIS) generally showed two capacitive contributions. The susceptibility to corrosion becomes a complex function, not only of copper concentration and structure, but also with interdendritic spacings and distribution of phases in the alloys.

  11. Identification of Tetragonal and Cubic Structures of Zirconia

    DTIC Science & Technology

    1990-05-29

    sample containing 13 mol.% yttria-stabilized zirconia possessed the cubic structure with ao = 0.51420 + 0.00012 nm. A sample containing 6.5 mol.% yttria...spectroscopic data for the crystalline phases. However, Benedetti et al.35 have recently reassigned a cubic structure to a zirconia sample prerarel in a...parameters calculated from the diffraction data using 13 a least-square fle, indicate that Sample A has a cubic structure with ao = 0.51420 + 0.00012 nm. This

  12. Strain tuning of topological band order in cubic semiconductors

    SciTech Connect

    Feng, wanxiang; Zhu, Wenguang; Weitering, Hanno; Stocks, George Malcolm; Yao, yugui; Xiao, Di

    2012-01-01

    We theoretically explore the possibility of tuning the topological order of cubic diamond/zinc-blende semi- conductors with external strain. Based on a simple tight-binding model, we analyze the evolution of the cubic semiconductor band structure under hydrostatic or biaxial lattice expansion, by which a generic guiding princi- ple is established that biaxial lattice expansion can induce a topological phase transition of small band-gap cubic semiconductors via a band inversion and symmetry breaking at point. Using density functional theory cal- culations, we demonstrate that a prototype topological trivial semiconductor, InSb, is converted to a nontrivial topological semiconductor with a 2% 3% biaxial lattice expansion.

  13. Epitaxial stabilization of cubic-SiN{sub x} in TiN/SiN{sub x} multilayers

    SciTech Connect

    Soederberg, Hans; Oden, Magnus; Larsson, Tommy; Hultman, Lars; Molina-Aldareguia, Jon M.

    2006-05-08

    The formation of cubic-phase SiN{sub x} is demonstrated in TiN/SiN{sub x} multilayers deposited by reactive dual magnetron sputtering. Transmission electron microscopy examination shows a transition from epitaxially stabilized growth of crystalline SiN{sub x} to amorphous growth as the layer thickness increases from 0.3 to 0.8 nm. The observations are supported by ab initio calculations on different polytypes, which show that the NaCl structure has the best lattice match to TiN. Calculations also reveal a large difference in elastic shear modulus between NaCl-SiN{sub x} and TiN. The results for phase structure and shear modulus offer an explanation for the superhardening effect determined by nanoindentation experiments.

  14. The compressibility of cubic white and orthorhombic, rhombohedral, and simple cubic black phosphorus

    SciTech Connect

    Clark, Simon M; Zaug, Joseph

    2010-03-10

    The effect of pressure on the crystal structure of white phosphorus has been studied up to 22.4 GPa. The ?alpha phase was found to transform into the alpha' phase at 0.87 +- 0.04 GPa with a volume change of 0.1 +- 0.3 cc/mol. A fit of a second order Birch- Murnaghan equation to the data gave Vo = 16.94 ? 0.08 cc/mol and Ko = 6.7 +- 0.5 GPa for the alpha phase and Vo = 16.4 +- 0.1 cc/mol and Ko = 9.1 +- 0.3 GPa for the alpha' phase. The alpha' phase was found to transform to the A17 phase of black phosphorus at 2.68 +- 0.34 GPa and then with increasing pressure to the A7 and then simple cubic phase of black phosphorus. A fit of a second order Birch-Murnaghan equation to our data combined with previous measurements gave Vo = 11.43 +- 0.05 cc/mol and Ko = 34.7 +- 0.5 GPa for the A17 phase, Vo = 9.62 +- 0.01 cc/mol and Ko = 65.0 +- 0.6 GPa for the A7 phase and , Vo = 9.23 +- 0.01 cc/mol and Ko = 72.5 +- 0.3 GPa for the simple cubic phase.

  15. Evaluation of various rapid chloride tests for assessing urinary NaCl excretion.

    PubMed

    Brüngel, M; Kluthe, R; Fürst, P

    2001-01-01

    The evidence linking NaCl intake to high blood pressure and probably to other diseases has become stronger. Therefore, a population-wide reduction of NaCl intake is generally recommended. Measuring NaCl excretion in urine is the preferred method for estimating dietary NaCl intake. Rapid tests measuring urinary NaCl excretion might be useful for self-monitoring the individual NaCl consumption. The accuracy of four rapid tests measuring chloride content in urine was assessed. Three tests were originally not designed for urine analysis, but for water and food analysis. Totally 204 urine samples were analysed both with the 4 different rapid tests and with quantitative routine laboratory procedures for chloride and sodium. Chloride and sodium were highly correlated (r = 0.96), indicating chloride determination as a reasonable method to assess sodium and NaCl contents in urine. Accuracy of the rapid tests was acceptable in three cases. The drawback of two tests was their narrow calibration range, so that most urine samples had to be diluted. Use of one test showed problems in interpreting its results because the decolouration of the test pads was difficult to recognize. It is concluded that rapid chloride tests designed for water analysis might be suitable to determine NaCl in urine samples. Copyright 2001 S. Karger AG, Basel

  16. Stable NaCl tolerance of tobacco cells is associated with enhanced accumulation of osmotin

    SciTech Connect

    LaRosa, P.C.; Hasegawa, P.M.; Bressan, R.A. ); Singh, N.K. )

    1989-11-01

    Osmotin is a major protein which accumulates in tobacco cells (Nicotiana tabacum L. var Wisconsin 38) adapted to low water potentials. Quantitation of osmotin levels by immunoblots indicated that cells adapted to 428 millimolar NaCl contained 4 to 30 times the level of osmotin found in unadapted cells, depending on the stage of growth. Unadapted cells accumulated low levels of osmotin with apparent isoelectric points, (pl) of 7.8 and >8.2. Upon transfer of NaCl-adapted cells to medium without NaCl and subsequent growth for many cell generations, the amount of osmotin declined gradually to a level intermediate between that found in adapted and unadapted cells. NaCl-adapted cells grown in the absence of NaCl accumulated both pl forms; however, the form accumulated by cells adapted to NaCl (pl >8.2) was most abundant. Adapted cells grown in the absence of NaCl exhibited absolute growth rates and NaCl tolerance levels which were intermediate to those of NaCl-adapted and unadapted cells. The association between osmotin accumulation and stable NaCl tolerance indicates that cells with a stable genetic change affecting the accumulation of osmotin are selected during prolonged exposure to high levels of NaCl. This stable alteration in gene expression probably affects salt tolerance.

  17. 19. 1500 CUBIC FEET CAPACITY SCRAP STEEL CHARGING BOX ON ...

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

    19. 1500 CUBIC FEET CAPACITY SCRAP STEEL CHARGING BOX ON THE CHARGING AISLE OF THE BOP SHOP LOOKING NORTHWEST. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  18. The Coulombic Lattice Potential of Ionic Compounds: The Cubic Perovskites.

    ERIC Educational Resources Information Center

    Francisco, E.; And Others

    1988-01-01

    Presents coulombic models representing the particles of a system by point charges interacting through Coulomb's law to explain coulombic lattice potential. Uses rubidium manganese trifluoride as an example of cubic perovskite structure. Discusses the effects on cluster properties. (CW)

  19. On the role of cubic structure in ice nucleation

    NASA Astrophysics Data System (ADS)

    Takahashi, Tōru

    1982-10-01

    To clarify the formation mechanism of snow polycrystals the possibility of formation of a cubic ice embryo is discussed on the basis of the homogeneous nucleation theory for supercooled water formed from ambient water molecules in the phase of supersaturated vapour. In this connection, attention is paid to a finding from a model of broken hydrogen bonds that the plane {111} of a cubic ice crystal has a smaller specific interfacial energy than each of the {0001} or {10ovbar|10} planes of a hexagonal ice crystal. Hence, it follows that a critical cubic embryo has a smaller activation energy than a critical hexagonal embryo below a critical temperature; namely, Ostwald's step rule (Stufenregel) holds for a change from cubic ice to hexagonal ice below a critical temperature. This discussion is reinforced by examining, from the viewpoint of this step rule, the observed misorientation of the c-axis of natural snow polycrystals and the results of experiments using frozen water droplets.

  20. Monotonicity preserving splines using rational cubic Timmer interpolation

    NASA Astrophysics Data System (ADS)

    Zakaria, Wan Zafira Ezza Wan; Alimin, Nur Safiyah; Ali, Jamaludin Md

    2017-08-01

    In scientific application and Computer Aided Design (CAD), users usually need to generate a spline passing through a given set of data, which preserves certain shape properties of the data such as positivity, monotonicity or convexity. The required curve has to be a smooth shape-preserving interpolant. In this paper a rational cubic spline in Timmer representation is developed to generate interpolant that preserves monotonicity with visually pleasing curve. To control the shape of the interpolant three parameters are introduced. The shape parameters in the description of the rational cubic interpolant are subjected to monotonicity constrained. The necessary and sufficient conditions of the rational cubic interpolant are derived and visually the proposed rational cubic Timmer interpolant gives very pleasing results.

  1. Late-time attractor for the cubic nonlinear wave equation

    SciTech Connect

    Szpak, Nikodem

    2010-08-15

    We apply our recently developed scaling technique for obtaining late-time asymptotics to the cubic nonlinear wave equation and explain the appearance and approach to the two-parameter attractor found recently by Bizon and Zenginoglu.

  2. March 20, 2012 Space Station Briefing: Cubic Satellite Deploy

    NASA Image and Video Library

    This animation, presented by Expedition 32 Lead Flight Director Dina Contella during the March 20, 2012 ISS Program and Science Overview Briefing, shows the deploy of small cubic satellites (often ...

  3. The Coulombic Lattice Potential of Ionic Compounds: The Cubic Perovskites.

    ERIC Educational Resources Information Center

    Francisco, E.; And Others

    1988-01-01

    Presents coulombic models representing the particles of a system by point charges interacting through Coulomb's law to explain coulombic lattice potential. Uses rubidium manganese trifluoride as an example of cubic perovskite structure. Discusses the effects on cluster properties. (CW)

  4. March 20, 2012 Space Station Briefing: Cubic Satellite Deploy (Narrated)

    NASA Image and Video Library

    This animation, presented by Expedition 32 Lead Flight Director Dina Contella during the March 20, 2012 ISS Program and Science Overview Briefing, shows the deploy of small cubic satellites (often ...

  5. Identification of Hammerstein models with cubic spline nonlinearities.

    PubMed

    Dempsey, Erika J; Westwick, David T

    2004-02-01

    This paper considers the use of cubic splines, instead of polynomials, to represent the static nonlinearities in block structured models. It introduces a system identification algorithm for the Hammerstein structure, a static nonlinearity followed by a linear filter, where cubic splines represent the static nonlinearity and the linear dynamics are modeled using a finite impulse response filter. The algorithm uses a separable least squares Levenberg-Marquardt optimization to identify Hammerstein cascades whose nonlinearities are modeled by either cubic splines or polynomials. These algorithms are compared in simulation, where the effects of variations in the input spectrum and distribution, and those of the measurement noise are examined. The two algorithms are used to fit Hammerstein models to stretch reflex electromyogram (EMG) data recorded from a spinal cord injured patient. The model with the cubic spline nonlinearity provides more accurate predictions of the reflex EMG than the polynomial based model, even in novel data.

  6. Effect of NaCl concentration in electrodeposited Co-P alloy thin films

    NASA Astrophysics Data System (ADS)

    Kim, John H.; Raja, M.; Thanikaikarasan, S.; Kim, Yong Deak; Srikumar, S. R.; Mahalingam, T.

    2009-04-01

    Cobalt-Phosphorous (Co-P) alloy thin films were prepared by electrodeposition technique from an aqueous electrolytic bath at various sodium chloride (NaCl) concentrations. The effect of sodium chloride concentration on electrochemical, structural, morphological, compositional and magnetic properties of the films was investigated by cyclic voltammetry, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and vibrating sample magnetometer techniques, respectively. The mechanism of formation of Co-P alloy thin films was studied using cyclic voltammetry. The compositional analysis shows that the content of phosphorous (P) increases and the content of cobalt (Co) decreases by adding NaCl. X-ray diffraction studies revealed amorphous nature for films obtained at high concentration of NaCl and hexagonal closed packed (hcp) structure for films obtained at low NaCl concentration. Magnetic properties illustrate that high value of coercivity, saturation magnetization, remanence, and saturating field were obtained at high concentration of NaCl.

  7. Proteome Analyses of Staphylococcus aureus Biofilm at Elevated Levels of NaCl

    PubMed Central

    Islam, Nazrul; Ross, Julia M; Marten, Mark R

    2016-01-01

    Our studies demonstrate that sodium chloride (NaCl) induces changes in biofilm, mediated by increased production of polysaccharides intercellular adhesion (PIA). We identified 12 proteins that showed higher abundance in increased level of NaCl. This includes one important protein (IsaA) known to be associated with biofilm stability. In addition, we also found higher abundance of a cold shock protein, CspA, at higher NaCl. We have also identified several other proteins that are differentially expressed to the elevated levels of NaCl and mapped them in the regulatory pathways of PIA. The majority of proteins are involved with various aspects bacterial metabolic function. Our results demonstrated that NaCl influences gene regulatory networks controlling exopolysaccharide expression. PMID:26973848

  8. Concentration and precipitation of NaCl and KCl from salt cake leach solutions by electrodialysis

    SciTech Connect

    Sreenivasarao, K; Patsiogiannis, F.; Hryn, J.N.

    1997-02-09

    Electrodialysis was investigated for cost-effective recovery of salt from salt cake leach solutions. (Salt cake is a waste stream generated by the aluminum industry during treatment of aluminum drosses and scrap.) We used a pilot-scale electrodialysis stack of 5 membrane pairs, each with an effective area of 0.02 m{sup 2}. The diluate stream contained synthetic NaCl, KCl,mixtures of NaCl and KCl, and actual salt cake leach solutions (mainly NaCl and KCl, with small amounts of MgCl{sub 2}). We concentrated and precipitated NaCl and KCl salts from the concentrate steam when the initial diluate stream concentration was 21.5 to 28.8 wt% NaCl and KCl. We found that water transferring through the membranes was a significant factor in overall efficiency of salt recovery by electrodialysis.

  9. Proteome Analyses of Staphylococcus aureus Biofilm at Elevated Levels of NaCl.

    PubMed

    Islam, Nazrul; Ross, Julia M; Marten, Mark R

    2015-10-01

    Our studies demonstrate that sodium chloride (NaCl) induces changes in biofilm, mediated by increased production of polysaccharides intercellular adhesion (PIA). We identified 12 proteins that showed higher abundance in increased level of NaCl. This includes one important protein (IsaA) known to be associated with biofilm stability. In addition, we also found higher abundance of a cold shock protein, CspA, at higher NaCl. We have also identified several other proteins that are differentially expressed to the elevated levels of NaCl and mapped them in the regulatory pathways of PIA. The majority of proteins are involved with various aspects bacterial metabolic function. Our results demonstrated that NaCl influences gene regulatory networks controlling exopolysaccharide expression.

  10. Twinning of cubic diamond explains reported nanodiamond polymorphs

    NASA Astrophysics Data System (ADS)

    Németh, Péter; Garvie, Laurence A. J.; Buseck, Peter R.

    2015-12-01

    The unusual physical properties and formation conditions attributed to h-, i-, m-, and n-nanodiamond polymorphs has resulted in their receiving much attention in the materials and planetary science literature. Their identification is based on diffraction features that are absent in ordinary cubic (c-) diamond (space group: Fd-3m). We show, using ultra-high-resolution transmission electron microscope (HRTEM) images of natural and synthetic nanodiamonds, that the diffraction features attributed to the reported polymorphs are consistent with c-diamond containing abundant defects. Combinations of {113} reflection and <011> rotation twins produce HRTEM images and d-spacings that match those attributed to h-, i-, and m-diamond. The diagnostic features of n-diamond in TEM images can arise from thickness effects of c-diamonds. Our data and interpretations strongly suggest that the reported nanodiamond polymorphs are in fact twinned c-diamond. We also report a new type of twin (<11> rotational), which can give rise to grains with dodecagonal symmetry. Our results show that twins are widespread in diamond nanocrystals. A high density of twins could strongly influence their applications.

  11. Taylor line swimming in microchannels and cubic lattices of obstacles

    NASA Astrophysics Data System (ADS)

    Münch, Jan L.; Alizadehrad, Davod; Babu, Sujin B.; Stark, Holger

    Microorganisms naturally move in microstructured fluids. Using the simulation method of multi-particle collision dynamics, we study an undulatory Taylor line swimming in a two-dimensional microchannel and in a cubic lattice of obstacles, which represent simple forms of a microstructured environment. In the microchannel the Taylor line swims at an acute angle along a channel wall with a clearly enhanced swimming speed due to hydrodynamic interactions with the bounding wall. While in a dilute obstacle lattice swimming speed is also enhanced, a dense obstacle lattice gives rise to geometric swimming. This new type of swimming is characterized by a drastically increased swimming speed. Since the Taylor line has to fit into the free space of the obstacle lattice, the swimming speed is close to the phase velocity of the bending wave traveling along the Taylor line. While adjusting its swimming motion within the lattice, the Taylor line chooses a specific swimming direction, which we classify by a lattice vector. When plotting the swimming velocity versus the magnitude of the lattice vector, all our data collapse on a single master curve. Finally, we also report more complex trajectories within the obstacle lattice.

  12. Taylor line swimming in microchannels and cubic lattices of obstacles.

    PubMed

    Münch, Jan L; Alizadehrad, Davod; Babu, Sujin B; Stark, Holger

    2016-09-21

    Microorganisms naturally move in microstructured fluids. Using the simulation method of multi-particle collision dynamics, we study in two dimensions an undulatory Taylor line swimming in a microchannel and in a cubic lattice of obstacles, which represent simple forms of a microstructured environment. In the microchannel the Taylor line swims at an acute angle along a channel wall with a clearly enhanced swimming speed due to hydrodynamic interactions with the bounding wall. While in a dilute obstacle lattice swimming speed is also enhanced, a dense obstacle lattice gives rise to geometric swimming. This new type of swimming is characterized by a drastically increased swimming speed. Since the Taylor line has to fit into the free space of the obstacle lattice, the swimming speed is close to the phase velocity of the bending wave traveling along the Taylor line. While adjusting its swimming motion within the lattice, the Taylor line chooses a specific swimming direction, which we classify by a lattice vector. When plotting the swimming velocity versus the magnitude of the lattice vector, all our data collapse on a single master curve. Finally, we also report more complex trajectories within the obstacle lattice.

  13. Twinning of cubic diamond explains reported nanodiamond polymorphs

    PubMed Central

    Németh, Péter; Garvie, Laurence A. J.; Buseck, Peter R.

    2015-01-01

    The unusual physical properties and formation conditions attributed to h-, i-, m-, and n-nanodiamond polymorphs has resulted in their receiving much attention in the materials and planetary science literature. Their identification is based on diffraction features that are absent in ordinary cubic (c-) diamond (space group: Fd-3m). We show, using ultra-high-resolution transmission electron microscope (HRTEM) images of natural and synthetic nanodiamonds, that the diffraction features attributed to the reported polymorphs are consistent with c-diamond containing abundant defects. Combinations of {113} reflection and <011> rotation twins produce HRTEM images and d-spacings that match those attributed to h-, i-, and m-diamond. The diagnostic features of n-diamond in TEM images can arise from thickness effects of c-diamonds. Our data and interpretations strongly suggest that the reported nanodiamond polymorphs are in fact twinned c-diamond. We also report a new type of twin (<11> rotational), which can give rise to grains with dodecagonal symmetry. Our results show that twins are widespread in diamond nanocrystals. A high density of twins could strongly influence their applications. PMID:26671288

  14. Random walks on cubic lattices with bond disorder

    SciTech Connect

    Ernst, M.H.; van Velthoven, P.F.J.

    1986-12-01

    The authors consider diffusive systems with static disorder, such as Lorentz gases, lattice percolation, ants in a labyrinth, termite problems, random resistor networks, etc. In the case of diluted randomness the authors can apply the methods of kinetic theory to obtain systematic expansions of dc and ac transport properties in powers of the impurity concentration c. The method is applied to a hopping model on a d-dimensional cubic lattice having two types of bonds with conductivity sigma and sigma/sub 0/ = 1, with concentrations c and 1-c, respectively. For the square lattice the authors explicitly calculate the diffusion coefficient D(c,sigma) as a function of c, to O(c/sup 2/) terms included for different ratios of the bond conductivity sigma. The probability of return at long times is given by P/sub 0/(t) approx. (4..pi..D(c,sigma)t)/sup -d/2/, which is determined by the diffusion coefficient of the disordered system.

  15. MAPK-mediated enhanced expression of vacuolar H(+)-ATPase confers the improved adaption to NaCl stress in a halotolerate peppermint (Mentha piperita L.).

    PubMed

    Li, Zhe; Zhen, Zhen; Guo, Kai; Harvey, Paul; Li, Jishun; Yang, Hetong

    2016-03-01

    Vacuolar H(+)-ATPase (V-H(+)-ATPase) has been proved to be of importance in maintenance of ion homeostasis inside plant cells under NaCl stress. In this study, the expression levels and salt-tolerate function of V-H(+)-ATPase genes were investigated in the roots and leaves of a halotolerate peppermint (Mentha × piperita L.) Keyuan-1 treated with different concentrations of NaCl. Results showed that the expressions of V-H(+)-ATPase in the transcriptional, protein and activity levels were significantly enhanced in the halotolerate peppermint Keyuan-1 compared to the wild-type (WT) peppermint under 50, 100, and 150 mM NaCl treatment. Moreover, inhibition experiments exhibited that V-H(+)-ATPase activity played vital roles in the salt tolerance of peppermint Keyuan-1 to 150 mM NaCl stress through increasing the vacuolar H(+) pumping activity and Na(+) compartmentalization capacity. Furthermore, results of Western blots showed that the activity of a mitogen-activated protein kinase (MAPK) was significantly increased under different concentrations of NaCl in the halotolerate peppermint Keyuan-1, which was much higher than that of WT peppermint. Further experiments with inhibitors suggested that this MAPK protein was responsible for the enhanced expression of V-H(+)-ATPase in the halotolerate peppermint Keyuan-1. In response to NaCl stress, increase of cytoplasmic calcium concentration ([Ca(2+)]cyt) occurred upstream of MAPK activation in the halotolerate peppermint Keyuan-1. In all, these findings demonstrated that increased V-H(+)-ATPase activity was positively correlated with the enhanced salt tolerance in the halotolerate peppermint Keyuan-1, providing the theoretic basis for the further development and utilization of peppermint in saline areas.

  16. MAPK-mediated regulation of growth and essential oil composition in a salt-tolerant peppermint (Mentha piperita L.) under NaCl stress.

    PubMed

    Li, Zhe; Wang, Wenwen; Li, Guilong; Guo, Kai; Harvey, Paul; Chen, Quan; Zhao, Zhongjuan; Wei, Yanli; Li, Jishun; Yang, Hetong

    2016-11-01

    Peppermint (Mentha × piperita L.) is an important and commonly used flavoring agent worldwide, and salinity is a major stress that limits plant growth and reduces crop productivity. This work demonstrated the metabolic responses of essential oil production including the yield and component composition, gene expression, enzyme activity, and protein activation in a salt-tolerant peppermint Keyuan-1 with respect to NaCl stress. Our results showed that Keyuan-1 maintained normal growth and kept higher yield and content of essential oils under NaCl stress than wild-type (WT) peppermint.Gas chromatography-mass spectrometry (GC-MS) and qPCR results showed that compared to WT seedlings, a 150-mM NaCl stress exerted no obvious changes in essential oil composition, transcriptional level of enzymes related to essential oil metabolism, and activity of pulegone reductase (Pr) in Keyuan-1 peppermint which preserved the higher amount of menthol and menthone as well as the lower content of menthofuran upon the 150-mM NaCl stress. Furthermore, it was noticed that a mitogen-activated protein kinase (MAPK) protein exhibited a time-dependent activation in the Keyuan-1 peppermint and primarily involved in the modulation of the essential oil metabolism in the transcript and enzyme levels during the 12-day treatment of 150 mM NaCl. In all, our data elucidated the effect of NaCl on metabolic responses of essential oil production, and demonstrated the MAPK-dependent regulation mechanism of essential oil biosynthesis in the salt-tolerant peppermint, providing scientific basis for the economic and ecological utilization of peppermint in saline land.

  17. Early free access to hypertonic NaCl solution induces a long-term effect on drinking, brain cell activity and gene expression of adult rat offspring.

    PubMed

    Macchione, A F; Beas, C; Dadam, F M; Caeiro, X E; Godino, A; Ponce, L F; Amigone, J L; Vivas, L

    2015-07-09

    Exposure to an altered osmotic environment during a pre/postnatal period can differentially program the fluid intake and excretion pattern profile in a way that persists until adulthood. However, knowledge about the programming effects on the underlying brain neurochemical circuits of thirst and hydroelectrolyte balance, and its relation with behavioral outputs, is limited. We evaluated whether early voluntary intake of hypertonic NaCl solution may program adult offspring fluid balance, plasma vasopressin, neural activity, and brain vasopressin and angiotensinergic receptor type 1a (AT1a)-receptor gene expression. The manipulation (M) period covered dams from 1 week before conception until offspring turned 1-month-old. The experimental groups were (i) Free access to hypertonic NaCl solution (0.45 M NaCl), food (0.18% NaCl) and water [M-Na]; and (ii) Free access to food and water only [M-Ctrol]. Male offspring (2-month-old) were subjected to iv infusion (0.15 ml/min) of hypertonic (1.5M NaCl), isotonic (0.15M NaCl) or sham infusion during 20 min. Cumulative water intake (140 min) and drinking latency to the first lick were recorded from the start of the infusion. Our results indicate that, after systemic sodium overload, the M-Na group had increased water intake, and diminished neuronal activity (Fos-immunoreactivity) in the subfornical organ (SFO) and nucleus of the solitary tract. They also showed reduced relative vasopressin (AVP)-mRNA and AT1a-mRNA expression at the supraoptic nucleus and SFO, respectively. The data indicate that the availability of a rich source of sodium during the pre/postnatal period induces a long-term effect on drinking, neural activity, and brain gene expression implicated in the control of hydroelectrolyte balance.

  18. On the assumption of cubic graphs of vascular networks

    NASA Astrophysics Data System (ADS)

    Cha, Sung-Hyuk; Chang, Sukmoon; Gargano, Michael L.

    2006-03-01

    A vascular network is often represented by a Reeb graph, which is a topological skeleton, and graph theory has been widely applied to analyze properties of a vascular network. A Reeb graph model for a vascular network is obtained by assigning the branch points of the network to be the vertices of the graph and the vessels between branch points to be the edges of the graph. Vascular networks develop by way of angiogenesis, a growth process that involves the biological mechanisms of vessel sprouting (budding) and splitting (intussusception). Vascular networks develop by way of two biological mechanisms of vessel sprouting (budding) and splitting (intussusception). According to a graph theory modeling of two vascular network growth mechanisms, all nodes in the Reeb graph must be cubic in degree except for two special nodes: the afferent (A) and efferent (E) nodes. We define that a vascular network is cubic if all internal nodes are cubic in degree. We consider six normal adult rat renal glomerular networks and use their reeb graphs already constructed and published in the literature. We observe that five of them contain internal vertices of degree higher than three. Branch points in vascular networks may appear to be of a higher degree if the imaging resolution cannot differentiate between blood vessels that are very close in proximity. Here, we propose a random graph theory model that edits a non-cubic vascular network into a cubic graph. We observe that the edited cubic graph from a non-cubic vascular network has the similar size and order as the one cubic vascular network.

  19. Data interpolation using rational cubic Ball spline with three parameters

    NASA Astrophysics Data System (ADS)

    Karim, Samsul Ariffin Abdul

    2016-11-01

    Data interpolation is an important task for scientific visualization. This research introduces new rational cubic Ball spline scheme with three parameters. The rational cubic Ball will be used for data interpolation with or without true derivative values. Error estimation show that the proposed scheme works well and is a very good interpolant to approximate the function. All graphical examples are presented by using Mathematica software.

  20. Physiological effects of NaCl on Apocynum venetum seedlings

    NASA Astrophysics Data System (ADS)

    Han, Wei; Cao, Ling

    2016-04-01

    The physiological effects of NaCl on the Apocynum venetum seedlings were investigated, including the chlorophyll a fluorescence, leaf potential and growth rate, etc. The findings indicated that along with hardness index increasing, the leaf sample's chlorophyll content assumed the fluctuation condition which dropped firstly elevated again; the leaf water potential maintained stable basically; the energy of light absorption, the assignment and the dissipation balanced at 10 g/L and the growth rate presented the maximum value 9.8 mm/d; Along with the stress extension, the greatest quantum yield Fv/Fm dropped, metallic ion's absorption increased. In the 21st day, non-photochemical quenching coefficient NPQ presented the maximum value, absorbed energy proportion parameter Y(II) dropped firstly restored again, 3 kind of energy absorptions, the assignment dissipation parameter proportion stabilized in 10 g/L at Y(II):Y(NO):Y(NPQ) = 65%:20%:15%.The results suggested that in the A. venetum nursery process in the southern edge of Taklimakan Desert, phased tending should be adopted according to the seedling stage: 5-10 g/L salinity water should be used in irrigation in the seedling stage to maintain a more high leaf water potential which could prevent the decomposition of chlorophyll in which higher proportion of photochemical energy conversion could be stable using 10 g/L salt water irrigation to give A. venetum a full play of stronger salt adaptability to the southern margin of the Taklimakan Desert Oasis-Desert Ecotone in its restoration and construction. Key words: saline water irrigation; leaf water potential; energy allocation strategies; growth rate

  1. The phase space of the focused cubic Schroedinger equation: A numerical study

    SciTech Connect

    Burlakov, Yuri O.

    1998-05-01

    In a paper of 1988 [41] on statistical mechanics of the nonlinear Schroedinger equation, it was observed that a Gibbs canonical ensemble associated with the nonlinear Schroedinger equation exhibits behavior reminiscent of a phase transition in classical statistical mechanics. The existence of a phase transition in the canonical ensemble of the nonlinear Schroedinger equation would be very interesting and would have important implications for the role of this equation in modeling physical phenomena; it would also have an important bearing on the theory of weak solutions of nonlinear wave equations. The cubic Schroedinger equation, as will be shown later, is equivalent to the self-induction approximation for vortices, which is a widely used equation of motion for a thin vortex filament in classical and superfluid mechanics. The existence of a phase transition in such a system would be very interesting and actually very surprising for the following reasons: in classical fluid mechanics it is believed that the turbulent regime is dominated by strong vortex stretching, while the vortex system described by the cubic Schroedinger equation does not allow for stretching. In superfluid mechanics the self-induction approximation and its modifications have been used to describe the motion of thin superfluid vortices, which exhibit a phase transition; however, more recently some authors concluded that these equations do not adequately describe superfluid turbulence, and the absence of a phase transition in the cubic Schroedinger equation would strengthen their argument. The self-induction approximation for vortices takes into account only very localized interactions, and the existence of a phase transition in such a simplified system would be very unexpected. In this thesis the authors present a numerical study of the phase transition type phenomena observed in [41]; in particular, they find that these phenomena are strongly related to the splitting of the phase space into

  2. Pronounced negative thermal expansion from a simple structure : Cubic ScF{sub 3}.

    SciTech Connect

    Greve, B. K.; Martin, K. L.; Lee, P. L.; Chupas, P. J.; Chapman, K. W.; Wilkinson, A. P.; X-Ray Science Division; Georgia Inst. of Tech.

    2010-10-19

    Scandium trifluoride maintains a cubic ReO{sub 3} type structure down to at least 10 K, although the pressure at which its cubic to rhombohedral phase transition occurs drops from >0.5 GPa at {approx}300 K to 0.1-0.2 GPa at 50 K. At low temperatures it shows strong negative thermal expansion (NTE) (60-110 K, {alpha}{sub l} {approx} -14 ppm K{sup -1}). On heating, its coefficient of thermal expansion (CTE) smoothly increases, leading to a room temperature CTE that is similar to that of ZrW{sub 2}O{sub 8} and positive thermal expansion above {approx}1100 K. While the cubic ReO{sub 3} structure type is often used as a simple illustration of how negative thermal expansion can arise from the thermally induced rocking of rigid structural units, ScF{sub 3} is the first material with this structure to provide a clear experimental illustration of this mechanism for NTE.

  3. Combination of extended X-ray absorption fine structure spectroscopy with lipidic cubic phases for the study of cation binding in bacteriorhodopsin.

    PubMed

    Perálvarez-Marín, Alex; Sepulcre, Francesc; Márquez, Mercedes; Proietti, Maria Grazia; Padrós, Esteve

    2011-08-01

    We have performed a quantitative X-ray absorption fine structure analysis of bacteriorhodopsin in purple membrane patches and in lipidic cubic phases regenerated with Mn(2+). Lipidic cubic phases and purple membrane results have been compared, demonstrating that the lipidic cubic phase process does not introduce relevant distortions in the local geometry of the cation binding sites. For both samples, we have observed similarities for Mn(2+) coordination in terms of type, number, and average distances of surrounding atoms, indicating a first coordination shell composed by 6 O atoms, and 3/4 C atoms located in the second coordination shell.

  4. Variational quantum Monte Carlo calculation of the cohesive properties of cubic boron nitride

    SciTech Connect

    Malatesta, A.; Fahy, S.; Bachelet, G.B.

    1997-11-01

    The cohesive properties of cubic boron nitride are calculated using the variational quantum Monte Carlo approach. The calculated properties are found to be in good agreement with experiment and demonstrate the effectiveness of the variational forms of wave functions previously used in sp-bonded systems involving only one chemical species when applied to solids with more than one type of atom. The formulation of variance minimization for the one-body term in solids without inversion symmetry is presented, and a particularly simple form of one-body term based on a charge-fluctuation picture of electron correlation is shown to obtain excellent results for ground-state energies of B, C, and N atoms, and for the cubic boron nitride solid. {copyright} {ital 1997} {ital The American Physical Society}

  5. Constant enthalpy change value during pyrophosphate hydrolysis within the physiological limits of NaCl.

    PubMed

    Wakai, Satoshi; Kidokoro, Shun-ichi; Masaki, Kazuo; Nakasone, Kaoru; Sambongi, Yoshihiro

    2013-10-11

    A decrease in water activity was thought to result in smaller enthalpy change values during PPi hydrolysis, indicating the importance of solvation for the reaction. However, the physiological significance of this phenomenon is unknown. Here, we combined biochemistry and calorimetry to solve this problem using NaCl, a physiologically occurring water activity-reducing reagent. The pyrophosphatase activities of extremely halophilic Haloarcula japonica, which can grow at ∼4 M NaCl, and non-halophilic Escherichia coli and Saccharomyces cerevisiae were maximal at 2.0 and 0.1 M NaCl, respectively. Thus, halophilic and non-halophilic pyrophosphatases exhibit distinct maximal activities at different NaCl concentration ranges. Upon calorimetry, the same exothermic enthalpy change of -35 kJ/mol was obtained for the halophile and non-halophiles at 1.5-4.0 and 0.1-2.0 M NaCl, respectively. These results show that solvation changes caused by up to 4.0 M NaCl (water activity of ∼0.84) do not affect the enthalpy change in PPi hydrolysis. It has been postulated that PPi is an ATP analog, having a so-called high energy phosphate bond, and that the hydrolysis of both compounds is enthalpically driven. Therefore, our results indicate that the hydrolysis of high energy phosphate compounds, which are responsible for biological energy conversion, is enthalpically driven within the physiological limits of NaCl.

  6. Effect of NaCl treatments on glucosinolate metabolism in broccoli sprouts*

    PubMed Central

    Guo, Rong-fang; Yuan, Gao-feng; Wang, Qiao-mei

    2013-01-01

    To understand the regulation mechanism of NaCl on glucosinolate metabolism in broccoli sprouts, the germination rate, fresh weight, contents of glucosinolates and sulforaphane, as well as myrosinase activity of broccoli sprouts germinated under 0, 20, 40, 60, 80, and 100 mmol/L of NaCl were investigated in our experiment. The results showed that glucoerucin, glucobrassicin, and 4-hydroxy glucobrassicin in 7-d-old broccoli sprouts were significantly enhanced and the activity of myrosinase was inhibited by 100 mmol/L of NaCl. However, the total glucosinolate content in 7-d-old broccoli sprouts was markedly decreased although the fresh weight was significantly increased after treatment with NaCl at relatively low concentrations (20, 40, and 60 mmol/L). NaCl treatment at the concentration of 60 mmol/L for 5 d maintained higher biomass and comparatively higher content of glucosinolates in sprouts of broccoli with decreased myrosinase activity. A relatively high level of NaCl treatment (100 mmol/L) significantly increased the content of sulforaphane in 7-d-old broccoli sprouts compared with the control. These results indicate that broccoli sprouts grown under a suitable concentration of NaCl could be desirable for human nutrition. PMID:23365011

  7. Relationship between extracellular osmolarity, NaCl concentration and cell volume in rat glioma cells.

    PubMed

    Rouzaire-Dubois, Béatrice; Ouanounou, Gilles; Dubois, Jean Marc

    2011-06-01

    The cell volume, which controls numerous cellular functions, is theoretically linearly related with the inverse osmolarity. However, deviations from this law have often been observed. In order to clarify the origin of these deviations we electronically measured the mean cell volume of rat glioma cells under three different experimental conditions, namely: at different osmolarities and constant NaCl concentration; at different NaCl concentrations and constant osmolarity and at different osmolarities caused by changes in NaCl concentration. In each condition, the osmolarity was maintained constant or changed with NaCl or mannitol. We showed that the cell volume was dependent on both the extracellular osmolarity and the NaCl concentration. The relationship between cell volume, osmolarity and NaCl concentration could be described by a new equation that is the product of the Boyle-van't Hoff law and the Michaelis-Menten equation at a power of 4. Together, these results suggest that in hyponatriemia, the cell volume deviates from the Boyle-van't Hoff law because either the activity of aquaporin 1, expressed in glioma cells, is decreased or the reduced NaCl influx decreases the osmotically obliged influx of water.

  8. Constant Enthalpy Change Value during Pyrophosphate Hydrolysis within the Physiological Limits of NaCl*

    PubMed Central

    Wakai, Satoshi; Kidokoro, Shun-ichi; Masaki, Kazuo; Nakasone, Kaoru; Sambongi, Yoshihiro

    2013-01-01

    A decrease in water activity was thought to result in smaller enthalpy change values during PPi hydrolysis, indicating the importance of solvation for the reaction. However, the physiological significance of this phenomenon is unknown. Here, we combined biochemistry and calorimetry to solve this problem using NaCl, a physiologically occurring water activity-reducing reagent. The pyrophosphatase activities of extremely halophilic Haloarcula japonica, which can grow at ∼4 m NaCl, and non-halophilic Escherichia coli and Saccharomyces cerevisiae were maximal at 2.0 and 0.1 m NaCl, respectively. Thus, halophilic and non-halophilic pyrophosphatases exhibit distinct maximal activities at different NaCl concentration ranges. Upon calorimetry, the same exothermic enthalpy change of −35 kJ/mol was obtained for the halophile and non-halophiles at 1.5–4.0 and 0.1–2.0 m NaCl, respectively. These results show that solvation changes caused by up to 4.0 m NaCl (water activity of ∼0.84) do not affect the enthalpy change in PPi hydrolysis. It has been postulated that PPi is an ATP analog, having a so-called high energy phosphate bond, and that the hydrolysis of both compounds is enthalpically driven. Therefore, our results indicate that the hydrolysis of high energy phosphate compounds, which are responsible for biological energy conversion, is enthalpically driven within the physiological limits of NaCl. PMID:23965994

  9. Effect of NaCl treatments on glucosinolate metabolism in broccoli sprouts.

    PubMed

    Guo, Rong-fang; Yuan, Gao-feng; Wang, Qiao-mei

    2013-02-01

    To understand the regulation mechanism of NaCl on glucosinolate metabolism in broccoli sprouts, the germination rate, fresh weight, contents of glucosinolates and sulforaphane, as well as myrosinase activity of broccoli sprouts germinated under 0, 20, 40, 60, 80, and 100 mmol/L of NaCl were investigated in our experiment. The results showed that glucoerucin, glucobrassicin, and 4-hydroxy glucobrassicin in 7-d-old broccoli sprouts were significantly enhanced and the activity of myrosinase was inhibited by 100 mmol/L of NaCl. However, the total glucosinolate content in 7-d-old broccoli sprouts was markedly decreased although the fresh weight was significantly increased after treatment with NaCl at relatively low concentrations (20, 40, and 60 mmol/L). NaCl treatment at the concentration of 60 mmol/L for 5 d maintained higher biomass and comparatively higher content of glucosinolates in sprouts of broccoli with decreased myrosinase activity. A relatively high level of NaCl treatment (100 mmol/L) significantly increased the content of sulforaphane in 7-d-old broccoli sprouts compared with the control. These results indicate that broccoli sprouts grown under a suitable concentration of NaCl could be desirable for human nutrition.

  10. Flexoelectric contribution to the phase demodulation by two-beam coupling on reflection and transmission gratings in cubic photorefractive crystals

    NASA Astrophysics Data System (ADS)

    Shandarov, S. M.; Burimov, N. I.; Shmakov, S. S.; Zlobin, A. O.; Shmidt, A. A.; Shepelevich, V. V.; Makarevich, A. V.; Kargin, Yu F.; Shcherbin, K.

    2017-06-01

    We study the linear and quadratic signals of phase demodulation in holographic interferometers, which are realized at interaction of light waves on dynamic hologram of diffusion type in the cubic photorefractive crystals, with taking into account the flexoelectric contribution to the nonlinear response.

  11. An unconventional bilayer ice structure on a NaCl(001) film.

    PubMed

    Chen, Ji; Guo, Jing; Meng, Xiangzhi; Peng, Jinbo; Sheng, Jiming; Xu, Limei; Jiang, Ying; Li, Xin-Zheng; Wang, En-Ge

    2014-05-30

    Water-solid interactions are of broad importance both in nature and technology. The hexagonal bilayer model based on the Bernal-Fowler-Pauling ice rules has been widely adopted to describe water structuring at interfaces. Using a cryogenic scanning tunnelling microscope, here we report a new type of two-dimensional ice-like bilayer structure built from cyclic water tetramers on an insulating NaCl(001) film, which is completely beyond this conventional bilayer picture. A novel bridging mechanism allows the interconnection of water tetramers to form chains, flakes and eventually a two-dimensional extended ice bilayer containing a regular array of Bjerrum D-type defects. Ab initio density functional theory calculations substantiate this bridging growth mode and reveal a striking proton-disordered ice structure. The formation of the periodic Bjerrum defects with unusually high density may have a crucial role as H donor sites in directing multilayer ice growth and in catalysing heterogeneous chemical reactions on water-coated salt surfaces.

  12. Reduction of NaCl increases survival of mammalian spinal neurons subjected to dendrite transection injury.

    PubMed

    Rosenberg, L J; Lucas, J H

    1996-09-23

    Neurites were transected from spinal neurons in media with normal (125 microM) or reduced NaCl (sucrose substitution). After 12 h the normal ionic environment (conditioned medium with serum) was restored. A one-factor ANOVA comparison found a significant difference in 48 h survival (P = 0.0001). Survival was highest when NaCl was reduced 50% (74% +/- 19 vs. 22% +/- 19 in normal NaCl). Na(+)- and Cl-mediated deterioration may contribute to both gray and white matter injury in CNS trauma.

  13. Encapsulation of epitaxial silicene on ZrB2 with NaCl

    NASA Astrophysics Data System (ADS)

    Wiggers, F. B.; Yamada-Takamura, Y.; Kovalgin, A. Y.; de Jong, M. P.

    2017-08-01

    Silicene and other two-dimensional materials, such as germanene and stanene, have chemically reactive surfaces and are prone to oxidation in air, and thus require an encapsulation layer for ex situ studies or integration in an electronic device. In this work, we investigated NaCl as an encapsulation material for silicene. NaCl was deposited on the surface of epitaxial silicene on ZrB2(0001) thin films near room temperature and studied using synchrotron-based high-resolution photoelectron spectroscopy. The deposition of NaCl resulted in dissociative chemisorption, where the majority of epitaxial silicene reacted to form Si-Clx species.

  14. Geometric and electronic properties of porphyrin molecules on Au(111) and NaCl surfaces

    NASA Astrophysics Data System (ADS)

    Kim, Seong Heon; Jeong, H. G.; Lim, S. J.; Ham, U. D.; Song, Y. J.; Yu, J.; Kuk, Y.

    2013-07-01

    Geometric and electronic properties of platinum octaethyl porphyrin (PtOEP) molecules on thin insulating sodium chloride (NaCl) and bare Au(111) surfaces are studied using scanning tunneling microscopy and scanning tunneling spectroscopy (STS). In the STS study, a slight downward shift of a highest occupied molecular orbital peak is observed for a PtOEP molecule on NaCl(100)/Au(111). Density functional theory calculations for PtOEP molecules on the NaCl(100)/Au(111) and the bare Au(111) confirm the experimental findings.

  15. Dislocation kink-pair energetics and pencil glide in body-centered-cubic crystals.

    PubMed

    Ngan, A H; Wen, M

    2001-08-13

    When body-centered-cubic crystals undergo plastic deformation, the slip planes are often noncrystallographic. By performing atomistic simulation on the activation pathway of dislocation jumps in bcc iron, we show that the main reason for bcc crystals to exhibit this phenomenon is that one type of kink pair has significantly lower energy than all the other types on the same slip plane. Dislocation motion therefore cannot continue on the same slip plane, and the dislocation has to cross slip onto an intersecting slip plane after each atomic jump. Thus in the long run, the average slip plane would be zigzag and noncrystallographic.

  16. Evidence for an apical Na-Cl cotransporter involved in ion uptake in a teleost fish

    USGS Publications Warehouse

    Hiroi, J.; Yasumasu, S.; McCormick, S.D.; Hwang, P.-P.; Kaneko, T.

    2008-01-01

    Cation-chloride cotransporters, such as the Na+/K +/2Cl- cotransporter (NKCC) and Na+/Cl - cotransporter (NCC), are localized to the apical or basolateral plasma membranes of epithelial cells and are involved in active ion absorption or secretion. The objectives of this study were to clone and identify 'freshwater-type' and 'seawater-type' cation-chloride cotransporters of euryhaline Mozambique tilapia (Oreochromis mossambicus) and to determine their intracellular localization patterns within mitochondria-rich cells (MRCs). From tilapia gills, we cloned four full-length cDNAs homologous to human cation-chloride cotransporters and designated them as tilapia NKCC1a, NKCC1b, NKCC2 and NCC. Out of the four candidates, the mRNA encoding NKCC1a was highly expressed in the yolk-sac membrane and gills (sites of the MRC localization) of seawater-acclimatized fish, whereas the mRNA encoding NCC was exclusively expressed in the yolk-sac membrane and gills of freshwater-acclimatized fish. We then generated antibodies specific for tilapia NKCC1a and NCC and conducted whole-mount immunofluorescence staining for NKCC1a and NCC, together with Na+/K+-ATPase, cystic fibrosis transmembrane conductance regulator (CFTR) and Na+/H+ exchanger 3 (NHE3), on the yolk-sac membrane of tilapia embryos acclimatized to freshwater or seawater. The simultaneous quintuple-color immunofluorescence staining allowed us to classify MRCs clearly into four types: types I, II, III and IV. The NKCC1a immunoreactivity was localized to the basolateral membrane of seawater-specific type-IV MRCs, whereas the NCC immunoreactivity was restricted to the apical membrane of freshwater-specific type-II MRCs. Taking account of these data at the level of both mRNA and protein, we deduce that NKCC1a is the seawater-type cotransporter involved in ion secretion by type-IV MRCs and that NCC is the freshwater-type cotransporter involved in ion absorption by type-II MRCs. We propose a novel ion-uptake model by MRCs in

  17. Lattice matched crystalline substrates for cubic nitride semiconductor growth

    DOEpatents

    Norman, Andrew G; Ptak, Aaron J; McMahon, William E

    2015-02-24

    Disclosed embodiments include methods of fabricating a semiconductor layer or device and devices fabricated thereby. The methods include, but are not limited to, providing a substrate having a cubic crystalline surface with a known lattice parameter and growing a cubic crystalline group III-nitride alloy layer on the cubic crystalline substrate by coincident site lattice matched epitaxy. The cubic crystalline group III-nitride alloy may be prepared to have a lattice parameter (a') that is related to the lattice parameter of the substrate (a). The group III-nitride alloy may be a cubic crystalline In.sub.xGa.sub.yAl.sub.1-x-yN alloy. The lattice parameter of the In.sub.xGa.sub.yAl.sub.1-x-yN or other group III-nitride alloy may be related to the substrate lattice parameter by (a')= 2(a) or (a')=(a)/ 2. The semiconductor alloy may be prepared to have a selected band gap.

  18. Cubic phases of ternary amphiphile-water systems.

    PubMed

    Fraser, Scott; Separovic, Frances; Polyzos, Anastasios

    2009-12-01

    The reversed cubic phases (Q(II)) are a class of self-assembled amphiphile-water structures that are rich in diversity and structural complexity. These nanostructured liquid crystalline materials are generating much interest owing to their unique surface morphology, biological relevance and potential technological and medical applications. The structure of Q(II) phases in binary amphiphile-water systems is affected by the molecular structure of surfactant, water content, temperature and pressure. The presence of additives also plays an important role. The structure and phase behaviour of ternary Q(II) phases, which are comprised of two miscible amphiphiles and water, significantly differ from the binary system alone. The modulation of the phase behaviour through the addition of a second amphiphile offers an opportunity to control the size and shape of the nanostructures using a 'bottom-up' approach. In this mini-review, we discuss the structure of reversed cubic phases of amphiphile-water systems and highlight the modulation of cubic-phase structure in ternary-phase systems. We also extend this review to bulk cubic phases and the corresponding nanoscale dispersions, cubic-phase nanoparticles.

  19. Evolution of cubic membranes as antioxidant defence system.

    PubMed

    Deng, Yuru; Almsherqi, Zakaria A

    2015-08-06

    Possibly the best-characterized cubic membrane transition has been observed in the mitochondrial inner membranes of free-living giant amoeba (Chaos carolinense). In this ancient organism, the cells are able to survive in extreme environments such as lack of food, thermal and osmolarity fluctuations and high levels of reactive oxygen species. Their mitochondrial inner membranes undergo rapid changes in three-dimensional organization upon food depletion, providing a valuable model to study this subcellular adaptation. Our data show that cubic membrane is enriched with unique ether phospholipids, plasmalogens carrying very long-chain polyunsaturated fatty acids. Here, we propose that these phospholipids may not only facilitate cubic membrane formation but may also provide a protective shelter to RNA. The potential interaction of cubic membrane with RNA may reduce the amount of RNA oxidation and promote more efficient protein translation. Thus, recognizing the role of cubic membranes in RNA antioxidant systems might help us to understand the adaptive mechanisms that have evolved over time in eukaryotes.

  20. Evolution of cubic membranes as antioxidant defence system

    PubMed Central

    Deng, Yuru; Almsherqi, Zakaria A.

    2015-01-01

    Possibly the best-characterized cubic membrane transition has been observed in the mitochondrial inner membranes of free-living giant amoeba (Chaos carolinense). In this ancient organism, the cells are able to survive in extreme environments such as lack of food, thermal and osmolarity fluctuations and high levels of reactive oxygen species. Their mitochondrial inner membranes undergo rapid changes in three-dimensional organization upon food depletion, providing a valuable model to study this subcellular adaptation. Our data show that cubic membrane is enriched with unique ether phospholipids, plasmalogens carrying very long-chain polyunsaturated fatty acids. Here, we propose that these phospholipids may not only facilitate cubic membrane formation but may also provide a protective shelter to RNA. The potential interaction of cubic membrane with RNA may reduce the amount of RNA oxidation and promote more efficient protein translation. Thus, recognizing the role of cubic membranes in RNA antioxidant systems might help us to understand the adaptive mechanisms that have evolved over time in eukaryotes. PMID:26464785

  1. Effect of drug loading on the transformation of vesicular into cubic nanoparticles during heat treatment of aqueous monoolein/poloxamer dispersions.

    PubMed

    Wörle, Gert; Siekmann, Britta; Bunjes, Heike

    2006-06-01

    Colloidal dispersions of the pre-equilibrated cubic phase in the monoolein/poloxamer 407/water system, which are under investigation as potential drug carriers, often contain a considerable fraction of undesired non-cubic particles, particularly when prepared with high concentrations of poloxamer. Recent investigations revealed that the non-cubic particles can be transformed into particles of cubic internal structure by heat treatment. The present study investigates the effect of drug loading on the non-cubic to cubic transformation process during autoclaving of the dispersions. The results indicate that the process can also proceed in dispersions loaded with different concentrations of ubidecarenone, tocopheryl acetate, betamethasone-17-valerate, chloramphenicol or miconazole. At low concentration, none of the drugs had pronounced influence on the autoclaved dispersions whereas with increasing drug concentration different effects were observed. Depending on the type of drug no effects (betamethasone-17-valerate), increasing particle size of the dispersions (chloramphenicol, miconazole) or phase separation upon autoclaving (high load of miconazole) was observed. Except for loading with high amounts of chloramphenicol, which led to the formation of cubic phase particles already without additional heat treatment, the properties of the thermally untreated dispersions were virtually unaffected by drug incorporation.

  2. Relationship between growth and pH gradients of individual cells of Debaryomyces hansenii as influenced by NaCl and solid substrate.

    PubMed

    Mortensen, H D; Gori, K; Siegumfeldt, H; Jespersen, L; Arneborg, N

    2007-03-01

    To examine the relationship between the growth and pH gradients of Debaryomyces hansenii at a single-cell level. Using bioimaging techniques, the cell areas and early pH gradients (Delta pH(10)), i.e. the pH gradients determined 10 min after initiation of experiments, were determined for single cells of two D. hansenii strains in fluid and on solid (agar) substrate with and without 8% (w/v) NaCl. The combination of NaCl and solid substrate prolonged the growth initiation of both D. hansenii strains additively. In all our experiments, primarily two groups of cells existed; a vital group consisting of growing single cells with intact early pH gradients, and a group of dead cells without early pH gradients. Our results show that growth initiation of the D. hansenii cells is severely affected by NaCl and to a lesser extent by the type of substrate in an additive and strain dependent way. Moreover, the early pH gradient of a vital D. hansenii cell cannot be correlated with the rate of its subsequent growth. Our study reveals new knowledge on the growth and pH gradients of D. hansenii on solid surfaces in the presence of NaCl.

  3. Free-sodium salts mixture and AlgySalt® use as NaCl substitutes in fresh and cooked meat products intended for the hypertensive population.

    PubMed

    Triki, M; Khemakhem, I; Trigui, I; Ben Salah, R; Jaballi, S; Ruiz-Capillas, C; Ayadi, M A; Attia, H; Besbes, S

    2017-11-01

    This work aims at reducing the use of added NaCl in processed meat products because of its negative effects on hypertensive population by replacing it by sodium-free salts mixture (SM: KCl, MgCl2 and CaCl2) in fresh and cooked sausages. The technological, sensory, and microbiological effects of SM were compared with a commercial replacer based on seaweed extracts (AlgySalt®). A total substitution of NaCl with the latter and a partial one with SM (80% and 50%) were studied in cooked sausages and a total NaCl substitution with both substitutes was performed in fresh sausages. As a result, hardness increased in AlgySalt® reformulated samples, while it decreased when 80% SM were used. Whereas, AlgySalt® induced less cooking loses than SM. To some extent, microbiological counts showed a similarity between reformulated and control samples for both sausage types, whereas reformulated products containing SM revealed better sensory properties for both meat products. Therefore, using SM as NaCl replacer is adequate for processed meat products. Copyright © 2017. Published by Elsevier Ltd.

  4. "JCE" Classroom Activity Connections: NaCl or CaCl[subscript 2], Smart Polymer Gel Tells More

    ERIC Educational Resources Information Center

    Chen, Yueh-Huey; Lin, Jia-Ying; Wang, Yu-Chen; Yaung, Jing-Fun

    2010-01-01

    This classroom activity connection demonstrates the differences between the effects of NaCl (a salt of monovalent metal ions) and CaCl[subscript 2] (a salt of polyvalent metal ions) on swollen superabsorbent polymer gels. Being ionic compounds, NaCl and CaCl[subscript 2] both collapse the swollen polymer gels. The gel contracted by NaCl reswells…

  5. "JCE" Classroom Activity Connections: NaCl or CaCl[subscript 2], Smart Polymer Gel Tells More

    ERIC Educational Resources Information Center

    Chen, Yueh-Huey; Lin, Jia-Ying; Wang, Yu-Chen; Yaung, Jing-Fun

    2010-01-01

    This classroom activity connection demonstrates the differences between the effects of NaCl (a salt of monovalent metal ions) and CaCl[subscript 2] (a salt of polyvalent metal ions) on swollen superabsorbent polymer gels. Being ionic compounds, NaCl and CaCl[subscript 2] both collapse the swollen polymer gels. The gel contracted by NaCl reswells…

  6. Synergistic inhibition effect of 2-mercaptobenzothiazole and Tween-80 on the corrosion of brass in NaCl solution

    NASA Astrophysics Data System (ADS)

    Ramji, Karpagavalli; Cairns, Darran R.; Rajeswari, S.

    2008-05-01

    The corrosion inhibition of brass in 0.2 M NaCl in the presence of 2-mercaptobenzothiazole (MBT) and polyoxyethylene sorbitan monooleate (Tween-80) has been investigated using potentiodynamic polarization, X-ray photoelectron spectroscopy and inductively coupled plasma analysis. Analysis of the results revealed that the addition of MBT and Tween-80 inhibits the corrosion of brass in 0.2 M NaCl. Potentiodynamic polarization measurements showed that MBT acts as a mixed-type inhibitor and Tween-80 as an anodic inhibitor. Corrosion inhibition occurs through adsorption of the inhibitor on brass surface without modifying the corrosion mechanism. The adsorption of MBT and Tween-80 both follow Langmuir adsorption isotherm. Potentiodynamic polarization results suggested that the mixture of MBT and Tween-80 acts as a mixed-type inhibitor. Inhibition efficiency of 79.0 and 62.5% were obtained in the presence of optimum concentration of MBT and Tween-80, respectively. The addition of the mixture of MBT and Tween-80 enhanced the inhibition efficiency to 94.0% and showed a synergism of inhibition. XPS analysis indicated that MBT adsorbed on brass surface along with Tween-80 in the presence of the mixture of MBT and Tween-80. The results of solution analysis using ICP showed that the mixture of MBT and Tween-80 effectively controlled the dezincification of brass.

  7. Oil-loaded monolinolein-based particles with confined inverse discontinuous cubic structure (Fd3m).

    PubMed

    Yaghmur, Anan; de Campo, Liliana; Salentinig, Stefan; Sagalowicz, Laurent; Leser, Martin E; Glatter, Otto

    2006-01-17

    In our recent work, we reported on the effect of varying temperature and solubilizing tetradecane (TC) on the structural transitions observed in dispersed particles based on the monolinolein (MLO)-water-TC system. At a given temperature, the addition of TC induces a transition of the internal structure from the bicontinuous cubic phase, Pn3m, to the reversed hexagonal, H2, and to the isotropic liquid phase (water-in-oil (W/O) microemulsions). Our present study focuses on the discovery of a Fd3m phase (reversed discontinuous micellar cubic), which is formed in the MLO-water-TC system at a specific TC/MLO weight ratio. It is situated between the H2 and the isotropic liquid phase (W/O microemulsion). Remarkably, it is not found in the absence of TC by increasing the temperature. The Fd3m structure was investigated in detail by means of small-angle X-ray scattering (SAXS), and cryogenic transmission electron microscopy (cryo-TEM). The present work proves that the structural transformation in the dispersed particles from H2 (hexosomes) to the W/O microemulsion system (emulsified microemulsion (EME)) is indirect and it occurs gradually via an emulsified intermediate phase. Specifically, in addition to the nanostructured aqueous dispersions described above, we present new TC-loaded aqueous dispersions with a confined intermediate phase, which is a discontinuous micellar cubic phase of the symmetry Fd3m. We denoted this type of emulsified particles as "micellar cubosomes".

  8. Free carrier accumulation at cubic AlGaN/GaN heterojunctions

    SciTech Connect

    Wei, Q. Y.; Li, T.; Huang, J. Y.; Ponce, F. A.; Tschumak, E.; Zado, A.; As, D. J.

    2012-04-02

    Cubic Al{sub 0.3}Ga{sub 0.7}N/GaN heterostructures were grown by plasma-assisted molecular beam epitaxy on 3C-SiC (001) substrates. A profile of the electrostatic potential across the cubic-AlGaN/GaN heterojunction was obtained using electron holography in the transmission electron microscope. The experimental potential profile indicates that the unintentionally doped layers show n-type behavior and accumulation of free electrons at the interface with a density of 5.1 x 10{sup 11}/cm{sup 2}, about one order of magnitude less than in wurtzite AlGaN/GaN junctions. A combination of electron holography and cathodoluminescence measurements yields a conduction-to-valence band offset ratio of 5:1 for the cubic AlGaN/GaN interface, which also promotes the electron accumulation. Band diagram simulations show that the donor states in the AlGaN layer provide the positive charges that to a great extent balance the two-dimensional electron gas.

  9. Graphitic Phase of NaCl. Bulk Properties and Nanoscale Stability.

    PubMed

    Kvashnin, Alexander G; Sorokin, Pavel B; Tománek, David

    2014-11-20

    We applied the ab initio approach to evaluate the stability and physical properties of the nanometer-thickness NaCl layered films and found that the rock salt films with a (111) surface become unstable with thickness below 1 nm and spontaneously split to graphitic-like films for reducing the electrostatic energy penalty. The observed sodium chloride graphitic phase displays an uncommon atomic arrangement and exists only as nanometer-thin quasi-two-dimensional films. The graphitic bulk counterpart is unstable and transforms to another hexagonal wurtzite NaCl phase that locates in the negative-pressure region of the phase diagram. It was found that the layers in the graphitic NaCl film are weakly bounded with each other with a binding energy order of 0.1 eV per stoichiometry unit. The electronic band gap of the graphitic NaCl displays an unusual nonmonotonic quantum confinement response.

  10. VizieR Online Data Catalog: Laboratory spectroscopy of sodium chloride (NaCl) (Cabezas+, 2016)

    NASA Astrophysics Data System (ADS)

    Cabezas, C.; Cernicharo, J.; Quintana-Lacaci, G.; Pena, I.; Agundez, M.; Velilla Prieto, L.; Castro-Carrizo, A.; Zuniga, J.; Bastida, A.; Alonso, J. L.; Requena, A.

    2016-09-01

    The rotational spectrum of sodium chloride (NaCl) has been obtained using two different Fourier transform microwave (FTMW) spectrometers constructed at the University of Valladolid. See section 2.1 for further explanations. (8 data files).

  11. Superhard cubic BC2N compared to diamond.

    PubMed

    Zhang, Yi; Sun, Hong; Chen, Changfeng

    2004-11-05

    Recent experiments claimed successful synthesis of cubic boron-carbonitride compounds BC2N with an extreme hardness second only to diamond. In the present Letter, we examine the ideal strength of cubic BC2N using first-principles calculations. Our results reveal that, despite the large elastic parameters, compositional anisotropy and strain dependent bonding character impose limitation on their strength. Consequently, the hardness of the optimal BC2N structure is predicted to be lower than that of cubic BN, the second hardest material known. The measured extreme hardness of BC2N nanocomposites is most likely due to the nanocrystalline size effect and the bonding to the surrounding amorphous carbon matrix. This may prove to be a general rule useful in the quest for new superhard covalent materials.

  12. Ferromagnetic Ground States in Face-Centered Cubic Hubbard Clusters

    PubMed Central

    Souza, T. X. R.; Macedo, C. A.

    2016-01-01

    In this study, the ground state energies of face-centered cubic Hubbard clusters are analyzed using the Lanczos method. Examination of the ground state energy as a function of the number of particle per site n showed an energy minimum for face-centered cubic structures. This energy minimum decreased in n with increasing coulombic interaction parameter U. We found that the ground state energy had a minimum at n = 0.6, when U = 3W, where W denotes the non-interacting energy bandwidth and the face-centered cubic structure was ferromagnetic. These results, when compared with the properties of nickel, shows strong similarity with other finite temperature analyses in the literature and supports the Hirsh’s conjecture that the interatomic direct exchange interaction dominates in driving the system into a ferromagnetic phase. PMID:27583653

  13. [Multimodal medical image registration using cubic spline interpolation method].

    PubMed

    He, Yuanlie; Tian, Lianfang; Chen, Ping; Wang, Lifei; Ye, Guangchun; Mao, Zongyuan

    2007-12-01

    Based on the characteristic of the PET-CT multimodal image series, a novel image registration and fusion method is proposed, in which the cubic spline interpolation method is applied to realize the interpolation of PET-CT image series, then registration is carried out by using mutual information algorithm and finally the improved principal component analysis method is used for the fusion of PET-CT multimodal images to enhance the visual effect of PET image, thus satisfied registration and fusion results are obtained. The cubic spline interpolation method is used for reconstruction to restore the missed information between image slices, which can compensate for the shortage of previous registration methods, improve the accuracy of the registration, and make the fused multimodal images more similar to the real image. Finally, the cubic spline interpolation method has been successfully applied in developing 3D-CRT (3D Conformal Radiation Therapy) system.

  14. Tetragonal and cubic zirconia multilayered ceramic constructs created by EPD.

    PubMed

    Mochales, Carolina; Frank, Stefan; Zehbe, Rolf; Traykova, Tania; Fleckenstein, Christine; Maerten, Anke; Fleck, Claudia; Mueller, Wolf-Dieter

    2013-02-14

    The interest in electrophoretic deposition (EPD) for nanomaterials and ceramics production has widely increased due to the versatility of this technique to effectively combine different materials in unique shapes and structures. We successfully established an EPD layering process with submicrometer sized powders of Y-TZP with different mol percentages of yttrium oxide (3 and 8%) and produced multilayers of alternating tetragonal and cubic phases with a clearly defined interface. The rationale behind the design of these multilayer constructs was to optimize the properties of the final ceramic by combining the high mechanical toughness of the tetragonal phase of zirconia together with the high ionic conductivity of its cubic phase. In this work, a preliminary study of the mechanical properties of these constructs proved the good mechanical integrity of the multilayered constructs obtained as well as crack deflection in the interface between tetragonal and cubic zirconia layers.

  15. Body-centered-cubic Ni and its magnetic properties.

    PubMed

    Tian, C S; Qian, D; Wu, D; He, R H; Wu, Y Z; Tang, W X; Yin, L F; Shi, Y S; Dong, G S; Jin, X F; Jiang, X M; Liu, F Q; Qian, H J; Sun, K; Wang, L M; Rossi, G; Qiu, Z Q; Shi, J

    2005-04-08

    The body-centered-cubic (bcc) phase of Ni, which does not exist in nature, has been achieved as a thin film on GaAs(001) at 170 K via molecular beam epitaxy. The bcc Ni is ferromagnetic with a Curie temperature of 456 K and possesses a magnetic moment of 0.52+/-0.08 micro(B)/atom. The cubic magnetocrystalline anisotropy of bcc Ni is determined to be +4.0x10(5) ergs x cm(-3), as opposed to -5.7x10(4) ergs x cm(-3) for the naturally occurring face-centered-cubic (fcc) Ni. This sharp contrast in the magnetic anisotropy is attributed to the different electronic band structures between bcc Ni and fcc Ni, which are determined using angle-resolved photoemission with synchrotron radiation.

  16. How NaCl and water content determine water activity during ripening of Gouda cheese, and the predicted effect on inhibition of Listeria monocytogenes.

    PubMed

    Wemmenhove, E; Wells-Bennik, M H J; Stara, A; van Hooijdonk, A C M; Zwietering, M H

    2016-07-01

    This study describes the diffusion of NaCl and water in Gouda cheese during brining and ripening. Furthermore, we established water activity as a function of the NaCl-in-moisture content in Gouda cheese during ripening. We determined NaCl content, water content, and water activity in block-type Gouda cheeses that were brined for 3.8d and foil-ripened for a period of 26 wk, and in wheel-type Gouda cheeses that were brined for 0.33, 2.1, or 8.9d and subsequently nature-ripened for a period of 26 wk. The calculated diffusion coefficients of NaCl during brining were 3.6·10(-10) m(2)s(-1) in the block-type Gouda cheeses and 3.5·10(-10) m(2)s(-1) in the wheel-type Gouda cheeses. Immediately after brining, gradients of NaCl and water were observed throughout both types of cheese. During ripening, these gradients disappeared, except for the water gradient in nature-ripened cheeses. An empirical model was derived for Gouda cheese, in which water activity is expressed as a function of the NaCl-in-moisture content, as established for different brining times, locations and ripening times. Moreover, the effect of reduced water activity on inhibition of growth of Listeria monocytogenes in Gouda cheese was calculated. In addition to the presence of lactate and a pH of 5.2 to 5.3, the reduced water activity as seen in Gouda cheese can substantially contribute to inhibition of microbial growth and even to inactivation when cheeses are brined and ripened for extended times and subjected to nature-ripening. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. Image interpolation by two-dimensional parametric cubic convolution.

    PubMed

    Shi, Jiazheng; Reichenbach, Stephen E

    2006-07-01

    Cubic convolution is a popular method for image interpolation. Traditionally, the piecewise-cubic kernel has been derived in one dimension with one parameter and applied to two-dimensional (2-D) images in a separable fashion. However, images typically are statistically nonseparable, which motivates this investigation of nonseparable cubic convolution. This paper derives two new nonseparable, 2-D cubic-convolution kernels. The first kernel, with three parameters (designated 2D-3PCC), is the most general 2-D, piecewise-cubic interpolator defined on [-2, 2] x [-2, 2] with constraints for biaxial symmetry, diagonal (or 90 degrees rotational) symmetry, continuity, and smoothness. The second kernel, with five parameters (designated 2D-5PCC), relaxes the constraint of diagonal symmetry, based on the observation that many images have rotationally asymmetric statistical properties. This paper also develops a closed-form solution for determining the optimal parameter values for parametric cubic-convolution kernels with respect to ensembles of scenes characterized by autocorrelation (or power spectrum). This solution establishes a practical foundation for adaptive interpolation based on local autocorrelation estimates. Quantitative fidelity analyses and visual experiments indicate that these new methods can outperform several popular interpolation methods. An analysis of the error budgets for reconstruction error associated with blurring and aliasing illustrates that the methods improve interpolation fidelity for images with aliased components. For images with little or no aliasing, the methods yield results similar to other popular methods. Both 2D-3PCC and 2D-5PCC are low-order polynomials with small spatial support and so are easy to implement and efficient to apply.

  18. Effect of NaCl on the biofilm formation by foodborne pathogens.

    PubMed

    Xu, Hua; Zou, Yunyun; Lee, Hyeon-Yong; Ahn, Juhee

    2010-01-01

    This study was designed to evaluate the effect of NaCl on the biofilm formation of Listeria monocytogenes, Staphylococcus aureus, Shigella boydii, and Salmonella Typhimurium. The biofilm cells were cultured in media containing different NaCl concentrations (0% to 10%) for 10 d of incubation at 37 °C using a 24-well polystyrene microtiter plate, collected by swabbing methods, and enumerated using plate count method. The attachment and detachment kinetic patterns were estimated according to the modified Gompertz model. The cell surface hydrophobicity and auto-aggregation were observed at different NaCl concentrations. Most strains showed 2 distinctive phases at lower than 6% NaCl, while the numbers of adhered cells gradually increased throughout the incubation period at 4% to 10% NaCl. At 0% NaCl, the numbers of adhered L. monocytogenes, S. aureus, S. boydii, and S. Typhimurium cells rapidly increased up to 7.04, 6.47, 6.39, and 7.27 log CFU/cm(2), respectively, within 4 d of incubation. The maximum growth rate (k(A)) and specific growth rate (μ(A)) of adherent pathogenic cells were decreased with increasing NaCl concentration. Noticeable decline in the numbers of adherent cells was observed at low concentration levels of NaCl (<2%). The adherence abilities of foodborne pathogens were influenced by the physicochemical surface properties. The hydrophobicity and auto-aggregation enhanced the biofilm formation during the incubation periods. Therefore, this study could provide useful information to better understand the adhesion and detachment capability of foodborne pathogens on food contact surfaces. © 2010 Institute of Food Technologists®

  19. Energy flux and osmoregulation of Saccharomyces cerevisiae grown in chemostats under NaCl stress.

    PubMed Central

    Olz, R; Larsson, K; Adler, L; Gustafsson, L

    1993-01-01

    The energetics and accumulation of solutes in Saccharomyces cerevisiae were investigated for cells grown aerobically in a chemostat under NaCl stress and glucose limitation. Changed energy requirements in relation to external salinity were examined by energy balance determinations performed by substrate and product analyses, with the latter including heat measurements by microcalorimetry. In both 0 and 0.9 M NaCl cultures, the catabolism was entirely respiratory at the lowest dilution rates tested but shifted to a mixed respiratory-fermentative metabolism at higher dilution rates. This shift occurred at a considerably lower dilution rate for salt-grown cells. The intracellular solute concentrations, as calculated on the basis of intracellular soluble space determinations, showed that the internal Na+ concentration increased from about 0.02 molal in basal medium to about 0.18 molal in 0.9 M NaCl medium, while intracellular K+ was maintained around 0.29 molal despite the variation in external salinity. The intracellular glycerol concentration increased from below 0.05 molal at low salinity to about 1.2 molal at 0.9 M NaCl. The concentrations of the internal solutes, however, changed insignificantly with growth rate and energy metabolism. The additional maintenance energy expenditure for growth at 0.9 M NaCl was, depending on the growth rate, 14 to 31% of the total energy requirement for growth at 0 M NaCl. Including the energy conserved in glycerol, the total additional energy demand for growth at 0.9 M NaCl corresponded to 28 to 51% of the energy required for growth at 0 M NaCl. Images PMID:8468281

  20. Opposing effects of NaCl restriction and carbohydrate loading on urine volume in diabetic rats.

    PubMed

    O'Neill, H A; Kwon, T-H; Ring, T; Dimke, H; Lebeck, J; Frøkiaer, J; Collins, P B; Nielsen, S; Frische, S

    2011-05-01

    To test the effects of dietary NaCl and carbohydrate content on urine volume in diabetic rats. Streptozotocin-induced diabetic rats were subjected to NaCl restriction using either a NaCl-deficient carbohydrate-rich synthetic diet (Altromin C1036) supplemented to contain 0.16% NaCl (C1036 + lowNaCl) or a modified normal cereal-based diet (Altromin 1320) containing 0.086% NaCl (lowNaCl-1320). Normal diet contained 0.2683% NaCl. Using the C1036 + lowNaCl diet, earlier reported paradoxical increases in water intake and urine volume of diabetic rats were reproduced. However, water intake and urine volume also increased in diabetic rats offered the synthetic C1036 diet supplemented with NaCl to normal levels. Using the lowNaCl-1320 diet, water intake and urine volume were markedly reduced. Highly significant correlations between urine volume and both osmotic output and urinary glucose excretion were found in diabetic rats on normal diet, but these correlations were absent in diabetic rats on synthetic diet, which showed higher urine volumes than expected from the correlations. In contrast, urine volume was significantly correlated with carbohydrate intake in diabetic rats, irrespective of the diet. (i) The synthetic diet dramatically increases the urine volume in STZ-DM rats irrespectively of NaCl content. (ii) Rats with STZ-DM on a normal diet show reduced water intake and urine volume in response to dietary NaCl restriction. (iii) A shift to high carbohydrate diet induces polyuria in STZ-DM rats. (iv) Urine volume in all STZ-DM rats only shows correlation with dietary carbohydrate intake. (v) Glucose-driven osmotic diuresis is unlikely to explain the carbohydrate-induced polyuria. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

  1. Dynamical stabilization of solitons in cubic-quintic nonlinear Schroedinger model

    SciTech Connect

    Abdullaev, Fatkhulla Kh.; Garnier, Josselin

    2005-09-01

    We consider the existence of a dynamically stable soliton in the one-dimensional cubic-quintic nonlinear Schroedinger model with strong cubic nonlinearity management for periodic and random modulations. We show that the predictions of the averaged cubic-quintic nonlinear Schroedinger (NLS) equation and modified variational approach for the arrest of collapse coincide. The analytical results are confirmed by numerical simulations of a one-dimensional cubic-quintic NLS equation with a rapidly and strongly varying cubic nonlinearity coefficient.

  2. Single-crystalline cubic structured InP nanosprings

    NASA Astrophysics Data System (ADS)

    Shen, G. Z.; Bando, Y.; Zhi, C. Y.; Yuan, X. L.; Sekiguchi, T.; Golberg, D.

    2006-06-01

    Cubic structured nanosprings, InP nanosprings, have been synthesized via a simple thermochemical process using InP and ZnS as the source materials. Each InP nanospring is formed by rolling up a single InP nanobelt with the growth direction along the ⟨111⟩ orientation. The formation of these novel nanostructures is mainly attributed to the minimization of the electrostatic energy due to the polar charges on the ±(002) side surfaces of cubic InP. Cathodoluminescence properties were also studied, which reveal that the InP nanosprings have three emission bands centered at ˜736, ˜920, and ˜980nm.

  3. The singular cubical set of a topological space

    NASA Astrophysics Data System (ADS)

    Antolini, Rosa; Wiest, Bert

    1999-01-01

    For any topological space X let C(X) be the realization of the singular cubical set of X; let * be the topological space consisting of one point. In [1] Antolini proves, as a corollary to a general theorem about cubical sets, that C(X) and X×C(*) are homotopy equivalent, provided X is a CW-complex. In this note we give a short geometric proof that for any topological space X there is a natural weak homotopy equivalence between C(X) and X×C(*).

  4. Stationary phase analysis of generalized cubic phase mask wavefront coding

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Dong, Liquan; Zhao, Yuejin; Hui, Mei; Jia, Wei

    2013-07-01

    The modified generalized cubic phase mask (GCPM) has recently been applied in wavefront coding systems including infrared imaging and microscopy. In this paper, the stationary phase method is employed to analyze the GCPM characteristics. The SPA of the modulation transfer function (MTF) under misfocus aberration is derived for a wavefront coding system with a GCPM. The approximation corresponds with the Fast Fourier Transform (FFT) approach. On the basis of this approximation, we compare the characteristics of GCPM and cubic phase masks (CPM). A GCPM design approach based on stationary phase approximation is presented which helps to determine the initial parameter of phase mask, significantly decreasing the computational time required for numerical simulation.

  5. Optical spectroscopy of cubic GaN in nanowires

    NASA Astrophysics Data System (ADS)

    Renard, J.; Tourbot, G.; Sam-Giao, D.; Bougerol, C.; Daudin, B.; Gayral, B.

    2010-08-01

    We show that highly homogeneous cubic GaN can be grown by plasma-assisted molecular beam epitaxy on wurtzite GaN nanowires. The line width of the donor bound exciton is below 3 meV and can reach 1.6 meV in the best parts of the studied sample. This allows to perform a detailed spectroscopy of cubic GaN, and, in particular, to determine the precise spectral positions of the donor bound exciton, the fundamental free exciton and the split-off exciton in a photoluminescence experiment.

  6. Process for producing wurtzitic or cubic boron nitride

    DOEpatents

    Holt, J. Birch; Kingman, deceased, Donald D.; Bianchini, Gregory M.

    1992-01-01

    Disclosed is a process for producing wurtzitic or cubic boron nitride comprising the steps of: [A] preparing an intimate mixture of powdered boron oxide, a powdered metal selected from the group consisting of magnesium or aluminum, and a powdered metal azide; [B] igniting the mixture and bringing it to a temperature at which self-sustaining combustion occurs; [C] shocking the mixture at the end of the combustion thereof with a high pressure wave, thereby forming as a reaction product, wurtzitic or cubic boron nitride and occluded metal oxide; and, optionally [D] removing the occluded metal oxide from the reaction product. Also disclosed are reaction products made by the process described.

  7. Surface enhanced Raman study of cubic boron nitride

    NASA Astrophysics Data System (ADS)

    Zhang, Xu

    2003-05-01

    Surface enhancement for Raman scattering of single crystal cubic boron nitride (c-BN) (1 1 1) and polycrystalline cubic BN was observed by depositing silver nanoparticles on the substrate surface. The c-BN samples were subjected to hydrogen plasma, as well as deuterium plasma treatment to observe the isotopic shift of surface binding species. Characteristic Raman peaks corresponding to the molecular vibrational modes of surface chemisorbed hydrogen and deuterium could be observed for the first time and were assigned according to ab initio molecular orbital calculations.

  8. Simple adaptive cubic spline interpolation of fluorescence decay functions

    NASA Astrophysics Data System (ADS)

    Kuśba, J.; Czuper, A.

    2007-05-01

    Simple method allowing for adaptive cubic spline interpolation of fluorescence decay functions is proposed. In the first step of the method, the interpolated function is integrated using the known adaptive algorithm based on Newton-Cotes quadratures. It is shown that, in this step, application of the Simpson's rule provides the smallest number of calls of the interpolated function. In the second step of the method, a typical cubic spline approximation is used to find values of the interpolated function between the points evaluated in the first step.

  9. Process for producing wurtzitic or cubic boron nitride

    DOEpatents

    Holt, J.B.; Kingman, D.D.; Bianchini, G.M.

    1992-04-28

    Disclosed is a process for producing wurtzitic or cubic boron nitride comprising the steps of: [A] preparing an intimate mixture of powdered boron oxide, a powdered metal selected from the group consisting of magnesium or aluminum, and a powdered metal azide; [B] igniting the mixture and bringing it to a temperature at which self-sustaining combustion occurs; [C] shocking the mixture at the end of the combustion thereof with a high pressure wave, thereby forming as a reaction product, wurtzitic or cubic boron nitride and occluded metal oxide; and, optionally [D] removing the occluded metal oxide from the reaction product. Also disclosed are reaction products made by the process described.

  10. Cubic metallic phase of aluminum hydride showing improved hydrogen desorption

    NASA Astrophysics Data System (ADS)

    Scheicher, R. H.; Kim, D. Y.; Lebègue, S.; Arnaud, B.; Alouani, M.; Ahuja, R.

    2008-05-01

    We report on our results calculated from density functional theory and GW of the dehydrogenation properties in a cubic phase of AlH3. The metallic nature of the electronic structure entails a more favorable hydrogen removal energy which is lowered by 75% compared to the insulating hexagonal phase. This remarkable reduction in the Al-H bond strength bears important consequences for feasible applications of AlH3 as an on-board hydrogen storage material for mobile applications. We suggest that the cubic phase could be prepared and stabilized experimentally at ambient pressure by off-board quenching.

  11. Interpolation in numerical optimization. [by cubic spline generation

    NASA Technical Reports Server (NTRS)

    Hall, K. R.; Hull, D. G.

    1975-01-01

    The present work discusses the generation of the cubic-spline interpolator in numerical optimization methods which use a variable-step integrator with step size control based on local relative truncation error. An algorithm for generating the cubic spline with successive over-relaxation is presented which represents an improvement over that given by Ralston and Wilf (1967). Rewriting the code reduces the number of N-vectors from eight to one. The algorithm is formulated in such a way that the solution of the linear system set up yields the first derivatives at the nodal points. This method is as accurate as other schemes but requires the minimum amount of storage.

  12. Hygroscopic growth and deliquescence of NaCl nanoparticles coated with surfactant AOT.

    PubMed

    Alshawa, Ahmad; Dopfer, Otto; Harmon, Christopher W; Nizkorodov, Sergey A; Underwood, Joelle S

    2009-07-02

    Aerosolized nanoparticles of NaCl coated with variable amounts of surfactant AOT were generated by electrospraying AOT/NaCl aqueous solutions, followed by neutralizing and drying the resulting particles. A tandem differential mobility analyzer was used to select a narrow size distribution of particles with mobility equivalent diameters below 20 nm and monitor their hygroscopic growth as a function of relative humidity. Effects of the particle size and relative amount of surfactant on the hygroscopic growth of NaCl were studied. For pure NaCl nanoparticles, the deliquescence relative humidity (DRH) increased as the particle size was decreased, in full agreement with previous measurements. Below the DRH the NaCl nanoparticles had an equivalent of one-four monolayers of water adsorbed on the surface. The addition of a sub-monolayer AOT coating reduced the DRH and suppressed the hygroscopic growth of the NaCl core. At AOT coverage levels exceeding one monolayer, a clear deliquescence transition was no longer discernible. The Zdanovskii-Stokes-Robinson (ZSR) model failed to predict the observed growth factors of mixed AOT/NaCl nanoparticles reflecting a large contribution of the interfacial interactions between NaCl and AOT to the total free energy of the particles. There were indications that AOT/NaCl nanoparticles prepared by the electrospray aerosol source were enhanced in the relative mass fraction of AOT in comparison with the solution from which they were electrosprayed.

  13. The use of NaCl addition for the improvement of polyhydroxyalkanoate production by Cupriavidus necator.

    PubMed

    Passanha, Pearl; Kedia, Gopal; Dinsdale, Richard M; Guwy, Alan J; Esteves, Sandra R

    2014-07-01

    External stress factors in the form of ionic species or temperature increases have been shown to produce a stress response leading to enhanced PHA production. The effect of five different NaCl concentrations, namely 3.5, 6.5, 9, 12 and 15 g/l NaCl on PHA productivity using Cupriavidus necator has been investigated alongside a control (no added NaCl). A dielectric spectroscopy probe was used to measure PHA accumulation online in conjunction with the chemical offline analysis of PHA. The highest PHA production was obtained with the addition of 9 g/l NaCl, which yielded 30% higher PHA than the control. Increasing the addition of NaCl to 15 g/l was found to inhibit the production of PHA. NaCl addition can therefore be used as a simple, low cost, sustainable, non toxic and non reactive external stress strategy for increasing PHA productivity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Effects of grain angularity on NaCl precipitation in porous media during evaporation

    NASA Astrophysics Data System (ADS)

    Norouzi Rad, Mansoureh; Shokri, Nima

    2014-11-01

    Three dimensional pore-scale analysis was carried out using X-ray microtomography to investigate the effects of grain angularity on NaCl precipitation dynamics and patterns during evaporation from saline porous media. To do so, quartz sand and glass beads with almost similar average particle size and porosity were used enabling us to constrain the effects of grain angularity on NaCl precipitation since the glass beads were spherical and smooth whereas the sand consisted of irregularly shaped grains. Presence of angularity resulted in different pore sizes and shapes influencing the dynamics of evaporation and NaCl precipitation. Our results demonstrate that the preferential evaporation exclusively in fine pores at the surface of porous media results in discrete efflorescence. We observed a higher cumulative NaCl precipitation in the case of glass beads at the early stages of precipitation due to the presence of a fewer number of evaporation sites at the surface. This phenomenon resulted in formation of a thicker and more discrete NaCl crust at the surface of glass beads compared to sand grains. Also, computed water saturation profiles reveals formation of a wider unsaturated zone above the receding drying front in the case of sand compared to glass beads due to the presence of finer pores affecting the capillary flow though the partially wet zone. Our results provide new insights regarding the effects of grain angularity on NaCl precipitation dynamics and patterns during evaporation from saline porous media.

  15. Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes

    PubMed Central

    Bo, Zheng; Yang, Huachao; Zhang, Shuo; Yang, Jinyuan; Yan, Jianhua; Cen, Kefa

    2015-01-01

    Vertically-oriented graphenes (VGs) are promising active materials for electric double layer capacitors (EDLCs) due to their unique morphological and structural features. This study, for the first time, reports the molecular dynamics (MD) simulations on aqueous NaCl electrolytes confined within VG channels with different surface charge densities and channel widths. Simulation results show that the accessibility of ions and the structure of EDLCs are determined by the ion type/size, surface charging, and VG channel width. For relatively narrow VG channels with the same width, the threshold charge density (to compensate the energy penalty for shedding hydration shell) and the dehydration rate of Cl− ions are larger than those of Na+ ions. To achieve the highest ion concentration coefficient, the effective VG channel width should be between the crystal and hydration diameters of the ions. The results are further quantified and elucidated by calculating the electrolyte density profiles. The molecular insights obtained in the current work are useful in guiding the design and fabrication of VGs for advancing their EDLC applications. PMID:26424365

  16. Theoretical study of Na-atom emission from NaCl (100) surfaces

    NASA Astrophysics Data System (ADS)

    Puchin, Vladimir; Shluger, Alexander; Nakai, Yasuo; Itoh, Noriaki

    1994-04-01

    Several models for the elementary processes causing the emission of alkali atoms by electronic excitation of NaCl (100) surfaces have been investigated theoretically. First, the desorption of a Na atom neighboring an electronically excited F center on the surface is simulated using a quantum-mechanical embedded-cluster technique. It is shown that emission of a Na atom is energetically favorable. The kinetics of this process is shown to be controlled by the probability of a nonradiative transition between the two states: the excited state of the F center and that corresponding to a Na atom desorbing from the surface. The potential barrier for desorption of an excited Na atom from the excited F-center state is found to be 2.1 eV. It is also found that the energy for emission of a Na atom from a cluster of F centers (the F3 center) is considerably reduced (for a certain configuration of the defect) with respect to the similar energy for a single F center. The energy barrier for emission of a Na atom neighboring an F' center on the surface is calculated to be 1 eV. It is shown that the electronic excitation of kinklike sites, with a Na atom at the edge, can lead to a barrierless emission of a Na atom, leaving a Vk-type defect behind. The results of calculations are discussed critically on the basis of existing experimental data.

  17. Effect of NaCl concentration on productivity and mineral composition of Salicornia europaea as a potential crop for utilization NaCl in LSS

    NASA Astrophysics Data System (ADS)

    Ushakova, S. A.; Kovaleva, N. P.; Gribovskaya, I. V.; Dolgushev, V. A.; Tikhomirova, N. A.

    The accumulation of solid and liquid wastes in manmade ecosystems presents a problem that has not been efficiently solved yet. Urine, containing NaCl, are part of these products. This is an obstacle to the creation of biological systems with a largely closed material cycling, because the amount of solid and liquid wastes in them must be reduced to a minimum. A possible solution to the problem is to select plant species capable of utilizing sufficiently high concentrations of NaCl, edible for humans, and featuring high productivity. Until recently, the life support systems have included the higher plants that were either sensitive to salinization (wheat, many of the legumes, carrot, potato, maize) or relatively salt-resistant (barley, sugar beet, spinach). Salicomia europaea, whose above-ground part is fully edible for humans, is one of the most promising candidates to be included in life support systems. It is reported in the literature that this plant is capable of accumulating up to 50% NaCl (dry basis). Besides, excessive accumulation of sodium ions should bring forth a decrease in the uptake of potassium ions and other biogenic elements. The aim of this work is to study the feasibility of using S. europaea plants in growth chambers to involve NaCl into material cycling. Plants were grown in vegetation chambers at the irradiance of 100 or 150 W/m 2 PAR (photosynthetically active radiation) and the air temperature 24 °C, by two methods. The first method was to grow the plants on substrate - peat. The peat was supplemented with either 3% NaCl (Variant 1) or 6% NaCl (Variant 2) of the oven-dry mass of the peat. The second method was to grow the plants in water culture, using the solution with a full complement of nutrients, which contained 0.0005% of NaCl, 1% or 2%. The study showed that the addition of NaCl to the substrate or to the solution resulted in the formation of more succulent plants, which considerably increased their biomass. The amount of NaCl uptake

  18. Insulin Increases the Functional Activity of the Renal NaCl cotransporter

    PubMed Central

    Chávez-Canales, María; Arroyo, Juan Pablo; Ko, Benajmin; Vázquez, Norma; Bautista, Rocio; Castañeda-Bueno, María; Bobadilla, Norma A.; Hoover, Robert S.; Gamba, Gerardo

    2013-01-01

    Objectives Insulin is recognized to increase renal salt reabsorption in the distal nephron and hyperinsulinemic states have been shown to be associated with increased expression of the renal NaCl cotransporter, NCC. However, the effect of insulin on NCC functional activity has not been reported. Methods Using a heterologous expression system of Xenopus laevis oocytes, a mouse distal convoluted cell line, mDCT15 cells, endogenously expressing NCC, and an ex vivo kidney perfusion technique, we assessed the effect of insulin on the activity and phosphorylation of NCC. The signaling pathway involved was analyzed. Results In Xenopus oocytes insulin increases the activity of NCC together with its phosphorylation at threonine residue 58. Activation of NCC by insulin was also observed in mDCT15 cells. Additionally, insulin increased the NCC phosphorylation in kidney under the ex vivo perfusion technique. In oocytes and mDCT15 cells, insulin effect on NCC was prevented with inhibitors of PI3K, mTORC2, and AKT1 kinases, but not by inhibitors of MAP or mTORC1 kinases, suggesting that PI3K-mTORC2-AKT1 is the intracellular pathway required. Additionally, activation of NCC by insulin was not affected by wild type or mutant versions of WNK1, WNK4, or SGK1, but it was no longer observed in the presence of wild type or the dominant negative, catalytically inactive WNK3, implicating this kinase in the process. Conclusion Insulin induces activation and phosphorylation of NCC. This effect could play an important role in arterial hypertension associated with hyperinsulinemic states, such as obesity, metabolic syndrome, or type 2 diabetes mellitus. PMID:23303355

  19. Molecular variants of the thiazide-sensitive Na+-Cl- cotransporter in hypertensive families.

    PubMed

    Keszei, András P; Tislér, András; Backx, Peter H; Andrulis, Irene L; Bull, Shelley B; Logan, Alexander G

    2007-10-01

    The thiazide-sensitive Na-Cl cotransporter (TSC) is involved in the fine regulation of sodium excretion by the kidney, and an increase in its activity causes salt-sensitive hypertension and hypercalciuria. To explore the possibility that activating mutations in the TSC gene may be involved in the pathogenesis of primary hypertension, we screened genomic DNA of 68 individuals from hypertensive families of patients with hypercalciuria for variations using single-strand conformation polymorphism and investigated the functional properties using the Xenopus laevis oocyte expression system. We identified 18 variants in the TSC and, of those, four were nonsynonymous. The A728T, R904Q and R919C variants were introduced into the human TSC cDNA and expressed in Xenopus oocytes to study their effect on Na transport. Although T728 and Q904 did not show any difference in Na uptake, the R919C mutant showed a 60% increase compared to wild-type human TSC and an exaggerated inhibitory action of hydrochlorothiazide. Immunocytochemical analysis revealed no difference in cell surface expression of R919C mutants compared to wild-type hTSC. There was no significant difference in the inhibitory effect of the carboxyl terminus of the serine-threonine kinase WNK4 on the R919C mutant and wild-type hTSC. Our results show that the substitution of arginine for cysteine at position 919 of TSC increases Na transport function, and provide support for the hypothesis that mutations in renal tubular sodium transporters may contribute to the development of primary hypertension, a polygenic disorder, by increasing renal sodium reabsorption.

  20. Insulin increases the functional activity of the renal NaCl cotransporter.

    PubMed

    Chávez-Canales, María; Arroyo, Juan Pablo; Ko, Benajmin; Vázquez, Norma; Bautista, Rocio; Castañeda-Bueno, María; Bobadilla, Norma A; Hoover, Robert S; Gamba, Gerardo

    2013-02-01

    Insulin is recognized to increase renal salt reabsorption in the distal nephron and hyperinsulinemic states have been shown to be associated with increased expression of the renal NaCl cotransporter (NCC). However, the effect of insulin on NCC functional activity has not been reported. Using a heterologous expression system of Xenopus laevis oocytes, a mouse distal convoluted cell line, mDCT15 cells, endogenously expressing NCC, and an ex-vivo kidney perfusion technique, we assessed the effect of insulin on the activity and phosphorylation of NCC. The signaling pathway involved was analyzed. In Xenopus oocytes insulin increases the activity of NCC together with its phosphorylation at threonine residue 58. Activation of NCC by insulin was also observed in mDCT15 cells. Additionally, insulin increased the NCC phosphorylation in kidney under the ex-vivo perfusion technique. In oocytes and mDCT15 cells, insulin effect on NCC was prevented with inhibitors of phosphatidylinositol 3-kinase (PI3K), mTORC2, and AKT1 kinases, but not by inhibitors of MAP or mTORC1 kinases, suggesting that PI3K-mTORC2-AKT1 is the intracellular pathway required. Additionally, activation of NCC by insulin was not affected by wild-type or mutant versions of with no lysine kinase 1, with no lysine kinase 4, or serum glucocorticoid kinase 1, but it was no longer observed in the presence of wild-type or the dominant negative, catalytically inactive with no lysine kinase 3, implicating this kinase in the process. Insulin induces activation and phosphorylation of NCC. This effect could play an important role in arterial hypertension associated with hyperinsulinemic states, such as obesity, metabolic syndrome, or type 2 diabetes mellitus.

  1. Mutations in the Na-Cl cotransporter reduce blood pressure in humans.

    PubMed

    Cruz, D N; Simon, D B; Nelson-Williams, C; Farhi, A; Finberg, K; Burleson, L; Gill, J R; Lifton, R P

    2001-06-01

    The relationship between salt homeostasis and blood pressure has remained difficult to establish from epidemiological studies of the general population. Recently, mendelian forms of hypertension have demonstrated that mutations that increase renal salt balance lead to higher blood pressure, suggesting that mutations that decrease the net salt balance might have the converse effect. Gitelman's syndrome, caused by loss of function mutations in the Na-Cl cotransporter of the distal convoluted tubule (NCCT), features inherited hypokalemic alkalosis with so-called "normal" blood pressure. We hypothesized that the mild salt wasting of Gitelman's syndrome results in reduced blood pressure and protection from hypertension. We have formally addressed this question through the study of 199 members of a large Amish kindred with Gitelman's syndrome. Through genetic testing, family members were identified as inheriting 0 (n=60), 1 (n=113), or 2 (n=26) mutations in NCCT, permitting an unbiased assessment of the clinical consequences of inheriting these mutations by comparison of the phenotypes of relatives with contrasting genotypes. The results demonstrate high penetrance of hypokalemic alkalosis, hypomagnesemia, and hypocalciuria in patients inheriting 2 mutant NCCT alleles. In addition, the NCCT genotype was a significant predictor of blood pressure, with homozygous mutant family members having significantly lower age- and gender-adjusted systolic and diastolic blood pressures than those of their wild-type relatives. Moreover, both homozygote and heterozygote subjects had significantly higher 24-hour urinary Na(+) than did wild-type subjects, reflecting a self-selected higher salt intake. Finally, heterozygous children, but not adults, had significantly lower blood pressures than those of the wild-type relatives. These findings provide formal demonstration that inherited mutations that impair renal salt handling lower blood pressure in humans.

  2. Collision-Induced Dissociation of Electrosprayed NaCl Clusters: Using Molecular Dynamics Simulations to Visualize Reaction Cascades in the Gas Phase

    NASA Astrophysics Data System (ADS)

    Schachel, Tilo D.; Metwally, Haidy; Popa, Vlad; Konermann, Lars

    2016-11-01

    Infusion of NaCl solutions into an electrospray ionization (ESI) source produces [Na( n+1)Cl n ]+ and other gaseous clusters. The n = 4, 13, 22 magic number species have cuboid ground state structures and exhibit elevated abundance in ESI mass spectra. Relatively few details are known regarding the mechanisms whereby these clusters undergo collision-induced dissociation (CID). The current study examines to what extent molecular dynamics (MD) simulations can be used to garner insights into the sequence of events taking place during CID. Experiments on singly charged clusters reveal that the loss of small neutrals is the dominant fragmentation pathway. MD simulations indicate that the clusters undergo extensive structural fluctuations prior to decomposition. Consistent with the experimentally observed behavior, most of the simulated dissociation events culminate in ejection of small neutrals ([NaCl] i , with i = 1, 2, 3). The MD data reveal that the prevalence of these dissociation channels is linked to the presence of short-lived intermediates where a relatively compact core structure carries a small [NaCl] i protrusion. The latter can separate from the parent cluster via cleavage of a single Na-Cl contact. Fragmentation events of this type are kinetically favored over other dissociation channels that would require the quasi-simultaneous rupture of multiple electrostatic contacts. The CID behavior of NaCl cluster ions bears interesting analogies to that of collisionally activated protein complexes. Overall, it appears that MD simulations represent a valuable tool for deciphering the dissociation of noncovalently bound systems in the gas phase.

  3. Collision-Induced Dissociation of Electrosprayed NaCl Clusters: Using Molecular Dynamics Simulations to Visualize Reaction Cascades in the Gas Phase.

    PubMed

    Schachel, Tilo D; Metwally, Haidy; Popa, Vlad; Konermann, Lars

    2016-11-01

    Infusion of NaCl solutions into an electrospray ionization (ESI) source produces [Na(n+1)Cl n ](+) and other gaseous clusters. The n = 4, 13, 22 magic number species have cuboid ground state structures and exhibit elevated abundance in ESI mass spectra. Relatively few details are known regarding the mechanisms whereby these clusters undergo collision-induced dissociation (CID). The current study examines to what extent molecular dynamics (MD) simulations can be used to garner insights into the sequence of events taking place during CID. Experiments on singly charged clusters reveal that the loss of small neutrals is the dominant fragmentation pathway. MD simulations indicate that the clusters undergo extensive structural fluctuations prior to decomposition. Consistent with the experimentally observed behavior, most of the simulated dissociation events culminate in ejection of small neutrals ([NaCl] i , with i = 1, 2, 3). The MD data reveal that the prevalence of these dissociation channels is linked to the presence of short-lived intermediates where a relatively compact core structure carries a small [NaCl] i protrusion. The latter can separate from the parent cluster via cleavage of a single Na-Cl contact. Fragmentation events of this type are kinetically favored over other dissociation channels that would require the quasi-simultaneous rupture of multiple electrostatic contacts. The CID behavior of NaCl cluster ions bears interesting analogies to that of collisionally activated protein complexes. Overall, it appears that MD simulations represent a valuable tool for deciphering the dissociation of noncovalently bound systems in the gas phase. Graphical Abstract ᅟ.

  4. CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES: Electro-oxidation of Formic Acid on Carbon Supported Edge-Truncated Cubic Platinum Nanoparticles Catalysts

    NASA Astrophysics Data System (ADS)

    Li, She-Qiang; Fu, Xing-Qiu; Hu, Bing; Deng, Jia-Jun; Chen, Lei

    2009-11-01

    The oxidation of formic acid on edge-truncated cubic platinum nanoparticles/C catalysts is investigated. X-ray photoelectron spectroscopy analysis indicates that the surface of edge-truncated cubic platinum nanoparticles is composed of two types of coordination sites. The oxidation behavior of formic acid on edge-truncated cubic platinum nanoparticles/C is investigated using cyclic voltammetry. The apparent activation energies are found to be 54.2, 55.0, 61.8, 69.5, 71.9, 69.26, 65.28kJ/mol at 0.15, 0.3, 0.4, 0.5, 0.6, 0.65, 0.7V, respectively. A specific surface area activity of 1.76 mA·cm-2 at 0.4 V indicates that the edge-truncated cubic Platinum nanoparticles are a promising anode catalyst for direct formic acid fuel cells.

  5. Early developmental exposure to high fructose intake in rats with NaCl stimulation causes cardiac damage.

    PubMed

    Araujo, I C; Andrade, R P; Santos, F; Soares, E S; Yokota, R; Mostarda, C; Fiorino, P; De Angelis, K; Irigoyen, M C; Morris, M; Farah, V

    2016-02-01

    Metabolic syndrome (MS) increases the risk of type 2 diabetes and cardiovascular disease. High consumption of fructose is a proposed cause of increased MS, manifested through hypertension, obesity, insulin resistance, and dyslipidemia. High NaCl also increases the risk of CD. The purpose of this study is to evaluate the influence of fructose and sodium on autonomic dysfunction and its relation with CD in MS. Fructose overload was started at weaning and continued through adulthood. Male Wistar rats (21 days) were divided into four groups: Control (C), fructose consumption (10%, F), NaCl consumption (salt 1% for the 10 last days, S), and fructose and NaCl (FS), and monitored for 8 weeks. Metabolic evaluations consisted of Lee index, glycemia, insulin and glucose tolerance tests, triglycerides, and total cholesterol measurements. Cardiovascular parameters measured were arterial pressure (AP) and cardiac function performed by echocardiography. They also measured the influence of renin angiotensin (RAS) and autonomic nervous systems by drug blockage with losartan, atropine, and atenolol. Energy analysis showed no change between groups. Fructose overload induced a MS state, confirmed by insulin resistance, glucose intolerance, and dyslipidemia. Fasting glucose was increased in F and FS rat groups compared with C and S groups. AP was higher in F, S, and FS groups in comparison with the C group. The hypotensive response after sympathetic blockade was increased in F, S, and FS versus C. The cardiac vagal tonus was reduced in F and FS animal groups. The intrinsic heart rate was decreased in the FS group (372 ± 9 bpm) compared with the C group (410 ± 13 bpm). The morphometric measurements evaluated through left ventricular diameter during diastole and the left ventricular diameter during systole decreased in the FS group (16 and 26%, respectively). Diastolic function was reduced in F and FS. The depressor response induced by losartan was increased in the F group in

  6. Role of csp genes in NaCl, pH, and ethanol stress response and motility in Clostridium botulinum ATCC 3502.

    PubMed

    Derman, Yağmur; Söderholm, Henna; Lindström, Miia; Korkeala, Hannu

    2015-04-01

    Clostridium botulinum is a notable food pathogen and responsible for botulism due to production of botulinum neurotoxin. Strains of C. botulinum can adapt to and survive in stress conditions and food processing. The cold shock protein coding genes (csp) are involved in growth at low temperature, but they may also possess other functions. In this mutational analysis we show that cspB and cspC, but not cspA, are important for NaCl, pH and ethanol stress responses and for motility of C. botulinum ATCC 3502. In all NaCl concentrations tested, the cspB mutant had lower maximum growth rate and, together with the cspC mutant, a longer lag phase compared to the wild-type strain. At low pH, the cspB and cspC mutants showed either lower maximum growth rates or longer lag phases compared to the wild type. In all ethanol concentrations tested, the cspB mutant had lower maximum growth rates and the cspC mutant had a longer lag phase than the wild-type strain. Motility was reduced in cspA and cspC mutants, and flagella formation was affected. The results suggest that cspB plays a universal role in stress response and cspC aids C. botulinum in NaCl, pH and ethanol stress in C. botulinum ATCC 3502.

  7. Lattice Green's Function for the Body-Centered Cubic Lattice

    NASA Astrophysics Data System (ADS)

    Sakaji, A. J.

    2002-05-01

    An expression for the Green's function (GF) of Body-Centered Cubic (BCC) lat tice is evaluated analytically and numerically for a single impurity lattice. Th e density of states (DOS), phase shift, and scattering cross section are express ed in terms of complete elliptic integrals of the first kind.

  8. Integrability of Lotka-Volterra Planar Complex Cubic Systems

    NASA Astrophysics Data System (ADS)

    Dukarić, Maša; Giné, Jaume

    In this paper, we study the Lotka-Volterra complex cubic systems. We obtain necessary conditions of integrability for these systems with some restriction on the parameters. The sufficiency is proved for all conditions, except one which remains open, using different methods.

  9. An effective packing density of binary cubic crystals

    NASA Astrophysics Data System (ADS)

    Eremin, I. E.; Eremina, V. V.; Sychev, M. S.; Moiseenko, V. G.

    2015-04-01

    The methodology of effective macroscopic calculation of numerical values of internuclear distances in binary crystals of a cubic crystal system is based on the use of coefficients of the structural packing density of the crystal lattice. The possibility of combining the reference data on the main physicochemical parameters of the substance is implemented by synthesis of the corresponding mathematical models.

  10. Connecting the Dots Parametrically: An Alternative to Cubic Splines.

    ERIC Educational Resources Information Center

    Hildebrand, Wilbur J.

    1990-01-01

    Discusses a method of cubic splines to determine a curve through a series of points and a second method for obtaining parametric equations for a smooth curve that passes through a sequence of points. Procedures for determining the curves and results of each of the methods are compared. (YP)

  11. Tangent Lines without Derivatives for Quadratic and Cubic Equations

    ERIC Educational Resources Information Center

    Carroll, William J.

    2009-01-01

    In the quadratic equation, y = ax[superscript 2] + bx + c, the equation y = bx + c is identified as the equation of the line tangent to the parabola at its y-intercept. This is extended to give a convenient method of graphing tangent lines at any point on the graph of a quadratic or a cubic equation. (Contains 5 figures.)

  12. Assessing Inquiry Learning: How Much Is a Cubic Metre?

    ERIC Educational Resources Information Center

    Fry, Kym

    2014-01-01

    In this article, Kym Fry uses the "Programme for International Student Assessment" (PISA) assessment framework to break down what her Year 6 students learned as they explored the inquiry question, "How much is a cubic metre?" First, an overview of the lessons in the unit is provided. Quality assessment opportunities are…

  13. Tangent Lines without Derivatives for Quadratic and Cubic Equations

    ERIC Educational Resources Information Center

    Carroll, William J.

    2009-01-01

    In the quadratic equation, y = ax[superscript 2] + bx + c, the equation y = bx + c is identified as the equation of the line tangent to the parabola at its y-intercept. This is extended to give a convenient method of graphing tangent lines at any point on the graph of a quadratic or a cubic equation. (Contains 5 figures.)

  14. Effective interatomic potential for body-centered-cubic metals

    SciTech Connect

    Wang, Y.R.; Boercker, D.B.

    1995-07-01

    An effective interatomic potential suitable for all body-centered-cubic (bcc) metals is developed based on the embedded atom method. The potential predicts all major anomalies displayed in the phonon spectra of the bcc transition metals, as well as the large relaxation of the (100) surface of V, Nb, and Ta. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  15. Cubic surfaces and their invariants: Some memories of Raymond Stora

    NASA Astrophysics Data System (ADS)

    Bauer, Michel

    2016-11-01

    Cubic surfaces embedded in complex projective 3-space are a classical illustration of the use of old and new methods in algebraic geometry. Recently, they made their appearance in physics, and in particular aroused the interest of Raymond Stora, to the memory of whom these notes are dedicated, and to whom I'm very much indebted.

  16. Rheology of cubic particles suspended in a Newtonian fluid.

    PubMed

    Cwalina, Colin D; Harrison, Kelsey J; Wagner, Norman J

    2016-05-18

    Many real-world industrial processes involve non-spherical particles suspended in a fluid medium. Knowledge of the flow behavior of these suspensions is essential for optimizing their transport properties and designing processing equipment. In the present work, we explore and report on the rheology of concentrated suspensions of cubic-shaped colloidal particles under steady and dynamic shear flow. These suspensions exhibit a rich non-Newtonian rheology that includes shear thickening and normal stress differences at high shear stresses. Scalings are proposed to connect the material properties of these suspensions of cubic particle to those measured for suspensions of spherical particles. Negative first normal stress differences indicate that lubrication hydrodynamic forces dominate the stress in the shear-thickened state. Accounting for the increased lubrication hydrodynamic interactions between the flat surfaces of the cubic particles allows for a quantitative comparison of the deviatoric stress in the shear-thickened state to that of spherical particles. New semi-empirical models for the viscosity and normal stress difference coefficients are presented for the shear-thickened state. The results of this study indicate that cubic particles offer new and unique opportunities to formulate colloidal dispersions for field-responsive materials.

  17. Structure and stability of pseudo-cubic tetragonal boron

    NASA Astrophysics Data System (ADS)

    Shirai, Koun; Uemura, Naoki; Dekura, Haruhiko

    2017-05-01

    Pseudo-cubic tetragonal boron, which may be another form of boron allotropes, has recently been discovered under high pressure and high temperature conditions. In this paper, the structure of pseudo-cubic tetragonal boron is studied by density-functional-theory (DFT) calculation. The structure is abnormal compared with other boron allotropes in many respects, making it difficult to comprehend. The lattice is very close to a cubic lattice, such that the icosahedra are largely distorted along the c-axis. Such distortions are normally not favorable for boron crystals; in fact, the present calculations supported this. The reported positions of partially occupied interstitial sites render the intericosahedral bonds unusually long or short, which were again not supported by the present calculations. Furthermore, the potential of involving impurities is unlikely in terms of the formation energy and lattice parameters. Therefore, the structure of pseudo-cubic tetragonal boron was not proven by calculation, despite this extensive study. Something may be overlooked in the present structural model, or something unusual may have happened in this structure, the solution of which is left as an open question.

  18. Magnetic relaxation of nanoparticles with cubic and uniaxial anisotropies

    NASA Astrophysics Data System (ADS)

    Correia, Marcos J.; Schwarzacher, Walther; Ferreira Chagas, Edson; Figueiredo, Wagner

    2016-01-01

    We use Monte Carlo methods to simulate the influence of Brownian rotation on the magnetic properties of a system of single-domain magnetic nanoparticles with cubic and uniaxial magnetic anisotropies. The distinguishing feature of the system is a strongly temperature-dependent viscosity. Such a system has been realized experimentally using magnetic nanoparticles suspended in a freeze-concentrated cryoprotectant solution.

  19. Cubic spline approximation techniques for parameter estimation in distributed systems

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Crowley, J. M.; Kunisch, K.

    1983-01-01

    Approximation schemes employing cubic splines in the context of a linear semigroup framework are developed for both parabolic and hyperbolic second-order partial differential equation parameter estimation problems. Convergence results are established for problems with linear and nonlinear systems, and a summary of numerical experiments with the techniques proposed is given.

  20. Connecting the Dots Parametrically: An Alternative to Cubic Splines.

    ERIC Educational Resources Information Center

    Hildebrand, Wilbur J.

    1990-01-01

    Discusses a method of cubic splines to determine a curve through a series of points and a second method for obtaining parametric equations for a smooth curve that passes through a sequence of points. Procedures for determining the curves and results of each of the methods are compared. (YP)

  1. Cubic Equations and the Ideal Trisection of the Arbitrary Angle

    ERIC Educational Resources Information Center

    Farnsworth, Marion B.

    2006-01-01

    In the year 1837 mathematical proof was set forth authoritatively stating that it is impossible to trisect an arbitrary angle with a compass and an unmarked straightedge in the classical sense. The famous proof depends on an incompatible cubic equation having the cosine of an angle of 60 and the cube of the cosine of one-third of an angle of 60 as…

  2. Estimating the board foot to cubic foot ratio

    Treesearch

    Steve P. Verrill; Victoria L. Herian; Henry N. Spelter

    2004-01-01

    Certain issues in recent softwood lumber trade negotiations have centered on the method for converting estimates of timber volumes reported in cubic meters to board feet. Such conversions depend on many factors; three of the most important of these are log length, diameter, and taper. Average log diameters vary by region and have declined in the western United States...

  3. Morphosynthesis of cubic silver cages on monolithic activated carbon.

    PubMed

    Wang, Fei; Zhao, Hong; Lai, Yijian; Liu, Siyu; Zhao, Binyuan; Ning, Yuesheng; Hu, Xiaobin

    2013-11-14

    Cubic silver cages were prepared on monolithic activated carbon (MAC) pre-absorbed with Cl(-), SO4(2-), or PO4(3-) anions. Silver insoluble salts served as templates for the morphosynthesis of silver cages. The silver ions were reduced by reductive functional groups on MAC micropores through a galvanic cell reaction mechanism.

  4. Aspects on mediated glucose oxidation at a supported cubic phase.

    PubMed

    Aghbolagh, Mahdi Shahmohammadi; Khani Meynaq, Mohammad Yaser; Shimizu, Kenichi; Lindholm-Sethson, Britta

    2017-12-01

    A supported liquid crystalline cubic phase housing glucose oxidase on an electrode surface has been suggested as bio-anode in a biofuel. The purpose of this investigation is to clarify some aspect on the mediated enzymatic oxidation of glucose in such a bio-anode where the mediator ferrocene-carboxylic acid and glucose were dissolved in the solution. The enzyme glucose oxidase was housed in the water channels of the mono-olein cubic phase. The system was investigated with cyclic voltammetry at different scan rates and the temperature was varied between 15°C and 30°C. The diffusion coefficient of the mediator and also the film resistance was estimated showing a large decrease in the mass-transport properties as the temperature was decreased. The current from mediated oxidation of glucose at the electrode surface increased with decreasing film thickness. The transport of the mediator in the cubic phase was the rate-limiting step in the overall reaction, where the oxidation of glucose took place at the outer surface of the cubic phase. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Hygroscopic properties of internally mixed particles composed of NaCl and water-soluble organic acids.

    PubMed

    Ghorai, Suman; Wang, Bingbing; Tivanski, Alexei; Laskin, Alexander

    2014-02-18

    Atmospheric aging of naturally emitted marine aerosol often leads to formation of internally mixed particles composed of sea salts and water-soluble organic compounds of anthropogenic origin. Mixing of sea salt and organic components has profound effects on the evolving chemical composition and hygroscopic properties of the resulted particles, which are poorly understood. Here, we have studied chemical composition and hygroscopic properties of laboratory generated NaCl particles mixed with malonic acid (MA) and glutaric acid (GA) at different molar ratios using micro-FTIR spectroscopy, atomic force microscopy, and X-ray elemental microanalysis. Hygroscopic properties of internally mixed NaCl and organic acid particles were distinctly different from pure components and varied significantly with the type and amount of organic compound present. Experimental results were in a good agreement with the AIM modeling calculations of gas/liquid/solid partitioning in studied systems. X-ray elemental microanalysis of particles showed that Cl/Na ratio decreased with increasing organic acid component in the particles with MA yielding lower ratios relative to GA. We attribute the depletion of chloride to the formation of sodium malonate and sodium glutarate salts resulted by HCl evaporation from dehydrating particles.

  6. Hygroscopic Properties of Internally Mixed Particles Composed of NaCl and Water-Soluble Organic Acids

    SciTech Connect

    Ghorai, Suman; Wang, Bingbing; Tivanski, Alexei V.; Laskin, Alexander

    2014-02-18

    Atmospheric aging of naturally emitted marine aerosol often leads to formation of internally mixed particles composed of sea salts and water soluble organic compounds of anthropogenic origin. Mixing of sea salt and organic components has profound effects on the evolving chemical composition and hygroscopic properties of the resulted particles, which are poorly understood. Here, we have studied chemical composition and hygroscopic properties of laboratory generated NaCl particles mixed with malonic acid (MA) and glutaric acid (GA) at different molar ratios using micro-FTIR spectroscopy and X-ray elemental microanalysis.Hygroscopic properties of inte rnally mixed NaCl and organic acid particles were distinctly different from pure components and varied significantly with the type and amount of organic compound present. Experimental results were in a good agreement with the AIM modeling calculations of gas/liquid/solid partitioning in studied systems. X-ray elemental microanalysis of particles showed that Cl/Na ratio decreased with increasing organic acid component in the particles with MA yielding lower ratios relative to GA. We attribute the depletion of chloride to the formation of Na-malonate and Na-glutarate salts resulted by HCl evaporation from dehydrating particles.

  7. Neuropathy target esterase catalyzes osmoprotective renal synthesis of glycerophosphocholine in response to high NaCl

    PubMed Central

    Gallazzini, Morgan; Ferraris, Joan D.; Kunin, Margarita; Morris, Ryan G.; Burg, Maurice B.

    2006-01-01

    Glycerophosphocholine (GPC) is an osmoprotective compatible and counteracting organic osmolyte that accumulates in renal inner medullary cells in response to high NaCl and urea. We previously found that high NaCl increases GPC in renal [Madin–Darby canine kidney (MDCK)] cells. The GPC is derived from phosphatidylcholine, catalyzed by a phospholipase that was not identified at that time. Neuropathy target esterase (NTE) was recently shown to be a phospholipase B that catalyzes production of GPC from phosphatidylcholine. The purpose of the present study was to test whether NTE contributes to the high NaCl-induced increase of GPC synthesis in renal cells. We find that in mouse inner medullary collecting duct cells, high NaCl increases NTE mRNA within 8 h and NTE protein within 16 h. Diisopropyl fluorophosphate, which inhibits NTE esterase activity, reduces GPC accumulation, as does an siRNA that specifically reduces NTE protein abundance. The 20-h half-life of NTE mRNA is unaffected by high NaCl. TonEBP/OREBP is a transcription factor that is activated by high NaCl. Knockdown of TonEBP/OREBP by a specific siRNA inhibits the high NaCl-induced increase of NTE mRNA. Further, the lower renal inner medullary interstitial NaCl concentration that occurs chronically in ClCK1−/− mice and acutely in normal mice given furosemide is associated with lower NTE mRNA and protein. We conclude that high NaCl increases transcription of NTE, likely mediated by TonEBP/OREBP, and that the resultant increase of NTE expression contributes to increased production and accumulation of GPC in mammalian renal cells in tissue culture and in vivo. PMID:17015841

  8. A high-throughput method to measure NaCl and acid taste thresholds in mice.

    PubMed

    Ishiwatari, Yutaka; Bachmanov, Alexander A

    2009-05-01

    To develop a technique suitable for measuring NaCl taste thresholds in genetic studies, we conducted a series of experiments with outbred CD-1 mice using conditioned taste aversion (CTA) and two-bottle preference tests. In Experiment 1, we compared conditioning procedures involving either oral self-administration of LiCl or pairing NaCl intake with LiCl injections and found that thresholds were the lowest after LiCl self-administration. In Experiment 2, we compared different procedures (30-min and 48-h tests) for testing conditioned mice and found that the 48-h test is more sensitive. In Experiment 3, we examined the effects of varying strength of conditioned (NaCl or LiCl taste intensity) and unconditioned (LiCl toxicity) stimuli and concluded that 75-150 mM LiCl or its mixtures with NaCl are the optimal stimuli for conditioning by oral self-administration. In Experiment 4, we examined whether this technique is applicable for measuring taste thresholds for other taste stimuli. Results of these experiments show that conditioning by oral self-administration of LiCl solutions or its mixtures with other taste stimuli followed by 48-h two-bottle tests of concentration series of a conditioned stimulus is an efficient and sensitive method to measure taste thresholds. Thresholds measured with this technique were 2 mM for NaCl and 1 mM for citric acid. This approach is suitable for simultaneous testing of large numbers of animals, which is required for genetic studies. These data demonstrate that mice, like several other species, generalize CTA from LiCl to NaCl, suggesting that they perceive taste of NaCl and LiCl as qualitatively similar, and they also can generalize CTA of a binary mixture of taste stimuli to mixture components.

  9. DNA double-strand breaks induced by high NaCl occur predominantly in gene deserts

    PubMed Central

    Dmitrieva, Natalia I.; Cui, Kairong; Kitchaev, Daniil A.; Zhao, Keji; Burg, Maurice B.

    2011-01-01

    High concentration of NaCl increases DNA breaks both in cell culture and in vivo. The breaks remain elevated as long as NaCl concentration remains high and are rapidly repaired when the concentration is lowered. The exact nature of the breaks, and their location, has not been entirely clear, and it has not been evident how cells survive, replicate, and maintain genome integrity in environments like the renal inner medulla in which cells are constantly exposed to high NaCl concentration. Repair of the breaks after NaCl is reduced is accompanied by formation of foci containing phosphorylated H2AX (γH2AX), which occurs around DNA double-strand breaks and contributes to their repair. Here, we confirm by specific comet assay and pulsed-field electrophoresis that cells adapted to high NaCl have increased levels of double-strand breaks. Importantly, γH2AX foci that occur during repair of the breaks are nonrandomly distributed in the mouse genome. By chromatin immunoprecipitation using anti-γH2AX antibody, followed by massive parallel sequencing (ChIP-Seq), we find that during repair of double-strand breaks induced by high NaCl, γH2AX is predominantly localized to regions of the genome devoid of genes (“gene deserts”), indicating that the high NaCl-induced double-strand breaks are located there. Localization to gene deserts helps explain why the DNA breaks are less harmful than are the random breaks induced by genotoxic agents such as UV radiation, ionizing radiation, and oxidants. We propose that the universal presence of NaCl around animal cells has directly influenced the evolution of the structure of their genomes. PMID:22106305

  10. Coexistence of Ferromagnetism and Superconductivity in Noncentrosymmetric Materials with Cubic Symmetry

    NASA Astrophysics Data System (ADS)

    Neupert, Titus; Sigrist, Manfred

    2011-11-01

    This is a model study for the emergence of superconductivity in ferromagnetically ordered phases of cubic materials whose crystal structure lacks inversion symmetry. A Ginzburg--Landau-type theory is used to find the ferromagnetic state and to determine the coupling of magnetic order to superconductivity. It is found that noncentrosymmetricity evokes a helical magnetic phase. If the wavelength of the magnetic order is long enough, it gives rise to modulations of the order parameter of superconductivity, both in modulus and complex phase. At magnetic domain walls the nucleation of superconductivity is found to be suppressed as compared to the interior of ferromagnetic domains.

  11. Structural, elastic, and electronic properties of new superhard isotropic cubic crystals of carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Enyashin, A. N.; Ivanovskii, A. L.

    2008-05-01

    The models of new isotropic cubic crystals of single-layered carbon nanotubes are proposed. The structural, elastic, and electronic properties and the energies of formation of these crystals were calculated using the density functional-based tight binding (DFTB) method. The crystals proposed were found to exhibit extreme compression moduli (550-650 GPa) and a minimum compressibility (0.0018-0.0015 GPa-1); in this case, the type of conduction of the parent nanotubes was retained. For this reason, the above crystals are of interest for the development of new superhard materials with controllable electrophysical properties.

  12. A new class of traveling solitons for cubic fractional nonlinear Schrödinger equations

    NASA Astrophysics Data System (ADS)

    Hong, Younghun; Sire, Yannick

    2017-04-01

    We consider the one-dimensional cubic fractional nonlinear Schrödinger equation i∂tu‑(‑Δ)σu + |u|2u=0, where σ \\in ≤ft(\\frac{1}{2},1\\right) and the operator {{(- Δ )}σ} is the fractional Laplacian of symbol |ξ {{|}2σ} . Despite the lack of any Galilean-type invariance, we construct a new class of traveling soliton solutions of the form u(t,x)=e‑it(|k|2σ‑ω2σ)Qω,k(x‑2tσ|k|2σ‑2k),k∈R, ω>0 by a rather involved variational argument.

  13. On the cubic zero-order solution of electromagnetic waves. I. Periodic slabs with lossy plasmas

    SciTech Connect

    Lee, Hyoung-In; Mok, Jinsik

    2010-07-15

    Electromagnetic waves are considered for periodic structures consisting of lossy plasmonic components and dielectric host media. For the plasmonic components, not only low-loss metals but also high-loss gas plasmas are taken into consideration. For small filling fractions of the plasmonic components, the intercell interactions are kept to a minimum. In this way, the zero-order solution to the dispersion relation is solved by focusing on its cubic nonlinearity in frequency. Analysis shows that there are two types of solutions: propagating waves and stationary states, depending on the magnitudes of the temporal attenuation rates. Depending on the relative strengths of the material loss of the plasmonic component and its filling fraction, several key critical parameters for the transitions between these two solution types are thus identified. In the following companion paper of Paper II, the cubic nonlinearities in frequency of the dispersion relations stem from different origins. Notwithstanding, they lead to strikingly similar features such as the transitions in wave types and Hopf bifurcations.

  14. Growth and antioxidant production of Spirulina in different NaCl concentrations.

    PubMed

    Liu, Chang; Li, Lu-Jia; Wu, Chun-Yuan; Guo, Kang-Ning; Li, Jian-Hong

    2016-07-01

    To evaluate the quantity of Spirulina cultured in seawater, salt-tolerant strains were screened out and their growth and antioxidant accumulation were studied in different salt concentrations Salt tolerance of five Spirulina strains were investigated with modified Zarrouk medium (with 200-800 mM NaCl). All strains grew well with 400 mM NaCl; their growth rates were almost same as in the control medium. Spirulina strains FACHB-843 (SP843) and FACHB-972 (SP972) had the highest salt tolerance their growth rates in 600 mM NaCl were nearly same as the control. Both strains produced more carotene, phycocyanin, polysaccharides, proline and betaine in 400-600 mM NaCl than the control. Salt stress also induced them to produce higher activities of superoxide dismutase and peroxidase. Total antioxidant capacities of SP843 and SP972 peaked at 600 and 400 mM NaCl, respectively. Spirulina strains cultured with seawater accumulate more bioactive substances and will have a higher nutritive value.

  15. Knockout of Ku86 accelerates cellular senescence induced by high NaCl.

    PubMed

    Dmitrieva, Natalia I; Chen, Hua Tang; Nussenzweig, André; Burg, Maurice B

    2009-02-01

    NaCl induces DNA breaks, thus leading to cellular senescence. Here we showed that Ku86 deficiency accelerated the high NaCl-induced cellular senescence. We find that 1) high NaCl induces rapid cellular senescence in Ku86 deficient(xrs5) cells, 2) Ku86 deficiency shortens lifespan of C. elegans in high NaCl, and 3) cellular senescence is greatly accelerated in renal inner medullas of Ku86 (-/-) mice. Further, although water balance is known to be compromised in old mice, this occurs at much earlier age in Ku86(-/-) mice. When subjected to mild water restriction, 3 month old Ku86(-/-), but not Ku86(+/+),mice rapidly become dehydrated as evidenced by decrease in body weight, increased production of antidiuretic hormone,increased urine osmolality and decreased urine volume. The deficiency in water balance does not occur in Ku86(+/+)mice until they are much older (14 months). We conclude that Ku86 deficiency accelerates high NaCl(-) induced cellular senescence,particularly in the renal medulla where NaCl normally is high.

  16. Role of osmosis in biliary NaCl secretion and bile formation.

    PubMed

    Mathisen, O; Schistad, O; Strand, M

    1985-10-01

    To challenge the osmotic hypothesis of biliary NaCl secretion and bile formation, experiments were performed in anaesthetized pigs. An increase in plasma osmolality of 7 +/- 1 mosm/kg H2O induced by intravenous sucrose infusion decreased NaCl secretion, NaHCO3 secretion, and bile flow by 36 +/- 3%, 34 +/- 2%, and 34 +/- 3%, respectively. There was no change in the biliary concentration of NaCl and NaHCO3. When bile acids were infused intravenously, the secretion of 1 mmol bile acids caused an osmotic flow of 12.0 ml bile containing 0.92 mmol NaCl and 0.30 mmol NaHCO3 in an isotonic solution. Bile acids are therefore much stronger choleretic substances than NaHCO3. When the plasma sodium concentration was increased to 200 mM, bile flow increased by 31 +/- 5% and the secretion of bile acids, NaHCO3, and NaCl was increased by 63 +/- 3%, 96 +/- 4%, and 93 +/- 4%, respectively. These data are consistent with osmotic transport as the main mode of bile formation, but diffusion could be responsible for a small fraction. A raised plasma sodium concentration stimulates osmotic formation of bile by increasing both the bile acid-dependent and -independent secretion through stimulation of biliary bile acid and NaHCO3 secretion.

  17. Influence of partial replacement of NaCl with KCl and CaCl(2) on texture and color of dry fermented sausages.

    PubMed

    Gimeno, O; Astiasarán, I; Bello, J

    1999-03-01

    A Spanish type of dry fermented sausage, Chorizo de Pamplona, was manufactured with a mixture of (2.29%) different salts (NaCl, KCl, and CaCl(2)) with an equivalent ionic strength to that of the control manufactured with 2.6% NaCl. The use of this salt mixture affected the texture profile analysis (TPA), giving rise to a significant reduction in hardness, cohesiveness, gumminess and chewiness. Instrumental color values showed higher b (yellowness) and L (lightness) values. Sensory texture and color intensity yielded lower scores, but they were classified as acceptable. Principal component analysis was carried out with the instrumental measures. The two principal components explained 76.9% of the variance. Modified and control samples were separated by the first component, which explained 57.1% of the variance and was defined basically by texture parameters.

  18. Triblock polyphiles through click chemistry: self-assembled thermotropic cubic phases formed by micellar and monolayer vesicular aggregates.

    PubMed

    Tan, Xiaoping; Kong, Leiyang; Dai, Heng; Cheng, Xiaohong; Liu, Feng; Tschierske, Carsten

    2013-11-25

    Three series of triblock polyphiles consisting of a rigid 4-phenyl-1,2,3-triazole or 1,4-diphenyl-1,2,3-triazole core with three lipophilic and flexible alkoxyl chains at one end and a polar glycerol group at the opposite end were synthesized by copper-catalyzed azide-alkyne click reactions. Their mesophase behavior was studied by polarizing optical microscopy, differential scanning calorimetry, and XRD. Depending on alkyl chain length and core length, a transition from hexagonal columnar to Pm3n-type cubic phases was observed. In the cubic phases, the molecules are organized as spherical objects. Remarkably, compounds with a longer core unit have a higher tendency to form these cubic phases, and their stability is strongly enhanced over those of the compounds with a shorter core, despite longer cores having a smaller cone angle and therefore being expected to disfavor the formation of spherical objects. There is a large difference in the number of molecules involved in the spherical aggregates formed by compounds with long and short cores. Whereas the aggregates in the cubic phases of the compounds with short rod units are small and could be regarded as micellar, the long-core compounds form much larger aggregates which are regarded as a kind of monolayer vesicular aggregate.

  19. CEMS study of corrosion products formed by NaCl aqueous solution

    NASA Astrophysics Data System (ADS)

    Nakanishi, A.

    2012-03-01

    Conversion electron Mössbauer spectroscopy was used to study corrosion products by NaCl aqueous solution. A drop of the solution is put on an iron foil and the foil is left at RT. During the evaporation of the solution, corrosion products are formed. Conversion electron Mössbauer spectra were taken at temperatures between 15 K and room temperature (RT). In the Mössbauer spectra a ferric doublet is observed at RT, but sextets are found at 15 K. These results show that the corrosion product mainly consists of γ - FeOOH and a small amount of β - FeOOH is noticed. As NaCl concentration increases, the corrosion layer becomes thick and β- FeOOH / γ - FeOOH ratio increases slightly. Consequently, it has been concluded that the produced amount of β- FeOOH increases more rapidly than that of γ - FeOOH with increasing NaCl concentration.

  20. Effect of NaCl Treatments on Tyramine Biosynthesis of Enterococcus faecalis.

    PubMed

    Liu, Fang; Wang, Xinxin; Du, Lihui; Wang, Daoying; Zhu, Yongzhi; Geng, Zhiming; Xu, Xiaoxi; Xu, Weimin

    2015-05-01

    The effect of NaCl stress (0 to 8%, wt/vol) on the growth and tyramine production in two Enterococcus faecalis strains was examined during culture time. The growth of E. faecalis was inhibited by the increase in NaCl concentration, but tyramine production was unaffected. Tyramine accumulated rapidly during the logarithmic phase of the strains, and the final tyramine levels were approximately 800 μg/ml. Relative gene expression of four genes in the tyrosine decarboxylase locus, namely, tyrRS, tyrDC, tyrP, and nhaC, was evaluated at different incubation times. The results showed that NaCl stress could upregulate the expression of tyrDC and tyrP to improve the tyramine production of a single E. faecalis strain under certain conditions, and TyrS could act as a negative regulator on the genetic regulation of the tyramine cluster.

  1. Neutralization of Hydroxide Ion in Melt-Grown NaCl Crystals

    NASA Technical Reports Server (NTRS)

    Otterson, Dumas A.

    1961-01-01

    Many recent studies of solid-state phenomena, particularly in the area of crystal imperfections, have involved the use of melt-grown NaCl single crystals. Quite often trace impurities in these materials have had a prominent effect on these phenomena. Trace amounts of hydroxide ion have been found in melt-grown NaCl crystals. This paper describes a nondestructive method of neutralizing the hydroxide ion in such crystals. Crystals of similar hydroxide content are maintained at an elevated temperature below the melting point of NaCl in a flowing atmosphere containing. dry hydrogen chloride. Heat treatment is continued until an analysis of the test specimens shows no excess hydroxide ion. A colorimetric method previously described4 is used for this analysis.

  2. Structural Stabilities of Ordered Arrays of Nb4 Clusters on NaCl(100) Surface

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Chun; Zhang, Jian-Hua; Wen, Yu-Hua; Zhu, Zi-Zhong

    2009-01-01

    Adsorption of ordered (2 × 2) arrays of Nb4 clusters on the insulating surface of NaCl(100) is studied by the first-principles calculations within the density functional theory. The calculations on the relaxed geometries and cohesive energies show that both the tetrahedron and quadrangle-Nb4 can be stably adsorbed on this substrate, which may have important applications. The adsorption of quadrangle-Nb4 on the NaCl(100) surface is more stable than that of tetrahedron-Nb4. Both the Nb4 clusters studied and a single Nb atom prefer the top site of the Cl atom in the NaCl(100) surface. Electronic structure analysis suggests that the interactions between the Nb4 clusters and the substrate are weak.

  3. A possible NaCl pathway in the bioregenerative human life support system

    NASA Astrophysics Data System (ADS)

    Polonskiy, V. I.; Gribovskaya, I. V.

    One of the ways to involve NaCl in the mass exchange of the bioregenerative human life support system (BLSS) is to grow some vegetables and leafy greens that can accumulate sodium chloride at high concentrations in their edible biomass. Lettuce, celery cabbage, chard, dill and radish plants were grown hydroponically in Knop's nutrient solution. In the first series of experiments, at the end of the growth period the plants were grown on solutions containing 2-14 g/L of NaCl for 1-5 days. It was found that the amount of sodium in edible biomass of the plants increased with NaCl concentration in the solution and with the time plants were irrigated with that solution. The content of NaCl in the biomass of leaves and edible roots was considerable—up to 10% dry matter. At the same time, the amount of water in the leaves decreased and productivity of the treatment plants was 14-28% lower than that of the control ones, grown on Knop's solution. The treatment plants contained less than half of the amount of nitrates recorded in the control ones. Expert evaluation showed that the taste of the vegetables and leafy greens of the treatment group were not inferior to the taste of the control plants. In the second series of experiments, prior to being grown on the NaCl solution, the plants were irrigated with water for 2, 4 or 6 days. It was found that lower salt status of the plants was not favorable for increased salt accumulation in their biomass. If a human consumes 30 g salad vegetables and follows a low-sodium diet (3 g/d of table salt), it may be feasible to recycle NaCl in the BLSS using vegetables and leafy greens.

  4. Some aspects of salinity responses in peppermint (Mentha × piperita L.) to NaCl treatment.

    PubMed

    Li, Zhe; Yang, Hetong; Wu, Xiaoqing; Guo, Kai; Li, Jishun

    2015-05-01

    Salinity is a major stress that adversely affects plant growth and crop production. Understanding the cellular responses and molecular mechanisms by which plants perceive and adopt salinity stress is of fundamental importance. In this work, some of the cellular signaling events including cell death, reactive oxygen species (ROS) generation, and the behaviors of organelles were analyzed in a salt-tolerant species (Keyuan-1) of peppermint (Mentha × piperita L.) under NaCl treatment. Our results showed that 200 mM NaCl treatment elicited a distinct progress of cell death with chromatin condensation and caspase-3-like activation and a dramatic burst of ROS which was required for the execution of cell death. The major ROS accumulation occurred in the mitochondria and chloroplasts, which were the sources of ROS production under NaCl stress. Moreover, mitochondrial activity and photosynthetic capacity also exhibited the obvious decrease in the ROS-dependent manner under 200 mM NaCl stress. Furthermore, the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) as well as the contents of ascorbate and glutathione changed in the concentration-dependent manner under NaCl stress. Altogether, our data showed the execution of programmed cell death (PCD), the ROS dynamics, and the behaviors of organelles especially mitochondria and chloroplasts in the cellular responses of peppermint to NaCl stress which can be used for the tolerance screening, and contributed to the understanding of the cellular responses and molecular mechanisms of peppermint to salinity stress, providing the theoretic basis for the further development and utilization of peppermint in saline areas.

  5. Regulation of Na-Cl absorption in rabbit proximal colon in vitro

    SciTech Connect

    Sellin, J.H.; De Siognie, R.

    1987-01-01

    Ion transport in rabbit proximal colon (PC) in vitro is dominated by a Na-Cl cotransport system stimulated by epinephrine. To further characterize the regulation of Na-Cl transport, the authors tested the effects of specific adrenergic agonists on ion fluxes under short-circuit conditions. Additionally, they tested the effects of the transport inhibitors bumetanide, furosemide, and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS). Basal Na and Cl absorption were essentially nil. The ..cap alpha../sub 2/-agonist clonidine significantly increased net Na and Cl absorption. The ..cap alpha../sub 1/-agonist phenylephrine and the ..beta..-agonist isoproterenol did not alter ion transport. The ..cap alpha../sub 2/-blocker yohimbine (YOH) had a complex, concentration-dependent effect. Propranolol (10/sup -5/ M) and pracozin (10/sup -6/ M) did not significantly alter either basal or stimulated ion transport. Neither bumetanide (10/sup -6/ or 10/sup -4/ M) nor furosemide (10/sup -4/ M) blocked epinephrine-stimulated Na absorption. SITS (10/sup -4/ M) and removal of mucosal K did not have a significant effect on ion transport. Conclusions: 1) Na-Cl cotransport in rabbit PC is primarily under ..cap alpha../sub 2/-adrenergic control, 2) YOH at high concentrations acts as an agonist in PC, 3) ..cap alpha../sub 2/-adrenergic agonists stimulate Na-Cl absorption in both rabbit ileum and PC. In PC, however, the process is electrically quiet and therefore does not appear to be associated with electrogenic HCO/sub 3/ secretion as found in ileum, 4) the lack of effect of bumetanide, furosemide, and 0 K on Na transport suggests that a single Na-Cl (or Na-K-2Cl) carrier is not involved in Na-Cl cotransport in proximal colon.

  6. Proteins Associated with Adaptation of Cultured Tobacco Cells to NaCl 1

    PubMed Central

    Singh, Narendra K.; Handa, Avtar K.; Hasegawa, Paul M.; Bressan, Ray A.

    1985-01-01

    Cultured tobacco cells (Nicotiana tabacum L. cv Wisconsin 38) adapted to grow in medium containing high levels of NaCl or polyethylene glycol (PEG) produce several new or enhanced polypeptide bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The intensities of some of the polypeptide bands (molecular weights of 58, 37, 35.5, 34, 26, 21, 19.5, and 18 kilodaltons) increase with increasing levels of NaCl adaptation, while the intensities of other polypeptide bands (54, 52, 17.5, and 16.5 kilodaltons) are reduced. Enhanced levels of 43- and 26-kilodalton polypeptides are present in both NaCl and PEG-induced water stress adapted cells but are not detectable in unadapted cells. In addition, PEG adapted cells have enhanced levels of 29-, 17.5-, 16.5-, and 11-kilodalton polypeptides and reduced levels of 58-, 54-, 52-, 37-, 35.5-, 34-, 21-, 19.5-, and 18-kilodalton polypeptide bands. Synthesis of 26-kilodalton polypeptide(s) occurs at two different periods during culture growth of NaCl adapted cells. Unadapted cells also incorporate 35S into a 26-kilodalton polypeptide during the later stage of culture growth beginning at midlog phase. The 26-kilodalton polypeptides from adapted and unadapted cells have similar partial proteolysis peptide maps and are immunologically cross-reactive. During adaptation to NaCl, unadapted cells synthesize and accumulate a major 26-kilodalton polypeptide, and the beginning of synthesis corresponds to the period of osmotic adjustment and culture growth. From our results, we suggest an involvement of the 26-kilodalton polypeptide in the adaptation of cultured tobacco cells to NaCl and water stress. Images Fig. 1 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 PMID:16664357

  7. Equilibrium, Kinetics, and Spectroscopic Studies of SF6 Hydrate in NaCl Electrolyte Solution.

    PubMed

    Seo, Youngrok; Moon, Donghyun; Lee, Changho; Park, Jeong-Woo; Kim, Byeong-Soo; Lee, Gang-Woo; Dotel, Pratik; Lee, Jong-Won; Cha, Minjun; Yoon, Ji-Ho

    2015-05-19

    Many studies have focused on desalination via hydrate formation; however, for their potential application, knowledge pertaining to thermodynamic stability, formation kinetics, and guest occupation behavior in clathrate hydrates needs to be determined. Herein, the phase equilibria of SF6 hydrates in the presence of NaCl solutions (0, 2, 4, and 10 wt %) were monitored in the temperature range of 277-286 K and under pressures of up to 1.4 MPa. The formation kinetics of SF6 hydrates in the presence of NaCl solutions (0, 2, and 4 wt %) was also investigated. Gas consumption curves of SF6 hydrates showed that a pure SF6 hydrate system allowed fast hydrate growth as well as high conversion yield, whereas SF6 hydrate in the presence of NaCl solutions showed retarded hydrate growth rate as well as low conversion yield. In addition, structural identification of SF6 hydrates with and without NaCl solutions was performed using spectroscopic tools such as Raman spectroscopy and X-ray diffraction. The Raman spectrometer was also used to evaluate the temperature-dependent release behavior of guest molecules in SF6 and SF6 + 4 wt % NaCl hydrates. The results indicate that whereas SF6 hydrate starts to decompose at around 240 K, the escape of SF6 molecules in SF6 + 4 wt % NaCl hydrate is initiated rapidly at around 205 K. The results of this study can provide a better understanding of guest-host interaction in electrolyte-containing systems.

  8. Exploring the intricate regulatory network controlling the thiazide-sensitive NaCl cotransporter (NCC).

    PubMed

    Dimke, Henrik

    2011-12-01

    The thiazide-sensitive NaCl cotransporter (NCC) plays key roles in renal electrolyte transport and blood pressure maintenance. Regulation of this cotransporter has received increased attention recently, prompted by the discovery that mutations in the with-no-lysine (WNK) kinases are the molecular explanation for pseudohypoaldosteronism type II (PHAII). Studies suggest that WNK4 regulates NCC via two distinct pathways, depending on its state of activation. Furthermore, an intact STE20-related proline-alanine-rich kinase (SPAK)/oxidative stress response 1 kinase (OSR1) pathway was found to be necessary for a WNK4 PHAII mutation to increase NCC phosphorylation and blood pressure in mice. The mouse protein 25α is a novel regulator of the SPAK/OSR1 kinase family, which greatly increases their activity. The phosphorylation status of NCC and the WNK is regulated by the serum- and glucocorticoid-inducible kinase 1, suggesting novel mechanisms whereby aldosterone modulates NCC activity. Dephosphorylation of NCC by protein phosphatase 4 strongly influences the activity of the cotransporter, confirming an important role for NCC phosphorylation. Finally, γ-adducin increases NCC activity. This stimulatory effect is dependent on the phosphorylation status of the cotransporter. γ-Adducin only binds the dephosphorylated cotransporter, suggesting that phosphorylation of NCC causes the dissociation of γ-adducin. Since γ-adducin is not a kinase, it is tempting to speculate that the protein exerts its function by acting as a scaffold between the dephosphorylated cotransporter and the regulatory kinase. As more molecular regulators of NCC are identified, the system-controlling NCC activity is becoming increasingly complex. This intricacy confers an ability to integrate a variety of stimuli, thereby regulating NCC transport activity and ultimately blood pressure.

  9. Alpha decay self-damage in cubic and monoclinic zirconolite

    SciTech Connect

    Clinard, F.W. Jr.; Land, C.C.; Peterson, D.E.; Rohr, D.L.; Roof, R.B.

    1981-01-01

    Samples of primarily-monoclinic /sup 238/Pu-doped zirconolite were stored at ambient temperature to allow accumulation of alpha decay self-damage to a dose of 1 x 10/sup 24/ ..cap alpha../m/sup 3/ (equivalent to a SYNROC age of approx. 10/sup 3/y). Bulk swelling reached 2.3 vol% with no tendency toward saturation, a damage response similar to that observed for cubic Pu-doped zirconolite. X-ray volumetric swelling at 4 x 10/sup 24/ ..cap alpha../m/sup 3/ was 1 vol%, considerably less than that for the cubic material. Changes in cell dimensions differed significantly from those reported by others for a monoclinic natural mineral. Extensive microcracking was observed, and is attributed at least partially to swelling differences between the matrix and minor phases.

  10. Cubic ideal ferromagnets at low temperature and weak magnetic field

    NASA Astrophysics Data System (ADS)

    Hofmann, Christoph P.

    2017-04-01

    The low-temperature series for the free energy density, pressure, magnetization and susceptibility of cubic ideal ferromagnets in weak external magnetic fields are discussed within the effective Lagrangian framework up to three loops. The structure of the simple, body-centered, and face-centered cubic lattice is taken into account explicitly. The expansion involves integer and half-integer powers of the temperature. The corresponding coefficients depend on the magnetic field and on low-energy effective constants that can be expressed in terms of microscopic quantities. Our formulas may also serve as efficiency or consistency check for other techniques like Green's function methods, where spurious terms in the low-temperature expansion have appeared. We explore the sign and magnitude of the spin-wave interaction in the pressure, magnetization and susceptibility, and emphasize that our effective field theory approach is fully systematic and rigorous.

  11. Reversible Nanoparticle Cubic Lattices in Blue Phase Liquid Crystals.

    PubMed

    Gharbi, Mohamed Amine; Manet, Sabine; Lhermitte, Julien; Brown, Sarah; Milette, Jonathan; Toader, Violeta; Sutton, Mark; Reven, Linda

    2016-03-22

    Blue phases (BPs), a distinct class of liquid crystals (LCs) with 3D periodic ordering of double twist cylinders involving orthogonal helical director twists, have been theoretically studied as potential templates for tunable colloidal crystals. Here, we report the spontaneous formation of thermally reversible, cubic crystal nanoparticle (NP) assemblies in BPs. Gold NPs, functionalized to be highly miscible in cyanobiphenyl-based LCs, were dispersed in BP mixtures and characterized by polarized optical microscopy and synchrotron small-angle X-ray scattering (SAXS). The NPs assemble by selectively migrating to periodic strong trapping sites in the BP disclination lines. The NP lattice, remarkably robust given the small particle size (4.5 nm diameter), is commensurate with that of the BP matrix. At the BP I to BP II phase transition, the NP lattice reversibly switches between two different cubic structures. The simultaneous presence of two different symmetries in a single material presents an interesting opportunity to develop novel dynamic optical materials.

  12. Conformal cubical 3D transformation-based metamaterial invisibility cloak.

    PubMed

    Savić, Slobodan V; Notaroš, Branislav M; Ilić, Milan M

    2013-01-01

    A conformal cubical transformation-based metamaterial invisibility cloak is presented and verified, in the near and the far field, by a rigorous full-wave numerical technique based on a higher-order, large-domain finite element method, employing large anisotropic, continuously inhomogeneous generalized hexahedral finite elements, with no need for discretization of the permittivity and permeability profiles of the cloak. The analysis requires about 30 times fewer unknowns than with commercial software. To our knowledge, this is the first conformal cubical cloak and the first full-wave computational characterization of such a structure with sharp edges. The presented methodology can also be used in development of conformal, transformation-based perfectly matched layers.

  13. Hermite cubic spline multi-wavelets on the cube

    NASA Astrophysics Data System (ADS)

    Cvejnová, Daniela; Černá, Dana; Finěk, Václav

    2015-11-01

    In 2000, W. Dahmen et al. proposed a construction of Hermite cubic spline multi-wavelets adapted to the interval [0, 1]. Later, several more simple constructions of wavelet bases based on Hermite cubic splines were proposed. We focus here on wavelet basis with respect to which both the mass and stiffness matrices are sparse in the sense that the number of non-zero elements in each column is bounded by a constant. Then, a matrix-vector multiplication in adaptive wavelet methods can be performed exactly with linear complexity for any second order differential equation with constant coefficients. In this contribution, we shortly review these constructions, use an anisotropic tensor product to obtain bases on the cube [0, 1]3, and compare their condition numbers.

  14. Extreme values of the Poisson's ratio of cubic crystals

    NASA Astrophysics Data System (ADS)

    Epishin, A. I.; Lisovenko, D. S.

    2016-10-01

    The problem of determining the extrema of Poisson's ratio for cubic crystals is considered, and analytical expressions are derived to calculate its extreme values. It follows from the obtained solution that, apart from extreme values at standard orientations, extreme values of Poisson's ratio can also be detected at special orientations deviated from the standard ones. The derived analytical expressions are used to calculate the extreme values of Poisson's ratio for a large number of known cubic crystals. The extremely high values of Poisson's ratio are shown to be characteristic of metastable crystals, such as crystals with the shape memory effect caused by martensitic transformation. These crystals are mainly represented by metallic alloys. For some crystals, the absolute extrema of Poisson's ratio can exceed the standard values, which are-1 for a standard minimum and +2 for a standard maximum.

  15. Nonlinear optical imaging of defects in cubic silicon carbide epilayers.

    PubMed

    Hristu, Radu; Stanciu, Stefan G; Tranca, Denis E; Matei, Alecs; Stanciu, George A

    2014-06-11

    Silicon carbide is one of the most promising materials for power electronic devices capable of operating at extreme conditions. The widespread application of silicon carbide power devices is however limited by the presence of structural defects in silicon carbide epilayers. Our experiment demonstrates that optical second harmonic generation imaging represents a viable solution for characterizing structural defects such as stacking faults, dislocations and double positioning boundaries in cubic silicon carbide layers. X-ray diffraction and optical second harmonic rotational anisotropy were used to confirm the growth of the cubic polytype, atomic force microscopy was used to support the identification of silicon carbide defects based on their distinct shape, while second harmonic generation microscopy revealed the detailed structure of the defects. Our results show that this fast and noninvasive investigation method can identify defects which appear during the crystal growth and can be used to certify areas within the silicon carbide epilayer that have optimal quality.

  16. Data reduction using cubic rational B-splines

    NASA Technical Reports Server (NTRS)

    Chou, Jin J.; Piegl, Les A.

    1992-01-01

    A geometric method is proposed for fitting rational cubic B-spline curves to data that represent smooth curves including intersection or silhouette lines. The algorithm is based on the convex hull and the variation diminishing properties of Bezier/B-spline curves. The algorithm has the following structure: it tries to fit one Bezier segment to the entire data set and if it is impossible it subdivides the data set and reconsiders the subset. After accepting the subset the algorithm tries to find the longest run of points within a tolerance and then approximates this set with a Bezier cubic segment. The algorithm uses this procedure repeatedly to the rest of the data points until all points are fitted. It is concluded that the algorithm delivers fitting curves which approximate the data with high accuracy even in cases with large tolerances.

  17. Circular dichroism in biological photonic crystals and cubic chiral nets.

    PubMed

    Saba, M; Thiel, M; Turner, M D; Hyde, S T; Gu, M; Grosse-Brauckmann, K; Neshev, D N; Mecke, K; Schröder-Turk, G E

    2011-03-11

    Nature provides impressive examples of chiral photonic crystals, with the notable example of the cubic so-called srs network (the label for the chiral degree-three network modeled on SrSi2) or gyroid structure realized in wing scales of several butterfly species. By a circular polarization analysis of the band structure of such networks, we demonstrate strong circular dichroism effects: The butterfly srs microstructure, of cubic I4(1)32 symmetry, shows significant circular dichroism for blue to ultraviolet light, that warrants a search for biological receptors sensitive to circular polarization. A derived synthetic structure based on four like-handed silicon srs nets exhibits a large circular polarization stop band of a width exceeding 30%. These findings offer design principles for chiral photonic devices.

  18. Negative thermal expansion materials related to cubic zirconium tungstate

    NASA Astrophysics Data System (ADS)

    Lind, Cora

    2001-12-01

    A non-hydrolytic sol-gel method for the preparation of ZrW2O 8 was developed. A new trigonal polymorph was discovered, which is structurally related to trigonal ZrMO2O8 and MnRe2O 8 as evidenced by powder x-ray diffraction and EXAFS studies. Seeding of the starting mixtures with cubic ZrW2O8 promoted crystallization of the cubic phase instead of trigonal material. Dehydration of ZrW2O7(OH)2·2H 2O gave cubic ZrW2O8 at 650°C, and a modification of this route led to the discovery of the new NTE materials cubic ZrMo 2O8 and HfMo2O8. These compounds crystallize in the same temperature range as the more stable trigonal AMo2O 8 polymorphs. To facilitate preparation of phase pure cubic molybdates, the influence of precursor chemistry on the crystallization behavior was investigated. The synthesis was extended to the solid solution system ZrxHf 1-xMoyW2-yO8 (0 ≤ x ≤ 1, 0 ≤ y ≤ 2). All compounds showed negative thermal expansion between 77 and 573 K. High-pressure in situ diffraction experiments were conducted on several AM2O8 polymorphs. With the exception of monoclinic ZrMo2O8, all materials underwent at least one pressure induced phase transition. Quasi-hydrostatic experiments on cubic AMo 2O8 led to a reversible transition to a new high-pressure structure, while low-pressure amorphization was observed under non-hydrostatic conditions. Isothermal kinetic studies of the cubic to trigonal transformation for ZrMo2O8 were carried out on four samples. Apparent activation energies of 170--290 kJ/mol were obtained using an Avrami model in combination with an Arrhenius analysis. This corresponds to 5% conversion levels after one year at temperatures between 220 and 315°C. Ex situ studies showed that the conversion at lower temperatures was considerably slower than what would be expected from extrapolation of the kinetic data. Drop solution calorimetry was carried out on several polymorphs of ZrMo 2O8, HfMo2O8 and ZrW2O 8. Only monoclinic ZrMo2O8 was enthalpically

  19. Highly Aminated Mesoporous Silica Nanoparticles with Cubic Pore Structure

    PubMed Central

    Suteewong, Teeraporn; Sai, Hiroaki; Cohen, Roy; Wang, Suntao; Bradbury, Michelle; Baird, Barbara; Gruner, Sol M.; Wiesner, Ulrich

    2010-01-01

    Mesoporous silica with cubic symmetry has attracted interest from researchers for some times. Here we present the room temperature synthesis of mesoporous silica nanoparticles possessing cubic Pm3̄n symmetry with very high molar ratios (>50%) of 3-aminopropyl triethoxysilane. The synthesis is robust allowing, e.g. for co-condensation of organic dyes without loss of structure. By means of pore expander molecules, the pore size can be enlarged from 2.7 to 5 nm, while particle size decreases. Adding pore expander and co-condensing fluorescent dyes in the same synthesis reduces average particle size further down to 100 nm. After PEGylation, such fluorescent aminated mesoporous silica nanoparticles are spontaneously uptaken by cells as demonstrated by fluorescence microscopy. PMID:21158438

  20. The Piecewise Cubic Method (PCM) for computational fluid dynamics

    NASA Astrophysics Data System (ADS)

    Lee, Dongwook; Faller, Hugues; Reyes, Adam

    2017-07-01

    We present a new high-order finite volume reconstruction method for hyperbolic conservation laws. The method is based on a piecewise cubic polynomial which provides its solutions a fifth-order accuracy in space. The spatially reconstructed solutions are evolved in time with a fourth-order accuracy by tracing the characteristics of the cubic polynomials. As a result, our temporal update scheme provides a significantly simpler and computationally more efficient approach in achieving fourth order accuracy in time, relative to the comparable fourth-order Runge-Kutta method. We demonstrate that the solutions of PCM converges at fifth-order in solving 1D smooth flows described by hyperbolic conservation laws. We test the new scheme on a range of numerical experiments, including both gas dynamics and magnetohydrodynamics applications in multiple spatial dimensions.

  1. Data reduction using cubic rational B-splines

    NASA Technical Reports Server (NTRS)

    Chou, Jin J.; Piegl, Les A.

    1992-01-01

    A geometric method is proposed for fitting rational cubic B-spline curves to data that represent smooth curves including intersection or silhouette lines. The algorithm is based on the convex hull and the variation diminishing properties of Bezier/B-spline curves. The algorithm has the following structure: it tries to fit one Bezier segment to the entire data set and if it is impossible it subdivides the data set and reconsiders the subset. After accepting the subset the algorithm tries to find the longest run of points within a tolerance and then approximates this set with a Bezier cubic segment. The algorithm uses this procedure repeatedly to the rest of the data points until all points are fitted. It is concluded that the algorithm delivers fitting curves which approximate the data with high accuracy even in cases with large tolerances.

  2. Novel approaches to the parametric cubic-spline interpolation.

    PubMed

    Hong, Shao-Hua; Wang, Lin; Truong, Trieu-Kien; Lin, Tsung-Ching; Wang, Lung-Jen

    2013-03-01

    The cubic-spline interpolation (CSI) scheme can be utilized to obtain a better quality reconstructed image. It is based on the least-squares method with cubic convolution interpolation (CCI) function. Within the parametric CSI scheme, it is difficult to determine the optimal parameter for various target images. In this paper, a novel method involving the concept of opportunity costs is proposed to identify the most suitable parameter for the CCI function needed in the CSI scheme. It is shown that such an optimal four-point CCI function in conjunction with the least-squares method can achieve a better performance with the same arithmetic operations in comparison with the existing CSI algorithm. In addition, experimental results show that the optimal six-point CSI scheme together with cross-zonal filter is superior in performance to the optimal four-point CSI scheme without increasing the computational complexity.

  3. A facile synthesis of cubic (Im3m) alumina films on glass with potential catalytic activity.

    PubMed

    Mitra, Anuradha; Jana, Debrina; De, Goutam

    2012-04-04

    Thermally stable phase pure mesoporous cubic (Im3m) alumina films were synthesized on glass substrates under ambient conditions. These cubic alumina films incorporated with Au NPs exhibited excellent catalytic property.

  4. Predicted cubic-foot yields of sawmill products for black cherry trees

    Treesearch

    Leland F. Hanks

    1980-01-01

    Equations and tables for estimating the cubic-foot volumes of lumber, sawdust, and sawmill residue for black cherry trees are presented. Also included are cubic-foot and board-foot predictions for the sawlog portion of the trees.

  5. Reactions of chromium with gaseous NaCl in an oxygen environment

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Kohl, F. J.; Fryburg, G. C.

    1976-01-01

    Target collection techniques and high pressure mass spectrometric sampling have been used to study the formation of volatile chromium-containing species in the reaction of Cr2O3 with O2 and NaCl gases. Experiments were performed at atmospheric pressure as a function of chromium temperature, oxygen pressure, and NaCl gas concentration. The major chromium-containing vapor species were found to be (NaCl)x CrO3 gas, with x = 1,2, and 3, which are products of heterogeneous reactions on the surface. The kinetics indicate first order dependence on oxygen and sodium chloride pressures.

  6. Effect of NaCl on the accumulation of glycerol by three Aspergillus species.

    PubMed

    Zidan, M A; Abdel-Mallek, A Y

    1987-01-01

    The accumulation of glycerol was investigated in three Aspergillus species, A. niger, A. ochraceus and A. tamarii after being grown in media containing different NaCl concentrations. Intra-extracellular as well as total glycerol were markedly accumulated by the three organisms in response to increased salinity. However, at salinity levels of 10-14% NaCl, extracellular glycerol was somewhat lowered. In addition, it was found that the maximum accumulation of glycerol in A. niger and A. tamarii was reached within the first 10 hours after salinization. However, after desalinization, the extracellular glycerol was continuously increased within the first 6 hours at the expense of intracellular glycerol.

  7. Reactions of NaCl with gaseous SO3, SO2, and O2

    NASA Technical Reports Server (NTRS)

    Fielder, W. L.; Stearns, C. A.; Kohl, F. J.

    1984-01-01

    Hot corrosion of gas turbine engine components involves deposits of Na2SO4 which are produced by reactions between NaCl and oxides of sulfur. For the present investigation, NaCl single crystals were exposed at 100 to 850 C to gaseous mixtures of SO3, SO2, and O2. The products formed during this exposure depend, primarily, on the temperatures. The four product films were: NaCl-SO3; Na2S2O7; Na2SO4; and NaCl-Na2SO4. The kinetics of the reactions were measured.

  8. Mechanical behavior of nanocrystalline NaCl islands on Cu(111).

    PubMed

    Bombis, Ch; Ample, F; Mielke, J; Mannsberger, M; Villagómez, C J; Roth, Ch; Joachim, C; Grill, L

    2010-05-07

    The mechanical response of ultrathin NaCl crystallites of nanometer dimensions upon manipulation with the tip of a scanning tunneling microscope (STM) is investigated, expanding STM manipulation to various nanostructuring modes of inorganic materials as cutting, moving, and cracking. In the light of theoretical calculations, our results reveal that atomic-scale NaCl islands can behave elastically and follow a classical Hooke's law. When the elastic limit of the nanocrystallites is reached, the STM tip induces atomic dislocations and consequently the regime of plastic deformation is entered. Our methodology is paving the way to understand the mechanical behavior and properties of other nanoscale materials.

  9. Multiscale Modeling of Point and Line Defects in Cubic Lattices

    DTIC Science & Technology

    2007-01-01

    and discli- nations with finite micropolar elastoplasticity . Int. J. Plasticity. 22:210–256, 2006. 56. Menzel, A., and Steinmann, P., On the contin...Voyiadjis, G. Z., A finite strain plastic- damage model for high velocity impact using combined viscosity and gradient localization limiters: Part I...Theoretical for- mulation. Int. J. Damage Mech. 15:293–334, 2006. 58. Milstein, F., and Chantasiriwan, S,. Theoretical study of the response of 12 cubic

  10. Radiating dipoles in woodpile and simple cubic structures

    NASA Astrophysics Data System (ADS)

    Enoch, Stefan; Tayeb, Gerard; Gralak, Boris

    2002-04-01

    The emission of a dipole in a finite-thickness photonic band gap structure is investigated. The dipole is located at a large value of the local density of states and its wavelength is taken at the edge of a full band gap. The resulting emission is highly enhanced and is confined in a small angular region. This is confirmed numerically for two different structures designed from two different tree-dimensional crystal: the woodpile and the simple cubic photonic crystals.

  11. Distribution coefficients of rare earth ions in cubic zirconium dioxide

    NASA Astrophysics Data System (ADS)

    Romer, H.; Luther, K.-D.; Assmus, W.

    1994-08-01

    Cubic zirconium dioxide crystals are grown with the skull melting technique. The effective distribution coefficients for Nd(exp 3+), Sm(exp 3+) and Er(sup 3+) as dopants are determined experimentally as a function of the crystal growth velocity. With the Burton-Prim-Slichter theory, the equilibrium distribution coefficients can be calculated. The distribution coefficients of all other trivalent rare earth ions can be estimated by applying the correlation towards the ionic radii.

  12. Photon-pair generation in arrays of cubic nonlinear waveguides.

    PubMed

    Solntsev, Alexander S; Sukhorukov, Andrey A; Neshev, Dragomir N; Kivshar, Yuri S

    2012-11-19

    We study photon-pair generation in arrays of cubic nonlinear waveguides through spontaneous four-wave mixing. We analyze numerically the quantum statistics of photon pairs at the array output as a function of waveguide dispersion and pump beam power. We show flexible spatial quantum state control such as pump-power-controlled transition between bunching and anti-bunching correlations due to nonlinear self-focusing.

  13. The Number of Real Roots of a Cubic Equation

    ERIC Educational Resources Information Center

    Kavinoky, Richard; Thoo, John B.

    2008-01-01

    To find the number of distinct real roots of the cubic equation (1) x[caret]3 + bx[caret]2 + cx + d = 0, we could attempt to solve the equation. Fortunately, it is easy to tell the number of distinct real roots of (1) without having to solve the equation. The key is the discriminant. The discriminant of (1) appears in Cardan's (or Cardano's) cubic…

  14. Quadratic and Cubic Nonlinear Oscillators with Damping and Their Applications

    NASA Astrophysics Data System (ADS)

    Li, Jibin; Feng, Zhaosheng

    We apply the qualitative theory of dynamical systems to study exact solutions and the dynamics of quadratic and cubic nonlinear oscillators with damping. Under certain parametric conditions, we also consider the van der Waals normal form, Chaffee-Infante equation, compound Burgers-KdV equation and Burgers-KdV equation for explicit representations of kink-profile wave solutions and unbounded traveling wave solutions.

  15. Why GPCRs behave differently in cubic and lamellar lipidic mesophases

    PubMed Central

    2012-01-01

    Recent successes in the crystallographic determination of structures of transmembrane proteins in the G protein-coupled receptor (GPCR) family have established the lipidic cubic phase (LCP) environment as the medium of choice for growing structure-grade crystals by the method termed “in meso”. The understanding of in meso crystallogenesis is currently at a descriptive level. To enable an eventual quantitative, energy-based description of the nucleation and crystallization mechanism, we have examined the properties of the lipidic cubic phase system and the dynamics of the GPCR rhodopsin reconstituted into the LCP with coarse-grained molecular dynamics simulations with the Martini force-field. Quantifying the differences in the hydrophobic/hydrophilic exposure of the GPCR to lipids in the cubic and lamellar phases, we found that the highly curved geometry of the cubic phase provides more efficient shielding of the protein from unfavorable hydrophobic exposure, which leads to a lesser hydrophobic mismatch and less unfavorable hydrophobic–hydrophilic interactions between the protein and lipid–water interface in the LCP, compared to the lamellar phase. Since hydrophobic mismatch is considered a driving force for oligomerization, the differences in exposure mismatch energies between the LCP and the lamellar structures suggest that the latter provide a more favorable setting in which GPCRs can oligomerize as a prelude to nucleation and crystal growth. These new findings lay the foundation for future investigations of in meso crystallization mechanisms related to the transition from the LCP to the lamellar phase and studies aimed at an improved rational approach for generating structure-quality crystals of membrane proteins. PMID:22931253

  16. Cubic lattice nanosheets: thickness-driven light emission.

    PubMed

    Golberg, Dmitri; Zhang, Chao; Xu, Zhi

    2014-07-22

    Silicon has a diamond-like cubic crystal lattice for which two-dimensional (2D) nanometer thickness nanosheet crystallization appears not to be trivial. However, in this issue of ACS Nano, the group led by Heon-Jin Choi demonstrates the gas-phase dendritic growth of Si nanosheets, only 1 to 13 nm thick. Moreover, such nanosheets display strong thickness-dependent photoluminescence in a visible range with red, green, and blue emission each documented.

  17. A resurgence analysis for cubic and quartic anharmonic potentials

    NASA Astrophysics Data System (ADS)

    Gahramanov, Ilmar; Tezgin, Kemal

    2017-02-01

    In this work, we explicitly show resurgence relations between perturbative and one instanton sectors of the resonance energy levels for cubic and quartic anharmonic potentials in one-dimensional quantum mechanics. Both systems satisfy the Dunne-Ünsal relation and hence we are able to derive one-instanton nonperturbative contributions with the fluctuation terms to the energy merely from the perturbative data. We confirm our results with previous results obtained in the literature.

  18. Nanoparticle Phosphors Manufactured Using the Bicontinuous Cubic Phase Process

    DTIC Science & Technology

    1997-11-18

    be lipids. Some typical surfactants userul in forming bicontinuous cubic phases include sodium diethyl hexylsulphosuccinate (AOT). potassium...CaS, SrS, Zn.Cd.-.S, Y,0:, Y202S, Zn2Si04, Y3A15012, Y3(AlGa)5012, Y2Si05, LaOCl, InB03, Gd202S, ZnGa204, yttrium niobate , TAG and YAGAG. 4 Some

  19. Image data compression using cubic convolution spline interpolation.

    PubMed

    Truong, T K; Wang, L J; Reed, I S; Hsieh, W S

    2000-01-01

    A new cubic convolution spline interpolation (CCSI )for both one-dimensional (1-D) and two-dimensional (2-D) signals is developed in order to subsample signal and image compression data. The CCSI yields a very accurate algorithm for smoothing. It is also shown that this new and fast smoothing filter for CCSI can be used with the JPEG standard to design an improved JPEG encoder-decoder for a high compression ratio.

  20. Higher-order numerical solutions using cubic splines

    NASA Technical Reports Server (NTRS)

    Rubin, S. G.; Khosla, P. K.

    1976-01-01

    A cubic spline collocation procedure was developed for the numerical solution of partial differential equations. This spline procedure is reformulated so that the accuracy of the second-derivative approximation is improved and parallels that previously obtained for lower derivative terms. The final result is a numerical procedure having overall third-order accuracy of a nonuniform mesh. Solutions using both spline procedures, as well as three-point finite difference methods, are presented for several model problems.

  1. Topological Expansion in the Complex Cubic Log-Gas Model: One-Cut Case

    NASA Astrophysics Data System (ADS)

    Bleher, Pavel; Deaño, Alfredo; Yattselev, Maxim

    2017-02-01

    We prove the topological expansion for the cubic log-gas partition function Z_N(t)= int _Γ \\cdots int _Γ prod _{1≤jcubic log-gas model exhibits two phase regions on the complex t-plane, with one cut and two cuts, separated by analytic critical arcs of the two types of phase transition: split of a cut and birth of a cut. The common point of the critical arcs is a tricritical point of the Painlevé I type. In the present paper we prove the topological expansion for log Z_N(t) in the one-cut phase region. The proof is based on the Riemann-Hilbert approach to semiclassical asymptotic expansions for the associated orthogonal polynomials and the theory of S-curves and quadratic differentials.

  2. Crystal Structure of the Glycophorin A Transmembrane Dimer in Lipidic Cubic Phase.

    PubMed

    Trenker, Raphael; Call, Matthew E; Call, Melissa J

    2015-12-23

    The mechanisms of assembly and function for many important type I/II (single-pass) transmembrane (TM) receptors are proposed to involve the formation and/or alteration of specific interfaces among their membrane-embedded α-helical TM domains. The application of lipidic cubic phase (LCP) bilayer media for crystallization of single-α-helical TM complexes has the potential to provide valuable structural and mechanistic insights into many such systems. However, the fidelity of the interfaces observed in crowded crystalline arrays has been difficult to establish from the very limited number of such structures determined using X-ray diffraction data. Here we examine this issue using the glycophorin A (GpA) model system, whose homodimeric TM helix interface has been characterized by solution and solid-state NMR and biochemical techniques but never crystallographically. We report that a GpA-TM peptide readily crystallized in a monoolein cubic phase bilayer, yielding a dimeric α-helical structure that is in excellent agreement with previously reported NMR measurements made in several different types of host media. These results provide compelling support for the wider application of LCP techniques to enable X-ray crystallographic analysis of single-pass TM interactions.

  3. Impact of phase on collision between vortex solitons in three-dimensional cubic-quintic complex Ginzburg-Landau equation.

    PubMed

    Liu, Bin; Liu, Yun-Feng; He, Xing-Dao

    2014-10-20

    We present a systematic analysis for three generic collisional outcomes between stable dissipative vortices with intrinsic vorticity S = 0, 1, or 2 upon variation of relative phase in the three-dimensional (3D) cubic-quintic complex Ginzburg-Landau equation. The first type outcome is merger of the vortices into a single one, of which velocity can be effectively controlled by relative phase. With the increase of the collision momentum, the following is creation of an extra vortex, and its velocity also increases with growth of relative phase. However, at largest collision momentum, the variety of relative phase cannot change the third type collisional outcomes, quasielastic interaction. In addition, the dynamic range of the outcome of creating an extra vortex decreases with the reduction of cubic-gain. The above features have potential applications in optical switching and logic gates based on interaction of optical solitons.

  4. Lattice dynamics of cubic PbTiO3

    NASA Astrophysics Data System (ADS)

    Tomeno, Izumi; Fernandez-Baca, Jaime A.; Marty, Karol J.; Tsunoda, Yorihiko; Oka, Kunihiko

    2012-02-01

    The lattice dynamics of cubic PbTiO3 has been investigated using inelastic neutron scattering. We found four kinds of soft modes in cubic PbTiO3: (1) the TO modes toward the γ point, (2) the TA λ3 mode toward the R point, (3) the TA λ3 mode around the midpoint (1/4,1/4,1/4), and (4) the TA branches in the entire range. Moreover, the TO σ4 branch becomes flat away from the zone center. The steep dispersion of the TO modes toward γ is isotropic and confined to the region ξ<0.2. The temperature dependence of the γ15 mode up to 1173 K is explained by a combination of the Lydanne-Sachs-Taller relation and the Curie-Weiss law. In contrast, the TA λ3 modes at the midpoint and R point are weakly temperature dependent. The coexistence of the soft γ15 and R25 modes is in agreement with the predicted phonon instability. The midpoint softening suggests the tendency toward forming a fourfold periodicity along the [1,1,1] direction. The energy of the TO δ5 branch for cubic PbTiO3 is considerably higher than that for Pb(Zn1/3Nb2/3)O3. This indicates that the TO modes are dominated by the B-site atom motion.

  5. Cubic and Hexagonal Liquid Crystals as Drug Delivery Systems

    PubMed Central

    Chen, Yulin; Ma, Ping; Gui, Shuangying

    2014-01-01

    Lipids have been widely used as main constituents in various drug delivery systems, such as liposomes, solid lipid nanoparticles, nanostructured lipid carriers, and lipid-based lyotropic liquid crystals. Among them, lipid-based lyotropic liquid crystals have highly ordered, thermodynamically stable internal nanostructure, thereby offering the potential as a sustained drug release matrix. The intricate nanostructures of the cubic phase and hexagonal phase have been shown to provide diffusion controlled release of active pharmaceutical ingredients with a wide range of molecular weights and polarities. In addition, the biodegradable and biocompatible nature of lipids demonstrates the minimum toxicity and thus they are used for various routes of administration. Therefore, the research on lipid-based lyotropic liquid crystalline phases has attracted a lot of attention in recent years. This review will provide an overview of the lipids used to prepare cubic phase and hexagonal phase at physiological temperature, as well as the influencing factors on the phase transition of liquid crystals. In particular, the most current research progresses on cubic and hexagonal phases as drug delivery systems will be discussed. PMID:24995330

  6. Cubic and hexagonal liquid crystals as drug delivery systems.

    PubMed

    Chen, Yulin; Ma, Ping; Gui, Shuangying

    2014-01-01

    Lipids have been widely used as main constituents in various drug delivery systems, such as liposomes, solid lipid nanoparticles, nanostructured lipid carriers, and lipid-based lyotropic liquid crystals. Among them, lipid-based lyotropic liquid crystals have highly ordered, thermodynamically stable internal nanostructure, thereby offering the potential as a sustained drug release matrix. The intricate nanostructures of the cubic phase and hexagonal phase have been shown to provide diffusion controlled release of active pharmaceutical ingredients with a wide range of molecular weights and polarities. In addition, the biodegradable and biocompatible nature of lipids demonstrates the minimum toxicity and thus they are used for various routes of administration. Therefore, the research on lipid-based lyotropic liquid crystalline phases has attracted a lot of attention in recent years. This review will provide an overview of the lipids used to prepare cubic phase and hexagonal phase at physiological temperature, as well as the influencing factors on the phase transition of liquid crystals. In particular, the most current research progresses on cubic and hexagonal phases as drug delivery systems will be discussed.

  7. Influence of immersion freezing in NaCl solutions and of frozen storage on the viscoelastic behavior of mozzarella cheese.

    PubMed

    Ribero, G G; Rubiolo, A C; Zorrilla, S E

    2007-06-01

    The freezing of Mozzarella cheese by immersion in NaCl solutions may be an innovative procedure for the dairy industry because it combines conveniently salting and freezing processes. In this work, the influence of this type of freezing method and of the frozen storage of samples on the viscoelastic behavior of Mozzarella cheese was studied. Slabs (2 x 10 x 10 cm(3)) were immersed in 23% w/w NaCl solutions (control samples: 4 degrees C, 90 min; frozen samples: -15 degrees C, 180 min). Half of the frozen samples were immediately thawed at 4 degrees C . The other half was stored at -20 degrees C for 2 mo and then was thawed at 4 degrees C (frozen-stored samples). Samples were stored at 4 degrees C and assayed at 1, 7, 14, 20, 27, 34, and 41 d. Rheological tests were carried out in oscillatory mode (parallel-plate geometry, diameter: 20 mm, gap: 1 mm, frequency: 1 Hz). Strain sweeps were run (0.001 type equation. Activation energy values of 15.9 +/- 0.4, 14.1 +/- 0.5, and 13.8 +/- 0.6 kcal/mol were obtained at 41 d for control, frozen, and frozen-stored samples, respectively. Although the immersion freezing of Mozzarella cheese affects some of the studied parameters, the differences observed between frozen and frozen-stored samples with control samples were small. Therefore, it was considered that the immersion freezing might be useful for the manufacture and commercialization of Mozzarella cheese.

  8. Tamarix hispida metallothionein-like ThMT3, a reactive oxygen species scavenger, increases tolerance against Cd(2+), Zn(2+), Cu(2+), and NaCl in transgenic yeast.

    PubMed

    Yang, Jingli; Wang, Yucheng; Liu, Guifeng; Yang, Chuanping; Li, Chenghao

    2011-03-01

    A metallothionein-like gene, ThMT3, encoding a type 3 metallothionein, was isolated from a Tamarix hispida leaf cDNA library. Expression analysis revealed that mRNA of ThMT3 was upregulated by high salinity as well as by heavy metal ions, and that ThMT3 was predominantly expressed in the leaf. Transgenic yeast (Saccharomyces cerevisiae) expressing ThMT3 showed increased tolerance to Cd(2+), Zn(2+), Cu(2+), and NaCl stress. Transgenic yeast also accumulated more Cd(2+), Zn(2+), and NaCl, but not Cu(2+). Analysis of the expression of four genes (GLR1, GTT2, GSH1, and YCF1) that aid in transporting heavy metal (Cd(2+)) from the cytoplasm to the vacuole demonstrated that none of these genes were induced under Cd(2+), Zn(2+), Cu(2+), and NaCl stress in ThMT3-transgenic yeast. H(2)O(2) levels in transgenic yeast under such stress conditions were less than half those in control yeast under the same conditions. Three antioxidant genes (SOD1, CAT1, and GPX1) were specifically expressed under Cd(2+), Zn(2+), Cu(2+), and NaCl stress in the transgenic yeast. Cd(2+), Zn(2+), and Cu(2+) increased the expression levels of SOD1, CAT1, and GPX1, respectively, whereas NaCl induced the expression of SOD1 and GPX1.

  9. Phosphonate-functionalized large pore 3-D cubic mesoporous (KIT-6) hybrid as highly efficient actinide extracting agent.

    PubMed

    Lebed, Pablo J; de Souza, Kellen; Bilodeau, François; Larivière, Dominic; Kleitz, Freddy

    2011-11-07

    A new type of radionuclide extraction material is reported based on phosphonate functionalities covalently anchored on the mesopore surface of 3-D cubic mesoporous silica (KIT-6). The easily prepared nanoporous hybrid shows largely superior performance in selective sorption of uranium and thorium as compared to the U/TEVA commercial resin and 2-D hexagonal SBA-15 equivalent. This journal is © The Royal Society of Chemistry 2011

  10. 16 CFR 500.14 - Statements of cubic measure and dry measure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Statements of cubic measure and dry measure... UNDER SECTION 4 OF THE FAIR PACKAGING AND LABELING ACT § 500.14 Statements of cubic measure and dry measure. Statements of cubic measure and dry measure shall be expressed in terms most appropriate to the...

  11. 16 CFR 500.14 - Statements of cubic measure and dry measure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Statements of cubic measure and dry measure... UNDER SECTION 4 OF THE FAIR PACKAGING AND LABELING ACT § 500.14 Statements of cubic measure and dry measure. Statements of cubic measure and dry measure shall be expressed in terms most appropriate to the...

  12. 16 CFR 500.14 - Statements of cubic measure and dry measure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Statements of cubic measure and dry measure... UNDER SECTION 4 OF THE FAIR PACKAGING AND LABELING ACT § 500.14 Statements of cubic measure and dry measure. Statements of cubic measure and dry measure shall be expressed in terms most appropriate to the...

  13. 16 CFR 500.14 - Statements of cubic measure and dry measure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Statements of cubic measure and dry measure... UNDER SECTION 4 OF THE FAIR PACKAGING AND LABELING ACT § 500.14 Statements of cubic measure and dry measure. Statements of cubic measure and dry measure shall be expressed in terms most appropriate to the...

  14. 16 CFR 500.14 - Statements of cubic measure and dry measure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Statements of cubic measure and dry measure... UNDER SECTION 4 OF THE FAIR PACKAGING AND LABELING ACT § 500.14 Statements of cubic measure and dry measure. Statements of cubic measure and dry measure shall be expressed in terms most appropriate to the...

  15. Structure and magnetic properties of the cubic oxide fluoride BaFeO{sub 2}F

    SciTech Connect

    Berry, Frank J.; Coomer, Fiona C.; Hancock, Cathryn; Helgason, Orn; Moore, Elaine A.; Slater, Peter R.; Wright, Adrian J.; Thomas, Michael F.

    2011-06-15

    Fluorination of the parent oxide, BaFeO{sub 3-{delta}}, with polyvinylidine fluoride gives rise to a cubic compound with a=4.0603(4) A at 298 K. {sup 57}Fe Moessbauer spectra confirmed that all the iron is present as Fe{sup 3+}. Neutron diffraction data showed complete occupancy of the anion sites, indicating a composition BaFeO{sub 2}F, with a large displacement of the iron off-site. The magnetic ordering temperature was determined as T{sub N}=645{+-}5 K. Neutron diffraction data at 4.2 K established G-type antiferromagnetism with a magnetic moment per Fe{sup 3+} ion of 3.95 {mu}{sub B}. However, magnetisation measurements indicated the presence of a weak ferromagnetic moment that is assigned to the canting of the antiferromagnetic structure. {sup 57}Fe Moessbauer spectra in the temperature range 10-300 K were fitted with a model of fluoride ion distribution that retains charge neutrality of the perovskite unit cell. - Graphical abstract: The cubic oxide fluoride of composition BaFeO{sub 2}F has been synthesised and characterised. Highlights: > Fluorination of BaFeO{sub 3-{delta}} with polyvinylidene fluoride gives a cubic oxide fluoride of composition BaFeO{sub 2}F. > BaFeO{sub 2}F adopts a canted antiferromagnetic structure and is different from the related phase of composition SrFeO{sub 2}F. > A model of fluoride ion distribution about iron in BaFeO{sub 2}F has been explored.

  16. Role of Trichoderma harzianum in mitigating NaCl stress in Indian mustard (Brassica juncea L) through antioxidative defense system

    PubMed Central

    Ahmad, Parvaiz; Hashem, Abeer; Abd-Allah, Elsayed Fathi; Alqarawi, A. A.; John, Riffat; Egamberdieva, Dilfuza; Gucel, Salih

    2015-01-01

    Salinity stress affected crop production of more than 20% of irrigated land globally. In the present study the effect of different concentrations of NaCl (0, 100, and 200 mM) on growth, physio-biochemical attributes, antioxidant enzymes, oil content, etc. in Brassica juncea and the protective role of Trichoderma harzianum (TH) was investigated. Salinity stress deteriorates growth, physio-biochemical attributes, that ultimately leads to decreased biomass yield in mustard seedlings. Higher concentration of NaCl (200 mM) decreased the plant height by 33.7%, root length by 29.7% and plant dry weight (DW) by 34.5%. On the other hand, supplementation of TH to NaCl treated mustard seedlings showed elevation by 13.8, 11.8, and 16.7% in shoot, root length and plant DW respectively as compared to plants treated with NaCl (200 mM) alone. Oil content was drastically affected by NaCl treatment; however, TH added plants showed enhanced oil percentage from 19.4 to 23.4% in the present study. NaCl also degenerate the pigment content and the maximum drop of 52.0% was recorded in Chl. ‘a’. Enhanced pigment content was observed by the application of TH to NaCl treated plants. Proline content showed increase by NaCl stress and maximum accumulation of 59.12% was recorded at 200 mM NaCl. Further enhancement to 70.37% in proline content was recorded by supplementation of TH. NaCl stress (200 mM) affirms the increase in H2O2 by 69.5% and MDA by 36.5%, but reduction in the accumulation is recorded by addition of TH to mustard seedlings. 200 mM NaCl elevated SOD, POD, APX, GR, GST, GPX, GSH, and GSSG in the present study. Further enhancement was observed by the application of TH to the NaCl fed seedlings. NaCl stress suppresses the uptake of important elements in both roots and shoots, however, addition of TH restored the elemental uptake in the present study. Mustard seedlings treated with NaCl and TH showed restricted Na uptake as compared to seedlings treated with NaCl alone. In

  17. Solving nonlinear Benjamin-Bona-Mahony equation using cubic B-spline and cubic trigonometric B-spline collocation methods

    NASA Astrophysics Data System (ADS)

    Rahan, Nur Nadiah Mohd; Ishak, Siti Noor Shahira; Hamid, Nur Nadiah Abd; Majid, Ahmad Abd.; Azmi, Amirah

    2017-04-01

    In this research, the nonlinear Benjamin-Bona-Mahony (BBM) equation is solved numerically using the cubic B-spline (CuBS) and cubic trigonometric B-spline (CuTBS) collocation methods. The CuBS and CuTBS are utilized as interpolating functions in the spatial dimension while the standard finite difference method (FDM) is applied to discretize the temporal space. In order to solve the nonlinear problem, the BBM equation is linearized using Taylor's expansion. Applying the von-Neumann stability analysis, the proposed techniques are shown to be unconditionally stable under the Crank-Nicolson scheme. Several numerical examples are discussed and compared with exact solutions and results from the FDM.

  18. Adsorption of Polyoxyethylenic Nonionic and Anionic Surfactants from Aqueous Solution: Effects Induced by the Addition of NaCl and CaCl2.

    PubMed

    Nevskaia; Guerrero-Ruíz; de D López-González J

    1998-09-01

    The adsorption processes of two different types of surfactant from aqueous solutions have been studied on several solids. The adsorbates used were a nonionic (TX-100) and a series of anionic (NP4S, NP10S, and NP25S) oxyethylenic surfactants. As adsorbent, five nonporous solids, including three quartz (QA, QB, and QC), a kaolin, and a dolomite, were chosen for this study, since these types of materials are frequently found in oil reservoirs. Great differences have been found in the adsorption plateaus, depending on the nature of the surfactant (anionic or nonionic). The influence of the presence of NaCl and CaCl2 in the solutions has been also studied. NaCl affects the adsorption of anionic surfactants on quartz and kaolin samples in a similar way. When this salt is added, the amount of anionic surfactants adsorbed on the solid surfaces increases. Some differences in the adsorption of the TX-100 surfactant, depending on the nature of the surface and the type of salt added, have been detected. Basically, three different adsorption behaviors have been found when NaCl is added. The amounts of TX-100 adsorbed decrease when NaCl is added to the solution on the QA sample; the amounts increase on the QB and kaolin samples; no alteration is observed on QC and dolomite samples. Changes in adsorption isotherms, depending on whether NaCl or CaCl2 is added, have also been observed. For the same five adsorbents, zeta potential measurements also have been carried out. When the nonionic TX-100 surfactant is adsorbed, a decrease in the negative values of the zeta potential takes place. However, for the adsorption of anionic surfactants, an increase in the negative values of the zeta potential is detected. The surface charge has been also determined by potentiometric titration (in presence and in absence of TX-100), and a decrease in surface charge when TX-100 is adsorbed on the sample surfaces has been detected. Copyright 1998 Academic Press.

  19. Synthesis and Characterization of Ru Cubic Nanocages with a Face-Centered Cubic Structure by Templating with Pd Nanocubes.

    PubMed

    Zhao, Ming; Figueroa-Cosme, Legna; Elnabawy, Ahmed O; Vara, Madeline; Yang, Xuan; Roling, Luke T; Chi, Miaofang; Mavrikakis, Manos; Xia, Younan

    2016-08-10

    Nanocages have received considerable attention in recent years for catalytic applications owing to their high utilization efficiency of atoms and well-defined facets. Here we report, for the first time, the synthesis of Ru cubic nanocages with ultrathin walls, in which the atoms are crystallized in a face-centered cubic (fcc) rather than hexagonal close-packed (hcp) structure. The key to the success of this synthesis is to ensure layer-by-layer deposition of Ru atoms on the surface of Pd cubic seeds by controlling the reaction temperature and the injection rate of a Ru(III) precursor. By selectively etching away the Pd from the Pd@Ru core-shell nanocubes, we obtain Ru nanocages with an average wall thickness of 1.1 nm or about six atomic layers. Most importantly, the Ru nanocages adopt an fcc crystal structure rather than the hcp structure observed in bulk Ru. The synthesis has been successfully applied to Pd cubic seeds with different edge lengths in the range of 6-18 nm, with smaller seeds being more favorable for the formation of Ru shells with a flat, smooth surface due to shorter distance for the surface diffusion of the Ru adatoms. Self-consistent density functional theory calculations indicate that these unique fcc-structured Ru nanocages might possess promising catalytic properties for ammonia synthesis compared to hcp Ru(0001), on the basis of strengthened binding of atomic N and substantially reduced activation energies for N2 dissociation, which is the rate-determining step for ammonia synthesis on hcp Ru catalysts.

  20. Gustatory Plasticity in "C. elegans" Involves Integration of Negative Cues and NaCl Taste Mediated by Serotonin, Dopamine, and Glutamate

    ERIC Educational Resources Information Center

    Hukema, Renate K.; Rademakers, Suzanne; Jansen, Gert

    2008-01-01

    While naive "Caenorhabditis elegans" individuals are attracted to 0.1-200 mM NaCl, they become strongly repelled by these NaCl concentrations after prolonged exposure to 100 mM NaCl. We call this behavior gustatory plasticity. Here, we show that "C. elegans" displays avoidance of low NaCl concentrations only when pre-exposure to NaCl is combined…

  1. Gustatory Plasticity in "C. elegans" Involves Integration of Negative Cues and NaCl Taste Mediated by Serotonin, Dopamine, and Glutamate

    ERIC Educational Resources Information Center

    Hukema, Renate K.; Rademakers, Suzanne; Jansen, Gert

    2008-01-01

    While naive "Caenorhabditis elegans" individuals are attracted to 0.1-200 mM NaCl, they become strongly repelled by these NaCl concentrations after prolonged exposure to 100 mM NaCl. We call this behavior gustatory plasticity. Here, we show that "C. elegans" displays avoidance of low NaCl concentrations only when pre-exposure to NaCl is combined…

  2. Knockout of Ku86 accelerates cellular senescence induced by high NaCl

    PubMed Central

    Dmitrieva, Natalia I.; Chen, Hua Tang; Nussenzweig, André; Burg, Maurice B.

    2009-01-01

    NaCl induces DNA breaks, thus leading to cellular senescence. Here we showed that Ku86 deficiency accelerated the high NaCl-induced cellular senescence. We find that 1) high NaCl induces rapid cellular senescence in Ku86 deficient (xrs5) cells, 2) Ku86 deficiency shortens lifespan of C. elegans in high NaCl, and 3) cellular senescence is greatly accelerated in renal inner medullas of Ku86-/- mice. Further, although water balance is known to be compromised in old mice, this occurs at much earlier age in Ku86-/- mice. When subjected to mild water restriction, 3 month old Ku86-/-, but not Ku86+/+, mice rapidly become dehydrated as evidenced by decrease in body weight, increased production of antidiuretic hormone, increased urine osmolality and decreased urine volume. The deficiency in water balance does not occur in Ku86+/+mice until they are much older (14 months). We conclude that Ku86 deficiency accelerates high NaCl-induced cellular senescence, particularly in the renal medulla where NaCl normally is high. PMID:19946467

  3. High concentrations of NaCl induce cell swelling leading to senescence in human cells.

    PubMed

    Yamakami, Yoshimi; Yonekura, Ryuzo; Matsumoto, Yuko; Takauji, Yuki; Miki, Kensuke; Fujii, Michihiko; Ayusawa, Dai

    2016-01-01

    Cell swelling and retardation in DNA replication are always observed in senescent cells. When DNA replication is slowed down with RNA and protein syntheses unchanged in proliferating cells, it causes a phenomenon known as unbalanced growth. The purpose of this study is to assess the role of cell swelling in unbalanced growth in terms of senescence and investigate the mechanism underlying this phenomenon. We tried to induce cell swelling with minimum damage to cells in this study. We perturbed the osmoregulatory functions to induce cell swelling under hypotonic and hypertonic conditions in normal human fibroblasts. Addition of excess NaCl was found to induce significant cell and nuclear swelling in dose- and time-dependent manners. Excess NaCl immediately retarded DNA replication, accumulated cells at G1 phase of the cell cycle, and eventually deprived division potential of the cells. Such cells showed typical senescent cell shape followed by expression of the typical senescence-associated genes. Excess NaCl also activated ERK1/2, p38, and JNK of the mitogen activated protein kinase family. Addition of U0126, an inhibitor of ERK1/2, prevented appearance of senescent features induced by excess NaCl. These results suggest that hypertonic conditions induce cell swelling due to unbalanced growth, thereby leading to cellular senescence.

  4. Bioethanol production from Gracilaria verrucosa using Saccharomyces cerevisiae adapted to NaCl or galactose.

    PubMed

    Nguyen, Trung Hau; Ra, Chae Hun; Sunwoo, InYung; Jeong, Gwi-Taek; Kim, Sung-Koo

    2016-12-18

    This study examined the pretreatment, enzymatic saccharification, and fermentation of the red macroalgae Gracilaria verrucosa using adapted saccharomyces cerevisiae to galactose or NaCl for the increase of bioethanol yield. Pretreatment with thermal acid hydrolysis to obtain galactose was carried out with 11.7% (w/v) seaweed slurry and 373 mM H2SO4 at 121 °C for 59 min. Glucose was obtained from enzymatic hydrolysis. Enzymatic saccharification was performed with a mixture of 16 U/mL Celluclast 1.5L and Viscozyme L at 45 °C for 48 h. Ethanol fermentation in 11.7% (w/v) seaweed hydrolysate was carried out using Saccharomyces cerevisiae KCTC 1126 adapted or non-adapted to high concentrations of galactose or NaCl. When non-adapted S. cerevisiae KCTC 1126 was used, the ethanol productivity was 0.09 g/(Lh) with an ethanol yield of 0.25. Ethanol productivity of 0.16 and 0.19 g/(Lh) with ethanol yields of 0.43 and 0.48 was obtained using S. cerevisiae KCTC 1126 adapted to high concentrations of galactose and NaCl, respectively. Adaptation of S. cerevisiae KCTC 1126 to galactose or NaCl increased the ethanol yield via adaptive evolution of the yeast.

  5. Morphological, Physiological, and Structural Responses of Two Species of Artemisia to NaCl Stress

    PubMed Central

    Guan, Zhi-Yong; Su, Yi-Ji; Teng, Nian-Jun; Chen, Su-Mei; Sun, Hai-Nan; Li, Chu-Ling; Chen, Fa-Di

    2013-01-01

    Effects of salt stress on Artemisia scoparia and A. vulgaris “Variegate” were examined. A. scoparia leaves became withered under NaCl treatment, whereas A. vulgaris “Variegate” leaves were not remarkably affected. Chlorophyll content decreased in both species, with a higher reduction in A. scoparia. Contents of proline, MDA, soluble carbohydrate, and Na+ increased in both species under salt stress, but A. vulgaris “Variegate” had higher level of proline and soluble carbohydrate and lower level of MDA and Na+. The ratios of K+/Na+, Ca2+/Na+, and Mg2+/Na+ in A. vulgaris “Variegate” under NaCl stress were higher. Moreover, A. vulgaris “Variegate” had higher transport selectivity of K+/Na+ from root to stem, stem to middle mature leaves, and upper newly developed leaves than A. scoparia under NaCl stress. A. vulgaris “Variegate” chloroplast maintained its morphological integrity under NaCl stress, whereas A. scoparia chloroplast lost integrity. The results indicated that A. scoparia is more sensitive to salt stress than A. vulgaris “Variegate.” Salt tolerance is mainly related to the ability of regulating osmotic pressure through the accumulation of soluble carbohydrates and proline, and the gradient distribution of K+ between roots and leaves was also contributed to osmotic pressure adjustment and improvement of plant salt tolerance. PMID:24235883

  6. Detection of NaCl solutions using terahertz time domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Wang, Cuicui; Liu, Shangjian; Zhao, Xiaojing; Zuo, Jian; Zhang, Cunlin

    2016-11-01

    Terahertz spectrum is corresponding with vibration and rotation of liquid molecules. It is suitable to identify and research the liquid molecular dynamics. As a powerful spectral detection technology, terahertz time-domain spectroscopy (THz- TDS) is widely used in solution detection. The absorption coefficient, refractive index and dielectric function of solutions can be extracted based on terahertz time-domain spectroscopy. NaCl exists in most biological tissues, and it is very important for life. In this paper, we detected NaCl solutions with different concentrations at room temperature by THz-TDS technique in the range of 0.2-1.5 THz. The liquid cell with a thickness of 0.2mm is made of quartz. A linear increase of the real and imaginary part of the dielectric function was observed when compared with pure water with increasing concentrations of NaCl solutions. We fitted the terahertz dielectric function of the NaCl solutions by Debye model, Where the dielectric relaxation time can be obtained. By means of dielectric relaxation process, it was found that the characteristic time of molecular movement and the information related to the liquid molecular structure and movement was obtained.

  7. Effects of NaCl stress on antioxidative enzymes of glycine Soja sieb.

    PubMed

    Li, Yan

    2009-03-15

    The activity of anti-oxidant enzymes (Superoxide dismutase (SOD), Peroxidase (POD), Catalase (CAT) and parameters of oxidative stress malondialdehyde (MDA) of shoots were investigated in S. sieb naturally salt-resistant halophyte. The seedlings of S. sieb were treated with varying (0, 80, 160 and 240 mM) NaCl stress. The results showed that NaCl played an important role in growth of S. sieb. It made obviously promotion of certain NaCl concentration to growth of S. sieb, the seeflings of S. sieb grew best under 80 mM salt stress. MDA concentration of S. sieb obviously decreased under 80 mM salt stress then increased with salt concentration increased. The activities of SOD, POD and CAT increased with the increase of the concentration of NaCl in S. sieb. The salt tolerance of this halophyte under salt stress condition are probably due to its ability to exhibit high SOD, POD and CAT enzyme activities and Soluble Sugar (SS) concentration.

  8. Cerebral regulation of renal sodium excretion in sheep infused intravenously with hypertonic NaCl.

    PubMed Central

    Chodobski, A; McKinley, M J

    1989-01-01

    1. The natriuretic response to intravenous infusion of 2 M-NaCl was investigated in six conscious sheep. This hypertonic NaCl load resulted in relatively small, physiological (2-3 mmol l-1) increases in plasma Na+ concentration and was followed by a natriuresis with a maximum mean urinary sodium excretion 5 times higher than pre-infusion values. 2. Intravenous infusion of isotonic NaCl, delivering the same Na+ load as hypertonic NaCl infusion, did not induce natriuresis. This suggested, therefore, that with the hypertonic sodium load administered in the present study, the rise in plasma Na+ and/or tonicity rather than increase in blood volume is important in evoking the natriuretic response. 3. Intracerebroventricular infusion of low-Na+ artificial cerebrospinal fluid (CSF) reduced CSF Na+ concentration, decreased plasma vasopressin (AVP) levels and caused a copious water diuresis. This was associated with excessive loss of water and large increases in plasma Na+ concentration and osmolality. 4. The natriuresis induced by intravenous hypertonic NaCl load could be blocked by lowering CSF Na+ concentration in situations where water diuresis was either prevented or reduced by intravenous infusion of AVP or by delayed intracerebroventricular infusion of low-Na+ CSF, respectively. 5. The results of the present study provide further evidence that renal sodium excretion can be controlled by the central nervous system. PMID:2621619

  9. Fabrication of large binary colloidal crystals with a NaCl structure.

    PubMed

    Vermolen, E C M; Kuijk, A; Filion, L C; Hermes, M; Thijssen, J H J; Dijkstra, M; van Blaaderen, A

    2009-09-22

    Binary colloidal crystals offer great potential for tuning material properties for applications in, for example, photonics, semiconductors and spintronics, because they allow the positioning of particles with quite different characteristics on one lattice. For micrometer-sized colloids, it is believed that gravity and slow crystallization rates hinder the formation of high-quality binary crystals. Here, we present methods for growing binary colloidal crystals with a NaCl structure from relatively heavy, hard-sphere-like, micrometer-sized silica particles by exploring the following external fields: electric, gravitational, and dielectrophoretic fields and a structured surface (colloidal epitaxy). Our simulations show that the free-energy difference between the NaCl and NiAs structures, which differ in their stacking of the hexagonal planes of the larger spheres, is very small (approximately 0.002 k(B)T). However, we demonstrate that the fcc stacking of the large spheres, which is crucial for obtaining the pure NaCl structure, can be favored by using a combination of the above-mentioned external fields. In this way, we have successfully fabricated large, 3D, oriented single crystals having a NaCl structure without stacking disorder.

  10. Stability study of epirubicin in NaCl 0.9% injection.

    PubMed

    Pujol, M; Muñoz, M; Prat, J; Girona, V; De Bolós, J

    1997-09-01

    To determine the stability of epirubicin in NaCl 0.9% injection under hospital storage conditions. NaCl 0.9% solution was added to epirubicin lyophilized powder to make a final concentration of 1 mg/mL to study the degradation kinetics and 2 mg/mL to study the stability in polypropylene syringes under hospital conditions. Physical chemistry laboratory, Unitat de Fisicoquímica, Universitat de Barcelona. Solutions of epirubicin at 2 mg/mL in NaCl 0.9% solutions stored in plastic syringes were studied under hospital conditions at room temperature (25 +/- 1 degrees C) and under refrigeration (4 +/- 1 degrees C) both protected from light and exposed to room light (approximately 50 lumens/m2). All samples were studied in triplicate and epirubicin concentrations were obtained periodically throughout each storage/time condition via a specific stability-indicating HPLC method. To determine the degradation kinetics, solutions of epirubicin in NaCl 0.9% at 1 mg/mL were stored at different temperatures (40, 50, and 60 degrees C) to obtain the rate degradation constant and the shelf life at room temperature and under refrigeration. The degradation of epirubicin in NaCl 0.9% solutions follows first-order kinetics. The shelf life was defined as the time by which the epirubicin concentration had decreased by 10% from the initial concentration. In this study, epirubicin was stable in NaCl 0.9% injection stored in polypropylene containers for all time periods and all conditions. That results in a shelf life of at least 14 and 180 days at 25 and 4 degrees C, respectively. The maximum decrease in epirubicin concentration observed at 25 degrees C and 14 days was 4%, and at 4 degrees C and 180 days was 8%. The predicted shelf life obtained from the Arrhenius equation was 72.9 +/- 0.2 and 3070 +/- 15 days at 25 and 4 degrees C, respectively, in both dark and illuminated conditions. Solutions of epirubicin in NaCl 0.9% at 2 mg/mL are chemically stable when they are stored in

  11. Stabilization of cubic structure in TlI with Ag +, Br -, NO 3-

    NASA Astrophysics Data System (ADS)

    Secco, E. A.

    1997-11-01

    The solid state phase transitions of Tl (1- x) Ag xI, TlI (1- x) Br x and TlI (1- x) (NO 3) x where x = 0.10 are reported. The differential scanning calorimetry (DSC) traces for all three systems show two common endotherms at 172°C and 222°C on first heating but only the 222°C endotherm survived on second heating. The reversible 222°C endotherm suggests a common solid-solid phase transition of the order-disorder type involving a common structure in the host TlI, viz, the Pm3m CsCl-type cubic structure, confirmed by its X-ray diffraction pattern.

  12. Growth of InAs Wurtzite Nanocrosses from Hexagonal and Cubic Basis.

    PubMed

    Krizek, Filip; Kanne, Thomas; Razmadze, Davydas; Johnson, Erik; Nygård, Jesper; Marcus, Charles M; Krogstrup, Peter

    2017-10-11

    Epitaxially connected nanowires allow for the design of electron transport experiments and applications beyond the standard two terminal device geometries. In this Letter, we present growth methods of three distinct types of wurtzite structured InAs nanocrosses via the vapor-liquid-solid mechanism. Two methods use conventional wurtzite nanowire arrays as a 6-fold hexagonal basis for growing single crystal wurtzite nanocrosses. A third method uses the 2-fold cubic symmetry of (100) substrates to form well-defined coherent inclusions of zinc blende in the center of the nanocrosses. We show that all three types of nanocrosses can be transferred undamaged to arbitrary substrates, which allows for structural, compositional, and electrical characterization. We further demonstrate the potential for synthesis of as-grown nanowire networks and for using nanowires as shadow masks for in situ fabricated junctions in radial nanowire heterostructures.

  13. Exceptionally Strong Phonon Scattering by B Substitution in Cubic SiC

    NASA Astrophysics Data System (ADS)

    Katre, Ankita; Carrete, Jesús; Dongre, Bonny; Madsen, Georg K. H.; Mingo, Natalio

    2017-08-01

    We use ab initio calculations to predict the thermal conductivity of cubic SiC with different types of defects. An excellent quantitative agreement with previous experimental measurements is found. The results unveil that BC substitution has a much stronger effect than any of the other defect types in 3 C -SiC , including vacancies. This finding contradicts the prediction of the classical mass-difference model of impurity scattering, according to which the effects of BC and NC would be similar and much smaller than that of the C vacancy. The strikingly different behavior of the BC defect arises from a unique pattern of resonant phonon scattering caused by the broken structural symmetry around the B impurity.

  14. Ultraviolet light-emitting diode of a cubic boron nitride pn junction made at high pressure

    NASA Astrophysics Data System (ADS)

    Mishima, Osamu; Era, Koh; Tanaka, Junzo; Yamaoka, Shinobu

    1988-09-01

    This paper reports on the first realization of an ultraviolet LED of a cubic boron nitride (cBN) pn junction. The pn junction was made by growing a Si-doped n-type crystal epitaxially on a Be-doped p-type seed crystal in a molybdenum growth cell placed in a high-pressure oven (at about 55 kbar and 1700 C) by using a temperature-difference method with LiCaBN2 as solvent, described by Mishima et al. (1987). The results of microscopic observations and spectroscopic studies showed that the light emission occurs near the junction region only in the forward-bias condition, with the spectra extending from about 215 nm to the red and only a few peaks, mainly in the UV region.

  15. Deliquescence, efflorescence and ice nucleating ability of NaCl/hydrated NaCl particles under upper tropospheric conditions

    NASA Astrophysics Data System (ADS)

    Wise, M. E.; Baustian, K. J.; Freedman, M. A.; Koop, T.; Tolbert, M. A.

    2010-12-01

    Sea-salt aerosol particles (SSA) are ubiquitous in marine boundary layer and over coastal areas. Therefore SSA have ability to directly and indirectly affect the Earth’s radiation balance. The influence SSA have on the Earth’s radiation balance is related to their water uptake and ice nucleation characteristics. In this study, optical microscopy coupled with Raman spectroscopy was used to determine the deliquescence and efflorescence phase transitions of NaCl particles (a proxy for SSA particles) at temperatures ranging from 233 to 258 K. It was found that NaCl (s) particles deliquesced at 75.7±2.5 % RH and NaCl (aq) particles effloresced at 42.7 ±6.9 % RH. When the temperature of NaCl (aq) particles was held between 236 and 252 K, a mixture of hydrated and non-hydrated particles effloresced. Thus the water uptake characteristics of hydrated NaCl (s) particles were studied. The deliquescence relative humidities (DRH) of hydrated NaCl (s) particles ranged from 75.6 to 94.5 % RH. The DRH values for hydrated NaCl (s) do not agree with the theoretical DRH for the dihydrate form of NaCl (s) particles (the predicted phase using a bulk phase diagram). Additionally, the ice nucleating abilities of NaCl (s) and hydrated NaCl (s) were determined at temperatures ranging from 221 to 230 K. NaCl (s) particles depositionally nucleated ice at an average Sice value of 1.11±0.07. Hydrated NaCl (s) particles depositionally nucleated ice at an average Sice value of 1.01±0.03. When a mixture of hydrated and anhydrous NaCl (s) particles was present in the same sample, ice preferentially nucleated on the hydrated particles 100% of the time. Thus hydrated NaCl (s) particles are better ice nuclei than NaCl (s) particles.

  16. [Physiological response and salt-tolerance of Gleditsia microphylla under NaCl stress].

    PubMed

    Lu, Bin; Hou, Yue-min; Li, Xin-yang; Chang, Yue-xia; Huang, Da-zhuang; Lu, Bing-she

    2015-11-01

    In order to exploit the salt-tolerance ability and mechanism of Gleditsia microphylla, the plant growth, cell membrane permeability, the activities of cell protective enzymes, and the distri- butions of Na+ and K+ in different tissues were investigated under various NaCl stress (0.053%, 0.15%, 0.3%, 0.45% and 0.6%) with potted two-year seedlings. The results were as follows: With the increase of NaCl concentration, the seedling growth decreased while the salt injured index in- creased, and the salt-tolerance thresholds of seedling was 0.42% NaCl. With the NaCl concentration increasing, the membrane permeability, superoxide anion radical generating rate and MDA content increased grandly, while the activities of SOD, POD and CAT demonstrated an increase-decrease curve which reached the peak at 0.3% or 0.45%. Under the high salt stress condition, the supero- xide anion could be consumed timely by increasing the activities of SOD, POD and CAT enzymes, which was useful to avoid cell injure. Under salt stress condition, the Na+ content in different tissues increased gradually, following the order of root > leaf > stem, and the K+ content and K+/Na+ in different tissues decreased, following the order of leaf > root > stem. The K+-Na+ selective transpor- tation coefficients (S(K+) · Na+) of stem and leaf tissues under the soil NaCl stress condition were both increased, following the order of leaf > stem. In conclusion, the findings suggested that the salt- adaptation mechanisms of G. microphylla were root salt-rejection by Na+ accumulation and restriction in root tissue and leaf salt-tolerance by a remarkably increased ability of K+ selective absorption and accumulation in leaf tissue.

  17. NaCl and sugar release, salivation and taste during mastication of salted chewing gum.

    PubMed

    Neyraud, Eric; Prinz, Jon; Dransfield, Eric

    2003-09-01

    Salt perception impacts on food acceptability and nutrition and depends upon salt release from foods that was determined in situ during mastication of chewing gum with up to 10% (1800 mmol/kg) added NaCl. The mechanical action of chewing increased salivation, which was further increased by the presence of salt, particularly above 180 mmol NaCl/kg gum or above 100 mM NaCl in saliva. The average resting salivary flow rate was 1 ml/min, increasing to 4 and 6 ml/min with gums containing low and high salt, respectively. Thus, stimulation of salivation by salt occurred at a concentration well above the taste threshold of 20 mM NaCl. NaCl concentration in nonstimulated saliva was about 10 mM and increased to 500 mM after 30 s chewing of the 10% NaCl gum and returned to near nonstimulated levels after 4 min chewing. Changes in pH of saliva were more gradual, increasing to a maximum at about 2 min and remaining elevated after 4 min. Salty taste was related to the free chloride ion concentration in saliva irrespective of the initial salt concentration in the gum with an indication of adaptation after 3 min chewing. During chewing, salty taste increased ahead of the increase in salivary conductivity and the salt concentration in the sublingual saliva varied in a cyclic fashion about every 20 s. This is consistent with a cyclic swallowing of saliva and replacement with newly secreted saliva of low salt content and mastication releasing further salt from the gum.

  18. Acclimation to NaCl and light stress of heterotrophic Chlamydomonas reinhardtii for lipid accumulation.

    PubMed

    Fan, Jianhua; Zheng, Lvhong

    2017-09-01

    Salt stress has been proven very effective in enhancing the lipid content among many photoautotrophically grown microalgae species including marine and freshwater algae. Nevertheless, its effect on heterotrophic grown cells and lipid accumulation is scarcely known. This study sought to demonstrate a new train of thought for cost-effective biofuels production by heterotrophic culture of Chlamydomonas reinhardtii coupling with subsequent salt and light stress. NaCl treatments (25-200 mM) gradually suppressed the cell growth. After one day's acclimation, the cells restored slow growth with light supplement (200 μmol/m2/s) in low salt concentration (0-50 mM). However, high concentration of NaCl (200 mM) dose caused permanent damage, with over 47% cells death after 3 days treatment. The highest lipid content of 35.8% and lipid productivity of 28.6 mg/L/d were achieved by 50 mM NaCl stress and light treatment upon heterotrophic grown cells. Cells lost their green pigmentation and became yellowish under 100-200 mM NaCl conditions, whereas cells grown in 0-50 mM NaCl retained their dark-green pigmentation. Variable-to-maximum fluorescence ratio (Fv/Fm) and non-photochemical quenching (NPQ) value were markedly influenced under salt and light stress, indicating that severe inhibition of photosynthetic ability was occurred. Moreover, we further demonstrated the dynamic changes of cell growth and lipid accumulation would potentially be caused by the increase of intracellular redox state. To our knowledge, this study is the first instance in which C. reinhardtii was applied to oil accumulation by using combination of heterotrophic culture and multiple stress, and opened up a new territory for the further development of microalgae-based biofuels production. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  19. Cumulative effect of nitrogen and sulphur on Brassica juncea L. genotypes under NaCl stress.

    PubMed

    Siddiqui, Manzer H; Mohammad, Firoz; Khan, M Masrooor A; Al-Whaibi, Mohamed H

    2012-01-01

    In the present study, N and S assimilation, antioxidant enzymes activity, and yield were studied in N and S-treated plants of Brassica juncea (L.) Czern. & Coss. (cvs. Chuutki and Radha) under salt stress. The treatments were given as follows: (1) NaCl(90) mM+N(0)S(0) mg kg(-1) sand (control), (2) NaCl(90) mM+N(60)S(0) mg kg(-1) sand, (3) NaCl(90) mM+N(60)S(20) mg kg(-1) sand, (4) NaCl(90) mM+N(60)S(40) mg kg(-1) sand, and (5) NaCl(90) mM+N(60)S(60) mg kg(-1) sand. The combined application of N (60 mg kg(-1) sand) and S (40 mg kg(-1) sand) proved beneficial in alleviating the adverse effect of salt stress on growth attributes (shoot length plant(-1), fresh weight plant(-1), dry weight plant(-1), and area leaf(-1)), physio-biochemical parameters (carbonic anhydrase activity, total chlorophyll, adenosine triphosphate-sulphurylase activity, leaf N, K and Na content, K/Na ratio, activity of nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase, catalase, superoxide dismutase, ascorbate peroxidase and glutathione reductase, and content of glutathione and ascorbate), and yield attributes (pods plant(-1), seeds pod(-1), and seed yield plant(-1)). Therefore, it is concluded that combined application of N and S induced the physiological and biochemical mechanisms of Brassica. The stimulation of antioxidant enzymes activity and its synergy with N and S assimilation may be one of the important mechanisms that help the plants to tolerate the salinity stress and resulted in an improved yield.

  20. [Effect of 5-aminolevulinic acid on photosynthetic characteristics of tomato seedlings under NaCl stress].

    PubMed

    Zhao, Yan-Yan; Yan, Fei; Hu, Li-Pan; Zhou, Xiao-Ting; Zou, Zhi-Rong

    2014-10-01

    In this research, the possibility of exogenous application of 5-aminolevulinic acid (ALA) on photosynthetic characteristics of tomato seedlings under NaCl stress was investigated. Five leaves seedlings of tomato (Solanum lycopersicum cv. Jinpeng No. 1) were used as starting materials, applied with 50 mg · L(-1) ALA by foliage spray or 10 mg · L(-1) ALA by root soaking to study the changes in their photosynthesis and fluorescence parameters under 100 mmol · L(-1) NaCl. The result showed that, photosynthetic gas exchange parameters (net photosynthetic rate P,, stomata conductance g(s), intercellular CO2 concentration Ci, transpiration Tr) and chlorophyll fluorescence parameters (Fv'/Fm', Fm', ΦPS II, ETR, qP, Pc) were severely reduced under NaCl treatment and ALA application by foliage spray or root soaking with proper concentrations exerted positive influences on tomato seedlings under salt stress, while there were some differences between foliage spray and root soaking in the influence on chlorophyll content, photosynthesis and chlorophyll fluorescence. Both foliage spray with 50 mg · L(-1) ALA and root soaking with 10 mg L(-1) ALA significantly increased Pn, Ci, g(s) and Tr of tomato seedlings under NaCl stress, alleviated photosynthetic inhibition. Root application of ALA had a better effect on the chlorophyll content than foliage application. However, the photosynthetic parameters showed that foliage application of ALA had a better effect than root application, and both treatments had no difference in the influence on chlorophyll fluorescence parameters of tomato seedlings. It could be deduced that the regulating effect of ALA on enhancing salt tolerance of tomato seedlings is attributed to its effect on improving chlorophyll biosynthesis and metabolism, increasing stomatal conductance and reducing stomatal limitation, thus, enhancing the photosynthetic capacity and PS II photochemical efficiency of tomato leaves under NaCl stress.

  1. NaCl reflection coefficients in proximal tubule apical and basolateral membrane vesicles. Measurement by induced osmosis and solvent drag.

    PubMed Central

    Pearce, D; Verkman, A S

    1989-01-01

    Two independent methods, induced osmosis and solvent drag, were used to determine the reflection coefficients for NaCl (sigma NaCl) in brush border and basolateral membrane vesicles isolated from rabbit proximal tubule. In the induced osmosis method, vesicles loaded with sucrose were subjected to varying inward NaCl gradients in a stopped-flow apparatus. sigma NaCl was determined from the osmolality of the NaCl solution required to cause no initial osmotic water flux as measured by light scattering (null point). By this method sigma NaCl was greater than 0.92 for both apical and basolateral membranes with best estimates of 1.0. sigma NaCl was determined by the solvent drag method using the Cl-sensitive fluorescent indicator, 6-methoxy-N-[3-sulfopropyl]quinolinium (SPQ), to detect the drag of Cl into vesicles by inward osmotic water movement caused by an outward osmotic gradient. sigma NaCl was determined by comparing experimental data with theoretical curves generated using the coupled flux equations of Kedem and Katchalsky. By this method we found that sigma NaCl was greater than 0.96 for apical and greater than 0.98 for basolateral membrane vesicles, with best estimates of 1.0 for both membranes. These results demonstrate that sigma NaCl for proximal tubule apical and basolateral membranes are near unity. Taken together with previous results, these data suggest that proximal tubule water channels are long narrow pores that exclude NaCl. PMID:2765660

  2. Performance of N95 FFRs Against Combustion and NaCl Aerosols in Dry and Moderately Humid Air: Manikin-based Study.

    PubMed

    Gao, Shuang; Kim, Jinyong; Yermakov, Michael; Elmashae, Yousef; He, Xinjian; Reponen, Tiina; Zhuang, Ziqing; Rengasamy, Samy; Grinshpun, Sergey A

    2016-07-01

    The first objective of this study was to evaluate the penetration of particles generated from combustion of plastic through National Institute for Occupational Safety and Health (NIOSH)-certified N95 filtering facepiece respirators (FFRs) using a manikin-based protocol and compare the data to the penetration of NaCl particles. The second objective was to investigate the effect of relative humidity (RH) on the filtration performance of N95 FFRs. Two NIOSH-certified N95 FFRs (A and B) were fully sealed on a manikin headform and challenged with particles generated by combustion of plastic and NaCl particles. The tests were performed using two cyclic flows [with mean inspiratory flow (MIF) rates = 30 and 85 l min(-1), representing human breathing under low and moderate workload conditions] and two RH levels (≈20 and ≈80%, representing dry and moderately humid air). The total and size-specific particle concentrations inside (C in) and outside (C out) of the respirators were measured with a condensation particle counter and an aerosol size spectrometer. The penetration values (C in/C out) were calculated after each test. The challenge aerosol, RH, MIF rate, and respirator type had significant (P < 0.05) effects on the performance of the manikin-sealed FFR. Its efficiency significantly decreased when the FFR was tested with plastic combustion particles compared to NaCl aerosols. For example, at RH ≈80% and MIF = 85 l min(-1), as much as 7.03 and 8.61% of combustion particles penetrated N95 respirators A and B, respectively. The plastic combustion particles and gaseous compounds generated by combustion likely degraded the electric charges on fibers, which increased the particle penetration. Increasing breathing flow rate or humidity increased the penetration (reduced the respirator efficiency) for all tested aerosols. The effect of particle size on the penetration varied depending on the challenge aerosol and respirator type. It was observed that the peak of the size

  3. X-ray Diffraction of Cubic Gd2)3/Er under High Pressure

    SciTech Connect

    X Zou; C Gong; B Liu; Q Li; Z Li; B Liu; R Liu; J Liu; Z Chen; et al.

    2011-12-31

    In this paper, we report the in situ high pressure X-ray diffraction studies on Er{sup 3+} doped Gd{sub 2}O{sub 3} in a diamond anvil cell up to 39.8 GPa at room temperature. Several phase transitions have been identified in our studies. The structural transformation from a starting cubic phase to a hexagonal phase occurred during the sample compression process, at 8.57 GPa. And the hexagonal phase was stable from 12.5 GPa up to the highest pressure in this study but was not quenchable and transformed to a monoclinic phase after pressure release. An anomalous high pressure behavior in the hexagonal type Gd{sub 2}O{sub 3} phase was observed, which might be caused by an electron transition influenced by Er{sup 3+} ions doping. By fitting the compression data to the Birch-Murnaghan equation of state, the bulk moduli of the cubic and two hexagonal (at p < 19.9 GPa and p > 27.0 GPa) Gd{sub 2}O{sub 3} phases were determined to be 164 {+-} 3, 185 {+-} 7, and 150 {+-} 10 GPa with B'{sub 0} = 4, respectively.

  4. Distortion induced magnetic phase transition in cubic BaFeO3

    NASA Astrophysics Data System (ADS)

    Rahman, Gul; Morbec, Juliana M.; Ferradás, Rubén; García-Suárez, Víctor M.; English, Niall J.

    2016-03-01

    The electronic and magnetic structures of cubic BaFeO3 (BFO) in the ferromagnetic (FM) and antiferromagnetic (AFM) states are studied using density functional theory (DFT) with the local spin density approximation (LSDA) and the generalized gradient approximation (GGA), with and without a Coulomb U term. Our LSDA/GGA and LSDA+U/GGA+U results show that cubic BFO has a FM ground state, in agreement with recent experimental studies. Two types of distortions, denoted as D1 and D2, are considered. The source of the distortion in the D1 (D2) case is the displacement of the oxygen (iron) atoms from their equilibrium positions. FM to ferrimagnetic (FIM) and FM to AFM magnetic phase transitions are found in the D1 and D2 distortions, respectively. Larger strains are required for the FM-AFM transition as compared to the FM-FIM. DFT+U calculations also show that the magnetic moments dramatically decrease at large strains due to strong overlapping between the iron and oxygen atoms. The origin of these transitions is discussed in terms of a competition between double exchange and superexchange interactions. From these results it is possible to conclude that oxygen and iron displacements are responsible for the magnetic phase transitions and the reduction of the magnetic moments in BFO.

  5. Growth and nitrogen fixation in Lotus japonicus and Medicago truncatula under NaCl stress: nodule carbon metabolism.

    PubMed

    López, Miguel; Herrera-Cervera, Jose A; Iribarne, Carmen; Tejera, Noel A; Lluch, Carmen

    2008-04-18

    Lotus japonicus and Medicago truncatula model legumes, which form determined and indeterminate nodules, respectively, provide a convenient system to study plant-Rhizobium interaction and to establish differences between the two types of nodules under salt stress conditions. We examined the effects of 25 and 50mM NaCl doses on growth and nitrogen fixation parameters, as well as carbohydrate content and carbon metabolism of M. truncatula and L. japonicus nodules. The leghemoglobin (Lb) content and nitrogen fixation rate (NFR) were approximately 10.0 and 2.0 times higher, respectively, in nodules of L. japonicus when compared with M. truncatula. Plant growth parameters and nitrogenase activity decreased with NaCl treatments in both legumes. Sucrose was the predominant sugar quantified in nodules of both legumes, showing a decrease in concentration in response to salt stress. The content of trehalose was low (less than 2.5% of total soluble sugars (TSS)) to act as an osmolyte in nodules, despite its concentration being increased under saline conditions. Nodule enzyme activities of trehalose-6-phosphate synthase (TPS) and trehalase (TRE) decreased with salinity. L. japonicus nodule carbon metabolism proved to be less sensitive to salinity than in M. truncatula, as enzymatic activities responsible for the carbon supply to the bacteroids to fuel nitrogen fixation, such as sucrose synthase (SS), alkaline invertase (AI), malate dehydrogenase (MDH) and phosphoenolpyruvate carboxylase (PEPC), were less affected by salt than the corresponding activities in barrel medics. However, nitrogenase activity was only inhibited by salinity in L. japonicus nodules.

  6. Explosive attractor solutions to a universal cubic delay equation

    NASA Astrophysics Data System (ADS)

    Sanz-Orozco, David

    2016-10-01

    This presentation describes new explosive attractor solutions to the universal cubic delay equation found in both the fluid and (for a kinetic system) in the plasma literature. Our results will be explained in the notation of the plasma problem, where a cubic delay equation describes the evolution of a wave in a kinetic system, and is characterized by a control parameter ϕ (its value is determined by the linear properties of the kinetic response). The linear eigenvalues do not exist in absence of the kinetic response (with exceptions for ϕ = 0 or π) but with the kinetic contribution, marginally unstable modes emerge when the kinetic drive is at a critical level. The simulation of the temporal evolution reveals the development of an explosive mode, i.e. a mode growing without bound in a finite time. The two main features of the response are: (1) a well-known explosive envelope (t0 - t) - 5 / 2, with t0 the blow-up time of the amplitude; (2) a spectrum with ever-increasing oscillation frequencies that is critically-dependent upon the parameter ϕ. A code has been constructed that resolves these oscillations over many periods by calculating their Fourier transform with respect to the pseudo-time x = - ln (t0 - t) . In addition, our analytic modeling explains the results and quantitatively nearly replicates the attractor solutions found in the simulations. A physical result of these solutions is the development of frequency chirping of the observed wave. This effect continues beyond the applicability of the cubic delay equation, and thus the attractor solutions that we study represent precursors to long-lived phenomena that may be used in an experimental situation to understand the nature of a system's equilibrium. Dr. Herbert L. Berk.

  7. Cubic Phases, Cubosomes and Ethosomes for Cutaneous Application.

    PubMed

    Esposito, Elisabetta; Drechsler, Markus; Nastruzzi, Claudio; Cortesi, Rita

    2016-01-01

    Cutaneous administration represents a good strategy to treat skin diseases, avoiding side effects related to systemic administration. Apart from conventional therapy, based on the use of semi-solid formulation such as gel, ointments and creams, recently the use of specialized delivery systems based on lipid has been taken hold. This review provides an overview about the use of cubic phases, cubosomes and ethosomes, as lipid systems recently proposed to treat skin pathologies. In addition in the final part of the review cubic phases, cubosomes and ethosomes are compared to solid lipid nanoparticles and lecithin organogel with respect to their potential as delivery systems for cutaneous application. It has been reported that lipid nanosystems are able to dissolve and deliver active molecules in a controlled fashion, thereby improving their bioavailability and reducing side-effects. Particularly lipid matrixes are characterized by skin affinity and biocompatibility allowing their application on skin. Indeed, after cutaneous administration, the lipid matrix of cubic phases and cubosomes coalesces with the lipids of the stratum comeum and leads to the formation of a lipid depot from which the drug associated to the nanosystem can be released in the deeper skin strata in a controlled manner. Ethosomes are characterized by a malleable structure that promotes their interaction with skin, improving their potential as skin delivery systems with respect to liposomes. Also in the case of solid lipid nanoparticles it has been suggested a deep interaction between lipid matrix and skin strata that endorses sustained and prolonged drug release. Concerning lecithin organogel, the peculiar structure of this system, where lecithin exerts a penetration enhancer role, allows a deep interaction with skin strata, promoting the transdermal absorption of the encapsulated drugs.

  8. Superconductivity of sodium tungsten bronze with cubic structure

    NASA Astrophysics Data System (ADS)

    Garif'yanov, N. N.; Khlebnikov, S. Ya.; Khlebnikov, I. S.; Garifullin, I. A.

    1996-02-01

    Sodium tungsten bronze Na x WO3 with cubic structure is reported to exhibit bulk superconductivity at sodium content 0.16≤ x≤0.4. The superconducting transition temperature T c and the temperature dependence of the critical field H c2 have been measured for the samples with different x. It was concluded that the enhancement of T c at low x-values occurs due to softening of the phonon spectrum. The possible reason for positive curvature of the H c2 vs T curve is discussed.

  9. A cubic extended interior penalty function for structural optimization

    NASA Technical Reports Server (NTRS)

    Prasad, B.; Haftka, R. T.

    1979-01-01

    This paper describes an optimization procedure for the minimum weight design of complex structures. The procedure is based on a new cubic extended interior penalty function (CEIPF) used with the sequence of unconstrained minimization technique (SUMT) and Newton's method. The Hessian matrix of the penalty function is approximated using only constraints and their derivatives. The CEIPF is designed to minimize the error in the approximation of the Hessian matrix, and as a result the number of structural analyses required is small and independent of the number of design variables. Three example problems are reported. The number of structural analyses is reduced by as much as 50 per cent below previously reported results.

  10. Orbital Non-Fermi-Liquid Behavior in Cubic Ruthenates

    NASA Astrophysics Data System (ADS)

    Laad, M. S.; Bradarić, I.; Kusmartsev, F. V.

    2008-03-01

    We peruse various anomalous physical responses of the cubic (ferromagnetic SrRuO3 and paramagnetic CaRuO3) ruthenates, such as fractional power-law conductivity, anomalous Raman line shapes, and Hall currents. We show how these exciting power-law observations are naturally described within a new, local (orbital) non-Fermi-liquid state arising from strong, multiorbital Coulomb interactions. Introducing a multiorbital, correlated model treated within the dynamical mean-field theory, we also find two distinct relaxation rates for relaxation of transport in complete agreement with experiment.

  11. Orbital non-fermi-liquid behavior in cubic ruthenates.

    PubMed

    Laad, M S; Bradarić, I; Kusmartsev, F V

    2008-03-07

    We peruse various anomalous physical responses of the cubic (ferromagnetic SrRuO3 and paramagnetic CaRuO3) ruthenates, such as fractional power-law conductivity, anomalous Raman line shapes, and Hall currents. We show how these exciting power-law observations are naturally described within a new, local (orbital) non-Fermi-liquid state arising from strong, multiorbital Coulomb interactions. Introducing a multiorbital, correlated model treated within the dynamical mean-field theory, we also find two distinct relaxation rates for relaxation of transport in complete agreement with experiment.

  12. Local environment of silicon in cubic boron nitride

    SciTech Connect

    Murata, Hidenobu Taniguchi, Takashi; Hishita, Shunichi; Yamamoto, Tomoyuki; Oba, Fumiyasu; Tanaka, Isao

    2013-12-21

    Si-doped cubic boron nitride (c-BN) is synthesized at high pressure and high temperature, and the local environment of Si is investigated using X-ray absorption near edge structure (XANES) and first-principles calculations. Si-K XANES indicates that Si in c-BN is surrounded by four nitrogen atoms. According to first-principles calculations, the model for substitutional Si at the B site well reproduces experimental Si-K XANES, and it is energetically more favorable than substitutional Si at the N site. Both the present experimental and theoretical results indicate that Si in c-BN prefers the B site to the N site.

  13. Inhomogeneous atomic Bose-Fermi mixtures in cubic lattices.

    PubMed

    Cramer, M; Eisert, J; Illuminati, F

    2004-11-05

    We determine the ground state properties of inhomogeneous mixtures of bosons and fermions in cubic lattices and parabolic confining potentials. For finite hopping we determine the domain boundaries between Mott-insulator plateaux and hopping-dominated regions for lattices of arbitrary dimension within mean-field and perturbation theory. The results are compared with a new numerical method that is based on a Gutzwiller variational approach for the bosons and an exact treatment for the fermions. The findings can be applied as a guideline for future experiments with trapped atomic Bose-Fermi mixtures in optical lattices.

  14. Rotary Ultrasonic Machining of Poly-Crystalline Cubic Boron Nitride

    NASA Astrophysics Data System (ADS)

    Kuruc, Marcel; Peterka, Jozef

    2014-12-01

    Poly-crystalline cubic boron nitride (PCBN) is one of the hardest material. Generally, so hard materials could not be machined by conventional machining methods. Therefore, for this purpose, advanced machining methods have been designed. Rotary ultrasonic machining (RUM) is included among them. RUM is based on abrasive removing mechanism of ultrasonic vibrating diamond particles, which are bonded on active part of rotating tool. It is suitable especially for machining hard and brittle materials (such as glass and ceramics). This contribution investigates this advanced machining method during machining of PCBN.

  15. Emission properties of body-centered cubic elemental metal photocathodes

    SciTech Connect

    Li, Tuo; Rickman, Benjamin L. Schroeder, W. Andreas

    2015-04-07

    A first principles analysis of photoemission is developed to explain the lower than expected rms transverse electron momentum measured using the solenoid scan technique for the body-centered cubic Group Vb (V, Nb, and Ta) and Group VIb (Cr, Mo, and W) metallic photocathodes. The density functional theory based analysis elucidates the fundamental role that the electronic band structure (and its dispersion) plays in determining the emission properties of solid-state photocathodes and includes evaluation of work function anisotropy using a thin-slab method.

  16. Pseudorecurrence and chaos of cubic-quintic nonlinear Schroedinger equation

    SciTech Connect

    Zhou, C.; Lai, C.H.

    1996-12-01

    Recurrence, pseudorecurrence, and chaotic solutions for a continuum Hamiltonian system in which there exist spatial patterns of solitary wave structures are investigated using the nonlinear Schrodinger equation (NSE) with cubic and quintic terms. The theoretical analyses indicate that there may exist Birkhoff`s recurrence for the arbitrary parameter values. The numerical experiments show that there may be Fermi-Pasta-Ulam (FPU) recurrence, pseudorecurrence, and chaos when different initial conditions are chosen. The fact that the system energy is effectively shared by finite Fourier modes suggests that it may be possible to describe the continuum system in terms of some effective degrees of freedom.

  17. A cubic extended interior penalty function for structural optimization

    NASA Technical Reports Server (NTRS)

    Prasad, B.; Haftka, R. T.

    1979-01-01

    This paper describes an optimization procedure for the minimum weight design of complex structures. The procedure is based on a new cubic extended interior penalty function (CEIPF) used with the sequence of unconstrained minimization technique (SUMT) and Newton's method. The Hessian matrix of the penalty function is approximated using only constraints and their derivatives. The CEIPF is designed to minimize the error in the approximation of the Hessian matrix, and as a result the number of structural analyses required is small and independent of the number of design variables. Three example problems are reported. The number of structural analyses is reduced by as much as 50 per cent below previously reported results.

  18. A topological coordinate system for the diamond cubic grid.

    PubMed

    Čomić, Lidija; Nagy, Benedek

    2016-09-01

    Topological coordinate systems are used to address all cells of abstract cell complexes. In this paper, a topological coordinate system for cells in the diamond cubic grid is presented and some of its properties are detailed. Four dependent coordinates are used to address the voxels (triakis truncated tetrahedra), their faces (hexagons and triangles), their edges and the points at their corners. Boundary and co-boundary relations, as well as adjacency relations between the cells, can easily be captured by the coordinate values. Thus, this coordinate system is apt for implementation in various applications, such as visualizations, morphological and topological operations and shape analysis.

  19. Synthesis and Optical Properties of Cubic Gold Nanoframes

    PubMed Central

    Au, Leslie; Chen, Yeechi; Zhou, Fei; Camargo, Pedro H. C.; Lim, Byungkwon; Li, Zhi-Yuan; Ginger, David S.; Xia, Younan

    2009-01-01

    This paper describes a facile method of preparing cubic Au nanoframes with open structures via the galvanic replacement reaction between Ag nanocubes and AuCl2−. A mechanistic study of the reaction revealed that the formation of Au nanoframes relies on the diffusion of both Au and Ag atoms. The effect of the edge length and ridge thickness of the nanoframes on the localized surface plasmon resonance peak was explored by a combination of discrete dipole approximation calculations and single nanoparticle spectroscopy. With their hollow and open structures, the Au nanoframes represent a novel class of substrates for applications including surface plasmonics and surface-enhanced Raman scattering. PMID:20200595

  20. Preparation of superhydrophobic nanodiamond and cubic boron nitride films

    NASA Astrophysics Data System (ADS)

    Zhou, Y. B.; Yang, Y.; Liu, W. M.; Ye, Q.; He, B.; Zou, Y. S.; Wang, P. F.; Pan, X. J.; Zhang, W. J.; Bello, I.; Lee, S. T.

    2010-09-01

    Superhydrophobic surfaces were achieved on the hardest and the second hardest materials, diamond and cubic boron nitride (cBN) films. Various surface nanostructures of nanocrystalline diamond (ND) and cBN films were constructed by carrying out bias-assisted reactive ion etching in hydrogen/argon plasmas; and it is shown that surface nanostructuring may enhance dramatically the hydrophobicity of ND and cBN films. Together with surface fluorination, superhydrophobic ND and cBN surfaces with a contact angle greater than 150° and a sliding angle smaller than 10° were demonstrated. The origin of hydrophobicity enhancement is discussed based on the Cassie model.

  1. 3D semiconducting nanostructures via inverse lipid cubic phases.

    PubMed

    Burton, M R; Lei, C; Staniec, P A; Terrill, N J; Squires, A M; White, N M; Nandhakumar, Iris S

    2017-07-25

    Well-ordered and highly interconnected 3D semiconducting nanostructures of bismuth sulphide were prepared from inverse cubic lipid mesophases. This route offers significant advantages in terms of mild conditions, ease of use and electrode architecture over other routes to nanomaterials synthesis for device applications. The resulting 3D bicontinous nanowire network films exhibited a single diamond topology of symmetry Fd3m (Q227) which was verified by Small angle X-ray scattering (SAXS) and Transmission electron microscopy (TEM) and holds great promise for potential applications in optoelectronics, photovoltaics and thermoelectrics.

  2. Cubic to tetragonal crystal lattice reconstruction during ordering or decomposition

    SciTech Connect

    Cheong, Byung-kl

    1992-09-01

    This thesis studied thermodynamic stability and morphology of product phases in diffusional phase transformations involving cubic-to-tetragonal crystal lattice reconstructions. Two different kinds of diffusional transformations were examined: L1{sub 0} ordering (fcc to fct lattice change) and decomposition of off-stoichiometric B2 ordering alloys accompanying bcc to fcc Bain transformation. In the first case, Fe-45 at.% Pd alloys were studied by TEM; in the second, the Bain strain relaxation during decomposition of hyper-eutectoid Cu-9.04 wt% Be alloy was studied. CuAu and InMg were also studied.

  3. Stable single-crystalline body centered cubic Fe nanoparticles.

    PubMed

    Lacroix, Lise-Marie; Huls, Natalie Frey; Ho, Don; Sun, Xiaolian; Cheng, Kai; Sun, Shouheng

    2011-04-13

    We report a facile synthesis of body centered cubic (bcc) Fe nanoparticles (NPs) via the thermal decomposition of iron pentacarbonyl, Fe(CO)(5), in the presence of hexadecylammonium chloride. These bcc-Fe NPs exhibit a drastically increased stability and magnetic moment (M(s) = 164 A·m(2)·kg(-1)(Fe)) even in physiological solutions, and have much enhanced magnetic imaging contrast (r(2) = 220 s(-1)·mM(-1)) and heating (SAR = 140 W·g(-1)(Fe)) effects. They may serve as robust probes for imaging and therapeutic applications.

  4. Comparison of oligonucleotide migration in a bicontinuous cubic phase of monoolein and water and in a fibrous agarose hydrogel.

    PubMed

    Sanandaji, Nima; Carlsson, Nils; Voinova, Marina; Akerman, Björn

    2006-08-01

    Porous hydrogels such as agarose are commonly used to analyze DNA and water-soluble proteins by electrophoresis. More recently lyotropic liquid crystals, such as the diamond cubic phase formed by the lipid monoolein and water, has become a new type of well-defined porous structure of interest for both hydrophilic and amphiphilic analytes. Here we compare these two types of matrixes by investigating the nature of retardation they confer to an oligonucleotide that migrates in their respective aqueous phases. The retardation for a 25-mer oligonucleotide was found to be about 35-fold stronger in the cubic phase than in an agarose hydrogel modified to have the same average pore size. According to modelling, the strong retardation is primarily due to the fact that hydrodynamic interaction with the continuous monoolein membrane is a stronger source of friction than the steric interactions (collisions) with discrete gel fibres. A secondary effect is that the regular liquid crystal has a narrower pore-size distribution than the random network of the agarose gel. In agreement with experiments, these two effects together predict that the retardation in the cubic phase is a 30-fold stronger than in an agarose gel with the same average pore radius.

  5. Atomic-scale imaging of the dissolution of NaCl islands by water at low temperature

    NASA Astrophysics Data System (ADS)

    Peng, Jinbo; Guo, Jing; Ma, Runze; Meng, Xiangzhi; Jiang, Ying

    2017-03-01

    The dissolution of sodium chloride (NaCl) in water is a frequently encountered process in our daily lives. While the NaCl dissolution process in liquid water has been extensively studied, whether and how the dissolution occurs below the freezing point is still not clear. Using a low-temperature scanning tunneling microscope (STM), here we were able to directly visualize the dissolution of Au-supported NaCl (0 0 1) bilayer islands by water at atomic level. We found that the single water molecule on the STM tip can assist the extraction of single Na+ from the NaCl surface even at 5 K, while leaving the Cl‑ intact. When covered with a full water monolayer, the NaCl islands started to dissolve from the step edges and also showed evidence of dissolution inside the terraces as the temperature was raised up to 145 K. At 155 K, the water molecules completely desorbed from the surface, which was accompanied with the decomposition and restructuring of the bilayer NaCl islands. Those results suggest that the dissolution of NaCl may occur well below the freezing point at the ice/NaCl interfaces and is mainly driven by the interaction between the water molecules and the Na+, which is in clear contrast with the NaCl dissolution in liquid water.

  6. Atomic-scale imaging of the dissolution of NaCl islands by water at low temperature.

    PubMed

    Peng, Jinbo; Guo, Jing; Ma, Runze; Meng, Xiangzhi; Jiang, Ying

    2017-03-15

    The dissolution of sodium chloride (NaCl) in water is a frequently encountered process in our daily lives. While the NaCl dissolution process in liquid water has been extensively studied, whether and how the dissolution occurs below the freezing point is still not clear. Using a low-temperature scanning tunneling microscope (STM), here we were able to directly visualize the dissolution of Au-supported NaCl (0 0 1) bilayer islands by water at atomic level. We found that the single water molecule on the STM tip can assist the extraction of single Na(+) from the NaCl surface even at 5 K, while leaving the Cl(-) intact. When covered with a full water monolayer, the NaCl islands started to dissolve from the step edges and also showed evidence of dissolution inside the terraces as the temperature was raised up to 145 K. At 155 K, the water molecules completely desorbed from the surface, which was accompanied with the decomposition and restructuring of the bilayer NaCl islands. Those results suggest that the dissolution of NaCl may occur well below the freezing point at the ice/NaCl interfaces and is mainly driven by the interaction between the water molecules and the Na(+), which is in clear contrast with the NaCl dissolution in liquid water.

  7. Effect of NaCl on heat resistance, antibiotic susceptibility, and Caco-2 cell invasion of Salmonella.

    PubMed

    Yoon, Hyunjoo; Park, Beom-Young; Oh, Mi-Hwa; Choi, Kyoung-Hee; Yoon, Yohan

    2013-01-01

    This study evaluated the effects of NaCl on heat resistance, antibiotic susceptibility, and Caco-2 cell invasion of Salmonella. Salmonella typhimurium NCCP10812 and Salmonella enteritidis NCCP12243 were exposed to 0, 2, and 4% NaCl and to sequential increase of NaCl concentrations from 0 to 4% NaCl for 24 h at 35°C. The strains were then investigated for heat resistance (60°C), antibiotic susceptibility to eight antibiotics, and Caco-2 cell invasion efficiency. S. typhimurium NCCP10812 showed increased thermal resistance (P < 0.05) after exposure to single NaCl concentrations. A sequential increase of NaCl concentration decreased (P < 0.05) the antibiotic sensitivities of S. typhimurium NCCP10812 to chloramphenicol, gentamicin, and oxytetracycline. NaCl exposure also increased (P < 0.05) Caco-2 cell invasion efficiency of S. enteritidis NCCP12243. These results indicate that NaCl in food may cause increased thermal resistance, cell invasion efficiency, and antibiotic resistance of Salmonella.

  8. Low-field NMR determination of water distribution in meat batters with NaCl and polyphosphate addition.

    PubMed

    Shao, Jun-Hua; Deng, Ya-Min; Jia, Na; Li, Ru-Ren; Cao, Jin-Xuan; Liu, Deng-Yong; Li, Jian-Rong

    2016-06-01

    The objective was to elucidate the influence of NaCl and polyphosphates in the stage of protein swelling on the water-holding capacity (WHC) of meat batter. The meat batters were formulated with salt in different ways by adding established amounts of only NaCl, only polyphosphates, jointly adding NaCl and polyphosphates, and a control without any salt. An increase (p<0.05) in water retention was found when a combination of NaCl and polyphosphates was used. A high textural parameter was observed in the two treatments with NaCl, but not in the group with only polyphosphate. For the polyphosphate group, T22 was lower (p<0.05) than in the other three before heating; however, after heating, T21 and T22 were both significantly decreased, and a new component emerged, T23, which was significantly lower than the others. For the NaCl treatment, heated or not, T22 was always the highest. It was revealed that NaCl had affected the WHC by increasing the mobility and distribution of water, particularly with polyphosphate, but polyphosphate could not be an equal substitute for NaCl given its resulting lowest textural properties and poor microstructure. By presenting different hydration states in the protein swelling stage, the meat batter qualities were differentiated. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Computational prediction of body-centered cubic carbon in an all-sp3 six-member ring configuration

    DOE PAGES

    Li, Zhen -Zhen; Lian, Chao -Sheng; Xu, Jing; ...

    2015-06-11

    Recent shock compression experiments produced clear evidence of a new carbon phase, but a full structural identification has remained elusive. Here we establish by ab initio calculations a body-centered cubic carbon phase in Ia3¯d(O10h) symmetry, which contains twelve atoms in its primitive cell, thus termed BC12, and comprises all-sp3 six-membered rings. This structural configuration places BC12 carbon in the same bonding type as cubic diamond, and its stability is verified by phonon mode analysis. Simulated x-ray diffraction patterns provide an excellent match to the previously unexplained distinct diffraction peak found in shock compression experiments. Electronic band and density of statesmore » calculations reveal that BC12 is a semiconductor with a direct band gap of ~2.97eV. Lastly, these results provide a solid foundation for further exploration of this new carbon allotrope.« less

  10. Precipitates of MnSi cubic phase in tetragonal Mn{sub 4}Si{sub 7} crystal

    SciTech Connect

    Suvorova, E. I. Klechkovskaya, V. V.

    2013-11-15

    Higher manganese silicides (HMSs) exhibit interesting thermoelectric and optoelectronic properties. Development of HMS-based thermoelements and microthermopiles of different designs may meet a number of problems, which can be solved only when the real structure of crystals and thin layers on which they are based is established. We have applied scanning and transmission electron microscopy and electron diffraction to investigate HMS crystals of two types: single crystals grown from melt by the Bridgman method and microislands formed by reactive diffusion during manganese vapor deposition on silicon substrates. The exact phase composition of these materials is established: matrix HMS crystal belonging to tetragonal system (Mn{sub 4}Si{sub 7} composition) and precipitates of cubic manganese monosilicide MnSi. The shape and sizes of precipitates are determined, the crystallographic relationships between the tetragonal and cubic phases are found, and the interface is investigated.

  11. Computational prediction of body-centered cubic carbon in an all-s p3 six-member ring configuration

    NASA Astrophysics Data System (ADS)

    Li, Zhen-Zhen; Lian, Chao-Sheng; Xu, Jing; Xu, Li-Fang; Wang, Jian-Tao; Chen, Changfeng

    2015-06-01

    Recent shock compression experiments produced clear evidence of a new carbon phase, but a full structural identification has remained elusive. Here we establish by ab initio calculations a body-centered cubic carbon phase in I a 3 ¯d (Oh10) symmetry, which contains twelve atoms in its primitive cell, thus termed BC12, and comprises all-s p3 six-membered rings. This structural configuration places BC12 carbon in the same bonding type as cubic diamond, and its stability is verified by phonon mode analysis. Simulated x-ray diffraction patterns provide an excellent match to the previously unexplained distinct diffraction peak found in shock compression experiments. Electronic band and density of states calculations reveal that BC12 is a semiconductor with a direct band gap of ˜2.97 eV . These results provide a solid foundation for further exploration of this new carbon allotrope.

  12. Theoretical and experimental study of laser radiation propagating in a medium with thermally induced birefringence and cubic nonlinearity.

    PubMed

    Kuzmina, M S; Martyanov, M A; Poteomkin, A K; Khazanov, E A; Shaykin, A A

    2011-10-24

    We consider a problem of laser radiation propagating in a medium with birefringence of two types: linear birefringence independent of intensity and polarization, and intensity and polarization dependent circular birefringence caused by cubic nonlinearity. It is shown theoretically and experimentally that the efficiency of the broadly employed method of linear depolarization compensation by means of a 90° polarization rotator decreases with increasing В-integral (nonlinear phase incursion induced by cubic nonlinearity). The accuracy of polarization transformation by means of a half-wave and a quarter-wave plate also decreases if В > 1. By the example of a λ/4 plate it is shown that this parasitic effect may be suppressed considerably by choosing an optimal angle of inclination of the optical axis of the plate.

  13. Temperature invariance of NaCl solubility in water: inferences from salt-water cluster behavior of NaCl, KCl, and NH4Cl.

    PubMed

    Bharmoria, Pankaj; Gupta, Hariom; Mohandas, V P; Ghosh, Pushpito K; Kumar, Arvind

    2012-09-27

    The growth and stability of salt-water clusters have been experimentally studied in aqueous solutions of NaCl, KCl, and NH(4)Cl from dilute to near-saturation conditions employing dynamic light scattering and zeta potential measurements. In order to examine cluster stability, the changes in the cluster sizes were monitored as a function of temperature. Compared to the other cases, the average size of NaCl-water clusters remained almost constant over the studied temperature range of 20-70 °C. Information obtained from the temperature-dependent solution compressibility (determined from speed of sound and density measurements), multinuclear NMR ((1)H, (17)O, (35)Cl NMR), and FTIR were utilized to explain the cluster behavior. Comparison of NMR chemical shifts of saturated salt solutions with solid-state NMR data of pure salts, and evaluation of spectral modifications in the OH stretch region of saturated salt solutions as compared to that of pure water, provided important clues on ion pair-water interactions and water structure in the clusters. The high stability and temperature independence of the cluster sizes in aqueous NaCl shed light on the temperature invariance of its solubility.

  14. The effect of NaCl 0.9% and NaCl 0.45% on sodium, chloride, and acid-base balance in a PICU population.

    PubMed

    Almeida, Helena Isabel; Mascarenhas, Maria Inês; Loureiro, Helena Cristina; Abadesso, Clara S; Nunes, Pedro S; Moniz, Marta S; Machado, Maria Céu

    2015-01-01

    To study the effect of two intravenous maintenance fluids on plasma sodium (Na), and acid-base balance in pediatric intensive care patients during the first 24h of hospitalization. A prospective randomized controlled study was performed, which allocated 233 patients to groups: (A) NaCl 0.9% or (B) NaCl 0.45%. Patients were aged 1 day to 18 years, had normal electrolyte concentrations, and suffered an acute insult (medical/surgical). change in plasma sodium. Parametric tests: t-tests, ANOVA, X(2) statistical significance level was set at α=0.05. Group A (n=130): serum Na increased by 2.91 (±3.9)mmol/L at 24h (p<0.01); 2% patients had Na higher than 150 mmol/L. Mean urinary Na: 106.6 (±56.8)mmol/L. No change in pH at 0 and 24h. Group B (n=103): serum Na did not display statistically significant changes. Fifteen percent of the patients had Na<135 mmol/L at 24h. The two fluids had different effects on respiratory and post-operative situations. The use of saline 0.9% was associated with a lower incidence of electrolyte disturbances. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  15. Characteristics of injury and recovery of net NO3- transport of barley seedlings from treatments of NaCl

    NASA Technical Reports Server (NTRS)

    Klobus, G.; Ward, M. R.; Huffaker, R. C.

    1988-01-01

    The nature of the injury and recovery of nitrate uptake (net uptake) from NaCl stress in young barley (Hordeum vulgare L, var CM 72) seedlings was investigated. Nitrate uptake was inhibited rapidly by NaCl, within 1 minute after exposure to 200 millimolar NaCl. The duration of exposure to saline conditions determined the time of recovery of NO3- uptake from NaCl stress. Recovery was dependent on the presence of NO3- and was inhibited by cycloheximide, 6-methylpurine, and cerulenin, respective inhibitors of protein, RNA, and sterol/fatty acid synthesis. These inhibitors also prevented the induction of the NO3- uptake system in uninduced seedlings. Uninduced seedlings exhibited endogenous NO3- transport activity that appeared to be constitutive. This constitutive activity was also inhibited by NaCl. Recovery of constitutive NO3- uptake did not require the presence of NO3-.

  16. Characteristics of injury and recovery of net NO3- transport of barley seedlings from treatments of NaCl

    NASA Technical Reports Server (NTRS)

    Klobus, G.; Ward, M. R.; Huffaker, R. C.

    1988-01-01

    The nature of the injury and recovery of nitrate uptake (net uptake) from NaCl stress in young barley (Hordeum vulgare L, var CM 72) seedlings was investigated. Nitrate uptake was inhibited rapidly by NaCl, within 1 minute after exposure to 200 millimolar NaCl. The duration of exposure to saline conditions determined the time of recovery of NO3- uptake from NaCl stress. Recovery was dependent on the presence of NO3- and was inhibited by cycloheximide, 6-methylpurine, and cerulenin, respective inhibitors of protein, RNA, and sterol/fatty acid synthesis. These inhibitors also prevented the induction of the NO3- uptake system in uninduced seedlings. Uninduced seedlings exhibited endogenous NO3- transport activity that appeared to be constitutive. This constitutive activity was also inhibited by NaCl. Recovery of constitutive NO3- uptake did not require the presence of NO3-.

  17. High Cubic-Phase Purity InN on MgO (001) Using Cubic-Phase GaN as a Buffer Layer

    SciTech Connect

    Sanorpim, S.; Kuntharin, S.; Parinyataramas, J.; Yaguchi, H.; Iwahashi, Y.; Orihara, M.; Hijikata, Y.; Yoshida, S.

    2011-12-23

    High cubic-phase purity InN films were grown on MgO (001) substrates by molecular beam epitaxy with a cubic-phase GaN buffer layer. The cubic phase purity of the InN grown layers has been analyzed by high resolution X-ray diffraction, {mu}-Raman scattering and transmission electron microscopy. It is evidenced that the hexagonal-phase content in the InN overlayer much depends on hexagonal-phase content in the cubic-phase GaN buffer layer and increases with increasing the hexagonal-phase GaN content. From Raman scattering measurements, in addition, the InN layer with lowest hexagonal component (6%), only Raman characteristics of cubic TO{sub InN} and LO{sub InN} modes were observed, indicating a formation of a small amount of stacking faults, which does not affect on vibrational property.

  18. Differential tolerance of 3 self-rooted Citrus limon cultivars to NaCl stress.

    PubMed

    Tsabarducas, V; Chatzistathis, T; Therios, I; Koukourikou-Petridou, M; Tananaki, C

    2015-12-01

    One-year-old self-rooted cuttings of three Citrus limon cultivars (Nouvel Athos, Lisbon, Maglini) were grown in 1 L black plastic bags, containing a mixture of sand: perlite (1:1), in order to investigate: i) if genotypic differences to salt stress existed, ii) if KNO3 can alleviate salinity stress, iii) the role of carbohydrates (such as the sugars fructose, glucose and sucrose) and proline as possible osmoregulators in C. limon osmoprotection, and iv) if genotypic differences to salt stress tolerance exist among the 3 studied cultivars. The experiment included 3 treatments: i) control (C), i.e. 25% modified Hoagland (No2) solution (MHS)-NaCl, ii) T1, 25% MHS+80 mM NaCl, iii) T2, 25% MHS+80 mM NaCl+5 mM KNO3. Plant growth was negatively affected by high NaCl (T1); the highest Cl and Na quantities have been absorbed by Lisbon, while the lowest ones by Maglini. Salt stress reduced macronutrient and Zn concentrations, as well as the total carbohydrate concentration, and increased peroxidase (POD) activity and chlorophyll fluorescence in the leaves of the 3 C. limon cultivars studied; five mM KNO3 application alleviated the harmful effect of salt stress on leaf total carbohydrate concentration and leaf N and K concentrations. Sucrose was dramatically reduced in all the three genotypes studied, while leaf fructose concentration was significantly increased in Nouvel Nouvel Nouvel Athos and Maglini under salt stress. Leaf proline concentration of Maglini was significantly decreased by the high NaCl concentration, while Nouvel Athos and Lisbon had high proline concentration in their leaves. In conclusion, from the significantly decreased levels of proline for Maglini, together with the greatest reduction of the ratio Fv/Fm and the least enhancement of POD activity-compared to the other two cultivars-it can be concluded that Maglini was more susceptible to salinity, and should not be preferred for cultivation under NaCl stress. Finally, rich KNO3 application

  19. Spectroscopic measurements of the pH in NaCl brines

    NASA Astrophysics Data System (ADS)

    Millero, Frank J.; DiTrolio, Benjamin; Suarez, Andres F.; Lando, Gabriele

    2009-06-01

    Spectrophotometric measurements of the pH in natural waters such as seawater have been shown to yield precise results. In this paper, the sulfonephthalein indicator m-cresol purple ( mCP, H 2I) has been used to determine the pH of NaCl brines. The indicator has been calibrated in NaCl solutions from 5 to 45 °C and ionic strengths from 0.03 to 5.5 m. The calibrations were made using TRIS buffers (0.03 m, TRIS/TRIS-HCl) with known dissociation constants pK TRIS in NaCl solutions [Foti C., Rigano C. and Sammartano S. (1999) Analysis of thermodynamic data for complex formation: protonation of THAM and fluoride ion at different temperatures and ionic strength. Ann. Chim. 89, 1-12]. The values of pH were determined from pH=pK+log{(R-e1)/(e2-Re3)} where R = 578A/ 434A, the ratios of the indicator absorbance maximum at 578 and 434 nm, e1 = 0.00691, e2 = 2.222 and e3 = 0.1331 [Clayton T. and Byrne R. H. (1993) Spectrophotometric seawater pH measurements: total hydrogen ion concentration scale calibration of m-cresol purple and at-sea results. Deep-Sea Res. 40, 2115-2129]. Measurements were also made in NaCl solutions with different levels of TRIS (0.01-0.11 m). At low levels of TRIS buffer (<0.03 m), the values of pK mCP increased significantly. This effect can lead to erroneous values of pK mCP at low ionic strengths in estuaries and lakes. The measured values of pK mCP in NaCl as a function of ionic strength ( I/m) and temperature ( T/K) were fitted to the equation ( σ = 0.0072) pK=-29.095+2639.2/T+5.0417lnT-0.3307I0.5-186.80I0.5/T-0.28346I+296.44I/T+0.12841I1.5-68.23I1.5/T These results should be useful in determining the pH of NaCl brines in natural waters from 0 to 50 °C.

  20. Final-state symmetry of Na 1s core-shell excitons in NaCl and NaF

    SciTech Connect

    Nagle, K.P.; Seidler, G.T.; Shirley, E.L.; Fister, T.T.; Bradley, J.A.; Brown, F.C.

    2009-08-13

    We report measurements of the Na 1s contribution to the nonresonant inelastic x-ray scattering (NRIXS) from NaCl and NaF. Prior x-ray absorption studies have observed two pre-edge excitons in both materials. The momentum-transfer dependence (q dependence) of the measured NRIXS cross section and of real-space full multiple scattering and Bethe-Salpeter calculations determine that the higher-energy core excitons are s type for each material. The lower-energy core excitons contribute at most weakly to the NRIXS signal and we propose that these may be surface core excitons, as have been observed in several other alkali halides. The analysis of the orbital angular momentum of these features leads to a discussion of the limited sensitivity of NRIXS measurements to d-type final states when investigating 1s initial states. In this case the s- and p-type final density of states can be characterized by measurements at a small number of momentum transfers. This is in contrast to the case of more complex initial states for which measurements at a large number of momentum transfers are needed to separate the rich admixture of accessible and contributing final-state symmetries.

  1. Synthesis of a New Cubic Conductive Cu6O8-yMX (M=Tb, Dy, Ho, Er, Tm, Yb, Lu, X=NO3, Cl) Family

    NASA Astrophysics Data System (ADS)

    Sugise, Ryoji; Ohdan, Kyoji; Hamamoto, Toshikazu; Kashiwagi, Kouichi; Shirai, Masashi; Yazawa, Ichiro; Ihara, Hideo

    1993-07-01

    A new cubic Cu6O8-yMX family (M=Tb, Dy, Ho, Er, Tm, Yb, Lu, X=NO3, Cl) was prepared. These compounds showed metallic resistivity and paramagnetism. The Cu6O8-yMX compounds could be easily synthesized when a trivalent metal element (M) whose oxide (M2O3) has a cubic Tl2O3-type structure was used. These compounds were prepared in the thermal decomposition process of a mixed copper nitrate, copper chloride and metal element oxide solution. The lattice constants of the Cu6O8-yMX compounds were related to those of M2O3.

  2. Interactions of solitons in Bragg gratings with dispersive reflectivity in a cubic-quintic medium

    NASA Astrophysics Data System (ADS)

    Dasanayaka, Sahan; Atai, Javid

    2011-08-01

    Interactions between quiescent solitons in Bragg gratings with cubic-quintic nonlinearity and dispersive reflectivity are systematically investigated. In a previous work two disjoint families of solitons were identified in this model. One family can be viewed as the generalization of the Bragg grating solitons in Kerr nonlinearity with dispersive reflectivity (Type 1). On the other hand, the quintic nonlinearity is dominant in the other family (Type 2). For weak to moderate dispersive reflectivity, two in-phase solitons will attract and collide. Possible collision outcomes include merger to form a quiescent soliton, formation of three solitons including a quiescent one, separation after passing through each other once, asymmetric separation after several quasielastic collisions, and soliton destruction. Type 2 solitons are always destroyed by collisions. Solitons develop sidelobes when dispersive reflectivity is strong. In this case, it is found that the outcome of the interactions is strongly dependent on the initial separation of solitons. Solitons with sidelobes will collide only if they are in-phase and their initial separation is below a certain critical value. For larger separations, both in-phase and π-out-of-phase Type 1 and Type 2 solitons may either repel each other or form a temporary bound state that subsequently splits into two separating solitons. Additionally, in the case of Type 2 solitons, for certain initial separations, the bound state disintegrates into a single moving soliton.

  3. Tolerance of submerged germinating rice to 50-200 mM NaCl in aerated solution.

    PubMed

    Kurniasih, Budiastuti; Greenway, Hank; Colmer, Timothy David

    2013-10-01

    This paper concerns tolerance to 50-200 mM NaCl of submerged rice (Oryza sativa cv. Amaroo) during germination and the first 138-186 h of development in aerated solution. Rice was able to germinate and the seedlings even tolerated exposure to 200 mM NaCl, albeit with severe growth restrictions. After return to 0.3 mM NaCl, growth increased, indicating that even at 200 mM NaCl there was no irreparable injury. Osmotic adjustment was achieved by using Na⁺ and Cl⁻ as the major osmotica. At 200 mM NaCl commenced at sowing, the shoot Na⁺ and Cl⁻ concentrations between 50-110 h were about 210 and 260 mM, respectively, i.e. above the external concentration. Thus, there was a high tissue tolerance to NaCl. The internal concentrations declined subsequently, concurrent with a decline in growth. At 50-200 mM NaCl, the contributions from ions to πsap were 81-92% in roots and 62-74% in shoots. The assessed turgor pressures at 200 mM NaCl were 0.33 MPa in shoots and 0.15 MPa in roots, compared to 0.62 and 0.43 MPa at 0.3 mM NaCl. In the General Discussion section, we compare the different responses of submerged seedlings to the responses of transpiring rice plants, reported in the literature, and suggest that the submerged system is useful to evaluate effects of NaCl on turgor pressure and particularly to establish whether there are specific effects of Na⁺ and Cl⁻ in tissues.

  4. Four-dimensional black holes in Einsteinian cubic gravity

    NASA Astrophysics Data System (ADS)

    Bueno, Pablo; Cano, Pablo A.

    2016-12-01

    We construct static and spherically symmetric generalizations of the Schwarzschild- and Reissner-Nordström-(anti-)de Sitter [RN-(A)dS] black-hole solutions in four-dimensional Einsteinian cubic gravity (ECG). The solutions are characterized by a single function which satisfies a nonlinear second-order differential equation. Interestingly, we are able to compute independently the Hawking temperature T , the Wald entropy S and the Abbott-Deser mass M of the solutions analytically as functions of the horizon radius and the ECG coupling constant λ . Using these we show that the first law of black-hole mechanics is exactly satisfied. Some of the solutions have positive specific heat, which makes them thermodynamically stable, even in the uncharged and asymptotically flat case. Further, we claim that, up to cubic order in curvature, ECG is the most general four-dimensional theory of gravity which allows for nontrivial generalizations of Schwarzschild- and RN-(A)dS characterized by a single function which reduce to the usual Einstein gravity solutions when the corresponding higher-order couplings are set to zero.

  5. Giant Born effective charges in cubic WO_3.

    NASA Astrophysics Data System (ADS)

    Detraux, Francois; Ghosez, Philippe; Gonze, Xavier

    1997-03-01

    WO3 crystallizes in many different phases. It is also sometimes considered in a reference idealized simple cubic structure (defect-perovskite) where the tungsten is at the center of the cell and the oxygens at the middle of each face. Using a variational formulation of the density functional perturbation theory and a planewave-pseudopotential approach, we compute the Born effective charges for this idealized cubic structure, with an optimized lattice parameter of 3.73 ÅThe values obtained are anomalously large with respect to the nominal ionic charge (+6 on W and -2 on O). For the tungsten atom, the effective charge tensor is isotropic and Z_W= +12.43. For the oxygen, we must consider two different elements corresponding respectively to a displacement of the atom parallel or perpendicular to the W-O bond: Z^*O allel= -9.07 and Z^*O ⊥= -1.66. The giant anomalous contributions to Z^*W and Z^*O allel can be explained by transfer of charge produced by dynamic changes of hybridization between the O-2p and W-5d orbitals.

  6. Magnetic ground states in nanocuboids of cubic magnetocrystalline anisotropy

    NASA Astrophysics Data System (ADS)

    Bonilla, F. J.; Lacroix, L.-M.; Blon, T.

    2017-04-01

    Flower and easy-axis vortex states are well-known magnetic configurations that can be stabilized in small particles. However, <111> vortex (V<111>), i.e. a vortex state with its core axis along the hard-axis direction, has been recently evidenced as a stable configuration in Fe nanocubes of intermediate sizes in the flower/vortex transition. In this context, we present here extensive micromagnetic simulations to determine the different magnetic ground states in ferromagnetic nanocuboids exhibiting cubic magnetocrystalline anisotropy (MCA). Focusing our study in the single-domain/multidomain size range (10-50 nm), we showed that V<111> is only stable in nanocuboids exhibiting peculiar features, such as a specific size, shape and magnetic environment, contrarily to the classical flower and easy-axis vortex states. Thus, to track experimentally these V<111> states, one should focused on (i) nanocuboids exhibiting a nearly perfect cubic shape (size distorsion <12%) made of (ii) a material which combines a zero or positive MCA and a high saturation magnetization, such as Fe or FeCo; and (iii) a low magnetic field environment, V<111> being only observed in virgin or remanent states.

  7. Observation of Body-Centered Cubic Gold Nanocluster.

    PubMed

    Liu, Chao; Li, Tao; Li, Gao; Nobusada, Katsuyuki; Zeng, Chenjie; Pang, Guangsheng; Rosi, Nathaniel L; Jin, Rongchao

    2015-08-17

    The structure of nanoparticles plays a critical role in dictating their material properties. Gold is well known to adopt face-centered cubic (fcc) structure. Herein we report the first observation of a body-centered cubic (bcc) gold nanocluster composed of 38 gold atoms protected by 20 adamantanethiolate ligands and two sulfido atoms ([Au38S2(SR)20], where R=C10H15) as revealed by single-crystal X-ray crystallography. This bcc structure is in striking contrast with the fcc structure of bulk gold and conventional Au nanoparticles, as well as the bi-icosahedral structure of [Au38(SCH2CH2Ph)24]. The bcc nanocluster has a distinct HOMO-LUMO gap of ca. 1.5 eV, much larger than the gap (0.9 eV) of the bi-icosahedral [Au38(SCH2CH2Ph)24]. The unique structure of the bcc gold nanocluster may be promising in catalytic applications.

  8. Partially Blended Constrained Rational Cubic Trigonometric Fractal Interpolation Surfaces

    NASA Astrophysics Data System (ADS)

    Chand, A. K. B.; Tyada, K. R.

    2016-08-01

    Fractal interpolation is an advance technique for visualization of scientific shaped data. In this paper, we present a new family of partially blended rational cubic trigonometric fractal interpolation surfaces (RCTFISs) with a combination of blending functions and univariate rational trigonometric fractal interpolation functions (FIFs) along the grid lines of the interpolation domain. The developed FIFs use rational trigonometric functions pi,j(θ) qi,j(θ), where pi,j(θ) and qi,j(θ) are cubic trigonometric polynomials with four shape parameters. The convergence analysis of partially blended RCTFIS with the original surface data generating function is discussed. We derive sufficient data-dependent conditions on the scaling factors and shape parameters such that the fractal grid line functions lie above the grid lines of a plane Π, and consequently the proposed partially blended RCTFIS lies above the plane Π. Positivity preserving partially blended RCTFIS is a special case of the constrained partially blended RCTFIS. Numerical examples are provided to support the proposed theoretical results.

  9. Microstructural characterization of random packings of cubic particles

    PubMed Central

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

    2016-01-01

    Understanding the properties of random packings of solid objects is of critical importance to a wide variety of fundamental scientific and practical problems. The great majority of the previous works focused, however, on packings of spherical and sphere-like particles. We report the first detailed simulation and characterization of packings of non-overlapping cubic particles. Such packings arise in a variety of problems, ranging from biological materials, to colloids and fabrication of porous scaffolds using salt powders. In addition, packing of cubic salt crystals arise in various problems involving preservation of pavements, paintings, and historical monuments, mineral-fluid interactions, CO2 sequestration in rock, and intrusion of groundwater aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We have developed a version of the random sequential addition algorithm to generate such packings, and have computed a variety of microstructural descriptors, including the radial distribution function, two-point probability function, orientational correlation function, specific surface, and mean chord length, and have studied the effect of finite system size and porosity on such characteristics. The results indicate the existence of both spatial and orientational long-range order in the packing, which is more distinctive for higher packing densities. The maximum packing fraction is about 0.57. PMID:27725736

  10. Microstructural characterization of random packings of cubic particles

    DOE PAGES

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

    2016-10-11

    Understanding the properties of random packings of solid objects is of critical importance to a wide variety of fundamental scientific and practical problems. The great majority of the previous works focused, however, on packings of spherical and sphere-like particles. We report the first detailed simulation and characterization of packings of non-overlapping cubic particles. Such packings arise in a variety of problems, ranging from biological materials, to colloids and fabrication of porous scaffolds using salt powders. In addition, packing of cubic salt crystals arise in various problems involving preservation of pavements, paintings, and historical monuments, mineral-fluid interactions, CO2 sequestration in rock,more » and intrusion of groundwater aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We have developed a version of the random sequential addition algorithm to generate such packings, and have computed a variety of microstructural descriptors, including the radial distribution function, two-point probability function, orientational correlation function, specific surface, and mean chord length, and have studied the effect of finite system size and porosity on such characteristics. Here, the results indicate the existence of both spatial and orientational long-range order in the packing, which is more distinctive for higher packing densities.« less

  11. Microstructural characterization of random packings of cubic particles

    SciTech Connect

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

    2016-10-11

    Understanding the properties of random packings of solid objects is of critical importance to a wide variety of fundamental scientific and practical problems. The great majority of the previous works focused, however, on packings of spherical and sphere-like particles. We report the first detailed simulation and characterization of packings of non-overlapping cubic particles. Such packings arise in a variety of problems, ranging from biological materials, to colloids and fabrication of porous scaffolds using salt powders. In addition, packing of cubic salt crystals arise in various problems involving preservation of pavements, paintings, and historical monuments, mineral-fluid interactions, CO2 sequestration in rock, and intrusion of groundwater aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We have developed a version of the random sequential addition algorithm to generate such packings, and have computed a variety of microstructural descriptors, including the radial distribution function, two-point probability function, orientational correlation function, specific surface, and mean chord length, and have studied the effect of finite system size and porosity on such characteristics. Here, the results indicate the existence of both spatial and orientational long-range order in the packing, which is more distinctive for higher packing densities.

  12. Bistable synchronization of coupled random network of cubic maps

    NASA Astrophysics Data System (ADS)

    Nag, Mayurakshi

    2017-06-01

    The spatiotemporal behavior of coupled cubic maps over a dynamic network having randomness in coupling connections is investigated here. Due to the bistable nature of cubic map the synchronization behavior is dependent on the initial conditions. The network can stabilize to any one of the nonzero unstable fixed point of the map depending on the initial conditions. Linear stability analysis of synchronized fixed point gives the value of coupling at which onset of synchronization occurs. The critical coupling strength depends on the randomness in rewiring, properties of the local map, but it is independent of lattice size. Numerical simulation results match very well with predictions from theoretical analysis. Behaviors of the network for synchronized initial conditions are pointed out. Looking at the case of stability in a network with static rewiring, it is found that, the range of synchronization of fixed point becomes shorter than the dynamical random one. Contribution of delay in the synchronization phenomenon is studied both analytically and numerically and the range of synchronized period-2 orbit is found to be quite similar in both the cases. Multistable nature of the delay coupled network is shown numerically.

  13. Microstructural characterization of random packings of cubic particles

    NASA Astrophysics Data System (ADS)

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

    2016-10-01

    Understanding the properties of random packings of solid objects is of critical importance to a wide variety of fundamental scientific and practical problems. The great majority of the previous works focused, however, on packings of spherical and sphere-like particles. We report the first detailed simulation and characterization of packings of non-overlapping cubic particles. Such packings arise in a variety of problems, ranging from biological materials, to colloids and fabrication of porous scaffolds using salt powders. In addition, packing of cubic salt crystals arise in various problems involving preservation of pavements, paintings, and historical monuments, mineral-fluid interactions, CO2 sequestration in rock, and intrusion of groundwater aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We have developed a version of the random sequential addition algorithm to generate such packings, and have computed a variety of microstructural descriptors, including the radial distribution function, two-point probability function, orientational correlation function, specific surface, and mean chord length, and have studied the effect of finite system size and porosity on such characteristics. The results indicate the existence of both spatial and orientational long-range order in the packing, which is more distinctive for higher packing densities. The maximum packing fraction is about 0.57.

  14. Proton Ordering of Cubic Ice Ic: Spectroscopy and Computer Simulations.

    PubMed

    Geiger, Philipp; Dellago, Christoph; Macher, Markus; Franchini, Cesare; Kresse, Georg; Bernard, Jürgen; Stern, Josef N; Loerting, Thomas

    2014-05-22

    Several proton-disordered crystalline ice structures are known to proton order at sufficiently low temperatures, provided that the right preparation procedure is used. For cubic ice, ice Ic, however, no proton ordering has been observed so far. Here, we subject ice Ic to an experimental protocol similar to that used to proton order hexagonal ice. In situ FT-IR spectroscopy carried out during this procedure reveals that the librational band of the spectrum narrows and acquires a structure that is observed neither in proton-disordered ice Ic nor in ice XI, the proton-ordered variant of hexagonal ice. On the basis of vibrational spectra computed for ice Ic and four of its proton-ordered variants using classical molecular dynamics and ab initio simulations, we conclude that the features of our experimental spectra are due to partial proton ordering, providing the first evidence of proton ordering in cubic ice. We further find that the proton-ordered structure with the lowest energy is ferroelectric, while the structure with the second lowest energy is weakly ferroelectric. Both structures fit the experimental spectral similarly well such that no unique assignment of proton order is possible based on our results.

  15. Cubic Metallic Phase of Aluminum Hydride Showing Improved Hydrogen Desorption

    NASA Astrophysics Data System (ADS)

    Scheicher, Ralph H.; Kim, Duck Young; Ahuja, Rajeev

    2009-03-01

    AlH3 is of great interest for hydrogen storage applications, with a particularly attractive feature being its large hydrogen capacity of 10 wt.%. Here we report the results of our density functional theory study of the dehydrogenation properties in a cubic phase of AlH3. The metallic nature of the electronic structure entails a more favorable hydrogen removal energy which is lowered by 75% compared to the insulating hexagonal phase. This remarkable reduction in the Al--H bond strength might bear important consequences for feasible applications of AlH3 as an on-board hydrogen storage material for mobile applications. Suggestions are made how the cubic phase could be prepared and stabilized at ambient pressure by off-board quenching. See also: R. H. Scheicher, D. Y. Kim, S. Lebègue, B. Arnaud, M.Alouani, and R. Ahuja, Appl. Phys. Lett. 92, 201903 (2008) and D. Y. Kim, R. H. Scheicher, and R. Ahuja, Phys. Rev. B 78, 100102(R) (2008).

  16. Characterization of a cubic EJ-309 liquid scintillator detector

    NASA Astrophysics Data System (ADS)

    Tomanin, A.; Paepen, J.; Schillebeeckx, P.; Wynants, R.; Nolte, R.; Lavietes, A.

    2014-08-01

    A cubic EJ-309 liquid scintillator of 10 cm width has been characterized for its response to γ-rays and neutrons. Response functions to γ-rays were measured with calibrated radionuclide γ-ray sources in the energy range from 400 keV to 6 MeV. Response functions for neutrons were obtained from measurements at the PTB Van de Graaff accelerator with quasi-monoenergetic neutron beams in the energy range from 500 keV to 2.7 MeV, and at the PTB cyclotron with time-of-flight (TOF) measurements in the energy range from 2.5 to 14 MeV. The light output and resolution functions for electrons and protons were derived by a least squares adjustment to experimental data using theoretical response functions determined with Monte Carlo simulations. The simulated response function for neutron was validated by results of measurements with an AmBe neutron source which was characterized for its total neutron intensity. The results indicate that the cubic EJ-309 detector is suitable for use in mixed γ-ray and neutron fields.

  17. Numerical simulation of Burgers' equation using cubic B-splines

    NASA Astrophysics Data System (ADS)

    Lakshmi, C.; Awasthi, Ashish

    2017-03-01

    In this paper, a numerical θ scheme is proposed for solving nonlinear Burgers' equation. By employing Hopf-Cole transformation, the nonlinear Burgers' equation is linearized to the linear Heat equation. The resulting Heat equation is further solved by cubic B-splines. The time discretization of linear Heat equation is carried out using Crank-Nicolson scheme (θ = {1 \\over 2}) as well as backward Euler scheme (θ = 1). Accuracy in temporal direction is improved by using Richardson extrapolation. This method hence possesses fourth order accuracy both in space and time. The system of matrix which arises by using cubic splines is always diagonal. Therefore, working with splines has the advantage of reduced computational cost and easy implementation. Stability of the schemes have been discussed in detail and shown to be unconditionally stable. Three examples have been examined and the L2 and L∞ error norms have been calculated to establish the performance of the method. The numerical results obtained on applying this method have shown to give more accurate results than existing works of Kutluay et al. [1], Ozis et al. [2], Dag et al. [3], Salkuyeh et al. [4] and Korkmaz et al. [5].

  18. Proton Ordering of Cubic Ice Ic: Spectroscopy and Computer Simulations

    PubMed Central

    2014-01-01

    Several proton-disordered crystalline ice structures are known to proton order at sufficiently low temperatures, provided that the right preparation procedure is used. For cubic ice, ice Ic, however, no proton ordering has been observed so far. Here, we subject ice Ic to an experimental protocol similar to that used to proton order hexagonal ice. In situ FT-IR spectroscopy carried out during this procedure reveals that the librational band of the spectrum narrows and acquires a structure that is observed neither in proton-disordered ice Ic nor in ice XI, the proton-ordered variant of hexagonal ice. On the basis of vibrational spectra computed for ice Ic and four of its proton-ordered variants using classical molecular dynamics and ab initio simulations, we conclude that the features of our experimental spectra are due to partial proton ordering, providing the first evidence of proton ordering in cubic ice. We further find that the proton-ordered structure with the lowest energy is ferroelectric, while the structure with the second lowest energy is weakly ferroelectric. Both structures fit the experimental spectral similarly well such that no unique assignment of proton order is possible based on our results. PMID:24883169

  19. Development of thermal inactivation models for Salmonella enteritidis and Escherichia coli O157:H7 with temperature, pH and NaCl as controlling factors.

    PubMed

    Blackburn, C W; Curtis, L M; Humpheson, L; Billon, C; McClure, P J

    1997-08-19

    The thermal inactivation of Salmonella enteritidis phage type 4 and Escherichia coli O157:H7 as affected by temperature (54.5-64.5 degrees C), pH (4.2-9.6 with HCl or NaOH) and NaCl concentration (0.5-8.5% w/w) was studied. Cell suspensions in modified tryptone soya broth were heated in a submerged-coil heating apparatus and survivors were enumerated on tryptone soya agar incubated aerobically. For most thermal inactivation data there was a logarithmic decrease in the viable cell concentration over the initial 4-6 log10 reduction and D-values were fitted. In some cases, tailing of the survivor curves was observed with cells surviving longer than the D-values predicted. Models describing the effect of temperature, pH and NaCl concentration on the thermal inactivation of S. enteritidis and E. coli O157:H7 were produced. For both organisms, predicted z-values of 4.6-7.0 C degrees were obtained depending on conditions, with larger z-values at higher levels of NaCl. Optimum survival occurred between pH 5 and pH 7 and increasing acidity or alkalinity caused a decrease in the predicted D-values. At equivalent pH, acetic acid and lactic acid (at 0.5, 1 and 2% w/w) generally had a similar, or increased, lethal effect compared with HCl, whereas in most cases citric acid had a less lethal effect. For E. coli O157:H7, increasing NaCl concentration had a protective effect up to the maximum tested (8.5% w/w), while for S. enteritidis optimal survival at a NaCl concentration of 5-7% w/w was predicted. The models were validated in foods by comparing predictions with published data. Most (80%) of the predicted D-values from the S. enteritidis model were within the 95% confidence interval (within 2.45-fold of the published data) for different Salmonella serotypes in whole egg, egg albumen, egg yolk, beef and milk. Most (93%) of the predicted D-values from the E. coli O157:H7 model were larger than the limited published data for this organism in meat, poultry, milk and apple juice

  20. Epitaxial Ag film formation on NaCl crystals in Knudsen gases of Ar

    NASA Astrophysics Data System (ADS)

    Ogura, Iwao; Suzuki, Shoetu; Nagashima, Seiichi

    Transportation of Ag atoms onto NaCl substrate in Knudsen Ar gas is studied according to the kinetic theory of gas. The results, as compared with our experiment, are as follows: (1) The temperature of Ar-Ag gas in a deposition chamber is estimated to be ˜900 K. (2) The concentration n( r) in radial flow of Ag atoms oto the substrate is given as n( r) = 4.7 × 10 16r-1 atoms m -3. (3) Estimated deposition rate, 1 nm/s, 9 cm of the Ag source agrees with the experimental value. (4) The number of dimers formed in the Ar sbnd Ag gas is ˜3% of the numbers of Ag atoms reaching the substrate. (5) Epitaxial Ag film formation on the NaCl at room temperature will be controlled by temperature and/or pressure of Ar gas.