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Sample records for cubic nacl type

  1. 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.

  2. 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.

  3. Anodic etching of p-type cubic silicon carbide

    NASA Technical Reports Server (NTRS)

    Harris, G. L.; Fekade, K.; Wongchotigul, K.

    1992-01-01

    p-Type cubic silicon carbide was anodically etched using an electrolyte of HF:HCl:H2O. The etching depth was determined versus time with a fixed current density of 96.4 mA/sq cm. It was found that the etching was very smooth and very uniform. An etch rate of 22.7 nm/s was obtained in a 1:1:50 HF:HCl:H2O electrolyte.

  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. The NaCl- to CsCl-type phase transition discussed on the basis of the cP to cI deformation with the symmetry Cmcm 4(c) m2m

    PubMed

    Sowa

    2000-05-01

    A structure forming a cubic primitive lattice cP may be deformed into a structure forming a cubic body-centred lattice cI in the space group Cmcm at position 4(c) m2m 0,y,1/4. If in related structures the sites are alternately occupied by unlike atoms, the NaCl and the CsCl types occur, respectively. The corresponding phase transition can be described as a deformation of a heterogeneous sphere packing in the subgroup Pmmn (a,-c,b) of Cmcm. All sphere configurations with symmetry Cmcm 4(c) m2m were derived. On the basis of this information, further possibilities for phase transitions that also correspond to sphere-packing deformations were found with this symmetry. Two of them possibly may take place in metals. The first one leads from a primitive hexagonal lattice to a hexagonal close packing, the other from a cubic body-centred lattice also to a hexagonal close packing.

  6. 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.

  7. The effect of NaCl on stomatal opening in Arabidopsis wild type and agb1 heterotrimeric G-protein mutant plants.

    PubMed

    Yu, Yunqing; Assmann, Sarah M

    2016-01-01

    Salinity is a major agricultural problem that affects crop yield. Na(+) is transported to the shoot through the transpiration stream. The mutant of the sole Arabidopsis heterotrimeric G protein β subunit, agb1, is hypersensitive to salinity in part due to a higher transpiration rate. Here, we investigated the direct effect of Na(+) on stomatal opening using detached epidermal peels of wild type and agb1 plants. In both genotypes, NaCl is equally as effective as KCl in mediating stomatal opening at the concentrations tested. In both genotypes, ABA is less effective in inhibiting Na(+) mediated stomatal opening than K(+) mediated stomatal opening. The agb1 mutant is hyposensitive to ABA inhibition of K(+)-mediated but not Na(+)-mediated stomatal opening. These results suggest that the greater transpiration observed in agb1 plants grown in saline conditions is likely not mediated by differential genotypic direct effects of Na(+) on stomatal apertures. PMID:26431457

  8. Extremely small thermal conductivity of the Al-based Mackay-type 1/1 -cubic approximants

    NASA Astrophysics Data System (ADS)

    Takeuchi, Tsunehiro; Nagasako, Naoyuki; Asahi, Ryoji; Mizutani, Uichiro

    2006-08-01

    Thermal conductivity (κ) of the Al-based Mackay-type 1/1 -cubic approximants ( α -phase) was investigated over a wide temperature range from 2Kto300K . Behaviors of κ(T) observed for these 1/1 -cubic approximants were essentially the same with those reported for the corresponding icosahedral quasicrystals; very small magnitude lower than 4.5W/mK , small contribution of electrons, and possession of a local maximum and a local minimum around 30-50K and 100-200K , respectively. By analyzing measured lattice thermal conductivity κlat(T) in terms both of local atomic arrangements and phonon dispersions, we revealed that κlat(T) is greatly reduced by combination of the small group velocity of phonons and the enhanced umklapp process of phonon scattering. Those characteristics are brought about by the large lattice constant and vacancies in the structure.

  9. 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.

  10. 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.

  11. 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. PMID:25113929

  12. 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. PMID:27442183

  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. 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.

  15. 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.

  16. Stabilization of cubic lithium-stuffed garnets of the type “Li7La3Zr2O12” by addition of gallium

    NASA Astrophysics Data System (ADS)

    El Shinawi, Hany; Janek, Jürgen

    2013-03-01

    Cubic lithium-stuffed garnets of the type Li7La3Zr2O12 have been successfully stabilized by incorporation of gallium. The materials have been prepared by a sol-gel procedure with final calcination at 1085 °C for 6 h. Under the applied synthesis conditions, 0.3 mole of gallium ions (per mole of Li7La3Zr2O12) were sufficient to fully stabilize the cubic garnet-type phase. Increasing the fraction of gallium led to significant improvement of sinterability and lithium ion conductivity. Excess gallium ions, in the form of LiGaO2, act as a sintering aid and reside exclusively at the grain boundaries. The gallium-modified garnets showed conductivities up to 5.4 × 10-4 S cm-1 at 20 °C, and activation energies in the range 0.32-0.37 eV.

  17. 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

  18. Hybrid thermoelastic properties of NaCl

    NASA Astrophysics Data System (ADS)

    Wentzcovitch, R. M.; Marcondes, M. L.; Shukla, G.

    2015-12-01

    Despite the importance of thermoelastic properties of minerals in geophysics, their measurements at high pressures and temperatures are limited. 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 and to approximations used in calculations of vibrational effects, 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 hybrid scheme to reconcile calculated and measured elastic coefficients and apply it to rock-salt-type NaCl, a challenging material to describe by ab initio and an important mineral in the context of oil/gas exploration. The approach is predictive within the temperature range of validity of the quasiharmonic approximation and results are used to generate velocities of NaCl at desirable geological conditions. [1] Marcondes, M. L. & Wentzcovitch, R.M. (2015). Hybrid ab-initio/experimental thermal equations of state: application to the NaCl pressure scale, J. Appl. Phys. 117:215902.

  19. Cubic Polynomials.

    ERIC Educational Resources Information Center

    Lipp, Alan

    2000-01-01

    Presents a classification of factorable cubics and shows how the associated factor graphs determine domains of disconnected branches and furnish a skeletal framework for the number and shape of the branches. Illustrates three dimensional visualization and examines level curves and spikes of surfaces. (KHR)

  20. 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…

  1. Genetic Architecture of NaCl Tolerance in Arabidopsis1

    PubMed Central

    Quesada, Víctor; García-Martínez, Santiago; Piqueras, Pedro; Ponce, María Rosa; Micol, José Luis

    2002-01-01

    The little success of breeding approaches toward the improvement of salt tolerance in crop species is thought to be attributable to the quantitative nature of most, if not all the processes implicated. Hence, the identification of some of the quantitative trait loci (QTL) that contribute to natural variation in salt tolerance should be instrumental in eventually manipulating the perception of salinity and the corresponding responses. A good choice to reach this goal is the plant model system Arabidopsis, whose complete genome sequence is now available. Aiming to analyze natural variability in salt tolerance, we have compared the ability of 102 wild-type races (named ecotypes or accessions) of Arabidopsis to germinate on 250 mm NaCl, finding a wide range of variation among them. Accessions displaying extremely different responses to NaCl were intercrossed, and the phenotypes found in their F2 progenies suggested that natural variation in NaCl tolerance during germination was under polygenic controls. Genetic distances calculated on the basis of variations in repeat number at 22 microsatellites, were analyzed in a group of either extremely salt-tolerant or extremely salt-sensitive accessions. We found that most but not all accessions with similar responses to NaCl are phylogenetically related. NaCl tolerance was also studied in 100 recombinant inbred lines derived from a cross between the Columbia-4 and Landsberg erecta accessions. We detected 11 QTL harboring naturally occurring alleles that contribute to natural variation in NaCl tolerance in Arabidopsis, six at the germination and five at the vegetative growth stages, respectively. At least five of these QTL are likely to represent loci not yet described by their relationship with salt stress. PMID:12376659

  2. Heteroepitaxial growth of cubic boron nitride films on diamond(001) substrates and their n-type doping

    NASA Astrophysics Data System (ADS)

    Yin, Hong

    2016-02-01

    This paper firstly introduces c-BN in general and its excellent properties that make c-BN a promising candidate competing with diamond as hard coating and as a future high temperature semiconductor material. Furthermore, this paper gives an overview of the recent advances of the different synthetic techniques towards the heteroepitaxial growth of c-BN films. In the end, it will describe the state of the art of n-type doping of these c-BN epitaxial films through which a c-BN/diamond pn diode can be anticipated.

  3. The c^2=E/m Velocity of Elastic Waves in Purely Ionic NaCl Type Lattices, the Direct Result of the 1932 Anderson Experiment, and what does E=mc^2 Really Mean

    NASA Astrophysics Data System (ADS)

    Simhony, Menahem

    1998-11-01

    By physics, the transfer of wave energy from one charged particle to the next, of opposite charge, is the faster the stronger their binding; and, impeded by inertia, is the slower the larger their masses. In fcc polycrystals, c is equal to the square root of the binding energy Ep per particle pair divided by the mass mp of the pair. (M.Simhony, The Epola Space, 1990, 160pp, and The Story of Matter and Space, 1998, 70pp (available from the author). Also, M.Simhony, Invitation to the Natural Physics of Matter, Space, and Radiation, World Scientific, 1994, (292pp).) In NaCI, E_p=8 eV, m_p=58 amu, yielding the experimental value of c=3.6 km/s. In the fcc electron positron lattice (epola), E_p=1.02 MeV, m_p=1.82·10-30 kg, yielding the vacuum light velocity c=300,000 km/s. Absorption of energy E=nEp frees a mass m=nmp of particle pairs in the lattice. Substitution to c=(E_p/m_p)^1/2 yields E=mc^2. This is not a "mass-energy equivalence". It connects the mass m of pairs, freed from bonds in their lattice (NaCl, epola) or fallen into them, with the energy absorbed or emitted for it in the lattice. Clearly, 8 eV cannot and does not "create" or turn into 58 amu, and 1.02 MeV cannot and does not "create" or turn into an electron AND positron, if with up to a million times higher energy "bombs", developed since 1932, nobody has ever "created" or destroyed a SINGLE electron or positron.

  4. Piecewise Cubic Interpolation Package

    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)more » 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.« less

  5. High-temperature single-crystal X-ray diffraction study of tetragonal and cubic perovskite-type PbTiO3 phases.

    PubMed

    Yoshiasa, Akira; Nakatani, Tomotaka; Nakatsuka, Akihiko; Okube, Maki; Sugiyama, Kazumasa; Mashimo, Tsutomu

    2016-06-01

    A high-temperature single-crystal X-ray diffraction study of a synthetic PbTiO3 perovskite was carried out over the wide temperature range 298-928 K. A transition from a tetragonal (P4mm) to a cubic (Pm \\bar 3 m) phase has been revealed near 753 K. In the non-centrosymmetric P4mm symmetry group, the difference in relative displacement between Pb and O along the c-axis is much larger than that between Ti and O. The Pb and Ti cations contribute sufficiently to polarization being shifted in the opposite direction compared with the shift of O atoms. Deviation from the linear changes in Debye-Waller factors and bonding distances in the tetragonal phases can be interpreted as a precursor phenomenon before the phase transition. Disturbance of the temperature factor Ueq for O is observed in the vicinity of the transition point, while Ueq values for Pb and Ti are continuously changing with increasing temperature. The O site includes the clear configurational disorder in the cubic phase. The polar local positional distortions remain in the cubic phase and are regarded as the cause of the paraelectricity. Estimated values of the Debye temperature ΘD for Pb and Ti are 154 and 467 K in the tetragonal phase and decrease 22% in the high-temperature phase. Effective potentials for Pb and Ti change significantly and become soft after the phase transition.

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

    PubMed Central

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

    2013-01-01

    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. PMID:23639808

  7. 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.

  8. 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.

  9. 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.

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

    PubMed

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

    2008-09-01

    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. PMID:18270148

  11. 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.

  12. 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.

  13. 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.

  14. Effect of NaCl Concentration on the Emulsifying Properties of Myofibrilla Protein in the Soybean Oil and Fish Oil Emulsion

    PubMed Central

    Jo, Yeon-Ji; Kwon, Yun-Joong; Min, Sang-Gi

    2015-01-01

    The aim of the present work was to investigate the effect of NaCl concentration on the emulsifying and rheological properties of porcine myofibrillar protein (MF)-stabilized soybean oil and fish oil emulsion (SO-EMs and FO-EMs). Emulsions (EMs) were prepared from 1% MF with 10% SO or FO at various NaCl concentration (0-0.5 M). The emulsifying ability index (EAI) of the EMs increased with increasing NaCl concentration for both oil types. Conversely, increasing NaCl manifested decrease in the emulsion stability index (ESI). In addition, creaming index (CI) also increased with NaCl concentration. From the microscopic observation, droplets of the EMs were more aggregated at relatively higher NaCl concentrations, especially for FO-EMs. All EMs had a gel-like structure owing to G' > G" from the rheological analysis. Comparing the oil types, the emulsifying capacity of SO-EMs was more stable than that of FO-EMs at all NaCl concentrations as determined from the CI value and microscopic observation. Therefore, it can be concluded that SO-EMs and FO-EMs are more stable at relatively lower concentrations of NaCl. In addition, the dispersed stability of SO-EMs was better than that of FO-EMs at the same concentration of NaCl. PMID:26761845

  15. Adaptation of Tobacco Cells to NaCl 1

    PubMed Central

    Binzel, Marla L.; Hasegawa, Paul M.; Handa, Avtar K.; Bressan, Ray A.

    1985-01-01

    Cell lines of tobacco (Nicotiana tabacum L. var Wisconsin 38) were obtained which are adapted to grow in media with varying concentrations of NaCl, up to 35 grams per liter (599 millimolar). Salt-adapted cells exhibited enhanced abilities to gain both fresh and dry weight in the presence of NaCl compared to cells which were growing in medium without NaCl (unadapted cells). Tolerance of unadapted cells and cells adapted to 10 grams per liter NaCl was influenced by the stage of growth, with the highest degree of tolerance exhibited by cells in the exponential phase. Cell osmotic potential and turgor varied through the growth cycle of unadapted cells and cells at all levels of adaptation, with maximum turgor occurring at approximately the onset of exponential fresh weight accumulation. Adaptation to NaCl led to reduced cell expansion and fresh weight gain, while dry weight gain remained unaffected. This reduction in cell expansion was not due to failure of the cells to maintain turgor since cells adapted to NaCl underwent osmotic adjustment in excess of the change in water potential caused by the addition of NaCl to the medium. Tolerance of the adapted cells, as indicated by fresh or dry weight gain, did not increase proportionately with the increase in turgor. Adaptation of these glycophytic cells to NaCl appears to involve mechanisms which result in an altered relationship between turgor and cell expansion. Images Fig. 3 PMID:16664356

  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. 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.

  18. Anisotropic cubic curvature couplings

    NASA Astrophysics Data System (ADS)

    Bailey, Quentin G.

    2016-09-01

    To complement recent work on tests of spacetime symmetry in gravity, cubic curvature couplings are studied using an effective field theory description of spacetime-symmetry breaking. The associated mass-dimension-eight coefficients for Lorentz violation studied do not result in any linearized gravity modifications and instead are revealed in the first nonlinear terms in an expansion of spacetime around a flat background. We consider effects on gravitational radiation through the energy loss of a binary system and we study two-body orbital perturbations using the post-Newtonian metric. Some effects depend on the internal structure of the source and test bodies, thereby breaking the weak equivalence principle for self-gravitating bodies. These coefficients can be measured in Solar-System tests, while binary-pulsar systems and short-range gravity tests are particularly sensitive.

  19. Growth and electronic properties of NaCl on HOPG

    NASA Astrophysics Data System (ADS)

    Mahapatra, O.; Kowalczyk, P. J.; Brown, S. A.

    2014-02-01

    We report the growth of cross-shaped islands of NaCl on highly oriented pyrolytic graphite (HOPG) and discuss the mechanism of formation and growth kinetics within the framework of diffusion limited aggregation (DLA). These structures are investigated using scanning probe microscopy. The shape and structure of these islands can be finely controlled by the deposition conditions. The islands exhibit large atomically flat surfaces which are ideal supports for investigations of the fundamental properties of deposited atoms, molecules or clusters. Bismuth nanostructures were deposited on the NaCl islands and were investigated via scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). The tunneling spectra recorded for particles on NaCl are surprisingly similar to those measured for similar particles on HOPG. We suggest that this is due to a 'dead' layer commonly observed for Bi thin films.

  20. Measurements of electric discharge characteristics in NaCl solution

    NASA Astrophysics Data System (ADS)

    Ablesimov, V. E.; Karyuk, V. M.; Pavlov, A. N.; Kirpichev, A. A.; Simchuk, A. A.

    2015-03-01

    The characteristics of electric discharge in a NaCl solution with a specific concentration of up to ˜1.7% (electrical conductivity up to 0.032 Sm/cm) are investigated. The discharge is produced by the Era-1 discharger in a vessel filled with water or a NaCl solution. We obtain the dependences of the maximal discharge current, pressure pulse, and the pressure amplitude at the shock front at a distance of 7 cm from the discharge axis on the electrolyte concentration.

  1. Polyolefin cubic silsesquioxane nanocomposites

    NASA Astrophysics Data System (ADS)

    Zheng, Lei

    This thesis focuses on the synthesis and characterization of polyolefin nanocomposites containing polyhedral oligomeric silsesquioxane (POSS) units. Two copolymerization methods were developed utilizing either ring-opening metathesis polymerization or metallocene-catalyzed reactions to incorporate cubic silsesquioxane into polyolefins. Ring-opening metathesis copolymerizations of cyclooctene and the POSS-norbornylene macromonomer have been performed using Grubbs' catalyst RuCl2(=CHPh)(PCy3)2. Random copolymers have been prepared and characterized with POSS loadings as high as 55 wt%. Diimide reduction of these copolymers affords polyethylene-POSS random copolymers. Polyethylene (PE) and isotactic polypropylene (PP) copolymers incorporating POSS have also been prepared using a metallocene/methylaluminoxane (MAO) cocatalyst system. A wide range of POSS concentrations was obtained in these polyolefin POSS copolymers under mild conditions; up to 56 wt% for PE-POSS copolymers and 73 wt% for PP-POSS copolymers were prepared. Copolymerizations of styrene and the POSS-styryl macromonomer have been performed using CpTiCl 3 in conjunction with MAO. Random copolymers of syndiotactic polystyrene and POSS copolymers have been formed and characterized. Novel nanocomposites of PE-POSS have been characterized using Wide Angle X-ray Scattering (WAXS). From both line broadening of the diffraction maxima and also the oriented diffraction in a drawn sample, we conclude that POSS forms anisotropically shaped crystallites. On the basis of this result, a novel approach to obtain nanocomposites containing inorganic nanolayers is proposed. Cubic silsesquioxane (POSS) nanoparticles are used to achieve the nanolayered "clay-like" structure through controlled self-assembly. The organic polymer, covalently connected to POSS, is intended to regulate the POSS crystallization into a two-dimensional lattice. The concept is demonstrated by random copolymers of polybutadiene and POSS. The data from

  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. PMID:17042605

  3. 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.

  4. 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.

  5. Substituting KCl for NaCl in fresh Queso Fresco

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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....

  6. 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.

  7. Self-assembly patterning of colloidal crystals constructed from opal structure or NaCl structure.

    PubMed

    Masuda, Yoshitake; Itoh, Tetsuya; Itoh, Minoru; Koumoto, Kunihito

    2004-06-22

    We developed a novel self-assembly process to fabricate an orderly array of particle wires constructed from a close-packed colloidal crystal without preparation of patterned templates. A substrate was immersed vertically into a SiO2 colloidal solution, and the liquid surface moved downward upon evaporation of solution. Particles formed a mono-/multiparticle layer, which was cut by the periodic drop-off of solution. The orderly array of particle wires was successfully fabricated, showing the suitability of the self-assembly process for the fabrication of nano-/microstructures constructed from nano-/microparticles or blocks. The mechanism of the assembly process and control of thickness, width, and interval of particle wires were further discussed. Moreover, an array of particle wires constructed not from close-packed face-centered cubic (or hexagonal close packed) structure but from two kinds of particles was realized to fabricate an array of particle wires with NaCl structure by this self-assembly process.

  8. 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.

  9. 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.

  10. 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

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

    PubMed

    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 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

  12. 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. PMID:25358487

  13. 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.

  14. 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…

  15. 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)

  16. Celestite (SrSO 4(s)) solubility in water, seawater and NaCl solution

    NASA Astrophysics Data System (ADS)

    Reardon, E. J.; Armstrong, D. K.

    1987-01-01

    Celestite solubility measurements have been conducted in pure water at temperatures from 10 to 90°C. Equilibrium was achieved with respect to a crystalline solid phase from both undersaturated and supersaturated solutions. The measurements show that the solubility undergoes a maximum near 20°C. LogK values for the solubility reaction are adequately described by the following expression over the temperature range 283.15 to 363.15 K: - logK= -35.3106+0.00422837 T+318312/ T2+14.99586 logT. The following thennodynamic values for the dissolution reaction of SrSO 4(s), at 25°C have been derived: ΔGR0 = 37852 ± 30 Jmol -1ΔHR0 = -1668±920 Jmol -1ΔSR0= -132.6±3.2 JK-1mol -1 Celestite solubility measurements were also determined in NaCl solutions up to 5 m concentration and from 10 to 40°C. These data are in good agreement with the work of StrÜbel (1966), who reports solubility measurements to temperatures of 100°C. The application of the Pitzer relations and the solubility constants determined in this study to calculate celestite solubility in NaCl solutions yields excellent agreement between predicted values and experimental measurements over the entire range of temperature and NaCl concentration conditions. For the limited number of solubility measurements in seawater-type solutions and mixed-salt brines, the agreement using the Pitzer relations is within three percent of the measured solubility.

  17. Use of Pom Pons To Illustrate Cubic Crystal Structures

    NASA Astrophysics Data System (ADS)

    Cady, Susan G.

    1997-07-01

    In general chemistry classes, students are introduced to the ways in which atoms are arranged in cubic crystal structures. Transposing the textbook illustrations into three dimensional structures is difficult for some students. This transitions is easier if a three dimensional model is available for examination. Several 3D models are cited. A quick to assemble, inexpensive, colorful, and durable alternative to these models and styrofoam balls is the use of olefin pom pons. Different sized pom pons can be used to demonstrate how the atomic radius will vary when comparing the different types of cubic crystal unit cells. Being made of a coarse material, pom pons can be stacked to illustrate different packing arrangements such as hexagonal close-packed and cubic close-packed structures. Pom pons make great atoms.

  18. 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…

  19. Atmospheric Corrosion of Ag and Cu with Ozone, UV and NaCl

    NASA Astrophysics Data System (ADS)

    Lin, Huang

    Ag and Cu are both used for electronics and are susceptible to atmospheric corrosion. They are also good corrosivity monitors used to evaluate aggressiveness of the environment. Unfortunately, laboratory exposure testing does not always represent field environments very well. Discrepancies between lab and field exposure tests are not uncommon. For example, Ag does not corrode in salt spray exposure during ASTM B117 test, while it corrodes everywhere outdoor. This suggests that new laboratory exposure test for Ag needs to be designed and studied. A full factorial experiment was carried out with three factors: ozone, UV intensity and relative humidity (RH). NaCl was loaded by fast evaporation of NaCl/ethanol solution before exposure. After exposure, corrosion products were identified by XRD and quantified by galvanostatic reduction technique. For lab exposure samples, AgCl was identified as the only corrosion product in high RH (87%) environments, while Ag2O and AgO formed as well during exposures at low RH. This result derived a qualitative prediction on corrosion behavior of Ag in field. It predicts that less stable silver compounds such as oxide and sulfate are possible corrosion products in field even silver chloride is the dominant corrosion product forming in field. This prediction was confirmed by analysis of field exposed Ag samples. By quantification of corrosion products, it is determined that UV has two contravening effects on atmospheric corrosion of Ag: photolysis of ozone to generate stronger oxidizing species such as atomic O and photodecomposition of Ag corrosion products by UV radiation. Following its success in Ag corrosion research, the environment of UV, ozone and NaCl was extended to study Cu corrosion. It is determined that UV alone can double Cu corrosion rate by generation of electron-hole pairs in n-type cuprous oxide. It is also found that ozone alone is not as aggressive on Ag as on Cu because protection of naturally formed cuprous oxide

  20. 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.

  1. Paleothermometry of NaCl as evidenced from thermoluminescence data

    NASA Astrophysics Data System (ADS)

    Gartia, R. K.

    2009-09-01

    The firing temperature of ancient ceramic artifacts, i.e. the paleothermometry of these materials has been estimated by various techniques including thermoluminescence (TL) and, more recently, Optically Stimulated Luminescence (OSL) where the OSL response of quartz to firing temperature is used. In this work we report the paleothermometry of sodium chloride (NaCl) by studying the TL response of the material as a function of annealing temperatures in the range of 100-500 °C. Annealing/measurement has been done in a commercial TL/OSL reader (Model No. Risø TL/OSL reader TL-DA-15) in a nitrogen atmosphere. Sodium chloride (NaCl) has been selected as the candidate to test the feasibility of the technique since in this system TL peaks are correlated with the thermal annealing of F-centers unlike the case of quartz where a one to one correlation with all the glow peaks and thermal annealing of defects has not been possible.

  2. 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.

  3. 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.

  4. [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

  5. 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.

  6. Electrochemistry of selenium in a basic AlCl{sub 3}-NaCl melt

    SciTech Connect

    Matsunaga, M.; Morimitsu, M.; Hosokawa, K.

    1995-09-01

    Sodium/molten-salt secondary batteries composed of a liquid sodium and chloroaluminate melt have been widely studied for electric vehicle and load-leveling applications. The authors have been interested in developing new cathode materials to be used in this type of battery. The electrochemical reactions of selenium species in a basic AlCl{sub 3}-NaCl melt has been studied by measuring EMF of an Na/SeCl{sub 4} cell. The reaction mechanism between elemental and tetravalent selenium consists of at least four electrochemical steps, including intermediates such as Se{sup 2+}, Se{sub 2}{sup 2+}, and Se{sub 8}{sup 2+}. The reaction sequence from Se{sup 4+} to Se{sub 8}{sup 2+} is discussed. The formal potential for each reaction is also determined.

  7. 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

    2016-08-01

    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.

  8. Natural variability in Drosophila larval and pupal NaCl tolerance.

    PubMed

    Riedl, Craig A L; Oster, Sara; Busto, Macarena; Mackay, Trudy F C; Sokolowski, Marla B

    2016-05-01

    The regulation of NaCl is essential for the maintenance of cellular tonicity and functionality, and excessive salt exposure has many adverse effects. The fruit fly, Drosophila melanogaster, is a good osmoregulator and some strains can survive on media with very low or high NaCl content. Previous analyses of mutant alleles have implicated various stress signaling cascades in NaCl sensitivity or tolerance; however, the genes influencing natural variability of NaCl tolerance remain for the most part unknown. Here, we use two approaches to investigate natural variation in D. melanogaster NaCl tolerance. We describe four D. melanogaster lines that were selected for different degrees of NaCl tolerance, and present data on their survival, development, and pupation position when raised on varying NaCl concentrations. After finding evidence for natural variation in salt tolerance, we present the results of Quantitative Trait Loci (QTL) mapping of natural variation in larval and pupal NaCl tolerance, and identify different genomic regions associated with NaCl tolerance during larval and pupal development. PMID:26874056

  9. 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

  10. 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

  11. Renal expression of parvalbumin is critical for NaCl handling and response to diuretics

    PubMed Central

    Belge, Hendrica; Gailly, Philippe; Schwaller, Beat; Loffing, Johannes; Debaix, Huguette; Riveira-Munoz, Eva; Beauwens, Renaud; Devogelaer, Jean-Pierre; Hoenderop, Joost G.; Bindels, René J.; Devuyst, Olivier

    2007-01-01

    The distal convoluted tubule (DCT) plays an essential role in the reabsorption of NaCl by the kidney, a process that can be inhibited by thiazide diuretics. Parvalbumin (PV), a Ca2+-binding protein that plays a role in muscle fibers and neurons, is selectively expressed in the DCT, where its role remains unknown. We therefore investigated the renal phenotype of PV knockout mice (Pvalb−/−) vs. wild-type (Pvalb+/+) littermates. PV colocalized with the thiazide-sensitive Na+-Cl− cotransporter (NCC) in the early DCT. The Pvalb−/− mice showed increased diuresis and kaliuresis at baseline with higher aldosterone levels and lower lithium clearance. Acute furosemide administration increased diuresis and natriuresis/kaliuresis, but, surprisingly, did not increase calciuria in Pvalb−/− mice. NaCl supplementation of Pvalb−/− mice increased calciuria at baseline and after furosemide. The Pvalb−/− mice showed no significant diuretic response to hydrochlorothiazide, but an accentuated hypocalciuria. A decreased expression of NCC was detected in the early DCT of Pvalb−/− kidneys in the absence of ultrastructural and apoptotic changes. The PV-deficient mice had a positive Ca2+ balance and increased bone mineral density. Studies in mouse DCT cells showed that endogenous NCC expression is Ca2+-dependent and can be modulated by the levels of PV expression. These results suggest that PV regulates the expression of NCC by modulating intracellular Ca2+ signaling in response to ATP in DCT cells. They also provide insights into the Ca2+-sparing action of thiazides and the pathophysiology of distal tubulopathies. PMID:17804801

  12. Black hole solutions in Horava-Lifshitz gravity with cubic terms

    SciTech Connect

    Koutsoumbas, George; Pasipoularides, Pavlos

    2010-08-15

    We study four-dimensional nonprojectable Horava-Lifshitz type gravity, in the case of an action with terms cubic in curvature. For special choices of the free parameters of the model, we obtain two new analytic black hole solutions which exhibit the standard Schwarzschild asymptotic behavior in the large-distance limit. The effect of cubic terms in the short-range behavior of the black hole solutions is discussed.

  13. The mechanism by which NaCl treatment alleviates PSI photoinhibition under chilling-light treatment.

    PubMed

    Yang, Cheng; Zhang, Zi-shan; Gao, Hui-yuan; Fan, Xing-li; Liu, Mei-jun; Li, Xiang-dong

    2014-11-01

    The effects of chilling-light stress combined with additional stress on PSI and PSII photoinhibition and their interrelationship have not been known. To explore whether NaCl affects the PSI and PSII photoinhibition and their interrelationship under chilling-light treatment, the PSI and PSII activities were studied under chilling-light with or without NaCl treatment. The results showed that the extent of PSI and PSII photoinhibition both increased under chilling-light, while NaCl aggravated PSII photoinhibition and severely damaged cytochrome b₆/f complex but alleviated PSI photoinhibition. Moreover, DCMU had a similar effect as NaCl in this study, which indicates that NaCl alleviated PSI photoinhibition through reducing electrons transported to PSI. It was also showed that the increased damage to PSII by NaCl did not depend on the inhibition of PSII repair and PSI electron transportation. In conclusion, NaCl alleviated PSI photoinhibition by inhibiting electron transport from PSII under chilling-light conditions. In addition, PSII photoinhibition was not affected by PSI photoinhibition because of a full inhibition of PSII repair by chilling-light treatment. We also speculate that NaCl aggravates PSII photoinhibition by enhancing the damage instead of inhibiting the repair of it under chilling-light conditions.

  14. An optimized cubic interpolator for image resampling

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    It is noted that the cubic resampling function is only one member of a family of functions, defined by the single parameter of the slope of the cubic function at its first zero crossing, whose other members are in some cases superior to the standard cubic. This superiority is especially noteworthy with respect to the extent of gray level overshoot induced by the resampling process at high contrast edges. It is shown that there is an optimum member of this 'parametric cubic convolution' family which minimizes the mean-squared radiometric error arising from interpolation. This interpolator requires no additional computation time over the conventional cubic one. These conclusions are supported and illustrated by resampling simulations with both a high resolution digitized aerial image and a Landsat Multispectral Scanner image.

  15. 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

    2015-07-01

    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.

  16. 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.

  17. Orientation dependence of the dislocation microstructure in compressed body-centered cubic molybdenum

    SciTech Connect

    Wang, S.; Wang, M.P.; Chen, C.; Xiao, Z.; Jia, Y.L.; Li, Z.; Wang, Z.X.

    2014-05-01

    The orientation dependence of the deformation microstructure has been investigated in commercial pure molybdenum. After deformation, the dislocation boundaries of compressed molybdenum can be classified, similar to that in face-centered cubic metals, into three types: dislocation cells (Type 2), and extended planar boundaries parallel to (Type 1) or not parallel to (Type 3) a (110) trace. However, it shows a reciprocal relationship between face-centered cubic metals and body-centered cubic metals on the orientation dependence of the deformation microstructure. The higher the strain, the finer the microstructure is and the smaller the inclination angle between extended planar boundaries and the compression axis is. - Highlights: • A reciprocal relationship between FCC metals and BCC metals is confirmed. • The dislocation boundaries can be classified into three types in compressed Mo. • The dislocation characteristic of different dislocation boundaries is different.

  18. Analysis of water and NaCl solution acceptance by schedule-induced polydipsia1

    PubMed Central

    Falk, John L.

    1966-01-01

    Animals were trained on a VI 1-min schedule for food pellets, and concurrent water intake was measured. The polydipsia induced was analyzed in terms of the frequency distribution of post-pellet licking burst sizes and the trend of polydipsia throughout the session. An ascending series of NaCl solutions was presented consecutively over daily sessions and a typical NaCl acceptance-rejection intake function was generated. Beginning in the 0.9-1.2% NaCl range, the animals drank less often during the session but took larger drinks when they did drink. Neither the frequency of drinks nor the mean licking burst size were simply related to the volumes of NaCl solution consumed. The NaCl acceptance-rejection function cannot be explained in terms of water repletion factors alone. PMID:5907821

  19. 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.

  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. Structural and magnetic transitions in cubic Mn3Ga.

    PubMed

    Kharel, P; Huh, Y; Al-Aqtash, N; Shah, V R; Sabirianov, R F; Skomski, R; Sellmyer, D J

    2014-03-26

    The structural, magnetic and electron-transport properties of cubic Mn3Ga have been investigated. The alloys prepared by arc melting and melt-spinning show an antiferromagnetic spin order at room temperature but undergo coupled structural and magnetic phase transitions at 600 and 800 K. First-principles calculations show that the observed magnetic properties are consistent with that of a cubic Mn3Ga crystallizing in the disordered Cu3Au-type structure. The samples exhibit metallic electron transport with a resistance minimum near 30 K, followed by a logarithmic upturn below the minimum. The observed anomaly in the low-temperature resistivity has been discussed as a consequence of electron scattering at the low-lying excitations of the structurally disordered Mn3Ga lattice.

  2. Gallium substitutions as a means to stabilize alkaline-earth and rare-earth metal pnictides with the cubic Th{sub 3}P{sub 4} type: Synthesis and structure of A{sub 7}Ga{sub 2}Sb{sub 6} (A=Sr, Ba, Eu)

    SciTech Connect

    Xia Shengqing; Hullmann, Jonathan; Bobev, Svilen

    2008-08-15

    Three new compounds-Sr{sub 7.04(2)}Ga{sub 1.94(2)}Sb{sub 6}, Ba{sub 7.02(3)}Ga{sub 1.98(3)}Sb{sub 6} and Eu{sub 7.04(3)}Ga{sub 1.90(3)}Sb{sub 6}-have been synthesized from reactions of the corresponding elements using gallium as a metal flux. Their crystal structures (space group I4-bar 3d (No. 220), Z=2 with unit cell parameters: a=9.9147(9) A for the Sr-compound; a=10.3190(9) A for the Ba-compound; and a=9.7866(8) A for the Eu-compound) have been established by single-crystal X-ray diffraction. The structures are best described as Ga-stabilized derivatives of the hypothetical Sr{sub 4}Sb{sub 3}, Ba{sub 4}Sb{sub 3} and Eu{sub 4}Sb{sub 3} phases with the cubic Th{sub 3}P{sub 4} type. Such an inclusion of interstitial Ga atoms in this atomic arrangement results in the formation of isolated [Ga{sub 2}Sb{sub 6}]{sup 14-} fragments, isoelectronic and isostructural with the [Sn{sub 2}Te{sub 6}]{sup 6-} anions in the K{sub 3}SnTe{sub 3} type, and allows for the attainment of a charge-balanced electron count. In that sense, the Sr{sub 4}Sb{sub 3}, Ba{sub 4}Sb{sub 3} and Eu{sub 4}Sb{sub 3} binaries, which are expected to be electron-deficient and are currently unknown, can be 'turned' into Sr{sub 7}Ga{sub 2}Sb{sub 6}, Ba{sub 7}Ga{sub 2}Sb{sub 6} and Eu{sub 7}Ga{sub 2}Sb{sub 6}, whose structures are readily rationalized following the Zintl concept. - Graphical abstract: Three new antimonides have been structurally characterized by single-crystal X-ray diffraction. Their structures are best described as derivatives of the body-centered cubic, anti-Th{sub 3}P{sub 4} type. Unlike the one-electron-deficient A{sub 4}Sb{sub 3} phases (A=Sr, Ba, Eu), the new, A{sub 7}Ga{sub 2}Sb{sub 6} compounds are Zintl phases with closed-shell configurations for both the cations and anions.

  3. 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.

  4. 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.

  5. 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.

  6. Pre- and initial stages of epitaxy in alkali halide systems. II. Interaction of molecular beams of CsCl with (100) surfaces of NaCl

    NASA Astrophysics Data System (ADS)

    Dabringhaus, H.; Haag, M.

    The interaction of molecular beams of CsCl with (100) surfaces of NaCl is studied for crystal temperatures between 560 and 620 K and for molecular beam fluxes between 2 × 10 7 and 2 × 10 13 cm -2 s -1 by measurements of transient and steady state desorption fluxes, by static SIMS, and by electron microscopy. Also for the large Cs + ions a fast cation exchange Cs + ⇌ Na + between CsCl molecules adsorbed on the terrace and the outermost surface layer of the NaCl crystal is observed. The results for undersaturation are interpreted by incorporation of Cs + ions in the outermost surface layer of the NaCl crystal and by adsorption of CsCl molecules at the monatomic steps on the surface. The outermost surface layer proves to have a maximum capacity for Cs + of 2.4 × 10 11 cm -2. The residence time of Cs + ions in the outermost surface layer is determined as τ0 = 1.6 × 10 -12 exp(1.49 (eV)/ kT), the time for desorption of CsCl molecules from the monatomic steps as τ1 = 2.9 × 10 -14 exp(1.60 (eV)/ kT). By experiments with an additional NaCl flux onto the surface it is shown that τ0 is the time for a back-exchange of Cs + ions from the outermost surface layer against Na + from NaCl admolecules. For supersaturation the growth of polymorphic CsCl islands is observed. In the first growth stages these islands show the NaCl-type structure, while for later growth stages the CsCl type structure is found. A comparative discussion of all studied alkali halide systems shows that the different results can be attributed to the different radii of guest and host cation and to lattice misfits, respectively.

  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. 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

  9. Synthesis of cubic silicon nitride

    NASA Astrophysics Data System (ADS)

    Zerr, Andreas; Miehe, Gerhard; Serghiou, George; Schwarz, Marcus; Kroke, Edwin; Riedel, Ralf; Fueß, Hartmut; Kroll, Peter; Boehler, Reinhard

    1999-07-01

    Silicon nitride (Si3N4) is used in a variety of important technological applications. The high fracture toughness, hardness and wear resistance of Si3N4-based ceramics are exploited in cutting tools and anti-friction bearings; in electronic applications, Si3N4 is used as an insulating, masking and passivating material. Two polymorphs of silicon nitride are known, both of hexagonal structure: α- and β-Si3N4. Here we report the synthesis of a third polymorph of silicon nitride, which has a cubic spinel structure. This new phase, c-Si3N4, is formed at pressures above 15GPa and temperatures exceeding 2,000K, yet persists metastably in air at ambient pressure to at least 700K. First-principles calculations of the properties of this phase suggest that the hardness of c-Si3N4 should be comparable to that of the hardest known oxide (stishovite, a high-pressure phase of SiO2), and significantly greater than the hardness of the two hexagonal polymorphs.

  10. Cubic phases and cubic phase dispersions in a phospholipid-based system.

    PubMed

    Johnsson, Markus; Barauskas, Justas; Tiberg, Fredrik

    2005-02-01

    A cubic liquid crystalline phase forming system based on the phospholipid dioleoylphosphatidylethanolamine (DOPE) which is fortified with small amounts of PEGylated (poly(ethylene) glycol) glycerol monooleate (PEG(660)-GMO) is characterized. The cubic phase formed by the DOPE/PEG(660)-GMO/water system coexists with water in the dilute part of the phase diagram and can be fragmented into colloidal size particles with retained cubic phase structure.

  11. New tetragonal derivatives of cubic NaZn13-type structure: RNi6Si6 compounds, crystal structure and magnetic ordering (R=Y, La, Ce, Sm, Gd-Yb)

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    Novel RNi6Si6 compounds adopt the new CeNi6Si6-type structure for R=La-Ce (tP52, space group P4/nbm N 125-1) and new YNi6Si6-type structure for R=Y, Sm, Gd-Yb (tP52, space group P4barb2N 117) that are tetragonal derivative of NaZn13-type structure, like LaCo9Si4-type. The CeNi6Si6, GdNi6Si6, TbNi6Si6, DyNi6Si6 and HoNi6Si6 compounds are Curie-Weiss paramagnets down to ~30 K, and do not order magnetically down to 5 K. However, the inverse paramagnetic susceptibility of LaNi6Si6 does not follow Curie-Weiss law. The DyNi6Si6 shows ferromagnetic-like saturation behaviour at 5 K in applied fields of 50 kOe, giving rise to a magnetic moment value of 6.5 μB/f.u. in 50 kOe. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi6Si6 with K=[±1/4, ±1/4, 0] wave vector below ~10 K. The CeNi6Si6, GdNi6Si6, TbNi6Si6, DyNi6Si6 and HoNi6Si6 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 TbNi6Si6 with K=[±1/4, ±1/4, 0] wave vector below ~10 K.

  12. 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. PMID:27085417

  13. "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…

  14. Growth of NaCl on thin epitaxial KCl films on Ag(100) studied by SPA-LEED

    NASA Astrophysics Data System (ADS)

    Marquardt, Christian; Paulheim, Alexander; Sokolowski, Moritz

    2015-11-01

    We investigated the growth of NaCl on thin (100)-oriented films of KCl by spot profile analysis of low energy electron diffraction (SPA-LEED). The underlying question of this investigation was how the system accommodates to the misfit of - 10% between the NaCl and KCl lattices. The KCl films (3 atomic layers thick) were epitaxially grown on a Ag(100) single crystal. We studied the heteroepitaxial growth of NaCl on KCl at 300 K and at 500 K, respectively. At 300 K, the first NaCl monolayer (ML) grows pseudomorphically on the KCl film. From the second layer onward, the NaCl lattice relaxes. The NaCl multilayers roughen, and a small rotational disorder (± 4°) of the NaCl domains is observed. The roughening results from the formation of multilayer islands of limited lateral size due to the misfit to the pseudomorphic first NaCl layer. At a growth temperature of 500 K, no pseudomorphic NaCl layer forms, instead relaxed multilayer island growth of NaCl is observed from the first layer onward. Similarly to the growth at 300 K, we find NaCl multilayer islands of limited lateral size. For both temperatures, we explain this growth behavior by the misfit that makes the adsorption sites at the island edges of the first relaxed NaCl layer less favorable for larger islands, promoting nucleation of multilayer islands.

  15. 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.

  16. 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

  17. 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

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

    PubMed

    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

  19. Ab initio molecular dynamics study of an aqueous NaCl solution under an electric field.

    PubMed

    Cassone, Giuseppe; Creazzo, Fabrizio; Giaquinta, Paolo V; Saija, Franz; Marco Saitta, A

    2016-08-17

    We report on an ab initio molecular dynamics study of an aqueous NaCl solution under the effect of static electric fields. We found that at low-to-moderate field intensity regimes chlorine ions have a greater mobility than sodium ions which, being a sort of "structure makers", are able to drag their own coordination shells. However, for field strengths exceeding 0.15 V Å(-1) the mobility of sodium ions overcomes that of chlorine ions as both types of ions do actually escape from their respective hydration cages. The presence of charged particles lowers the water dissociation threshold (i.e., the minimum field strength which induces a transfer of protons) from 0.35 V Å(-1) to 0.25 V Å(-1); moreover, a protonic current was also recorded at the estimated dissociation threshold of the solution. The behaviour of the current-voltage diagram of the protonic response to the external electric field is Ohmic as in pure water, with a resulting protonic conductivity of about 2.5 S cm(-1). This value is approximately one third of that estimated in pure water (7.8 S cm(-1)), which shows that the partial breaking of hydrogen bonds induced by the solvated ions hinders the migration of protonic defects. Finally, the conductivity of Na(+) and Cl(-) ions (0.2 S cm(-1)) is in fair agreement with the available experimental data for a solution molarity of 1.7 M. PMID:27494789

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    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.

  1. Expression of Virulence-Related Genes in Listeria monocytogenes Grown on Danish Hard Cheese as Affected by NaCl Content.

    PubMed

    Larsen, Nadja; Jespersen, Lene

    2015-06-01

    Expression of virulence-related genes in Listeria monocytogenes incubated on cheese was assessed by real-time quantitative polymerase chain reaction. The objective of the study was to investigate the impact of sodium chloride concentration in cheese on transcription of virulence genes and, thereby, virulence potential of L. monocytogenes. The expression studies were performed with L. monocytogenes strains characterized by different tolerance to salt stress. Strains ATCC(®) 51779 and DSMZ 15675 were incubated on the Danish hard-cheese type Samsoe, with low (<0.15% [wt/wt]) and high (3.6% [wt/wt]) content of NaCl. Genes differentially expressed (p<0.05) through the 48-h incubation were transcriptional regulators prfA and agrA, genes of the main virulence cluster inlA, hly, actA, involved in invasion of the epithelial cells, and genes bsh, opuC, gadC, clpP, and ami, associated with osmotic stress responses in L. monocytogenes. The more sensitive strain ATCC(®) 51779 was most responsive, showing significant upregulation of prfA, actA, hly, and bsh both at low and high NaCl. Strain DSMZ 15675 was less responsive to NaCl stress, showing reduced or consistent gene transcription at all conditions. Decreased transcription of agrA, ami, gadC, and opuC in both strains was promoted by low NaCl content. The study indicated that virulence gene expression of L. monocytogenes grown in cheese was affected by NaCl content and that effect was more significant in strains sensitive to both hypo- and hyperosmotic stresses.

  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. Expression of Virulence-Related Genes in Listeria monocytogenes Grown on Danish Hard Cheese as Affected by NaCl Content.

    PubMed

    Larsen, Nadja; Jespersen, Lene

    2015-06-01

    Expression of virulence-related genes in Listeria monocytogenes incubated on cheese was assessed by real-time quantitative polymerase chain reaction. The objective of the study was to investigate the impact of sodium chloride concentration in cheese on transcription of virulence genes and, thereby, virulence potential of L. monocytogenes. The expression studies were performed with L. monocytogenes strains characterized by different tolerance to salt stress. Strains ATCC(®) 51779 and DSMZ 15675 were incubated on the Danish hard-cheese type Samsoe, with low (<0.15% [wt/wt]) and high (3.6% [wt/wt]) content of NaCl. Genes differentially expressed (p<0.05) through the 48-h incubation were transcriptional regulators prfA and agrA, genes of the main virulence cluster inlA, hly, actA, involved in invasion of the epithelial cells, and genes bsh, opuC, gadC, clpP, and ami, associated with osmotic stress responses in L. monocytogenes. The more sensitive strain ATCC(®) 51779 was most responsive, showing significant upregulation of prfA, actA, hly, and bsh both at low and high NaCl. Strain DSMZ 15675 was less responsive to NaCl stress, showing reduced or consistent gene transcription at all conditions. Decreased transcription of agrA, ami, gadC, and opuC in both strains was promoted by low NaCl content. The study indicated that virulence gene expression of L. monocytogenes grown in cheese was affected by NaCl content and that effect was more significant in strains sensitive to both hypo- and hyperosmotic stresses. PMID:26067229

  4. 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

    2016-09-01

    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.

  5. 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

  6. NaCl multi-layer islands grown on Au(111)-([Formula: see text]) probed by scanning tunneling microscopy.

    PubMed

    Sun, Xiaonan; Felicissimo, Marcella P; Rudolf, Petra; Silly, Fabien

    2008-12-10

    The growth of multi-layer NaCl islands on Au(111)-([Formula: see text]) surfaces was investigated using scanning tunneling microscopy (STM). We observed that the aspect of the NaCl islands drastically differs depending on the tunneling conditions. It is therefore possible to observe the layers forming an NaCl island or to image the gold reconstruction below the first NaCl layer. Atomically resolved STM images obtained on the first NaCl layer demonstrate that NaCl grows as an epitaxial crystalline film on Au(111)-([Formula: see text]). STM images also suggest that some NaCl layers can be non-crystalline. PMID:21730671

  7. 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. PMID:24437520

  8. Stable isotope labelling reveals that NaCl stress decreases the production of Ensifer (Sinorhizobium) arboris lipochitooligosaccharide signalling molecules.

    PubMed

    Penttinen, Petri; Räsänen, Leena A; Lortet, Gilles; Lindström, Kristina

    2013-12-01

    Ensifer (Sinorhizobium) arboris is a symbiont of salt-tolerant leguminous trees in the genera Acacia and Prosopis that are utilized in the prevention of soil erosion and desertification and in phytoremediation of salinized soil. Signalling between the plant and the rhizobia is essential for the formation of effective symbiosis that increases the success of reclaiming saline sites. We assessed the effect of salt stress on the growth and the production of lipochitooligosaccharide signalling molecules (LCOs) of S. arboris HAMBI 2361, an LCO-overproducing derivative of the S. arboris type strain HAMBI 1552. The strain tolerated NaCl up to 750 mM. To obtain both qualitative and quantitative information on the LCO production under salt stress, we devised a method where LCOs were differentially labelled by stable isotopes of nitrogen, (14)N and (15)N, and analysed by mass spectrometry. Under control conditions, the strain produced altogether 27 structural LCO variants. In 380 mM NaCl, 13 LCO variants were produced in detectable amounts, and six of these were reliably quantified, ranging from one-tenth to one-third of the non-stressed one.

  9. Hypertonic Saline (NaCl 7.5%) Reduces LPS-Induced Acute Lung Injury in Rats.

    PubMed

    Petroni, Ricardo Costa; Biselli, Paolo Jose Cesare; de Lima, Thais Martins; Theobaldo, Mariana Cardillo; Caldini, Elia Tamaso; Pimentel, Rosângela Nascimento; Barbeiro, Hermes Vieira; Kubo, Suely Ariga; Velasco, Irineu Tadeu; Soriano, Francisco Garcia

    2015-12-01

    Acute respiratory distress syndrome (ARDS) is the most severe lung inflammatory manifestation and has no effective therapy nowadays. Sepsis is one of the main illnesses among ARDS causes. The use of fluid resuscitation is an important treatment for sepsis, but positive fluid balance may induce pulmonary injury. As an alternative, fluid resuscitation with hypertonic saline ((HS) NaCl 7.5%) has been described as a promising therapeutical agent in sepsis-induced ARDS by the diminished amount of fluid necessary. Thus, we evaluated the effect of hypertonic saline in the treatment of LPS-induced ARDS. We found that hypertonic saline (NaCl 7.5%) treatment in rat model of LPS-induced ARDS avoided pulmonary function worsening and inhibited type I collagen deposition. In addition, hypertonic saline prevented pulmonary injury by decreasing metalloproteinase 9 (MMP-9) activity in tissue. Focal adhesion kinase (FAK) activation was reduced in HS group as well as neutrophil infiltration, NOS2 expression and NO content. Our study shows that fluid resuscitation with hypertonic saline decreases the progression of LPS-induced ARDS due to inhibition of pulmonary remodeling that is observed when regular saline is used.

  10. 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.

  11. Genistein attenuates the hypertensive effects of dietary NaCl in hypertensive male rats.

    PubMed

    Cho, Taehyeon M; Peng, Ning; Clark, John T; Novak, Lea; Roysommuti, Sanya; Prasain, Jeevan; Wyss, J Michael

    2007-11-01

    Diets high in polyphenols may protect estrogen-depleted women and rats from hypertension, but there is little evidence for this beneficial effect in males. On a polyphenol-free diet, ovariectomized spontaneously hypertensive rats (SHRs), high dietary NaCl increases arterial pressure, and this effect is greatly blunted by a soy-based diet. High NaCl diets also elevate arterial pressure in male SHRs, and pilot studies indicated that soy polyphenols blunt this effect. The present studies tested the hypothesis that genistein (the primary polyphenol in soy) reduces NaCl-sensitive hypertension in young, male stroke-prone SHRs (SHR-SP, a very NaCl-sensitive strain of SHR). Seven-week-old male SHR-SPs were placed on polyphenol-free diets with or without normal dietary amounts of genistein [0.06% (wt/wt)] and containing high (4%), moderate (2%), or basal (0.7%) NaCl. SHR-SP on the genistein-free diet displayed a dose-related increase in arterial pressure in response to dietary NaCl, and dietary genistein blunted this response. Ganglionic blockade with hexamethonium reduced arterial pressure to similar levels in all six groups, suggesting that the antihypertensive effects of genistein are influenced by the autonomic nervous system. We further hypothesized that genistein, like estrogen, would improve insulin sensitivity and lipid profiles. Thus, in study 2, 7-wk-old male SHR-SP were placed on high (6%) or basal (0.7%) NaCl diets with or without genistein (0.06%). Dietary genistein reduced plasma insulin and insulin resistance in SHR-SP on a high NaCl diet and decreased plasma cholesterol and triglycerides in SHR-SP on the basal NaCl diet. Thus, in male SHR-SP, dietary genistein blunts NaCl-sensitive hypertension, and these effects may be regulated, in part, by the autonomic nervous system and/or metabolic mechanisms.

  12. Superhard BC(3) in cubic diamond structure.

    PubMed

    Zhang, Miao; Liu, Hanyu; Li, Quan; Gao, Bo; Wang, Yanchao; Li, Hongdong; Chen, Changfeng; Ma, Yanming

    2015-01-01

    We solve the crystal structure of recently synthesized cubic BC(3) using an unbiased swarm structure search, which identifies a highly symmetric BC(3) phase in the cubic diamond structure (d-BC(3)) 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-BC(3) are in excellent agreement with experimental data. Calculated stress-strain relations of d-BC(3) 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. The present results establish the first boron carbide in the cubic diamond structure with remarkable properties, and these new findings also provide insights for exploring other covalent solids with complex bonding configurations.

  13. Quadratic-Like Dynamics of Cubic Polynomials

    NASA Astrophysics Data System (ADS)

    Blokh, Alexander; Oversteegen, Lex; Ptacek, Ross; Timorin, Vladlen

    2016-02-01

    A small perturbation of a quadratic polynomial f with a non-repelling fixed point gives a polynomial g with an attracting fixed point and a Jordan curve Julia set, on which g acts like angle doubling. However, there are cubic polynomials with a non-repelling fixed point, for which no perturbation results into a polynomial with Jordan curve Julia set. Motivated by the study of the closure of the Cubic Principal Hyperbolic Domain, we describe such polynomials in terms of their quadratic-like restrictions.

  14. 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.

  15. Comparison between NaCl tolerance response and acclimation to cold temperature in Shewanella putrefaciens.

    PubMed

    Leblanc, Laurence; Leboeuf, Céline; Leroi, Françoise; Hartke, Axel; Auffray, Yanick

    2003-03-01

    Two strains of the spoiling bacterium S. putrefaciens showed an adaptation capacity to hyperosmotic shock when they were pretreated with a sublethal concentration of NaCl. The maximal tolerance factor for the CIP 69.29 strain was obtained when cells were incubated for 1 h in the presence of 1.5% NaCl, whereas for the J13.1 strain, an incubation of 15 min in the presence of 1% NaCl seemed to be the optimal conditions to harden the cells against a subsequent lethal salt treatment. During NaCl adaptation and growth at low temperatures (2 degrees C), 37 and 32 polypeptides were induced respectively. Interestingly, 11 proteins were common between the two different stress responses. These proteins and the corresponding genes seem to play a key role in the observed cross-protection towards the NaCl challenge induced by growth of the cultures at 2 degrees C. One of the overlapping proteins has been identified to correspond to the alkyl hydroperoxide reductase (AhpC) of S. putrefaciens. Northern blot analysis showed that induction of this enzyme was accompanied by accumulation of the corresponding transcript under both conditions. PMID:12567236

  16. 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.

  17. Heterogeneous nucleation of ice from supercooled NaCl solution confined in porous cement paste

    NASA Astrophysics Data System (ADS)

    Zeng, Qiang; Li, Kefei; Fen-Chong, Teddy

    2015-01-01

    Clarifying the nucleation process of chloride-based deicing salt solution (e.g., NaCl solution) confined in cement-based porous materials remains an important issue to understand its detrimental effects on material substrates. In this study, the pore structures of hardened cement pastes were characterized by mercury-intrusion and nitrogen-sorption porosimetry. The ice nucleation temperature of NaCl solution of different concentrations confined in the hardened cement pastes was measured and analyzed by classical heterogeneous nucleation theory. The kinetic factor, contact-angle factor including the contact angle between ice and the substrate were evaluated. The results revealed that the contact angle between ice and the substrate showed the minimum value when adding 3% NaCl into water. The heterogeneous ice nucleation rates were found to be proportional to the water activity shifts.

  18. 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.

  19. 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.

  20. 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)

  1. 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.

  2. 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.

  3. 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. PMID:25893445

  4. 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.

  5. 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.

  6. Switching osmolyte strategies: response of Methanococcus thermolithotrophicus to changes in external NaCl.

    PubMed

    Martin, D D; Ciulla, R A; Robinson, P M; Roberts, M F

    2001-11-15

    Methanococcus thermolithotrophicus, a thermophilic methanogenic archaeon, produces and accumulates beta-glutamate and L-alpha-glutamate as osmolytes when grown in media with <1 M NaCl. When the organism is adapted to grow in >1 M NaCl, a new zwitterionic solute, N(epsilon)-acetyl-beta-lysine, is synthesized and becomes the dominant osmolyte. Several techniques, including in vivo and in vitro NMR spectroscopy, HPLC analyses of ethanol extracts, and potassium atomic absorption, have been used to monitor the immediate response of M. thermolithotrophicus to osmotic stress. There is a temporal hierarchy in the response of intracellular osmolytes. Changes in intracellular K(+) occur within the first few minutes of altering the external NaCl. Upon hypoosmotic shock, K(+) is released from the cell; relatively small changes occur in the organic osmolyte pool on a longer time scale. Upon hyperosmotic shock, M. thermolithotrophicus immediately internalizes K(+), far more than would be needed stoichiometrically to balance the new salt concentration. This is followed by a decrease to a new K(+) concentration (over 10-15 min), at which point synthesis and accumulation of primarily L-alpha-glutamate occur. Once growth of the M. thermolithotrophicus culture begins, typically 30-100 min after the hyperosmotic shock, the intracellular levels of organic anions decrease and the zwitterion (N(epsilon)-acetyl-beta-lysine) begins to represent a larger fraction of the intracellular pool. The observation that N(epsilon)-acetyl-beta-lysine accumulation occurs in osmoadapted cells but not immediately after osmotic shock is consistent with the hypothesis that lysine 2,3-aminomutase, an enzyme involved in N(epsilon)-acetyl-beta-lysine synthesis, is either not present at high levels or has low activity in cells grown and adapted to lower NaCl. That lysine aminomutase specific activity is 8-fold lower in protein extracts from cells adapted to low NaCl compared to those adapted to 1.4 M NaCl

  7. Anisotropy of a cubic ferromagnet at criticality

    NASA Astrophysics Data System (ADS)

    Kudlis, A.; Sokolov, A. I.

    2016-10-01

    Critical fluctuations change the effective anisotropy of cubic ferromagnet near the Curie point. If the crystal undergoes phase transition into orthorhombic phase and the initial anisotropy is not too strong, reduced anisotropy of nonlinear susceptibility acquires at Tc the universal value δ4*=2/v* 3 (u*+v*) where u* and v* are coordinates of the cubic fixed point on the flow diagram of renormalization group equations. In the paper, the critical value of the reduced anisotropy is estimated within the pseudo-ɛ expansion approach. The six-loop pseudo-ɛ expansions for u*, v*, and δ4* are derived for the arbitrary spin dimensionality n . For cubic crystals (n =3 ) higher-order coefficients of the pseudo-ɛ expansions obtained turn out to be so small that use of simple Padé approximants yields reliable numerical results. Padé resummation of the pseudo-ɛ series for u*, v*, and δ4* leads to the estimate δ4*=0.079 ±0.006 , indicating that detection of the anisotropic critical behavior of cubic ferromagnets in physical and computer experiments is certainly possible.

  8. 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.

  9. 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.

  10. Electrochemical Behavior of 2205 Duplex Stainless Steel in NaCl Solution with Different Chromate Contents

    NASA Astrophysics Data System (ADS)

    Luo, H.; Dong, C. F.; Cheng, X. Q.; Xiao, K.; Li, X. G.

    2012-07-01

    The electrochemical behavior of 2205 duplex stainless steel in NaCl solution with different chromate contents were investigated by potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, and scanning electron microscope (SEM). The effect of chromate on passivity and pitting behavior of stainless steel was also studied. The results showed that pitting susceptibility as well as semiconducting properties of passive film is heavily dependent on the chromate concentration. There exists a critical chromate value (about 0.03 M in 1 M NaCl solutions) below which the pitting corrosion on the stainless steel would be inhibited and above which it would be accelerated.

  11. 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.

  12. 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. PMID:3449615

  13. Role of Trichoderma harzianum in mitigating NaCl stress in Indian mustard (Brassica juncea L) through antioxidative defense system.

    PubMed

    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

  14. Role of Trichoderma harzianum in mitigating NaCl stress in Indian mustard (Brassica juncea L) through antioxidative defense system.

    PubMed

    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

  15. 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

  16. 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…

  17. 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.

  18. [Effects of NaCl stress on cation contents in different pumpkin cultivars' seedlings].

    PubMed

    Li, Wei-Xin; Chen, Gui-Lin; Ren, Liang-Yu; Wang, Peng

    2008-03-01

    With the seedlings of 19 pumpkin cultivars as test materials, this paper studied the variations of Na+, K+, Ca2+, Na+/K+, Na+/Ca2+, SN+, K+ and SNa+, ca2+ in their shoots and roots under the stress of 300 mmol NaCl x L(-1). The results showed that after an 8-day exposure to 300 mmol NaCl x L(-1), the Na+ content in the seedlings increased significantly while the K+ content decreased, resulting in the brokenness of ion balance. The root Na+ content, shoot Na+/K+ and Na+/Ca2+ ratios, and SNa+, K+ and SNa+, Ca2+ of Cucurbita moschata (Q1) were significantly higher than those of C. maxima (H2) and C. ficifolia (H3). The variation tendency of these parameters of different pumpkin cultivars' seedlings were nearly consistent with the salt injury index of the seedlings under NaCl stress, which further proved that the strong salt-tolerance of Q1 was related to the lower values of shoot Na+/K+, Na+/Ca2+, SNa+, K+ and SNa+, Ca2+, and the high contents of K+ and Ca2+, while the salt-sensitivity of H2 and H3 was related to the higher values of shoot Na+/K+, Na+/Ca2+, SNa+, K+ and SNa+, Ca2+, and low contents of K+ and Ca2+ under NaCl stress.

  19. Evaluation of Potential Effects of NaCl and Sorbic Acid on Staphylococcal Enterotoxin A Formation

    PubMed Central

    Zeaki, Nikoleta; Rådström, Peter; Schelin, Jenny

    2015-01-01

    The prophage-encoded staphylococcal enterotoxin A (SEA) is recognized as the main cause of staphylococcal food poisoning (SFP), a common foodborne intoxication disease, caused by Staphylococcus aureus. Studies on the production of SEA suggest that activation of the SOS response and subsequent prophage induction affect the regulation of the sea gene and the SEA produced, increasing the risk for SFP. The present study aims to evaluate the effect of NaCl and sorbic acid, in concentrations relevant to food production, on SOS response activation, prophage induction and SEA production. The impact of stress was initially evaluated on steady state cells for a homogenous cell response. NaCl 2% was found to activate the SOS response, i.e., recA expression, and trigger prophage induction, in a similar way as the phage-inducer mitomycin C. In contrast, sorbic acid decreased the pH of the culture to a level where prophage induction was probably suppressed, even when combined with NaCl stress. The impact of previous physiological state of the bacteria was also addressed on cells pre-exposed to NaCl, and was found to potentially affect cell response upon exposure to further stress. The results obtained highlight the possible SFP-related risks arising from the use of preservatives during food processing.

  20. 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.

  1. Morphological, physiological, and structural responses of two species of artemisia to NaCl stress.

    PubMed

    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(+), Ca(2+)/Na(+), and Mg(2+)/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

  2. The electronic structure of NaCl adlayers on W(110) studied by ionizing radiation

    NASA Astrophysics Data System (ADS)

    Dieckhoff, S.; Müller, H.; Maus-Friedrichs, W.; Brenten, H.; Kempter, V.

    1992-12-01

    The electronic structure of thin NaCl adlayers deposited on W(110) at room temperature is studied with electron energy loss spectroscopy (EELS), ion impact electron spectroscopy (IIES) with He + and He 2+ ions, metastable impact electron spectroscopy (MIES) with He ∗ atoms, ultraviolet photoelectron spectroscopy (UPS), and AES. It is concluded that NaCl adsorbs molecularly under the studied conditions. The transition from the electronic structure of single adsorbed NaCl molecules to the well-known bulk structure could be studied by following the emergence of bulk properties, such as interband transitions and excitonic excitations, as a function of the NaCl exposure. Our results are consistent with lateral growth of two-dimensional islands during the formation of the first adlayer. The electronic transition processes at the surface induced by electrons as well as He projectiles in different excitation and charge states, in particular the vacancy production in the Cl - 3p valence band, are studied. Their relevance for desorption induced by electronic transitions (DIET) is discussed.

  3. 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.

  4. Purinergic mechanisms of lateral parabrachial nucleus facilitate sodium depletion-induced NaCl intake.

    PubMed

    Menezes, Miguel F; Barbosa, Silas P; De Andrade, Carina A F; Menani, José V; De Paula, Patrícia M

    2011-02-01

    Purinergic receptors are present in the lateral parabrachial nucleus (LPBN), a pontine structure involved in the control of sodium intake. In the present study, we investigated the effects of α,β-methyleneadenosine 5'-triphosphate (α,β-methylene ATP, selective P2X purinergic agonist) alone or combined with pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS, P2X purinergic antagonist) or suramin (non-selective P2 purinergic antagonist) injected into the LPBN on sodium depletion-induced 1.8% NaCl intake. Male Holtzman rats with stainless steel cannulas implanted into the LPBN were used. Sodium depletion was induced by treating rats with the diuretic furosemide (20mg/kg of body weight) followed by 24h of sodium-deficient diet. Bilateral injections of α,β-methylene ATP (2.0 and 4.0nmol/0.2μl) into the LPBN increased sodium depletion-induced 1.8% NaCl intake (25.3±0.8 and 26.5±0.9ml/120min, respectively, vs. saline: 15.2±1.3ml/120min). PPADS (4nmol/0.2μl) alone into the LPBN did not change 1.8% NaCl intake, however, pretreatment with PPADS into the LPBN abolished the effects of α,β-methylene ATP on 1.8% NaCl intake (16.9±0.9ml/120min). Suramin (2.0nmol/0.2μl) alone into the LPBN reduced sodium depletion-induced 1.8% NaCl intake (5.7±1.9ml/120min, vs. saline: 15.5±1.1ml/120min), without changing 2% sucrose intake or 24h water deprivation-induced water intake. The combination of suramin and α,β-methylene ATP into the LPBN produced no change of 1.8% NaCl intake (15.2±1.2ml/120min). The results suggest that purinergic P2 receptor activation in the LPBN facilitates NaCl intake, probably by restraining LPBN mechanisms that inhibit sodium intake.

  5. NaCl reflection coefficients in proximal tubule apical and basolateral membrane vesicles. Measurement by induced osmosis and solvent drag.

    PubMed

    Pearce, D; Verkman, A S

    1989-06-01

    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

  6. NaCl reflection coefficients in proximal tubule apical and basolateral membrane vesicles. Measurement by induced osmosis and solvent drag.

    PubMed

    Pearce, D; Verkman, A S

    1989-06-01

    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.

  7. 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. PMID:21479761

  8. [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. PMID:25796901

  9. [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.

  10. [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.

  11. [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. PMID:26915182

  12. Cosmological evolution with the cubic order field derivative coupling

    NASA Astrophysics Data System (ADS)

    Minamitsuji, Masato

    2016-03-01

    We investigate cosmological evolution in the scalar-tensor theory with the field derivative coupling to the double-dual of the Riemann tensor (the cubic-type theory). The theory can be seen as the straightforward extension of the scalar-tensor with the quadratic order field derivative coupling to the Einstein tensor (the quadratic-type theory). Both the field derivative couplings to the Einstein tensor and the double-dual of the Riemann tensor have been argued in terms of the successful realization of the self-tuning of the cosmological constant within the Horndeski theory. Assuming the constant potential given by the sum of the cosmological constant and the quantum vacuum energy, the shift symmetry for the scalar field and no matter fields, in the spatially-flat Friedmann-Lemaître-Robertson-Walker spacetime, we can reduce the set of the field equations to the first-order ordinary nonlinear differential equation for the Hubble parameter, showing the existence of the self-tuned and runaway de Sitter solutions, in addition to the standard de Sitter solutions in general relativity and the finite Hubble singularities which can be reached within the finite time. We then argue the possible cosmological evolution in terms of the values of the effective cosmological constant, the kinetic coupling constants and the initial Hubble parameter. Although the behavior of the universe around each of the de Sitter solutions as well as the finite time singularities is very similar in both theories, we find that the crucial difference appears in terms of no bounce or turnaround behavior across the vanishing Hubble parameter as well as no limitation for the range of the Hubble parameter in the cubic-type theory.

  13. Deterministic implementation of weak quantum cubic nonlinearity

    SciTech Connect

    Marek, Petr; Filip, Radim; Furusawa, Akira

    2011-11-15

    We propose a deterministic implementation of weak cubic nonlinearity, which is a basic building block of a full-scale continuous-variable quantum computation. Our proposal relies on preparation of a specific ancillary state and transferring its nonlinear properties onto the desired target by means of deterministic Gaussian operations and feed forward. We show that, despite the imperfections arising from the deterministic nature of the operation, the weak quantum nonlinearity can be implemented and verified with the current level of technology.

  14. 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. PMID:26830593

  15. 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.

  16. 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.

  17. 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.

  18. 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.; Materials Science Division; Univ. of Washington; NIST

    2009-01-01

    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.

  19. 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-.

  20. Strength and Mechanical Response of NaCl Using In-Situ Transmission Electron Microscopy Compression and Nanoindentation.

    PubMed

    Lin, Kai-Peng; Fang, Te-Hua; Kang, Sho-Hui

    2016-03-01

    Strength and mechanical properties of single crystal sodium chloride (NaCl) are characterized. Critical deformation variations of NaCl pillared structures and films are estimated using in-situ transmission electron microscope (TEM) compression tests and nanoindentation experiments. Young's modulus and contact stiffness of NaCl pillars with diameters of 300 to 500 nm were 10.4-23.9 GPa, and 159-230 N/m, respectively. The nanohardness and Vickers hardness of the NaCl (001) film were 282-596 and 196-260 MPa, respectively. The results could provide useful information for understanding the mechanical properties, contact and local deformation of NaCl pillars and films. PMID:27455676

  1. 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

  2. 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

  3. 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.

  4. Fluid evolution in the H 2O-CH 4-CO 2-NaCl system during emerald mineralization at Gravelotte, Murchison Greenstone Belt, Northeast Transvaal, South Africa

    NASA Astrophysics Data System (ADS)

    Nwe, Yin Yin; Morteani, Giulio

    1993-01-01

    Fluid evolution during emerald mineralization at the Gravelotte emerald mine has been studied by microthermometry and laser Raman microprobe spectrometry. The emeralds and associated phenakites occur on the flanks of a highly metasomatised albitite pegmatoid body and in the biotite schists at and near its contact. The fluids lie in the H 2O-CH 4-CO 2-NaCl system and four types of inclusions are characterised based on time of trapping and fluid contents. The earliest type 1 inclusions, found in phenakites and the emeralds which formed from them, are low salinity (<6 wt% NaCl) with up to 18 mol% CH 4. The carbonic phase contains over 93 mol% CH 4 and variable small amounts of CO 2, C 2H 6, N 2, and H 2S. The solvus crest for this system lies at ≈400°C, closer to the H 2O end of the join. With time the fluids become less CH 4 rich and more saline. The type 2 fluids are highly variable in both CH 4-CO 2 contents and salinity, reflecting mixing of type 1 fluids with higher salinity brines. The late type 3 and 4 inclusions are CH 4-CO 2-free high salinity inclusions with up to 38 wt% NaCl. Trapping conditions for the type 1 fluids were around 450-500°C and 4 kb based on model isochores and geologic evidence. During the trapping of type 2 inclusions, fluid pressures probably fluctuated due to opening and resealing of fractures. Approximate P- T ranges of trapping for these and other later inclusions have been defined, minimum trapping temperatures for types 2, 3, and 4 being, respectively, 250, 150, and 240°C, and pressures in the range of 1-4 kb. Calculations of ƒ O 2 show an initial low ƒ O 2 between QFM and the synthetic graphite-CH 4 buffer for the type 1 fluids. This rises to above QFM in the later stages. Such low initial values are uncharacteristic of granitic pegmatite systems, and it is suggested that the phenakites formed in the post-magmatic stage of alkali metasomatism when the albitization took place. In the later stages, phenakite was converted to

  5. Structure and orientation of small particles of platinum deposited on NaCl and mica

    NASA Technical Reports Server (NTRS)

    Renou, A.; Gillet, M.

    1979-01-01

    The structure of small platinum particles condensed in vacuum onto NaCl (001), NaCl (111) and mica substrates was studied by electron diffraction and electron microscopy. Results show that above a certain substrate temperature decahedral or icosahedral particles are formed. These particles are practically absent with substrates cleaved in high vacuum. They are always much less numerous than in gold films prepared under the same conditions. Assumptions made to explain this phenomenon are: (1) the initial growth of an abnormal structure of the nuclei as opposed by the substrate; (2) the particles disappear before they attain a size which corresponds to the observations; and (3) the particles result from a coalescence mechanism leading to multiple twinned particles.

  6. Effect of NaCl and KCl doping on the growth of sulphamic acid crystals

    NASA Astrophysics Data System (ADS)

    Thaila, T.; Kumararaman, S.

    2011-11-01

    The nonlinear optical single crystals of doped sulphamic acid (SA) were grown from aqueous solution by doping with NaCl and KCl using slow evaporation method. Powder X-ray diffraction studies confirm that the grown crystals belong to orthorhombic system. The density and melting point measurements of the grown crystals were determined by floatation technique and capillary tube method, respectively. The range of optical transmittance was ascertained by recording the UV-Vis-NIR spectrum. Atomic absorption study reveals the presence of dopants in the doped crystals. The thermal analyses indicated that the doped SA crystals are more stable than pure crystals. The Vicker's microhardness studies revealed that the dopants increased the hardness of the crystals. SHG efficiency studies of the crystals are found to be increased in the presence of NaCl and KCl dopants.

  7. Corrosion Behavior of Titanium Grade 7 in Fluoride-Containing NaCl Brines

    SciTech Connect

    Lian, T; Whalen, M T; Wong, L

    2004-10-25

    The effects of fluoride on the corrosion behavior of Titanium Grade 7 (0.12-0.25% Pd) have been investigated. Up to 0.1 mol/L fluoride was added to the NaCl brines at 95 C, and three pH values of 4, 8, and 11 were selected for studying pH dependence of fluoride effects. It was observed that fluoride significantly altered the anodic polarization behavior, at all three pH values of 4, 8, and 11. Under acidic condition fluoride caused active corrosion. The corrosion of Titanium grade 7 was increased by three orders of magnitude when a 0.1 mol/L fluoride was added to the NaCl brines at pH 4, and the Pd ennoblement effect was not observed in acidic fluoride-containing environments. The effects of fluoride were reduced significantly when pH was increased to 8 and above.

  8. Effect of NaCl and KCl doping on the growth of sulphamic acid crystals.

    PubMed

    Thaila, T; Kumararaman, S

    2011-11-01

    The nonlinear optical single crystals of doped sulphamic acid (SA) were grown from aqueous solution by doping with NaCl and KCl using slow evaporation method. Powder X-ray diffraction studies confirm that the grown crystals belong to orthorhombic system. The density and melting point measurements of the grown crystals were determined by floatation technique and capillary tube method, respectively. The range of optical transmittance was ascertained by recording the UV-Vis-NIR spectrum. Atomic absorption study reveals the presence of dopants in the doped crystals. The thermal analyses indicated that the doped SA crystals are more stable than pure crystals. The Vicker's microhardness studies revealed that the dopants increased the hardness of the crystals. SHG efficiency studies of the crystals are found to be increased in the presence of NaCl and KCl dopants.

  9. Effect of Acacia Gum, NaCl, and Sucrose on Physical Properties of Lotus Stem Starch

    PubMed Central

    Gill, Balmeet Singh

    2014-01-01

    Consumer preferences in east Asian part of the world pave the way for consumption of lotus stem starch (LSS) in preparations such as breakfast meals, fast foods, and traditional confectioneries. The present study envisaged the investigation and optimization of additives, that is, acacia gum, sodium chloride (NaCl), and sucrose, on water absorption (WA), water absorption index (WAI), and water solubility index (WSI) of LSS employing response surface methodology (RSM). Acacia gum resulted in increased water uptake and swelling of starch; however, NaCl reduced the swelling power of starch by making water unavailable to starch and also due to starch-ion electrostatic interaction. Sucrose restricted the water absorption by binding free water and decreased amylose leaching by building bridges with starch chains and thus forming rigid structure. PMID:26904639

  10. Solubility of NaCl in aqueous electrolyte solutions from 10 to 100°C

    USGS Publications Warehouse

    Clynne, M.A.; Potter, R.W.; Haas, J.L.

    1981-01-01

    The solubilities of NaCl in aqueous KCl, MgCl2, CaCl2, and mixed CaCl2-KCl solutions have been determined from 10 to 100??C. The data were fit to an equation, and the equation was used to calculate values of the change in solubility of NaCl, ???[NaCl]/???T. These values are required for calculations of the rate of migration of fluids in a thermal gradient in rock salt. The data obtained here indicate that the values of ???[NaCl]/???T are 36-73% greater for solutions containing divalent ions than for the NaCl-H2O system.

  11. Interfacial free energy and stiffness of the solid-melt interface of NaCl

    NASA Astrophysics Data System (ADS)

    Zykova-Timan, Tatyana; Tosatti, Erio; Frenkel, Daan

    2011-03-01

    The importance of the interfacial free energy for the equilibrium morphology of crystals is well understood. In contrast, much less is known about to the so-called ``interfacial stiffness'' that governs fluctuations of, e.g., solid-liquid interfaces. We carried out molecular dynamics simulations of capillary wave fluctuations on various faces of NaCl crystals in contact with its melt, that provides new information on the behaviour of this interface at the atomistic level. The capillary fluctuations connect directly with the interfacial stiffness, and indirectly also to the interface free energy. In our simulations we studied the (100)-liquid interface and adjacent vicinals. From the angular dependence of the surface stiffness, we deduce an estimate of NaCl(100)-melt interfacial free energy and discuss limitations of the fluctuation approach. Finally we compare this estimate of the surface free energy with values obtained through other methods [1,2,3] and discuss the differences [4].

  12. Thermodynamic and Transport Properties of H2O + NaCl from Polarizable Force Fields.

    PubMed

    Jiang, Hao; Mester, Zoltan; Moultos, Othonas A; Economou, Ioannis G; Panagiotopoulos, Athanassios Z

    2015-08-11

    Molecular dynamics and Monte Carlo simulations were performed to obtain thermodynamic and transport properties of the binary H2O + NaCl system using the polarizable force fields of Kiss and Baranyai ( J. Chem. Phys. 2013 , 138 , 204507 and 2014 , 141 , 114501 ). In particular, liquid densities, electrolyte and crystal chemical potentials of NaCl, salt solubilities, mean ionic activity coefficients, vapor pressures, vapor-liquid interfacial tensions, and viscosities were obtained as functions of temperature, pressure, and salt concentration. We compared the performance of the polarizable force fields against fixed-point-charge (nonpolarizable) models. Most of the properties of interest are better represented by the polarizable models, which also remain physically realistic at elevated temperatures. PMID:26574461

  13. VizieR Online Data Catalog: VY CMa ALMA NaCl images (Decin+, 2016)

    NASA Astrophysics Data System (ADS)

    Decin, L.; Richards, A. M. S.; Millar, T. J.; Baudry, A.; de, Beck E.; Homan, W.; Smith, N.; van de Sande, M.; Walsh, C.

    2016-07-01

    VY CMa was observed for ALMA Science Verification on 2013 16-19 August using 16-20 12-m antennas on baselines from 0.014-2.7km. The main objective was to map the H2O maser lines at 321 and 325GHz (Band 7) and 658GHz (Band 9), but several thermal lines identified with various rotational transitions of NaCl, TiO2, SO2, and SiO were also present in the spectral setting in addition to the continuum data. Four NaCl lines in the ground or first vibrational state are covered in the ALMA band 7 data. All of them are detected, albeit only two are unblended (see Table 1). (3 data files).

  14. Chemical identification of ions in doped NaCl by scanning force microscopy.

    PubMed

    Foster, Adam S; Barth, Clemens; Henry, Claude R

    2009-06-26

    A quantitative comparison between experiment and theory is presented, which shows that all ions of the Suzuki structure on (001) surfaces of Mg2+ or Cd2+ doped NaCl crystals can be identified despite the tip-surface distance, differences in impurity chemistry, and surface termination. The identification can be used to calibrate the potential of the tip's last atom, and it is proposed to use these surfaces for better characterization of deposited nano-objects.

  15. The Influence of NaCl Crystallization on the Long-Term Mechanical Behavior of Sandstone

    NASA Astrophysics Data System (ADS)

    Zheng, Hong; Feng, Xia-Ting; Jiang, Quan

    2015-01-01

    Salt precipitation can occur in saline aquifers when the pore-fluid concentration exceeds saturation during carbon dioxide sequestration, especially in the dry-out region closest to the wellbore. Results from uniaxial and triaxial compression tests, creep tests, and poromechanical tests indicate that NaCl crystallization in pores enhances the compressive strength and bulk modulus under the given confining pressure, and reduces creep. In addition, it makes the pore liquid pressure in the sandstone less sensitive to changes in the hydrostatic stress under undrained conditions. A poro-viscoelastic model with crystals in the pores is proposed to quantitatively estimate the influence of in-pore NaCl crystallization on the long-term mechanical behavior of sandstone. By considering the thermodynamics of crystallization, a geometrical model of a crystal in a pore space is applied to the quasi-static equilibrium state of the crystallization. The solid-liquid interfacial energy is introduced to provide a convenient approach to couple the mechanical properties of sandstone (as a porous material) and the thermochemistry of the in-pore NaCl crystallization. By adding the solid-liquid interfacial energy, the Clausius-Duhem inequality for the skeleton is established for the viscoelasticity based on the proposed geometrical model of a crystal in the pore space. The constitutive equations are deduced from the free energy balance relationship to evaluate the influence of crystallization on the effective stress in terms of the solid-liquid interfacial energies and the pore-size distribution. By comparing the model's output with the test results, it is found that the poro-viscoelastic model describes the influence of in-pore NaCl crystallization on the long-term mechanical behavior of the sandstone reasonably well.

  16. Body Temperatures During Exercise in Deconditioned Dogs: Effect of NACL and Glucose Infusion

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Kruk, B.; Nazar, K.; Kaciuba-Usciko, H.

    2000-01-01

    Infusion of glucose (Glu) into normal exercising dogs attenuates the rise in rectal temperature (Delta-Tre) when compared with delta-Tre during FFA infusion or no infusion. Rates of rise and delta-=Tre levels are higher during exercise after confinement. Therefore, the purpose of this study was to determine if Glu infusion would attenuate the exercise-induced excess hyperthermia after deconditioning. Rectal and quadricep femoris muscle temperatures (Tmu) were measured in 7 male, mongrel dogs dogs (19.6 +/- SD 3.0 kg) during 90 minutes of treadmill exercise (3.1 +/-SD 0.2 W/kg) with infusion (30ml/min/kg) of 40% Glu or 0.9% NaCL before BC) and after confinement (AC) in cages (40 x 110 x 80 cm) for 8 wk. Mean (+/-SE body wt. were 19.6 +/- 1.1 kg BC and 19.5 +/- 1.1kg AC, exercise VO2 were not different (40.0 - 42.0 mi/min/kg-1). With NaCl AC, NaCl BC, GluAC, and GluBC: Delta-Tre were, 1.8, 1.4, 1.3 and 0.9C respectively; and Delta-Tmu were 2.3, 1.9, 1.6, and 1.4C. respectively (P<0.05 from GluBC). Compared with NaCl infusion, attenuated both Delta-Tre and Delta-Tmu BC and AC, respectively. Compared with GluBC, GluAC attenuated Delta-Tmu but not Delta-Tre. Thus. with similar heat production, the mechanism for attenuation at bad body temperature with Glu infusion must affect avenues of heat dissipation.

  17. An amorphous monolayer: Infrared spectroscopic and theoretical studies of SO2 on NaCl (100)

    NASA Astrophysics Data System (ADS)

    Berg, Otto; Ewing, George E.; Meredith, Andrew W.; Stone, Anthony J.

    1996-05-01

    At temperatures between 100 and 110 K, exposing the (100) face of NaCl to unsaturated SO2 gas yields a stable adlayer. Infrared spectra of adsorbed SO2 contain complex resonances near the origins of the molecular symmetric and asymmetric stretching vibrations. On photometric grounds the absolute coverage of the surface is found to be one molecule per exposed Na+Cl- ion pair. The spectra of this monolayer consist of several sharp lines overlapping one broad feature for each molecular mode. By comparison to vibrational excitons in simpler systems, the coexistence of crystalline and amorphous adlayer structures is strongly indicated. This partial ordering is pressure dependent, and develops spontaneously on a time scale of minutes. The disordered component, in contrast, is never in equilibrium with the gas phase. Computational simulations have detailed the microscopic basis of this behavior. Accurate ab initio models of the SO2 molecule and NaCl(100) surface were used in a Monte Carlo simulation of the experimental conditions. At both half and full coverage, an amorphous two-dimensional condensate developed. This is minimally consistent with the polarized infrared photometry. Seemingly equilibrated Monte Carlo runs retained some memory of the initial molecular configuration, again consistent with hysteresis observed in the spectroscopic experiments. No structural order developed in the simulations, but the energetic state of affairs was clarified: the potential driving adsorption and condensation is deep in comparison to available thermal energy, but relatively insensitive to molecular orientation.

  18. [Effects of NaCl stress on cation contents in seedlings of two pumpkin varieties].

    PubMed

    Wang, Ran; Chen, Gui-Lin; Song, Wei; Lü, Gui-Yun; Liang, Jing; Li, Wei-Xin

    2006-02-01

    Effects of different concentration NaCl stress on cation contents of pumpkin cultivars (Cucurbita ficifolia and Cucurbita moschata) usually used as rootstocks of cucumber were studied. The results showed that, in both cultivars treated with 150, 300 and 500 mmol/L NaCl for 7 d, increasing salinity caused in increasing retardation of shoot and root growth, and reduction of shoot relative water content (Table 1). With increasing NaCl concentration, Na(+) content increased while K(+) content decreased distinctly in roots, stems and leaves of both cultivars. And Na(+) and K(+) contents in different organs were in the orders roots>stems>leaves and stems>leaves>roots respectively (Fig.3). There were less Na(+) in root, stem and leaf (Fig.3), more free proline and soluble sugar in leaves (Fig.1, 2), and higher shoot relative water content (Table 1) in C. ficifolia than in C. moschata. So there are differences between C. ficifolia and C. moschata in osmotic adjustment mechanisms and selective absorption and transportation of different cations, and the salt tolerance of C. ficifolia is higher than C. moschata. PMID:16477137

  19. Direct Synthesis of Few-Layer Graphene on NaCl Crystals.

    PubMed

    Shi, Liurong; Chen, Ke; Du, Ran; Bachmatiuk, Alicja; Rümmeli, Mark Hermann; Priydarshi, Manish Kumar; Zhang, Yanfeng; Manivannan, Ayyakkannu; Liu, Zhongfan

    2015-12-16

    Chemical vapor deposition is used to synthesize few-layer graphene on micro crystalline sodium chloride (NaCl) powder. The water-soluble nature of NaCl makes it convenient to produce free standing graphene layers via a facile and low-cost approach. Unlike traditional metal-catalyzed or oxygen-aided growth, the micron-size NaCl crystal planes play an important role in the nucleation and growth of few-layer graphene. Moreover, the possibility of synthesizing cuboidal graphene is also demonstrated in the present approach for the first time. Raman spectroscopy, optical microscopy, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy are used to evaluate the quality and structure of the few-layer graphene along with cuboidal graphene obtained in this process. The few-layer graphene synthesized using the present method has an adsorption ability for anionic and cationic dye molecules in water. The present synthesis method may pave a facile way for manufacturing few-layer graphene on a large scale. PMID:26524105

  20. Relative osmotic effects of raffinose, KCl, and NaCl across basolateral cell membrane.

    PubMed

    Welling, L W; Welling, D J; Ochs, T

    1990-10-01

    Lumen-collapsed segments of rabbit S2 proximal tubule were bathed in isotonic medium and then exposed acutely to a medium made hypertonic by the addition of raffinose, NaCl, KCl, Na gluconate, K gluconate, or choline Cl. The result was a rapid efflux of water and a shrinking of the tubule, which could be measured by video techniques within the first 0.1 s. After reequilibration in isotonic medium, each tubule was then exposed to a second hypertonic medium to provide a direct comparison between two different solutes, either NaCl vs. KCl or raffinose vs. any one of the other solutes. Because raffinose is impermeant across the basolateral cell membrane, the ratio of its effect to that of another solute is a measure of the reflection coefficient (sigma) of that other solute. The following results were obtained: sigma KCl = 0.70 +/- 0.02, sigma K gluconate = 0.97 +/- 0.07, sigma Na gluconate = 0.84 +/- 0.06, and sigma choline Cl = 0.75 +/- 0.06. We previously have reported sigma NaCl = 0.56 +/- 0.07. If sigma of each salt is considered to be the arithmetic average of its component parts, and if gluconate and choline are considered to be impermeant, we also obtain sigma Na+ = 0.68, sigma K+ = 0.94, and sigma Cl- = 0.50. PMID:2221098

  1. Effects of dilute aqueous NaCl solution on caffeine aggregation

    SciTech Connect

    Sharma, Bhanita; Paul, Sandip

    2013-11-21

    The effect of salt concentration on association properties of caffeine molecule was investigated by employing molecular dynamics simulations in isothermal-isobaric ensemble of eight caffeine molecules in pure water and three different salt (NaCl) concentrations, at 300 K temperature and 1 atm pressure. The concentration of caffeine was taken almost at the solubility limit. With increasing salt concentration, we observe enhancement of first peak height and appearance of a second peak in the caffeine-caffeine distribution function. Furthermore, our calculated solvent accessible area values and cluster structure analyses suggest formation of higher order caffeine cluster on addition of salt. The calculated hydrogen bond properties reveal that there is a modest decrease in the average number of water-caffeine hydrogen bonds on addition of NaCl salt. Also observed are: (i) decrease in probability of salt contact ion pair as well as decrease in the solvent separated ion pair formation with increasing salt concentration, (ii) a modest second shell collapse in the water structure, and (iii) dehydration of hydrophobic atomic sites of caffeine on addition of NaCl.

  2. Effects of dilute aqueous NaCl solution on caffeine aggregation

    NASA Astrophysics Data System (ADS)

    Sharma, Bhanita; Paul, Sandip

    2013-11-01

    The effect of salt concentration on association properties of caffeine molecule was investigated by employing molecular dynamics simulations in isothermal-isobaric ensemble of eight caffeine molecules in pure water and three different salt (NaCl) concentrations, at 300 K temperature and 1 atm pressure. The concentration of caffeine was taken almost at the solubility limit. With increasing salt concentration, we observe enhancement of first peak height and appearance of a second peak in the caffeine-caffeine distribution function. Furthermore, our calculated solvent accessible area values and cluster structure analyses suggest formation of higher order caffeine cluster on addition of salt. The calculated hydrogen bond properties reveal that there is a modest decrease in the average number of water-caffeine hydrogen bonds on addition of NaCl salt. Also observed are: (i) decrease in probability of salt contact ion pair as well as decrease in the solvent separated ion pair formation with increasing salt concentration, (ii) a modest second shell collapse in the water structure, and (iii) dehydration of hydrophobic atomic sites of caffeine on addition of NaCl.

  3. High-temperature corrosion of metallic alloys in an oxidizing atmosphere containing NaCl

    SciTech Connect

    Federer, J.I.

    1989-02-01

    A particular heat-exchanger application involved metallic alloys exposed to flue gases of an aluminum remelt furnace. Because the flue gases might contain NaCl and other halides, the corrosion behavior of the alloys was to be investigated. Planned direct exposure of candidate alloys to the flue gases, however, was not conducted because of premature termination of the project. Complementary laboratory testing was conducted on seven commercially available alloys and two nickel aluminides. These materials were exposed to an oxidizing atmosphere containing 0.06 wt % NaCl for 1100 h at 1000/degree/C. Most of the alloy exhibited grain-boundary attack, which resulted in complete oxidation of enveloped grains. The alloys Incoloy MA-956, Incoloy 800, Inconel 625, Inconel 601, Hastelloy X, Haynes 188, and nickel aluminide IC-50 were substantially more corroded than Alloy 214 and nickel aluminide IC-221. The latter two alloys, therefore, would probably be superior to the others in application involving flue gases containing NaCl. Strength fabricability, and weldability, which are briefly discussed, would also affect selection of materials. 8 refs., 12 figs., 5 tabs.

  4. [Effects of NaCl stress on cation contents in seedlings of two pumpkin varieties].

    PubMed

    Wang, Ran; Chen, Gui-Lin; Song, Wei; Lü, Gui-Yun; Liang, Jing; Li, Wei-Xin

    2006-02-01

    Effects of different concentration NaCl stress on cation contents of pumpkin cultivars (Cucurbita ficifolia and Cucurbita moschata) usually used as rootstocks of cucumber were studied. The results showed that, in both cultivars treated with 150, 300 and 500 mmol/L NaCl for 7 d, increasing salinity caused in increasing retardation of shoot and root growth, and reduction of shoot relative water content (Table 1). With increasing NaCl concentration, Na(+) content increased while K(+) content decreased distinctly in roots, stems and leaves of both cultivars. And Na(+) and K(+) contents in different organs were in the orders roots>stems>leaves and stems>leaves>roots respectively (Fig.3). There were less Na(+) in root, stem and leaf (Fig.3), more free proline and soluble sugar in leaves (Fig.1, 2), and higher shoot relative water content (Table 1) in C. ficifolia than in C. moschata. So there are differences between C. ficifolia and C. moschata in osmotic adjustment mechanisms and selective absorption and transportation of different cations, and the salt tolerance of C. ficifolia is higher than C. moschata.

  5. Fluorescence properties of biochemicals in dry NaCl composite aerosol particles and in solutions

    NASA Astrophysics Data System (ADS)

    Putkiranta, M.; Manninen, A.; Rostedt, A.; Saarela, J.; Sorvajärvi, T.; Marjamäki, M.; Hernberg, R.; Keskinen, J.

    2010-06-01

    Several fluorophores, such as tryptophan, NADH, NADPH, and riboflavin are found in airborne micro-organisms. In this work, the fluorescence properties of these biochemicals were studied both in dry NaCl composite aerosol particles and in saline solutions by means of laser-induced fluorescence. Fluorescence spectra were measured from individual, airborne aerosol particles and from solutions in cuvette. The excitation wavelength was varied in steps from 210 nm to 419 nm and the fluorescence was detected within a wavelength band of 310-670 nm. For each sample, the measured fluorescence emission spectra were combined into fluorescence maps. The fluorescence maximum of riboflavin in a dry NaCl composite particle is 20 nm red-shifted compared with the solution, whereas the maxima are blue-shifted by about 25 nm for tryptophan and 15 nm for NADH and NADPH. The molecular fluorescence cross sections have significant differences between the aerosol particles and the solutions, except for tryptophan. For NADH and NADPH the cross sections are over 20 times larger in the aerosol particles than in the solutions probably as a result of partial quenching of fluorescence in solution caused by the collision or stacking with the adenine moiety. The fluorescence cross section of riboflavin is almost 60 times larger in the solution than in the dry NaCl composite aerosol. This is probably caused by the different microenvironment around the fluorophore molecule and by the concentration quenching in the particles where the fluorescing molecules are relatively close to each other.

  6. Solubility of KF and NaCl in water by molecular simulation

    NASA Astrophysics Data System (ADS)

    Sanz, E.; Vega, C.

    2007-01-01

    The solubility of two ionic salts, namely, KF and NaCl, in water has been calculated by Monte Carlo molecular simulation. Water has been modeled with the extended simple point charge model (SPC/E), ions with the Tosi-Fumi model and the interaction between water and ions with the Smith-Dang model. The chemical potential of the solute in the solution has been computed as the derivative of the total free energy with respect to the number of solute particles. The chemical potential of the solute in the solid phase has been calculated by thermodynamic integration to an Einstein crystal. The solubility of the salt has been calculated as the concentration at which the chemical potential of the salt in the solution becomes identical to that of the pure solid. The methodology used in this work has been tested by reproducing the results for the solubility of KF determined previously by Ferrario et al. [J. Chem. Phys. 117, 4947 (2002)]. For KF, it was found that the solubility of the model is only in qualitative agreement with experiment. The variation of the solubility with temperature for KF has also been studied. For NaCl, the potential model used predicts a solubility in good agreement with the experimental value. The same is true for the hydration chemical potential at infinite dilution. Given the practical importance of solutions of NaCl in water the model used in this work, whereas simple, can be of interest for future studies.

  7. Computational investigation of the influence of organic-aqueous interfaces on NaCl dissociation dynamics

    SciTech Connect

    Wick, Collin D.; Dang, Liem X.

    2010-01-26

    NaCl pairing and dissociation was investigated at the CCl4-water and 1,2-dichloroethane (DCE)-water interfaces, and compared with dissociation results in the bulk and at the air-water interface utilizing polarizable potentials. The transition path sampling methodology was used to calculate the rate constant for dissociation, while umbrella sampling was used to map out a free energy profile for NaCl dissociation. The results found that ion pairing was weakest at the organic-water interfaces, even weaker than in the water bulk. This is in contrast to what has been observed previously for the air-water interface, in which NaCl ion paring is stronger than in the bulk [Wick, C.D. J. Phys. Chem. C, 2009, 113, 6356]. The consequence of the weaker binding at the organic-water interfaces was that ion dissociation was faster than in the other systems studied. Interactions of the organic phase with the ions influenced the magnitude of the Cl- dipole moment, and at the organic-water interfaces, the average Cl- dipole was found to be lower than at the air-water interface, weakening interactions with Na+. Work was performed at the Pacific Northwest National Laboratory (PNNL) was supported by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy (DOE). PNNL is operated by Battelle for the DOE.

  8. Repartitioning of NaCl and Protein Impurities in Lysozyme Crystallization

    NASA Technical Reports Server (NTRS)

    Vekilov, Peter G.; Monaco, Lisa A.; Thomas, Bill R.; Stojanoff, Vivian; Rosenberger, Franz

    1996-01-01

    Nonuniform precipitant and impurity incorporation in protein crystals can cause lattice strain and, thus, possibly decrease the X-ray diffraction resolution. To address this issue, a series of crystallization experiments were carried out, in which initial supersaturation, NaCl concentration, protein purity level and crystallized fraction were varied. Lysozyme and protein impurities, as well as sodium and chloride were independently determined in the initial solution, supernatant and crystals. The segregation coefficients for Na(+) and Cl(-) were found to be independent of supersaturation and NaCl concentration, and decreased with crystallized fraction/crystal size. Numerical evaluation of the extensive body of data, based on a nucleation-growth- repartitioning model, suggests a core of approx. 40 microns in which salt is incorporated in much greater concentrations than during later growth. Small crystals containing higher amounts of incorporated NaCl also had higher protein impurity contents. This suggests that the excess salt is associated with the protein impurities in the core. X-ray topography revealed strain fields in the center of the crystals comparable in size to the inferred core. The growth rates of crystals smaller than 30-40 pm in size were consistently 1.5-2 times lower than those of larger crystals, presumably due to higher chemical potentials in the core.

  9. 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

  10. Phonon softening induced cubic-to-tetragonal phase transition in ReO3

    NASA Astrophysics Data System (ADS)

    Liu, Yaming; Zhang, Niu; Jia, Yu; Sun, Qiang; Chao, Mingju

    2015-10-01

    Within density functional theory, the structural, electronic and lattice dynamical properties of ReO3 in cubic Pm-3m and tetragonal P4/mbm phases are studied by using quasiharmonic approximation. The enthalpy-pressure curves show that a phase transition may take place at 5.0 kbar and the nonexistence of imaginary frequency in phonon dispersions demonstrates the two phases are dynamically stable under proper conditions. With the increase of pressure, an obvious softening of M3 mode at M point appears in cubic phase, and a cubic-to-tetragonal phase transition is accompanied with the presence of negative frequency in M3 mode at 5.0 kbar. In detail, one type of O atoms displaced from x = 0.2500 to x = 0.2401, which corresponds to the softening of M3 mode, are responsible for the phase transition. Our theoretical results show that ReO3 can exist in the tetragonal P4/mbm phase, and a cubic-to-tetragonal phase transition will appear at around 5.0 kbar.

  11. A combined physicochemical-biological method of NaCl extraction from the irrigation solution in the BTLSS

    NASA Astrophysics Data System (ADS)

    Trifonov, Sergey V.; Tikhomirov, Alexander A.; Ushakova, Sofya; Tikhomirova, Natalia

    2016-07-01

    The use of processed human wastes as a source of minerals for plants in closed biotechnical life support systems (BTLSS) leads to high salt levels in the irrigation solution, as urine contains high concentrations of NaCl. It is important to develop a process that would effectively decrease NaCl concentration in the irrigation solution and return this salt to the crew's diet. The salt-tolerant plants (Salicornia europea) used to reduce NaCl concentration in the irrigation solution require higher salt concentrations than those of the solution, and this problem cannot be resolved by concentrating the solution. At the same time, NaCl extracted from mineralized wastes by physicochemical methods is not pure enough to be included in the crew's diet. This study describes an original physicochemical method of NaCl extraction from the solution, which is intended to be used in combination with the biological method of NaCl extraction by using saltwort plants. The physicochemical method produces solutions with high NaCl concentrations, and saltwort plants serve as a biological filter in the final phase, to produce table salt. The study reports the order in which physicochemical and biological methods of NaCl extraction from the irrigation solution should be used to enable rapid and effective inclusion of NaCl into the cycling of the BTLSS with humans. This study was carried out in the IBP SB RAS and supported by the grant of the Russian Science Foundation (Project No. 14-14-00599).

  12. Determination of oxidative stress in wheat leaves as influenced by boron toxicity and NaCl stress.

    PubMed

    Masood, Sajid; Saleh, Livia; Witzel, Katja; Plieth, Christoph; Mühling, Karl H

    2012-07-01

    Boron (B) toxicity symptoms are visible in the form of necrotic spots and may worsen the oxidative stress caused by salinity. Hence, the interactive effects of combined salinity and B toxicity stress on antioxidative activities (TAC, LUPO, SOSA, CAT, and GR) were investigated by novel luminescence assays and standard photometric procedures. Wheat plants grown under hydroponic conditions were treated with 2.5 μM H₃BO₃ (control), 75 mM NaCl, 200 μM H₃BO₃, or 75 mM NaCl + 200 μM H₃BO₃, and analysed 6 weeks after germination. Shoot fresh weight (FW), shoot dry weight (DW), and relative water content (RWC) were significantly reduced, whereas the antioxidative activity of all enzymes was increased under salinity compared with the control. High B application led to necrotic leaf spots but did not influence growth parameters. Following NaCl + B treatment, shoot DW, RWC, SOSA, GR, and CAT activities remained the same compared with NaCl alone, whereas the TAC and LUPO activities were increased under the combined stress compared with NaCl alone. However, shoot FW was significantly reduced under NaCl + B compared with NaCl alone, as an additive effect of combined stress. Thus, we found an adjustment of antioxidative enzyme activity to the interactive effects of NaCl and high B. The stress factor "salt" mainly produced more oxidative stress than that of the factor "high B". Furthermore, addition of higher B in the presence of NaCl increases TAC and LUPO demonstrating that increased LUPO activity is an important physiological response in wheat plants against multiple stresses. PMID:22592001

  13. Chronic effect of NaCl salinity on a freshwater strain of Daphnia magna Straus (Crustacea: Cladocera): a demographic study.

    PubMed

    Martínez-Jerónimo, Fernando; Martínez-Jerónimo, Laura

    2007-07-01

    Daphnia magna is mainly recognized as a freshwater cladoceran, but there are some strains that grow in brackish waters. The tolerance to salinity of a freshwater strain was assessed at NaCl concentrations of 0, 2, 4, 6, and 7 g L(-1). The green microalga Ankistrodesmus falcatus was fed at optimal concentration (4 x 10(5)cells mL(-1)). Reproduction and survival were recorded in two experimental series: in the first one, 20 female neonates were individually studied for each treatment. In the second, cohorts of 10 female neonates were distributed in each of five replicates per treatment. In both cases, experiments were conducted over a full life-cycle. The determined 48-h LC(50) for NaCl was 5.48 g L(-1), but we recorded reproduction at up to 7 g NaCl L(-1). The average clutch size, total progeny, number of clutches, and longevity were significantly reduced by the NaCl concentration (P<0.01); total progeny ranged from 467 to 25 neonates as edge values for NaCl concentrations of 0-7 g L(-1). Inter-brood time was significantly higher for females grown at 7 g NaCl L(-1) (3.9 days). The Life Table analysis demonstrates that average lifespan, life expectancy at birth, net reproductive rate and intrinsic rate of growth were also significantly reduced according to NaCl concentration. Based on the results for the two highest NaCl concentrations (6 and 7 g L(-1)), we conclude that the used D. magna strain was acclimated to develop satisfactorily under concentrations of up to 6 g NaCl L(-1); however, the established salinity conditions reduced significantly reproduction and survival in this strain. PMID:17055052

  14. 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.

  15. NaCl osmotic perturbation can modulate hydration control in rabbit cornea.

    PubMed

    Ruberti, Jeffrey W; Klyce, Stephen D

    2003-03-01

    The corneal endothelium transports solute from the stroma to the aqueous humor, maintaining corneal hydration. Currently, little is known about how this active transport system is controlled. The purpose of this study is to investigate in greater detail the corneal response to small NaCl osmotic perturbations using a more refined automatic thickness measurement system in a search for response signatures of transport control. Adult New Zealand White rabbit corneas were debrided of their epithelium, excised and mounted in perfusion chambers. The endothelium, thus isolated, was bathed in isotonic Glutathione Bicarbonate Ringer's (GBR) solution and the bare anterior stroma was covered with silicone oil. Following stabilization in isotonic GBR, the endothelial perfusate was altered by +/-15 mOsm or+/-45 mOsm for 1 hr and 45 min by addition or removal of NaCl and returned (reversal) to GBR for 1 hr and 45 min. An enhanced, automatic scanning specular microscope monitored stromal thickness. The effective membrane transport coefficients were determined from the stromal thickness vs. time curves using an established numerical model of corneal hydration dynamics. It was found that the small (+/-15 mOsm) NaCl perturbations of the rabbit corneal endothelium resulted in a rapid trans-endothelial stromal volume control response that was not reversible after return to GBR. Long after the expected dissipation of the induced transients, this thickness 'controlling' response ultimately resulted in a sustained net thinning of 14 microm following the hypotonic perturbation and reversal, and a net swelling of 16 microm following the hypertonic perturbation and reversal. Model calculations indicated that the change induced by the perturbation could be explained by an immediate and persistent reduction of the passive endothelial NaCl permeability by 26% for the -15 mOsm perturbation compared to the +15 mOsm perturbation. This change persisted even after return to GBR. In contrast, the

  16. Lack of effect of peritubular protein on passive NaCl transport in the rabbit proximal tubule.

    PubMed Central

    Berry, C A

    1983-01-01

    The effect of peritubular protein removal on passive NaCl transport was examined in the isolated rabbit proximal convoluted tubule (PCT). Three modes of passive NaCl transport were tested: (a) paracellular backflux of NaCl, (b) convective flow of NaCl through junctional complexes, and (c) anion gradient-dependent NaCl transport. The effect of peritubular protein removal on the paracellular permeability to NaCl was examined using transepithelial specific resistance. Eight PCT were perfused with ultrafiltrate (UF) and bathed in either serum or UF. Transepithelial specific resistance averaged 14.5 +/- 1.9 in the presence and 13.7 +/- 1.7 omega cm2 in the absence of peritubular protein. The effect of peritubular protein removal on the convective flow of a NaCl solution across functional complexes was examined in the absence of active transport by using colloid osmotic pressure (COP) gradients. 12 PCT were perfused with simple salt solutions in Donnan equilibrium with and without protein at 20 degrees C. A COP gradient of 60.1 and -60.1 mmHg drove only 0.06 and -0.23 nl/min, respectively. These values are approximately 10% of the value predicted for an effect of peritubular protein on NaCl solution flow (1.98 nl/min) and are approximately equal to the value predicted for pure water equilibration for the small osmotic pressure difference between solutions in Donnan equilibrium (0.17-0.18 nl/min). The effect of peritubular protein removal on the passive absorption of NaCl driven by anion concentration gradients was examined in seven PCT perfused with a high chloride solution simulating late proximal tubular fluid and bathed in either serum or UF at 20 degrees C. Volume absorption averaged 0.34 +/- 0.20 in the presence and 0.39 +/- 0.20 nl/mm min in the absence of peritubular protein. In conclusion, peritubular protein removal did not significantly affect any of the three distinct modes of passive NaCl transport tested. The lack of effect of peritubular protein removal on

  17. Measurement and Modeling of Mean Activity Coefficients of NaCl in an Aqueous Mixed Electrolyte Solution Containing Glycine

    NASA Astrophysics Data System (ADS)

    Sheikholeslami, Paniz; Dehghani, M. R.; Safahieh, Tina

    2016-08-01

    An electrochemical cell with two ion-selective electrodes (Na+ glass) and (Cl- solid state) was used to measure the mean ionic activity coefficient of NaCl in an aqueous mixture containing NaCl, glycine, and NaNO3 at 308.15 K. The experiments were conducted at fixed molality of NaNO3 (0.1 m) and various molalities of glycine (0-1 m) and NaCl (up to 0.8 m). The experimental data were modeled using a modified version of the Pitzer equation. Finally the activity coefficient ratio of glycine was determined based on the Maxwell equation.

  18. A comparison of electrochemical and electrokinetic parameters determined for cellophane membranes in contact with NaCl and NaNO3 solutions.

    PubMed

    Cañas, A; Ariza, M J; Benavente, J

    2002-02-01

    Electrochemical and electrokinetic characterizations of cellophane membrane samples have been carried out by measuring membrane potential, salt diffusion, and tangential streaming potential, which allow the determination of different characteristic membrane parameters. Experiments were made with the membrane samples in contact with NaCl and NaNO(3) solutions at different concentrations and under different external conditions (concentration gradients), in order to obtain differences in transport and membrane characteristic parameters, depending on the electrolyte considered. Salt permeability across the membrane, which was obtained from diffusion measurements, is about twice as high for NaCl solutions as for NaNO(3) solutions, which is attributed to the different sizes of the electrolytes. Membrane potential measurements keeping the concentration ratio constant (C(1)/C(2)=2) were used to determine both the effective fixed charge concentration in the membrane, X(f), and the average value of transport numbers, t(i); taking into account these values, concentration dependence of membrane potential under a different external condition (C(1)=cte=0.01 M, 5 x 10(-3)< or =C(M)< or =5 x 10(-2)) was predicted. Results show that cellophane membrane behaves as a weak cation-exchange membrane and its permselectivity to cations is practically independent of the electrolyte considered. From electrokinetic results, assuming a Langmuir-type adsorption of anions on the cellophane surface, the number of accessible sites per surface unit was obtained, which is higher for Cl(-) than for NO(3)(-), in agreement with the small radii of chlorine ions; however, no significant differences in the specific adsorption free energy were found (DeltaG(Nacl)=-22.0 x 10(3) J/mol) and (DeltaG(NaNO(3))=-23.2 x 10(3) J/mol).

  19. Influence of stearic acid coating of the NaCl surface on the reactivity with NO2 under humidity.

    PubMed

    Sobanska, S; Barbillat, J; Moreau, M; Nuns, N; De Waele, I; Petitprez, D; Tobon, Y; Brémard, C

    2015-04-28

    In the atmosphere, sea salt aerosols, containing mainly NaCl, can accumulate fatty acids and undergo heterogeneous chemistry with atmospheric nitrogen oxides. The effect of stearic acid (SA) coating on the reactivity of the NaCl(100) surface with NO2 under humidity was studied by atomic force microscopy (AFM), Raman mapping and time-of-flight secondary ion mass spectrometry (ToF-SIMS) to highlight processes occurring on NaCl surfaces. The vapor-deposition of SA on the NaCl surface generates heterogeneous coating with discontinuous monolayer islands. The SA molecules with all-trans conformation stick to the NaCl surface through -CO2H groups and are organized in parallel between them and nearly perpendicularly to the surface. The SA coating does not prevent the NaNO3 particle formation when the sample is exposed to NO2 under low humidity conditions. The initial abilities of the NaCl surface coated with SA to pick up NO2 from the gas phase are correlated with the fraction of bare NaCl area evidencing the spatially heterogeneous reactivity of the surface. The role of H2O in the NO2 uptake and the catalytic conversion of NaCl to NaNO3 is shown. Under humidity (RH = 50%), the H2O uptake by NaNO3 particles on the coated-NaCl surface is significantly more important than that adsorbed under analogous conditions without the presence of NaNO3 particles. This unusual water absorption initiates transitions (i) from solid NaNO3 particles to NaNO3 aqueous solution and (ii) from the SA monolayer with well-ordered all trans alkyl chains to the SA gel with completely disordered conformation. This mixed SA/NaNO3 layer on the particle surface may have significant consequences on the hygroscopic properties and reactivity of the sea salt aerosols in the atmosphere.

  20. Solubility of NaCl and KCl in aqueous HCl from 20 to 85°C

    USGS Publications Warehouse

    Potter, Robert W.; Clynne, Michael A.

    1980-01-01

    The solubilities of NaCl and KCl in aqueous HCl solutions were determined from 20 to 85°C at concentrations ranging from 0 to 20 g of HCl/100 g of solution. Equations are given that describe the solubilities over the range of conditions studied. For NaCl and KCl respectively measured solubilities show an average deviation from these equations of ??0.10 and ??0.08 g/100 g of saturated solution.

  1. Growth, compatible solute and salt accumulation of five mycorrhizal fungal species grown over a range of NaCl concentrations.

    PubMed

    Bois, G; Bertrand, A; Piché, Y; Fung, M; Khasa, D P

    2006-03-01

    The oil sand industry in northeastern Alberta produces vast areas of severely disturbed land. The sodicity of these anthropic soils is one of the principal constraints that impede their revegetation. Previous in vitro studies have shown that the ectomycorrhizal fungi Laccaria bicolor (Maire) Orton UAMH 8232 and Hebeloma crustuliniforme (Bull) Quel. UAMH 5247 have certain salt-resistant traits and thus are candidate species for the inoculation of tree seedlings to be outplanted on salt-affected soil. In this study, the in vitro development of these fungi was compared to that of three mycorrhizal fungi [Suillus tomentosus (Kauff.) Sing., Snell and Dick; Hymenoscyphus sp. and Phialocephala sp.] isolated from a sodic site created by Syncrude Canada Ltd. Their growth, osmotica and Na/Cl contents were assessed over a range (0, 50, 100, 200 mM) of NaCl concentrations. After 21 days, the two ascomycetes (Hymenoscyphus sp. and Phialocephala sp.) were shown to be more resistant to the NaCl treatments than the three basidiomycete species. Of the basidiomycetes, L. bicolor was the most sensitive to NaCl stress, while H. crustuliniforme showed greater water stress resistance, and the S. tomentosus isolate exhibited greater Na and Cl filtering capacities and had a better biomass yield over the NaCl gradient tested. Both ascomycetes used mechanisms other than carbohydrate accumulation to palliate NaCl stress. While the Hymenoscyphus isolate accumulated proline in response to NaCl treatments, the darker Phialocephala isolate may have used compounds such as melanin. The basidiomycete species accumulated mainly mannitol and/or proline in response to increasing concentrations of NaCl.

  2. A mechanism for NaCl inhibition of Reactive Blue 19 decolorization and ABTS oxidation by laccase.

    PubMed

    Champagne, P-P; Nesheim, M E; Ramsay, J A

    2013-07-01

    Laccases produced by white rot fungi have been extensively evaluated for their potential to decolorize textile wastewaters which contain salts like sodium chloride and sodium sulfate. The effect of sodium chloride and sodium sulfate on Trametes versicolor laccase during the decolorization of an anthraquinone dye (Reactive Blue 19) and the oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were evaluated by steady-state kinetic analysis. The results showed that, while sodium sulfate did not affect laccase activity, sodium chloride inhibited both ABTS oxidation and dye decolorization. However, the type of inhibition was substrate-dependent: it was hyperbolic, noncompetitive with ABTS and parabolic, noncompetitive with Reactive Blue 19. Furthermore, the results suggested that two chlorides may bind to laccase in the presence of the dye unlike recent inhibition models which suggest that there is only one inhibition site. This investigation is the first to provide evidence for and to propose a two-site model of laccase inhibition, providing new insight into NaCl inhibition of laccase. The proposed model is also useful to predict decolorization rates in the presence of sodium chloride and to determine operating conditions that will minimize inhibition.

  3. H+ homeostasis, osmolality, and body temperature during controlled NaCl and H2O intake.

    PubMed

    Anderson, J W; Jennings, D B

    1988-07-01

    Arterial PCO2, arterial [H+] ([H+]a), electrolytes, and osmolality, as well as rectal temperature (Tre), were monitored in six awake dogs over sequential 12- or 13-day periods in which their NaCl intake was first less than 5 meq/day, then approximately 120 meq/day, and finally less than 5 meq/day. Water intake was maintained constant at 77 ml.kg-1.day-1 throughout. During low-NaCl periods, decreases in body and plasma water, indicated by weight loss did not prevent lower arterial [Na+] ([Na+]a), arterial [Cl-] ([Cl-]a), and osmolality relative to the high-NaCl period. During high dietary NaCl, the arterial strong ion difference [[SID]a = ([Na+]a + [K+]a) - (arterial [lactate-] + [Cl-]a)] was lower. From physicochemistry, this lowered [SID]a results in a higher [H+]a. However, independent of NaCl intake, [H+]a was positively correlated with plasma osmolality; moreover, [H+]a, relative to plasma osmolality, was higher at lower Tre than at higher Tre. We speculate that this spectrum of plasma osmolality and body temperature may contribute to the creation of an appropriate protein pK to match plasma [H+]a. We also found that the difference between plasma [protein] (measured by the biuret test) and [ATOT]a (an estimation of plasma protein as total weak acid from physicochemistry) was related to plasma osmolality, [SID]a, and [Na+]a. These latter relations may reflect the effect of plasma water concentration (osmolality) and strong ions on the pK of plasma proteins.

  4. Proteomic and Physiological Analyses Reveal Putrescine Responses in Roots of Cucumber Stressed by NaCl.

    PubMed

    Yuan, Yinghui; Zhong, Min; Shu, Sheng; Du, Nanshan; Sun, Jin; Guo, Shirong

    2016-01-01

    Soil salinity is a major environmental constraint that threatens agricultural productivity. Different strategies have been developed to improve crop salt tolerance, among which the effects of polyamines have been well-reported. To gain a better understanding of the cucumber (Cucumis sativus L.) responses to NaCl and unravel the underlying mechanism of exogenous putrescine (Put) alleviating salt-induced damage, comparative proteomic analysis was conducted on cucumber roots treated with NaCl, and/or Put for 7 days. The results showed that exogenous Put restored the root growth inhibited by NaCl. Sixty-two differentially expressed proteins implicated in various biological processes were successfully identified by MALDI-TOF/TOF MS. The four largest categories included proteins involved in defense response (24.2%), protein metabolism (24.2%), carbohydrate metabolism (19.4%), and amino acid metabolism (14.5%). Exogenous Put up-regulated most identified proteins involved in carbohydrate metabolism, implying an enhancement in energy generation. Proteins involved in defense response and protein metabolism were differently regulated by Put, which indicated the roles of Put in stress resistance and proteome rearrangement. Put also increased the abundance of proteins involved in amino acid metabolism. Meanwhile, physiological analysis showed that Put could further up-regulated the levels of free amino acids in salt stressed-roots. In addition, Put also improved endogenous polyamines contents by regulating the transcription levels of key enzymes in polyamine metabolism. Taken together, these results suggest that Put may alleviate NaCl-induced growth inhibition through degradation of misfolded/damaged proteins, activation of stress defense, and the promotion of carbohydrate metabolism to generate more energy. PMID:27471514

  5. Proteomic and Physiological Analyses Reveal Putrescine Responses in Roots of Cucumber Stressed by NaCl

    PubMed Central

    Yuan, Yinghui; Zhong, Min; Shu, Sheng; Du, Nanshan; Sun, Jin; Guo, Shirong

    2016-01-01

    Soil salinity is a major environmental constraint that threatens agricultural productivity. Different strategies have been developed to improve crop salt tolerance, among which the effects of polyamines have been well-reported. To gain a better understanding of the cucumber (Cucumis sativus L.) responses to NaCl and unravel the underlying mechanism of exogenous putrescine (Put) alleviating salt-induced damage, comparative proteomic analysis was conducted on cucumber roots treated with NaCl, and/or Put for 7 days. The results showed that exogenous Put restored the root growth inhibited by NaCl. Sixty-two differentially expressed proteins implicated in various biological processes were successfully identified by MALDI-TOF/TOF MS. The four largest categories included proteins involved in defense response (24.2%), protein metabolism (24.2%), carbohydrate metabolism (19.4%), and amino acid metabolism (14.5%). Exogenous Put up-regulated most identified proteins involved in carbohydrate metabolism, implying an enhancement in energy generation. Proteins involved in defense response and protein metabolism were differently regulated by Put, which indicated the roles of Put in stress resistance and proteome rearrangement. Put also increased the abundance of proteins involved in amino acid metabolism. Meanwhile, physiological analysis showed that Put could further up-regulated the levels of free amino acids in salt stressed-roots. In addition, Put also improved endogenous polyamines contents by regulating the transcription levels of key enzymes in polyamine metabolism. Taken together, these results suggest that Put may alleviate NaCl-induced growth inhibition through degradation of misfolded/damaged proteins, activation of stress defense, and the promotion of carbohydrate metabolism to generate more energy. PMID:27471514

  6. How does NaCl improve tolerance to cadmium in the halophyte Sesuvium portulacastrum?

    PubMed

    Mariem, Wali; Kilani, Ben Rjab; Benet, Gunsé; Abdelbasset, Lakdhar; Stanley, Lutts; Charlotte, Poschenrieder; Chedly, Abdelly; Tahar, Ghnaya

    2014-12-01

    Sesuvium portulacastrum is a halophyte with considerable Cd tolerance and accumulation, especially under high salinity. The species seems a good candidate for phytoremediation of Cd-contaminated, saline soils. However, the mechanisms sustaining salt-induced alleviation of Cd toxicity remain unknown. Seedlings of S. portulacastrum were submitted hydroponically to different Cd concentrations (0, 25 and 50 μM Cd) in combination with low (0.09 mM), or high (200 mM) NaCl. Cadmium distribution within leaves and stems was assessed by total Cd, cell sap Cd, and Cd in different cell fractions. In plants with low salt supply (LS) Cd induced severe toxicity. The presence of 200 mM NaCl (HS) significantly alleviated Cd toxicity symptoms. HS drastically reduced both Cd-induced H2O2 production and membrane damage. In HS plants the reduced Cd uptake was only in part responsible for the lower Cd toxicity. Even at equal internal leaf Cd concentrations less Cd toxicity was observed in HS than in LS plants. In HS plants proportionally more Cd was bound in cell walls and proportionally less accumulated in the soluble fraction than in LS plants. Our results show that NaCl improves plant performance under Cd stress by both a decrease of Cd(2+) activity in the medium leading to less Cd uptake and a change of Cd speciation and compartmentation inside tissues. More efficient internal detoxification seems mainly brought about by preferential Cd binding to chloride and cell walls in plants treated with a high salt concentration. PMID:25104648

  7. NaCl stress impact on the key enzymes in glycolysis from Lactobacillus bulgaricus during freeze-drying.

    PubMed

    Li, Chun; Sun, Jinwei; Qi, Xiaoxi; Liu, Libo

    2015-01-01

    The viability of Lactobacillus bulgaricus in freeze-drying is of significant commercial interest to dairy industries. In the study, L.bulgaricus demonstrated a significantly improved (p < 0.05) survival rate during freeze-drying when subjected to a pre-stressed period under the conditions of 2% (w/v) NaCl for 2 h in the late growth phase. The main energy source for the life activity of lactic acid bacteria is related to the glycolytic pathway. To investigate the phenomenon of this stress-related viability improvement in L. bulgaricus, the activities and corresponding genes of key enzymes in glycolysis during 2% NaCl stress were studied. NaCl stress significantly enhanced (p < 0.05) glucose utilization. The activities of glycolytic enzymes (phosphofructokinase, pyruvate kinase, and lactate dehydrogenase) decreased during freeze-drying, and NaCl stress were found to improve activities of these enzymes before and after freeze-drying. However, a transcriptional analysis of the corresponding genes suggested that the effect of NaCl stress on the expression of the pfk2 gene was not obvious. The increased survival of freeze-dried cells of L. bulgaricus under NaCl stress might be due to changes in only the activity or translation level of these enzymes in different environmental conditions but have no relation to their mRNA transcription level.

  8. Structural, magnetic and optical properties of Rh2+ centres in NaCl lattices: An explanation

    NASA Astrophysics Data System (ADS)

    Barriuso, M. T.; Fernandez, P. G.; Aramburu, J. A.; Moreno, M.

    2003-01-01

    A method for exploring Jahn-Teller systems in the framework of Density Functional Theory is described in the present work. Using such a method the properties of the Rh2+ centre in NaCl with remote charge compensation are studied. The calculations support the existence of a strong Jahn-Teller effect and account reasonably for the main features of EPR and optical spectra. The onset of charge transfer excitations is calculated to be at about 3.7 eV a fact which concurs with available experimental data. The elongated geometry is found to be about 200 cm(-1) more stable than the compressed one in agreement with experiments.

  9. Mini-review: regulation of the renal NaCl cotransporter by hormones.

    PubMed

    Rojas-Vega, Lorena; Gamba, Gerardo

    2016-01-01

    The renal thiazide-sensitive NaCl cotransporter, NCC, is the major pathway for salt reabsorption in the distal convoluted tubule. The activity of this cotransporter is critical for regulation of several physiological variables such as blood pressure, serum potassium, acid base metabolism, and urinary calcium excretion. Therefore, it is not surprising that numerous hormone-signaling pathways regulate NCC activity to maintain homeostasis. In this review, we will provide an overview of the most recent evidence on NCC modulation by aldosterone, angiotensin II, vasopressin, glucocorticoids, insulin, norepinephrine, estradiol, progesterone, prolactin, and parathyroid hormone.

  10. 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

    2011-11-01

    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.

  11. 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.

  12. Capturing dynamic cation hopping in cubic pyrochlores

    NASA Astrophysics Data System (ADS)

    Brooks Hinojosa, Beverly; Asthagiri, Aravind; Nino, Juan C.

    2011-08-01

    In direct contrast to recent reports, density functional theory predicts that the most stable structure of Bi2Ti2O7 pyrochlore is a cubic Fd3¯m space group by accounting for atomic displacements. The displaced Bi occupies the 96g(x,x,z) Wyckoff position with six equivalent sites, which create multiple local minima. Using nudged elastic band method, the transition states of Bi cation hopping between equivalent minima were investigated and an energy barrier between 0.11 and 0.21 eV was determined. Energy barriers associated with the motion of Bi between equivalent sites within the 96g Wyckoff position suggest the presence of dielectric relaxation in Bi2Ti2O7.

  13. Black holes in a cubic Galileon universe

    NASA Astrophysics Data System (ADS)

    Babichev, E.; Charmousis, C.; Lehébel, A.; Moskalets, T.

    2016-09-01

    We find and study the properties of black hole solutions for a subclass of Horndeski theory including the cubic Galileon term. The theory under study has shift symmetry but not reflection symmetry for the scalar field. The Galileon is assumed to have linear time dependence characterized by a velocity parameter. We give analytic 3-dimensional solutions that are akin to the BTZ solutions but with a non-trivial scalar field that modifies the effective cosmological constant. We then study the 4-dimensional asymptotically flat and de Sitter solutions. The latter present three different branches according to their effective cosmological constant. For two of these branches, we find families of black hole solutions, parametrized by the velocity of the scalar field. These spherically symmetric solutions, obtained numerically, are different from GR solutions close to the black hole event horizon, while they have the same de-Sitter asymptotic behavior. The velocity parameter represents black hole primary hair.

  14. Double P2X2/P2X3 Purinergic Receptor Knockout Mice Do Not Taste NaCl or the Artificial Sweetener SC45647

    PubMed Central

    Eddy, Meghan C.; Eschle, Benjamin K.; Barrows, Jennell; Hallock, Robert M.; Finger, Thomas E.

    2009-01-01

    The P2X ionotropic purinergic receptors, P2X2 and P2X3, are essential for transmission of taste information from taste buds to the gustatory nerves. Mice lacking both P2X2 and P2X3 purinergic receptors (P2X2/P2X3Dbl−/−) exhibit no taste-evoked activity in the chorda tympani and glossopharyngeal nerves when stimulated with taste stimuli from any of the 5 classical taste quality groups (salt, sweet, sour, bitter, and umami) nor do the mice show taste preferences for sweet or umami, or avoidance of bitter substances (Finger et al. 2005. ATP signaling is crucial for communication from taste buds to gustatory nerves. Science. 310[5753]:1495–1499). Here, we compare the ability of P2X2/P2X3Dbl−/− mice and P2X2/P2X3Dbl+/+ wild-type (WT) mice to detect NaCl in brief-access tests and conditioned aversion paradigms. Brief-access testing with NaCl revealed that whereas WT mice decrease licking at 300 mM and above, the P2X2/P2X3Dbl−/− mice do not show any change in lick rates. In conditioned aversion tests, P2X2/P2X3Dbl−/− mice did not develop a learned aversion to NaCl or the artificial sweetener SC45647, both of which are easily avoided by conditioned WT mice. The inability of P2X2/P2X3Dbl−/− mice to show avoidance of these taste stimuli was not due to an inability to learn the task because both WT and P2X2/P2X3Dbl−/− mice learned to avoid a combination of SC45647 and amyl acetate (an odor cue). These data suggest that P2X2/P2X3Dbl−/− mice are unable to respond to NaCl or SC45647 as taste stimuli, mirroring the lack of gustatory nerve responses to these substances. PMID:19833661

  15. Photocatalytic water splitting for hydrogen generation on cubic, orthorhombic, and tetragonal KNbO3 microcubes

    NASA Astrophysics Data System (ADS)

    Zhang, Tingting; Zhao, Kun; Yu, Jiaguo; Jin, Jian; Qi, Yang; Li, Huiquan; Hou, Xinjuan; Liu, Gang

    2013-08-01

    Potassium niobate (KNbO3) microcubes with orthorhombic and tetragonal phases were hydrothermally prepared and characterized by powder X-ray diffraction, nitrogen adsorption-desorption, micro-Raman spectroscopy, Fourier transform infrared spectroscopy, diffuse reflectance UV-visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The photoreactivity of the as-prepared KNbO3 samples was evaluated regarding the hydrogen evolution from aqueous methanol under UV, and the results were compared with that of cubic KNbO3 microcubes. The photocatalytic reactivity was shown to be phase-dependent, following the order cubic > orthorhombic > tetragonal. Insight into the phase-dependent photocatalytic properties was gained by first-principles density functional calculations. The best photocatalytic performance of cubic KNbO3 is ascribed to it having the highest symmetry in the bulk structure and associated unique electronic structure. Further, the surface electronic structure plays a key role leading to the discrepancy in photoreactivity between orthorhombic and tetragonal KNbO3. The results from this study are potentially applicable to a range of perovskite-type mixed metal oxides useful in water splitting as well as other areas of heterogeneous photocatalysis.Potassium niobate (KNbO3) microcubes with orthorhombic and tetragonal phases were hydrothermally prepared and characterized by powder X-ray diffraction, nitrogen adsorption-desorption, micro-Raman spectroscopy, Fourier transform infrared spectroscopy, diffuse reflectance UV-visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The photoreactivity of the as-prepared KNbO3 samples was evaluated regarding the hydrogen evolution from aqueous methanol under UV, and the results were compared with that of cubic KNbO3 microcubes. The photocatalytic reactivity was

  16. 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.

  17. Expression of an alfalfa (Medicago sativa L.) peroxidase gene in transgenic Arabidopsis thaliana enhances resistance to NaCl and H2O2.

    PubMed

    Teng, K; Xiao, G Z; Guo, W E; Yuan, J B; Li, J; Chao, Y H; Han, L B

    2016-01-01

    Peroxidases (PODs) are enzymes that play important roles in catalyzing the reduction of H2O2 and the oxidation of various substrates. They function in many different and important biological processes, such as defense mechanisms, immune responses, and pathogeny. The POD genes have been cloned and identified in many plants, but their function in alfalfa (Medicago sativa L.) is not known, to date. Based on the POD gene sequence (GenBank accession No. L36157.1), we cloned the POD gene in alfalfa, which was named MsPOD. MsPOD expression increased with increasing H2O2. The gene was expressed in all of the tissues, including the roots, stems, leaves, and flowers, particularly in stems and leaves under light/dark conditions. A subcellular analysis showed that MsPOD was localized outside the cells. Transgenic Arabidopsis with MsPOD exhibited increased resistance to H2O2 and NaCl. Moreover, POD activity in the transgenic plants was significantly higher than that in wild-type Arabidopsis. These results show that MsPOD plays an important role in resistance to H2O2 and NaCl. PMID:27323080

  18. Novel molecular variants of the Na-Cl cotransporter gene are responsible for Gitelman syndrome

    SciTech Connect

    Mastroianni, N.; De Fusco, M.; Casari, G.

    1996-11-01

    A hereditary defect of the distal tubule accounts for the clinical features of Gitelman syndrome (GS), an autosomal recessive disease characterized by hypokalemia, hypomagnesemia, metabolic alkalosis, and hypocalciuria. Recently, we cloned the cDNA coding for the human Na-Cl thiazide-sensitive cotransporter (TSC; also known as {open_quotes}NCCT{close_quotes} or {open_quotes}SLC12A3{close_quotes}) as a possible candidate for GS, and Simon et al., independently, described rotation in patients with GS. Now, we show 12 additional mutations consistent with a loss of function of the Na-Cl cotransporter in GS. Two missense replacements, R09W and P349L, are common to both studies and could represent ancient mutations. The other mutations include three deletions, two insertions, and six missense mutations. When all mutations from both studies are considered, missense mutations seem to be more frequently localized within the intracellular domains of the molecule, rather than in transmembrane or extracellular domains. One family, previously reported as a GS form with dominant inheritance, has proved to be recessive, with the affected child being a compound heterozygote. A highly informative intragenic tetranucleotide marker, useful for molecular diagnostic studies, has been identified at the acceptor splice site of exon 9. 12 refs., 3 figs., 2 tabs.

  19. Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica).

    PubMed

    Sanzo, Domenico; Hecnar, Stephen J

    2006-03-01

    Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2,636 and 5,109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1,030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted.

  20. Evaporation of NaCl solution from porous media with mixed wettability

    NASA Astrophysics Data System (ADS)

    Bergstad, Mina; Shokri, Nima

    2016-05-01

    Evaporation of saline water from porous media is ubiquitous in many processes including soil salinization, crop production, and CO2 sequestration in deep saline acquirer. It is controlled by the transport properties of porous media, atmospheric conditions, and properties of the evaporating saline solution. In the present study, the effects of mixed wettability conditions on the general dynamics of water evaporation from porous media saturated with NaCl solution were investigated. To do so, we conducted a comprehensive series of evaporation experiments using sand mixtures containing different fractions of hydrophobic grains saturated with NaCl solutions. Our results showed that increasing fraction of hydrophobic grains in the mixed wettability sand pack had minor impact on the evaporative mass losses due to the presence of salt whose precipitation patterns were significantly influenced by the mixed wettability condition. Through macroscale and microscale investigations, we found formation of patchy efflorescence in the case of mixed wettability sand pack as opposed to crusty efflorescence in the case of completely hydrophilic porous media. Furthermore, the presence of salty water and hydrophobic grains in the sand pack significantly influenced the general dynamics and morphology of the receding drying front. Our results extend the understanding of the saline water evaporation from porous media with direct applications to various hydrological and engineering processes.

  1. Transient concentrations of NaCl affect the PHA accumulation in mixed microbial culture.

    PubMed

    Palmeiro-Sánchez, T; Fra-Vázquez, A; Rey-Martínez, N; Campos, J L; Mosquera-Corral, A

    2016-04-01

    The present study explores the feasibility of the accumulation of polyhydroxyalkanoates (PHAs) under the presence of transient concentrations of added sodium chloride, by means of a mixed microbial culture (MMC). This culture was enriched on a mixture of volatile fatty acids (VFAs) containing 0.8g Na(+)/L as NaOH. This MMC presented a maximum PHA accumulation capacity of 53wt% with 27Cmol% HV. Accumulation experiments performed with added NaCl at concentrations of 7, 13 and 20g/L shown that this salt provoked a decrease of the biomass PHA production rate, with an IC50 value close to 7gNaCl/L. The accumulated PHA was lower than the corresponding value of the assay without the addition of salt. Furthermore, the composition of the biopolymer, in terms of HB:HV ratio, changed from 2.71 to 6.37Cmol/Cmol, which means a HV decrease between 27 and 14Cmol%. Summarizing, the PHA accumulation by a MMC non-adapted to saline conditions affected the polymer composition and lead to lower production yields and rates than in absence of added NaCl. PMID:26780589

  2. Computational observation of enhanced solvation of the hydroxyl radical with increased NaCl concentration

    SciTech Connect

    Wick, Collin D.; Dang, Liem X.

    2006-05-11

    Classical molecular dynamics simulations with many-body potentials were carried out to quantitatively determine the effect of NaCl salt concentration on the aqueous solvation and surface concentration of hydroxyl radicals. The potential of mean force technique was used to track the incremental free energy of the hydroxyl radical from the vapor, crossing the air-water interface into the aqueous bulk. Results showed increased NaCl salt concentration significantly enhanced hydroxyl radical solvation, which should significantly increase its accommodation on water droplets. This has been experimentally observed for ozone aqueous accommodation with increased NaI concentration, but to our knowledge, no experimental study has probed this for hydroxyl radicals. The origin for this effect was found to be very favorable hydroxyl radical-chloride ion interactions, being stronger than for water-chloride. This work was performed at Pacific Northwest National Laboratory (PNNL) under the auspices of the Division of Chemical Sciences, Office of Basic Energy Sciences, U.S. Department of Energy. Battelle operates PNNL for the Department of Energy.

  3. The solubility of noble gases in water and in NaCl brine

    NASA Astrophysics Data System (ADS)

    Smith, S. P.; Kennedy, B. M.

    1983-03-01

    A direct-sampling, mass-spectrometric technique has been used to measure simultaneously the solubilities of He, Ne, Ar, Kr, and Xe in fresh water and NaCl brine (0 to 5.2 molar) from 0° to 65 °C, and at 1 atm total pressure of moist air. The argon solubility in the most concentrated brines is 4 to 7 times less than in fresh water at 65 °C and 0°C, respectively. The salt effect is parameterized using the Setschenow equation. ln [ β io(T) /β i(T) = MK iM(T) where M is NaCl moiarity, βio( T) and βi( T) the Bunsen solubility coefficients for gas i in fresh water and brine, and KiM( T) the empirical salting coefficient. Values of KiM( T) are calculated using volumetric concentration units for noble gas and NaCl content and are independent of NaCl molarity. Below about 40°C, temperature coefficients of all KiM are negative. The value of KHeM is a minimum at 40°C. KArM decreases from about 0.40 at 0°C to 0.28 at 65 °C. The absolute magnitudes of the differences in salting coefficients (relative to KArM) decrease from 0° to 65°C. Over the range of conditions studied, all noble gases are salted out, and KHeM ≲ KNeM < KArM < KKrM < KXeM. From the solubility data, we calculated Δ overlineG0tr, Δ overlineS0tr, Δ overlineH0tr and Δ overlineCOp,tr for the transfer of noble gases from fresh water to 1 molar NaCl solutions. At low temperatures Δ overlineS0tr, is positive, but decreases and becomes negative at temperatures ranging from about 25°C for He to 45°C for Xe. At low temperatures, the dissolved electrolyte apparently interferes with the formation of a cage of solvent molecules about the noble gas atom. At higher temperatures, the local environment of the gas atom in the brine appears to be slightly more ordered than in pure water, possibly reflecting the longer effective range of the ionic fields at higher temperature. The measured solubilities can be used to model noble gas partitioning in two-phase geothermal systems at low temperatures. The data

  4. Osmotic injury of PC-3 cells by hypertonic NaCl solutions at temperatures above 0 degrees C.

    PubMed

    Zawlodzka, Sylwia; Takamatsu, Hiroshi

    2005-02-01

    Cell injury due to osmotic dehydration, which is regarded as a major cause of injury during freeze-thaw processes, was examined closely using a perfusion microscope. Human prostatic adenocarcinoma cells (PC-3), which were put in a chamber, were subjected to hyperosmotic stresses by perfusing NaCl solutions of varying concentrations into the chamber. Cells were exposed to 2.5 and 4.5M NaCl solutions for 1-60 min by changing the concentrations at 0.2, 1, and 10 M/min. Decrease in cell viability was biphasic: the viability decreased first after the increase in NaCl concentration due to dehydration and then after return to isotonic conditions due to rehydration. Rehydration was substantially more responsible for cell injury than dehydration, which was marked at lower NaCl concentrations and lower temperatures. Injury resulting from contraction was negligible at the 2.5 M NaCl solution. While the hypertonic cell survival, which was determined without a return to isotonic conditions, was almost independent of time of exposure to hyperosmotic concentrations, the post-hypertonic survival after returning to isotonic conditions decreased with increasing exposure time, suggesting that the rehydration-induced injury was a consequence of time-dependent alteration of the plasma membrane. The post-hypertonic survival was lower for higher NaCl concentrations and higher temperatures, which was qualitatively consistent with previous studies. Effects of the rate of concentration change on the post-hypertonic cell survival were observed at 4.5 M; the highest rate of survival was obtained by slower increase and faster decrease in the NaCl concentration. However, the effect was negligible at 2.5 M. PMID:15710370

  5. [Effects of NaCl stress on Hippophae rhamnoides and Shepherdia argentea seedlings growth and photosynthetic characteristics].

    PubMed

    Qin, Jing; He, Kang-Ning; Tan, Guo-Dong; Wang, Zhan-Lin; Chen, Jing

    2009-04-01

    With two-year old seedlings of Hippophea rhamnoides and Shepherdia argentea as test materials, this paper studied their growth and photosynthetic characteristics under the stress of different concentration (0, 200, 400 and 600 mmol x L(-1)) NaCl. The results showed that the biomass and total leaf area per plant of H. rhamnoides and S. argentea seedlings decreased significantly with increasing NaCl concentration. Comparing with the control, the root/shoot ratio of H. rhamnoides and S. argentea seedlings under NaCl stress increased obviously, while the leaf mass per area (LMA) decreased slightly. When the NaCl concentration increased and the stress time prolonged, the net photosynthetic rate (P(n)), transpiration rate (T(r)), and stomatal conductance (G(s)) of H. rhamnoides and S. argentea seedlings declined markedly, the intercellular CO2 concentration (C(i)) increased after an initial decrease, whereas the water use efficiency (WUE) and stomatal limiting value (L(s)) decreased after an initial increase. The dynamic changes of G(s), C(i) and L(s) indicated that the decline of P(n) was mainly caused by the stomatal limitation in a short-term stress, and by non-stomatal limitation in a long-term stress. The poorer the salt tolerance of tree species and the higher the NaCl concentration, the earlier the transition from stomatal limitation to non-stomatal limitation would occur. As for H. rhamnoides, its morphological symptoms of salt injury appeared on the 10th day, and all of its seedlings were died on the 22th day under 600 mmol NaCl x L(-1) stress. In contrast, S. argentea could tolerate 600 mmol NaCl x L(-1) stress for above 30 days, illustrating that S. argentea, as an introduced tree species, had higher salt tolerance than H. rhamnoides, and could be planted widely in saline regions of China.

  6. Effect of NaCl reduction and replacement on the growth of fungi important to the spoilage of bread.

    PubMed

    Samapundo, S; Deschuyffeleer, N; Van Laere, D; De Leyn, I; Devlieghere, F

    2010-09-01

    The effect of NaCl and various NaCl replacers (CaCl(2), MgCl(2), KCl and MgSO(4)) on the growth of Penicillium roqueforti and Aspergillus niger was evaluated at 22 degrees C. In addition, challenge tests were performed on white bread to determine the consequences of NaCl reduction with or without partial replacement on the growth of P. roqueforti. From the results obtained it can be concluded that at equivalent water phase concentrations the isolates exhibited differing sensitivities to the salts evaluated with NaCl and MgCl(2) having the greatest inhibitory action on the growth of A. niger and P. roqueforti, respectively. MgSO(4) had the least antifungal activity. At equivalent molalities, CaCl(2) had in general the largest antifungal activity. Although the water activity (a(w)) lowering effects of the compounds studied play a large role in explaining the trends observed, at equivalent water phase concentrations MgCl(2) was found to have a smaller inhibitory effect on A. niger than that expected from its a(w) depressing effect. The challenge tests revealed that no difference occurred in the growth of P. roqueforti on standard white bread, bread with 30% less NaCl and bread in which 30% of the NaCl has been partially replaced by a mixture of KCl and Sub4Salt. These results are of importance in assessing the possible microbiological consequences of NaCl reduction or replacement in bread and similar bakery products.

  7. 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.

  8. [Effects of NaCl stress on the seedling growth and K(+)- and Na(+) -allocation of four leguminous tree species].

    PubMed

    Mo, Hai-Bo; Yin, Yun-Long; Lu, Zhi-Guo; Wei, Xiu-Jun; Xu, Jian-Hua

    2011-05-01

    Taking the pot-cultured seedlings of four leguminous tree species (Albizia julibrissin, Robinia pseudoacacia, Sophora japonica, and Gleditsia sinensis) as test materials, this paper studied their growth indices, critical salt concentration (C50), and K+ and Na+ allocation under different levels of NaCl stress, aimed to understand the difference of test tree species in salt tolerance. NaCl stress inhibited the seedling growth of the tree species. Under NaCl stress, the dry matter accumulation decreased, while the root/shoot ratio increased, especially for A. julibrissin and G. sinensis. Quadratic regression analysis showed that the C50 of A. julibrissin, R. pseudoacacia, S. japonica, and G. sinensis was 3.0 per thousand, 5.0 per thousand, 4.5 per thousand, and 3.9 per thousand, respectively, i.e., the salt tolerance of the four tree species was in the order of R. pseudoacacia > S. japonica > G. sinensis > A. julibrissin. In the root, stem, and leaf of the four tree species seedlings, the Na+ content increased with the increase of NaCl stress, while the K+ content (except in the root of A. julibrissin) decreased after an initial increase, resulting in a larger difference in the K+/Na+ ratio in the organs. Under the same NaCl stress, the allocation of Na+ in different organs of the four tree species seedlings decreased in the order of root>stem>leaf, while that of K+ differed with tree species and NaCl stress, and leaf was the main storage organ for K+. The K+/Na+ ratio in different organs decreased in the sequence of leaf>stem>root. R. pseudoacacia under NaCl stress accumulated more K+ and less Na+ in stem and leaf, and had higher K+/Na+ ratio in all organs and higher dry mass, being assessed to be more salt-tolerant. In contrast, A. julibrissin under high NaCl stress accumulated more Na+ in stem and leaf, and had a lower K+/Na+ ratio in all organs and lower dry mass, being evaluated to be lesser salt-tolerant. The K+ accumulation in seedling stem and leaf and the Na

  9. Growth, structure and magnetic properties of FePt nanostructures on NaCl(001) and MgO(001).

    PubMed

    Liscio, F; Makarov, D; Maret, M; Doisneau-Cottignies, B; Roussel, H; Albrecht, M

    2010-02-10

    A comparison of the structural and magnetic properties of FePt nanostructures grown at different temperatures on NaCl(001) and MgO(001) substrates is presented. A strong influence of the deposition temperature on the epitaxial growth as well as on the size distribution of FePt nanostructures grown on NaCl substrates is observed. In spite of a large lattice mismatch between FePt and NaCl, a 'cube-over-cube' growth of nanostructures with a narrow size distribution was achieved at 520 K. Moreover, the growth of FePt nanostructures on NaCl(001) is not preceded by the formation of a wetting layer as observed on MgO(001). The higher degree of L1(0) chemical ordering in FePt nanostructures grown on MgO(001) accompanied by the absence of L1(0) variants with an in-plane tetragonal c-axis indicates that the tensile epitaxial stress induced by the MgO substrate is a key factor in the formation of the L1(0) phase with an out-of-plane c-axis. Superparamagnetic behavior is revealed for the FePt nanostructures grown on NaCl(001) due to their small size and relatively poor chemical order.

  10. Growth, structure and magnetic properties of FePt nanostructures on NaCl(001) and MgO(001)

    NASA Astrophysics Data System (ADS)

    Liscio, F.; Makarov, D.; Maret, M.; Doisneau-Cottignies, B.; Roussel, H.; Albrecht, M.

    2010-02-01

    A comparison of the structural and magnetic properties of FePt nanostructures grown at different temperatures on NaCl(001) and MgO(001) substrates is presented. A strong influence of the deposition temperature on the epitaxial growth as well as on the size distribution of FePt nanostructures grown on NaCl substrates is observed. In spite of a large lattice mismatch between FePt and NaCl, a 'cube-over-cube' growth of nanostructures with a narrow size distribution was achieved at 520 K. Moreover, the growth of FePt nanostructures on NaCl(001) is not preceded by the formation of a wetting layer as observed on MgO(001). The higher degree of L10 chemical ordering in FePt nanostructures grown on MgO(001) accompanied by the absence of L10 variants with an in-plane tetragonal c-axis indicates that the tensile epitaxial stress induced by the MgO substrate is a key factor in the formation of the L10 phase with an out-of-plane c-axis. Superparamagnetic behavior is revealed for the FePt nanostructures grown on NaCl(001) due to their small size and relatively poor chemical order.

  11. Shape-memory NiTi foams produced by replication of NaCl space-holders.

    PubMed

    Bansiddhi, A; Dunand, D C

    2008-11-01

    NiTi foams were created with a structure (32-36% open pores 70-400 microm in size) and mechanical properties (4-25 GPa stiffness, >1000 MPa compressive strength, >42% compressive ductility, and shape-memory strains up to 4%) useful for bone implant applications. A mixture of NiTi and NaCl powders was hot-isostatically pressed at 950 and 1065 degrees C and the NaCl phase was then dissolved in water. The resulting NiTi foams show interconnected pores that replicate the shape and size of the NaCl powders, indicating that NiTi powders densified significantly before NaCl melted at 801 degrees C. Densifying NiTi or other metal powders above the melting point of the space-holder permits the use of NaCl, with the following advantages compared with higher-melting, solid space-holders such as oxides and fluorides used to date: (i) no temperature limit for densification; (ii) lower cost; (iii) greater flexibility in powder (and thus pore) shape; (iv) faster dissolution; (v) reduced metal corrosion during dissolution; (vi) lower toxicity if space-holder residues remain in the foam.

  12. Consensus on the solubility of NaCl in water from computer simulations using the chemical potential route.

    PubMed

    Benavides, A L; Aragones, J L; Vega, C

    2016-03-28

    The solubility of NaCl in water is evaluated by using three force field models: Joung-Cheatham for NaCl dissolved in two different water models (SPC/E and TIP4P/2005) and Smith Dang NaCl model in SPC/E water. The methodology based on free-energy calculations [E. Sanz and C. Vega, J. Chem. Phys. 126, 014507 (2007)] and [J. L. Aragones et al., J. Chem. Phys. 136, 244508 (2012)] has been used, except, that all calculations for the NaCl in solution were obtained by using molecular dynamics simulations with the GROMACS package instead of homemade MC programs. We have explored new lower molalities and made longer runs to improve the accuracy of the calculations. Exploring the low molality region allowed us to obtain an analytical expression for the chemical potential of the ions in solution as a function of molality valid for a wider range of molalities, including the infinite dilute case. These new results are in better agreement with recent estimations of the solubility obtained with other methodologies. Besides, two empirical simple rules have been obtained to have a rough estimate of the solubility of a certain model, by analyzing the ionic pairs formation as a function of molality and/or by calculating the difference between the NaCl solid chemical potential and the standard chemical potential of the salt in solution. PMID:27036458

  13. Molecular dynamics simulations of carbon dioxide hydrate growth in electrolyte solutions of NaCl and MgCl2

    NASA Astrophysics Data System (ADS)

    Yi, Lizhi; Liang, Deqing; Zhou, Xuebing; Li, Dongliang; Wang, Jianwei

    2014-12-01

    Molecular dynamics simulations are performed to study the growth of carbon dioxide (CO2) hydrate in electrolyte solutions of NaCl and MgCl2. The kinetic behaviour of the hydrate growth is examined in terms of cage content, density profile, and mobility of ions and water molecules, and how these properties are influenced by added NaCl and MgCl2. Our simulation results show that both NaCl and MgCl2 inhibit the CO2 hydrate growth. With a same mole concentration or ion density, MgCl2 exhibits stronger inhibition on the growth of CO2 hydrate than NaCl does. The growth rate of the CO2 hydrate in NaCl and MgCl2 solutions decreases slightly with increasing pressure. During the simulations, the Na+, Mg2+, and Cl- ions are mostly excluded by the growing interface front. We find that these ions decrease the mobility of their surrounding water molecules, and thus reduce the opportunity for these water molecules to form cage-like clusters toward hydrate formation. We also note that during the growth processes, several 51263 cages appear at the hydrate/solution interface, although they are finally transformed to tetrakaidecahedral (51262) cages. Structural defects consisting of one water molecule trapped in a cage with its hydrogen atoms being attracted by two Cl- ions have also been observed.

  14. Consensus on the solubility of NaCl in water from computer simulations using the chemical potential route.

    PubMed

    Benavides, A L; Aragones, J L; Vega, C

    2016-03-28

    The solubility of NaCl in water is evaluated by using three force field models: Joung-Cheatham for NaCl dissolved in two different water models (SPC/E and TIP4P/2005) and Smith Dang NaCl model in SPC/E water. The methodology based on free-energy calculations [E. Sanz and C. Vega, J. Chem. Phys. 126, 014507 (2007)] and [J. L. Aragones et al., J. Chem. Phys. 136, 244508 (2012)] has been used, except, that all calculations for the NaCl in solution were obtained by using molecular dynamics simulations with the GROMACS package instead of homemade MC programs. We have explored new lower molalities and made longer runs to improve the accuracy of the calculations. Exploring the low molality region allowed us to obtain an analytical expression for the chemical potential of the ions in solution as a function of molality valid for a wider range of molalities, including the infinite dilute case. These new results are in better agreement with recent estimations of the solubility obtained with other methodologies. Besides, two empirical simple rules have been obtained to have a rough estimate of the solubility of a certain model, by analyzing the ionic pairs formation as a function of molality and/or by calculating the difference between the NaCl solid chemical potential and the standard chemical potential of the salt in solution.

  15. Photosynthetic limitations of a halophyte sea aster (Aster tripolium L) under water stress and NaCl stress.

    PubMed

    Ueda, Akihiro; Kanechi, Michio; Uno, Yuichi; Inagaki, Noboru

    2003-02-01

    To understand the mechanisms of salt tolerance in a halophyte, sea aster ( Aster tripolium L.), we studied the changes of water relation and the factors of photosynthetic limitation under water stress and 300 mM NaCl stress. The contents of Na(+) and Cl(-) were highest in NaCl-stressed leaves. Leaf osmotic potentials ( Psi(s)) were decreased by both stress treatments, whereas leaf turgor pressure ( Psi(t)) was maintained under NaCl stress. Decrease in Psi(s) without any loss of Psi(t) accounted for osmotic adjustment using Na(+) and Cl(-) accumulated under NaCl stress. Stress treatments affected photosynthesis, and stomatal limitation was higher under water stress than under NaCl stress. Additionally, maximum CO(2) fixation rate and O(2) evolution rate decreased only under water stress, indicating irreversible damage to photosynthetic systems, mainly by dehydration. Water stress severely affected the water relation and photosynthetic capacity. On the other hand, turgid leaves under NaCl stress have dehydration tolerance due to maintenance of Psi(t) and photosynthetic activity. These results show that sea aster might not suffer from tissue dehydration in highly salinized environments. We conclude that the adaptation of sea aster to salinity may be accomplished by osmotic adjustment using accumulated Na(+) and Cl(-), and that this plant has typical halophyte characteristics, but not drought tolerance.

  16. Consensus on the solubility of NaCl in water from computer simulations using the chemical potential route

    NASA Astrophysics Data System (ADS)

    Benavides, A. L.; Aragones, J. L.; Vega, C.

    2016-03-01

    The solubility of NaCl in water is evaluated by using three force field models: Joung-Cheatham for NaCl dissolved in two different water models (SPC/E and TIP4P/2005) and Smith Dang NaCl model in SPC/E water. The methodology based on free-energy calculations [E. Sanz and C. Vega, J. Chem. Phys. 126, 014507 (2007)] and [J. L. Aragones et al., J. Chem. Phys. 136, 244508 (2012)] has been used, except, that all calculations for the NaCl in solution were obtained by using molecular dynamics simulations with the GROMACS package instead of homemade MC programs. We have explored new lower molalities and made longer runs to improve the accuracy of the calculations. Exploring the low molality region allowed us to obtain an analytical expression for the chemical potential of the ions in solution as a function of molality valid for a wider range of molalities, including the infinite dilute case. These new results are in better agreement with recent estimations of the solubility obtained with other methodologies. Besides, two empirical simple rules have been obtained to have a rough estimate of the solubility of a certain model, by analyzing the ionic pairs formation as a function of molality and/or by calculating the difference between the NaCl solid chemical potential and the standard chemical potential of the salt in solution.

  17. Effect of trace amounts of NaCl vapor on high-temperature oxidation of TiAl

    SciTech Connect

    Hara, M.; Kitagawa, Y.

    1999-08-01

    The effect of trace amounts of NaCl vapor on the high-temperature oxidation of TiAl was examined by thermogravimetry and analysis of the scale formed on TiAl. The mass gain due to oxidation at 1273 K in O{sub 2} with trace amounts of NaCl vapor was far lower than that in pure O{sub 2} without NaCl vapor. This low mass gain in the atmosphere with trace amounts of NaCl vapor resulted from the saturation behavior of mass gain during the initial period of oxidation. It was found from X-ray photoemission spectroscopy (XPS) analyses of the specimen surface that the oxide film formed during the initial period in the atmosphere with trace amounts of NaCl vapor consisted of dense Al{sub 2}O{sub 3}, thus, the low oxidation rate of TiAl was attributed to a protective oxide film of dense Al{sub 2}O{sub 3}.

  18. 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.

  19. 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

  20. 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. PMID:27510576

  1. 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.

  2. Twinning of cubic diamond explains reported nanodiamond polymorphs.

    PubMed

    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 (<121> 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.

  3. Twinning of cubic diamond explains reported nanodiamond polymorphs.

    PubMed

    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 (<121> 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

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

    NASA Video Gallery

    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. Multitarget tracking with cubic energy optical neural nets.

    PubMed

    Barnard, E; Casasent, D P

    1989-02-15

    A neural net processor and its optical realization are described for a multitarget tracking application. A cubic energy function results and a new optical neural processor is required. Initial simulation data are presented.

  6. 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)

  7. 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

  8. 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.

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

    NASA Video Gallery

    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 ...

  10. Hydrothermal growth of amethyst and citrine in NaCl and KCl solutions

    NASA Astrophysics Data System (ADS)

    Hosaka, Masahiro; Taki, Sadao

    1983-12-01

    Natural quartz grows from solutions containing mainly Na +, K + and Cl - ions. In this experiment, the growth of synthetic quartz under the same growth conditions as those of natural quartz was attempted using NaCl and KCl solutions as a growth solution. As a result, colored quartz equivalent in quality and color tone to natural amethyst and citrine was obtained. The quartz grown from r-cut and R-cut plate seeds with iron added to the growth solution was colorless but γ-ray irradiation produced a purplish tint. The quartz grown from X-cut plate and Y-bar seeds had a yellowish tint. Although the depth of color increased in proportion to the amount of iron, it reached close to saturation with an iron concentration of approximately 90 υg/ml solvent.

  11. Calorimetry of heterogeneous systems: H+ binding to TiO2 in NaCl

    USGS Publications Warehouse

    Mehr, S.R.; Eatough, D.J.; Hansen, L.D.; Lewis, E.A.; Davis, J.A.

    1989-01-01

    A simultaneous calorimetric and potentiometric technique has been developed for measuring the thermodynamics of proton binding to mineral oxides in the presence of a supporting electrolyte. Modifications made to a commercial titration calorimeter to add a combination pH electrode and maintain an inert atmosphere in the calorimeter reaction vessel are described. A procedure to calibrate potentiometric measurements in heterogeneous systems to correct for the suspension effect on pH is given. The enthalpy change for proton dissociation from TiO2 in aqueous suspension as a function of pH is reported for 0.01, 0.1, and 0.5 M NaCl. The enthalpy change for proton dissociation is endothermic, ranging from 10.5 ?? 3.8 to 45.0 ?? 3.8 kJ mol-1 over the pH range from 4 to 10. ?? 1989.

  12. Mean ionic activity coefficients in aqueous NaCl solutions from molecular dynamics simulations

    SciTech Connect

    Mester, Zoltan; Panagiotopoulos, Athanassios Z.

    2015-01-28

    The mean ionic activity coefficients of aqueous NaCl solutions of varying concentrations at 298.15 K and 1 bar have been obtained from molecular dynamics simulations by gradually turning on the interactions of an ion pair inserted into the solution. Several common non-polarizable water and ion models have been used in the simulations. Gibbs-Duhem equation calculations of the thermodynamic activity of water are used to confirm the thermodynamic consistency of the mean ionic activity coefficients. While the majority of model combinations predict the correct trends in mean ionic activity coefficients, they overestimate their values at high salt concentrations. The solubility predictions also suffer from inaccuracies, with all models underpredicting the experimental values, some by large factors. These results point to the need for further ion and water model development.

  13. Hydrothermal alteration of graywacke and basalt by 4 molal NaCl.

    USGS Publications Warehouse

    Rosenbauer, R.J.; Bischoff, J.L.; Radtke, A.S.

    1983-01-01

    Rock-water interaction experiments were carried out at 350oC and 500 bar at a 1/10 rock/fluid ratio using 4 molal NaCl brine. Reaction of brine and greywacke lead to the conversion of illite, dolomite and quartz to albite and smectite. In the process, the rock gained Na and released Ca, K, heavy metals and CO2 to solution. Metal mobilization was found to primarily depend on acidity which was produced by Na metasomatism and by dedolomitization. Reaction of brine and basalt produced only minor alteration in which some smectite and little albite formed. No significant acidity was produced nor did metals become mobilized. Production of acidity during albitization depends entirely on the phase being altered. Albitization of greywacke produces H+ whereas the albitization of basalt apparently consumes this ion. -J.E.S.

  14. Na+,Cl- cotransport in Ehrlich ascites tumor cells activated during volume regulation (regulatory volume increase).

    PubMed

    Hoffmann, E K; Sjøholm, C; Simonsen, L O

    1983-01-01

    Ehrlich ascites cells were preincubated in hypotonic medium with subsequent restoration of tonicity. After the initial osmotic shrinkage the cells recovered their volume within 5 min with an associated KCl uptake. The volume recovery was inhibited when NO-3 was substituted for Cl-, and when Na+ was replaced by K+, or by choline (at 5 mM external K+). The volume recovery was strongly inhibited by furosemide and bumetanide, but essentially unaffected by DIDS. The net uptake of Cl- was much larger than the value predicted from the conductive Cl- permeability. The undirectional 36Cl flux, which was insensitive to bumetanide under steady-state conditions, was substantially increased during regulatory volume increase, and showed a large bumetanide-sensitive component. During volume recovery the Cl- flux ratio (influx/efflux) for the bumetanide-sensitive component was estimated at 1.85, compatible with a coupled uptake of Na+ and Cl-, or with an uptake via a K+,Na+,2Cl- cotransport system. The latter possibility is unlikely, however, because a net uptake of KCl was found even at low external K+, and because no K+ uptake was found in ouabain-poisoned cells. In the presence of ouabain a bumetanide-sensitive uptake during volume recovery of Na+ and Cl- in nearly equimolar amounts was demonstrated. It is proposed that the primary process during the regulatory volume increase is an activation of an otherwise quiescent, bumetanide-sensitive Na+,Cl- cotransport system with subsequent replacement of Na+ by K+ via the Na+/K+ pump, stimulated by the Na+ influx through the Na+,Cl- cotransport system. PMID:6100866

  15. Aquaporin Expression Contributes to Human Transurothelial Permeability In Vitro and Is Modulated by NaCl

    PubMed Central

    Rubenwolf, Peter C.; Georgopoulos, Nikolaos T.; Kirkwood, Lisa A.; Baker, Simon C.; Southgate, Jennifer

    2012-01-01

    It is generally considered that the bladder is impervious and stores urine in unmodified form on account of the barrier imposed by the highly-specialised uro-epithelial lining. However, recent evidence, including demonstration of aquaporin (AQP) expression by human urothelium, suggests that urothelium may be able to modify urine content. Here we have we applied functional assays to an in vitro-differentiated normal human urothelial cell culture system and examined both whether AQP expression was responsive to changes in osmolality, and the effects of blocking AQP channels on water and urea transport. AQP3 expression was up-regulated by increased osmolality, but only in response to NaCl. A small but similar effect was seen with AQP9, but not AQP4 or AQP7. Differentiated urothelium revealed significant barrier function (mean TER 3862 Ω.cm2), with mean diffusive water and urea permeability coefficients of 6.33×10−5 and 2.45×10−5 cm/s, respectively. AQP blockade with mercuric chloride resulted in decreased water and urea flux. The diffusive permeability of urothelial cell sheets remained constant following conditioning in hyperosmotic NaCl, but there was a significant increase in water and urea flux across an osmotic gradient. Taken collectively with evidence emerging from studies in other species, our results support an active role for human urothelium in sensing and responding to hypertonic salt concentrations through alterations in AQP protein expression, with AQP channels providing a mechanism for modifying urine composition. These observations challenge the traditional concept of an impermeable bladder epithelium and suggest that the urothelium may play a modulatory role in water and salt homeostasis. PMID:23028946

  16. Fast responses of metabolites in Vicia faba L. to moderate NaCl stress.

    PubMed

    Geilfus, Christoph-Martin; Niehaus, Karsten; Gödde, Victoria; Hasler, Mario; Zörb, Christian; Gorzolka, Karin; Jezek, Mareike; Senbayram, Mehmet; Ludwig-Müller, Jutta; Mühling, Karl H

    2015-07-01

    Salt stress impairs global agricultural crop production by reducing vegetative growth and yield. Despite this importance, a number of gaps exist in our knowledge about very early metabolic responses that ensue minutes after plants experience salt stress. Surprisingly, this early phase remains almost as a black box. Therefore, systematic studies focussing on very early plant physiological responses to salt stress (in this case NaCl) may enhance our understanding on strategies to develop crop plants with a better performance under saline conditions. In the present study, hydroponically grown Vicia faba L. plants were exposed to 90 min of NaCl stress, whereby every 15 min samples were taken for analyzing short-term physiologic responses. Gas chromatography-mass spectrometry-based metabolite profiles were analysed by calculating a principal component analysis followed by multiple contrast tests. Follow-up experiments were run to analyze downstream effects of the metabolic changes on the physiological level. The novelty of this study is the demonstration of complex stress-induced metabolic changes at the very beginning of a moderate salt stress in V. faba, information that are very scant for this early stage. This study reports for the first that the proline analogue trans-4-hydroxy-L-proline, known to inhibit cell elongation, was increasingly synthesized after NaCl-stress initiation. Leaf metabolites associated with the generation or scavenging of reactive oxygen species (ROS) were affected in leaves that showed a synchronized increase in ROS formation. A reduced glutamine synthetase activity indicated that disturbances in the nitrogen assimilation occur earlier than it was previously thought under salt stress.

  17. Total reflection infrared spectroscopy of water-ice and frozen aqueous NaCl solutions

    SciTech Connect

    Walker, Rachel L.; Searles, Keith; Willard, Jesse A.; Michelsen, Rebecca R. H.

    2013-12-28

    Liquid-like and liquid water at and near the surface of water-ice and frozen aqueous sodium chloride films were observed using attenuated total reflection infrared spectroscopy (ATR-IR). The concentration of NaCl ranged from 0.0001 to 0.01 M and the temperature varied from the melting point of water down to 256 K. The amount of liquid brine at the interface of the frozen films with the germanium ATR crystal increased with salt concentration and temperature. Experimental spectra are compared to reflection spectra calculated for a simplified morphology of a uniform liquid layer between the germanium crystal and the frozen film. This morphology allows for the amount of liquid observed in an experimental spectrum to be converted to the thickness of a homogenous layer with an equivalent amount of liquid. These equivalent thickness ranges from a nanometer for water-ice at 260 K to 170 nm for 0.01 M NaCl close to the melting point. The amounts of brine observed are over an order of magnitude less than the total liquid predicted by equilibrium thermodynamic models, implying that the vast majority of the liquid fraction of frozen solutions may be found in internal inclusions, grain boundaries, and the like. Thus, the amount of liquid and the solutes dissolved in them that are available to react with atmospheric gases on the surfaces of snow and ice are not well described by thermodynamic equilibrium models which assume the liquid phase is located entirely at the surface.

  18. Effect of porosity and NaCl concentration on the osmotic efficiency of a sodium bentonite membrane

    SciTech Connect

    Fritz, S.J.; Marine, I.W.

    1982-01-01

    Osmosis has been cited as a mechanism for explaining anomalously high fluid pressures in the subsurface. Clays and shales act as membranes, and osmotic flux across these units may result in pressures sufficiently high to explain these anomalies. The theoretical osmotic pressures as calculated solely from solution properties can be quite large; however, it is not yet resolved whether these geologic membranes are sufficiently ideal to generate such pressures. Osmotic efficiencies of a Na-bentonite were measured by a series of hyperfiltration experiments using various molarities of NaCl at two different porosities. The highest osmotic efficiency (0.8912) occurred at the lower porosity and the lowest NaCl input solution. The lowest measured osmotic efficiency (0.0423) occurred at the higher porosity and the highest NaCl input concentration. 26 references, 2 figures, 2 tables.

  19. Investigation into the role of NaCl deposited on oxide and metal substrates in the initiation of hot corrosion

    NASA Technical Reports Server (NTRS)

    Birks, N.

    1981-01-01

    Morphological aspects of the conversion to Na2SO4 of NaCl deposits over the temperature range 500-700 C, in air with added SO2 and H2O. Progress of the reaction was observed by withdrawing samples at various times and examining them under the scanning electron microscope using EDAX to assess the extent of chloride to sulfate conversion. These initial results show that the conversion to Na2SO4 proceeds directly on the sodium chloride surface as well as on the surrounding substrate due to evaporation of NaCl from the solid particle. The mechanism of this reaction could involve reaction in the vapor to produce Na2SO4 which then deposits, alternatively Na2SO4 could form directly on the substrate surface due to direct reaction there between the vapors NaCl, SO2 and O2.

  20. Affinity-defining domains in the Na-Cl cotransporter: a different location for Cl- and thiazide binding.

    PubMed

    Moreno, Erika; Cristóbal, Pedro San; Rivera, Manuel; Vázquez, Norma; Bobadilla, Norma A; Gamba, Gerardo

    2006-06-23

    The thiazide-sensitive Na+-Cl- cotransporter (NCC) is the major pathway for salt reabsorption in the distal convoluted tubule, serves as a receptor for thiazide-type diuretics, and is involved in inherited diseases associated with abnormal blood pressure. Little is known regarding the structure-function relationship in this cotransporter. Previous studies from our group reveal that mammalian NCC exhibits higher affinity for ions and thiazides than teleost NCC and suggest a role for glycosylation upon thiazide affinity. Here we have constructed a series of chimeric and mutant cDNAs between rat and flounder NCC to define the role of glycosylation status, the amino-terminal domain, the carboxyl-terminal domain, the extracellular glycosylated loop, and the transmembrane segments upon affinity for Na+, Cl-, and metolazone. Xenopus laevis oocytes were used as the heterologous expression system. We observed that elimination of glycosylation sites in flounder NCC did not affect the affinity of the cotransporter for metolazone. Also, swapping the amino-terminal domain, the carboxyl-terminal domain, the glycosylation sites, or the entire extracellular glycosylation loop between rat and flounder NCC had no effect upon ions or metolazone affinity. In contrast, interchanging transmembrane regions between rat and flounder NCC revealed that affinity-modifying residues for chloride are located within the transmembrane 1-7 region and for thiazides are located within the transmembrane 8-12 region, whereas both segments seem to be implicated in defining sodium affinity. These observations strongly suggest that binding sites for chloride and thiazide in NCC are different. PMID:16624820

  1. TOPICAL REVIEW: Nonlinear photonic crystals: III. Cubic nonlinearity

    NASA Astrophysics Data System (ADS)

    Babin, Anatoli; Figotin, Alexander

    2003-10-01

    Weakly nonlinear interactions between wavepackets in a lossless periodic dielectric medium are studied based on the classical Maxwell equations with a cubic nonlinearity. We consider nonlinear processes such that: (i) the amplitude of the wave component due to the nonlinearity does not exceed the amplitude of its linear component; (ii) the spatial range of a probing wavepacket is much smaller than the dimension of the medium sample, and it is not too small compared with the dimension of the primitive cell. These nonlinear processes are naturally described in terms of the cubic interaction phase function based on the dispersion relations of the underlying linear periodic medium. It turns out that only a few quadruplets of modes have significant nonlinear interactions. They are singled out by a system of selection rules including the group velocity, frequency and phase matching conditions. It turns out that the intrinsic symmetries of the cubic interaction phase stemming from assumed inversion symmetry of the dispersion relations play a significant role in the cubic nonlinear interactions. We also study canonical forms of the cubic interaction phase leading to a complete quantitative classification of all possible significant cubic interactions. The classification is ultimately based on a universal system of indices reflecting the intensity of nonlinear interactions.

  2. A study on the implications of NaCl reduction in the fermentation profile of Conservolea natural black olives.

    PubMed

    Panagou, E Z; Hondrodimou, O; Mallouchos, A; Nychas, G-J E

    2011-10-01

    This study examined the impact of different mixtures of NaCl, KCl, and CaCl(2) on the fermentation profiles of Conservolea natural black olives. Five different combinations of chloride salts were investigated, namely (i) 8% NaCl (control treatment), (ii) 4% NaCl and 4% KCl, (iii) 4% NaCl and 4% CaCl(2), (iv) 4% KCl and 4% CaCl(2), and (v) 2.6% NaCl-2.6% KCl-2.6% CaCl(2). The changes in the microbial association (lactic acid bacteria, yeasts, Enterobacteriaceae), pH, titratable acidity, organic acids, volatile compounds, and mineral content in olive flesh were analyzed. Results demonstrated that all salt combinations led to vigorous lactic acid processes based on the obtained values of pH (3.9-4.2) and titratable acidity (0.70-0.86 g lactic acid per 100 ml brine). Organoleptic evaluation was a critical factor in the acceptability of the final product. Increasing concentrations of CaCl(2) or a combination of KCl and CaCl(2) rendered the product bitter with low acceptability by the taste panel. Only one combination of chloride salts (4% NaCl and 4% KCl) could finally produce olives with lower sodium content and good organoleptic attributes. The results of this study could be employed by the Greek table olive industry in an attempt to produce natural black olives with less sodium without affecting the traditional taste of fermented olives in order to meet consumers' demand for low sodium dietary intake.

  3. Direct measurement of translingual epithelial NaCl and KCl currents during the chorda tympani taste response.

    PubMed Central

    Heck, G L; Persaud, K C; DeSimone, J A

    1989-01-01

    We have measured the NaCl or KCl currents under voltage clamp across the dorsal lingual epithelium of the rat and simultaneously the response of the taste nerves. Under short-circuit conditions a NaCl stimulus evoked an inward current (first current) that coincided with excitation of the chorda tympani. This was followed by a slower inward current (second current) that matched the kinetics of taste nerve adaptation. The peak first current and the coincident neural response satisfied the same saturating NaCl concentration dependence. Both first and second currents were partially blocked by amiloride as were the phasic and tonic components of the neural response. The NaCl-evoked second current was completely blocked by ouabain. Investigation of the NaCl-evoked current and the neural response over a range of clamped voltages showed that inward negative potentials enhanced the inward current and the neural response to 0.3 M NaCl. Sufficiently high inward positive potentials reversed the current, and made the neural response independent of further changes in voltage. Therefore, one of the NaCl taste transduction mechanisms is voltage dependent while the other is voltage independent. A KCl stimulus also evoked an inward short-circuit current, but this and the neural response were not amiloride-sensitive. The data indicate that neural adaptation to a NaCl stimulus, but not a KCl stimulus, is mediated by cell Na/K pumps. A model is proposed in which the connection between the NaCl-evoked second current and cell repolarization is demonstrated. PMID:2541822

  4. Halopriming of seeds imparts tolerance to NaCl and PEG induced stress in Vigna radiata (L.) Wilczek varieties.

    PubMed

    Jisha, K C; Puthur, Jos T

    2014-07-01

    The investigation was carried out to study the effect of halopriming on NaCl and polyethylene glycol-6000 (PEG-6000) induced stress tolerance potential of three Vigna radiata (L.) Wilczek varieties, with varied abiotic stress tolerance potential. Halopriming is a seed priming technique in which the seeds were soaked in various salt solutions (in this study NaCl was used). The results of the study indicated that the application of stresses (both NaCl and PEG) induced retardation of growth attributes (measured in terms of shoot length, fresh weight, dry weight) and decrease in physiological attributes like total chlorophyll content, metabolites, photosynthetic and mitochondrial activity of the seedlings in all three V. radiata (L.) varieties. However, halopriming of the seeds could reduce the extent of decrease in these biological attributes. NaCl and PEG stress also caused increase in MDA content (a product of membrane lipid peroxidation) in all the varieties studied and this increase was significantly minimized under halopriming. From the present investigation it was evident that among the green gram varieties studied, Pusa Vishal, a NaCl tolerant variety showed enhanced tolerance to NaCl and PEG induced stress, when the seeds were subjected to halopriming followed by Pusa Ratna (stress sensitive variety). Pusa 9531 (drought tolerant variety) also showed positive halopriming effects but it was less significant when compared to other two varieties. It could be concluded that halopriming improved the drought and salinity stress tolerance potential of all varieties and it was significantly higher in the Pusa Vishal as compared to Pusa 9531 and Pusa Ratna.

  5. CORROSION OF AMORPHOUS AND NANOCRYSTALLINE Fe-BASED ALLOYS IN NaCl AND H2SO4 SOLUTIONS

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Lu, Wei; Wang, Yuxin; Yan, Biao; Pan, Deng

    2013-07-01

    Corrosion resistance of nanocrystalline Fe73.5Si13.5B9Nb3Cu1 alloy was investigated and compared to its amorphous counterpart. Low-temperature crystallization occurred during the annealing of amorphous tapes was used to obtain a nanocrystalline structure. The influence of annealing condition on the structure and corrosion resistance of the alloy in NaCl and H2SO4 solutions was investigated. Based on the testing results, it was found that nanocrystalline tapes have higher corrosion resistance than amorphous counterpart and H2SO4 can promote the occurrence of corrosion compared with NaCl.

  6. Solvent drag measurement of transcellular and basolateral membrane NaCl reflection coefficient in kidney proximal tubule.

    PubMed

    Shi, L B; Fushimi, K; Verkman, A S

    1991-08-01

    The NaCl reflection coefficient in proximal tubule has important implications for the mechanisms of near isosmotic volume reabsorption. A new fluorescence method was developed and applied to measure the transepithelial (sigma NaClTE) and basolateral membrane (sigma NaClcl) NaCl reflection coefficients in the isolated proximal straight tubule from rabbit kidney. For sigma NaClTE measurement, tubules were perfused with buffers containing 0 Cl, the Cl-sensitive fluorescent indicator 6-methoxy-N-[3-sulfopropyl] quinolinium and a Cl-insensitive indicator fluorescein sulfonate, and bathed in buffers of differing cryoscopic osmolalities containing NaCl. The transepithelial Cl gradient along the length of the tubule was measured in the steady state by a quantitative ratio imaging technique. A mathematical model based on the Kedem-Katchalsky equations was developed to calculate the axial profile of [Cl] from tubule geometry, lumen flow, water (Pf) and NaCl (PNaCl) permeabilities, and sigma NaClTE. A fit of experimental results to the model gave PNaCl = (2.25 +/- 0.2) x 10(-5) cm/s and sigma NaClTE = 0.98 +/- 0.03 at 23 degrees C. For measurement of sigma NaClbl, tubule cells were loaded with SPQ in the absence of Cl. NaCl solvent drag was measured from the time course of NaCl influx in response to rapid (less than 1 s) Cl addition to the bath solution. With bath-to-cell cryoscopic osmotic gradients of 0, -60, and +30 mosmol, initial Cl influx was 1.23, 1.10, and 1.25 mM/s; a fit to a mathematical model gave sigma NaClbl = 0.97 +/- 0.04. These results indicate absence of NaCl solvent drag in rabbit proximal tubule. The implications of these findings for water and NaCl movement in proximal tubule are evaluated.

  7. 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.

  8. Cubic potential models for cluster radioactivity

    NASA Astrophysics Data System (ADS)

    Shanmugam, G.

    1999-09-01

    Cluster radioactivity is a process by which nuclei equal and heavier than the a-particleis emitted spontaneously. The clusters usually emitted in this process are the a-particle, carbon, oxygen, neon, magnesium, silicon etc. When the mass of the cluster becomes comparable with the mass of the daughter, symmetric fission takes place. Thus the cluster radioactivity is an intermediate process between the well known a-decay and the spontaneous fission. In earlier years such cluster radioactivity was found mostly in actinide nuclei like radium, uranium etc. Very recently it has been predicted that such decays are possible in a new region around 114Ba. There has been an exciting experimental detection of the emission of 12C from 114Ba leading to 102Sn, which is attracting a lot of attention recently. To study the phenomenon of cluster radioactivity there are various theoretical models in vogue. The existing models generally fall under two categories: the unified fission model (UFM) and the preformed cluster model (PCM). The physics of the UFM and the PCM are completely different. The UFM considers cluster radioactivity simply as a barrier penetration phenomenon in between the fission and the a-decay without worrying about the cluster being or not being preformed in the parent nucleus. In the PCM clusters are assumed to be preborn in a parent nucleus before they could penetrate the potential barrier with a given Q-value. The basic assumption of the UFM is that heavy clusters as well as the a-particle have equal probability of being preformed. In PCM, clusters of different sizes have different probabilities of their being preformed in the parent nucleus. We have developed three fission models during the last decade using the cubic potential for the pre-scission region. The use of these models in the study of cluster radioactivity in both the actinide and barium regions will be discussed in this talk in comparison with the other existing theories.

  9. Comparative measurements of the external radiation exposure in a 137Cs contaminated village in Belarus based on optically stimulated luminescence in NaCl and thermoluminescence in LiF.

    PubMed

    Bernhardsson, Christian; Matskevich, Svetlana; Mattsson, Sören; Rääf, Christopher

    2012-12-01

    Laboratory studies have shown that ordinary household salt (NaCl) exhibits several promising properties for retrospective dosimetry; e.g., a linear dose response and a low detection limit, down to a few mGy or even less. In an attempt to test NaCl as a dosimeter outside the laboratory, the first results from the use of NaCl as a dosimeter under normal environmental conditions are reported here. For this purpose, special dosimeter kits with NaCl and lithium fluoride (LiF) chips were designed. The dosimeter kits were positioned at different locations in a Chernobyl Cs-contaminated village in Belarus during the summers of 2008, 2009, and 2010. The results from the two luminescent detectors were also compared with those of measurements carried out with a handheld 75 cm NaI(Tl) detector and with a 8 dm high pressure ionization chamber. The radiation level in the village was inhomogeneous, and depending on the type of house and countermeasures carried out, the ambient dose rate inside and around the houses varied between 0.05 μSv h and 0.50 μSv h. Based on the different measurements, the annual external effective dose to a hypothetical adult population in the village was estimated as 1-1.5 mSv y. Detector readings from the two luminescent materials correlated relatively strongly to that of the ambient survey NaI(Tl) detector. After three repeated surveys using similar dosimeter kits for prospective dosimetry, the potential use of ordinary household salt as a complement to other techniques for retrospective dose estimations is more evident, and shortcomings of the technique have been identified. PMID:23111521

  10. Comparative measurements of the external radiation exposure in a 137Cs contaminated village in Belarus based on optically stimulated luminescence in NaCl and thermoluminescence in LiF.

    PubMed

    Bernhardsson, Christian; Matskevich, Svetlana; Mattsson, Sören; Rääf, Christopher

    2012-12-01

    Laboratory studies have shown that ordinary household salt (NaCl) exhibits several promising properties for retrospective dosimetry; e.g., a linear dose response and a low detection limit, down to a few mGy or even less. In an attempt to test NaCl as a dosimeter outside the laboratory, the first results from the use of NaCl as a dosimeter under normal environmental conditions are reported here. For this purpose, special dosimeter kits with NaCl and lithium fluoride (LiF) chips were designed. The dosimeter kits were positioned at different locations in a Chernobyl Cs-contaminated village in Belarus during the summers of 2008, 2009, and 2010. The results from the two luminescent detectors were also compared with those of measurements carried out with a handheld 75 cm NaI(Tl) detector and with a 8 dm high pressure ionization chamber. The radiation level in the village was inhomogeneous, and depending on the type of house and countermeasures carried out, the ambient dose rate inside and around the houses varied between 0.05 μSv h and 0.50 μSv h. Based on the different measurements, the annual external effective dose to a hypothetical adult population in the village was estimated as 1-1.5 mSv y. Detector readings from the two luminescent materials correlated relatively strongly to that of the ambient survey NaI(Tl) detector. After three repeated surveys using similar dosimeter kits for prospective dosimetry, the potential use of ordinary household salt as a complement to other techniques for retrospective dose estimations is more evident, and shortcomings of the technique have been identified.

  11. Effect of NaCl Salts on the Activation Energy of Excited-State Proton Transfer Reaction of Coumarin 183.

    PubMed

    Joung, Joonyoung F; Kim, Sangin; Park, Sungnam

    2015-12-17

    Coumarin 183 (C183) was used as a photoacid to study excited-state proton transfer (ESPT) reactions. Here, we studied the effect of ions on the ESPT of C183 in aqueous NaCl solutions using a steady-state fluorescence spectroscopy and time-correlated single photon counting (TCSPC) method. The acid dissociation equilibrium of excited-state C183 and the activation energy for the ESPT of C183 were determined as a function of NaCl concentration. The change in the equilibrium constant was found to be correlated with the solvation energy of deprotonated C183. Frequency-resolved TCSPC signals measured at several temperatures were analyzed by using a global fitting analysis method which enabled us to extract all the rate constants involving the ESPT reaction and the spectra of individual species. The activation energy for the ESPT reaction of C183 was highly dependent on NaCl concentration. Quantum chemical calculations were used to calculate the local hydrogen-bond (H-bond) configurations around C183 in aqueous NaCl solutions. It was found that the activation energy for the ESPT was determined by the local H-bond configurations around C183 which were significantly influenced by the dissolved ions.

  12. Ecotoxicological evaluation of three deicers (NaCl, NaFo, CMA)-effect on terrestrial organisms.

    PubMed

    Robidoux, P Y; Delisle, C E

    2001-02-01

    The use of chemical deicers such as sodium chloride (NaCl) has increased significantly during the past three decades. Deicers induce metal corrosion and alter the physicochemical properties of soils and water. Environmental damage caused by the use of NaCl has prompted government agencies to find alternative deicers. This article presents a comparative ecotoxicological study of three deicers on soil organisms. Sodium formiate (NaFo) and calcium-magnesium acetate (CMA) are the most interesting commercially available deicers based upon their characteristics and potential toxicity. Organisms used in this study were four species of macrophytes (cress (Lepidium sativum), barley (Ordeum vulgare), red fescue grass (Festuca rubra), Kentucky bluegrass (Poa pratensis)) and an invertebrate (Eisenia fetida). Using standardized and modified methods, the relative toxicity of deicers was CMA < NaFo congruent with NaCl. The results demonstrate that these chemicals could have similar impacts in terrestrial environments since similar quantities of NaFo and greater amounts of CMA are necessary to achieve the same efficiency as NaCl. The toxicity of the tested substances was lower in natural composted soil than in artificial substrate (silica or OECD soil), indicating decreased environmental bioavailability. The response of the organisms changed according to endpoint, species, and soil characteristics (artificial substrate as compared to natural organic soil). The most sensitive endpoint measured was macrophyte growth with Kentucky bluegrass being the most sensitive species.

  13. Use of halophytic plants for recycling NaCl in human liquid waste in a bioregenerative life support system

    NASA Astrophysics Data System (ADS)

    Balnokin, Yurii; Nikolai, Myasoedov; Larisa, Popova; Alexander, Tikhomirov; Sofya, Ushakova; Christophe, Lasseur; Jean-Bernard, Gros

    2010-09-01

    The purpose of this work was to develop technology for recycling NaCl containing in human liquid waste as intrasystem matter in a bioregenerative life support system (BLSS). The circulation of Na + and Cl - excreted in urine is achieved by inclusion of halophytes, i.e. plants that naturally inhabit salt-rich soils and accumulate NaCl in their organs. A model of Na + and Cl - recycling in a BLSS was designed, based on the NaCl turnover in the human-urine-nutrient solution-halophytic plant-human cycle. The study consisted of (i) selecting a halophyte suitable for inclusion in a BLSS, and (ii) determining growth conditions supporting maximal Na + and Cl - accumulation in the shoots of the halophyte growing in a nutrient solution simulating mineralized urine. For the selected halophytic plant, Salicornia europaea, growth rate under optimal conditions, biomass production and quantities of Na + and Cl - absorbed were determined. Characteristics of a plant production conveyor consisting of S.europaea at various ages, and allowing continuity of Na + and Cl - turnover, were estimated. It was shown that closure of the NaCl cycle in a BLSS can be attained if the daily ration of fresh Salicornia biomass for a BLSS inhabitant is approximately 360 g.

  14. Effects of NaCl and sultopride on striatal [(3)H]spiperone binding in neonatal, adult and senescent rats.

    PubMed

    Makihata, J; Nomura, Y

    1984-01-01

    Effects of NaCl, (+)-and (-)-sultopride on striatal [(3)H]spiperone binding was investigated in 7-day, 70-day and 2-year-old rats. The amount of specific [(3)H]spiperone binding was the highest at 70 days and the value at adult stage was significantly (P < 0.001) higher than those at 7 days and 2 years. NaCl (100 mM) significantly increased [(3)H]spiperone binding in neonatal (P < 0.01), adult (P < 0.05) and senescent (P < 0.05) animals. Scatchard analysis showed that the Bmax of low-affinity [(3)H]spiperone binding was significantly elevated by 100 mM NaCl compared to the value in control of adult animals. More potent inhibition of (-)-sultopride for [(3)H]spiperone binding than that of the (+)-enantiomer at adult stage was also observed at neonatal and senescent stages. NaCl (100 mM) significantly enhanced inhibitory activities of (+)- and (-)-sultopride at every stage. It is suggested that stabilizing effect of Na(+) on dopamine (DA) receptor complexes and increasing effect of Na(+) on binding affinity of benzamide to DA2 receptors keep functions through development and aging.

  15. Direct Coexistence Methods to Determine the Solubility of Salts in Water from Numerical Simulations. Test Case NaCl.

    PubMed

    Manzanilla-Granados, Héctor M; Saint-Martín, Humberto; Fuentes-Azcatl, Raúl; Alejandre, José

    2015-07-01

    The solubility of NaCl, an equilibrium between a saturated solution of ions and a solid with a crystalline structure, was obtained from molecular dynamics simulations using the SPC/E and TIP4P-Ew water models. Four initial setups on supersaturated systems were tested on sodium chloride (NaCl) solutions to determine the equilibrium conditions and computational performance: (1) an ionic solution confined between two crystal plates of periodic NaCl, (2) a solution with all the ions initially distributed randomly, (3) a nanocrystal immersed in pure water, and (4) a nanocrystal immersed in an ionic solution. In some cases, the equilibration of the system can take several microseconds. The results from this work showed that the solubility of NaCl was the same, within simulation error, for the four setups, and in agreement with previously reported values from simulations with the setup (1). The system of a nanocrystal immersed in supersaturated solution was found to equilibrate faster than others. In agreement with laser-Doppler droplet measurements, at equilibrium with the solution the crystals in all the setups had a slight positive charge.

  16. The effects of arginine glutamate, a promising excipient for protein formulation, on cell viability: Comparisons with NaCl

    PubMed Central

    Kheddo, Priscilla; Golovanov, Alexander P.; Mellody, Kieran T.; Uddin, Shahid; van der Walle, Christopher F.; Dearman, Rebecca J.

    2016-01-01

    The effects of an equimolar mixture of l-arginine and l-glutamate (Arg·Glu) on cell viability and cellular stress using in vitro cell culture systems are examined with reference to NaCl, in the context of monoclonal antibody formulation. Cells relevant to subcutaneous administration were selected: the human monocyte cell line THP-1, grown as a single cell suspension, and adherent human primary fibroblasts. For THP-1 cells, the mechanism of cell death caused by relatively high salt concentrations was investigated and effects on cell activation/stress assessed as a function of changes in membrane marker and cytokine (interleukin-8) expression. These studies demonstrated that Arg·Glu does not have any further detrimental effects on THP-1 viability in comparison to NaCl at equivalent osmolalities, and that both salts at higher concentrations cause cell death by apoptosis; there was no significant effect on measures of THP-1 cellular stress/activation. For adherent fibroblasts, both salts caused significant toxicity at ~ 400 mOsm/kg, although Arg·Glu caused a more precipitous subsequent decline in viability than did NaCl. These data indicate that Arg·Glu is of equivalent toxicity to NaCl and that the mechanism of toxicity is such that cell death is unlikely to trigger inflammation upon subcutaneous injection in vivo. PMID:26873863

  17. The effects of arginine glutamate, a promising excipient for protein formulation, on cell viability: Comparisons with NaCl.

    PubMed

    Kheddo, Priscilla; Golovanov, Alexander P; Mellody, Kieran T; Uddin, Shahid; van der Walle, Christopher F; Dearman, Rebecca J

    2016-06-01

    The effects of an equimolar mixture of l-arginine and l-glutamate (Arg·Glu) on cell viability and cellular stress using in vitro cell culture systems are examined with reference to NaCl, in the context of monoclonal antibody formulation. Cells relevant to subcutaneous administration were selected: the human monocyte cell line THP-1, grown as a single cell suspension, and adherent human primary fibroblasts. For THP-1 cells, the mechanism of cell death caused by relatively high salt concentrations was investigated and effects on cell activation/stress assessed as a function of changes in membrane marker and cytokine (interleukin-8) expression. These studies demonstrated that Arg·Glu does not have any further detrimental effects on THP-1 viability in comparison to NaCl at equivalent osmolalities, and that both salts at higher concentrations cause cell death by apoptosis; there was no significant effect on measures of THP-1 cellular stress/activation. For adherent fibroblasts, both salts caused significant toxicity at ~400 mOsm/kg, although Arg·Glu caused a more precipitous subsequent decline in viability than did NaCl. These data indicate that Arg·Glu is of equivalent toxicity to NaCl and that the mechanism of toxicity is such that cell death is unlikely to trigger inflammation upon subcutaneous injection in vivo. PMID:26873863

  18. Synthesis and characterization of AgCl nanoparticles produced by laser ablation of Ag in NaCl solution

    NASA Astrophysics Data System (ADS)

    Mahmoodi, Afsaneh; Shoorshinie, Seyedeh Zahra; Dorranian, Davoud

    2016-04-01

    In this work, the structural and optical properties of silver chloride nanoparticles produced by laser ablation of Ag plate in NaCl solution were investigated. Five different concentrations of NaCl solution were used as the ablation environment. The beam of a Q-switched Nd:YAG laser of 1064 nm wavelength and 7 ns pulse width was employed to irradiate the Ag target in NaCl solutions. Fluence of laser pulse was 1.5 J/cm2, and repetition rate was 5 Hz. Samples were prepared using 1500 pulses. Produced nanoparticles were characterized using UV-visible-NIR absorption, and transmission spectrum, transmission electron microscopy, scanning electron microscopy, X-ray diffraction pattern, photoluminescence spectrum, and dynamic light scattering method. Results show that laser ablation is a promising method to produce AgCl nanoparticles. Size of nanoparticles, their lattice structure, and bandgap energy as well as the production rate may be controlled by the concentration of NaCl in the ablation environment.

  19. Densities of L-Glutamic Acid HCl Drug in Aqueous NaCl and KCl Solutions at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Ryshetti, Suresh; Raghuram, Noothi; Rani, Emmadi Jayanthi; Tangeda, Savitha Jyostna

    2016-04-01

    Densities (ρ ) of (0.01 to 0.07) {mol}{\\cdot } {kg}^{-1} L-Glutamic acid HCl (L-HCl) drug in water, and in aqueous NaCl and KCl (0.5 and 1.0) {mol}{\\cdot } {kg}^{-1} solutions have been reported as a function of temperature at T = (298.15, 303.15, 308.15, and 313.15) K and atmospheric pressure. The accurate density (ρ ) values are used to estimate the various parameters such as the apparent molar volume (V_{2,{\\upphi }}), the partial molar volume (V2^{∞}), the isobaric thermal expansion coefficient (α 2), the partial molar expansion (E2^{∞}), and Hepler's constant (partial 2V2^{∞}/partial T2)P. The Cosphere overlap model is used to understand the solute-solvent interactions in a ternary mixture (L-HCl drug + NaCl or KCl + water). Hepler's constant (partial 2V2^{∞}/partial T2)_P is utilized to interpret the structure-making or -breaking ability of L-HCl drug in aqueous NaCl and KCl solutions, and the results are inferred that L-HCl drug acts as a structure maker, i.e., kosmotrope in aqueous NaCl solutions and performs as a structure breaker, i.e., chaotrope in aqueous KCl solutions.

  20. Hydrogen and oxygen isotope fractionation between brucite and aqueous NaCl solutions from 250 to 450°C

    USGS Publications Warehouse

    Saccocia, Peter J.; Seewald, Jeffrey S.; Shanks, Wayne C.

    1998-01-01

    Hydrogen and oxygen isotope fractionation factors between brucite and aqueous NaCl solutions (1000lnαbr-sw) have been calibrated by experiment from 250 to 450°C at 0.5 Kb. For D/H fractionation, 1000lnα br-sw values are as follows: −32 ± 6‰ (250°C, 3.2 wt% NaCl), −21 ± 2‰ (350°C, 10.0 wt% NaCl), and −22 ± 2‰ (450°C, 3.2 wt% NaCl), indicating that brucite is depleted in D relative to coexisting aqueous NaCl solutions. These results are in good agreement with previous D/H fractionation factors determined in the brucite-water system, indicating that any effects of dissolved salt on D/H fractionation are relatively small, particularly in solutions with near seawater salinity. The maximum salt effect (+4‰) was observed in 10.0 wt% NaCl solutions at 350°C, suggesting that the addition of dissolved NaCl increases the amount of deuterium fractionated into mineral structures. For 18O/16O fractionation, 1000lnαbr-sw values in 3.0 wt% NaCl solutions are −6.0 ± 1.3‰, −5.6 ± 0.7‰ and −4.1 ± 0.2‰, at 250, 350, and 450°C, respectively, and −5.8 ± 0.6‰ in 10.0 wt % NaCl at 350°C. These data indicate that brucite is depleted in 18O relative to coexisting aqueous NaCl solutions and that the degree of depletion decreases slightly with increasing temperature and is not strongly dependent on salinity. We calculated 18O/16O brucite-water fractionation factors from available calibrations of the salt-effect on 18O/16O fractionation between coexisting phases. The resulting values were fit to the following equation that is valid from 250 to 450°C 1000ln αbr-w = 9.54 × 106T−2 − 3.53 × 104T−1 + 26.58 where T is temperature in Kelvins. These new data have been used to improve the prediction of 18O/16O fractionation factors in the talc-water and serpentine-water systems by modifying existing empirical bond-water models. The results of this analysis indicate that the δ18O composition of talc-brucite and serpentine

  1. Tracing groundwater salinization processes in coastal aquifers: a hydrogeochemical and isotopic approach in Na-Cl brackish waters of north-western Sardinia, Italy

    NASA Astrophysics Data System (ADS)

    Mongelli, G.; Monni, S.; Oggiano, G.; Paternoster, M.; Sinisi, R.

    2013-01-01

    In the Mediterranean area the demand of good quality water is often threatened by salinization, especially in coastal areas. The salinization is the result of concomitant processes due to both marine water intrusion and rock-water interaction, which in some cases are hardly distinguishable. In northwestern Sardinia, in the Nurra area, salinization due to marine water intrusion has been recently evidenced as consequence of bore hole exploitation. However, the geology of the Nurra records a long history from Paleozoic to Quaternary, resulting in relative structural complexity and in a wide variety of lithologies, including Triassic evaporites. To elucidate the origin of the saline component in the Nurra aquifer, may furnish a useful and more general model for the salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activities and recent climatic changes, the Nurra has become vulnerable to desertification and, similarly to other Mediterranean islands, surface-water resources can periodically suffer from drastic shortage. With this in mind we report new data, regarding brackish waters of Na-Cl type of the Nurra, including major ions and selected trace elements (B, Br, I and Sr) and isotopic data, including δ18O, δD in water, and δ34S and δ18O in dissolved sulphate. To better depict the origin of the salinity we also analyzed a set of Nurra Triassic evaporites for mineralogical and isotopic composition. The brackish waters have Cl contents up to 2025 mg L-1 and the ratios between dissolved ions and chlorine, with the exception of the Br/Cl ratio, are not those expected on the basis of a simple mixing between rain water and seawater. The δ18O and δD data indicate that most of the waters are within the Regional Meteoric Water Line and the Global Meteoric Water Line supporting the idea that they are meteoric in origin. A relevant consequence of the

  2. SAXS investigation of a cubic to a sponge (L3) phase transition in self-assembled lipid nanocarriers.

    PubMed

    Angelov, Borislav; Angelova, Angelina; Mutafchieva, Rada; Lesieur, Sylviane; Vainio, Ulla; Garamus, Vasil M; Jensen, Grethe V; Pedersen, Jan Skov

    2011-02-28

    The encapsulation and release of peptides, proteins, nucleic acids, and drugs in nanostructured lipid carriers depend on the type of the self-assembled liquid-crystalline organization and the structural dimensions of the aqueous and membraneous compartments, which can be tuned by the multicomponent composition of the systems. In this work, small-angle X-ray scattering (SAXS) investigation is performed on the 'melting' transition of the bicontinuous double diamond cubic phase, formed by pure glycerol monooleate (MO), upon progressive inclusion of varying fractions of pharmaceutical-grade glycerol monooleate (GO) in the hydrated system. The self-assembled MO/GO mixtures are found to form diamond (Pn3m) inverted cubic, inverted hexagonal (H(II)), and sponge (L(3)) phases at ambient temperature in excess of aqueous medium without heat treatment. Mixing of the inverted-cubic-phase-forming MO and the sponge-phase-forming GO components, in equivalent proportions (50/50 w/w), yields an inverted hexagonal (H(II)) phase nanostructured carrier. Scattering models are applied for fitting of the experimental SAXS patterns and identification of the structural changes in the aqueous and lipid bilayer subcompartments. The possibility of transforming, at ambient temperature (20 °C), the bicontinuous cubic nanostructures into inverted hexagonal (H(II)) or sponge (L(3)) mesophases may facilitate novel biomedical applications of the investigated liquid crystalline self-assemblies. PMID:21079857

  3. 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.

  4. 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

  5. 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.

  6. Cubic titanium dioxide photoanode for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Chae, Jinho; Kang, Misook

    Following from the recently evolved concept of significantly improving the photovoltaic efficiency in dye-sensitized solar cells (DSSCs) by reducing the loss of electrons on the spherical surface of titanium dioxide, this study examines the synthesis of cubic TiO 2 with a special morphology to overcome this electron loss and investigates its application to DSSCs. Cubic TiO 2 is synthesized by an advanced rapid hydrothermal method, with the addition of an amine species additive. Transmission electron microscopy (TEM) images confirm the cubic shape of the TiO 2 particles with a diameter less than 5-10 nm. Using N719 dye under illumination with 100 mW cm -2 simulated sunlight, the application of cubic TiO 2 to DSSCs affords an energy conversion efficiency of approximately 9.77% (4.0-μm thick TiO 2 film), which is considerably enhanced compared with that achieved using a commercial, spherical TiO 2. Electrostatic force microscopy (EFM) and impedance analyses reveal that the electrons are transferred more rapidly to the surface of a cubic TiO 2 film than on a spherical TiO 2 film.

  7. 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.

  8. 49 CFR 178.33a-2 - Type and size.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Specifications for Inside Containers, and Linings § 178.33a-2 Type and size. (a) Single-trip inside containers... capacity of containers in this class shall not exceed 1 L (61.0 cubic inches). The maximum inside...

  9. 49 CFR 178.33-2 - Type and size.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Specifications for Inside Containers, and Linings § 178.33-2 Type and size. (a) Single-trip inside containers... capacity of containers in this class shall not exceed one liter (61.0 cubic inches). The maximum...

  10. Epithelial restitution and cellular proliferation after gastric mucosal damage caused by hypertonic NaCl in rats.

    PubMed

    Sørbye, H; Svanes, C; Stangeland, L; Kvinnsland, S; Svanes, K

    1988-01-01

    Hypertonic NaCl enhances gastric cancer in rats induced by N-nitroso compounds. This study was designed to examine the structural changes and alterations in mitotic activity occurring after mucosal exposure to hypertonic NaCl. Wistar rats were given one ml of 4.5 M NaCl by gastric tube and groups of 4-5 animals were sacrificed at different time intervals up to 120 h. An i.p. injection of thymidine was given 1 h before death. Samples of antral and corpus mucosa were prepared for microscopy and autoradiography. Hypertonic NaCl caused uniform destruction of surface mucous cells and pits in the corpus and antrum. Epithelial restitution with the formation of a thin epithelial layer occurred within one h of damage. The mucosa changed towards normal within 24-48 h. The distance between mucosal surface and the replicating cells decreased during the first 2 h. The proliferation zone remained in the middle of the glandular layer throughout the experiment. The proliferative activity increased during the first 24 h after mucosal damage. The number of labelled cells per unit area of mucosa was somewhat larger in the corpus than the antrum, but in the corpus the distance between proliferating cells and mucosal surface was double that of the antrum. Hypertonic NaCl causes a series of changes in the gastric mucosa. The increased mitotic activity can only partly explain the cocarcinogenic effect, since N-nitroso-induced adenocarcinomas occur predominantly in the antrum while the mitotic activity is maximal in the corpus.

  11. Influence of NaCl, urea, potassium and pH on HSP72 expression in MDCK cells.

    PubMed

    Neuhofer, W; Müller, E; Grünbein, R; Thurau, K; Beck, F X

    1999-12-01

    The renal inner medulla is characterised by elevated extracellular concentrations of NaCl, urea, potassium and hydrogen ions, an environment that may affect cell viability negatively. High amounts of HSP72, a stress protein allowing cells to resist harmful situations, are also observed in this region. The present study examined HSP72 induction by various medullary stress factors, individually or in combination, in MDCK cells, a renal epithelial cell line expressing characteristics of the medullary collecting duct. MDCK cells were incubated for 3 days in media containing elevated concentrations of NaCl, urea, potassium and hydrogen ions individually or in combination. HSP72 mRNA and protein expression were determined by Northern and Western blot analyses, respectively. HSP72 expression was enhanced moderately by addition of 50 mM NaCl to normal medium at pH 7.4 but enhanced strongly when added at pH 6.5. The latter degree of HSP72 induction was comparable to that observed when 150 mM NaCl was added at pH 7.4. In normal medium (pH 7.4) containing 300 mM urea, MDCK HSP72 expression was not different from controls. In contrast, urea-induced HSP72 expression was clearly evident when medium pH was lowered to 6.5. Potassium at 20 or 40 mM induced HSP72 only slightly. These results indicate that expression of HSP72 in renal epithelial cells is regulated synergistically by NaCl, urea and pH. Since HSP72 is only slightly induced by increased potassium, this probably reflects the changes in medium osmolality rather than a specific effect of potassium. The high medullary HSP72 content observed even in diuresis may be due to co-operative effects of medullary solutes on HSP72 expression.

  12. The effect of sugar, amino acid, metal ion, and NaCl on model Maillard reaction under pH control.

    PubMed

    Kwak, E-J; Lim, S-I

    2004-08-01

    The color intensities was determined of Maillard reaction products (MRPs) prepared by heating each of five sugars (maltose, fructose, glucose, arabinose, and xylose) with each of 12 amino acids (aspartic acid, glutamic acid, alanine, leucine, isoleucine, valine, proline, serine, cysteine, phenylalanine, arginine, and lysine). The remaining percentages of glucose and rate of change of color intensity due to the addition of a metal ion and NaCl were monitored for nine MRPs that had been formed between glucose and each of nine amino acids (aspartic acid, glutamic acid, alanine, valine, serine, cysteine, phenylalanine, arginine, and lysine). Model MRPs were prepared in a block heater at 100 degrees C for 1-12 h with the pH value controlled at 6.5. The resulting color intensity of each MRPs formed from the basic amino acids was greater due to the higher reactivity than those from the acidic amino acids. The remaining percentage of glucose in each MRPs from the basic amino acids was lower than those from the acidic amino acids. The MRPs from the nonpolar amino acids showed an intermediate color intensity and remaining percentages of glucose between those formed from the basic and acidic amino acids. Browning tended to be accelerated in the presence of metal ions, especially Fe2+ and Cu2+, although it was affected by the property of the amino acid and heating time as well as by the type of metal ion. On the other hand, browning was greatly inhibited by a high concentration of NaCl.

  13. Effects of NaCl concentration and potassium chloride substitutions on the thermal properties and lipid oxidation of dry-cured pork.

    PubMed

    Zhang, Yingyang; Feng, Xianchao; Wu, Haizhou; Tang, Jing; Zhang, Jianhao

    2014-09-01

    The thermal properties of cured meat are important for determining storage life and nutritional quality. However, few studies have focused on the thermal properties of dry-cured pork, particularly in relation to salt level and type. In order to study the thermal properties of dry-cured pork, we used differential scanning calorimetry (DSC) to evaluate the net heat energy (enthalpy, ΔH), onset (T(onset)), and maximum (T(max)) temperatures of different pork cuts salted with mixtures of chloride (NaCl and KCl) salts within the curing and ripening temperature range. Within the curing temperature range (-5 to 20 °C), the T(onset), T(max), and ΔH of cured meat treated with different NaCl : KCl mixtures were generally lower than for fresh meat, which indicates that the addition of NaCl or KCl can reduce the melting of lipids and water (especially lipids), in different pork cuts. Within the ripening temperature range (5 to 50 °C), heat absorption peaks in belly and leg cuts were between 29 and 33 °C. However, no obvious heat absorption peak was found in loin cuts. Compared to non-KCl substitutions, a slightly higher KCl substitution could significantly (P < 0.05) enhance ΔH values of dry-cured belly and leg cuts. The likely cause of this phenomenon is that high KCl substitutions promote lipid oxidation (r = 0.98, for belly; r = 0.95, for leg cuts). Therefore, KCl substitution should be no more than 30% (wt/wt), especially for high lipid pork, to prevent excessive melting and oxidation of lipids during the dry-curing process.

  14. Desalination feasibility study of an industrial NaCl stream by bipolar membrane electrodialysis.

    PubMed

    Ghyselbrecht, Karel; Silva, Ana; Van der Bruggen, Bart; Boussu, Katleen; Meesschaert, Boudewijn; Pinoy, Luc

    2014-07-01

    The industrial implementation of alternative technologies in the processing of saline effluent streams is a topic of growing importance. In this technical feasibility study, the desalination of an industrial saline stream containing about 75 g L(-1) NaCl contaminated with some organic matter using bipolar membrane electrodialysis (EDBM) was investigated on lab-scale. Bipolar membranes of two different manufacturers (PCA - PolymerChemie Altmeier GmbH and FuMA-Tech GmbH) were tested and compared in terms of electrical resistance, current efficiency and purity of the produced acid and base stream. In both cases, almost complete desalination (>99%) was achieved and simultaneously HCl and NaOH were produced with a concentration between 1.5 and 2 M with a relatively good purity. The Fumasep bipolar membranes scored slightly better for electrical resistance and current efficiency. On the other hand, slightly higher current densities were achieved with PCA bipolar membranes. Simultaneously, some information was obtained on the transport behavior of the organic matter present in the saline stream. It was observed that a transport competition occurred between the organic matter and the accompanying chlorides. From this lab-scale study it was concluded that EDBM is a promising and attractive technology in the area of saline effluent reclamation and reuse. PMID:24726967

  15. Stress corrosion cracking of stainless steels in NaCl solutions

    NASA Astrophysics Data System (ADS)

    Speidel, Markus O.

    1981-05-01

    The metallurgical influences on the stress corrosion resistance of many commercial stainless steels have been studied using the fracture mechanics approach. The straight-chromium ferritic stainless steels, two-phase ferritic-austenitic stainless steels and high-nickel solid solutions (like alloys 800 and 600) investigated are all fully resistant to stress corrosion cracking at stress intensity (K1) levels ≤ MN • m-3/2 in 22 pct NaCl solutions at 105 °C. Martensitic stainless steels, austenitic stainless steels and precipitation hardened superalloys, all with about 18 pct chromium, may be highly susceptible to stress corrosion cracking, depending on heat treatment and other alloying elements. Molybdenum additions improve the stress corrosion cracking resistance of austenitic stainless steels significantly. The fracture mechanics approach to stress corrosion testing of stainless steels yields results which are consistent with both the service experience and the results from testing with smooth specimens. In particular, the well known “Copson curve” is reproduced by plotting the stress corrosion threshold stress intensity (ATISCC) vs the nickel content of stainless steels with about 18 pct chromium.

  16. [NaCl 0.9 % for volume substitution : blessing or curse?].

    PubMed

    Kümpers, P

    2015-07-01

    The nonphysiological high chloride content of 0.9 % saline causes hyperchloremic acidosis and rapidly reduces renal perfusion in healthy volunteers-negative affects not seen with balanced crystalloids with low chloride content. Evidence from recently published studies strongly suggests that 0.9 % saline negatively effects outcome in surgical and critically ill patients. Major complications are the increased incidence of acute kidney injury and need for renal replacement therapy, as well as higher postoperative in-hospital mortality. Although implemented as the gold standard in many clinical guidelines, there are currently no data supporting the use of 0.9 % saline instead of modern balanced crystalloids. This is also and even particularly true for patients with hypokalemia and acute or chronic kidney injury. In-house training is an effective tool for sustainably raising the awareness of this issue among nursing and medical staff, and identifying alternative strategies to the use of NaCl 0.9 % in clinical practice.

  17. Fragile to strong crossover at the Widom line in supercooled aqueous solutions of NaCl

    SciTech Connect

    Gallo, P.; Corradini, D.; Rovere, M.

    2013-11-28

    We study by molecular dynamics simulations the dynamical properties of an aqueous solution of NaCl at a concentration of 0.67 mol/kg upon supercooling. In a previous study of the same ionic solution, we have located the liquid-liquid critical point (LLCP) and determined the Widom line connected to the liquid-liquid transition. We present here the results obtained from the study of the self-intermediate scattering function in a large range of temperatures and densities approaching the LLCP. The structural relaxation is in agreement with the mode coupling theory (MCT) in the region of mild supercooling. In the deeper supercooled region the α-relaxation time as function of temperature deviates from the MCT power law prediction showing a crossover from a fragile to a strong behavior. This crossover is found upon crossing the Widom line. The same trend was found in bulk water upon supercooling and it appears almost unchanged by the interaction with ions apart from a shift in the thermodynamic plane toward lower pressures and higher temperatures. These results show that the phenomenology of supercooled water transfers from bulk to solution where the study of the supercooled region is experimentally less difficult.

  18. Thermodynamic modeling of neptunium(V)-acetate complexation in concentrated NaCl media

    SciTech Connect

    Novak, C.F.; Borkowski, M.; Choppin, G.R.

    1995-09-01

    The complexation of neptunium(V), Np(V), with the acetate anion, Ac{sup -}, was measured in sodium chloride media to high concentration using an extraction technique. The data were interpreted using the thermodynamic formalism of Pitzer, which is valid to high electrolyte concentrations. A consistent model for the deprotonation constants of acetic acid in NaCl and NaClO{sub 4} media was developed. For the concentrations of acetate expected in a waste repository, only the neutral complex NpO{sub 2}Ac(aq) was important in describing the interactions between the neptunyl ion and acetate. The thermodynamic stability constant log {beta}{sup 0}{sub 101} for the reaction NpO{sub 2}{sup +} + Ac{sup -} {leftrightarrow} NpO{sub 2}Ac was calculated to be 1.46{plus_minus}0.11. This weak complexing behavior between the neptunyl ion and acetate indicates that acetate will not significantly enhance dissolved Np(V) concentrations in ground waters associated with nuclear waste repositories that may contain acetate.

  19. Contributions of cellular leak pathways to net NaHCO3 and NaCl absorption.

    PubMed Central

    Preisig, P A; Alpern, R J

    1989-01-01

    Proton and formic acid permeabilities were measured in the in vivo microperfused rat proximal convoluted tubule by examining the effect on intracellular pH when [H] and/or [formic acid] were rapidly changed in the luminal or peritubular fluids. Apical and basolateral membrane H permeabilities were 0.52 +/- 0.07 and 0.67 +/- 0.18 cm/s, respectively. Using these permeabilities we calculate that proton backleak from the luminal fluid to cell does not contribute significantly to net proton secretion in the early proximal tubule, but may contribute in the late proximal tubule. Apical and basolateral membrane formic acid permeabilities measured at extracellular pH 6.62 were 4.6 +/- 0.5 X 10(-2) and 6.8 +/- 1.5 X 10(-2) cm/s, respectively. Control studies demonstrated that the formic acid permeabilities were not underestimated by either the simultaneous movement of formate into the cell or the efflux of formic acid across the opposite membrane. The measured apical membrane formic acid permeability is too small to support all of transcellular NaCl absorption in the rat by a mechanism that involves Na/H-Cl/formate transporters operating in parallel with formic acid nonionic diffusion. PMID:2542374

  20. Corrosion inhibition properties of graphene oxide on mild steel in 3.5% NaCl

    NASA Astrophysics Data System (ADS)

    Anandh Senthilvasan, Prem; Rangarajan, Murali

    2016-09-01

    In this work the corrosion inhibition of mild steel in 3.5% Sodium chloride (NaCl) solution at ambient conditions by Graphene Oxide (GO) has been studied. Graphene oxide was prepared by Modified Hummers Method and characterized by Fourier Transform Infrared spectroscopy (FTIR), UV-Visible spectroscopy (UV-Vis), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Thermo-Gravimetric Analysis (TGA). The electrochemical corrosion behaviour of mild steel has been studied in the absence and presence of GO coatings by Tafel polarization and impedance analyses. The modified electrode has 44.8mV potential shift in the cathodic direction and reduction in current by 41.9 μA (61%). This indicates the strong protection offered by graphene oxide film. The obtained impedance spectra also clearly show that the charge transfer resistance of graphene oxide film is much higher than that of the uncoated steel electrode, demonstrating the strong protection offered by graphene oxide films for mild steel.

  1. Hygroscopic Behavior of Multicomponent Aerosols Involving NaCl and Dicarboxylic Acids.

    PubMed

    Peng, Chao; Jing, Bo; Guo, Yu-Cong; Zhang, Yun-Hong; Ge, Mao-Fa

    2016-02-25

    Atmospheric aerosols are usually complex mixtures of inorganic and organic compounds. The hygroscopicity of mixed particles is closely related to their chemical composition and interactions between components, which is still poorly understood. In this study, the hygroscopic properties of submicron particles composed of NaCl and dicarboxylic acids including oxalic acid (OA), malonic acid (MA), and succinic acid (SA) with various mass ratios are investigated with a hygroscopicity tandem differential mobility analyzer (HTDMA) system. Both the Zdanovskii-Stokes-Robinson (ZSR) method and extended aerosol inorganics model (E-AIM) are applied to predict the water uptake behaviors of sodium chloride/dicarboxylic acid mixtures. For NaCl/OA mixed particles, the measured growth factors were significantly lower than predictions from the model methods, indicating a change in particle composition caused by chloride depletion. The hygroscopic growth of NaCl/MA particles was well described by E-AIM, and that of NaCl/SA particles was dependent upon mixing ratio. Compared with model predictions, it was determined that water uptake of the NaCl/OA mixture could be enhanced and could be closer to the predictions by addition of levoglucosan or malonic acid, which retained water even at low relative humidity (RH), leading to inhibition of HCl evaporation during dehydration. These results demonstrate that the coexisting hygroscopic species have a strong influence on the phase state of particles, thus affecting chemical interactions between inorganic and organic compounds as well as the overall hygroscopicity of mixed particles. PMID:26820230

  2. NaCl crystallization in apolar nanometer-sized confinement studied by atomistic simulations.

    PubMed

    Kalcher, Immanuel; Dzubiella, Joachim

    2013-12-01

    The structure and growth of molecular NaCl crystals in bulk and in a narrow, nanometer-sized apolar confinement are examined by explicit-water molecular dynamics computer simulations. It is demonstrated that fast crystallization and subsequent diffusion-controlled cluster growth in bulk is triggered by supersaturations that exceed a certain threshold value. In confinement, simulated in a pseudo grand canonical setup, salt is shown to be expelled from the narrow apolar slab region, and the effective ion concentration inside the nanoconfinement is always considerably lower than the reservoir salt concentration so that no fast crystallization takes place. For very small slab widths (d<1.5 nm) salt is almost entirely expelled while water remains in the slab, indicating a capillary evaporation phenomenon for the polar ions. If forced into the apolar confinement by simulating in a strictly canonical setup, we find stable crystals only if at least three crystalline planes fit into the slab, which happens above a 2-nm slab width. In this case the (100) plane of the bulk crystal is oriented parallel to the apolar surface delimited by a subnanometer thin hydration layer. This work presents molecular-level insight of salt crystallization in apolar confinements of a nanometer scale with possible implications in double-layer supercapacitor physics and geological salt weathering. PMID:24483449

  3. Recognising terrestrially-derived salt (NaCl) in SE Australian dust

    NASA Astrophysics Data System (ADS)

    Shiga, Y.; Greene, R. S. B.; Scott, K. M.; Stelcer, E.

    2011-03-01

    The terrestrial and oceanic salt (NaCl) components in 39 dust samples from eight sites across south eastern Australia have been calculated from chemical data derived by ion beam analysis (IBA). For samples identified as having a positive terrestrial salt ratio (TSR; i.e., the abundance of terrestrial salt relative to total salt expressed as a percentage), back trajectory analysis (estimation of the path of the wind affecting the site) was used to verify the likelihood of a terrestrial source for such salt. This procedure indicated that the terrestrial salt input to south eastern Australia is non-negligible compared to that of sea salt and the most likely sources of the terrestrial salt deposited in such area are the inland saline regions of the Lake Eyre and Murray Darling Basins. Terrestrial salt ratio values readily screen out the majority of samples for which a terrestrial salt component is unlikely. Thus, calculating the ratios to identify samples which are potentially influenced by terrestrial salt (e.g., prior to conducting a back trajectory analysis on such samples) appears to be useful, especially since such determinations can be done with small sample sets for which statistical analysis is not appropriate.

  4. Ovarian hormones and prolactin increase renal NaCl cotransporter phosphorylation.

    PubMed

    Rojas-Vega, Lorena; Reyes-Castro, Luis A; Ramírez, Victoria; Bautista-Pérez, Rocío; Rafael, Chloe; Castañeda-Bueno, María; Meade, Patricia; de Los Heros, Paola; Arroyo-Garza, Isidora; Bernard, Valérie; Binart, Nadine; Bobadilla, Norma A; Hadchouel, Juliette; Zambrano, Elena; Gamba, Gerardo

    2015-04-15

    Unique situations in female physiology require volume retention. Accordingly, a dimorphic regulation of the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC) has been reported, with a higher activity in females than in males. However, little is known about the hormones and mechanisms involved. Here, we present evidence that estrogens, progesterone, and prolactin stimulate NCC expression and phosphorylation. The sex difference in NCC abundance, however, is species dependent. In rats, NCC phosphorylation is higher in females than in males, while in mice both NCC expression and phosphorylation is higher in females, and this is associated with increased expression and phosphorylation of full-length STE-20 proline-alanine-rich kinase (SPAK). Higher expression/phosphorylation of NCC was corroborated in humans by urinary exosome analysis. Ovariectomy in rats resulted in decreased expression and phosphorylation of the cotransporter and promoted the shift of SPAK isoforms toward the short inhibitory variant SPAK2. Conversely, estradiol or progesterone administration to ovariectomized rats restored NCC phosphorylation levels and shifted SPAK expression and phosphorylation towards the full-length isoform. Estradiol administration to male rats induced a significant increase in NCC phosphorylation. NCC is also modulated by prolactin. Administration of this peptide hormone to male rats induced increased phosphorylation of NCC, an effect that was observed even using the ex vivo kidney perfusion strategy. Our results indicate that estradiol, progesterone, and prolactin, the hormones that are involved in sexual cycle, pregnancy and lactation, upregulate the activity of NCC.

  5. Interleukin 18 function requires both interleukin 18 receptor and Na-Cl co-transporter

    PubMed Central

    Wang, Jing; Sun, Chongxiu; Gerdes, Norbert; Liu, Conglin; Liao, Mengyang; Liu, Jian; Shi, Michael A.; He, Aina; Zhou, Yi; Sukhova, Galina K.; Chen, Huimei; Cheng, Xianwu; Kuzuya, Masafumi; Murohara, Toyoaki; Zhang, Jie; Cheng, Xiang; Jiang, Mengmeng; Shull, Gary E.; Rogers, Shaunessy; Yang, Chao-Ling; Ke, Qiang; Jelen, Sabina; Bindels, René; Ellison, David H.; Jarolim, Petr; Libby, Peter; Shi, Guo-Ping

    2015-01-01

    Interleukin-18 (IL18) participates in atherogenesis through several putative mechanisms1,2. Interruption of IL18 action reduces atherosclerosis in mice3,4. This study shows that the absence of IL18 receptor (IL18r) does not affect atherosclerosis in apolipoprotein E-deficient (Apoe−/−) mice, nor does it affect IL18 cell surface binding or signaling. IL18 antibody-mediated immunoprecipitation identified an interaction between IL18 and Na-Cl co-transporter (NCC), a 12-transmembrane-domain ion transporter protein preferentially expressed in the kidney5. Yet, we find NCC expression and colocalization with IL18r in atherosclerotic lesions and both molecules form a complex. IL18 also binds to the cell surface and induces cell signaling and down-stream cytokine expression in NCC-transfected COS-7 cells that do not express IL18r. In Apoe−/− mice, combined deficiency of IL18r and NCC, but not single deficiency, protects mice from atherosclerosis. Peritoneal macrophages from Apoe−/− mice or those lacking IL18r or NCC respond to IL18 binding or IL18 induction of cell signaling and cytokine and chemokine production, but those with combined deficiency of IL18r and NCC do not. This study identifies NCC as an IL18-binding protein that coordinates with IL18r in cell signaling, inflammatory molecule expression, and experimental atherogenesis. PMID:26099046

  6. The effects of temperature and NaCl concentration on tetragonal lysozyme face growth rates

    NASA Technical Reports Server (NTRS)

    Forsythe, Elizabeth; Pusey, Marc Lee

    1994-01-01

    Measurements were made of the (110) and (101) face growth rates of the tetragonal form of hen egg white lysozyme at 0.1M sodium acetate buffer, pH 4.0, from 4 to 22 C and with 3.0%, 5.0%, and 7.0% NaCl used as the precipitating salt. The data were collected at supersaturation ratios ranging from approximately 4 to approximately 63. Both decreasing temperature and increasing salt concentrations shifted plots of the growth rate versus C/C(sat) to the right, i.e. higher supersaturations were required for comparable growth rates. The observed trends in the growth data are counter to those expected from the solubility data. If tetragonal lysozyme crystal growth is by addition of ordered aggregates from the solution, then the observed growth data could be explained as a result of the effects of lowered temperature and increased salt concentration on the kinetics and equilibrium processes governing protein-protein interactions in solution. The data indicate that temperature would be a more tractable means of controlling the growth rate for tetragonal lysozyme crystals contrary to the usual practice in, e.g., vapor diffusion protein crystal growth, where both the precipitant and protein concentrations are simultaneously increased. However, the available range for control is dependent upon the protein concentration, with the greatest growth rate control being at the lower concentration.

  7. Characterization and identification of Na-Cl sources in ground water

    USGS Publications Warehouse

    Panno, S.V.; Hackley, Keith C.; Hwang, H.-H.; Greenberg, S.E.; Krapac, I.G.; Landsberger, S.; O'Kelly, D. J.

    2006-01-01

    Elevated concentrations of sodium (Na+) and chloride (Cl -) in surface and ground water are common in the United States and other countries, and can serve as indicators of, or may constitute, a water quality problem. We have characterized the most prevalent natural and anthropogenic sources of Na+ and Cl- in ground water, primarily in Illinois, and explored techniques that could be used to identify their source. We considered seven potential sources that included agricultural chemicals, septic effluent, animal waste, municipal landfill leachate, sea water, basin brines, and road deicers. The halides Cl-, bromide (Br-), and iodide (I-) were useful indicators of the sources of Na+-Cl- contamination. Iodide enrichment (relative to Cl-) was greatest in precipitation, followed by uncontaminated soil water and ground water, and landfill leachate. The mass ratios of the halides among themselves, with total nitrogen (N), and with Na+ provided diagnostic methods for graphically distinguishing among sources of Na+ and Cl- in contaminated water. Cl/Br ratios relative to Cl- revealed a clear, although overlapping, separation of sample groups. Samples of landfill leachate and ground water known to be contaminated by leachate were enriched in I- and Br-; this provided an excellent fingerprint for identifying leachate contamination. In addition, total N, when plotted against Cl/Br ratios, successfully separated water contaminated by road salt from water contaminated by other sources. Copyright ?? 2005 National Ground Water Association.

  8. Effects of NaCl on metabolic heat evolution rates by barley roots

    NASA Technical Reports Server (NTRS)

    Criddle, R. S.; Hansen, L. D.; Breidenbach, R. W.; Ward, M. R.; Huffaker, R. C.

    1989-01-01

    The effect of salinity stress on metabolic heat output of barley (Hordeum vulgare L.) root tips was measured by isothermal microcalorimetry. Several varieties differing in tolerance to salinity were compared and differences quantified. Two levels of inhibition by increasing salt were found. Following the transition from the initial rate of the first level, inhibition remained at about 50% with further increases in salt concentration up to 150 millimolar. The concentration of salt required to inhibit to this level was cultivar dependent. At highter concentrations (>150 millimolar) of salt, metabolism was further decreased. This decrease was not cultivar dependent. The decreased rate of metabolic heat output at the first transition could be correlated with decreases in uptake of NO3-, NH4+, and Pi that occurred as the salt concentration was increased. The high degree of dependence of the inhibition of metabolic heat output on NaCl concentration points to a highly cooperative reaction responsible for the general inhibition of metabolism and nutrient uptake. The time required to attain the first level of salt inhibition is less than 20 minutes. Inhibition of root tips was not reversible by washing with salt free solutions. In addition to revealing these features of salt inhibition, isothermal microcalorimetry is a promising method for convenient and rapid determination of varietal differences in response to increasing salinity.

  9. Desalination feasibility study of an industrial NaCl stream by bipolar membrane electrodialysis.

    PubMed

    Ghyselbrecht, Karel; Silva, Ana; Van der Bruggen, Bart; Boussu, Katleen; Meesschaert, Boudewijn; Pinoy, Luc

    2014-07-01

    The industrial implementation of alternative technologies in the processing of saline effluent streams is a topic of growing importance. In this technical feasibility study, the desalination of an industrial saline stream containing about 75 g L(-1) NaCl contaminated with some organic matter using bipolar membrane electrodialysis (EDBM) was investigated on lab-scale. Bipolar membranes of two different manufacturers (PCA - PolymerChemie Altmeier GmbH and FuMA-Tech GmbH) were tested and compared in terms of electrical resistance, current efficiency and purity of the produced acid and base stream. In both cases, almost complete desalination (>99%) was achieved and simultaneously HCl and NaOH were produced with a concentration between 1.5 and 2 M with a relatively good purity. The Fumasep bipolar membranes scored slightly better for electrical resistance and current efficiency. On the other hand, slightly higher current densities were achieved with PCA bipolar membranes. Simultaneously, some information was obtained on the transport behavior of the organic matter present in the saline stream. It was observed that a transport competition occurred between the organic matter and the accompanying chlorides. From this lab-scale study it was concluded that EDBM is a promising and attractive technology in the area of saline effluent reclamation and reuse.

  10. 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

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

    PubMed

    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

  12. Closure of the cubic tensor polynomial failure surface

    NASA Technical Reports Server (NTRS)

    Jiang, Zhiqing; Tennyson, R. C.

    1989-01-01

    An analytical method has been developed to ensure closure of the cubic form of the tensor polynomial strength criterion. The intrinsic complexity of the cubic function is such that special conditions must be met to close the failure surface in three-dimensional stress space. These requirements are derived in terms of non-intersecting conditions for asymptotes and an asymptotic plane. To demonstrate the validity of this approach, closed failure surfaces were derived for two graphite/epoxy material systems (3M SP288-T300 and IM7 8551-7). The agreement of test data with this model clearly shows that it is possible to use a higher order cubic failure theory with confidence.

  13. Boron suboxide: As hard as cubic boron nitride

    NASA Astrophysics Data System (ADS)

    He, Duanwei; Zhao, Yusheng; Daemen, L.; Qian, J.; Shen, T. D.; Zerda, T. W.

    2002-07-01

    The Vickers hardness of boron suboxide single crystals was measured using a diamond indentation method. Under a loading force of 0.98 N, our test gave an average Vickers hardness of 45 GPa. The average fracture toughness was measured as 4.5 MPa m1/2. We also measured the hardness of the cubic boron nitride and sapphire single crystals for comparison. The average measured hardness for boron suboxide was found to be very close to that of cubic boron nitride under the same loading force. Our results suggest that the boron suboxide could be a new superhard material for industrial applications, surpassed in hardness only by diamond and cubic boron nitride.

  14. 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.

  15. 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.

  16. Gustatory neuron types in rat geniculate ganglion.

    PubMed

    Lundy, R F; Contreras, R J

    1999-12-01

    We used extracellular single-cell recording procedures to characterize the chemical and thermal sensitivity of the rat geniculate ganglion to lingual stimulation, and to examine the effects of specific ion transport antagonists on salt transduction mechanisms. Hierarchical cluster analysis of the responses from 73 single neurons to 3 salts (0.075 and 0.3 M NaCl, KCl, and NH(4) Cl), 0.5 M sucrose, 0.01 M HCl, and 0.02 M quinine HCl (QHCl) indicated 3 main groups that responded best to either sucrose, HCl, or NaCl. Eight narrowly tuned neurons were deemed sucrose-specialists and 33 broadly tuned neurons as HCl-generalists. The NaCl group contained three identifiable subclusters: 18 NaCl-specialists, 11 NaCl-generalists, and 3 QHCl-generalists. Sucrose- and NaCl-specialists responded specifically to sucrose and NaCl, respectively. All generalist neurons responded to salt, acid, and alkaloid stimuli to varying degree and order depending on neuron type. Response order was NaCl > HCl = QHCl > sucrose in NaCl-generalists, HCl > NaCl > QHCl > sucrose in HCl-generalists, and QHCl = NaCl = HCl > sucrose in QHCl-generalists. NaCl-specialists responded robustly to low and high NaCl concentrations, but weakly, if at all, to high KCl and NH(4) Cl concentrations after prolonged stimulation. HCl-generalist neurons responded to all three salts, but at twice the rate to NH(4) Cl than to NaCl and KCl. NaCl- and QHCl-generalists responded equally to the three salts. Amiloride and 5-(N,N-dimethyl)-amiloride (DMA), antagonists of Na(+) channels and Na(+)/H(+) exchangers, respectively, inhibited the responses to 0.075 M NaCl only in NaCl-specialist neurons. The K(+) channel antagonist, 4-aminopyridine (4-AP), was without a suppressive effect on salt responses, but, when applied alone in solution, it evoked a response in many HCl-generalists and one QHCl-generalist neuron so tested. Of the 39 neurons tested for their sensitivity to temperature, 23 responded to cooling and chemical

  17. [Effects of NaCl stress on Hovenia dulcis and Gleditsia sinensis seedlings growth, chlorophyll fluorescence, and active oxygen metabolism].

    PubMed

    Feng, Lei; Bai, Zhi-ying; Lu, Bing-she; Cai, Sheng-wen; Feng, Li-na

    2008-11-01

    With potted Hovenia dulcis and Gleditsia sinensis seedlings as test materials, their plant growth, chlorophyll fluorescence characteristics, and active oxygen metabolism under stress of different concentration (0, 0.15%, 0.30%, 0.45%, and 0.60%) NaCl were studied. The results showed that with increasing concentration of NaCl, the plant growth, leaf chlorophyll content, photochemical efficiency of PS II (Fv/Fm), quantum yield of PS II (phi(PS II)), and photochemical quenching (q(P)) decreased gradually, while the non-photochemical quenching of fluorescence (q(N)) was in adverse. After 10 days of 0. 15% NaCl stress, the leaf chlorophyll content, Fv/Fm, phi(PS II), and q(P) of H. dulcis seedlings decreased by 19.77%, 2.94%, 29.03%, and 8.16%, respectively, with significant differences (P<0.05) to the control, while no significant differences were observed for G. sinensis seedlings. Compared with the control, the Fv/Fm and phi(PS II), of G. sinensis seedlings in treatment 0.30% NaCl decreased significantly by 1.91% and 14.66%, and the chlorophyll content and q(P) of the seedling in treatment 0.45% NaCl decreased significantly by 29.28% and 11.36%, respectively (P<0.05). With increasing concentration of NaCl, the SOD activity of G. sinensis seedlings showed a consistent increasing trend, and that of H. dulcis seedlings increased first and decreased then. The POD and CAT activities of G. sinensis and H. dulci seedlings tended to increase first and decrease then, with the increment being higher for G. sinensis than for H. dulci, while the MDA content of the seedlings had an increasing trend, with the increment being higher for H. dulcis than for G. sinensis, suggesting that the cell membrane lipid peroxidation of H. dulcis was more serious than that of G. sinensis. It was concluded that G. sinensis had greater salt tolerance than H. dulcis, which was related toits higher anti-oxidation enzyme activities. PMID:19238854

  18. Evidence for neutral transcellular NaCl transport and neutral basolateral chloride exit in the rabbit proximal convoluted tubule.

    PubMed Central

    Baum, M; Berry, C A

    1984-01-01

    The electrical nature of active NaCl transport and the significance of a basolateral membrane chloride conductance were examined in isolated perfused rabbit proximal convoluted tubules (PCT). PCT were perfused with a high chloride solution that simulated late proximal tubular fluid and were bathed in an albumin solution that simulated rabbit serum in the control and recovery periods. The electrical nature of NaCl transport was examined by bathing the tubules in a high chloride albumin solution where there were no anion gradients. Volume reabsorption (Jv) during the control and recovery period was 0.56 and 0.51 nl/mm X min, respectively, and 0.45 nl/mm X min when the tubules were bathed in a high chloride bath. The transepithelial potential difference (PD) during the control and recovery periods averaged 2.3 mV, but decreased to 0.0 mV in the absence of anion gradients, which indicated that NaCl transport is electroneutral. Further evidence that NaCl transport is electroneutral was obtained by examining the effect of addition of 0.01 mM ouabain in PCT perfused and bathed with high chloride solutions. The Jv was 0.54 nl/mm X min in the control period and not statistically different from zero after inhibition of active transport. The PD was not different from zero in both periods. Two groups of studies examined the role of basolateral membrane Cl- conductance in NaCl transport. First, depolarizing the basolateral membrane with 2 mM bath Ba++ did not significantly affect Jv or PD. Second, the effect of the presumptive Cl- conductance inhibitor anthracene-9-CO2H was examined. Anthracene-9-CO2H did not significantly affect Jv or PD. In conclusion, these data show that NaCl transport in the PCT is electroneutral and transcellular and provide evidence against a significant role for basolateral membrane chloride conductance in the rabbit PCT. PMID:6736248

  19. The stability of sodalite in the system NaAlSiO sub 4 -NaCl

    SciTech Connect

    Sharp, Z.D. ); Helffrich, G.R. ); Bohlen, S.R. ); Essene, E.J. )

    1989-08-01

    The reaction sodalite = {beta}-nepheline + NaCl (s) was reversed in solid-medium apparatus and the reaction sodalite = carnegieite + NaCl (l) was reversed at 1 bar (1,649-1,652 K). The experimental reversals between 923 K and 973 K can be fit with a dP/dT of {minus}11 bar/K, suggesting that the excess entropy for sodalite is present only above 923 K. A phase diagram for the NaAlSiO{sub 4}-NaCl system that is consistent with the measured thermochemical data and the experiments between 973 and 1,650 K can be generated if the 61.7 J/mol{center dot}K entropy contribution is included in the S{sup 0}{sub 298} of sodalite. This entropy contribution must be removed below 973 K for the experiments to fit with calculations. Previously unreported thermodynamic data estimated in this study are {Delta}G{sup 0}{sub 298} for sodalite ({minus}12,697 kJ/mol) and carnegieite (NaAlSiO{sub 4}) ({minus}1,958 kJ/mol), S{sup 0}{sub 298} of carnegieite (129.6 J/mol{center dot}K) and compressibility of NaCl{sub liquid} (V{sup P}{sub 298} (cm{sup 3}) = 31.6{center dot}(1 - 24.7{center dot}10{sup {minus}3}{center dot}P + 800{center dot}10{sup {minus}6}{center dot}P{sup 2}))(T in K; P in kbar). Sodalite is a high-temperature, low-pressure phase, stable well above the solidus in sodic silica-undersaturated magmas enriched in NaCl, and its presence constrains NaCl activities in magmas. Estimates of minimum NaCl (l) activities in the Mont St-Hilaire sodalite syenites are 0.05 at 1,073 K and 0.13 at 1,273 K. Density calculations are consistent with the field observations that sodalite phenocrysts will float in a nepheline syenite liquid. This explains the enrichment of sodalite in the upper levels of the sodalite syenites at Mont St.Hilaire and elsewhere.

  20. Influence of NaCl Concentrations on Coagulation, Temperature, and Electrical Conductivity Using a Perfusion Radiofrequency Ablation System: An Ex Vivo Experimental Study

    SciTech Connect

    Aube, Christophe Schmidt, Diethard; Brieger, Jens; Schenk, Martin; Kroeber, Stefan; Vielle, Bruno; Claussen, Claus D.; Goldberg, S. Nahum; Pereira, Philippe L.

    2007-02-15

    Purpose. To determine, by means of an ex vivo study, the effect of different NaCl concentrations on the extent of coagulation obtained during radiofrequency (RF) ablation performed using a digitally controlled perfusion device. Method. Twenty-eight RF ablations were performed with 40 W for 10 min using continuous NaCl infusion in fresh excised bovine liver. For perfusion, NaCl concentrations ranging from 0 (demineralized water) to 25% were used. Temperature, the amount of energy, and the dimensions of thermal-induced white coagulation were assessed for each ablation. These parameters were compared using the nonparametric Mann-Whitney test. Correlations were calculated according to the Spearman test. Results. RF ablation performed with 0.9% to 25% concentrations of NaCl produced a mean volume of coagulation of 30.7 {+-} 3.8 cm{sup 3}, with a mean short-axis diameter of 3.6 {+-} 0.2 cm. The mean amount of energy was 21,895 {+-} 1,674 W and the mean temperature was 85.4 {+-} 12.8 deg. C. Volume of coagulation, short-axis diameter, and amount of energy did not differ significantly among NaCl concentrations (p > 0.5). A correlation was found between the NaCl concentration and the short-axis diameter of coagulation (r = 0.64) and between the NaCl concentration and the mean temperature (r = 0.67), but not between the NaCl concentration and volume of coagulation. Conclusion. In an ex vivo model, continuous perfusion with high NaCl concentrations does not significantly improve the volume of thermal-induced coagulation. This may be because the use of a low-power generator cannot sufficiently exploit the potential advantage of better tissue conductivity provided by NaCl perfusion.

  1. Topological Expansion in the Complex Cubic Log-Gas Model: One-Cut Case

    NASA Astrophysics Data System (ADS)

    Bleher, Pavel; Deaño, Alfredo; Yattselev, Maxim

    2016-09-01

    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. From insect scales to sensor design: modelling the mechanochromic properties of bicontinuous cubic structures.

    PubMed

    Wu, Xia; Ma, Duancheng; Eisenlohr, Philip; Raabe, Dierk; Fabritius, Helge-Otto

    2016-06-15

    Many of the three-dimensional photonic crystals occurring in the scales of insects have bicontinuous cubic structures. Their optical properties have been studied extensively, however little is known about their mechanical properties and their optical response under deformation. We demonstrated a mechanochromic effect by deforming the scales of a weevil and calculated the elastic, optical and mechanochromic (assuming homogeneous deformation) properties of the three types of bicontinuous cubic structures occurring in nature: P-structure (primitive), G-structure (gyroid) and D-structure (diamond). The results show that all investigated properties of these three structure types strongly depend on their geometry, structural parameters such as volume fractions of the two constituting phases and the directions of the incident light or applied stress, respectively. Interestingly, the mechanochromic simulation results predict that these structures may show blue-shift or even red-shift under compression along certain directions. Our results provide design guidelines for mechanochromic sensing materials operating in the elastic regime, including parameters such as sensitivity and direction of spectral shift.

  3. How do water striders, Aquarius paludum, react to brackish water simulated by NaCl solutions?

    PubMed

    Kishi, Manabu; Fujisaki, Kenji; Harada, Tetsuo

    2006-01-01

    Several stages, from eggs to adults, of the water strider, Aquarius paludum (Fabricius), inhabiting fresh water are sometimes conveyed by heavy flow in the rainy or typhoon seasons in Japan to lotic brackish water in the mouth of rivers. The water striders might then respond to salinity either by remaining to wait for extensive rainfall to reduce osmotic pressure locally before reproducing ("breed here and later tactic") or by flying away to reproduce in fresh waters elsewhere ("breed elsewhere and later tactic"). All first instars died before the first molt when they were exposed to 1.75 and 3.5% NaCl solutions in a laboratory experiment. Living on 0.5 and 0.9% solutions through larval and adult stages slowed down larval growth and suppressed female reproduction. When exposed to the 0.5 and 0.9% solutions, 90 and 92% of males, respectively, showed histolysis of their flight muscles. Therefore, in brackish natural habitats, larvae and adults seem to follow the strategy "breed here and later." When water striders were exposed to 0.9% solution either just after emergence or 20 days later, females showed a higher flight propensity than those kept on fresh waters throughout, and they delayed the deposition of eggs. Therefore, when conveyed to brackish water after emergence by stream flow after heavy rain, adults seem to leave the area by flight, demonstrating the strategy "breed elsewhere and later" tactic. We conclude that water striders use alternative tactics for responding to salinity, depending on the stage of exposure.

  4. How do water striders, Aquarius paludum, react to brackish water simulated by NaCl solutions?

    NASA Astrophysics Data System (ADS)

    Kishi, Manabu; Fujisaki, Kenji; Harada, Tetsuo

    2006-01-01

    Several stages, from eggs to adults, of the water strider, Aquarius paludum (Fabricius), inhabiting fresh water are sometimes conveyed by heavy flow in the rainy or typhoon seasons in Japan to lotic brackish water in the mouth of rivers. The water striders might then respond to salinity either by remaining to wait for extensive rainfall to reduce osmotic pressure locally before reproducing (“breed here and later tactic”) or by flying away to reproduce in fresh waters elsewhere (“breed elsewhere and later tactic”). All first instars died before the first molt when they were exposed to 1.75 and 3.5% NaCl solutions in a laboratory experiment. Living on 0.5 and 0.9% solutions through larval and adult stages slowed down larval growth and suppressed female reproduction. When exposed to the 0.5 and 0.9% solutions, 90 and 92% of males, respectively, showed histolysis of their flight muscles. Therefore, in brackish natural habitats, larvae and adults seem to follow the strategy “breed here and later.” When water striders were exposed to 0.9% solution either just after emergence or 20 days later, females showed a higher flight propensity than those kept on fresh waters throughout, and they delayed the deposition of eggs. Therefore, when conveyed to brackish water after emergence by stream flow after heavy rain, adults seem to leave the area by flight, demonstrating the strategy “breed elsewhere and later” tactic. We conclude that water striders use alternative tactics for responding to salinity, depending on the stage of exposure.

  5. Molecular dynamics simulations of Palmitic acid adsorbed on NaCl

    NASA Astrophysics Data System (ADS)

    Lovrić, Josip; Brizquez, Stéphane; Duflot, Denis; Monnerville, Maurice; Pouilly, Brigitte; Toubin, Céline

    2015-04-01

    The aerosol and gases effects in the atmosphere play an important role on health, air quality and climate, affecting both political decisions and economic activities around the world [1]. Among the several approaches of studying the origin of these effects, computational modeling is of fundamental importance, providing insights on the elementary chemical processes. Sea salts are the most important aerosol in the troposphere (109T/year) [2]. Our theoretical work consists in modeling a (100) NaCl surface coated with palmitic acid (PA) molecules. Molecular dynamics simulations are carried out with the GROMACS package [3], in the NPT ensemble at different temperatures, different PA coverages and various humidity. We focus on two aspects of the PA organization at the salt surface: the first one is related to transition in molecular orientation of the adsorbate as a function of PA coverage. The second one implies the effect of humidity, by adding water molecules, on the organization of the fatty acid at the salt surface, and especially on the occurrence of PA isolated islands as observed in the experiments [4]. For high humidity conditions, PA are removed from the salt surface and form islands on top of the water. This effect is enhanced when temperature increases. Acknowledgments: this research has been supported by the CaPPA project (Chemical and Physical Properties of the Atmosphere), funded by the French National Research Agency (ANR) through the PIA (Programme d'Investissement d'Avenir) under contract ANR-10-LABX-005. [1] O. Boucher et al, 5th Assessment Report IPCC, (2013) [2] B. J. Finlayson-Pitts, Chem. Rev.103, 4801-4822 (2003) [3] http://www.gromacs.org/ [4] S. Sobanska et al, private communication

  6. Global Transcriptome Profiling of Salicornia europaea L. Shoots under NaCl Treatment

    PubMed Central

    Ma, Jinbiao; Zhang, Meiru; Xiao, Xinlong; You, Jinjin; Wang, Junru; Wang, Tao; Yao, Yinan; Tian, Changyan

    2013-01-01

    Background Soil salinity is a major abiotic stress that limits agriculture productivity worldwide. Salicornia europaea is well adapted to extreme saline environments with more than 1,000 mM NaCl in the soil, so it could serve as an important model species for studying halophilic mechanisms in euhalophytes. To obtain insights into the molecular basis of salt tolerance, we present here the first extensive transcriptome analysis of this species using the Illumina HiSeq™ 2000. Principal Findings A total of 41 and 39 million clean reads from the salt-treated (Se200S) and salt-free (SeCKS) tissues of S. europaea shoots were obtained, and de novo assembly produced 97,865 and 101,751 unigenes, respectively. Upon further assembly with EST data from both Se200S and SeCKS, 109,712 high-quality non-redundant unigenes were generated with a mean unigene size of 639 bp. Additionally, a total of 3,979 differentially expressed genes (DEGs) were detected between the Se200S and SeCKS libraries, with 348 unigenes solely expressed in Se200S and 460 unigenes solely expressed in SeCKS. Furthermore, we identified a large number of genes that are involved in ion homeostasis and osmotic adjustment, including cation transporters and proteins for the synthesis of low-molecular compounds. All unigenes were functionally annotated within the COG, GO and KEGG pathways, and 10 genes were validated by qRT-PCR. Conclusion Our data contains the extensive sequencing and gene-annotation analysis of S. europaea. This genetic knowledge will be very useful for future studies on the molecular adaptation to abiotic stress in euhalophytes and will facilitate the genetic manipulation of other economically important crops. PMID:23825526

  7. MIGRATION OF GAS-LIQUID INCLUSIONS IN KCl AND NaCl SINGLE CRYSTALS

    SciTech Connect

    Olander, Donald R.; Machiels, Albert J.; Muchowski, Eugen

    1980-08-01

    Natural salt deposits contain small brine inclusions which can be set into motion by a temperature gradient arising from storage of nuclear wastes in the salt. Inclusions totally filled with liquid move up the temperature gradient, but cavities which are filled partly with liquid and partly by an insoluble gas move in the opposite direction. The velocities of these gas-liquid inclusions are calculated from a model which includes: heat transport in the gas/liquid/solid composite medium; vapor transport of water in the gas bubble as the principal mechanism causing cavity motion; and the effect of molecular and thermal diffusion on transport of salt in the liquid phase. An analytical expression for the inclusion velocity is obtainable with certain simplifications, which include: approximating the cubical cavity in the solid as a spherical hole containing a central gas bubble and an annular shell of liquid; neglecting interface kinetics (i.e., slow dissolution and crystallization steps) and assuming the process to be diffusion-controlled and disregarding fluid motion generated by surface tension gradients at the gas/liquid interface. The theory predicts a change in the migration direction at a critical volume fraction gas in the cavity. For gas fractions greater than this critical value, the theory gives the velocities of migration down the temperature gradient which are in satisfactory agreement with available experimental data.

  8. Effect of NaCl on leaf salt secretion and antioxidative enzyme level in roots of a mangrove, Aegiceras corniculatum.

    PubMed

    Mishra, Sujatarani; Das, A B

    2003-02-01

    Short-term salt (NaCl) treatment on Aegiceras corniculatum in roots and leaves showed no change in fresh and dry weight of leaves, roots and leaf area. There was no significant change in total soluble root protein, photosynthetic pigments of leaves and spectral characteristics of thylakoids. However, the activity of antioxidative enzymes (catalase, ascorbate peroxidase and guaiacol peroxidase) in roots decreased by 72, 58 and 80% respectively after 96 hr of treatment (300 mM of NaCl). Secretion of salts from the leaf salt glands and salt accumulation on upper surface of the leaves were quantified that revealed linear increase of salt secretion of leaf with increase in period of salt treatment. It was concluded that loss of activities of antioxidative enzymes at high salt treatment, caused leaf senescence in spite of high rates of salt secretion by Aegiceras corniculatum. PMID:15255609

  9. The experimental determination of the solubility product for NpO{sub 2}OH in NaCl solutions

    SciTech Connect

    Roberts, K.E.; Torretto, P.C.; Prussin, T.

    1995-09-01

    The solubility of Np(V) was measured in NaCl solutions ranging from 0.30 to 5.6 molal at room temperature ({approximately}21 {plus_minus} 2{degrees}C). Experiments were conducted from undersaturation and allowed to equilibrate in a CO{sub 2}-free environment for 37 days. The apparent solubility products varied with NaCl concentration and were between 10{sup -9} and 10{sup -8} mol{sup 2}{sm_bullet}L{sup -2}. Using the specific ion interaction theory (SIT), the log of the solubility product of NpO{sub 2}OH(am) at infinite dilution was found to be - 8.79 {plus_minus} 0.12. The interaction coefficient, {epsilon}(NpO{sub 2}{sup +} - Cl{sup -}), was found to be (0.08 {plus_minus} 0.05).

  10. Melting properties of radiation-induced Na and Cl2 precipitates in ultra-heavily irradiated NaCl

    NASA Astrophysics Data System (ADS)

    Sugonyako, A. V.; Vainshtein, D. I.; den Hartog, H. P.; Turkin, A. A.; den Hartog, H. W.

    2005-01-01

    Exposure of NaCl to high doses of ionizing radiation leads to the formation of nano-particles of metallic Na, very small chlorine precipitates, vacancy voids, and dislocations. A useful way to monitor the stage of the damage formation process is measuring the latent heat of melting of the Na-particles (100 °C) and chlorine precipitates (-101 °C). In this paper we will present data, showing that for doses in the range of TRad (1010 Gy) the concentration of radiolytic Na may become very large. Even in pure samples, we have converted more than 20% of all NaCl molecules into metallic Na and chlorine, but often higher percentages can be achieved. In this paper we will present new data obtained for ultra-high irradiation doses and a first attempt will be made to understand the results.

  11. Effect of X-irradiation on impurity-vacancy dipoles in lead and calcium-doped NaCl

    NASA Astrophysics Data System (ADS)

    M, J. García; A, J. Hernández; S, H. Murrieta; O, J. Rubio

    1983-08-01

    In the present paper the effects of the room temperature X-irradiation in calcium and lead-doped NaCl have been reinvestigated in order to get a deeper insight into the nature of the radiation induced halogen interstitial traps. Special attention has been paid to determine whether a correlation exists between the change in the concentration of Ca 2+ (Pb 2+-cation vacancy dipoles and the color center formation. Our results indicate that for both systems, the dipoles are the fundamental traps for the interstitial defects in agreement with the theoretical models recently developed for F-center formation in alkali halides doped with divalent impurities. This conclusion is, however, in disagreement with that reported by Ikeya et al in a previous work on calcium-doped NaCl in which it was concluded that the isolated positive ion vacancies were the dominant traps for the halogen interstitial defects. Some comments about this discrepancy are given.

  12. The AKT2 potassium channel mediates NaCl induced depolarization in the root of Arabidopsis thaliana

    PubMed Central

    Salvador-Recatalà, Vicenta

    2016-01-01

    ABSTRACT Soil salinization is a major cause of plant stress, partly due to the physicochemical similarities between Na+ and K+. Na+ ions compete with K+ ions for their transport into root cells. However, the point of Na+ entry remains unidentified. Here, I have applied the Electrical Penetration Graph as a method for whole plant electrophysiology in order to test if (a) root exposure to NaCl induces depolarization waves that propagate from root to shoot via the phloem, and if (b) the electrophysiological effects of root exposure to NaCl require expression of the potassium channels AKT1 and/or AKT2. The data suggest that AKT2 subunit containing K+ channels mediate NaCl-induced depolarization of root cells, and that this depolarization does not propagate to leaves via the phloem. PMID:27043750

  13. A Unified Approach to Teaching Quadratic and Cubic Equations.

    ERIC Educational Resources Information Center

    Ward, A. J. B.

    2003-01-01

    Presents a simple method for teaching the algebraic solution of cubic equations via completion of the cube. Shows that this method is readily accepted by students already familiar with completion of the square as a method for quadratic equations. (Author/KHR)

  14. Hydrophobic Surfactant Proteins Induce a Phosphatidylethanolamine to Form Cubic Phases

    PubMed Central

    Chavarha, Mariya; Khoojinian, Hamed; Schulwitz, Leonard E.; Biswas, Samares C.; Rananavare, Shankar B.; Hall, Stephen B.

    2010-01-01

    Abstract The hydrophobic surfactant proteins SP-B and SP-C promote rapid adsorption of pulmonary surfactant to an air/water interface. Previous evidence suggests that they achieve this effect by facilitating the formation of a rate-limiting negatively curved stalk between the vesicular bilayer and the interface. To determine whether the proteins can alter the curvature of lipid leaflets, we used x-ray diffraction to investigate how the physiological mixture of these proteins affects structures formed by 1-palmitoyl-2-oleoyl phosphatidylethanolamine, which by itself undergoes the lamellar-to-inverse hexagonal phase transition at 71°C. In amounts as low as 0.03% (w:w) and at temperatures as low as 57°C, the proteins induce formation of bicontinuous inverse cubic phases. The proteins produce a dose-related shift of diffracted intensity to the cubic phases, with minimal evidence of other structures above 0.1% and 62°C, but no change in the lattice-constants of the lamellar or cubic phases. The induction of the bicontinuous cubic phases, in which the individual lipid leaflets have the same saddle-shaped curvature as the hypothetical stalk-intermediate, supports the proposed model of how the surfactant proteins promote adsorption. PMID:20409474

  15. 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.

  16. 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.)

  17. 46 CFR 160.035-9 - Cubic capacity of lifeboats.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... its cubic capacity. (1) Length (L). The length is the distance in feet from the inside of the plating... square stern, the after terminus is the inside of the transom. (2) Breadth (B). The breadth is the...) Depth (D). The depth is the distance in feet amidships inside the plating from the top of the keel...

  18. 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.

  19. Dynamic mirror-symmetry breaking in bicontinuous cubic phases.

    PubMed

    Dressel, Christian; Liu, Feng; Prehm, Marko; Zeng, Xiangbing; Ungar, Goran; Tschierske, Carsten

    2014-11-24

    Chiral segregation of enantiomers or chiral conformers of achiral molecules during self-assembly in well-ordered crystalline superstructures has fascinated chemists since Pasteur. Here we report spontaneous mirror-symmetry breaking in cubic phases formed by achiral multichain-terminated diphenyl-2,2'-bithiophenes. It was found that stochastic symmetry breaking is a general phenomenon observed in bicontinuous cubic liquid crystal phases of achiral rod-like compounds. In all compounds studied the Im3̄m cubic phase is always chiral, while the Ia3̄d phase is achiral. These intriguing observations are explained by propagation of homochiral helical twist across the entire networks through helix matching at network junctions. In the Ia3̄d phase the opposing chiralities of the two networks cancel, but not so in the three-networks Im3̄m phase. The high twist in the Im3̄m phase explains its previously unrecognized chirality, as well as the origin of this complex structure and the transitions between the different cubic phases.

  20. Preparation of cubic boron nitride films by RF bias sputtering

    SciTech Connect

    Tsuda, Osamu; Yamada, Yukiko; Tatebayashi, Yoshinao

    1995-07-01

    Cubic boron nitride (cBN) films were successfully prepared by the phase-regulated rf bias sputtering with the aid of magnetic field. The effects of the substrate bias voltage (V{sub s}), the working gas pressure (p) and the deposition time were investigated systematically. Cubic phase was formed in the filmed deposited with V{sub s} above the threshold which depended on p. Even at p = 0.4 mTorr, cBN films were grown with V{sub s} above 100 V. The prepared cBN films had a double-layered structure which consists of an initially deposited layer of sp{sup 2} phase and a layer of cubic phase subsequently grown. The maximum growth rate of the cubic layer was estimated to be approximately 1 nm/s. Stress measurements of the cBN films were also carried out, revealing that the cBN films had compressive stress of a few GPa.

  1. On a Cubically Convergent Iterative Method for Matrix Sign

    PubMed Central

    Sharifi, M.; Karimi Vanani, S.; Khaksar Haghani, F.; Arab, M.; Shateyi, S.

    2015-01-01

    We propose an iterative method for finding matrix sign function. It is shown that the scheme has global behavior with cubical rate of convergence. Examples are included to show the applicability and efficiency of the proposed scheme and its reciprocal. PMID:25954769

  2. 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…

  3. Synthesis of nanowires and nanoparticles of cubic aluminium nitride

    NASA Astrophysics Data System (ADS)

    Balasubramanian, C.; Godbole, V. P.; Rohatgi, V. K.; Das, A. K.; Bhoraskar, S. V.

    2004-03-01

    Nanostructures of cubic aluminium nitride were synthesized by DC arc-plasma-induced melting of aluminium in a nitrogen-argon ambient. The material flux ejected from the molten aluminium surface was found to react with nitrogen under highly non-equilibrium conditions and subsequently condense on a water-cooled surface to yield a mixture of nanowires and nanoparticles of crystalline cubic aluminium nitride. Both x-ray diffraction and electron diffraction measurements revealed that the as-synthesized nitrides adopted the cubic phase. Fourier transform infrared spectroscopy was used to understand the bonding configuration. Microstructural features of the synthesized material were best studied by transmission electron microscopy. From these analyses cubic aluminium nitride was found to be the dominating phase for both nanowires and nanoparticles synthesized at low currents. The typical particle size distribution was found to range over 15-80 nm, whereas the wires varied from 30 to 100 nm in diameter and 500 to 700 nm in length, depending upon the process parameters such as arc current and the nitrogen pressure. The reaction products inside the plasma zone were also obtained theoretically by minimization of free energy and the favourable zone temperature necessary for the formation of aluminium nitride was found to be {\\sim } 6000 K. Results are discussed in view of the highly non-equilibrium conditions that prevail during the arc-plasma synthesis.

  4. Dynamic Mirror-Symmetry Breaking in Bicontinuous Cubic Phases**

    PubMed Central

    Dressel, Christian; Liu, Feng; Prehm, Marko; Zeng, Xiangbing; Ungar, Goran; Tschierske, Carsten

    2014-01-01

    Chiral segregation of enantiomers or chiral conformers of achiral molecules during self-assembly in well-ordered crystalline superstructures has fascinated chemists since Pasteur. Here we report spontaneous mirror-symmetry breaking in cubic phases formed by achiral multichain-terminated diphenyl-2,2′-bithiophenes. It was found that stochastic symmetry breaking is a general phenomenon observed in bicontinuous cubic liquid crystal phases of achiral rod-like compounds. In all compounds studied the ${{\\it Im}\\bar 3m}$ cubic phase is always chiral, while the ${Ia\\bar 3d}$ phase is achiral. These intriguing observations are explained by propagation of homochiral helical twist across the entire networks through helix matching at network junctions. In the ${Ia\\bar 3d}$ phase the opposing chiralities of the two networks cancel, but not so in the three-networks ${{\\it Im}\\bar 3m}$ phase. The high twist in the ${{\\it Im}\\bar 3m}$ phase explains its previously unrecognized chirality, as well as the origin of this complex structure and the transitions between the different cubic phases. PMID:25257551

  5. [Effects of NaCl stress on free polyamines content and reactive oxygen species level in pumpkin roots].

    PubMed

    Zhou, Jun-Guo; Hu, Hui-Ling; Zhu, Yue-Lin; Zhang, Gu-Wen; Liu, Zheng-Lu

    2008-09-01

    Taking Cucurbita moschata Duch hybrid 360-3 x 112-2 and C. ficifolia Bouche as test materials, the effects of NaCl stress on their plant growth and the O2*- production rate and H2O2 and free polyamines (PAs) contents in their roots were studied with hydroponic culture. The results showed that after 10 d NaCl stress, the plant growth of the two pumpkin varieties was strongly inhibited, compared with the control, and C. ficifolia was more injured than hybrid 360-3 x 112-2. Under NaCl stress, the root O2*- production rate and H2O2 content of the two pumpkin varieties were increased, but their absolute values were lower in hybrid 360-3 x 112-2 than in C. ficifolia. The contents of PAs, putrescine (Put), spermidine (Spd) and spermine (Spm) and Put/PAs ratio in the roots of the two pumpkin varieties were always higher than the control and had a trend of increased first and decreased then; while the (Spd + Spm)/Put ratio was lower than the control and decreased first and increased then. Compared with C. ficifolia Bouche, hybrid 360-3 x 112-2 always had a lower Put/PAs ratio and a lower Put content in its roots, but the (Spd + Spm)/Put ratio and Spd and Spm contents were always higher. It was concluded that under NaCl stress, the increasing PAs content in the roots of test materials played an active role in decreasing or scavenging reactive oxygen species (ROS). The conversion of Put to Spd and Spm was advantageous to the increase of plant salt tolerance. The higher salt tolerance of hybrid 360-3 x 112-2 was closely related to the lower Put/PAs ratio and the higher (Spd + Spm)/Put ratio and PAs content in its roots, and thus, the stronger capacity to scavenge ROS.

  6. Effects of Oxide Film on the Corrosion Resistance of Titanium Grade 7 in Fluoride-Containing NaCl Brines

    SciTech Connect

    Lian, T; Whalen, M T; Wong, L

    2004-11-30

    The effects of oxide film on the corrosion behavior of Titanium Grade 7 (0.12-0.25% Pd) in fluoride-containing NaCl brines have been investigated. With the presence of a 0.6 {micro}m thick oxide layer, the annealed Ti grade 7 exhibited a significant improvement on the anodic polarization behavior. However, the oxide film did not demonstrate sustainable corrosion resistance in fluoride-containing solutions.

  7. Reverse osmosis transport of alkali halides and nickel salts through cellulose triacetate membranes. Performance prediction from NaCl experiments

    SciTech Connect

    Nirmal, J.D.; Pandya, V.P.; Desai, N.V.; Rangarajan, R. )

    1992-10-01

    The separation of alkali metal halides, nickel chloride, and nickel sulfate was determined for cellulose triacetate reverse osmosis (CTA RO) membranes. From transport analysis, the relative free energy parameters for transport of these salts through CTA membranes were determined. From these relative free energy parameters of salts, the solute separation by CTA membranes could be predicted from RO experiment with NaCl solution. The transport analysis and an illustration of how the concept is useful are presented in this paper.

  8. Osmoadaptation Strategy of the Most Halophilic Fungus, Wallemia ichthyophaga, Growing Optimally at Salinities above 15% NaCl

    PubMed Central

    Zajc, Janja; Kogej, Tina; Galinski, Erwin A.; Ramos, José

    2014-01-01

    Wallemia ichthyophaga is a fungus from the ancient basidiomycetous genus Wallemia (Wallemiales, Wallemiomycetes) that grows only at salinities between 10% (wt/vol) NaCl and saturated NaCl solution. This obligate halophily is unique among fungi. The main goal of this study was to determine the optimal salinity range for growth of the halophilic W. ichthyophaga and to unravel its osmoadaptation strategy. Our results showed that growth on solid growth media was extremely slow and resulted in small colonies. On the other hand, in the liquid batch cultures, the specific growth rates of W. ichthyophaga were higher, and the biomass production increased with increasing salinities. The optimum salinity range for growth of W. ichthyophaga was between 15 and 20% (wt/vol) NaCl. At 10% NaCl, the biomass production and the growth rate were by far the lowest among all tested salinities. Furthermore, the cell wall content in the dry biomass was extremely high at salinities above 10%. Our results also showed that glycerol was the major osmotically regulated solute, since its accumulation increased with salinity and was diminished by hypo-osmotic shock. Besides glycerol, smaller amounts of arabitol and trace amounts of mannitol were also detected. In addition, W. ichthyophaga maintained relatively small intracellular amounts of potassium and sodium at constant salinities, but during hyperosmotic shock, the amounts of both cations increased significantly. Given our results and the recent availability of the genome sequence, W. ichthyophaga should become well established as a novel model organism for studies of halophily in eukaryotes. PMID:24162565

  9. 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.

  10. Comparative investigations of the P- V- T relationship of NaCl at high pressure and temperature

    NASA Astrophysics Data System (ADS)

    Sun, X. W.; Wang, X. G.; Song, T.; Li, Y. H.; Liu, Y. X.; Chen, Q. F.

    2008-09-01

    Two different potential models of molecular dynamics (MD) simulations have been applied to investigate the pressure-volume-temperature ( P- V- T) relationship and lattice parameter of NaCl under high pressure and temperature. The first one is the shell model (SM) potentials in which due to the short-range interaction pairs of ions are moved together as is the case in polarization of a crystal due to the motion of the positive and negative ions, and the second one is the two-body rigid-ion Born-Mayer-Huggins-Fumi-Tosi (BMHFT) potentials with full treatment of long-range Coulomb forces. The P- V relationship at 300 K, T- V relationship at zero pressure, and lattice parameter a, have been obtained and compared with the available experimental data and other theoretical results. Compared with SM potentials, the MD simulation with BMHFT potentials is very successful in reproducing accurately the measured volumes of NaCl. At an extended pressure and temperature ranges, P- V relationship under different isotherms at selected temperatures, T- V relationship under different pressures, and lattice parameter a have also been predicted. The properties of NaCl are summarized in the pressure range 0-30 GPa and the temperature up to 2000 K.

  11. NaCl content and temperature effects on moisture diffusivity in the Gluteus medius muscle of pork ham.

    PubMed

    Gou, P; Comaposada, J; Arnau, J

    2003-01-01

    Dry-cured meat products are salted with different amounts of NaCl and then dried under different conditions (temperature and relative humidity) in order to stabilize the product. The effective moisture diffusivity values (D(e)) in Gluteus medius muscles, unsalted or soaked in different salting solutions (0.02, 0.05 and 0.08 kg NaCl/kg H(2)O), and dried at different temperatures (5, 13, 19 and 26 °C) and 80% of air relative humidity were determined. Water diffusion was only allowed parallel to meat fibre direction. The D(e) values were determined by applying Fick's second law. As temperature increased or NaCl content decreased, the D(e) increased. At low temperatures, the D(e) was less dependent on NaCl content than at higher ones. The energy of activation, obtained from the Arrhenius equation, is lower for unsalted compared with salted samples. Therefore, the effective moisture diffusivity of salted meat products is more sensitive to temperature variations than that of unsalted meat. PMID:22061981

  12. Effects of NaCl and seawater induced salinity on survival and reproduction of three soil invertebrate species.

    PubMed

    Pereira, C S; Lopes, I; Sousa, J P; Chelinho, S

    2015-09-01

    The increase of global mean temperature is raising serious concerns worldwide due to its potential negative effects such as droughts and melting of glaciers and ice caps leading to sea level rise. Expected impacts on soil compartment include floodings, seawater intrusions and use of saltwater for irrigation, with unknown effects on soil ecosystems and their inhabitants. The present study aimed at evaluating the effects of salinisation on soil ecosystems due to sea level rise. The reproduction and mortality of three standard soil invertebrate species (Folsomia candida, Enchytraeus crypticus, Hypoaspis aculeifer) in standard artificial OECD soil spiked with serial dilutions of seawater/gradient of NaCl were evaluated according to standard guidelines. An increased sensitivity was observed in the following order: H. aculeifer≪E. crypticus≈F. candida consistent with the different exposure pathways: springtails and enchytraeids are exposed by ingestion and contact while mites are mainly exposed by ingestion due to a continuous and thick exoskeleton. Although small differences were observed in the calculated effect electrical conductivity values, seawater and NaCl induced the same overall effects (with a difference in the enchytraeid tests where a higher sensitivity was found in relation to NaCl). The adverse effects described in the present study are observed on soils not considered saline. Therefore, the actual limit to define saline soils (4000 μS cm(-1)) does not reflect the existing knowledge when considering soil fauna. PMID:25930052

  13. Experiments on the temperature dependence of heterogeneous nucleation on nanometer-sized NaCl and Ag particles.

    PubMed

    Schobesberger, Siegfried; Winkler, Paul M; Pinterich, Tamara; Vrtala, Aron; Kulmala, Markku; Wagner, Paul E

    2010-12-17

    Experimental investigations on the activation of NaCl and Ag aerosol particles by heterogeneous nucleation of n-propanol vapor at well-defined vapor saturation ratios are presented. Particular emphasis is placed on the temperature dependence of this process from -11 to +14 °C. Aerosols are generated in a tube furnace and electrostatically classified at mean geometric mobility equivalent diameters between 3.6 and 11 nm. Activation probabilities are measured by means of expansion chamber experiments, and onset n-propanol saturation ratios are subsequently determined. The experiments with Ag particles do not produce any unexpected results. The results for NaCl particles, however, show a temperature trend of the onset saturation ratios that is opposite to that predicted by classical nucleation theory. This stresses the important role that surface properties play in heterogeneous nucleation processes. By tentatively assuming a temperature-dependent contact angle, we are able to theoretically reproduce this reversed temperature trend. In addition, the shrinkage of NaCl condensation particles is investigated for varying amounts of n-propanol vapor, and contact angle measurements are performed at temperatures ranging from -7 to +30 °C.

  14. NaCl Effects on In Vitro Germination and Growth of Some Senegalese Cowpea (Vigna unguiculata (L.) Walp.) Cultivars.

    PubMed

    Thiam, Mahamadou; Champion, Antony; Diouf, Diaga; Ourèye Sy, Mame

    2013-01-01

    Cowpea (Vigna unguiculata (L.) Walp.) is one of the most important grain legumes in sub-Saharian regions. It contributes to man food security by providing a protein-rich diet. However, its production is limited by abiotic stresses such as salinity. This study aims to evaluate the salt tolerance of 15 cowpea cultivars, at germination stage. The seed germination process consisted of sowing them in agarified water (8 g·L(-1)) supplemented with 6 different concentrations of NaCl (0, 10, 50, 100, 150, and 200 mM). Results highlighted that high salt concentrations drastically reduced germination and significantly delayed the process for all varieties. A cowpea varietal effect towards the salt tolerance was noticed. Genotypes Diongoma, 58-78, and 58-191 were more salt-tolerant cultivars while Mougne and Yacine were more salt-sensitive ones as confirmed in the three groups of the dendrogram. NaCl effects on the early vegetative growth of seedlings were assessed with a tolerant (58-191) and a susceptible (Yacine) cultivar. Morphological (length and dry biomass) and physiological (chlorophyll and proline contents) parameter measurements revealed a negative effect of high (NaCl). However, 58-191 was much more salt tolerant, and the chlorophyll and proline contents were higher than those of Yacine genotype at increasing salt concentrations.

  15. Opposite effects of oxytocin on water intake induced by hypertonic NaCl or polyethylene glycol administration.

    PubMed

    Bernal, Antonio; Mahía, Javier; Mediavilla, Cristina; Puerto, Amadeo

    2015-03-15

    Oxytocin (OT), a neurohormone, has been related to natriuretic and diuretic effects and also to water intake and sodium appetite. The objective of the present study was to determine the effect of subcutaneous OT administration on water intake and urine-related measures induced by the administration of hypertonic NaCl (experiment 1) or polyethylene glycol (PEG) (experiment 2). Experiment 1 showed that OT administration increases the urine volume, urinary sodium concentration, and natriuresis and reduces the water intake, water and sodium balances, and estimated plasma sodium concentration induced by hypertonic NaCl administration. Conversely, experiment 2 showed that OT administration increases the water intake and the antidiuretic response induced by PEG administration. These results show that the opposite effects of OT on the water intake induced by hypertonic NaCl or PEG administration are accompanied by differential regulatory effects, enhancing a natriuretic response in the first experiment and generating an antidiuretic reaction in the second experiment. This study suggests a differential regulatory effect of OT during states of intra- and extracellular thirst.

  16. Chemistry of Frozen NaCl and MgSO4 Brines - Implications for Surface Expression of Europa's Ocean Composition

    NASA Astrophysics Data System (ADS)

    Johnson, P. V.; Hodyss, R. P.; Choukroun, M.; Vu, T. H.

    2015-12-01

    The composition of Europa's subsurface ocean is a critical determinant of its habitability, but current analysis of the ocean composition is limited to its expression on the Europan surface. While there is observational evidence indicating that ocean materials make their way to the surface, our understanding of the chemical processes that can alter this material under Europan surface conditions is limited. We present experimental data on the chemistry of mixed solutions of NaCl and MgSO4 as they are frozen to 100 K, replicating the conditions that may occur when subsurface ocean fluids are emplaced onto Europa's surface. Confocal micro-Raman spectroscopy is used to study the formation of salts during the freezing process, and the interaction of ions in the frozen brines. Our data indicate that mixed aqueous solutions of NaCl and MgSO4 form Na2SO4 and MgCl2 preferentially when frozen, rather than making NaCl and MgSO4 precipitates. The detection of epsomite (MgSO4Ÿ•7H2O) on Europa's surface may therefore imply an ocean composition relatively low in sodium, unless radiolytic chemistry converts MgCl2 to MgSO4 as suggested by Hand and Brown 2013 (ApJ 145 110). These results have important implications for the interpretation of remote sensing data of Europa's surface.

  17. NaCl Effects on In Vitro Germination and Growth of Some Senegalese Cowpea (Vigna unguiculata (L.) Walp.) Cultivars

    PubMed Central

    Thiam, Mahamadou; Ourèye SY, Mame

    2013-01-01

    Cowpea (Vigna unguiculata (L.) Walp.) is one of the most important grain legumes in sub-Saharian regions. It contributes to man food security by providing a protein-rich diet. However, its production is limited by abiotic stresses such as salinity. This study aims to evaluate the salt tolerance of 15 cowpea cultivars, at germination stage. The seed germination process consisted of sowing them in agarified water (8 g·L−1) supplemented with 6 different concentrations of NaCl (0, 10, 50, 100, 150, and 200 mM). Results highlighted that high salt concentrations drastically reduced germination and significantly delayed the process for all varieties. A cowpea varietal effect towards the salt tolerance was noticed. Genotypes Diongoma, 58-78, and 58-191 were more salt-tolerant cultivars while Mougne and Yacine were more salt-sensitive ones as confirmed in the three groups of the dendrogram. NaCl effects on the early vegetative growth of seedlings were assessed with a tolerant (58-191) and a susceptible (Yacine) cultivar. Morphological (length and dry biomass) and physiological (chlorophyll and proline contents) parameter measurements revealed a negative effect of high (NaCl). However, 58-191 was much more salt tolerant, and the chlorophyll and proline contents were higher than those of Yacine genotype at increasing salt concentrations. PMID:25937976

  18. Effects of NaCl and seawater induced salinity on survival and reproduction of three soil invertebrate species.

    PubMed

    Pereira, C S; Lopes, I; Sousa, J P; Chelinho, S

    2015-09-01

    The increase of global mean temperature is raising serious concerns worldwide due to its potential negative effects such as droughts and melting of glaciers and ice caps leading to sea level rise. Expected impacts on soil compartment include floodings, seawater intrusions and use of saltwater for irrigation, with unknown effects on soil ecosystems and their inhabitants. The present study aimed at evaluating the effects of salinisation on soil ecosystems due to sea level rise. The reproduction and mortality of three standard soil invertebrate species (Folsomia candida, Enchytraeus crypticus, Hypoaspis aculeifer) in standard artificial OECD soil spiked with serial dilutions of seawater/gradient of NaCl were evaluated according to standard guidelines. An increased sensitivity was observed in the following order: H. aculeifer≪E. crypticus≈F. candida consistent with the different exposure pathways: springtails and enchytraeids are exposed by ingestion and contact while mites are mainly exposed by ingestion due to a continuous and thick exoskeleton. Although small differences were observed in the calculated effect electrical conductivity values, seawater and NaCl induced the same overall effects (with a difference in the enchytraeid tests where a higher sensitivity was found in relation to NaCl). The adverse effects described in the present study are observed on soils not considered saline. Therefore, the actual limit to define saline soils (4000 μS cm(-1)) does not reflect the existing knowledge when considering soil fauna.

  19. Cationic Phospholipids Forming Cubic Phases: Lipoplex Structure and Transfection Efficiency

    SciTech Connect

    Koynova, Rumiana; Wang, Li; MacDonald, Robert C.

    2008-10-29

    The transfection activity and the phase behavior of two novel cationic O-alkyl-phosphatidylcholines, 1,2-dioleoyl-sn-glycero-3-hexylphosphocholine (C6-DOPC) and 1,2-dierucoyl-sn-glycero-3-ethylphosphocholine (di22:1-EPC), have been examined with the aim of more completely understanding the mechanism of lipid-mediated DNA delivery. Both lipids form cubic phases: C6-DOPC in the entire temperature range from -10 to 90 C, while di22:1-EPC exhibits an irreversible lamellar-cubic transition between 50 and 70 C on heating. The lipoplexes formed by C6-DOPC arrange into hexagonal phase, while the lipoplexes of di22:1-EPC are lamellar. Both lipids exhibit lower transfection activity than the lamellar-forming 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EDOPC). Thus, for the studied cationic phospholipid-DNA systems, the lipoplex phase state is a factor that does not seem to correlate with transfection activity. The parameter that exhibits better correlation with the transfection activity within the present data set is the phase state of the lipid dispersion prior to the addition of DNA. Thus, the lamellar lipid dispersion (EDOPC) produces more efficient lipoplexes than the dispersion with coexisting lamellar and cubic aggregates (diC22:1-EPC), which is even more efficient than the purely cubic dispersions (C6-DOPC; diC22:1-EPC after heating). It could be inferred from these data and from previous research that cubic phase lipid aggregates are unlikely to be beneficial to transfection. The lack of correlation between the phase state of lipoplexes and their transfection activity observed within the present data set does not mean that lipid phase state is generally unimportant for lipofection: a viewpoint now emerging from our previous studies is that the critical factor in lipid-mediated transfection is the structural evolution of lipoplexes within the cell, upon interacting and mixing with cellular lipids.

  20. The relative effects of transection of the gustatory branches of the seventh and ninth cranial nerves on NaCl taste detection in rats.

    PubMed

    Blonde, Ginger D; Garcea, Mircea; Spector, Alan C

    2006-06-01

    Chorda tympani nerve (CT) transection in rats severely impairs NaCl taste detection. These rats can detect higher concentrations of NaCl, however, suggesting that remaining oral nerves maintain some salt sensibility. Rats were tested in a gustometer with a 2-response operant taste-detection task before and after sham surgery (n = 5), combined transection of the CT and the greater superficial petrosal nerves (GSP; 7x, n = 6), or transection of the glossopharyngeal nerve (GL; 9x, n = 4). Thresholds did not significantly change after sham surgery. Although the GL responds to NaCl and innervates nearly 60% of total taste buds, 9x surgery had no effect. However, 7x surgery increased NaCl detection threshold by approximately 2.5 log(10) units, greater than that reported for CT transection alone. These results suggest that the GSP contributes to NaCl sensitivity in rats and also demonstrate that the GL and perhaps the superior laryngeal and lingual nerve proper can maintain some NaCl detectability at high concentrations. These findings confirm the primacy of the 7th nerve relative to the 9th nerve in sensibility of NaCl in the rat model.

  1. [Choice of the NaCl concentration for optimizing the detection of methicillin resistance in Staphylococcus using the gel diffusion method].

    PubMed

    Bemer-Melchior, P; Drugeon, H B

    2001-04-01

    The detection of oxacillin resistance is evaluated by the disk diffusion method in a collection of 374 Staphylococcus sp strains. The disk diffusion assay is performed with 5-microgram oxacillin disk and a 10(8) CFU/mL inoculum on Mueller-Hinton agar plates supplemented with 2 or 5% NaCl and incubated at 37 degrees C for 24 h. Strains are considered resistant in accordance to the French recommendations (any growth around the disk is observed). The detection of mecA gene is performed by PCR almost for resistant and discordant strains. Results are concordant for 246 of 256 Staphylococcus aureus strains (182 susceptible and 64 resistant strains) and for 105 of 118 S. epidermidis isolates tested (37 susceptible and 68 resistant strains). Six mecA-negative strains (3 S. aureus and 3 S. epidermidis) give false resistant results on agar with 2 and 5% NaCl. Seventeen isolates are discordant on 5% NaCl: 7 mecA-negative S. aureus strains are susceptible on 2% NaCl agar but resistant at 5% (3% false-positive results), 10 mecA-positive S. epidermidis strains are resistant on 2% NaCl agar but susceptible at 5% NaCl (5% false-negative results). The detection of meticillin resistance is improved on agar supplemented with 2% NaCl.

  2. [Choice of the NaCl concentration for optimizing the detection of methicillin resistance in Staphylococcus using the gel diffusion method].

    PubMed

    Bemer-Melchior, P; Drugeon, H B

    2001-04-01

    The detection of oxacillin resistance is evaluated by the disk diffusion method in a collection of 374 Staphylococcus sp strains. The disk diffusion assay is performed with 5-microgram oxacillin disk and a 10(8) CFU/mL inoculum on Mueller-Hinton agar plates supplemented with 2 or 5% NaCl and incubated at 37 degrees C for 24 h. Strains are considered resistant in accordance to the French recommendations (any growth around the disk is observed). The detection of mecA gene is performed by PCR almost for resistant and discordant strains. Results are concordant for 246 of 256 Staphylococcus aureus strains (182 susceptible and 64 resistant strains) and for 105 of 118 S. epidermidis isolates tested (37 susceptible and 68 resistant strains). Six mecA-negative strains (3 S. aureus and 3 S. epidermidis) give false resistant results on agar with 2 and 5% NaCl. Seventeen isolates are discordant on 5% NaCl: 7 mecA-negative S. aureus strains are susceptible on 2% NaCl agar but resistant at 5% (3% false-positive results), 10 mecA-positive S. epidermidis strains are resistant on 2% NaCl agar but susceptible at 5% NaCl (5% false-negative results). The detection of meticillin resistance is improved on agar supplemented with 2% NaCl. PMID:11367555

  3. The role of NaCl in flame chemistry, in the deposition process, and in its reactions with protective oxides as related to hot corrosion

    NASA Technical Reports Server (NTRS)

    Kohl, F. J.; Stearns, C. A.

    1979-01-01

    Sodium chloride is believed to be the primary source of turbine engine contamination that contributes to hot corrosion. The behavior of NaCl-containing aerosols ingested with turbine intake air is very complex; some of the NaCl may vaporize during combustion while some may remain as particulates. The NaCl can lead to Na2SO4 formation by several possible routes or it can contribute to corrosion directly. Hydrogen or oxygen atom reaction with NaCl(c) was shown to result in the release of Na(g). Gaseous NaCl in flames can be partially converted to gaseous Na2SO4 by homogeneous reactions. The remaining gaseous NaCl and other Na-containing molecules can act as sodium carriers for condensate deposition of Na2SO4 on cool surfaces. A frozen boundary layer theory was developed to predict the rates of deposition. The condensed phase NaCl can be converted directly to condensed Na2SO4 by reaction with sulfur oxides and O2. Reaction of gaseous NaCl with Cr2O3 results in the vapor phase transport of chromium by the formation of complex Cr-containing gaseous molecules. Similar gaseous complexes are formed with molybdenum. The presence of gaseous NaCl was shown to affect the oxidation kinetics of Ni-Cr alloys. It also causes changes in the surface morphology of Al2O3 scales formed on Al-containing alloys.

  4. 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...

  5. 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...

  6. Fluid deprivation increases isotonic NaCl intake, but not hypertonic salt intake, under normal and heated conditions in obese Zucker rats.

    PubMed

    Omouessi, S T; Lemamy, G J; Kiki-Mvouaka, S; Fernette, B; Falconetti, C; Ndeboko, B; Mouecoucou, J; Thornton, S N

    2016-02-01

    In the course of exposure to fluid deprivation and heated environment, mammals regulate their hydromineral balance and body temperature by a number of mechanisms including sweating, water and salt intakes. Here we challenged obese Zucker rats, known to have a predisposition to hypertension, with 0.9%NaCl alone or with 2%NaCl solution + water to drink under fluid deprivation and heated conditions. Food and fluid intakes, body weight, diuresis and natriuresis were measured daily throughout. Serum aldosterone levels and Na(+) concentration were also analyzed. Data showed that obese and lean rats presented similar baseline measurements of food, 0.9%NaCl and fluid intakes, diuresis and fluid balance; whereas hypertonic 2%NaCl consumption was almost absent. Before and during fluid deprivation animals increased isotonic but not hypertonic NaCl intake; the obese showed significant increases in diuresis and Na(+) excretion, whereas, total fluid intake was similar between groups. Heat increased isotonic NaCl intake and doubled natriuresis in obese which were wet on their fur and displayed a paradoxical increase of fluid gain. Fluid deprivation plus heat produced similar negative fluid balance in all groups. Body weight losses, food intake and diuresis reductions were amplified under the combined conditions. Animals exposed to 2%NaCl showed higher circulating levels of aldosterone and obese were lower than leans. In animals which drank 0.9%NaCl, obese showed higher serum levels of Na(+) than leans. We conclude that in spite of their higher sensitivity to high salt and heat obese Zucker rats can control hydromineral balance in response to fluid deprivation and heat by adjusting isotonic NaCl preference with sodium balance and circulating levels of aldosterone. This suggests a key hormonal role in the mechanisms underlying thermoregulation, body fluid homeostasis and sodium intake. PMID:26621332

  7. The Correlation between NaCl Adaptation and Heat Sensitivity of Listeria monocytogenes, a Foodborne Pathogen through Fresh and Processed Meat.

    PubMed

    Lee, Jeeyeon; Ha, Jimyeong; Kim, Sejeong; Lee, Soomin; Lee, Heeyoung; Yoon, Yohan; Choi, Kyoung-Hee

    2016-01-01

    This study examined the relationship between NaCl sensitivity and stress response of Listeria monocytogenes. Nine strains of L. monocytogenes (NCCP10805, NCCP10806, NCCP10807, NCCP10808, NCCP10809, NCCP10810, NCCP10811, NCCP10920 and NCCP 10943) were exposed to 0%, 1%, 2% and 4% NaCl, and then incubated at 60℃ for 60 min to select strains that were heat-sensitized (HS) and non-sensitized (NS) by NaCl exposure. After heat challenge, L. monocytogenes strains were categorized as HS (NCCP 10805, NCCP10806, NCCP10807, NCCP10810, NCCP10811 and NCCP10920) or NS (NCCP10808, NCCP10809 and NCCP10943). Total mRNA was extracted from a HS strain (NCCP10811) and two NS strains (NCCP10808 and NCCP10809), and then cDNA was prepared to analyze the expression of genes (inlA, inlB, opuC, betL, gbuB, osmC and ctc) that may be altered in response to NaCl stress, by qRT-PCR. The expression levels of two invasion-related genes (inlA and inlB) and two stress response genes (opuC and ctc) were increased (p<0.05) in NS strains after NaCl exposure in an NaCl concentration-dependent manner. However, only betL expression was increased (p<0.05) in the HS strains. These results indicate that the effect of NaCl on heat sensitization of L. monocytogenes is strain dependent and that opuC and ctc may prevent NS L. monocytogenes strains from being heat sensitized by NaCl. Moreover, NaCl also increases the expression of invasion-related genes (inlA and inlB). PMID:27621687

  8. Fluid deprivation increases isotonic NaCl intake, but not hypertonic salt intake, under normal and heated conditions in obese Zucker rats.

    PubMed

    Omouessi, S T; Lemamy, G J; Kiki-Mvouaka, S; Fernette, B; Falconetti, C; Ndeboko, B; Mouecoucou, J; Thornton, S N

    2016-02-01

    In the course of exposure to fluid deprivation and heated environment, mammals regulate their hydromineral balance and body temperature by a number of mechanisms including sweating, water and salt intakes. Here we challenged obese Zucker rats, known to have a predisposition to hypertension, with 0.9%NaCl alone or with 2%NaCl solution + water to drink under fluid deprivation and heated conditions. Food and fluid intakes, body weight, diuresis and natriuresis were measured daily throughout. Serum aldosterone levels and Na(+) concentration were also analyzed. Data showed that obese and lean rats presented similar baseline measurements of food, 0.9%NaCl and fluid intakes, diuresis and fluid balance; whereas hypertonic 2%NaCl consumption was almost absent. Before and during fluid deprivation animals increased isotonic but not hypertonic NaCl intake; the obese showed significant increases in diuresis and Na(+) excretion, whereas, total fluid intake was similar between groups. Heat increased isotonic NaCl intake and doubled natriuresis in obese which were wet on their fur and displayed a paradoxical increase of fluid gain. Fluid deprivation plus heat produced similar negative fluid balance in all groups. Body weight losses, food intake and diuresis reductions were amplified under the combined conditions. Animals exposed to 2%NaCl showed higher circulating levels of aldosterone and obese were lower than leans. In animals which drank 0.9%NaCl, obese showed higher serum levels of Na(+) than leans. We conclude that in spite of their higher sensitivity to high salt and heat obese Zucker rats can control hydromineral balance in response to fluid deprivation and heat by adjusting isotonic NaCl preference with sodium balance and circulating levels of aldosterone. This suggests a key hormonal role in the mechanisms underlying thermoregulation, body fluid homeostasis and sodium intake.

  9. The Correlation between NaCl Adaptation and Heat Sensitivity of Listeria monocytogenes, a Foodborne Pathogen through Fresh and Processed Meat

    PubMed Central

    Choi, Kyoung-Hee

    2016-01-01

    This study examined the relationship between NaCl sensitivity and stress response of Listeria monocytogenes. Nine strains of L. monocytogenes (NCCP10805, NCCP10806, NCCP10807, NCCP10808, NCCP10809, NCCP10810, NCCP10811, NCCP10920 and NCCP 10943) were exposed to 0%, 1%, 2% and 4% NaCl, and then incubated at 60℃ for 60 min to select strains that were heat-sensitized (HS) and non-sensitized (NS) by NaCl exposure. After heat challenge, L. monocytogenes strains were categorized as HS (NCCP 10805, NCCP10806, NCCP10807, NCCP10810, NCCP10811 and NCCP10920) or NS (NCCP10808, NCCP10809 and NCCP10943). Total mRNA was extracted from a HS strain (NCCP10811) and two NS strains (NCCP10808 and NCCP10809), and then cDNA was prepared to analyze the expression of genes (inlA, inlB, opuC, betL, gbuB, osmC and ctc) that may be altered in response to NaCl stress, by qRT-PCR. The expression levels of two invasion-related genes (inlA and inlB) and two stress response genes (opuC and ctc) were increased (p<0.05) in NS strains after NaCl exposure in an NaCl concentration-dependent manner. However, only betL expression was increased (p<0.05) in the HS strains. These results indicate that the effect of NaCl on heat sensitization of L. monocytogenes is strain dependent and that opuC and ctc may prevent NS L. monocytogenes strains from being heat sensitized by NaCl. Moreover, NaCl also increases the expression of invasion-related genes (inlA and inlB).

  10. The Correlation between NaCl Adaptation and Heat Sensitivity of Listeria monocytogenes, a Foodborne Pathogen through Fresh and Processed Meat

    PubMed Central

    Choi, Kyoung-Hee

    2016-01-01

    This study examined the relationship between NaCl sensitivity and stress response of Listeria monocytogenes. Nine strains of L. monocytogenes (NCCP10805, NCCP10806, NCCP10807, NCCP10808, NCCP10809, NCCP10810, NCCP10811, NCCP10920 and NCCP 10943) were exposed to 0%, 1%, 2% and 4% NaCl, and then incubated at 60℃ for 60 min to select strains that were heat-sensitized (HS) and non-sensitized (NS) by NaCl exposure. After heat challenge, L. monocytogenes strains were categorized as HS (NCCP 10805, NCCP10806, NCCP10807, NCCP10810, NCCP10811 and NCCP10920) or NS (NCCP10808, NCCP10809 and NCCP10943). Total mRNA was extracted from a HS strain (NCCP10811) and two NS strains (NCCP10808 and NCCP10809), and then cDNA was prepared to analyze the expression of genes (inlA, inlB, opuC, betL, gbuB, osmC and ctc) that may be altered in response to NaCl stress, by qRT-PCR. The expression levels of two invasion-related genes (inlA and inlB) and two stress response genes (opuC and ctc) were increased (p<0.05) in NS strains after NaCl exposure in an NaCl concentration-dependent manner. However, only betL expression was increased (p<0.05) in the HS strains. These results indicate that the effect of NaCl on heat sensitization of L. monocytogenes is strain dependent and that opuC and ctc may prevent NS L. monocytogenes strains from being heat sensitized by NaCl. Moreover, NaCl also increases the expression of invasion-related genes (inlA and inlB). PMID:27621687

  11. Probabilistic Models to Predict Listeria monocytogenes Growth at Low Concentrations of NaNO2 and NaCl in Frankfurters

    PubMed Central

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

    2015-01-01

    This study developed probabilistic models to describe Listeria monocytogenes growth responses in meat products with low concentrations of NaNO2 and NaCl. A five-strain mixture of L. monocytogenes was inoculated in NBYE (nutrient broth plus 0.6% yeast extract) supplemented with NaNO2 (0-141 ppm) and NaCl (0-1.75%). The inoculated samples were then stored under aerobic and anaerobic conditions at 4, 7, 10, 12, and 15℃ for up to 60 d. Growth response data [growth (1) or no growth (0)] for each combination were determined by turbidity. The growth response data were analyzed using logistic regression to predict the growth probability of L. monocytogenes as a function of NaNO2 and NaCl. The model performance was validated with the observed growth responses. The effect of an obvious NaNO2 and NaCl combination was not observed under aerobic storage condition, but the antimicrobial effect of NaNO2 on the inhibition of L. monocytogenes growth generally increased as NaCl concentration increased under anaerobic condition, especially at 7-10℃. A single application of NaNO2 or NaCl significantly (p<0.05) inhibited L. monocytogenes growth at 4-15℃, but the combination of NaNO2 or NaCl more effectively (p<0.05) inhibited L. monocytogenes growth than single application of either compound under anaerobic condition. Validation results showed 92% agreement between predicted and observed growth response data. These results indicate that the developed model is useful in predicting L. monocytogenes growth response at low concentrations of NaNO2 and NaCl, and the antilisterial effect of NaNO2 increased by NaCl under anaerobic condition. PMID:26877642

  12. Calcium-induced proline accumulation contributes to amelioration of NaCl injury and expression of glutamine synthetase in greater duckweed (Spirodela polyrhiza L.).

    PubMed

    Cheng, Tai-Sheng; Hung, Meng-Ju; Cheng, Yen-I; Cheng, Lee-Ju

    2013-11-15

    The calcium-mediated proline accumulation is a critical response under NaCl stress and the function of the induced proline as a glutamine synthetase (GS) protectant in greater duckweed was investigated. The plants were treated with solutions containing 100mM NaCl, 200 mM NaCl, 200 mM NaCl plus 10mM CaCl2, or 10mM CaCl2 alone for 4 days. At the end of the experiment, the fronds of inoculum treated with 200 mM NaCl showed the chlorotic effect, higher glutamate dehydrogenase (NADH-GDH) activity and lower GS activity. At the lower salinity, the activities of GS and NADH-GDH were not altered markedly. A significant accumulation of proline was not found under either low or high salinity. The activity of Δ(1)-pyrroline-5-carboxylate reductase (P5CR) was enhanced only at 200 mM NaCl but remained unchanged at 100mM NaCl. The activity of Δ(1)-pyrroline-5-carboxylate synthetase (P5CS) did not change under salinity-stressed. Addition of CaCl2 to the salt stressed plants not only lowered NaCl injury but also showed an elevated level of proline contents in response to the salinity treatment. In addition, both GS activity and corresponding polypeptides were expressed close to the level of control. Exogenous proline protects GS2 and the 32 kDa protein in photosystem II reaction center (D1) from H2O2-induced redox degradation in the chloroplast lysates of duckweed. The results suggest that calcium-induced proline accumulation may play an important role as a GS protectant under NaCl exposure in S. polyrhiza.

  13. 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.

  14. Electron correlation in the self-trapped hole and exciton in the NaCl crystal

    NASA Astrophysics Data System (ADS)

    Puchin, V. E.; Shluger, A. L.; Itoh, N.

    1995-09-01

    An ab initio embedded molecular cluster method was used to find equilibrium configurations of the self-trapped hole (VK center) and self-trapped exciton in the NaCl crystal. The results obtained in the Hartree-Fock approximation are compared with those using the Mo/ller-Plesset second-order perturbation theory (MP2) for the calculation of the electron correlation correction to the total energy. The excitation energies for the VK center and self-trapped exciton (STE) were calculated using the configuration interaction for single excitations (CIS) combined with the MP2 method. It is demonstrated that the Σ band of the optical absorption spectrum of the VK center consists of two bands. These correspond to the intramolecular electron transition in the Cl-2 molecular ion, and the ``host-to-molecule'' transition from the surrounding lattice anions. For the self-trapped exciton, it is found that the atomic structure of the ``off-center'' configuration of the ground state of the triplet STE is not strongly affected by taking account of the electron correlation. In particular, the off-center displacement of the center of mass of the hole component of the STE from the on-center configuration is less than half that corresonding to a pair of nearest F and H centers. The intramolecular distance in the hole component of the STE obtained in this calculation is much shorter than in previous calculations and close to that in the H center. Two Σ polarized transitions with the energies of 3.7 and 4.02 eV were found for the hole component of the ``off-center'' STE. The correlated treatment, in contrast with the Hartree-Fock and one-electron approximations, predicts the existence of the local minimum on the adiabatic potential surface which corresponds to the ``on-center'' STE configuration (electron trapped by the VK center). The calculated energy of optical absorption by the electron component of the triplet STE in this configuration is 0.6 eV and that of the hole component is

  15. Tracing groundwater salinization processes in coastal aquifers: a hydrogeochemical and isotopic approach in the Na-Cl brackish waters of northwestern Sardinia, Italy

    NASA Astrophysics Data System (ADS)

    Mongelli, G.; Monni, S.; Oggiano, G.; Paternoster, M.; Sinisi, R.

    2013-07-01

    Throughout the Mediterranean, salinization threatens water quality, especially in coastal areas. This salinization is the result of concomitant processes related to both seawater intrusion and water-rock interaction, which in some cases are virtually indistinguishable. In the Nurra region of northwestern Sardinia, recent salinization related to marine water intrusion has been caused by aquifer exploitation. However, the geology of this region records a long history from the Palaeozoic to the Quaternary, and is structurally complex and comprises a wide variety of lithologies, including Triassic evaporites. Determining the origin of the saline component of the Jurassic and Triassic aquifers in the Nurra region may provide a useful and more general model for salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activity and recent climatic change, the Nurra has become vulnerable to desertification and, in common with other Mediterranean islands, surface water resources periodically suffer from severe shortages. With this in mind, we report new data regarding brackish and surface waters (outcrop and lake samples) of the Na-Cl type from the Nurra region, including major ions and selected trace elements (B, Br, I, and Sr), in addition to isotopic data including δ18O, δD in water, and δ34S and δ18O in dissolved SO4. To identify the origin of the salinity more precisely, we also analysed the mineralogical and isotopic composition of Triassic evaporites. The brackish waters have Cl contents of up to 2025 mg L-1 , and the ratios between dissolved ions and Cl, with the exception of the Br / Cl ratio, are not those expected on the basis of simple mixing between rainwater and seawater. The δ18O and δD data indicate that most of the waters fall between the regional meteoric water line and the global meteoric water line, supporting the conclusion that they are

  16. The lipid cubic phase or in meso method for crystallizing proteins. Bushings for better manual dispensing

    PubMed Central

    Caffrey, Martin; Eifert, Robert; Li, Dianfan; Howe, Nicole

    2014-01-01

    The lipid cubic phase or in meso method can be used to set up crystallization trials of soluble and membrane proteins. The cubic phase is noted for being a sticky and viscous mesophase. Dispensing the protein-laden mesophase by hand into wells on crystallization plates has been facilitated by the use of an inexpensive repeat dispenser. However, the assembled dispensing device is prone to damage. Specifically, the delicate plunger used to dispense the viscous mesophase by positive displacement can be bent and scarred when the locking nut that fixes the plunger to the ratchet-driven dispensing mechanism is inadvertently overtightened. A defective plunger can render the device useless as a dispensing tool. More importantly, it can lead to catastrophic loss of valuable protein and lipid due to leakage when the dispensing syringe is being recharged with fresh mesophase. This note describes two types of bushings designed to protect the plunger from mechanical damage, which provide facile and reliable dispenser performance. One is a split bushing in brass and is a highly durable solution. The other is a small sleeve made from readily available plastic tubing. While it lacks durability, the plastic sleeve is simple yet highly effective, and can be replaced as the need arises. PMID:25294983

  17. The lipid cubic phase or in meso method for crystallizing proteins. Bushings for better manual dispensing.

    PubMed

    Caffrey, Martin; Eifert, Robert; Li, Dianfan; Howe, Nicole

    2014-10-01

    The lipid cubic phase or in meso method can be used to set up crystallization trials of soluble and membrane proteins. The cubic phase is noted for being a sticky and viscous mesophase. Dispensing the protein-laden mesophase by hand into wells on crystallization plates has been facilitated by the use of an inexpensive repeat dispenser. However, the assembled dispensing device is prone to damage. Specifically, the delicate plunger used to dispense the viscous mesophase by positive displacement can be bent and scarred when the locking nut that fixes the plunger to the ratchet-driven dispensing mechanism is inadvertently overtightened. A defective plunger can render the device useless as a dispensing tool. More importantly, it can lead to catastrophic loss of valuable protein and lipid due to leakage when the dispensing syringe is being recharged with fresh mesophase. This note describes two types of bushings designed to protect the plunger from mechanical damage, which provide facile and reliable dispenser performance. One is a split bushing in brass and is a highly durable solution. The other is a small sleeve made from readily available plastic tubing. While it lacks durability, the plastic sleeve is simple yet highly effective, and can be replaced as the need arises. PMID:25294983

  18. Results from Boiling Temperature Measurements for Saturated Solutions in the Systems NaCl + Ca(NO3)2 + H2O, NaNO3 + KNO3 + H2O, and NaCl + KNO3 + H2O, and Dry Out Temperatures for NaCl + NaNO3 + KNO3 + Ca(NO3)2 + H2O

    SciTech Connect

    Rard, J A

    2005-11-29

    Boiling temperature measurements have been made for saturated ternary solutions of NaCl + KNO{sub 3} + H{sub 2}O and NaNO{sub 3} + KNO{sub 3} + H{sub 2}O at three selected salt ratios and for NaCl + Ca(NO{sub 3}){sub 2} + H{sub 2}O over the full composition range. The maximum boiling temperature found for the NaCl + Ca(NO{sub 3}){sub 2} + H{sub 2}O system is 164.7 {+-} 0.6 C, and the composition is estimated to occur at x(Ca(NO{sub 3}){sub 2}) {approx} 0.25. Experiments were also performed for the five component NaCl + NaNO{sub 3} + KNO{sub 3} + Ca(NO{sub 3}){sub 2} + H{sub 2}O mixtures with the molar ratio of NaCl:NaNO{sub 3}:KNO{sub 3} held essentially constant at 1:0.9780:1.1468 as the solute mole fraction of Ca(NO{sub 3}){sub 2}, x(Ca(NO{sub 3}){sub 2}), was varied between 0 and 0.25. The NaCl + NaNO{sub 3} + KNO{sub 3} + Ca(NO{sub 3}){sub 2} + H{sub 2}O system forms low melting mixtures and thus boiling temperatures for saturated were not determined. Instead, the temperatures corresponding to the cessation of boiling (i.e., dry out temperatures) of these liquid mixtures were determined. These dry out temperatures range from {approx} 300 C when x(Ca(NO{sub 3}){sub 2}) = 0 to {ge} 400 C when x(Ca(NO{sub 3}){sub 2}) = 0.20 and 0.25. The investigated mixture compositions correspond to some of the major mineral assemblages that are predicted to control the deliquescence relative humidity of salts formed by leaching dust samples from the proposed nuclear repository at Yucca Mountain, Nevada.

  19. Cs diffusion in cubic silicon carbide

    NASA Astrophysics Data System (ADS)

    Shrader, David; Szlufarska, Izabela; Morgan, Dane

    2012-02-01

    Undesired release of Cs through a silicon carbide coating of nuclear fuel is a significant concern for the design of the Very High Temperature Reactor (VHTR). However, mechanisms of Cs transport are currently unclear. To better understand the possible mechanisms of Cs release here we use density functional theory to study diffusion of Cs in crystalline bulk SiC. Cs point defects and Cs - vacancy clusters have been investigated for stability and structure. The most stable state for the Cs impurity in SiC, under n-type doping conditions, is found to be a negatively charged Cs atom substituting for a C atom and bound to two Si vacancies ( Cs-2VSi3-). Bulk diffusion coefficients are estimated for several Cs impurity states. The Cs-2VSi3- defect structure is found to have the lowest overall activation energy for diffusion with a value of approximately 5.14 eV. This activation energy agrees well with diffusion activation energies estimated for Cs in SiC based on high temperature integral release experiments.

  20. Heterogeneous reactions of HNO3(g) + NaCl(s) yields HCl(g) + NaNO3(s) and N2O5(g) + NaCl(s) yields ClNO2(g) + NaNO3(s)

    NASA Technical Reports Server (NTRS)

    Leu, Ming-Taun; Timonen, Raimo S.; Keyser, Leon F.; Yung, Yuk L.

    1995-01-01

    The heterogeneous reactions of HNO3(g) + NaCl(s) yields HCl(g) + NaNO3(s) (eq 1) and N2O5(g) + NaCl(s) yields ClNO2(g) + NaNO3(S) (eq 2) were investigated over the temperature range 223-296 K in a flow-tube reactor coupled to a quadrupole mass spectrometer. Either a chemical ionization mass spectrometer (CIMS) or an electron-impact ionization mass spectrometer (EIMS) was used to provide suitable detection sensitivity and selectivity. In order to mimic atmospheric conditions, partial pressures of HNO3 and N2O5 in the range 6 x 10(exp -8) - 2 x 10(exp -6) Torr were used. Granule sizes and surface roughness of the solid NaCl substrates were determined by using a scanning electron microscope. For dry NaCl substrates, decay rates of HNO3 were used to obtain gamma(1) = 0.013 +/- 0.004 (1sigma) at 296 K and > 0.008 at 223 K, respectively. The error quoted is the statistical error. After all corrections were made, the overall error, including systematic error, was estimated to be about a factor of 2. HCl was found to be the sole gas-phase product of reaction 1. The mechanism changed from heterogeneous reaction to predominantly physical adsorption when the reactor was cooled from 296 to 223 K. For reaction 2 using dry salts, gamma(2) was found to be less than 1.0 x 10(exp -4) at both 223 and 296 K. The gas-phase reaction product was identified as ClNO2 in previous studies using an infrared spectrometer. An enhancement in reaction probability was observed if water was not completely removed from salt surfaces, probably due to the reaction of N2O5(g) + H2O(s) yields 2HNO3(g). Our results are compared with previous literature values obtained using different experimental techniques and conditions. The implications of the present results for the enhancement of the hydrogen chloride column density in the lower stratosphere after the El Chichon volcanic eruption and for the chemistry of HCl and HNO3 in the marine troposphere are discussed.

  1. Characterization of the size and orientation of Na and Cl2 nanocrystals in electron irradiated NaCl crystals by means of synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Sulyanov, S. N.; Kheiker, D. M.; Dorovatovskii, P. V.; Sugonyako, A. V.; Vainshtein, D. I.; den Hartog, H. W.

    2007-06-01

    Samples of synthetic NaCl crystals have been exposed to doses of electron irradiation up to 10-2 TGy (1 Trad) at about 100 °C, and studied subsequently at T = 95 K by means of synchrotron radiation (SR). In addition to the earlier established Kurdjumov-Sachs orientation relationship (K-S OR) for Na precipitates, the following OR is revealed between solid chlorine and the host NaCl crystal system: {\\{}001{\\}}_{\\mathrm {Cl}} \\parallel {\\{}001{\\}}_{\\mathrm {NaCl}} , \\langle 110\\rangle_{\\mathrm {Cl}}\\parallel \\langle 110\\rangle_{\\mathrm {NaCl}} . The size and shape of the Cl2 precipitates has been studied as a function of the amount of radiation damage (i.e. the concentrations of Na and Cl2).

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. Lipidic cubic phase injector facilitates membrane protein serial femtosecond crystallography.

    PubMed

    Weierstall, Uwe; James, Daniel; Wang, Chong; White, Thomas A; Wang, Dingjie; Liu, Wei; Spence, John C H; Bruce Doak, R; Nelson, Garrett; Fromme, Petra; Fromme, Raimund; Grotjohann, Ingo; Kupitz, Christopher; Zatsepin, Nadia A; Liu, Haiguang; Basu, Shibom; Wacker, Daniel; Han, Gye Won; Katritch, Vsevolod; Boutet, Sébastien; Messerschmidt, Marc; Williams, Garth J; Koglin, Jason E; Marvin Seibert, M; Klinker, Markus; Gati, Cornelius; Shoeman, Robert L; Barty, Anton; Chapman, Henry N; Kirian, Richard A; Beyerlein, Kenneth R; Stevens, Raymond C; Li, Dianfan; Shah, Syed T A; Howe, Nicole; Caffrey, Martin; Cherezov, Vadim

    2014-01-01

    Lipidic cubic phase (LCP) crystallization has proven successful for high-resolution structure determination of challenging membrane proteins. Here we present a technique for extruding gel-like LCP with embedded membrane protein microcrystals, providing a continuously renewed source of material for serial femtosecond crystallography. Data collected from sub-10-μm-sized crystals produced with less than 0.5 mg of purified protein yield structural insights regarding cyclopamine binding to the Smoothened receptor.

  7. Multinomial Combinatorial Group Representations of the Octahedral and Cubic Symmetries

    SciTech Connect

    Balasubramanian, K

    2003-12-22

    We consider the full multinomial combinatorics of all irreducible representations of the octahedral (cubic) symmetry as a function of partitions for vertex, face and edge colorings. Full combinatorial tables for all irreducible representations and all multinomial partitions are constructed. These enumerations constitute multinomial expansions of character-based cycle index polynomials, and grow in combinatorial complexity as a function of edge or vertex coloring partitions.

  8. A highly ordered cubic mesoporous silica/graphene nanocomposite

    NASA Astrophysics Data System (ADS)

    Lee, Chang-Wook; Roh, Kwang Chul; Kim, Kwang-Bum

    2013-09-01

    A highly ordered cubic mesoporous silica (KIT-6)/graphene nanocomposite and 2D KIT-6 nanoflakes were synthesized using a novel synthesis methodology. The non-ionic triblock copolymer, P123, played a dual role as a structure-directing agent in the formation of the cubic mesoporous structure and as a cross-linking agent between mesoporous silica and graphene. The prepared (KIT-6)/graphene nanocomposite could act as a template for the preparation of mesoporous material/graphene nanocomposites.A highly ordered cubic mesoporous silica (KIT-6)/graphene nanocomposite and 2D KIT-6 nanoflakes were synthesized using a novel synthesis methodology. The non-ionic triblock copolymer, P123, played a dual role as a structure-directing agent in the formation of the cubic mesoporous structure and as a cross-linking agent between mesoporous silica and graphene. The prepared (KIT-6)/graphene nanocomposite could act as a template for the preparation of mesoporous material/graphene nanocomposites. Electronic supplementary information (ESI) available: S1: TEM images of disordered mesoporous silica/graphene nanocomposite; S2: TEM images of KIT-6/GO nanocomposite; S3: Thermogravimetric analysis of KIT-6/GO and KG-400-700; S4: SEM and TEM images of KIT-6; S5: Low angle XRD, Raman spectra, N2 adsorption isotherms, pore size distribution and photographic images of the prepared samples; S6: TEM image and N2 adsorption isotherms of mesoporous carbon/graphene nanocomposite; S7: XPS C1s spectra of the prepared samples. See DOI: 10.1039/c3nr03108j

  9. Lipidic cubic phase injector facilitates membrane protein serial femtosecond crystallography

    PubMed Central

    Weierstall, Uwe; James, Daniel; Wang, Chong; White, Thomas A.; Wang, Dingjie; Liu, Wei; Spence, John C.H.; Doak, R. Bruce; Nelson, Garrett; Fromme, Petra; Fromme, Raimund; Grotjohann, Ingo; Kupitz, Christopher; Zatsepin, Nadia A.; Liu, Haiguang; Basu, Shibom; Wacker, Daniel; Han, Gye Won; Katritch, Vsevolod; Boutet, Sébastien; Messerschmidt, Marc; Williams, Garth J.; Koglin, Jason E.; Seibert, M. Marvin; Klinker, Markus; Gati, Cornelius; Shoeman, Robert L.; Barty, Anton; Chapman, Henry N.; Kirian, Richard A.; Beyerlein, Kenneth R.; Stevens, Raymond C.; Li, Dianfan; Shah, Syed T.A.; Howe, Nicole; Caffrey, Martin; Cherezov, Vadim

    2014-01-01

    Lipidic cubic phase (LCP) crystallization has proven successful for high-resolution structure determination of challenging membrane proteins. Here we present a technique for extruding gel-like LCP with embedded membrane protein microcrystals, providing a continuously-renewed source of material for serial femtosecond crystallography. Data collected from sub-10 μm-sized crystals produced with less than 0.5 mg of purified protein yield structural insights regarding cyclopamine binding to the Smoothened receptor. PMID:24525480

  10. Infinite Simple 3d Cubic Network of Identical Capacitors

    NASA Astrophysics Data System (ADS)

    Asad, Jihad H.

    2013-06-01

    In this paper, the effective capacitance between the origin (0, 0, 0) and any other lattice site (l1, l2, l3), in an infinite simple cubic (SC) network consisting of identical capacitors each of capacitance C, has been expressed rationally in terms of the known value go and π. The asymptotic behavior is also investigated, and some numerical values for the effective capacitance are presented.

  11. Lipidic cubic phase injector facilitates membrane protein serial femtosecond crystallography.

    PubMed

    Weierstall, Uwe; James, Daniel; Wang, Chong; White, Thomas A; Wang, Dingjie; Liu, Wei; Spence, John C H; Bruce Doak, R; Nelson, Garrett; Fromme, Petra; Fromme, Raimund; Grotjohann, Ingo; Kupitz, Christopher; Zatsepin, Nadia A; Liu, Haiguang; Basu, Shibom; Wacker, Daniel; Han, Gye Won; Katritch, Vsevolod; Boutet, Sébastien; Messerschmidt, Marc; Williams, Garth J; Koglin, Jason E; Marvin Seibert, M; Klinker, Markus; Gati, Cornelius; Shoeman, Robert L; Barty, Anton; Chapman, Henry N; Kirian, Richard A; Beyerlein, Kenneth R; Stevens, Raymond C; Li, Dianfan; Shah, Syed T A; Howe, Nicole; Caffrey, Martin; Cherezov, Vadim

    2014-01-01

    Lipidic cubic phase (LCP) crystallization has proven successful for high-resolution structure determination of challenging membrane proteins. Here we present a technique for extruding gel-like LCP with embedded membrane protein microcrystals, providing a continuously renewed source of material for serial femtosecond crystallography. Data collected from sub-10-μm-sized crystals produced with less than 0.5 mg of purified protein yield structural insights regarding cyclopamine binding to the Smoothened receptor. PMID:24525480

  12. Mitigation of NaCl Stress by Arbuscular Mycorrhizal Fungi through the Modulation of Osmolytes, Antioxidants and Secondary Metabolites in Mustard (Brassica juncea L.) Plants

    PubMed Central

    Sarwat, Maryam; Hashem, Abeer; Ahanger, Mohammad A.; Abd_Allah, Elsayed F.; Alqarawi, A. A.; Alyemeni, Mohammed N.; Ahmad, Parvaiz; Gucel, Salih

    2016-01-01

    Present work was carried out to investigate the possible role of arbuscular mycorrhizal fungi (AMF) in mitigating salinity-induced alterations in Brassica juncea L. Exposure to NaCl stress altered the morphological, physio-biochemical attributes, antioxidant activity, secondary metabolites and phytohormones in the mustard seedlings. The growth and biomass yield, leaf water content, and total chlorophyll content were decreased with NaCl stress. However, AMF-inoculated plants exhibited enhanced shoot and root length, elevated relative water content, enhanced chlorophyll content, and ultimately biomass yield. Lipid peroxidation and proline content were increased by 54.53 and 63.47%, respectively with 200 mM NaCl concentration. Further increase in proline content and decrease in lipid peroxidation was observed in NaCl-treated plants inoculated with AMF. The antioxidants, superoxide dismutase, ascorbate peroxidase, glutathione reductase, and reduced glutathione were increased by 48.35, 54.86, 43.85, and 44.44%, respectively, with 200 mM NaCl concentration. Further increase in these antioxidants has been observed in AMF-colonized plants indicating the alleviating role of AMF to salinity stress through antioxidant modulation. The total phenol, flavonoids, and phytohormones increase with NaCl treatment. However, NaCl-treated plants colonized with AMF showed further increase in the above parameters except ABA, which was reduced with NaCl+AMF treatment over the plants treated with NaCl alone. Our results demonstrated that NaCl caused negative effect on B. juncea seedlings; however, colonization with AMF enhances the NaCl tolerance by reforming the physio-biochemical attributes, activities of antioxidant enzymes, and production of secondary metabolites and phytohormones. PMID:27458462

  13. Mitigation of NaCl Stress by Arbuscular Mycorrhizal Fungi through the Modulation of Osmolytes, Antioxidants and Secondary Metabolites in Mustard (Brassica juncea L.) Plants.

    PubMed

    Sarwat, Maryam; Hashem, Abeer; Ahanger, Mohammad A; Abd Allah, Elsayed F; Alqarawi, A A; Alyemeni, Mohammed N; Ahmad, Parvaiz; Gucel, Salih

    2016-01-01

    Present work was carried out to investigate the possible role of arbuscular mycorrhizal fungi (AMF) in mitigating salinity-induced alterations in Brassica juncea L. Exposure to NaCl stress altered the morphological, physio-biochemical attributes, antioxidant activity, secondary metabolites and phytohormones in the mustard seedlings. The growth and biomass yield, leaf water content, and total chlorophyll content were decreased with NaCl stress. However, AMF-inoculated plants exhibited enhanced shoot and root length, elevated relative water content, enhanced chlorophyll content, and ultimately biomass yield. Lipid peroxidation and proline content were increased by 54.53 and 63.47%, respectively with 200 mM NaCl concentration. Further increase in proline content and decrease in lipid peroxidation was observed in NaCl-treated plants inoculated with AMF. The antioxidants, superoxide dismutase, ascorbate peroxidase, glutathione reductase, and reduced glutathione were increased by 48.35, 54.86, 43.85, and 44.44%, respectively, with 200 mM NaCl concentration. Further increase in these antioxidants has been observed in AMF-colonized plants indicating the alleviating role of AMF to salinity stress through antioxidant modulation. The total phenol, flavonoids, and phytohormones increase with NaCl treatment. However, NaCl-treated plants colonized with AMF showed further increase in the above parameters except ABA, which was reduced with NaCl+AMF treatment over the plants treated with NaCl alone. Our results demonstrated that NaCl caused negative effect on B. juncea seedlings; however, colonization with AMF enhances the NaCl tolerance by reforming the physio-biochemical attributes, activities of antioxidant enzymes, and production of secondary metabolites and phytohormones.

  14. Na/Cl molar ratio changes during a salting cycle and its application to the estimation of sodium retention in salted watersheds.

    PubMed

    Sun, Hongbing; Huffine, Maria; Husch, Jonathan; Sinpatanasakul, Leeann

    2012-08-01

    Using soil column experiments and data from natural watersheds, this paper analyzes the changes in Na/Cl molar ratios during a salting cycle of aqueous-soil systems. The soil column experiments involved introducing NaCl salt at various initial concentrations into multiple soil columns. At the start of a salting cycle in the column experiments, sodium was adsorbed more than chloride due to cation exchange processes. As a result, the initial Na/Cl molar ratio in column effluent was lower than 1, but increased thereafter. One-dimensional PHREEQC geochemical transport simulations also were conducted to further quantify these trends under more diverse scenarios. The experimentally determined Na/Cl molar ratio pattern was compared to observations in the annual salting cycle of four natural watersheds where NaCl is the dominant applied road deicing salt. Typically, Na/Cl molar ratios were low from mid-winter to early spring and increased after the bulk of the salt was flushed out of the watersheds during the summer, fall and early winter. The established relationship between the Na/Cl molar ratios and the amount of sodium retention derived from the column experiments and computer simulations present an alternative approach to the traditional budget analysis method for estimating sodium retention when the experimental and natural watershed patterns of Na/Cl molar ratio change are similar. Findings from this study enhance the understanding of sodium retention and help improve the scientific basis for future environmental policies intended to suppress the increase of sodium concentrations in salted watersheds.

  15. Mitigation of NaCl Stress by Arbuscular Mycorrhizal Fungi through the Modulation of Osmolytes, Antioxidants and Secondary Metabolites in Mustard (Brassica juncea L.) Plants.

    PubMed

    Sarwat, Maryam; Hashem, Abeer; Ahanger, Mohammad A; Abd Allah, Elsayed F; Alqarawi, A A; Alyemeni, Mohammed N; Ahmad, Parvaiz; Gucel, Salih

    2016-01-01

    Present work was carried out to investigate the possible role of arbuscular mycorrhizal fungi (AMF) in mitigating salinity-induced alterations in Brassica juncea L. Exposure to NaCl stress altered the morphological, physio-biochemical attributes, antioxidant activity, secondary metabolites and phytohormones in the mustard seedlings. The growth and biomass yield, leaf water content, and total chlorophyll content were decreased with NaCl stress. However, AMF-inoculated plants exhibited enhanced shoot and root length, elevated relative water content, enhanced chlorophyll content, and ultimately biomass yield. Lipid peroxidation and proline content were increased by 54.53 and 63.47%, respectively with 200 mM NaCl concentration. Further increase in proline content and decrease in lipid peroxidation was observed in NaCl-treated plants inoculated with AMF. The antioxidants, superoxide dismutase, ascorbate peroxidase, glutathione reductase, and reduced glutathione were increased by 48.35, 54.86, 43.85, and 44.44%, respectively, with 200 mM NaCl concentration. Further increase in these antioxidants has been observed in AMF-colonized plants indicating the alleviating role of AMF to salinity stress through antioxidant modulation. The total phenol, flavonoids, and phytohormones increase with NaCl treatment. However, NaCl-treated plants colonized with AMF showed further increase in the above parameters except ABA, which was reduced with NaCl+AMF treatment over the plants treated with NaCl alone. Our results demonstrated that NaCl caused negative effect on B. juncea seedlings; however, colonization with AMF enhances the NaCl tolerance by reforming the physio-biochemical attributes, activities of antioxidant enzymes, and production of secondary metabolites and phytohormones. PMID:27458462

  16. Field-effect transistors based on cubic indium nitride

    PubMed Central

    Oseki, Masaaki; Okubo, Kana; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

    2014-01-01

    Although the demand for high-speed telecommunications has increased in recent years, the performance of transistors fabricated with traditional semiconductors such as silicon, gallium arsenide, and gallium nitride have reached their physical performance limits. Therefore, new materials with high carrier velocities should be sought for the fabrication of next-generation, ultra-high-speed transistors. Indium nitride (InN) has attracted much attention for this purpose because of its high electron drift velocity under a high electric field. Thick InN films have been applied to the fabrication of field-effect transistors (FETs), but the performance of the thick InN transistors was discouraging, with no clear linear-saturation output characteristics and poor on/off current ratios. Here, we report the epitaxial deposition of ultrathin cubic InN on insulating oxide yttria-stabilized zirconia substrates and the first demonstration of ultrathin-InN-based FETs. The devices exhibit high on/off ratios and low off-current densities because of the high quality top and bottom interfaces between the ultrathin cubic InN and oxide insulators. This first demonstration of FETs using a ultrathin cubic indium nitride semiconductor will thus pave the way for the development of next-generation high-speed electronics. PMID:24492240

  17. Field-effect transistors based on cubic indium nitride.

    PubMed

    Oseki, Masaaki; Okubo, Kana; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

    2014-02-04

    Although the demand for high-speed telecommunications has increased in recent years, the performance of transistors fabricated with traditional semiconductors such as silicon, gallium arsenide, and gallium nitride have reached their physical performance limits. Therefore, new materials with high carrier velocities should be sought for the fabrication of next-generation, ultra-high-speed transistors. Indium nitride (InN) has attracted much attention for this purpose because of its high electron drift velocity under a high electric field. Thick InN films have been applied to the fabrication of field-effect transistors (FETs), but the performance of the thick InN transistors was discouraging, with no clear linear-saturation output characteristics and poor on/off current ratios. Here, we report the epitaxial deposition of ultrathin cubic InN on insulating oxide yttria-stabilized zirconia substrates and the first demonstration of ultrathin-InN-based FETs. The devices exhibit high on/off ratios and low off-current densities because of the high quality top and bottom interfaces between the ultrathin cubic InN and oxide insulators. This first demonstration of FETs using a ultrathin cubic indium nitride semiconductor will thus pave the way for the development of next-generation high-speed electronics.

  18. 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. PMID:24995330

  19. 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

  20. Specificity and Ligand Affinities of the Cocaine Aptamer: Impact of Structural Features and Physiological NaCl.

    PubMed

    Sachan, Ashish; Ilgu, Muslum; Kempema, Aaron; Kraus, George A; Nilsen-Hamilton, Marit

    2016-08-01

    The cocaine aptamer has been seen as a good candidate for development as a probe for cocaine in many contexts. Here, we demonstrate that the aptamer binds cocaine, norcocaine, and cocaethylene with similar affinities and aminoglycosides with similar or higher affinities in a mutually exclusive manner with cocaine. Analysis of its affinities for a series of cocaine derivatives shows that the aptamer specificity is the consequence of its interaction with all faces of the cocaine molecule. Circular dichroism spectroscopy and 2-aminopurine (2AP) fluorescence studies show no evidence of large structural rearrangement of the cocaine aptamer upon ligand binding, which is contrary to the general view of this aptamer. The aptamer's affinity for cocaine and neomycin-B decreases with the inclusion of physiological NaCl. The substitution of 2AP for A in position 6 (2AP6) of the aptamer sequence eliminated the effect of NaCl on its affinities for cocaine and analogues, but not for neomycin-B, showing a selective effect of 2AP substitution on cocaine binding. The affinity for cocaine also decreased with increasing concentrations of serum or urine, with the 2AP6 substitution blunting the effect of urine. Its low affinities for cocaine and metabolites and its ability to bind irrelevant compounds limit the opportunities for application of this aptamer in its current form as a selective and reliable sensor for cocaine. However, these studies also show that a small structural adjustment to the aptamer (2AP exchanged for adenine) can increase its specificity for cocaine in physiological NaCl relative to an off-target ligand.

  1. Specificity and Ligand Affinities of the Cocaine Aptamer: Impact of Structural Features and Physiological NaCl.

    PubMed

    Sachan, Ashish; Ilgu, Muslum; Kempema, Aaron; Kraus, George A; Nilsen-Hamilton, Marit

    2016-08-01

    The cocaine aptamer has been seen as a good candidate for development as a probe for cocaine in many contexts. Here, we demonstrate that the aptamer binds cocaine, norcocaine, and cocaethylene with similar affinities and aminoglycosides with similar or higher affinities in a mutually exclusive manner with cocaine. Analysis of its affinities for a series of cocaine derivatives shows that the aptamer specificity is the consequence of its interaction with all faces of the cocaine molecule. Circular dichroism spectroscopy and 2-aminopurine (2AP) fluorescence studies show no evidence of large structural rearrangement of the cocaine aptamer upon ligand binding, which is contrary to the general view of this aptamer. The aptamer's affinity for cocaine and neomycin-B decreases with the inclusion of physiological NaCl. The substitution of 2AP for A in position 6 (2AP6) of the aptamer sequence eliminated the effect of NaCl on its affinities for cocaine and analogues, but not for neomycin-B, showing a selective effect of 2AP substitution on cocaine binding. The affinity for cocaine also decreased with increasing concentrations of serum or urine, with the 2AP6 substitution blunting the effect of urine. Its low affinities for cocaine and metabolites and its ability to bind irrelevant compounds limit the opportunities for application of this aptamer in its current form as a selective and reliable sensor for cocaine. However, these studies also show that a small structural adjustment to the aptamer (2AP exchanged for adenine) can increase its specificity for cocaine in physiological NaCl relative to an off-target ligand. PMID:27348073

  2. Influence of NaCl on Growth, Proline, and Phosphoenolpyruvate Carboxylase Levels in Mesembryanthemum crystallinum Suspension Cultures 1

    PubMed Central

    Thomas, John C.; De Armond, Richard L.; Bohnert, Hans J.

    1992-01-01

    The facultative halophyte Mesembryanthemum crystallinum responds to salt stress by increasing the levels of phosphoenolpyruvate carboxylase (PEPCase) and other enzymes associated with Crassulacean acid metabolism. A more common response to salt stress in sensitive and tolerant species, including M. crystallinum, is the accumulation of proline. We have established M. crystallinum suspension cultures to investigate whether both these salt-induced responses occur at the cellular level. Leaf-and root-derived cultures maintain 5% of the total soluble amino acids as proline. Cell culture growth slows upon addition of 400 millimolar NaCl, and proline levels increase to 40% of the total soluble amino acids. These results suggest a functional salt-stress and response program in Mesembryanthemum cells. Suspension cultures grown with or without 400 millimolar NaCl have PEPCase levels that compare with those from roots and unstressed leaves. The predominant protein cross-reacting with an anti-PEPCase antibody corresponds to 105 kilodaltons (apparent molecular mass), whereas a second species of approximately 110 kilodaltons is present at low levels. In salt-stressed leaves, the 110 kilodalton protein is more prevalent. Levels of mRNA for both ppc1 (salt stress induced in leaves) and ppc2 (constitutive) genes in salt-treated suspensions cultures are equal to unstressed leaves, and only twice the levels found in untreated suspension cultures. Whereas cells accumulate proline in response to NaCl, PEPCase protein amounts remain similar in salt-treated and untreated cultures. The induction upon salt stress of the 110 kilodalton PEPCase protein and other Crassulacean acid metabolism enzymes in organized tissues is not observed in cell culture and may depend on tissue-dependent or photoautotrophy-dependent programs. ImagesFigure 4Figure 5 PMID:16668687

  3. Effect of particle water on ozone and secondary organic aerosol formation from benzene-NO2-NaCl irradiations

    NASA Astrophysics Data System (ADS)

    Wang, Yujie; Luo, Hao; Jia, Long; Ge, Shuangshuang

    2016-09-01

    Ozone (O3) and secondary organic aerosol (SOA) are important pollutants in the urban atmosphere. Benzene is one of the most important aromatic species in urban air, which could produce O3 and SOA in the presence of NOx (x = 1, 2) and UV light. A series of experiments was carried out to study the effect of particle water on O3 and SOA formation from benzene under various humid conditions in an indoor smog chamber. The results show that the peak O3 concentrations decreased with the increase of RH or the mass concentration of liquid NaCl particles. The peak O3 concentration reduced by 30% as RH increased from 9% to 87% with the similar initial concentrations of NaCl (about 46 μg m-3), and decreased by 10% as the initial NaCl concentrations increased from 36.0 μg m-3 to 152.1 μg m-3 at about 73% RH. The relationships between liquid water content (LWC) and O3 or SOA were investigated. The results show that LWC is the key factor that leads to an opposite effect on O3 and SOA formation from benzene. The peak O3 concentration exponentially decreased 37% as LWC0 increased from zero to 349.8 μg m-3. Heterogeneous reaction of dinitrogen pentoxide (N2O5) with particle water is the major reason for the decrease of O3. The yields of SOA increased from 5.2 to 10.5% as LWC0 increased from zero to 349.8 μg m-3. The relative intensities of bands Osbnd H, Cdbnd O, Csbnd OH and NO3- increased by 22.9, 6.8, 6.7 and 13.1 times respectively as compared with dry condition. Alcohols or hydrates are confirmed to be the major contributors to SOA with increasing LWC.

  4. Effects of inhibitors and NaCl on the oxidation of reduced inorganic sulfur compounds by a marine acidophilic, sulfur-oxidizing bacterium, Acidithiobacillus thiooxidans strain SH.

    PubMed

    Kamimura, Kazuo; Higashino, Emi; Kanao, Tadayoshi; Sugio, Tsuyoshi

    2005-02-01

    The effect of NaCl and the pathways of the oxidation of reduced inorganic sulfur compounds were studied using resting cells and cell-free extracts of Acidithiobacillus thiooxidans strain SH. This isolate specifically requires NaCl for growth. The oxidation of sulfur and sulfite by resting cells was strongly inhibited by 2-heptyl-4-hydroxyquinoline-N-oxide. Carbonylcyanide m-chlorophenyl-hydrazone and monensin were also relatively strong inhibitors. Thiosulfate-oxidizing activity was not inhibited by these uncouplers. Valinomycin did not inhibit the oxidation of sulfur compounds. NaCl stimulated the sulfur- and sulfite-oxidizing activities in resting cells but not in cell-free extracts. The tetrathionate-oxidizing activity in resting cells was slightly stimulated by NaCl, whereas it did not influence the thiosulfate-oxidizing activity. Sulfide oxidation was biphasic, suggesting the formation of intermediate sulfur. The initial phase of sulfide oxidation was not affected by NaCl, whereas the subsequent oxidation of sulfur in the second phase was Na+-dependent. A model is proposed for the role of NaCl in the metabolism of reduced sulfur compounds in A. thiooxidans strain SH.

  5. 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. PMID:27458871

  6. Chirped Peregrine solitons in a class of cubic-quintic nonlinear Schrödinger equations

    NASA Astrophysics Data System (ADS)

    Chen, Shihua; Baronio, Fabio; Soto-Crespo, Jose M.; Liu, Yi; Grelu, Philippe

    2016-06-01

    We shed light on the fundamental form of the Peregrine soliton as well as on its frequency chirping property by virtue of a pertinent cubic-quintic nonlinear Schrödinger equation. An exact generic Peregrine soliton solution is obtained via a simple gauge transformation, which unifies the recently-most-studied fundamental rogue-wave species. We discover that this type of Peregrine soliton, viable for both the focusing and defocusing Kerr nonlinearities, could exhibit an extra doubly localized chirp while keeping the characteristic intensity features of the original Peregrine soliton, hence the term chirped Peregrine soliton. The existence of chirped Peregrine solitons in a self-defocusing nonlinear medium may be attributed to the presence of self-steepening effect when the latter is not balanced out by the third-order dispersion. We numerically confirm the robustness of such chirped Peregrine solitons in spite of the onset of modulation instability.

  7. Structure and luminescence of gadolinium-doped cubic boron nitride powder

    NASA Astrophysics Data System (ADS)

    Leonchik, S. V.; Karotki, A. V.

    2012-09-01

    The structural characteristics and chemical, morphological, and optical properties of cBN and cBN:Gd micropowders are studied by x-ray diffraction, energy-dispersive electron probe microanalysis (x-ray spectral microanalysis), and photoluminescence techniques. Cubic boron nitride (cBN) micropowders were synthesized at high pressures and temperatures from hexagonal boron nitride (hBN) micropowder and Li3N catalyst. cBN:Gd micropowders were synthesized from mixtures of hBN, Li3N, and GdF3 micropowders. A lattice parameter of a~3.615 Å is calculated for both types of powder (cBN and cBN:Gd). The photoluminescence spectra of the cBN:Gd powder are found to contain emission lines attributable to intracenter optical transitions of Gd3+ ions.

  8. Mechanical properties of polycrystalline translucent cubic boron nitride as characterized by the Vickers indentation method

    SciTech Connect

    Taniguchi, Takashi; Akaishi, Minoru; Yamaoka, Shinobu

    1996-02-01

    Mechanical properties of polycrystalline translucent cubic boron nitride (cBN) were characterized by Vickers indentation measurement. The calculated hardness decreased from 54 to 49 GPa as the load increased to 39 N, and then remained constant for values above this load. According to the relationship between crack length and applied indentation load, the formation of the median/radial type of cracks seems to take place at an applied load above 29 N. Assuming that the ratio of hardness and Young`s modulus is constant in the polycrystalline cBN, the fracture toughness, K{sub IC}, of cBN was estimated to be 5.0 {+-} 0.5 MPa {center_dot} m{sup 1/2}.

  9. Experimental Results of Hydrogen Slosh in a 62 Cubic Foot (1750 Liter) Tank

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.; Mcnelis, Nancy B.; Kudlac, Maureen T.; Haberbusch, Mark S.; Satornino, George A.

    1994-01-01

    Extensive slosh testing with liquid and slush hydrogen was conducted in a 62 cubic foot spherical tank to characterize the thermodynamic response of the system under normal gravity conditions. Slosh frequency and amplitude, pressurant type, ramp pressure, and ullage volume were parametrically varied to assess the effect of each of these parameters on the tank pressure and fluid/wall temperatures. A total of 91 liquid hydrogen and 62 slush hydrogen slosh tests were completed. Both closed tank tests and expulsions during sloshing were performed. This report presents and discusses highlights of the liquid hydrogen closed tank results in detail and introduces some general trends for the slush hydrogen tests. Summary comparisons between liquid and slush hydrogen slosh results are also presented.

  10. Anisotropy of the electron g factor in quantum wells based on cubic semiconductors

    SciTech Connect

    Alekseev, P. S.

    2013-09-15

    A new mechanism for the spin splitting of electron levels in asymmetric quantum wells based on GaAs-type semiconductors relative to rotations of the magnetic field in the well plane is suggested. It is demonstrated that the anisotropy of the Zeeman splitting (linear in a magnetic field) arises in asymmetric quantum wells due to the interface spin-orbit terms in the electron Hamiltonian. In the case of symmetric quantum wells, it is shown that the anisotropy of the Zeeman splitting is a cubic function of the magnitude of the magnetic field, depends on the direction of the magnetic field in the interface plane as the fourth-order harmonic, and is governed by the spin-orbit term of the fourth order by the kinematic momentum in the electron Hamiltonian of a bulk semiconductor.

  11. Multiple delta doping of single crystal cubic boron nitride films heteroepitaxially grown on (001)diamonds

    SciTech Connect

    Yin, H.; Ziemann, P.

    2014-06-23

    Phase pure cubic boron nitride (c-BN) films have been epitaxially grown on (001) diamond substrates at 900 °C. The n-type doping of c-BN epitaxial films relies on the sequential growth of nominally undoped (p-) and Si doped (n-) layers with well-controlled thickness (down to several nanometer range) in the concept of multiple delta doping. The existence of nominally undoped c-BN overgrowth separates the Si doped layers, preventing Si dopant segregation that was observed for continuously doped epitaxial c-BN films. This strategy allows doping of c-BN films can be scaled up to multiple numbers of doped layers through atomic level control of the interface in the future electronic devices. Enhanced electronic transport properties with higher hall mobility (10{sup 2} cm{sup 2}/V s) have been demonstrated at room temperature as compared to the normally continuously Si doped c-BN films.

  12. Experimental results of hydrogen slosh in a 62 cubic foot (1750 liter) tank

    NASA Astrophysics Data System (ADS)

    Moran, Matthew E.; McNelis, Nancy B.; Kudlac, Maureen T.; Haberbusch, Mark S.; Satornino, George A.

    1994-06-01

    Extensive slosh testing with liquid and slush hydrogen was conducted in a 62 cubic foot spherical tank to characterize the thermodynamic response of the system under normal gravity conditions. Slosh frequency and amplitude, pressurant type, ramp pressure, and ullage volume were parametrically varied to assess the effect of each of these parameters on the tank pressure and fluid/wall temperatures. A total of 91 liquid hydrogen and 62 slush hydrogen slosh tests were completed. Both closed tank tests and expulsions during sloshing were performed. This report presents and discusses highlights of the liquid hydrogen closed tank results in detail and introduces some general trends for the slush hydrogen tests. Summary comparisons between liquid and slush hydrogen slosh results are also presented.

  13. Bioelectricity production from food waste leachate using microbial fuel cells: effect of NaCl and pH.

    PubMed

    Li, Xiao Min; Cheng, Ka Yu; Wong, Jonathan W C

    2013-12-01

    Microbial fuel cells are a promising technology for simultaneous treatment and energy recovery from food waste leachate. This study evaluates the effects of NaCl (0-150 mM) and pH on the treatment of food waste leachate using microbial fuel cells. The food waste leachate amended with 100mM NaCl enabled the highest maximum power density (1000 mW/m(3)) and lowest internal resistance (371Ω). Increasing the anodic pH gradually from acidic to alkaline conditions (pH 4-9) resulted in a gradual increase in maximum power density to 9956 mW/m(3) and decrease in internal cell resistance to 35.3Ω. The coulombic efficiency obtained under acidic conditions was only 17.8%, but increased significantly to 60.0% and 63.4% in the neutral and alkaline pH's MFCs, respectively. Maintaining a narrow pH window (6.3-7.6) was essential for efficient bioelectricity production and COD removal using microbial fuel cells for the treatment of food waste leachate.

  14. Tailoring band gaps of insulators by adsorption at surface defects: Benzoic acids on NaCl surfaces

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Tegenkamp, Christoph; Pfnür, Herbert; Bredow, Thomas

    2009-06-01

    The adsorption of benzoic acid and its OH-substituted derivatives, namely, salicylic acid (SA) and parasalicylic acid on various NaCl surfaces has been investigated by density-functional theory with hybrid exchange-correlation functional. The ideal NaCl(100) surface is chemically inert as evidenced by the low binding energies. The molecular adsorption can be enhanced by both an anion vacancy and a surface step site. The bonding between the surface Na and the carboxylic O atom is of covalent character for all adsorption geometries. Our calculations show that the adsorption of SA has the largest binding energy of all three acids due to the additional interaction between Na and the phenolic O atom. Charge transfer between the molecule and the surface is generally very small, except in the presence of an anion vacancy where the unpaired electron is mostly transferred to the adsorbate. Surface defects generally have a strong influence on the electronic structure of the adsorbed molecules. Specifically, the adsorption of SA at [011]-oriented steps can significantly reduce the effective band gap to 1.6 eV due to the up shift of the Cl3p levels at the undercoordinated step edge. Implications of these results to the contact charging effect between wide-band-gap insulators will be discussed.

  15. [Effects of NaCl stress on leaf photosynthesis characteristics and free amino acid metabolism of Heyedysarum scoparium].

    PubMed

    Yan, Hui; Peng, Xiao-Bang; Xue, Jian-Jie

    2012-07-01

    This paper studied the variations of leaf photosynthesis gas exchange, chlorophyll fluorescence, and free amino acid contents of Heyedysarum scoparium under the stress of different concentration NaCl, aimed to understand the effects of salt stress on the leaf physiological characteristics and free amino acid metabolism of the plant. Under mild salt stress, the photo-damage of the leaf photosystem II was avoided via the dissipation of excess excitation energy, and stomatal limitation was the main factor reducing the photosynthesis rate. With the increase of salt stress, the leaf photoprotection was not sufficient to avoid oxidative damage, and thus, the damage to photosystem II happened. Under the stress of 200 mmol NaCl x L(-1), non-stomatal limitation was the main factor responsible for the inhibition of photosynthesis. The accumulation and metabolism of major free amino acids in H. scoparium leaves varied under salt stress. Under mild salt stress, the major free amino acids such as proline, glutamate, aspartate, and alanine had a significant accumulation, but with the further increase of salt stress, the aspartate and alanine contents in H. scoparium leaves decreased, while the synthesis and accumulation of praline increased.

  16. Absence of a salt (NaCl) preference or appetite in sodium-replete or depleted kittens.

    PubMed

    Yu, S; Rogers, Q R; Morris, J G

    1997-08-01

    Many omnivores and herbivores exhibit an appetite for sodium or salt (NaCl) solutions, but a similar sodium appetite has not been demonstrated in carnivores. The choice for or against sodium-adequate diets of sodium-replete and depleted kittens (confirmed by an elevated plasma aldosterone concentration) was examined using a two-bowl choice test. Both bowls contained purified diets, one bowl with one of various levels of sodium (as NaCl) and the other bowl a sodium-deficient diet (0.1 g Na/Kg). Neither sodium-replete nor depleted kittens showed a choice of the diet containing 2 g Na/kg over the deficient diet. Both groups of kittens showed significant aversion to a diet containing 10 g Na/kg diet, with no change in total food intake. Kittens previously exposed to a diet containing 10 g Na/kg diet appeared to have a learned aversion to sodium in subsequent choice tests. We conclude that kittens do not possess an innate sodium appetite and that a sodium appetite is not induced in sodium-depleted kittens.

  17. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... exceed 50 millimeters (2 inches) of water at an air flow of 115 liters (4 cubic feet) per minute. (b) The exhalation resistance to a flow of air at a rate of 85 liters (3 cubic feet) per minute shall not exceed 25... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance test; Type C...

  18. Effects of NaCl on responses of ectomycorrhizal black spruce (Picea mariana), white spruce (Picea glauca) and jack pine (Pinus banksiana) to fluoride.

    PubMed

    Calvo-Polanco, Mónica; Zwiazek, Janusz J; Jones, Melanie D; MacKinnon, Michael D

    2009-01-01

    Black spruce (Picea mariana), white spruce (Picea glauca) and jack pine (Pinus banksiana) were inoculated with Suillus tomentosus and subjected to potassium fluoride (1 mM KF and 5 mM KF) in the presence and absence of 60 mM NaCl. The NaCl and KF treatments reduced total dry weights in jack pine and black spruce seedlings, but they did not affect total dry weights in white spruce seedlings. The addition of 60 mM NaCl to KF treatment solutions alleviated fluoride-induced needle injury in ectomycorrhizal (ECM) black spruce and white spruce, but had little effect in jack pine seedlings. Both KF and 60 mM NaCl treatments reduced E values compared with non-treated control seedlings. However, with the exception of small reductions of K(r) by NaCl treatments in black spruce, the applied KF and NaCl treatments had little effect on K(r) in ECM plants. Chloride tissue concentrations in NaCl-treated plants were not affected by the presence of KF in treatment solutions. However, shoot F concentrations in ECM black spruce and white spruce treated with 5 mM KF + 60 mM NaCl were significantly reduced compared with the 5 mM KF treatment. The results point to a possible competitive inhibition of F transport by Cl. We also suggest that the possibility that aquaporins may be involved in the transmembrane transport of F should be further investigated.

  19. [Absorption and allocation characteristics of K+, Ca2+, Na+ and Cl- in different organs of Broussonetia papyrifera seedlings under NaCl stress].

    PubMed

    Yang, Fan; Ding, Fei; Du, Tian-Zhen

    2009-04-01

    One-year-old Broussonetia papyrifera seedlings were subjected to 0.4, 1, 2, 3, and 4 g x kg(-1) of soil NaCl stress, and their biomass accumulation, leaf plasma membrane permeability, and the absorption, allocation and translocation of K+, Ca2+, Na+, and Cl-, as well as the symptoms of salt injury, were studied and investigated. The leaf plasma membrane permeability increased with the increase of soil NaCl concentration and of the duration of soil NaCl stress, and the seedling's root/shoot ratio also increased with increasing soil NaCl concentration. When the soil NaCl concentration exceeded 3 g x kg(-1), leaf plasma membrane permeability and seedling' s biomass accumulation were affected significantly. The Na+ and Cl- concentrations in different organs of seedlings increased with increasing soil NaCl concentration while the K+ and Ca2+ concentrations were in adverse, and the ion contents in leaves were always much higher than those in other organs, illustrating that soil NaCl stress affected the K+ and Ca2+ absorbing capability of roots, and inhibited the selective translocation of K+ and Ca2+ to aboveground parts. As a result, the K+ and Ca2+ concentrations in leaves and stems decreased. The study showed that B. papyrifera could effectively resist the injury of osmotic stress from soil salt via absorbing and accumulating Na+ and Cl-, but excessive accumulation of Na+ and Cl- could induce salt toxicity. As a non-halophyte species with relatively strong salt resistance, the aboveground parts of B. papyrifera did not have significant salt-exclusion effect.

  20. Cubic phase nanoparticles for sustained release of ibuprofen: formulation, characterization, and enhanced bioavailability study

    PubMed Central

    Dian, Linghui; Yang, Zhiwen; Li, Feng; Wang, Zhouhua; Pan, Xin; Peng, Xinsheng; Huang, Xintian; Guo, Zhefei; Quan, Guilan; Shi, Xuan; Chen, Bao; Li, Ge; Wu, Chuanbin

    2013-01-01

    In order to improve the oral bioavailability of ibuprofen, ibuprofen-loaded cubic nanoparticles were prepared as a delivery system for aqueous formulations. The cubic inner structure was verified by cryogenic transmission electron microscopy. With an encapsulation efficiency greater than 85%, the ibuprofen-loaded cubic nanoparticles had a narrow size distribution around a mean size of 238 nm. Differential scanning calorimetry and X-ray diffraction determined that ibuprofen was in an amorphous and molecular form within the lipid matrix. The in vitro release of ibuprofen from cubic nanoparticles was greater than 80% at 24 hours, showing sustained characteristics. The pharmacokinetic study in beagle dogs showed improved absorption of ibuprofen from cubic nanoparticles compared to that of pure ibuprofen, with evidence of a longer half-life and a relative oral bioavailability of 222% (P < 0.05). The ibuprofen-loaded cubic nanoparticles provide a promising carrier candidate with an efficient drug delivery for therapeutic treatment. PMID:23468008

  1. Rapid phase-controlled microwave synthesis of nanostructured hierarchical tetragonal and cubic β-In 2S 3 dandelion flowers

    NASA Astrophysics Data System (ADS)

    Naik, S. D.; Jagadale, T. C.; Apte, S. K.; Sonawane, R. S.; Kulkarni, M. V.; Patil, S. I.; Ogale, S. B.; Kale, B. B.

    2008-02-01

    Phase controlled synthesis of hierarchical nanostructured β-In 2S 3 dandelion flowers is realized by a rapid microwave solvothermal process using indium metal, nitric acid and thiourea as precursors. The tetragonal and cubic phases of the compound have been successfully and separately stabilized in the same type of dandelion morphology by using aqueous-mediated and methanol-mediated synthesis, respectively. The possible mechanism responsible for phase control is discussed. Optical properties of the flowers as well as their hydrogen generation capability by photodecomposition of H 2S under visible light are also reported.

  2. Specific heat and phonon density of state of cubic phase of protonic conductor LaAlO3

    NASA Astrophysics Data System (ADS)

    Sharma, Anupam Deep; Sinha, M. M.

    2016-05-01

    Perovskite oxides find wide range of applications like oxygen sensors, catalyst support, high frequency capacitors, high temperature superconducting microwave devices, solid state oxide fuel cell (SOFC) etc. LaAlO3 is one of such type of prominent perovskite oxides and very prominent material for protonic conductions. Therefore knowledge of the thermal properties of LaAlO3 is most significant. Hence in the present study we have studied phonon density of states and specific heat of LaAlO3 in cubic structure by applying lattice dynamical theoretical model. The calculated results are interpreted with existing experimental or theoretical results.

  3. Revisiting the NaCl cotransporter regulation by with-no-lysine kinases

    PubMed Central

    Bazúa-Valenti, Silvana

    2015-01-01

    The renal thiazide-sensitive Na+-Cl− cotransporter (NCC) is the salt transporter in the distal convoluted tubule. Its activity is fundamental for defining blood pressure levels. Decreased NCC activity is associated with salt-remediable arterial hypotension with hypokalemia (Gitelman disease), while increased activity results in salt-sensitive arterial hypertension with hyperkalemia (pseudohypoaldosteronism type II; PHAII). The discovery of four different genes causing PHAII revealed a complex multiprotein system that regulates the activity of NCC. Two genes encode for with-no-lysine (K) kinases WNK1 and WNK4, while two encode for kelch-like 3 (KLHL3) and cullin 3 (CUL3) proteins that form a RING type E3 ubiquitin ligase complex. Extensive research has shown that WNK1 and WNK4 are the targets for the KLHL3-CUL3 complex and that WNKs modulate the activity of NCC by means of intermediary Ste20-type kinases known as SPAK or OSR1. The understanding of the effect of WNKs on NCC is a complex issue, but recent evidence discussed in this review suggests that we could be reaching the end of the dark ages regarding this matter. PMID:25788573

  4. 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. PMID:27580205

  5. 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.

  6. Inhomogeneous atomic Bose-Fermi mixtures in cubic lattices.

    PubMed

    Cramer, M; Eisert, J; Illuminati, F

    2004-11-01

    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.

  7. 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.

  8. Higher excited states of acceptors in cubic semiconductors

    NASA Astrophysics Data System (ADS)

    Said, M.; Kanehisa, M. A.; Balkanski, M.

    1986-02-01

    For the first time, higher excited states of shallow acceptors up to the 3s and 4s states are calculated based on the Balderschi and Lipari theory including the cubic correction. The eigenvalues and eigenvectors of the effective mass Hamiltonian for shallow acceptor states were obtained by the finite element method. The resultant sparse matrix is diagonalized by a newly developed Saad's method based on Arnoldi's algorithm. Comparison with experimental spectra on ZnTe:Li and ZnTe:P gives best valence band parameters for ZnTe; μ = 0.60 and δ = 0.12.

  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. 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.

  11. Temperature dependent cubic and hexagonal close packing in micellar structures.

    PubMed

    Wolff, Nicole; Gerth, Stefan; Gutfreund, Philipp; Wolff, Max

    2014-11-14

    The interfacial structure and phase diagram of a micellar solution formed by the three block copolymer (EO20-PO70-EO20) also known as P123 solved in deuterated water close to a solid boundary is investigated with respect to temperature. We find a hysteretic behavior of the d-spacing of the micellar crystal and a spontaneous change in the lateral correlation length going hand in hand with a structural reorganization between cubic and hexagonal. The phase transitions may be initiated by a change in the shape of the micelles from spherical to elongated together with a minimization of the polymer water interface. PMID:25212786

  12. Submicron cubic boron nitride as hard as diamond

    NASA Astrophysics Data System (ADS)

    Liu, Guoduan; Kou, Zili; Yan, Xiaozhi; Lei, Li; Peng, Fang; Wang, Qiming; Wang, Kaixue; Wang, Pei; Li, Liang; Li, Yong; Li, Wentao; Wang, Yonghua; Bi, Yan; Leng, Yang; He, Duanwei

    2015-03-01

    Here, we report the sintering of aggregated submicron cubic boron nitride (sm-cBN) at a pressure of 8 GPa. The sintered cBN compacts exhibit hardness values comparable to that of single crystal diamond, fracture toughness about 5-fold that of cBN single crystal, in combination with a high oxidization temperature. Thus, another way has been demonstrated to improve the mechanical properties of cBN besides reducing the grain size to nano scale. In contrast to other ultrahard compacts with similar hardness, the sm-cBN aggregates are better placed for potential industrial application, as their relative low pressure manufacturing perhaps be easier and cheaper.

  13. Preparation of superhydrophobic nanodiamond and cubic boron nitride films

    SciTech Connect

    Zhou, Y. B.; Liu, W. M.; Wang, P. F.; Yang, Y.; Ye, Q.; He, B.; Pan, X. J.; Zhang, W. J.; Bello, I.; Lee, S. T.; Zou, Y. S.

    2010-09-27

    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 deg. and a sliding angle smaller than 10 deg. were demonstrated. The origin of hydrophobicity enhancement is discussed based on the Cassie model.

  14. Thermal expansion of rock-salt cubic AlN

    NASA Astrophysics Data System (ADS)

    Bartosik, M.; Todt, M.; Holec, D.; Todt, J.; Zhou, L.; Riedl, H.; Böhm, H. J.; Rammerstorfer, F. G.; Mayrhofer, P. H.

    2015-08-01

    We combine continuum mechanics modeling and wafer curvature experiments to characterize the thermal expansion coefficient of AlN in its metastable cubic rock-salt (B1) structure. The latter was stabilized as nm thin layers by coherency strains in CrN/AlN epitaxial multilayers deposited on Si (100) substrates using reactive magnetron sputtering. The extraction of the B1-AlN thermal expansion coefficient, from experimentally recorded temperature dependent wafer curvature data, is formulated as an inverse problem using continuum mechanics modeling. The results are cross-validated by density functional theory calculations.

  15. Inhomogeneous atomic Bose-Fermi mixtures in cubic lattices.

    PubMed

    Cramer, M; Eisert, J; Illuminati, F

    2004-11-01

    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. PMID:15600816

  16. Vacancy-dependent stability of cubic and wurtzite Ti1−xAlxN

    PubMed Central

    Euchner, H.; Mayrhofer, P.H.

    2015-01-01

    While it is well-known that supersaturated cubic-structured Ti1−xAlxN can be prepared by physical vapor deposition, the impact of point defects on formation process and cubic to wurtzite transition is largely unexplored. Irrespective of point defects, ab initio calculations correctly predict the Al concentration of the cubic to wurtzite transition. By means of density functional theory we show that vacancies on metal and/or non-metal sites only slightly affect the cubic to wurtzite transition region, whereas they clearly affect the physical properties. PMID:26412921

  17. Three-Dimensional Structure of a Simple Liquid at a Face-Centered-Cubic (001) Solid Surface Interface.

    PubMed

    Bao, Luyao; Hu, Haibao; Wen, Jun; Sepri, Paavo; Luo, Kai

    2016-07-19

    A liquid in the vicinity of a solid-liquid interface (SLI) may exhibit complex structures. In this study, we used molecular dynamics simulations demonstrating for the first time that the liquid adjacent to the SLI can have a two-level structure in some cases: a major structure and a minor structure. Through a time-averaging process of molecular motions, we identified the type of the liquid structure by calculating positions of the maximum liquid density in three spatial dimensions, and these positions were found to distribute in many dispersed zones (called high-density zones (HDZs)). The major structure appears throughout the SLI, while the minor structure only occurs significantly within the third layer. Instead of the previously reported body-centered cubic (BCC) or face-centered-cubic (FCC) types, the major structure was found to show a body-centered tetragonal (BCT) type. The adjacent HDZs are connected by specific junctions, demonstrating that atoms diffuse along some particular high probability paths from one HDZ to another. By considering the three-dimensional liquid density distribution from the continuum point of view, more complete details of the structure and diffusive behavior of liquids in the SLI are also possible to be revealed.

  18. Three-Dimensional Structure of a Simple Liquid at a Face-Centered-Cubic (001) Solid Surface Interface

    PubMed Central

    Bao, Luyao; Hu, Haibao; Wen, Jun; Sepri, Paavo; Luo, Kai

    2016-01-01

    A liquid in the vicinity of a solid-liquid interface (SLI) may exhibit complex structures. In this study, we used molecular dynamics simulations demonstrating for the first time that the liquid adjacent to the SLI can have a two-level structure in some cases: a major structure and a minor structure. Through a time-averaging process of molecular motions, we identified the type of the liquid structure by calculating positions of the maximum liquid density in three spatial dimensions, and these positions were found to distribute in many dispersed zones (called high-density zones (HDZs)). The major structure appears throughout the SLI, while the minor structure only occurs significantly within the third layer. Instead of the previously reported body-centered cubic (BCC) or face-centered-cubic (FCC) types, the major structure was found to show a body-centered tetragonal (BCT) type. The adjacent HDZs are connected by specific junctions, demonstrating that atoms diffuse along some particular high probability paths from one HDZ to another. By considering the three-dimensional liquid density distribution from the continuum point of view, more complete details of the structure and diffusive behavior of liquids in the SLI are also possible to be revealed. PMID:27430188

  19. Three-Dimensional Structure of a Simple Liquid at a Face-Centered-Cubic (001) Solid Surface Interface

    NASA Astrophysics Data System (ADS)

    Bao, Luyao; Hu, Haibao; Wen, Jun; Sepri, Paavo; Luo, Kai

    2016-07-01

    A liquid in the vicinity of a solid-liquid interface (SLI) may exhibit complex structures. In this study, we used molecular dynamics simulations demonstrating for the first time that the liquid adjacent to the SLI can have a two-level structure in some cases: a major structure and a minor structure. Through a time-averaging process of molecular motions, we identified the type of the liquid structure by calculating positions of the maximum liquid density in three spatial dimensions, and these positions were found to distribute in many dispersed zones (called high-density zones (HDZs)). The major structure appears throughout the SLI, while the minor structure only occurs significantly within the third layer. Instead of the previously reported body-centered cubic (BCC) or face-centered-cubic (FCC) types, the major structure was found to show a body-centered tetragonal (BCT) type. The adjacent HDZs are connected by specific junctions, demonstrating that atoms diffuse along some particular high probability paths from one HDZ to another. By considering the three-dimensional liquid density distribution from the continuum point of view, more complete details of the structure and diffusive behavior of liquids in the SLI are also possible to be revealed.

  20. Doping of MBE grown cubic GaN on 3C-SiC (001) by CBr{sub 4}

    SciTech Connect

    Zado, A.; Tschumak, E.; Lischka, K.; As, D. J.; Gerlach, J. W.

    2010-11-01

    We report on carbon doping of cubic GaN by CBr{sub 4} using plasma-assisted molecular beam epitaxy on 3C-SiC (001) substrates. The samples consist of a 70 nm thick GaN buffer followed by a 550 nm thick GaN:C layer. Carbon doping is realized with a home-made carbon tetrabromide sublimation source. The CBr{sub 4} beam equivalent pressure was established by a needle valve and was varied between 2x10{sup -9} mbar and 6x10{sup -6} mbar. The growth was controlled by in-situ reflection high energy electron diffraction. The incorporated carbon concentration is obtained from secondary ion mass spectroscopy. Capacitance voltage characteristics were measured using metal-insulator-semiconductor structures. Capacitance voltage measurements on nominally undoped cubic GaN showed n-type conductivity with N{sub D}-N{sub A} = 1x10{sup 17} cm{sup -3}. With increasing CBr{sub 4} flux the conductivity type changes to p-type and for the highest CBr{sub 4} flux N{sub A}-N{sub D} = 4{center_dot}5x10{sup 18} cm{sup -3} was obtained.

  1. Three-Dimensional Structure of a Simple Liquid at a Face-Centered-Cubic (001) Solid Surface Interface.

    PubMed

    Bao, Luyao; Hu, Haibao; Wen, Jun; Sepri, Paavo; Luo, Kai

    2016-01-01

    A liquid in the vicinity of a solid-liquid interface (SLI) may exhibit complex structures. In this study, we used molecular dynamics simulations demonstrating for the first time that the liquid adjacent to the SLI can have a two-level structure in some cases: a major structure and a minor structure. Through a time-averaging process of molecular motions, we identified the type of the liquid structure by calculating positions of the maximum liquid density in three spatial dimensions, and these positions were found to distribute in many dispersed zones (called high-density zones (HDZs)). The major structure appears throughout the SLI, while the minor structure only occurs significantly within the third layer. Instead of the previously reported body-centered cubic (BCC) or face-centered-cubic (FCC) types, the major structure was found to show a body-centered tetragonal (BCT) type. The adjacent HDZs are connected by specific junctions, demonstrating that atoms diffuse along some particular high probability paths from one HDZ to another. By considering the three-dimensional liquid density distribution from the continuum point of view, more complete details of the structure and diffusive behavior of liquids in the SLI are also possible to be revealed. PMID:27430188

  2. Effects of strongly anisosmotic and NaCl deficient solutions on muscimol- and glutamate evoked whole-cell currents in freshly dissociated hippocampal neurons.

    PubMed

    Vreugdenhil, M; Somjen, G G; Wadman, W J

    1995-01-23

    Sudden exposure of dissociated hippocampal neurons to strongly hypo- or hyperosmotic solutions suppresses voltage gated Na+, K+ and Ca2+ currents. We investigated whether ligand gated ion currents were similarly shut down by exposure to anisosmotic solutions. The effect of hypo-osmotic, NaCl deficient (mannitol-substituted), or hyper-osmotic test solutions delivered from a flow pipette was tested on voltage gated Ca2+ currents and on currents and conductance changes evoked by brief administration of either the GABAA-agonist muscimol or glutamate. Hyper-osmotic solution caused cells to shrink, but cell membrane capacitance did not change. Muscimol-induced conductance increases were depressed by hypo-osmotic and by NaCl deficient solutions and often by hyper-osmotic solution. Voltage gated Ca2+ currents were depressed by anisosmotic, but not by NaCl deficient isosmotic solution. NMDA- and non-NMDA evoked conductance increases were depressed by hyperosmotic solution; hypo-osmotic and NaCl deficient solutions were not tested on glutamate induced currents. Ligand gated currents are suppressed by anisosmotic solutions more slowly than are voltage gated channels. The changes caused by anisosmotic and NaCl deficient solutions were much greater then expected from calculated electrochemical effects and are probably the result of change in receptor controlled channels. PMID:7536614

  3. A facile and environmentally friendly NaCl nonaqueous ionic liquid route to prepare crystalline β-CaSiO3 nanowires.

    PubMed

    Wang, Wenzhong; Zhang, Suyun; Wang, Lijuan; Shi, Honglong

    2013-05-01

    We described an environmentally friendly and facile NaCl nonaqueous ionic liquid route for the first time to synthesize β-CaSiO3 nanowires. β-CaSiO3 nanowires were prepared by annealing precursor calcium silicate hydrate (CSH) nanostructures in NaCl nonaqueous ionic liquid, in which the precursor CSH nanostructures were first prepared by a facile one-step, solid state reaction, ground with both NaCl and surfactant nonyl phenyl ether (9) (NP-9), and heated at 850 °C for 2 h. β-CaSiO3 nanowires were characterized by XRD, TEM and HRTEM. The comparative experiments have been conducted systemically to investigate the growth mechanism of β-CaSiO3 nanowires, and the roles of salt NaCl nonaqueous ionic liquid and NP-9 on the formation of β-CaSiO3 nanowires. The results demonstrated that both salt NaCl nonaqueous ionic liquid and surfactant NP-9 played key roles on the formation of β-CaSiO3 nanowires. A rational growth mechanism of β-CaSiO3 nanowires has been proposed on the basis of experimental results.

  4. In vivo stimulation of AMP-activated protein kinase enhanced tubuloglomerular feedback but reduced tubular sodium transport during high dietary NaCl intake.

    PubMed

    Huang, Dan Yang; Gao, Huanhuan; Boini, Krishna M; Osswald, Hartmut; Nürnberg, Bernd; Lang, Florian

    2010-06-01

    AMP-activated protein kinase (AMPK) is expressed in the apical membrane of cortical thick ascending limb, distal, and collecting tubules as well as macula densa cells of the kidneys. AMPK is an active modulator of epithelial Na(+) channels, Na(+)-2Cl(-)-K(+) cotransporter, and the ATP-dependent potassium channel. The present experiments explored whether AMPK participates in the regulation of tubuloglomerular feedback (TGF) and renal tubular sodium handling. To this end, renal clearance and micropuncture experiments were performed in anesthetized rats. Under normal NaCl diet, neither TGF response nor renal fluid and sodium excretion were altered by pharmacological activation of AMPK in vivo. However, under high NaCl diet, the TGF response was significantly enhanced after intravenous or intratubular application of the AMPK activator AICAR. Moreover, AICAR application significantly increased fractional delivery of fluid and sodium to the end of the proximal tubule. High dietary NaCl intake increased the renal transcript levels encoding the AMPK-alpha1 subunit, while it decreased the expression of AMPK-beta1 and AMPK-gamma2 subunits. Immunoblots revealed that high dietary NaCl intake reduced renal expression of activated AMPK by about three times compared to normal NaCl diet whereas additional AICAR application increased AMPK activity. Our results suggest that AMPK regulates tubuloglomerular balance as well as tubular transport upon change of renal work load.

  5. Size-selective DNA separation: recovery spectra help determine the sodium chloride (NaCl) and polyethylene glycol (PEG) concentrations required.

    PubMed

    He, Zhangyong; Xu, Hong; Xiong, Min; Gu, Hongchen

    2014-10-01

    In the presence of sodium chloride (NaCl), DNA fragments can be size-selectively separated by varying the final concentration of polyethylene glycol (PEG). This separation strategy in combination with the use of paramagnetic particles provides a valuable platform for achieving the desired DNA size interval, which is important in automated library preparation for high-throughput DNA sequencing. Here, we report the establishment of recovery spectra of DNA fragments that enable the determination of suitable NaCl and PEG concentrations for size-selective separation. Firstly, at a given NaCl concentration, the recovery equation was obtained by fitting the DNA recovery ratios versus the PEG concentrations using the logistic function to determine the required parameters. Secondly, the slope function of the recovery equation was achieved by deducing its first derivative. Therefore, the recovery spectrum can be generated using the slope function based on those parameters. According to the recovery spectra of different length DNA fragments, suitable NaCl and PEG concentrations can be determined, respectively, by calculating their resolution values and recovery ratios. The strategy was effectively applied to the size-selective separation of 532-, 400-, and 307-bp fragments at the selected reagent concentrations with recoveries of 96.9, 64.7, and 85.9%, respectively. Our method enables good predictions of NaCl and PEG concentrations for size-selective DNA separation.

  6. Effect of partial substitution of NaCl with KCl on Halloumi cheese during storage: chemical composition, lactic bacterial count, and organic acids production.

    PubMed

    Ayyash, Mutamed M; Shah, Nagendra P

    2010-08-01

    The effect of partial substitution of NaCl with KCl on chemical composition, lactic bacterial count, and organic acids profile of Halloumi cheese was investigated. Halloumi cheeses were made and kept in 4 different brine solutions at 18% including NaCl only (HA), 3NaCl : 1KCl (HB), 1NaCl : 1KCl (HC), and 1NaCl : 3KCl (HD) and then stored at 4 degrees C for 56 d. No significant effect was observed between control and experimental cheeses in terms of moisture, fat, protein, lactic bacterial count, and pH values at the same storage period. There was a significant difference in ash, sodium, and potassium contents among experimental cheeses at the same storage period. Ash, sodium, and potassium contents increased significantly during storage at same salt treatment. There was no significant difference in lactic and citric acid contents among experimental cheeses and that of the control. In contrary, there was a significant difference in acetic acid among experimental cheeses. A strong positive correlation was observed between ash, Na, and K contents. An inverse correlation between organic acids and both Na and K contents was also observed.

  7. Plasma-membrane H(+)-ATPase gene expression is regulated by NaCl in cells of the halophyte Atriplex nummularia L.

    PubMed

    Niu, X; Zhu, J K; Narasimhan, M L; Bressan, R A; Hasegawa, P M

    1993-01-01

    An Atriplex nummularia L. cDNA probe encoding the partial sequence of an isoform of the plasma-membrane H(+)-ATPase was isolated, and used to characterize the NaCl regulation of mRNA accumulation in cultured cells of this halophyte. The peptide (477 amino acids) translated from the open reading frame has the highest sequence homology to the Nicotiana plumbaginifolia plasma-membrane H(+)-ATPase isoform pma4 (greater than 80% identity) and detected a transcript of approximately 3.7 kb on Northern blots of both total and poly(A)+ RNA. The mRNA levels were comparable in unadapted cells, adapted cells (cells adapted to and growing in 342 mM NaCl) and deadapted cells (cells previously adapted to 342 mM NaCl that are now growing without salt). Increased mRNA abundance was detected in deadapted cells within 24 h after exposure to NaCl but not in unadapted cells with similar salt treatments. The NaCl up-regulation of message abundance in deadapted cells was subject to developmental control. Analogous to those reported for glycophytes, the plasma-membrane H(+)-ATPase are encoded by a multigene family in the halophyte. PMID:7763822

  8. Physicochemical and sensory characterization of Cheddar cheese with variable NaCl levels and equal moisture content.

    PubMed

    Møller, K K; Rattray, F P; Bredie, W L P; Høier, E; Ardö, Y

    2013-04-01

    The present study investigated the effect of salt (NaCl) on the flavor and texture of Cheddar cheese with the particular aim to elucidate consequences of, and strategies for, reducing the salt concentration. Descriptive sensory analysis and physicochemical mapping of 9-mo-old Cheddar cheeses containing 0.9, 1.3, 1.7, and 2.3% salt and an equal level of moisture (37.6 ± 0.1%) were undertaken. Moisture regulation during manufacture resulted in slightly higher calcium retention (158 to 169 mmol/kg) with decreasing NaCl concentration. Lactose was depleted only at 0.9 and 1.3% salt, resulting in concomitantly higher levels of lactate. Lower levels of casein components and free amino acids were observed with decreasing NaCl concentration, whereas levels of pH 4.6-soluble peptides were higher. Key taste-active compounds, including small hydrophobic peptides, lactose, lactate, and free amino acids, covaried positively with bitter, sweet, sour, and umami flavor intensities, respectively. An additional direct effect of salt due to taste-taste enhancement and suppression was noted. Sensory flavor profiles spanned a principal component dimension of palatability projecting true flavor compensation of salt into the space between cheeses containing 1.7 and 2.3% salt. This space was characterized by salt, umami, sweet, and a range of sapid flavors, and was contrasted by bitter and other off-flavors. Rheological and sensory measurements of texture were highly correlated. Cheeses made with 2.3% salt had a longer and slightly softer texture than cheeses containing 0.9, 1.3, and 1.7% salt, which all shared similar textural properties. Moisture regulation contributed to restoring the textural properties upon a 50% reduction in salt, but other factors were also important. On the other hand, significant flavor deterioration occurred inevitably. We discuss the potential of engineering a favorable basic taste profile to restore full palatability of Cheddar with a 50% reduction in salt

  9. Differential sensitivity to chloride and sodium ions in seedlings of Glycine max and G. soja under NaCl stress.

    PubMed

    Luo, Qingyun; Yu, Bingjun; Liu, Youliang

    2005-09-01

    High Na+ and Cl- concentrations in soil cause hyperionic and hyperosmotic stress effects, the consequence of which can be plant demise. Ion-specific stress effects of Na+ and Cl- on seedlings of cultivated (Glycine max (L.) Merr) and wild soybean (Glycine soja Sieb. Et Zucc.) were evaluated and compared in isoosmotic solutions of Cl-, Na+ and NaCl. Results showed that under NaCl stress, Cl- was more toxic than Na+ to seedlings of G. max. Injury of six G. max cultivars, including 'Jackson' (salt sensitive) and 'Lee 68' (salt tolerant), was positively correlated with the content of Cl- in the leaves, and negatively with that in the roots. In subsequent research, seedlings of two G. max cultivars (salt-tolerant Nannong 1138-2, and salt-sensitive Zhongzihuangdou-yi) and two G. soja populations (BB52 and N23232) were subjected to isoosmotic solutions of 150mM Na+, Cl- and NaCl, respectively. G. max cv. Nannong 1138-2 and Zhongzihuangdou-yi were damaged much more heavily in the solution of Cl- than in that of Na+. Their Leaves were found to be more sensitive to Cl- than to Na+, and salt tolerance of these two G. max cultivars was mainly due to successful withholding of Cl- in the roots and stems to decrease its content in the leaves. The reverse response to isoosmotic stress of 150 mM Na+ and Cl- was shown in G. soja populations of BB52 and N23232; their leaves were not as susceptible to toxicity of Cl- as that of Na+. Salt tolerance of BB52 and N23232 was mainly due to successful withholding of Na+ in the roots and stems to decrease its content in the leaves. These results indicate that G. soja have advantages over G. max in those traits associated with the mechanism of Cl-tolerance, such as its withholding in roots and vacuoles of leaves. It is possible to use G. soja to improve the salt tolerance of G. max.

  10. Inhibition of goby posterior intestinal NaCl absorption by natriuretic peptides and by cardiac extracts.

    PubMed

    Loretz, C A

    1996-01-01

    Natriuretic peptides abolish active Na+ and Cl- absorption across the posterior intestine of the euryhaline goby Gillichthys mirabilis. Inhibition by eel and human natriuretic peptides is dose-dependent with the following sequence of potencies based on experimentally determined ID50 values for inhibition of short-circuit current: eel ventricular natriuretic peptide (78 nmol.l-1), eel atrial natriuretic peptide (156 nmol.l-1), human brain natriuretic peptide (326 nmol.l-1), human alpha atrial natriuretic peptide (1.05 mumol.l-1), and eel C-type natriuretic peptide (75 mumol.l-1). Natriuretic peptides also significantly increase transcellular conductance. The observed sequence of natriuretic peptide potencies is suggestive of cellular mediation by GC-A-type NP-R1 receptors in this tissue; as expected for guanylyl-cyclase-coupled NP-R1 receptors, cyclic GMP mimics the action of natriuretic peptides on the goby intestine. Crude aqueous extracts of goby atrium and ventricle inhibited short circuit current and increased tissue conductance in a dose-dependent manner. Ventricular extract was more potent than atrial extract on both a per organ and per milligram basis.

  11. Point defects stabilise cubic Mo-N and Ta-N

    NASA Astrophysics Data System (ADS)

    Koutná, Nikola; Holec, David; Svoboda, Ondřej; Klimashin, Fedor F.; Mayrhofer, Paul H.

    2016-09-01

    We employ ab initio calculations to investigate energetics of point defects in metastable rocksalt cubic Ta-N and Mo-N. Our results reveal a strong tendency to off-stoichiometry, i.e. defected structures are surprisingly predicted to be more stable than perfect ones with 1:1 metal-to-nitrogen stoichiometry. Despite the similarity of Ta-N and Mo-N systems in exhibiting this unusual behaviour, we also point out their crucial differences. While Ta-N significantly favours metal vacancies, Mo-N exhibits similar energies of formation regardless of the vacancy type (V Mo, V N) as long as their concentration is below ≈ 15~\\text{at}. % . The overall lowest energies of formation were obtained for \\text{T}{{\\text{a}}0.78}\\text{N} and \\text{M}{{\\text{o}}0.91}\\text{N} , which are hence predicted to be the most stable compositions. To account for various experimental conditions during synthesis, we further evaluated the phase stability as a function of chemical potential of individual species. The proposed phase diagrams reveal four stable compositions, \\text{M}{{\\text{o}}0.84}\\text{N} , \\text{M}{{\\text{o}}0.91}\\text{N} , \\text{Mo}{{\\text{N}}0.69} and \\text{Mo}{{\\text{N}}0.44} , in the case of Mo-N and nine stable compositions in the case of Ta-N indicating the important role of metal under-stoichiometry, since \\text{T}{{\\text{a}}0.75}\\text{N} and \\text{T}{{\\text{a}}0.78}\\text{N} significantly dominate the diagram. This is particularly important for understanding and designing experiments using non-equilibrium deposition techniques. Finally, we discuss the role of defect ordering and estimate a cubic lattice parameter as a function of defect contents and put them in the context of existing literature theoretical and experimental data.

  12. 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

  13. 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.

  14. 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

  15. Cubic titanium trialuminide thermal spray coatings—A review

    NASA Astrophysics Data System (ADS)

    Dewald, D.; Austin, M.; Laitila, E.; Mikkola, D.

    2001-03-01

    The recently discovered Cr-stabilized cubic titanium trialuminides of the form (Al,Cr)3Ti exhibit excellent oxidation resistance up to 1200 °C and have formed the basis for development of a new family of protective coatings. These intermetallic compounds can be fabricated into powders and thermal spray coatings much the same as traditional metal alloys. Cubic trialuminide coatings have physical properties that are compatible with a variety of common engineering materials, including alloys based on Ti, TiAl, Fe, Ni, and Al. Typically, the coatings will impart sufficient protection to permit an increase in the service temperature of a substrate alloy by 150 °C, or more. The purpose here is to summarize the development of these new thermal spray coatings, including properties and microstructures, as well as performance of the coating on various substrates. A brief comparison is made between the deposition processes used to date, which include low-pressure plasma spray (LPPS), air plasma spray (APS), and high-velocity oxy-fuel (HVOF) deposition. Recent successes in modifying the coatings to a composite form by incorporating a very fine dispersion of nanoscale carbide particles are also discussed.

  16. 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.

  17. Optical properties of cubic hafnia stabilized with yttria.

    PubMed

    Wood, D L; Nassau, K; Kometani, T Y; Nash, D L

    1990-02-01

    The composition, transparency, refractive index, and infrared reflectance of yttria-stabilized cubic hafnia (c-HfO(2)) single crystals were measured. The material is transparent from the ultraviolet to the mid-infrared and for 9.6-mol % Y(2)O(3), the index is slightly smaller than for comparable cubic zirconia c-ZrO(2) or for diamond, but the dispersion (n(F) - n(c) = 0.02811) is larger than that of diamond. The index vs wavelength from 0.36 microm in the ultraviolet to 5.0 microm in the infrared is represented by a three-term Sellmeier formula to 1 x 10(-4). The temperature dependence of refractive index is similar to that of c-ZrO(2). The infrared reflectance spectrum is fitted in a classical dispersion analysis with seven oscillators derived from the transverse optical phonon as well as acoustic frequencies with splittings due to lowered symmetry derived from the randomly distributed stabilizer ions.

  18. 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.

  19. Corrosion Performance Based on the Microstructural Array of Al-Based Monotectic Alloys in a NaCl Solution

    NASA Astrophysics Data System (ADS)

    Osório, Wislei R.; Freitas, Emmanuelle S.; Garcia, Amauri

    2014-01-01

    The aim of this study is to compare the electrochemical behavior of three monotectic Al-based alloys (Al-Pb, Al-Bi, and Al-In) in a 0.5 M NaCl solution at room temperature. Two distinct microstructure arrays were experimentally obtained for each Al monotectic alloy by using a water-cooled unidirectional solidification system. Results of electrochemical impedance spectroscopy (EIS) plots, potentiodynamic polarization curves, and impedance parameters obtained by an equivalent circuit analysis are discussed. It was found that the Al-Pb alloy has lower corrosion current density, higher polarization resistance, lower relative weight, and cost than the corresponding values of Al-Bi and Al-In alloys. It is also shown that the electrochemical behavior of the three alloys examined are intimately correlated with the scale of the corresponding microstructure, with smaller droplets and spacings (i.e., cell and interphase spacings) being associated with a decrease in the corrosion resistance.

  20. Structural and electronic properties of aqueous NaCl solutions from ab initio molecular dynamics simulations with hybrid density functionals

    NASA Astrophysics Data System (ADS)

    Gaiduk, Alex P.; Zhang, Cui; Gygi, François; Galli, Giulia

    2014-06-01

    We present a study of a dilute solution (1 M) of NaCl in water, carried out using ab initio molecular dynamics with semilocal and hybrid functionals. We showed that the structural and electronic properties of the solute and the solvent are the same as those obtained in the infinite dilution limit, i.e. for aqueous ions in the presence of a uniform compensating background. Compared to semilocal functionals, simulations with hybrid functionals yield a less structured solution with a smaller number of hydrogen bonds and a larger coordination number for the Cl- anion. In addition, hybrid functionals predict qualitatively correct positions of the energy levels of the ions with respect to the valence band of water.

  1. The effects of 7.5% NaCl/6% dextran 70 on coagulation and platelet aggregation in humans

    NASA Technical Reports Server (NTRS)

    Hess, J. R.; Dubick, M. A.; Summary, J. J.; Bangal, N. R.; Wade, C. E.

    1992-01-01

    The combination solution of 7.5% NaCl/6% dextran 70 (HSD) administered IV gives hemodynamic improvement in the treatment of hemorrhagic hypotension. Since earlier dextran solutions were reported to interfere with blood coagulation, the effects of HSD on the prothrombin time (PT), the activated partial thromboplastin time (APTT), platelet aggregation, and platelet concentration were studied. The HSD mixed with human plasma (1:5 and 1:10) slightly prolonged PT, but had no effect on the APTT, compared with saline controls. The HSD also decreased human platelet aggregation at the 1:5 dilution. In separate mixing studies, the hypertonic saline component of HSD was associated with the prolongation of PT and decreased platelet aggregation. The data from these studies indicate that at its proposed therapeutic dose, HSD is expected to have minimal effect on blood coagulation.

  2. Viscosity of NaCl and other solutions up to 350{sup 0}C and 50 MPa pressures

    SciTech Connect

    Phillips, S.L.; Ozbek, H.; Igbene, A.; Litton, G.

    1980-11-01

    Experimental values for the viscosity of sodium chloride solutions are critically reviewed for application to geothermal energy. Data published recently by Kestin, Los, Pepinov, and Semenyuk as well as earlier data are included. A theoretically based equation for calculating relative viscosity was developed, and used to generate tables of smoothed values over the ranges 20{sup 0}C to 350{sup 0}C, 0 to 5 m and pressures up to 50 MPa. The equation reproduces selected data to an average of better than 2 percent over the entire range of temperatures and pressures. Selected tables of data are included for KCl up to 150{sup 0}C, CaCl{sub 2} solutions up to 100{sup 0}C, and for mixtures of NaCl with KCl and CaCl{sub 2}. Recommendations are given for additional data needs.

  3. Comparing the antimicrobial effectiveness of NaCl and KCl with a view to salt/sodium replacement.

    PubMed

    Bidlas, Eva; Lambert, Ronald J W

    2008-05-10

    A study using a small range of pathogenic bacterial species (Aeromonas hydrophila, Enterobacter sakazakii, Shigella flexneri, Yersinia enterocolitica and 3 strains of Staphylococcus aureus) has shown that potassium chloride has an equivalent antimicrobial effect on these organisms when calculated on a molar basis. Combined NaCl and KCl experiments were carried out and data was analysed using a modification to the Lambert and Lambert [Lambert, R.J.W., and Lambert, R., 2003. A model for the efficacy of combined inhibitors. Journal of Applied Microbiology 95, 734-743.] model for combined inhibitors and showed that in combination KCl is a direct 1:1 molar replacement for the antimicrobial effect of common salt. If this is a general finding then, where salt is used to help preserve a product, partial or complete replacement by KCl is possible.

  4. Electronic absorption spectra of rare earth (III) species in NaCl-2CsCl eutectic based melts

    NASA Astrophysics Data System (ADS)

    Volkovich, V. A.; Ivanov, A. B.; Yakimov, S. M.; Tsarevskii, D. V.; Golovanova, O. A.; Sukhikh, V. V.; Griffiths, T. R.

    2016-09-01

    Electronic absorption spectra of ions of trivalent rare earth elements were measured in the melts based on NaCl-2CsCl eutectic in the wavelength ranges of 190-1350 and 1450-1700 nm. The measurements were performed at 550-850 °C. The EAS of Y, La, Ce and Lu containing melts have no absorption bands in the studied regions. For the remaining REEs (Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) the absorption bands in the EAS were assigned to the corresponding f-f electron transitions. The Stark effect was observed for Yb(III) F5/2 excited state. Increasing temperature leads to decreasing intensity of the absorption bands, except for the bands resulting from hypersensitive transitions. Beer's law was confirmed up to 0.4 M solutions of REE.

  5. Structure of the sodium dodecyl sulfate surfactant on a solid surface in different NaCl solutions.

    PubMed

    Domínguez, Hector

    2009-08-18

    Studies of molecular dynamics simulations of sodium dodecyl sulfate (SDS) molecules adsorbed on a graphite surface in different salt (NaCl)/water solutions were conducted. The results showed the formation of hemicylindrical aggregates, at different salt concentrations, in agreement with atomic force microscopy (AFM) results. However, the hemicylinders exhibited different structures as the salt concentration was increased. At low concentrations, the internal structure of the hemicylinder formed well-defined SDS layers, parallel to the surface. However, when the amount of salt was increased, the top layer became less pronounced until it disappeared at the highest concentration. Density profiles of the SDS headgroups were also analyzed, and those profiles were found to become sharper as the NaCl concentration increased. The phenomenon was investigated in terms of how the aggregates wet the solid surface.

  6. Investigation into the role of NaCL deposited on oxide and metal substrates in the initiation of hot corrosion

    NASA Technical Reports Server (NTRS)

    Birks, N.

    1981-01-01

    The conversion to Na2SO4 of NaCl deposited on oxide substrates was studied as a function of temperature, in air with various SO2 and H2O partial pressures. The substrate was either a pure oxide or an oxide scale growing on a metal specimen. The progress of the reaction was observed using the SEM-EDAX technique to monitor morphological effects and, as far as possible, establish the rate of the process. The physical characteristics of the interaction between salt and substrate were also examined with particular reference to physical damage to the underlying oxide, especially when this is a scale on a metal specimen. An effort was also made to establish the conditions under which liquid phases may form and the mechanisms by which they form.

  7. Atomic ordering in cubic bismuth telluride alloy phases at high pressure

    NASA Astrophysics Data System (ADS)

    Loa, I.; Bos, J.-W. G.; Downie, R. A.; Syassen, K.

    2016-06-01

    Pressure-induced transitions from ordered intermetallic phases to substitutional alloys to semi-ordered phases were studied in a series of bismuth tellurides. By using angle-dispersive x-ray diffraction, the compounds Bi4Te5 , BiTe, and Bi2Te were observed to form alloys with the disordered body-centered cubic (bcc) crystal structure upon compression to above 14-19 GPa at room temperature. The BiTe and Bi2Te alloys and the previously discovered high-pressure alloys of Bi2Te3 and Bi4Te3 were all found to show atomic ordering after gentle annealing at very moderate temperatures of ˜100 ∘C . Upon annealing, BiTe transforms from bcc to the B2 (CsCl) crystal-structure type, and the other phases adopt semi-disordered variants thereof, featuring substitutional disorder on one of the two crystallographic sites. The transition pressures and atomic volumes of the alloy phases show systematic variations across the BimTen series including the end members Bi and Te. First-principles calculations were performed to characterize the electronic structure and chemical bonding properties of B2-type BiTe and to identify the driving forces of the ordering transition. The calculated Fermi surface of B2-type BiTe has an intricate structure and is predicted to undergo three topological changes between 20 and 60 GPa.

  8. Effects of NaCl and pH on the structural conformations of kidney bean vicilin.

    PubMed

    Mundi, Sule; Aluko, Rotimi E

    2013-08-15

    Structural changes as a result of variations in pH value and salt concentration were determined for purified vicilin, the major globular protein in kidney beans using intrinsic fluorescence and circular dichroism (CD). The vicilin consisted of two polypeptide chains of about 43 and 45 kDa in size when analysed under reducing SDS-PAGE. Amino acid analysis showed that the vicilin had high contents of acidic amino acids and a low lysine/arginine ratio. Intrinsic fluorescence measurements were performed to measure exposure of tyrosine and tryptophan as a means of estimating protein conformational changes. Generally, the vicilin showed an unfolded structure at pH 3.0, 5.0, 7.0, and 9.0 as evident by the extensive red shift (>350 nm) of the wavelength of maximum tryptophan fluorescence intensity. At pH 3.0 and 5.0, the fluorescence intensity (FI) was greater than values obtained at pH 7.0 and 9.0, which suggests that the microenvironment of tryptophan was less hydrophilic at acidic pH. Addition of NaCl also led to increased FI, an indication of structural changes of tryptophan in response to the hydrophilic environment. These changes in FI were due mostly to tryptophan emission because tyrosine emission (at 303 nm) was suppressed. The far-UV CD spectra showed that vicilin had minimal measurable secondary structures at pH 3.0 and 5.0 when compared to pH 7.0 and 9.0. Addition of NaCl led to an increase in the tertiary structure conformation of vicilin as determined from the near-UV CD spectra.

  9. Changes of antioxidative enzymes and cell membrane osmosis in tomato colonized by arbuscular Mycorrhizae under NaCl stress.

    PubMed

    He, Zhongqun; He, Chaoxing; Zhang, Zhibin; Zou, Zhirong; Wang, Huaisong

    2007-10-01

    Salinity toxicity is a worldwide agricultural and eco-environmental problem. Many literatures show that arbuscular mycorrhizal fungi (AMF) can enhance salt tolerance of many plants and some physiological changes occurred in AM symbiosis under salt stress. However, the role of ROS-scavenging enzymes in AM tomato is still unknown in continuous salt stress. This study investigated the effect of Glomus mosseae on tomato growth, cell membrane osmosis and examined the antioxidants (superoxide-dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX; peroxidase, POD) responses in roots of mycorrhizal tomato and control under different NaCl stress for 40 days in potted culture. NaCl solution (0, 0.5 and 1%) was added to organic soil in the irrigation water after 45 days inoculated by AMF (Glomus mosseae). (1) AMF inoculation improved tomato growth under salt or saltless condition and reduced cell membrane osmosis, MDA (malonaldehyde) content in salinity. So the salt tolerance of tomato was enhanced by AMF; (2) SOD, APX and POD activity in roots of AM symbiosis were significantly higher than corresponding non-AM plants in salinity or saltless condition. However, CAT activity was transiently induced by AMF and then suppressed to a level similar with non-AM seedlings; (3) higher salinity (1% level) and long stress time suppressed the effect of AMF on SOD, APX, POD and CAT activity; (4) this research suggested that the enhanced salt tolerance in AM symbiosis was mainly related with the elevated SOD, POD and APX activity by AMF which degraded more reactive oxygen species and so alleviated the cell membrane damages under salt stress. Whereas, the elevated SOD, POD and APX activity due to AMF depended on salinity environment.

  10. Changes of antioxidative enzymes and cell membrane osmosis in tomato colonized by arbuscular Mycorrhizae under NaCl stress.

    PubMed

    He, Zhongqun; He, Chaoxing; Zhang, Zhibin; Zou, Zhirong; Wang, Huaisong

    2007-10-01

    Salinity toxicity is a worldwide agricultural and eco-environmental problem. Many literatures show that arbuscular mycorrhizal fungi (AMF) can enhance salt tolerance of many plants and some physiological changes occurred in AM symbiosis under salt stress. However, the role of ROS-scavenging enzymes in AM tomato is still unknown in continuous salt stress. This study investigated the effect of Glomus mosseae on tomato growth, cell membrane osmosis and examined the antioxidants (superoxide-dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX; peroxidase, POD) responses in roots of mycorrhizal tomato and control under different NaCl stress for 40 days in potted culture. NaCl solution (0, 0.5 and 1%) was added to organic soil in the irrigation water after 45 days inoculated by AMF (Glomus mosseae). (1) AMF inoculation improved tomato growth under salt or saltless condition and reduced cell membrane osmosis, MDA (malonaldehyde) content in salinity. So the salt tolerance of tomato was enhanced by AMF; (2) SOD, APX and POD activity in roots of AM symbiosis were significantly higher than corresponding non-AM plants in salinity or saltless condition. However, CAT activity was transiently induced by AMF and then suppressed to a level similar with non-AM seedlings; (3) higher salinity (1% level) and long stress time suppressed the effect of AMF on SOD, APX, POD and CAT activity; (4) this research suggested that the enhanced salt tolerance in AM symbiosis was mainly related with the elevated SOD, POD and APX activity by AMF which degraded more reactive oxygen species and so alleviated the cell membrane damages under salt stress. Whereas, the elevated SOD, POD and APX activity due to AMF depended on salinity environment. PMID:17560092

  11. A MYB transcription factor from the grey mangrove is induced by stress and confers NaCl tolerance in tobacco.

    PubMed

    Ganesan, G; Sankararamasubramanian, H M; Harikrishnan, M; Ganpudi, Ashwin; Ashwin, G; Parida, Ajay

    2012-07-01

    MYB transcription factor genes play important roles in developmental and various other processes in plants. In this study, functional characterization of AmMYB1, a single-repeat MYB transcription factor isolated from the salt-tolerant mangrove tree Avicennia marina is reported. AmMYB1 cDNA was 1046 bp in length with an open reading frame of 783 bp, encoding 260 amino acids. The corresponding gene had two introns and three exons and was present as a single copy in A. marina. The deduced amino acid sequence showed similarities to MYB proteins reported in other plants, including the conserved MYB binding domain. RNA gel blot analysis showed that the AmMYB1 transcript expression was more pronounced in green photosynthetic tissue and was strongly induced by stresses such as salt (500 mM), light (500 µE m(-2) s(-1)), and the exogenous application of ABA (100 µM). An analysis of the upstream sequence of AmMYB1 gene revealed the presence of regulatory elements identical to those present in the promoters of stress inducible genes. The promoter was responsive to NaCl and could enhance reporter gene expression in planta. An in vitro DNA binding assay using the promoter region (TGGTTAG) of the AtRD22 gene and a transactivation assay in yeast cells suggest the possibility of AmMYB1 protein regulating the expression of other genes during salt stress. Transgenic tobacco plants constitutively expressing the AmMYB1 transcription factor showed better tolerance to NaCl stress.

  12. Salting-out effect in aqueous NaCl solutions: trends with size and polarity of solute molecules.

    PubMed

    Endo, Satoshi; Pfennigsdorff, Andrea; Goss, Kai-Uwe

    2012-02-01

    Salting-out in aqueous NaCl solutions is relevant for the environmental behavior of organic contaminants. In this study, Setschenow (or salting-out) coefficients (K(s) [M(-1)]) for 43 diverse neutral compounds in NaCl solutions were measured using a shared headspace passive dosing method and a negligible depletion solid phase microextraction technique. The results were used to calibrate and evaluate estimation models for K(s). The molar volume of the solute correlated only moderately with K(s) (R(2) = 0.49, SD = 0.052). The polyparameter linear free energy relationship (pp-LFER) model that uses five compound descriptors resulted in a more accurate fit to our data (R(2) = 0.83, SD = 0.031). The pp-LFER analysis revealed that Na(+) and Cl(-) in aqueous solutions increase the cavity formation energy cost and the polar interaction energies toward neutral organic solutes. Accordingly, the salting-out effect increases with the size and decreases with the polarity of the solute molecule. COSMO-RS, a quantum mechanics-based fully predictive model, generally overpredicted the experimental K(s), but the predicted values were moderately correlated with the experimental values (R(2) = 0.66, SD = 0.042). Literature data (n = 93) were predicted by the calibrated pp-LFER and COSMO-RS models with root mean squared errors of 0.047 and 0.050, respectively. This study offers prediction models to estimate K(s), allowing implementation of the salting-out effect in contaminant fate models, linkage of various partition coefficients (such as air-water, sediment-water, and extraction phase-water partition coefficients) measured for fresh water and seawater, and estimation of enhancement of extraction efficiency in analytical procedures.

  13. [Accumulation characteristics of applied cinnamic acid in cucumber seedling-soil system under NaCl stress].

    PubMed

    Wang, Ying; Wu, Feng-Zhi; Wang, Yu-Yan

    2011-11-01

    Taking cucumber cultivars' Jinlv No. 5' (salt-tolerant) and 'Jinyou No. 1' (salt-sensitive) as test materials, a pot experiment was conducted to study the effects of applying cinnamic acid on the accumulation of applied cinnamic acid in cucumber seedling-soil system under NaCl (585 mg x kg(-1) soil) stress. The concentration of applied cinnamic acid was the main factor affecting the accumulation of the exogenous cinnamic acid in the cucumber plant and soil. With the increasing concentration of applied cinnamic acid, except in the treatment of highest concentration (200 mg x kg(-1) soil) cinnamic acid, the total content of cinnamic acid in cucumber plant was increased. NaCl stress enhanced the toxicity of cinnamic acid. In the treatments of low and medium concentration cinnamic acid, the cinnamic acid content in cucumber plant increased; whereas in the treatments of high concentration cinnamic acid, the decline of the seedlings growth was observed, and led to the decrease of the cinnamic acid content in the plant. The content of cinnamic acid in 'Jinlv No. 5' plant decreased at the concentration of applied cinnamic acid being > 200 mg x kg(-1) soil, while that in 'Jinyou No. 1' started to decrease when the concentration of applied cinnamic acid was > 100 mg x kg(-1) soil, reflecting the discrepancy in salt tolerance of the two cultivars. For the cucumber plant, its leaf had the highest content of cinnamic acid. In the cucumber seedling-soil system, most of applied cinnamic acid was mainly accumulated in soil.

  14. Effects of NaCl and pH on the structural conformations of kidney bean vicilin.

    PubMed

    Mundi, Sule; Aluko, Rotimi E

    2013-08-15

    Structural changes as a result of variations in pH value and salt concentration were determined for purified vicilin, the major globular protein in kidney beans using intrinsic fluorescence and circular dichroism (CD). The vicilin consisted of two polypeptide chains of about 43 and 45 kDa in size when analysed under reducing SDS-PAGE. Amino acid analysis showed that the vicilin had high contents of acidic amino acids and a low lysine/arginine ratio. Intrinsic fluorescence measurements were performed to measure exposure of tyrosine and tryptophan as a means of estimating protein conformational changes. Generally, the vicilin showed an unfolded structure at pH 3.0, 5.0, 7.0, and 9.0 as evident by the extensive red shift (>350 nm) of the wavelength of maximum tryptophan fluorescence intensity. At pH 3.0 and 5.0, the fluorescence intensity (FI) was greater than values obtained at pH 7.0 and 9.0, which suggests that the microenvironment of tryptophan was less hydrophilic at acidic pH. Addition of NaCl also led to increased FI, an indication of structural changes of tryptophan in response to the hydrophilic environment. These changes in FI were due mostly to tryptophan emission because tyrosine emission (at 303 nm) was suppressed. The far-UV CD spectra showed that vicilin had minimal measurable secondary structures at pH 3.0 and 5.0 when compared to pH 7.0 and 9.0. Addition of NaCl led to an increase in the tertiary structure conformation of vicilin as determined from the near-UV CD spectra. PMID:23561154

  15. The combination effect of L-arginine and NaCl on bitterness suppression of amino acid solutions.

    PubMed

    Ogawa, Tazuko; Nakamura, Tomoko; Tsuji, Eriko; Miyanaga, Yohko; Nakagawa, Hiroyo; Hirabayashi, Hitomi; Uchida, Takahiro

    2004-02-01

    The purpose of the present study was to quantify the degree of suppression of the bitterness of two amino acids (L-isoleucine (L-Ile), and L-phenylalanine (L-Phe)) which could be achieved by the addition of various test chemicals, and to examine the mechanism of this bitterness suppression. The test chemicals used were two sweeteners (sucrose, aspartame), NaCl, various acidic (L-aspartic acid, L-glutamic acid), or basic (L-histidine, L-lysine and L-arginine) amino acids, tannic acid and phosphatidic acid. The combination of L-arginine (L-Arg) and NaCl together was the most effective in reducing the bitterness of 100 mM L-Ile and L-Phe solutions in human gustatory sensation tests. Even in bitterness of 0.1 mM quinine solution, L-Arg was also successful in reducing the bitterness. This bitterness-suppression effect was specific to L-Arg and not to the other basic amino acids. No comparable taste-masking effect was observed for the acidic amino acids. The artificial taste sensor failed to predict completely the bitterness-suppressing effect of L-Arg. It seems likely that the bitterness-suppressing effect of L-Arg is mediated not only by binding at the receptor site, but also elsewhere in the process of bitterness perception, such as a direct effect on the sodium channel. It is conjectured that the guanidinium group of L-Arg may interact with sodium channels in taste bud membranes.

  16. Monosodium glutamate, disodium inosinate, disodium guanylate, lysine and taurine improve the sensory quality of fermented cooked sausages with 50% and 75% replacement of NaCl with KCl.

    PubMed

    dos Santos, Bibiana Alves; Campagnol, Paulo Cezar Bastianello; Morgano, Marcelo Antônio; Pollonio, Marise Aparecida Rodrigues

    2014-01-01

    Fermented cooked sausages were produced by replacing 50% and 75% of NaCl with KCl and adding monosodium glutamate, disodium inosinate, disodium guanylate, lysine and taurine. The manufacturing process was monitored by pH and water activity measurements. The sodium and potassium contents of the resulting products were measured. The color values (L*, a* and b*), texture profiles and sensory profiles were also examined. Replacing 50% and 75% NaCl with KCl depreciated the sensory quality of the products. The reformulated sausages containing monosodium glutamate combined with lysine, taurine, disodium inosinate and disodium guanylate masked the undesirable sensory attributes associated with the replacement of 50% and 75% NaCl with KCl, allowing the production of fermented cooked sausages with good sensory acceptance and approximately 68% sodium reduction. PMID:24008059

  17. Impact of NaCl reduction in Danish semi-hard Samsoe cheeses on proliferation and autolysis of DL-starter cultures.

    PubMed

    Søndergaard, Lise; Ryssel, Mia; Svendsen, Carina; Høier, Erik; Andersen, Ulf; Hammershøj, Marianne; Møller, Jean R; Arneborg, Nils; Jespersen, Lene

    2015-11-20

    Reduction of sodium chloride (NaCl) in cheese manufacturing is a challenge for the dairy industry. NaCl has a profound role on microbial development influencing cheese sensory and technological properties. The purpose of this work was to investigate how proliferation, distribution and autolysis of two commercial DL-starter cultures (C1 and C2) used in the production of Danish semi-hard Samsoe cheeses were affected by reduced NaCl levels. Cheeses containing <0.3% (unsalted), 2.3% (reduced-salt) and 3.4% (normal-salted) (w/v) NaCl in moisture were produced and analyzed during 12 weeks of ripening. Lactic acid bacteria (LAB), distribution of bacteria as single cells or microcolonies, their viability in the cheeses and cell autolysis were monitored during ripening, as well as the impact of NaCl content and autolysis on the formation of free amino acids (FAA). Reduction of NaCl resulted in higher LAB counts at the early stages of ripening, with differences between the two DL-starter cultures. The unsalted cheeses produced with C1 had retained a significantly higher number of the initial LAB counts (cfu/g) after 1 and 2 weeks of ripening (i.e. 58% and 71%), compared to the normal-salted cheeses (i.e. 22% and 21%), whereas no significant difference was found between the reduced-salt (i.e. 31% and 35%) and normal-salted cheeses. At the later stages of ripening (i.e. 7 and 11 weeks) NaCl had no significant influence. For cheeses produced with C2, a significant influence of NaCl was only found in cheeses ripened for 7 weeks, where the unsalted and reduced-salt cheeses had retained a significantly higher number of the initial LAB counts (cfu/g) (i.e. 39% and 38%), compared to the normal-salted cheeses (i.e. 21%). In the Samsoe cheeses, bacteria were organized as single cells, in groups of 2-3 cells or in groups of ≥4 cells. During ripening the decrease in the number of viable bacteria was mainly due to a reduction in the number of viable bacteria organized in groups of ≥4

  18. Exogenous proline relieves growth inhibition caused by NaCl in petunia cells: Metabolism of L-( sup 15 M)-proline followed by sup 15 N NMR

    SciTech Connect

    Heyser, J.W.; Chacon, M.J. )

    1989-04-01

    Exogenous proline stimulated the growth of Petunia hybrida cells on 195 mM NaCl 10-fold as compared with cells grown on 195 mM CaCl medium minus proline. L-({sup 15}N)-proline was fed to cells growing on 0 and 195 mM CaCl, and its metabolism was followed by {sup 15}N NMR analysis of cell extracts. Total proline and amino acids were determined by ninhydrin assay. Proline and primary amino acids were easily resolved in NMR spectra and the amount of {sup 15}N-label which remained in proline was determined. Reduced catabolism of proline in cells grown on NaCl was evident. The role of exogenous proline in conferring increased NaCl tolerance in this nonhalophyte will be discussed.

  19. Fluid evolution in H2O-CO2-NaCl system and metallogenic analysis of the Surian metamorphic complex, Bavanat Cu deposit, Southwest Iran

    NASA Astrophysics Data System (ADS)

    Asadi, Sina; Moore, Farid

    2016-07-01

    The Bavanat Cu deposit occurs as veins controlled by a NE-trending structure within the Permo-Triassic Surian metamorphic complex (SMC), southwest of Iran. The SMC rocks exposed in the area have undergone greenschist-facies metamorphism. The ore-forming process can be divided into early, middle, and late stages, represented by, respectively, pyrite-quartz, polymetallic sulfide-quartz, and late-stage barren quartz veins. Systematic studies of fluid inclusions (FIs) in the quartz veins found four types: aqueous, mixed aqueous-carbonic, carbonic, and multiphase-bearing inclusions. The FIs of early, middle and late-stages are mainly homogenized at temperatures of 335-417 °C, 230-380 °C, and 190-227 °C, with salinities of 1.1-6.7, 2.9-36.6, and 0.8-2.6 wt.% NaCl equivalent, respectively. The main stage of Cu mineralization is related to the middle-stage, where FIs show evidence of fluid immiscibility. The metal precipitation resulted from a decrease in copper solubility during the fluid immiscibility, cooling, crystallization of multiphase-bearing inclusions, and a small increase in pH. Laser Raman spectroscopy and FIs evidences indicate that the metallogenic system evolved from metamorphic CO2 (+CH4)-rich, relatively high fO2 (10-25 to 10-29 bars) to CO2-poor and relatively low fO2 (10-31 to 10-34 bars). Muscovite from the middle-stage veins yields 40Ar/39Ar plateau age of 195.2 ± 1.0 Ma, suggesting that the Cu mineralization at Bavanat formed in the Early Jurassic coeval with the retrograde metamorphic events during the post-early Cimmerian orogeny.

  20. Porphyrins as Corrosion Inhibitors for N80 Steel in 3.5% NaCl Solution: Electrochemical, Quantum Chemical, QSAR and Monte Carlo Simulations Studies.

    PubMed

    Singh, Ambrish; Lin, Yuanhua; Quraishi, Mumtaz A; Olasunkanmi, Lukman O; Fayemi, Omolola E; Sasikumar, Yesudass; Ramaganthan, Baskar; Bahadur, Indra; Obot, Ime B; Adekunle, Abolanle S; Kabanda, Mwadham M; Ebenso, Eno E

    2015-08-18

    The inhibition of the corrosion of N80 steel in 3.5 wt. % NaCl solution saturated with CO2 by four porphyrins, namely 5,10,15,20-tetrakis(4-hydroxyphenyl)-21H,23H-porphyrin (HPTB), 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphyrin (T4PP), 4,4',4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrakis(benzoic acid) (THP) and 5,10,15,20-tetraphenyl-21H,23H-porphyrin (TPP) was studied using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electrochemical microscopy (SECM) and scanning electron microscopy (SEM) techniques. The results showed that the inhibition efficiency, η% increases with increasing concentration of the inhibitors. The EIS results revealed that the N80 steel surface with adsorbed porphyrins exhibited non-ideal capacitive behaviour with reduced charge transfer activity. Potentiodynamic polarization measurements indicated that the studied porphyrins acted as mixed type inhibitors. The SECM results confirmed the adsorption of the porphyrins on N80 steel thereby forming a relatively insulated surface. The SEM also confirmed the formation of protective films of the porphyrins on N80 steel surface thereby protecting the surface from direct acid attack. Quantum chemical calculations, quantitative structure activity relationship (QSAR) were also carried out on the studied porphyrins and the results showed that the corrosion inhibition performances of the porphyrins could be related to their EHOMO, ELUMO, ω, and μ values. Monte Carlo simulation studies showed that THP has the highest adsorption energy, while T4PP has the least adsorption energy in agreement with the values of σ from quantum chemical calculations.

  1. The Strain-Driven Pyrochlore to ''Defect Fluorite'' Phase Transition in Rare Earth Sesquioxide Stabilized Cubic Zirconias

    SciTech Connect

    Tabira, Y.; Withers, R.L.; Barry, J.C.; Elcoro, L.

    2001-06-01

    The relationship between the ordering characteristic of the pyrochlore structure type and that characteristic of the ''defect fluorite'' structure type (immediately on either side of two phase regions separating the two structure types) in a range of rare earth sesquioxide-stabilized cubic zirconias was investigated by electron diffraction and imaging. Systematic structural change as a function of composition and relative size of the constituent metal ions is highlighted, and a multi-q to single-q = {1/2} [111]* model is proposed for the observed pyrochlore-to-defect fluorite phase transition. Strain introduced into the close-packed {l_brace}111{r_brace} metal ion planes of the defect fluorite average structure by the local cation and oxygen vacancy distribution is pointed to as the likely origin of the observed behavior.

  2. Evaluation of Salmonella Growth at Low Concentrations of NaNO2 and NaCl in Processed Meat Products Using Probabilistic Model

    PubMed Central

    Gwak, E.; Lee, H.; Lee, S.; Oh, M-H.; Park, B-Y.; Ha, J.; Lee, J.; Kim, S.; Yoon, Y.

    2016-01-01

    This study developed probabilistic models to predict Salmonella growth in processed meat products formulated with varying concentrations of NaCl and NaNO2. A five-strain mixture of Salmonella was inoculated in nutrient broth supplemented with NaCl (0%, 0.25%, 0.5%, 0.75%, 0.5%, 1.0%, 1.25%, and 1.75%) and NaNO2 (0, 15, 30, 45, 60, 75, 90, 105, and 120 ppm). The inoculated samples were then incubated under aerobic and anaerobic conditions at 4°C, 7°C, 10°C, 12°C, and 15°C for up to 60 days. Growth (assigned the value of 1) or no growth (assigned the value of 0) for each combination was evaluated by turbidity. These growth response data were analyzed with a logistic regression to evaluate the effect of NaCl and NaNO2 on Salmonella growth. The results from the developed model were compared to the observed data obtained from the frankfurters to evaluate the performance of the model. Results from the developed model showed that a single application of NaNO2 at low concentrations did not inhibit Salmonella growth, whereas NaCl significantly (p<0.05) inhibited Salmonella growth at 10°C, 12°C, and 15°C, regardless of the presence of oxygen. At 4°C and 7°C, Salmonella growth was not observed in either aerobic or anaerobic conditions. When NaNO2 was combined with NaCl, the probability of Salmonella growth decreased. The validation value confirmed that the performance of the developed model was appropriate. This study indicates that the developed probabilistic models should be useful for describing the combinational effect of NaNO2 and NaCl on inhibiting Salmonella growth in processed meat products. PMID:26954121

  3. Probabilistic Models to Predict the Growth Initiation Time for Pseudomonas spp. in Processed Meats Formulated with NaCl and NaNO2

    PubMed Central

    Park, Beomyoung; Oh, Mihwa

    2014-01-01

    This study developed probabilistic models to determine the initiation time of growth of Pseudomonas spp. in combinations with NaNO2 and NaCl concentrations during storage at different temperatures. The combination of 8 NaCl concentrations (0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, and 1.75%) and 9 NaNO2 concentrations (0, 15, 30, 45, 60, 75, 90, 105, and 120 ppm) were prepared in a nutrient broth. The medium was placed in the wells of 96-well microtiter plates, followed by inoculation of a five-strain mixture of Pseudomonas in each well. All microtiter plates were incubated at 4, 7, 10, 12, and 15℃ for 528, 504, 504, 360 and 144 h, respectively. Growth (growth initiation; GI) or no growth was then determined by turbidity every 24 h. These growth response data were analyzed by a logistic regression to produce growth/no growth interface of Pseudomonas spp. and to calculate GI time. NaCl and NaNO2 were significantly effective (p<0.05) on inhibiting Pseudomonas spp. growth when stored at 4-12℃. The developed model showed that at lower NaCl concentration, higher NaNO2 level was required to inhibit Pseudomonas growth at 4-12℃. However, at 15℃, there was no significant effect of NaCl and NaNO2. The model overestimated GI times by 58.2±17.5 to 79.4±11%. These results indicate that the probabilistic models developed in this study should be useful in calculating the GI times of Pseudomonas spp. in combination with NaCl and NaNO2 concentrations, considering the over-prediction percentage. PMID:26761668

  4. NaCl does not affect hypothalamic noradrenergic input in deoxycorticosterone acetate/NaCl and Dahl salt-sensitive rats.

    PubMed

    Chen, Y F; Meng, Q C; Wyss, J M; Jin, H K; Rogers, C F; Oparil, S

    1990-07-01

    Previous studies from our laboratories demonstrated that dietary NaCl supplementation in NaCl-sensitive spontaneously hypertensive rats elevates blood pressure, increases peripheral sympathetic nervous system activity, and depresses endogenous norepinephrine stores and turnover in the anterior hypothalamus. These findings suggest that reduced noradrenergic input to sympathoinhibitory neurons in anterior hypothalamus contributes to NaCl-sensitive hypertension in spontaneously hypertensive rats. The current study tested the hypothesis that dietary NaCl supplementation depresses endogenous norepinephrine stores and turnover in anterior hypothalamus of two other NaCl-sensitive models of hypertension, the Dahl salt-sensitive rat and the deoxycorticosterone acetate/NaCl hypertensive rat, thus increasing blood pressure by reducing noradrenergic input to the anterior hypothalamus. Dahl salt-sensitive rats were fed a high (8%) NaCl diet, and deoxycorticosterone acetate/NaCl rats rats drank 1% NaCl solution ad libitum for 2 or 4 weeks. Age-matched Dahl salt-sensitive rats fed a basal 1% NaCl diet and uninephrectomized Sprague-Dawley rats drinking tap water were controls. Regional brain catecholamines were determined by high-performance liquid chromatography with electrochemical detection. Norepinephrine turnover in hypothalamus (anterior, posterior, and ventral regions) and brain stem (pons and medulla) was assessed using the dopamine beta-hydroxylase inhibitor 1-cyclohexyl-2-mercapto-imidazole. High NaCl treatment caused significant elevations in blood pressure in Dahl salt-sensitive and deoxycorticosterone acetate/NaCl rats, but endogenous norepinephrine levels and turnover rates were not significantly different in anterior hypothalamus or any other brain region studied between the NaCl-supplemented and control groups.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. NaCl stress-induced changes in the essential oil quality and abietane diterpene yield and composition in common sage

    PubMed Central

    Tounekti, Taieb; Khemira, Habib

    2015-01-01

    Aim: The purpose of this study was to evaluate how increasing NaCl salinity in the medium can affects the essential oils (EOs) composition and phenolic diterpene content and yield in leaves of Salvia officinalis L. The protective role of such compounds against NaCl stress was also argued with regard to some physiological characteristics of the plant (water and ionic relations as well as the leaf gas exchanges). Materials and Methods: Potted plants were exposed to increasing NaCl concentrations (0, 50, 75, and 100 mM) for 4 weeks during July 2012. Replicates from each treatment were harvested after 0, 2, 3, and 4 weeks of adding salt to perform physiological measurements and biochemical analysis. Results: Sage EOs were rich in manool, viridiflorol, camphor, and borneol. Irrigation with a solution containing 100 mM NaCl for 4 weeks increased considerably 1.8-cineole, camphor and β-thujone concentrations, whereas lower concentrations (50 and 75 mM) had no effects. On the contrary, borneol and viridiflorol concentrations decreased significantly under the former treatment while manool and total fatty acid concentrations were not affected. Leaf extracts also contained several diterpenes such as carnosic acid (CA), carnosol, and 12-O-methoxy carnosic acid (MCA). The concentrations and total contents of CA and MCA increased after 3 weeks of irrigation with 75 or 100 mM NaCl. The 50 mM NaCl had no effect on these diterpenes. Our results suggest a protective role for CA against salinity stress. Conclusion: This study may provide ways to manipulate the concentration and yield of some phenolic diterpenes and EOs in sage. In fact, soil salinity may favor a directional production of particular components of interest. PMID:26401409

  6. Fabrication and Properties of Carbon-Encapsulated Cobalt Nanoparticles over NaCl by CVD

    NASA Astrophysics Data System (ADS)

    Li, Haipeng; Li, Yue; Zhang, Yongguang; Liang, Chunyong; Wang, Hongshui; Li, Baoe; Adair, Desmond; Bakenov, Zhumabay

    2016-09-01

    Carbon-encapsulated cobalt (Co@C) nanoparticles, with a tunable structure, were synthesized by chemical vapor deposition using Co nanoparticles as the catalyst and supported on a water-soluble substrate (sodium chloride), which was easily removed by washing and centrifugation. The influences of growth temperature and time on the structure and magnetic properties of the Co@C nanoparticles were systematically investigated. For different growth temperatures, the magnetic Co nanoparticles were encapsulated by different types of carbon layers, including amorphous carbon layers, graphitic layers, and carbon nanofibers. This inferred a close relationship between the structure of the carbon-encapsulated metal nanoparticles and the growth temperature. At a fixed growth temperature of 400 °C, prolonged growth time caused an increase in thickness of the carbon layers. The magnetic characterization indicated that the magnetic properties of the obtained Co@C nanoparticles depend not only on the graphitization but also on the thickness of the encapsulated carbon layer, which were easily controlled by the growth temperatures and times. Optimization of the synthesis process allowed achieving relatively high coercivity of the synthesized Co@C nanoparticles and enhancement of its ferromagnetic properties, which make this system promising as a magnetic material, particularly for high-density magnetic recording applications.

  7. Fabrication and Properties of Carbon-Encapsulated Cobalt Nanoparticles over NaCl by CVD.

    PubMed

    Li, Haipeng; Li, Yue; Zhang, Yongguang; Liang, Chunyong; Wang, Hongshui; Li, Baoe; Adair, Desmond; Bakenov, Zhumabay

    2016-12-01

    Carbon-encapsulated cobalt (Co@C) nanoparticles, with a tunable structure, were synthesized by chemical vapor deposition using Co nanoparticles as the catalyst and supported on a water-soluble substrate (sodium chloride), which was easily removed by washing and centrifugation. The influences of growth temperature and time on the structure and magnetic properties of the Co@C nanoparticles were systematically investigated. For different growth temperatures, the magnetic Co nanoparticles were encapsulated by different types of carbon layers, including amorphous carbon layers, graphitic layers, and carbon nanofibers. This inferred a close relationship between the structure of the carbon-encapsulated metal nanoparticles and the growth temperature. At a fixed growth temperature of 400 °C, prolonged growth time caused an increase in thickness of the carbon layers. The magnetic characterization indicated that the magnetic properties of the obtained Co@C nanoparticles depend not only on the graphitization but also on the thickness of the encapsulated carbon layer, which were easily controlled by the growth temperatures and times. Optimization of the synthesis process allowed achieving relatively high coercivity of the synthesized Co@C nanoparticles and enhancement of its ferromagnetic properties, which make this system promising as a magnetic material, particularly for high-density magnetic recording applications. PMID:27677303

  8. Molecular dynamics study of interfacial confinement effects of aqueous NaCl brines in nanoporous carbon

    SciTech Connect

    Wander, M. C. F.; Shuford, K. L.

    2010-12-09

    In this paper, studies of aqueous electrolyte solutions in contact with a family of porous carbon geometries using classical molecular dynamics simulations are presented. These simulations provide an atomic scale depiction of ion transport dynamics in different environments to elucidate power of aqueous electrolyte supercapacitors. The electrolyte contains alkali metal and halide ions, which allow for the examination of size trends within specific geometries as well as trends in concentration. The electrode pores are modeled as planar graphite sheets and carbon nanotubes with interstices ranging from one to four nanometers. Ordered layers form parallel to the carbon surface, which facilitates focused ion motion under slightly confining conditions. As a result, the ion’s diffusivities are enhanced in the direction of the slit or pore. Further confining the system leads to decreased ion diffusivities. The ions are fully hydrated in all but the smallest slits and pores with those sizes showing increased ion pairing. There is strong evidence of charge separation perpendicular to the surface at all size scales, concentrations, and ion types, providing a useful baseline for examining differential capacitance behavior and future studies on energy storage. These systems show promise as high-power electrical energy storage devices.

  9. Deformation-induced structural transition in body-centred cubic molybdenum

    PubMed Central

    Wang, S. J.; Wang, H.; Du, K.; Zhang, W.; Sui, M. L.; Mao, S. X.

    2014-01-01

    Molybdenum is a refractory metal that is stable in a body-centred cubic structure at all temperatures before melting. Plastic deformation via structural transitions has never been reported for pure molybdenum, while transformation coupled with plasticity is well known for many alloys and ceramics. Here we demonstrate a structural transformation accompanied by shear deformation from an original <001>-oriented body-centred cubic structure to a <110>-oriented face-centred cubic lattice, captured at crack tips during the straining of molybdenum inside a transmission electron microscope at room temperature. The face-centred cubic domains then revert into <111>-oriented body-centred cubic domains, equivalent to a lattice rotation of 54.7°, and ~15.4% tensile strain is reached. The face-centred cubic structure appears to be a well-defined metastable state, as evidenced by scanning transmission electron microscopy and nanodiffraction, the Nishiyama–Wassermann and Kurdjumov–Sachs relationships between the face-centred cubic and body-centred cubic structures and molecular dynamics simulations. Our findings reveal a deformation mechanism for elemental metals under high-stress deformation conditions. PMID:24603655

  10. Using a CAS in the Mathematics Classroom: Two Examples for Exploring Cubic Curves.

    ERIC Educational Resources Information Center

    Leinbach, Carl

    2001-01-01

    Illustrates two ways of exploring the properties of cubic polynomials. The first exploration uses a Computer Algebra System (CAS) to help students understand an important part of mathematical history, the discovery of an algorithm to find the roots of a cubic equation. The second exploration states some conditions required for a curve and finds a…

  11. Deformation-induced structural transition in body-centred cubic molybdenum.

    PubMed

    Wang, S J; Wang, H; Du, K; Zhang, W; Sui, M L; Mao, S X

    2014-03-07

    Molybdenum is a refractory metal that is stable in a body-centred cubic structure at all temperatures before melting. Plastic deformation via structural transitions has never been reported for pure molybdenum, while transformation coupled with plasticity is well known for many alloys and ceramics. Here we demonstrate a structural transformation accompanied by shear deformation from an original <001>-oriented body-centred cubic structure to a <110>-oriented face-centred cubic lattice, captured at crack tips during the straining of molybdenum inside a transmission electron microscope at room temperature. The face-centred cubic domains then revert into <111>-oriented body-centred cubic domains, equivalent to a lattice rotation of 54.7°, and ~15.4% tensile strain is reached. The face-centred cubic structure appears to be a well-defined metastable state, as evidenced by scanning transmission electron microscopy and nanodiffraction, the Nishiyama-Wassermann and Kurdjumov-Sachs relationships between the face-centred cubic and body-centred cubic structures and molecular dynamics simulations. Our findings reveal a deformation mechanism for elemental metals under high-stress deformation conditions.

  12. Extending a Property of Cubic Polynomials to Higher-Degree Polynomials

    ERIC Educational Resources Information Center

    Miller, David A.; Moseley, James

    2012-01-01

    In this paper, the authors examine a property that holds for all cubic polynomials given two zeros. This property is discovered after reviewing a variety of ways to determine the equation of a cubic polynomial given specific conditions through algebra and calculus. At the end of the article, they will connect the property to a very famous method…

  13. Deformation-induced structural transition in body-centred cubic molybdenum.

    PubMed

    Wang, S J; Wang, H; Du, K; Zhang, W; Sui, M L; Mao, S X

    2014-01-01

    Molybdenum is a refractory metal that is stable in a body-centred cubic structure at all temperatures before melting. Plastic deformation via structural transitions has never been reported for pure molybdenum, while transformation coupled with plasticity is well known for many alloys and ceramics. Here we demonstrate a structural transformation accompanied by shear deformation from an original <001>-oriented body-centred cubic structure to a <110>-oriented face-centred cubic lattice, captured at crack tips during the straining of molybdenum inside a transmission electron microscope at room temperature. The face-centred cubic domains then revert into <111>-oriented body-centred cubic domains, equivalent to a lattice rotation of 54.7°, and ~15.4% tensile strain is reached. The face-centred cubic structure appears to be a well-defined metastable state, as evidenced by scanning transmission electron microscopy and nanodiffraction, the Nishiyama-Wassermann and Kurdjumov-Sachs relationships between the face-centred cubic and body-centred cubic structures and molecular dynamics simulations. Our findings reveal a deformation mechanism for elemental metals under high-stress deformation conditions. PMID:24603655

  14. Re-sintered boron-rich polycrystalline cubic boron nitride and method for making same

    SciTech Connect

    Lavens, T.R.; Corrigan, F.R.; Shott, R.L.; Bovenkerk, H.P.

    1987-06-16

    A method is described for making re-sintered polycrystalline cubic boron nitride (CBN) which comprises: (a) placing sintered substantially catalyst-free boron-rich polycrystalline cubic boron nitride particles in a high pressure/high temperature apparatus, the particles being substantially free of sintering inhibiting impurities; (b) subjecting the boron-rich cubic boron nitride particles to a pressure and a temperature adequate to re-sinter the particles, the temperature being below the CBN reconversion temperature; (c) maintaining the temperature and pressure for a time sufficient to re-sinter the boron-rich cubic boron nitride particles in the apparatus, and (d) recovering the re-sintered polycrystalline cubic boron nitride from the apparatus.

  15. Traveling kinks in cubic nonlinear Ginzburg-Landau equations.

    PubMed

    Rosu, H C; Cornejo-Pérez, O; Ojeda-May, P

    2012-03-01

    Nonlinear cubic Euler-Lagrange equations of motion in the traveling variable are usually derived from Ginzburg-Landau free energy functionals frequently encountered in several fields of physics. Many authors considered in the past damped versions of such equations, with the damping term added by hand simulating the friction due to the environment. It is known that even in this damped case kink solutions can exist. By means of a factorization method, we provide analytic formulas for several possible kink solutions of such equations of motion in the undriven and constant field driven cases, including the recently introduced Riccati parameter kinks, which were not considered previously in such a context. The latter parameter controls the delay of the switching stage of the kinks. The delay is caused by antikink components that are introduced in the structure of the solution through this parameter. PMID:22587214

  16. Ferrimagnetic behaviors in a double-wall cubic metal nanotube

    NASA Astrophysics Data System (ADS)

    Liang, Ji-Yan; Zou, Cheng-Long; Jiang, Wei; Li, Xiao-Xi

    2015-05-01

    A double-wall cubic metal nanotube consists of the ferromagnetic spin-1 inner shell and spin-3/2 surface shell. It is of the ferrimagnetic exchange coupling between two shells. Considering the single-ion anisotropy and transverse field exist together, the magnetization, the initial susceptibility, the internal energy and the specific heat have been investigated by using the effective-field theory with correlations. Some interesting phenomena have been found in the thermal variations of the system. Magnetization appears two or three compensation points in certain parameters. It is an unconventional ferrimagnetic behavior in the nanotube. The shapes of total magnetization and the initial susceptibility are great influenced by the surface exchange coupling, surface single-ion anisotropy and surface transverse field. Some results of nanotube may have potential applications in different research fields, such as electronics, optics, mechanics, and even biomedicine and molecular devices.

  17. Lipidic cubic phase serial millisecond crystallography using synchrotron radiation

    PubMed Central

    Nogly, Przemyslaw; James, Daniel; Wang, Dingjie; White, Thomas A.; Zatsepin, Nadia; Shilova, Anastasya; Nelson, Garrett; Liu, Haiguang; Johansson, Linda; Heymann, Michael; Jaeger, Kathrin; Metz, Markus; Wickstrand, Cecilia; Wu, Wenting; Båth, Petra; Berntsen, Peter; Oberthuer, Dominik; Panneels, Valerie; Cherezov, Vadim; Chapman, Henry; Schertler, Gebhard; Neutze, Richard; Spence, John; Moraes, Isabel; Burghammer, Manfred; Standfuss, Joerg; Weierstall, Uwe

    2015-01-01

    Lipidic cubic phases (LCPs) have emerged as successful matrixes for the crystallization of membrane proteins. Moreover, the viscous LCP also provides a highly effective delivery medium for serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs). Here, the adaptation of this technology to perform serial millisecond crystallography (SMX) at more widely available synchrotron microfocus beamlines is described. Compared with conventional microcrystallography, LCP-SMX eliminates the need for difficult handling of individual crystals and allows for data collection at room temperature. The technology is demonstrated by solving a structure of the light-driven proton-pump bacteriorhodopsin (bR) at a resolution of 2.4 Å. The room-temperature structure of bR is very similar to previous cryogenic structures but shows small yet distinct differences in the retinal ligand and proton-transfer pathway. PMID:25866654

  18. Bistable dark solitons of a cubic-quintic Helmholtz equation

    SciTech Connect

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

    2010-05-15

    We provide a report on exact analytical bistable dark spatial solitons of a nonlinear Helmholtz equation with a cubic-quintic refractive-index model. Our analysis begins with an investigation of the modulational instability characteristics of Helmholtz plane waves. We then derive a dark soliton by mapping the desired asymptotic form onto a uniform background field and obtain a more general solution by deploying rotational invariance laws in the laboratory frame. The geometry of the new soliton is explored in detail, and a range of new physical predictions is uncovered. Particular attention is paid to the unified phenomena of arbitrary-angle off-axis propagation and nondegenerate bistability. Crucially, the corresponding solution of paraxial theory emerges in a simultaneous multiple limit. We conclude with a set of computer simulations that examine the role of Helmholtz dark solitons as robust attractors.

  19. Serial femtosecond crystallography of soluble proteins in lipidic cubic phase

    SciTech Connect

    Fromme, Raimund; Ishchenko, Andrii; Metz, Markus; Chowdhury, Shatabdi Roy; Basu, Shibom; Boutet, Sébastien; Fromme, Petra; White, Thomas A.; Barty, Anton; Spence, John C. H.; Weierstall, Uwe; Liu, Wei; Cherezov, Vadim

    2015-08-04

    Serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs) enables high-resolution protein structure determination using micrometre-sized crystals at room temperature with minimal effects from radiation damage. SFX requires a steady supply of microcrystals intersecting the XFEL beam at random orientations. An LCP–SFX method has recently been introduced in which microcrystals of membrane proteins are grown and delivered for SFX data collection inside a gel-like membrane-mimetic matrix, known as lipidic cubic phase (LCP), using a special LCP microextrusion injector. Here, it is shown enabling a dramatic reduction in the amount of crystallized protein required for data collection compared with crystals delivered by liquid injectors. High-quality LCP–SFX data sets were collected for two soluble proteins, lysozyme and phycocyanin, using less than 0.1 mg of each protein.

  20. High-order numerical solutions using cubic splines

    NASA Technical Reports Server (NTRS)

    Rubin, S. G.; Khosla, P. K.

    1975-01-01

    The cubic spline collocation procedure for the numerical solution of partial differential equations was 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 for a nonuniform mesh and overall fourth-order accuracy for a uniform mesh. Application of the technique was made to the Burger's equation, to the flow around a linear corner, to the potential flow over a circular cylinder, and to boundary layer problems. The results confirmed the higher-order accuracy of the spline method and suggest that accurate solutions for more practical flow problems can be obtained with relatively coarse nonuniform meshes.