WorldWideScience

Sample records for salt ion distribution

  1. Salt Distribution, Domain Spacing, and Interfacial Characteristics in Lithium Ion-Doped Block Polymer Electrolyte Films

    Science.gov (United States)

    Gartner, Thomas; Shelton, Cameron; Morris, Melody; Jayaraman, Arthi; Epps, Thomas, III

    Block polymer (BP) electrolytes have significant potential for use as battery membranes; however, to enable the design of efficient and reliable battery materials, open questions must be answered about the effects of lithium ion dopants on BP microstructure (including domain spacing and mixing near the interface) and the distribution of lithium ions in the BP domains. In this work, X-ray and neutron reflectometry (XRR and NR, respectively) revealed the morphological changes introduced by doping lamellar polystyrene- b-poly(oligo(oxyethylene methacrylate)) (PS-POEM) block polymer films with various lithium salts, as well as the lithium ion distribution in the ion-conducting POEM domain. XRR indicated swelling of both the POEM and PS domains with increasing salt content, with a corresponding decrease in the interfacial width as the salt increased the segregation strength of the BP. However, at very high salt concentrations ([EO]:[Li] = 6:1), roughening of the film caused a slight increase in the interfacial width. NR showed similar trends in domain spacing with salt content, and fits to the NR allow for determination of the lithium salt distribution across the POEM domains. These results help identify the implications of doping lithium salts into BP battery membranes and inform the design of BP electrolyte materials with controlled structure and properties.

  2. Intrinsic potential of cell membranes: opposite effects of lipid transmembrane asymmetry and asymmetric salt ion distribution

    DEFF Research Database (Denmark)

    Gurtovenko, Andrey A; Vattulainen, Ilpo

    2009-01-01

    Using atomic-scale molecular dynamics simulations, we consider the intrinsic cell membrane potential that is found to originate from a subtle interplay between lipid transmembrane asymmetry and the asymmetric distribution of monovalent salt ions on the two sides of the cell membrane. It turns out......Cl saline solution and the PE leaflet is exposed to KCl, the outcome is that the effects of asymmetric lipid and salt ion distributions essentially cancel one another almost completely. Overall, our study highlights the complex nature of the intrinsic potential of cell membranes under physiological...

  3. Charged patchy particle models in explicit salt: Ion distributions, electrostatic potentials, and effective interactions.

    Science.gov (United States)

    Yigit, Cemil; Heyda, Jan; Dzubiella, Joachim

    2015-08-14

    We introduce a set of charged patchy particle models (CPPMs) in order to systematically study the influence of electrostatic charge patchiness and multipolarity on macromolecular interactions by means of implicit-solvent, explicit-ion Langevin dynamics simulations employing the Gromacs software. We consider well-defined zero-, one-, and two-patched spherical globules each of the same net charge and (nanometer) size which are composed of discrete atoms. The studied mono- and multipole moments of the CPPMs are comparable to those of globular proteins with similar size. We first characterize ion distributions and electrostatic potentials around a single CPPM. Although angle-resolved radial distribution functions reveal the expected local accumulation and depletion of counter- and co-ions around the patches, respectively, the orientation-averaged electrostatic potential shows only a small variation among the various CPPMs due to space charge cancellations. Furthermore, we study the orientation-averaged potential of mean force (PMF), the number of accumulated ions on the patches, as well as the CPPM orientations along the center-to-center distance of a pair of CPPMs. We compare the PMFs to the classical Derjaguin-Verwey-Landau-Overbeek theory and previously introduced orientation-averaged Debye-Hückel pair potentials including dipolar interactions. Our simulations confirm the adequacy of the theories in their respective regimes of validity, while low salt concentrations and large multipolar interactions remain a challenge for tractable theoretical descriptions.

  4. Charged patchy particle models in explicit salt: Ion distributions, electrostatic potentials, and effective interactions

    Energy Technology Data Exchange (ETDEWEB)

    Yigit, Cemil; Dzubiella, Joachim, E-mail: joachim.dzubiella@helmholtz-berlin.de [Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, 14109 Berlin (Germany); Helmholtz Virtual Institute “Multifunctional Biomaterials for Medicine,” 14513 Teltow (Germany); Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Heyda, Jan [Department of Physical Chemistry, University of Chemistry and Technology, Prague, 166 28 Praha 6 (Czech Republic)

    2015-08-14

    We introduce a set of charged patchy particle models (CPPMs) in order to systematically study the influence of electrostatic charge patchiness and multipolarity on macromolecular interactions by means of implicit-solvent, explicit-ion Langevin dynamics simulations employing the Gromacs software. We consider well-defined zero-, one-, and two-patched spherical globules each of the same net charge and (nanometer) size which are composed of discrete atoms. The studied mono- and multipole moments of the CPPMs are comparable to those of globular proteins with similar size. We first characterize ion distributions and electrostatic potentials around a single CPPM. Although angle-resolved radial distribution functions reveal the expected local accumulation and depletion of counter- and co-ions around the patches, respectively, the orientation-averaged electrostatic potential shows only a small variation among the various CPPMs due to space charge cancellations. Furthermore, we study the orientation-averaged potential of mean force (PMF), the number of accumulated ions on the patches, as well as the CPPM orientations along the center-to-center distance of a pair of CPPMs. We compare the PMFs to the classical Derjaguin-Verwey-Landau-Overbeek theory and previously introduced orientation-averaged Debye-Hückel pair potentials including dipolar interactions. Our simulations confirm the adequacy of the theories in their respective regimes of validity, while low salt concentrations and large multipolar interactions remain a challenge for tractable theoretical descriptions.

  5. Contribution and distribution of inorganic ions and organic compounds to the osmotic adjustment in Halostachys caspica response to salt stress

    Science.gov (United States)

    Zeng, Youling; Li, Ling; Yang, Ruirui; Yi, Xiaoya; Zhang, Baohong

    2015-01-01

    The mechanism by which plants cope with salt stress remains poorly understood. The goal of this study is to systematically investigate the contribution and distribution of inorganic ions and organic compounds to the osmotic adjustment (OA) in the halophyte species Halostachys caspica. The results indicate that 100–200 mM NaCl is optimal for plant growth; the water content and degree of succulence of the assimilating branches are higher in this treatment range than that in other treatments; parenchyma cells are more numerous with 100 mM NaCl treatment than they are in control. Inorganic ions (mainly Na+ and Cl-) may play a more important role than organic compounds in NaCl-induced OA and are the primary contributors in OA in H. caspica. The inorganic ions and organic solutes display a tissue-dependent distribution. Na+ and Cl− are accumulated in the reproductive organs and within assimilating branches, which may represent a mechanism for protecting plant growth by way of salt ion dilution and organ abscission. Additionally, OA via increased accumulation of organic substances also protected plant growth and development. This finding provides additional evidence for plant tolerance to salinity stress which can be used for breeding new cultivars for stress tolerance. PMID:26350977

  6. Contribution and distribution of inorganic ions and organic compounds to the osmotic adjustment in Halostachys caspica response to salt stress.

    Science.gov (United States)

    Zeng, Youling; Li, Ling; Yang, Ruirui; Yi, Xiaoya; Zhang, Baohong

    2015-09-09

    The mechanism by which plants cope with salt stress remains poorly understood. The goal of this study is to systematically investigate the contribution and distribution of inorganic ions and organic compounds to the osmotic adjustment (OA) in the halophyte species Halostachys caspica. The results indicate that 100-200 mM NaCl is optimal for plant growth; the water content and degree of succulence of the assimilating branches are higher in this treatment range than that in other treatments; parenchyma cells are more numerous with 100 mM NaCl treatment than they are in control. Inorganic ions (mainly Na+ and Cl-) may play a more important role than organic compounds in NaCl-induced OA and are the primary contributors in OA in H. caspica. The inorganic ions and organic solutes display a tissue-dependent distribution. Na+ and Cl- are accumulated in the reproductive organs and within assimilating branches, which may represent a mechanism for protecting plant growth by way of salt ion dilution and organ abscission. Additionally, OA via increased accumulation of organic substances also protected plant growth and development. This finding provides additional evidence for plant tolerance to salinity stress which can be used for breeding new cultivars for stress tolerance.

  7. Contribution and distribution of inorganic ions and organic compounds to the osmotic adjustment in Halostachys caspica response to salt stress

    OpenAIRE

    Youling Zeng; Ling Li; Ruirui Yang; Xiaoya Yi; Baohong Zhang

    2015-01-01

    The mechanism by which plants cope with salt stress remains poorly understood. The goal of this study is to systematically investigate the contribution and distribution of inorganic ions and organic compounds to the osmotic adjustment (OA) in the halophyte species Halostachys caspica. The results indicate that 100–200 mM NaCl is optimal for plant growth; the water content and degree of succulence of the assimilating branches are higher in this treatment range than that in other treatments; pa...

  8. Quantitative Visualization of Salt Concentration Distributions in Lithium-Ion Battery Electrolytes during Battery Operation Using X-ray Phase Imaging.

    Science.gov (United States)

    Takamatsu, Daiko; Yoneyama, Akio; Asari, Yusuke; Hirano, Tatsumi

    2018-02-07

    A fundamental understanding of concentrations of salts in lithium-ion battery electrolytes during battery operation is important for optimal operation and design of lithium-ion batteries. However, there are few techniques that can be used to quantitatively characterize salt concentration distributions in the electrolytes during battery operation. In this paper, we demonstrate that in operando X-ray phase imaging can quantitatively visualize the salt concentration distributions that arise in electrolytes during battery operation. From quantitative evaluation of the concentration distributions at steady states, we obtained the salt diffusivities in electrolytes with different initial salt concentrations. Because of no restriction on samples and high temporal and spatial resolutions, X-ray phase imaging will be a versatile technique for evaluating electrolytes, both aqueous and nonaqueous, of many electrochemical systems.

  9. Effect of phytohormones on absorption and distribution of ions in salt-stressed bean plants

    Directory of Open Access Journals (Sweden)

    Zofia Starck

    2014-01-01

    Full Text Available Bean plant seedlings grown in water culture were treated for 5 days either with NaCl or with 7-times concentrated nutrient solution (diminished water potential by 3-103 hPa in both cases. Control and stressed plants were treated for 24 hrs with zeatin and GA,. NaCl-stress reduced distinctly ion absorption rate (K, Ca and P. Zeatin and GA3 promoted potassium uptake, but only in NaCI-treated plants. These hormones diminished Na accumulation in metabolically active organs but increased P- and Ca-content. In plants grown under both kind of stresses zeatin and GA3 partially reestablished the ratio of the main mono- to divalent cations, which increased in the leaves and apical part of the stressed plants. ABA introduced into the nutrient solution caused inhibition of the ion uptake (K, Ca, Mg and P. similar to that caused by NaCl-stress. The above reported results seem to confirm the supposition, that hormones act as an important factor contributing to regulation of both uptake and distribution of ions. In this way growth substances may also participate in the regulation of transport of various substances (among others - assimilates in the whole plant.

  10. Electrochemical ion separation in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Spoerke, Erik David; Ihlefeld, Jon; Waldrip, Karen; Wheeler, Jill S.; Brown-Shaklee, Harlan James; Small, Leo J.; Wheeler, David R.

    2017-12-19

    A purification method that uses ion-selective ceramics to electrochemically filter waste products from a molten salt. The electrochemical method uses ion-conducting ceramics that are selective for the molten salt cations desired in the final purified melt, and selective against any contaminant ions. The method can be integrated into a slightly modified version of the electrochemical framework currently used in pyroprocessing of nuclear wastes.

  11. Ion aggregation in high salt solutions. VI. Spectral graph analysis of chaotropic ion aggregates

    Science.gov (United States)

    Choi, Jun-Ho; Cho, Minhaeng

    2016-11-01

    Carrying out molecular dynamics simulations and graph theoretical analyses of high salt solutions, and comparing numerically calculated vibrational spectroscopic properties of water with femtosecond IR pump-probe experimental data, we have recently found that ions in high salt solutions can form two morphologically different ion aggregate structures. In the cases of NaCl solutions, Na+ and Cl- tend to form compact cluster-like ion aggregate in high NaCl solutions. In contrast, K+ and SCN- form spatially extended network-like ion aggregates that also exhibit a percolating network behavior. Interestingly, a variety of graph theoretical properties of ion network in high KSCN solutions were found to be very similar to those of water H-bonding network. It was shown that spatially extended ion networks in high KSCN solutions are completely intertwined with water H-bonding networks, which might be the key to understand the high solubility of thiocyanate salts in water. Here, we further consider two salts that have been extensively studied experimentally by using femtosecond IR pump-probe technique, which are NaClO4 and NaBF4. Note that ClO4 - and BF4 - are well-known chaotropic ions that have been believed to behave as water structure breaker. To understand how such chaotropic ions affect water H-bonding structure, we carried out spectral graph analyses of molecular dynamics simulation data of these aqueous solutions. Graph spectra and degree distribution of ion aggregates formed in high NaBF4 and NaClO4 solutions show that these chaotropic anions also have a strong propensity to form ion networks. The fact that salts containing chaotropic ions like SCN-, BF4 - , and ClO4 - have very high solubility limits in water could then be related to our observation that these chaotropic anions with counter cations in high salt solutions are capable of forming intricate ion networks intertwined with water H-bonding networks. We anticipate that the present graph theoretical analysis

  12. Ion aggregation in high salt solutions. V. Graph entropy analyses of ion aggregate structure and water hydrogen bonding network

    Science.gov (United States)

    Choi, Jun-Ho; Cho, Minhaeng

    2016-05-01

    Dissolved ions in water tend to form polydisperse ion aggregates such as ion pairs, relatively compact ion clusters, and even spatially extended ion networks with increasing salt concentration. Combining molecular dynamics simulation and graph theoretical analysis methods, we recently studied morphological structures of ion aggregates with distinctively different characteristics. They can be distinguished from each other by calculating various spectral graph theoretical properties such as eigenvalues and eigenvectors of adjacency matrices of ion aggregates and water hydrogen-bonding networks, minimum path lengths, clustering coefficients, and degree distributions. Here, we focus on percolation and graph entropic properties of ion aggregates and water hydrogen-bonding networks in high salt solutions. Ion network-forming K+ and SCN- ions at high concentrations show a percolating behavior in their aqueous solutions, but ion cluster-forming ions in NaCl solutions do not show such a transition from isolated ion aggregates to percolating ion-water mixture morphology. Despite that the ion aggregate structures are strikingly different for either cluster- or network-forming ions in high salt solutions, it is interesting that the water structures remain insensitive to the electrostatic properties, such as charge densities and polydentate properties, of dissolved ions, and morphological structures of water H-bonding networks appear to be highly robust regardless of the nature and concentration of salt. We anticipate that the present graph entropy analysis results would be of use in understanding a variety of anomalous behaviors of interfacial water around biomolecules as well as electric conductivities of high electrolyte solutions.

  13. Ion aggregation in high salt solutions. V. Graph entropy analyses of ion aggregate structure and water hydrogen bonding network.

    Science.gov (United States)

    Choi, Jun-Ho; Cho, Minhaeng

    2016-05-28

    Dissolved ions in water tend to form polydisperse ion aggregates such as ion pairs, relatively compact ion clusters, and even spatially extended ion networks with increasing salt concentration. Combining molecular dynamics simulation and graph theoretical analysis methods, we recently studied morphological structures of ion aggregates with distinctively different characteristics. They can be distinguished from each other by calculating various spectral graph theoretical properties such as eigenvalues and eigenvectors of adjacency matrices of ion aggregates and water hydrogen-bonding networks, minimum path lengths, clustering coefficients, and degree distributions. Here, we focus on percolation and graph entropic properties of ion aggregates and water hydrogen-bonding networks in high salt solutions. Ion network-forming K(+) and SCN(-) ions at high concentrations show a percolating behavior in their aqueous solutions, but ion cluster-forming ions in NaCl solutions do not show such a transition from isolated ion aggregates to percolating ion-water mixture morphology. Despite that the ion aggregate structures are strikingly different for either cluster- or network-forming ions in high salt solutions, it is interesting that the water structures remain insensitive to the electrostatic properties, such as charge densities and polydentate properties, of dissolved ions, and morphological structures of water H-bonding networks appear to be highly robust regardless of the nature and concentration of salt. We anticipate that the present graph entropy analysis results would be of use in understanding a variety of anomalous behaviors of interfacial water around biomolecules as well as electric conductivities of high electrolyte solutions.

  14. Ion aggregation in high salt solutions. VII. The effect of cations on the structures of ion aggregates and water hydrogen-bonding network

    Science.gov (United States)

    Choi, Jun-Ho; Choi, Hyung Ran; Jeon, Jonggu; Cho, Minhaeng

    2017-10-01

    Ions in high salt solutions have a strong propensity to form polydisperse ion aggregates with broad size and shape distributions. In a series of previous comparative investigations using femtosecond IR pump-probe spectroscopy, molecular dynamics simulation, and graph theoretical analysis, we have shown that there exists a morphological difference in the structures of ion aggregates formed in various salt solutions. As salt concentration increases, the ions in high salt solutions form either cluster-like structures excluding water molecules or network-like structures entwined with water hydrogen-bonding networks. Interestingly, such morphological characteristics of the ion aggregates have been found to be in correlation with the solubility limits of salts. An important question that still remains unexplored is why certain salts with different cations have notably different solubility limits in water. Here, carrying out a series of molecular dynamics simulations of aqueous salt solutions and analyzing the distributions and connectivity patterns of ion aggregates with a spectral graph analysis method, we establish the relationship between the salt solubility and the ion aggregate morphology with a special emphasis on the cationic effects on water structures and ion aggregation. We anticipate that the understanding of large scale ion aggregate structures revealed in this study will be critical for elucidating the specific ion effects on the solubility and conformational stability of co-solute molecules such as proteins in water.

  15. Ion aggregation in high salt solutions. III. Computational vibrational spectroscopy of HDO in aqueous salt solutions.

    Science.gov (United States)

    Choi, Jun-Ho; Kim, Heejae; Kim, Seongheun; Lim, Sohee; Chon, Bonghwan; Cho, Minhaeng

    2015-05-28

    The vibrational frequency, frequency fluctuation dynamics, and transition dipole moment of the O-D stretch mode of HDO molecule in aqueous solutions are strongly dependent on its local electrostatic environment and hydrogen-bond network structure. Therefore, the time-resolved vibrational spectroscopy the O-D stretch mode has been particularly used to investigate specific ion effects on water structure. Despite prolonged efforts to understand the interplay of O-D vibrational dynamics with local water hydrogen-bond network and ion aggregate structures in high salt solutions, still there exists a gap between theory and experiment due to a lack of quantitative model for accurately describing O-D stretch frequency in high salt solutions. To fill this gap, we have performed numerical simulations of Raman scattering and IR absorption spectra of the O-D stretch mode of HDO in highly concentrated NaCl and KSCN solutions and compared them with experimental results. Carrying out extensive quantum chemistry calculations on not only water clusters but also ion-water clusters, we first developed a distributed vibrational solvatochromic charge model for the O-D stretch mode in aqueous salt solutions. Furthermore, the non-Condon effect on the vibrational transition dipole moment of the O-D stretch mode was fully taken into consideration with the charge response kernel that is non-local polarizability density. From the fluctuating O-D stretch mode frequencies and transition dipole vectors obtained from the molecular dynamics simulations, the O-D stretch Raman scattering and IR absorption spectra of HDO in salt solutions could be calculated. The polarization effect on the transition dipole vector of the O-D stretch mode is shown to be important and the asymmetric line shapes of the O-D stretch Raman scattering and IR absorption spectra of HDO especially in highly concentrated NaCl and KSCN solutions are in quantitative agreement with experimental results. We anticipate that this

  16. Mitochondrial membranes with mono- and divalent salt: changes induced by salt ions on structure and dynamics

    DEFF Research Database (Denmark)

    Pöyry, Sanja; Róg, Tomasz; Karttunen, Mikko

    2009-01-01

    We employ atomistic simulations to consider how mono- (NaCl) and divalent (CaCl(2)) salt affects properties of inner and outer membranes of mitochondria. We find that the influence of salt on structural properties is rather minute, only weakly affecting lipid packing, conformational ordering......, and membrane electrostatic potential. The changes induced by salt are more prominent in dynamical properties related to ion binding and formation of ion-lipid complexes and lipid aggregates, as rotational diffusion of lipids is slowed down by ions, especially in the case of CaCl(2). In the same spirit, lateral...... diffusion of lipids is slowed down rather considerably for increasing concentration of CaCl(2). Both findings for dynamic properties can be traced to the binding of ions with lipid head groups and the related changes in interaction patterns in the headgroup region, where the binding of Na(+) and Ca(2+) ions...

  17. Ion aggregation in high salt solutions. IV. Graph-theoretical analyses of ion aggregate structure and water hydrogen bonding network

    Science.gov (United States)

    Choi, Jun-Ho; Cho, Minhaeng

    2015-09-01

    Ions in high salt solutions form a variety of ion aggregates, from ion pairs to clusters and networks. Their influences on water hydrogen bonding (H-bonding) network structures have long been of great interest. Recently, we have shown that the morphological structures of ion aggregates can be analyzed by using a spectral graph analysis theory, where each ion cluster or ion network is represented by a properly defined graph with edges and vertices. Here, to further examine the network properties of ion aggregates and water H-bonding networks in high salt solutions, we consider a few representative graph-theoretical descriptors: clustering coefficient, minimum path length, global efficiency, and degree distribution of ion aggregates. From the molecular dynamics trajectories, these graph theoretical properties of ion aggregates and water structures in NaCl and kosmotropic solutions are calculated and shown to be strongly dependent on the two types of ion aggregate structures, i.e., ion cluster and ion network. Ion clusters in high NaCl solutions exhibit typical behaviors of scale free network. The corresponding graph theoretical properties of ion networks in high KSCN solutions are notably different from those of NaCl ion clusters and furthermore they are very similar to those of water hydrogen-bonding network. The present graph-theoretical analysis results indicate that the high solubility limits of KSCN and other ion-network-forming salts might originate from their ability to form a large scale morphological network that can be intertwined with co-existing water H-bonding network. Furthermore, it is shown that the graph-theoretical properties of water H-bonding network structures do not strongly depend on the nature of dissolved ions nor on the morphological structures of ion aggregates, indicating that water's H-bonding interaction and network-forming capability are highly robust. We anticipate that the present graph-theoretical analysis results of high salt

  18. Ion aggregation in high salt solutions. IV. Graph-theoretical analyses of ion aggregate structure and water hydrogen bonding network.

    Science.gov (United States)

    Choi, Jun-Ho; Cho, Minhaeng

    2015-09-14

    Ions in high salt solutions form a variety of ion aggregates, from ion pairs to clusters and networks. Their influences on water hydrogen bonding (H-bonding) network structures have long been of great interest. Recently, we have shown that the morphological structures of ion aggregates can be analyzed by using a spectral graph analysis theory, where each ion cluster or ion network is represented by a properly defined graph with edges and vertices. Here, to further examine the network properties of ion aggregates and water H-bonding networks in high salt solutions, we consider a few representative graph-theoretical descriptors: clustering coefficient, minimum path length, global efficiency, and degree distribution of ion aggregates. From the molecular dynamics trajectories, these graph theoretical properties of ion aggregates and water structures in NaCl and kosmotropic solutions are calculated and shown to be strongly dependent on the two types of ion aggregate structures, i.e., ion cluster and ion network. Ion clusters in high NaCl solutions exhibit typical behaviors of scale free network. The corresponding graph theoretical properties of ion networks in high KSCN solutions are notably different from those of NaCl ion clusters and furthermore they are very similar to those of water hydrogen-bonding network. The present graph-theoretical analysis results indicate that the high solubility limits of KSCN and other ion-network-forming salts might originate from their ability to form a large scale morphological network that can be intertwined with co-existing water H-bonding network. Furthermore, it is shown that the graph-theoretical properties of water H-bonding network structures do not strongly depend on the nature of dissolved ions nor on the morphological structures of ion aggregates, indicating that water's H-bonding interaction and network-forming capability are highly robust. We anticipate that the present graph-theoretical analysis results of high salt

  19. Electrolyte materials containing highly dissociated metal ion salts

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.S.; Geng, L.; Skotheim, T.A.

    1996-07-23

    The present invention relates to metal ion salts which can be used in electrolytes for producing electrochemical devices, including both primary and secondary batteries, photoelectrochemical cells and electrochromic displays. The salts have a low energy of dissociation and may be dissolved in a suitable polymer to produce a polymer solid electrolyte or in a polar aprotic liquid solvent to produce a liquid electrolyte. The anion of the salts may be covalently attached to polymer backbones to produce polymer solid electrolytes with exclusive cation conductivity. 2 figs.

  20. Electrolyte materials containing highly dissociated metal ion salts

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hung-Sui (East Setauket, NY); Geng, Lin (Coram, NY); Skotheim, Terje A. (Shoreham, NY)

    1996-07-23

    The present invention relates to metal ion salts which can be used in electrolytes for producing electrochemical devices, including both primary and secondary batteries, photoelectrochemical cells and electrochromic displays. The salts have a low energy of dissociation and may be dissolved in a suitable polymer to produce a polymer solid electrolyte or in a polar aprotic liquid solvent to produce a liquid electrolyte. The anion of the salts may be covalently attached to polymer backbones to produce polymer solid electrolytes with exclusive cation conductivity.

  1. Salt stress induced ion accumulation, ion homeostasis, membrane ...

    African Journals Online (AJOL)

    The increase in Na+ was positively related to total soluble sugars, resulting in an osmotic adjustment of the membrane that maintained water availability. The accumulation of sugars in PT1 roots may be a primary salt-defense mechanism and may function as an osmotic control. Key words: Mannitol, membrane injury, ...

  2. Preferential solvation, ion pairing, and dynamics of concentrated aqueous solutions of divalent metal nitrate salts

    Science.gov (United States)

    Yadav, Sushma; Chandra, Amalendu

    2017-12-01

    We have investigated the characteristics of preferential solvation of ions, structure of solvation shells, ion pairing, and dynamics of aqueous solutions of divalent alkaline-earth metal nitrate salts at varying concentration by means of molecular dynamics simulations. Hydration shell structures and the extent of preferential solvation of the metal and nitrate ions in the solutions are investigated through calculations of radial distribution functions, tetrahedral ordering, and also spatial distribution functions. The Mg2+ ions are found to form solvent separated ion-pairs while the Ca2+ and Sr2+ ions form contact ion pairs with the nitrate ions. These findings are further corroborated by excess coordination numbers calculated through Kirkwood-Buff G factors for different ion-ion and ion-water pairs. The ion-pairing propensity is found to be in the order of Mg(NO3) 2 coefficients. It is found that proper modeling of these solutions requires the inclusion of electronic polarization of the ions which is achieved in the current study through electronic continuum correction force fields. A detailed analysis of the effects of ion-pairs on the structure and dynamics of water around the hydrated ions is done through classification of water into different subspecies based on their locations around the cations or anions only or bridged between them. We have looked at the diffusion coefficients, relaxation of orientational correlation functions, and also the residence times of different subspecies of water to explore the dynamics of water in different structural environments in the solutions. The current results show that the water molecules are incorporated into fairly well-structured hydration shells of the ions, thus decreasing the single-particle diffusivities and increasing the orientational relaxation times of water with an increase in salt concentration. The different structural motifs also lead to the presence of substantial dynamical heterogeneity in these solutions

  3. Hypertension: salt restriction, sodium homeostasis, and other ions.

    Science.gov (United States)

    Gupta, Neeru; Jani, Kishan Kumar; Gupta, Nivedita

    2011-03-01

    Salt is composed of Sodium Chloride (NaCl) which in body water becomes essential electrolytes, viz., Sodium (Na⁺) and Chloride (Cl⁻) ions, including in the blood and other extracellular fluids (ECF). Na⁺ ions are necessary cations in muscle contractions and their depletion will effect all the muscles in body including smooth muscle contraction of blood vessels, a fact which is utilized in lowering the blood pressure. Na⁺ ions also hold water with them in the ECF. Na⁺ homeostasis in body is maintained by thirst (water intake), kidneys (urinary excretion) and skin (sweating). In Na⁺ withdrawal, body tries to maintain homeostasis as far as possible. However, in certain conditions (e.g., during exercise, intake of drugs and in disorders causing Syndrome of Inappropriate Anti Diuretic Hormone Secretion (SIADH), diuretics, diarrhea) coupled with moderate or severe dietary salt restriction (anorexia nervosa), hyponatremia can get precipitated. Hyponatremia is one end point in the spectrum of disorders caused by severe Na⁺ depletion whereas in moderate depletion it can cause hypohydration (or less total body water) and lower urinary volume (U v ). Moreover, salt sensitivity varies in various populations leading to different responses in relation to dietary Na⁺ intake. Diabetes and Hypertension often co-exist but Na⁺ withdrawal in salt sensitive subjects worsens diabetes though hypertension gets better and reverse occurs in salt loading. Therefore, Na⁺ or salt restriction may be non-physiological. In hypertensive subjects other alternatives to Na⁺ withdrawal could be Potassium (K⁺) and Calcium (Ca⁺²) supplementation. Further studies are required to monitor safety/side effects of salt restriction.

  4. Enhanced Salt Removal by Unipolar Ion Conduction in Ion Concentration Polarization Desalination

    Science.gov (United States)

    Kwak, Rhokyun; Pham, Van Sang; Kim, Bumjoo; Chen, Lan; Han, Jongyoon

    2016-01-01

    Chloride ion, the majority salt in nature, is ∼52% faster than sodium ion (DNa+ = 1.33, DCl− = 2.03[10−9m2s−1]). Yet, current electrochemical desalination technologies (e.g. electrodialysis) rely on bipolar ion conduction, removing one pair of the cation and the anion simultaneously. Here, we demonstrate that novel ion concentration polarization desalination can enhance salt removal under a given current by implementing unipolar ion conduction: conducting only cations (or anions) with the unipolar ion exchange membrane stack. Combining theoretical analysis, experiment, and numerical modeling, we elucidate that this enhanced salt removal can shift current utilization (ratio between desalted ions and ions conducted through electrodes) and corresponding energy efficiency by the factor ∼(D− − D+)/(D− + D+). Specifically for desalting NaCl, this enhancement of unipolar cation conduction saves power consumption by ∼50% in overlimiting regime, compared with conventional electrodialysis. Recognizing and utilizing differences between unipolar and bipolar ion conductions have significant implications not only on electromembrane desalination, but also energy harvesting applications (e.g. reverse electrodialysis). PMID:27158057

  5. Electrodialysis-ion exchange for the separation of dissolved salts

    Energy Technology Data Exchange (ETDEWEB)

    Baroch, C.J. [Wastren, Inc., Westminster, CO (United States); Grant, P.J. [Wastren, Inc., Hummelstown, PA (United States)

    1995-10-01

    The Department of Energy generates and stores a significant quantity of low level, high level, and mixed wastes. As some of the DOE facilities are decontaminated and decommissioned, additional and possibly different forms of wastes will be generated. A significant portion of these wastes are aqueous streams containing acids, bases, and salts, or are wet solids containing inorganic salts. Some of these wastes are quite dilute solutions, whereas others contain large quantities of nitrates either in the form of dissolved salts or acids. Many of the wastes are also contaminated with heavy metals, radioactive products, or organics. Some of these wastes are in storage because a satisfactory treatment and disposal processes have not been developed. There is considerable interest in developing processes that remove or destroy the nitrate wastes. Electrodialysis-Ion Exchange (EDIX) is a possible process that should be more cost effective in treating aqueous waste steams. This report describes the EDIX process.

  6. The Impact of magnetic water treatment on salt distribution in a large unsaturated soil column

    Directory of Open Access Journals (Sweden)

    Vladimir Zlotopolski

    2017-12-01

    Full Text Available The use of saline water for crop production leads to soil salinization. Magnetically-treated water (MTW has been used for many years and has shown promise in leaching some ions from soil. At the same time, results have been inconsistent and somewhat controversial. In this study, we used large unsaturated columns (diameter 15 cm and length 90 cm to determine: 1 salt distributions at depths of up to 90 cm after adding magnetically-treated, saline water to soil; 2 whether MTW could reduce the rate of accumulation of salts (measured by EC in soil, and; 3 whether MTW could increase the leaching effect of soluble salts below root zones compared to control. The soil tested had a lower salt content compared to the water, a real-world scenario often faced when farmers elect to switch from higher-cost municipal water sources to ground water sources that have a higher saline content. Results indicated that the rate of salt accumulation was greater in the control group at the 30–60 cm depth. At the same time, the salt content at the 90 cm depth was greater in the MTW column. The results have shown that MTW changes the distribution of salts between soil layers reducing their content in the upper layers which are more important for agriculture. Keywords: Magnetic water treatment, Agriculture, Soil, Irrigation water

  7. Structure, Ion Transport, and Rheology of Nanoparticle Salts

    KAUST Repository

    Wen, Yu Ho

    2014-07-08

    Above a critical surface chemistry-dependent particle loading associated with nanoscale interparticle spacing, ligand-ligand interactions-both electrostatic and steric-come into play and govern the structure and dynamics of charged oligomer-functionalized nanoparticle suspensions. We report in particular on the structure, ion transport, and rheology of suspensions of nanoparticle salts created by cofunctionalization of silica particles with tethered sulfonate salts and oligomers. Dispersion of the hairy ionic particles into medium and high dielectric constant liquids yields electrolytes with unique structure and transport properties. We find that electrostatic repulsion imparted by ion dissociation can be tuned to control the dispersion state and rheology through counterion size (i.e., Li+, Na+, and K+) and dielectric properties of the dispersing medium. Analysis of small-angle X-ray scattering (SAXS) structure factors and the mechanical modulus shows that when the interparticle spacing approaches nanometer dimensions, weakly entangled anchored ligands experience strong and long-lived topological constraints analogous to those normally found in well-entangled polymeric fluids. This finding provides insight into the molecular origins of the surprisingly similar rubbery plateau moduli observed in hairy nanoparticle suspensions and entangled polymers of the same chemistry as the tethered ligands. Additionally, we find that a time-composition superposition (TCS) principle exists for the suspensions, which can be used to substantially extend the observation time over which dynamics are observed in jammed, soft glassy suspensions. Application of TCS reveals dynamical similarities between the suspensions and entangled solutions of linear polymer chains; i.e., a hairy particle trapped in a cage appears to exhibit analogous dynamics to a long polymer chain confined to a tube. © 2014 American Chemical Society.

  8. Ion aggregation in high salt solutions. II. Spectral graph analysis of water hydrogen-bonding network and ion aggregate structures

    Science.gov (United States)

    Choi, Jun-Ho; Cho, Minhaeng

    2014-10-01

    Graph theory in mathematics and computer science is the study of graphs that are structures with pairwise connections between any objects. Here, the spectral graph theory and molecular dynamics simulation method are used to describe both morphological variation of ion aggregates in high salt solutions and ion effects on water hydrogen-bonding network structure. From the characteristic value analysis of the adjacency matrices that are graph theoretical representations of ion clusters, ion networks, and water H-bond structures, we obtained the ensemble average eigenvalue spectra revealing intricate connectivity and topology of ion aggregate structure that can be classified as either ion cluster or ion network. We further show that there is an isospectral relationship between the eigenvalue spectra of ion networks in high KSCN solutions and those of water H-bonding networks. This reveals the isomorphic relationship between water H-bond structure and ion-ion network structure in KSCN solution. On the other hand, the ion clusters formed in high NaCl solutions are shown to be graph-theoretically and morphologically different from the ion network structures in KSCN solutions. These observations support the bifurcation hypothesis on large ion aggregate growth mechanism via either ion cluster or ion network formation. We thus anticipate that the present spectral graph analyses of ion aggregate structures and their effects on water H-bonding network structures in high salt solutions can provide important information on the specific ion effects on water structures and possibly protein stability resulting from protein-water interactions.

  9. Ion aggregation in high salt solutions. II. Spectral graph analysis of water hydrogen-bonding network and ion aggregate structures.

    Science.gov (United States)

    Choi, Jun-Ho; Cho, Minhaeng

    2014-10-21

    Graph theory in mathematics and computer science is the study of graphs that are structures with pairwise connections between any objects. Here, the spectral graph theory and molecular dynamics simulation method are used to describe both morphological variation of ion aggregates in high salt solutions and ion effects on water hydrogen-bonding network structure. From the characteristic value analysis of the adjacency matrices that are graph theoretical representations of ion clusters, ion networks, and water H-bond structures, we obtained the ensemble average eigenvalue spectra revealing intricate connectivity and topology of ion aggregate structure that can be classified as either ion cluster or ion network. We further show that there is an isospectral relationship between the eigenvalue spectra of ion networks in high KSCN solutions and those of water H-bonding networks. This reveals the isomorphic relationship between water H-bond structure and ion-ion network structure in KSCN solution. On the other hand, the ion clusters formed in high NaCl solutions are shown to be graph-theoretically and morphologically different from the ion network structures in KSCN solutions. These observations support the bifurcation hypothesis on large ion aggregate growth mechanism via either ion cluster or ion network formation. We thus anticipate that the present spectral graph analyses of ion aggregate structures and their effects on water H-bonding network structures in high salt solutions can provide important information on the specific ion effects on water structures and possibly protein stability resulting from protein-water interactions.

  10. Ion distributions upstream of an interplanetary shock

    Science.gov (United States)

    Kajdic, Primoz; Hietala, Heli; Blanco-Cano, Xochitl

    2017-04-01

    It is well known that supercritical collisionless shocks in the interplanetary (IP) space reflect part of the incoming particles (ions, electrons) in order to dissipate the kinetic energy of the upstream solar wind flow. When the conditions are right the reflected particles can escape far upstream from the shock. Their interaction with incoming ions and electrons results in the formation of the foreshock region which is populated by ultra-low frequency magnetic field fluctuations and different populations of reflected ions. Our knowledge on the latter comes mostly from observations of our planet's foreshock. However, the bow shock of the Earth typically has high Mach numbers, and the relatively small global curvature radius of the shock's shape affects the ion distribution characteristics. Interplanetary (IP) shocks, on the other hand, typically have lower Mach numbers and larger global curvature radii. In the past the majority of observed ion distributions detected upstream of IP shocks were diffuse. In only a couple of works the field-aligned ion beams were reported and even then the details of the ion distributions functions could not be determined. Here we present the first study showing clear observations of different types of ion distributions upstream of an interplanetary shock. The shock was observed on 8 October 2013 by several spacecraft, namely Wind, ACE, and the two ARTEMIS spacecraft P1 and P2. By using combined data from the Electrostatic Analyzer and the Solid State Telescope instruments onboard both ARTEMIS spacecraft we observed different types of ion distributions upstream of the shock: The distributions changed from field-aligned ion beams that were detected farthest from the shock, to intermediate and then to almost diffuse ion distributions near the shock transition. Furthermore, the observations at P1 and P2 locations also show spatial variability of the foreshock and the IP shock. The angle between the local shock normal and the upstream

  11. Interaction of the model alkyltrimethylammonium ions with alkali halide salts: an explicit water molecular dynamics study

    Directory of Open Access Journals (Sweden)

    M. Druchok

    2013-01-01

    Full Text Available We present an explicit water molecular dynamics simulation of dilute solutions of model alkyltrimethylammonium surfactant ions (number of methylene groups in the tail is 3, 5, 8, 10, and 12 in mixture with NaF, NaCl, NaBr, and NaI salts, respectively. The SPC/E model is used to describe water molecules. Results of the simulation at 298 K are presented in form of the radial distribution functions between nitrogen and carbon atoms of CH2 groups on the alkyltrimethylammonium ion, and the counterion species in the solution. The running coordination numbers between carbon atoms of surfactants and counterions are also calculated. We show that I- counterion exhibits the highest, and F- the lowest affinity to "bind" to the model surfactants. The results are discussed in view of the available experimental and simulation data for this and similar solutions.

  12. The Acute Toxicity of Major Ion Salts to Ceriodaphnia dubia. III. Mathematical models for mixture toxicity

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset concerns the development of models for describing the acute toxicity of major ions to Ceriodaphnia dubia using data from single salt tests and binary...

  13. Behavior of Time-Resolved Ion Energy Distribution Functions during Ion-Ion Instability

    Science.gov (United States)

    Saitou, Yoshifumi; Nakamura, Yoshiharu; Tanaka, Masayoshi; Komori, Akio; Kawai, Yoshinobu

    1993-10-01

    When an external RF field is applied to an ion beam plasma system, ion-ion instability is suppressed at f/fii≳1, where f and fii are the frequency of the external RF field and the peak frequency of the instability, respectively. It is also observed that the time-averaged energy distribution function of the ion beam broadens when the instability is suppressed. In order to investigate the cause of this broadening, time-resolved energy distribution functions of ions are measured with a boxcar integrator. As a result, it is found that the energy distribution functions periodically change with the external RF field and the above broadening is apparently caused by the time-averaging of the energy distribution functions.

  14. Effect of salt stress on growth, inorganic ion and proline ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... 4Institute of Molecular Bio Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand. Accepted 26 March ... cultures of KDML105 rice were exposed to salt stress by placing on Murashige and Skoog (MS) medium ... Key word: Aromatic rice, osmoprotectant, callus culture, salt stress.

  15. Effect of salt stress on growth, inorganic ion and proline ...

    African Journals Online (AJOL)

    The inhibitory effect of salt stress in rice is complex and is one of the main reasons for reduction of plant growth and crop productivity. In the present study, the response of rice callus cultivar Khao Dawk Mali 105 (KDML105), commonly known as Thai jasmine rice, to salt stress was examined. Callus cultures of KDML105 rice ...

  16. Ion transport mechanisms in lamellar phases of salt-doped PS-PEO block copolymer electrolytes.

    Science.gov (United States)

    Sethuraman, Vaidyanathan; Mogurampelly, Santosh; Ganesan, Venkat

    2017-11-01

    We use a multiscale simulation strategy to elucidate, at an atomistic level, the mechanisms underlying ion transport in the lamellar phase of polystyrene-polyethylene oxide (PS-PEO) block copolymer (BCP) electrolytes doped with LiPF6 salts. Explicitly, we compare the results obtained for ion transport in the microphase separated block copolymer melts to those for salt-doped PEO homopolymer melts. In addition, we also present results for dynamics of the ions individually in the PEO and PS domains of the BCP melt, and locally as a function of the distance from the lamellar interfaces. When compared to the PEO homopolymer melt, ions were found to exhibit slower dynamics in both the block copolymer (overall) and in the PEO phase of the BCP melt. Such results are shown to arise from the effects of slower polymer segmental dynamics in the BCP melt and the coordination characteristics of the ions. Polymer backbone-ion residence times analyzed as a function of distance from the interface indicate that ions have a larger residence time near the interface compared to that near the bulk of lamella, and demonstrates the influence of the glassy PS blocks and microphase segregation on the ion transport properties. Ion transport mechanisms in BCP melts reveal that there exist five distinct mechanisms for ion transport along the backbone of the chain and exhibit qualitative differences from the behavior in homopolymer melts. We also present results as a function of salt concentration which show that the mean-squared displacements of the ions decrease with increasing salt concentration, and that the ion residence times near the polymer backbone increase with increasing salt concentration.

  17. Ion transport mechanisms in lamellar phases of salt-doped PS–PEO block copolymer electrolytes

    KAUST Repository

    Sethuraman, Vaidyanathan

    2017-10-23

    We use a multiscale simulation strategy to elucidate, at an atomistic level, the mechanisms underlying ion transport in the lamellar phase of polystyrene–polyethylene oxide (PS–PEO) block copolymer (BCP) electrolytes doped with LiPF6 salts. Explicitly, we compare the results obtained for ion transport in the microphase separated block copolymer melts to those for salt-doped PEO homopolymer melts. In addition, we also present results for dynamics of the ions individually in the PEO and PS domains of the BCP melt, and locally as a function of the distance from the lamellar interfaces. When compared to the PEO homopolymer melt, ions were found to exhibit slower dynamics in both the block copolymer (overall) and in the PEO phase of the BCP melt. Such results are shown to arise from the effects of slower polymer segmental dynamics in the BCP melt and the coordination characteristics of the ions. Polymer backbone-ion residence times analyzed as a function of distance from the interface indicate that ions have a larger residence time near the interface compared to that near the bulk of lamella, and demonstrates the influence of the glassy PS blocks and microphase segregation on the ion transport properties. Ion transport mechanisms in BCP melts reveal that there exist five distinct mechanisms for ion transport along the backbone of the chain and exhibit qualitative differences from the behavior in homopolymer melts. We also present results as a function of salt concentration which show that the mean-squared displacements of the ions decrease with increasing salt concentration, and that the ion residence times near the polymer backbone increase with increasing salt concentration.

  18. Mathematical modeling of salt-gradient ion-exchange simulated moving bed chromatography for protein separations.

    Science.gov (United States)

    Lu, Jian-Gang

    2004-12-01

    The salt-gradient operation mode used in ion-exchange simulated moving bed chromatography (SMBC) can improve the efficiency of protein separations. A detailed model that takes into account any kind of adsorption/ion-exchange equilibrium, salt gradient, size exclusion, mass transfer resistance, and port periodic switching mechanism, was developed to simulate the complex dynamics. The model predictions were verified by the experimental data on upward and downward gradients for protein separations reported in the literature. All design and operating parameters (number, configuration, length and diameter of columns, particle size, switching period, flow rates of feed, raffinate, desorbent and extract, protein concentrations in feed, different salt concentrations in desorbent and feed) can be chosen correctly by numerical simulation. This model can facilitate the design, operation, optimization, control and scale-up of salt-gradient ion-exchange SMBC for protein separations.

  19. Distribution and metabolism of quaternary amines in salt marshes

    Science.gov (United States)

    King, Gary M.

    1985-01-01

    Quaternary amines such as glycine betaine (GBT) are common osmotically active solutes in much of the marine biota. GBT is accumulated by various bacteria, algae, higher plants, invertebrates, and vertebrates in response to salinity or water stresses; in some species, GBT occurs at tens to hundreds of millimolar concentrations and can account for a significant fraction of total nitrogen. Initial studies suggest that GBT is readily converted to two potential methane precursors, trimethylamine (TMA) and acetate, in anoxic sediments. TMA is apparently the most important methane precursor in surface sediments containing sulfate reducing bacteria. In salt marshes, the bulk of the methane formed may be due to the metabolism of TMA rather than other substrates. Current research is focussed on testing this hypothesis and on determining the role of quaternary amino osmoregulatory solutes in methane fluxes from marine environments. Preliminary studies have dealt with several problems: (1) determination of GBT concentrations in the dominant flora and fauna of salt marshes; (2) synthesis of radiolabelled GBT for metabolic studies; and (3) determination of fates of BGT in marine sediments using radiotracers. Both GC and HPLC techniques have been used to assay GBT concentrations in plant and animal tissues. S. alterniflora is probably the only significant source of GBT (and indirectly of methane) since the biomass and distribution of most other species is limited. Current estimates suggest that S. alterniflora GBT could account for most of the methane efflux from salt marshes.

  20. Transport of organic cationic drugs: effect of ion-pair formation with bile salts on the biliary excretion and pharmacokinetics.

    Science.gov (United States)

    Song, I S; Choi, M K; Shim, W S; Shim, C K

    2013-04-01

    More than 40% of clinically used drugs are organic cations (OCs), which are positively charged at a physiologic pH, and recent reports have established that these drugs are substrates of membrane transporters. The transport of OCs via membrane transporters may play important roles in gastrointestinal absorption, distribution to target sites, and biliary and/or renal elimination of various OC drugs. Almost 40 years ago, a molecular weight (Mw) threshold of 200 was reported to exist in rats for monoquaternary ammonium (mono QA) compounds to be substantially (e.g., >10% of iv dose) excreted to bile. It is well known that some OCs interact with appropriate endogenous organic anions in the body (e.g., bile salts) to form lipophilic ion-pair complexes. The ion-pair formation may influence the affinity or binding of OCs to membrane transporters that are relevant to biliary excretion. In that sense, the association of the ion-pair formation with the existence of the Mw threshold appears to be worthy of examination. It assumes the ion-pair formation of high Mw mono QA compounds (i.e., >200) in the presence of bile salts in the liver, followed by accelerated transport of the ion-pair complexes via relevant bile canalicular transporter(s). In this article, therefore, the transport of OC drugs will be reviewed with a special focus on the ion-pair formation hypothesis. Such information will deepen the understanding of the pharmacokinetics of OC drugs as well as the physiological roles of endogenous bile salts in the detoxification or phase II metabolism of high Mw QA drugs. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Effect of salt stress on growth, inorganic ion and proline ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Wanlchananan et al., 2003). Reports of high-quality aromatic rice linked to salt stress are very few. Thus, the effects of high salinity on total fresh and dry weight, relative water content, proline content, Na+, K+, Ca+ and Na+/K+ ratio in callus ...

  2. Regulation of ion homeostasis by aminolevulinic acid in salt-stressed wheat seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Türk, Hülya, E-mail: hulyaa.turk@hotmail.com [Biology Department, Science Faculty, Ataturk University, Erzurum (Turkey); East Anatolian High Technology Research and Application Center, Ataturk University, Erzurum (Turkey); Genişel, Mucip, E-mail: m.genisel@hotmail.com [Department of Crop and Animal Production, Vocational High School, Agri (Turkey); Erdal, Serkan, E-mail: serkanerdal25@hotmail.com [Biology Department, Science Faculty, Ataturk University, Erzurum (Turkey)

    2016-04-18

    Salinity is regarded as a worldwide agricultural threat, as it seriously limits plant development and productivity. Salt stress reduces water uptake in plants by disrupting the osmotic balance of soil solution. In addition, it creates a damaged metabolic process by causing ion imbalance in cells. In this study, we aim to examine the negative effects of 5-aminolevulinic acid (ALA) (20 mg/l) on the ion balance in wheat seedling leaves exposed to salt stress (150 mM). Sodium is known to be highly toxic for plant cells at high concentrations, and is significantly increased by salt stress. However, it can be reduced by combined application of ALA and salt, compared to salt application alone. On the other hand, while the K{sup +}/Na{sup +} ratio was reduced by salt stress, ALA application changed this ratio in favor of K{sup +}. Manganese, iron, and copper were also able to reduce stress. However, ALA pre-treatment resulted in mineral level increments. Conversely, the stress-induced rise in magnesium, potassium, calcium, phosphorus, zinc, and molybdenum were further improved by ALA application. These data clearly show that ALA has an important regulatory effect of ion balance in wheat leaves.

  3. New type of imidazole based salts designed specifically for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Niedzicki, L., E-mail: asalm@ch.pw.edu.p [Department of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00664 Warsaw (Poland); Zukowska, G.Z.; Bukowska, M.; Szczecinski, P. [Department of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00664 Warsaw (Poland); Grugeon, S.; Laruelle, S.; Armand, M. [Laboratoire de Reactivite et de Chimie des Solides University de Picardie Jules Verne, 33 rue de Saint-Leu, 80039 Amiens (France); Panero, S.; Scrosati, B. [Department of Chemistry, University of Rome ' La Sapienza' , Piazzale Aldo Moro 5, 00185 Rome (Italy); Marcinek, M.; Wieczorek, W. [Department of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00664 Warsaw (Poland)

    2010-01-25

    In this manuscript we announce new type of 'tailored' imidazole-derived salts designed, synthesized and tested for application in lithium conductive electrolytes. Basic characterization of the structure of described materials has been made by Raman, IR and NMR ({sup 13}C NMR, {sup 19}F NMR) techniques. DSC and CV studies showed thermal stability of all salts over 200 deg. C and electrochemical stability in liquid and solid polymer solvents up to +4.6 V vs. metallic lithium anode and Al collectors. Such properties proved applicability of these salts as lithium electrolytes for modern types of lithium ion batteries.

  4. NMR-based localization of ions involved in salting out of hen egg white lysozyme.

    Science.gov (United States)

    Poznański, Jarosław

    2006-01-01

    NaCl-induced aggregation of hen egg white lysozyme (HEWL) was monitored by NMR spectroscopy. Small, but significant, changes induced by salt addition in TOCSY spectra were attributed to the effect of local reorganization of protein backbone upon ion binding. Salt-induced variations in HN and H alpha chemical shifts were mapped on the HEWL 3D structure which allowed the construction of a scheme of the spatial localization of potential ion binding sites. It was found that in a 0.5 M NaCl solution six chloride anions and at least one sodium cation are bound to preferred sites on the HEWL surface.

  5. Fluid distribution in grain boundaries of natural fine-grained rock salt deformed at low differential stress (Qom Kuh salt fountain, central Iran): Implications for rheology and transport properties

    NARCIS (Netherlands)

    Desbois, G.; Urai, J.L.; Bresser, J.H.P. de

    2012-01-01

    We used a combination of broad ion beam cross-sectioning and cryogenic SEM to image polished surfaces and corresponding pairs of fractured grain boundaries in an investigation of grain boundary microstructures and fluid distribution in naturally deformed halite from the Qom Kuh salt glacier (central

  6. Recovery process for phenolic compounds from coal-derived oils by ions of soluble metal salts

    Energy Technology Data Exchange (ETDEWEB)

    Yizhang Ge; Hong Jin [Hefei Institute of Coal, Hefei (China)

    1996-11-01

    Phenolic compounds in a fraction (170-210{degree}C) of multistage rotary furnace coal tar pyrolysed from Tian Zhu brown coal at 550{degree}C were efficiently recovered by precipitation using ions of soluble metal salts as precipitant. The method overcomes the defects of the extraction method using 10 wt% NaOH solution. 8 refs., 2 figs., 3 tabs.

  7. Electrokinetic salt removal from porous building materials using ion exchange membranes

    NARCIS (Netherlands)

    Kamran, K.; Van Soestbergen, M.; Pel, L.

    The removal of salt from porous building materials under the influence of an applied voltage gradient normally results in high pH gradients due to the formation of protons and hydroxyl ions at the electrodes. The formed acidic and alkaline regions not only lead to disintegration of the porous

  8. Variation in viscosity and ion conductivity of a polymer–salt complex ...

    Indian Academy of Sciences (India)

    Variation in viscosity and ion conductivity of a polymer–salt complex exposed to gamma irradiation. SUJATA TARAFDAR1,∗,SKDE2, SUJIT MANNA2, UDAYAN DE3 and PRADYOT NANDA1. 1Physics Department, Condensed Matter Physics Research Centre, Jadavpur University,. Kolkata 700 032, India. 2Material Science ...

  9. Ion size effects on the electrokinetics of salt-free concentrated suspensions in ac fields

    Science.gov (United States)

    Roa, Rafael; Carrique, Félix; Ruiz-Reina, Emilio

    2012-12-01

    We analyze the influence of finite ion size effects in the response of a salt-free concentrated suspension of spherical particles to an oscillating electric field. Salt-free suspensions are just composed of charged colloidal particles and the added counterions released by the particles to the solution, that counterbalance their surface charge. In the frequency domain, we study the dynamic electrophoretic mobility of the particles and the dielectric response of the suspension. We find that the Maxwell-Wagner-O'Konski process associated with the counterions condensation layer, is enhanced for moderate to high particle charges, yielding an increment of the mobility for such frequencies. We also find that the increment of the mobility grows with ion size and particle charge. All these facts show the importance of including ion size effects in any extension attempting to improve standard electrokinetic models.

  10. Ion Dynamics Study of Potato Starch + Sodium Salts Electrolyte System

    Directory of Open Access Journals (Sweden)

    Tuhina Tiwari

    2013-01-01

    Full Text Available The effect of different anions, namely, SCN−, I−, and ClO4−, on the electrical properties of starch-based polymer electrolytes has been studied. Anion size and conductivity are having an inverse trend indicating systems to be predominantly anionic conductor. Impact of anion size and multiplet forming tendency is reflected in number of charge carriers and mobility, respectively. Ion dynamics study reveals the presence of different mechanisms in different frequency ranges. Interestingly, superlinear power law (SLPL is found to be present at <5 MHz frequency, which is further confirmed by dielectric data.

  11. Experiment on Chloride Ion Content of Concrete Structure in Coastal Salt-fog Area

    Directory of Open Access Journals (Sweden)

    Nie Ming

    2016-01-01

    Full Text Available This paper chose the south-east coastal salt-fog area Shantou to carry out the experiment study on chloride ion content of concrete structure, through the chloride ion content field test on reinforced concrete structure in Shantou, respectively for the slat-fog atmosphere zone and the splash zone in marine environment, discuss the corrosion by chloride ion of long-time existing concrete structure.And then measure the chloride ion content of concrete cover in different depth, and determine the chloride ion diffusion model in different conditions concrete through comparative analysis.The result of study, can be used in directing the selection of design scheme for building in planning, and also it will help predict the corrosion time of reinforcement inside the concrete on different positions for existing structure.

  12. Unraveling Salt Tolerance Mechanisms in Halophytes: A Comparative Study on Four Mediterranean Limonium Species with Different Geographic Distribution Patterns

    Directory of Open Access Journals (Sweden)

    Mohamad Al Hassan

    2017-08-01

    Full Text Available We have performed an extensive study on the responses to salt stress in four related Limonium halophytes with different geographic distribution patterns, during seed germination and early vegetative growth. The aims of the work were twofold: to establish the basis for the different chorology of these species, and to identify relevant mechanisms of salt tolerance dependent on the control of ion transport and osmolyte accumulation. Seeds were germinated in vitro, in the presence of increasing NaCl concentrations, and subjected to “recovery of germination” tests; germination percentages and velocity were determined to establish the relative tolerance and competitiveness of the four Limonium taxa. Salt treatments were also applied to young plants, by 1-month irrigation with NaCl up to 800 mM; then, growth parameters, levels of monovalent and divalent ions (in roots and leaves, and leaf contents of photosynthetic pigments and common osmolytes were determined in control and stressed plants of the four species. Seed germination is the most salt-sensitive developmental phase in Limonium. The different germination behavior of the investigated species appears to be responsible for their geographical range size: L. narbonense and L. virgatum, widespread throughout the Mediterranean, are the most tolerant and the most competitive at higher soil salinities; the endemic L. santapolense and L. girardianum are the most sensitive and more competitive only at lower salinities. During early vegetative growth, all taxa showed a strong tolerance to salt stress, although slightly higher in L. virgatum and L. santapolense. Salt tolerance is based on the efficient transport of Na+ and Cl− to the leaves and on the accumulation of fructose and proline for osmotic adjustment. Despite some species-specific quantitative differences, the accumulation patterns of the different ions were similar in all species, not explaining differences in tolerance, except for the

  13. Comparative study of imide-based Li salts as electrolyte additives for Li-ion batteries

    Science.gov (United States)

    Sharova, Varvara; Moretti, Arianna; Diemant, Thomas; Varzi, Alberto; Behm, R. Jürgen; Passerini, Stefano

    2018-01-01

    Herein, we report the results of a detailed study on the use of different Li imide salts (LiTFSI, LiFSI, and LiFTFSI) as electrolyte additives for lithium-ion batteries. The introduction of lithium imide salts in the electrolyte is shown to considerably improve the first cycle coulombic efficiency and the long-term cycling stability of graphite/LiFePO4 cells. Using LiTFSI, a capacity fading of only ∼2% occurred over 600 cycles while the control cell with the state-of-the-art additive (VC) lost ∼20% of the initial capacity at 20 °C. The results of the XPS and impedance spectroscopy measurements of graphite electrodes show that, after the formation cycle, the SEI obtained in the presence of imide salts is thinner, contains more LiF and is less resistive than that obtained using VC. Despite the beneficial effect of the imide salts on the lithium-ion cell performance, a slightly reduced thermal stability of the SEI is observed.

  14. Modeling of salt and pH gradient elution in ion-exchange chromatography.

    Science.gov (United States)

    Schmidt, Michael; Hafner, Mathias; Frech, Christian

    2014-01-01

    The separation of proteins by internally and externally generated pH gradients in chromatofocusing on ion-exchange columns is a well-established analytical method with a large number of applications. In this work, a stoichiometric displacement model was used to describe the retention behavior of lysozyme on SP Sepharose FF and a monoclonal antibody on Fractogel SO3 (S) in linear salt and pH gradient elution. The pH dependence of the binding charge B in the linear gradient elution model is introduced using a protein net charge model, while the pH dependence of the equilibrium constant is based on a thermodynamic approach. The model parameter and pH dependences are calculated from linear salt gradient elutions at different pH values as well as from linear pH gradient elutions at different fixed salt concentrations. The application of the model for the well-characterized protein lysozyme resulted in almost identical model parameters based on either linear salt or pH gradient elution data. For the antibody, only the approach based on linear pH gradients is feasible because of the limited pH range useful for salt gradient elution. The application of the model for the separation of an acid variant of the antibody from the major monomeric form is discussed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Investigation of salt distribution in porous stone material using paper pulp poultices under laboratory condititions and on site

    Science.gov (United States)

    Egartner, Isabel; Sass, Oliver

    2016-04-01

    The presented investigation is part of a longer-term project which deals with the influence of salt and moisture on weathering of historic stonework. The main investigation object in the field is a part of the 300 hundred year old boundary wall of the Worchester College in Oxford, UK. A range of non-destructive techniques were applied in course of field campaigns, e.g. mapping of weathering phenomena; handheld moisture sensors; and salt sampling by paper pulp poultices. In a second step we investigated the behaviour and distribution of water and salt solution in a porous material, similar to the limestone of the College wall, under laboratory condititions. Limestone cube samples (5x5x5 cm) were soaked first with ultrapure H2O and second with different concentration of saline solutions of NaCl and Na2SO4. During the dehydration process of the stone cubes a multi-method approach including sampling by drilling, paper pulp poultices, handheld moisture sensor, conductivity sensor and Ion Chromatography (IC) were applied to investigate the moisture and salt content and distribution within the samples. The laboratory analyses were carried out at the department of applied geoscience of the Technical University of Graz, Austria. The main aim was to investigate the effectivity of the paper pulp poultices in soaking up salts from the stone samples and to use the results of the laboratory analysis to interpret and calibrate the field work results from the College wall in Oxford. Keywords: Salt weathering, paper pulp poultices, cultural heritage, field work and laboratory investigation

  16. Compound ion salt, a novel low-sodium salt substitute: from animal study to community-based population trial.

    Science.gov (United States)

    Zhou, Xin; Liu, Jun-Xiang; Shi, Rui; Yang, Ning; Song, Dong-Lin; Pang, Wei; Li, Yu-Ming

    2009-09-01

    Salt restriction, an important approach for primary and secondary prevention of hypertension, is undermined by unsatisfactory adherence. A salt-restriction study tested the efficacy and safety of a compound ion salt (CISalt) with low sodium content in an animal model and in a community-based population. In part 1, 8-week-old male spontaneously hypertensive rats (SHRs) were fed 1% CISalt in the study group and 8% or 1% normal salt (NSalt) in controls (n = 10 each) for 12 weeks. Blood pressure (BP) and urinary electrolytes were measured every 3 weeks. After 12 weeks, collagen deposition in the heart and kidney and the levels of angiotensin II (Ang II) and nitric oxide (NO) in plasma and renal cortex were measured. In part 2, a single-blind, randomized, 6-month controlled trial with CISalt was conducted in 248 persons (age >or=65 years) in 10 rural communities. Plasma renin activity and Ang II were included in blood and urinary measures at baseline and 6 months. Reduced BP urinary protein excretion and reduced collagen in the heart and kidneys were significantly different in animals fed CISalt compared to controls. In human studies, at 6 months, mean systolic BP (SBP) was decreased by 9.6 mm Hg (95% confidence interval (CI): 13.1 to 6.1, P < 0.001) and diastolic BP (DBP) by 5.3 mm Hg (95% CI: 7.9 to 2.6, P < 0.001), respectively, compared to controls; urinary sodium excretion also decreased by 67.4 mmol/24 h (95% CI: 84.8 to 50.0, P < 0.001), and plasma renin activity was slightly increased by 0.19 ng/ml/h (95% CI: 0.04-0.33, P = 0.013). No adverse cardiovascular events were reported. In these studies, CISalt lowered BP and showed end-organ protection in hypertensive animals and BP reduction in humans. CISalt appears to be a safe and acceptable strategy to reduce BP.

  17. Introductory lecture: interpreting and predicting Hofmeister salt ion and solute effects on biopolymer and model processes using the solute partitioning model.

    Science.gov (United States)

    Record, M Thomas; Guinn, Emily; Pegram, Laurel; Capp, Michael

    2013-01-01

    local-bulk partition coefficients quantifying the distribution of solutes (e.g. urea, glycine betaine) and Hofmeister salt ions in the vicinity of each functional group make good chemical sense when interpreted in terms of competitive noncovalent interactions. These interaction potentials allow solute and Hofmeister (noncoulombic) salt effects on protein and nucleic acid processes to be interpreted or predicted, and allow the use of solutes and salts as probes of

  18. Faraday Discussion 160 Introductory Lecture: Interpreting and Predicting Hofmeister Salt Ion and Solute Effects on Biopolymer and Model Processes Using the Solute Partitioning Model

    Science.gov (United States)

    Record, M. Thomas; Guinn, Emily; Pegram, Laurel; Capp, Michael

    2013-01-01

    quantifying the distribution of solutes (e.g. urea, glycine betaine) and Hofmeister salt ions in the vicinity of each functional group make good chemical sense when interpreted in terms of competitive noncovalent interactions. These interaction potentials allow solute and Hofmeister (noncoulombic) salt effects on protein and nucleic acid processes to be interpreted or predicted, and allow the use of solutes and salts as probes of interface formation and large-scale conformational changes in the steps of a biopolymer mechanism. PMID:23795491

  19. Fluxes of microbes, organic aerosols, dust, sea-salt Na ions, non-sea-salt Ca ions, and methanesulfonate onto Greenland and Antarctic ice

    Directory of Open Access Journals (Sweden)

    P. B. Price

    2009-03-01

    Full Text Available Using a spectrofluorimeter with 224-nm laser excitation and six emission bands from 300 to 420 nm to measure fluorescence intensities at 0.3-mm depth intervals in ice cores, we report results of the first comparative study of concentrations of microbial cells (using the spectrum of protein-bound tryptophan (Trp as a proxy and of aerosols with autofluorescence spectra different from Trp (denoted "non-Trp" as a function of depth in ice cores from West Antarctica (WAIS Divide and Siple Dome and Greenland (GISP2. The ratio of fluxes of microbial cells onto West Antarctic (WAIS Divide versus Greenland sites is 0.13±0.06; the ratio of non-Trp aerosols onto WAIS Divide versus Greenland sites is 0.16±0.08; and the ratio of non-sea-salt Ca2+ ions (a proxy for dust grains onto WAIS Divide versus Greenland sites is 0.06±0.03. All of these are roughly comparable to the ratio of fluxes of dust onto Antarctic versus Greenland sites (0.08±0.05. By contrast to those values, which are considerably lower than unity, the ratio of fluxes of methanesulfonate (MSA onto Antarctic versus Greenland sites is 1.9±0.4 and the ratio of sea-salt Na2+ ions onto WAIS Divide versus Greenland sites is 3.0±2. These ratios are more than an order of magnitude higher than those in the first grouping. We infer that the correlation of microbes and non-Trp aerosols with non-sea-salt Ca and dust suggests a largely terrestrial rather than marine origin. The lower fluxes of microbes, non-Trp aerosols, non-sea-salt Ca and dust onto WAIS Divide ice than onto Greenland ice may be due to the smaller areas of their source regions and less favorable wind patterns for transport onto Antarctic ice than onto Greenland ice. The correlated higher relative fluxes of MSA and marine Na onto Antarctic versus Greenland ice is consistent with the view that both originate largely on or around sea ice, with the Antarctic sea ice being far more extensive than that around Greenland.

  20. Comparative Salt Stress Study on Intracellular Ion Concentration in Marine and Salt-adapted Freshwater Strains of Microalgae

    Directory of Open Access Journals (Sweden)

    Ahmad Farhad TALEBI

    2013-08-01

    Full Text Available Salinity imposes significant stresses in various living organisms including microalgae. High extracellular concentration of Na+ directly influences ionic balance inside the cell and subsequently the cellular activities. In the present study, the effect of such stress on growth and intracellular ions concentration (IIC of Dunaliella salina and Chlorella Spp. was investigated. IIC was analyzed using Ion chromatography technique. D. salina showed the highest degree of resistance to increase in salinity as little changes occurred both in IIC and in growth parameters. D. salina could maintain the balance of K+ inside the cell and eject the excess Na+ even at NaCl concentrations above 1M. Moreover, D. salina accumulated β-carotene in order to protect its photosynthetic apparatus. Among Chlorella species, C. vulgaris showed signs of adaptation to high content of salinity, though it is a fresh water species by nature. Moreover, the response shown by C. vulgaris to rise in salinity was even stronger than that of C. salina, which is presumably a salt-water resistant species. In fact, C. vulgaris could maintain intracellular K+ better than C. salina in response to increasing salinity, and as a result, it could survive at NaCl concentrations as high as 0.75 M. Marine strains such as D. salina well cope with the fluctuations in salinity through the existing adaptation mechanisms i.e. maintaining the K+/N+ balance inside the cell, K+ accumulation and Na+ ejection, accumulation of photosynthetic pigments like β-carotene.

  1. Optimisation strategies for the preparation of bipolar membranes with reduced salt ion leakage in acid-base electrodialysis

    NARCIS (Netherlands)

    Wilhelm, F.G.; Punt, Ineke G.M.; van der Vegt, N.F.A.; Wessling, Matthias; Strathmann, H.

    2001-01-01

    The salt ion fluxes across commercial bipolar membranes (BPMs) result in the salt contamination of the produced acids or bases especially at increased product concentrations. Often, bipolar membrane electrodialysis can only be applied when these fluxes are reduced. Here, a model is presented to

  2. Distribution and Aggregate Thickness of Salt Deposits of the United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — The map shows the distribution and aggregate thickness of salt deposits of the United States. This information is from contour map sheets, scanned and processed for...

  3. Distribution and Aggregate Thickness of Salt Deposits of the United States

    Science.gov (United States)

    The map shows the distribution and aggregate thickness of salt deposits of the United States. This information is from contour map sheets, scanned and processed for use in a global mineral resource assessment, produced by the U.S. Geological Survey. It is used here to provide a geospatial context to the distribution of rock-salt deposits in the US. It is useful in illustrating sources of chlorides.

  4. Towards more thermally stable Li-ion battery electrolytes with salts and solvents sharing nitrile functionality

    Science.gov (United States)

    Kerner, Manfred; Lim, Du-Hyun; Jeschke, Steffen; Rydholm, Tomas; Ahn, Jou-Hyeon; Scheers, Johan

    2016-11-01

    The overall safety of Li-ion batteries is compromised by the state-of-the-art electrolytes; the thermally unstable lithium salt, lithium hexafluorophosphate (LiPF6), and flammable carbonate solvent mixtures. The problem is best addressed by new electrolyte compositions with thermally robust salts in low flammability solvents. In this work we introduce electrolytes with either of two lithium nitrile salts, lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA) or lithium 4,5-dicyano-2-trifluoromethylimidazolide (LiTDI), in solvent mixtures with high flashpoint adiponitrile (ADN), as the main component. With sulfolane (SL) and ethylene carbonate (EC) as co-solvents the liquid temperature range of the electrolytes are extended to lower temperatures without lowering the flashpoint, but at the expense of high viscosities and moderate ionic conductivities. The anodic stabilities of the electrolytes are sufficient for LiFePO4 cathodes and can be charged/discharged for 20 cycles in Li/LiFePO4 cells with coulombic efficiencies exceeding 99% at best. The excellent thermal stabilities of the electrolytes with the solvent combination ADN:SL are promising for future electrochemical investigations at elevated temperatures (> 60 °C) to compensate the moderate transport properties and rate capability. The electrolytes with EC as a co-solvent, however, release CO2 by decomposition of EC in presence of a lithium salt, which potentially makes EC unsuitable for any application targeting higher operating temperatures.

  5. The distribution of free calcium ions in the cholesteatoma epithelium

    DEFF Research Database (Denmark)

    Svane-Knudsen, Viggo; Rasmussen, Gurli; Ottosen, Peter D

    2005-01-01

    The distribution of free calcium ions in normal skin and cholesteatoma epithelium was investigated using the oxalate precipitation method. In agreement with previous observations, we could demonstrate a calcium ion gradient in normal epidermis where the cells in stratum basale and spinosum reside...

  6. Vegetation effects on fish distribution in impounded salt marshes

    Science.gov (United States)

    Stolen, Eric D.; Collazo, Jaime; Percival, H. Franklin

    2009-01-01

    We compared the density and biomass of resident fish in vegetated and unvegetated flooded habitats of impounded salt marshes in the northern Indian River Lagoon (IRL) Estuary of east-central Florida. A 1-m2 throw trap was used to sample fish in randomly located, paired sample plots (n = 198 pairs) over 5 seasons in 7 impoundments. We collected a total of 15 fish taxa, and 88% of the fishes we identified from the samples belonged to three species: Cyprinodon variegatus (Sheepshead Minnow), Gambusia holbrooki (Eastern Mosquitofish), and Poecilia latipinna (Sailfin Molly). Vegetated habitat usually had higher density and biomass of fish. Mean fish density (and 95% confidence interval) for vegetated and unvegetated sites were 8.2 (6.7–9.9) and 2.0 (1.6–2.4) individuals m-2, respectively; mean biomass (and 95%) confidence interval) for vegetated and unvegetated sites were 3.0 (2.5–3.7) and 1.1 (0.9–1.4) g m-2, respectively. We confirmed previous findings that impounded salt marshes of the northern IRL Estuary produce a high standing stock of resident fishes. Seasonal patterns of abundance were consistent with fish moving between vegetated and unvegetated habitat as water levels changed in the estuary. Differences in density, mean size, and species composition of resident fishes between vegetated and unvegetated habitats have important implications for movement of biomass and nutrients out of salt marsh by piscivores (e.g., wading birds and fishes) via a trophic relay.

  7. Microwave irradiation affects ion pairing in aqueous solutions of alkali halide salts

    Science.gov (United States)

    Mohorič, Tomaž; Bren, Urban

    2017-01-01

    Using the molecular dynamics simulations with separate thermostats for translational and rotational degrees of freedom, we investigate the effects of water's rotational motion on the ion pairing of ionic solutes in aqueous solutions. The situation with rotational temperature higher than the translational one, Trot>Ttrs , is mimicking the non-equilibrium effects of microwaves on model solutions of alkali halide salts. The simulations reveal that an increase in the rotational temperature at constant translational temperature exerts significant changes in the structure of the solution. The latter are reflected in increased pairing of the oppositely charged ions, which can be explained by the weaker ability of rotationally excited water to screen and separate the opposite charges. It seems that Collins' law of matching water affinities retains its validity also in the non-equilibrium situation where the rotational temperature exceeds the translational one. On the other hand, the equilibrium effect (i.e., an increase in the solution's overall temperature T ≡Trot = Ttrs) favors the formation of small-small (NaCl), while it has a little effect on large-large (CsI) ion pairs. This is in accordance with water becoming less polar solvent upon a temperature increase. Furthermore, we investigated the effects of excited translational motion of water (and ions) on the ion pairing by increasing the translational temperature, while keeping the rotational one unchanged (i.e., Ttrs>Trot ). Interestingly, in certain cases the faster translational motion causes an increase in correlations. The temperature variations in the like-ion association constants, Kas++ and Kas-, are also examined. Here the situation is more complex but, in most cases, a decrease in the ion pairing is observed.

  8. Removal of Cr(III ions from salt solution by nanofiltration: experimental and modelling analysis

    Directory of Open Access Journals (Sweden)

    Kowalik-Klimczak Anna

    2016-09-01

    Full Text Available The aim of this study was experimental and modelling analysis of the nanofiltration process used for the removal of chromium(III ions from salt solution characterized by low pH. The experimental results were interpreted with Donnan and Steric Partitioning Pore (DSP model based on the extended Nernst-Planck equation. In this model, one of the main parameters, describing retention of ions by the membrane, is pore dielectric constant. In this work, it was identified for various process pressures and feed compositions. The obtained results showed the satisfactory agreement between the experimental and modelling data. It means that the DSP model may be helpful for the monitoring of nanofiltration process applied for treatment of chromium tannery wastewater.

  9. Graphene Visualizes the Ion Distribution on Air-Cleaved Mica

    Science.gov (United States)

    Bampoulis, Pantelis; Sotthewes, Kai; Siekman, Martin H.; Zandvliet, Harold J. W.; Poelsema, Bene

    2017-03-01

    The distribution of potassium (K+) ions on air-cleaved mica is important in many interfacial phenomena such as crystal growth, self-assembly and charge transfer on mica. However, due to experimental limitations to nondestructively probe single ions and ionic domains, their exact lateral organization is yet unknown. We show, by the use of graphene as an ultra-thin protective coating and scanning probe microscopies, that single potassium ions form ordered structures that are covered by an ice layer. The K+ ions prefer to minimize the number of nearest neighbour K+ ions by forming row-like structures as well as small domains. This trend is a result of repulsive ionic forces between adjacent ions, weakened due to screening by the surrounding water molecules. Using high resolution conductive atomic force microscopy maps, the local conductance of the graphene is measured, revealing a direct correlation between the K+ distribution and the structure of the ice layer. Our results shed light on the local distribution of ions on the air-cleaved mica, solving a long-standing enigma. They also provide a detailed understanding of charge transfer from the ionic domains towards graphene.

  10. Vacuolar Chloride Fluxes Impact Ion Content and Distribution during Early Salinity Stress1

    Science.gov (United States)

    Baetz, Ulrike; Tohge, Takayuki; Martinoia, Enrico; De Angeli, Alexis

    2016-01-01

    The ability to control the cytoplasmic environment is a prerequisite for plants to cope with changing environmental conditions. During salt stress, for instance, Na+ and Cl− are sequestered into the vacuole to help maintain cytosolic ion homeostasis and avoid cellular damage. It has been observed that vacuolar ion uptake is tied to fluxes across the plasma membrane. The coordination of both transport processes and relative contribution to plant adaptation, however, is still poorly understood. To investigate the link between vacuolar anion uptake and whole-plant ion distribution during salinity, we used mutants of the only vacuolar Cl− channel described to date: the Arabidopsis (Arabidopsis thaliana) ALMT9. After 24-h NaCl treatment, almt9 knock-out mutants had reduced shoot accumulation of both Cl− and Na+. In contrast, almt9 plants complemented with a mutant variant of ALMT9 that exhibits enhanced channel activity showed higher Cl− and Na+ accumulation. The altered shoot ion contents were not based on differences in transpiration, pointing to a vacuolar function in regulating xylem loading during salinity. In line with this finding, GUS staining demonstrated that ALMT9 is highly expressed in the vasculature of shoots and roots. RNA-seq analysis of almt9 mutants under salinity revealed specific expression profiles of transporters involved in long-distance ion translocation. Taken together, our study uncovers that the capacity of vacuolar Cl− loading in vascular cells plays a crucial role in controlling whole-plant ion movement rapidly after onset of salinity. PMID:27503602

  11. Ion pair dissociation effects of aza-based anion receptors on lithium salts in polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X.Q.; Lee, H.S.; Xiang, C.; McBreen, J. [Brookhaven National Lab., Upton, NY (United States); Choi, L.S. [Naval Research Lab., Washington, DC (United States); Okamoto, Y. [Polytechnic Univ., Brooklyn, NY (United States)

    1996-12-31

    The addition of aza-based anion receptors greatly increases the conductivity of polymer electrolytes based on LiCl and KI complexes with poly(ethylene oxide) (PEO). In some cases the conductivity increase is more than two orders of magnitude. Also the addition of the anion acceptors imparts a rubber like consistency to the normally stiff PEO salt films. Ion-ion, ion-polymer and anion-complex interactions were studied using Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy at the K and Cl K edges and at the I L{sub I} edge. The NEXAFS results show that Cl{sup {minus}} and I{sup {minus}} anions are complexed with the nitrogen groups of the anion receptors. The degree of complexation is related the chain length of the complexing agent and the number of R{double_bond}CF{sub 3}SO{sub 2} groups that are used to substitute for the amine hydrogen atoms in these aza-ether compounds. NEXAFS spectra at potassium K edge provide supplemental evidence for the ion pair dissociation effects of the anion receptors. The results show that dissociated K{sup +} cations are complexed with oxygen atoms of the PEO chains.

  12. dc Electrokinetics for spherical particles in salt-free concentrated suspensions including ion size effects.

    Science.gov (United States)

    Roa, Rafael; Carrique, Félix; Ruiz-Reina, Emilio

    2011-11-21

    We study the electrophoretic mobility of spherical particles and the electrical conductivity in salt-free concentrated suspensions including finite ion size effects. An ideal salt-free suspension is composed of just charged colloidal particles and the added counterions that counterbalance their surface charge. In a very recent paper [Roa et al., Phys. Chem. Chem. Phys., 2011, 13, 3960-3968] we presented a model for the equilibrium electric double layer for this kind of suspensions considering the size of the counterions, and now we extend this work to analyze the response of the suspension under a static external electric field. The numerical results show the high importance of such corrections for moderate to high particle charges, especially when a region of closest approach of the counterions to the particle surface is considered. The present work sets the basis for further theoretical models with finite ion size corrections, concerning particularly the ac electrokinetics and rheology of such systems. This journal is © the Owner Societies 2011

  13. Fast-ion-beam laser probing of ion-source energy distributions and atomic structure

    Energy Technology Data Exchange (ETDEWEB)

    Holt, Richard A., E-mail: rholt@uwo.ca; Rosner, S. David [University of Western Ontario, Physics and Astronomy Department (Canada)

    2013-04-15

    Collinear fast-ion-beam laser spectroscopy is a very high resolution probe for measuring ion-beam energy distributions and atomic structure parameters of interest in nuclear physics, atomic physics, and astrophysics. We have used offline 10-keV beams of atomic ions and a CW laser system to study the behavior of a Penning ion source and to measure hyperfine structure, isotope shifts, atomic lifetimes, spontaneous-emission branching fractions, oscillator strengths, and absolute wavelengths of a variety of atomic species from the lanthanide and transition-metal groups.

  14. Modulation of ion uptake in tomato (Lycopersicon esculentum L. plants with exogenous application of calcium under salt stress condition

    Directory of Open Access Journals (Sweden)

    Khursheda Parvin

    2016-11-01

    Full Text Available Salinity affects almost every aspect of the physiology and biochemistry of plants due to both osmotic stress and ionic toxicity. We studied the variation of ion uptake in tomato cv. BARI Tomato-5 under different levels of salinity (0, 2, 4, 6 and 8 dS m-1 and their mitigation by different concentration of Ca2+ (0, 5, 10 mM. The results showed that salt stress significantly affects the stomatal conductance of tomato. Salt treatment markedly increased the uptake of Na+ and decreased both K+ and Ca2+ uptake in the leaves of tomato. The uptake of Na+ decreased and uptake of Ca2+ and K+ increased in tomato when salt-stressed plants were treated with Ca2+. Our results revealed that Ca supplementation can effectively reduce the salt-induced ionic toxicity in tomato plants. Exogenous application of Ca2+ significantly mitigates the adverse effects of salt-induced ionic toxicity.

  15. Ion angular distribution in plasma of vacuum arc ion source with composite cathode and elevated gas pressure.

    Science.gov (United States)

    Nikolaev, A G; Savkin, K P; Yushkov, G Yu; Oks, E M

    2014-02-01

    The Metal Vapor Vacuum Arc (MEVVA) ion sources are capable of generating ion beams of almost all metals of the periodic table. For this kind of ion source, a combination of gas feeding with magnetic field allows the simultaneous generation of both metal and gaseous ions. That makes the MEVVA ion source an excellent instrument for science and application. This work presents results of investigation for ion angular distributions in vacuum arc plasma of Mevva-V.Ru ion source for composite cathodes and for elevated gas pressure. It was shown that for all the cathode materials, singly charged ions have wider angular distribution than multiply charged ions. Increasing the working gas pressure leads to a significant change in the angular distribution of gaseous ions, while with the distribution of metal ions gas remains practically unchanged. The reasons for such different influences are discussed.

  16. The role of salinity tolerance and competition in the distribution of an endangered desert salt marsh endemic

    Science.gov (United States)

    DeFalco, Lesley; Scoles, Sara; Beamguard, Emily R.

    2017-01-01

    Rare plants are often associated with distinctive soil types, and understanding why endemic species occur in unique environments is fundamental for their management. At Ash Meadows National Wildlife Refuge in southern Nevada, USA, we evaluated whether the limited distribution of endangered Amargosa niterwort (Nitrophila mohavensis) is explained by this species’ tolerance of saline soils on salt-encrusted mud flats compared with the broadly distributed desert saltgrass (Distichlis spicata var. stricta). We simultaneously explored whether niterwort distribution is restricted from expanding due to interspecific competition with saltgrass. Surface soils collected throughout niterwort’s range were unexpectedly less saline with lower extractable Na, seasonal electroconductivity, and Na absorption ratio, and higher soil moisture than in adjacent saltgrass or mixed shrub habitats. Comparison of niterwort and saltgrass growth along an experimental salinity gradient in a greenhouse demonstrated lower growth of niterwort at all but the highest NaCl concentrations. Although growth of niterwort ramets was similar when transplanted into both habitats at the refuge below Crystal Reservoir, niterwort reproductive effort was considerably higher in saltgrass compared to its own habitat, implying reallocation of resources to sexual reproduction to maximize fitness when the probability of ramet mortality increases with greater salinity stress. Saltgrass was not a demonstrated direct competitor of niterwort; however, this species is known to increase soil salinity by exuding salt ions and through litterfall. Niterwort conservation will benefit from protecting hydrological processes that reduce salinity stress and preventing saltgrass colonization into niterwort habitat.

  17. IONIZING INFLUENCE OF SALTS WITH TRIVALENT AND TETRAVALENT IONS ON CRYSTALLINE EGG ALBUMIN AT THE ISOELECTRIC POINT

    Science.gov (United States)

    Loeb, Jacques

    1922-01-01

    1. While crystalline egg albumin is highly soluble in water at low temperature at the pH of its isoelectric point, it is coagulated by heating. It has long been known that this coagulation can be prevented by adding either acid or alkali, whereby the protein is ionized. 2. It is shown in this paper that salts with trivalent or tetravalent ions, e.g. LaCl3 or Na4Fe(CN)6, are also able to prevent the heat coagulation of albumin at the isoelectric point (i.e. pH 4.8), while salts with a divalent ion, e.g. CaCl2, BaCl4, Na2SO4, or salts like NaCl, have no such effect. 3. This is in harmony with the fact shown in a preceding paper that salts with trivalent or tetravalent ions can cause the ionization of proteins at its isoelectric point and thus give rise to a membrane potential between micellæ of isoelectric protein and surrounding aqueous solution, while the above mentioned salts with divalent and monovalent ions have apparently no such effect. PMID:19871973

  18. Exploring Salt Bridge Structures of Gas-Phase Protein Ions using Multiple Stages of Electron Transfer and Collision Induced Dissociation

    Science.gov (United States)

    Zhang, Zhe; Browne, Shaynah J.; Vachet, Richard W.

    2014-04-01

    The gas-phase structures of protein ions have been studied by electron transfer dissociation (ETD) and collision-induced dissociation (CID) after electrospraying these proteins from native-like solutions into a quadrupole ion trap mass spectrometer. Because ETD can break covalent bonds while minimally disrupting noncovalent interactions, we have investigated the ability of this dissociation technique together with CID to probe the sites of electrostatic interactions in gas-phase protein ions. By comparing spectra from ETD with spectra from ETD followed by CID, we find that several proteins, including ubiquitin, CRABP I, azurin, and β-2-microglobulin, appear to maintain many of the salt bridge contacts known to exist in solution. To support this conclusion, we also performed calculations to consider all possible salt bridge patterns for each protein, and we find that the native salt bridge pattern explains the experimental ETD data better than nearly all other possible salt bridge patterns. Overall, our data suggest that ETD and ETD/CID of native protein ions can provide some insight into approximate location of salt bridges in the gas phase.

  19. Communication: Counter-ion solvation and anomalous low-angle scattering in salt-free polyelectrolyte solutions

    Science.gov (United States)

    Chremos, Alexandros; Douglas, Jack F.

    2017-12-01

    We investigate the influence of counter-ion solvation on the homogeneity of salt-free polyelectrolyte solutions based on a coarse-grained model that includes an explicit solvent. We show that the solvation of the counter-ions can cause a transformation between a nearly homogeneous to a non-uniform polymer solution, in which there is both a chain clustering and the formation of large charge-free domains, i.e., "voids." The emergence of these heterogeneous structures induced by counter-ion solvation is accompanied by the localization and formation of counter-ion rich domains that are symptomatic of emergent effective long-range attractive interchain interactions.

  20. Communication: Counter-ion solvation and anomalous low-angle scattering in salt-free polyelectrolyte solutions.

    Science.gov (United States)

    Chremos, Alexandros; Douglas, Jack F

    2017-12-28

    We investigate the influence of counter-ion solvation on the homogeneity of salt-free polyelectrolyte solutions based on a coarse-grained model that includes an explicit solvent. We show that the solvation of the counter-ions can cause a transformation between a nearly homogeneous to a non-uniform polymer solution, in which there is both a chain clustering and the formation of large charge-free domains, i.e., "voids." The emergence of these heterogeneous structures induced by counter-ion solvation is accompanied by the localization and formation of counter-ion rich domains that are symptomatic of emergent effective long-range attractive interchain interactions.

  1. Angular distribution of plasma in the vacuum arc ion source.

    Science.gov (United States)

    Nikolaev, A G; Yushkov, G Yu; Savkin, K P; Oks, E M

    2012-02-01

    This paper presents measurements of the angular distribution of the plasma components and different charge states of metal ions generated by a MEVVA-type ion source and measured by a time-of-flight mass-spectrometer. The experiments were performed for different cathode materials (Al, Cu, and Ti) and for different parameters of the vacuum arc discharge. The results are compared with prior results reported by other authors. The influence of different discharge parameters on the angular distribution in a vacuum arc source is discussed.

  2. Optical measurement of the longitudinal ion distribution of bunched ion beams in the ESR

    Energy Technology Data Exchange (ETDEWEB)

    Wen, W.Q. [Institute of Modern Physics, Chinese Academy of Sciences, 730000 Lanzhou (China); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); University of Chinese Academy of Sciences, 100049 Beijing (China); Lochmann, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Institut für Kernchemie, Universität Mainz, 55128 Mainz (Germany); Ma, X., E-mail: x.ma@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, 730000 Lanzhou (China); Bussmann, M. [Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Winters, D.F.A. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Nörtershäuser, W. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Institut für Kernchemie, Universität Mainz, 55128 Mainz (Germany); Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Botermann, B. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Institut für Kernchemie, Universität Mainz, 55128 Mainz (Germany); Geppert, C.; Frömmgen, N.; Hammen, M. [Institut für Kernchemie, Universität Mainz, 55128 Mainz (Germany); Hannen, V.; Jöhren, R. [Institut für Kernphysik, Universität Münster, 48149 Münster (Germany); and others

    2013-05-21

    An optical technique to study the longitudinal distribution of ions in a bunched ion beam circulating in a storage ring is presented. It is based on the arrival-time analysis of photons emitted after collisional excitation of residual gas molecules. The beam-induced fluorescence was investigated in the ultraviolet regime with a channeltron and in the visible region using a photomultiplier tube. Both were applied to investigate the longitudinal shape of bunched and electron-cooled {sup 209}Bi{sup 80+} ion beams at about 400 MeV/u in the experimental storage ring (ESR) at GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. Bunch lengths were determined with an uncertainty of about 0.5 m using the UV-sensitive channeltron and with slightly lower accuracy from the photomultiplier data due to the slower transitions in the red region of the spectrum. The Gaussian shape of the longitudinal distribution of ions inside the bunch was confirmed. With the information of the transverse beam size that can be measured simultaneously by a newly installed ionization profile monitor (IPM) at the ESR, an accurate determination of the ion density in the bunched beam will be allowed. -- Highlights: ► Optical methods to measure the bunch shape of ion beam at storage ring. ► High resolution of bunch length was obtained from the UV-sensitive channeltron. ► The Gaussian shape of longitudinal distribution of the ions in the bunch was confirmed.

  3. Roles of boundary conditions in DNA simulations: analysis of ion distributions with the finite-difference Poisson-Boltzmann method.

    Science.gov (United States)

    Ye, Xiang; Cai, Qin; Yang, Wei; Luo, Ray

    2009-07-22

    The wide use of lattice-sum strategies in biomolecular simulations has raised many questions on potential artifacts in these strategies. One interesting question is the artifacts in the counterion distributions of highly charged systems. As one would anticipate, Coulombic interactions under the periodic boundary condition may deviate noticeably from those under the free boundary condition in the highly charged systems, significantly influencing their counterion distributions. On the other hand, the electrostatic screening due to water molecules and mobile ions may effectively damp the possible periodic distortions in Coulombic interactions. Therefore, the magnitude of periodicity-induced artifacts in counterion distributions is not straightforward to dissect without detailed analyses. In this study, we have developed a hybrid explicit counterion/implicit salt representation of mobile ions to address this question. We have chosen a well-studied DNA for easy validation of the minimal hybrid ion representation. Our detailed analysis of continuum ion distributions, explicit ion distributions, radial counterion distribution functions, and sequence-dependent counterion distributions, however, indicates that periodicity artifacts are not apparent at the surface of the tested DNA. Nevertheless, influence of boundary conditions does show up starting at the second solvation shell and becomes apparent at the cell boundary.

  4. Temperature dependence of ion pairing of a potassium salt in nonaqueous liquid and polymer electrolytes: X-ray absorption studies

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X.Q.; Lee, H.S.; McBreen, J. (Brookhaven National Laboratory, Upton, New York 11973 (United States)); Xu, Z.S.; Skotheim, T.A. (Moltech Corporation, Stony Brook, New York 11794-2275 (United States)); Okamoto, Y. (Polytechnic University, Brooklyn, New York 11201 (United States)); Lu, F. (CFFLS, University of Kentucky, Lexington, Kentucky 40506 (United States))

    1994-08-15

    Near-edge x-ray absorption fine structure spectroscopy was used to study the effect of temperature on ion pairing of a potassium salt in a modified carbonate (MC3) solution and in a poly(ethylene oxide)-potassium salt complex that used MC3 as a plasticizer. The modified carbonate was made by attaching three ethylene oxide units to the four position of ethylene carbonate. Spectra were obtained, at the [ital K] edge of potassium, over the temperature range of 25--110 [degree]C. Studies of reference systems showed a correlation between ion pairing and white line splitting in the near-edge region of the spectra. The degree of white line splitting was used as a qualitative indicator of the degree of ion pairing as a function of temperature. The results indicate that, in both systems, the number of ion pairs increases with increasing temperature.

  5. Distribution of root-associated bacterial communities along a salt-marsh primary succession

    NARCIS (Netherlands)

    Wang, Miao; Yang, Pu; Falcao Salles, Joana

    2016-01-01

    Proper quantification of the relative influence of soil and plant host on the root-associated microbiome can only be achieved by studying its distribution along an environmental gradient. Here we used an undisturbed salt marsh chronosequence to study the bacterial communities associated with the

  6. Thoron, radon and air ions spatial distribution in indoor air.

    Science.gov (United States)

    Kolarž, Predrag; Vaupotič, Janja; Kobal, Ivan; Ujić, Predrag; Stojanovska, Zdenka; Žunić, Zora S

    2017-07-01

    Spatial distribution of radioactive gasses thoron (Tn) and radon (Rn) in indoor air of 9 houses mostly during winter period of 2013 has been studied. According to properties of alpha decay of both elements, air ionization was also measured. Simultaneous continual measurements using three Rn/Tn and three air-ion active instruments deployed on to three different distances from the wall surface have shown various outcomes. It has turned out that Tn and air ions concentrations decrease with the distance increase, while Rn remained uniformly distributed. Exponential fittings function for Tn variation with distance was used for the diffusion length and constant as well as the exhalation rate determination. The obtained values were similar with experimental data reported in the literature. Concentrations of air ions were found to be in relation with Rn and obvious, but to a lesser extent, with Tn. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Sources and distribution of sedimentary organic matter along the Andong salt marsh, Hangzhou Bay

    Science.gov (United States)

    Yuan, Hong-Wei; Chen, Jian-Fang; Ye, Ying; Lou, Zhang-Hua; Jin, Ai-Min; Chen, Xue-Gang; Jiang, Zong-Pei; Lin, Yu-Shih; Chen, Chen-Tung Arthur; Loh, Pei Sun

    2017-10-01

    Lignin oxidation products, δ13C values, C/N ratios and particle size were used to investigate the sources, distribution and chemical stability of sedimentary organic matter (OM) along the Andong salt marsh located in the southwestern end of Hangzhou Bay, China. Terrestrial OM was highest at the upper marshes and decreased closer to the sea, and the distribution of sedimentary total organic carbon (TOC) was influenced mostly by particle size. Terrestrial OM with a C3 signature was the predominant source of sedimentary OM in the Spartina alterniflora-dominated salt marsh system. This means that aside from contributions from the local marsh plants, the Andong salt marsh received input mostly from the Qiantang River and the Changjiang Estuary. Transect C, which was situated nearer to the Qiantang River mouth, was most likely influenced by input from the Qiantang River. Likewise, a nearby creek could be transporting materials from Hangzhou Bay into Transect A (farther east than Transect C), as Transect A showed a signal resembling that of the Changjiang Estuary. The predominance of terrestrial OM in the Andong salt marsh despite overall reductions in sedimentary and terrestrial OM input from the rivers is most likely due to increased contributions of sedimentary and terrestrial OM from erosion. This study shows that lower salt marsh accretion due to the presence of reservoirs upstream may be counterbalanced by increased erosion from the surrounding coastal areas.

  8. Colloidal Plasmas: Effect of nonthermal ion distribution and dust ...

    Indian Academy of Sciences (India)

    The effects of nonthermal ion distribution and finite dust temperature are incorporated in the investigation of nonlinear dust acoustic waves in an unmagnetized dusty plasma. Sagdeev pseudopotential method which takes into account the full nonlinearity of plasma equations, is used here to study solitary wave solutions.

  9. On-line method to study dynamics of ion adsorption from mixtures of salts in capacitive deionization

    NARCIS (Netherlands)

    Dykstra, J.E.; Dijkstra, J.; Wal, van der A.; Hamelers, H.V.M.; Porada, S.

    2016-01-01

    Capacitive Deionization (CDI) is a water desalination technology that adsorbs ions into two oppositely polarized porous carbon electrodes, under the action of an applied voltage. Here, we introduce a novel method to analyze the effluent concentration of multiple ionic species in mixtures of salt

  10. Ion flux and ion distribution function measurements in synchronously pulsed inductively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Brihoum, Melisa; Cunge, Gilles; Darnon, Maxime; Joubert, Olivier [Laboratoire des Technologies de la Microelectronique CNRS, Grenoble Cedex 9, Isere 38054 (France); Gahan, David [Impedans Ltd., Dublin 17 (Ireland); Braithwaite, Nicholas St. J. [Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2013-03-15

    Changes in the ion flux and the time-averaged ion distribution functions are reported for pulsed, inductively coupled RF plasmas (ICPs) operated over a range of duty cycles. For helium and argon plasmas, the ion flux increases rapidly after the start of the RF pulse and after about 50 {mu}s reaches the same steady state value as that in continuous ICPs. Therefore, when the plasma is pulsed at 1 kHz, the ion flux during the pulse has a value that is almost independent of the duty cycle. By contrast, in molecular electronegative chlorine/chlorosilane plasmas, the ion flux during the pulse reaches a steady state value that depends strongly on the duty cycle. This is because both the plasma chemistry and the electronegativity depend on the duty cycle. As a result, the ion flux is 15 times smaller in a pulsed 10% duty cycle plasma than in the continuous wave (CW) plasma. The consequence is that for a given synchronous RF biasing of a wafer-chuck, the ion energy is much higher in the pulsed plasma than it is in the CW plasma of chlorine/chlorosilane. Under these conditions, the wafer is bombarded by a low flux of very energetic ions, very much as it would in a low density, capacitively coupled plasma. Therefore, one can extend the operating range of ICPs through synchronous pulsing of the inductive excitation and capacitive chuck-bias, offering new means by which to control plasma etching.

  11. Rock-Salt Growth-Induced (003) Cracking in a Layered Positive Electrode for Li-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hanlei [Materials; amp, Department; NorthEast; Omenya, Fredrick [NorthEast; Yan, Pengfei [Environmental; Luo, Langli [Environmental; Whittingham, M. Stanley [NorthEast; Wang, Chongmin [Environmental; Zhou, Guangwen [Materials; amp, Department; NorthEast

    2017-10-20

    For the first time, the (003) cracking is observed and determined to be the major cracking mechanism for the primary particles of Ni-rich layered dioxides as the positive electrode for Li-ion batteries. Using transmission electron microscopy techniques, here we show that the propagation and fracturing of platelet-like rock-salt phase along the (003) plane of the layered oxide are the leading cause for the cracking of primary particles. The fracturing of the rock-salt platelet is induced by the stress discontinuity between the parent layered oxide and the rock-salt phase. The high nickel content is considered to be the key factor for the formation of the rock-salt platelet and thus the (003) cracking. The (003)-type cracking can be a major factor for the structural degradation and associated capacity fade of the layered positive electrode.

  12. Salt marsh sediment bacteria: their distribution and response to external nutrient inputs.

    Science.gov (United States)

    Bowen, Jennifer L; Crump, Byron C; Deegan, Linda A; Hobbie, John E

    2009-08-01

    A primary focus among microbial ecologists in recent years has been to understand controls on the distribution of microorganisms in various habitats. Much less attention has been paid to the way that environmental disturbance interacts with processes that regulate bacterial community composition. We determined how human disturbance affected the distribution and community structure of salt marsh sediment bacteria by using denaturing gradient gel electrophoresis of 16S rRNA in five different habitats in each of four salt marshes located in northeastern Massachusetts, USA. Two of the four marsh creeks were experimentally enriched 15 x above background by the addition of nitrogen and phosphorus fertilizers for two or more growing seasons. Our results indicate that extrinsic factors acting at broad scales do not influence the distribution of salt marsh sediment bacteria. Intrinsic factors, controlled by local-scale environmental heterogeneity, do play a role in structuring these sediment microbial communities, although nutrient enrichment did not have a consequential effect on the microbial community in most marsh habitats. Only in one habitat, a region of the marsh creek wall that is heavily colonized by filamentous algae, did we see any effect of fertilization on the microbial community structure. When similar habitats were compared among marshes, there was considerable convergence in the microbial community composition during the growing season. Environmental factors that correlated best with microbial community composition varied with habitat, suggesting that habitat-specific intrinsic forces are primarily responsible for maintaining microbial diversity in salt marsh sediments.

  13. Decolorization of Reactive Black-5 by Shewanella sp. in the Presence of Metal Ions and Salts.

    Science.gov (United States)

    Imran, Muhammad; Arshad, Muhammad; Khalid, Azeem; Hussain, Sabir; Mumtaz, Muhammad Waseem; Crowley, David E

    2015-07-01

    In this study, effect of various metal ions and salts on biodecolorization of Reactive black-5, azoreductase activity, and growth of Shewanella sp. strain IFN4 was evaluated. Among the tested metals, Cr²⁺, Pb(²⁺, Ni²⁺, Fe²⁺, and Mn²⁺ did not inhibit the biodecolorization of reactive black-5, azoreductase activity and bacterial growth. Three metals (Cu²⁺, Zn²⁺, and Co²⁺) delayed the decolorization process without completely inhibiting the reaction and also suppressed the bacterial growth. However, no dye decolorization was observed in the presence of Cd²⁺ (10 mg L⁻¹). Furthermore, bacterium decolorized the dye at high concentration (15 mg L⁻¹) of mixed metal ions. Strain IFN4 was also able to decolorize the dye at 50 g NaCl L⁻¹ and 60 g Na₂SO₄ L⁻¹. NaCl was found to be more inhibitory to bacterial growth than Na₂SO₄and the reverse was observed for azoreductase activity. These findings suggest that strain IFN4 could be used in designing a bioreactor for the treatment of textile effluent.

  14. Safe and recyclable lithium-ion capacitors using sacrificial organic lithium salt

    Science.gov (United States)

    Jeżowski, P.; Crosnier, O.; Deunf, E.; Poizot, P.; Béguin, F.; Brousse, T.

    2018-02-01

    Lithium-ion capacitors (LICs) shrewdly combine a lithium-ion battery negative electrode capable of reversibly intercalating lithium cations, namely graphite, together with an electrical double-layer positive electrode, namely activated carbon. However, the beauty of this concept is marred by the lack of a lithium-cation source in the device, thus requiring a specific preliminary charging step. The strategies devised thus far in an attempt to rectify this issue all present drawbacks. Our research uncovers a unique approach based on the use of a lithiated organic material, namely 3,4-dihydroxybenzonitrile dilithium salt. This compound can irreversibly provide lithium cations to the graphite electrode during an initial operando charging step without any negative effects with respect to further operation of the LIC. This method not only restores the low CO2 footprint of LICs, but also possesses far-reaching potential with respect to designing a wide range of greener hybrid devices based on other chemistries, comprising entirely recyclable components.

  15. A Grand Canonical Monte Carlo simulation program for computing ion distributions around biomolecules in hard sphere solvents

    Energy Technology Data Exchange (ETDEWEB)

    2017-02-24

    The GIBS software program is a Grand Canonical Monte Carlo (GCMC) simulation program (written in C++) that can be used for 1) computing the excess chemical potential of ions and the mean activity coefficients of salts in homogeneous electrolyte solutions; and, 2) for computing the distribution of ions around fixed macromolecules such as, nucleic acids and proteins. The solvent can be represented as neutral hard spheres or as a dielectric continuum. The ions are represented as charged hard spheres that can interact via Coulomb, hard-sphere, or Lennard-Jones potentials. In addition to hard-sphere repulsions, the ions can also be made to interact with the solvent hard spheres via short-ranged attractive square-well potentials.

  16. LITERATURE REVIEWS TO SUPPORT ION EXCHANGE TECHNOLOGY SELECTION FOR MODULAR SALT PROCESSING

    Energy Technology Data Exchange (ETDEWEB)

    King, W

    2007-11-30

    This report summarizes the results of literature reviews conducted to support the selection of a cesium removal technology for application in a small column ion exchange (SCIX) unit supported within a high level waste tank. SCIX is being considered as a technology for the treatment of radioactive salt solutions in order to accelerate closure of waste tanks at the Savannah River Site (SRS) as part of the Modular Salt Processing (MSP) technology development program. Two ion exchange materials, spherical Resorcinol-Formaldehyde (RF) and engineered Crystalline Silicotitanate (CST), are being considered for use within the SCIX unit. Both ion exchange materials have been studied extensively and are known to have high affinities for cesium ions in caustic tank waste supernates. RF is an elutable organic resin and CST is a non-elutable inorganic material. Waste treatment processes developed for the two technologies will differ with regard to solutions processed, secondary waste streams generated, optimum column size, and waste throughput. Pertinent references, anticipated processing sequences for utilization in waste treatment, gaps in the available data, and technical comparisons will be provided for the two ion exchange materials to assist in technology selection for SCIX. The engineered, granular form of CST (UOP IE-911) was the baseline ion exchange material used for the initial development and design of the SRS SCIX process (McCabe, 2005). To date, in-tank SCIX has not been implemented for treatment of radioactive waste solutions at SRS. Since initial development and consideration of SCIX for SRS waste treatment an alternative technology has been developed as part of the River Protection Project Waste Treatment Plant (RPP-WTP) Research and Technology program (Thorson, 2006). Spherical RF resin is the baseline media for cesium removal in the RPP-WTP, which was designed for the treatment of radioactive waste supernates and is currently under construction in Hanford, WA

  17. Ring/Shell Ion Distributions at Geosynchronous Orbit

    Science.gov (United States)

    Thomsen, M. F.; Denton, M. H.; Gary, S. P.; Liu, Kaijun; Min, Kyungguk

    2017-12-01

    One year's worth of plasma observations from geosynchronous orbit is examined for ion distributions that may simultaneously be subject to the ion Bernstein (IB) instability (generating fast magnetosonic waves) and the Alfvén cyclotron (AC) instability (generating electromagnetic ion cyclotron waves). Confirming past analyses, distributions with robust ∂fp(v⊥)/∂v⊥ > 0 near v|| = 0, which we denote as "ring/shell" distributions, are commonly found primarily on the dayside of the magnetosphere. A new approach to high-fidelity representation of the observed ring/shell distribution functions in a form readily suited to both analytical moment calculation and linear dispersion analysis is presented, which allows statistical analysis of the ring/shell properties. The ring/shell temperature anisotropy is found to have a clear upper limit that depends on the parallel beta of the ring/shell (β||r) in a manner that is diagnostic of the operation of the AC instability. This upper limit is only reached in the postnoon events, which are primarily produced by the energy- and pitch angle-dependent magnetic drifts of substorm-injected ions. Further, it is primarily the leading edge of such injections, where the distribution is strongly ring-like, that the AC instability appears to be operating. By contrast, the ratio of the ring energy to the Alfvén energy remains well within the range of 0.25-4.0 suitable for IB instability throughout essentially all of the events, except those that occur in denser cold plasma of the outer plasmasphere.

  18. Effects of salt stress on ion balance and nitrogen metabolism of old and young leaves in rice (Oryza sativa L.)

    Science.gov (United States)

    2012-01-01

    Background It is well known that salt stress has different effects on old and young tissues. However, it remains largely unexplored whether old and young tissues have different regulatory mechanism during adaptation of plants to salt stress. The aim of this study was to investigate whether salt stress has different effects on the ion balance and nitrogen metabolism in the old and young leaves of rice, and to compare functions of both organs in rice salt tolerance. Results Rice protected young leaves from ion harm via the large accumulation of Na+ and Cl− in old leaves. The up-regulation of OsHKT1;1, OsHAK10 and OsHAK16 might contribute to accumulation of Na+ in old leaves under salt stress. In addition, lower expression of OsHKT1;5 and OsSOS1 in old leaves may decrease frequency of retrieving Na+ from old leaf cells. Under salt stress, old leaves showed higher concentration of NO3− content than young leaves. Up-regulation of OsNRT1;2, a gene coding nitrate transporter, might contribute to the accumulation of NO3− in the old leaves of salt stressed-rice. Salt stress clearly up-regulated the expression of OsGDH2 and OsGDH3 in old leaves, while strongly down-regulated expression of OsGS2 and OsFd-GOGAT in old leaves. Conclusions The down-regulation of OsGS2 and OsFd-GOGAT in old leaves might be a harmful response to excesses of Na+ and Cl−. Under salt stress, rice might accumulate Na+ and Cl− to toxic levels in old leaves. This might influence photorespiration process, reduce NH4+ production from photorespiration, and immediately down-regulate the expression of OsGS2 and OsFd-GOGAT in old leaves of salt stressed rice. Excesses of Na+ and Cl− also might change the pathway of NH4+ assimilation in old leaves of salt stressed rice plants, weaken GOGAT/GS pathway and elevate GDH pathway. PMID:23082824

  19. A molecular simulation study on the role of ion sizes and dielectric images in near-surface ion distribution far from the strong coupling limit

    Science.gov (United States)

    Wang, Zhi-yong; Ma, Yu-qiang

    2012-06-01

    A series of Monte Carlo simulations of the planar electric double layers are carried out in the primitive model for two electrolyte mixtures next to a smooth and uniformly charged hard wall representing an ideal biological interface with low and moderate surface charge densities. The structural information of the double layers is applied to reveal charge inversion and overcharging through the addition of multivalent electrolyte at a certain physiological concentration. Various values for the radius of the ions are taken into account to capture the impact of short-range correlations. Meanwhile, the influence of image charges on ion distribution is analyzed, which stems from dielectric discontinuity between the interior and exterior of the membrane matrix. It is clearly shown that depending on the amount of foreign salt, the large size of charged species regardless of its polarity plays a positive role in promoting charge inversion. Moreover, our findings indicate that charge inversion do not signify the reversal of the electrophoretic mobility, in consistent with the recent theoretical predictions by Horno and co-workers [J. Colloid Interface Sci. 356, 325 (2011)], 10.1016/j.jcis.2010.12.063. In addition, the depletion effect triggered by repulsive image forces which are intertwined with the excluded volume correlations gives rise to an anomalous overcharging for low surface charged surface in the high concentrations of trivalent salt. Overall, the ion distribution in a double layer is exclusively governed by entropic and electrostatic contributions but with preferentially leading status for different magnitudes of surface charge.

  20. The effects of pre-salting methods on salt and water distribution of heavily salted cod, as analyzed by 1H and 23Na MRI, 23Na NMR, low-field NMR and physicochemical analysis

    DEFF Research Database (Denmark)

    Guðjónsdóttir, María; Traoré, Amidou; Jónsson, Ásbjörn

    2015-01-01

    The effect of different pre-salting methods (brine injection with salt with/without polyphosphates, brining and pickling) on the water and salt distribution in dry salted Atlantic cod (Gadus morhua) fillets was studied with proton and sodium NMR and MRI methods, supported by physicochemical...... analysis of salt and water content as well as water holding capacity. The study indicated that double head brine injection with salt and phosphates lead to the least heterogeneous water distribution, while pickle salting had the least heterogeneous salt distribution. Fillets from all treatments contained...

  1. Particle size distribution of inorganic and organic ions in coastal and inland Antarctic aerosol.

    Science.gov (United States)

    Barbaro, Elena; Padoan, Sara; Kirchgeorg, Torben; Zangrando, Roberta; Toscano, Giuseppa; Barbante, Carlo; Gambaro, Andrea

    2017-01-01

    The concentration and particle-size distribution of ionic species in Antarctic aerosol samples were determined to investigate their potential sources, chemical evolution, and transport. We analyzed aerosol samples collected at two different Antarctic sites: a coastal site near Victoria Land close to the Italian Research Base "Mario Zucchelli", and another site located on the Antarctic plateau, close to Italian-French Concordia Research Station. We investigated anionic compounds using ion-chromatography coupled to mass spectrometry, and cationic species through capillary ion chromatography with conductometry. Aerosol collected close to the coast was mainly characterized by sea salt species such as Na+, Mg2+, and SO42-. These species represented a percentage of 88% of the total sum of all detected ionic species in the aerosol samples from the coastal site. These species were mainly distributed in the coarse fraction, confirming the presence of primary aerosol near the ocean source. Aerosol collected over the Antarctic plateau was characterized by high acidity, with nss-SO42-, NO3-, and methanesulfonic acid as the most abundant species. These species were mainly distributed in the <0.49 μm fraction, and they had a behavior of a typical secondary aerosol, where several chemical and physical processes occurred.

  2. Silicon enhanced salt tolerance by improving the root water uptake and decreasing the ion toxicity in cucumber

    Science.gov (United States)

    Wang, Shiwen; Liu, Peng; Chen, Daoqian; Yin, Lina; Li, Hongbing; Deng, Xiping

    2015-01-01

    Although the effects of silicon application on enhancing plant salt tolerance have been widely investigated, the underlying mechanism has remained unclear. In this study, seedlings of cucumber, a medium silicon accumulator plant, grown in 0.83 mM silicon solution for 2 weeks were exposed to 65 mM NaCl solution for another 1 week. The dry weight and shoot/root ratio were reduced by salt stress, but silicon application significantly alleviated these decreases. The chlorophyll concentration, net photosynthetic rate, transpiration rate and leaf water content were higher in plants treated with silicon than in untreated plants under salt stress conditions. Further investigation showed that salt stress decreased root hydraulic conductance (Lp), but that silicon application moderated this salt-induced decrease in Lp. The higher Lp in silicon-treated plants may account for the superior plant water balance. Moreover, silicon application significantly decreased Na+ concentration in the leaves while increasing K+ concentration. Simultaneously, both free and conjugated types of polyamines were maintained at high levels in silicon-treated plants, suggesting that polyamines may be involved in the ion toxicity. Our results indicate that silicon enhances the salt tolerance of cucumber through improving plant water balance by increasing the Lp and reducing Na+ content by increasing polyamine accumulation. PMID:26442072

  3. Organic ion association in aqueous phase and ab initio-based force fields: The case of carboxylate/ammonium salts

    Science.gov (United States)

    Houriez, Céline; Vallet, Valérie; Réal, Florent; Meot-Ner Mautner, Michael; Masella, Michel

    2017-10-01

    We performed molecular dynamics simulations of carboxylate/methylated ammonium ion pairs solvated in bulk water and of carboxylate/methylated ammonium salt solutions at ambient conditions using an ab initio-based polarizable force field whose parameters are assigned to reproduce only high end quantum computations, at the Møller-Plesset second-order perturbation theory/complete basis set limit level, regarding single ions and ion pairs as isolated and micro-hydrated in gas phase. Our results agree with the available experimental results regarding carboxylate/ammonium salt solutions. For instance, our force field approach predicts the percentage of acetate associated with ammonium ions in CH3 COO-/CH3 NH3+ solutions at the 0.2-0.8M concentration scale to range from 14% to 35%, in line with the estimates computed from the experimental ion association constant in liquid water. Moreover our simulations predict the number of water molecules released from the ion first hydration shell to the bulk upon ion association to be about 2.0 ± 0.6 molecules for acetate/protonated amine ion pairs, 3.1 ± 1.5 molecules for the HCOO-/NH4+ pair and 3.3 ± 1.2 molecules for the CH3COO-/(CH3)4N+ pair. For protonated amine-based ion pairs, these values are in line with experiment for alkali/halide pairs solvated in bulk water. All these results demonstrate the promising feature of ab initio-based force fields, i.e., their capacity in accurately modeling chemical systems that cannot be readily investigated using available experimental techniques.

  4. Simultaneous removal of organic matter and salt ions from saline wastewater in bioelectrochemical systems

    KAUST Repository

    Kim, Younggy

    2013-01-01

    A new bioelectrochemical system is proposed for simultaneous removal of salinity and organic matter. In this process, exoelectrogenic microorganisms oxidize organic matter and transfer electrons to the anode, hydrogen is evolved at the cathode by supplying additional voltage, and salt is removed from the wastewater due to the electric potential generated and the use of two ion-exchange membranes. Salinity removal (initial conductivity ~40mS/cm) increased from 21 to 84% by increasing the substrate (sodium acetate) from 2 to 8g/L. A total of 72-94% of the chemical oxygen demand was degraded in the anode and cathode chambers, with 1-4% left in the anode chamber and the balance lost through the anion-exchange membrane into the concentrate waste chamber. The maximum hydrogen production rate was 3.6m3-H2/m3-electrolyte per day at an applied potential of 1.2V. The Coulombic efficiency was ~100%, while the cathode recovery varied from 57 to 100%, depending on the extent of methanogenesis. Exoelectrogenic microbes generated high current densities (7.8mA/cm2) at ≤36g/L of total dissolved solids, but >41g/L eliminated current. These results provide a new method for achieving simultaneous removal of salinity and organic matter from a saline wastewater with H2 production. © 2012 Elsevier B.V.

  5. Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation of Sodium Salts

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A.; Bonnesen, Peter V.; Custelcean, Radu; Delmau, Laetitia H.; Engle, Nancy L.; Kang, Hyun-Ah; Keever, Tamara J.; Marchand, Alan P.; Gadthula, Srinivas; Gore, Vinayak K.; Huang, Zilin; Sivappa, Rasapalli; Tirunahari, Pavan K.; Levitskaia, Tatiana G.; Lumetta, Gregg J.

    2005-09-26

    The purpose of this research involving collaboration between Oak Ridge National Laboratory (ORNL) and Pacific Northwest National Laboratory (PNNL) is to explore new approaches to the separation of sodium hydroxide, sodium nitrate, and other sodium salts from high-level alkaline tank waste. The principal potential benefit is a major reduction in disposed waste volume, obviating the building of expensive new waste tanks and reducing the costs of vitrification. Principles of ion recognition are being researched toward discovery of liquid-liquid extraction systems that selectively separate sodium hydroxide and sodium nitrate from other waste components. The successful concept of pseudo hydroxide extraction using fluorinated alcohols and phenols is being developed at ORNL and PNNL toward a greater understanding of the controlling equilibria, role of solvation, and of synergistic effects involving crown ethers. Synthesis efforts are being directed toward enhanced sodium binding by crown ethers, both neutral and proton-ionizable. Studies with real tank waste at PNNL will provide feedback toward solvent compositions that have promising properties.

  6. PC based electrolytes with LiDFOB as an alternative salt for lithium-ion batteries

    Science.gov (United States)

    Knight, Brandon M.

    Lithium-ion batteries (LIBs) have been greatly sought after as a source of renewable energy storage. LIBs have a wide range of applications including but not limited portable electronic devices, electric vehicles, and power tools. As a direct result of their commercial viability an insatiable hunger for knowledge, advancement within the field of LIBs has been omnipresent for the last two decades. However, there are set backs evident within the LIB field; most notably the limitations of standard electrolyte formulations and LiPF6 lithium salt. The standard primary carbonate of ethylene carbonate (EC) has a very limited operating range due to its innate physical properties, and the LiPF6 salt is known to readily decompose to form HF which can further degrade LIB longevity. The goal of our research is to explore the use of a new primary salt LiDFOB in conjunction with a propylene carbonate based electrolyte to establish a more flexible electrolyte formulation by constructing coin cells and cycling them under various conditions to give a clear understanding of each formulation inherent performance capabilities. Our studies show that 1.2M LiDFOB in 3:7 PC/EMC + 1.5% VC is capable of performing comparably to the standard 1.2M LiPF6 in 3:7 EC/EMC at 25°C and the PC electrolyte also illustrates performance superior to the standard at 55°C. The degradation of lithium manganese spinel electrodes, including LiNi 0.5Mn1.5O4, is an area of great concern within the field of lithium ion batteries (LIBs). Manganese containing cathode materials frequently have problems associated with Mn dissolution which significantly reduces the cycle life of LIB. Thus the stability of the cathode material is paramount to the performance of Mn spinel cathode materials in LIBs. In an effort to gain a better understanding of the stability of LiNi0.5 Mn1.5O4 in common LiPF6/carbonate electrolytes, samples were stored at elevated temperature in the presence of electrolyte. Then after storage both

  7. Spectroscopic measurement of ion temperature and ion velocity distributions in the flux-coil generated FRC.

    Science.gov (United States)

    Gupta, D; Bolte, N; Gota, H; Hayashi, R; Kiyashko, V; Marsili, P; Morehouse, M; Primavera, S; Roche, T; Wessel, F

    2010-10-01

    One aim of the flux-coil generated field reversed configuration at Tri Alpha Energy (TAE) is to establish the plasma where the ion rotational energy is greater than the ion thermal energy. To verify this, an optical diagnostic was developed to simultaneously measure the Doppler velocity-shift and line-broadening using a 0.75 m, 1800 groves/mm, spectrometer. The output spectrum is magnified and imaged onto a 16-channel photomultiplier tube (PMT) array. The individual PMT outputs are coupled to high-gain, high-frequency, transimpedance amplifiers, providing fast-time response. The Doppler spectroscopy measurements, along with a survey spectrometer and photodiode-light detector, form a suite of diagnostics that provide insights into the time evolution of the plasma-ion distribution and current when accelerated by an azimuthal-electric field.

  8. Spectroscopic measurement of ion temperature and ion velocity distributions in the flux-coil generated FRC

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, D.; Gota, H.; Hayashi, R.; Kiyashko, V.; Morehouse, M.; Primavera, S. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Bolte, N. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Marsili, P. [Department of Physics, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Roche, T. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Wessel, F. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States)

    2010-10-15

    One aim of the flux-coil generated field reversed configuration at Tri Alpha Energy (TAE) is to establish the plasma where the ion rotational energy is greater than the ion thermal energy. To verify this, an optical diagnostic was developed to simultaneously measure the Doppler velocity-shift and line-broadening using a 0.75 m, 1800 groves/mm, spectrometer. The output spectrum is magnified and imaged onto a 16-channel photomultiplier tube (PMT) array. The individual PMT outputs are coupled to high-gain, high-frequency, transimpedance amplifiers, providing fast-time response. The Doppler spectroscopy measurements, along with a survey spectrometer and photodiode-light detector, form a suite of diagnostics that provide insights into the time evolution of the plasma-ion distribution and current when accelerated by an azimuthal-electric field.

  9. Effects of 24-epibrassinolide on plant growth, osmotic regulation and ion homeostasis of salt-stressed canola.

    Science.gov (United States)

    Liu, J; Gao, H; Wang, X; Zheng, Q; Wang, C; Wang, X; Wang, Q

    2014-03-01

    This study evaluated effects of foliar spraying 24-epibrassinoide (24-EBL) on the growth of salt-stressed canola. Seedlings at the four-leaf stage were treated with 150 mM NaCl and different concentrations of 24-EBL (10(-6), 10(-8), 10(-10), 10(-12) M) for 15 days. A concentration of 10(-10) M 24-EBL was chosen as optimal and used in a subsequent experiment on plant biomass and leaf water potential parameters. The results showed that 24-EBL mainly promoted shoot growth of salt-stressed plants and also ameliorated leaf water status. Foliar spraying of salt-stressed canola with 24-EBL increased osmotic adjustment ability in all organs, especially in younger leaves and roots. This was mainly due to an increase of free amino acid content in upper leaves, soluble sugars in middle leaves, organic acids and proline in lower leaves, all of these compounds in roots, as well as essential inorganic ions. Na(+) and Cl(-) sharply increased in different organs under salt stress, and 24-EBL reduced their accumulation. 24-EBL improved the uptake of K(+), Ca(2+), Mg(2+) and NO3(-) in roots, which were mainly transported to upper leaves, while NO3(-) was mainly transported to middle leaves. Thus, 24-EBL improvements in ion homeostasis of K(+)/Na(+), Ca(2+)/Na(+), Mg(2+)/Na(+) and NO3(-)/Cl(-), especially in younger leaves and roots, could be explained. As most important parts, younger leaves and roots were the main organs protected by 24-EBL via improvement in osmotic adjustment ability and ion homeostasis. Further, physiological status of growth of salt-stressed canola was ameliorated after 24-EBL treatment. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  10. Fast ion distribution in the presence of flow

    Science.gov (United States)

    Davidovits, Seth; Fisch, Nathaniel

    2014-10-01

    Experiments and simulations in multiple ICF related configurations have observed signs of bulk flow near stagnation. These configurations include both laser driven implosions such as at the NIF, as well as Z-Pinches. We investigate the possibilities for enhancement or depletion of fast ion tails in simplified flow models, with an eye towards applicability to ICF experiments. Small effects on the tail populations may substantially affect fusion output, as the fast ions in these tails have much larger fusion cross sections than thermal ions and make up the majority of fusion production for typical ICF temperatures. While in collisional plasma the bulk of the distribution function is driven toward Maxwellian in a few collision times, the high velocity tails can take much longer to form. Furthermore, the long mean free paths of the fast ions means they may sample differing regions of flow, while thermal particles only sample the local flow. This work was supported by DOE through Contracts DE-AC02-09CH1-1466 and 67350-9960 (Prime # DOE DE-NA0001836). Seth Davidovits would like to acknowledge support by the DOE-CSGF program under Grant DE-FG02-97ER25308.

  11. Ion angular distribution simulation of the HEMP Thruster

    Science.gov (United States)

    Duras, Julia; Koch, Norbert; Kahnfeld, Daniel; Bandelow, Gunnar; Matthias, Paul; Lüskow, Karl Felix; Schneider, Ralf; Kemnitz, Stefan

    2016-10-01

    Ion angular current and energy distributions are important parameters for ion thrusters, which are typically measured at a few tens of centimetres to a few meters distance from thruster exit. However, fully kinetic Particle-in-Cell simulations are not able to simulate such domain sizes, due to high computational costs. Therefore, a parallelisation strategy of the code is presented to reduce computational time. To map diagnostics information from the domain boundary of the calculational domain to the positions of experimental diagnostics the concept of transfer functions is introduced. The calculated ion beam angular distributions in the plume region are quite sensitive to boundary conditions of the potential, possible additional source contributions, e.g. from secondary electron emission at vessel walls, and charge exchange collisions. This work was supported by the Bavarian State Ministry of Education Science and the Arts and the German Space Agency DLR. We also like to thank R. Heidemann from THALES Electron Devices GmbH, for interesting and stimulating discussions.

  12. Fluorine-free electrolytes for all-solid sodium-ion batteries based on percyano-substituted organic salts

    OpenAIRE

    Anna Bitner-Michalska; Gene M. Nolis; Grażyna Żukowska; Aldona Zalewska; Marcin Poterała; Tomasz Trzeciak; Maciej Dranka; Michał Kalita; Piotr Jankowski; Leszek Niedzicki; Janusz Zachara; Marek Marcinek; Władysław Wieczorek

    2017-01-01

    A new family of fluorine-free solid-polymer electrolytes, for use in sodium-ion battery applications, is presented. Three novel sodium salts withdiffuse negative charges: sodium pentacyanopropenide (NaPCPI), sodium 2,3,4,5-tetracyanopirolate (NaTCP) and sodium 2,4,5-tricyanoimidazolate (NaTIM) were designed andtested in a poly(ethylene oxide) (PEO) matrix as polymer electrolytes for anall-solid sodium-ion battery. Due to unique, non-covalent structural configurations of anions, improved ionic...

  13. Energy distributions for ionization in ion-atom collisions

    CERN Document Server

    Amaya-Tapia, A

    2016-01-01

    In this paper we discuss how through the process of applying the Fourier transform to solutions of the Schr\\"odinger equation in the Close Coupling approach, good results for the ionization differential cross section in energy for electrons ejected in ion-atom collisions are obtained. The differential distributions are time dependent and through their time average, the comparison with experimental and theoretical data reported in the literature can be made. The procedure is illustrated with reasonable success in two systems, $p+H$ and $p+He$, and is expected to be extended without inherent difficulties to more complex systems. This allows advancing in the understanding of the calculation of ionization processes in ion-atom collisions.

  14. Influences of nitrification inhibitor 3,4-dimethyl pyrazole phosphate on nitrogen and soil salt-ion leaching.

    Science.gov (United States)

    Yu, Qiaogang; Ye, Xuezhu; Chen, Yingxu; Zhang, Zhijian; Tian, Guangming

    2008-01-01

    An undisturbed heavy clay soil column experiment was conducted to examine the influence of the new nitrification inhibitor, 3,4-dimethylpyrazole phosphate (DMPP), on nitrogen and soil salt-ion leaching. Regular urea was selected as the nitrogen source in the soil. The results showed that the cumulative leaching losses of soil nitrate-N under the treatment of urea with DMPP were from 57.5% to 63.3% lower than those of the treatment of urea without DMPP. The use of nitrification inhibitors as nitrate leaching retardants may be a proposal in regulations to prevent groundwater contaminant. However, there were no great difference between urea and urea with DMPP treatments on ammonium-N leaching. Moreover, the soil salt-ion leaching losses of Ca2+, Mg2+, K+, and Na+ were reduced from 26.6% to 28.8%, 21.3% to 27.8%, 33.3% to 35.5%, and 21.7% to 32.1%, respectively. So, the leaching losses of soil salt-ion were declined for nitrification inhibitor DMPP addition, being beneficial to shallow groundwater protection and growth of crop. These results indicated the possibility of ammonium or ammonium producing compounds using nitrification inhibitor DMPP to control the nitrate and nutrient cation leaching losses, minimizing the risk of nitrate pollution in shallow groundwater.

  15. Hydroxy double salts loaded with bioactive ions: Synthesis, intercalation mechanisms, and functional performance

    Energy Technology Data Exchange (ETDEWEB)

    Kaassis, Abdessamad Y.A. [UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX (United Kingdom); Xu, Si-Min; Guan, Shanyue; Evans, David G. [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wei, Min, E-mail: weimin@mail.buct.edu.cn [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Williams, Gareth R., E-mail: g.williams@ucl.ac.uk [UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX (United Kingdom)

    2016-06-15

    The intercalation of the anions of diclofenac (Dic), naproxen (Nap), and valproic acid (Val) into three hydroxy double salts (HDSs) has been explored in this work. Experiments were performed with [Co{sub 1.2}Zn{sub 3.8}(OH){sub 8}](NO{sub 3}){sub 2}·2H{sub 2}O (CoZn-NO{sub 3}), [Ni{sub 2}Zn{sub 3}(OH){sub 8}](NO{sub 3}){sub 2}·2H{sub 2}O (NiZn-NO{sub 3}) and [Zn{sub 5}(OH){sub 8}](NO{sub 3}){sub 2}·2H{sub 2}O (Zn-NO{sub 3}). It proved possible to intercalate diclofenac and naproxen into all three HDSs. In contrast, Val could be intercalated into CoZn-NO{sub 3} but when it was reacted with Zn-NO{sub 3} the HDS structure was destroyed, and the product comprised ZnO. Successful intercalation was verified by X-ray diffraction, IR spectroscopy, and elemental microanalysis. Molecular dynamics simulations showed the Dic and Nap ions to arrange themselves in an “X” shape in the interlayer space, forming a bilayer. Val was found to adopt a position with its aliphatic groups parallel to the HDS layer, again in a bilayer. In situ time resolved X-ray diffraction experiments revealed that intercalation of Dic and Nap into CoZn-NO{sub 3} and Zn-NO{sub 3} is mechanistically complex, with a number of intermediate phases observed. In contrast, the intercalation of all three guests into NiZn-NO{sub 3} and of Val into CoZn-NO{sub 3} are simple one step reactions proceeding directly from the starting material to the product. The HDS-drug composites were found to have sustained release profiles. - Graphical abstract: Seven new drug intercalates of hydroxy double salts (HDSs) have been prepared and characterised. The intercalation mechanisms have been explored, and the drug release properties of the HDS/drug composites quantified. Display Omitted.

  16. Distribution and Invasion Potential of Limonium ramosissimum subsp. provinciale in San Francisco Estuary Salt Marshes

    Directory of Open Access Journals (Sweden)

    Gavin Archbald

    2014-06-01

    Full Text Available Non-native sea lavenders (Limonium spp. are invasive in salt marshes of southern California and were first documented in the San Francisco Estuary (the estuary in 2007. In this study, we mapped distributions of L. ramosissimum subsp. provinciale (LIRA and L. duriusculum within the estuary and investigated how the invasion potential of the more common species, LIRA, varies with elevation and edaphic conditions. We contacted colleagues and conducted field searches to find and then map sea lavender populations. In addition, we measured LIRA’s elevational range at three salt marshes. Across this range we measured (1 soil properties: salinity, moisture, bulk density, and texture; and (2 indicators of invasion potential: LIRA size, seed production, percent cover, spread (over 1 year, recruitment, and competition with native halophytes (over 6 months. We found LIRA in 15,144 m2 of upper salt marsh habitat in central and south San Francisco bays and L. duriusculum in 511 m2 in Richardson and San Pablo bays. LIRA was distributed from mean high water (MHW to 0.42 m above mean higher high water (MHHW. In both spring and summer, soil moisture and salinity were lowest at higher elevations within LIRA’s range, which corresponded with greater rosette size, inflorescence and seed production (up to 17,400 seeds per plant, percent cover, and recruitment. LIRA cover increased on average by 11% in 1 year across marshes and elevations. Cover of the native halophytes Salicornia pacifica, Jaumea carnosa, and Distichlis spicata declined significantly at all elevations if LIRA were present in plots (over a 6-month, fall–winter period. Results suggest LIRA’s invasion potential is highest above MHHW where salinity and moisture are lower, but that LIRA competes with native plants from MHW to above MHHW. We recommend removal efforts with emphasis on the salt marsh-terrestrial ecotone where LIRA seed output is highest.

  17. Towards Bayesian Inference of the Fast-Ion Distribution Function

    DEFF Research Database (Denmark)

    Stagner, L.; Heidbrink, W.W.; Salewski, Mirko

    2012-01-01

    The fast-ion distribution function (DF) has a complicated dependence on several phase-space variables. The standard analysis procedure in energetic particle research is to compute the DF theoretically, use that DF in forward modeling to predict diagnostic signals, then compare with measured data...... sensitivity of the measurements are incorporated into Bayesian likelihood probabilities, while prior probabilities enforce physical constraints. As an initial step, this poster uses Bayesian statistics to infer the DIII-D electron density profile from multiple diagnostic measurements. Likelihood functions...

  18. Polarized Parton Distributions at an Electron-Ion Collider

    CERN Document Server

    Ball, Richard D.; Guffanti, Alberto; Nocera, Emanuele R.; Ridolfi, Giovanni; Rojo, Juan

    2014-01-01

    We study the potential impact of inclusive deep-inelastic scattering data from a future electron-ion collider (EIC) on longitudinally polarized parton distribution (PDFs). We perform a PDF determination using the NNPDF methodology, based on sets of deep-inelastic EIC pseudodata, for different realistic choices of the electron and proton beam energies. We compare the results to our current polarized PDF set, NNPDFpol1.0, based on a fit to fixed-target inclusive DIS data. We show that the uncertainties on the first moments of the polarized quark singlet and gluon distributions are substantially reduced in comparison to NNPDFpol1.0, but also that more measurements may be needed to ultimately pin down the size of the gluon contribution to the nucleon spin.

  19. Accumulation, distribution and cellular partitioning of mercury in several halophytes of a contaminated salt marsh.

    Science.gov (United States)

    Castro, Rita; Pereira, Sofia; Lima, Ana; Corticeiro, Sofia; Válega, Mónica; Pereira, Eduarda; Duarte, Armando; Figueira, Etelvina

    2009-09-01

    This work evaluates the role of a plant community in mercury (Hg) stabilization and mobility in a contaminated Portuguese salt marsh. With this aim, the distribution of Hg in below and aboveground tissues, as well as the metal partitioning between cellular fractions (soluble and insoluble) in four different species (Triglochin maritima L., Juncus maritimus Lam, Sarcocornia perennis (Miller) A.J. Scott, and Halimione portulacoides (L.) Aellen) was assessed. Mercury accumulation, translocation and compartmentation between organs and cellular fractions were related to the plant species. Results showed that the degree of Hg absorption and retention was influenced both by environmental parameters and metal translocation/partitioning strategies. Different plant species presented different allocation patterns, with marked differences between monocots (T. maritima and J. maritimus) and dicots (S. perennis, H. portulacoides). Overall, the two monocots, in particular T. maritima showed higher Hg retention in the belowground organs whereas the dicots, particularly S. perennis presented a more pronounced translocation to the aboveground tissues. Considering cellular Hg partitioning, all species showed a higher Hg binding to cell walls and membranes rather than in the soluble fractions. This strategy can be related to the high degree of tolerance observed in the studied species. These results indicate that the composition of salt marsh plant communities can be very important in dictating the Hg mobility within the marsh ecosystem and in the rest of the aquatic system as well as providing important insights to future phytoremediation approaches in Hg contaminated salt marshes.

  20. Distributed ion pump related transverse instability in CESR

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.T.; Holmquist, T. [Cornell Univ., Ithaca, NY (United States). Lab. of Nuclear Studies

    1996-08-01

    An anomalous damping or growth of transverse coupled bunch modes is observed in the Cornell Electron Storage Ring (CESR). The growth rates and tune shifts of these modes are a highly nonlinear function of current. Unlike an instability produced by the coupling impedance of the vacuum chamber, the magnitude of the growth rate first increases, then declines, as the beam current is increased. The effect is known to be related to the operation of the distributed ion pumps, as it disappears when the pumps are not powered. We review the observations of this effect, and show that it can be explained by the presence of electrons trapped in the CESR chamber by the field of the dipole magnets and the electrostatic leakage field of the distributed ion pumps. Photoelectrons are introduced into the chamber by synchrotron radiation and can be captured in or ejected from the chamber by the passage of the beam. The transverse position of the beam thus modulates the trapped photoelectron charge density, which in turn deflects the beam, creating growth or damping and a tune shift for each coupled bunch mode. Predictions of the dependence of growth rate and tune shift on bunch current and bunch pattern by a numerical model of this process are in approximate agreement with observations. (author)

  1. Massive-scale aircraft observations of giant sea-salt aerosol particle size distributions in atmospheric marine boundary layers

    Science.gov (United States)

    Jensen, J. B.

    2015-12-01

    iant sea-salt aerosol particles (dry radius, rd > 0.5 μm) occur nearly everywhere in the marine boundary layer and frequently above. This study presents observations of atmospheric sea-salt size distributions in the range 0.7 Chile and the 2011 ICE-T in the Caribbean. In each deployment, size distributions using hundreds of slides are used to relate fitted log-normal size distributions parameters to wind speed, altitude and other atmospheric conditions. The size distributions provide a unique observational set for initializing cloud models with coarse-mode aerosol particle observations for marine atmospheres.

  2. On aquifer thicknesses and geological complexity affecting fresh/salt groundwater distribution

    Science.gov (United States)

    Zamrsky, Daniel; Oude Essink, Gualbert; Bierkens, Marc

    2017-04-01

    Large coastal populations will face serious issues associated with global sea level rise in the near future. Among those are increased risk of coastal flooding and upconing of old saline groundwater caused by expected regional groundwater overexploitation initiated by growing urbanization. With predictions of rising sea level by 60-100cm by 2100 and a recent study suggesting even much larger changes than previously thought, it is essential to conduct a study to identify the most threatened coastal aquifers worldwide. Previous global studies dealing with salt water intrusion into coastal aquifers only considered homogenous geological conditions. However, literature and local data show a higher degree of heterogeneity. In our study, we consider possible geological scenarios and their impact on the fresh/salt groundwater distribution. The focus is on coastal aquifers that consist of unconsolidated sediments formed during the recent geological times and are underlain by a consolidated bedrock formation. Aquifer thickness and inland extent are the two most important parameters that determine the vulnerability of the coastal aquifer to salt water intrusion. To estimate these two parameters, a method using the latest global geological and elevation datasets is presented. By combining these inputs, we can estimate the slope of a bedrock formation that underlies a coastal aquifer consisting of unconsolidated sediments. Our estimated thicknesses are compared to a validation dataset of open source boreholes and literature information collected over numerous locations worldwide. While our results show that using our method to estimate coastal aquifer (made of unconsolidated sediments) thickness leads to satisfying results, it remains challenging to obtain information about the type of the sediments (gravel, sand, clay) themselves on such a scale. Therefore, we constructed a substantial set of 2D vertical variable-density groundwater flow models perpendicular to the shoreline

  3. Ion velocity distributions in dipolarization events: Distributions in the central plasma sheet

    Science.gov (United States)

    Birn, J.; Runov, A.; Zhou, X.-Z.

    2017-08-01

    Using combined MHD/test particle simulations, we further explore characteristic ion velocity distributions in the central plasma sheet (CPS) in relation to dipolarization events. Distributions in the CPS within the dipolarized flux bundle (DFB) that follows the passage of a dipolarization front typically show two opposing low subthermal-energy beams with a ring-like component perpendicular to the magnetic field at about twice the thermal energy. The dominance of the perpendicular anisotropy and a field-aligned peak at lower energy agree qualitatively with ion distribution functions derived from "Time History of Events and Macroscale Interactions during Substorms" observations. At locations somewhat off the equatorial plane the field-aligned peaks are shifted by a field-aligned component of the bulk flow, such that one peak becomes centered near zero net velocity, which makes it less likely to be observed. The origins of the field-aligned peaks are low-energy lobe (or near plasma sheet boundary layer) regions, while the ring distribution originates mostly from thermal plasma sheet particles on extended field lines. The acceleration mechanisms are also quite different: the beam ions are accelerated first by the E × B drift motion of the DFB and then by a slingshot effect of the earthward convecting DFB (akin to first-order Fermi, type B, acceleration), which causes an increase in field-aligned speed. In contrast, the ring particles are accelerated by successive, betatron-like acceleration after entering the high electric field region of an earthward propagating DFB.

  4. Effect of dust size distribution and dust charge fluctuation on dust ion ...

    Indian Academy of Sciences (India)

    The effects of dust size distribution and dust charge fluctuation of dust grains on the small but finite amplitude nonlinear dust ion-acoustic shock waves, in an unmagnetized multi-ion dusty plasma which contains negative ions, positive ions and electrons, are studied in this paper. A Burgers equation and its stationary ...

  5. Kinetic investigation of the ion angular distribution in capacitive radio-frequency plasmas

    Science.gov (United States)

    Shihab, Mohammed; Mussenbrock, Thomas

    2017-11-01

    One of the key parameters in the context of plasma assisted processing in semiconductor fabrication using capacitive radio-frequency plasmas is the ion flux distribution at the substrate. Whereas the ion energy distribution function determines the etching rate and selectivity, the ion angular distribution controls the etching profile. In this contribution, we reveal the effect of the ion flux and the sheath potential on the ion angular distribution and the direct ion heat flux at the bottom of etching profiles in geometrically symmetric plasma reactors. The ion angular distribution and the direct ion heat flux are calculated as a function of the sheath potential, the driving frequency, and the phase shift between the two distinct harmonics of the driving voltage of dual frequency discharges. For this task, self-consistent particle-in-cell simulations subject to Monte Carlo collision are carried out. The results from particle-in-cell simulations which are computationally very expensive are compared and verified with those from the novel ensemble-in-spacetime model. It is confirmed that increasing the voltage of the high-frequency component, the high-frequency component, and/or make a phase shift of π/2 between the dual frequency, narrow the ion angular distribution and increase the direct ion heat flux to the etching profile bottom. In all simulation cases, a correlation between the narrowing of the ion angular distribution and the increase of the sheath potential and the sheath ion flux is found.

  6. Lithium salt with a super-delocalized perfluorinated sulfonimide anion as conducting salt for lithium-ion cells: Physicochemical and electrochemical properties

    Science.gov (United States)

    Zhang, Heng; Han, Hongbo; Cheng, Xiaorong; Zheng, Liping; Cheng, Pengfei; Feng, Wenfang; Nie, Jin; Armand, Michel; Huang, Xuejie; Zhou, Zhibin

    2015-11-01

    Lithium salt with a super-delocalized imide anion, namely (trifluoromethane(S-trifluoromethanesulfonylimino)sulfonyl) (trifluoromethanesulfonyl)imide ([CF3SO(=NSO2CF3)2]-), [sTFSI]-), has been prepared and studied as conducting salt for Li-ion cells. The fundamental physicochemical and electrochemical properties of neat Li[sTFSI] and its carbonate-based liquid electrolyte have been characterized with various chemical and electrochemical tools. Li[sTFSI] shows a low melting point at 118 °C, and is thermally stable up to 300 °C without decomposition on the spectra of differential scanning calorimetry-thermogravimetry-mass spectrometry (DSC-TG-MS). The electrolyte of 1.0 M (mol dm-3) Li[sTFSI] in ethylene carbonate (EC)/ethyl-methyl-carbonate (EMC) (3:7, v/v) containing 0.3% water does not show any hydrolytic decomposition on the spectra of 1H and 19F NMR, after storage at 85 °C for 10 days. The conductivities of 1.0 M Li[sTFSI]-EC/EMC (3:7, v/v) are slightly lower than those of Li[(CF3SO2)2N] (LiTFSI), but higher than those of Li[(C2F5SO2)2N] (LiBETI). The electrochemical behavior of Al foil in the Li[sTFSI]-based electrolyte has been investigated by using cyclic voltammetry and chronoamperometry, and scanning electron microscope (SEM). It is illustrated that Al metal does not corrode in the high potential region (3-5 V vs. Li/Li+) in the Li[sTFSI]-based electrolyte. On Pt electrode, the Li[sTFSI]-based electrolyte is highly resistant to oxidation (ca. 5 V vs. Li/Li+), and is also resistant to reduction to allow Li deposition and stripping. The applicability of Li[sTFSI] as conducting salt for Li-ion cells has been tested using graphite/LiCoO2 cells. It shows that the cell with Li[sTFSI] displays better cycling performance than that with LiPF6.

  7. Ion-exchange properties of cell walls of Spinacia oleracea L. roots under different environmental salt conditions.

    Science.gov (United States)

    Meychik, N R; Nikolaeva, Yu I; Yermakov, I P

    2006-07-01

    Ion-exchange properties of the polymeric matrix of cell walls isolated from roots of 55-day-old Spinacia oleracea L. (Matador cv.) plants grown in nutrient solution in the presence of 0.5, 150, and 250 mM NaCl and from roots of Suaeda altissima L. Pall plants of the same age grown in the presence of 0.5 and 250 mM NaCl were studied. The ion-exchange capacity of the spinach cell walls was determined at pH values from 2 to 12 and different ionic strength of the solution (10 and 250 mM NaCl). In the structure of the root cell walls, four types of ionogenic groups were found: amine, two types of carboxyl (the first being galacturonic acid residue), and phenolic groups. The content of each type of group and their ionization constants were evaluated. The ion-exchange properties of spinach and the halophyte Suaeda altissima L. Pall were compared, and the qualitative composition of the ion-exchange groups in the cell walls of roots of these plants appeared to be the same and not depend on conditions of the root nutrition. The content of carboxyl groups of polygalacturonic acid changed in the cell walls of the glycophyte and halophyte depending on the salt concentration in the medium. These changes in the composition of functional groups of the cell wall polymers seemed to be a response of these plants to salt and were more pronounced in the halophyte. A sharp increase in the NaCl concentration in the medium caused a decrease in pH in the extracellular water space as a result of exchange reactions between sodium ions entering from the external solution and protons of carboxyl groups of the cell walls. The findings are discussed from the standpoint of involvement of root cell walls of different plant species in response to salinity.

  8. Theoretical predictions of lactate and hydrogen ion distributions in tumours.

    Directory of Open Access Journals (Sweden)

    Maymona Al-Husari

    Full Text Available High levels of lactate and H(+-ions play an important role in the invasive and metastatic cascade of some tumours. We develop a mathematical model of cellular pH regulation focusing on the activity of the Na(+/H(+ exchanger (NHE and the lactate/H(+ symporter (MCT to investigate the spatial correlations of extracellular lactate and H(+-ions. We highlight a crucial role for blood vessel perfusion rates in determining the spatial correlation between these two cations. We also predict critical roles for blood lactate, the activity of the MCTs and NHEs on the direction of the cellular pH gradient in the tumour. We also incorporate experimentally determined heterogeneous distributions of the NHE and MCT transporters. We show that this can give rise to a higher intracellular pH and a lower intracellular lactate but does not affect the direction of the reversed cellular pH gradient or redistribution of protons away from the glycolytic source. On the other hand, including intercellular gap junction communication in our model can give rise to a reversed cellular pH gradient and can influence the levels of pH.

  9. Polyelectrolyte Microcapsules: Ion Distributions from a Poisson-Boltzmann Model

    Science.gov (United States)

    Tang, Qiyun; Denton, Alan R.; Rozairo, Damith; Croll, Andrew B.

    2014-03-01

    Recent experiments have shown that polystyrene-polyacrylic-acid-polystyrene (PS-PAA-PS) triblock copolymers in a solvent mixture of water and toluene can self-assemble into spherical microcapsules. Suspended in water, the microcapsules have a toluene core surrounded by an elastomer triblock shell. The longer, hydrophilic PAA blocks remain near the outer surface of the shell, becoming charged through dissociation of OH functional groups in water, while the shorter, hydrophobic PS blocks form a networked (glass or gel) structure. Within a mean-field Poisson-Boltzmann theory, we model these polyelectrolyte microcapsules as spherical charged shells, assuming different dielectric constants inside and outside the capsule. By numerically solving the nonlinear Poisson-Boltzmann equation, we calculate the radial distribution of anions and cations and the osmotic pressure within the shell as a function of salt concentration. Our predictions, which can be tested by comparison with experiments, may guide the design of microcapsules for practical applications, such as drug delivery. This work was supported by the National Science Foundation under Grant No. DMR-1106331.

  10. OBTAINING OF THE MG2+ FORM OF THE ZEOLITE 4A WITH ION EXCHANGE OF MAGNESIUM SALTS

    Directory of Open Access Journals (Sweden)

    Blagica Cekova

    2016-01-01

    Full Text Available Zeolites are sodium alumino silicates which in in their composition contain zeolite water. They have a three-dimensional structure. Spatial structure defined by a strictly defined geometry of pores and cavities. For ionic еchange is used magnesium salt (MgCl2*6H2O whose aqueous solutions were with the following concentrations (MgCl2*6H2O = 2,5; 3.5; 4,5 mol / dm3 , and other parameters of the ion exchange: time t = 20, 30, 40 and temperature of 298 and 330 K. Ionian capacity is calculated as mmgMgO / 1g zeolite.

  11. Does elevation matter? Living foraminiferal distribution in a hyper tidal salt marsh (Canche Estuary, Northern France)

    Science.gov (United States)

    Francescangeli, F.; Bouchet, V. M. P.; Trentesaux, A.; Armynot du Chatelet, E.

    2017-07-01

    In the present study we investigate the ecology and distribution of living benthic foraminifera to test the effect of hyper tidal exposure and their suitability as sea level indicators. Within a salt marsh area along the Canche Estuary (northern France), four transects were sampled to see the effects of maximal tidal constraints (shore transects) and minimal tidal constraints (alongshore transects). Multivariate analyses have been performed to determine the correlations between biotic (foraminiferal absolute abundances) and abiotic factors (elevation, grain-size, TOC and total sulphur). For each of the principal benthic foraminiferal species the tolerance to subaerial exposure have been estimated as well. Two distinctive foraminiferal zones have been identified along the vertical tidal gradient: a zone I in the higher part of the salt marsh dominated by agglutinated and porcelaneous taxa, and a zone II in the lower one dominated by hyaline specimens. Hyper tidal exposure constraints the foraminiferal vertical zonation in accordance with the tidal frame. However it does not constitute a threshold parameter able by itself to explain all the faunal variations in the Canche Estuary. For sea level indicators, foraminifera should be considered relative to tidal subaerial exposure rather than to absolute altitude.

  12. X-ray absorption of the effect of plasticizers on ion-pair dissociation in a poly(ethylene oxide)-potassium salt complex

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X.Q.; Lee, H.S.; Hanson, L.K.; McBreen, J. (Brookhaven National Lab., Upton, NY (United States)); Xu, Z.S.; Skotheim, T.A. (Moltech Corp., Stony Brook, NY (United States)); Okamoto, Y. (Polytechnic Univ., Brooklyn, NY (United States)); Lu, F. (Univ. of Kentucky, Lexington, KY (United States))

    1995-01-01

    Polyethylene oxide (PEO)-salt systems are an important new class of electrolytes that are being considered for use in high specific energy rechargeable lithium batteries. Near-edge X-ray absorption fine structure (NEXAFS) spectra, at the potassium K edge, were obtained for a potassium salt in the following systems: (1) a propylene carbonate (PC) solution, (2) a modified carbonate (MC3) solution, and (3) poly(ethylene oxide) (PEO)-potassium salt complexes with either PC or MC3 as a plasticizer. MC3 is a new plasticizer developed in the authors' laboratory which is similar to PC except that, instead of a methyl group, there are three ethylene oxide units attached to the 4-position. By examining the NEXAFS of various potassium salt reference systems, it was found that the white line splitting in the near-edge region was correlated with ion-pairing. The degree of white line splitting was used to study ion-pair dissociation effects of PC and MC3 qualitatively. When used as a solvent, MC3 has a stronger ion-pair dissociation effect compared to PC. When used as a plasticizer in a PEO-potassium salt complex, the enhancement effect on ion-pair dissociation of MC3 is superior to PC. These results were corroborated by Raman spectroscopy which showed that MC3 has a stronger ion-pair dissociation effect than PC.

  13. Recovery of salts from ion-exchange regeneration streams by a coupled nanofiltration-membrane distillation process.

    Science.gov (United States)

    Jiříček, Tomáš; De Schepper, Wim; Lederer, Tomáš; Cauwenberg, Peter; Genné, Inge

    2015-01-01

    Ion-exchange tap water demineralization for process water preparation results in a saline regeneration wastewater (20-100 mS cm(-1)) that is increasingly problematic in view of discharge. A coupled nanofiltration-membrane distillation (NF-MD) process is evaluated for the recovery of water and sodium chloride from this wastewater. NF-MD treatment of mixed regeneration wastewater is compared to NF-MD treatment of separate anion- and cation-regenerate fractions. NF on mixed regeneration wastewater results in a higher flux (30 L m(-2) h(-1) at 7 bar) compared to NF on the separate fractions (6-9 L m(-2) h(-1) at 30 bar). NF permeate recovery is strongly limited by scaling (50% for separate and 60% for mixed, respectively). Physical signs of scaling were found during MD treatment of the NF permeates but did not result in flux decline for mixed regeneration wastewater. Final salt composition is expected to qualify as a road de-icing salt. NF-MD is an economically viable alternative compared to external disposal of wastewater for larger-scale installations (1.4 versus 2.5 euro m(-3) produced demineralized water for a 10 m3 regenerate per day plant). The cost benefits of water re-use and salt recuperation are small when compared to total treatment costs for mixed regenerate wastewater.

  14. Characterization of secondary ion emission processes of sub-MeV C60ion impacts via analysis of statistical distributions of the emitted ion number.

    Science.gov (United States)

    Hirata, K; Yamada, K; Chiba, A; Narumi, K; Saitoh, Y

    2016-12-21

    We report probability distributions of the number of secondary ions (SIs) emitted by sub-MeV C 60 ion impacts on an organic polymer target and the characterization of their emission processes through the analysis of the distributions. The probability distributions were obtained by analyzing experimental SI counting data obtained by a time-of-flight SI mass spectrometer combined with pulsed primary ion beams, using an analytical model developed to derive the distributions from the experimental data. A series of probability distribution functions was investigated for ion impacts of C 60 with sub-MeV energies (0.12-0.54 MeV), which can provide sufficient SIs per impact to determine the functions. Their complicated and undefined SI emission processes were characterized based on the determined functions.

  15. Study of quantitative interactions of potato and corn starch granules with ions in diluted solutions of heavy metal salts.

    Science.gov (United States)

    Szymońska, Joanna; Molenda, Marcin; Wieczorek, Jerzy

    2015-12-10

    Interactions of potato and corn starch granules with ions in diluted solutions of silver, lead, copper or iron salts were investigated. It was shown experimentally that granules accumulated the cations in amounts depending on the granule structure and water content as well as a type of both metal and counter-ions present in solution. Potato starch retained almost three times more cations compared to corn starch what was proportional to the total phosphorous content in these starches. Quantity of milligrams of cations bound by 1g of starch was inversely correlated with the cation hydration. Ag(+), Pb(2+) and Cu(2+) were connected in stoichiometric amounts of moles to semicrystalline and amorphous parts of the granules. Fe(3+) ions were accumulated in higher than stoichiometric quantities mainly in granule amorphous regions. Metal ions penetrated into granules together with anions except nitrates which remained on surface of potato starch granules. Cations facilitated the starch thermal decomposition in accordance with values of their standard redox potentials. Nitrates supported this process only in the presence of base metal cations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. A method for determining and exploring the distribution of organic matters and hardness salts in natural waters

    Science.gov (United States)

    Sargsyan, Suren

    2017-11-01

    A question regarding how organic matters in water are associated with hardness salts hasn't been completely studied. For partially clarifying this question, a water fractional separation and investigation method has been recommended. The experiments carried out by the recommended method showed that the dynamics of the distribution of total hardness and permanganate oxidation values in the fractions of frozen and melted water samples coincided completely based on which it has been concluded that organic matters in natural waters are associated with hardness salts and always distributed in this form. All these findings are useful information for the deep study of macro- and microelements in water.

  17. Mechanisms of distribution and targeting of neuronal ion channels.

    Science.gov (United States)

    Thayer, Desiree A; Jan, Lily Y

    2010-09-01

    The discovery and development of pharmaceutical drugs targeting ion channels is important for treating a variety of medical conditions and diseases. Ion channels are expressed ubiquitously throughout the body, and are involved in many basic physiological processes. Neuronal ion channels are particularly appealing drug targets, and recent advances in screening ion channel function using optical-based and electrophysiological technologies have improved drug development in this field. Moreover, methods for the discovery of peptide-based neurotoxins and other natural products have proven useful in the pharmacological assessment of ion channel structure and function, while also contributing to the identification of lead molecules for drug development.

  18. Complementary experimental-simulational study of surfactant micellar phase in the extraction process of metallic ions: Effects of temperature and salt concentration

    Science.gov (United States)

    Soto-Ángeles, Alan Gustavo; Rodríguez-Hidalgo, María del Rosario; Soto-Figueroa, César; Vicente, Luis

    2018-02-01

    The thermoresponsive micellar phase behaviour that exhibits the Triton-X-100 micelles by temperature effect and addition of salt in the extraction process of metallic ions was explored from mesoscopic and experimental points. In the theoretical study, we analyse the formation of Triton-X-100 micelles, load and stabilization of dithizone molecules and metallic ions extraction inside the micellar core at room temperature; finally, a thermal analysis is presented. In the experimental study, the spectrophotometric outcomes confirm the solubility of the copper-dithizone complex in the micellar core, as well as the extraction of metallic ions of aqueous environment via a cloud-point at 332.2 K. The micellar solutions with salt present a low absorbance value compared with the micellar solutions without salt. The decrease in the absorbance value is attributed to a change in the size of hydrophobic region of colloidal micelles. All transitory stages of extraction process are discussed and analysed in this document.

  19. On the influence of the shape of kappa distributions of ions and electrons on the ion-cyclotron instability

    Science.gov (United States)

    Ziebell, L. F.; Gaelzer, R.

    2017-10-01

    The dispersion relation for ion-cyclotron waves propagating along the direction of the ambient magnetic field is investigated numerically by considering different forms of kappa functions as velocity distributions of ions and electrons. General forms of kappa distributions, isotropic and anisotropic, are defined and used to obtain the dispersion relations for ion-cyclotron waves. With suitable choice of parameters, the general forms reduce to anisotropic versions of the kappa distributions most frequently employed in the literature. The analysis is focused in cases with a small value of the kappa index, for which the non thermal character of the kappa distributions is enhanced. The results show the effects of the superthermal tails of the velocity distributions of both particle species (ions and electrons) on the growth rate of the ion-cyclotron instability. It is seen that different forms of anisotropic kappa distributions, which are used in the current literature, can have a significantly different effect on the growth rates of the instability.

  20. Using chloride and other ions to trace sewage and road salt in the Illinois Waterway

    Science.gov (United States)

    Kelly, W.R.; Panno, S.V.; Hackley, Keith C.; Hwang, H.-H.; Martinsek, A.T.; Markus, M.

    2010-01-01

    Chloride concentrations in waterways of northern USA are increasing at alarming rates and road salt is commonly assumed to be the cause. However, there are additional sources of Cl- in metropolitan areas, such as treated wastewater (TWW) and water conditioning salts, which may be contributing to Cl- loads entering surface waters. In this study, the potential sources of Cl- and Cl- loads in the Illinois River Basin from the Chicago area to the Illinois River's confluence with the Mississippi River were investigated using halide data in stream samples and published Cl- and river discharge data. The investigation showed that road salt runoff and TWW from the Chicago region dominate Cl- loads in the Illinois Waterway, defined as the navigable sections of the Illinois River and two major tributaries in the Chicago region. Treated wastewater discharges at a relatively constant rate throughout the year and is the primary source of Cl- and other elements such as F- and B. Chloride loads are highest in the winter and early spring as a result of road salt runoff which can increase Cl- concentrations by up to several hundred mg/L. Chloride concentrations decrease downstream in the Illinois Waterway due to dilution, but are always elevated relative to tributaries downriver from Chicago. The TWW component is especially noticeable downstream under low discharge conditions during summer and early autumn when surface drainage is at a minimum and agricultural drain tiles are not flowing. Increases in population, urban and residential areas, and roadways in the Chicago area have caused an increase in the flux of Cl- from both road salt and TWW. Chloride concentrations have been increasing in the Illinois Waterway since around 1960 at a rate of about 1 mg/L/a. The increase is largest in the winter months due to road salt runoff. Shallow groundwater Cl- concentrations are also increasing, potentially producing higher base flow concentrations. Projected increases in population and

  1. ABA pretreatment can alter the distribution of polysomes in salt-stressed barley sprouts

    Directory of Open Access Journals (Sweden)

    Szypulska Ewa

    2016-12-01

    Full Text Available The study analyzed caryopses of barley (Hordeum vulgare cv. Stratus. Caryopses were germinated in darkness at 20°C in three experimental setups: (a in distilled water for 24 hours, followed by 100 mM NaCl for another 24 hours (salinity stress, SS, (b in 100 μM of abscisic acid for the first 24 hours, followed by rinsing with distilled water to remove residual ABA, and in 100 mM NaCl for another 24 hours (ABA pretreatment + salinity stress, ABAS, (c in distilled water only (control, C. Changes in the content of free polysomes (FP, membrane-bound polysomes (MBP, cytoskeleton-bound polysomes (CBP and cytomatrix-bound polysomes (CMBP were examined in barley sprouts germinated in SS and ABAS treatments for 48 hours. In salt-stressed barley sprouts, the concentrations of membrane-bound and cytoskeleton-bound polysomes (MBP, CBP and CMBP decreased significantly, whereas an increase was noted only in the free polysome (FP fraction. ABA pretreatment altered the distribution of polysomes in stressed plants. The content of cytoskeletonbound polysomes (CBP and CMBP increased, FP levels decreased, whereas no changes in MBP content were observed in response to ABA treatment. Our results suggest that plants respond to salt stress by increasing the concentrations of free polysomes that are probably released from damaged cell structures, mainly membranes. Our present and previous findings indicate that ABA could inhibit the release of FP in stressed plants by enhancing polysome binding to the cytoskeleton.

  2. Chromatin compaction under mixed salt conditions: opposite effects of sodium and potassium ions on nucleosome array folding.

    Science.gov (United States)

    Allahverdi, Abdollah; Chen, Qinming; Korolev, Nikolay; Nordenskiöld, Lars

    2015-02-17

    It is well known that chromatin structure is highly sensitive to the ionic environment. However, the combined effects of a physiologically relevant mixed ionic environment of K(+), Mg(2+) and Na(+), which are the main cations of the cell cytoplasm, has not been systematically investigated. We studied folding and self-association (aggregation) of recombinant 12-mer nucleosome arrays with 177 bp DNA repeat length in solutions of mixtures of K(+) and Mg(2+) or Na(+) and Mg(2+). In the presence of Mg(2+), the addition of sodium ions promotes folding of array into 30-nm fibres, whereas in mixtures of K(+) and Mg(2+), potassium ions abrogate folding. We found that self-association of nucleosome arrays in mixed salt solutions is synergistically promoted by Mg(2+) and monovalent ions, with sodium being slightly more efficient than potassium in amplifying the self-association. The results highlight the importance of a mixed ionic environment for the compaction of chromatin under physiological conditions and demonstrate the complicated nature of the various factors that determine and regulate chromatin compaction in vivo.

  3. The salt and lipid composition of model cheeses modifies in-mouth flavour release and perception related to the free sodium ion content.

    Science.gov (United States)

    Boisard, Lauriane; Andriot, Isabelle; Martin, Christophe; Septier, Chantal; Boissard, Vanessa; Salles, Christian; Guichard, Elisabeth

    2014-02-15

    Reducing salt and lipid levels in foodstuffs without any effect on acceptability is a major challenge, particularly because of their interactions with other ingredients. This study used a multimodal approach to understand the effects of changes to the composition of model cheeses (20/28, 24/24, 28/20 lipid/protein ratios, 0% and 1% added NaCl) on sodium ion mobility ((23)Na NMR), in-mouth sodium release and flavour perception. An increase in the salt content decreased cheese firmness and perceived hardness, and increased sodium ion mobility, in vivo sodium release and both saltiness and aroma perception. With the same amount of salt, a lower lipid/protein ratio increased the firmness of the cheeses, perceived hardness, and decreased sodium ion mobility, in vivo sodium release, saltiness and aroma perception. These findings suggest on one hand that it could be possible to increase saltiness perception by varying cheese composition, thus inducing differences in sodium ion mobility and in free sodium ion concentration, leading to differences in in-mouth sodium release and saltiness perception, and on the other hand that the reformulation of foods in line with health guidelines needs to take account of both salt content and the lipid/protein ratio. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Six-Membered-Ring Malonatoborate-Based Lithium Salts as Electrolytes for Lithium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li; Zhang, Hanjun; Driscoll, Peter; Lucht, Brett; Kerr, John

    2011-09-30

    A new class of lithium salts of malonatoborate anions has been synthesized. These six-membered-ring salts provided slightly lower ionic conductivity than that of LiBOB and LiBF4. Nevertheless, compared with LiBOB and LiPF6, the lowered ring strains in the malonatoborate structures and reduced numbers of fluorine atoms in the molecules was found to enhance the thermal and water stabilities and compatibilities of these salts with ether solvents. Small amount LiDMMDFB when used as an additive, was found to stabilize LiPF6 in carbonate electrolytes at 80°C for one month. Employing LiMDFB as the electrolyte in Li/Li cells and full cells, large interfacial impedances were observed on lithium metal and the cathode. Moreover, the large impedances are at least partially attributed to the acidic hydrogen atoms in the malonate structure. This issue can be addressed by replacing the acidic atoms with methyl groups.

  5. Radial distribution of ions in pores with a surface charge

    NARCIS (Netherlands)

    van der Stegen, J.H.G.; van der Stegen, J.H.G.; Gortzen, J.; Gortzen, J.; Kuipers, J.A.M.; Hogendoorn, Kees; Versteeg, Geert

    2001-01-01

    A sorption model applicable to calculate the radial equilibrium concentrations of ions in the pores of ion-selective membranes with a pore structure is developed. The model is called the radial uptake model. Because the model is applied to a Nafion sulfonic layer with very small pores and the radial

  6. Interfacial behavior of perchlorate versus chloride ions in saturated aqueous salt solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ghosal, S; Kuo, I W; Baer, M D; Bluhm, H

    2009-04-14

    In recent years combination of theoretical and experimental work have presented a novel view of the aqueous interface wherein hard and/or multiply charged ions are excluded from the interface, but large polarizable anions show interfacial enhancement relative to the bulk. The observed trend in the propensity of anions to adsorb at the air/water interface appears to be reverse of the Hofmeister series for anions. This study focuses on experimental and theoretical examination of the partitioning behavior of perchlorate (ClO{sub 4}{sup -}) and chloride (Cl{sup -}) ions at the air/water interface. We have used ambient pressure X-ray photoelectron spectroscopy technique to directly probe the interfacial concentrations of ClO{sub 4}{sup -} and Cl{sup -} ions in sodium perchlorate and sodium chloride solutions, respectively. Experimental observations are compared with first principles molecular dynamics simulations. Both experimental and simulation results show enhancement of ClO{sub 4}{sup -} ion at the interface, compared with the absence of such enhancement in the case of Cl{sup -} ion. These observations are in agreement with the expected trend in the interfacial propensity of anions based on the Hofmeister series.

  7. Exogenous nitric oxide improves salt tolerance during establishment of Jatropha curcas seedlings by ameliorating oxidative damage and toxic ion accumulation.

    Science.gov (United States)

    Gadelha, Cibelle Gomes; Miranda, Rafael de Souza; Alencar, Nara Lídia M; Costa, José Hélio; Prisco, José Tarquinio; Gomes-Filho, Enéas

    2017-05-01

    Jatropha curcas is an oilseed species that is considered an excellent alternative energy source for fossil-based fuels for growing in arid and semiarid regions, where salinity is becoming a stringent problem to crop production. Our working hypothesis was that nitric oxide (NO) priming enhances salt tolerance of J. curcas during early seedling development. Under NaCl stress, seedlings arising from NO-treated seeds showed lower accumulation of Na + and Cl - than those salinized seedlings only, which was consistent with a better growth for all analyzed time points. Also, although salinity promoted a significant increase in hydrogen peroxide (H 2 O 2 ) content and membrane damage, the harmful effects were less aggressive in NO-primed seedlings. The lower oxidative damage in NO-primed stressed seedlings was attributed to operation of a powerful antioxidant system, including greater glutathione (GSH) and ascorbate (AsA) contents as well as catalase (CAT) and glutathione reductase (GR) enzyme activities in both endosperm and embryo axis. Priming with NO also was found to rapidly up-regulate the JcCAT1, JcCAT2, JcGR1 and JcGR2 gene expression in embryo axis, suggesting that NO-induced salt responses include functional and transcriptional regulations. Thus, NO almost completely abolished the deleterious salinity effects on reserve mobilization and seedling growth. In conclusion, NO priming improves salt tolerance of J. curcas during seedling establishment by inducing an effective antioxidant system and limiting toxic ion and reactive oxygen species (ROS) accumulation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  8. Dependence of the depth distribution of implanted silver ions on the temperature of irradiated glass

    CERN Document Server

    Stepanov, A L

    2001-01-01

    The peculiarities of the glass ion implantation by the silver ions in dependence on the substrate temperature within the interval of 20-100 deg C are studied. Modeling the profiles of the implanted ions distribution in depth with an account of the thermostimulated increase in the admixture diffusion mobility is carried out. It is shown, that increase in the substrate temperature leads to the diffusion wash-out of the introduced admixture ions distribution. The analysis of the modeling results indicates the necessity of strict control of the substrate temperature by the dielectrics implantation for obtaining the conditions for the metal nanoparticles synthesis

  9. Synthesis of rock-salt type lithium borohydride and its peculiar Li+ ion conduction properties

    Science.gov (United States)

    Miyazaki, R.; Maekawa, H.; Takamura, H.

    2014-05-01

    The high energy density and excellent cycle performance of lithium ion batteries makes them superior to all other secondary batteries and explains why they are widely used in portable devices. However, because organic liquid electrolytes have a higher operating voltage than aqueous solution, they are used in lithium ion batteries. This comes with the risk of fire due to their flammability. Solid electrolytes are being investigated to find an alternative to organic liquid. However, the nature of the solid-solid point contact at the interface between the electrolyte and electrode or between the electrolyte grains is such that high power density has proven difficult to attain. We develop a new method for the fabrication of a solid electrolyte using LiBH4, known for its super Li+ ion conduction without any grain boundary contribution. The modifications to the conduction pathway achieved by stabilizing the high pressure form of this material provided a new structure with some LiBH4, more suitable to the high rate condition. We synthesized the H.P. form of LiBH4 under ambient pressure by doping LiBH4 with the KI lattice by sintering. The formation of a KI - LiBH4 solid solution was confirmed both macroscopically and microscopically. The obtained sample was shown to be a pure Li+ conductor despite its small Li+ content. This conduction mechanism, where the light doping cation played a major role in ion conduction, was termed the "Parasitic Conduction Mechanism." This mechanism made it possible to synthesize a new ion conductor and is expected to have enormous potential in the search for new battery materials.

  10. Synthesis of rock-salt type lithium borohydride and its peculiar Li+ ion conduction properties

    Directory of Open Access Journals (Sweden)

    R. Miyazaki

    2014-05-01

    Full Text Available The high energy density and excellent cycle performance of lithium ion batteries makes them superior to all other secondary batteries and explains why they are widely used in portable devices. However, because organic liquid electrolytes have a higher operating voltage than aqueous solution, they are used in lithium ion batteries. This comes with the risk of fire due to their flammability. Solid electrolytes are being investigated to find an alternative to organic liquid. However, the nature of the solid-solid point contact at the interface between the electrolyte and electrode or between the electrolyte grains is such that high power density has proven difficult to attain. We develop a new method for the fabrication of a solid electrolyte using LiBH4, known for its super Li+ ion conduction without any grain boundary contribution. The modifications to the conduction pathway achieved by stabilizing the high pressure form of this material provided a new structure with some LiBH4, more suitable to the high rate condition. We synthesized the H.P. form of LiBH4 under ambient pressure by doping LiBH4 with the KI lattice by sintering. The formation of a KI - LiBH4 solid solution was confirmed both macroscopically and microscopically. The obtained sample was shown to be a pure Li+ conductor despite its small Li+ content. This conduction mechanism, where the light doping cation played a major role in ion conduction, was termed the “Parasitic Conduction Mechanism.” This mechanism made it possible to synthesize a new ion conductor and is expected to have enormous potential in the search for new battery materials.

  11. Distribution of root-associated bacterial communities along a salt-marsh primary succession

    Directory of Open Access Journals (Sweden)

    Miao eWang

    2016-01-01

    Full Text Available Proper quantification of the relative influence of soil and plant host on the root-associated microbiome can only be achieved by studying its distribution along an environmental gradient. Here we used an undisturbed salt marsh chronosequence to study the bacterial communities associated with the soil, rhizosphere and the root endopshere of Limonium vulgare using 454-pyrosequencing. We hypothesize that the selective force exerted by plants rather than soil would regulate the dynamics of the root-associated bacterial assembly along the chronosequence. Our results showed that the soil and rhizosphere bacterial communities were phylogenetically more diverse than those in the endosphere. Moreover, the diversity of the rhizosphere microbiome followed the increased complexity of the abiotic and biotic factors during succession while remaining constant in the other microbiomes. Multivariate analyses showed that the rhizosphere and soil-associated communities clustered by successional stages, whereas the endosphere communities were dispersed. Interestingly, the endosphere microbiome showed higher turnover, while the bulk and rhizosphere soil microbiomes became more similar at the end of the succession. Overall, we showed that soil characteristics exerted an overriding influence on the rhizosphere microbiome, although plant effect led to a clear diversity pattern along the succession. Conversely, the endosphere microbiome was unaffected by any of the environmental measurements and very distinct from other communities.

  12. Spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources. Experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Panitzsch, Lauri

    2013-02-08

    The experimental determination of the spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources (ECRIS) defines the focus of this thesis. The spatial distributions of different ion species were obtained in the object plane of the bending magnet ({approx}45 cm downstream from the plasma electrode) and in the plane of the plasma electrode itself, both in high spatial resolution. The results show that each of the different ion species forms a bloated, triangular structure in the aperture of the plasma electrode. The geometry and the orientation of these structures are defined by the superposition of the radial and axial magnetic fields. The radial extent of each structure is defined by the charge of the ion. Higher charge states occupy smaller, more concentrated structures. The total current density increases towards the center of the plasma electrode. The circular and star-like structures that can be observed in the beam profiles of strongly focused, extracted ion beams are each dominated by ions of a single charge state. In addition, the spatially resolved current density distribution of charged particles in the plasma chamber that impinge on the plasma electrode was determined, differentiating between ions and electrons. The experimental results of this work show that the electrons of the plasma are strongly connected to the magnetic field lines in the source and thus spatially well confined in a triangular-like structure. The intensity of the electrons increases towards the center of the plasma electrode and the plasma chamber, as well. These electrons are surrounded by a spatially far less confined and less intense ion population. All the findings mentioned above were already predicted in parts by simulations of different groups. However, the results presented within this thesis represent the first (and by now only) direct experimental verification of those predictions and are qualitatively transferable to

  13. Sodium transport and distribution in sweet pepper during and after salt stress

    NARCIS (Netherlands)

    Blom-Zandstra, M.

    2000-01-01

    In hydroponic systems often saline water is used in nutrient solutions. Transpiration leads to a steady increase of the salt concentration. To avoid unfavourable salt conditions, solutions are renewed, regularly. So, plants are exposed to varying sodium concentrations. In this paper, the sodium

  14. Salt stress alters fluid and ion transport by Malpighian tubules of Drosophila melanogaster: evidence for phenotypic plasticity.

    Science.gov (United States)

    Naikkhwah, Wida; O'Donnell, Michael J

    2011-10-15

    Drosophila are tolerant of high levels of dietary salt and can provide a useful model for studies of the physiology of salt stress. The effects of NaCl- and KCl-rich diets on haemolymph ionoregulation and Malpighian tubule (MT) fluid secretion, Na(+) and K(+) secretion and transepithelial potential were examined in larval and adult Drosophila melanogaster. K(+) concentrations in the haemolymph of adults reared on the KCl-rich (0.4 mol l(-1)) diet did not differ from the values for insects reared on the control diet. In the haemolymph of larvae reared on the K-rich diet, K(+) concentrations increased from 23 to 75 mmol l(-1) after 6 h, then returned to the control value within 48 h. Na(+) concentrations in the haemolymph of adults or larvae reared for 1-7 days on the NaCl-rich (0.4 mol l(-1)) diet increased by ~50% relative to values for insects reared on the control diet. Rates of secretion of fluid, Na(+) and K(+) by MTs isolated from larvae reared on the Na-rich diet for >6 h and bathed in control saline containing 20 mmol l(-1) K(+) did not differ from the values for tubules of larvae reared on the control diet. Evidence of phenotypic plasticity was seen in the response of MTs isolated from larvae reared on the K-rich diet for >6 h and bathed in saline containing 60 mmol l(-1) K(+); secretion of fluid and K(+) increased by >50% relative to the values for tubules of larvae reared on the control diet. Secretion of fluid, Na(+) and K(+) increased when tubules were bathed in haemolymph collected from larvae reared on the Na- or K-rich diets. Secretion was further increased by addition of exogenous cAMP but not by addition of thapsigargin to the haemolymph. The results show that haemolymph ionoregulation in larvae reared on salt-rich diets involves both alterations in the basal secretion rates of Na(+) and/or K(+) as well as stimulatory effects of diuretic factors present in the haemolymph. The results suggest that such factors stimulate tubule fluid and ion

  15. Moisture distribution in the stone portal of a church: how it influences the salt accumulation in porous limestone

    Science.gov (United States)

    Török, Ákos; Galambos, Éva

    2017-04-01

    Mathias Church of Budapest (Hungary) is an emblematic stone monument that represents various phases of constructions from Medieval period to the early 20th century. The church is found at the elevated Castle Hill and forms a landmark at the UNESCO World Heritage Site of Budapest. Its main construction material is porous Miocene limestone. Besides porous limestone travertine was also extensively used. The current study focuses on the Medieval Gate of the church which encompasses richly decorated porous limestone ornaments. The gate is now sheltered and form an interior portal of the church. It shows various forms of stone decay. The most striking one is efflorescence of salts. This feature has become more intense in the past years leading to flaking and granular disintegration of the limestone, causing damage to the monument. This study focuses on the detection of moisture content within the stone structure and its role in the salt accumulation. To obtain this goal in situ moisture measurements were made along vertical profiles by a portable moisture detector (Gann-Hydromette). It allowed outlining the moisture distribution within the studied structure. The moisture measurement was combined with sampling of salt efflorescence and porous limestone of the gate, itself. The samples were tested by optical microscopy. Conductivity, salt content and main elements were also detected from solutions. Mineralogical composition was recorded by XRD and Thermogravimetric analyses. Magnesium-sulphates were found to be the main salts responsible for damages. Besides sulphates chlorides were also detected. Gypsum was also found in the weathering crusts of the previously exposed limestone surfaces. It accumulated in black crusts but was also detected in white efflorescence and below the stone surface. The salt distribution clearly correlates with the moisture content. The financial support of NKFI Fund (ref. no. K 116532) is appreciated.

  16. Anisotropic and asymmetric fast ion distribution generated by magnetic reconnection in MST plasmas

    Science.gov (United States)

    Kim, Jungha; Anderson, Jay; Bonofiglo, Phillip; Harvey, Robert; Sarff, John

    2017-10-01

    Magnetic reconnection is important in particle transport and energization in both astrophysical and laboratory plasmas. Global reconnection events in MST spontaneously generate an anisotropic ion distribution with a high energy tail extending up to 30x thermal energy, likely through a multi-step process that involves multiple physical scale lengths. First, thermal ions are heated by a mechanism that operates preferentially perpendicular to the magnetic field. Second, the higher energy portion of the thermal ion distribution moves into orbits that drift off the stochastic background magnetic field. In the reversed field pinch (RFP) configuration, these drift velocities contribute to stable fast ion orbits that are low in diffusivity and favorable to confinement. These fast ions, separated from the background magnetic field, are unaffected by fluctuation-based, dynamo-like emfs that reduce the total electric field to 0.5 V/m. Finally, a parallel electric field ( 80 V/m), induced by the fast change in the equilibrium during magnetic relaxation, accelerates these fast ions, resulting in an ion distribution that favors high energy, parallel-streaming ions. Work is underway to model the time evolution of the fast ion distribution using CQL3D (Fokker-Planck equation solver) and RIO (full orbit tracer). Work supported by US DOE.

  17. Ring-averaged ion velocity distribution function probe for laboratory magnetized plasma experiment

    Science.gov (United States)

    Kawamori, Eiichirou; Chen, Jinting; Lin, Chiahsuan; Lee, Zongmau

    2017-10-01

    Ring-averaged velocity distribution function of ions at a fixed guiding center position is a fundamental quantity in the gyrokinetic plasma physics. We have developed a diagnostic tool for the ring averaged velocity distribution function of ions for laboratory plasma experiments, which is named as the ring-averaged ion distribution function probe (RIDFP). The RIDFP is a set of ion collectors for different velocities. It is designed to be immersed in magnetized plasmas and achieves momentum selection of incoming ions by the selection of the ion Larmor radii. To nullify the influence of the sheath potential surrounding the RIDFP on the orbits of the incoming ions, the electrostatic potential of the RIDFP body is automatically adjusted to coincide with the space potential of the target plasma with the use of an emissive probe and a voltage follower. The developed RIDFP successfully measured the equilibrium ring-averaged velocity distribution function of a laboratory magnetized plasma, which was in accordance with the Maxwellian distribution having an ion temperature of 0.2 eV.

  18. Ring-averaged ion velocity distribution function probe for laboratory magnetized plasma experiment.

    Science.gov (United States)

    Kawamori, Eiichirou; Chen, Jinting; Lin, Chiahsuan; Lee, Zongmau

    2017-10-01

    Ring-averaged velocity distribution function of ions at a fixed guiding center position is a fundamental quantity in the gyrokinetic plasma physics. We have developed a diagnostic tool for the ring averaged velocity distribution function of ions for laboratory plasma experiments, which is named as the ring-averaged ion distribution function probe (RIDFP). The RIDFP is a set of ion collectors for different velocities. It is designed to be immersed in magnetized plasmas and achieves momentum selection of incoming ions by the selection of the ion Larmor radii. To nullify the influence of the sheath potential surrounding the RIDFP on the orbits of the incoming ions, the electrostatic potential of the RIDFP body is automatically adjusted to coincide with the space potential of the target plasma with the use of an emissive probe and a voltage follower. The developed RIDFP successfully measured the equilibrium ring-averaged velocity distribution function of a laboratory magnetized plasma, which was in accordance with the Maxwellian distribution having an ion temperature of 0.2 eV.

  19. Inhibiting Polysulfide Shuttle in Lithium-Sulfur Batteries through Low-Ion-Pairing Salts and a Triflamide Solvent.

    Science.gov (United States)

    Shyamsunder, Abhinandan; Beichel, Witali; Klose, Petra; Pang, Quan; Scherer, Harald; Hoffmann, Anke; Murphy, Graham K; Krossing, Ingo; Nazar, Linda F

    2017-05-22

    The step-change in gravimetric energy density needed for electrochemical energy storage devices to power unmanned autonomous vehicles, electric vehicles, and enable low-cost clean grid storage is unlikely to be provided by conventional lithium ion batteries. Lithium-sulfur batteries comprising lightweight elements provide a promising alternative, but the associated polysulfide shuttle in typical ether-based electrolytes generates loss in capacity and low coulombic efficiency. The first new electrolyte based on a unique combination of a relatively hydrophobic sulfonamide solvent and a low ion-pairing salt, which inhibits the polysulfide shuttle, is presented. This system behaves as a sparingly solvating electrolyte at slightly elevated temperatures, where it sustains reversible capacities as high as 1200-1500 mAh g-1 over a wide range of current density (2C-C/5, respectively) when paired with a lithium metal anode, with a coulombic efficiency of >99.7 % in the absence of LiNO3 additive. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Path-length distribution of ions reflected from a solid: Theory and computer simulation

    Science.gov (United States)

    Tolmachev, A. I.; Forlano, L.

    2017-07-01

    Theoretical methods and Monte Carlo procedure are used to study path-length distributions of ions reflected from a solid. The theoretical analysis is based on the solution of the integral Chandrasekhar equation for the Laplace transform of the distribution function. A family of curves is obtained for path-length distributions at several ion energies and mass ratios of ions and target atoms. A computer code for simulation is based on the approximation of pair collisions and a gas model of solid. The simulated results are compared with the theoretical results and published data.

  1. Analysis of high-altitude planetary ion velocity space distributions detected by the Ion Mass Analyzer aboard Mars Express

    Science.gov (United States)

    Johnson, B. C.; Liemohn, M. W.; Fraenz, M.; Curry, S.; Mitchell, D. L.

    2012-12-01

    We present observations of planetary ion velocity space distributions from the Ion Mass Analyzer (IMA) onboard Mars Express (MEX). The magnetometer data from Mars Global Surveyor is used to obtain a rough estimate of the interplanetary magnetic field (IMF) orientation. Characteristic features of the velocity space distributions will be examined and discussed for orbits aligned with the convective electric field and those in the Mars terminator plane. This study will focus on the high (keV) energy ions, as well as the relative importance of a high-altitude magnetosheath source of escaping planetary ions. Furthermore, this paper will examine various methods for converting the IMA detector counts to species-specific fluxes. After mimicking the methods previously used by researchers, we apply each of these methods of species extraction to data collected during the same time intervals. We discuss the implications for planetary ion motion around Mars, using the details of the velocity space observations to better understand the solar wind interaction with Mars. Comparisons to virtual detections using a test particle simulation will also provide insight into ion origins and trajectories.

  2. Hydrocarbons in the Hauptsalz formation of the Gorleben salt dome. Content, distribution and origin

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Maximilian; Hammer, Joerg; Ostertag-Henning, Christian [Federal Institute for Geosciences and Natural Resources (BGR), Hannover (Germany)

    2015-07-01

    In the frame of the geological exploration of the Gorleben salt dome (November 2010 to November 2012) concentrations and compositions of hydrocarbons occuring in the main rock salt (Hauptsalz, Stassfurt series, z2) have been investigated. These exploration works followed former investigations of Gerling et al. (2002) and Bornemann et al. (2008). In order to get fresh, unaltered and representative samples beyond the EDZ (excavation damaged zone) for mineralogical and geochemical analyses, about 45 boreholes have been drilled at the 840 m level of the Gorleben exploration mine. These boreholes have been arranged in equal distances (depending on the mine structure) alongside crosscut 1 west (each 6 m long) and crosscut 1 east (each 9 m long). In addition 20 packer boreholes (10 packer boreholes per crosscut) for pressure build-up recording and hydrocarbon sampling have also been established. Immediately after drilling, core samples from the Hauptsalz for organic geochemical analyses have been retrieved and were dissolved in deionised and degased water. The results of analyses of about 210 samples scattered over all 45 boreholes reveal a total background concentration of hydrocarbons (C{sub 1} to C{sub 40}) of 0,24 mg/kg. 70 samples have concentrations between 1 mg/kg and 50 mg/kg (average 2,66 mg/kg) with 5 outliers up to 442 mg/kg in crosscut 1 west (Hammer et al. 2012, 2013). The drill cores have been investigated and documented by using ultraviolet light (l = 254 nm) in respect of visible indications of the existence of fluorescing aromatic hydrocarbons. Analyses revealed a high level of heterogeneous hydrocarbon distribution in the shape of isolated, irregular streaks, clusters, clouds and occasionally layers mainly located in recrystallized zones of the Hauptsalz. Thin sections and thick sections showed that hydrocarbons in z2HS1 (Knaeuelsalz) and z2HS2 (Streifensalz) samples are either located as black to brownish dendritical fluid inclusions alongside the grain

  3. A novel approach for measuring the radial distribution of charge in a heavy ion track

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.W. Jr.; Block, R.C. (Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Nuclear Engineering and Engineering Physics); Stapor, W.J.; McDonald, P.T.; Knudson, A.R. (Naval Research Lab., Washington, DC (United States)); Dussault, H. (Rome Lab., Griffiss AFB, NY (United States)); Pinto, M.R. (AT and T Bell Lab., Murray Hill, NJ (United States))

    1994-12-01

    The energy deposited by the passage of a single, energetic, heavy-ion through a semiconductor produces dense electron-hole (eh) pair concentrations near the ion trajectory. The size, shape, and charge density of an ion track represent critical parameters for many models of single event phenomena. The authors describe the design and uses of possible semiconductor test structures for measuring the initial radial distribution of charge and subsequent charge transport in a high energy, heavy-ion track. Numerical simulations show how the test structure can resolve different radial distributions of charge within an ion track. The test structure simulations also show the importance of accurately representing ion track structure in single event effects simulations.

  4. 4D Imaging of Salt Precipitation during Evaporation from Saline Porous Media Influenced by the Particle Size Distribution

    Science.gov (United States)

    Norouzi Rad, M.; Shokri, N.

    2014-12-01

    Understanding the physics of water evaporation from saline porous media is important in many processes such as evaporation from porous media, vegetation, plant growth, biodiversity in soil, and durability of building materials. To investigate the effect of particle size distribution on the dynamics of salt precipitation in saline porous media during evaporation, we applied X-ray micro-tomography technique. Six samples of quartz sand with different grain size distributions were used in the present study enabling us to constrain the effects of particle and pore sizes on salt precipitation patterns and dynamics. The pore size distributions were computed using the pore-scale X-ray images. The packed beds were saturated with NaCl solution of 3 Molal and the X-ray imaging was continued for one day with temporal resolution of 30 min resulting in pore scale information about the evaporation and precipitation dynamics. Our results show more precipitation at the early stage of the evaporation in the case of sand with the larger particle size due to the presence of fewer evaporation sites at the surface. The presence of more preferential evaporation sites at the surface of finer sands significantly modified the patterns and thickness of the salt crust deposited on the surface such that a thinner salt crust was formed in the case of sand with smaller particle size covering larger area at the surface as opposed to the thicker patchy crusts in samples with larger particle sizes. Our results provide new insights regarding the physics of salt precipitation in porous media during evaporation.

  5. A model for membrane potential and intracellular ion distribution.

    Science.gov (United States)

    Khitrin, A K; Khitrin, K A; Model, M A

    2014-12-01

    Most cells carry a negative electric charge. It produces a potential difference across the membrane, which regulates voltage-sensitive ion transport and ATP synthesis in mitochondria. The negative charge comes partly from an excess of negative ions in the cell interior (Donnan potential) and partly from ionized groups on the membrane (surface potential). In this work we propose some important modifications to the existing theory of membrane potential. First, we calculate the concentration profile of intracellular positive ions and derive a simple equation to assess the submembrane depletion of positive ions that gives rise to the Donnan potential. The extent of depletion varies with potential, which may provide a regulatory mechanism for ion pumps and channels. Next we consider the surface component of the potential and note that the standard Gouy-Chapman theory has been developed for planar membranes, whereas real cell membranes have a closed geometry. In this case, charges on the membrane surface are not expected to generate fields extending into the cell interior. This fact calls for reinterpretation of some theoretical points as well as experimental data. In particular, the experimentally demonstrated electrostatic attraction between cationic proteins and the negative membrane must now be explained without invoking intracellular fields, and we suggest a new mechanism that can account for this interaction. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Hemolymph osmolality and cation concentrations in Litopenaeus vannamei during exposure to artificial sea salt or a mixed-ion solution: relationship to potassium flux.

    Science.gov (United States)

    Sowers, A D; Young, S P; Grosell, M; Browdy, C L; Tomasso, J R

    2006-10-01

    Interest in culturing the Pacific white shrimp Litopenaeus vannamei in low-salinity and brackish-well waters has led to questions about the ability of this species to osmo- and ionoregulate in environments containing low concentrations of ions and in environments with ionic ratios that differ from those found in sea water. After seven days, hemolymph osmolality and potassium, sodium and calcium values were all significantly affected by salinity (as artificial sea salt) with values decreasing with decreasing salinity. These decreases were small, however, relative to decreases in salinity, indicating iono- and osmoregulation with adjustment for gradients. The hemolymph osmolality and sodium and calcium concentrations in shrimp exposed to either 2 g/L artificial sea salt or 2 g/L mixed-ion solution (a mixture of sodium, potassium, calcium, and magnesium chlorides that approximate the concentrations and ratios of these cations found in 2 g/L dilute seawater) did not differ significantly. However, hemolymph potassium levels were significantly lower in shrimp held in the mixed-ion environment. Potassium influx rates were similar in shrimp held in either artificial sea salt or mixed ions. The results of this study indicate that salinity affects hemolymph-cation concentrations and osmolality. Further, differential potassium-influx rates do not appear to be the basis for low hemolymph potassium levels observed in shrimp held in mixed-ion environments.

  7. Physicochemical properties of magnesium aluminum silicate (smectone) gels prepared using electrolytic-reduction ion water (2): Effects of various salts on the phase diagram.

    Science.gov (United States)

    Okajima, Masahiro; Shimokawa, Ken-ichi; Ishii, Fumiyoshi

    2009-09-01

    We produced gels using electrolytic-reduction ion water and magnesium aluminum silicates (smectone), and evaluated in detail gel properties in the presence of various types of salt (NaCl, KCl, CaCl(2), MgCl(2), and AlCl(3)). Each salt was added to deionized-distilled water or electrolytic-reduction ion water, and phase diagrams for the smectone concentration (2.0-4.0%) were produced. The areas of the three phases of smectone (gel, sol, and separation) at each salt concentration were expressed as percentages of the total area. As a result, uni- and polyvalent cations (excluding Ca(2+) ions) affected the stability of gels produced using electrolytic-reduction ion water, and, particularly, univalent cations (Na(+), K(+)) markedly improved gel stability. Using electrolytic-reduction ion water as a dispersal medium, drug delivery systems (DDS) that can maintain the gelling state can be prepared. Thus, gel preparations with maintained functions or controlled-release transdermal drugs can be obtained.

  8. Differential subcellular distribution of ion channels and the diversity of neuronal function.

    Science.gov (United States)

    Nusser, Zoltan

    2012-06-01

    Following the astonishing molecular diversity of voltage-gated ion channels that was revealed in the past few decades, the ion channel repertoire expressed by neurons has been implicated as the major factor governing their functional heterogeneity. Although the molecular structure of ion channels is a key determinant of their biophysical properties, their subcellular distribution and densities on the surface of nerve cells are just as important for fulfilling functional requirements. Recent results obtained with high resolution quantitative localization techniques revealed complex, subcellular compartment-specific distribution patterns of distinct ion channels. Here I suggest that within a given neuron type every ion channel has a unique cell surface distribution pattern, with the functional consequence that this dramatically increases the computational power of nerve cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Symmetry Properties of Proton Velocity Distributions: a Vlasov Simulation Study of the Ion Cyclotron Instability

    Science.gov (United States)

    Araneda, J. A.; López, R. A.; Vinas, A. F.

    2014-12-01

    The ion cyclotron instability is driven by a sufficiently large proton temperature anisotropy, generating a spectrum of counterpropagating field-aligned ion cyclotron fluctuations. In this work, we use low-noise one-dimensional electromagnetic Vlasov simulations in a magnetized and collisionless plasma of fluid electrons and one ion species to study the evolution of proton velocity distributions during the thermal relaxation process. Special attention is given to deviations from initial bi-Maxwellian shapes.

  10. Methods to determine fast-ion distribution functions from multi-diagnostic measurements

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Salewski, Mirko

    Understanding the behaviour of fast ions in a fusion plasma is very important, since the fusion-born alpha particles are expected to be the main source of heating in a fusion power plant. Preferably, the entire fast-ion velocity-space distribution function would be measured. However, no fast...

  11. Angular distributions of ions channeled in the <1 0 0> Si crystals

    CERN Document Server

    Petrovic, S; Kokkoris, M; Neskovic, N

    2002-01-01

    In this study we analyze the angular distributions of Ne sup 1 sup 0 sup + ions channeled in the Si crystals. The ion energy is 60 MeV and the crystal thickness is varied from 286 to 3435 nm. This thickness range corresponds to the reduced crystal thickness range from 0.5 to 6, i.e. from the second to the twelfth rainbow cycle. The angular distributions were obtained via the numerical solution of the ion equations of motion and the computer simulation method. The analysis shows that the angular distribution has a periodic behavior. We also analyze the transmission patterns corresponding to the angular distributions. These patterns should be compared to the experimental patterns obtainable by a two-dimensional position sensitive detector. We demonstrate that, when the ion beam divergence is sufficiently large, i.e. much larger than the critical angle for channeling, the channeling star effect occurs in the transmission patterns.

  12. Effect of nonthermal ion distribution and dust temperature on ...

    Indian Academy of Sciences (India)

    Dust-acoustic solitary waves in unmagnetized dusty plasma whose constituents are iner- tial charged dust grains, Boltzmannian electrons and nonthermal ions have been investigated by taking into account finite dust temperature. The pseudopotential has been used to study solitary solution. The existence of solitary waves ...

  13. Effect of nonthermal ion distribution and dust temperature on ...

    Indian Academy of Sciences (India)

    the investigation of nonlinear dust acoustic waves in an unmagnetized dusty plasma. Sagdeev pseu- dopotential ... Solitons; dust acoustic wave; Sagdeev potential; dusty plasma; nonthermal ion. PACS No. 52.25. 1. ... ties of large amplitude stationary dust acoustic solitons, we assume that all the dependent variables in ...

  14. Effect of calcium in brine on salt diffusion and water distribution of Mozzarella cheese during brining.

    Science.gov (United States)

    Luo, J; Pan, T; Guo, H Y; Ren, F Z

    2013-02-01

    A soft, pasty, high-moisture surface defect occurs with progressive brining of Mozzarella cheese. Addition of calcium is traditionally used to prevent this defect but the underlying mechanism is not clear. Mozzarella cheese was formed into a cylinder inside brine on its plane surface to ensure semi-infinite, unidirectional mass transfer and placed into brine containing 0, 0.1, or 0.25% (wt/wt) calcium chloride. To monitor the effect on cheese composition of calcium in brine, we measured calcium and water contents of the cheese during brining. The extent of calcium loss from the cheese decreased significantly with the addition of calcium. Addition of calcium to a final concentration of 0.25% decreased the loss of calcium from 94.13 to 18.22% from the outside region of the cheese after 30 d, and the water content of the cheese was decreased from 67.8 to 48.8%. To further elucidate the effect of calcium in brine, the Boltzmann method was used to determine the effective diffusion coefficient value, and low-field nuclear magnetic resonance was used to measure the cheese transversal relaxation time. The migration of calcium interfered with salt diffusion. At the end of brining, the amount of water bound to the protein of the cheese significantly increased. Addition of calcium to a final concentration of 0.25% diminished the proportion of bound water by 20.96%. In conclusion, addition of calcium hinders the diffusion of sodium and modifies the distribution of water in Mozzarella cheese during brining. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Selective transport of ions and molecules across layer-by-layer assembled membranes of polyelectrolytes, p-sulfonato-calix[n]arenes and Prussian Blue-type complex salts.

    Science.gov (United States)

    Tieke, Bernd; Toutianoush, Ali; Jin, Wanqin

    2005-11-30

    Our recent studies in the field of ultrathin membranes prepared upon layer-by-layer assembly of various polyionic compounds such as polyelectrolytes, calixarenes and polyelectrolytes, and metal hexacyanoferrate salts such as Prussian Blue are reviewed. It is demonstrated that polyelectrolyte multilayers can be used (a) as nanofiltration and reverse osmosis membranes suitable for water softening and seawater desalination and (b) as molecular sieves and ion sieves for size-selective separation of neutral and charged aromatic compounds. Furthermore, hybrid membranes of p-sulfonato-calixarenes and cationic polyelectrolytes showing specific host-guest interactions with permeating ions are described. The membranes exhibit high selectivities for distinct metal ions. Finally, it is demonstrated that purely inorganic membranes of Prussian Blue (PB) and analogues can be prepared upon multiple sequential adsorption of transition metal cations and hexacyanoferrate anions. Due to the porous lattice of PB, the membranes are useful as ion filters able to separate cesium from sodium ions, for example.

  16. Scaling up the production and distribution of double-fortified salt in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    effective, double-fortified salt formulation has been successfully tested for efficacy and use ... The technology will be specifically tailored to existing manufacturing capabilities, ensuring sustainability and adherence to quality standards beyond the ...

  17. Salt distribution in dry-cured ham measured by computed tomography and image analysis

    DEFF Research Database (Denmark)

    Vestergaard, Christian Sylvest; Erbou, Søren G.; Thauland, T.

    2005-01-01

    Forty-seven hams were scanned four times by computed tomography (CT) while being manufactured into dry-cured hams. An image-processing algorithm measured CT values in the lean part of the hams and provided line profiles reflecting the magnitude and spatial location of salt gradients. At the end...... of manufacturing, seven entire hams were dissected and the salt content of the lean part determined. Likewise, in the remaining 40 hams, the lean meat of the slices corresponding to the CT images was dissected, analyzed chemically for NaCl and compared to the CT value. The salt content of entire dry-cured hams...... section were demonstrated. Line profiles illustrating the combined salt tribution and dehydration within a ham related to the physical characteristics of the ham as well as to the manufacturing process. These findings reveal that the effects of altered manufacturing practices can be followed non...

  18. X-ray absorption studies of the effect of plasticizers on ion-pair dissociation in a poly(ethylene oxide)-potassium salt complex

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X.Q.; Lee, H.S.; McBreen, J. [Brookhaven National Lab., Upton, NY (United States); Xu, Z.S.; Skotheim, T.A. [Moltech Corp., Stony Brook, NY (United States); Okamoto, Y. [Polytechnic Univ., Brooklyn, NY (United States); Lu, F. [Univ. of Kentucky, Lexington, KY (United States)

    1994-12-31

    Polyethylene oxide (PEO)-salt systems are an important new class of electrolytes that are being considered for use in high specific energy rechargeable lithium batteries. Near-edge x-ray absorption fine structure (NEXAFS) spectra, at the potassium K-edge, were obtained for the following systems: a potassium salt in (1) a propylene carbonate (PC) solution, (2) a modified carbonate (MC3) solution and (3) in a poly(ethylene oxide) (PEO)-potassium salt complexes having either PC or MC3 as a plasticizer. MC3 is similar to PC except that, instead of a methyl group, there are three ethylene oxide units attached to the 4-position. The degree of white line splitting was used to study ion pair dissociation effects of PC and MC3 qualitatively. When used as a solvent, MC3 has a stronger ion pair dissociation effect compared to PC. When used as a plasticizer in a PEO-potassium salt complex, the enhancement effect an ion pair dissociation of MC3 is superior to PC. This is in good agreement with temperature conductivity study.

  19. Formation of Hydrogen-Ion in Isomolar Solution of Hydrochloric and Hydrobromic Acids and Their Salts

    Directory of Open Access Journals (Sweden)

    M.A. Kovaleva

    2016-09-01

    Full Text Available Despite the presence of a large amount of factual material on thermodynamic parameters of complexation of agents in different solvents, including mixed ones, obtained knowledge is specific in nature. In order to identify more general patterns, studies are relevant that would allow to interpret the obtained data taking into account the interaction between chemical forms in solutions. This paper presents a general approach to studying weak ionic interactions in solutions that allows to simultaneously determine the constants of these interactions and the parameters characterizing the influence of changes in the ionic environment on these constants by the example of chlorides and bromides of alkali metals. The obtained constants for hydrosulfate-ion formation and the imperfection parameters can be a reference material for more accurate calculation of the concentration of hydrogen ions in sulfuric acid solutions. The developed approach and patterns identified in the work can be used to study the balanced states for formation of low and medium stable complexes.

  20. Effect of Dopant Ions on the Electrical Conductivity and Microstructure of Polyaniline (Emeraldine Salt

    Directory of Open Access Journals (Sweden)

    M. D. Catedral

    2004-12-01

    Full Text Available Samples of polyaniline (emeraldine salt were prepared with different protonic acid dopants, namely, hydrochloric acid (HCl, nitric acid (HNO3, perchloric acid (HClO4, sulfuric acid (H2SO4, and hydroiodic acid (HI. Using the two-point probe method, it was found that the samples had ohmic behaviors in which high linear coefficients were found in the range 0.9686–0.9997. On the other hand, the electrical conductivities were measured using the Van der Pauw method. The undoped sample had a conductivity of 5x10–4 S/cm. The highest conductivity of 109.04 S/cm was observed for the HClO4-doped sample, while the lowest value (0.02 S/cm was obtained for the HI-doped sample. These conductivities were compared with the computed energy gap between the highest occupied molecular orbital (HOMO and lowest unoccupied molecular orbital (LUMO where it was found that they are inversely proportional to each other. Scanning electron microscopy revealed significant differences among the samples in terms of shapes and morphologies.

  1. Origins of ion energy distribution function (IEDF) in high power impulse magnetron sputtering (HIPIMS) plasma discharge

    Science.gov (United States)

    Hecimovic, A.; Burcalova, K.; Ehiasarian, A. P.

    2008-05-01

    The ion energy distribution function (IEDF) in high power impulse magnetron sputtering (HIPIMS) discharges was studied by plasma sampling energy-resolved mass spectroscopy. HIPIMS of chromium (Cr), titanium (Ti) and carbon (C) targets in argon (Ar) atmosphere was analysed. Singly and doubly charged ions of both the target and the gas were detected. Time-averaged IEDFs were measured for all detected ions at the substrate position at a distance of 150 mm from the target. The effects of target current and discharge pressure on the IEDF were investigated. Measurements were done at two pressures and for three peak discharge currents. The IEDF of both the target and the gas ions was found to comprise two Maxwellian distributions. Quantitative analysis of target IEDFs at a low pressure showed that the main peak had a lower average energy with an approximate value of EAV = 1 eV which is attributed to collisions with thermalized gas atoms and ions. The higher energy distribution has a tail extending up to 70 eV, which is assumed to originate from a Thompson distribution of sputtered metal atoms which, due to collisions, are thermalized and appear as a Maxwell distribution. The proportion of high energy IEDFs for metal ions increases monotonically as a function of Id. The effective ion temperature kBT, extracted from the main low energy peak, showed a weak dependence on peak current. The effective ion temperature extracted from the high energy tail showed a strong correlation with the change in Id. The IEDF at high pressure shows that a proportion of high energy IEDFs was very low and dominated by a low energy main peak. The gas IEDF at high pressure was completely thermalized. The metal-ion-to-gas-ion ratio was found to increase with Id and with the sputtering yield of the target material.

  2. Relating chromatographic retention and electrophoretic mobility to the ion distribution within electrosprayed droplets.

    Science.gov (United States)

    Bökman, C Fredrik; Bylund, Dan; Markides, Karin E; Sjöberg, Per J R

    2006-03-01

    Ions that are observed in a mass spectrum obtained with electrospray mass spectrometry can be assumed to originate preferentially from ions that have a high distribution to the surface of the charged droplets. In this study, a relation between chromatographic retention and electrophoretic mobility to the ion distribution (derived from measured signal intensities in mass spectra and electrospray current) within electrosprayed droplets for a series of tetraalkylammonium ions, ranging from tetramethyl to tetrapentyl, is presented. Chromatographic retention in a reversed-phase system was taken as a measure of the analyte's surface activity, which was found to have a large influence on the ion distribution within electrosprayed droplets. In addition, different transport mechanisms such as electrophoretic migration and diffusion can influence the surface partitioning coefficient. The viscosity of the solvent system is affected by the methanol content and will influence both diffusion and ion mobility. However, as diffusion and ion mobility are proportional to each other, we have, in this study, chosen to focus on the ion mobility parameter. It was found that the influence of ion mobility relative to surface activity on the droplet surface partitioning of analyte ions decreases with increasing methanol content. This effect is most probably coupled to the decrease in droplet size caused by the decreased surface tension at increasing methanol content. The same observation was made upon increasing the ionic strength of the solvent system, which is also known to give rise to a decreased initial droplet size. The observed effect of ionic strength on the droplet surface partitioning of analyte ions could also be explained by the fact that at higher ionic strength, a larger number of ions are initially closer to the droplet surface and, thus, the contribution of ionic transport from the bulk liquid to the liquid/air surface interface (jet and droplet surface), attributable to

  3. Ion-dipole interactions are asymptotically unscreened by water in dipolar nanopores, yielding patterned ion distributions

    OpenAIRE

    Leung, Kevin

    2008-01-01

    The permeation, rejection, and transport of electrolytes in water-filled nanopores are critical to ion current gating and desalinalion processes in synthetic porous membranes and the functions of biological ion channels. Mile the effects of confinement pore polarizability, and discrete channel charge sites have been much studied, the potentially dramatic impact of dipole-lined synthetic pores on electrolytes has seldom been addressed. Dipole layers naturally occur on the interior surfaces of ...

  4. Electrodialysis-ion exchange for the separation of dissolved salts. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, J.L.; Baroch, C.J.; Litz, J.

    1996-07-19

    The program described in this report studies the suitability of electrodialysis-ion exchange (EDIX) to treat aqueous streams containing heavy metals and radioactive cations in a solution containing sodium and nitrates. The goal of the program was to produce a cation stream containing sodium, heavy metals, and radioactive cations; an anion stream of nitric acid free of heavy metals and radioactive cations; and a product stream that meets discharge criteria. The experimental results, described in detail, indicated that EDIX was not a suitable process for treating wastes containing metals that formed insoluble hydroxides in a basic solution; the metals precipitate in the catholyte and feed compartments, and in the cathode membrane. The test program was therefore terminated prior to completion of all planned activities. 2 refs., 22 figs., 8 tabs.

  5. Charged Hadron Multiplicity Distribution at Relativistic Heavy-Ion Colliders

    Directory of Open Access Journals (Sweden)

    Ashwini Kumar

    2013-01-01

    Full Text Available The present paper reviews facts and problems concerning charge hadron production in high energy collisions. Main emphasis is laid on the qualitative and quantitative description of general characteristics and properties observed for charged hadrons produced in such high energy collisions. Various features of available experimental data, for example, the variations of charged hadron multiplicity and pseudorapidity density with the mass number of colliding nuclei, center-of-mass energies, and the collision centrality obtained from heavy-ion collider experiments, are interpreted in the context of various theoretical concepts and their implications. Finally, several important scaling features observed in the measurements mainly at RHIC and LHC experiments are highlighted in the view of these models to draw some insight regarding the particle production mechanism in heavy-ion collisions.

  6. [Effects of non-sufficient irrigation with saline water on soil water-salt distribution and spring corn yield].

    Science.gov (United States)

    Jiang, Jing; Feng, Shao-yuan; Sun, Zhen-hua; Huo, Zai-lin

    2008-12-01

    A field experiment was conducted to study the effects of sufficient and non-sufficient irrigation with saline water on the soil water-salt distribution and spring corn yield in the middle reach of Shiyanghe River Basin. The results showed that under both sufficient and non-sufficient irrigation, the peak value of soil water content all appeared during irrigation period, and the variation range of the water content was higher under sufficient than under non-sufficient irrigation. Soil salinity was positively correlated with the salinity of irrigation water. At the same salinity of irrigation water, the soil salinity under non-sufficient irrigation was lower than that under sufficient irrigation. Under non-sufficient irrigation, the soil layer with salt accumulation was moved up, but the water and salt contents in 80-100 cm soil layer were less affected by the amount and salinity of irrigation water. Comparing with that under fresh water irrigation, the spring corn yield under saline water irrigation was decreased by 15%-22%. Under non-sufficient irrigation with 9 g x L(-1), 6 g x L(-1), and 3 g x L(-1) of saline water, the average salt content in 1 m soil layer after harvest was decreased by 8.1%, 12.4%, and 18.4%, and the corn yield was only decreased by 3.4%, 6.8%, and 3.0%, respectively, compared with those under sufficient irrigation.

  7. Determination of interstellar pickup ion distributions in the solar wind with SOHO and Cluster

    Directory of Open Access Journals (Sweden)

    E. Möbius

    1996-05-01

    Full Text Available Over the last 10 years, the experimental basis for the study of the local interstellar medium has been substantially enhanced by the direct detection of interstellar pickup ions and of interstellar neutral helium within the heliosphere. Pickup ions can be studied for a wide range of interstellar species. However, currently the accuracy of the method to determine the parameters of the interstellar medium, namely neutral density, temperature and relative velocity, is hampered by two problems: (1 In most cases the crucial ionization rates are not available from simultaneous measurements and (2 the transport of the pickup ions in the interplanetary medium substantially modifies the measured spatial distribution of the ions. In this study we will discuss how the enhanced capabilities of the instrumentation on SOHO and Cluster in combination with ongoing efforts to model the pickup ion distributions will lead to a significant improvement over the coming years.

  8. Determination of interstellar pickup ion distributions in the solar wind with SOHO and Cluster

    Directory of Open Access Journals (Sweden)

    E. Möbius

    Full Text Available Over the last 10 years, the experimental basis for the study of the local interstellar medium has been substantially enhanced by the direct detection of interstellar pickup ions and of interstellar neutral helium within the heliosphere. Pickup ions can be studied for a wide range of interstellar species. However, currently the accuracy of the method to determine the parameters of the interstellar medium, namely neutral density, temperature and relative velocity, is hampered by two problems: (1 In most cases the crucial ionization rates are not available from simultaneous measurements and (2 the transport of the pickup ions in the interplanetary medium substantially modifies the measured spatial distribution of the ions. In this study we will discuss how the enhanced capabilities of the instrumentation on SOHO and Cluster in combination with ongoing efforts to model the pickup ion distributions will lead to a significant improvement over the coming years.

  9. Ion distribution and gas exchange of hydroponically grown sunflower plants as affected by salinity

    Directory of Open Access Journals (Sweden)

    Anna Rita Rivelli

    Full Text Available This paper reports the results of a trial carried out on sunflower plants (Helianthus annuus L., Romsun HS90 grown in the greenhouse using inert substrate and two automatic and closed hydroponic systems: one of them hosting the control (C with plants grown under optimal conditions on Hoagland nutrient solution, the other one, the salt treatment (S, with plants exposed to constant salt stress through adding 150 mM of NaCl to the nutrient solution. Salt supply caused a sharp reduction in leaf area development and dry matter production, especially in the first 4 weeks when leaves showed to be more sensitive than stem and roots. Such a reduction is attributable to the drop in net CO2 assimilation rate, transpiration and stomatal conductance and it was, on average, equal to 30, 26 and 40%, respectively, with respect to the control. The investigated genotype was not able to exclude Cl- and Na+ and considerable amounts accumulated in leaves, stem and roots. Concentration increased in leaves in the basipetal direction. Though sunflower has an efficient endogenous adaptation system by which it redistributes ions in the whole plant, with greater accumulation in older leaves, growth inhibition could be attributed to specific ion toxicity effects, and of chlorine in particular, on metabolic processes and thus on photosynthesis.

  10. A high sensitive ion pairing probe (the interaction of pyrenetetrasulphonate and methyl viologen): Salt and temperature dependences and applications

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Jeferson [Departamento de Bioquímica e Departamento de Química, Instituto de Química, Universidade de São Paulo, SP (Brazil); Perez, Katia R. [Departamento de Biofísica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo-SP (Brazil); Pisco, Thiago B.; Pavanelli, David D.; Briotto Filho, Décio; Rezende, Daisy [Departamento de Bioquímica e Departamento de Química, Instituto de Química, Universidade de São Paulo, SP (Brazil); Rezende Triboni, Eduardo [Universidade Nove de Julho, São Paulo, São Paulo-SP (Brazil); Chagas Alves Lima, Francisco das [Coordenação de Química, Universidade Estadual do Piauí, Teresina-PI (Brazil); Lopes Magalhães, Janildo [Departamento de Química, Centro de Ciências da Natureza, Universidade Federal do Piauí, Centro de Ciências da Natureza, Teresina, PI (Brazil); Midea Cuccovia, Iolanda [Departamento de Bioquímica e Departamento de Química, Instituto de Química, Universidade de São Paulo, SP (Brazil); and others

    2014-07-01

    The interaction between pyrenetetrasulphonate (PTS) and methyl viologen (MV{sup 2+}) leads to a 1:1 charge transfer complex (CTC) in the concentration range below mmol L{sup −1} of the ligands. Quantum mechanical calculations show the 1:1 complex having the planar moiety of PTS and the charges of the sulfonate groups stabilized by the twisted rings of the positively charged MV{sup 2+} species. The peculiar nature of PTS includes high fluorescence quantum yield (∼1), clear specular UV–vis spectra and fluorescence emission images, as well similar S{sub 2}←S{sub 0} and S{sub 3}←S{sub 0} transitions as those of S{sub 1}←S{sub 0,} all of them exhibiting well resolved vibrational structure. MV{sup 2+} has well known electron-accepting properties that favor the complexation. These features were studied as a function of salt concentration and temperature dependences allowing a detailed comprehension of static and dynamic association processes. Quantum mechanical calculations show the 1:1 stabilization of PTS/MV{sup 2+}. In addition the effect of urea on the CTC equilibrium is presented, as expected the additive acts towards the non-complexed species (solvated free ions). The fluorescence quenching of MV{sup 2+}over PTS highlights is one of the applications of this effect for giant vesicles characterization. - Highlights: • We determined the details of PTS/MV{sup 2+} 1:1 complex formation. • Ground and excited states formation is operative. • Ion pairing effects due to urea effect are shown. • Vesicle formation is illustrated by the pair.

  11. Distribution of products in polymer materials induced by ion-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Masaki; Kudoh, Hisaaki; Sasuga, Tsuneo; Seguchi, Tadao [Japan Atomic Energy Research Inst., Tokyo (Japan); Hama, Yoshimasa; Hamanaka, Ken-ichi; Matsumoto, Hideya

    1997-03-01

    The depth profile of double bond formed in low density polyethylene (LDPE) sheet by ion beams irradiation was observed by a micro FT-IR spectrometer in order to investigate the linear energy transfer (LET) dependency on radiation effects to polymer materials. The distribution of double bond formation in LDPE by irradiation of light ions as H+ was found to be same with the dose distribution calculated from TRIM code, and the yield was also same with that by gamma-rays irradiation, which means that the LET dependency is very small. However, the distribution of double bond to depth was much different from the calculated depth-dose in heavy ions irradiation as Ar and Kr. Then, the dose evaluation was difficult from the TRIM code calculation for heavy ions. (author)

  12. Attainable high capacity in Li-excess Li-Ni-Ru-O rock-salt cathode for lithium ion battery

    Science.gov (United States)

    Wang, Xingbo; Huang, Weifeng; Tao, Shi; Xie, Hui; Wu, Chuanqiang; Yu, Zhen; Su, Xiaozhi; Qi, Jiaxin; Rehman, Zia ur; Song, Li; Zhang, Guobin; Chu, Wangsheng; Wei, Shiqiang

    2017-08-01

    Peroxide structure O2n- has proven to appear after electrochemical process in many lithium-excess precious metal oxides, representing extra reversible capacity. We hereby report construction of a Li-excess rock-salt oxide Li1+xNi1/2-3x/2Ru1/2+x/2O2 electrode, with cost effective and eco-friendly 3d transition metal Ni partially substituting precious 4d transition metal Ru. It can be seen that O2n- is formed in pristine Li1.23Ni0.155Ru0.615O2, and stably exists in subsequent cycles, enabling discharge capacities to 295.3 and 198 mAh g-1 at the 1st/50th cycle, respectively. Combing ex-situ X-ray absorption near edge spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, high resolution transmission electron microscopy and electrochemical characterization, we demonstrate that the excellent electrochemical performance comes from both percolation network with disordered structure and cation/anion redox couples occurring in charge-discharge process. Li-excess and substitution of common element have been demonstrated to be a breakthrough for designing novel high performance commercial cathodes in rechargeable lithium ion battery field.

  13. Progress on Bayesian Inference of the Fast Ion Distribution Function

    DEFF Research Database (Denmark)

    Stagner, L.; Heidbrink, W.W,; Chen, X.

    2013-01-01

    sensitivity of the measurements are incorporated into Bayesian likelihood probabilities. Prior probabilities describe physical constraints. This poster will show reconstructions of classically described, low-power, MHD-quiescent distribution functions from actual FIDA measurements. A description of the full...

  14. Radial dose distribution around an energetic heavy ion and an ion track structure model

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Katsutoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ohno, Shin-ichi; Namba, Hideki; Taguchi, Mitsumasa; Watanabe, Ritsuko

    1997-03-01

    Ionization currents produced in a small wall-less ionization chamber located at varying distance from the 200 MeV Ni{sup 12+} ion`path traversing Ar gas were measured and utilized to construct a track structure model. Using the LET value of 200 MeV Ni{sup 12+} and G(Fe{sup 3+}) in Fricke solutions (= 15.4) for fast electrons, we estimate G(Fe{sup 3+}) for this ion to be 5.0. (author)

  15. Clusters distributions on charges and dimensions at ion metal sputtering

    CERN Document Server

    Matveev, V I

    2001-01-01

    The theory on the metal sputtering in form of large (with the atoms number N >= 5) neutral and charged clusters under the impact of the ion bombardment is considered. The probability of the cluster emission, consisting of the N atoms, is calculated on the basis of the Einstein model. The charge state of the cluster, consisting of the N atoms, is determined. The obtained formulae agree well with the experimental results. It is noted, that the mass-spectra of the neutral clusters slightly depend on the target temperature, whereas the mass-spectra of the single charge clusters essentially depend on the target temperature

  16. Small amplitude ion acoustic solitons in a weakly magnetized plasma with anisotropic ion pressure and kappa distributed electrons

    Science.gov (United States)

    Adnan, Muhammad; Mahmood, S.; Qamar, Anisa

    2014-03-01

    The Zakharov-Kuznetzov (ZK) equation is derived for nonlinear electrostatic waves in a weakly magnetized plasma in the presence of anisotropic ion pressure and superthermal electrons. The anisotropic ion pressure is defined using Chew-Goldberger-Low (CGL) while a generalized Lorentzian (kappa) distribution is assumed for the non-thermal electrons. The standard reductive perturbation method (RPM) is employed to derive the two dimensional ZK equation for the dynamics of obliquely propagating low frequency ion acoustic wave. The influence of spectral index (kappa) of non-thermal electron on the soliton is discussed in the presence of anisotropic ion pressure in plasmas. It is found that ion pressure anisotropy and superthermality of electrons affect both the width and amplitude of the solitary waves. On the other hand the magnetic field is found to alter the dispersive property of the plasma only, and hence the width of the solitons is affected while the amplitude of the solitary waves is independent of external magnetic field. The numerical results are also presented for illustrations.

  17. Distribution and abundance of breeding birds and small mammals in the high salt marsh and the adjacent upland critical edge in southern Maine

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The primary objective of the study was to document breeding bird and small mammal distribution and abundance in the high salt marsh and the adjacent riparian zone...

  18. Controlling plasma distributions as driving forces for ion migration during fs laser writing

    CERN Document Server

    Fernandez, Toney Teddy; Hoyo, Jesus; Sotillo, Belen; Fernandez, Paloma; Solis, Javier

    2014-01-01

    The properties of structures written inside dielectrics with high repetition rate femtosecond lasers are known to depend strongly on the complex interplay of a large number of writing parameters. Recently, ion migration within the laser-excited volume has been identified as a powerful mechanism for changing the local element distribution and producing efficient optical waveguides. In this work it is shown that the transient plasma distribution induced during laser irradiation is a reliable monitor for predicting the final refractive index distribution of the waveguide caused by ion migration. By performing in-situ plasma emission microscopy during the writing process inside a La-phosphate glass it is found that the long axis of the plasma distribution determines the axis of ion migration, being responsible for the local refractive index increase. This observation is also valid when strong positive or negative spherical aberration is induced, greatly deforming the focal volume and inverting the index profile. ...

  19. Effect of soil surface salt on the density and distribution of the snail Bithynia siamensis goniomphalos in northeast Thailand

    Directory of Open Access Journals (Sweden)

    Apiporn Suwannatrai

    2011-05-01

    Full Text Available Opisthorchis viverrini infection is associated with human cholangiocarcinoma and northeast Thailand has the highest incidence of this disease in the world. Bithynia siamensis goniomphalos is the major freshwater snail intermediate host of O. viverrini in this area and an analysis based on geographical information systems was used to determine the effect of variation in soil surface salt on the density and distribution of this snail. A malacological survey was carried out in 56 water bodies in the Khorat basin, northeast Thailand at locations with various soil surface salt levels. Mollusk samples were collected from 10 ecologically representative water body sites with 10-20 sampling stations in each. The shoreline of clear, shallow water bodies was found to be the preferred B. s. goniomphalos habitat. The snails were exclusively found in water with salinity levels ranging between 0.05 and 22.11 parts per thousand (ppt, which supports the notion that B. s. goniomphalos prefers water with some saline content over pure, freshwater. The highest snail population densities were in rice fields, ponds, road-side ditches and canals within a water salinity range of 2.5-5.0 ppt. However, the presence of B. s. goniomphalos was negatively correlated with water salinity (P ≤0.05, both with regard to density and distribution. The areas with the highest density of B. s. goniomphalos were those with less than 1% soil surface salt (potential index = 0.314, while the lowest densities were found in areas exceeding 50% soil surface salt (potential index = 0.015.

  20. Ion distributions at charged aqueous surfaces: Synchrotron X-ray scattering studies

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Wei [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    Surface sensitive synchrotron X-ray scattering studies were performed to obtain the distribution of monovalent ions next to a highly charged interface at room temperature. To control surface charge density, lipids, dihexadecyl hydrogen-phosphate (DHDP) and dimysteroyl phosphatidic acid (DMPA), were spread as monolayer materials at the air/water interface, containing CsI at various concentrations. Five decades in bulk concentrations (CsI) are investigated, demonstrating that the interfacial distribution is strongly dependent on bulk concentration. We show that this is due to the strong binding constant of hydronium H3O+ to the phosphate group, leading to proton-transfer back to the phosphate group and to a reduced surface charge. Using anomalous reflectivity off and at the L3 Cs+ resonance, we provide spatial counterion (Cs+) distributions next to the negatively charged interfaces. The experimental ion distributions are in excellent agreement with a renormalized surface charge Poisson-Boltzmann theory for monovalent ions without fitting parameters or additional assumptions. Energy Scans at four fixed momentum transfers under specular reflectivity conditions near the Cs+ L3 resonance were conducted on 10-3 M CsI with DHDP monolayer materials on the surface. The energy scans exhibit a periodic dependence on photon momentum transfer. The ion distributions obtained from the analysis are in excellent agreement with those obtained from anomalous reflectivity measurements, providing further confirmation to the validity of the renormalized surface charge Poisson-Boltzmann theory for monovalent ions. Moreover, the dispersion corrections f0 and f00 for Cs+ around L3 resonance, revealing the local environment of a Cs+ ion in the solution at the interface, were extracted simultaneously with output of ion distributions.

  1. Dust charging processes with a Cairns-Tsallis distribution function with negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Abid, A. A., E-mail: abidaliabid1@hotmail.com [Applied Physics Department, Federal Urdu University of Arts, Science and Technology, Islamabad Campus, Islamabad 45320 (Pakistan); Khan, M. Z., E-mail: mzk-qau@yahoo.com [Applied Physics Department, Federal Urdu University of Arts, Science and Technology, Islamabad Campus, Islamabad 45320 (Pakistan); Plasma Technology Research Center, Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Yap, S. L. [Plasma Technology Research Center, Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Terças, H., E-mail: hugo.tercas@tecnico.ul.pt [Physics of Information Group, Instituto de Telecomunicações, Av. Rovisco Pais, Lisbon 1049-001 (Portugal); Mahmood, S. [Science Place, University of Saskatchewan, Saskatoon, Saskatchewan S7N5A2 (Canada)

    2016-01-15

    Dust grain charging processes are presented in a non-Maxwellian dusty plasma following the Cairns-Tsallis (q, α)–distribution, whose constituents are the electrons, as well as the positive/negative ions and negatively charged dust grains. For this purpose, we have solved the current balance equation for a negatively charged dust grain to achieve an equilibrium state value (viz., q{sub d} = constant) in the presence of Cairns-Tsallis (q, α)–distribution. In fact, the current balance equation becomes modified due to the Boltzmannian/streaming distributed negative ions. It is numerically found that the relevant plasma parameters, such as the spectral indexes q and α, the positive ion-to-electron temperature ratio, and the negative ion streaming speed (U{sub 0}) significantly affect the dust grain surface potential. It is also shown that in the limit q → 1 the Cairns-Tsallis reduces to the Cairns distribution; for α = 0 the Cairns-Tsallis distribution reduces to pure Tsallis distribution and the latter reduces to Maxwellian distribution for q → 1 and α = 0.

  2. Spatial distribution of upstream magnetospheric ≥50 keV ions

    Directory of Open Access Journals (Sweden)

    G. C. Anagnostopoulos

    2000-01-01

    Full Text Available We present for the first time a statistical study of \\geq50 keV ion events of a magnetospheric origin upstream from Earth's bow shock. The statistical analysis of the 50-220 keV ion events observed by the IMP-8 spacecraft shows: (1 a dawn-dusk asymmetry in ion distributions, with most events and lower intensities upstream from the quasi-parallel pre-dawn side (4 LT-6 LT of the bow shock, (2 highest ion fluxes upstream from the nose/dusk side of the bow shock under an almost radial interplanetary magnetic field (IMF configuration, and (3 a positive correlation of the ion intensities with the solar wind speed and the index of geomagnetic index Kp, with an average solar wind speed as high as 620 km s-1 and values of the index Kp > 2. The statistical results are consistent with (1 preferential leakage of ~50 keV magnetospheric ions from the dusk magnetopause, (2 nearly scatter free motion of ~50 keV ions within the magnetosheath, and (3 final escape of magnetospheric ions from the quasi-parallel dawn side of the bow shock. An additional statistical analysis of higher energy (290-500 keV upstream ion events also shows a dawn-dusk asymmetry in the occurrence frequency of these events, with the occurrence frequency ranging between ~16%-~34% in the upstream region.Key words. Interplanetary physics (energetic particles; planetary bow shocks

  3. Spatial distribution of upstream magnetospheric ≥50 keV ions

    Directory of Open Access Journals (Sweden)

    G. Kaliabetsos

    Full Text Available We present for the first time a statistical study of geq50 keV ion events of a magnetospheric origin upstream from Earth's bow shock. The statistical analysis of the 50-220 keV ion events observed by the IMP-8 spacecraft shows: (1 a dawn-dusk asymmetry in ion distributions, with most events and lower intensities upstream from the quasi-parallel pre-dawn side (4 LT-6 LT of the bow shock, (2 highest ion fluxes upstream from the nose/dusk side of the bow shock under an almost radial interplanetary magnetic field (IMF configuration, and (3 a positive correlation of the ion intensities with the solar wind speed and the index of geomagnetic index Kp, with an average solar wind speed as high as 620 km s-1 and values of the index Kp > 2. The statistical results are consistent with (1 preferential leakage of ~50 keV magnetospheric ions from the dusk magnetopause, (2 nearly scatter free motion of ~50 keV ions within the magnetosheath, and (3 final escape of magnetospheric ions from the quasi-parallel dawn side of the bow shock. An additional statistical analysis of higher energy (290-500 keV upstream ion events also shows a dawn-dusk asymmetry in the occurrence frequency of these events, with the occurrence frequency ranging between ~16%-~34% in the upstream region.Key words. Interplanetary physics (energetic particles; planetary bow shocks

  4. Ion Partitioning at the liquid/vapor interface of a multi-component alkali halidesolution: A model for aqueous sea salt aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Ghosal, Sutapa; Brown, Matthew A.; Bluhm, Hendrik; Krisch, Maria J.; Salmeron, Miquel; Jungwirth, Pavel; Hemminger, John C.

    2008-12-22

    The chemistry of Br species associated with sea salt ice and aerosols has been implicated in the episodes of ozone depletion reported at Arctic sunrise. However, Br{sup -} is only a minor component in sea salt, which has a Br{sup -}/Cl{sup -} molar ratio of {approx}0.0015. Sea salt is a complex mixture of many different species, with NaCl as the primary component. In recent years experimental and theoretical studies have reported enhancement of the large, more polarizable halide ion at the liquid/vapor interface of corresponding aqueous alkali halide solutions. The proposed enhancement is likely to influence the availability of sea salt Br{sup -} for heterogeneous reactions such as those involved in the ozone depletion episodes. We report here ambient pressure x-ray photoelectron spectroscopy studies and molecular dynamics simulations showing direct evidence of Br{sup -} enhancement at the interface of an aqueous NaCl solution doped with bromide. The experiments were carried out on samples with Br{sup -}/Cl{sup -} ratios in the range 0.1% to 10%, the latter being also the ratio for which simulations were carried out. This is the first direct measurement of interfacial enhancement of Br{sup -} in a multi-component solution with particular relevance to sea salt chemistry.

  5. Salts and nutrients present in regenerated waters induce changes in water relations, antioxidative metabolism, ion accumulation and restricted ion uptake in Myrtus communis L. plants.

    Science.gov (United States)

    Acosta-Motos, José R; Alvarez, Sara; Barba-Espín, Gregorio; Hernández, José A; Sánchez-Blanco, María J

    2014-12-01

    The use of reclaimed water (RW) constitutes a valuable strategy for the efficient management of water and nutrients in landscaping. However, RW may contain levels of toxic ions, affecting plant production or quality, a very important aspect for ornamental plants. The present paper evaluates the effect of different quality RWs on physiological and biochemical parameters and the recovery capacity in Myrtus communis L. plants. M. communis plants were submitted to 3 irrigation treatments with RW from different sources (22 weeks): RW1 (1.7 dS m(-1)), RW2 (4.0 dS m(-1)) and RW3 (8.0 dS m(-1)) and one control (C, 0.8 dS m(-1)). During a recovery period of 11 weeks, all plants were irrigated with the control water. The RW treatments did not negatively affect plant growth, while RW2 even led to an increase in biomass. After recovery,only plants irrigated with RW3 showed some negative effects on growth, which was related to a decrease in the net photosynthesis rate, higher Na accumulation and a reduction in K levels. An increase in salinity was accompanied by decreases in leaf water potential, relative water content and gas exchange parameters, and increases in Na and Cl uptake. Plants accumulated Na in roots and restricted its translocation to the aerial part. The highest salinity levels produced oxidative stress, as seen from the rise in electrolyte leakage and lipid peroxidation. The use of regenerated water together with carefully managed drainage practices, which avoid the accumulation of salt by the substrate, will provide economic and environmental benefits.

  6. Changes in mobile phase ion distribution when combining pressurized flow and electric field.

    Science.gov (United States)

    Eriksson, Björn O; Dahl, Magnus; Andersson, Magnus B O; Blomberg, Lars G

    2004-10-01

    The distribution of ions in a capillary with both pressurized flow and an electric field has been studied. We have earlier reported that the overall concentration of ions increase in a capillary with high electric field and a pressurized flow. Now we describe how the ions are distributed in the capillary both along the capillary length and in the radial direction as a result of the parabolic flow profile. We have combined current measurements with finite element techniques in order to get better understanding of the system. We have found that the concentration of the ions that because of the electric mobility moves towards the flow primarily increases at the beginning of the electric field and close to the capillary wall. In view of the results we have proposed an alterative explanation of earlier published results concerning voltage-induced variation in capacity factors. Copyright 2004 WILEY-VCH Verlag GmbH & Co.

  7. Tomography of fast-ion velocity-space distributions from synthetic CTS and FIDA measurements

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Nielsen, Stefan Kragh

    2012-01-01

    We compute tomographies of 2D fast-ion velocity distribution functions from synthetic collective Thomson scattering (CTS) and fast-ion D (FIDA) 1D measurements using a new reconstruction prescription. Contradicting conventional wisdom we demonstrate that one single 1D CTS or FIDA view suffices...... simultaneous views on the same measurement volume, the resemblance improves with the number of available views, even if the resolution in each view is varied inversely proportional to the number of views, so that the total number of measurements in all views is the same. With a realistic four-view system......, tomographies of a beam ion velocity distribution function at ASDEX Upgrade reproduce the general shape of the function and the location of the maxima at full and half injection energy of the beam ions. By applying our method to real many-view CTS or FIDA measurements, one could determine tomographies of 2D...

  8. Angular distribution of hypersatellite and satellite radiation emitted after resonant and excitation into $U^{91+}$ ions

    CERN Document Server

    Zakowicz, S; Harman, Z; Scheid, W

    2003-01-01

    In collisions of heavy few-electron projectile ions with light targets, an electron can be transferred from the target with the simultaneous excitation of a projectile electron. We study the angular distribution of de-excitation X rays following the resonant capture process. Our results are compared to experimental values of Ma et al. [Phys. Rev. A (joint to this issue)] for collisions of U91+ ions with a hydrogen gas target.

  9. Angle-resolved intensity and energy distributions of positive and negative hydrogen ions released from tungsten surface by molecular hydrogen ion impact

    Energy Technology Data Exchange (ETDEWEB)

    Kato, S., E-mail: eun1302@mail4.doshsha.ac.jp [Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Tanaka, N. [Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Sasao, M. [Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Kisaki, M.; Tsumori, K. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Nishiura, M. [University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Matsumoto, Y. [Tokushima Bunri University, Yamashiro, Tokushima 770-8514 (Japan); Kenmotsu, T.; Wada, M. [Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Yamaoka, H. [RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan)

    2015-08-15

    Hydrogen ion reflection properties have been investigated following the injection of H{sup +}, H{sub 2}{sup +} and H{sub 3}{sup +} ions onto a polycrystalline W surface. Angle- and energy-resolved intensity distributions of both scattered H{sup +} and H{sup −} ions are measured by a magnetic momentum analyzer. We have detected atomic hydrogen ions reflected from the surface, while molecular hydrogen ions are unobserved within our detection limit. The reflected hydrogen ion energy is approximately less than one-third of the incident beam energy for H{sub 3}{sup +} ion injection and less than a half of that for H{sub 2}{sup +} ion injection. Other reflection properties are very similar to those of monoatomic H{sup +} ion injection. Experimental results are compared to the classical trajectory simulations using the ACAT code based on the binary collision approximation.

  10. Effect of salting-out on distribution behavior of di(2-ethylhexyl) phthalate and its analogues between water and sediment.

    Science.gov (United States)

    Yuwatini, Erini; Hata, Noriko; Kuramitz, Hideki; Taguchi, Shigeru

    2013-01-01

    A higher enrichment of organic pollutant, di(2-ethylhexyl) phthalate (DEHP) was found in estuary of Oyabe River and Jinzu River, Japan. Based on this, the distribution of DEHP between water and bed sediment was investigated as a model of organic pollutant through both the field investigation and laboratory experiment. The laboratory experiment was performed to examine the effect of seawater, organic matter in sediment and hydrophobicity (log K ow ) of organic pollutants. The result showed that salting-out effect due to the high salinity in seawater and organic matter in sediment contributed towards the increasing of DEHP distribution between water and sediment. Furthermore, the hydrophobicity of organic pollutant also enhances the distribution between water and sediment to a higher magnitude in the presence of seawater.

  11. Self-Similar Structure and Experimental Signatures of Suprathermal Ion Distribution in Inertial Confinement Fusion Implosions.

    Science.gov (United States)

    Kagan, Grigory; Svyatskiy, D; Rinderknecht, H G; Rosenberg, M J; Zylstra, A B; Huang, C-K; McDevitt, C J

    2015-09-04

    The distribution function of suprathermal ions is found to be self-similar under conditions relevant to inertial confinement fusion hot spots. By utilizing this feature, interference between the hydrodynamic instabilities and kinetic effects is for the first time assessed quantitatively to find that the instabilities substantially aggravate the fusion reactivity reduction. The ion tail depletion is also shown to lower the experimentally inferred ion temperature, a novel kinetic effect that may explain the discrepancy between the exploding pusher experiments and rad-hydro simulations and contribute to the observation that temperature inferred from DD reaction products is lower than from DT at the National Ignition Facility.

  12. Self-similar structure and experimental signatures of suprathermal ion distribution in inertial confinement fusion implosions

    CERN Document Server

    Kagan, Grigory; Rinderknecht, H G; Rosenberg, M J; Zylstra, A B; Huang, C -K

    2015-01-01

    The distribution function of suprathermal ions is found to be self-similar under conditions relevant to inertial confinement fusion hot-spots. By utilizing this feature, interference between the hydro-instabilities and kinetic effects is for the first time assessed quantitatively to find that the instabilities substantially aggravate the fusion reactivity reduction. The ion tail depletion is also shown to lower the experimentally inferred ion temperature, a novel kinetic effect that may explain the discrepancy between the exploding pusher experiments and rad-hydro simulations and contribute to the observation that temperature inferred from DD reaction products is lower than from DT at National Ignition Facility.

  13. Calculating method for confinement time and charge distribution of ions in electron cyclotron resonance sources

    Energy Technology Data Exchange (ETDEWEB)

    Dougar-Jabon, V.D. [Escuela de Fisica, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia); Umnov, A.M. [Russian Friendship University, 117198 Moscow (Russia); Kutner, V.B. [Joint Institute for Nuclear Research, Dubna (Russia)

    1996-03-01

    It is common knowledge that the electrostatic pit in a core plasma of electron cyclotron resonance sources exerts strict control over generation of ions in high charge states. This work is aimed at finding a dependence of the lifetime of ions on their charge states in the core region and to elaborate a numerical model of ion charge dispersion not only for the core plasmas but for extracted beams as well. The calculated data are in good agreement with the experimental results on charge distributions and magnitudes for currents of beams extracted from the 14 GHz DECRIS source. {copyright} {ital 1996 American Institute of Physics.}

  14. Efficient calculation of local dose distributions for response modeling in proton and heavier ion beams

    DEFF Research Database (Denmark)

    Greilich, Steffen; Hahn, Ute; Kiderlen, Markus

    2014-01-01

    We present an algorithm for fast and accurate computation of the local dose distribution in MeV beams of protons, carbon ions or other heavy charged particles. It uses compound Poisson modeling of track interaction and successive convolutions for fast computation. It can handle arbitrary complex ...... mixed particle fields over a wide range of fluences. Since the local dose distribution is the essential part of several approaches to model detector efficiency and cellular response it has potential use in ion-beam dosimetry, radiotherapy, and radiobiology.......We present an algorithm for fast and accurate computation of the local dose distribution in MeV beams of protons, carbon ions or other heavy charged particles. It uses compound Poisson modeling of track interaction and successive convolutions for fast computation. It can handle arbitrary complex...

  15. Energy distribution of ions produced by laser ablation of silver in vacuum

    DEFF Research Database (Denmark)

    Christensen, Bo Toftmann; Schou, Jørgen; Canulescu, Stela

    2013-01-01

    the ablation process. A silver target in vacuum was irradiated with a Nd:YAG laser at a wavelength of 355nm and detailed measurements of the time-resolved angular distribution of plume ions were made. In contrast to earlier work, the beam spot was circular such that any flip-over effect of the plume is avoided....... The angular energy distribution of ions in forward direction exceeds values of 500eV, while at large angles the ion energy tail is below 100eV. The maximum for the time-of-flight distributions agrees consistently with the prediction of Anisimov's model in the low fluence range, in which hydrodynamic motion...

  16. Spatial distributions of soluble salts in surface snow of East Antarctica

    Directory of Open Access Journals (Sweden)

    Yoshinori Iizuka

    2016-07-01

    Full Text Available To better understand how sea salt reacts in surface snow of Antarctica, we collected and identified non-volatile particles in surface snow along a traverse in East Antarctica. Samples were obtained during summer 2012/2013 from coastal to inland regions within 69°S to 80°S and 39°E to 45°E, a total distance exceeding 800 km. The spatial resolution of samples is about one sample per latitude between 1500 and 3800 m altitude. Here, we obtain the atomic ratios of Na, S and Cl, and calculate the masses of sodium sulphate and sodium chloride. The results show that, even in the coast snow sample (69°S, sea salt is highly modified by acid (HNO3 or H2SO4. The fraction of sea salt that reacts with acid increases in the region from 70°S to 74°S below 3000 m a.s.l., where some NaCl remains. At the higher altitudes (above 3300 m a.s.l. in the inland region (74°S to 80°S, the reaction uses almost all of the available NaCl.

  17. Ion velocity distributions within the LLBL and their possible implication to multiple reconnections

    Directory of Open Access Journals (Sweden)

    O. L. Vaisberg

    2004-01-01

    Full Text Available We analyze two LLBL crossings made by the Interball-Tail satellite under a southward or variable magnetosheath magnetic field: one crossing on the flank of the magnetosphere, and another one closer to the subsolar point. Three different types of ion velocity distributions within the LLBL are observed: (a D-shaped distributions, (b ion velocity distributions consisting of two counter-streaming components of magnetosheath-type, and (c distributions with three components, one of which has nearly zero parallel velocity and two counter-streaming components. Only the (a type fits to the single magnetic flux tube formed by reconnection between the magnetospheric and magnetosheath magnetic fields. We argue that two counter-streaming magnetosheath-like ion components observed by Interball within the LLBL cannot be explained by the reflection of the ions from the magnetic mirror deeper within the magnetosphere. Types (b and (c ion velocity distributions would form within spiral magnetic flux tubes consisting of a mixture of alternating segments originating from the magnetosheath and from magnetospheric plasma. The shapes of ion velocity distributions and their evolution with decreasing number density in the LLBL indicate that a significant part of the LLBL is located on magnetic field lines of long spiral flux tube islands at the magnetopause, as has been proposed and found to occur in magnetopause simulations. We consider these observations as evidence for multiple reconnection Χ-lines between magnetosheath and magnetospheric flux tubes.

    Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; solar wind-magnetosphere interactions

  18. Ion velocity distributions within the LLBL and their possible implication to multiple reconnections

    Directory of Open Access Journals (Sweden)

    O. L. Vaisberg

    2004-01-01

    Full Text Available We analyze two LLBL crossings made by the Interball-Tail satellite under a southward or variable magnetosheath magnetic field: one crossing on the flank of the magnetosphere, and another one closer to the subsolar point. Three different types of ion velocity distributions within the LLBL are observed: (a D-shaped distributions, (b ion velocity distributions consisting of two counter-streaming components of magnetosheath-type, and (c distributions with three components, one of which has nearly zero parallel velocity and two counter-streaming components. Only the (a type fits to the single magnetic flux tube formed by reconnection between the magnetospheric and magnetosheath magnetic fields. We argue that two counter-streaming magnetosheath-like ion components observed by Interball within the LLBL cannot be explained by the reflection of the ions from the magnetic mirror deeper within the magnetosphere. Types (b and (c ion velocity distributions would form within spiral magnetic flux tubes consisting of a mixture of alternating segments originating from the magnetosheath and from magnetospheric plasma. The shapes of ion velocity distributions and their evolution with decreasing number density in the LLBL indicate that a significant part of the LLBL is located on magnetic field lines of long spiral flux tube islands at the magnetopause, as has been proposed and found to occur in magnetopause simulations. We consider these observations as evidence for multiple reconnection Χ-lines between magnetosheath and magnetospheric flux tubes. Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; solar wind-magnetosphere interactions

  19. Ion pairing with bile salts modulates intestinal permeability and contributes to food-drug interaction of BCS class III compound trospium chloride.

    Science.gov (United States)

    Heinen, Christian A; Reuss, Stefan; Amidon, Gordon L; Langguth, Peter

    2013-11-04

    In the current study the involvement of ion pair formation between bile salts and trospium chloride (TC), a positively charged Biopharmaceutical Classification System (BCS) class III substance, showing a decrease in bioavailability upon coadministration with food (negative food effect) was investigated. Isothermal titration calorimetry provided evidence of a reaction between TC and bile acids. An effect of ion pair formation on the apparent partition coefficient (APC) was examined using (3)H-trospium. The addition of bovine bile and bile extract porcine led to a significant increase of the APC. In vitro permeability studies of trospium were performed across Caco-2-monolayers and excised segments of rat jejunum in a modified Ussing chamber. The addition of bile acids led to an increase of trospium permeation across Caco-2-monolayers and rat excised segments by approximately a factor of 1.5. The addition of glycochenodeoxycholate (GCDC) was less effective than taurodeoxycholate (TDOC). In the presence of an olive oil emulsion, a complete extinction of the permeation increasing effects of bile salts was observed. Thus, although there are more bile acids in the intestine in the fed state compared to the fasted state, these are not able to form ion pairs with trospium in fed state, because they are involved in the emulsification of dietary fats. In conclusion, the formation of ion pairs between trospium and bile acids can partially explain its negative food effect. Our results are presumably transferable to other organic cations showing a negative food effect.

  20. Transmembrane ion distribution during recovery from freezing in the woolly bear caterpillar Pyrrharctia isabella (Lepidoptera: Arctiidae).

    Science.gov (United States)

    Boardman, Leigh; Terblanche, John S; Sinclair, Brent J

    2011-08-01

    During extracellular freezing, solutes in the haemolymph are concentrated, resulting in osmotic dehydration of the cells, which must be reversed upon thawing. Here, we used freeze tolerant Pyrrharctia isabella (Lepidoptera: Arctiidae) larvae to examine the processes of ion redistribution after thawing. To investigate the effect of the intensity of cold exposure on ion redistribution after thawing, we exposed caterpillars to -14°C, -20°C or -30°C for 35h. To investigate the effect of duration of cold exposure on ion redistribution after thawing, we exposed the caterpillars to -14°C for up to 6 weeks while sampling several time points. The concentrations of Na(+), K(+), Mg(2+) and Ca(2+) were measured after thawing in the haemolymph, fat body, muscle, midgut tissue and hindgut tissue. Being frozen for long durations (>3 weeks) or at low temperatures (-30°C) both result in 100% mortality, although different ions and tissues appear to be affected by each treatment. Both water distribution and ion content changes were detected after thawing, with the largest effects seen in the fat body and midgut tissue. Magnesium homeostasis appears to be vital for post-freeze survival in these larvae. The movement of ions during thawing lagged behind the movement of water, and ion homeostasis was not restored within the same time frame as water homeostasis. Failure to regain ion homeostasis after thawing is therefore implicated in mortality of freeze tolerant insects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Evaluation of physiological and defense characteristics and ions contents of Red and Brooms cultivars of sorghum (Sorghum biolor under salt stress stress in vitro

    Directory of Open Access Journals (Sweden)

    Roya Razavizadeh

    2016-12-01

    Full Text Available The present study was conducted to evaluate defense and physiological responses of some red and broomscultivars of Sorghum to salinity stress under in vitro culture. Seeds of Sorghum cultivars were cultured on MS (Murashig and Skoog, 1962 medium containing 0, 50, 100 and 150 mM NaCl under in vitro condition. After 2 weeks, the effect of salinity was studied on percentage of germination, growth parameters, photosynthetic capacity (total chlorophyll and carotenoids, total anthocyanin, total felavonoids, reducing sugars, proline, Na+/K+/Ca2+ ions, total soluble protein content, ascorbate peroxidase and catalase activities in roots and shoots. According to percentage of seed germination and growth parameters, Red and brooms cultivars were selected as susceptible and resistant to salinity in the study, respectively. The photosynthetic pigments (chlorophyll and carotenoids and the anthocyanin content decreased by increasing salt levels in both cultivars, while flavonoids increased in three wavelengths 270, 300 and 330 nm. The results showed proline, suger and protein contents increased in roots and shoots of two cultivars by increasing salinity. The content of Na+ ion increased in the roots of red and brooms cultivars and shoot of Red cultivar. Ratio Na/K increased in roots of two cultivars and shoots of red by increasing salinity. Ratio Na/K in the shoots of brooms cultivar didn’t change significantly under salt stress. Generally in the presence of salt, potassium decreased in roots and shoots of two cultivars. Calcium ion amount in the roots of two cultivars didn’t change significantly under salt stress while it increased in shoots of two cultivars. The CAT activity increased in roots and shoots of two cultivars but APX activity increased in brooms cultivar and decreased significantly in red cultivar.

  2. Ion and electron angular distributions in the Io torus region of the Jovian magnetosphere

    Science.gov (United States)

    Lanzerotti, L. J.; Maclennan, C. G.; Armstrong, T. P.; Krimigis, S. M.; Lepping, R. P.; Ness, N. F.

    1981-01-01

    Angular distributions are presented of ion (about 0.5-2 MeV) and electron (greater than 10 MeV) fluxes measured during the Voyager 1 spacecraft passage through the inner regions of the Jovian magnetosphere. In the regions of peak flux intensities, just outside the orbit of Io, the ion angular distributions are most sharply peaked at 90 deg local pitch angle, a configuration consistent with diffusion of the particles inward from large radial distances. Inside the orbit of Io the lower-energy ions exhibit angular distributions depleted at 90 deg local pitch angles, suggesting the possibility of charge-exchange scattering loss of these particles. In the vicinity of the Io flux tube, no significant effect is observed in the flux or pitch angle distributions of the ions. The relativistic electrons are depleted in the flux tube region and exhibit an asymmetrical pitch angle distribution, with more electrons appearing to arrive from the equatorial region (the direction of Io) than from the low-altitude mirror point.

  3. Characteristics of ion distribution functions in dipolarizing flux bundles: Event studies

    Science.gov (United States)

    Runov, A.; Angelopoulos, V.; Artemyev, A.; Birn, J.; Pritchett, P. L.; Zhou, X.-Z.

    2017-06-01

    Taking advantage of multipoint observations from a repeating configuration of the five Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes separated by 1 to 2 Earth radii (RE) along X, Y, and Z in the geocentric solar magnetospheric system (GSM), we study ion distribution functions collected by the probes during three dipolarizing flux bundle (DFB) events observed at geocentric distances 9 GSM directions and |Bx| levels, which characterize the distance from the neutral sheet. We found that the characteristics of the ion distribution functions strongly depended on the |Bx| level, whereas changes with respect to X and Y were minor. In all three events, ion distribution functions f(v) observed inside DFBs were organized by magnetic and electric fields. The probes near the magnetic equator observed perpendicular anisotropy of the phase space density in the range between thermal energy and twice the thermal energy, although the distribution in the ambient plasma sheet was isotropic. The anisotropic ion distribution in DFBs injected toward the inner magnetosphere may provide the free energy for waves and instabilities, which are important elements of particle energization.

  4. 3D ion velocity distribution function measurement in an electric thruster using laser induced fluorescence tomography.

    Science.gov (United States)

    Elias, P Q; Jarrige, J; Cucchetti, E; Cannat, F; Packan, D

    2017-09-01

    Measuring the full ion velocity distribution function (IVDF) by non-intrusive techniques can improve our understanding of the ionization processes and beam dynamics at work in electric thrusters. In this paper, a Laser-Induced Fluorescence (LIF) tomographic reconstruction technique is applied to the measurement of the IVDF in the plume of a miniature Hall effect thruster. A setup is developed to move the laser axis along two rotation axes around the measurement volume. The fluorescence spectra taken from different viewing angles are combined using a tomographic reconstruction algorithm to build the complete 3D (in phase space) time-averaged distribution function. For the first time, this technique is used in the plume of a miniature Hall effect thruster to measure the full distribution function of the xenon ions. Two examples of reconstructions are provided, in front of the thruster nose-cone and in front of the anode channel. The reconstruction reveals the features of the ion beam, in particular on the thruster axis where a toroidal distribution function is observed. These findings are consistent with the thruster shape and operation. This technique, which can be used with other LIF schemes, could be helpful in revealing the details of the ion production regions and the beam dynamics. Using a more powerful laser source, the current implementation of the technique could be improved to reduce the measurement time and also to reconstruct the temporal evolution of the distribution function.

  5. 3D ion velocity distribution function measurement in an electric thruster using laser induced fluorescence tomography

    Science.gov (United States)

    Elias, P. Q.; Jarrige, J.; Cucchetti, E.; Cannat, F.; Packan, D.

    2017-09-01

    Measuring the full ion velocity distribution function (IVDF) by non-intrusive techniques can improve our understanding of the ionization processes and beam dynamics at work in electric thrusters. In this paper, a Laser-Induced Fluorescence (LIF) tomographic reconstruction technique is applied to the measurement of the IVDF in the plume of a miniature Hall effect thruster. A setup is developed to move the laser axis along two rotation axes around the measurement volume. The fluorescence spectra taken from different viewing angles are combined using a tomographic reconstruction algorithm to build the complete 3D (in phase space) time-averaged distribution function. For the first time, this technique is used in the plume of a miniature Hall effect thruster to measure the full distribution function of the xenon ions. Two examples of reconstructions are provided, in front of the thruster nose-cone and in front of the anode channel. The reconstruction reveals the features of the ion beam, in particular on the thruster axis where a toroidal distribution function is observed. These findings are consistent with the thruster shape and operation. This technique, which can be used with other LIF schemes, could be helpful in revealing the details of the ion production regions and the beam dynamics. Using a more powerful laser source, the current implementation of the technique could be improved to reduce the measurement time and also to reconstruct the temporal evolution of the distribution function.

  6. First experimental-based characterization of oxygen ion beam depth dose distributions at the Heidelberg Ion-Beam Therapy Center

    Science.gov (United States)

    Kurz, C.; Mairani, A.; Parodi, K.

    2012-08-01

    Over the last decades, the application of proton and heavy-ion beams to external beam radiotherapy has rapidly increased. Due to the favourable lateral and depth dose profile, the superposition of narrow ion pencil beams may enable a highly conformal dose delivery to the tumour, with better sparing of the surrounding healthy tissue in comparison to conventional radiation therapy with photons. To fully exploit the promised clinical advantages of ion beams, an accurate planning of the patient treatments is required. The clinical treatment planning system (TPS) at the Heidelberg Ion-Beam Therapy Center (HIT) is based on a fast performing analytical algorithm for dose calculation, relying, among others, on laterally integrated depth dose distributions (DDDs) simulated with the FLUKA Monte Carlo (MC) code. Important input parameters of these simulations need to be derived from a comparison of the simulated DDDs with measurements. In this work, the first measurements of 16O ion DDDs at HIT are presented with a focus on the determined Bragg peak positions and the understanding of factors influencing the shape of the distributions. The measurements are compared to different simulation approaches aiming to reproduce the acquired data at best. A simplified geometrical model is first used to optimize important input parameters, not known a priori, in the simulations. This method is then compared to a more realistic, but also more time-consuming simulation approach better accounting for the experimental set-up and the measuring process. The results of this work contributed to a pre-clinical oxygen ion beam database, which is currently used by a research TPS for corresponding radio-biological cell experiments. A future extension to a clinical database used by the clinical TPS at HIT is foreseen. As a side effect, the performed investigations showed that the typical water equivalent calibration approach of experimental data acquired with water column systems leads to slight

  7. Distribution coefficient data and preliminary estimates of movement of radionuclides, Tatum salt dome, Lamar County, Mississippi. Technical letter: Dribble 31

    Energy Technology Data Exchange (ETDEWEB)

    Beetem, W.A.; Janzer, V.J.

    1963-04-10

    Estimates are made relating radionuclide movement to ground water velocity as part of the safety program for a proposed experiment to detonate nuclear devices within the Tatum salt dome. The estimates are based on distribution coefficients obtained from laboratory studies. Core samples obtained from hydrologic test well HT-3, Tatum salt dome, Lamar County, Mississippi, were equilibrated with radionuclides in solutions simulating aquifer waters found in the area. The combinations of Cenozoic sand and silty clay, and quality of water of the area were studied and summarized. The distribution coefficients obtained for different radionuclides were tested and indicate retardation factors from 1.3 to 857 for the travel time of these radionuclides when compared to the travel time of water in the aquifer system. Laboratory results indicate that migration of any radioisotope inadvertently introduced to the aquifers in the vicinity of the dome as a result of proposed nuclear test explosions would be extremely slow. Revised estimates of the rate of dissolved radioisotope movement will be made on the basis of further laboratory studies utilizing chromatographic adsorption columns of 0.5 to 4.0 feet in length.

  8. Effect of Lithium Ions on Copper Nanoparticle Size, Shape, and Distribution

    Directory of Open Access Journals (Sweden)

    Kyung-Deok Jang

    2012-01-01

    Full Text Available Copper nanoparticles were synthesized using lithium ions to increase the aqueous electrical conductivity of the solution and precisely control the size, shape, and size distribution of the particles. In this study, the conventional approach of increasing particle size by the concentration of copper ions and PGPPE in a copper chloride solution was compared to increasing the concentration of lithium chloride when the copper chloride concentration was held constant. Particle size and shape were characterized by TEM, and the size distribution of the particles at different concentrations was obtained by particle size analysis. Increasing the concentration of copper ion in the solution greatly increased the aqueous electric conductivity and the size of the particles but led to a wide size distribution ranging from 150 nm to 400 nm and rough particle morphology. The addition of lithium ions increased the size of the particles, but maintains them in a range of 250 nm. In addition the particles exhibited spherical shape as determined by TEM. The addition of lithium ions to the solution has the potential to synthesize nanoparticles with optimal characteristics for printing applications by maintaining a narrow size range and spherical shape.

  9. Equatorial distributions of energetic ion moments in Saturn's magnetosphere using Cassini/MIMI measurements

    Science.gov (United States)

    Dialynas, K.; Roussos, E.; Regoli, L.; Paranicas, C.; Krimigis, S. M.; Kane, M.; Mitchell, D. G.; Hamilton, D. C.

    2016-12-01

    We use kappa distribution fits to combined Charge Energy Mass Spectrometer (CHEMS, 3 to 236 keV/e), Low Energy Magnetosphere Measurements System (LEMMS, 0.024 220 keV for H+) proton and singly ionized energetic ion spectra to calculate the >20 keV energetic ion moments inside Saturn's magnetosphere. Using a realistic magnetic field model (Khurana et al. 2007) and data from the entire Cassini mission to date (2004-2016), we map the ion measurements to the equatorial plane and via the modeled kappa distribution spectra we produce the equatorial distributions of all ion integral moments, focusing on partial density, integral intensity, partial pressure, integral energy intensity; as well as the characteristic energy (EC=IE/In), Temperature and κ-index of these ions as a function of Local Time (00:00 to 24:00 hrs) and L-Shell (5-20). A modified version of the semi-empirical Roelof and Skinner [2000] model is then utilized to retrieve the equatorial H+ and O+ pressure, density and temperature in Saturn's magnetosphere in both local time and L-shell. We find that a) although the H+ and O+ partial pressures and densities are nearly comparable, the >20 keV protons have higher number and energy intensities at all radial distances (L>5) and local times; b) the 12

  10. Quantum tunneling recombination in a system of randomly distributed trapped electrons and positive ions.

    Science.gov (United States)

    Pagonis, Vasilis; Kulp, Christopher; Chaney, Charity-Grace; Tachiya, M

    2017-09-13

    During the past 10 years, quantum tunneling has been established as one of the dominant mechanisms for recombination in random distributions of electrons and positive ions, and in many dosimetric materials. Specifically quantum tunneling has been shown to be closely associated with two important effects in luminescence materials, namely long term afterglow luminescence and anomalous fading. Two of the common assumptions of quantum tunneling models based on random distributions of electrons and positive ions are: (a) An electron tunnels from a donor to the nearest acceptor, and (b) the concentration of electrons is much lower than that of positive ions at all times during the tunneling process. This paper presents theoretical studies for arbitrary relative concentrations of electrons and positive ions in the solid. Two new differential equations are derived which describe the loss of charge in the solid by tunneling, and they are solved analytically. The analytical solution compares well with the results of Monte Carlo simulations carried out in a random distribution of electrons and positive ions. Possible experimental implications of the model are discussed for tunneling phenomena in long term afterglow signals, and also for anomalous fading studies in feldspars and apatite samples.

  11. Iron ions distribution profile obtained by irradiating the silicon single crystal

    Science.gov (United States)

    Shemukhin, A. A.; Kozhemiako, A. V.; Balakshin, Y. V.; Chernysh, V. S.

    2017-11-01

    Iron ions with energies of 90 and 250 keV and the irradiation dose of 1016 ions/cm2 and xenon ions with energies of 100 keV and dose 7,7×1014 cm-2, 200 keV and dose 2,6 × 1014 cm-2 were implanted in the single crystal of silicon (110). The distribution profiles of implanted impurity, as well as the distribution profiles of the radiation defects in the crystal lattice, were studied by the Rutherford backscattering method in combination with channeling. The experimental results were compared with the results of simulations of binary collisions of the Monte Carlo method in the TRIM program. It is shown that the difference between the experimental data and the calculation program TRIM is more than 35% in all cases.

  12. Saline distribution during multicomponent salting in pre-cooked quail eggs

    Directory of Open Access Journals (Sweden)

    Dionísio Borsato

    2012-06-01

    Full Text Available The relationship of NaCl with problems of arterial hypertension has led to a reduction in the levels of this salt in food production. KCl has been used as a partial substitute for NaCl since it cannot be completely substituted without affecting the acceptability of the end product. In this study, the diffusion that occurs during quail egg salting in static and stirred brine was simulated. The mathematical model used was based on a generalization of the Fick's 2nd law, and the COMSOL Multiphysics software was used to simulate the diffusion in the NaCl-KCl-water system. The deviations in the simulated data and experimental data were 2.50% for NaCl and 6.98% for KCl in static brine, while in the stirred brine they were 3.48% for NaCl and 4.72% for KCl. The simulation results presented good agreement with the experimental values and validated the predictive capacity of the model.

  13. Angle-resolved energy distributions of laser ablated silver ions in vacuum

    DEFF Research Database (Denmark)

    Hansen, T.N.; Schou, Jørgen; Lunney, J.G.

    1998-01-01

    The energy distributions of ions ablated from silver in vacuum have been measured in situ for pulsed laser irradiation at 355 nm. We have determined the energy spectra for directions ranging from 5 degrees to 75 degrees with respect to the normal in the intensity range from 100 to 400 MW/cm(2...

  14. Effect of dust size distribution and dust charge fluctuation on dust ion ...

    Indian Academy of Sciences (India)

    2016-06-17

    Jun 17, 2016 ... Dusty plasma; dust-acoustic shock wave; dust size distribution; adiabatic dust charge variation; negative ions. PACS Nos 52.27.Lw; 52.35.Tc; 52.35.Mw. 1. Introduction ... processes has relation to some phenomena including. Landau damping, collisions between charged particles and neutrals and ...

  15. Effects of a chirped bias voltage on ion energy distributions in inductively coupled plasma reactors

    Science.gov (United States)

    Lanham, Steven J.; Kushner, Mark J.

    2017-08-01

    The metrics for controlling reactive fluxes to wafers for microelectronics processing are becoming more stringent as feature sizes continue to shrink. Recent strategies for controlling ion energy distributions to the wafer involve using several different frequencies and/or pulsed powers. Although effective, these strategies are often costly or present challenges in impedance matching. With the advent of matching schemes for wide band amplifiers, other strategies to customize ion energy distributions become available. In this paper, we discuss results from a computational investigation of biasing substrates using chirped frequencies in high density, electronegative inductively coupled plasmas. Depending on the frequency range and chirp duration, the resulting ion energy distributions exhibit components sampled from the entire frequency range. However, the chirping process also produces transient shifts in the self-generated dc bias due to the reapportionment of displacement and conduction with frequency to balance the current in the system. The dynamics of the dc bias can also be leveraged towards customizing ion energy distributions.

  16. Fluorescence imaging of ion distributions in an inductively coupled plasma with laser ablation sample introduction

    Energy Technology Data Exchange (ETDEWEB)

    Moses, Lance M.; Ellis, Wade C. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States); Jones, Derick D. [Giesel School of Medicine, Hanover, NH 03755 (United States); Farnsworth, Paul B. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States)

    2015-03-01

    High-resolution images of the spatial distributions of Sc II, Ca II, and Ba II ion densities in the 10 mm upstream from the sampling cone in a laser ablation-inductively coupled plasma-mass spectrometer (LA-ICP-MS) were obtained using planar laser induced fluorescence. Images were obtained for each analyte as a function of the carrier gas flow rate with laser ablation (LA) sample introduction and compared to images with solution nebulization (SN) over the same range of flow rates. Additionally, images were obtained using LA at varying fluences and with varying amounts of helium added to a constant flow of argon gas. Ion profiles in SN images followed a pattern consistent with previous work: increasing gas flow caused a downstream shift in the ion profiles. When compared to SN, LA led to ion profiles that were much narrower radially and reached a maximum near the sampling cone at higher flow rates. Increasing the fluence led to ions formed in the ICP over greater axial and radial distances. The addition of He to the carrier gas prior to the ablation cell led to an upstream shift in the position of ionization and lower overall fluorescence intensities. - Highlights: • We map distributions of analytes in the ICP using laser ablation sample introduction. • We compare images from laser ablation with those from a pneumatic nebulizer. • We document the effects of water added to the laser ablation aerosol. • We compare distributions from a metal to those from crystalline solids. • We document the effect of laser fluence on ion distributions.

  17. Mn{sup 2+} ions distribution in doped sol–gel deposited ZnO films

    Energy Technology Data Exchange (ETDEWEB)

    Stefan, Mariana, E-mail: mstefan@infim.ro [National Institute of Materials Physics, P.O. Box MG-7, 077125 Magurele (Romania); Ghica, Daniela; Nistor, Sergiu V.; Maraloiu, Adrian V. [National Institute of Materials Physics, P.O. Box MG-7, 077125 Magurele (Romania); Plugaru, Rodica [National Institute for R & D in Microtechnologies (IMT), Erou Iancu Nicolae Str. 126A, 077190 Bucharest (Romania)

    2017-02-28

    Highlights: • Several Mn{sup 2+} centers observed by EPR in sol–gel ZnO films. • Mn{sup 2+} ions localized at Zn{sup 2+} sites in ZnO grains and disordered ZnO phase. • Sixfold coordinated Mn{sup 2+} ions localized in inter-grain region. • Aggregated Mn in insular-like regions between ZnO grains in the ZnO:5%Mn film. • Aggregated Mn phase presence and distribution observed by EPR and EDX-STEM. - Abstract: The localization and distribution of the Mn{sup 2+} ions in two sol–gel deposited ZnO films doped with different manganese concentrations were investigated by electron paramagnetic resonance spectroscopy and analytical transmission electron microscopy. In the lightly doped sample the Mn{sup 2+} ions are mainly localized substitutionally at isolated tetrahedrally coordinated Zn{sup 2+} sites in both crystalline ZnO nanograins (34%) and surrounding disordered ZnO (52%). In the highly doped ZnO film, a much smaller proportion of manganese substitutes Zn{sup 2+} in the crystalline and disordered ZnO (10%). The main amount (85%) of manganese aggregates in a secondary phase as an insular-like distribution between the ZnO nanograins. The remaining Mn{sup 2+} ions (14% and 5% at low and high doping levels, respectively) are localized at isolated, six-fold coordinated sites, very likely in the disordered intergrain region. Annealing at 600 °C induced changes in the Mn{sup 2+} ions distribution, reflecting the increase of the ZnO crystallization degree, better observed in the lightly doped sample.

  18. Structural Peculiarities of Ion-Conductive Organic-Inorganic Polymer Composites Based on Aliphatic Epoxy Resin and Salt of Lithium Perchlorate

    Science.gov (United States)

    Matkovska, Liubov; Iurzhenko, Maksym; Mamunya, Yevgen; Tkachenko, Igor; Demchenko, Valeriy; Synyuk, Volodymyr; Shadrin, Andriy; Boiteux, Gisele

    2017-06-01

    The article is concerned with hybrid amorphous polymers synthesized basing on epoxy oligomer of diglycide aliphatic ester of polyethylene glycol that was cured by polyethylene polyamine and lithium perchlorate salt. Structural peculiarities of organic-inorganic polymer composites were studied by differential scanning calorimetry, wide-angle X-ray spectra, infrared spectroscopic, scanning electron microscopy, elemental analysis, and transmission and reflective optical microscopy. On the one hand, the results showed that the introduction of LiClO4 salt into epoxy polymer leads to formation of the coordinative metal-polymer complexes of donor-acceptor type between central Li+ ion and ligand. On the other hand, the appearance of amorphous microinclusions, probably of inorganic nature, was also found.

  19. Revisiting the theory of the evolution of pick-up ion distributions: magnetic or adiabatic cooling?

    Directory of Open Access Journals (Sweden)

    H. J. Fahr

    2008-01-01

    Full Text Available We study the phasespace behaviour of heliospheric pick-up ions after the time of their injection as newly created ions into the solar wind bulk flow from either charge exchange or photoionization of interplanetary neutral atoms. As interaction with the ambient MHD wave fields we allow for rapid pitch angle diffusion, but for the beginning of this paper we shall neglect the effect of quasilinear or nonlinear energy diffusion (Fermi-2 acceleration induced by counterflowing ambient waves. In the up-to-now literature connected with the convection of pick-up ions by the solar wind only adiabatic cooling of these ions is considered which in the solar wind frame takes care of filling the gap between the injection energy and energies of the thermal bulk of solar wind ions. Here we reinvestigate the basics of the theory behind this assumption of adiabatic pick-up ion reactions and correlated predictions derived from it. We then compare it with the new assumption of a pure magnetic cooling of pick-up ions simply resulting from their being convected in an interplanetary magnetic field which decreases in magnitude with increase of solar distance. We compare the results for pick-up ion distribution functions derived along both ways and can point out essential differences of observational and diagnostic relevance. Furthermore we then include stochastic acceleration processes by wave-particle interactions. As we can show, magnetic cooling in conjunction with diffusive acceleration by wave-particle interaction allows for an unbroken power law with the unique power index γ=−5 beginning from lowest velocities up to highest energy particles of about 100 KeV which just marginally can be in resonance with magnetoacoustic turbulences. Consequences for the resulting pick-up ion pressures are also analysed.

  20. Mixed-bed ion exchange chromatography employing a salt-free pH gradient for improved sensitivity and compatibility in MudPIT.

    Science.gov (United States)

    Mommen, Geert P M; Meiring, Hugo D; Heck, Albert J R; de Jong, Ad P J M

    2013-07-16

    In proteomics, comprehensive analysis of peptides mixtures necessitates multiple dimensions of separation prior to mass spectrometry analysis to reduce sample complexity and increase the dynamic range of analysis. The main goal of this work was to improve the performance of (online) multidimensional protein identification technology (MudPIT) in terms of sensitivity, compatibility and recovery. The method employs weak anion and strong cation mixed-bed ion exchange chromatography (ACE) in the first separation dimension and reversed phase chromatography (RP) in the second separation dimension (Motoyama et.al. Anal. Chem 2007, 79, 3623-34.). We demonstrated that the chromatographic behavior of peptides in ACE chromatography depends on both the WAX/SCX mixing ratio as the ionic strength of the mobile phase system. This property allowed us to replace the conventional salt gradient by a (discontinuous) salt-free, pH gradient. First dimensional separation of peptides was accomplished with mixtures of aqueous formic acid and dimethylsulfoxide with increasing concentrations. The overall performance of this mobile phase system was found comparable to ammonium acetate buffers in application to ACE chromatography, but clearly outperformed strong cation exchange for use in first dimensional peptide separation. The dramatically improved compatibility between (salt-free) ion exchange chromatography and reversed phase chromatography-mass spectrometry allowed us to downscale the dimensions of the RP analytical column down to 25 μm i.d. for an additional 2- to 3-fold improvement in performance compared to current technology. The achieved levels of sensitivity, orthogonality, and compatibility demonstrates the potential of salt-free ACE MudPIT for the ultrasensitive, multidimensional analysis of very modest amounts of sample material.

  1. Influences of hydrological regime on heavy metal and salt ion concentrations in intertidal sediment from Chongming Dongtan, Changjiang River estuary, China

    Science.gov (United States)

    Zhao, Jiale; Gao, Xiaojiang; Yang, Jin

    2017-11-01

    The tidal flat along the Changjiang (Yangtze) River estuary has long been reclaimed for the agricultural purposes, with the prevailing hydrological conditions during such pedogenic transformations being of great importance to their successful development. In this study, samples of surface sediment from Chongming Dongtan, situated at the mouth of the Changjiang River estuary, were collected and analyzed in order to understand how hydrological management can influence the concentrations of heavy metals and salt ions in pore water, and chemical fractionation of heavy metals during the reclamation process. We performed a series of experiments that simulated three different hydrological regimes: permanent flooding (R1), alternative five-day periods of wetting and drying (R2), continuous field capacity (R3). Our results exhibited good Pearson correlations coefficients between heavy metals and salt ions in the pore water for both R1 and R2. In particular, the concentrations of salt ions in the pore water decreased in all three regimes, but showed the biggest decline in R2. With this R2 experiment, the periodic concentration patterns in the pore water varied for Fe and Mn, but not for Cr, Cu, Pb and Zn. Neither the fractionation of Ni nor the residual fractions of any metals changed significantly in any regime. In R1, the reducible fractions of heavy metals (Cr, Cu, Zn and Pb) in the sediment decreased, while the acid extractable fractions increased. In R2, the acid extractable and the reducible fractions of Cr, Cu, Zn and Pb both decreased, as did the oxidizable fraction of Cu. These data suggest that an alternating hydrological regime can reduce both salinity and the availability of heavy metals in sediments.

  2. Measurement of a 2D fast-ion velocity distribution function by tomographic inversion of fast-ion D-alpha spectra

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Jacobsen, Asger Schou

    2014-01-01

    We present the first measurement of a local fast-ion 2D velocity distribution function f(v‖, v⊥). To this end, we heated a plasma in ASDEX Upgrade by neutral beam injection and measured spectra of fast-ion Dα (FIDA) light from the plasma centre in three views simultaneously. The measured spectra ...

  3. Verification of Dose Distribution in Carbon Ion Radiation Therapy for Stage I Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Irie, Daisuke; Saitoh, Jun-ichi, E-mail: junsaito@gunma-u.ac.jp; Shirai, Katsuyuki; Abe, Takanori; Kubota, Yoshiki; Sakai, Makoto; Noda, Shin-ei; Ohno, Tatsuya; Nakano, Takashi

    2016-12-01

    Purpose: To evaluate robustness of dose distribution of carbon-ion radiation therapy (C-ion RT) in non-small cell lung cancer (NSCLC) and to identify factors affecting the dose distribution by simulated dose distribution. Methods and Materials: Eighty irradiation fields for delivery of C-ion RT were analyzed in 20 patients with stage I NSCLC. Computed tomography images were obtained twice before treatment initiation. Simulated dose distribution was reconstructed on computed tomography for confirmation under the same settings as actual treatment with respiratory gating and bony structure matching. Dose-volume histogram parameters, such as %D95 (percentage of D95 relative to the prescribed dose), were calculated. Patients with any field for which the %D95 of gross tumor volume (GTV) was below 90% were classified as unacceptable for treatment, and the optimal target margin for such cases was examined. Results: Five patients with a total of 8 fields (10% of total number of fields analyzed) were classified as unacceptable according to %D95 of GTV, although most patients showed no remarkable change in the dose-volume histogram parameters. Receiver operating characteristic curve analysis showed that tumor displacement and change in water-equivalent pathlength were significant predictive factors of unacceptable cases (P<.001 and P=.002, respectively). The main cause of degradation of the dose distribution was tumor displacement in 7 of the 8 unacceptable fields. A 6-mm planning target volume margin ensured a GTV %D95 of >90%, except in 1 extremely unacceptable field. Conclusions: According to this simulation analysis of C-ion RT for stage I NSCLC, a few fields were reported as unacceptable and required resetting of body position and reconfirmation. In addition, tumor displacement and change in water-equivalent pathlength (bone shift and/or chest wall thickness) were identified as factors influencing the robustness of dose distribution. Such uncertainties should be regarded

  4. Modeling and simulation of ion energy distribution functions in technological plasmas

    CERN Document Server

    Mussenbrock, Thomas

    2011-01-01

    The highly advanced treatment of surfaces as etching and deposition is mainly enabled by the extraordinary properties of technological plasmas. The primary factors that influence these processes are the flux and the energy of various species, particularly ions, that impinge the substrate surface. These features can be theoretically described using the ion energy distribution function (IEDF). The article is intended to summarize the fundamental concepts of modeling and simulation of IEDFs from simplified models to self-consistent plasma simulations. Finally, concepts for controlling the IEDF are discussed.

  5. Measurements of the ion velocity distribution in an ultracold neutral plasma derived from a cold, dense Rydberg gas

    OpenAIRE

    S. D. Bergeson; Lyon, M.

    2016-01-01

    We report measurements of the ion velocity distribution in an ultracold neutral plasma derived from a dense, cold Rydberg gas in a MOT. The Rydberg atoms are excited using a resonant two-step excitation pathway with lasers of 4 ns duration. The plasma forms spontaneously and rapidly. The rms width of the ion velocity distribution is determined by measuring laser-induced fluorescence (LIF) of the ions. The measured excitation efficiency is compared with a Monte-Carlo wavefunction calculation, ...

  6. Ion energy distribution function in the wall layer at a negative wall potential with respect to the plasma

    Science.gov (United States)

    Sukhomlinov, Vladimir S.; Mustafaev, Alexander S.; Murillo, Oskar

    2018-01-01

    On the basis of the kinetic approach, the self-consistent problem of the gas discharge ion distribution function in the sheath near a surface at a negative potential with respect to the plasma is solved. For the first time, the solution takes into account the dependence of the ion charge exchange cross section from the atom on the ion energy, as well as the real ion distribution function in the unperturbed plasma. It is shown that the dependence of the charge exchange cross section on the ion energy significantly affects the shape of the ion distribution function. It is found that the mean energy of the ions near the wall depends on the electron mean energy in the unperturbed plasma. It was also found that, at the same electron mean energy, the form of the distribution function has practically no effect on the ion distribution function in the wall sheath. The calculations are in good agreement with the known mass spectrometric measurements of the ion distribution function. The obtained results give an opportunity to develop a self-consistent solution of the wall layer structure problem including the quasi-neutral presheath.

  7. Effects of partial defoliation on the growth, ion relations and photosynthesis of Lycium chinense Mill. under salt stress

    Directory of Open Access Journals (Sweden)

    Guo Yuan

    2015-01-01

    Full Text Available In this study, we investigated the effects of artificial defoliation on the growth and physiological response of Lycium chinense Mill. to salt stress. Our results show that partial defoliation increases the plant relative growth rate, leaf water content and dry weight-based leaf Na+ content, and reduces the fresh weight-based leaf Na+ content under salt stress. In response to defoliation, the leaf Na+/Ca2+ and Na+/Mg2+ ratios were decreased, but the K+ content remained unchanged. The contents of ROS and MDA were decreased in defoliated plants. Net The photosynthetic rate (PN, stomatal conductance (gs, electron transport rate (ETR, actual photochemical quenching (ΦPSII and photochemical quenching (qp were enhanced by defoliation. Together, these findings indicate that partial defoliation mitigates the salt-induced growth inhibition and physiological damage in L. chinense.

  8. β-NMR measurements of molecular-scale lithium-ion dynamics in poly(ethylene oxide)-lithium-salt thin films.

    Science.gov (United States)

    McKenzie, Iain; Cortie, David L; Harada, Masashi; Kiefl, Robert F; Levy, C D Philip; MacFarlane, W Andrew; McFadden, Ryan M L; Morris, Gerald D; Ogata, Shin-Ichi; Pearson, Matthew R; Sugiyama, Jun

    2017-06-28

    β-detected NMR (β-NMR) has been used to study the molecular-scale dynamics of lithium ions in thin films of poly(ethylene oxide) (PEO) containing either lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium trifluoroacetate (LiTFA) salts at monomer-to-salt ratios (EO/Li) of 8.3. The results are compared with previous β-NMR measurements on pure PEO and PEO with lithium triflate (LiOTf) at the same loading [McKenzie et al., J. Am. Chem. Soc. 136, 7833 (2014)]. Activated hopping of (8)Li(+) was observed in all of the films above ∼250 K, with the hopping parameters strongly correlated with the ionicity of the lithium salt rather than the polymer glass transition temperature. The pre-exponential factor increases exponentially with ionicity, while the activation energy for hopping increases approximately linearly, going from 6.3±0.2 kJ mol(-1) in PEO:LiTFA to 17.8±0.2 kJ mol(-1) in PEO:LiTFSI. The more rapid increase in the pre-exponential factor outweighs the effect of the larger activation energy and results in (8)Li(+) hopping being fastest in PEO followed by PEO:LiTFSI, PEO:LiOTf, and PEO:LiTFA.

  9. β-NMR measurements of molecular-scale lithium-ion dynamics in poly(ethylene oxide)-lithium-salt thin films

    Science.gov (United States)

    McKenzie, Iain; Cortie, David L.; Harada, Masashi; Kiefl, Robert F.; Levy, C. D. Philip; MacFarlane, W. Andrew; McFadden, Ryan M. L.; Morris, Gerald D.; Ogata, Shin-Ichi; Pearson, Matthew R.; Sugiyama, Jun

    2017-06-01

    β -detected NMR (β -NMR) has been used to study the molecular-scale dynamics of lithium ions in thin films of poly(ethylene oxide) (PEO) containing either lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium trifluoroacetate (LiTFA) salts at monomer-to-salt ratios (EO/Li) of 8.3. The results are compared with previous β -NMR measurements on pure PEO and PEO with lithium triflate (LiOTf) at the same loading [McKenzie et al., J. Am. Chem. Soc. 136, 7833 (2014)]. Activated hopping of 8Li+ was observed in all of the films above ˜250 K, with the hopping parameters strongly correlated with the ionicity of the lithium salt rather than the polymer glass transition temperature. The pre-exponential factor increases exponentially with ionicity, while the activation energy for hopping increases approximately linearly, going from 6.3 ±0.2 kJ mol-1 in PEO:LiTFA to 17.8 ±0.2 kJ mol-1 in PEO:LiTFSI. The more rapid increase in the pre-exponential factor outweighs the effect of the larger activation energy and results in 8Li+ hopping being fastest in PEO followed by PEO:LiTFSI, PEO:LiOTf, and PEO:LiTFA.

  10. Ion-pairing of phosphonium salts in solution: C-H⋅⋅⋅halogen and C-H⋅⋅⋅π hydrogen bonds.

    Science.gov (United States)

    Ammer, Johannes; Nolte, Christoph; Karaghiosoff, Konstantin; Thallmair, Sebastian; Mayer, Peter; de Vivie-Riedle, Regina; Mayr, Herbert

    2013-10-18

    The (1) H NMR chemical shifts of the C(α)H protons of arylmethyl triphenylphosphonium ions in CD2 Cl2 solution strongly depend on the counteranions X(-) . The values for the benzhydryl derivatives Ph2 CHPPh3 (+)  X(-) , for example, range from δH =8.25 (X(-) =Cl(-) ) over 6.23 (X(-) =BF4 (-) ) to 5.72 ppm (X(-) =BPh4 (-) ). Similar, albeit weaker, counterion-induced shifts are observed for the ortho-protons of all aryl groups. Concentration-dependent NMR studies show that the large shifts result from the deshielding of the protons by the anions, which decreases in the order Cl(-) > Br(-) ≫ BF4 (-) > SbF6 (-) . For the less bulky derivatives PhCH2 PPh3 (+)  X(-) , we also find CH⋅⋅⋅Ph interactions between C(α)H and a phenyl group of the BPh4 (-) anion, which result in upfield NMR chemical shifts of the C(α)H protons. These interactions could also be observed in crystals of (p-CF3 -C6 H4 )CH2 PPh3 (+)  BPh4 (-) . However, the dominant effects causing the counterion-induced shifts in the NMR spectra are the CH⋅⋅⋅X(-) hydrogen bonds between the phosphonium ion and anions, in particular Cl(-) or Br(-) . This observation contradicts earlier interpretations which assigned these shifts predominantly to the ring current of the BPh4 (-) anions. The concentration dependence of the (1) H NMR chemical shifts allowed us to determine the dissociation constants of the phosphonium salts in CD2 Cl2 solution. The cation-anion interactions increase with the acidity of the C(α)H protons and the basicity of the anion. The existence of CH⋅⋅⋅X(-) hydrogen bonds between the cations and anions is confirmed by quantum chemical calculations of the ion pair structures, as well as by X-ray analyses of the crystals. The IR spectra of the Cl(-) and Br(-) salts in CD2 Cl2 solution show strong red-shifts of the CH stretch bands. The CH stretch bands of the tetrafluoroborate salt PhCH2 PPh3 (+)  BF4 (-) in CD2 Cl2

  11. Silicon enhanced salt tolerance by improving the root water uptake and decreasing the ion toxicity in cucumber

    OpenAIRE

    Wang, Shiwen; Liu, Peng; Chen, Daoqian; Yin, Lina; Li, Hongbing; Deng, Xiping

    2015-01-01

    Although the effects of silicon application on enhancing plant salt tolerance have been widely investigated, the underlying mechanism has remained unclear. In this study, seedlings of cucumber, a medium silicon accumulator plant, grown in 0.83 mM silicon solution for 2 weeks were exposed to 65 mM NaCl solution for another 1 week. The dry weight and shoot/root ratio were reduced by salt stress, but silicon application significantly alleviated these decreases. The chlorophyll concentration, net...

  12. Hydronium-dominated ion transport in carbon-dioxide-saturated electrolytes at low salt concentrations in nanochannels

    DEFF Research Database (Denmark)

    Lund Jensen, Kristian; Kristensen, Jesper Toft; Crumrine, Andrew Michael

    2011-01-01

    the nanochannel conductance at low salt concentrations and identify a conductance minimum before saturation at a value independent of salt concentration in the dilute limit. Via the Poisson-Boltzmann equation, our model self-consistently couples chemical-equilibrium dissociation models of the silica wall...... and of the electrolyte bulk, parametrized by the dissociation reaction constants. Experimental data with aqueous KCl solutions in 165-nm-high silica nanochannels are described well by our model, both with and without extra hydronium from added HCl....

  13. Influence of pressure on ion energy distribution functions in EUV-induced hydrogen plasmas

    Science.gov (United States)

    van de Ven, T. H. M.; Reefman, P.; de Meijere, C. A.; Banine, V. Y.; Beckers, J.

    2016-09-01

    Next-generation lithography tools currently use Extreme Ultraviolet (EUV) radiation to create even smaller features on computer chips. The high energy photons (92 eV) induce a plasma in the low pressure background gas by photoionization. Industries have realized that these plasmas are of significant importance with respect to machine lifetime because impacting ions affect exposed surfaces. The mass resolved ion energy distribution function (IEDF) is therefore one of the main plasma parameters of interest. In this research an ion mass spectrometer is used to investigate IEDFs of ions impacting on surfaces in EUV-induced plasmas. EUV radiation is focused into a vessel with a low pressure hydrogen environment. Here, photoionization creates free electrons with energies up to 76 eV, which further ionize the background gas. The influence of the pressure on plasma composition and IEDFs has been investigated in the range 0.1-10 Pa. In general the ion fluxes towards the surface increase with pressure. However, above 5 Pa the flux of H2+ is not affected by the increase in pressure due to the balance between the creation of H2+ and the conversion of H2+ to H3+. These results will be used to benchmark plasma scaling models and verify numerical simulations.

  14. Determination of plasma ion velocity distribution via charge-exchange recombination spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fonck, R.J.; Darrow, D.S.; Jaehnig, K.P.

    1983-12-01

    Spectroscopy of line radiation from plasma impurity ions excited by charge-exchange recombination reactions with energetic neutral beam atoms is rapidly becoming recognized as a powerful technique for measuring ion temperature, bulk plasma motion, impurity transport, and more exotic phenomena such as fast alpha particle distributions. In particular, this diagnostic offers the capability of obtaining space- and time-resolved ion temperature and toroidal plasma rotation profiles with relatively simple optical systems. Cascade-corrected excitation rate coefficients for use in both fully stripped impurity density studies and ion temperature measurements have been calculated to the principal ..delta..n = 1 transitions of He+, C/sup 5 +/, and O/sup 7 +/ with neutral beam energies of 5 to 100 keV/amu. A fiber optically coupled spectrometer system has been used on PDX to measure visible He/sup +/ radiation excited by charge exchange. Central ion temperatures up to 2.4 keV and toroidal rotation speeds up to 1.5 x 10/sup 7/ cm/s were observed in diverted discharges with P/sub INJ/ less than or equal to 3.0 MW.

  15. Effect of dust size distribution on ion-acoustic solitons in dusty plasmas with different dust grains

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Dong-Ning; Yang, Yang; Yan, Qiang [Northwest Normal University, College of Physics and Electronic Engineering (China); Wang, Xiao-Yun [Lanzhou Jiao Tong University, Department of Mathematics and Physics (China); Duan, Wen-Shan, E-mail: duanws@126.com [Northwest Normal University, College of Physics and Electronic Engineering (China)

    2017-02-15

    Theoretical studies are carried out for ion acoustic solitons in multicomponent nonuniform plasma considering the dust size distribution. The Korteweg−de Vries equation for ion acoustic solitons is given by using the reductive perturbation technique. Two special dust size distributions are considered. The dependences of the width and amplitude of solitons on dust size parameters are shown. It is found that the properties of a solitary wave depend on the shape of the size distribution function of dust grains.

  16. Nonsequential multiple ionization in intense laser pulses: interpretation of ion momentum distributions within the classical 'rescattering' model

    Energy Technology Data Exchange (ETDEWEB)

    Feuerstein, B.; Moshammer, R.; Ullrich, J. [Fakultaet fuer Physik, Universitaet Freiburg, D-79104 Freiburg (Germany)

    2000-11-14

    The classical 'rescattering' model is used to give an interpretation of ion momentum distributions for multiple ionization of atoms in intense fs laser pulses. Kinematical constraints for the ion momenta derived from simple classical considerations reproduce the positions of the maxima observed in experimental momentum distributions of Ne{sup 2+} and Ne{sup 3+} ions. Based on these constraints we present a first prediction on the principle structure of differential ion momentum distributions for multiple ionization. We show that different ionization channels can be characterized by their kinematics, leading to specific ion momentum distributions. A qualitative analysis of the intensity dependence is also given. (author). Letter-to-the-editor.

  17. Clay mineralogy, grain size distribution and their correlations with trace metals in the salt marsh sediments of the Skallingen barrier spit, Danish Wadden Sea

    DEFF Research Database (Denmark)

    He, Changling; Bartholdy, Jesper; Christiansen, Christian

    2012-01-01

    To understand the behavior of trace metals in the salt marsh at Skallingen, Danish Wadden Sea, we investigated a profile from surface to 25 cm depth of the salt marsh sediment, focusing primarily on clay mineralogy and grain size distribution of the sediments and their relationship with trace...... but decreased after 1964. This increase was contributed mainly by the grains finer than 20 µm while the fraction of 40–63 µm actually decreased soon after the invasion. The relation between most of the trace metals and grain size distributions is close in general but far from linear. The drastic turning point...... with the other adsorbents and to low availability of the mobile trace metals in the system. Correlation between trace metals and clay minerals may therefore be used as an indicator in environmental assessment. Fine grain fractions of the sediment increased markedly after salt marsh invasion in about 1931...

  18. The Distribution of Salted Groundwater and the Impact to Settlement Areas in Grogol Sub District

    Directory of Open Access Journals (Sweden)

    S Suharjo

    2004-01-01

    Full Text Available This research is aimed at studying the ground water salinity and the geographicaal aspect of Grogol subdistrict area. This study, therefore, dials withs (a the ground water salinity and the factors influencing; (b the classes of land suitability for settlement in Grogol subdistrict; and (c the influences of the ground water salinity to the suitability of sattlement areas. This research put its emphasis on the geomorphological approach and uses lends units as the basis of its studt. The research area consists of four landform units and nine land units. From land unit maps, we can make the distribution maps of the ground water salinity and its influences to the suitability between settlement and the level suitability for settlement data. The ground water salinity data are obtained by measuring in the field and laboratory analysis. The result of this research shows that the distribution of the ground water salinity is located in the landform unit of the old floid and in the deposition processes. The distribution of the ground water salinity in the research area does not influence the growth pattern of settlement but influences the physical building.

  19. Lorentz Force on Sodium and Chlorine Ions in a Salt Water Solution Flow under a Transverse Magnetic Field

    Science.gov (United States)

    De Luca, R.

    2009-01-01

    It is shown that, by applying elementary concepts in electromagnetism and electrochemistry to a system consisting of salt water flowing in a thin rectangular pipe at an average velocity v[subscript A] under the influence of a transverse magnetic field B[subscript 0], an electromotive force generator can be conceived. In fact, the Lorentz force…

  20. The distribution of soluble radionuclide-relevant trace elements between salt minerals and saline solutions; Die Verteilung loeslicher Radionuklid-relevanter Spurenelemente zwischen Salzmineralen und salinaren Loesungen

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Ina

    2015-07-16

    The research platform ENTRIA (Disposal options for radioactive residues Interdisciplinary analyses and development of evaluation principles) includes the sub-project ''Final disposal in deep geological formations without any arrangements for retrieval''. This approach considers rock salt (beside clay and granite) as host rock formation for disposal of heat-producing long-live waste. Most rock salt formations contain Mg-rich brines derived from highly evolved sea water evaporation processes now included in the rock salt mass. If such brines get access to metal-canister corrosion will allow release of soluble nuclides to the brine. In this scenario, it cannot be excluded that contaminated brines leave the deep seated disposal area and move along geological or technical migration pathways towards the rock salt/cap rock contact. The temperature of the brine will drop from near 80 C to 25 or 30 C. The deceasing temperature of the brine causes precipitation of magnesian chloride and sulfate phase in equilibrium with the brine. In order to understand the salt precipitation and the retention mechanism of dissolved trace elements experiments have been set up which allow formation of sylvite, carnallite, kainite, and hydrous Mg-sulphates under controlled conditions. The retention capacity of crystallizing salt minerals based occurring in magnesian brine solutions at decreasing temperature within a salt dome is best measured as the distribution coefficient D. This concept assumes incorporation of trace elements into the lattice of salt minerals. The distribution coefficients of the trace elements, Rb, Cs, Co, Ni, Zn, Li and B between sylvite, carnallite, kainite, and MgSO{sub 4} phases have been determined at experimental temperatures of 25, 35, 55 and 83 C. The results clearly indicate the following range of distribution coefficients (D): Sylvite D > 1 Rb and Br, D < 1 Co, Ni, Zn, Li and B, Carnallite D > 1 Rb and Cs, D < 1 Co, Ni, Zn, Li and B, Kainite D

  1. Does salt stress constrain spatial distribution of dune building grasses Ammophila arenaria and Elytrichia juncea on the beach?

    Science.gov (United States)

    van Puijenbroek, Marinka E B; Teichmann, Corry; Meijdam, Noortje; Oliveras, Imma; Berendse, Frank; Limpens, Juul

    2017-09-01

    Rising sea levels threaten coastal safety by increasing the risk of flooding. Coastal dunes provide a natural form of coastal protection. Understanding drivers that constrain early development of dunes is necessary to assess whether dune development may keep pace with sea-level rise. In this study, we explored to what extent salt stress experienced by dune building plant species constrains their spatial distribution at the Dutch sandy coast. We conducted a field transplantation experiment and a glasshouse experiment with two dune building grasses Ammophila arenaria and Elytrigia juncea. In the field, we measured salinity and monitored growth of transplanted grasses in four vegetation zones: (I) nonvegetated beach, (II) E. juncea occurring, (III) both species co-occurring, and (IV) A. arenaria dominant. In the glasshouse, we subjected the two species to six soil salinity treatments, with and without salt spray. We monitored biomass, photosynthesis, leaf sodium, and nutrient concentrations over a growing season. The vegetation zones were weakly associated with summer soil salinity; zone I and II were significantly more saline than zones III and IV. Ammophila arenaria performed equally (zone II) or better (zones III, IV) than E. juncea, suggesting soil salinity did not limit species performance. Both species showed severe winter mortality. In the glasshouse, A. arenaria biomass decreased linearly with soil salinity, presumably as a result of osmotic stress. Elytrigia juncea showed a nonlinear response to soil salinity with an optimum at 0.75% soil salinity. Our findings suggest that soil salinity stress either takes place in winter, or that development of vegetated dunes is less sensitive to soil salinity than hitherto expected.

  2. Distributed agro-hydrological modeling with SWAP to improve water and salt management of the Voshmgir Irrigaton and Drainage Network in Northern Iran

    NARCIS (Netherlands)

    Noory, H.; Zee, van der S.E.A.T.M.; Liaghat, A.M.; Parsinejad, M.; Dam, van J.C.

    2011-01-01

    The agro-hydrological model SWAP was used in a distributed manner to quantify irrigation water management effects on the water and salt balances of the Voshmgir Network of North Iran during the agricultural year 2006–2007. Field experiments, satellite images and geographical data were processed into

  3. Screening for the Location of RNA using the Chloride Ion Distribution in Simulations of Virus Capsids.

    Science.gov (United States)

    Larsson, Daniel S D; van der Spoel, David

    2012-07-10

    The complete structure of the genomic material inside a virus capsid remains elusive, although a limited amount of symmetric nucleic acid can be resolved in the crystal structure of 17 icosahedral viruses. The negatively charged sugar-phosphate backbone of RNA and DNA as well as the large positive charge of the interior surface of the virus capsids suggest that electrostatic complementarity is an important factor in the packaging of the genomes in these viruses. To test how much packing information is encoded by the electrostatic and steric envelope of the capsid interior, we performed extensive all-atom molecular dynamics (MD) simulations of virus capsids with explicit water molecules and solvent ions. The model systems were two small plant viruses in which significant amounts of RNA has been observed by X-ray crystallography: satellite tobacco mosaic virus (STMV, 62% RNA visible) and satellite tobacco necrosis virus (STNV, 34% RNA visible). Simulations of half-capsids of these viruses with no RNA present revealed that the binding sites of RNA correlated well with regions populated by chloride ions, suggesting that it is possible to screen for the binding sites of nucleic acids by determining the equilibrium distribution of negative ions. By including the crystallographically resolved RNA in addition to ions, we predicted the localization of the unresolved RNA in the viruses. Both viruses showed a hot-spot for RNA binding at the 5-fold symmetry axis. The MD simulations were compared to predictions of the chloride density based on nonlinear Poisson-Boltzmann equation (PBE) calculations with mobile ions. Although the predictions are superficially similar, the PBE calculations overestimate the ion concentration close to the capsid surface and underestimate it far away, mainly because protein dynamics is not taken into account. Density maps from chloride screening can be used to aid in building atomic models of packaged virus genomes. Knowledge of the principles of

  4. Energy & mass-charge distribution peculiarities of ion emitted from penning source

    Science.gov (United States)

    Mamedov, N. V.; Kolodko, D. V.; Sorokin, I. A.; Kanshin, I. A.; Sinelnikov, D. N.

    2017-05-01

    The optimization of hydrogen Penning sources used, in particular, in plasma chemical processing of materials and DLC deposition, is still very important. Investigations of mass-charge composition of these ion source emitted beams are particular relevant for miniature linear accelerators (neutron flux generators) nowadays. The Penning ion source energy and mass-charge ion distributions are presented. The relation between the discharge current abrupt jumps with increasing plasma density in the discharge center and increasing potential whipping (up to 50% of the anode voltage) is shown. Also the energy spectra in the discharge different modes as the pressure and anode potential functions are presented. It has been revealed that the atomic hydrogen ion concentration is about 5-10%, and it weakly depends on the pressure and the discharge current (in the investigated range from 1 to 10 mTorr and from 50 to 1000 μA) and increases with the anode voltage (up 1 to 3,5 kV).

  5. Postmortem tissue distribution of MDPV following lethal intoxication by "bath salts".

    Science.gov (United States)

    Wyman, John F; Lavins, Eric S; Engelhart, David; Armstrong, Erica J; Snell, Kimberly D; Boggs, Paul D; Taylor, Shaena M; Norris, Rindi N; Miller, Frank P

    2013-04-01

    3,4-Methylenedioxypyrovalerone (MDPV) is a psychoactive, synthetic analog of the central nervous system stimulant cathinone. Its recent popularity as a recreational drug in the United States has led to numerous reports to poison control centers across the country. As with other synthetic cathinones, the recreational use of MDPV has resulted in death. MDPV is thought to exert its pharmacologic effects by inhibiting the reuptake of dopamine and norepinephrine. This report describes the case of an exposure of a 39-year-old male to MDPV, which resulted in his death. Postmortem concentrations of MDPV in various tissues were measured. The detection of MDPV in tissues and fluids was accomplished using gas chromatography-mass spectrometry analysis after solid-phase extraction. Blood analysis also demonstrated therapeutic levels of lamotrigine, fluoxetine, risperidone, benztropine, pseudoephedrine and ibuprofen. The detection of cathinones in hair was conducted using high-performance liquid chromatography-tandem mass spectrometry after solid-phase extraction. MDPV was uniformly distributed among multiple tissues (blood, brain, muscle, cerebrospinal fluid and lung) at concentrations of approximately 0.4 to 0.6 µg/mL. Tissue and fluids responsible for detoxification/excretion had higher concentrations of MDPV (kidney, liver and bile > 0.8 µg/mL). A blood concentration ≥ 0.4 µg/mL was judged sufficient to cause death. The cause of death was ruled MDPV intoxication resulting in cardiac arrhythmia.

  6. Momentum distributions of Ne{sup n+} ions created by an intense ultrashort laser pulse

    Energy Technology Data Exchange (ETDEWEB)

    Moshammer, R. [Freiburg Univ. (Germany); Feuerstein, B.; Schmitt, W. (and others)

    1999-09-01

    Vector momentum distributions of Ne{sup n+} (n=1,2,3) ions created by 30 fs, {approx}1 PW/cm{sup 2} laser pulses at 795 nm have been measured using Recoil-Ion Momentum Spectroscopy. Distinct maxima along the light polarization axis are observed at 4.0 a.u. and 7.5 a.u. for Ne{sup 2+} and Ne{sup 3+} production, respectively. Hence, mechanisms based on an instantaneous release of two (or more) electrons can be ruled out as dominant contribution to non-sequential strong-field multiple ionization. The positions of the maxima are in accord with kinematical constraints set by the classical ''rescattering model''. (orig.)

  7. Photoelectron angular distributions from photodetachment of negative ions in strong laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Bai Lihua; Liu Yuheng; Cui Tingting; Wang Yan; Zhang Huifang; Deng Dongmei [Department of Physics, Shanghai University, Shanghai 200444 (China); Ren Xianghe, E-mail: lhbai@163.com [Institute of Advance Energy, Kyoto University, Gokasho, Uji, Kyoto, 611-0011 (Japan)

    2011-02-01

    Using a nonperturbative scattering theory, the photoelectron angular distributions (PADs) of negative ions irradiated by intense laser fields are studied. Various PADs are obtained. Similar to that of atoms, PADs of negative ions show main lobes and jet-like structures. Here, the main lobe means the formation of the detached photoelectrons around the direction of laser polarization, while the jet-like structure means a peaked-out formation of photoelectrons emitted from the waist between the two main lobes. For a set of above-threshold-detachment peaks, with one-more-photon absorption, the number of the jet-like structures is not always increased by one, which verifies that the jet-like structures are irrelevant to photoelectron angular momentum.

  8. High-Resolution Secondary Ion Mass Spectrometry Reveals the Contrasting Subcellular Distribution of Arsenic and Silicon in Rice Roots

    National Research Council Canada - National Science Library

    Katie L. Moore; Markus Schröder; Zhongchang Wu; Barry G.H. Martin; Chris R. Hawes; Steve P. McGrath; Malcolm J. Hawkesford; Jian Feng Ma; Fang-Jie Zhao; Chris R.M. Grovenor

    2011-01-01

    .... In this study, the cellular and subcellular distributions of As and silicon (Si) in rice roots were investigated using high-pressure freezing, high-resolution secondary ion mass spectrometry, and transmission electron microscopy...

  9. Ion spatial distributions at the liquid-vapor interface of aqueous potassium fluoride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M A; D' Auria, R; Kuo, I W; Krisch, M J; Starr, D E; Bluhm, H; Tobias, D J; Hemminger, J C

    2008-04-23

    X-ray photoemission spectroscopy operating under ambient pressure conditions is used to probe ion distributions throughout the interfacial region of a free-flowing aqueous liquid micro-jet of 6 M potassium fluoride. Varying the energy of the ejected photoelectrons by carrying out experiments as a function of x-ray wavelength measures the composition of the aqueous-vapor interfacial region at various depths. The F{sup -} to K{sup +} atomic ratio is equal to unity throughout the interfacial region to a depth of 2 nm. The experimental ion profiles are compared with the results of a classical molecular dynamics simulation of a 6 M aqueous KF solution employing polarizable potentials. The experimental results are in qualitative agreement with the simulations when integrated over an exponentially decaying probe depth characteristic of an APPES experiment. First principles molecular dynamics simulations have been used to calculate the potential of mean force for moving a fluoride anion across the air-water interface. The results show that the fluoride anion is repelled from the interface, and this is consistent with the depletion of F{sup -} at the interface revealed by the APPES experiment and polarizable force field-based molecular dynamics simulation. Together, the APPES and MD simulation data provide a detailed description of the aqueous-vapor interface of alkali fluoride systems. This work offers the first direct observation of the ion distribution at a potassium fluoride aqueous solution interface. The current experimental results are compared to those previously obtained for saturated solutions of KBr and KI to underscore the strong difference in surface propensity between soft/large and hard/small halide ions in aqueous solution.

  10. Ion spatial distributions at the liquid-vapor interface of aqueous potassium fluoride solutions.

    Science.gov (United States)

    Brown, Matthew A; D'Auria, Raffaella; Kuo, I-F William; Krisch, Maria J; Starr, David E; Bluhm, Hendrik; Tobias, Douglas J; Hemminger, John C

    2008-08-28

    X-Ray photoemission spectroscopy operating under ambient pressure conditions is used to probe ion distributions throughout the interfacial region of a free-flowing aqueous liquid micro-jet of 6 M potassium fluoride. Varying the energy of the ejected photoelectrons by carrying out experiments as a function of X-ray wavelength measures the composition of the aqueous-vapor interfacial region at various depths. The F(-) to K(+) atomic ratio is equal to unity throughout the interfacial region to a depth of 2 nm. The experimental ion profiles are compared with the results of a classical molecular dynamics simulation of a 6 M aqueous KF solution employing polarizable potentials. The experimental results are in qualitative agreement with the simulations when integrated over an exponentially decaying probe depth characteristic of an APPES experiment. First principles molecular dynamics simulations have been used to calculate the potential of mean force for moving a fluoride anion across the air-water interface. The results show that the fluoride anion is repelled from the interface, consistent with the depletion of F(-) at the interface revealed by the APPES experiment and polarizable force field-based molecular dynamics simulation. Together, the APPES and MD simulation data provide a detailed description of the aqueous-vapor interface of alkali fluoride systems. This work offers the first direct observation of the ion distribution at an aqueous potassium fluoride solution interface. The current experimental results are compared to those previously obtained for saturated solutions of KBr and KI to underscore the strong difference in surface propensity between soft/large and hard/small halide ions in aqueous solution.

  11. Polymer Conformations in Ionic Microgels in the Presence of Salt: Theoretical and Mesoscale Simulation Results

    Directory of Open Access Journals (Sweden)

    Hideki Kobayashi

    2017-01-01

    Full Text Available We investigate the conformational properties of polymers in ionic microgels in the presence of salt ions by molecular dynamics simulations and analytical theory. A microgel particle consists of coarse-grained linear polymers, which are tetra-functionally crosslinked. Counterions and salt ions are taken into account explicitly, and charge-charge interactions are described by the Coulomb potential. By varying the charge interaction strength and salt concentration, we characterize the swelling of the polyelectrolytes and the charge distribution. In particular, we determine the amount of trapped mobile charges inside the microgel and the Debye screening length. Moreover, we analyze the polymer extension theoretically in terms of the tension blob model taking into account counterions and salt ions implicitly by the Debye–Hückel model. Our studies reveal a strong dependence of the amount of ions absorbed in the interior of the microgel on the electrostatic interaction strength, which is related to the degree of the gel swelling. This implies a dependence of the inverse Debye screening length κ on the ion concentration; we find a power-law increase of κ with the Coulomb interaction strength with the exponent 3 / 5 for a salt-free microgel and an exponent 1 / 2 for moderate salt concentrations. Additionally, the radial dependence of polymer conformations and ion distributions is addressed.

  12. Lipoic acid mitigates oxidative stress and recovers metabolic distortions in salt-stressed wheat seedlings by modulating ion homeostasis, the osmo-regulator level and antioxidant system.

    Science.gov (United States)

    Gorcek, Zeynep; Erdal, Serkan

    2015-11-01

    Soil salinity is one of the most detrimental environmental factors affecting the growth of plants and limiting their agricultural productivity. This study investigated whether exogenous lipoic acid (LA) pretreatment plays a role in promoting salt tolerance in wheat seedlings. The seedlings were treated with LA (1.75 mmol L(-1)) and salt (100 mmol L(-1) NaCl) separately and a combination of them. Salt stress significantly reduced relative water content, leaf surface area, ribulose bisphosphate carboxylase expression, and chlorophyll content but increased the content of osmo-regulator protein, carbohydrates and proline. In addition, salinity led to an imbalance in the inorganic composition of wheat leaves. While it elevated Na(+) content compared to control, Ca content and K(+)/Na(+) ratio were reduced. Under saline conditions, despite increases in antioxidant enzyme activity and levels of antioxidant compounds (ascorbate and glutathione), the content of reactive oxygen species (superoxide anion, hydrogen peroxide) and malondialdehyde were higher than in control seedlings. LA significantly promoted osmo-regulator level and antioxidant enzyme activities compared to stressed seedlings alone. Also, it both increased levels of ascorbate and glutathione and regenerated their oxidised forms, thus contributing to maintaining cellular redox status. Similarly, LA prevented excessive accumulation of Na(+) and promoted K(+)/Na(+) ratio and Ca content. Reactive oxygen species content was significantly reduced, and the inhibitions in the above parameters markedly recovered. LA reduced salinity-induced oxidative damage and thus contributed to the growth and development of plants in saline soils by modulating ion homeostasis between plant and soil as well as in osmo-regulator content and antioxidant system. © 2014 Society of Chemical Industry.

  13. Electrolyte salts for nonaqueous electrolytes

    Science.gov (United States)

    Amine, Khalil; Zhang, Zhengcheng; Chen, Zonghai

    2012-10-09

    Metal complex salts may be used in lithium ion batteries. Such metal complex salts not only perform as an electrolyte salt in a lithium ion batteries with high solubility and conductivity, but also can act as redox shuttles that provide overcharge protection of individual cells in a battery pack and/or as electrolyte additives to provide other mechanisms to provide overcharge protection to lithium ion batteries. The metal complex salts have at least one aromatic ring. The aromatic moiety may be reversibly oxidized/reduced at a potential slightly higher than the working potential of the positive electrode in the lithium ion battery. The metal complex salts may also be known as overcharge protection salts.

  14. Imprints from the solar cycle on the helium atom and helium pickup ion distributions

    Directory of Open Access Journals (Sweden)

    D. Rucinski

    2003-06-01

    Full Text Available Neutral interstellar helium atoms penetrate into the solar system almost unaffected by gas–plasma interactions in the heliospheric interface region, and thus can be considered as carriers of original information on the basic parameters (like density, temperature, bulk velocity of the Very Local Interstellar Medium (VLISM. Such information can nowadays be derived from analysis of data obtained from different experimental methods: in situ measurements of He atoms (Ulysses, observations of the solar backscattered He 584 A radiation (EUVE, in situ measurements of He + pickup ions (AMPTE, Ulysses, Wind, SOHO, ACE. In view of the current coordinated international ISSI campaign devoted to the study of the helium focusing cone structure and its evolution, we analyze expected variations of neutral He density, of He + pickup fluxes and of their phase space distributions at various phases of the solar activity cycle based on a realistic time-dependent modelling of the neutral helium and He + pickup ion distributions, which reflect solar cycle-induced variations of the photoionization rate. We show that the neutral helium density values are generally anticorrelated with the solar activity phase and in extreme cases (near the downwind axis the maximum-to-minimum density ratio may even exceed factors of ~ 3 at 1 AU. We also demonstrate that in the upwind hemisphere (at 1 AU and beyond the He + fluxes are correlated with the solar cycle activity, whereas on the downwind side the maximum of the expected flux up to distances of ~ 3 AU occurs around solar minimum epoch, and only further away does the correlation with solar activity become positive. Finally, we present the response of the phase space distribution spectra of He + pickup ions (in the solar wind frame for different epochs of the solar cycle and heliocentric distances from 1 to 5 AU covering the range of Ulysses, Wind and ACE observations.Key words. Solar physics, astrophysics and astronomy

  15. Instability of Waves in Magnetized Vortex-Like Ion Distribution Dusty Plasmas

    Science.gov (United States)

    Duan, Wen-Shan; Chen, Jian-Hong; Hong, Xue-Ren; Wan, Gui-Xin

    2007-01-01

    A modified Zakharov-Kuznetsov equation for small but finite amplitude dust acoustic waves in a magnetized votex-like ion distribution dusty plasma is obtained in this paper. It seems that there are instability for a soliton under higher-order transverse perturbations in this system. There is a certain critical value 4λ0. If the ratio of the wave length of the higher-order perturbations to the width of the soliton is larger than this critical value, the solitary wave is unstable, otherwise it is stable.

  16. Energy and charge distribution of energetic helium ions in the outer radiation belt of the earth

    Science.gov (United States)

    Klecker, B.; Hovestadt, D.; Scholer, M.; Gloeckler, G.; Ipavich, F. M.; Fan, C. Y.

    1983-01-01

    The first direct measurement of the charge states of helium at energies greater than 0.5 MeV/nucleon in the outer radiation belt, obtained aboard the ISEE-1 spacecraft in 1977, is reported. High abundances of singly ionized helium, with He(+)/He(2+) = 0.4 + or - 0.1 at L = 3.3 was found during one perigee pass, with a sudden decrease of that ratio by a factor of about 10 between L = 3.3 and 3.7. It is shown that nonstationary and/or nonadiabatic processes may play an important role for the distribution of helium ions in the outer radiation belt.

  17. MESSENGER Observations of the Spatial Distribution of Planetary Ions Near Mercury

    Science.gov (United States)

    Zurbuchen, Thomas H.; Raines, Jim M.; Slavin, James A.; Gershman, Daniel J.; Gilbert, Jason A.; Gloeckler, George; Anderson, Brian J.; Baker, Daniel N.; Korth, Haje; Krimigis, Stamatios M.; hide

    2011-01-01

    Global measurements by MESSENGER of the fluxes of heavy ions at Mercury, particularly sodium (Na(+)) and oxygen (O(+)), exhibit distinct maxima in the northern magnetic-cusp region, indicating that polar regions are important sources of Mercury's ionized exosphere, presumably through solar-wind sputtering near the poles. The observed fluxes of helium (He(+)) are more evenly distributed, indicating a more uniform source such as that expected from evaporation from a helium-saturated surface. In some regions near Mercury, especially the nightside equatorial region, the Na(+) pressure can be a substantial fraction of the proton pressure.

  18. Nuclear fragmentation energy and momentum transfer distributions in relativistic heavy-ion collisions

    Science.gov (United States)

    Khandelwal, Govind S.; Khan, Ferdous

    1989-01-01

    An optical model description of energy and momentum transfer in relativistic heavy-ion collisions, based upon composite particle multiple scattering theory, is presented. Transverse and longitudinal momentum transfers to the projectile are shown to arise from the real and absorptive part of the optical potential, respectively. Comparisons of fragment momentum distribution observables with experiments are made and trends outlined based on our knowledge of the underlying nucleon-nucleon interaction. Corrections to the above calculations are discussed. Finally, use of the model as a tool for estimating collision impact parameters is indicated.

  19. On the stability of pick-up ion ring distributions in the outer heliosheath

    Energy Technology Data Exchange (ETDEWEB)

    Summerlin, Errol J.; Viñas, Adolfo F.; Moore, Thomas E.; Christian, Eric R.; Cooper, John F., E-mail: errol.summerlin@nasa.gov, E-mail: adolfo.figueroa-vinas-1@nasa.gov, E-mail: thomas.e.moore@nasa.gov, E-mail: eric.r.christian@nasa.gov, E-mail: john.f.cooper@nasa.gov [Heliophysics Science Division, NASAs Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD (United States)

    2014-10-01

    The 'secondary energetic neutral atom (ENA)' hypothesis for the ribbon feature observed by the Interstellar Boundary Explorer (IBEX) posits that the neutral component of the solar wind continues beyond the heliopause and charge exchanges with interstellar ions in the Outer Heliosheath (OHS). This creates pick-up ions that gyrate about the draped interstellar magnetic field (ISMF) lines at pitch angles near 90° on the locus where the ISMF lies tangential to the heliopause and perpendicular to the heliocentric radial direction. This location closely coincides with the location of the ribbon feature according to the prevailing inferences of the ISMF orientation and draping. The locally gyrating ions undergo additional charge exchange and escape as free-flying neutral atoms, many of which travel back toward the inner solar system and are imaged by IBEX as a ribbon tracing out the locus described above. For this mechanism to succeed, the pick-up ions must diffuse in pitch angle slowly enough to permit secondary charge exchange before their pitch angle distribution substantially broadens away from 90°. Previous work using linear Vlasov dispersion analysis of parallel propagating waves has suggested that the ring distribution in the OHS is highly unstable, which, if true, would make the secondary ENA hypothesis incapable of rendering the observed ribbon. In this paper, we extend this earlier work to more realistic ring distribution functions. We find that, at the low densities necessary to produce the observed IBEX ribbon via the secondary ENA hypothesis, growth rates are highly sensitive to the temperature of the beam and that even very modest temperatures of the ring beam corresponding to beam widths of <1° are sufficient to damp the self-generated waves associated with the ring beam. Thus, at least from the perspective of linear Vlasov dispersion analysis of parallel propagating waves, there is no reason to expect that the ring distributions necessary to

  20. Velocity-space tomography of the fast-ion distribution function

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Salewski, Mirko; Geiger, Benedikt

    2013-01-01

    probes certain regions in velocity-space, determined by the geometry of the set-up. Exploiting this, the fast-ion distribution function can be inferred using a velocity-space tomography method. This poster contains a tomography calculated from measured spectra from three different FIDA views at ASDEX....... The number of experimentally available views can be increased by combining different types of diagnostics in a joint velocity-space tomography. Using this, up to 7 views are available at ASDEX Upgrade from 2014....

  1. The influence of salt type on the retention of bovine serum albumin in ion-exchange chromatography

    DEFF Research Database (Denmark)

    Al-Jibbouri, Sattar

    2007-01-01

    that the mechanism of protein retention in ion-exchange chromatography (IEC) involves interactions between the protein solute, the mobile phase constituents and the stationary phase. The effect of protein activity coefficient in the mobile phase on the protein retention volumes is verified....

  2. Electrostatic Solvation Energy for Two Oppositely Charged Ions in a Solvated Protein System: Salt Bridges Can Stabilize Proteins

    Science.gov (United States)

    Gong, Haipeng; Freed, Karl F.

    2010-01-01

    Abstract Born-type electrostatic continuum methods have been an indispensable ingredient in a variety of implicit-solvent methods that reduce computational effort by orders of magnitude compared to explicit-solvent MD simulations and thus enable treatment using larger systems and/or longer times. An analysis of the limitations and failures of the Born approaches serves as a guide for fundamental improvements without diminishing the importance of prior works. One of the major limitations of the Born theory is the lack of a liquidlike description of the response of solvent dipoles to the electrostatic field of the solute and the changes therein, a feature contained in the continuum Langevin-Debye (LD) model applied here to investigate how Coulombic interactions depend on the location of charges relative to the protein/water boundary. This physically more realistic LD model is applied to study the stability of salt bridges. When compared head to head using the same (independently measurable) physical parameters (radii, dielectric constants, etc.), the LD model is in good agreement with observations, whereas the Born model is grossly in error. Our calculations also suggest that a salt bridge on the protein's surface can be stabilizing when the charge separation is ≤4 Å. PMID:20141761

  3. [Spatiotemporal distribution of negative air ion concentration in urban area and related affecting factors: a review].

    Science.gov (United States)

    Huang, Xiang-Hua; Wang, Jian; Zeng, Hong-Da; Chen, Guang-Shui; Zhong, Xian-Fang

    2013-06-01

    Negative air ion (NAI) concentration is an important indicator comprehensively reflecting air quality, and has significance to human beings living environment. This paper summarized the spatiotemporal distribution features of urban NAI concentration, and discussed the causes of these features based on the characteristics of the environmental factors in urban area and their effects on the physical and chemical processes of NAI. The temporal distribution of NAI concentration is mainly controlled by the periodic variation of solar radiation, while the spatial distribution of NAI concentration along the urban-rural gradient is mainly affected by the urban aerosol distribution, underlying surface characters, and urban heat island effect. The high NAI concentration in urban green area is related to the vegetation life activities and soil radiation, while the higher NAI concentration near the water environment is attributed to the water molecules that participate in the generation of NAI through a variety of ways. The other environmental factors can also affect the generation, life span, component, translocation, and distribution of NAI to some extent. To increase the urban green space and atmospheric humidity and to maintain the soil natural attributes of underlying surface could be the effective ways to increase the urban NAI concentration and improve the urban air quality.

  4. Measurement of nucleosomal structural stability distribution along individual giant native chromatin fibers at different salt concentrations using a microfluidic channel with microstructures.

    Science.gov (United States)

    Mori, Hiroki; Okeyo, Kennedy O; Washizu, Masao; Oana, Hidehiro

    2017-10-12

    Identifying the distribution of the higher-order structure of chromatin-a complex of DNA and proteins-along genomic DNA can clarify the mechanisms underlying cell development and differentiation, including gene regulation. However, genome-wide analysis of this distribution at the single-cell level remains an outstanding challenge. Here, we report a new method for investigating changes in and the distribution of higher-order structures along native chromatin fibers-ranging over 100 μm in length-relative to changes in salt concentration. To this end, we developed a microfluidic platform that enabled us to isolate chromatin fibers from single cells and tether them to microstructures in a microfluidic channel without fragmentation. The fibers were then exposed to varying concentrations of salt solution under microscopic observation. As a result, the fibers were non-uniformly elongated by up to 2-3 times along the fiber axis as salt concentration was increased from 0 to 3 M, suggesting that chromosome structural stability is non-uniformly distributed along chromatin fibers in their native form. Thus, our system enables direct microscopic analysis of individual chromatin fibers from single cells, which can provide insights into epigenetic mechanisms of cell development, cell differentiation, and carcinogenesis. This article is protected by copyright. All rights reserved.

  5. Nanoscale optical imaging of lithium-ion distribution on a LiCoO2 cathode surface

    Science.gov (United States)

    Hara, Kosuke; Yano, Taka-aki; Hata, Junichi; Hikima, Kazuhiro; Suzuki, Kota; Hirayama, Masaaki; Kanno, Ryoji; Hara, Masahiko

    2017-05-01

    Nanoscale analysis of the local lithium-ion concentration in lithium-ion battery cathode materials is essential for achieving high-performance batteries. We developed a near-field optical technique to visualize the lithium-ion distribution in a lithium-ion battery cathode on a nanometer scale. A plasmonic metallic tip was employed to locally enhance and probe the electric field in close proximity to the LiCoO2 thin film, since it is correlated with the lithium-ion concentration at the surface. We also utilized this technique to map the electrochemically induced ion diffusion at the grain boundaries under the application of a DC voltage to the surface through the plasmonic metallic tip.

  6. Salt deposition at particle contact points

    Science.gov (United States)

    Nie, Xiaodong; Evitts, Richard W.; Besant, Robert W.; Kennell, Glyn F.

    2015-09-01

    Caking may occur when granular potash fertilizer with a moisture content greater than 0.25 % (w/w) undergoes drying. Since cake strength is proportional to the mass of crystal deposited per unit volume near contact points (and other factors) the modelling of mass deposition near contact points is important. The Young-Laplace equation for the air-salt-solution interface is used to determine the geometry of a 2-D planar saline film between two cubic potash particles. A 2-D theoretical model is developed and applied for ion diffusion and deposition near the contact point during drying. The numerical predictions of ion diffusion in an initially saturated salt illustrate the transient spatial distribution of new KCl deposits along the solid surfaces near the contact line. These results indicate the average salt deposition commences at the air-liquid-solid intersection, where the liquid film is thinnest, and moves toward the particle contact point with increasing area averaged KCl deposits, causing the formation of crystal deposits and bridges near contact points. It is concluded that the average salt deposit height increases inversely with distance from the contact point and decreases with initial contact angle of the contact region, but the deposition is nearly independent of the evaporation or drying rate near each contact region. Caking strength depends on, among other parameters, the amount of salt deposition near contact points.

  7. Atomic ionization of hydrogen-like ions by twisted photons: angular distribution of emitted electrons

    Science.gov (United States)

    Matula, O.; Hayrapetyan, A. G.; Serbo, V. G.; Surzhykov, A.; Fritzsche, S.

    2013-10-01

    We investigate the angular distribution of electrons that are emitted in the ionization of hydrogen-like ions by twisted photons. Analysis is performed based on the first-order perturbation theory and the non-relativistic Schrödinger equation. Special attention is paid to the dependence of the electron emission pattern on the impact parameter b of the ion with respect to the centre of the twisted wave front. In order to explore such a dependence, detailed calculations were carried out for the photoionization of the 1s ground and 2 py excited states of neutral hydrogen atoms. Based on these calculations, we argue that for relatively small impact parameters, the electron angular distributions may be strongly affected by altering the position of the atom within the wave front. In contrast, if the atom is placed far from the front centre, the emission pattern of the electrons is independent of the impact parameter b and resembles that observed in the photoionization by plane wave photons.

  8. Ion charge state distributions of vacuum arc plasmas: The origin of species

    Energy Technology Data Exchange (ETDEWEB)

    Anders, A. [Ernest O. Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)

    1997-01-01

    Vacuum arc plasmas are produced at micrometer-size, nonstationary cathode spots. Ion charge state distributions (CSD{close_quote}s) are experimentally known for 50 elements, but the theoretical understanding is unsatisfactory. In this paper, CSD{close_quote}s of vacuum arc plasmas are calculated under the assumption that the spot plasma experiences an instantaneous transition from equilibrium to nonequilibrium while expanding. Observable charge state distributions are the result of a freezing process at this transition. {open_quotes}Frozen{close_quotes} CSD{close_quote}s have been calculated using Saha equations in the Debye-H{umlt u}ckel approximation of the nonideal plasma for all metals of the Periodic Table and for boron, carbon, silicon, and germanium. The results are presented in a {open_quotes}periodic table of CSD.{close_quotes} The table contains also the mean ion charge state, the neutral vapor fraction, and the effective plasma temperature and density at the freezing point for each element. The validity of the concepts of {open_quotes}instantaneous freezing{close_quotes} and {open_quotes}effective temperature and density{close_quotes} is discussed for low and high currents and for the presence of a magnetic field. Temperature fluctuations have been identified to cause broadening of CSD{close_quote}s. {copyright} {ital 1997} {ital The American Physical Society}

  9. Ion charge state distributions of vacuum arc plasmas: The origin of species

    Science.gov (United States)

    Anders, André

    1997-01-01

    Vacuum arc plasmas are produced at micrometer-size, nonstationary cathode spots. Ion charge state distributions (CSD's) are experimentally known for 50 elements, but the theoretical understanding is unsatisfactory. In this paper, CSD's of vacuum arc plasmas are calculated under the assumption that the spot plasma experiences an instantaneous transition from equilibrium to nonequilibrium while expanding. Observable charge state distributions are the result of a freezing process at this transition. ``Frozen'' CSD's have been calculated using Saha equations in the Debye-Hüautckel approximation of the nonideal plasma for all metals of the Periodic Table and for boron, carbon, silicon, and germanium. The results are presented in a ``periodic table of CSD.'' The table contains also the mean ion charge state, the neutral vapor fraction, and the effective plasma temperature and density at the freezing point for each element. The validity of the concepts of ``instantaneous freezing'' and ``effective temperature and density'' is discussed for low and high currents and for the presence of a magnetic field. Temperature fluctuations have been identified to cause broadening of CSD's.

  10. Ion shell distributions as free energy source for plasma waves on auroral field lines mapping to plasma sheet boundary layer

    Directory of Open Access Journals (Sweden)

    A. Olsson

    2004-06-01

    Full Text Available Ion shell distributions are hollow spherical shells in velocity space that can be formed by many processes and occur in several regions of geospace. They are interesting because they have free energy that can, in principle, be transmitted to ions and electrons. Recently, a technique has been developed to estimate the original free energy available in shell distributions from in-situ data, where some of the energy has already been lost (or consumed. We report a systematic survey of three years of data from the Polar satellite. We present an estimate of the free energy available from ion shell distributions on auroral field lines sampled by the Polar satellite below 6 RE geocentric radius. At these altitudes the type of ion shells that we are especially interested in is most common on auroral field lines close to the polar cap (i.e. field lines mapping to the plasma sheet boundary layer, PSBL. Our analysis shows that ion shell distributions that have lost some of their free energy are commonly found not only in the PSBL, but also on auroral field lines mapping to the boundary plasma sheet (BPS, especially in the evening sector auroral field lines. We suggest that the PSBL ion shell distributions are formed during the so-called Velocity Dispersed Ion Signatures (VDIS events. Furthermore, we find that the partly consumed shells often occur in association with enhanced wave activity and middle-energy electron anisotropies. The maximum downward ion energy flux associated with a shell distribution is often 10mWm-2 and sometimes exceeds 40mWm-2 when mapped to the ionosphere and thus may be enough to power many auroral processes. Earlier simulation studies have shown that ion shell distributions can excite ion Bernstein waves which, in turn, energise electrons in the parallel direction. It is possible that ion shell distributions are the link between the X-line and the auroral wave activity and electron

  11. Liquid-liquid extraction of ion-association complexes of cobalt(II-4-(2-pyridylazoresorcinol with ditetrazolium salts

    Directory of Open Access Journals (Sweden)

    Divarova Vidka V.

    2015-01-01

    Full Text Available The formation and liquid-liquid extraction of ion-association complexes between Co(II-4-(2-Pyridylazoresorcinol (PAR anionic chelates and cations of three ditetrazolium chlorides were studied: Blue Tetrazolium chloride (BTC, Neotetrazolium chloride (NTC and Nitro Blue Tetrazolium chloride (NBT. The optimum conditions for the formation and solvent extraction of the ion-association comlpex chelates were determined. It has been found that in the systems of Co(II-PAR-DTS, the reactants are reacted in molar ratios 1:2:1 and the general formula of complexes was suggested. The extraction equilibria were investigated and quantitatively characterized by the equilibrium constants and the recovery factors. The analytical characteristics of the complexes were calculated.

  12. Effects of solvents and salt on the thermal stability of lithiated graphite used in lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qingsong, E-mail: pinew@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, No. 96, Jinzhai Road, Hefei, Anhui 230026 (China); Sun Jinhua [State Key Laboratory of Fire Science, University of Science and Technology of China, No. 96, Jinzhai Road, Hefei, Anhui 230026 (China); Chen Chunhua [Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2009-08-15

    The thermal stability of lithiated graphite in the presence of solvents, electrolytes and LiPF{sub 6} salt was studied using C80 micro-calorimeter. The presence of cyclic carbonates or linear carbonates increases the activity of Li{sub x}C{sub 6}-solvent coexisting system, especially for the Li{sub x}C{sub 6}-linear carbonates one. LiPF{sub 6} was detected that it increases the activity greatly of its coexisting system with lithiated graphite. The coexisting system of Li{sub x}C{sub 6} with the electrolyte of LiPF{sub 6}/ethylene carbonate + diethyl carbonate shows less thermal stability, which is attributed to the activity between diethyl carbonate and Li{sub x}C{sub 6}. This also agrees with the experiment result of Li{sub x}C{sub 6}-diethyl carbonate coexisting system.

  13. Ion velocity distributions in dipolarization events: Beams in the vicinity of the plasma sheet boundary

    Science.gov (United States)

    Birn, J.; Chandler, M.; Moore, T.; Runov, A.

    2017-08-01

    Using combined MHD/test particle simulations, we further explore characteristic ion velocity distributions in relation to magnetotail reconnection and dipolarization events, focusing on distributions at and near the plasma sheet boundary layer (PSBL). Simulated distributions right at the boundary are characterized by a single earthward beam, as discussed earlier. However, farther inside, the distributions consist of multiple beams parallel and antiparallel to the magnetic field, remarkably similar to recent Magnetospheric Multiscale observations. The simulations provide insight into the mechanisms: the lowest earthward beam results from direct acceleration at an earthward propagating dipolarization front (DF), with a return beam at somewhat higher energy. A higher-energy earthward beam results from dual acceleration, first near the reconnection site and then at the DF, again with a corresponding return beam resulting from mirroring closer to Earth. Multiple acceleration at the X line or the propagating DF with intermediate bounces may produce even higher-energy beams. Particles contributing to the lower energy beams are found to originate from the PSBL with thermal source energies, increasing with increasing beam energy. In contrast, the highest-energy beams consist mostly of particles that have entered the acceleration region via cross-tail drift with source energies in the suprathermal range.

  14. Regulation of cation transporter genes by the arbuscular mycorrhizal symbiosis in rice plants subjected to salinity suggests improved salt tolerance due to reduced Na(+) root-to-shoot distribution.

    Science.gov (United States)

    Porcel, Rosa; Aroca, Ricardo; Azcon, Rosario; Ruiz-Lozano, Juan Manuel

    2016-10-01

    Rice is a salt-sensitive crop whose productivity is strongly reduced by salinity around the world. Plants growing in saline soils are subjected to the toxicity of specific ions such as sodium, which damage cell organelles and disrupt metabolism. Plants have evolved biochemical and molecular mechanisms to cope with the negative effects of salinity. These include the regulation of genes with a role in the uptake, transport or compartmentation of Na(+) and/or K(+). Studies have shown that the arbuscular mycorrhizal (AM) symbiosis alleviates salt stress in several host plant species. However, despite the abundant literature showing mitigation of ionic imbalance by the AM symbiosis, the molecular mechanisms involved are barely explored. The objective of this study was to elucidate the effects of the AM symbiosis on the expression of several well-known rice transporters involved in Na(+)/K(+) homeostasis and measure Na(+) and K(+) contents and their ratios in different plant tissues. Results showed that OsNHX3, OsSOS1, OsHKT2;1 and OsHKT1;5 genes were considerably upregulated in AM plants under saline conditions as compared to non-AM plants. Results suggest that the AM symbiosis favours Na(+) extrusion from the cytoplasm, its sequestration into the vacuole, the unloading of Na(+) from the xylem and its recirculation from photosynthetic organs to roots. As a result, there is a decrease of Na(+) root-to-shoot distribution and an increase of Na(+) accumulation in rice roots which seems to enhance the plant tolerance to salinity and allows AM rice plants to maintain their growing processes under salt conditions.

  15. Size distributions of nano/micron dicarboxylic acids and inorganic ions in suburban PM episode and non-episodic aerosol

    Science.gov (United States)

    Hsieh, Li-Ying; Kuo, Su-Ching; Chen, Chien-Lung; Tsai, Ying I.

    The distribution of nano/micron dicarboxylic acids and inorganic ions in size-segregated suburban aerosol of southern Taiwan was studied for a PM episode and a non-episodic pollution period, revealing for the first time the distribution of these nanoscale particles in suburban aerosols. Inorganic species, especially nitrate, were present in higher concentrations during the PM episode. A combination of gas-to-nuclei conversion of nitrate particles and accumulation of secondary photochemical products originating from traffic-related emissions was likely a crucial cause of the PM episode. Sulfate, ammonium, and oxalic acid were the dominant anion, cation, and dicarboxylic acid, respectively, accounting for a minimum of 49% of the total anion, cation or dicarboxylic acid mass. Peak concentrations of these species occurred at 0.54 μm in the droplet mode during both non-episodic and PM episode periods, indicating an association with cloud-processed particles. On average, sulfate concentration was 16-17 times that of oxalic acid. Oxalic acid was nevertheless the most abundant dicarboxylic acid during both periods, followed by succinic, malonic, maleic, malic and tartaric acid. The mass median aerodynamic diameter (MMAD) of oxalic acid was 0.77 μm with a bi-modal presence at 0.54 μm and 18 nm during non-episodic pollution and an MMAD of 0.67 μm with mono-modal presence at 0.54 μm in PM episode aerosol. The concomitant formation of malonic acid and oxalic acid was attributed to in-cloud processes. During the PM episode in the 5-100 nm nanoscale range, an oxalic acid/sulfate mass ratio of 40.2-82.3% suggested a stronger formation potential for oxalic acid than for sulfate in the nuclei mode. For total cations (TC), total inorganic anions (TIA) and total dicarboxylic acids (TDA), major contributing particles were in the droplet mode, with least in the nuclei mode. The ratio of TDA to TIA in the nuclei mode increased greatly from 8.40% during the non-episodic pollution

  16. 2-dimensional ion velocity distributions measured by laser-induced fluorescence above a radio-frequency biased silicon wafer

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Nathaniel B.; Gekelman, Walter; Pribyl, Patrick [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); Zhang, Yiting; Kushner, Mark J. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States)

    2013-08-15

    The dynamics of ions traversing sheaths in low temperature plasmas are important to the formation of the ion energy distribution incident onto surfaces during microelectronics fabrication. Ion dynamics have been measured using laser-induced fluorescence (LIF) in the sheath above a 30 cm diameter, 2.2 MHz-biased silicon wafer in a commercial inductively coupled plasma processing reactor. The velocity distribution of argon ions was measured at thousands of positions above and radially along the surface of the wafer by utilizing a planar laser sheet from a pulsed, tunable dye laser. Velocities were measured both parallel and perpendicular to the wafer over an energy range of 0.4–600 eV. The resulting fluorescence was recorded using a fast CCD camera, which provided resolution of 0.4 mm in space and 30 ns in time. Data were taken at eight different phases during the 2.2 MHz cycle. The ion velocity distributions (IVDs) in the sheath were found to be spatially non-uniform near the edge of the wafer and phase-dependent as a function of height. Several cm above the wafer the IVD is Maxwellian and independent of phase. Experimental results were compared with simulations. The experimental time-averaged ion energy distribution function as a function of height compare favorably with results from the computer model.

  17. Preliminary calculation of RBE-weighted dose distribution for cerebral radionecrosis in carbon-ion treatment planning.

    Science.gov (United States)

    Kase, Yuki; Himukai, Takeshi; Nagano, Ai; Tameshige, Yuji; Minohara, Shinichi; Matsufuji, Naruhiro; Mizoe, Junetsu; Fossati, Piero; Hasegawa, Azusa; Kanai, Tatsuaki

    2011-01-01

    Cerebral radionecrosis is a significant side effect in radiotherapy for brain cancer. The purpose of this study is to calculate the relative biological effectiveness (RBE) of carbon-ion beams on brain cells and to show RBE-weighted dose distributions for cerebral radionecrosis speculation in a carbon-ion treatment planning system. The RBE value of the radionecrosis for the carbon-ion beam is calculated by the modified microdosimetric kinetic model on the assumption of a typical clinical α/β ratio of 2 Gy for cerebral radionecrosis in X-rays. This calculation method for the RBE-weighted dose is built into the treatment planning system for the carbon-ion radiotherapy. The RBE-weighted dose distributions are calculated on computed tomography (CT) images of four patients who had been treated by carbon-ion radiotherapy for astrocytoma (WHO grade 2) and who suffered from necrosis around the target areas. The necrotic areas were detected by brain scans via magnetic resonance imaging (MRI) after the treatment irradiation. The detected necrotic areas are easily found near high RBE-weighted dose regions. The visual comparison between the RBE-weighted dose distribution and the necrosis region indicates that the RBE-weighted dose distribution will be helpful information for the prediction of radionecrosis areas after carbon-ion radiotherapy.

  18. Extended Tonks-Langmuir-type model with non-Boltzmann-distributed electrons and cold ion sources

    Science.gov (United States)

    Kamran, M.; Kuhn, S.; Tskhakaya, D. D.; Khan, M.; Khan

    2013-04-01

    A general formalism for calculating the potential distribution Φ(z) in the quasineutral region of a new class of plane Tonks-Langmuir (TL)-type bounded-plasma-system (BPS) models differing from the well-known `classical' TL model (Tonks, L. and Langmuir, I. 1929 A general theory of the plasma of an arc. Phys. Rev. 34, 876) by allowing for arbitrary (but still cold) ion sources and arbitrary electron distributions is developed. With individual particles usually undergoing microscopic collision/sink/source (CSS) events, extensive use is made here of the basic kinetic-theory concept of `CSS-free trajectories' (i.e., the characteristics of the kinetic equation). Two types of electron populations, occupying the `type-t' and `type-p' domains of electron phase space, are distinguished. By definition, the type-t and type-p domains are made up of phase points lying on type-t (`trapped') CSS-free trajectories (not intersecting the walls and closing on themselves) and type-p (`passing') ones (starting at one of the walls and ending at the other). This work being the first step, it is assumed that ɛ ≡ λ D /l -> 0+ (where λ D and l are a typical Debye length and a typical ionization length respectively) so that the system exhibits a finite quasineutral `plasma' region and two infinitesimally thin `sheath' regions associated with the `sheath-edge singularities' | dΦ/dz| z->+/-zs -> ∞. The potential in the plasma region is required to satisfy a plasma equation (quasineutrality condition) of the form n i {Φ} = n e (Φ), where the electron density n e (Φ) is given and the ion density n i {Φ} is expressed in terms of trajectory integrals of the ion kinetic equation, with the ions produced by electron-impact ionization of cold neutrals. While previous TL-type models were characterized by electrons diffusing under the influence of frequent collisions with the neutral background particles and approximated by Maxwellian (Riemann, K.-U. 2006 Plasma-sheath transition in the

  19. Estimation of Total Fusion Reactivity and Contribution from Suprathermal Tail using 3-parameter Dagum Ion Speed Distribution

    CERN Document Server

    Majumdar, Rudrodip

    2016-01-01

    Thermonuclear fusion reactivity is a pivotal quantity in the studies pertaining to fusion energy production, fusion ignition and energy break-even analysis in both inertially and magnetically confined systems. Although nuclear fusion reactivity and thereafter the power density of a magnetic confinement fusion reactor and the fulfillment of the ignition criterion are quantitatively determined by assuming the ion speed distribution to be Maxwellian, a significant population of suprathermal ions,with energy greater than the quasi-Maxwellian background plasma temperature, is generated by the fusion reactions and auxiliary heating in the fusion devices. In the current work 3-parameter Dagum speed distribution has been introduced to include the effect of suprathermal ion population in the calculation of total fusion reactivity. The extent of enhancement in the fusion reactivity, at different back-ground temperatures of the fusion fuel plasma, due to the suprathermal ion population has also been discussed.

  20. Physiological mechanisms for high salt tolerance in wild soybean (Glycine soja) from Yellow River Delta, China: photosynthesis, osmotic regulation, ion flux and antioxidant capacity.

    Science.gov (United States)

    Chen, Peng; Yan, Kun; Shao, Hongbo; Zhao, Shijie

    2013-01-01

    Glycine soja (BB52) is a wild soybean cultivar grown in coastal saline land in Yellow River Delta, China. In order to reveal the physiological mechanisms adapting to salinity, we examined photosynthesis, ion flux, antioxidant system and water status in Glycine soja under NaCl treatments, taking a cultivated soybean, ZH13, as control. Upon NaCl exposure, higher relative water content and water potential were maintained in the leaf of BB52 than ZH13, which might depend on the more accumulation of osmotic substances such as glycinebetaine and proline. Compared with ZH13, activities of antioxidant enzymes including superoxide dismutase, catalase, ascorbate peroxidase and contents of ascorbate, glutathione and phenolics were enhanced to a higher level in BB52 leaf under NaCl stress, which could mitigate the salt-induced oxidative damage in BB52. Consistently, lipid peroxidation indicated by malondialdehyde content was lower in BB52 leaf. Photosynthetic rate (Pn) was decreased by NaCl stress in BB52 and ZH13, and the decrease was greater in ZH13. The decreased Pn in BB52 was mainly due to stomatal limitation. The inhibited activation of rubisco enzyme in ZH13 due to the decrease of rubisco activase content became an important limiting factor of Pn, when NaCl concentration increased to 200 mM. Rubisco activase in BB52 was not affected by NaCl stress. Less negative impact in BB52 derived from lower contents of Na(+) and Cl(-) in the tissues, and non-invasive micro-test technique revealed that BB52 roots had higher ability to extrude Na(+) and Cl(-). Wild soybean is a valuable genetic resource, and our study may provide a reference for molecular biologist to improve the salt tolerance of cultivated soybean in face of farmland salinity.

  1. Modeling the evolution of lithium-ion particle contact distributions using a fabric tensor approach

    Energy Technology Data Exchange (ETDEWEB)

    Stershic, Andrew [Duke University; Simunovic, Srdjan [ORNL; Nanda, Jagjit [ORNL

    2015-08-25

    Electrode microstructure and processing can strongly influence lithium-ion battery performance such as capacity retention, power, and rate. Battery electrodes are multi-phase composite structures wherein conductive diluents and binder bond active material to a current collector. The structure and response of this composite network during repeated electrochemical cycling directly affects battery performance characteristics. We propose the fabric tensor formalism for describing the structure and evolution of the electrode microstructure. Fabric tensors are directional measures of particulate assemblies based on inter-particle connectivity, relating to the structural and transport properties of the electrode. Fabric tensor analysis is applied to experimental data-sets for positive electrode made of lithium nickel manganese cobalt oxide, captured by X-ray tomography for several compositions and consolidation pressures. We show that fabric tensors capture the evolution of inter-particle contact distribution and are therefore good measures for the internal state of and electronic transport within the electrode. The fabric tensor analysis is also applied to Discrete Element Method (DEM) simulations of electrode microstructures using spherical particles with size distributions from the tomography. Furthermore, these results do not follow the experimental trends, which indicates that the particle size distribution alone is not a sufficient measure for the electrode microstructures in DEM simulations.

  2. Vertical distribution of overpotentials and irreversible charge losses in lithium ion battery electrodes.

    Science.gov (United States)

    Klink, Stefan; Schuhmann, Wolfgang; La Mantia, Fabio

    2014-08-01

    Porous lithium ion battery electrodes are characterized using a vertical distribution of cross-currents. In an appropriate simplification, this distribution can be described by a transmission line model (TLM) consisting of infinitely thin electrode layers. To investigate the vertical distribution of currents, overpotentials, and irreversible charge losses in a porous graphite electrode in situ, a multi-layered working electrode (MWE) was developed as the experimental analogue of a TLM. In this MWE, each layer is in ionic contact but electrically insulated from the other layers by a porous separator. It was found that the negative graphite electrodes get lithiated and delithiated stage-by-stage and layer-by-layer. Several mass-transport- as well as non-mass-transport-limited processes could be identified. Local current densities can reach double the average, especially on the outermost layer at the beginning of each intercalation stage. Furthermore, graphite particles close to the counter electrode act as "electrochemical sieve" reducing the impurities present in the electrolyte such as water. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. The effect of secondary circulation on the salt distribution in a sinuous coastal plain estuary: Satilla River, GA, USA

    Science.gov (United States)

    Seim, H. E.; Blanton, J. O.; Elston, S. A.

    2009-01-01

    An analysis of observational data suggests salt exchange in a sinuous coastal plain estuary is significantly impacted by counter-rotating residual horizontal eddies formed by channel curvature in meandering channels. The parts of adjacent eddies that advect material downstream follow the deep part of the channel where the flow continually criss-crosses from one side of the channel to the other and follows a relatively unimpeded trajectory to the sea. On the other hand, the parts of adjacent eddies that advect material upstream cross the channel at a different location where it encounters a series of shoals. In this case, the resulting upstream transport of salt is relatively inefficient and retards the rate at which salt can disperse upstream into the estuary. The strength of these circulations is modulated by the spring/neap cycle, allowing for a stronger gravitational mode of exchange to develop near neap tides, but has minimal impact on the length of the salt intrusion. It is suggested that the impeded upstream salt transport accounts for the observation that an impulse of river discharge advects a given isohaline 10 km downstream in 20 days, but that after the impulse, 70 days are required to return the isohaline to a similar position, counter to the notion of a simple dependence of intrusion length on river discharge.

  4. Distribution and Expression of Non-Neuronal Transient Receptor Potential (TRPV) Ion Channels in Rosacea

    Science.gov (United States)

    Sulk, Mathias; Seeliger, Stephan; Aubert, Jerome; Schwab, Verena D.; Cevikbas, Ferda; Rivier, Michel; Nowak, Pawel; Voegel, Johannes J.; Buddenkotte, Jörg; Steinhoff, Martin

    2011-01-01

    Rosacea is a frequent chronic inflammatory skin disease of unknown etiology. Because early rosacea reveals all characteristics of neurogenic inflammation, a central role of sensory nerves in its pathophysiology has been discussed. Neuroinflammatory mediators and their receptors involved in rosacea are poorly defined. Good candidates may be transient receptor potential (TRP) ion channels of vanilloid type (TRPV), which can be activated by many trigger factors of rosacea. Interestingly, TRPV2, TRPV3, and TRPV4 are expressed by both neuronal and non-neuronal cells. Here, we analyzed the expression and distribution of TRPV receptors in the various subtypes of rosacea on non-neuronal cells using immunohistochemistry, morphometry, double immunoflourescence, and quantitative real-time PCR (qRT-PCR) as compared with healthy skin and lupus erythematosus. Our results show that dermal immunolabeling of TRPV2 and TRPV3 and gene expression of TRPV1 is significantly increased in erythematotelangiectatic rosacea (ETR). Papulopustular rosacea (PPR) displayed an enhanced immunoreactivity for TRPV2, TRPV4, and also of TRPV2 gene expression. In phymatous rosacea (PhR)-affected skin, dermal immunostaining of TRPV3 and TRPV4 and gene expression of TRPV1 and TRPV3 was enhanced, whereas epidermal TRPV2 staining was decreased. Thus, dysregulation of TRPV channels also expressed by non-neuronal cells may be critically involved in the initiation and/or development of rosacea. TRP ion channels may be targets for the treatment of rosacea. PMID:22189789

  5. Integral equation models for the inverse problem of biological ion channel distributions

    Energy Technology Data Exchange (ETDEWEB)

    French, D A [Department of Mathematical Sciences, University of Cincinnati, Cincinnati, OH 45221-0025 (United States); Groetsch, C W [School of Science and Mathematics, The Citadel, Charleston, SC 29409 (United States)

    2007-06-15

    Olfactory cilia are thin hair-like filaments that extend from olfactory receptor neurons into the nasal mucus. Transduction of an odor into an electrical signal is accomplished by a depolarizing influx of ions through cyclic-nucleotide-gated channels in the membrane that forms the lateral surface of the cilium. In an experimental procedure developed by S. Kleene, a cilium is detached at its base and drawn into a recording pipette. The cilium base is then immersed in a bath of a channel activating agent (cAMP) which is allowed to diffuse into the cilium interior, opening channels as it goes and initiating a transmembrane current. The total current is recorded as a function of time and serves as data for a nonlinear integral equation of the first kind modeling the spatial distribution of ion channels along the length of the cilium. We discuss some linear Fredholm integral equations that result from simplifications of this model. A numerical procedure is proposed for a class of integral equations suggested by this simplified model and numerical results using simulated and laboratory data are presented.

  6. Ion velocity distribution function and electric field measurements in a dual-frequency rf sheath

    Science.gov (United States)

    Moore, Nathaniel; Gekelman, Walter; Prybil, Patrick; Zhang, Yiting; Kushner, Mark

    2013-10-01

    Ion dynamics are investigated in a dual-frequency rf sheath above a 300 mm diameter biased silicon wafer in an industrial inductively coupled (440 kHz, 500 W) plasma etch tool. Ion velocity distribution (IVD) function measurements in the argon plasma are taken using laser induced fluorescence (LIF). Planar sheets of laser light enter the chamber both parallel and perpendicular to the surface of the wafer in order to measure both parallel and perpendicular IVDs at thousands of spatial positions. A fast (30 ns exposure) CCD camera measures the resulting fluorescence with a spatial resolution of 0.4 mm. The dual-frequency bias on the wafer is comprised of a 2 MHz low frequency bias and an adjustable 10-20 MHz high frequency bias. The bias voltages may be switched on and off (frep up to 1 kHz, duty cycle 10-90%). IVDs are measured with several different bias and timing combinations. For the 2 MHz bias, it was found that the IVD is uniform to within 5% across the wafer. IVDs as a function of phase of the bias were also measured. The electric field in the sheath was measured volumetrically over the wafer at thousands of positions using an emissive probe. The experimental results are compared with a simulation specifically designed for this particular plasma tool. Work supported by the NSF and DOE.

  7. Distribution and expression of non-neuronal transient receptor potential (TRPV) ion channels in rosacea.

    Science.gov (United States)

    Sulk, Mathias; Seeliger, Stephan; Aubert, Jerome; Schwab, Verena D; Cevikbas, Ferda; Rivier, Michel; Nowak, Pawel; Voegel, Johannes J; Buddenkotte, Jörg; Steinhoff, Martin

    2012-04-01

    Rosacea is a frequent chronic inflammatory skin disease of unknown etiology. Because early rosacea reveals all characteristics of neurogenic inflammation, a central role of sensory nerves in its pathophysiology has been discussed. Neuroinflammatory mediators and their receptors involved in rosacea are poorly defined. Good candidates may be transient receptor potential (TRP) ion channels of vanilloid type (TRPV), which can be activated by many trigger factors of rosacea. Interestingly, TRPV2, TRPV3, and TRPV4 are expressed by both neuronal and non-neuronal cells. Here, we analyzed the expression and distribution of TRPV receptors in the various subtypes of rosacea on non-neuronal cells using immunohistochemistry, morphometry, double immunoflourescence, and quantitative real-time PCR (qRT-PCR) as compared with healthy skin and lupus erythematosus. Our results show that dermal immunolabeling of TRPV2 and TRPV3 and gene expression of TRPV1 is significantly increased in erythematotelangiectatic rosacea (ETR). Papulopustular rosacea (PPR) displayed an enhanced immunoreactivity for TRPV2, TRPV4, and also of TRPV2 gene expression. In phymatous rosacea (PhR)-affected skin, dermal immunostaining of TRPV3 and TRPV4 and gene expression of TRPV1 and TRPV3 was enhanced, whereas epidermal TRPV2 staining was decreased. Thus, dysregulation of TRPV channels also expressed by non-neuronal cells may be critically involved in the initiation and/or development of rosacea. TRP ion channels may be targets for the treatment of rosacea.

  8. Effects of ρ-meson width on pion distributions in heavy-ion collisions

    Science.gov (United States)

    Huovinen, Pasi; Lo, Pok Man; Marczenko, Michał; Morita, Kenji; Redlich, Krzysztof; Sasaki, Chihiro

    2017-06-01

    The influence of the finite width of ρ meson on the pion momentum distribution is studied quantitatively in the framework of the S-matrix approach combined with a blast-wave model to describe particle emissions from an expanding fireball. We find that the proper treatment of resonances which accounts for their production dynamics encoded in data for partial wave scattering amplitudes can substantially modify spectra of daughter particles originating in their two body decays. In particular, it results in an enhancement of the low-pT pions from the decays of ρ mesons which improves the quantitative description of the pion spectra in heavy ion collisions obtained by the ALICE collaboration at the LHC energy.

  9. Modulated ion acoustic waves in a plasma with Cairns-Gurevich distribution

    Science.gov (United States)

    El-Labany, S. K.; El-Taibany, W. F.; Zedan, N. A.

    2017-11-01

    The amplitude modulation of ion acoustic envelope solitary waves in the presence of Cairns-Gurevich distributed electrons has been investigated. Using a reductive perturbation technique, a modified nonlinear Schrödinger equation has been derived. The modulational instability (MI) and its dependence on the system physical parameters and the combined effects of trapped and nonthermal electrons have been analyzed. It is found that the MI maximum growth rate increases (decreases) as the nonthermality (trapping) parameter increases. The present results could be applicable in explaining the basic features of localized electrostatic disturbance in space observations such as the solar energetic particle flows in interplanetary space and the energetic particle events in the Earth's magnetosphere and also in the laser plasma interaction.

  10. Differential distribution of voltage-gated ion channels in cortical neurons: implications for epilepsy.

    Science.gov (United States)

    Child, Nicholas D; Benarroch, Eduardo E

    2014-03-18

    Neurons contain different functional somatodendritic and axonal domains, each with a characteristic distribution of voltage-gated ion channels, synaptic inputs, and function. The dendritic tree of a cortical pyramidal neuron has 2 distinct domains, the basal and the apical dendrites, both containing dendritic spines; the different domains of the axon are the axonal initial segment (AIS), axon proper (which in myelinated axons includes the node of Ranvier, paranodes, juxtaparanodes, and internodes), and the axon terminals. In the cerebral cortex, the dendritic spines of the pyramidal neurons receive most of the excitatory synapses; distinct populations of γ-aminobutyric acid (GABA)ergic interneurons target specific cellular domains and thus exert different influences on pyramidal neurons. The multiple synaptic inputs reaching the somatodendritic region and generating excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) sum and elicit changes in membrane potential at the AIS, the site of initiation of the action potential.

  11. Time resolved measurements of hydrogen ion energy distributions in a pulsed 2.45 GHz microwave plasma

    Science.gov (United States)

    Megía-Macías, A.; Cortázar, O. D.; Tarvainen, O.; Koivisto, H.

    2017-11-01

    A plasma diagnostic study of the Ion Energy Distribution Functions (IEDFs) of H+, H2+ , and H3+ ions in a 2.45 GHz hydrogen plasma reactor called TIPS is presented. The measurements are conducted by using a Plasma Ion Mass Spectrometer with an energy sector and a quadrupole detector from HIDEN Analytical Limited in order to select an ion species and to measure its energy distribution. The reactor is operated in the pulsed mode at 100 Hz with a duty cycle of 10% (1 ms pulse width). The IEDFs of H+, H2+ , and H3+ are obtained each 5 μs with 1 μs time resolution throughout the entire pulse. The temporal evolution of the plasma potential and ion temperature of H+ is derived from the data. It is shown that the plasma potential is within the range of 15-20 V, while the ion temperature reaches values of 0.25-1 eV during the pulse and exhibits a fast transient peak when the microwave radiation is switched off. Finally, the ion temperatures are used to predict the transverse thermal emittance of a proton beam extracted from 2.45 GHz microwave discharges.

  12. Mapping changing distributions of dominant species in oil-contaminated salt marshes of Louisiana using imaging spectroscopy

    Science.gov (United States)

    Beland, Michael; Roberts, Dar A.; Peterson, Seth H.; Biggs, Trent W.; Kokaly, Raymond F.; Piazza, Sarai; Roth, Keely L.; Khanna, Shruti; Ustin, Susan L.

    2016-01-01

    The April 2010 Deepwater Horizon (DWH) oil spill was the largest coastal spill in U.S. history. Monitoring subsequent change in marsh plant community distributions is critical to assess ecosystem impacts and to establish future coastal management priorities. Strategically deployed airborne imaging spectrometers, like the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), offer the spectral and spatial resolution needed to differentiate plant species. However, obtaining satisfactory and consistent classification accuracies over time is a major challenge, particularly in dynamic intertidal landscapes.Here, we develop and evaluate an image classification system for a time series of AVIRIS data for mapping dominant species in a heavily oiled salt marsh ecosystem. Using field-referenced image endmembers and canonical discriminant analysis (CDA), we classified 21 AVIRIS images acquired during the fall of 2010, 2011 and 2012. Classification results were evaluated using ground surveys that were conducted contemporaneously to AVIRIS collection dates. We analyzed changes in dominant species cover from 2010 to 2012 for oiled and non-oiled shorelines.CDA discriminated dominant species with a high level of accuracy (overall accuracy = 82%, kappa = 0.78) and consistency over three imaging dates (overall2010 = 82%, overall2011 = 82%, overall2012 = 88%). Marshes dominated by Spartina alterniflora were the most spatially abundant in shoreline zones (≤ 28 m from shore) for all three dates (2010 = 79%, 2011 = 61%, 2012 = 63%), followed by Juncus roemerianus (2010 = 11%, 2011 = 19%, 2012 = 17%) and Distichlis spicata (2010 = 4%, 2011 = 10%, 2012 = 7%).Marshes that were heavily contaminated with oil exhibited variable responses from 2010 to 2012. Marsh vegetation classes converted to a subtidal, open water class along oiled and non-oiled shorelines that were similarly situated in the landscape. However, marsh loss along oil-contaminated shorelines

  13. Salt Content Distribution and Paleoclimatic Significance of the Lop Nur “Ear” Feature: Results from Analysis of EO-1 Hyperion Imagery

    Directory of Open Access Journals (Sweden)

    Tingting Zhang

    2014-08-01

    Full Text Available Lop Nur, a playa lake located on the eastern margin of Tarim Basin in northwestern China, is famous for the “Ear” feature of its salt crust, which appears in remote-sensing images. In this study, partial least squares (PLS regression was used to estimated Lop Nur playa salt-crust properties, including total salt, Ca2+, Mg2+, Na+, Si2+, and Fe2+ using laboratory hyperspectral data. PLS results for laboratory-measured spectra were compared with those for resampled laboratory spectra with the same spectral resolution as Hyperion using the coefficient of determination (R2 and the ratio of standard deviation of sample chemical concentration to root mean squared error (RPD. Based on R2 and RPD, the results suggest that PLS can predict Ca2+ using Hyperion reflectance spectra. The Ca2+ distribution was compared to the “Ear area” shown in a Landsat Thematic Mapper (TM 5 image. The mean value of reflectance from visible bands for a 14 km transversal profile to the “Ear area” rings was extracted with the TM 5 image. The reflectance was used to build a correlation with Ca2+ content estimated with PLS using Hyperion. Results show that the correlation between Ca2+ content and reflectance is in accordance with the evolution of the salt lake. Ca2+ content variation was consistent with salt deposition. Some areas show a negative correlation between Ca2+ content and reflectance, indicating that there could have been a small-scale temporary runoff event under an arid environmental background. Further work is needed to determine whether these areas of small-scale runoff are due to natural (climate events or human factors (upstream channel changes.

  14. Mechanisms and distribution of ion channels in retinal ganglion cells: using temperature as an independent variable.

    Science.gov (United States)

    Fohlmeister, Jürgen F; Cohen, Ethan D; Newman, Eric A

    2010-03-01

    Trains of action potentials of rat and cat retinal ganglion cells (RGCs) were recorded intracellularly across a temperature range of 7-37 degrees C. Phase plots of the experimental impulse trains were precision fit using multicompartment simulations of anatomically reconstructed rat and cat RGCs. Action potential excitation was simulated with a "Five-channel model" [Na, K(delayed rectifier), Ca, K(A), and K(Ca-activated) channels] and the nonspace-clamped condition of the whole cell recording was exploited to determine the channels' distribution on the dendrites, soma, and proximal axon. At each temperature, optimal phase-plot fits for RGCs occurred with the same unique channel distribution. The "waveform" of the electrotonic current was found to be temperature dependent, which reflected the shape changes in the experimental action potentials and confirmed the channel distributions. The distributions are cell-type specific and adequate for soma and dendritic excitation with a safety margin. The highest Na-channel density was found on an axonal segment some 50-130 microm distal to the soma, as determined from the temperature-dependent "initial segment-somadendritic (IS-SD) break." The voltage dependence of the gating rate constants remains invariant between 7 and 23 degrees C and between 30 and 37 degrees C, but undergoes a transition between 23 and 30 degrees C. Both gating-kinetic and ion-permeability Q10s remain virtually constant between 23 and 37 degrees C (kinetic Q10s = 1.9-1.95; permeability Q10s = 1.49-1.64). The Q10s systematically increase for T channels were consistently "sleepy" (non-Arrhenius) for T <8 degrees C, with a loss of spiking for T <7 degrees C.

  15. In situ NMR spectroscopy: inulin biomass conversion in ZnCl₂ molten salt hydrate medium-SnCl₄ addition controls product distribution.

    Science.gov (United States)

    Wang, Yingxiong; Pedersen, Christian Marcus; Qiao, Yan; Deng, Tiansheng; Shi, Jing; Hou, Xianglin

    2015-01-22

    The dehydration of inulin biomass to the platform chemicals, 5-hydroxymethylfurfural (5-HMF) and levulinic acid (LA), in ZnCl2 molten salt hydrate medium was investigated. The influence of the Lewis acid catalyst, SnCl4, on the product distribution was examined. An in situ(1)H NMR technique was employed to follow the reaction at the molecular level. The experimental results revealed that only 5-HMF was obtained from degradation of inulin biomass in ZnCl2 molten salt hydrate medium, while the LA was gradually becoming the main product when the reaction temperature was increased in the presence of the Lewis acid catalyst SnCl4. In situ NMR spectroscopy could monitor the reaction and give valuable insight. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Effect of initial salt concentrations on cell performance and distribution of internal resistance in microbial desalination cells.

    Science.gov (United States)

    Yang, Euntae; Choi, Mi-Jin; Kim, Kyoung-Yeol; Chae, Kyu-Jung; Kim, In S

    2015-01-01

    Microbial desalination cells (MDCs) are modified microbial fuel cells (MFCs) that concurrently produce electricity and desalinate seawater, but adding a desalination compartment and an ion-exchange membrane may increase the internal resistance (Ri), which can limit the cell performance. However, the effects of a desalination chamber and initial NaCl concentrations on the internal resistances and the cell performances (i.e. Coulombic efficiency (CE), current and power density) of MDCs have yet to be thoroughly explored; thus, the cell performance and Ri distributions of MDCs having different initial concentrations and an MFC having no desalination chamber were compared. In the MDCs, the current and power density generation increased from 2.82 mA and 158.2 mW/m2 to 3.17 mA and 204.5 mW/m2 when the initial NaCl concentrations were increased from 5 to 30 g/L, as a consequence of the internal resistances decreasing from 2432.0 to 2328.4 Ω. And even though the MFC has a lower Ri than the MDCs, lower cell performances (current: 2.59 mA; power density: 141.6 mW/m2 and CE: 62.1%) were observed; there was no effect of improved junction potential in the MFC. Thus, in the MDCs, the higher internal resistances due to the addition of a desalination compartment can be offset by reducing the electrolyte resistance and improving the junction potential at higher NaCl concentrations.

  17. How to resolve microsecond current fluctuations in single ion channels: The power of beta distributions

    Science.gov (United States)

    Schroeder, Indra

    2015-01-01

    Abstract A main ingredient for the understanding of structure/function correlates of ion channels is the quantitative description of single-channel gating and conductance. However, a wealth of information provided from fast current fluctuations beyond the temporal resolution of the recording system is often ignored, even though it is close to the time window accessible to molecular dynamics simulations. This kind of current fluctuations provide a special technical challenge, because individual opening/closing or blocking/unblocking events cannot be resolved, and the resulting averaging over undetected events decreases the single-channel current. Here, I briefly summarize the history of fast-current fluctuation analysis and focus on the so-called “beta distributions.” This tool exploits characteristics of current fluctuation-induced excess noise on the current amplitude histograms to reconstruct the true single-channel current and kinetic parameters. A guideline for the analysis and recent applications demonstrate that a construction of theoretical beta distributions by Markov Model simulations offers maximum flexibility as compared to analytical solutions. PMID:26368656

  18. Glass-Fiber Networks as an Orbit for Ions: Fabrication of Excellent Antistatic PP/GF Composites with Extremely Low Organic Salt Loadings.

    Science.gov (United States)

    Gu, Senlin; Zhu, Leon; Mercier, Claude; Li, Yongjin

    2017-05-31

    Polypropylene (PP)/glass fiber (GF) composites showing excellent antistatic performance were prepared by a simple melt process blending PP with GF and a small amount of organic salts (OSs). Two types of OSs, tribuyl(octyl)phosphonium bis(trifloromethanesulfonyl)imide (TBOP-TFSI) and lithium bis(trifloromethanesulfonyl)imide (Li-TFSI), with equivalent anions were used as antistatic agents for the composites. It was found that the GF and OSs exhibited significant synergistic effects on the antistatic performance as well as the mechanical properties of the composites. On the one hand, the incorporation of GF significantly enhanced the electric conductivity of the composites at a constant OS loading. On the other hand, the two types of OSs improved the interfacial adhesion between the GF and the PP matrix, which led to an enhancement of the mechanical properties. This study showed that OSs had specific interactions with GFs and were absorbed exclusively on the GF surface. The GF network in the PP matrix provided perfect orbits for the movement of ions, inducing the excellent antistatic performance exhibited by the PP/GF composites at an OS loading of as low as 0.25 wt % when the GF formed a network in the PP matrix.

  19. Charge-state distribution of Li ions from the β decay of laser-trapped 6He atoms

    Science.gov (United States)

    Hong, R.; Leredde, A.; Bagdasarova, Y.; Fléchard, X.; García, A.; Knecht, A.; Müller, P.; Naviliat-Cuncic, O.; Pedersen, J.; Smith, E.; Sternberg, M.; Storm, D. Â. W.; Swanson, H. Â. E.; Wauters, F.; Zumwalt, D.

    2017-11-01

    The accurate determination of atomic final states following nuclear β decay plays an important role in several experiments. In particular, the charge state distributions of ions following nuclear β decay are important for determinations of the β -ν angular correlation with improved precision. Beyond the hydrogenic cases, the decay of neutral 6He presents the simplest case. Our measurement aims at providing benchmarks to test theoretical calculations. The kinematics of Lin + ions produced following the β decay of 6He within an electric field were measured using 6He atoms in the metastable (1 s 2 s ,S31) and (1 s 2 p ,P32) states confined by a magneto-optical trap. The electron shakeoff probabilities were deduced, including their dependence on ion energy. We find significant discrepancies on the fractions of Li ions in the different charge states with respect to a recent calculation.

  20. New possibilities of the isotope distribution examination in irradiated absorbing materials using secondary ion mass spectrometry method

    Energy Technology Data Exchange (ETDEWEB)

    Goncharenko, Y. D.; Evseev, L.A.; Risovany, V.D.

    2005-01-01

    The SIMS technique (with using a linear analysis and 2D surface imaging) has been to measure the radial distribution of the boron isotope ratio in the boron carbide pellets irradiated in the fast reactor. It was revealed that a radial distribution of isotope ratio in the boron carbide pellets is significantly different after irradiation in fast and thermal reactors. It was showed the advisability of using ion images for such examinations. (Author)

  1. Measurements of the ion velocity distribution in an ultracold neutral plasma derived from a cold, dense Rydberg gas

    CERN Document Server

    Bergeson, S D

    2016-01-01

    We report measurements of the ion velocity distribution in an ultracold neutral plasma derived from a dense, cold Rydberg gas in a MOT. The Rydberg atoms are excited using a resonant two-step excitation pathway with lasers of 4 ns duration. The plasma forms spontaneously and rapidly. The rms width of the ion velocity distribution is determined by measuring laser-induced fluorescence (LIF) of the ions. The measured excitation efficiency is compared with a Monte-Carlo wavefunction calculation, and significant differences are observed. We discuss the conditions for blockaded Rydberg excitation and the subsequent spatial ordering of Rydberg atom domains. While the blockade interaction is greater than the Rabi frequency in portions of the atomic sample, no evidence for spatial ordering is observed.

  2. Investigation of subauroral ion drifts and related field-aligned currents and ionospheric Pedersen conductivity distribution

    Directory of Open Access Journals (Sweden)

    S. Figueiredo

    2004-03-01

    Full Text Available Based on Astrid-2 satellite data, results are presented from a statistical study on subauroral ion drift (SAID occurrence. SAID is a subauroral phenomenon characterized by a westward ionospheric ion drift with velocity greater than 1000m/s, or equivalently, by a poleward-directed electric field with intensity greater than 30mV/m. SAID events occur predominantly in the premidnight sector, with a maximum probability located within the 20:00 to 23:00 MLT sector, where the most rapid SAID events are also found. They are substorm related, and show first an increase in intensity and a decrease in latitudinal width during the expansion phase, followed by a weakening and widening of the SAID structures during the recovery phase. The potential drop across a SAID structure is seen to remain roughly constant during the recovery phase. The field-aligned current density and the height-integrated Pedersen conductivity distribution associated with the SAID events were calculated. The results reveal that the strongest SAID electric field peaks are associated with the lowest Pedersen conductivity minimum values. Clear modifications are seen in the ionospheric Pedersen conductivity distribution associated with the SAID structure as time evolves: the SAID peak is located on the poleward side of the corresponding region of reduced Pedersen conductivity; the shape of the regions of reduced conductivity is asymmetric, with a steeper poleward edge and a more rounded equatorward edge; the SAID structure becomes less intense and widens with evolution of the substorm recovery phase. From the analysis of the SAID occurrence relative to the mid-latitude trough position, SAID peaks are seen to occur relatively close to the corresponding mid-latitude trough minimum. Both these features show a similar response to magnetospheric disturbances, but on different time scales - with increasing magnetic activity, the SAID structure shows a faster movement towards lower latitudes

  3. Overexpression of a Plasma Membrane Bound Na+/H+ Antiporter-Like Protein (SbNHXLP) Confers Salt Tolerance and Improves Fruit Yield in Tomato by Maintaining Ion Homeostasis.

    Science.gov (United States)

    Kumari, P Hima; Kumar, S Anil; Sivan, Pramod; Katam, Ramesh; Suravajhala, Prashanth; Rao, K S; Varshney, Rajeev K; Kishor, Polavarapu B Kavi

    2016-01-01

    A Na+/H+ antiporter-like protein (NHXLP) was isolated from Sorghum bicolor L. (SbNHXLP) and validated by overexpressing in tomato for salt tolerance. Homozygous T2 transgenic lines when evaluated for salt tolerance, accumulated low Na+ and displayed enhanced salt tolerance compared to wild-type plants (WT). This is consistent with the amiloride binding assay of the protein. Transgenics exhibited higher accumulation of proline, K+, Ca2+, improved cambial conductivity, higher PSII, and antioxidative enzyme activities than WT. Fluorescence imaging results revealed lower Na+ and higher Ca2+ levels in transgenic roots. Co-immunoprecipitation experiments demonstrate that SbNHXLP interacts with a Solanum lycopersicum cation proton antiporter protein2 (SlCHX2). qRT-PCR results showed upregulation of SbNHXLP and SlCHX2 upon treatment with 200 mM NaCl and 100 mM potassium nitrate. SlCHX2 is known to be involved in K+ acquisition, and the interaction between these two proteins might help to accumulate more K+ ions, and thus maintain ion homeostasis. These results strongly suggest that plasma membrane bound SbNHXLP involves in Na+ exclusion, maintains ion homeostasis in transgenics in comparison with WT and alleviates NaCl stress.

  4. Space and phase resolved ion energy and angular distributions in single- and dual-frequency capacitively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yiting; Kushner, Mark J. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States); Moore, Nathaniel; Pribyl, Patrick; Gekelman, Walter [Department of Physics, University of California, Los Angeles, California 90095 (United States)

    2013-11-15

    The control of ion energy and angular distributions (IEADs) is critically important for anisotropic etching or deposition in microelectronic fabrication processes. With single frequency capacitively coupled plasmas (CCPs), the narrowing in angle and spread in energy of ions as they cross the sheath are definable functions of frequency, sheath width, and mean free path. With increases in wafer size, single frequency CCPs are finding difficulty in meeting the requirement of simultaneously controlling plasma densities, ion fluxes, and ion energies. Dual-frequency CCPs are being investigated to provide this flexible control. The high frequency (HF) is intended to control the plasma density and ion fluxes, while the ion energies are intended to be controlled by the low frequency (LF). However, recent research has shown that the LF can also influence the magnitude of ion fluxes and that IEADs are determined by both frequencies. Hence, separate control of fluxes and IEADs is complex. In this paper, results from a two-dimensional computational investigation of Ar/O{sub 2} plasma properties in an industrial reactor are discussed. The IEADs are tracked as a function of height above the substrate and phase within the rf cycles from the bulk plasma to the presheath and through the sheath with the goal of providing insights to this complexity. Comparison is made to laser-induced fluorescence experiments. The authors found that the ratios of HF/LF voltage and driving frequency are critical parameters in determining the shape of the IEADs, both during the transit of the ion through the sheath and when ions are incident onto the substrate. To the degree that contributions from the HF can modify plasma density, sheath potential, and sheath thickness, this may provide additional control for the IEADs.

  5. Coverage of Adequately Iodized Salt Is Suboptimal and Rice Fortification Using Public Distribution Channels Could Reach Low-Income Households: Findings from a Cross-Sectional Survey of Anganwadi Center Catchment Areas in Telangana, India.

    Directory of Open Access Journals (Sweden)

    James P Wirth

    Full Text Available Food fortification is a cost-effective approach to prevent and control of micronutrient deficiencies in India. A cross-sectional survey of children 0-35 months of age residing in the catchment areas of anganwadi centers in the state of Telangana was conducted to assess the coverage of adequately iodized salt and the potential for rice fortification. Salt samples were collected and tested for iodine concentration using iodometric titration. Information on demographics, household rice consumption, and Telangana's rice sector was collected and interpreted. In households of selected children, 79% of salt samples were found to be adequately iodized. Salt brand and district were significant predictors of inadequately iodized salt. Daily rice consumption among children and women averaged 122 grams and 321 grams per day, respectively. Approximately 28% of households reported consuming rice produced themselves or purchased from a local farmer, 65% purchased rice from a market or shop, 6% got rice from a public distribution system site, and 2% obtained it from a rice mill. In the catchment areas of Telangana's anganwadi centers, there is significant variation in the coverage of adequately iodized salt by district. Future surveys in Telangana should measure the coverage of salt iodization in the general population using quantitative methods. Nonetheless, increasing the adequacy of iodization of smaller salt manufacturers would help achieve universal salt iodization in Telangana. Despite high consumption of rice, our findings suggest that large-scale market-based rice fortification is not feasible in Telangana due to a large proportion of households producing their own rice and highly fragmented rice distribution. Distributing fortified rice via Telangana's public distribution system may be a viable approach to target low-income households, but would only reach a small proportion of the population in Telangana.

  6. Coverage of Adequately Iodized Salt Is Suboptimal and Rice Fortification Using Public Distribution Channels Could Reach Low-Income Households: Findings from a Cross-Sectional Survey of Anganwadi Center Catchment Areas in Telangana, India.

    Science.gov (United States)

    Wirth, James P; Leyvraz, Magali; Sodani, Prahlad R; Aaron, Grant J; Sharma, Narottam D; Woodruff, Bradley A

    2016-01-01

    Food fortification is a cost-effective approach to prevent and control of micronutrient deficiencies in India. A cross-sectional survey of children 0-35 months of age residing in the catchment areas of anganwadi centers in the state of Telangana was conducted to assess the coverage of adequately iodized salt and the potential for rice fortification. Salt samples were collected and tested for iodine concentration using iodometric titration. Information on demographics, household rice consumption, and Telangana's rice sector was collected and interpreted. In households of selected children, 79% of salt samples were found to be adequately iodized. Salt brand and district were significant predictors of inadequately iodized salt. Daily rice consumption among children and women averaged 122 grams and 321 grams per day, respectively. Approximately 28% of households reported consuming rice produced themselves or purchased from a local farmer, 65% purchased rice from a market or shop, 6% got rice from a public distribution system site, and 2% obtained it from a rice mill. In the catchment areas of Telangana's anganwadi centers, there is significant variation in the coverage of adequately iodized salt by district. Future surveys in Telangana should measure the coverage of salt iodization in the general population using quantitative methods. Nonetheless, increasing the adequacy of iodization of smaller salt manufacturers would help achieve universal salt iodization in Telangana. Despite high consumption of rice, our findings suggest that large-scale market-based rice fortification is not feasible in Telangana due to a large proportion of households producing their own rice and highly fragmented rice distribution. Distributing fortified rice via Telangana's public distribution system may be a viable approach to target low-income households, but would only reach a small proportion of the population in Telangana.

  7. The health gains and cost savings of dietary salt reduction interventions, with equity and age distributional aspects

    Directory of Open Access Journals (Sweden)

    Nhung Nghiem

    2016-05-01

    Full Text Available Abstract Background A “diet high in sodium” is the second most important dietary risk factor for health loss identified in the Global Burden of Disease Study 2013. We therefore aimed to model health gains and costs (savings of salt reduction interventions related to salt substitution and maximum levels in bread, including by ethnicity and age. We also ranked these four interventions compared to eight other modelled interventions. Methods A Markov macro-simulation model was used to estimate QALYs gained and net health system costs for four dietary sodium reduction interventions, discounted at 3 % per annum. The setting was New Zealand (NZ (2.3 million adults, aged 35+ years which has detailed individual-level administrative cost data. Results The health gain was greatest for an intervention where most (59 % of the sodium in processed foods was replaced by potassium and magnesium salts. This intervention gained 294,000 QALYs over the remaining lifetime of the cohort (95 % UI: 238,000 to 359,000; 0.13 QALY per 35+ year old. Such salt substitution also produced the highest net cost-savings of NZ$ 1.5 billion (US$ 1.0 billion (95 % UI: NZ$ 1.1 to 2.0 billion. All interventions generated relatively larger per capita QALYs for men vs women and for the indigenous Māori population vs non-Māori (e.g., 0.16 vs 0.12 QALYs per adult for the 59 % salt substitution intervention. Of relevance to workforce productivity, in the first 10 years post-intervention, 22 % of the QALY gain was among those aged <65 years (and 37 % for those aged <70. Conclusions The benefits are consistent with the international literature, with large health gains and cost savings possible from some, but not all, sodium reduction interventions. Health gain appears likely to occur among working-age adults and all interventions contributed to reducing health inequalities.

  8. [Characteristics of mass size distributions of water-soluble, inorganic ions during summer and winter haze days of Beijing].

    Science.gov (United States)

    Huang, Yi-Min; Liu, Zi-Rui; Chen, Hong; Wang, Yue-Si

    2013-04-01

    To investigate the size distribution characteristics of water soluble inorganic ions in haze days, the particle samples were collected by two Andersen cascade impactors in Beijing during summer and winter time and each sampling period lasted two weeks. Online measurement of PM10 and PM2.5 using TEOM were also conducted at the same time. Sources and formation mechanism of water soluble inorganic ions were analyzed based on their size distributions. The results showed that average concentrations of PM10 and PM 2.5 were (245.5 +/- 8.4) microg x m(-3) and (120.2 +/- 2.0) microg x m(-3) during summer haze days (SHD), and were (384.2 +/- 30.2) microg x m(-3) and (252.7 +/- 47.1) microg x m(-3) during winter haze days (WHD), which suggested fine particles predominated haze pollution episode in both seasons. Total water-soluble inorganic ions concentrations were higher in haze days than those in non-haze days, especially in fine particles. Furthermore, concentrations of secondary inorganic ions (SO4(2-), NO3(-) and NH4(+)) increased quicker than other inorganic ions in fine particles during haze days, indicating secondary inorganic ions played an important role in the formation of haze pollution. Similar size distributions were found for all Sinorganic water soluble ions except for NO3(-), during SHD and WHD. SO4(2-) and NH4(+) dominated in the fine mode (PM1.0) while Mg2+ and Ca2+ accumulated in coarse fraction, Na+, Cl- and K+ showed a bimodal distribution. For NO3(-), however, it showed a bimodal distribution during SHD and a unimodal distribution dominated in the fine fraction was found during WHD. The average mass median aerodynamic diameter (MMAD) of SO4(2-) was 0.64 microm in SHD, which suggested the formation of SO4(2-) was mainly attributed to in-cloud processes. Furthermore, a higher apparent conversion rate of sulfur dioxide (SOR) was found in SHD, indicating more fine particles were produced by photochemical reaction in haze days than that in non-haze days. The

  9. Effect of non-uniform electron energy distribution function on plasma production in large arc driven negative ion source.

    Science.gov (United States)

    Shibata, T; Koga, S; Terasaki, R; Inoue, T; Dairaku, M; Kashiwagi, M; Taniguchi, M; Tobari, H; Tsuchida, K; Umeda, N; Watanabe, K; Hatayama, A

    2012-02-01

    Spatially non-uniform electron energy distribution function (EEDF) in an arc driven negative ion source (JAEA 10A negative ion source: 10 A NIS) is calculated numerically by a three-dimensional Monte Carlo kinetic model for electrons to understand spatial distribution of plasma production (such as atomic and ionic hydrogen (H(0)∕H(+)) production) in source chamber. The local EEDFs were directly calculated from electron orbits including electromagnetic effects and elastic∕inelastic collision forces. From the EEDF, spatial distributions of H(0)∕H(+) production rate were obtained. The results suggest that spatial non-uniformity of H(0)∕H(+) productions is enhanced by high energy component of EEDF.

  10. Determination and shaping of the ion-velocity distribution function in a single-ended Q machine

    DEFF Research Database (Denmark)

    Andersen, S.A.; Jensen, Vagn Orla; Michelsen, Poul

    1971-01-01

    An electrostatic energy analyzer with a resolution better than 0.03 eV was constructed. This analyzer was used to determine the ion-velocity distribution function at different densities and plate temperatures in a single-ended Q machine. In all regions good agreement with theoretical predictions...... based on simple, physical pictures is obtained. It is shown that within certain limits the velocity distribution function can be shaped; double-humped distribution functions have been obtained. The technique used here is suggested as an accurate method for determination of plasma densities within 10......% in single-ended Q machines...

  11. Magnetochemistry of the tetrahaloferrate (III) ions: Crystal structure and magnetic ordering in [(4-chloropyridinium)FeCl4]2ṡ4-chloropyridinium chloride and related salts (abstract)

    Science.gov (United States)

    Lowe, C. B.; Shum, D. P.; Carlin, Richard L.

    1990-05-01

    The yellow compound of stoichiometry (4-chloropyridinium)3Fe2Cl9 belongs to the space group P21/n with four formula units in the unit cell. Structural analysis shows that the iron is present as the FeX4- ion. Magnetic measurements on single crystals show that the material orders as a canted antiferromagnet at 2.725 K. Replacement of the 4-chloro cation by the 4-bromo analog yields an isomorphous material and shifts the transition temperature to 2.34 K. The phase diagrams of both salts have also been determined. For [(4-chloropyridinium)FeCl4]2ṡ4-chloropyridinium chloride, the bicritical point is at 2.40 K and 7 kOe, and HSF(0)=5.5 kOe. With Hc(0)=56 kOe, α=HA/HE=1.9×10-2. In the case of [(4-bromopyridinium)FeCl4]2ṡ4-bromopyridinium chloride, HSF(0)=3 kOe, Hc(0)=42 kOe, α=1.0×10-2, and the bicritical point is at 2.24 K and 4.2 kOe. Crystallographic investigations at 25 K are reported on the isomorphous (4-chloropyridinium)3Fe2Br9 and on (4-bromopyridinium)3Fe2Cl1.3Br7.7. Magnetic measurements on single crystals show that (4-bromopyridinium)3Fe2Cl1.3Br7.7 orders as a canted antiferromagnet at 5.67 K, while (4-chloropyridinium)3Fe2Br9 orders similarly at 7.96 K. These compounds behave approximately as S=5/2, three-dimensional Heisenberg antiferromagnets.

  12. Modeling and evaluation of the global sea-salt aerosol distribution: sensitivity to size-resolved and sea-surface temperature dependent emission schemes

    Directory of Open Access Journals (Sweden)

    M. Spada

    2013-12-01

    Full Text Available One of the major sources of uncertainty in model estimates of the global sea-salt aerosol distribution is the emission parameterization. We evaluate a new sea-salt aerosol life cycle module coupled to the online multiscale chemical transport model NMMB/BSC-CTM. We compare 5 yr global simulations using five state-of-the-art sea-salt open-ocean emission schemes with monthly averaged coarse aerosol optical depth (AOD from selected AERONET sun photometers, surface concentration measurements from the University of Miami's Ocean Aerosol Network, and measurements from two NOAA/PMEL cruises (AEROINDOEX and ACE1. Model results are highly sensitive to the introduction of sea-surface-temperature (SST-dependent emissions and to the accounting of spume particles production. Emission ranges from 3888 Tg yr−1 to 8114 Tg yr−1, lifetime varies between 7.3 h and 11.3 h, and the average column mass load is between 5.0 Tg and 7.2 Tg. Coarse AOD is reproduced with an overall correlation of around 0.5 and with normalized biases ranging from +8.8% to +38.8%. Surface concentration is simulated with normalized biases ranging from −9.5% to +28% and the overall correlation is around 0.5. Our results indicate that SST-dependent emission schemes improve the overall model performance in reproducing surface concentrations. On the other hand, they lead to an overestimation of the coarse AOD at tropical latitudes, although it may be affected by uncertainties in the comparison due to the use of all-sky model AOD, the treatment of water uptake, deposition and optical properties in the model and/or an inaccurate size distribution at emission.

  13. Modeling and Evaluation of the Global Sea-Salt Aerosol Distribution: Sensitivity to Emission Schemes and Resolution Effects at Coastal/Orographic Sites

    Science.gov (United States)

    Spada, M.; Jorba, O.; Perez Garcia-Pando, C.; Janjic, Z.; Baldasano, J. M.

    2013-01-01

    One of the major sources of uncertainty in model estimates of the global sea-salt aerosol distribution is the emission parameterization. We evaluate a new sea-salt aerosol life cycle module coupled to the online multi-scale chemical transport model NMMB/BSC-CTM. We compare 5 year global simulations using five state-of-the-art sea-salt open-ocean emission schemes with monthly averaged coarse aerosol optical depth (AOD) from selected AERONET sun photometers, surface concentration measurements from the University of Miami's Ocean Aerosol Network, and measurements from two NOAA/PMEL cruises (AEROINDOEX and ACE1). Model results are highly sensitive to the introduction of sea-surface-temperature (SST)-dependent emissions and to the accounting of spume particles production. Emission ranges from 3888 teragrams per year to 8114 teragrams per year, lifetime varies between 7.3 hours and 11.3 hours, and the average column mass load is between 5.0 teragrams and 7.2 teragrams. Coarse AOD is reproduced with an overall correlation of around 0.5 and with normalized biases ranging from +8.8 percent to +38.8 percent. Surface concentration is simulated with normalized biases ranging from minus 9.5 percent to plus 28 percent and the overall correlation is around 0.5. Our results indicate that SST-dependent emission schemes improve the overall model performance in reproducing surface concentrations. On the other hand, they lead to an overestimation of the coarse AOD at tropical latitudes, although it may be affected by uncertainties in the comparison due to the use of all-sky model AOD, the treatment of water uptake, deposition and optical properties in the model and/or an inaccurate size distribution at emission.

  14. Depth distribution of Frank loop defects formed in ion-irradiated stainless steel and its dependence on Si addition

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dongyue, E-mail: dychen@safety.n.t.u-tokyo.ac.jp [The University of Tokyo, Department of Nuclear Engineering and Management, School of Engineering, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8656 (Japan); Murakami, Kenta [The University of Tokyo, Nuclear Professional School, School of Engineering, 2-22 Shirakata-Shirane, Tokai-mura, Ibaraki 319-1188 (Japan); Dohi, Kenji; Nishida, Kenji; Soneda, Naoki [Central Research Institute of Electric Power Industry, 2-11-1 Iwado-kita, Komae, Tokyo 201-8511 (Japan); Li, Zhengcao, E-mail: zcli@tsinghua.edu.cn [Tsinghua University, School of Materials Science and Engineering, Beijing 100084 (China); Liu, Li; Sekimura, Naoto [The University of Tokyo, Department of Nuclear Engineering and Management, School of Engineering, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-12-15

    Although heavy ion irradiation is a good tool to simulate neutron irradiation-induced damages in light water reactor, it produces inhomogeneous defect distribution. Such difference in defect distribution brings difficulty in comparing the microstructure evolution and mechanical degradation between neutron and heavy ion irradiation, and thus needs to be understood. Stainless steel is the typical structural material used in reactor core, and could be taken as an example to study the inhomogeneous defect depth distribution in heavy ion irradiation and its influence on the tested irradiation hardening by nano-indentation. In this work, solution annealed stainless steel model alloys are irradiated by 3 MeV Fe{sup 2+} ions at 400 °C to 3 dpa to produce Frank loops that are mainly interstitial in nature. The silicon content of the model alloys is also tuned to change point defect diffusion, so that the loop depth distribution influenced by diffusion along the irradiation beam direction could be discussed. Results show that in low Si (0% Si) and base Si (0.42% Si) samples the depth distribution of Frank loop density quite well matches the dpa profile calculated by the SRIM code, but in high Si sample (0.95% Si), the loop number density in the near-surface region is very low. One possible explanation could be Si’s role in enhancing the effective vacancy diffusivity, promoting recombination and thus suppressing interstitial Frank loops, especially in the near-surface region, where vacancies concentrate. By considering the loop depth distribution, the tested irradiation hardening is successfully explained by the Orowan model. A hardening coefficient of around 0.30 is obtained for all the three samples. This attempt in interpreting hardening results may make it easier to compare the mechanical degradation between different irradiation experiments.

  15. One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong - Part 1: Inorganic ions and oxalate

    Science.gov (United States)

    Bian, Q.; Huang, X. H. H.; Yu, J. Z.

    2014-09-01

    Size distribution data of major aerosol constituents are essential in source apportioning of visibility degradation, testing and verification of air quality models incorporating aerosols. We report here 1-year observations of mass size distributions of major inorganic ions (sulfate, nitrate, chloride, ammonium, sodium, potassium, magnesium and calcium) and oxalate at a coastal suburban receptor site in Hong Kong, China. A total of 43 sets of size-segregated samples in the size range of 0.056-18 μm were collected from March 2011 to February 2012. The size distributions of sulfate, ammonium, potassium and oxalate were characterized by a dominant droplet mode with a mass mean aerodynamic diameter (MMAD) in the range of ~ 0.7-0.9 μm. Oxalate had a slightly larger MMAD than sulfate on days with temperatures above 22 °C as a result of the process of volatilization and repartitioning. Nitrate was mostly dominated by the coarse mode but enhanced presence in fine mode was detected on winter days with lower temperature and lower concentrations of sea salt and soil particles. This data set reveals an inversely proportional relationship between the fraction of nitrate in the fine mode and product of the sum of sodium and calcium in equivalent concentrations and the dissociation constant of ammonium nitrate (i.e., (1/([Na+] + 2[Ca2+]) × (1/Ke')) when Pn_fine is significant (> 10%). The seasonal variation observed for sea salt aerosol abundance, with lower values in summer and winter, is possibly linked with the lower marine salinities in these two seasons. Positive matrix factorization was applied to estimate the relative contributions of local formation and transport to the observed ambient sulfate level through the use of the combined data sets of size-segregated sulfate and select gaseous air pollutants. On average, the regional/super-regional transport of air pollutants was the dominant source at this receptor site, especially on high-sulfate days while local formation

  16. In-situ measurement of the lithium distribution in Li-ion batteries using micro-IBA techniques

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, A., E-mail: yamazaki@tac.tsukuba.ac.jp [Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Orikasa, Y.; Chen, K.; Uchimoto, Y. [Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsucho, Sakyo-ku, Kyoto 606-8501 (Japan); Kamiya, T.; Koka, M.; Satoh, T. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency (JAEA), 1233, Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Mima, K.; Kato, Y.; Fujita, K. [The Graduate School for the Creation of New Photonics Industries, 1955-1, Kurematsu, NIshi-ku, Hamamatsu, Shizuoka 431-1202 (Japan)

    2016-03-15

    Direct observation of lithium concentration distribution in lithium-ion battery composite electrodes has been performed for the first time. Lithium-ion battery model cells for particle induced X-ray emission (PIXE) and particle induced gamma ray emission (PIGE) measurements were designed and fabricated. Two dimensional images of lithium concentration in LiFePO{sub 4} composite electrodes were obtained with PIXE and PIGE by scanning the proton microbeam for various charged states of the electrodes. Lithium concentration in LiFePO{sub 4} composite electrodes was decreased from the contact interface between LiFePO{sub 4} electrode and liquid electrolyte during the charge reaction.

  17. Distribution of ion contents and microorganisms during the electro-bioremediation of petroleum-contaminated saline soil.

    Science.gov (United States)

    Zhang, Meng; Guo, Shuhai; Li, Fengmei; Wu, Bo

    2017-10-15

    This study investigated the distribution of ion contents and microorganisms during the electro-bioremediation (EK-Bio) of petroleum-contaminated saline soil. The results showed that soil ions tend to accumulate around the electrodes, and the concentration was correlated with the distance from the electrodes. The average soil ion content was 7.92 g/kg around the electrodes (site A) and 0.55 g/kg at the furthest distance from the electrodes (site B) after 112 days of treatment, while the initial average content was 3.92 g/kg. Smooth linear (R2 = 0.98) loss of soil ions was observed at site C, which was closer to the electrodes than site B, and had a final average soil ion content of 1.96 g/kg. The dehydrogenase activity was much higher in EK-Bio test soil than in the Bio test soil after 28 days of treatment, and followed the order: site C > site B > site A. However, the soil dehydrogenase activity dropped continuously when the soil ion reached very high and low concentrations at sites A and B. The soil microbial community varied in sample sites that had different ion contents, and the soil microbial diversity followed the order: site C > site B > site A. The applied electric field clearly enhanced the biodegradation efficiency for soil petroleum contaminants. However, the biodegradation promotion effects were weakening in soils where the ion contents were extremely high and low (sites A and B). These results can provide useful information for EK-Bioremediation of organic-contaminated saline soil.

  18. Modeling and evaluation of the global sea-salt aerosol distribution: sensitivity to emission schemes and resolution effects at coastal/orographic sites

    Science.gov (United States)

    Spada, M.; Jorba, O.; Perez, C.; Janjic, Z.; Baldasano, J. M.

    2013-05-01

    We investigate two of the major sources of uncertainty in the model estimation of the global distribution of sea-salt aerosol, i.e. the sensitivity to the emission parameterization and the influence of model resolution in coastal regions characterized by complex topography and/or steep orographic barriers where some observation sites are located. We evaluate a new sea-salt aerosol lifecycle module implemented within the online chemical transport model NMMB/BSC-CTM. Because of its multiscale core, the model is able to cover a wide range of scales. Global simulations using four state-of-the-art sea-salt emission schemes are evaluated against monthly-averaged aerosol optical depth (AOD) from selected AERONET Sun photometers, surface concentration measurements from the University of Miami's Ocean Aerosol Network and measurements from two NOAA/PMEL cruises (AEROINDOEX and ACE1). The model results are highly sensitive to the introduction of SST-dependent emissions and to the accounting of spume particles production. Depending on emission scheme, annual emissions range from 4312.9 Tg to 8979.7 Tg in the 2006. Sea-salt lifetime varies between 7.7 h and 12.0 h and the annual mean column mass load is between 5.9 Tg and 7.9 Tg. Observed coarse AOD monthly averages are reproduced with an overall correlation around 0.8 (a correlation of 0.6 is produced when applying the SST dependent scheme). Although monthly-averaged surface concentrations are overall in good agreement with the observations, there is a subset of coastal sites surrounded by complex topography where the global model overestimates by a factor of 2 or more. Using regional high-resolution simulations, we show that these large errors are mostly due to the global model's inability to capture local scale effects. In New Zeland, the increase in resolution produces a significant decrease of surface concentrations (up to 40%) - due to changes in the wind circulation and precipitation driven by the orographic barrier

  19. X-Ray Spectroscopy: An Experimental Technique to Measure Charge State Distribution Right at the Ion-Solid Interaction

    CERN Document Server

    Sharma, Prashant

    2015-01-01

    Charge state distributions of $^{56}$Fe and $^{58}$Ni projectile ions passing through thin carbon foils have been studied in the energy range of 1.44 - 2.69 MeV/u using a novel method from the x-ray spectroscopy technique. Interestingly the charge state distribution in the bulk show Lorentzian behavior instead of usual Gaussian distribution. Further, different parameters of charge state distribution like mean charge state, distribution width and asymmetric parameter are determined and compared with the empirical calculations and ETACHA predictions. It is found that the x-ray measurement technique is appropriate to determine the mean charge state right at the interaction zone or in the bulk. Interestingly, empirical formalism predicts much lower projectile mean charge states compare to x-ray measurements which clearly indicate multi-electron capture from the target surface. The ETACHA predictions and experimental results are found to be comparable for energies $\\geq$ 2 MeV/u.

  20. Molten salt-directed synthesis method for LiMn2O4 nanorods as a cathode material for a lithium-ion battery with superior cyclability

    CSIR Research Space (South Africa)

    Kebede, Mesfin A

    2017-02-01

    Full Text Available A molten salt synthesis technique has been used to prepare nanorods of Mn2O3 and single-crystal LiMn2O4 nanorods cathode material with superior capacity retention. The molten salt-directed synthesis involved the use of NaCl as the eutectic melt...

  1. Break Point Distribution on Chromosome 3 of Human Epithelial Cells exposed to Gamma Rays, Neutrons and Fe Ions

    Science.gov (United States)

    Hada, M.; Saganti, P. B.; Gersey, B.; Wilkins, R.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    Most of the reported studies of break point distribution on the damaged chromosomes from radiation exposure were carried out with the G-banding technique or determined based on the relative length of the broken chromosomal fragments. However, these techniques lack the accuracy in comparison with the later developed multicolor banding in situ hybridization (mBAND) technique that is generally used for analysis of intrachromosomal aberrations such as inversions. Using mBAND, we studied chromosome aberrations in human epithelial cells exposed in vitro to both low or high dose rate gamma rays in Houston, low dose rate secondary neutrons at Los Alamos National Laboratory and high dose rate 600 MeV/u Fe ions at NASA Space Radiation Laboratory. Detailed analysis of the inversion type revealed that all of the three radiation types induced a low incidence of simple inversions. Half of the inversions observed after neutron or Fe ion exposure, and the majority of inversions in gamma-irradiated samples were accompanied by other types of intrachromosomal aberrations. In addition, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosome exchanges. We further compared the distribution of break point on chromosome 3 for the three radiation types. The break points were found to be randomly distributed on chromosome 3 after neutrons or Fe ions exposure, whereas non-random distribution with clustering break points was observed for gamma-rays. The break point distribution may serve as a potential fingerprint of high-LET radiation exposure.

  2. Investigation of subauroral ion drifts and related field-aligned currents and ionospheric Pedersen conductivity distribution

    Directory of Open Access Journals (Sweden)

    S. Figueiredo

    2004-03-01

    Full Text Available Based on Astrid-2 satellite data, results are presented from a statistical study on subauroral ion drift (SAID occurrence. SAID is a subauroral phenomenon characterized by a westward ionospheric ion drift with velocity greater than 1000m/s, or equivalently, by a poleward-directed electric field with intensity greater than 30mV/m. SAID events occur predominantly in the premidnight sector, with a maximum probability located within the 20:00 to 23:00 MLT sector, where the most rapid SAID events are also found. They are substorm related, and show first an increase in intensity and a decrease in latitudinal width during the expansion phase, followed by a weakening and widening of the SAID structures during the recovery phase. The potential drop across a SAID structure is seen to remain roughly constant during the recovery phase.

    The field-aligned current density and the height-integrated Pedersen conductivity distribution associated with the SAID events were calculated. The results reveal that the strongest SAID electric field peaks are associated with the lowest Pedersen conductivity minimum values. Clear modifications are seen in the ionospheric Pedersen conductivity distribution associated with the SAID structure as time evolves: the SAID peak is located on the poleward side of the corresponding region of reduced Pedersen conductivity; the shape of the regions of reduced conductivity is asymmetric, with a steeper poleward edge and a more rounded equatorward edge; the SAID structure becomes less intense and widens with evolution of the substorm recovery phase. From the analysis of the SAID occurrence relative to the mid-latitude trough position, SAID peaks are seen to occur relatively close to the corresponding mid-latitude trough minimum. Both these features show a similar response to magnetospheric disturbances, but on different time scales - with increasing magnetic activity, the SAID structure shows a faster

  3. Temporal evolution of confined fast-ion velocity distributions measured by collective Thomson scattering in TEXTOR

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Bindslev, Henrik; Porte, L.

    2008-01-01

    Fast ions created in the fusion processes will provide up to 70% of the heating in ITER. To optimize heating and current drive in magnetically confined plasmas insight into fast-ion dynamics is important. First measurements of such dynamics by collective Thomson scattering (CTS) were recently...

  4. Concentration Distribution of Chloride Ion under the Influence of the Convection-Diffusion Coupling

    Directory of Open Access Journals (Sweden)

    Q. L. Zhao

    2017-01-01

    Full Text Available The transfer process of chloride ion under the action of the convection-diffusion coupling was analyzed in order to predict the corrosion of reinforcement and the durability of structure more accurately. Considering the time-varying properties of diffusion coefficient and the space-time effect of the convection velocity, the differential equation for chloride ion transfer under the action of the convection-diffusion coupling was constructed. And then the chloride ion transfer model was validated by the existing experimental datum and the actual project datum. The results showed that when only diffusion was considered, the chlorine ion concentration increased with the time and decreased with the decay index of time. Under the action of the convection-diffusion coupling, at each point of coupling region, the chloride ion concentration first increased and then decreased and tended to stabilize, and the maximum appeared at the moment of convection velocity being 0; in the diffusion zone, the chloride ion concentration increased over time, and the chloride ion concentration of the same location increased with the depth of convection (in the later period, the velocity of convection (in the early period, and the chloride ion concentration of the surface.

  5. Ion distribution measured by electron probe X-ray microanalysis in ...

    Indian Academy of Sciences (India)

    2012-08-13

    Aug 13, 2012 ... were studied in sunflower plants exposed to moderate salinity (EC=6). ... Salt stress is one of the major abiotic stresses limiting crop ... mally not in sufficient concentration to have major ability for inward water movement in such situations. Some of plants try to accumulate high levels of compatible solutes in ...

  6. Ion distribution measured by electron probe X-ray microanalysis in ...

    Indian Academy of Sciences (India)

    This phenomenon may be able to increase salt tolerance in sunflower plants. Supplemental calcium has been found to be effective in reducing radial transport of Na+ across the root cells and their loading into the xylem, but not sodium absorption. Supplemental calcium enhanced Ca2+ uptake and influx into roots and ...

  7. INNER SALTS

    Science.gov (United States)

    been characterized include: (1) mesomeric phosphonium salts possessing phototropic properties; (2) pentavalent phosphorus compounds; and (3) a...Products that have been characterized include: (1) mesomeric phosphonium salts possessing phototropic properties; (2) pentavalent phosphorus compounds; and (3) a mesomeric inner salt . (Author)...Novel phosphonium and phosphorane compounds ere prepared by a variety of m hods from triphenylphosphine and methylene bromide. Products that have

  8. Spatial distribution of the electrical potential and ion concentration in the downstream area of atmospheric pressure remote plasma

    Directory of Open Access Journals (Sweden)

    M. V. Mishin

    2014-10-01

    Full Text Available This paper presents the results from an experimental study of the ion flux characteristics behind the remote plasma zone in a vertical tube reaction chamber for atmospheric pressure plasma enhanced chemical vapor deposition. Capacitively coupled radio frequency plasma was generated in pure He and gas mixtures: He–Ar, He–O2, He–TEOS. We previously used the reaction system He–TEOS for the synthesis of self-assembled structures of silicon dioxide nanoparticles. It is likely that the electrical parameters of the area, where nanoparticles have been transported from the synthesis zone to the substrate, play a significant role in the self-organization processes both in the vapor phase and on the substrate surface. The results from the spatial distribution of the electrical potential and ion concentration in the discharge downstream area measured by means of the external probe of original design and the special data processing method are demonstrated in this work. Positive and negatives ions with maximum concentrations of 106–107 cm−3 have been found at 10–80 mm distance behind the plasma zone. On the basis of the revealed distributions for different gas mixtures, the physical model of the observed phenomena is proposed. The model illustrates the capability of the virtual ion emitter formation behind the discharge gap and the presence of an extremum of the electrical potential at the distance of approximately 10−2–10−1 mm from the grounded electrode.

  9. Unified solution of the Boltzmann equation for electron and ion velocity distribution functions and transport coefficients in weakly ionized plasmas

    Science.gov (United States)

    Konovalov, Dmitry A.; Cocks, Daniel G.; White, Ronald D.

    2017-10-01

    The velocity distribution function and transport coefficients for charged particles in weakly ionized plasmas are calculated via a multi-term solution of Boltzmann's equation and benchmarked using a Monte-Carlo simulation. A unified framework for the solution of the original full Boltzmann's equation is presented which is valid for ions and electrons, avoiding any recourse to approximate forms of the collision operator in various limiting mass ratio cases. This direct method using Lebedev quadratures over the velocity and scattering angles avoids the need to represent the ion mass dependence in the collision operator through an expansion in terms of the charged particle to neutral mass ratio. For the two-temperature Burnett function method considered in this study, this amounts to avoiding the need for the complex Talmi-transformation methods and associated mass-ratio expansions. More generally, we highlight the deficiencies in the two-temperature Burnett function method for heavy ions at high electric fields to calculate the ion velocity distribution function, even though the transport coefficients have converged. Contribution to the Topical Issue "Physics of Ionized Gases (SPIG 2016)", edited by Goran Poparic, Bratislav Obradovic, Dragana Maric and Aleksandar Milosavljevic.

  10. Closed form S matrix in terms of matter distributions and nucleon-nucleon interaction for heavy ion scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gambhir, Y.K.; Shastry, C.S.

    1984-10-01

    We derive an approximate analytical expression for the S matrix in terms of the parameters of the nuclear matter distributions and nucleon-nucleon interaction in the framework of folding model for heavy ion scattering. The numerical calculations carried out for /sup 18/O+ /sup 58/Ni scattering (E/sub lab/ = 60 MeV), a test case, agree well with the corresponding results of the phenomenological optical model.

  11. Investigation on target normal sheath acceleration through measurements of ions energy distribution

    Energy Technology Data Exchange (ETDEWEB)

    Tudisco, S., E-mail: tudisco@lns.infn.it; Cirrone, G. A. P.; Mascali, D.; Schillaci, F. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Altana, C. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Via S. Sofia 64, 95123 Catania (Italy); Lanzalone, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Università degli Studi di Enna “Kore,” Via delle Olimpiadi, 94100 Enna (Italy); Muoio, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina, Viale F.S. D’Alcontres 31, 98166 Messina (Italy); Brandi, F. [Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica, Intense Laser Irradiation Laboratory, Via G. Moruzzi 1, 56124 Pisa (Italy); Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Cristoforetti, G.; Ferrara, P.; Fulgentini, L.; Koester, P. [Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica, Intense Laser Irradiation Laboratory, Via G. Moruzzi 1, 56124 Pisa (Italy); Labate, L.; Gizzi, L. A. [Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica, Intense Laser Irradiation Laboratory, Via G. Moruzzi 1, 56124 Pisa (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); and others

    2016-02-15

    An experimental campaign aiming at investigating the ion acceleration mechanisms through laser-matter interaction in femtosecond domain has been carried out at the Intense Laser Irradiation Laboratory facility with a laser intensity of up to 2 × 10{sup 19} W/cm{sup 2}. A Thomson parabola spectrometer was used to obtain the spectra of the ions of the different species accelerated. Here, we show the energy spectra of light-ions and we discuss their dependence on structural characteristics of the target and the role of surface and target bulk in the acceleration process.

  12. In Situ Studies on Twin-Thickness-Dependent Distribution of Defect Clusters in Heavy Ion-Irradiated Nanotwinned Ag

    Science.gov (United States)

    Li, Jin; Chen, Y.; Wang, H.; Zhang, X.

    2017-03-01

    Recent studies have shown that twin boundaries are effective defect sinks in heavy ion irradiated nanotwinned (nt) metals. Prior in situ radiation studies on nt Ag at room temperature indicate that the accumulative defect concentration is higher in center areas in the 60-nm-thick twins, and twin boundaries are distorted and self-heal during the absorption of different types of defect clusters. In this follow-up study, we show that the spatial distribution of accumulative defect concentrations in nt metals has a clear dependence on twin thickness, and in certain cases, the trend of spatial distribution is reversed. Potential mechanisms for the counterintuitive findings are discussed.

  13. Dietary salt reduction for control of hypertension

    Directory of Open Access Journals (Sweden)

    Richard Tjan

    2016-02-01

    Full Text Available In developed as well as developing countries, the four main factors affecting blood pressure are high salt intake, low potassium intake, overweight, and low physical activity level. This is also true for the increase in blood pressure with advancing age, occurring in all societies. It is now accepted that excess dietary salt raises blood pressure levels, whereas dietary salt reduction reduces blood pressure and prevents vascular complications.(1 The effect of salt on blood pressure is presumably due to the inability of the kidneys to excrete large amounts of salt, as humans are evolutionary adapted to ingest and excrete less than 1 gram of salt per day.(2 In this connection it should be noted that the more important element in common salt (sodium chloride is the sodium ion, and any restrictions applying to common salt also apply to all food items that contain sodium ions, such as sodium glutamate and baking soda.

  14. The distribution of ion energies at the substrate in an asymmetric bi-polar pulsed DC magnetron discharge

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J W [Department of Physics, UMIST, Sackville Street, Manchester, M60 1QD (United Kingdom); Baecker, H [Department of Physics, UMIST, Sackville Street, Manchester, M60 1QD (United Kingdom); Aranda-Gonzalvo, Y [Department of Physics, UMIST, Sackville Street, Manchester, M60 1QD (United Kingdom); Kelly, P J [Institute for Materials Research, University of Salford, M5 4WT (United Kingdom); Arnell, R D [Institute for Materials Research, University of Salford, M5 4WT (United Kingdom)

    2002-05-01

    Using an energy-resolved mass spectrometer and a time-resolved Langmuir probe, the distribution of bombarding ion energies, their fluxes and energy fluxes at a substrate in an asymmetric bi-polar pulsed DC magnetron have been determined. The discharge was operated in Ar at a pressure of 0.53 Pa with a Ti target and pulsed DC frequencies of 100 and 350 kHz with a range of duty cycles (from 50 to 96%). At 100 kHz, the Ar{sup +}and Ti{sup +} time-averaged ion energy distribution functions (IEDFs) reveal three peaks, which are at low energy (<10 eV), in a mid-range (20-50 eV) and at high energy (60-100 eV). We correlate these peaks with distinct phases of the discharge voltage. At 350 kHz the IEDFs show four peaks reflecting a more complex voltage waveform. The low-energy ions are generated in the 'on' phase when the plasma potential is typically a few volts above ground. The Ti{sup +} energy spectra show a remnant of the original sputter-neutral energy distribution function. The mid-range ions are produced in the quiescent region of the voltage reverse phase, when the plasma potential is raised globally a few volts above the cathode potential, typically 10-30 V. The high-energy ions are generated in a period of {approx}0.3 {mu}s, during the discharge voltage overshoot, when the target potential rises to typically over +140 V. However, given the time resolution of the Langmuir probe (0.5 {mu}s), it is not possible to determine if plasma potential is lifted globally to this high potential or only close to the cathode. At 350 kHz, these 'fast' ions make up to about a quarter of the total ion flux at the substrate and an upper bound transient power flux of about 2.5 times the maximum delivered in the 'on' phase. The total power flux to a substrate in the sustained phase of the discharge is found to increase with frequency and reverse time.

  15. Arbitrary amplitude ion-acoustic solitary waves in electronegative plasmas with electrons featuring Tsallis distribution

    Science.gov (United States)

    Ghebache, Siham; Tribeche, Mouloud

    2017-10-01

    The problem of arbitrary amplitude ion-acoustic solitary waves (IASWs), which accompany electronegative plasmas having positive ions, negative ions, and nonextensive electrons is addressed. The energy integral equation with a new Sagdeev potential is analyzed to examine the existence regions of the IASWs. Different types of electronegative plasmas inspired from the experimental studies of Ichiki et al. (2001) are discussed. Our results show that in such plasmas IASWs, the amplitude and nature of which depend sensitively on the mass and density ratio of the positive and negative ions as well as the q-nonextensive parameter, can exist. Interestingly, one finds that our plasma model supports the coexistence of smooth rarefactive and spiky compressive IASWs. Our results complement and provide new insights on previously published findings on this problem.

  16. Analytical modeling and simulation of porous electrodes: Li-ion distribution and diffusion-induced stress

    Science.gov (United States)

    Ji, Liang; Guo, Zhansheng

    2017-08-01

    A new model of porous electrodes based on the Gibbs free energy is developed, in which lithium-ion (Li-ion) diffusion, diffusion-induced stress (DIS), Butler-Volmer (BV) reaction kinetics, and size polydispersity of electrode particles are considered. The influence of BV reaction kinetics and concentration-dependent exchange current density (ECD) on concentration profile and DIS evolution are numerically investigated. BV reaction kinetics leads to a decrease in Li-ion concentration and DIS. In addition, concentration-dependent ECD results in a decrease in Li-ion concentration and an increase in DIS. Size polydispersity of electrode particles significantly affects the concentration profile and DIS. Optimal macroscopic state of charge (SOC) should consider the influence of the microscopic SOC values and mass fractions of differently sized particles.

  17. Using Cassini's spacecraft potential as an intrinsic link between ion and electron distributions

    Science.gov (United States)

    Livi, R.; Goldstein, J.; Burch, J. L.; Rymer, A. M.; Mitchell, D. G.; Hill, T. W.

    2012-12-01

    We present an algorithm for automated derivation of plasma moments in Saturn's inner and equatorial magnetosphere by analyzing data from the Cassini CAPS suite, specifically using the Electron Spectrometer (ELS) and the Ion Mass Spectrometer (IMS). Ions within Saturn's magnetosphere exhibit a drift motion around the planet together with corotating magnetic field lines, and as a result, all singly charged ion species should corotate with the same bulk velocity at any given location and time. However, initial analysis of an ensemble of bulk drift velocities shows a strong (5%-30%) discrepancy for ions of different masses. With the assumption of equal drift velocity for all ion species, we conclude that the discrepancy results from the presence of a potential field between Cassini and the ambient plasma. To address this feature, the spacecraft (S/C) potential is accounted for in the ion moment derivation as an additional parameter in the forward modeling of the data. Electron moments need a similar adjustment. For positive charging of the S/C, the electron data shows the presence of photoelectrons, which are used to determine the magnitude of the potential difference. Negative S/C potentials cannot be derived from the electron data. Therefore, negative S/C potentials are taken from the ion derivation and used to adjust the electron data. The plasma moments yielded from this methodology are compared to electron (i.e., total) number density obtained from wave measurements by the RPWS instrument and show excellent agreement between the total number densities obtained respectively from CAPS and RPWS. Our results validate the automated plasma moment algorithm, enabling routine and comprehensive determination of plasma moments from the CAPS (electron and ion) data set.

  18. Ion fluxes and ion distribution function moments in the Martian and Venusian magnetospheres for 2007 - 2017 time interval. The data of the ASPERA instrument onboard of Mars Express and Venus Express missions

    Science.gov (United States)

    Fedorov, A.; Knizhnikova, E.; Barabash, S.

    2017-09-01

    We present ion moments data set that have been obtained from the IMA mass-spectrometer which is a part of ASPERA plasma package. IMA is a sophisticate ion mass-spectrometer with almost omnidirectional field of view. It produces 3D distribution function of H+, He++, He+, O+, and O2+ with excelent energy and angular resolution.

  19. Distribution and mapping of the snail Cerithideopsis (Cerithidea) californica at Carpinteria Salt Marsh, California USA, June to August 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — We collected detailed spatial data on the density and size distribution of intertidal snails as part of a broader effort to understand food webs in California...

  20. Background and Pickup Ion Velocity Distribution Dynamics in Titan's Plasma Environment: 3D Hybrid Simulation and Comparison with CAPS T9 Observations

    Science.gov (United States)

    Lipatov, A. S.; Sittler, E. C., Jr.; Hartle, R. E.; Cooper, J. F.; Simpson, D. G.

    2011-01-01

    In this report we discuss the ion velocity distribution dynamics from the 3D hybrid simulation. In our model the background, pickup, and ionospheric ions are considered as a particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. We also take into account the collisions between the ions and neutrals. The current simulation shows that mass loading by pickup ions H(+); H2(+), CH4(+) and N2(+) is stronger than in the previous simulations when O+ ions are introduced into the background plasma. In our hybrid simulations we use Chamberlain profiles for the atmospheric components. We also include a simple ionosphere model with average mass M = 28 amu ions that were generated inside the ionosphere. The moon is considered as a weakly conducting body. Special attention will be paid to comparing the simulated pickup ion velocity distribution with CAPS T9 observations. Our simulation shows an asymmetry of the ion density distribution and the magnetic field, including the formation of the Alfve n wing-like structures. The simulation also shows that the ring-like velocity distribution for pickup ions relaxes to a Maxwellian core and a shell-like halo.

  1. Angular distribution and recoil effect for 1 MeV Au{sup +} ions through a Si{sub 3}N{sub 4} thin foil

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Ke [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Zhu, Zihua, E-mail: zihua.zhu@pnnl.gov [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); Manandhar, Sandeep; Liu, Jia [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); Chen, Chien-Hung [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Shutthanandan, Vaithiyalingam; Thevuthasan, Suntharampillai [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); Weber, William J. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Zhang, Yanwen, E-mail: Zhangy1@ornl.gov [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States)

    2014-08-01

    The Stopping and Range of Ions in Matter (SRIM) code has been widely used to predict nuclear stopping power and angular distribution of ion–solid collisions. However, experimental validation of the predictions is insufficient for slow heavy ions in nonmetallic compounds. In this work, time-of-flight secondary ion mass spectrometry (ToF-SIMS) is applied to determine the angular distribution of 1 MeV Au ions after penetrating a Si{sub 3}N{sub 4} foil with a thickness of ∼100 nm. The exiting Au ions are collected by a Si wafer located ∼14 mm behind the Si{sub 3}N{sub 4} foil, and the resulting 2-dimensional distribution of Au ions on the Si wafer is measured by ToF-SIMS. The SRIM-predicted angular distribution of Au ions through the Si{sub 3}N{sub 4} thin foil is compared with the measured results, indicating that SRIM slightly overestimates the nuclear stopping power by up to 10%. In addition, thickness reduction of the suspended Si{sub 3}N{sub 4} foils induced by 1 MeV Au ion irradiation is observed with an average loss rate of ∼107 atoms/ion.

  2. Resedimented salt deposits

    Energy Technology Data Exchange (ETDEWEB)

    Slaczka, A.; Kolasa, K. (Jagiellonian Univ., Krakow (Poland))

    1988-08-01

    Carparthian foredeep's Wieliczka salt mine, unique gravity deposits were lately distinguished. They are mainly built of salt particles and blocks with a small admixture of fragments of Miocene marls and Carpathian rocks, deposited on precipitated salt. The pattern of sediment distribution is similar to a submarine fan. Gravels are dominant in the upper part and sands in lower levels, creating a series of lobes. Coarse-grained deposits are represented by disorganized, self-supported conglomerates passing into matrix-supported ones, locally with gradation, and pebbly sandstones consisting of salt grains and scattered boulder-size clasts. The latter may show in the upper part of a single bed as indistinct cross-bedding and parallel lamination. These sediments are interpreted as debris-flow and high-density turbidity current deposits. Salt sandstones (saltstones) which build a lower part of the fan often show Bouma sequences and are interpreted as turbidity-current deposits. The fan deposits are covered by a thick series of debrites (olistostromes) which consist of clay matrix with salt grains and boulders. The latter as represented by huge (up to 100,000 m{sup 3}) salt blocks, fragments of Miocene marls and Carpathian rocks. These salt debrites represent slumps and debris-flow deposits. The material for resedimented deposits was derived from the southern part of the salt basin and from the adjacent, advancing Carpathian orogen. The authors believe the distinct coarsening-upward sequence of the series is the result of progressive intensification of tectonic movements with paroxysm during the sedimentation of salt debrites (about 15 Ma).

  3. Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

    Directory of Open Access Journals (Sweden)

    Keslarek Amauri José

    2004-01-01

    Full Text Available Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM. Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the particles, while S is uniformly distributed within then. The Na and N elemental maps show that the respective monovalent ions (Na+ and NH4+ have different distributions, in the latex: Na signal within the particles is stronger than in the background, while N is accumulated at the particle borders. The distributions of surfactant and counter-ions are thus different from some current assumptions, but they support recent results on the distribution of ionic constituents in latex films, by scanning electric potential microscopy.

  4. Depth dependent charge state distributions of heavy MeV ions in RBS and ERD experiments

    Science.gov (United States)

    Jamecsny, S.; Carstanjen, H. D.

    1997-04-01

    At the Max-Planck-Institut für Metallforschung in Stuttgart, Germany, a 6 MV Pelletron accelerator is being used for surface analysis by means of high resolution RBS and ERD using an electrostatic spectrometer. For the ERD analysis of ions heavier than hydrogen the recording of a second parameter is necessary to identify the particle species and its charge state. For this purpose a set-up was installed that combines the high energy resolution of the spectrometer with a measurement of the time of flight of the ions through the spectrometer using a chopped ion beam. The technique also allows to measure charge state dependent depth profiles. Energy spectra of all observable charge states were recorded for backscattered Ne and Ar ions from Au and of recoil O ions from Ta 2O 5 and Al 2O 3. The comparison of a computer simulation of the charge exchange processes with the measurements of Ar scattering on Au yields mean free path lengths for electron capture and loss.

  5. A Distributed Monitoring and Control System for the Laser Ion Source RILIS at CERN-ISOLDE

    CERN Document Server

    AUTHOR|(SzGeCERN)715185; Richter, Detlef; Wendt, Klaus

    In this work, the implementation of the LabVIEW-based RILIS Equipment Acquisition and Control Toolset (REACT) software framework is documented, revised, and further developed to accomplish remotely operated in-source laser spectroscopy experiments at CERN-ISOLDE. The Resonance Ionization Laser Ion Source (RILIS) is an integral part of the radioactive ion beam user facility ISOLDE at CERN. Its task as an ion source is to ensure high isobaric purity and production efficiency of the ion beams that are generated for the various experimental setups of the facility. Reliable operation requires directing 3 pulsed laser beams, precisely wavelength-tuned and overlapped in time to a precision of 5 nanoseconds, to converge into a 3mm diameter ion source cavity located 25m away in an inaccessible radioactive environment. These stable conditions have to be maintained for up to 7 days at a time per experiment setup. Within recent years, the array of RILIS equipment and its need to interface with other experimental apparatu...

  6. Beam loss distribution calculation and collimation efficiency simulation of a cooler storage ring in a heavy ion research facility

    Directory of Open Access Journals (Sweden)

    Peng Li

    2014-08-01

    Full Text Available The Heavy Ion Research Facility in Lanzhou is an ion cooler storage ring facility in China’s Institute of Modern Physics. The beams are accumulated, electron cooled, accelerated, and extracted from the main cooler storage ring (CSRm to the experimental ring or different terminals. The heavy ion beams are easily lost at the vacuum chamber along the CSRm when it is used to accumulate intermediate charge state particles. The vacuum pressure bump due to the ion-induced desorption in turn leads to an increase in beam loss rate. In order to avoid the complete beam loss, the collimation system is investigated and planned to be installed in the CSRm. First, the beam loss distribution is simulated considering the particle charge exchanged process. Then the collimation efficiency of the lost particles is calculated and optimized under different position and geometry of the collimators and beam emittance and so on. Furthermore, the beam orbit distortion that is caused by different types of errors in the ring will affect the collimation efficiency. The linearized and inhomogeneous equations of particle motion with these errors are derived and solved by an extended transfer matrix method. Actual magnet alignment errors are adopted to investigate the collimation efficiency of the lost particles in the CSRm. Estimation of the beam loss positions and optimization of the collimation system is completed by a newly developed simulation program.

  7. Ion Impact Energy Distributions and Properties of Amorphous Hydrogenated Carbon Thin Films Deposited in a Self-Biased RF Discharge

    Science.gov (United States)

    Tatsuta, Toshiaki; Tachibana, Kunihide; Tsuji, Osamu

    1994-11-01

    In a self-biased RF discharge in CH4 we have investigated the relationships between the properties of hydrogenated amorphous carbon (a-C:H) film and ion impact energy distributions (IIEDs) measured by retarding-type ion energy analyzer at both parallel-plate electrodes. On the RF electrode a high-energy peak (HEP) dur to the ion beam component was observed in IIED. The height of HEP decreased with increasing pressure at a given self-bias voltage (V dc) and the central energy of HEP increased linearly with V dc at a given pressure. The micro hardness of the film increased in proportion to the total incident ion current (TIIC) and central energy of HEP. The hydrogen content decreased and the surface morphology became fine as the central energy of HEP increased. From Raman and IR absorption spectra it turned out that there was an optimal energy of HEP to increase the content of the sp3 bonding structure in the film.

  8. Brine migration in salt in a thermal gradient

    Science.gov (United States)

    Kang, M.; Lerche, M.; Lesher, C. E.

    2015-12-01

    Salt deposits have long been considered viable repositories for long-term storage of high-level nuclear waste. However, brine trapped in salt tends to migrate up thermal gradients, such as can develop around radioactive waste storage containers, potentially promoting corrosion of containment structures. Brine inclusions move up the temperature gradient through the three main steps: 1) the dissolution of salt at the hot side of the inclusion caused by increased salt solubility, 2) ordinary and thermal diffusion of dissolved salt ions within the inclusion, and 3) precipitation of salt at the cold side of the inclusion due to local supersaturation. This process of brine transport through salt under a thermal gradient is generally referred to as thermal migration. Here we investigated thermal migration of brine inclusion in salts for a wide range of mean temperatures (~ 50 °C to ~200 °C) and temperature gradients (~ 10 °C/cm to ~57 °C/cm). With time brine inclusions moving towards the heat source become elongated parallel to the thermal gradient. We quantified the rate of brine migration as a function of mean temperature and thermal gradient using time-lapse optical microscope. X -ray and neutron tomography were used to visualize and quantify 3D spatial distribution of brine inclusion in a salt crystal at different stages of thermal migration. Migration velocities are shown to increase with temperature, temperature gradient and size of inclusion. We find an abrupt increase in migration velocity at certain time steps of thermal migration. Migration velocities of brine inclusions ranged from 0.1 m/year to 30.7 m/year. Empirical equations at different velocity regions for brine inclusions were obtained by fitting exponential equations to the experimental data with high coefficient of determination values (R2> 0.94).The experimental results are in good agreement with the theoretical migration rates obtained using a previous analytical model.

  9. Dust ion acoustic freak waves in a plasma with two temperature electrons featuring Tsallis distribution

    Science.gov (United States)

    Chahal, Balwinder Singh; Singh, Manpreet; Shalini; Saini, N. S.

    2018-02-01

    We present an investigation for the nonlinear dust ion acoustic wave modulation in a plasma composed of charged dust grains, two temperature (cold and hot) nonextensive electrons and ions. For this purpose, the multiscale reductive perturbation technique is used to obtain a nonlinear Schrödinger equation. The critical wave number, which indicates where the modulational instability sets in, has been determined precisely for various regimes. The influence of plasma background nonextensivity on the growth rate of modulational instability is discussed. The modulated wavepackets in the form of either bright or dark type envelope solitons may exist. Formation of rogue waves from bright envelope solitons is also discussed. The investigation indicates that the structural characteristics of these envelope excitations (width, amplitude) are significantly affected by nonextensivity, dust concentration, cold electron-ion density ratio and temperature ratio.

  10. A natural saline soil as a model for understanding to what extent the concentration of salt affects the distribution of microorganisms

    Science.gov (United States)

    Canfora, Loredana; Pinzari, Flavia; Lo Papa, Giuseppe; Vittori Antisari, Livia; Vendramin, Elisa; Salvati, Luca; Dazzi, Carmelo; Benedetti, Anna

    2017-04-01

    Soils preserve and sustain life. Their health and functioning are crucial for crop production and for the maintenance of major ecosystem services. Human induced salinity is one of the main soil threats that reduces soil fertility and affect crop yields. In recent times, great attention has been paid to the general shortage of arable land and to the increasing demand for ecological restoration of areas affected by salinization processes. Despite the diffuse interest on the effects of salinization on plants' growth, and all the derived socioeconomic issues, very few studies analyzed the ecology of the microbial species in naturally saline soils and the resilience of biological fertility in these extreme habitats. Microorganisms inhabiting such environments may share a strategy, may have developed multiple adaptations for maintaining their populations, and cope eventually to extreme conditions by altruistic or cooperative behaviors for maintaining their metabolism active. The understanding and the knowledge of the composition and distribution of microbial communities in natural hypersaline soils can be interesting for ecological reasons but also to develop new restoration strategy where soil fertility was compromised by natural accidents or human mismanagement. The aim of this research was to provide specific information on saline soils in Italy, stressing mainly their distribution, the socioeconomic issues and the understanding of the characterizing ecological processes. Moreover, natural saline soils were used as a model for understanding to what extent the concentration of salt can affect some basic microbial processes. In the present study, physical, chemical and microbiological soil properties were investigated in the shallower horizons of natural salt affected soils in Sicily (Italy), where some ecological contrasting variables acted as strong drivers in fungal and bacterial spatial distribution. Furthermore, the interface between biological and geochemical

  11. FT-IR and FT-Raman studies of cross-linking processes with Ca(2+) ions, glutaraldehyde and microwave radiation for polymer composition of poly(acrylic acid)/sodium salt of carboxymethyl starch--part I.

    Science.gov (United States)

    Grabowska, Beata; Sitarz, Maciej; Olejnik, Ewa; Kaczmarska, Karolina

    2015-01-25

    FT-IR and FT-Raman spectroscopic methods allowed to identify the cross-linking process of the aqueous composition of poly(acrylic acid)/sodium salt of carboxymethyl starch (PAA/CMS-Na) applied as a binder for moulding sands. The cross-linking was performed by chemical methods by introducing cross-linking substances with Ca(2+) ions or glutaraldehyde and by physical way, applying the microwave radiation. It was found that Ca(2+) ions cause formation of cross-linking ionic bonds within carboxyl and carboxylate groups. Glutaraldehyde generates formation of cross-linking bonds with hemiacetal and acetal structures. Whereas in the microwave radiation field, due to dehydration, lattices are formed by anhydride bonds. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Time-of-flight secondary ion mass spectrometry-based molecular distribution distinguishing healthy and osteoarthritic human cartilage

    CERN Document Server

    Cillero-Pastor, Berta; Kiss, Andras; Blanco, Francisco J; Heeren, Ron M A

    2013-01-01

    Osteoarthritis (OA) is a pathology that ultimately causes joint destruction. The cartilage is one of the principal affected tissues. Alterations in the lipid mediators and an imbalance in the metabolism of cells that form the cartilage (chondrocytes) have been described as contributors to the OA development. In this study, we have studied the distribution of lipids and chemical elements in healthy and OA human cartilage. Time of flight-secondary ion mass spectrometry (TOF-SIMS) allows us to study the spatial distribution of molecules at a high resolution on a tissue section. TOF-SIMS revealed a specific peak profile that distinguishes healthy from OA cartilages. The spatial distribution of cholesterol-related peaks exhibited a remarkable difference between healthy and OA cartilages. A distinctive colocalization of cholesterol and other lipids in the superficial area of the cartilage was found. A higher intensity of oleic acid and other fatty acids in the OA cartilages exhibited a similar localization. On the ...

  13. Charge distribution of Kr ions produced upon photoionization around the 2s edge

    Energy Technology Data Exchange (ETDEWEB)

    Santos, A.C.F., E-mail: toni@if.ufrj.br [Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21991-972 (Brazil); Pilling, S. [Laboratório Nacional de Luz Síncroton, Campinas 13084-971 (Brazil); Almeida, D.P. [Departamento de Física, Universidade Federal de Santa Catarina, Florianópolis 88040-979 (Brazil)

    2015-08-15

    Highlights: • Charge spectra of Kr after photoionization of the L shell have been measured. • Multiple photoionization of krypton around the 2s edge is a collective process. • Electron correlation plays an important role in multiple ionization of heavy atoms. - Abstract: Charge state spectra of krypton ions generated after ionization (by a single photon) of the L shell have been measured by using the PEPICO technique. Relative abundances of Kr{sup q+} ions in charge state up to 8+ were obtained using monochromatized synchrotron radiation. A comparison with other experimental and theoretical data is presented.

  14. Ion distributions at the water/1,2-dichloroethane interface: potential of mean force approach to analyzing X-ray reflectivity and interfacial tension measurements.

    Science.gov (United States)

    Hou, Binyang; Laanait, Nouamane; Yu, Hao; Bu, Wei; Yoon, Jaesung; Lin, Binhua; Meron, Mati; Luo, Guangming; Vanysek, Petr; Schlossman, Mark L

    2013-05-02

    We present X-ray reflectivity and interfacial tension measurements of the electrified liquid/liquid interface between two immiscible electrolyte solutions for the purpose of understanding the dependence of interfacial ion distributions on the applied electric potential difference across the interface. The aqueous phase contains alkali-metal chlorides, including LiCl, NaCl, RbCl, or CsCl, and the organic phase is a 1,2-dichloroethane solution of bis(triphenylphosphor anylidene) ammonium tetrakis(pentafluorophenyl)borate (BTPPATPFB). Selected data for a subset of electric potential differences are analyzed to determine the potentials of mean force for Li(+), Rb(+), Cs(+), BTPPA(+), and TPFB(-). These potentials of mean force are then used to analyze both X-ray reflectivity and interfacial tension data measured over a wide range of electric potential differences. Comparison of X-ray reflectivity data for strongly hydrated alkali-metal ions (Li(+) and Na(+)), for which ion pairing to TPFB(-) ions across the interface is not expected, to data for weakly hydrated alkali-metal ions (Rb(+) and Cs(+)) indicates that the Gibbs energy of adsorption due to ion pairing at the interface must be small (X-ray reflectivity measurements that probe the nanoscale ion distribution and the consequences of these underlying distributions for thermodynamic studies, such as interfacial tension measurements, that yield quantities related to the integrated ion distribution.

  15. Ion energy and angular distributions onto polymer surfaces delivered by dielectric barrier discharge filaments in air: II. Particles

    Energy Technology Data Exchange (ETDEWEB)

    Babaeva, Natalia Yu; Kushner, Mark J, E-mail: nbabaeva@umich.edu, E-mail: mjkush@umich.edu [University of Michigan, Department of Electrical Engineering and Computer Science 1301 Beal Ave, Ann Arbor, MI 48109 (United States)

    2011-06-15

    Atmospheric pressure streamers intersecting particles are of interest in the context of plasma aided combustion, where the particle may be a fuel aerosol droplet, or in sterilization of air, where the particle may be a bacterium. The ion energy and angular distributions (IEADs) incident on the particles, small curved dielectric surfaces, then in part determine the propensity for activating chemical reactions or, in the case of bacteria, the plasma's sterilization capability. In this paper, we discuss results from a computational investigation of IEADs on small particles (45 {mu}m radius) produced by atmospheric pressure discharge. Streamers intersecting a particle momentarily generate a large sheath potential as the streamer passes by as the particle charges towards the plasma floating potential. During that time, ions of energies up to 3-10 eV can strike the particle. The permittivity of the particle and the streamer polarity in part determine the character of the IEAD.

  16. Profiling measurements of metal ion distribution in thin polymer inclusion membranes by Rutherford backscattering spectrometry

    Science.gov (United States)

    Guedioura, B.; Bendjaballah, N.; Alioui, N.

    2014-05-01

    Polymer inclusion membranes (PIMs) composed of a homogeneous mixture of cellulose triacetate matrix, 2-nitro-phenyl-octyl-ether as plasticizer and tri-octyl-phosphine-oxyde as carrier were synthesized by the spin coating method. Synthesized membranes were doped with molybdenum metal ions and then characterized by four experimental techniques: thermo gravimetric and differential analyses, scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and Rutherford backscattering (RBS) spectrometry using a 3.2 MeV He+ ion beam. The RBS analysis has established both the elemental composition as well as the Mo+ metal profiling of the studied PIMs. The experimental irradiation conditions were optimized in order to determine the ion fluence thresholds resulting in measurable changes in elemental composition of membranes. Changes in physico-chemical properties of the irradiated PIMs vs He+ ion fluence were observed with the ATR-FTIR analysis. Also, the SEM analysis of PIMs surfaces has revealed a porous texture, while the thermal analysis of annealed PIMs at 105°C has showed no significant changes of mass (∼1%) of the studied samples.

  17. Expression and distribution of voltage-gated ion channels in ferret sinoatrial node.

    Science.gov (United States)

    Brahmajothi, Mulugu V; Morales, Michael J; Campbell, Donald L; Steenbergen, Charles; Strauss, Harold C

    2010-10-01

    Spontaneous diastolic depolarization in the sinoatrial (SA) node enables it to serve as pacemaker of the heart. The variable cell morphology within the SA node predicts that ion channel expression would be heterogeneous and different from that in the atrium. To evaluate ion channel heterogeneity within the SA node, we used fluorescent in situ hybridization to examine ion channel expression in the ferret SA node region and atrial appendage. SA nodal cells were distinguished from surrounding cardiac myocytes by expression of the slow (SA node) and cardiac (surrounding tissue) forms of troponin I. Nerve cells in the sections were identified by detection of GAP-43 and cytoskeletal middle neurofilament. Transcript expression was characterized for the 4 hyperpolarization-activated cation channels, 6 voltage-gated Na(+) channels, 3 voltage-gated Ca(2+) channels, 24 voltage-gated K(+) channel α-subunits, and 3 ancillary subunits. To ensure that transcript expression was representative of protein expression, immunofluorescence was used to verify localization patterns of voltage-dependent K(+) channels. Colocalizations were performed to observe any preferential patterns. Some overlapping and nonoverlapping binding patterns were observed. Measurement of different cation channel transcripts showed heterogeneous expression with many different patterns of expression, attesting to the complexity of electrical activity in the SA node. This study provides insight into the possible role ion channel heterogeneity plays in SA node pacemaker activity.

  18. Ion and neutral temperature distributions in the E-region observed by the EISCAT Tromsø and Svalbard radars

    Directory of Open Access Journals (Sweden)

    S. Maeda

    Full Text Available Simultaneous Common Program Two experiments by the EISCAT UHF radar at Tromsø and the EISCAT Svalbard radar at Longyearbyen from 00:00 to 15:00 UT on 22 September 1998 and 9 March 1999 have been utilized to investigate distributions of the ion and neutral temperatures in the E-region between 105 and 115 km. During the experiments, soft particle precipitations in the dayside cusp were observed over the Svalbard radar site by the Defense Meteorological Satellite Program (DMSP F11 satellite. It is found that the dayside electric field in the regions of the low-latitude boundary of the polar cap and the cusp was greater and more variable than that in the auroral region. The ion temperature, parallel to the geomagnetic field at Longyearbyen, was higher than that at Tromsø during the daytime from 06:00 to 12:00 UT. The steady-state ion energy equation has been applied to derive neutral temperature under the assumption of no significant heat transport and viscous heating. The estimated neutral temperature at Longyearbyen was also higher than that at Tromsø. The ion and neutral energy budget was discussed in terms of the ion frictional heating and the Joule heating. The results indicate two possibilities: either the neutral temperature was high in the low latitude boundary of the polar cap and the cusp, or the heat transport by the polar cap neutral winds toward the dayside sector was significant.

    Key words. Ionosphere (auroral ionosphere; ionosphere–atmosphere interactions; polar ionosphere

  19. Mechanisms of radiation induced cationic polymerization in the presence of onium salts

    Science.gov (United States)

    Malmström, E.; Sundell, P. E.; Hult, A.; Jönsson, S. E.

    1995-11-01

    Cationic polymerization of various monomers in the presence of onium salts were induced by hv, EB and γ irradiation. The mechanism for the initiation process involves the photoreduction of onium salts by a direct photolysis or by an indirect redox reaction from organic free radicals or solvated electrons depending on the reduction potentials of the onium salts. For EB and γ irradiation only solvated electrons were capable of reducing the onium salts with reduction potentials lower than approximately -100 kJ/mol. An enhanced production of protons and/or carbenium ions takes place if the reduction potentials of the onium salts are higher than -60 kJ/mol. This paper will give some indications of useful onium structures that fulfill the needs in EB and γ induced cationic polymerization. Typical examples are fragmenting type of dialkylphenacyl and cyclic ringopening phenacylic sulfonium salts. The influence of typical "polymer or monomer backbone" structural groups, such as esters and ethers on the proton formation under high energy irradiation, was studied by UV spectroscopy at 540 nm. The formation of acid was monitored in the presence of various onium salts, and α-naphtylred was used as an indicator. By comparing aromatic versus aliphatic structural group influences on the generation of protons and carbenium ions a good correlation was found between experimental data and theoretical calculations on nucleophilicity, electron charge density distributions and electron scavenging effects by the use of simplified Hückel calculations (SHMO).

  20. Effect of Quark Spins to the Hadron Distributions for Chiral Magnetic Wave in Ultrarelativistic Heavy-Ion Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Byungsik [Korea University, Seoul (Korea, Republic of)

    2017-07-15

    Topological fluctuation of the gluon field in quantum chromodynamics modifies the vacuum structure, and causes various chiral anomalies. In the strong magnetic field generated by semi-central heavy-ion collisions, the axial and vector density fluctuations propagate along the external magnetic field, called the chiral magnetic wave. Up to now the investigation of the various chiral anomalies in heavy ion collisions has been focussed on the charge distribution in the transverse plane. However, this paper points out that the information on the charge distribution is not enough and the spin effect should also be taken into account. Considering the charge and spin distributions together, π{sup ±} with spin 0 are not proper particle species to study the chiral anomalies, as the signal may be significantly suppressed as one of the constituent (anti)quarks should come from background to form the pseudoscalar states. It is, therefore, necessary to analyze explicitly the vector mesons with spin 1 (K⋆{sup ±} (892)) and baryons with spin 3/2 (Δ{sup ++}(1232), Σ{sup −} (1385) and Ω{sup −} ). If the chiral anomaly effects exist, the elliptic flow parameter is expected to be larger for negative particles for each particle species.

  1. ENA Observations from the IMAGE Mission: Global Evolution and Validation of the Ring Current Ion Distribution and Future Outlook

    Science.gov (United States)

    Brandt, P. C.; Hsieh, S. Y. W.; Demajistre, R.; Sitnov, M. I.; Stephens, G. K.; Gkioulidou, M.

    2016-12-01

    Energetic Neutral Atom (ENA) imaging is the only technique that can capture the instantaneous state of the ring current ion distribution, which can vary globally on MEDICI, has been defined in the Heliophysics Decadal Survey. In this presentation we provide an overview of the global storm-time ring current ion evolution in the 10-200 keV range for several storms during the 2000-2005 era using ENA observations from the IMAGE mission obtained by the HENA Camera. A constrained linear inversion technique has proven to be one of the more effective and convenient techniques to retrieve the spatial and pitch-angle distributions (PAD) of the ring current. We briefly describe the technique and focus on how to ensure that the unique and best solution has been found by using both simulations using synthetic data and validations against the simultaneous in-situ measurements from the Cluster mission for several geomagnetic storms. Results of the global evolution of the ring current is summarized in terms of build-up and decay, and symmetrization timescales, degree of spatial asymmetry, temporal variability due to injections and spatial variability of PADs. We present comparisons with empirical ring current distributions retrieved from the global magnetic field model TS07d and Van Allen Probes in-situ measurements for similar driving conditions. Lastly, we discuss the lessons learned and implications for the second-generation of imaging missions such as MEDICI.

  2. Observations of the He{sup +} pickup ion torus velocity distribution function with SOHO/CELIAS/CTOF

    Energy Technology Data Exchange (ETDEWEB)

    Taut, Andreas, E-mail: taut@physik.uni-kiel.de; Berger, Lars; Drews, Christian; Wimmer-Schweingruber, Robert F. [Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universitaät zu Kiel, Leibnizstrasse 11, 24118 Kiel (Germany); Bochsler, Peter [Physikalisches Institut, Universität Bern, Sidlerstrasse 5, 3012 Bern (Switzerland); Klecker, Berndt [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching (Germany)

    2016-03-25

    Interstellar PickUp Ions (PUIs) are created from neutrals coming from the interstellar medium that get ionized inside the heliosphere. Once ionized, the freshly created ions are injected into the magnetized solar wind plasma with a highly anisotropic torus-shaped Velocity Distribution Function (VDF). It has been commonly assumed that wave-particle interactions rapidly destroy this torus by isotropizing the distribution in one hemisphere of velocity space. However, recent observations of a He{sup +} torus distribution using PLASTIC on STEREO showed that the assumption of a rapid isotropization is oversimplified. The aim of this work is to complement these studies. Using He{sup +} data from the Charge Time-Of-Flight (CTOF) sensor of the Charge, ELement, and Isotope Analysis System (CELIAS) on-board the SOlar and Heliospheric Observatory (SOHO) and magnetic field data from the Magnetic Field Investigation (MFI) magnetometer of the WIND spacecraft, we derive the projected 1-D VDF of He{sup +} for different magnetic field configurations. Depending on the magnetic field direction, the initial torus VDF lies inside CTOF’s aperture or not. By comparing the VDFs derived under different magnetic field directions with each other we reveal an anisotropic signature of the He{sup +} VDF.

  3. Subcellular boron and fluorine distributions with SIMS ion microscopy in BNCT and cancer research

    Energy Technology Data Exchange (ETDEWEB)

    Subhash Chandra

    2008-05-30

    The development of a secondary ion mass spectrometry (SIMS) based technique of Ion Microscopy in boron neutron capture therapy (BNCT) was the main goal of this project, so that one can study the subcellular location of boron-10 atoms and their partitioning between the normal and cancerous tissue. This information is fundamental for the screening of boronated drugs appropriate for neutron capture therapy of cancer. Our studies at Cornell concentrated mainly on studies of glioblastoma multiforme (GBM). The early years of the grant were dedicated to the development of cryogenic methods and correlative microscopic approaches so that a reliable subcellular analysis of boron-10 atoms can be made with SIMS. In later years SIMS was applied to animal models and human tissues of GBM for studying the efficacy of potential boronated agents in BNCT. Under this grant the SIMS program at Cornell attained a new level of excellence and collaborative SIMS studies were published with leading BNCT researchers in the U.S.

  4. Dust ion acoustic solitary structures in presence of nonthermally distributed electrons and positrons

    CERN Document Server

    Paul, Ashesh; Das, K P

    2016-01-01

    The purpose of this paper is to extend the recent work of Paul & Bandyopadhyay [Astrophys. Space Sci. 361, 172(2016)] on the existence of different dust ion acoustic solitary structures in an unmagnetized collisionless dusty plasma consisting of negatively charged static dust grains, adiabatic warm ions, nonthermal electrons and isothermal positrons in a more generalized form by considering nonthermal positrons instead of isothermal positrons. The present system supports both positive and negative potential double layers, coexistence of solitary waves of both polarities and positive potential supersolitons. The qualitative and the quantitative changes in existence domains of different solitary structures which occur for the presence of nonthermal positrons have been presented in comparison with the results of Paul & Bandyopadhyay [Astrophys. Space Sci. 361, 172(2016)]. The formation of supersoliton structures and their limitations have been analyzed with the help of phase portraits of the dynamical sy...

  5. The mathematical principles and design of the NAIS – a spectrometer for the measurement of cluster ion and nanometer aerosol size distributions

    Directory of Open Access Journals (Sweden)

    S. Mirme

    2013-04-01

    Full Text Available The paper describes the Neutral cluster and Air Ion Spectrometer (NAIS – a multichannel aerosol instrument capable of measuring the distribution of ions (charged particles and cluster ions of both polarities in the electric mobility range from 3.2 to 0.0013 cm2 V−1 s−1 and the distribution of aerosol particles in the size range from 2.0 to 40 nm. We introduce the principles of design, data processing and spectrum deconvolution of the instrument.

  6. Depth distribution of carrier lifetime in 65 MeV oxygen ion irradiated silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.S. [Ecotopia Science Institute, Division of Energy Science, Nagoya University, Nagoya (Japan); Dahiwale, S.S. [Department of Physics, University of Pune, Pune 411 007 (India); Kanjilal, D. [Nuclear Science Centre, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411 007 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 411 007 (India)]. E-mail: sanjay@physics.unipune.ernet.in

    2006-03-15

    CZ-grown, n-doped crystalline Si(1 1 1) of resistivity 60 {omega} cm and 140 {omega} cm were irradiated with 65 MeV energy oxygen ions, in the fluence range of 2 x 10{sup 1}-10{sup 14} ions/cm{sup 2}. The depth and spatial profile of excess minority carrier recombination time {tau} (lifetime) was measured using photoconductive decay (PCD) method. Lifetime measurements were carried out before the stopping range of impinging ions. Results show a monotonous decrease in lifetime with fluence, which is attributed to defect creation mechanism by electronic energy loss based on the thermal spike model. Also, surface modification is expected with a small loss in crystalline quality. This surface is considered to be a multi-crystalline surface with large grain boundaries that act as trapping sites for excess holes in n-Si(1 1 1). Annealing of the irradiated samples showed a near complete recovery at 750 deg. C for a period of 1 h.

  7. Gene Expression, Protein Function and Pathways of Arabidopsis thaliana Responding to Silver Nanoparticles in Comparison to Silver Ions, Cold, Salt, Drought, and Heat

    Directory of Open Access Journals (Sweden)

    Eisa Kohan-Baghkheirati

    2015-03-01

    Full Text Available Silver nanoparticles (AgNPs have been widely used in industry due to their unique physical and chemical properties. However, AgNPs have caused environmental concerns. To understand the risks of AgNPs, Arabidopsis microarray data for AgNP, Ag+, cold, salt, heat and drought stresses were analyzed. Up- and down-regulated genes of more than two-fold expression change were compared, while the encoded proteins of shared and unique genes between stresses were subjected to differential enrichment analyses. AgNPs affected the fewest genes (575 in the Arabidopsis genome, followed by Ag+ (1010, heat (1374, drought (1435, salt (4133 and cold (6536. More genes were up-regulated than down-regulated in AgNPs and Ag+ (438 and 780, respectively while cold down-regulated the most genes (4022. Responses to AgNPs were more similar to those of Ag+ (464 shared genes, cold (202, and salt (163 than to drought (50 or heat (30; the genes in the first four stresses were enriched with 32 PFAM domains and 44 InterPro protein classes. Moreover, 111 genes were unique in AgNPs and they were enriched in three biological functions: response to fungal infection, anion transport, and cell wall/plasma membrane related. Despite shared similarity to Ag+, cold and salt stresses, AgNPs are a new stressor to Arabidopsis.

  8. Low temperature molten salt synthesis of Y(sub2)Sn(sub2)O(sub7) anode material for lithium ion batteries

    CSIR Research Space (South Africa)

    Nithyadharseni, P

    2015-10-01

    Full Text Available For the first time, yttrium tin oxide (Y(sub2)Sn(sub2)O(sub7)) compound is prepared at low temperature (400 _C) with cubic pyrochlore structure via molten salt method using KOH as a flux for their electrochemical applications. The final product...

  9. Salt splitting with ceramic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Kurath, D. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-10-01

    The purpose of this task is to develop ceramic membrane technologies for salt splitting of radioactively contaminated sodium salt solutions. This technology has the potential to reduce the low-level waste (LLW) disposal volume, the pH and sodium hydroxide content for subsequent processing steps, the sodium content of interstitial liquid in high-level waste (HLW) sludges, and provide sodium hydroxide free of aluminum for recycle within processing plants at the DOE complex. Potential deployment sites include Hanford, Savannah River, and Idaho National Engineering Laboratory (INEL). The technical approach consists of electrochemical separation of sodium ions from the salt solution using sodium (Na) Super Ion Conductors (NaSICON). As the name implies, sodium ions are transported rapidly through these ceramic crystals even at room temperatures.

  10. Evaluation of Spatial Resolution for Heavy Ion CT System Based on the Measurement of Residual Range Distribution With HIMAC

    Science.gov (United States)

    Muraishi, H.; Nishimura, K.; Abe, S.; Satoh, H.; Hara, S.; Hara, H.; Takahashi, Y.; Mogaki, T.; Kawai, R.; Yokoyama, K.; Yasuda, N.; Tomida, T.; Ohno, Y.; Kanai, T.

    2009-10-01

    We report experimental results from a heavy ion CT system based on the measurement of residual range distribution using an X-ray intensifying screen and a charged coupled device (CCD) camera system. This technique was first investigated by Zygmanski (2000) for proton beams, and they reported that the spatial resolution was significantly degraded by multiple Coulomb scattering (MCS) effects in the irradiated medium. Experiments were done on the spatial resolution phantom by using helium and carbon beams accelerated up to 120 MeV/u and 230 MeV/u by the Heavy Ion Medical Accelerator in Chiba (HIMAC), installed in the National Institute of Radiological Sciences (NIRS) in Japan, using a high performance intensified CCD (ICCD) camera. We show that the MCS blurring effect can be significantly reduced in the reconstructed image by using a carbon beam with this technique. Our results suggest that heavier particles such as carbon would be more useful if this technique is envisioned as a clinical tool to obtain data that would aid proton and/or heavy ion treatment planning.

  11. Chemical Potentials of Quarks Extracted from Particle Transverse Momentum Distributions in Heavy Ion Collisions at RHIC Energies

    Directory of Open Access Journals (Sweden)

    Hong Zhao

    2014-01-01

    Full Text Available In the framework of a multisource thermal model, the transverse momentum distributions of charged particles produced in nucleus-nucleus (A-A and deuteron-nucleus (d-A collisions at relativistic heavy ion collider (RHIC energies are investigated by a two-component revised Boltzmann distribution. The calculated results are in agreement with the PHENIX experimental data. It is found that the source temperature increases obviously with increase of the particle mass and incident energy, but it does not show an obvious change with the collision centrality. Then, the values of chemical potentials for up, down, and strange quarks can be obtained from the antiparticle to particle yield ratios in a wide transverse momentum range. The relationship between the chemical potentials of quarks and the transverse momentum with different centralities is investigated, too.

  12. Measurement of ion beam angular distribution at different helium gas pressures in a plasma focus device by large-area polycarbonate detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sohrabi, M.; Habibi, M., E-mail: mortezahabibi@gmail.com; Ramezani, V. [Amirkabir University of Technology, Energy Engineering and Physics Department (Iran, Islamic Republic of)

    2017-02-15

    The paper presents an experimental study and analysis of full helium ion density angular distributions in a 4-kJ plasma focus device (PFD) at pressures of 10, 15, 25, and 30 mbar using large-area polycarbonate track detectors (PCTDs) (15-cm etchable diameter) processed by 50-Hz-HV electrochemical etching (ECE). Helium ion track distributions at different pressures, in particular, at the main axis of the PFD are presented. Maximum ion track density of ~4.4 × 10{sup 4} tracks/cm{sup 2} was obtained in the PCTD placed 6 cm from the anode. The ion distributions for all pressures applied are ring-shaped, which is possibly due to the hollow cylindrical copper anode used. The large-area PCTD processed by ECE proves, at the present state-of-theart, a superior method for direct observation and analysis of ion distributions at a glance with minimum efforts and time. Some observations of the ion density distributions at different pressures are reported and discussed.

  13. Ion-acoustic dressed solitary structures in two component plasma with Tsallis-nonthermal velocity distribution of electrons

    Science.gov (United States)

    Bala, Parveen; Gill, Tarsem Singh; Bains, Amandeep Singh; Kaur, Harvinder

    2017-12-01

    The present investigation deals with the study of small amplitude nonlinear ion-acoustic dressed solitary structures in two component plasma model consisting of cold positive ions and electrons. The electrons are assumed as featuring hybrid q-nonextensive nonthermal distribution also known as Cairns-Tsallis velocity distribution. In the lowest order of potential, the basic set of fluid equations is reduced to the well known Korteweg-de Vries ( KdV) equation. By including the contribution of higher order potential, an inhomogeneous KdV-type nonliner equation results that contains fifth order dispersion. The numerical values of the parameters like nonthermal (α) and nonextensive ( q) are according to the range suggested by Williams et al. (Phys Rev E 88:023103, 2013). The finite value of nonthermal parameter results into the formation of rarefactive type solitary structures. A comparison of amplitudes of higher order correction, dressed and KdV solitons has been presented pictorially. The combined effect of nonextensive parameter q and nontermal parameter on the soliton dynamics has also been studied and the results are shown in the form of two and three dimensional profiles.

  14. 3D Ion and Electron Distribution Function Measurements from the Fast Plasma Investigation on the Magnetospheric Multiscale Mission

    Science.gov (United States)

    Giles, B. L.; Pollock, C. J.; Avanov, L. A.; Barrie, A. C.; Burch, J. L.; Chandler, M. O.; Clark, G. B.; Coffey, V. N.; Dickson, C.; Dorelli, J.; Ergun, R. E.; Fuselier, S. A.; Gershman, D. J.; Gliese, U.; Holland, M. P.; Jacques, A. D.; Kreisler, S.; Lavraud, B.; MacDonald, E.; Mauk, B.; Moore, T. E.; Mukai, T.; Nakamura, R.; Paterson, W. R.; Rager, A. C.; Saito, Y.; Salo, C.; Sauvaud, J. A.; Torbert, R. B.; Vinas, A. F.; Yokota, S.

    2015-12-01

    The primary focus of the Magnetospheric Multiscale (MMS) mission, launched in March 2015, is magnetic reconnection and associated processes. Understanding hinges critically on the kinetic physics that allows reconnection to take place. The Fast Plasma Investigation (FPI) provides electron and ion distribution functions at 4.5s cadence and, for select periods of time, at cadences of 30ms for electrons and 150ms for ions. These select time periods are chosen after in situ acquisition based on inspection of the low resolution data. Thus the FPI provides, independent of spacecraft spin rate, the time resolution needed to resolve the small, fast-moving reconnection diffusion regions. The first mission phase focuses on the dayside magnetopause and this presentation is intended to demonstrate the capabilities of FPI to resolve the important spatial scales relevant to the reconnection process. Magnetopause and other boundary crossings will be examined and the phase-space trajectories identified at the tetrahedral satellite locations through analysis of the 3D distribution functions.

  15. Accumulation and distribution of platinum and rhodium in the European eel Anguilla anguilla following aqueous exposure to metal salts

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, S.; Baumann, U.; Taraschewski, H.; Sures, B

    2004-01-01

    The platinum group metals (PGM) Pt and Rh are emitted into the environment mainly by catalytic exhaust gas converters of cars and by effluents of hospitals, which use Pt based anti-cancer drugs. However, there is still a lack of information on the availability of these precious metals to the biosphere. As PGM accumulate in sediments of aquatic ecosystems we focused our study on the uptake of the noble metals by European eels, Anguilla anguilla. Therefore, eels were exposed in tap water and humic water containing Pt{sup 4+} and Rh{sup 3+} at a concentration of 170 and 260 {mu}g/l, respectively. After an exposure period of 6 weeks the mean Pt levels in bile, liver, kidney and intestine of the exposed eels ranged between 68 ng/g and 840 ng/g and the mean Rh levels between 35 ng/g and 155 ng/g whereas the PGM levels of the unexposed controls were below the detection limit of 50 ng/g for Pt and 5 ng/g for Rh. Rh was also taken up by gill and spleen. No PGM uptake was found for muscle and blood. The pattern of metal distribution within the eel differed between Pt and Rh and was dependent on the water type. Due to their accumulation capacity for PGM eels are suitable as accumulation indicators to detect PGM pollution in aquatic ecosystems. - Eels are suitable accumulation indicators for platinum group metals in aquatic ecosystems.

  16. Determination of the Ion Velocity Distribution in a Rotating Plasma from Measurements of Doppler Broadening

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, Alfred Hegaard

    1979-01-01

    The Doppler-broadened profile of the He II 4685.75 AA line was measured along a chord in a rotating plasma, transverse to the magnetic field. Using a single-particle orbit picture, the corresponding velocity spectrum of ions confirm the measurements, so it can be concluded that the single......-particle orbit picture is valid for the discharge period under investigation, except for the first few microseconds during breakdown when a strong interaction between plasma and remaining neutral gas takes place by Alfvens critical velocity mechanism. A simple relation is given between the measured half...

  17. Comparison and distribution of copper oxide nanoparticles and copper ions in activated sludge reactors.

    Science.gov (United States)

    Zhang, Dongqing; Trzcinski, Antoine P; Oh, Hyun-Suk; Chew, Evelyn; Tan, Soon Keat; Ng, Wun Jern; Liu, Yu

    2017-05-12

    Copper oxide nanoparticles (CuO NPs) are being increasingly applied in the industry which results inevitably in the release of these materials into the hydrosphere. In this study, simulated waste-activated sludge experiments were conducted to investigate the effects of Copper Oxide NPs at concentrations of 0.1, 1, 10 and 50 mg/L and to compare it with its ionic counterpart (CuSO4). It was found that 0.1 mg/L of CuO NPs had negligible effects on Chemical Oxygen Demand (COD) and ammonia removal. However, the presence of 1, 10 and 50 mg/L of CuO NPs decreased COD removal from 78.7% to 77%, 52.1% and 39.2%, respectively (P copper ions were more toxic towards microorganisms compared to CuO NPs. CuO NPs were removed effectively (72-93.2%) from wastewater due to a greater biosorption capacity of CuO NPs onto activated sludge, compared to the copper ions (55.1-83.4%). The SEM images clearly showed the accumulation and adsorption of CuO NPs onto activated sludge. The decrease in Live/dead ratio after 5 h of exposure of CuO NPs and Cu(2+) indicated the loss of cell viability in sludge flocs.

  18. Salt cookbook

    CERN Document Server

    Saha, Anirban

    2015-01-01

    If you are a professional associated with system and infrastructure management, looking at automated infrastructure and deployments, then this book is for you. No prior experience of Salt is required.

  19. Protein separation through preliminary experiments concerning pH and salt concentration by tube radial distribution chromatography based on phase separation multiphase flow using a polytetrafluoroethylene capillary tube.

    Science.gov (United States)

    Kan, Hyo; Tsukagoshi, Kazuhiko

    2017-07-01

    Protein mixtures were separated using tube radial distribution chromatography (TRDC) in a polytetrafluoroethylene (PTFE) capillary (internal diameter=100µm) separation tube. Separation by TRDC is based on the annular flow in phase separation multiphase flow and features an open-tube capillary without the use of specific packing agents or application of high voltages. Preliminary experiments were conducted to examine the effects of pH and salt concentration on the phase diagram of the ternary mixed solvent solution of water-acetonitrile-ethyl acetate (8:2:1 volume ratio) and on the TRDC system using the ternary mixed solvent solution. A model protein mixture containing peroxidase, lysozyme, and bovine serum albumin was analyzed via TRDC with the ternary mixed solvent solution at various pH values, i.e., buffer-acetonitrile-ethyl acetate (8:2:1 volume ratio). Protein was separated on the chromatograms by the TRDC system, where the elution order was determined by the relation between the isoelectric points of protein and the pH values of the solvent solution. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Application of electron-beam irradiation on the production of salted and seasoned short-necked clam, Tapes Pilippinarum, for safe distribution

    Science.gov (United States)

    Kim, B.; Song, H. P.; Choe, J. H.; Jung, S.; Jang, A.; Kim, Y. J.; Jo, C.

    2009-07-01

    Salted and seasoned short-necked clam ( Tapes Philippinarum; SNC) and its major ingredients, red hot pepper powder, ginger, garlic and onion were irradiated at 0.5, 1, 2 and 5 kGy, respectively, and the microbiological and sensory quality were evaluated. The water activities of SNC and red pepper powder were 0.91 and 0.56, respectively, and others were higher than 0.97. The initial microbial populations of SNC were approximately 3.99, 4.38 and 2.22 log CFU/g for total aerobic bacteria, yeast and mold, and coliform bacteria. The highest contamination of total aerobic bacteria was detected from ground ginger among ingredients at 5.51 log CFU/g. Electron-beam irradiation (0, 0.5, 1, 2 and 5 kGy) significantly reduced the initial microbial level of SNC and its ingredients not only immediately after irradiation, but also during storage at 10 °C for 4 weeks ( ponion irradiated at 5 kGy, which results in a lower score than control. From the results electron-beam irradiation is a useful tool to enhance the storage stability and safe distribution of SNC.

  1. Analysis of synthetic cathinones commonly found in bath salts in human performance and postmortem toxicology: method development, drug distribution and interpretation of results.

    Science.gov (United States)

    Marinetti, Laureen J; Antonides, Heather M

    2013-04-01

    To date, the Toxicology Section of the Montgomery County Coroner's Office/Miami Valley Regional Crime Laboratory has identified six synthetic cathinones, commonly found in bath salt products, in 43 cases. Thirty-two cases will be reviewed here, including all of the postmortem cases, all of the human performance cases that had blood specimens submitted, and one urine-only human performance case. The following compounds have been confirmed: 3,4-methylenedioxypyrovalerone (MDPV), 3,4-methylenedioxymethcathinone (methylone), pyrovalerone, pentylone, alpha-pyrrolidinopentiophenone (alpha-PVP) and methedrone. The method also screens for mephedrone, butylone and 3-fluoromethcathinone. Case demographics show 42 white males and females ranging in age from 19 to 53 years. The remaining case was that of a 34-year-old Hispanic male. The 43 cases represent 17 driving under the influence, two domestic violence, four suicides, 12 overdoses, six accidents, one drug-facilitated assault and one homicide. Data will be presented on the distribution of some of these cathinones in various matrices. After review, blood concentration does not appear to predict outcome regarding fatalities or impairment. The highest MDPV concentration occurred in a suicide by hanging and the highest methylone concentration was in a driver. The confirmation method is a liquid-liquid extraction with detection by liquid chromatography triple quadrupole mass spectrometry using electrospray ionization in multiple reaction monitoring mode.

  2. Application of electron-beam irradiation on the production of salted and seasoned short-necked clam, Tapes Pilippinarum, for safe distribution

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B.; Song, H.P.; Choe, J.H.; Jung, S. [Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Jang, A. [Quality Control and Utilization of Animal Products, National Institute of Animal Science, Suwon 441-706 (Korea, Republic of); Kim, Y.J. [Food Safety Research Division, Korea Food Research Institute, Seongnam 463-746 (Korea, Republic of); Jo, C. [Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)], E-mail: cheorun@cnu.ac.kr

    2009-07-15

    Salted and seasoned short-necked clam (Tapes Philippinarum; SNC) and its major ingredients, red hot pepper powder, ginger, garlic and onion were irradiated at 0.5, 1, 2 and 5 kGy, respectively, and the microbiological and sensory quality were evaluated. The water activities of SNC and red pepper powder were 0.91 and 0.56, respectively, and others were higher than 0.97. The initial microbial populations of SNC were approximately 3.99, 4.38 and 2.22 log CFU/g for total aerobic bacteria, yeast and mold, and coliform bacteria. The highest contamination of total aerobic bacteria was detected from ground ginger among ingredients at 5.51 log CFU/g. Electron-beam irradiation (0, 0.5, 1, 2 and 5 kGy) significantly reduced the initial microbial level of SNC and its ingredients not only immediately after irradiation, but also during storage at 10 {sup o}C for 4 weeks (p<0.05). There was no adverse change of sensory score except for the color of onion irradiated at 5 kGy, which results in a lower score than control. From the results electron-beam irradiation is a useful tool to enhance the storage stability and safe distribution of SNC.

  3. Effect of iron salt counter ion in dose-response curves for inactivation of Fusarium solani in water through solar driven Fenton-like processes

    Science.gov (United States)

    Aurioles-López, Verónica; Polo-López, M. Inmaculada; Fernández-Ibáñez, Pilar; López-Malo, Aurelio; Bandala, Erick R.

    2016-02-01

    The inactivation of Fusarium solani in water was assessed by solar driven Fenton-like processes using three different iron salts: ferric acetylacetonate (Fe(acac)3), ferric chloride (FeCl3) and ferrous sulfate (FeSO4). The experimental conditions tested were [Fe] ≈ 5 mg L-1, [H2O2] ≈ 10 mg L-1 and [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1 mild and high, respectively, and pH 3.0 and 5.0, under solar radiation. The highest inactivation rates were observed at high reaction conditions for the three iron salts tested at pH 5.0 with less than 3.0 kJ L-1 of accumulate energy (QUV) to achieve over 99.9% of F. solani inactivation. Fe(acac)3 was the best iron salt to accomplishing F. solani inactivation. The modified Fermi equation was used to fix the experimental inactivation, data showed it was helpful for modeling the process, adequately describing dose-response curves. Inactivation process using FeSO4 at pH 3.0 was modeled fairly with r2 = 0.98 and 0.99 (mild and high concentration, respectively). Fe(acac)3, FeCl3 and FeSO4 at high concentration (i.e. [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1) and pH 5.0 showed the highest fitting values (r2 = 0.99). Iron salt type showed a remarkable influence on the Fenton-like inactivation process.

  4. Sources of household salt in South Africa.

    Science.gov (United States)

    Jooste, Pieter L

    2005-01-01

    Marketing of non-iodized salt through unconventional distribution channels is one of the factors weakening the national salt iodization program in South Africa. The aim of this study was therefore to quantify the various sources of household salt, and to relate this information to socio-economic status. Questionnaire information was collected by personal interview during home visits from a multistage, cluster, probability sample of 2164 adults representative of the adult population. Nationally 77.7% of households obtained their table salt from the typical food shops distributing iodized salt. However, in the nine different provinces between 8 and 37.3% of households used unconventional sources, distributing mainly non-iodized salt, to obtain their household salt. These alternative sources include distributors of agricultural salt, small general dealer shops called spaza shops, in peri-urban and rural townships, street vendors and salt saches placed in the packaging of maize meal bags. Country-wide around 30% of low socio-economic households obtained their salt from unconventional sources compared to less than 5% in high socio-economic households, emphasizing the vulnerability of low socio-economic groups to the use of non-iodized salt. Intervention strategies should mobilize all role players involved in unconventional marketing channels of household salt to provide only iodized salt to consumers, as required by law.

  5. The effects of decreased management on plant-species distribution patterns in a salt marsh nature reserve in the Wadden Sea

    NARCIS (Netherlands)

    Esselink, Peter; Zijlstra, W; Dijkema, KS; van Diggelen, R

    To restore natural salt-marsh habitats, maintenance of the artificial drainage system was discontinued and cattle grazing was reduced in man-made salt marshes in the Dollard estuary, the Netherlands. We studied the vegetation development in these marshes shortly after these marshes became a nature

  6. Particularities of ion-implanted deuterium distribution in stainless steel X18H10T

    CERN Document Server

    Tolstolutskaya, G D; Ruzhitskij, I E

    2001-01-01

    Features of distribution of the deuterium implanted with energy of 6 keV in 18Cr10NiTi steel to doses in the range of 2.10 sup 1 sup 7...2.10 sup 1 sup 8 cm sup - sup 2 have been investigated. Data on the trapping retention, depth distribution and thermo-activated release of the deuterium in the irradiation temperature range of 300...600 K and post implantation annealing in the range 300...600 K and post implantation annealing in the range 300...1500 K were obtained.

  7. Comparison of measured and simulated fast ion velocity distributions in the TEXTOR tokamak

    DEFF Research Database (Denmark)

    Moseev, Dmitry; Meo, Fernando; Korsholm, Søren Bang

    2011-01-01

    Here we demonstrate a comprehensive comparison of collective Thomson scattering (CTS) measurements with steady-state Monte Carlo simulations performed with the ASCOT and VENUS codes. The measurements were taken at a location on the magnetic axis as well as at an off-axis location, using two...... projection directions at each location. The simulations agree with the measurements on-axis, but for the off-axis geometries discrepancies are observed for both projection directions. For the near perpendicular projection direction with respect to the magnetic field, the discrepancies between measurement...... and simulations can be explained by uncertainty in plasma parameters. However, the discrepancies between measurement and simulations for the more parallel projection direction cannot be explained solely by uncertainties in plasma parameters. Here anomalous fast ion transport is a possible explanation...

  8. Americium separations from high salt solutions

    Energy Technology Data Exchange (ETDEWEB)

    Mary E. Barr; Gordon D. Jarvinen; Louis D. Schulte; Peter C. Stark; Rebecca M. Chamberlin; Kent D. Abney; Thomas E. Ricketts; Yvette E. Valdez; Richard A. Bartsch

    2000-03-01

    Americium (III) exhibits an unexpectedly high affinity for anion-exchange material from the high-salt evaporator bottoms solutions--an effect which has not been duplicated using simple salt solutions. Similar behavior is observed for its lanthanide homologue, Nd(III), in complex evaporator bottoms surrogate solutions. There appears to be no single controlling factor--acid concentration, total nitrate concentration or solution ionic strength--which accounts for the approximately 2-fold increase in retention of the trivalent ions from complex solutions relative to simple solutions. Calculation of species activities (i.e., water, proton and nitrate) in such concentrated mixed salt solutions is difficult and of questionable accuracy, but it is likely that the answer to forcing formation of anionic nitrate complexes of americium lies in the relative activities of water and nitrate. From a practical viewpoint, the modest americium removal needs (ca. 50--75%) from nitric acid evaporator bottoms allow sufficient latitude for the use of non-optimized conditions such as running existing columns filled with older, well-used Reillex HPQ. Newer materials, such as HPQ-100 and the experimental bifunctional resins, which exhibit higher distribution coefficients, would allow for either increased Am removal or the use of smaller columns. It is also of interest that one of the experimental neutral-donor solid-support extractants, DHDECMP, exhibits a similarly high level of americium (total alpha) removal from EV bottoms and is much less sensitive to total acid content than commercially-available material.

  9. Energy distributions of plume ions from silver at different angles ablated in vacuum

    DEFF Research Database (Denmark)

    Christensen, Bo Toftmann; Schou, Jørgen; Canulescu, Stela

    be comparatively difficult to measure the energy and angular distribution of neutrals, measurements of the ionic fraction will be valuable for any modeling of PLD. We have irradiated silver in a vacuum chamber (~ 10-7 mbar) with a Nd:YAG laser at a wavelength of 355 nm and made detailed measurements of the time...

  10. Exploring local disorder in fast oxygen ion conductors by atomic pair distribution function analysis

    OpenAIRE

    Brunelli, M.; Ceretti, M.

    2015-01-01

    A preliminary structural investigation of local disorder in fully oxidized La2NiO4+δ was performed by Pair Distribution Function (PDF) analyses of X-ray and neutron powder diffraction data. X-ray diffraction data were recorded in-situ on warming from room temperature up to 450 ∘C.

  11. Exploring local disorder in fast oxygen ion conductors by atomic pair distribution function analysis

    Directory of Open Access Journals (Sweden)

    Brunelli Michela

    2015-01-01

    Full Text Available A preliminary structural investigation of local disorder in fully oxidized La2NiO4+δ was performed by Pair Distribution Function (PDF analyses of X-ray and neutron powder diffraction data. X-ray diffraction data were recorded in-situ on warming from room temperature up to 450 ∘C.

  12. Dust-acoustic solitons in quantum plasma with kappa-distributed ions

    Indian Academy of Sciences (India)

    The comparison of the existence domain for higher and lower values of shows that suprathermality results in propagation of solitons with lower values of Mach number, and the quantum effects, lead to a higher values of Mach number. The existence domain of solitons for nondegenerate -distributed electrons is ...

  13. Higher moments of net-proton multiplicity distributions in a heavy-ion event pile-up scenario

    Science.gov (United States)

    Garg, P.; Mishra, D. K.

    2017-10-01

    High-luminosity modern accelerators, like the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) and Large Hadron Collider (LHC) at European Organization for Nuclear Research (CERN), inherently have event pile-up scenarios which significantly contribute to physics events as a background. While state-of-the-art tracking algorithms and detector concepts take care of these event pile-up scenarios, several offline analytical techniques are used to remove such events from the physics analysis. It is still difficult to identify the remaining pile-up events in an event sample for physics analysis. Since the fraction of these events is significantly small, it may not be as serious of an issue for other analyses as it would be for an event-by-event analysis. Particularly when the characteristics of the multiplicity distribution are observable, one needs to be very careful. In the present work, we demonstrate how a small fraction of residual pile-up events can change the moments and their ratios of an event-by-event net-proton multiplicity distribution, which are sensitive to the dynamical fluctuations due to the QCD critical point. For this study, we assume that the individual event-by-event proton and antiproton multiplicity distributions follow Poisson, negative binomial, or binomial distributions. We observe a significant effect in cumulants and their ratios of net-proton multiplicity distributions due to pile-up events, particularly at lower energies. It might be crucial to estimate the fraction of pile-up events in the data sample while interpreting the experimental observable for the critical point.

  14. Ion energy and angular distributions onto polymer surfaces delivered by dielectric barrier discharge filaments in air: I. Flat surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Babaeva, Natalia Yu; Kushner, Mark J, E-mail: nbabaeva@umich.edu, E-mail: mjkush@umich.edu [University of Michigan, Department of Electrical Engineering and Computer Science 1301 Beal Ave, Ann Arbor, MI 48109 (United States)

    2011-06-15

    In atmospheric pressure discharges, ion energies are typically thought to be thermal with values dominantly <1 eV. In the heads of filaments in dielectric barrier discharges (DBDs), electric fields can exceed 200 kV cm{sup -1} when the filament is far from a surface. As the filament approaches and intersects a dielectric surface, much of the applied potential is compressed into the voltage drop across the head of the filament due to the high conductivity of the trailing plasma channel. When the filament strikes the surface, this voltage is transferred to the resulting sheath and into the material of the surface. The degree of electric field compression depends on the dielectric constant {epsilon}/{epsilon}{sub 0} of the surface. Upon intersection of the filament with the surface, the electric fields in the resulting sheath can exceed 400-800 kV cm{sup -1}, with larger values corresponding to larger {epsilon}/{epsilon}{sub 0}. When accelerated in these fields, ions can gain energies across their mean free path (0.5-1 {mu}m) up to 20 eV for dielectrics with low {epsilon}/{epsilon}{sub 0} and up to 150 eV for dielectrics with high {epsilon}/{epsilon}{sub 0}, albeit only for the duration of the intersection of the streamer with the surface of a few ns. In this paper we report on results from a computational investigation of the ion energy and angular distributions (IEADs) incident on dielectric flat surfaces resulting from the intersection of DBD filaments sustained in atmospheric pressure air. We describe the transient and spatially dependent IEADs as the filament spreads across the polymer.

  15. Acceleration and transport of ions in turbulent current sheets: formation of non-maxwelian energy distribution

    Directory of Open Access Journals (Sweden)

    A. V. Artemyev

    2009-11-01

    Full Text Available The paper is devoted to particle acceleration in turbulent current sheet (CS. Our results show that the mechanism of CS particle interaction with electromagnetic turbulence can explain the formation of power law energy distributions. We study the ratio between adiabatic acceleration of particles in electric field in the presence of stationary turbulence and acceleration due to electric field in the case of dynamic turbulence. The correlation between average energy gained by particles and average particle residence time in the vicinity of the neutral sheet is discussed. It is also demonstrated that particle velocity distributions formed by particle-turbulence interaction are similar in essence to the ones observed near the far reconnection region in the Earth's magnetotail.

  16. Analysis of angular distribution of fragments in relativistic heavy-ion collisions by quantum molecular dynamics

    Directory of Open Access Journals (Sweden)

    Ogawa Tatsuhiko

    2016-01-01

    Full Text Available To predict angular distribution of fragments produced in nucleusnucleus collisions, JAERI quantum molecular dynamics model (JQMD was improved. Because JQMD underestimated fragments in the forward angle, which were mainly produced by peripheral collisions, JQMD was revised so as to simulate peripheral collisions accurately. Density-dependent in-medium effect and relativistic effect on nucleonnucleon interactions were incorporated for this purpose. The revised version of JQMD coupled with a statistical decay model was used to calculate differential fragment production cross sections measured in earlier studies. Comparison of the measured data and calculation by the revised and old JQMD showed that the revised JQMD can predict fragment angular distribution better than old JQMD. Particularly, agreement of fragment yield in the forward angle is substantially improved.

  17. Ion energy distributions from photon- and electron-stimulated desorption. II. The quasiclassical final state and reneutralization

    Science.gov (United States)

    Clinton, William L.; Pal, Sipra; Jutila, Ronald E.

    1987-09-01

    Franck-Condon overlap integrals are calculated to fit ion energy distributions (IED's) resulting from photon- or electron-stimulated desorption. The WKB or quasiclassical trajectory approximation is used to compute the final-state wave function. The final-state potential consists of a repulsive exponential and an image term. The calculated IED's compare well with those found previously using the reflection or classical trajectory approximation. Both methods agree well with a wide range of experimental IED's all of which are mildly asymmetric Gaussian functions of the ion energy. It is shown how these two approximations are related through the classical limit of the final-state wave function. In addition, the quasiclassical wave function is generalized to include an optical potential giving rise in a natural way to the reneutralization reduction factor. The Gaussian asymmetry in the IED's is usually to the high-energy side reflecting a ``normal'' exponential repulsion. However, in a few anomalous cases the Gaussian is skewed to the low-energy side of the IED peak. This anomaly cannot be explained by expected influences on the initial-state wave function such as anharmonicities. On the other hand, the reneutralization factor, when it predominates, provides a natural explanation for this effect. In addition, this reneutralization factor can cause significant shifts in the IED peak, away from the Franck-Condon peak.

  18. Effects of pored separator films at the anode and cathode sides on concentration changes of electrolyte salt in lithium ion batteries

    Science.gov (United States)

    Yamanaka, Toshiro; Nakagawa, Hiroe; Tsubouchi, Shigetaka; Domi, Yasuhiro; Doi, Takayuki; Abe, Takeshi; Ogumi, Zempachi

    2017-12-01

    The concentration change of ions in the electrolyte solution in deep narrow spaces between electrodes in batteries was studied by in situ multi-probe Raman spectroscopy. When two separator films were placed at the anode and cathode sides, the concentration change became greater, suggesting that the resistance for ion migration at the anode side increased more than that at the cathode side. Thus, there seems to be a concerted effect of the surface film at the anode [solid electrolyte interphase (SEI)] and the adjacent separator film to form an effective diffusion barrier for Li+.

  19. Relativistic electron's butterfly pitch angle distribution modulated by localized background magnetic field perturbation driven by hot ring current ions

    Science.gov (United States)

    Xiong, Ying; Chen, Lunjin; Xie, Lun; Fu, Suiyan; Xia, Zhiyang; Pu, Zuyin

    2017-05-01

    Dayside modulated relativistic electron's butterfly pitch angle distributions (PADs) from ˜200 keV to 2.6 MeV were observed by Van Allen Probe B at L = 5.3 on 15 November 2013. They were associated with localized magnetic dip driven by hot ring current ion (60-100 keV proton and 60-200 keV helium and oxygen) injections. We reproduce the electron's butterfly PADs at satellite's location using test particle simulation. The simulation results illustrate that a negative radial flux gradient contributes primarily to the formation of the modulated electron's butterfly PADs through inward transport due to the inductive electric field, while deceleration due to the inductive electric field and pitch angle change also makes in part contribution. We suggest that localized magnetic field perturbation, which is a frequent phenomenon in the magnetosphere during magnetic disturbances, is of great importance for creating electron's butterfly PADs in the Earth's radiation belts.

  20. X-ray microanalysis in cryosections of natively frozen Paramecium caudatum with regard to ion distribution in ciliates

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, M.; Meyer, R.; Zierold, K.

    1985-01-01

    Cells of Paramecium caudatum were shock-frozen without pretreatment for cryoultramicrotomy and freeze-dried for subsequent X-ray microanalysis. Na, Mg, P, S, Cl, K, and Ca were detected in different amounts in several subcellular compartments. In particular, calcium was localized below the cell surface (pellicle). Trichocysts were found to contain significant amounts of Na in their base but not in the tip. Na, Mg, P, S, Cl, K, Ca were found in electron dense deposits within the lumen of the contractile vacuole. A small K concentration was found in the cytoplasm and in the mitochondria. X-ray microanalysis of the element distribution in different subcellular compartments provides information for the understanding of cellular functions such as exocytosis, locomotion, and ion regulation.

  1. Root adaptation and ion selectivity affects the nutritional value of salt-stressed hidroponically grown baby-leaf Nasturtium officinale and Lactuca sativa

    OpenAIRE

    Fernández, Juan A.; Diana, Niñirola; Jesús, Ochoa; Francesco, Orsini; Giuseppina, Pennisi; Giorgio, Gianquinto; Catalina, Egea-gilabert

    2016-01-01

    The response of watercress (Nasturtium officinale L.) to salinity has been scarcely addressed in literature despite its growing importance in the baby-leaf market and its wide cultivation in salt-affected agricultural regions. This work evaluates the effect of salinity (2.5, 5 and 10 dS m-1) on productive and quality features of watercress compared with another crop widely cultivated for the baby-leaf sector (lettuce, Lactuca sativa). In watercress, a linear relationship (R2=0.75) was observe...

  2. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    OpenAIRE

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A.

    2013-01-01

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spe...

  3. Strain distribution and failure mode of polymer separators for Li-ion batteries under biaxial loading

    Science.gov (United States)

    Kalnaus, Sergiy; Kumar, Abhishek; Wang, Yanli; Li, Jianlin; Simunovic, Srdjan; Turner, John A.; Gorney, Phillip

    2018-02-01

    Deformation of polymer separators for Li-ion batteries has been studied under biaxial tension by using a dome test setup. This deformation mode provides characterization of separator strength under more complex loading conditions, closer representing deformation of an electric vehicle battery during crash event, compared to uniaxial tension or compression. Two polymer separators, Celgard 2325 and Celgard 2075 were investigated by deformation with spheres of three different diameters. Strains in separators were measured in situ by using Digital Image Correlation (DIC) technique. The results show consistent rupture of separators along the machine direction coinciding with areas of high strain accumulation. The critical first principal strain for failure was independent of the sphere diameter and was determined to be approximately 34% and 43% for Celgard 2325 and Celgard 2075 respectively. These values can be taken as a criterion for internal short circuit in a battery following an out-of-plane impact. A Finite Element (FE) model was built with the anisotropic description of separator behavior, derived from tensile tests in orthogonal directions. The results of simulations predicted the response of separator rather well when compared to experimental results for various sizes of rigid sphere.

  4. Mass-energy distribution of fragments in Langevin dynamics of fission induced by heavy ions

    Directory of Open Access Journals (Sweden)

    Vanin D. V.

    2012-12-01

    Full Text Available Four-dimensional Langevin equation was employed to calculate mass-energy distributions of fission fragments of highly excited compound nuclei. The research took into account not only three shape collective coordinates introduced on the basis of {c,h,α}-parametrization but also orientation degree of freedom (K-state— spin about the symmetry axis. Overdamped Langevin equation was used to describe the evolution of the K-state. Friction tensor was calculated using the “wall+window” model of the modified one-body dissipation mechanism with a reduction coeffcient from the “wall” formula ks. The calculations have been performed with ks = 0:25 and ks = 1:0. To learn more about the role of the dissipation effects the calculations have also been done with use of the chaoticity measure of nucleon movements in the nuclear shape configuration as ks parameter. Calculations were performed for the large number of compound nuclei with Z2/A parameter in the range 21 ≤ Z2/A ≤ 44. The goal was to study the mass-energy distributions not only for heavy nuclei but also for light nuclei close to the Businaro-Gallone point. Mass-energy distributions and variances of the mass fragments are well reproduced in the applied calculations for all considered compound nuclei. It was shown that inclusion of the K-state in the dynamical model produces considerable increase of the mass and energy variances. Inclusion of the chaoticity measure to the friction tensor provides a better agreement with the experiment results on mass variances.

  5. Surfactant protein C peptides with salt-bridges (“ion-locks” promote high surfactant activities by mimicking the α-helix and membrane topography of the native protein

    Directory of Open Access Journals (Sweden)

    Frans J. Walther

    2014-07-01

    Full Text Available Background. Surfactant protein C (SP-C; 35 residues in lungs has a cationic N-terminal domain with two cysteines covalently linked to palmitoyls and a C-terminal region enriched in Val, Leu and Ile. Native SP-C shows high surface activity, due to SP-C inserting in the bilayer with its cationic N-terminus binding to the polar headgroup and its hydrophobic C-terminus embedded as a tilted, transmembrane α-helix. The palmitoylcysteines in SP-C act as ‘helical adjuvants’ to maintain activity by overriding the β-sheet propensities of the native sequences.Objective. We studied SP-C peptides lacking palmitoyls, but containing glutamate and lysine at 4-residue intervals, to assess whether SP-C peptides with salt-bridges (“ion-locks” promote surface activity by mimicking the α-helix and membrane topography of native SP-C.Methods. SP-C mimics were synthesized that reproduce native sequences, but without palmitoyls (i.e., SP-Css or SP-Cff, with serines or phenylalanines replacing the two cysteines. Ion-lock SP-C molecules were prepared by incorporating single or double Glu−–Lys+ into the parent SP-C’s. The secondary structures of SP-C mimics were studied with Fourier transform infrared (FTIR spectroscopy and PASTA, an algorithm that predicts β-sheet propensities based on the energies of the various β-sheet pairings. The membrane topography of SP-C mimics was investigated with orientated and hydrogen/deuterium (H/D exchange FTIR, and also Membrane Protein Explorer (MPEx hydropathy analysis. In vitro surface activity was determined using adsorption surface pressure isotherms and captive bubble surfactometry, and in vivo surface activity from lung function measures in a rabbit model of surfactant deficiency.Results. PASTA calculations predicted that the SP-Css and SP-Cff peptides should each form parallel β-sheet aggregates, with FTIR spectroscopy confirming high parallel β-sheet with ‘amyloid-like’ properties. The enhanced

  6. Exploring drivers of sodium salt toxicity to the mayfly Neocloeon triangulifer, and comparing trends in mayfly and daphnid responses to major ions

    Science.gov (United States)

    Field studies have shown that mayflies (Ephemeroptera) tend to be more sensitive than other benthic macroinvertebrates to elevated levels of total dissolved solids in streams. While work with other species has shown that major ion toxicity is dependent on the ionic composition o...

  7. A relationship between ion balance and the chemical compounds of salt inclusions found in the Greenland Ice Core Project and Dome Fuji ice cores

    DEFF Research Database (Denmark)

    Johnsen, Sigfus Johann; Dahl-Jensen, Dorthe; Steffensen, Jørgen Peder

    2008-01-01

    We have proposed a method of deducing the chemical compounds found in deep polar ice cores by analyzing the balance between six major ions (Cl-, NO3 -, SO4 2-, Na+, Mg2+, and Ca2+). The method is demonstrated for the Holocene and last glacial maximum regions of the Dome Fuji and GRIP ice cores...

  8. Cellular distribution and function of ion channels involved in transport processes in rat tracheal epithelium.

    Science.gov (United States)

    Hahn, Anne; Faulhaber, Johannes; Srisawang, Lalita; Stortz, Andreas; Salomon, Johanna J; Mall, Marcus A; Frings, Stephan; Möhrlen, Frank

    2017-06-01

    Transport of water and electrolytes in airway epithelia involves chloride-selective ion channels, which are controlled either by cytosolic Ca2+ or by cAMP The contributions of the two pathways to chloride transport differ among vertebrate species. Because rats are becoming more important as animal model for cystic fibrosis, we have examined how Ca2+- dependent and cAMP- dependent Cl- secretion is organized in the rat tracheal epithelium. We examined the expression of the Ca2+-gated Cl- channel anoctamin 1 (ANO1), the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel, the epithelial Na+ channel ENaC, and the water channel aquaporin 5 (AQP5) in rat tracheal epithelium. The contribution of ANO1 channels to nucleotide-stimulated Cl- secretion was determined using the channel blocker Ani9 in short-circuit current recordings obtained from primary cultures of rat tracheal epithelial cells in Ussing chambers. We found that ANO1, CFTR and AQP5 proteins were expressed in nonciliated cells of the tracheal epithelium, whereas ENaC was expressed in ciliated cells. Among nonciliated cells, ANO1 occurred together with CFTR and Muc5b and, in addition, in a different cell type without CFTR and Muc5b. Bioelectrical studies with the ANO1-blocker Ani9 indicated that ANO1 mediated the secretory response to the nucleotide uridine-5'-triphosphate. Our data demonstrate that, in rat tracheal epithelium, Cl- secretion and Na+ absorption are routed through different cell types, and that ANO1 channels form the molecular basis of Ca2+-dependent Cl- secretion in this tissue. These characteristic features of Cl--dependent secretion reveal similarities and distinct differences to secretory processes in human airways. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  9. Measurements of the fast-ion distribution function at ASDEX upgrade by collective Thomson scattering (CTS) using active and passive views

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Stejner Pedersen, Morten; Rasmussen, Jesper

    2015-01-01

    Collective Thomson scattering (CTS) can provide measurements of the confined fast-ion distribution function resolved in space, time and 1D velocity space. On ASDEX Upgrade, the measured spectra include an additional signal which previously has hampered data interpretation. A new set-up using two......, the measured spectra agree quantitatively with the synthetic spectra in periods with and without NBI heating. For the discharges investigated, the central velocity distribution of neutral beam ions can be described by classical slowing down. These results will have a major impact on ITER physics exploration...

  10. Study of In distribution on GaInSb:Al crystals by ion beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Streicher, M., E-mail: smorgana@gmail.com [Pontifícia Universidade Católica do Rio Grande do Sul, Av. Ipiranga, 6681, Porto Alegre, RS (Brazil); Instituto de Plasmas e Fusão Nuclear (IPFN), Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2695-066 Bobadela LRS (Portugal); Corregidor, V.; Catarino, N. [Instituto de Plasmas e Fusão Nuclear (IPFN), Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2695-066 Bobadela LRS (Portugal); Alves, L.C. [Centro de Ciências e Tecnologias Nucleares (C2TN), Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2695-066 Bobadela LRS (Portugal); Franco, N. [Instituto de Plasmas e Fusão Nuclear (IPFN), Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2695-066 Bobadela LRS (Portugal); Fonseca, M. [Universidade Europeia, Laureate International Universities, 1500-210 Lisboa (Portugal); Laboratório de Instrumentação, Engenharia Biomédica e Física da Radiação (LIBPhys-UNL), Departamento de Física, FCT-UNL, 2829-516 Monte da Caparica (Portugal); and others

    2016-03-15

    III–V ternary alloys semiconductor materials, in particular Ga{sub 1−x}In{sub x}Sb, are ideal candidates for device substrates because of the possibility to define the lattice constant as a function of the third element, indium. Aluminum, an isoelectric dopant for Ga and In, increases the carrier mobility in GaSb crystals and has influence over the concentration of native defects by passivating and/or compensating them. To understand the influence of Al on the distribution of indium in ternary alloys of Ga{sub 0.8}In{sub 0.2}Sb, pure and doped ingots were obtained with approximately 10{sup 20} atoms/cm{sup 3} of Al using a vertical Bridgman system. Analysis by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), particle induced X-ray emission (PIXE) and particle induced gamma ray emission (PIGE) were used to obtain information on the structure defects and chemical composition of the crystals. The doped ingots showed good structural homogeneity when compared with the undoped alloy, and they were free from cracks and micro cracks. All of the obtained ingots present precipitates, twins and grains with different concentrations of In. The small compositional variation observed in the doped ingots along the radial direction (measured by PIXE), may be related to the solid–liquid interface’s quasi-equilibrium behavior. Regarding to the growth direction, it was observed that the undoped ingots exhibit a higher segregation phenomenon of the third element than the doped ingots. The obtained results indicate that aluminum influences the indium distribution in the ingots, thus ternary ingots with more homogeneous composition can be obtained and consequently electrical properties improved.

  11. Study on Mobility, Distribution and Rapid Ion Mobility Spectrometry Detection of Seven Pesticide Residues in Cucumber, Apple, and Cherry Tomato.

    Science.gov (United States)

    Zou, Nan; Yuan, Chunhao; Chen, Ronghua; Yang, Juan; Li, Yifan; Li, Xuesheng; Pan, Canping

    2017-01-11

    This research explores the mobility and distribution rules of simazine, acetamiprid, hexazinone, paclobutrazol, amitraz, clofentezine, and boscalid in the pulp and peel of apple, cucumber, and cherry tomato. A laboratory test was carried out by treating the matrices with standard solution for different periods of time. The percentage sorption of pesticides ranged from 0.02 to 89.3% for the three matrices. The pesticides' distribution was also determined, and all pesticides showed ratio values (Q) between pulp and peel concentrations in the three matrices of <0.8, which proved that the highest pesticides' content was found in the peel. In addition, a rapid and simple process combining a surface swab capture method and pulse glow discharge-ion mobility spectrometry (PGD-IMS) detection was established for the detection of pesticides on matrix surfaces. In the swab method, the whole matrix surface was swabbed manually by swab sticks, and swab sticks were agitated in acetonitrile to release the pesticides. The releasing factors of pesticides in the three matrices were calculated. The linearity, LOD, LOQ, and matrix effect were investigated to assess the applicability of the swab-IMS process in practical analysis. The swab-IMS method is rapid, sensitive, and quantitative and can be achieved in the field.

  12. Proton and neutron density distributions at supranormal density in low- and medium-energy heavy-ion collisions

    Science.gov (United States)

    Stone, J. R.; Danielewicz, P.; Iwata, Y.

    2017-07-01

    Background: The distribution of protons and neutrons in the matter created in heavy-ion collisions is one of the main points of interest for the collision physics, especially at supranormal densities. These distributions are the basis for predictions of the density dependence of the symmetry energy and the density range that can be achieved in a given colliding system. We report results of the first systematic simulation of proton and neutron density distributions in central heavy-ion collisions within the beam energy range of Ebeam≤800 MeV /nucl . The symmetric 40Ca+40Ca , 48Ca+48Ca , 100Sn+100Sn , and 120Sn+120Sn and asymmetric 40Ca+48Ca and 100Sn+120Sn systems were chosen for the simulations. Purpose: We simulate development of proton and neutron densities and asymmetries as a function of initial state, beam energy, and system size in the selected collisions in order to guide further experiments pursuing the density dependence of the symmetry energy. Methods: The Boltzmann-Uhlenbeck-Uehling (pBUU) transport model with four empirical models for the density dependence of the symmetry energy was employed. Results of simulations using pure Vlasov dynamics were added for completeness. In addition, the time-dependent Hartree-Fock (TDHF) model, with the SV-bas Skyrme interaction, was used to model the heavy-ion collisions at Ebeam≤40 MeV /nucl . Maximum proton and neutron densities ρpmax and ρnmax, reached in the course of a collision, were determined from the time evolution of ρp and ρn. Results: The highest total densities predicted at Ebeam=800 MeV /nucl . were of the order of ˜2.5 ρ0 (ρ0=0.16 fm-3 ) for both Sn and Ca systems. They were found to be only weakly dependent on the initial conditions, beam energy, system size, and a model of the symmetry energy. The proton-neutron asymmetry δ =(ρnmax-ρpmax) /(ρnmax+ρpmax) at maximum density does depend, though, on these parameters. The highest value of δ found in all systems and at all investigated beam

  13. A new family of anion receptors and their effects on ion pair dissociation and conductivity of lithium salts in non-aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.S.; Yang, X.Q.; McBreen, J. [Brookhaven National Lab., Upton, NY (United States); Okamoto, Y. [Polytechnic Univ., Brooklyn, NY (United States)

    1994-08-01

    A new family of anion receptors based on aza-ether compounds have been synthesized. Since the anion complexation of these compounds is not based on either positively charged sites or hydrogen bonding, they have a potential to be used in lithium batteries as electrolyte additives. When these compounds are added into nonaqueous electrolytes using lithium salts, such as LiCl/BF or LiBr/THF, the ionic conductivity can be dramatically increased. Near Edge X-ray Absorption Fine Structure (NF-XAFS) spectroscopy studies show that Cl{sup {minus}} anions are completed with the nitrogen groups in these compounds. The increase in ionic conductivity and the degree of complexation, are both related to the number of R=CF{sub 3}SO{sub 2} groups that are used to substitute the amine hydrogen atoms in these aza-ether compounds.

  14. Root adaptation and ion selectivity affects the nutritional value of salt-stressed hydroponically grown baby-leaf Nasturtium officinale and Lactuca sativa

    Directory of Open Access Journals (Sweden)

    Juan A. Fernández

    2016-12-01

    Full Text Available The response of watercress (Nasturtium officinale L. to salinity has been scarcely addressed in literature despite its growing importance in the baby-leaf market and its wide cultivation in salt-affected agricultural regions. This work evaluates the effect of salinity (2.5, 5 and 10 dS m-1 on productive and quality features of watercress compared with another crop widely cultivated for the baby-leaf sector (lettuce, Lactuca sativa. In watercress, a linear relationship (R2=0.75 was observed between yield decrease and Cl– accumulation in leaves, whereas yield was not affected by salinity in lettuce. NaCl application increased Na+ accumulation at the expense of Ca2+ uptake in the leaf tissues of both crops, but also of K+ in watercress. Health-related features were improved by salinity (e.g. increased phenolics and reduced nitrates, especially in watercress, with limited sensorial quality evaluation effects.

  15. Hydration patterns and salting effects in sodium chloride solution.

    Science.gov (United States)

    Li, Weifeng; Mu, Yuguang

    2011-10-07

    The salting effects of 2M sodium chloride electrolyte are studied based on a series of model solutes with properties ranging from hydrophobic to hydrophilic. Generally, hydrophobic solutes will be salted out and hydrophilic solutes will be salted in by NaCl solution. The solvation free energy changes are highly correlated with Kirkwood-Buff integrals. The underlying mechanism resorts to the preferential binding of ions and water to solutes. Our results demonstrate that the salting effect not only depends on the salt's position in Hofmeister series, but also on the solutes' specifics. Taking the hydration free energies of solutes and ions as independent variables, a schematic diagram of salting effects is suggested. The resolved multifaceted salting effects rely on the sensitive balance of the tripartite interaction among solutes, ions, and water. © 2011 American Institute of Physics

  16. Low molecular weight salts combined with fluorinated solvents for electrolytes

    Science.gov (United States)

    Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan; Lei, Norman; Guerrero-Zavala, Guillermo; Kwong, Kristie W.

    2015-11-10

    Provided are electrochemical cells and electrolytes used to build such cells. An electrolyte includes at least one salt having a molecular weight less than about 250. Such salts allow forming electrolytes with higher salt concentrations and ensure high conductivity and ion transport in these electrolytes. The low molecular weight salt may have a concentration of at least about 0.5M and may be combined with one or more other salts, such as linear and cyclic imide salts and/or methide salts. The concentration of these additional salts may be less than that of the low molecular weight salt, in some embodiments, twice less. The additional salts may have a molecular weight greater than about 250. The electrolyte may also include one or more fluorinated solvents and may be capable of maintaining single phase solutions at between about -30.degree. C. to about 80.degree. C.

  17. A Monte Carlo study for the calculation of the average linear energy transfer (LET) distributions for a clinical proton beam line and a radiobiological carbon ion beam line.

    Science.gov (United States)

    Romano, F; Cirrone, G A P; Cuttone, G; Rosa, F Di; Mazzaglia, S E; Petrovic, I; Fira, A Ristic; Varisano, A

    2014-06-21

    Fluence, depth absorbed dose and linear energy transfer (LET) distributions of proton and carbon ion beams have been investigated using the Monte Carlo code Geant4 (GEometry ANd Tracking). An open source application was developed with the aim to simulate two typical transport beam lines, one used for ocular therapy and cell irradiations with protons and the other for cell irradiations with carbon ions. This tool allows evaluation of the primary and total dose averaged LET and predict their spatial distribution in voxelized or sliced geometries. In order to reproduce the LET distributions in a realistic way, and also the secondary particles' contributions due to nuclear interactions were considered in the computations. Pristine and spread-out Bragg peaks were taken into account both for proton and carbon ion beams, with the maximum energy of 62 MeV/n. Depth dose distributions were compared with experimental data, showing good agreement. Primary and total LET distributions were analysed in order to study the influence of contributions of secondary particles in regions at different depths. A non-negligible influence of high-LET components was found in the entrance channel for proton beams, determining the total dose averaged LET by the factor 3 higher than the primary one. A completely different situation was obtained for carbon ions. In this case, secondary particles mainly contributed in the tail that is after the peak. The results showed how the weight of light and heavy secondary ions can considerably influence the computation of LET depth distributions. This has an important role in the interpretation of results coming from radiobiological experiments and, therefore, in hadron treatment planning procedures.

  18. Tailoring Ion Charge State Distribution in Tetramethyltin Clusters under Influence of Moderate Intensity Picosecond Laser Pulse: Role of Laser Wavelength and Rate of Energy Deposition

    Science.gov (United States)

    Sharma, Pramod; Das, Soumitra; Vatsa, Rajesh K.

    2017-07-01

    Systematic manipulation of ionic-outcome in laser-cluster interaction process has been realized for studies carried out on tetramethyltin (TMT) clusters under picosecond laser conditions, determined by choice of laser wavelength and intensity. As a function of laser intensity, TMT clusters exhibit gradual enhancement in overall ionization of its cluster constituents, up to a saturation level of ionization, which was distinct for different wavelengths (266, 355, and 532 nm). Simultaneously, systematic appearance of higher multiply charged atomic ions and shift in relative abundance of multiply charged atomic ions towards higher charge state was observed, using time-of-flight mass spectrometer. At saturation level, multiply charged atomic ions up to (C2+, Sn2+) at 266 nm, (C4+, Sn4+) at 355 nm, and (C4+, Sn6+) at 532 nm were detected. In addition, at 355 nm intra-cluster ion chemistry within the ionized cluster leads to generation of molecular hydrogen ion (H2 +) and triatomic molecular hydrogen ion (H3 +). Generation of multiply charged atomic ions is ascribed to efficient coupling of laser pulse with the cluster media, facilitated by inner-ionized electrons produced within the cluster, at the leading edge of laser pulse. Role of inner-ionized electrons is authenticated by measuring kinetic energy distribution of electrons liberated upon disintegration of excessively ionized cluster, under the influence of picosecond laser pulse.

  19. Characterization of charge and kinetic energy distribution of ions emitted during nanosecond pulsed laser ablation of several metals

    Science.gov (United States)

    Dogar, A. H.; Ullah, S.; Qayyum, H.; Rehman, Z. U.; Qayyum, A.

    2017-09-01

    The ion flux from various metals (Al, Ti, Cu, Sn and W) ablated with 20 ns Nd:YAG laser radiation at a wavelength of 1064 nm was investigated by an ion collector operating in time-of-flight (TOF) configuration. The laser irradiance at the target was varied in the range of 1.7  ×  108-5.73  ×  108 W cm-2. Ion yield from various metals showed a linearly increasing trend with increasing laser irradiance, whereas ion yield was found to decrease with an increasing atomic mass of the target. Our results clearly indicate that ion yield is not a function of the volatility of the metal. TOF ion spectra showed at least two groups of low intensity peaks due to fast ions. The first group of ion peaks, which was present in the spectra of all five metals, was due to surface contamination. The additional fast ion structures in the spectra of Sn and W can be related to the ion acceleration due to the prompt electron emission from these high-Z metals. The ion velocity follows the anticipated inverse square root dependence on the ion mass. For the range of laser irradiance investigated here, the most probable energy of the Cu ions increases from about 100-600 eV. The fast increase in ion energy above ~3  ×  108 W cm-2 is related to the increase of the Columb part of the ion energy due to the production of multiply charged ions.

  20. Measurements of charge state distributions of 0.74 and 1.4  MeV/u heavy ions passing through dilute gases

    Directory of Open Access Journals (Sweden)

    P. Scharrer

    2017-04-01

    Full Text Available In many modern heavy-ion accelerator facilities, gas strippers are used to increase the projectile charge state for improving the acceleration efficiency of ion beams to higher energies. For this application, the knowledge on the behavior of charge state distributions of heavy-ions after passing through dilute gases is of special interest. Charge state distributions of uranium (^{238}U, bismuth (^{209}Bi, titanium (^{50}Ti, and argon (^{40}Ar ion beams with energies of 0.74  MeV/u and 1.4  MeV/u after passing through hydrogen (H_{2}, helium (He, carbon dioxide (CO_{2}, nitrogen (N_{2}, oxygen (O_{2}, neon (Ne, and argon (Ar gases were measured. Gas stripper target thicknesses up to 100  μg/cm^{2} were applied. The observed behavior of the charge state distributions, including their width and mean charge state, are discussed. The measurements show the highest equilibrium charge state at 1.4  MeV/u for ^{238}U on H_{2} gas of 29.2±1.2. Narrow charge state distributions are observed for ^{238}U and ^{209}Bi on H_{2} and He gas, which are highly beneficial, e.g., for the production of beams of high intensities in accelerators.

  1. Measurements of charge state distributions of 0.74 and 1.4 MeV /u heavy ions passing through dilute gases

    Science.gov (United States)

    Scharrer, P.; Düllmann, Ch. E.; Barth, W.; Khuyagbaatar, J.; Yakushev, A.; Bevcic, M.; Gerhard, P.; Groening, L.; Horn, K. P.; Jäger, E.; Krier, J.; Vormann, H.

    2017-04-01

    In many modern heavy-ion accelerator facilities, gas strippers are used to increase the projectile charge state for improving the acceleration efficiency of ion beams to higher energies. For this application, the knowledge on the behavior of charge state distributions of heavy-ions after passing through dilute gases is of special interest. Charge state distributions of uranium (238U), bismuth (209Bi), titanium (50Ti), and argon (40Ar) ion beams with energies of 0.74 MeV /u and 1.4 MeV /u after passing through hydrogen (H2 ), helium (He), carbon dioxide (CO2 ), nitrogen (N2 ), oxygen (O2 ), neon (Ne), and argon (Ar) gases were measured. Gas stripper target thicknesses up to 100 μ g /cm2 were applied. The observed behavior of the charge state distributions, including their width and mean charge state, are discussed. The measurements show the highest equilibrium charge state at 1.4 MeV /u for 238U on H2 gas of 29.2 ±1.2 . Narrow charge state distributions are observed for 238U and 209Bi on H2 and He gas, which are highly beneficial, e.g., for the production of beams of high intensities in accelerators.

  2. Electromagnetic ion-cyclotron instability in the presence of a parallel electric field with general loss-cone distribution function - particle aspect analysis

    Directory of Open Access Journals (Sweden)

    G. Ahirwar

    2006-08-01

    Full Text Available The effect of parallel electric field on the growth rate, parallel and perpendicular resonant energy and marginal stability of the electromagnetic ion-cyclotron (EMIC wave with general loss-cone distribution function in a low β homogeneous plasma is investigated by particle aspect approach. The effect of the steepness of the loss-cone distribution is investigated on the electromagnetic ion-cyclotron wave. The whole plasma is considered to consist of resonant and non-resonant particles. It is assumed that resonant particles participate in the energy exchange with the wave, whereas non-resonant particles support the oscillatory motion of the wave. The wave is assumed to propagate parallel to the static magnetic field. The effect of the parallel electric field with the general distribution function is to control the growth rate of the EMIC waves, whereas the effect of steep loss-cone distribution is to enhance the growth rate and perpendicular heating of the ions. This study is relevant to the analysis of ion conics in the presence of an EMIC wave in the auroral acceleration region of the Earth's magnetoplasma.

  3. Quenching of electronically excited N2 molecules and Tb3+ /Eu3+ ions by polyatomic sulfur-containing gases upon triboluminescence of inorganic lanthanide salts.

    Science.gov (United States)

    Sharipov, G L; Tukhbatullin, A A; Bagautdinova, A R

    2017-08-01

    The triboluminescence of Eu2 (SO4 )3 ·8H2 O and Tb2 (SO4 )3 ·8H2 O crystals in an atmosphere of sulfur dioxide (SO2 ) or sulfur hexafluoride (SF6 ) was studied. Quenching of the gaseous (emitter N2 ) and solid-state (emitter Ln3+ ) components of the triboluminescence (TL) emission spectrum was seen when compared with the TL spectra of the crystals in air. One reason for the quenching is a reduction in the effective charge both on the crystal surface and in micro-cracks under an SO2 or SF6 atmosphere, leading to a decrease in the probability of electrical breakdown and a reduction in electric field strength responsible for the electroluminescence excitation of lanthanide ions in TL. In an SO2 atmosphere, there is an additional mode of quenching, as confirmed by quenching of the crystal photoluminescence (emitter Ln3+ ). It is supposed that this quenching is due to an exchange of energy on electronic excitation of the lanthanide ions to the vibrational sublevels of the SO2 molecules adsorbed on the crystal surface. Another additional channel of TL quenching originates from non-radiative transfer of excitation energy during collisions between the *N2 and SO2 molecules in the gaseous phase. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Novel synthetic approach for 1, 4-dihydroxyanthraquinone and the development of its Lithiated salts as anode material for aqueous rechargeable Lithium-ion batteries

    KAUST Repository

    Gurukar, Suresh Shivappa

    2015-08-17

    The influence of organic electrode materials in the field of lithium ion battery is becoming a keen interest for the present generation scientists. Here we are reporting a novel method of synthesis of electrode material by the combination of sono-chemical and thermal methods. The advantages of organic active material towards lithium ion battery are of core interest of this study. The structural confirmations are by FT-IR, 1H NMR, MALDI-TOF Mass Spectroscopy and powder XRD data. The electrochemical properties of Lithiated-1,4-dihydroxyanthraquinone were studied using electrochemical-techniques such as Cyclic Voltammetry, Galvanostatic Cyclic Potential Limitation and Potentiostatic Electrochemical Impedance Spectroscopy. The satisfactory results towards stability of active species in the aqueous media, reasonable discharge capacity with 0.9 V average voltages and agreeable cycling performance during charge-discharge process with reproducibility are achieved. For the construction of the full cell, the anode material was coupled with the LiNi1/3Co1/3Mn1/3O2 as a cathode material.

  5. CLASSICS The Ions

    Indian Academy of Sciences (India)

    Arrhenius theory of electrolytic dissociation, viz., in general, salts in solution dissociate to give ions. Ostwald, in 1888 gave a quantitative description of the dissociation, which was very useful in understanding the physical chemistry of solutions. The following portion 'The Ions' is from the book The Fundamental Principles of.

  6. Salting-in and salting-out of water-soluble polymers in aqueous salt solutions.

    Science.gov (United States)

    Sadeghi, Rahmat; Jahani, Farahnaz

    2012-05-03

    To obtain further experimental evidence for the mechanisms of the salting effect produced by the addition of salting-out or sating-in inducing electrolytes to aqueous solutions of water-soluble polymers, systematic studies on the vapor-liquid equilibria and liquid-liquid equilibria of aqueous solutions of several polymers are performed in the presence of a large series of electrolytes. Polymers are polyethylene glycol 400 (PEG400), polyethylene glycol dimethyl ether 250 (PEGDME250), polyethylene glycol dimethyl ether 2000 (PEGDME2000), and polypropylene glycol 400 (PPG400), and the investigated electrolytes are KCl, NH(4)Cl, MgCl(2), (CH(3))(4)NCl, NaCl, NaNO(3), Na(2)CO(3), Na(2)SO(4), and Na(3)Cit (tri-sodium citrate). Aqueous solutions of PPG400 form aqueous two-phase systems with all the investigated salts; however, other investigated polymers form aqueous two-phase systems only with Na(2)CO(3), Na(2)SO(4), and Na(3)Cit. A relation was found between the salting-out or sating-in effects of electrolyte on the polymer aqueous solutions and the slopes of the constant water activity lines of ternary polymer-salt aqueous solutions, so that, in the case of the salting-out effect, the constant water activity lines had a concave slope, but in the case of the salting-in effects, the constant water activity lines had a convex slope. The effect of temperature, anion of electrolyte, cation of electrolyte, and type and molar mass of polymers were studied and the results interpreted in terms of the solute-water and solute-solute interactions. The salting-out effect results from the formation of ion (specially anion)-water hydration complexes, which, in turn, decreases hydration, and hence, the solubility of the polymer and the salting-in effect results from a direct binding of the cations to the ether oxygens of the polymers.

  7. Salt effects in electromembrane extraction

    DEFF Research Database (Denmark)

    Seip, Knut Fredrik; Jensen, Henrik; Kieu, Thanh Elisabeth

    2014-01-01

    Electromembrane extraction (EME) was performed on samples containing substantial amounts of NaCl to investigate how the presence of salts affected the recovery, repeatability, and membrane current in the extraction system. A group of 17 non-polar basic drugs with various physical chemical...... this loss and the physical chemical properties of these substances was seen. The recovery loss was hypothesized to be caused by ion pairing in the SLM, and a mathematical model for the extraction recovery in the presence of salts was made according to the experimental observations. Some variations...... improves the theoretical understanding of the extraction process, and can contribute to the future development and optimization of the technique....

  8. Ion Beam Extraction by Discrete Ion Focusing

    DEFF Research Database (Denmark)

    2010-01-01

    An apparatus (900) and methods are disclosed for ion beam extraction. In an implementation, the apparatus includes a plasma source (or plasma) (802) and an ion extractor (804). The plasma source is adapted to generate ions and the ion extractor is immersed in the plasma source to extract a fraction...... of the generated ions. The ion extractor is surrounded by a space charge (810) formed at least in part by the extracted ions. The ion extractor includes a biased electrode (806) forming an interface with an insulator (808). The interface is customized to form a strongly curved potential distribution (812......) in the space-charge surrounding the ion extractor. The strongly curved potential distribution focuses the extracted ions towards an opening (814) on a surface of the biased electrode thereby resulting in an ion beam....

  9. Ion Exchange Distribution Coefficient Tests and Computer Modeling at High Ionic Strength Supporting Technetium Removal Resin Maturation

    Energy Technology Data Exchange (ETDEWEB)

    Nash, Charles A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hamm, L. Larry [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Smith, Frank G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-12-19

    The primary treatment of the tank waste at the DOE Hanford site will be done in the Waste Treatment and Immobilization Plant (WTP) that is currently under construction. The baseline plan for this facility is to treat the waste, splitting it into High Level Waste (HLW) and Low Activity Waste (LAW). Both waste streams are then separately vitrified as glass and poured into canisters for disposition. The LAW glass will be disposed onsite in the Integrated Disposal Facility (IDF). There are currently no plans to treat the waste to remove technetium, so its disposition path is the LAW glass. Due to the water solubility properties of pertechnetate and long half-life of 99Tc, effective management of 99Tc is important to the overall success of the Hanford River Protection Project mission. To achieve the full target WTP throughput, additional LAW immobilization capacity is needed, and options are being explored to immobilize the supplemental LAW portion of the tank waste. Removal of 99Tc, followed by off-site disposal, would eliminate a key risk contributor for the IDF Performance Assessment (PA) for supplemental waste forms, and has potential to reduce treatment and disposal costs. Washington River Protection Solutions (WRPS) is developing some conceptual flow sheets for supplemental LAW treatment and disposal that could benefit from technetium removal. One of these flowsheets will specifically examine removing 99Tc from the LAW feed stream to supplemental immobilization. To enable an informed decision regarding the viability of technetium removal, further maturation of available technologies is being performed. This report contains results of experimental ion exchange distribution coefficient testing and computer modeling using the resin SuperLig® 639a to selectively remove perrhenate from high ionic strength simulated LAW. It is advantageous to operate at higher concentration in order to treat the waste

  10. Optical properties and size distribution of the nanocolloids made of rare-earth ion-doped NaYF4

    Science.gov (United States)

    Patel, Darayas N.; Lewis, Ashley; Wright, Donald M.; Lewis, Danielle; Valentine, Rueben; Valentine, Maucus; Wessley, Dennis; Sarkisov, Sergey; Darwish, Abdalla M.

    2015-03-01

    In this paper we investigate optical properties and size distribution of the nano-colloids made of trivalent rare-earth ion doped fluorides: holmium and ytterbium, thulium and ytterbium, and erbium and ytterbium co-doped NaYF4. These materials were synthesized by using simple co-precipitation synthetic method. The initially prepared micro-crystals had very weak or no visible upconversion fluorescence signals when being pumped with a 980-nm laser. The fluorescence intensity significantly increased after the crystals were annealed at a temperature of 400°C - 600°C undergoing the transition from cubic alpha to hexagonal beta phase of the fluoride host. Nano-colloids of the crystals were made in polar solvents using the laser ablation and ball milling methods. Size analyses of the prepared nano-colloids were conducted using a dynamic light scatterometer and atomic force microscope. The nano-colloids were filled in holey PCFs and their fluorescent properties were studied and the feasibility of new a type of fiber amplifier/laser was evaluated.

  11. Lunar pickup ions observed by ARTEMIS: Spatial and temporal distribution and constraints on species and source locations

    Science.gov (United States)

    Halekas, J. S.; Poppe, A. R.; Delory, G. T.; Sarantos, M.; Farrell, W. M.; Angelopoulos, V.; McFadden, J. P.

    2012-06-01

    ARTEMIS observes pickup ions around the Moon, at distances of up to 20,000 km from the surface. The observed ions form a plume with a narrow spatial and angular extent, generally seen in a single energy/angle bin of the ESA instrument. Though ARTEMIS has no mass resolution capability, we can utilize the analytically describable characteristics of pickup ion trajectories to constrain the possible ion masses that can reach the spacecraft at the observation location in the correct energy/angle bin. We find that most of the observations are consistent with a mass range of ˜20-45 amu, with a smaller fraction consistent with higher masses, and very few consistent with masses below ˜15 amu. With the assumption that the highest fluxes of pickup ions come from near the surface, the observations favor mass ranges of ˜20-24 and ˜36-40 amu. Although many of the observations have properties consistent with a surface or near-surface release of ions, some do not, suggesting that at least some of the observed ions have an exospheric source. Of all the proposed sources for ions and neutrals about the Moon, the pickup ion flux measured by ARTEMIS correlates best with the solar wind proton flux, indicating that sputtering plays a key role in either directly producing ions from the surface, or producing neutrals that subsequently become ionized.

  12. Comparison of monovalent and divalent ion distributions around a DNA duplex with molecular dynamics simulation and a Poisson-Boltzmann approach.

    Science.gov (United States)

    Robbins, Timothy J; Ziebarth, Jesse D; Wang, Yongmei

    2014-08-01

    The ion atmosphere created by monovalent (Na(+) ) or divalent (Mg(2+) ) cations surrounding a B-form DNA duplex were examined using atomistic molecular dynamics (MD) simulations and the nonlinear Poisson-Boltzmann (PB) equation. The ion distributions predicted by the two methods were compared using plots of radial and two-dimensional cation concentrations and by calculating the total number of cations and net solution charge surrounding the DNA. Na(+) ion distributions near the DNA were more diffuse in PB calculations than in corresponding MD simulations, with PB calculations predicting lower concentrations near DNA groove sites and phosphate groups and a higher concentration in the region between these locations. Other than this difference, the Na(+) distributions generated by the two methods largely agreed, as both predicted similar locations of high Na(+) concentration and nearly identical values of the number of cations and the net solution charge at all distances from the DNA. In contrast, there was greater disagreement between the two methods for Mg(2+) cation concentration profiles, as both the locations and magnitudes of peaks in Mg(2+) concentration were different. Despite experimental and simulation observations that Mg(2+) typically maintains its first solvation shell when interacting with nucleic acids, modeling Mg(2+) as an unsolvated ion during PB calculations improved the agreement of the Mg(2+) ion atmosphere predicted by the two methods and allowed for values of the number of bound ions and net solution charge surrounding the DNA from PB calculations that approached the values observed in MD simulations. © 2014 Wiley Periodicals, Inc.

  13. A light-driven sodium ion pump in marine bacteria.

    Science.gov (United States)

    Inoue, Keiichi; Ono, Hikaru; Abe-Yoshizumi, Rei; Yoshizawa, Susumu; Ito, Hiroyasu; Kogure, Kazuhiro; Kandori, Hideki

    2013-01-01

    Light-driven proton-pumping rhodopsins are widely distributed in many microorganisms. They convert sunlight energy into proton gradients that serve as energy source of the cell. Here we report a new functional class of a microbial rhodopsin, a light-driven sodium ion pump. We discover that the marine flavobacterium Krokinobacter eikastus possesses two rhodopsins, the first, KR1, being a prototypical proton pump, while the second, KR2, pumps sodium ions outward. Rhodopsin KR2 can also pump lithium ions, but converts to a proton pump when presented with potassium chloride or salts of larger cations. These data indicate that KR2 is a compatible sodium ion-proton pump, and spectroscopic analysis showed it binds sodium ions in its extracellular domain. These findings suggest that light-driven sodium pumps may be as important in situ as their proton-pumping counterparts.

  14. Recycling of aluminum salt cake

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-12-01

    The secondary aluminum industry generates more than 110 {times} 10{sup 3} tons of salt-cake waste every year. This waste stream contains about 3--5% aluminum, 15--30% aluminum oxide, 30--40% sodium chloride, and 20--30% potassium chloride. As much as 50% of the content of this waste is combined salt (sodium and potassium chlorides). Salt-cake waste is currently disposed of in conventional landfills. In addition, over 50 {times} 10{sup 3} tons of black dross that is not economical to reprocess a rotary furnace for aluminum recovery ends up in landfills. The composition of the dross is similar to that of salt cake, except that it contains higher concentrations of aluminum (up to 20%) and correspondingly lower amounts of salts. Because of the high solubility of the salts in water, these residues, when put in landfills, represent a potential source of pollution to surface-water and groundwater supplies. The increasing number of environmental regulations on the generation and disposal of industrial wastes are likely to restrict the disposal of these salt-containing wastes in conventional landfills. Processes exist that employ the dissolution and recovery of the salts from the waste stream. These wet-processing methods are economical only when the aluminum concentration in that waste exceeds about 10%. Argonne National Laboratory (ANL) conducted a study in which existing technologies were reviewed and new concepts that are potentially more cost-effective than existing processes were developed and evaluated. These include freeze crystallization, solvent/antisolvent extraction, common-ion effect, high-pressure/high-temperature process, and capillary-effect systems. This paper presents some of the technical and economic results of the aforementioned ANL study.

  15. Comparative physiology of salt and water stress.

    Science.gov (United States)

    Munns, R.

    2002-02-01

    Plant responses to salt and water stress have much in common. Salinity reduces the ability of plants to take up water, and this quickly causes reductions in growth rate, along with a suite of metabolic changes identical to those caused by water stress. The initial reduction in shoot growth is probably due to hormonal signals generated by the roots. There may be salt-specific effects that later have an impact on growth; if excessive amounts of salt enter the plant, salt will eventually rise to toxic levels in the older transpiring leaves, causing premature senescence, and reduce the photosynthetic leaf area of the plant to a level that cannot sustain growth. These effects take time to develop. Salt-tolerant plants differ from salt-sensitive ones in having a low rate of Na+ and Cl-- transport to leaves, and the ability to compartmentalize these ions in vacuoles to prevent their build-up in cytoplasm or cell walls and thus avoid salt toxicity. In order to understand the processes that give rise to tolerance of salt, as distinct from tolerance of osmotic stress, and to identify genes that control the transport of salt across membranes, it is important to avoid treatments that induce cell plasmolysis, and to design experiments that distinguish between tolerance of salt and tolerance of water stress.

  16. Spatial distribution, temporal variability, and chemistry of the salt wedge in the lower Charles River, Massachusetts, June 1998 to July 1999

    Science.gov (United States)

    Breault, R.F.; Barlow, L.K.; Reisig, K.D.; Parker, G.W.

    2000-01-01

    The Charles River is of great recreational and ecological value to the Boston metropolitan region and the Commonwealth of Massachusetts. It is also the focus of the U.S. Environmental Protection Agency (USEPA) Region I, Clean Charles 2005 Task Force. The main goal of the Task Force is to make the Charles River 'fishable and swimmable' by the year 2005. Achieving 'fishable and swimmable' conditions will require continued progress in addressing a range of environmental conditions now degrading water quality, including the infiltration of saltwater from Boston Harbor into the freshwater Charles River.To better understand the pattern of saltwater intrusion, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (USEPA), Massachusetts Department of Environmental Management (MADEM), and New England Interstate Water Pollution Control Commission (NEIWPCC), collected data on the spatial distribution, temporal variability, and chemistry of the saltwater that entered the lower Charles River from June 1998 to July 1999. The purpose of this investigation is to extend and complement a regional-scale study of Charles River water quality conducted in 1996 (T. Faber, U.S. Environmental Protection Agency, written commun., 1997), and the ongoing water monitoring activities of the Massachusetts Water Resources Authority (MWRA) and the Charles River Watershed Association (CRWA). The data collected by this investigation supports the Clean Charles 2005 Task Force by providing detailed information concerning a major factor limiting 'fishable and swimmable' conditions in the lower Charles River. Finally, the study will be used to assist current planning efforts of the Metropolitan District Commission (MDC) to restore the historic parklands of the lower Charles River.The 'Basin' is the local term for the reach of the Charles River that begins at the Watertown Dam in Watertown, Mass., and extends about 8 mi through suburban and urban areas to Boston

  17. High-resolution radial distribution function of pure ion-implanted amorphous silicon measured using tilted-illumination selected-area electron diffraction.

    Science.gov (United States)

    Gorecki, Alexander; Liu, Amelia C Y; Petersen, Timothy C

    2014-02-01

    High-resolution radial distribution functions of as-implanted and thermally relaxed amorphous silicon created by ion implantation were measured using tilted-illumination selected area electron diffraction at room temperature. The diffracted intensities were measured out to a maximum scattering vector 2 sin(θ)/λ of 3.3-3.7 Å-1. The volume-averaged pair-correlation statistics of as-implanted and relaxed ion-implanted amorphous silicon are virtually indistinguishable with coordination numbers of 3.7 ± 0.3 and 3.9 ± 0.3 (for neighbors closer than 3 Å) and average bond angles of 109 ± 0.5° and 110 ± 0.6°, respectively. The atomic rearrangements in ion-implanted amorphous silicon due to a low temperature anneal are subtle.

  18. The distribution of lead between sea salt, dust, and lead-rich aerosols in the mid South Pacific Easterlies at American Samoa

    Energy Technology Data Exchange (ETDEWEB)

    Rosman, K.J.R.; Patterson, C.C.; Settle, D.M. (California Inst. of Tech., Pasadena (United States))

    1990-03-20

    Aerosols in the South Pacific Easterlies have been sampled at American Samoa with a cascade impactor and analyzed for Pb, Ba, K, Ca, Sr, and Rb by isotope dilution mass spectrometry using ultraclean procedures. Some 84% of the Pb was found in fine ({le}0.5 {mu}m) aerosols which were collected on the backup filter with an efficiency of only 33%. Sea salt and eroded terrestrial material (dust) containing 6% and < 1% respectively, of the Pb (sea salt indexed by the metals K, Ca, Sr, and Rb and dust indexed by Ba) were collected on early stages of the impactor, although 65% of the dust, because of its larger size, was lost to surfaces of the rain shelter before reaching the impactor. The remaining 10% of the Pb was associated with plant leaf waxes of continental origin which produced Pb and Ba peaks on stage 4 (0.5 {mu}m) of the impactor.

  19. Small-Ion and Nano-Aerosol Production During Candle Burning: Size Distribution and Concentration Profile with Time

    National Research Council Canada - National Science Library

    Wright, Matthew D; Fews, A. Peter; Keitch, Paul A; Henshaw, Denis L

    2007-01-01

    The characteristics of small-ions and aerosols in the diameter range 0.4 nm to 1.1 μm, produced during burning of paraffin wax tea-light candles, were investigated using a custom-built aspiration condenser ion mobility spectrometer...

  20. Salt Effect on Osmotic Pressure of Polyelectrolyte Solutions: Simulation Study

    Directory of Open Access Journals (Sweden)

    Jan-Michael Y. Carrillo

    2014-07-01

    Full Text Available Abstract: We present results of the hybrid Monte Carlo/molecular dynamics simulations of the osmotic pressure of salt solutions of polyelectrolytes. In our simulations, we used a coarse-grained representation of polyelectrolyte chains, counterions and salt ions. During simulation runs, we alternate Monte Carlo and molecular dynamics simulation steps. Monte Carlo steps were used to perform small ion exchange between simulation box containing salt ions (salt reservoir and simulation box with polyelectrolyte chains, counterions and salt ions (polyelectrolyte solution. This allowed us to model Donnan equilibrium and partitioning of salt and counterions across membrane impermeable to polyelectrolyte chains. Our simulations have shown that the main contribution to the system osmotic pressure is due to salt ions and osmotically active counterions. The fraction of the condensed (osmotically inactive counterions first increases with decreases in the solution ionic strength then it saturates. The reduced value of the system osmotic coefficient is a universal function of the ratio of the concentration of osmotically active counterions and salt concentration in salt reservoir. Simulation results are in a very good agreement with osmotic pressure measurements in sodium polystyrene sulfonate, DNA, polyacrylic acid, sodium polyanetholesulfonic acid, polyvinylbenzoic acid, and polydiallyldimethylammonium chloride solutions.

  1. Salt reduction in sheeted dough: A successful technological approach.

    Science.gov (United States)

    Diler, Guénaëlle; Le-Bail, Alain; Chevallier, Sylvie

    2016-10-01

    The challenge of reducing the salt content while maintaining shelf life, stability and acceptability of the products is major for the food industry. In the present study, we implemented processing adjustments to reduce salt content while maintaining the machinability and the saltiness perception of sheeted dough: the homogeneous distribution of a layer of encapsulated salt grains on the dough during the laminating process. During sheeting, for an imposed deformation of 0.67, the final strain remained unchanged around 0.50 for salt reduction below 50%, and then, increased significantly up to 0.53 for a dough without salt. This increase is, in fine, positive regarding the rolling process since the decrease of salt content induces less shrinkage of dough downstream, which is the main feature to be controlled in the process. Moreover, the final strain was negatively correlated to the resistance to extension measured with a texture analyzer, therefore providing a method to evaluate the machinability of the dough. From these results, a salt reduction of 25% was achieved by holding 50% of the salt in the dough recipe to maintain the dough properties and saving 25% as salt grains to create high-salted areas that would enhance the saltiness perception of the dough. The distributor mounted above the rollers of the mill proved to be able to distribute evenly salt grains at a calculated step of the rolling out process. An innovative method based on RX micro-tomography allowed to follow the salt dissolving and to demonstrate the capability of the coatings to delay the salt dissolving and consequently the diffusion of salt within the dough piece. Finally, a ranking test on the salted perception of different samples having either an even distribution of encapsulated salt grains, a single layer of salt grains or a homogeneous distribution of salt, demonstrated that increasing the saltiness perception in salt-reduced food product could be achieved by a technological approach

  2. Content of sodium ions in the tissues of Crimean flora halophytes depending on the varying degree of salinity

    OpenAIRE

    S. N. Kabuzenko; A. V. Omelchenko; L. N. Mikhalskaya; SCHWARTAU V.V.

    2015-01-01

    The quantitative content and distribution in organs and tissue compartments of Na + ions in halophytes Suaeda prostrata Pall., Salicornia perennans Willd., Artemisia santonica L. growing in the areas with chloride-sulfate type of salinization of soil in the vicinity of the Sasyk salt lake (Northwest Crimea) has been determined. It was found that for S. perennans and S. prostrata euhalophytes the strategy of translocation of Na + ions to the organs of the aerial part with increasing NaCl conce...

  3. Influence of intracellular Na + , K + and Cl - on the salt tolerance in ...

    African Journals Online (AJOL)

    In the process of selection for salt tolerance, it is important to understand the physiological basis of ion management executed by the cells through the exclusion, accumulation or maintenance of ratios of specific ions. Intracellular accumulation of Na+, K+ and Cl- ions in the cells in vitro was studied as a factor in salt ...

  4. Distributions of neutron yields and doses around a water phantom bombarded with 290-MeV/nucleon and 430-MeV/nucleon carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, D., E-mail: satoh.daiki@jaea.go.jp [Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kajimoto, T. [Hiroshima University, Kagamiyama, Higashi-Hiroshima-shi, Hiroshima 739-8527 (Japan); Shigyo, N.; Itashiki, Y.; Imabayashi, Y. [Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Koba, Y.; Matsufuji, N. [National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Sanami, T. [High Energy Accelerator Research Organization, Oho-cho, Tsukuba-shi, Ibaraki 305-0801 (Japan); Nakao, N. [Shimizu Corporation, Etchujima, Koto-ku, Tokyo 135-8530 (Japan); Uozumi, Y. [Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

    2016-11-15

    Double-differential neutron yields from a water phantom bombarded with 290-MeV/nucleon and 430-MeV/nucleon carbon ions were measured at emission angles of 15°, 30°, 45°, 60°, 75°, and 90°, and angular distributions of neutron yields and doses around the phantom were obtained. The experimental data were compared with results of the Monte-Carlo simulation code PHITS. The PHITS results showed good agreement with the measured data. On the basis of the PHITS simulation, we estimated the angular distributions of neutron yields and doses from 0° to 180° including thermal neutrons.

  5. Numerical simulation and experimental validation of the three-dimensional flow field and relative analyte concentration distribution in an atmospheric pressure ion source.

    Science.gov (United States)

    Poehler, Thorsten; Kunte, Robert; Hoenen, Herwart; Jeschke, Peter; Wissdorf, Walter; Brockmann, Klaus J; Benter, Thorsten

    2011-11-01

    In this study, the validation and analysis of steady state numerical simulations of the gas flows within a multi-purpose ion source (MPIS) are presented. The experimental results were obtained with particle image velocimetry (PIV) measurements in a non-scaled MPIS. Two-dimensional time-averaged velocity and turbulent kinetic energy distributions are presented for two dry gas volume flow rates. The numerical results of the validation simulations are in very good agreement with the experimental data. All significant flow features have been correctly predicted within the accuracy of the experiments. For technical reasons, the experiments were conducted at room temperature. Thus, numerical simulations of ionization conditions at two operating points of the MPIS are also presented. It is clearly shown that the dry gas volume flow rate has the most significant impact on the overall flow pattern within the APLI source; far less critical is the (larger) nebulization gas flow. In addition to the approximate solution of Reynolds-Averaged Navier-Stokes equations, a transport equation for the relative analyte concentration has been solved. The results yield information on the three-dimensional analyte distribution within the source. It becomes evident that for ion transport into the MS ion transfer capillary, electromagnetic forces are at least as important as fluid dynamic forces. However, only the fluid dynamics determines the three-dimensional distribution of analyte gas. Thus, local flow phenomena in close proximity to the spray shield are strongly impacting on the ionization efficiency.

  6. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 1 covers papers on the advances of gas phase ion chemistry. The book discusses the advances in flow tubes and the measurement of ion-molecule rate coefficients and product distributions; the ion chemistry of the earth's atmosphere; and the classical ion-molecule collision theory. The text also describes statistical methods in reaction dynamics; the state selection by photoion-photoelectron coincidence; and the effects of temperature and pressure in the kinetics of ion-molecule reactions. The energy distribution in the unimolecular decomposition of ions, as well

  7. Salt resistant crop plants

    KAUST Repository

    Roy, Stuart J.

    2014-04-01

    Soil salinity is a major constraint to agriculture. To improve salinity tolerance of crops, various traits can be incorporated, including ion exclusion, osmotic tolerance and tissue tolerance. We review the roles of a range of genes involved in salt tolerance traits. Different tissues and cells are adapted for specific and often diverse function, so it is important to express the genes in specific cell-types and to pyramid a range of traits. Modern biotechnology (marker- assisted selection or genetic engineering) needs to be increasingly used to introduce the correct combination of genes into elite crop cultivars. Importantly, the effects of introduced genes need to be evaluated in the field to determine their effect on salinity tolerance and yield improvement.

  8. Salt resistant crop plants.

    Science.gov (United States)

    Roy, Stuart J; Negrão, Sónia; Tester, Mark

    2014-04-01

    Soil salinity is a major constraint to agriculture. To improve salinity tolerance of crops, various traits can be incorporated, including ion exclusion, osmotic tolerance and tissue tolerance. We review the roles of a range of genes involved in salt tolerance traits. Different tissues and cells are adapted for specific and often diverse function, so it is important to express the genes in specific cell-types and to pyramid a range of traits. Modern biotechnology (marker-assisted selection or genetic engineering) needs to be increasingly used to introduce the correct combination of genes into elite crop cultivars. Importantly, the effects of introduced genes need to be evaluated in the field to determine their effect on salinity tolerance and yield improvement. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Salt Bridge Rearrangement (SaBRe) Explains the Dissociation Behavior of Noncovalent Complexes

    Science.gov (United States)

    Loo, Rachel R. Ogorzalek; Loo, Joseph A.

    2016-06-01

    Native electrospray ionization-mass spectrometry, with gas-phase activation and solution compositions that partially release subcomplexes, can elucidate topologies of macromolecular assemblies. That so much complexity can be preserved in gas-phase assemblies is remarkable, although a long-standing conundrum has been the differences between their gas- and solution-phase decompositions. Collision-induced dissociation of multimeric noncovalent complexes typically distributes products asymmetrically (i.e., by ejecting a single subunit bearing a large percentage of the excess charge). That unexpected behavior has been rationalized as one subunit "unfolding" to depart with more charge. We present an alternative explanation based on heterolytic ion-pair scission and rearrangement, a mechanism that inherently partitions charge asymmetrically. Excessive barriers to dissociation are circumvented in this manner, when local charge rearrangements access a lower-barrier surface. An implication of this ion pair consideration is that stability differences between high- and low-charge state ions usually attributed to Coulomb repulsion may, alternatively, be conveyed by attractive forces from ion pairs (salt bridges) stabilizing low-charge state ions. Should the number of ion pairs be roughly inversely related to charge, symmetric dissociations would be favored from highly charged complexes, as observed. Correlations between a gas-phase protein's size and charge reflect the quantity of restraining ion pairs. Collisionally-facilitated salt bridge rearrangement (SaBRe) may explain unusual size "contractions" seen for some activated, low charge state complexes. That some low-charged multimers preferentially cleave covalent bonds or shed small ions to disrupting noncovalent associations is also explained by greater ion pairing in low charge state complexes.

  10. Salt Tolerance of Desorption Electrospray Ionization (DESI)

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Ayanna U. [Purdue University; Talaty, Nari [Purdue University; Cooks, R G [Purdue University; Van Berkel, Gary J [ORNL

    2007-01-01

    Suppression of ion intensity in the presence of high salt matrices is common in most mass spectrometry ionization techniques. Desorption electrospray ionization (DESI) is an ionization method that exhibits salt tolerance, and this is investigated. DESI analysis was performed on three different drug mixtures in the presence of 0, 0.2, 2, 5, 10, and 20% NaCl:KCl weight by volume from seven different surfaces. At physiological concentrations individual drugs in each mixture were observed with each surface. Collision-induced dissociation (CID) was used to provide additional confirmation for select compounds. Multiple stage experiments, to MS5, were performed for select compounds. Even in the absence of added salt, the benzodiazepine containing mixture yielded sodium and potassium adducts of carbamazepine which masked the ions of interest. These adducts were eliminated by adding 0.1% 7M ammonium acetate to the standard methanol:water (1:1) spray solvent. Comparison of the salt tolerance of DESI with that of electrospray ionization (ESI) demonstrated much better signal/noise characteristics for DESI in this study. The salt tolerance of DESI was also studied by performing limit of detection and dynamic range experiments. Even at a salt concentration significantly above physiological concentrations, select surfaces were effective in providing spectra that allowed the ready identification of the compounds of interest. The already high salt tolerance of DESI can be optimized further by appropriate choices of surface and spray solution.

  11. Effect of salt-stresses on the hormonal regulation of growth, photosynthesis and distribution of 14C-assimilates in bean plants

    Directory of Open Access Journals (Sweden)

    Z. Starck

    2015-01-01

    Full Text Available The experiments were carried out to study the effect of salt-stresses and ABA on the growth, photosynthesis and translocation of assimilates in bean plants. It was planed to reduce the content of GA3 and cytokinins and increase ABA content in salinized plants. The results show that salt-stress (NaCl and concentrated nutrient solution, reduce all the investigated processes in a different degree. NaCl-stress retarded most seriously growth of apical part and blades in contrast to 7-times concentrated nutrient solution decreasing mainly the rate of root and blade growth. Photosynthesis and 14C-translocation of 14C-assimilates were retarded more seriously by NaCl than by 7-times concentrated nutrient. solution. In the case of seriously stressed plants GA3 and cytokinins (more effectively reversed the ,negative effect of stress conditions both on the photosynthesis and on the 14C-tramslocation. On the basis of the obtained results, it seemes that changes in the rate of investigated processes in salinized plants are due to hormonal disturbances which cause directly or indirectly retardation of photosynthesis and trans-location of assimilates.

  12. Physical chemistry and evolution of salt tolerance in halobacteria

    Science.gov (United States)

    Lanyi, J. K.

    1980-01-01

    The cellular constituents of extremely halophilic bacteria not only tolerate high salt concentration, but in many cases require it for optical functioning. The characteristics affected by salt include enzyme activity, stability, allosteric regulation, conformation and subunit association. The salt effects are of two major kinds: electrostatic shielding of negative charges by cations at low salt concentration, and hydrophobic stabilization by salting-out type salts at high salt concentration. The composition of halobacterial proteins shows an excess of acidic amino acids and a deficiency of nonpolar amino acids, which accounts for these effects. Since the cohesive forces are weaker and the repulsing forces are stronger in these proteins, preventing aggregation in salt, these structures are no longer suited for functioning in the absence of high salt concentrations. Unlike these nonspecific effects, ribosomes in halobacteria show marked preference for potassium over sodium ions. To ensure the proper intracellular ionic composition, powerful ion transport systems have evolved in the halobacteria, resulting in the extrusion of sodium ions and their replacement by potassium. It is likely that such membrane transport system for ionic movements is a necessary requisite for salt tolerance.

  13. Multiscale Simulations of Lamellar PS–PEO Block Copolymers Doped with LiPF6 Ions

    KAUST Repository

    Sethuraman, Vaidyanathan

    2017-06-02

    We report the results of atomistic simulations of the structural equilibrium properties of PS–PEO block copolymer (BCP) melt in the ordered lamellar phase doped with LiPF6 salt. A hybrid simulation strategy, consisting of steps of coarse-graining and inverse coarse-graining, was employed to equilibrate the melt at an atomistic resolution in the ordered phase. We characterize the structural distributions between different atoms/ions and compare the features arising in BCPs against the corresponding behavior in PEO homopolymers for different salt concentrations. In addition, the local structural distributions are characterized in the lamellar phase as a function of distance from the interface. The cation–anion radial distribution functions (RDF) display stronger coordination in the block copolymer melts at high salt concentrations, whereas the trends are reversed for low salt concentrations. Radial distribution functions isolated in the PEO and PS domains demonstrate that the stronger coordination seen in BCPs arises from the influence of both the higher fraction of ions segregated in the PS phase and the influence of interactions in the PS domain. Such a behavior also manifests in the cation–anion clusters, which show a larger fraction of free ions in the BCP. While the average number of free anions (cations) decreases with increasing salt concentration, higher order aggregates of LiPF6 increase with increasing salt concentration. Further, the cation–anion RDFs display spatial heterogeneity, with a stronger cation–anion binding in the interfacial region compared to bulk of the PEO domain.

  14. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    Science.gov (United States)

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A.

    2013-07-01

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions.

  15. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    Energy Technology Data Exchange (ETDEWEB)

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A. [High Temperature Gasdynamics Laboratory, Stanford University, Stanford, California 94305 (United States)

    2013-07-15

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions.

  16. Photoionization of He in the 3lnl' doubly-excited state energy region: angular distribution of the fluorescence from the residual ion He{sup +}(2p){sup 2}P

    Energy Technology Data Exchange (ETDEWEB)

    Harries, James R [Photon Factory, IMSS, KEK, 1-1 Oho, Tsukuba 305-0081 (Japan); Sullivan, James P [Atomic and Molecular Physics Laboratories, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT (Australia); Hammond, Peter [School of Physics, CAMSP, University of Western Australia, Nedlands, Perth (Australia); Azuma, Yoshiro [Photon Factory, IMSS, KEK, 1-1 Oho, Tsukuba 305-0081 (Japan)

    2006-12-14

    We present experimental observations of the photoexcitation of 3lnl' doubly-excited states of helium decaying by autoionization into the (2p){sup 2}P excited ion final-state channel. By determining the angular distribution of the fluorescence from the final ion state, the alignment of the ion and hence the partial 2pks and 2pkd cross-sections are determined and compared to recent theoretical calculations.

  17. Influence of water vapour on the height distribution of positive ions, effective recombination coefficient and ionisation balance in the quiet lower ionosphere

    Directory of Open Access Journals (Sweden)

    V. Barabash

    2014-03-01

    vapour concentration upper limit at altitudes between 75 and 87 km, beyond which the water vapour concentration ceases to influence the numerical densities of Cl2+ and Cl1+, the effective recombination coefficient and the electron number density in the summer ionosphere. This water vapour concentration limit corresponds to values found in the H2O-1 profile that was observed in the summer mesosphere by the Upper Atmosphere Research Satellite (UARS. The electron density modelled using the H2O-1 profile agreed well with the electron density measured in the summer ionosphere when the measured profiles did not have sharp gradients. For sharp gradients in electron and positive ion number densities, a water profile that can reproduce the characteristic behaviour of the ionospheric parameters should have an inhomogeneous height distribution of water vapour.

  18. Metal Ion Binding at the Catalytic Site Induces Widely Distributed Changes in a Sequence Specific Protein-DNA Complex.

    Science.gov (United States)

    Sinha, Kaustubh; Sangani, Sahil S; Kehr, Andrew D; Rule, Gordon S; Jen-Jacobson, Linda

    2016-11-08

    Metal ion cofactors can alter the energetics and specificity of sequence specific protein-DNA interactions, but it is unknown if the underlying effects on structure and dynamics are local or dispersed throughout the protein-DNA complex. This work uses EcoRV endonuclease as a model, and catalytically inactive lanthanide ions, which replace the Mg 2+ cofactor. Nuclear magnetic resonance (NMR) titrations indicate that four Lu 3+ or two La 3+ cations bind, and two new crystal structures confirm that Lu 3+ binding is confined to the active sites. NMR spectra show that the metal-free EcoRV complex with cognate (GATATC) DNA is structurally distinct from the nonspecific complex, and that metal ion binding sites are not assembled in the nonspecific complex. NMR chemical shift perturbations were determined for 1 H- 15 N amide resonances, for 1 H- 13 C Ile-δ-CH 3 resonances, and for stereospecifically assigned Leu-δ-CH 3 and Val-γ-CH 3 resonances. Many chemical shifts throughout the cognate complex are unperturbed, so metal binding does not induce major conformational changes. However, some large perturbations of amide and side chain methyl resonances occur as far as 34 Å from the metal ions. Concerted changes in specific residues imply that local effects of metal binding are propagated via a β-sheet and an α-helix. Both amide and methyl resonance perturbations indicate changes in the interface between subunits of the EcoRV homodimer. Bound metal ions also affect amide hydrogen exchange rates for distant residues, including a distant subdomain that contacts DNA phosphates and promotes DNA bending, showing that metal ions in the active sites, which relieve electrostatic repulsion between protein and DNA, cause changes in slow dynamics throughout the complex.

  19. Metal Ion Binding at the Catalytic Site Induces Widely Distributed Changes in a Sequence Specific Protein–DNA Complex

    Science.gov (United States)

    2016-01-01

    Metal ion cofactors can alter the energetics and specificity of sequence specific protein–DNA interactions, but it is unknown if the underlying effects on structure and dynamics are local or dispersed throughout the protein–DNA complex. This work uses EcoRV endonuclease as a model, and catalytically inactive lanthanide ions, which replace the Mg2+ cofactor. Nuclear magnetic resonance (NMR) titrations indicate that four Lu3+ or two La3+ cations bind, and two new crystal structures confirm that Lu3+ binding is confined to the active sites. NMR spectra show that the metal-free EcoRV complex with cognate (GATATC) DNA is structurally distinct from the nonspecific complex, and that metal ion binding sites are not assembled in the nonspecific complex. NMR chemical shift perturbations were determined for 1H–15N amide resonances, for 1H–13C Ile-δ-CH3 resonances, and for stereospecifically assigned Leu-δ-CH3 and Val-γ-CH3 resonances. Many chemical shifts throughout the cognate complex are unperturbed, so metal binding does not induce major conformational changes. However, some large perturbations of amide and side chain methyl resonances occur as far as 34 Å from the metal ions. Concerted changes in specific residues imply that local effects of metal binding are propagated via a β-sheet and an α-helix. Both amide and methyl resonance perturbations indicate changes in the interface between subunits of the EcoRV homodimer. Bound metal ions also affect amide hydrogen exchange rates for distant residues, including a distant subdomain that contacts DNA phosphates and promotes DNA bending, showing that metal ions in the active sites, which relieve electrostatic repulsion between protein and DNA, cause changes in slow dynamics throughout the complex. PMID:27786446

  20. Energy loss and charge state distribution of calcium ions in dense moderately coupled carbon plasma; Energieverlust und Ladungsverteilung von Calciumionen in dichtem, schwach gekoppeltem Kohlenstoffplasma

    Energy Technology Data Exchange (ETDEWEB)

    Ortner, Alex

    2015-07-15

    In this thesis the interaction of swift calcium ions (Energy: 3.5 MeV/u) with a dense and moderately coupled carbon plasma (Coupling parameter: Γ=0.1-0.5) is investigated. The plasma state is generated by heating a thin carbon foil volumetrically by thermal X-ray radiation. The thermal X-ray radiation itself is generated by the conversion of a high energy laser beam in a hohlraum cavity. Compared to earlier ion stopping experiments the electron density and the plasma coupling parameter could be increased by an order of magnitude. This work provides the first time experimental energy loss and charge state distribution data in this moderately coupled interaction regime. The thesis consists of a theoretical part where the ion beam plasma interaction is studied for a broad range of plasma parameters and an experimental part where the ion beam interaction with the hohlraum plasma target is measured. All the described experiments were carried out at the GSI Helmholtzzentrum fuer Schwerionenforschung in Darmstadt. This facility offers the unique possibility to combine a heavy ion beam from an accelerator with a high energy laser beam in one interaction chamber. An intense laser pulse (150 J of laser energy in 1 ns at λ{sub L}=527 nm) is focused inside a 600 μm diameter spherical cavity and generates a hot gold plasma that emits X-rays. The absorbed and reemitted radiation establishes a spatially uniform temperature distribution in the cavity and serves as an intense, isotropic X-ray source with a quasi-thermal spectral distribution. These thermal X-rays with a radiation temperature of T{sub r}=98±6 eV then propagate into a secondary cylindrical hohlraum (diameter: 1000 μm, length: 950 μm) where they volumetrically heat two thin carbon foils to the plasma state. The radiation temperature in the secondary hohlraum is T{sub r}=33±5 eV. This indirect laser heating scheme has the advantage that the whole sample volume is instantaneously heated and that the plasma is

  1. Macroevolutionary patterns of salt tolerance in angiosperms

    Science.gov (United States)

    Bromham, Lindell

    2015-01-01

    Background Halophytes are rare, with only 0·25 % of angiosperm species able to complete their life cycle in saline conditions. This could be interpreted as evidence that salt tolerance is difficult to evolve. However, consideration of the phylogenetic distribution of halophytes paints a different picture: salt tolerance has evolved independently in many different lineages, and halophytes are widely distributed across angiosperm families. In this Viewpoint, I will consider what phylogenetic analysis of halophytes can tell us about the macroevolution of salt tolerance. Hypothesis Phylogenetic analyses of salt tolerance have shown contrasting patterns in different families. In some families, such as chenopods, salt tolerance evolved early in the lineage and has been retained in many lineages. But in other families, including grasses, there have been a surprisingly large number of independent origins of salt tolerance, most of which are relatively recent and result in only one or a few salt-tolerant species. This pattern of many recent origins implies either a high transition rate (salt tolerance is gained and lost often) or a high extinction rate (salt-tolerant lineages do not tend to persist over macroevolutionary timescales). While salt tolerance can evolve in a wide range of genetic backgrounds, some lineages are more likely to produce halophytes than others. This may be due to enabling traits that act as stepping stones to developing salt tolerance. The ability to tolerate environmental salt may increase tolerance of other stresses or vice versa. Conclusions Phylogenetic analyses suggest that enabling traits and cross-tolerances may make some lineages more likely to adapt to increasing salinization, a finding that may prove useful in assessing the probable impact of rapid environmental change on vegetation communities, and in selecting taxa to develop for use in landscape rehabilitation and agriculture. PMID:25452251

  2. Long-term effect of salinity on plant quality, water relations, photosynthetic parameters and ion distribution in Callistemon citrinus.

    Science.gov (United States)

    Álvarez, S; Sánchez-Blanco, M J

    2014-07-01

    The effect of saline stress on physiological and morphological parameters in Callistemon citrinus plants was studied to evaluate their adaptability to irrigation with saline water. C. citrinus plants, grown under greenhouse conditions, were subjected to two irrigation treatments lasting 56 weeks: control (0.8 dS·m(-1)) and saline (4 dS·m(-1)). The use of saline water in C. citrinus plants decreased aerial growth, increased the root/shoot ratio and improved the root system (increased root diameter and root density), but flowering and leaf colour were not affected. Salinity caused a decrease in stomatal conductance and evapotranspiration, which may prevent toxic levels being reached in the shoot. Net photosynthesis was reduced in plants subjected to salinity, although this response was evident much later than the decrease in stomatal conductance. Stem water potential was a good indicator of salt stress in C. citrinus. The relative salt tolerance of Callistemon was related to storage of higher levels of Na+ and Cl- in the roots compared with the leaves, especially in the case of Na+, which could have helped to maintain the quality of plants. The results show that saline water (around 4 dS·m(-1)) could be used for growing C. citrinus commercially. However, the cumulative effect of irrigating with saline water for 11 months was a decrease in photosynthesis and intrinsic water use efficiency, meaning that the interaction of the salinity level and the time of exposure to the salt stress should be considered important in this species. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  3. A liquid-helium-free superconducting coil system forming a flat minimum-magnetic-field distribution of an electron cyclotron resonance ion source.

    Science.gov (United States)

    Yoshida, Ken-ichi; Nara, Takayuki; Saitoh, Yuichi; Yokota, Watalu

    2014-02-01

    A flat distribution of the minimum magnetic field (flat-Bmin) of an electron cyclotron resonance ion source (ECRIS) is expected to perform better in highly charged ion production than classical Bmin. To form a flat-Bmin structure with a liquid helium-free superconducting device, a coil system of seven coils with four current leads has been designed. The lead number was reduced by connecting the plural coils in series to maintain the flat-Bmin structure even when the coil currents are changed for adjustment. This coil system can be operated with a helium-free cryostat, since the estimation of heat from the leads to the coils is nearly equivalent to the existing superconducting ECRIS of a similar type.

  4. A liquid-helium-free superconducting coil system forming a flat minimum-magnetic-field distribution of an electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Ken-ichi, E-mail: yoshida.kennichi71@jaea.go.jp; Nara, Takayuki; Saitoh, Yuichi; Yokota, Watalu [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2014-02-15

    A flat distribution of the minimum magnetic field (flat-B{sub min}) of an electron cyclotron resonance ion source (ECRIS) is expected to perform better in highly charged ion production than classical B{sub min}. To form a flat-B{sub min} structure with a liquid helium-free superconducting device, a coil system of seven coils with four current leads has been designed. The lead number was reduced by connecting the plural coils in series to maintain the flat-B{sub min} structure even when the coil currents are changed for adjustment. This coil system can be operated with a helium-free cryostat, since the estimation of heat from the leads to the coils is nearly equivalent to the existing superconducting ECRIS of a similar type.

  5. A liquid-helium-free superconducting coil system forming a flat minimum-magnetic-field distribution of an electron cyclotron resonance ion source

    Science.gov (United States)

    Yoshida, Ken-ichi; Nara, Takayuki; Saitoh, Yuichi; Yokota, Watalu

    2014-02-01

    A flat distribution of the minimum magnetic field (flat-Bmin) of an electron cyclotron resonance ion source (ECRIS) is expected to perform better in highly charged ion production than classical Bmin. To form a flat-Bmin structure with a liquid helium-free superconducting device, a coil system of seven coils with four current leads has been designed. The lead number was reduced by connecting the plural coils in series to maintain the flat-Bmin structure even when the coil currents are changed for adjustment. This coil system can be operated with a helium-free cryostat, since the estimation of heat from the leads to the coils is nearly equivalent to the existing superconducting ECRIS of a similar type.

  6. Spatial distribution of atomic and ion hydrogen flux and its effect on hydrogen recycling in long duration confined and non-confined plasmas

    Directory of Open Access Journals (Sweden)

    A. Kuzmin

    2017-08-01

    Full Text Available In order to understand the atomic hydrogen distribution in different kinds of plasma and its influence on the recycling, two kinds of plasmas were used: non-confined annular electron cyclotron resonance (ECR and confined long duration plasmas. The permeation probes are used to measure directly the atomic hydrogen flux at several poloidal positions. The permeation through metals due to the ion and atom component of the hydrogen flux to the wall is indistinguishable. To estimate the contribution of the ions directly, Langmuir probes were used. The Гinc profile behind the plasma facing components (PFCs is almost constant, ∼2 ×1018 H/s/m2.

  7. Distribution and inventories of fallout radionuclides ({sup 239+24}Pu, {sup 137}Cs) and {sup 21}Pb to study the filling velocity of salt marshes in Donana National Park (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Departamento de Medio Ambiente, Avda. Complutense 22, Madrid 28040 (Spain); Anton, M.P. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Departamento de Medio Ambiente, Avda. Complutense 22, Madrid 28040 (Spain)]. E-mail: maripaz.anton@ciemat.es; Pozuelo, M. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Departamento de Medio Ambiente, Avda. Complutense 22, Madrid 28040 (Spain); Clemente, L. [Consejo Superior de Investigaciones Cientificas, Instituto de Recursos Naturales y Agrobiologia, CSIC-IRNA, Departamento de Geoecolo