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Sample records for extracellular sodium ion

  1. Coupling Substrate and Ion Binding to Extracellular Gate of a Sodium-Dependent Aspartate Transporter

    Energy Technology Data Exchange (ETDEWEB)

    Boudker,O.; Ryan, R.; Yernool, D.; Shimamoto, K.; Gouaux, E.

    2007-01-01

    Secondary transporters are integral membrane proteins that catalyze the movement of substrate molecules across the lipid bilayer by coupling substrate transport to one or more ion gradients, thereby providing a mechanism for the concentrative uptake of substrates. Here we describe crystallographic and thermodynamic studies of Glt{sub Ph}, a sodium (Na{sup +})-coupled aspartate transporter, defining sites for aspartate, two sodium ions and D,L-threo-{beta}-benzyloxyaspartate, an inhibitor. We further show that helical hairpin 2 is the extracellular gate that controls access of substrate and ions to the internal binding sites. At least two sodium ions bind in close proximity to the substrate and these sodium-binding sites, together with the sodium-binding sites in another sodium-coupled transporter, LeuT, define an unwound {alpha}-helix as the central element of the ion-binding motif, a motif well suited to the binding of sodium and to participation in conformational changes that accompany ion binding and unbinding during the transport cycle.

  2. T-type channels become highly permeable to sodium ions using an alternative extracellular turret region (S5-P) outside the selectivity filter.

    Science.gov (United States)

    Senatore, Adriano; Guan, Wendy; Boone, Adrienne N; Spafford, J David

    2014-04-25

    T-type (Cav3) channels are categorized as calcium channels, but invertebrate ones can be highly sodium-selective channels. We illustrate that the snail LCav3 T-type channel becomes highly sodium-permeable through exon splicing of an extracellular turret and descending helix in domain II of the four-domain Cav3 channel. Highly sodium-permeable T-type channels are generated without altering the invariant ring of charged residues in the selectivity filter that governs calcium selectivity in calcium channels. The highly sodium-permeant T-type channel expresses in the brain and is the only splice isoform expressed in the snail heart. This unique splicing of turret residues offers T-type channels a capacity to serve as a pacemaking sodium current in the primitive heart and brain in lieu of Nav1-type sodium channels and to substitute for voltage-gated sodium channels lacking in many invertebrates. T-type channels would also contribute substantially to sodium leak conductances at rest in invertebrates because of their large window currents.

  3. Brain intra- and extracellular sodium concentration in multiple sclerosis: a 7 T MRI study.

    Science.gov (United States)

    Petracca, Maria; Vancea, Roxana O; Fleysher, Lazar; Jonkman, Laura E; Oesingmann, Niels; Inglese, Matilde

    2016-03-01

    Intra-axonal accumulation of sodium ions is one of the key mechanisms of delayed neuro-axonal degeneration that contributes to disability accrual in multiple sclerosis. In vivo sodium magnetic resonance imaging studies have demonstrated an increase of brain total sodium concentration in patients with multiple sclerosis, especially in patients with greater disability. However, total sodium concentration is a weighted average of intra- and extra-cellular sodium concentration whose changes reflect different tissue pathophysiological processes. The in vivo, non-invasive measurement of intracellular sodium concentration is quite challenging and the few applications in patients with neurological diseases are limited to case reports and qualitative assessments. In the present study we provide first evidence of the feasibility of triple quantum filtered (23)Na magnetic resonance imaging at 7 T, and provide in vivo quantification of global and regional brain intra- and extra-cellular sodium concentration in 19 relapsing-remitting multiple sclerosis patients and 17 heathy controls. Global grey matter and white matter total sodium concentration (respectively P brain regional level, clusters of increased total sodium concentration and intracellular sodium concentration and decreased intracellular sodium volume fraction were found in several cortical, subcortical and white matter regions when patients were compared with healthy controls (P < 0.05 family-wise error corrected for total sodium concentration, P < 0.05 uncorrected for multiple comparisons for intracellular sodium concentration and intracellular sodium volume fraction). Measures of total sodium concentration and intracellular sodium volume fraction, but not measures of intracellular sodium concentration were correlated with T2-weighted and T1-weighted lesion volumes (0.05 < P < 0.01) and with Expanded Disability Status Scale (P < 0.05). Thus, suggesting that while intracellular sodium volume fraction decrease could

  4. Effects of extracellular calcium and sodium on depolarization-induced automaticity in guinea pig papillary muscle.

    Science.gov (United States)

    Katzung, B G

    1975-07-01

    Regenerative discharge of action potentials is induced in mammalian papillary muscles by passage of small depolarizing currents. In this paper, the effects of various extracellular calcium and sodium concentrations and of tetrodotoxin on this phenomenon were studied in guinea pig papillary muscles in a sucrose gap chamber. Phase 4 diastolic depolarization was found to be associated with an increase in membrane resistance. The slope of phase 4 depolarization was decreased by reductions in extracellular calcium or sodium concentration. The range of maximum diastolic potentials and the thresholds from which regenerative potentials arose were reduced, especially at the positive limit of potentials, by a reduction in either ion. It was concluded that both calcium and sodium influence diastolic depolarization and participate in the regenerative action potentials of depolarization-induced ventricular automaticity.

  5. Epithelial Sodium and Acid-Sensing Ion Channels

    Science.gov (United States)

    Kellenberger, Stephan

    The epithelial Na+ channel (ENaC) and acid-sensing ion channels (ASICs) are non-voltage-gated Na+ channels that form their own subfamilies within the ENaC/degenerin ion channel family. ASICs are sensors of extracellular pH, and ENaC, whose main function is trans-epithelial Na+ transport, can sense extra- and intra-cellular Na+. In aldosterone-responsive epithelial cells of the kidney, ENaC plays a critical role in the control of sodium balance, blood volume and blood pressure. In airway epithelia, ENaC has a distinct role in controlling fluid reabsorption at the air-liquid interface, thereby determining the rate of mucociliary transport. In taste receptor cells of the tongue, ENaC is involved in salt taste sensation. ASICs have emerged as key sensors for extracellular protons in central and peripheral neurons. Although not all of their physiological and pathological functions are firmly established yet, there is good evidence for a role of ASICs in the brain in learning, expression of fear, and in neurodegeneration after ischaemic stroke. In sensory neurons, ASICs are involved in nociception and mechanosensation. ENaC and ASIC subunits share substantial sequence homology and the conservation of several functional domains. This chapter summarises our current understanding of the physiological functions and of the mechanisms of ion permeation, gating and regulation of ENaC and ASICs.

  6. Electrolytic process to produce sodium hypochlorite using sodium ion conductive ceramic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Balagopal, Shekar; Malhotra, Vinod; Pendleton, Justin; Reid, Kathy Jo

    2012-09-18

    An electrochemical process for the production of sodium hypochlorite is disclosed. The process may potentially be used to produce sodium hypochlorite from seawater or low purity un-softened or NaCl-based salt solutions. The process utilizes a sodium ion conductive ceramic membrane, such as membranes based on NASICON-type materials, in an electrolytic cell. In the process, water is reduced at a cathode to form hydroxyl ions and hydrogen gas. Chloride ions from a sodium chloride solution are oxidized in the anolyte compartment to produce chlorine gas which reacts with water to produce hypochlorous and hydrochloric acid. Sodium ions are transported from the anolyte compartment to the catholyte compartment across the sodium ion conductive ceramic membrane. Sodium hydroxide is transported from the catholyte compartment to the anolyte compartment to produce sodium hypochlorite within the anolyte compartment.

  7. Adsorption of sodium ions and hydrated sodium ions on a hydrophobic graphite surface via cation-π interactions

    Institute of Scientific and Technical Information of China (English)

    Shi Guo-Sheng; Wang Zhi-Gang; Zhao Ji-Jun; Hu Jun; Fang Hai-Ping

    2011-01-01

    Using density functional theory computation, we show that sodium ions and hydrated sodium ions can be strongly adsorbed onto a hydrophobic graphite surface via cation-π interactions. The key to this cation-π interaction is the coupling of the delocalized π states of graphite and the empty orbitals of sodium ions. This finding implies that the property of the graphite surface is extremely dependent on the existence of the ions on the surface, suggesting that the hydrophobic property of the graphite surface may be affected by the existence of the sodium ions.

  8. Life cycle assessment of sodium-ion batteries

    OpenAIRE

    2016-01-01

    Sodium-ion batteries are emerging as potential alternatives to lithium-ion batteries. This study presents a prospective life cycle assessment for the production of a sodium-ion battery with a layered transition metal oxide as a positive electrode material and hard carbon as a negative electrode material on the battery component level. The complete and transparent inventory data are disclosed, which can easily be used as a basis for future environmental assessments. Na-ion batteries are found ...

  9. A Fractional Anomalous Diffusion Model and Numerical Simulation for Sodium Ion Transport in the Intestinal Wall

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    Bo Yu

    2013-01-01

    Full Text Available The authors present a fractional anomalous diffusion model to describe the uptake of sodium ions across the epithelium of gastrointestinal mucosa and their subsequent diffusion in the underlying blood capillaries using fractional Fick’s law. A heterogeneous two-phase model of the gastrointestinal mucosa is considered, consisting of a continuous extracellular phase and a dispersed cellular phase. The main mode of uptake is considered to be a fractional anomalous diffusion under concentration gradient and potential gradient. Appropriate partial differential equations describing the variation with time of concentrations of sodium ions in both the two phases across the intestinal wall are obtained using Riemann-Liouville space-fractional derivative and are solved by finite difference methods. The concentrations of sodium ions in the interstitial space and in the cells have been studied as a function of time, and the mean concentration of sodium ions available for absorption by the blood capillaries has also been studied. Finally, numerical results are presented graphically for various values of different parameters. This study demonstrates that fractional anomalous diffusion model is appropriate for describing the uptake of sodium ions across the epithelium of gastrointestinal mucosa.

  10. Adsorption of Potassium and Sodium Ions by Variable Charge Soils

    Institute of Scientific and Technical Information of China (English)

    LIHONG-YAN; JIGUO-LIANG

    1992-01-01

    Adsorption of potassium and sodium ions by four typical variable charge soils of South China was studied.The results indicated that the variable charge soils saturated with H and Al showed a much higher preference for potassium ions relative to sodium ions,and this tendence could not be changed by such factors as the pH,the concentration of the cations,the dielectric constant of solvent,the accompanying anions and the iron oxide content etc.,suggesting that this difference in affinity is caused by the difference in the nature of the two cations.It was observed that a negative adsorption of sodium ions by latosol and lateritic red soil in a mixed system containing equal amount of potassium and sodium ions at low pH,which is caused by a competitive adsorption of potassium and sodium ions and repulsion of positive charge on the surfaces of soil particles for cations.The adsorption of potassium and sodium ions increased with the decreases in the dielectric constant of solvent and the iron oxide content.Sulfate affected the adsorption of potassium and sodium ions through changing the surface properties of the soils.

  11. Tin-phosphate glass anode for sodium ion batteries

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    Tsuyoshi Honma

    2013-11-01

    Full Text Available The electrochemical property of tin-phosphate (designate as GSPO glass anode for the sodium ion battery was studied. During the first charge process, sodium ion diffused into GSPO glass matrix and due to the reduction of Sn2+ to Sn0 state sodiated tin metal nano-size particles are formed in oxide glass matrix. After the second cycle, we confirmed the steady reversible reaction ∼320 mAh/g at 0–1 V cutoff voltage condition by alloying process in NaxSn4. The tin-phosphate glass is a promising candidate of new anode active material that realizes high energy density sodium ion batteries.

  12. Electrode Materials for Lithium/Sodium-Ion Batteries

    DEFF Research Database (Denmark)

    Shen, Yanbin

    2014-01-01

    Shen systematically investigated the controlled synthesis of electrode materials for lithium/sodium ion batteries. She also investigated their formation mechanisms and structural evolution during the operation of batteries using in situ/operando X-ray diffraction techniques. The research findings...... provide insights into formation mechanisms of Li4Ti5O12 anode material from both hydrothermal and solid-state reaction. The results also contribute to a thorough understanding of the intercalation and decay mechanisms of O3/P2 layered sodium cathode materials in sodium ion batteries.......The synthesis of electrode materials for lithium/sodium ion batteries and their structural stability during lithium/sodium insertion/extraction are the two essential issues that have limited battery application in the fields requiring long cycle life and high safety. During her PhD studies, Yanbin...

  13. Electrode Materials for Lithium/Sodium-Ion Batteries

    DEFF Research Database (Denmark)

    Shen, Yanbin

    2014-01-01

    The synthesis of electrode materials for lithium/sodium ion batteries and their structural stability during lithium/sodium insertion/extraction are the two essential issues that have limited battery application in the fields requiring long cycle life and high safety. During her PhD studies, Yanbin...... Shen systematically investigated the controlled synthesis of electrode materials for lithium/sodium ion batteries. She also investigated their formation mechanisms and structural evolution during the operation of batteries using in situ/operando X-ray diffraction techniques. The research findings...... provide insights into formation mechanisms of Li4Ti5O12 anode material from both hydrothermal and solid-state reaction. The results also contribute to a thorough understanding of the intercalation and decay mechanisms of O3/P2 layered sodium cathode materials in sodium ion batteries....

  14. Nanocomposite anode materials for sodium-ion batteries

    Science.gov (United States)

    Manthiram, Arumugam; Kim Il, Tae; Allcorn, Eric

    2016-06-14

    The disclosure relates to an anode material for a sodium-ion battery having the general formula AO.sub.x--C or AC.sub.x--C, where A is aluminum (Al), magnesium (Mg), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), zirconium (Zr), molybdenum (Mo), tungsten (W), niobium (Nb), tantalum (Ta), silicon (Si), or any combinations thereof. The anode material also contains an electrochemically active nanoparticles within the matrix. The nanoparticle may react with sodium ion (Na.sup.+) when placed in the anode of a sodium-ion battery. In more specific embodiments, the anode material may have the general formula M.sub.ySb-M'O.sub.x--C, Sb-MO.sub.x--C, M.sub.ySn-M'C.sub.x--C, or Sn-MC.sub.x--C. The disclosure also relates to rechargeable sodium-ion batteries containing these materials and methods of making these materials.

  15. Method and system for producing hydrogen using sodium ion separation membranes

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    Bingham, Dennis N; Klingler, Kerry M; Turner, Terry D; Wilding, Bruce M; Frost, Lyman

    2013-05-21

    A method of producing hydrogen from sodium hydroxide and water is disclosed. The method comprises separating sodium from a first aqueous sodium hydroxide stream in a sodium ion separator, feeding the sodium produced in the sodium ion separator to a sodium reactor, reacting the sodium in the sodium reactor with water, and producing a second aqueous sodium hydroxide stream and hydrogen. The method may also comprise reusing the second aqueous sodium hydroxide stream by combining the second aqueous sodium hydroxide stream with the first aqueous sodium hydroxide stream. A system of producing hydrogen is also disclosed.

  16. Ion selectivity strategies of sodium channel selectivity filters.

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    Dudev, Todor; Lim, Carmay

    2014-12-16

    CONSPECTUS: Sodium ion channels selectively transport Na(+) cations across the cell membrane. These integral parts of the cell machinery are implicated in regulating the cardiac, skeletal and smooth muscle contraction, nerve impulses, salt and water homeostasis, as well as pain and taste perception. Their malfunction often results in various channelopathies of the heart, brain, skeletal muscles, and lung; thus, sodium channels are key drug targets for various disorders including cardiac arrhythmias, heart attack, stroke, migraine, epilepsy, pain, cancer, and autoimmune disorders. The ability of sodium channels to discriminate the native Na(+) among other competing ions in the surrounding fluids is crucial for proper cellular functions. The selectivity filter (SF), the narrowest part of the channel's open pore, lined with amino acid residues that specifically interact with the permeating ion, plays a major role in determining Na(+) selectivity. Different sodium channels have different SFs, which vary in the symmetry, number, charge, arrangement, and chemical type of the metal-ligating groups and pore size: epithelial/degenerin/acid-sensing ion channels have generally trimeric SFs lined with three conserved neutral serines and/or backbone carbonyls; eukaryotic sodium channels have EKEE, EEKE, DKEA, and DEKA SFs with an invariant positively charged lysine from the second or third domain; and bacterial voltage-gated sodium (Nav) channels exhibit symmetrical EEEE SFs, reminiscent of eukaryotic voltage-gated calcium channels. How do these different sodium channel SFs achieve high selectivity for Na(+) over its key rivals, K(+) and Ca(2+)? What factors govern the metal competition in these SFs and which of these factors are exploited to achieve Na(+) selectivity in the different sodium channel SFs? The free energies for replacing K(+) or Ca(2+) bound inside different model SFs with Na(+), evaluated by a combination of density functional theory and continuum dielectric

  17. Implantation of sodium ions into germanium

    Energy Technology Data Exchange (ETDEWEB)

    Korol' , V. M., E-mail: vkorol@ctsnet.ru [Southern Federal University, Research Institute of Physics (Russian Federation); Kudriavtsev, Yu. [CINVESTAV, Dep. Ingenieria Electrica (Mexico)

    2012-02-15

    The donor properties of Na atoms introduced by ion implantation into p-Ge with the resistivity 20-40 {Omega} cm are established for the first time. Na profiles implanted into Ge (the energies 70 and 77 keV and the doses (0.8, 3, 30) Multiplication-Sign 10{sup 14} cm{sup -2}) are studied. The doses and annealing temperatures at which the thermoprobe detects n-type conductivity on the sample surface are established. After implantation, the profiles exhibit an extended tail. The depth of the concentration maximum is in good agreement with the calculated mean projected range of Na ions R{sub p}. Annealing for 30 min at temperatures of 250-700 Degree-Sign C brings about a redistribution of Na atoms with the formation of segregation peaks at a depth, which is dependent on the ion dose, and is accompanied by the diffusion of Na atoms to the surface with subsequent evaporation. After annealing at 700 Degree-Sign C less than 7% of the implanted ions remain in the matrix. The shape of the profile tail portions measured after annealing at temperatures 300-400 Degree-Sign C is indicative of the diffusion of a small fraction of Na atoms into the depth of the sample.

  18. Nanocomposite anode materials for sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Manthiram, Arumugam; Kim Il, Tae; Allcorn, Eric

    2016-06-14

    The disclosure relates to an anode material for a sodium-ion battery having the general formula AO.sub.x--C or AC.sub.x--C, where A is aluminum (Al), magnesium (Mg), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), zirconium (Zr), molybdenum (Mo), tungsten (W), niobium (Nb), tantalum (Ta), silicon (Si), or any combinations thereof. The anode material also contains an electrochemically active nanoparticles within the matrix. The nanoparticle may react with sodium ion (Na.sup.+) when placed in the anode of a sodium-ion battery. In more specific embodiments, the anode material may have the general formula M.sub.ySb-M'O.sub.x--C, Sb-MO.sub.x--C, M.sub.ySn-M'C.sub.x--C, or Sn-MC.sub.x--C. The disclosure also relates to rechargeable sodium-ion batteries containing these materials and methods of making these materials.

  19. Modified Graphene Oxide for Long Cycle Sodium-Ion Batteries

    Science.gov (United States)

    Shareef, Muhamed; Gunn, Harrison; Voigt, Victoria; Singh, Gurpreet

    Hummer's process was modified to produce gram levels of 2-dimensional nanosheets of graphene oxide (GO) with varying degree of exfoliation and chemical functionalization. This was achieved by varying the weight ratios and reaction times of oxidizing agents used in the process. Based on Raman and Fourier transform infra red spectroscopy we show that potassium permanganate (KMnO4) is the key oxidizing agent while sodium nitrate (NaNO3) and sulfuric acid (H2SO4) play minor role during the exfoliation of graphite. Tested as working electrode in sodium-ion half-cell, the GO nanosheets produced using this optimized approach showed high rate capability and exceptionally high energy density of ~500 mAh/g for up to at least 100 cycles, which is among the highest reported for sodium/graphite electrodes. The average Coulombic efficiency was approximately 99 %. NSF Grant No. 1454151.

  20. Diet and arterial hypertension: is the sodium ion alone important?

    Science.gov (United States)

    Buemi, Michele; Senatore, Massimino; Corica, Francesco; Aloisi, Carmela; Romeo, Adolfo; Tramontana, Domenico; Frisina, Nicola

    2002-07-01

    Hypertension is a widespread phenomenon whose ultimate cause is still unknown. Many factors contribute to this disease, and partially for this reason, hypertension responds to different treatments in different individuals. It is difficult to generalize about therapies for general populations. In particular, the role of electrolytes in hypertension varies widely across individuals. This review focuses its attention on sodium, potassium, calcium, and magnesium ions in order to investigate whether these electrolytes play a role in the pathogenesis of arterial hypertension and its treatment. Some individuals are especially sensitive to sodium, and changing their intake of dietary sodium may lead to variations in the levels of the other electrolytes. These changes in electrolyte levels can complicate treatments for arterial hypertension in some patients.

  1. From lithium-ion to sodium-ion batteries: A materials perspective.

    Science.gov (United States)

    Nayak, Prasant Kumar; Yang, Liangtao; Brehm, Wolfgang; Adelhelm, Philipp

    2017-06-19

    Mobile and stationary energy storage by rechargeable batteries is a topic of broad societal and economical relevance. Lithium-ion battery (LIB) technology is at the forefront of the development but a massively growing market will likely put severe pressure on resources and supply chains. Recently, sodium-ion batteries (SIBs) are being reconsidered with the aim of providing a lower-cost alternative that is less susceptible to resource and supply risks. On paper, the replacement of lithium by sodium in a battery seems straightforward at first but unpredictable surprises are often found in practice. What happens when replacing lithium by sodium in electrode reactions? This review provides a state-of-the art overview on the redox behavior of materials when used as electrodes in lithium-ion and sodium-ion batteries, respectively. Advantages and challenges related to the use of sodium instead of lithium are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. The sodium ion affinities of asparagine, glutamine, histidine and arginine

    Science.gov (United States)

    Wang, Ping; Ohanessian, Gilles; Wesdemiotis, Chrys

    2008-01-01

    The sodium ion affinities of the amino acids Asn, Gln, His and Arg have been determined by experimental and computational approaches (for Asn, His and Arg). Na+-bound heterodimers with amino acid and peptide ligands (Pep1, Pep2) were produced by electrospray ionization. From the dissociation kinetics of these Pep1-Na+-Pep2 ions to Pep1-Na+ and Pep2-Na+, determined by collisionally activated dissociation, a ladder of relative affinities was constructed and subsequently converted to absolute affinities by anchoring the relative values to known Na+ affinities. The Na+ affinities of Asn, His and Arg, were calculated at the MP2(full)/6-311+G(2d,2p)//MP2/6-31G(d) level of ab initio theory. The resulting experimental and computed Na+ affinities are in excellent agreement with one another. These results, combined with those of our previous studies, yield the sodium ion affinities of 18 out of the 20 [alpha]-amino acids naturally occurring in peptides and proteins of living systems.

  3. Sodium hydrosulfide prevents myocardial dysfunction through modulation of extracellular matrix accumulation and vascular density.

    Science.gov (United States)

    Pan, Li-Long; Wang, Xian-Li; Wang, Xi-Ling; Zhu, Yi-Zhun

    2014-12-12

    The aim was to examine the role of exogenous hydrogen sulfide (H2S) on cardiac remodeling in post-myocardial infarction (MI) rats. MI was induced in rats by ligation of coronary artery. After treatment with sodium hydrosulfide (NaHS, an exogenous H2S donor, 56 μM/kg·day) for 42 days, the effects of NaHS on left ventricular morphometric features, echocardiographic parameters, heme oxygenase-1 (HO-1), matrix metalloproteinases-9 (MMP-9), type I and type III collagen, vascular endothelial growth factor (VEGF), CD34, and α-smooth muscle actin (α-SMA) in the border zone of infarct area were analyzed to elucidate the protective mechanisms of exogenous H2S on cardiac function and fibrosis. Forty-two days post MI, NaHS-treatment resulted in a decrease in myocardial fibrotic area in association with decreased levels of type I, type III collagen and MMP-9 and improved cardiac function. Meanwhile, NaHS administration significantly increased cystathionine γ-lyase (CSE), HO-1, α-SMA, and VEGF expression. This effect was accompanied by an increase in vascular density in the border zone of infarcted myocardium. Our results provided the strong evidences that exogenous H2S prevented cardiac remodeling, at least in part, through inhibition of extracellular matrix accumulation and increase in vascular density.

  4. Sodium Hydrosulfide Prevents Myocardial Dysfunction through Modulation of Extracellular Matrix Accumulation and Vascular Density

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    Li-Long Pan

    2014-12-01

    Full Text Available The aim was to examine the role of exogenous hydrogen sulfide (H2S on cardiac remodeling in post-myocardial infarction (MI rats. MI was induced in rats by ligation of coronary artery. After treatment with sodium hydrosulfide (NaHS, an exogenous H2S donor, 56 μM/kg·day for 42 days, the effects of NaHS on left ventricular morphometric features, echocardiographic parameters, heme oxygenase-1 (HO-1, matrix metalloproteinases-9 (MMP-9, type I and type III collagen, vascular endothelial growth factor (VEGF, CD34, and α-smooth muscle actin (α-SMA in the border zone of infarct area were analyzed to elucidate the protective mechanisms of exogenous H2S on cardiac function and fibrosis. Forty-two days post MI, NaHS-treatment resulted in a decrease in myocardial fibrotic area in association with decreased levels of type I, type III collagen and MMP-9 and improved cardiac function. Meanwhile, NaHS administration significantly increased cystathionine γ-lyase (CSE, HO-1, α-SMA, and VEGF expression. This effect was accompanied by an increase in vascular density in the border zone of infarcted myocardium. Our results provided the strong evidences that exogenous H2S prevented cardiac remodeling, at least in part, through inhibition of extracellular matrix accumulation and increase in vascular density.

  5. Heart Rate and Extracellular Sodium and Potassium Modulation of Gap Junction Mediated Conduction in Guinea Pigs.

    Science.gov (United States)

    Entz, Michael; George, Sharon A; Zeitz, Michael J; Raisch, Tristan; Smyth, James W; Poelzing, Steven

    2016-01-01

    Recent studies suggested that cardiac conduction in murine hearts with narrow perinexi and 50% reduced connexin43 (Cx43) expression is more sensitive to relatively physiological changes of extracellular potassium ([K(+)]o) and sodium ([Na(+)]o). Determine whether similar [K(+)]o and [Na(+)]o changes alter conduction velocity (CV) sensitivity to pharmacologic gap junction (GJ) uncoupling in guinea pigs. [K(+)]o and [Na(+)]o were varied in Langendorff perfused guinea pig ventricles (Solution A: [K(+)]o = 4.56 and [Na(+)]o = 153.3 mM. Solution B: [K(+)]o = 6.95 and [Na(+)]o = 145.5 mM). Gap junctions were inhibited with carbenoxolone (CBX) (15 and 30 μM). Epicardial CV was quantified by optical mapping. Perinexal width was measured with transmission electron microscopy. Total and phosphorylated Cx43 were evaluated by western blotting. Solution composition did not alter CV under control conditions or with 15μM CBX. Decreasing the basic cycle length (BCL) of pacing from 300 to 160 ms decreased CV uniformly with both solutions. At 30 μM CBX, a change in solution did not alter CV either longitudinally or transversely at BCL = 300 ms. However, reducing BCL to 160 ms caused CV to decrease more in hearts perfused with Solution B than A. Solution composition did not alter perinexal width, nor did it change total or phosphorylated serine 368 Cx43 expression. These data suggest that the solution dependent CV changes were independent of altered perinexal width or GJ coupling. Action potential duration was always shorter in hearts perfused with Solution B than A, independent of pacing rate and/or CBX concentration. Increased heart rate and GJ uncoupling can unmask small CV differences caused by changing [K(+)]o and [Na(+)]o. These data suggest that modulating extracellular ionic composition may be a novel anti-arrhythmic target in diseases with abnormal GJ coupling, particularly when heart rate cannot be controlled.

  6. Heart Rate and Extracellular Sodium and Potassium Modulation of Gap Junction Mediated Conduction in Guinea Pigs

    Directory of Open Access Journals (Sweden)

    Michael eEntz

    2016-02-01

    Full Text Available Background: Recent studies suggested that cardiac conduction in murine hearts with narrow perinexi and 50% reduced connexin43 (Cx43 expression is more sensitive to relatively physiological changes of extracellular potassium ([K+]o and sodium ([Na+]o. Purpose: Determine whether similar [K+]o and [Na+]o changes alter conduction velocity (CV sensitivity to pharmacologic gap junction (GJ uncoupling in guinea pigs.Methods: [K+]o and [Na+]o were varied in Langendorff perfused guinea pig ventricles (Solution A: [K+]o=4.56 and [Na+]o=153.3 mM. Solution B: [K+]o=6.95 and [Na+]o=145.5 mM. Gap junctions were inhibited with carbenoxolone (CBX (15 and 30 μM. Epicardial CV was quantified by optical mapping. Perinexal width was measured with transmission electron microscopy. Total and phosphorylated Cx43 were evaluated by western blotting. Results: Solution composition did not alter CV under control conditions or with 15M CBX. Decreasing the basic cycle length (BCL of pacing from 300 to 160ms decreased CV uniformly with both solutions. At 30 M CBX, a change in solution did not alter CV either longitudinally or transversely at BCL=300ms. However, reducing BCL to 160ms caused CV to decrease more in hearts perfused with Solution B than A. Solution composition did not alter perinexal width, nor did it change total or phosphorylated serine 368 Cx43 expression. These data suggest that the solution dependent CV changes were independent of altered perinexal width or GJ coupling. Action potential duration was always shorter in hearts perfused with Solution B than A, independent of pacing rate and/or CBX concentration. Conclusions: Increased heart rate and GJ uncoupling can unmask small CV differences caused by changing [K+]o and [Na+]o. These data suggest that modulating extracellular ionic composition may be a novel anti-arrhythmic target in diseases with abnormal GJ coupling, particularly when heart rate cannot be controlled.

  7. Gelling process of sodium alginate with bivalent ions rich microsphere: Nature of bivalent ions

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    Mauri, Marco; Vicini, Silvia; Castellano, Maila

    2016-05-01

    In the paper we present a new approach for obtaining a controlled gelling process of sodium alginate, based on the quantity of bivalent ions rich alginate micro-beads added as crosslinkers. Typically, calcium ions are used in gelation of alginate solutions. In this study we present different gelling systems realized with alginate microspheres, made by electrospinning methodology, enriched with different bivalent ions (Ca2+, Ba2+ and Mg2+). The microspheres were characterized under the point of view of the morphology by OM and as the ions content. Realized gels were characterized in light of the amount of the ions added to the alginate solution, and in light of the different dimensions of the micro-beads, using rheological measurements to assess the variation in the storage modulus (G'), loss modulus (G″) and complex viscosity (η*).

  8. Gelation of Na-alginate aqueous solution: A study of sodium ion dynamics via NMR relaxometry.

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    Zhao, Congxian; Zhang, Chao; Kang, Hongliang; Xia, Yanzhi; Sui, Kunyan; Liu, Ruigang

    2017-08-01

    Sodium alginate (SA) hydrogels have a wide range of applications including tissue engineering, drug delivery and formulations for preventing gastric reflux. The dynamics of sodium ions during the gelation process of SA solution is critical for clarification of the gelation procedure. In this work, nuclear magnetic resonance (NMR) relaxometry and pulsed-field-gradient (PFG) NMR diffusometry were used to investigate the dynamics of the sodium ions during the gelation of SA alginate. We find that sodium ions are in two different states with the addition of divalent calcium ions, corresponding to Ca(2+) crosslinked and un-crosslinked regions in the hydrogels. The sodium ions within the un-crosslinked regions are those released from the alginate chains without Ca(2+) crosslinking. The relative content of sodium ions within the Ca(2+) crosslinked regions decreased with the increase in the content of calcium ions in the system. The relaxation time T2 of sodium ions within the Ca(2+) crosslinked and un-crosslinked regions shift to shorter and longer relaxation time with the increase in concentration of calcium ion, which indicates the closer package of SA chains and the larger space for the diffusion of free sodium ions. This work clarifies the dynamics of (23)Na(+) in a calcium alginate gel at the equilibrium state. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Rhombohedral Prussian White as Cathode for Rechargeable Sodium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L; Song, J; Qiao, RM; Wray, LA; Hossain, MA; Chuang, YD; Yang, WL; Lu, YH; Evans, D; Lee, JJ; Vail, S; Zhao, X; Nishijima, M; Kakimoto, S; Goodenough, JB

    2015-02-25

    A novel air-stable sodium iron hexacyanoferrate (R-Na1.92Fe[Fe(CN)(6)]) with rhombohedral structure is demonstrated to be a scalable, low-cost cathode material for sodium-ion batteries exhibiting high capacity, long cycle life, and good rate capability. The cycling mechanism of the iron redox is clarified and understood through synchrotron-based soft X-ray absorption spectroscopy, which also reveals the correlation between the physical properties and the cell performance of this novel material. More importantly, successful preparation of a dehydrated iron hexacyanoferrate with high sodium-ion concentration enables the fabrication of a discharged sodium-ion battery with a non-sodium metal anode, and the manufacturing feasibility of low cost sodium-ion batteries with existing lithium-ion battery infrastructures has been tested.

  10. Rhombohedral prussian white as cathode for rechargeable sodium-ion batteries.

    Science.gov (United States)

    Wang, Long; Song, Jie; Qiao, Ruimin; Wray, L Andrew; Hossain, Muhammed A; Chuang, Yi-De; Yang, Wanli; Lu, Yuhao; Evans, David; Lee, Jong-Jan; Vail, Sean; Zhao, Xin; Nishijima, Motoaki; Kakimoto, Seizoh; Goodenough, John B

    2015-02-25

    A novel air-stable sodium iron hexacyanoferrate (R-Na1.92Fe[Fe(CN)6]) with rhombohedral structure is demonstrated to be a scalable, low-cost cathode material for sodium-ion batteries exhibiting high capacity, long cycle life, and good rate capability. The cycling mechanism of the iron redox is clarified and understood through synchrotron-based soft X-ray absorption spectroscopy, which also reveals the correlation between the physical properties and the cell performance of this novel material. More importantly, successful preparation of a dehydrated iron hexacyanoferrate with high sodium-ion concentration enables the fabrication of a discharged sodium-ion battery with a non-sodium metal anode, and the manufacturing feasibility of low cost sodium-ion batteries with existing lithium-ion battery infrastructures has been tested.

  11. Design of fast ion conducting cathode materials for grid-scale sodium-ion batteries.

    Science.gov (United States)

    Wong, Lee Loong; Chen, Haomin; Adams, Stefan

    2017-03-15

    The obvious cost advantage as well as attractive electrochemical properties, including excellent cycling stability and the potential of high rate performance, make sodium-ion batteries prime candidates in the race to technically and commercially enable large-scale electrochemical energy storage. In this work, we apply our bond valence site energy modelling method to further the understanding of rate capabilities of a wide range of potential insertion-type sodium-ion battery cathode materials. We demonstrate how a stretched exponential function permits us to systematically quantify the rate performance, which in turn reveals guidelines for the design of novel sodium-ion battery chemistries suitable for high power, grid-scale applications. Starting from a diffusion relaxation model, we establish a semi-quantitative prediction of the rate-performance of half-cells from the structure of the cathode material that factors in dimensionality of Na(+) ion migration pathways, the height of the migration barriers and the crystallite size of the active material. With the help of selected examples, we also illustrate the respective roles of unoccupied low energy sites within the pathway and temperature towards the overall rate capability of insertion-type cathode materials.

  12. Structural Insight into the Ion-Exchange Mechanism of the Sodium/Calcium Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Jun; Li, Hua; Zeng, Weizhong; Sauer, David B.; Belmares, Ricardo; Jiang, Youxing (UTSMC)

    2012-06-19

    Sodium/calcium (Na{sup +}/Ca{sup 2+}) exchangers (NCX) are membrane transporters that play an essential role in maintaining the homeostasis of cytosolic Ca{sup 2+} for cell signaling. We demonstrated the Na{sup +}/Ca{sup 2+}-exchange function of an NCX from Methanococcus jannaschii (NCX{_}Mj) and report its 1.9 angstrom crystal structure in an outward-facing conformation. Containing 10 transmembrane helices, the two halves of NCX{_}Mj share a similar structure with opposite orientation. Four ion-binding sites cluster at the center of the protein: one specific for Ca{sup 2+} and three that likely bind Na{sup +}. Two passageways allow for Na{sup +} and Ca{sup 2+} access to the central ion-binding sites from the extracellular side. Based on the symmetry of NCX{_}Mj and its ability to catalyze bidirectional ion-exchange reactions, we propose a structure model for the inward-facing NCX{_}Mj.

  13. Advanced Nanostructured Anode Materials for Sodium-Ion Batteries.

    Science.gov (United States)

    Wang, Qidi; Zhao, Chenglong; Lu, Yaxiang; Li, Yunming; Zheng, Yuheng; Qi, Yuruo; Rong, Xiaohui; Jiang, Liwei; Qi, Xinguo; Shao, Yuanjun; Pan, Du; Li, Baohua; Hu, Yong-Sheng; Chen, Liquan

    2017-09-19

    Sodium-ion batteries (NIBs), due to the advantages of low cost and relatively high safety, have attracted widespread attention all over the world, making them a promising candidate for large-scale energy storage systems. However, the inherent lower energy density to lithium-ion batteries is the issue that should be further investigated and optimized. Toward the grid-level energy storage applications, designing and discovering appropriate anode materials for NIBs are of great concern. Although many efforts on the improvements and innovations are achieved, several challenges still limit the current requirements of the large-scale application, including low energy/power densities, moderate cycle performance, and the low initial Coulombic efficiency. Advanced nanostructured strategies for anode materials can significantly improve ion or electron transport kinetic performance enhancing the electrochemical properties of battery systems. Herein, this Review intends to provide a comprehensive summary on the progress of nanostructured anode materials for NIBs, where representative examples and corresponding storage mechanisms are discussed. Meanwhile, the potential directions to obtain high-performance anode materials of NIBs are also proposed, which provide references for the further development of advanced anode materials for NIBs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Conserved charged amino acid residues in the extracellular region of sodium/iodide symporter are critical for iodide transport activity

    Directory of Open Access Journals (Sweden)

    Liang Ji-An

    2010-11-01

    Full Text Available Abstract Background Sodium/iodide symporter (NIS mediates the active transport and accumulation of iodide from the blood into the thyroid gland. His-226 located in the extracellular region of NIS has been demonstrated to be critical for iodide transport in our previous study. The conserved charged amino acid residues in the extracellular region of NIS were therefore characterized in this study. Methods Fourteen charged residues (Arg-9, Glu-79, Arg-82, Lys-86, Asp-163, His-226, Arg-228, Asp-233, Asp-237, Arg-239, Arg-241, Asp-311, Asp-322, and Asp-331 were replaced by alanine. Iodide uptake abilities of mutants were evaluated by steady-state and kinetic analysis. The three-dimensional comparative protein structure of NIS was further modeled using sodium/glucose transporter as the reference protein. Results All the NIS mutants were expressed normally in the cells and targeted correctly to the plasma membrane. However, these mutants, except R9A, displayed severe defects on the iodide uptake. Further kinetic analysis revealed that mutations at conserved positively charged amino acid residues in the extracellular region of NIS led to decrease NIS-mediated iodide uptake activity by reducing the maximal rate of iodide transport, while mutations at conserved negatively charged residues led to decrease iodide transport by increasing dissociation between NIS mutants and iodide. Conclusions This is the first report characterizing thoroughly the functional significance of conserved charged amino acid residues in the extracellular region of NIS. Our data suggested that conserved charged amino acid residues, except Arg-9, in the extracellular region of NIS were critical for iodide transport.

  15. An acidic amino acid transmembrane helix 10 residue conserved in the neurotransmitter:sodium:symporters is essential for the formation of the extracellular gate of the γ-aminobutyric acid (GABA) transporter GAT-1.

    Science.gov (United States)

    Ben-Yona, Assaf; Kanner, Baruch I

    2012-03-01

    GAT-1 mediates transport of GABA together with sodium and chloride in an electrogenic process enabling efficient GABAergic transmission. Biochemical and modeling studies based on the structure of the bacterial homologue LeuT are consistent with a mechanism whereby the binding pocket is alternately accessible to either side of the membrane and which predicts that the extracellular part of transmembrane domain 10 (TM10) exhibits aqueous accessibility in the outward-facing conformation only. In this study we have engineered cysteine residues in the extracellular half of TM10 of GAT-1 and probed their state-dependent accessibility to sulfhydryl reagents. In three out of four of the accessible cysteine mutants, the inhibition of transport by a membrane impermeant sulfhydryl reagent was diminished under conditions expected to increase the proportion of inward-facing transporters, such as the presence of GABA together with the cotransported ions. A conserved TM10 aspartate residue, whose LeuT counterpart participates in a "thin" extracellular gate, was found to be essential for transport and only the D451E mutant exhibited residual transport activity. D451E exhibited robust sodium-dependent transient currents with a voltage-dependence indicative of an increased apparent affinity for sodium. Moreover the accessibility of an endogenous cysteine to a membrane impermeant sulfhydryl reagent was enhanced by the D451E mutation, suggesting that sodium binding promotes an outward-facing conformation of the transporter. Our results support the idea that TM10 of GAT-1 lines an accessibility pathway from the extracellular space into the binding pocket and plays a role in the opening and closing of the extracellular transporter gate.

  16. Neutralization by metal ions of the toxicity of sodium selenide.

    Directory of Open Access Journals (Sweden)

    Marc Dauplais

    Full Text Available Inert metal-selenide colloids are found in animals. They are believed to afford cross-protection against the toxicities of both metals and selenocompounds. Here, the toxicities of metal salt and sodium selenide mixtures were systematically studied using the death rate of Saccharomyces cerevisiae cells as an indicator. In parallel, the abilities of these mixtures to produce colloids were assessed. Studied metal cations could be classified in three groups: (i metal ions that protect cells against selenium toxicity and form insoluble colloids with selenide (Ag⁺, Cd²⁺, Cu²⁺, Hg²⁺, Pb²⁺ and Zn²⁺, (ii metal ions which protect cells by producing insoluble metal-selenide complexes and by catalyzing hydrogen selenide oxidation in the presence of dioxygen (Co²⁺ and Ni²⁺ and, finally, (iii metal ions which do not afford protection and do not interact (Ca²⁺, Mg²⁺, Mn²⁺ or weakly interact (Fe²⁺ with selenide under the assayed conditions. When occurring, the insoluble complexes formed from divalent metal ions and selenide contained equimolar amounts of metal and selenium atoms. With the monovalent silver ion, the complex contained two silver atoms per selenium atom. Next, because selenides are compounds prone to oxidation, the stabilities of the above colloids were evaluated under oxidizing conditions. 5,5'-dithiobis-(2-nitrobenzoic acid (DTNB, the reduction of which can be optically followed, was used to promote selenide oxidation. Complexes with cadmium, copper, lead, mercury or silver resisted dissolution by DTNB treatment over several hours. With nickel and cobalt, partial oxidation by DTNB occurred. On the other hand, when starting from ZnSe or FeSe complexes, full decompositions were obtained within a few tens of minutes. The above properties possibly explain why ZnSe and FeSe nanoparticles were not detected in animals exposed to selenocompounds.

  17. Sodium Chloride interaction with solvated and crystalline cellulose : sodium ion affects the tetramer and fibril in aqueous solution

    OpenAIRE

    Bellesia, Giovanni; Gnanakaran, S.

    2013-01-01

    Inorganic salts are a natural component of biomass which have a significant effect on the product yields from a variety of biomass conversion processes. Understanding their effect on biomass at the microscopic level can help discover their mechanistic role. We present a study of the effect of aqueous sodium chloride (NaCl) on the largest component of biomass, cellulose, focused on the thermodynamic and structural effect of a sodium ion on the cellulose tetramer, and fibril. Replica exchange m...

  18. Ouabain enhancement of compound 48/80 induced histamine secretion from rat peritoneal mast cells: dependence on extracellular sodium

    DEFF Research Database (Denmark)

    Knudsen, T; Bertelsen, Niels Haldor; Johansen, Torben

    1992-01-01

    a measure of the Na(+)-K+ pump activity of the cells. Ouabain caused an immediate inhibition of the pump activity and a time-dependent increase in histamine secretion in the absence of extracellular calcium. No effect on the secretion was observed in the presence of calcium. The effect of ouabain......-free medium, the pump activity was inhibited and the enhancement by ouabain of the secretion of histamine was blocked. A less marked inhibition of the pump was found in a calcium-free medium containing magnesium. The inhibition exerted by magnesium was concentration-dependent (0-5 mM) as was the counteraction...... of sodium-calcium exchange caused by a decreased inward directed sodium gradient, the mechanism by which ouabain enhances the secretory response is likely to involve an increased binding of calcium to membrane binding sites....

  19. Influence of temperature on the myocardial cells death by an extracellular talaporfin sodium-induced photosensitization reaction

    Science.gov (United States)

    Ogawa, Emiyu; Takenoya, Hiromi; Arai, Tsunenori

    2016-03-01

    We have proposed to apply the photosensitization reaction in myocardium interstitial fluid using talaporfin sodium to realize less-heated electrical conduction block for a tachyarrhythmia treatment: PD Ablation®. The cytotoxicity of the extracellular photosensitization reaction efficiency may change by the talaporfin sodium binding with serum proteins. These binding would change with solution temperature. We investigated the binding behavior of talaporfin sodium with human serum albumin (HSA), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) changing solution temperature from 17 to 37°C. We also studied the photocytotoxicity change by solution temperature of 17 and 37°C measuring cell lethality by WST assay using fetal bovine serum. The binding ratio of talaporfin sodium with HDL and LDL decreased 6.3% and 12.8% with temperature increasing from 17 to 37°C. There was no significant difference in the case of HSA. The cell lethality was increased about 30% with temperature increasing from 17 to 37°C. The myocardium tissue temperature increase was reported that less than 5°C in the case of our PD Ablation®. We think that the photocytotoxicity change by these temperature increasing would be negligible in our PD Ablation®. We suggest that the temperature maintaining would be necessary to keep the photocytotoxicity efficiency in the case of the open surgery that would cause the tissue surface temperature decreasing.

  20. Extracellular talaporfin sodium-induced photosensitization reaction with various albumin animal species on myocardial cells in vitro

    Science.gov (United States)

    Ogawa, Emiyu; Arai, Tsunenori

    2017-02-01

    It is reported that the albumin has different structure among animal species. We have proposed a new methodology of cardiac ablation using talaporfin sodium-induced photosensitization reaction with short drug-light interval to realize immediate and permanent therapeutic effect by singlet oxygen production mainly in the interstitial space. The photosensitization reaction efficacy with different animal species should be investing to consider the optimal animal therapeutic model to evaluate the therapeutic effect of new cardiac ablation methodology. We studied the cell-killing efficacy of extracellular talaporfin sodium-induced photosensitization reaction using talaporfin sodium on myocardial cells in vitro with different albumin animal species: human, canine, bovine, and porcine serum albumin. We obtained that the albumin concentration tendency on the binding ratio and cell lethality was different among the animal species but there was no correlation between binding ratio and cell lethality. We found that the cell lethality dependence on albumin concentration showed 2 different groups, human-canine and bovine-porcine. We think that the canine might be useful as a therapeutic animal model since the cytotoxicity tendency on albumin concentration was similar with that of human albumin. These cell lethality tendency difference would be suggested to explain by the existence of the diazepam site that talaporfin sodium binds mainly.

  1. Conformational Dynamics on the Extracellular Side of LeuT Controlled by Na+ and K+ Ions and the Protonation State of Glu290.

    Science.gov (United States)

    Khelashvili, George; Schmidt, Solveig Gaarde; Shi, Lei; Javitch, Jonathan A; Gether, Ulrik; Loland, Claus J; Weinstein, Harel

    2016-09-16

    Ions play key mechanistic roles in the gating dynamics of neurotransmitter:sodium symporters (NSSs). In recent microsecond scale molecular dynamics simulations of a complete model of the dopamine transporter, a NSS protein, we observed a partitioning of K(+) ions from the intracellular side toward the unoccupied Na2 site of dopamine transporter following the release of the Na2-bound Na(+) Here we evaluate with computational simulations and experimental measurements of ion affinities under corresponding conditions, the consequences of K(+) binding in the Na2 site of LeuT, a bacterial homolog of NSS, when both Na(+) ions and substrate have left, and the transporter prepares for a new cycle. We compare the results with the consequences of binding Na(+) in the same apo system. Analysis of >50-μs atomistic molecular dynamics and enhanced sampling trajectories of constructs with Glu(290), either charged or neutral, point to the Glu(290) protonation state as a main determinant in the structural reconfiguration of the extracellular vestibule of LeuT in which a "water gate" opens through coordinated motions of residues Leu(25), Tyr(108), and Phe(253) The resulting water channel enables the binding/dissociation of the Na(+) and K(+) ions that are prevalent, respectively, in the extracellular and intracellular environments.

  2. Excessive sodium ions delivered into cells by nanodiamonds: implications for tumor therapy.

    Science.gov (United States)

    Zhu, Ying; Li, Wenxin; Zhang, Yu; Li, Jing; Liang, Le; Zhang, Xiangzhi; Chen, Nan; Sun, Yanhong; Chen, Wen; Tai, Renzhong; Fan, Chunhai; Huang, Qing

    2012-06-11

    Nanodiamonds (NDs) possess many excellent physical and chemical properties that make them attractive materials for applications in biomedicine. In this paper, the adsorption and delivery of a large amount of sodium ions into the cell interior by NDs in serum-free medium is demonstrated. The excess sodium ions inside the cells induce osmotic stresses followed by cell swelling and an increase in the intracellular levels of calcium and reactive oxygen species (ROS), which leads to severe cellular damage. In complete culture medium, however, serum proteins wrapped around the NDs effectively prevent the sodium ions from adsorbing onto the NDs, and thus the NDs show no cytotoxicity. This work is the first to elaborate on the correlation between the sodium ions adsorbed on the nanomaterials and their bio-effects. Excessive ions delivered into cells by NDs might have potential applications in tumor therapy.

  3. THE TESTS AND MECHANISM ABOUT SODIUM IONS FROM AN ANION EXCHANGER

    Institute of Scientific and Technical Information of China (English)

    ZhuXingbao; YuJinchun; 等

    1996-01-01

    There exists a universal phenomena that sodium ions are leaked from the strong basic anion exdchanger in operation,which has been puzzling the researchers working in the field of water treatment for years.It is well known that the leakage of sodium ions will seriously affect the pruity of effluent.On the basis of lots of laboratory and industrial experiments,the mechanism of the sodium ions leaked from an anion exchanger has been preliminarily made out and some new chemical reaction equations as well as some improving measures have been put forward in this article.

  4. [The relationship between PMI and concentration of potassium ion and sodium ion in swine aqueous humor after death].

    Science.gov (United States)

    Han, Ju; Yu, Guang-biao; Dong, Ye-qiang; Fang, Chao; Jing, Hua-lan; Luo, Si-min

    2010-04-01

    To explored the relationship between the concentration of potassium ion as well as sodium ion in the aqueous humor and post-mortem interval (PMI). The concentrations of potassium ion and sodium ion in the aqueous humor of swine within 48 h after death at 4 degrees C and 28 degrees C were detected using Z-500 atomic absorption spectrophotometer. The concentrations of potassium ion and sodium ion in aqueous humor of isolated swine eyeballs within 48 h after death when the environmental temperature was 4 degrees C were significantly related to PMI. The relationship between PMI and the concentration of potassium ion was PMI = -0.178[K+]2 + 49.978 (R2 = 0.995). The relationship between PMI and the rate of sodium ion and potassium ion was PMI = 120.987/[Na+/K+]-28.834 (R2 = 0.905). The concentration of potassium in aqueous humor of isolated swine eyeballs may be one of the reference indicators to estimate PMI of the corpses at lower temperatures.

  5. SURFACE MODIFICATION OF TITANIUM FILMS WITH SODIUM ION IMPLANTATION: SURFACE PROPERTIES AND PROTEIN ADSORPTION

    Institute of Scientific and Technical Information of China (English)

    K. Y. Cai

    2007-01-01

    Sodium implanted titanium films with different ion doses were characterized to correlate their ion implantation parameters. Native titanium films and ion implanted titanium films were characterized with combined techniques of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and light microscopy (LM). The surface presented increased sodium concentration on treated titanium films with ion dose increasing, except for the group with the highest ion dose of 4× 1017 ions/cm2. XPS depth profiling displayed that sodium entered titanium film around 25-50 nm depth depending on its implantation ion dose. AFM characterization showed that sodium ion implantation treatment changed the surface morphology from a relatively smooth titanium film to rough surfaces corresponding to different implantation doses.After sodium implantation, implanted titanium films presented big particles with island structure morphology. The surface morphology and particle growth displayed the corresponding trend.Fibrinogen adsorption on these titanium films was performed to correlate with the surface properties of treated titanium films. The results show that protein adsorption on ion-implanted samples with dose of 2 × 1017 and 4 × 1017 are statistically higher (p < 0. 01) than samples treated with dose of 5×1016 and 1 ×1017, as well as the control samples.

  6. Effect of ion interactions on the IR spectrum of benzenesulfonate ion. Restoration of sulfonate ion symmetry in sodium benzenesulfonate dimer

    Science.gov (United States)

    Shishlov, N. M.; Khursan, S. L.

    2016-11-01

    Literature data concerning the assignment of IR spectra of benzenesulfonate salts that serve as model compounds for aromatic sulfonate-containing ionomers and polyelectrolytes have been analyzed. The structures and IR spectra of free benzenesulfonate ion and its potassium and sodium salts have been calculated in B3LYP/6-311G(d,p) approximation. The bidentate coordination of counter-ions is energetically favorable for isolated ion pairs. In this coordination, the symmetry of sulfonate ion changes noticeably, which manifests itself as strong splitting of calculated vibrational modes of asymmetric stretching vibrations of Ssbnd O bonds, Δνas(SO3) = 154 cm-1 (K) and 180 cm-1 (Na). For sodium benzenesulfonate it is thermodynamically favorable to form a dimer (ΔG° = -37.6 kcal/mol) in which the joint effects of monodentate and bidentate coordinated Na cations result in equalization of Ssbnd O bond lengths and thus a considerable restoration of C3V symmetry of the sulfonate ion. The IR spectrum of the dimer in which Δνas(SO3) splitting is considerably smaller much better matches the experimental spectrum than the spectrum of an isolated ion pair. The major absorption bands in the IR spectrum of sodium benzenesulfonate have been assigned to theoretical vibrational modes of the dimer and, based on visualization of modes, to vibrations of certain bonds in the anion. In particular, the bands at 1200 and 1186 cm-1 have been assigned to νas(SO3), that at 1049 cm-1 to νs(SO3), and those at 628 and 572 cm-1 to δ(oop)s(SO3), and δ(ip)as(SO3), respectively. The strong effect of sulfonate ion environment on the positions of the absorption bands of stretching vibrations of Ssbnd O bonds makes it necessary to obtain data on exact structures of ion clusters for reliable assignment of absorption bands in experimental IR spectra of real sulfonate-containing systems.

  7. An ion selectivity filter in the extracellular domain of Cys-loop receptors reveals determinants for ion conductance.

    Science.gov (United States)

    Hansen, Scott B; Wang, Hai-Long; Taylor, Palmer; Sine, Steven M

    2008-12-26

    Neurotransmitter binding to Cys-loop receptors promotes a prodigious transmembrane flux of several million ions/s, but to date, structural determinants of ion flux have been identified flanking the membrane-spanning region. Using x-ray crystallography, sequence analysis, and single-channel recording, we identified a novel determinant of ion conductance near the point of entry of permeant ions. Co-crystallization of acetylcholine-binding protein with sulfate anions revealed coordination of SO4(2-) with a ring of lysines at a position equivalent to 24 A above the lipid membrane in homologous Cys-loop receptors. Analysis of multiple sequence alignments revealed that residues equivalent to the ring of lysines are negatively charged in cation-selective receptors but are positively charged in anion-selective receptors. Charge reversal of side chains at homologous positions in the nicotinic receptor from the motor end plate decreases unitary conductance up to 80%. Selectivity filters stemming from transmembrane alpha-helices have similar pore diameters and compositions of amino acids. These findings establish that when the channel opens under a physiological electrochemical gradient, permeant ions are initially stabilized within the extracellular vestibule of Cys-loop receptors, and this stabilization is a major determinant of ion conductance.

  8. Acid-sensing ion channels contribute to the effect of extracellular acidosis on proliferation and migration of A549 cells.

    Science.gov (United States)

    Wu, Yu; Gao, Bo; Xiong, Qiu-Ju; Wang, Yu-Chan; Huang, Da-Ke; Wu, Wen-Ning

    2017-06-01

    Acid-sensing ion channels, a proton-gated cation channel, can be activated by low extracellular pH and involved in pathogenesis of some tumors such as glioma and breast cancer. However, the role of acid-sensing ion channels in the growth of lung cancer cell is unclear. In this study, we investigated the expression of acid-sensing ion channels in human lung cancer cell line A549 and their possible role in proliferation and migration of A549 cells. The results show that acid-sensing ion channel 1, acid-sensing ion channel 2, and acid-sensing ion channel 3 are expressed in A549 cells at the messenger RNA and protein levels, and acid-sensing ion channel-like currents were elicited by extracellular acid stimuli. Moreover, we found that acidic extracellular medium or overexpressing acid-sensing ion channel 1a promotes proliferation and migration of A549 cells. In addition psalmotoxin 1, a specific acid-sensing ion channel 1a inhibitor, or acid-sensing ion channel 1a knockdown can abolish the effect of acid stimuli on A549 cells. In addition, acid-sensing ion channels mediate increase of [Ca(2+)]i induced by low extracellular pH in A549 cells. All these results indicate that acid-sensing ion channel-calcium signal mediate lung cancer cell proliferation and migration induced by extracellular acidosis, and acid-sensing ion channels may serve as a prognostic marker and a therapeutic target for lung cancer.

  9. Extracellular calcium modulates persistent sodium current-dependent burst-firing in hippocampal pyramidal neurons.

    Science.gov (United States)

    Su, H; Alroy, G; Kirson, E D; Yaari, Y

    2001-06-15

    The generation of high-frequency spike bursts ("complex spikes"), either spontaneously or in response to depolarizing stimuli applied to the soma, is a notable feature in intracellular recordings from hippocampal CA1 pyramidal cells (PCs) in vivo. There is compelling evidence that the bursts are intrinsically generated by summation of large spike afterdepolarizations (ADPs). Using intracellular recordings in adult rat hippocampal slices, we show that intrinsic burst-firing in CA1 PCs is strongly dependent on the extracellular concentration of Ca(2+) ([Ca(2+)](o)). Thus, lowering [Ca(2+)](o) (by equimolar substitution with Mn(2+) or Mg(2+)) induced intrinsic bursting in nonbursters, whereas raising [Ca(2+)](o) suppressed intrinsic bursting in native bursters. The induction of intrinsic bursting by low [Ca(2+)](o) was associated with enlargement of the spike ADP. Low [Ca(2+)](o)-induced intrinsic bursts and their underlying ADPs were suppressed by drugs that reduce the persistent Na(+) current (I(NaP)), indicating that this current mediates the slow burst depolarization. Blocking Ca(2+)-activated K(+) currents with extracellular Ni(2+) or intracellular chelation of Ca(2+) did not induce intrinsic bursting. This and other evidence suggest that lowering [Ca(2+)](o) may induce intrinsic bursting by augmenting I(NaP). Because repetitive neuronal activity in the hippocampus is associated with marked decreases in [Ca(2+)](o), the regulation of intrinsic bursting by extracellular Ca(2+) may provide a mechanism for preferential recruitment of this firing mode during certain forms of hippocampal activation.

  10. Ability of sodium copper chlorophyllin complex to repair photoaged skin by stimulation of biomarkers in human extracellular matrix

    Directory of Open Access Journals (Sweden)

    McCook JP

    2016-07-01

    Full Text Available John P McCook,1 Thomas J Stephens,2 Lily I Jiang,2 Robert M Law,3 Vincent Gotz4 1Discovery Partners LLC, Frisco, 2Thomas J. Stephens & Associates, Inc., Richardson, 3ProPath, Dallas, TX, 4MDRejuvena, Inc., San Diego, CA, USA Purpose: To examine the effect of sodium copper chlorophyllin complex on the expression of biomarkers of photoaged dermal extracellular matrix indicative of skin repair.Patients and methods: Following a previously published 12-day clinical assessment model, skin biopsy samples from the forearms of four healthy females with signs of photoaged skin were obtained and samples were analyzed by immunohistochemistry for key biomarkers of aging skin after each subject was treated with a test material consisting of a gel containing a liposomal dispersion of sodium copper chlorophyllin complex 0.05%, a positive control of tretinoin cream 0.025%, and an untreated negative control.Results: There was a statistically significantly greater amount of fibrillin/amyloid P and epidermal mucins found for skin treated with the test material containing 0.05% sodium copper chlorophyllin complex and the reference control tretinoin 0.025% cream compared to the negative control (untreated site. Expression of procollagen 1 and dermal mucin also showed a greater presence in the samples treated with the test material and the reference control compared to the negative control, though the differences were not statistically significant. No adverse events were observed or reported by the subjects during the course of the study.Conclusion: The results of this human biopsy study suggest that both retinoids and sodium copper chlorophyllin complex have beneficial effects on biomarkers of photoaged skin. Products containing both sodium copper chlorophyllin complex and retinols may provide a dual approach to reversing age-related decreases in hyaluronic acid (HA in the skin: inhibition of the breakdown of HA via sodium copper chlorophyllin complex by inhibition

  11. Sodium chlorite as an efficient oxidant and hydroxy ion pump in osmium-catalyzed asymmetric dihydroxylation.

    Science.gov (United States)

    Junttila, Mikko H; Hormi, Osmo E O

    2004-07-09

    Sodium chlorite is an efficient stoichiometric oxidant in Sharpless asymmetric dihydroxylation. One sodium chlorite provides the reaction with the stoichiometric number of electrons and hydroxide ions needed to dihydroxylate two olefins without the consumption of any additional base. 100% conversion in sodium chlorite asymmetric dihydroxylation of styrene was achieved twice as fast as in the established Sharpless K(3)[Fe(CN)(6)] dihydroxylation. Even internal olefins were dihydroxylated fast with sodium chlorite without hydrolysis aids. Eight olefins were dihydroxylated to corresponding vicinal diols with yields and ees as good as those reported in the literature for other similar processes.

  12. [Determination of sodium chlorite in processed herring roe by ion chromatography with a conductivity detector].

    Science.gov (United States)

    Kawasaki, Yoko; Kubota, Hiroki; Yomota, Chikako; Tanamoto, Kenichi

    2005-08-01

    An analytical method for residual sodium chlorite in several kinds of processed herring roe treated with sodium chlorite was studied. Sodium chlorite was extracted with 9 mmol/L sodium carbonate. After centrifugation, the supernatant was filtered through a 0.2 microm nylon filter. The filtrate was deproteinized by ultrafiltration and chloride ion was removed with an On-Guard Ag cartridge column. The eluate was subjected to conductivity detector-ion chromatography. Recoveries of sodium chlorite from herring roe spiked at the level of 5 mg/kg were 88 +/- 3.7% (n = 5, CV 4.2%). The method had a quantitation limit of 5 mg/kg for processed herring roes.

  13. Thiocarboxylate Organic Electrodes for Ultrahigh Capacity Room Temperature Sodium Ion Battery.

    Science.gov (United States)

    Zhao, Hongyang; Wang, Jianwei; Zheng, Yuheng; Li, Ju; Han, Xiaogang; He, Gang; Du, Yaping

    2017-10-05

    Organic room temperature sodium ion battery electrodes with carboxylate and carbonyl groups have been widely studied. Herein, for the first time, we report a family of sodium ion battery electrodes with stepwise substitution of oxygen in carboxylate group with sulfur, which improves electron delocalization, electrical conductivity and sodium uptake capacity. The versatile strategy based on molecular engineering can greatly enhance the specific capacity of organic electrodes with the same carbon scaffold. By introducing two sulfur atoms to a single carboxylate scaffold, the molecular solid can reach a reversible capacity of 466 mAh g-1 at current density of 50 mA g-1, when four sulfur atoms are introduced, the capacity increases to 567 mAh g-1 at current density of 50 mA g-1, which is the highest capacity value among reported organic sodium ion battery anodes until now. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Expanded-bed adsorption utilizing ion-exchange resin to purify extracellular beta-galactosidase.

    Science.gov (United States)

    Pereira, J A; Vieira E Rosa, P De T; Pastore, G M; Santana, C C

    1998-01-01

    The application of expanded-bed ion-exchange resins allows the elimination of intermediary particulate separation steps like filtration or centrifugation prior to adsorption steps in enzyme-purification processes from crude fermentation broths. This work is concerned with the experimental evaluation data of a process related to the adsorption of an extracellular p-galactosidase from the fungi Scopulariopsis. The protein recovery in the ion-exchange resin Accell Plus QMA was accomplished using a continuous-monitoring method. The direct adsorption step was followed by a elution step with concentrated NaCl solutions aiming to improve the enzyme-specific activity. Experimental data for fixed and expanded bed were compared.

  15. Ionization of Sodium Cluster by Heavy Ion Impact

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Energetic ions have recently been used as an efficient means to produce highly charged cold clusters~[1]. There are two ways to obtain highly-charged clusters: low-fluence nano-second lasers irradiation and energetic highly charged ions impact. Compared to the low-density laser, heavy ions, e.g. delivered by ECR sources, have the

  16. Removal of sodium and chloride ions from aqueous solutions using fique fibers (Furcraea spp.).

    Science.gov (United States)

    Agudelo, Nikolay; Hinestroza, Juan P; Husserl, Johana

    2016-01-01

    Fique fibers obtained from the leaves of Furcraea spp., a highly abundant plant in the mountains of South America, may offer an alternative as biosorbents in desalination processes as they exhibit high removal capacities (13.26 meq/g for chloride ions and 15.52 meq/g for sodium ions) up to four times higher than exchange capacities commonly observed in synthetic resins. The ion removal capacity of the fibers was also found to be a function of the pH of the solution with the maximum removal of ions obtained at pH 8. Unlike most commercial ion exchange resins, our results suggest that fique fibers allow simultaneous removal of chloride and sodium ions.

  17. Electronic transition dipole moment and radiative lifetime calculations of sodium dimer ion-pair states.

    Science.gov (United States)

    Sanli, Aydin; Beser, Bediha; Edwardson, John R; Magnier, Sylvie; Ahmed, Ergin H; Marjatta Lyyra, A

    2015-09-14

    We report here ab initio calculated electronic transition dipole moments for the sodium dimer ion pair states of (1)Σg (+) symmetry. They vary strongly as a function of internuclear distance because of the effect of the Na(+) + Na(-) ion pair potential, which also causes the formation of additional wells and shoulders in the molecular potential energy curves. We also present a computational study of the transition dipole moment matrix elements and lifetimes for these ion-pair states.

  18. Adsorption characteristics of zinc ions on sodium dodecyl sulfate in process of micellar-enhanced ultrafiltration

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To separate zinc ions from aqueous solution efficiently, micellar-enhanced ultrafiltration(MEUF) of hollow ultrafiltration membrane was used with sodium dodecyl sulfate(SDS) as surfactant. The formation of micellar and the adsorption mechanism were investigated, including the influence of the ratio of SDS to zinc ions on the micelle quantity, the micelle ratio, the gross adsorptive capacity, the rejection of zinc ions and the adsorption isotherm law. The results show that the rejection rate of zinc ions reaches 97% and the adsorption of zinc ions on SDS conforms to the Langmuir adsorption isotherm and the adsorption is a chemical adsorption process.

  19. Extracellular polymeric substances mediate bioleaching/biocorrosion via interfacial processes involving iron(III) ions and acidophilic bacteria.

    Science.gov (United States)

    Sand, Wolfgang; Gehrke, Tilman

    2006-01-01

    Extracellular polymeric substances seem to play a pivotal role in biocorrosion of metals and bioleaching, biocorrosion of metal sulfides for the winning of precious metals as well as acid rock drainage. For better control of both processes, the structure and function of extracellular polymeric substances of corrosion-causing or leaching bacteria are of crucial importance. Our research focused on the extremophilic bacteria Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, because of the "simplicity" and knowledge about the interactions of these bacteria with their substrate/substratum and their environment. For this purpose, the composition of the corresponding extracellular polymeric substances and their functions were analyzed. The extracellular polymeric substances of both species consist mainly of neutral sugars and lipids. The functions of the exopolymers seem to be: (i) to mediate attachment to a (metal) sulfide surface, and (ii) to concentrate iron(III) ions by complexation through uronic acids or other residues at the mineral surface, thus, allowing an oxidative attack on the sulfide. Consequently, dissolution of the metal sulfide is enhanced, which may result in an acceleration of 20- to 100-fold of the bioleaching process over chemical leaching. Experiments were performed to elucidate the importance of the iron(III) ions complexed by extracellular polymeric substances for strain-specific differences in oxidative activity for pyrite. Strains of A. ferrooxidans with a high amount of iron(III) ions in their extracellular polymeric substances possess greater oxidation activity than those with fewer iron(III) ions. These data provide insight into the function of and consequently the advantages that extracellular polymeric substances provide to bacteria. The role of extracellular polymeric substances for attachment under the conditions of a space station and resulting effects like biofouling, biocorrosion, malodorous gases, etc. will be discussed.

  20. Sodium ion channel mutations in glioblastoma patients correlate with shorter survival

    Directory of Open Access Journals (Sweden)

    Velculescu Victor E

    2011-02-01

    Full Text Available Abstract Background Glioblastoma Multiforme (GBM is the most common and invasive astrocytic tumor associated with dismal prognosis. Treatment for GBM patients has advanced, but the median survival remains a meager 15 months. In a recent study, 20,000 genes from 21 GBM patients were sequenced that identified frequent mutations in ion channel genes. The goal of this study was to determine whether ion channel mutations have a role in disease progression and whether molecular targeting of ion channels is a promising therapeutic strategy for GBM patients. Therefore, we compared GBM patient survival on the basis of presence or absence of mutations in calcium, potassium and sodium ion transport genes. Cardiac glycosides, known sodium channel inhibitors, were then tested for their ability to inhibit GBM cell proliferation. Results Nearly 90% of patients showed at least one mutation in ion transport genes. GBM patients with mutations in sodium channels showed a significantly shorter survival compared to patients with no sodium channel mutations, whereas a similar comparison based on mutational status of calcium or potassium ion channel mutations showed no survival differences. Experimentally, targeting GBM cells with cardiac glycosides such as digoxin and ouabain demonstrated preferential cytotoxicity against U-87 and D54 GBM cells compared to non-tumor astrocytes (NTAs. Conclusions These pilot studies of GBM patients with sodium channel mutations indicate an association with a more aggressive disease and significantly shorter survival. Moreover, inhibition of GBM cells by ion channel inhibitors such as cardiac glycosides suggest a therapeutic strategy with relatively safe drugs for targeting GBM ion channel mutations. Key Words: glioblastoma multiforme, ion channels, mutations, small molecule inhibitors, cardiac glycosides.

  1. The involvement of extracellular matrix remodeling and up-regulated TNF-α in asthma rat and the interventions of montelukast sodium

    Institute of Scientific and Technical Information of China (English)

    Wei-Qiang Cao; Zu-Yong Li; Jin-Zhong Su

    2015-01-01

    Objective: The present research aimed to explore the involvement of extracellular matrix remodeling and up-regulated TNF-α in asthma rat and the interventions of montelukast sodium. Methods: Clean SD rats were divided into 3 groups: control, model and drug intervention group. The expression of TNF-α, MMP2, MMP9 and its inhibitor TIMP1 was detected by Western Blotting. Results: The expression of TNF-α, MMP2, MMP9 and its inhibitor TIMP1 was increased in asthma lung when compared with control. These abnormalities were normalized by the medication of montelukast sodium with a statistical difference when compared with model group. Conclusions: Extracellular matrix remodeling and up-regulated TNF-α were participated in the pathogenesis of asthma lung injury and montelukast sodium alleviates the injury by normalizing those abnormal proteins expression.

  2. Solvation behavior of carbonate-based electrolytes in sodium ion batteries.

    Science.gov (United States)

    Cresce, Arthur V; Russell, Selena M; Borodin, Oleg; Allen, Joshua A; Schroeder, Marshall A; Dai, Michael; Peng, Jing; Gobet, Mallory P; Greenbaum, Steven G; Rogers, Reginald E; Xu, Kang

    2016-12-21

    Sodium ion batteries are on the cusp of being a commercially available technology. Compared to lithium ion batteries, sodium ion batteries can potentially offer an attractive dollar-per-kilowatt-hour value, though at the penalty of reduced energy density. As a materials system, sodium ion batteries present a unique opportunity to apply lessons learned in the study of electrolytes for lithium ion batteries; specifically, the behavior of the sodium ion in an organic carbonate solution and the relationship of ion solvation with electrode surface passivation. In this work the Li(+) and Na(+)-based solvates were characterized using electrospray mass spectrometry, infrared and Raman spectroscopy, (17)O, (23)Na and pulse field gradient double-stimulated-echo pulse sequence nuclear magnetic resonance (NMR), and conductivity measurements. Spectroscopic evidence demonstrate that the Li(+) and Na(+) cations share a number of similar ion-solvent interaction trends, such as a preference in the gas and liquid phase for a solvation shell rich in cyclic carbonates over linear carbonates and fluorinated carbonates. However, quite different IR spectra due to the PF6(-) anion interactions with the Na(+) and Li(+) cations were observed and were rationalized with the help of density functional theory (DFT) calculations that were also used to examine the relative free energies of solvates using cluster - continuum models. Ion-solvent distances for Na(+) were longer than Li(+), and Na(+) had a greater tendency towards forming contact pairs compared to Li(+) in linear carbonate solvents. In tests of hard carbon Na-ion batteries, performance was not well correlated to Na(+) solvent preference, leading to the possibility that Na(+) solvent preference may play a reduced role in the passivation of anode surfaces and overall Na-ion battery performance.

  3. SODIUM ION-DEPENDENT AMINO-ACID-TRANSPORT IN MEMBRANE-VESICLES OF BACILLUS-STEAROTHERMOPHILUS

    NARCIS (Netherlands)

    HEYNE, RIR; DEVRIJ, W; CRIELAARD, W; KONINGS, WN

    1991-01-01

    Amino acid transport in membrane vesicles of Bacillus stearothermophilus was studied. A relatively high concentration of sodium ions is needed for uptake of L-alanine (K(t) = 1.0 mM) and L-leucine (K(t) = 0.4 mM). In contrast, the Na+-H+-L-glutamate transport system has a high affinity for sodium io

  4. Carbonized-leaf Membrane with Anisotropic Surfaces for Sodium-ion Battery.

    Science.gov (United States)

    Li, Hongbian; Shen, Fei; Luo, Wei; Dai, Jiaqi; Han, Xiaogang; Chen, Yanan; Yao, Yonggang; Zhu, Hongli; Fu, Kun; Hitz, Emily; Hu, Liangbing

    2016-01-27

    A simple one-step thermal pyrolysis route has been developed to prepare carbon membrane from a natural leaf. The carbonized leaf membrane possesses anisotropic surfaces and internal hierarchical porosity, exhibiting a high specific capacity of 360 mAh/g and a high initial Coulombic efficiency of 74.8% as a binder-free, current-collector-free anode for rechargeable sodium ion batteries. Moreover, large-area carbon membranes with low contact resistance are fabricated by simply stacking and carbonizing leaves, a promising strategy toward large-scale sodium-ion battery developments.

  5. Sodium Chloride interaction with solvated and crystalline cellulose : sodium ion affects the tetramer and fibril in aqueous solution

    CERN Document Server

    Bellesia, Giovanni

    2013-01-01

    Inorganic salts are a natural component of biomass which have a significant effect on the product yields from a variety of biomass conversion processes. Understanding their effect on biomass at the microscopic level can help discover their mechanistic role. We present a study of the effect of aqueous sodium chloride (NaCl) on the largest component of biomass, cellulose, focused on the thermodynamic and structural effect of a sodium ion on the cellulose tetramer, and fibril. Replica exchange molecular dynamics simulations of a cellulose tetramer reveal a number of preferred cellulose-Na contacts and bridging positions. Large scale MD simulations on a model cellulose fibril find that Na+ perturbs the hydroxymethyl rotational state population and consequently disrupts the "native" hydrogen bonding network.

  6. Sodium-ion transfer at the interface between ceramic and organic electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Sagane, Fumihiro; Abe, Takeshi; Ogumi, Zempachi [Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan)

    2010-11-01

    Sodium-ion transfer through the interface between ceramic and organic electrolytes was studied by AC impedance spectroscopy. Na{sub 3}Zr{sub 1.88}Y{sub 0.12}Si{sub 2}PO{sub 12} (NASICON) and Na-{beta}''-alumina were used as ceramic electrolytes, and propylene carbonate (PC) and dimethyl sulfoxide (DMSO) containing 0.05 mol dm{sup -3} NaCF{sub 3}SO{sub 3} were used as organic electrolytes. The semi-circle ascribed to interfacial charge transfer resistance (R{sub ct}) was observed. The activation energies for sodium-ion transfer at the interface between ceramic and organic electrolytes were evaluated by the temperature dependency of R{sub ct}. As a result, the activation energies depended on the ceramic electrolytes but not on the solvents. These results suggest that sodium-ion transfer from ceramic to organic electrolytes should be responsible for the activation energies, which is contrary to the case in a lithium-ion transfer system. Based on these results, the mechanism of interfacial sodium-ion transfer was discussed. (author)

  7. A Safer Sodium-Ion Battery Based on Nonflammable Organic Phosphate Electrolyte.

    Science.gov (United States)

    Zeng, Ziqi; Jiang, Xiaoyu; Li, Ran; Yuan, Dingding; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2016-09-01

    Sodium-ion batteries are now considered as a low-cost alternative to lithium-ion technologies for large-scale energy storage applications; however, their safety is still a matter of great concern for practical applications. In this paper, a safer sodium-ion battery is proposed by introducing a nonflammable phosphate electrolyte (trimethyl phosphate, TMP) coupled with NaNi0.35Mn0.35Fe0.3O2 cathode and Sb-based alloy anode. The physical and electrochemical compatibilities of the TMP electrolyte are investigated by igniting, ionic conductivity, cyclic voltammetry, and charge-discharge measurements. The results exhibit that the TMP electrolyte with FEC additive is completely nonflammable and has wide electrochemical window (0-4.5 V vs. Na/Na(+)), in which both the Sb-based anode and NaNi0.35Mn0.35Fe0.3O2 cathode show high reversible capacity and cycling stability, similarly as in carbonate electrolyte. Based on these results, a nonflammable sodium-ion battery is constructed by use of Sb anode, NaNi0.35Mn0.35Fe0.3O2 cathode, and TMP + 10 vol% FEC electrolyte, which works very well with considerable capacity and cyclability, demonstrating a promising prospect to build safer sodium-ion batteries for large-scale energy storage applications.

  8. Self-organized sodium titanate/titania nanoforest for the negative electrode of sodium-ion microbatteries

    Energy Technology Data Exchange (ETDEWEB)

    Cabello, Marta [Laboratorio de Química Inorgánica, Universidad de Córdoba, Edificio Marie Curie, Campus de Rabanales, 14071 Córdoba (Spain); Ortiz, Gregorio F., E-mail: q72maorg@uco.es [Laboratorio de Química Inorgánica, Universidad de Córdoba, Edificio Marie Curie, Campus de Rabanales, 14071 Córdoba (Spain); López, María C.; Alcántara, Ricardo; González, José R.; Tirado, José L. [Laboratorio de Química Inorgánica, Universidad de Córdoba, Edificio Marie Curie, Campus de Rabanales, 14071 Córdoba (Spain); Stoyanova, Radostina; Zhecheva, Ekaterina [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str. Bldg. 11, 1113 Sofia (Bulgaria)

    2015-10-15

    A nanocomposite of sodium titanate/titania nanotrees self-organized in a parallel fashion to form nanoforests is successfully prepared and used as high-performance anode for Na-ion microbatteries. The first step of the synthesis is the anodic oxidation of Ti foils to form self-organized amorphous TiO{sub 2} nanotubes followed by insertion of sodium in aqueous media at room temperature. Then the composite is thermally dehydrated and crystallized as monoclinic Na{sub 2}Ti{sub 6}O{sub 13}/rutile nanotrees. EPR spectra evidence a significant increase in Ti{sup 3+} content during sodium/proton insertion and a decrease on heating. SEM images reveal that while the height of the nanotubes is similar to the nanoforest (c.a. 8.0 μm) the morphology changes from aligned nanotubes to nanotrees of complex texture. The electrochemical results of sodium test cells in non-aqueous electrolyte using the Na{sub 2}Ti{sub 6}O{sub 13}/TiO{sub 2} nanocomposite electrodes show flat profiles of sodium insertion and de-insertion at 0.7 and 0.9 V, respectively. The observed reversible capacity of 130 μA h cm{sup −2} over 150 cycles is almost threefold the value of titania nanotubes annealed at a same temperature. Both characteristics are of great interest to achieve safe and efficient Na-ion microbatteries. - Highlights: • Thin films of self-organized amorphous Na{sub x}TiO{sub 2} nanotubes can be thermally converted to Na{sub 2}Ti{sub 6}O{sub 13}/TiO{sub 2} composite nanoforests. • The 8 μm, 3-D films of branched nanotrees insert sodium reversibly at an average potential of 0.8 V. • The capacity is three times higher than that of TiO{sub 2} nanotubes obtained under the same temperature.

  9. Comparative equilibrium studies of sorption of Pb(II) ions by sodium and calcium alginate

    Institute of Scientific and Technical Information of China (English)

    KHOTIMCHENKO Maxim; KOVALEV Valeri; KHOTIMCHENKO Yuri

    2008-01-01

    The absorption of Pb(II) ions from aqueous solution by different alginate compounds was studied in a batch sorption system. Water soluble sodium alginate and insoluble calcium alginate beads were investigated. The lead-binding capacity of both alginate compounds was highest within the pH range 6-8. The binding capacities and rates of Pb(II) ions by alginate compounds were evaluated. The Langmuir, Freundlich and Bruneaur, Emmet and Teller (BET) sorption models were applied to describe the isotherms and isotherm constants. Sorption isothermal data could be well interpreted by the Langmuir model. The results obtained through the study suggest that alginate compounds are favorable sorbents. The largest amount of Pb(II) ions were bound by sodium alginate although the difference between two compounds was slight. Therefore, alginate substances may be considered as alternative for sorption and removal of Pb(II) ions from wastewaters.

  10. Electron impact excitation of highly charged sodium-like ions

    Science.gov (United States)

    Blaha, M.; Davis, J.

    1978-01-01

    Optical transition probabilities and electron collision strengths for Ca X, Fe XVI, Zn XX, Kr XXVI and Mo XXXII are calculated for transitions between n equal to 3 and n equal to 4 levels. The calculations neglect relativistic effects on the radial functions. A semi-empirical approach provides wave functions of the excited states; a distorted wave function without exchange is employed to obtain the excitation cross sections. The density dependence of the relative intensities of certain emission lines in the sodium isoelectronic sequence is also discussed.

  11. Scale-up of Metal Hexacyanoferrate Cathode Material for Sodium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dzwiniel, Trevor L. [Argonne National Lab. (ANL), Argonne, IL (United States); Pupek, Krzysztof Z. [Argonne National Lab. (ANL), Argonne, IL (United States); Krumdick, Gregory K. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-04

    Sharp Laboratories of America (SLA) approached Argonne National Laboratory with a bench-scale process to produce material for a sodium-ion battery, referred to as Prussian Blue, and a request to produce 1 kg of material for their ARPA-E program. The target performance criteria was an average capacity of >150 mAh/g.

  12. Improving the cyclability of sodium-ion cathodes by selection of electrolyte solvent

    Science.gov (United States)

    Vidal-Abarca, C.; Lavela, P.; Tirado, J. L.; Chadwick, A. V.; Alfredsson, M.; Kelder, E.

    2012-01-01

    A composite material containing orthorhombic Na1.8FePO4F and carbon is prepared by mechanical activation and ceramic procedures. The material is studied in sodium test cells as a potential candidate for sodium-ion battery cathodes. The effect of the solvents in the electrolyte on the electrochemical performance is analysed by X-ray absorption spectroscopy. The structural changes on cycling are small, while the changes in the oxidation state of iron agree with the sodium insertion-extraction processes. The oxidation state is especially affected by the upper limit of the voltage window, and the discharge capacity is strongly affected when using propylene carbonate solvent. Capacity and capacity retention are higher for sodium cells using mixtures of ethylene carbonate and diethyl carbonate as the solvent of NaPF6 electrolytes.

  13. Dextran sulphate crowding and sodium deoxycholate lysis of primary breast fibroblast cells achieve extracellular matrix deposition and decellularization for breast cancer stem cell culture

    Directory of Open Access Journals (Sweden)

    Aroem Naruni

    2016-01-01

    Full Text Available AbstrakLatar belakang: Lingkungan mikro yaitu sel stromal dam matriks ekstraseluler saat ini dinyatakansebagai kontributor dalam perkembangan tumor. Beberapa penelitian telah mengembangkan matriksekstraseluler yang mendukung perkembangan sel in vitro. Matriks ekstraseluler adalah suatu komplekssusunan supramolekuler dari berbagai macam glycoprotein dan proteoglycan. Matriks ekstraselulermenyediakan integritas jaringan, bertindak sebagai scaffold alami tempat sel melekat dan berinteraksiserta berperan sebagai reservoir pertumbuhan sel. Penelitian ini bertujuan untuk mendapatkan deposisidan deselularisasi yang optimal pada matriks ekstraseluler.Metode: Dalam penelitian ini, kami mengembangkan cells crowder untuk meningkatkan deposit matriksekstraseluler dari kultur sel primer fibroblast payudara yang diperoleh dari spesimen hasil operasimammoplasty. Dextran 500 kDa ditambahkan dalam media kultur DMEM lengkap yang telah ditambahkan0.5% FBS dan 100μM L-ascorbic acid 2-phosphate. Setelah tujuh hari, sel dilisis dengan menggunakanSodium Deoxycolate (DOC.Hasil: Deposisi matriks ekstraseluler dan proses deselulerisasi dari sel primer fibroblas payudara dapatterdeteksi dengan menggunakan antibodi Rabbit anti human fibronectin yang selanjutnya ditambahkandengan anti rabbit IgG yang telah dikonjugasi dengan Alexa Fluor 488.Kesimpulan: Penambahan dextran sulfat dan prosesing lysis dengan sodium deoxycolate dapatmeningkatkan deposisi dan menghasilkan deselularisasi matriks ekstraseluler. (Health Science Journalof Indonesia 2015;6:43-7Kata kunci: matriks ekstra selular, kanker mammae, stem cell, sel fibroblast AbstractBackground: The microenvironment including stromal cells and extracellular matrix (ECM is now consideredan active contributor to tumor progression. Certain studies have developed ECM which supports a suitable cellulargrowth in vitro. The ECM is a complex supramolecular assembly of a variety of glycoproteins and proteoglycans.Extracellular

  14. Zinc naphthalenedicarboxylate coordination complex: A promising anode material for lithium and sodium-ion batteries with good cycling stability.

    Science.gov (United States)

    Fei, Hailong; Feng, Wenjing; Xu, Tan

    2017-02-15

    It is important to discover new, cheap and environmental friendly electrode materials with high capacity and good cycling stability for lithium and sodium-ion batteries. Zinc 1,4-naphthalenedicarboxylate was firstly found to be stable anode materials for lithium and sodium-ion batteries. The discharge capacity can be up to 468.9mAhg(-1) after 100 cycles at a current density of 100mAg(-1) for lithium-ion batteries, while the second discharge capacity of 320.7mAhg(-1) was achieved as anode materials for sodium-ion batteries. A possible electrochemical reaction mechanism was discussed.

  15. Alkali-Metal-Ion-Functionalized Graphene Oxide as a Superior Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Wan, Fang; Li, Yu-Han; Liu, Dai-Huo; Guo, Jin-Zhi; Sun, Hai-Zhu; Zhang, Jing-Ping; Wu, Xing-Long

    2016-06-06

    Although graphene oxide (GO) has large interlayer spacing, it is still inappropriate to use it as an anode for sodium-ion batteries (SIBs) because of the existence of H-bonding between the layers and ultralow electrical conductivity which impedes the Na(+) and e(-) transformation. To solve these issues, chemical, thermal, and electrochemical procedures are traditionally employed to reduce GO nanosheets. However, these strategies are still unscalable, consume high amounts of energy, and are expensive for practical application. Here, for the first time, we describe the superior Na storage of unreduced GO by a simple and scalable alkali-metal-ion (Li(+) , Na(+) , K(+) )-functionalized process. The various alkali metals ions, connecting with the oxygen on GO, have played different effects on morphology, porosity, degree of disorder, and electrical conductivity, which are crucial for Na-storage capabilities. Electrochemical tests demonstrated that sodium-ion-functionalized GO (GNa) has shown outstanding Na-storage performance in terms of excellent rate capability and long-term cycle life (110 mAh g(-1) after 600 cycles at 1 A g(-1) ) owing to its high BET area, appropriate mesopore, high degree of disorder, and improved electrical conductivity. Theoretical calculations were performed using the generalized gradient approximation (GGA) to further study the Na-storage capabilities of functionalized GO. These calculations have indicated that the Na-O bond has the lowest binding energy, which is beneficial to insertion/extraction of the sodium ion, hence the GNa has shown the best Na-storage properties among all comparatives functionalized by other alkali metal ions.

  16. High Temperature Carbonized Grass as a High Performance Sodium Ion Battery Anode.

    Science.gov (United States)

    Zhang, Fang; Yao, Yonggang; Wan, Jiayu; Henderson, Doug; Zhang, Xiaogang; Hu, Liangbing

    2017-01-11

    Hard carbon is currently considered the most promising anode candidate for room temperature sodium ion batteries because of its relatively high capacity, low cost, and good scalability. In this work, switchgrass as a biomass example was carbonized under an ultrahigh temperature, 2050 °C, induced by Joule heating to create hard carbon anodes for sodium ion batteries. Switchgrass derived carbon materials intrinsically inherit its three-dimensional porous hierarchical architecture, with an average interlayer spacing of 0.376 nm. The larger interlayer spacing than that of graphite allows for the significant Na ion storage performance. Compared to the sample carbonized under 1000 °C, switchgrass derived carbon at 2050 °C induced an improved initial Coulombic efficiency. Additionally, excellent rate capability and superior cycling performance are demonstrated for the switchgrass derived carbon due to the unique high temperature treatment.

  17. The emerging chemistry of sodium ion batteries for electrochemical energy storage.

    Science.gov (United States)

    Kundu, Dipan; Talaie, Elahe; Duffort, Victor; Nazar, Linda F

    2015-03-01

    Energy storage technology has received significant attention for portable electronic devices, electric vehicle propulsion, bulk electricity storage at power stations, and load leveling of renewable sources, such as solar energy and wind power. Lithium ion batteries have dominated most of the first two applications. For the last two cases, however, moving beyond lithium batteries to the element that lies below-sodium-is a sensible step that offers sustainability and cost-effectiveness. This requires an evaluation of the science underpinning these devices, including the discovery of new materials, their electrochemistry, and an increased understanding of ion mobility based on computational methods. The Review considers some of the current scientific issues underpinning sodium ion batteries.

  18. Effect of calcium/sodium ion exchange on the osmotic properties and structure of polyelectrolyte gels.

    Science.gov (United States)

    Horkay, Ferenc; Basser, Peter J; Hecht, Anne-Marie; Geissler, Erik

    2015-12-01

    We discuss the main findings of a long-term research program exploring the consequences of sodium/calcium ion exchange on the macroscopic osmotic and elastic properties, and the microscopic structure of representative synthetic polyelectrolyte (sodium polyacrylate, (polyacrylic acid)) and biopolymer gels (DNA). A common feature of these gels is that above a threshold calcium ion concentration, they exhibit a reversible volume phase transition. At the macroscopic level, the concentration dependence of the osmotic pressure shows that calcium ions influence primarily the third-order interaction term in the Flory-Huggins model of polymer solutions. Mechanical tests reveal that the elastic modulus is practically unaffected by the presence of calcium ions, indicating that ion bridging does not create permanent cross-links. At the microscopic level, small-angle neutron scattering shows that polyacrylic acid and DNA gels exhibit qualitatively similar structural features in spite of important differences (e.g. chain flexibility and chemical composition) between the two polymers. The main effect of calcium ions is that the neutron scattering intensity increases due to the decrease in the osmotic modulus. At the level of the counterion cloud around dissolved macroions, anomalous small-angle X-ray scattering measurements made on DNA indicate that divalent ions form a cylindrical sheath enveloping the chain, but they are not localized. Small-angle neutron scattering and small-angle X-ray scattering provide complementary information on the structure and interactions in polymer solutions and gels.

  19. Electrochemical selective ion separation in capacitive deionization with sodium manganese oxide.

    Science.gov (United States)

    Kim, Seonghwan; Yoon, Hansun; Shin, Dongyoon; Lee, Jaehan; Yoon, Jeyong

    2017-11-15

    Electrochemical selective ion separation via capacitive deionization, for example, separation of lithium resource from brine, using lithium ion batteries is proposed and demonstrated to have the potential for separating specific ions selectively from a solution containing diverse ions. This separation method is of great industrial concern because of applicability in various fields such as deionization, water softening, purification, heavy metal removal, and resource recovery. Nevertheless, besides the selectivity of materials for lithium ion batteries toward Li(+), there is very little investigation on the selectivity of the materials for sodium ion batteries toward Na(+). Here, the electrochemical selectivity of sodium manganese oxide (Na0.44MnO2), one of the most widely used material in sodium ion batteries, for Na(+) and other cations (K(+), Mg(2+), and Ca(2+)) is investigated. Selective Na(+) separation using the system consisting of Na0.44MnO2 and a Ag/AgCl electrode is successfully demonstrated from a solution containing diverse cations (Na(+), K(+), Mg(2+), and Ca(2+)) via a two-step process that involves a capturing step (charging process) and a releasing step (discharging process). The results showed that Na0.44-xMnO2 has over 13 times higher selectivity for Na(+) than for K(+) and 6-8times higher selectivity for Na(+) than for Mg(2+) and Ca(2+) in the electrolyte containing equal concentrations of the respective ions. Additionally, as a practical demonstration, Na(+) was successfully separated from an industrial raw material used for pure KOH production (estimated ratio of Na(+):K(+)=1:200). Copyright © 2017 Elsevier Inc. All rights reserved.

  20. 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.

  1. Conserved Aspartic Acid Residues Lining the Extracellular Loop I of Sodium-coupled Bile Acid Transporter ASBT Interact with Na+ and 7α-OH Moieties on the Ligand Cholestane Skeleton*

    Science.gov (United States)

    Hussainzada, Naissan; Da Silva, Tatiana Claro; Zhang, Eric Y.; Swaan, Peter W.

    2008-01-01

    Functional contributions of residues Val-99—Ser-126 lining extracellular loop (EL) 1 of the apical sodium-dependent bile acid transporter were determined via cysteine-scanning mutagenesis, thiol modification, and in silico interpretation. Despite membrane expression for all but three constructs (S112C, Y117C, S126C), most EL1 mutants (64%) were inactivated by cysteine mutation, suggesting a functional role during sodium/bile acid co-transport. A negative charge at conserved residues Asp-120 and Asp-122 is required for transport function, whereas neutralization of charge at Asp-124 yields a functionally active transporter. D124A exerts low affinity for common bile acids except deoxycholic acid, which uniquely lacks a 7α-hydroxyl (OH) group. Overall, we conclude that (i) Asp-122 functions as a Na+ sensor, binding one of two co-transported Na+ ions, (ii) Asp-124 interacts with 7α-OH groups of bile acids, and (iii) apolar EL1 residues map to hydrophobic ligand pharmacophore features. Based on these data, we propose a comprehensive mechanistic model involving dynamic salt bridge pairs and hydrogen bonding involving multiple residues to describe sodium-dependent bile acid transporter-mediated bile acid and cation translocation. PMID:18508772

  2. Chemically bonded phosphorus/graphene hybrid as a high performance anode for sodium-ion batteries.

    Science.gov (United States)

    Song, Jiangxuan; Yu, Zhaoxin; Gordin, Mikhail L; Hu, Shi; Yi, Ran; Tang, Duihai; Walter, Timothy; Regula, Michael; Choi, Daiwon; Li, Xiaolin; Manivannan, Ayyakkannu; Wang, Donghai

    2014-11-12

    Room temperature sodium-ion batteries are of great interest for high-energy-density energy storage systems because of low-cost and natural abundance of sodium. Here, we report a novel phosphorus/graphene nanosheet hybrid as a high performance anode for sodium-ion batteries through facile ball milling of red phosphorus and graphene stacks. The graphene stacks are mechanically exfoliated to nanosheets that chemically bond with the surfaces of phosphorus particles. This chemical bonding can facilitate robust and intimate contact between phosphorus and graphene nanosheets, and the graphene at the particle surfaces can help maintain electrical contact and stabilize the solid electrolyte interphase upon the large volume change of phosphorus during cycling. As a result, the phosphorus/graphene nanosheet hybrid nanostructured anode delivers a high reversible capacity of 2077 mAh/g with excellent cycling stability (1700 mAh/g after 60 cycles) and high Coulombic efficiency (>98%). This simple synthesis approach and unique nanostructure can potentially be applied to other phosphorus-based alloy anode materials for sodium-ion batteries.

  3. Vanadium Sulfide on Reduced Graphene Oxide Layer as a Promising Anode for Sodium Ion Battery.

    Science.gov (United States)

    Sun, Ruimin; Wei, Qiulong; Li, Qidong; Luo, Wen; An, Qinyou; Sheng, Jinzhi; Wang, Di; Chen, Wei; Mai, Liqiang

    2015-09-23

    As an alternative system of rechargeable lithium ion batteries, sodium ion batteries revitalize researchers' interest due to the low cost, abundant sodium resources, and similar storage mechanism to lithium ion batteries. VS4 has emerged as a promising anode material for SIBs due to low cost and its unique linear chains structure that can offer potential sites for sodium storage. Herein, we present the growth of VS4 on reduced graphene oxide (rGO) as SIBs anode for the first time. The VS4/rGO anode exhibits promising performance in SIBs. It delivers a reversible capacity of 362 mAh g(-1) at 100 mA g(-1) and a good rate performance. We also investigate the sodium storage behavior of the VS4/rGO. Different than most transition metal sulfides, the VS4/rGO composite experiences a three-step separation mechanism during the sodiation process (VS4 to metallic V and Na2S, then the electrochemical mechanism is akin to Na-S). The VS4/rGO composite proves to be a promising material for rechargeable SIBs.

  4. Surface modification of g-Al2O3 by sodium ions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    1H/23Na double resonance NMR techniques were employed to study the modification of surface hydroxyls on g-Al2O3 by sodium ions. 1H→23Na cross polarization (CP) experiment can resolve three kinds of sodium cations that are closely associated with surface hydroxyl groups, while the signal of deposited salt-Na2CO3, which is not connected to surface hydroxyl groups, is completely suppressed. 1H{23Na} spin echo double resonance experiments reveal the surface modification in more detail. At low Na+ coverage (5%, 10%), the acidic hydroxyl groups are preferentially coordinated with sodium ions, while both the acidic and the basic hydroxyl groups are accessible for sodium ions at high coordination that causes proton of the OH groups to be easily dissolved, which is evidenced by the fact that with calcination temperature of the catalysts increasing, the acidic hydroxyl groups are preferentially removed and only the basic hydroxyl groups remain when the calcination temperature is raised to 600℃.

  5. Cerebrospinal fluid sodium rhythms

    Directory of Open Access Journals (Sweden)

    Johnson Benjamin

    2010-01-01

    Full Text Available Abstract Background Cerebrospinal fluid (CSF sodium levels have been reported to rise during episodic migraine. Since migraine frequently starts in early morning or late afternoon, we hypothesized that natural sodium chronobiology may predispose susceptible persons when extracellular CSF sodium increases. Since no mammalian brain sodium rhythms are known, we designed a study of healthy humans to test if cation rhythms exist in CSF. Methods Lumbar CSF was collected every ten minutes at 0.1 mL/min for 24 h from six healthy participants. CSF sodium and potassium concentrations were measured by ion chromatography, total protein by fluorescent spectrometry, and osmolarity by freezing point depression. We analyzed cation and protein distributions over the 24 h period and spectral and permutation tests to identify significant rhythms. We applied the False Discovery Rate method to adjust significance levels for multiple tests and Spearman correlations to compare sodium fluctuations with potassium, protein, and osmolarity. Results The distribution of sodium varied much more than potassium, and there were statistically significant rhythms at 12 and 1.65 h periods. Curve fitting to the average time course of the mean sodium of all six subjects revealed the lowest sodium levels at 03.20 h and highest at 08.00 h, a second nadir at 09.50 h and a second peak at 18.10 h. Sodium levels were not correlated with potassium or protein concentration, or with osmolarity. Conclusion These CSF rhythms are the first reports of sodium chronobiology in the human nervous system. The results are consistent with our hypothesis that rising levels of extracellular sodium may contribute to the timing of migraine onset. The physiological importance of sodium in the nervous system suggests that these rhythms may have additional repercussions on ultradian functions.

  6. 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.

  7. Nanogel and superparamagnetic nanocomposite based on sodium alginate for sorption of heavy metal ions.

    Science.gov (United States)

    Lakouraj, Moslem Mansour; Mojerlou, Fatemeh; Zare, Ehsan Nazarzadeh

    2014-06-15

    Novel sodium alginate supported tetrasodium thiacalix[4]arene tetrasulfonate (TSTC[4]AS-s-SA) nanogel was prepared using sodium alginate nanoparticles. Then, superparamagnetic nanocomposite of sodium alginate (Fe3O4@TSTC[4]AS-s-SA) was fabricated from coprecipitation of sodium alginate supported tetrasodium thiacalix[4]arene tetrasulfonate and in situ generated Fe3O4 nanoparticles. Structural, morphological, surface, thermal and magnetic properties of the nanoadsorbents were studied by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM), respectively. Adsorptions of Cu(II), Cd(II), Pb(II), Co(II), Ni(II) and Cr(III) ions onto nanoadsorbents were studied in aqueous condition at pH=7. The results indicated that incorporation of thiacalix[4]arene tetrasulfonate and Fe3O4 into sodium alginate nanoparticles increased the adsorption capacity of sodium alginate bioadsorbents, and led to the magnetic property. The TSTC[4]AS-s-SA nanogels consist of rod-like structure with an average diameter of 50 nm. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Selective separation of sodium ions from a mixture with phenylalanine by Donnan dialysis with a profiled sulfogroup cation exchange membrane

    Science.gov (United States)

    Vasil'eva, V. I.; Goleva, E. A.

    2013-11-01

    The possibility of separating ions of metal from a mixture with ampholyte (an amino acid) by Donnan dialysis with an MK-40 sulfogroup cation exchange membrane is demonstrated. Conditions ensuring the selectivity and intensity of the mass transfer of sodium ions from a mixture with bipolar phenylalanine ions into a diffusate containing hydrochloric acid through a cation exchange membrane are found.

  9. Determination of Trace Iodide in Sodium Bisulfite Aqueous Solution by Ion Chromatography with UV Detection

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y.S.; Kim, D.Y.; Choi, K.S.; Park, S.D.; Han, S.H. [Korea Atomic Energy Research Institute, Taejon (Korea)

    2000-06-01

    The iodide was recovered from a simulated spent fuel to the sodium bisulfite aqueous solution. It was discussed that the trace iodide (below 1 ppm) was determined without the matrix effect of 0.1 M sodium bisulfite and 1 mM HNO{sub 3} in aqueous solution by ion chromatography with UV detection. AS4A-SC(DIONEX) column and UV-absorption spectrophotometer were used. The UV-absorption spectra of sodium bisulfite nitric acid and iodide were obtained, and then 230 nm was selected as an absorption wavelength for iodide determination. 0.1 M NaCl eluent was optimum condition. In this condition the calibration curve of iodide was obtained on the range of about 0-1,000 ppb. The linear coefficient was 0.99993 and the detection limit was 5 ppb. The relative standard deviation was 1.26%. (author). 17 refs., 3 tabs., 4 figs.

  10. Shock Tube Studies on Recombination Kinetics of Sodium Ion with Electron

    Institute of Scientific and Technical Information of China (English)

    WANG Su; CUI Ji-Ping; HE Yu-Zhong; FAN Bing-Cheng; WANG Jing

    2001-01-01

    The ionization kinetics of sodium diluted in argon is studied in a shock tube, in which the test gas mixture is ionized by a reflected shock wave and subsequently quenched by a strong rarefaction wave. A Langmuir electrostatic probe is used to monitor the variation of the ion number density at the reflection shock wave region. The working state of the probe is in the near free fall region and a correction for reduction of the probe current due to elastic scattering in the probe sheath is introduced. At the temperature range of 800 to 2600K and in the ambience of argon gas, the three-body recombination rate coefficient of the sodium ion with electron is determined: 3.43 × l0-14T-3.77 cm6.s-1.

  11. Multilayered Electride Ca2N Electrode via Compression Molding Fabrication for Sodium Ion Batteries.

    Science.gov (United States)

    Chen, Guanghai; Bai, Ying; Li, Hui; Li, Yu; Wang, Zhaohua; Ni, Qiao; Liu, Lu; Wu, Feng; Yao, Yugui; Wu, Chuan

    2017-03-01

    Pursuing for novel electrode materials is significant for the progress of sodium ion batteries (SIBs). Here, a multilayered electride prepared by simple thermal decomposition of solid Ca3N2, namely Ca2N, is introduced as a new anode material of SIBs for the first time, and a compression molding electrode fabricated by pressing Ca2N powder into nickel foam is applied to protect Ca2N from trace moisture and oxygen. The as-prepared electrode delivers an initial discharge capacity of 1110.5 mAh g(-1) and a reversible discharge capacity of ∼320 mAh g(-1). These results suggest that Ca2N has a great potential for sodium ion batteries.

  12. Electrical and electrochemical studies on sodium ion-based gel polymer electrolytes

    Science.gov (United States)

    Isa, K. B. Md; Othman, L.; Hambali, D.; Osman, Z.

    2017-09-01

    Gel polymer electrolytes (GPEs) have captured great attention because of their unique properties such as good mechanical stability, high flexibility and high conductivity approachable to that of the liquid electrolytes. In this work, we have prepared sodium ion conducting gel polymer electrolyte (GPE) films consisting of polyvinylidenefluoride-co-hexafluoropropylene (PVdF-HFP) as a polymer host using the solution casting technique. Sodium trifluoromethane- sulfonate (NaCF3SO3) was used as an ionic salt and the mixture of ethylene carbonate (EC) and propylene carbonate (PC) as a plasticizing solvent. Impedance spectroscopy measurements were carried out to determine the ionic conductivity of the GPE films. The sample containing 20 wt.% of NaCF3SO3 salt exhibits the highest room temperature ionic conductivity of 2.50 × 10-3 S cm-1. The conductivity of the GPE films was found to depend on the salt concentration that added to the films. The ionic and cationic transference numbers of GPE films were estimated by DC polarization and the combination of AC and DC polarization method, respectively. The results had shown that both ionic and cationic transference numbers are consistent with the conductivity studies. The electrochemical stability of the GPE films was tested using linear sweep voltammetry (LSV) and the value of working voltage range appears to be high enough to be used as an electrolyte in sodium batteries. The cyclic voltammetry (CV) studies confirmed the sodium ion conduction in the GPE films.

  13. Alloy-Based Anode Materials toward Advanced Sodium-Ion Batteries.

    Science.gov (United States)

    Lao, Mengmeng; Zhang, Yu; Luo, Wenbin; Yan, Qingyu; Sun, Wenping; Dou, Shi Xue

    2017-06-28

    Sodium-ion batteries (SIBs) are considered as promising alternatives to lithium-ion batteries owing to the abundant sodium resources. However, the limited energy density, moderate cycling life, and immature manufacture technology of SIBs are the major challenges hindering their practical application. Recently, numerous efforts are devoted to developing novel electrode materials with high specific capacities and long durability. In comparison with carbonaceous materials (e.g., hard carbon), partial Group IVA and VA elements, such as Sn, Sb, and P, possess high theoretical specific capacities for sodium storage based on the alloying reaction mechanism, demonstrating great potential for high-energy SIBs. In this review, the recent research progress of alloy-type anodes and their compounds for sodium storage is summarized. Specific efforts to enhance the electrochemical performance of the alloy-based anode materials are discussed, and the challenges and perspectives regarding these anode materials are proposed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Na3Ti2(PO4)(3) as a sodium-bearing anode for rechargeable aqueous sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z; Ravnsbaek, DB; Xiang, K; Chiang, YM

    2014-07-01

    Na3Ti2(PO4)(3) synthesized as fine carbon-coated powders is demonstrated for the first time to be a suitable sodium-bearing anode material for rechargeable aqueous sodium-ion batteries (ANaBs). Importantly, Na3Ti2(PO4)(3) is found to be stable in deoxygenated water, enabling use of this material in aqueous systems. As a sodiated anode, it allows use of sodium-depleted cathode materials that require supply of sodium-ions from the anode. As an example, we demonstrate for the first time the use of olivine FePO4 as a cathode in an ANaB. (C) 2014 Elsevier B.V. All rights reserved.

  15. The mutual co-regulation of extracellular polymeric substances and iron ions in biocorrosion of cast iron pipes.

    Science.gov (United States)

    Jin, Juntao; Guan, Yuntao

    2014-10-01

    New insights into the biocorrosion process may be gained through understanding of the interaction between extracellular polymeric substances (EPS) and iron. Herein, the effect of iron ions on the formation of biofilms and production of EPS was investigated. Additionally, the impact of EPS on the corrosion of cast iron coupons was explored. The results showed that a moderate concentration of iron ions (0.06 mg/L) promoted both biofilm formation and EPS production. The presence of EPS accelerated corrosion during the initial stage, while inhibited corrosion at the later stage. The functional groups of EPS acted as electron shuttles to enable the binding of iron ions. Binding of iron ions with EPS led to anodic dissolution and promoted corrosion, while corrosion was later inhibited through oxygen reduction and availability of phosphorus from EPS. The presence of EPS also led to changes in crystalline phases of corrosion products.

  16. Tire-derived carbon composite anodes for sodium-ion batteries

    Science.gov (United States)

    Li, Yunchao; Paranthaman, M. Parans; Akato, Kokouvi; Naskar, Amit K.; Levine, Alan M.; Lee, Richard J.; Kim, Sang-Ok; Zhang, Jinshui; Dai, Sheng; Manthiram, Arumugam

    2016-06-01

    Hard-carbon materials are considered as one of the most promising anodes for the emerging sodium-ion batteries. Here, we report a low-cost, scalable waste tire-derived carbon as an anode for sodium-ion batteries (SIBs). Tire-derived carbons obtained by pyrolyzing acid-treated tire at 1100 °C, 1400 °C and 1600 °C show capacities of 179, 185 and 203 mAh g-1, respectively, after 100 cycles at a current density of 20 mA g-1 in sodium-ion batteries with good electrochemical stability. The portion of the low-voltage plateau region in the charge-discharge curves increases as the heat-treatment temperature increases. The low-voltage plateau is beneficial to enhance the energy density of the full cell. This study provides a new pathway for inexpensive, environmentally benign and value-added waste tire-derived products towards large-scale energy storage applications.

  17. Challenges and Perspectives for NASICON-Type Electrode Materials for Advanced Sodium-Ion Batteries.

    Science.gov (United States)

    Chen, Shuangqiang; Wu, Chao; Shen, Laifa; Zhu, Changbao; Huang, Yuanye; Xi, Kai; Maier, Joachim; Yu, Yan

    2017-06-19

    Sodium-ion batteries (SIBs) have attracted increasing attention in the past decades, because of high overall abundance of precursors, their even geographical distribution, and low cost. Apart from inherent thermodynamic disadvantages, SIBs have to overcome multiple kinetic problems, such as fast capacity decay, low rate capacities and low Coulombic efficiencies. A special case is sodium super ion conductor (NASICON)-based electrode materials as they exhibit - besides pronounced structural stability - exceptionally high ion conductivity, rendering them most promising for sodium storage. Owing to the limiting, comparatively low electronic conductivity, nano-structuring is a prerequisite for achieving satisfactory rate-capability. In this review, we analyze advantages and disadvantages of NASICON-type electrode materials and highlight electrode structure design principles for obtaining the desired electrochemical performance. Moreover, we give an overview of recent approaches to enhance electrical conductivity and structural stability of cathode and anode materials based on NASICON structure. We believe that this review provides a pertinent insight into relevant design principles and inspires further research in this respect. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Recent Progress in Design of Biomass-Derived Hard Carbons for Sodium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Joanna Górka

    2016-12-01

    Full Text Available Sodium ion batteries (SIBs have attracted lots of attention over last few years due to the abundance and wide availability of sodium resources, making SIBs the most cost-effective alternative to the currently used lithium ion batteries (LIBs. Many efforts are underway to find effective anodes for SIBs since the commercial anode for LIBs, graphite, has shown very limited capacity for SIBs. Among many different types of carbons, hard carbons—especially these derived from biomass—hold a great deal of promise for SIB technology thanks to their constantly improving performance and low cost. The main scope of this mini-review is to present current progress in preparation of negative electrodes from biomass including aspects related to precursor types used and their impact on the final carbon characteristics (structure, texture and composition. Another aspect discussed is how certain macro- and microstructure characteristics of the materials translate to their performance as anode for Na-ion batteries. In the last part, current understanding of factors governing sodium insertion into hard carbons is summarized, specifically those that could help solve existing performance bottlenecks such as irreversible capacity, initial low Coulombic efficiency and poor rate performance.

  19. Carbon Quantum Dots and Their Derivative 3D Porous Carbon Frameworks for Sodium-Ion Batteries with Ultralong Cycle Life.

    Science.gov (United States)

    Hou, Hongshuai; Banks, Craig E; Jing, Mingjun; Zhang, Yan; Ji, Xiaobo

    2015-12-16

    A new methodology for the synthesis of carbon quantum dots (CQDs) for large production is proposed. The as-obtained CQDs can be transformed into 3D porous carbon frameworks exhibiting superb sodium storage properties with ultralong cycle life and ultrahigh rate capability, comparable to state-of-the-art carbon anode materials for sodium-ion batteries.

  20. Characterization of Electrode Materials for Lithium Ion and Sodium Ion Batteries using Synchrotron Radiation Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, Apurva; Stanford Synchrotron Radiation Lightsource; Doeff, Marca M.; Chen, Guoying; Cabana, Jordi; Richardson, Thomas J.; Mehta, Apurva; Shirpour, Mona; Duncan, Hugues; Kim, Chunjoong; Kam, Kinson C.; Conry, Thomas

    2013-04-30

    We describe the use of synchrotron X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) techniques to probe details of intercalation/deintercalation processes in electrode materials for Li ion and Na ion batteries. Both in situ and ex situ experiments are used to understand structural behavior relevant to the operation of devices.

  1. Reduction of microbial pathogens during apple cider production using sodium hypochlorite, copper ion, and sonication.

    Science.gov (United States)

    Rodgers, Stephanie L; Ryser, Elliot T

    2004-04-01

    Sodium hypochlorite (100 ppm), copper ion water (1 ppm), and sonication (22 to 44 kHz and 44 to 48 kHz) were assessed individually and in combination for their ability to reduce populations of Escherichia coli O157:H7 and Listeria monocytogenes on apples and in apple cider. Commercial unpasteurized cider was inoculated to contain approximately 10(6) CFU/ml of either pathogen and then sonicated at 44 to 48 kHz, with aliquots removed at intervals of 30 to 60 s for up to 5 min and plated to determine numbers of survivors. Subsequently, whole apples were inoculated by dipping to contain approximately 10(6) CFU/g E. coli O157:H7 or L. monocytogenes, held overnight, and then submerged in 1 ppm copper ion water with or without 100 ppm sodium hypochlorite for 3 min with or without sonication at 22 to 44 kHz and examined for survivors. Treated apples were also juiced, with the resulting cider sonicated for 3 min. Populations of both pathogens decreased 1 to 2 log CFU/ml in inoculated cider following 3 min of sonication. Copper ion water alone did not significantly reduce populations of either pathogen on inoculated apples. However, when used in combination with sodium hypochlorite, pathogen levels decreased approximately 2.3 log CFU/g on apples. Sonication of this copper ion-sodium hypochlorite solution at 22 to 44 kHz did not further improve pathogen reduction on apples. Numbers of either pathogen in the juice fraction were approximately 1.2 log CFU/ml lower after being juiced, with sonication (44 to 48 kHz) of the expressed juice decreasing L. monocytogenes and E. coli O157:H7 populations an additional 2 log. Hence, a 5-log reduction was achievable for both pathogens with the use of copper ion water in combination with sodium hypochlorite followed by juicing and sonication at 44 to 48 kHz.

  2. Giant extracellular Glossoscolex paulistus Hemoglobin (HbGp) upon interaction with cethyltrimethylammonium chloride (CTAC) and sodium dodecyl sulphate (SDS) surfactants: Dissociation of oligomeric structure and autoxidation.

    Science.gov (United States)

    Santiago, Patricia S; Moreira, Leonardo M; de Almeida, Erika V; Tabak, Marcel

    2007-04-01

    The effects of two ionic surfactants on the oligomeric structure of the giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) in the oxy - form have been studied through the use of several spectroscopic techniques such as electronic optical absorption, fluorescence emission, light scattering, and circular dichroism. The use of anionic sodium dodecyl sulphate (SDS) and cationic cethyltrimethyl ammonium chloride (CTAC) has allowed to differentiate the effects of opposite headgroup charges on the oligomeric structure dissociation and hemoglobin autoxidation. At pH 7.0, both surfactants induce the protein dissociation and a significant oxidation. Spectral changes occur at very low CTAC concentrations suggesting a significant electrostatic contribution to the protein-surfactant interaction. At low protein concentration, 0.08 mg/ml, some light scattering within a narrow CTAC concentration range occurs due to protein-surfactant precipitation. Light scattering experiments showed the dissociation of the oligomeric structure by SDS and CTAC, and the effect of precipitation induced by CTAC. At higher protein concentrations, 3.0 mg/ml, a precipitation was observed due to the intense charge neutralization upon formation of ion pair in the protein-surfactant precipitate. The spectral changes are spread over a much wider SDS concentration range, implying a smaller electrostatic contribution to the protein-surfactant interactions. The observed effects are consistent with the acid isoelectric point (pI) of this class of hemoglobins, which favors the intense interaction of HbGp with the cationic surfactant due to the existence of excess acid anionic residues at the protein surface. Protein secondary structure changes are significant for CTAC at low concentrations while they occur at significantly higher concentrations for SDS. In summary, the cationic surfactant seems to interact more strongly with the protein producing more dramatic spectral changes as compared to the

  3. Desalination and hydrogen, chlorine, and sodium hydroxide production via electrophoretic ion exchange and precipitation.

    Science.gov (United States)

    Shkolnikov, Viktor; Bahga, Supreet S; Santiago, Juan G

    2012-08-28

    We demonstrate and analyze a novel desalination method which works by electrophoretically replacing sodium and chloride in feed salt water with a pair of ions, calcium and carbonate, that react and precipitate out. The resulting calcium carbonate precipitate is benign to health, and can be filtered or settled out, yielding low ionic strength product water. The ion exchange and precipitation employs self-sharpening interfaces induced by movement of multiple ions in an electric field to prevent contamination of the product water. Simultaneously, the electrolysis associated with the electromigration produces hydrogen gas, chlorine gas, and sodium hydroxide. We conducted an experimental study of this method's basic efficacy to desalinate salt water from 100 to 600 mol m(-3) sodium chloride. We also present physicochemical models of the process, and analyze replacement reagents consumption, permeate recovery ratio, and energy consumption. We hypothesize that the precipitate can be recycled back to replacement reagents using the well-known, commercially implemented Solvay process. We show that the method's permeate recovery ratio is 58% to 46%, which is on par with that of reverse osmosis. We show that the method's energy consumption requirement over and above that necessary to generate electrolysis is 3 to 10 W h l(-1), which is on par with the energy consumed by state-of-the-art desalination methods. Furthermore, the method operates at ambient temperature and pressure, and uses no specialized membranes. The process may be feasible as a part of a desalination-co-generation facility: generating fresh water, hydrogen and chlorine gas, and sodium hydroxide.

  4. Comparison of reduction products from graphite oxide and graphene oxide for anode applications in lithium-ion batteries and sodium-ion batteries.

    Science.gov (United States)

    Sun, Yige; Tang, Jie; Zhang, Kun; Yuan, Jinshi; Li, Jing; Zhu, Da-Ming; Ozawa, Kiyoshi; Qin, Lu-Chang

    2017-02-16

    Hydrazine-reduced graphite oxide and graphene oxide were synthesized to compare their performances as anode materials in lithium-ion batteries and sodium-ion batteries. Reduced graphite oxide inherits the layer structure of graphite, with an average spacing between neighboring layers (d-spacing) of 0.374 nm; this exceeds the d-spacing of graphite (0.335 nm). The larger d-spacing provides wider channels for transporting lithium ions and sodium ions in the material. We showed that reduced graphite oxide as an anode in lithium-ion batteries can reach a specific capacity of 917 mA h g(-1), which is about three times of 372 mA h g(-1), the value expected for the LiC6 structures on the electrode. This increase is consistent with the wider d-spacing, which enhances lithium intercalation and de-intercalation on the electrodes. The electrochemical performance of the lithium-ion batteries and sodium-ion batteries with reduced graphite oxide anodes show a noticeable improvement compared to those with reduced graphene oxide anodes. This improvement indicates that reduced graphite oxide, with larger interlayer spacing, has fewer defects and is thus more stable. In summary, we found that reduced graphite oxide may be a more favorable form of graphene for the fabrication of electrodes for lithium-ion and sodium-ion batteries and other energy storage devices.

  5. Two-dimensional layered compound based anode materials for lithium-ion batteries and sodium-ion batteries.

    Science.gov (United States)

    Xie, Xiuqiang; Wang, Shijian; Kretschmer, Katja; Wang, Guoxiu

    2017-03-20

    Rechargeable batteries, such as lithium-ion and sodium-ion batteries, have been considered as promising energy conversion and storage devices with applications ranging from small portable electronics, medium-sized power sources for electromobility, to large-scale grid energy storage systems. Wide implementations of these rechargeable batteries require the development of electrode materials that can provide higher storage capacities than current commercial battery systems. Within this greater context, this review will present recent progresses in the development of the 2D material as anode materials for battery applications represented by studies conducted on graphene, molybdenum disulfide, and MXenes. This review will also discuss remaining challenges and future perspectives of 2D materials in regards to a full utilization of their unique properties and interactions with other battery components.

  6. SnSe2 Two Dimensional Anodes for Advanced Sodium Ion Batteries

    KAUST Repository

    Zhang, Fan

    2017-05-30

    Sodium-ion batteries (SIBs) are considered as a promising alternative to lithium-ion batteries (LIBs) for large-scale renewable energy storage units due to the abundance of sodium resource and its low cost. However, the development of anode materials for SIBs to date has been mainly limited to some traditional anodes for LIBs, such as carbonaceous materials. SnSe2 is a member of two dimensional layered transition metal dichalcogenide (TMD) family, which has been predicted to have high theoretical capacity as anode material for sodium ion batteries (756 mAh g-1), thanks to its layered crystal structure. Yet, there have been no studies on using SnSe2 as Na ion battery anode. In this thesis, we developed a simple synthesis method to prepare pure SnSe2 nanosheets, employing N2 saturated NaHSe solution as a new selenium source. The SnSe2 2D sheets achieve theoretical capacity during the first cycle, and a stable and reversible specific capacity of 515 mAh g-1 at 0.1 A g-1 after 100 cycles, with excellent rate performance. Among all of the reported transition metal selenides, our SnSe2 sample has the highest reversible capacity and the best rate performances. A combination of ex-situ high resolution transmission electron microscopy (HRTEM) and X-ray diffraction was used to study the mechanism of sodiation and desodiation process in this SnSe2, and to understand the reason for the excellent results that we have obtained. The analysis indicate that a combination of conversion and alloying reactions take place with SnSe2 anodes during battery operation, which helps to explain the high capacity of SnSe2 anodes for SIBs compared to other binary selenides. Density functional theory was used to elucidate the volume changes taking place in this important 2D material.

  7. Evolutions of Molecular Oxygen Formation and Sodium Migration in Xe Ion Irradiated Borosilicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liang; Zhang, Duofei F.; Lv, Peng; Zhang, Jiandong; Du, Xing; Yuan, Wei; Nan, Shuai; Zhu, Zihua; Wang, Tieshan

    2016-07-23

    The modifications of a commercial borosilicate glass induced by Xe ion irradiation have been studied by Raman spectroscopy and ToF-SIMS depth profiling. A decrease in the average Si–O–Si angle, an increase in the population of three-membered rings and an increase of the glass polymerization are evidenced. The molecular oxygen appears in the irradiated glasses after the irradiation fluence reaches approximately 1015 ions/cm2. The O2 concentration decreaseswith the depth of irradiated glass at the ion fluence of 2 × 1016 ions/cm2. A sodiumdepleted layer at the surface and a depleted zone at around the penetration depth of 5 MeV Xe ions are observed. The thickness of the sodium depleted layer increases with the irradiation fluence. Moreover, comparing with previous results after electron and Ar ion irradiation, it can be concluded that the nuclear energy deposition can partially inhibit the formation of molecular oxygen and increase the threshold value of electron energy deposition for the molecular oxygen formation.

  8. Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes.

    Science.gov (United States)

    Licht, Stuart; Douglas, Anna; Ren, Jiawen; Carter, Rachel; Lefler, Matthew; Pint, Cary L

    2016-03-23

    The cost and practicality of greenhouse gas removal processes, which are critical for environmental sustainability, pivot on high-value secondary applications derived from carbon capture and conversion techniques. Using the solar thermal electrochemical process (STEP), ambient CO2 captured in molten lithiated carbonates leads to the production of carbon nanofibers (CNFs) and carbon nanotubes (CNTs) at high yield through electrolysis using inexpensive steel electrodes. These low-cost CO2-derived CNTs and CNFs are demonstrated as high performance energy storage materials in both lithium-ion and sodium-ion batteries. Owing to synthetic control of sp(3) content in the synthesized nanostructures, optimized storage capacities are measured over 370 mAh g(-1) (lithium) and 130 mAh g(-1) (sodium) with no capacity fade under durability tests up to 200 and 600 cycles, respectively. This work demonstrates that ambient CO2, considered as an environmental pollutant, can be attributed economic value in grid-scale and portable energy storage systems with STEP scale-up practicality in the context of combined cycle natural gas electric power generation.

  9. Electrochemical performance of fulvic acid-based electrospun hard carbon nanofibers as promising anodes for sodium-ion batteries

    Science.gov (United States)

    Zhao, Pin-Yi; Zhang, Jie; Li, Qi; Wang, Cheng-Yang

    2016-12-01

    The electrochemical performance of fulvic acid-based electrospun hard carbon nanofibers (PF-CNFs) as anodes for sodium-ion batteries is reported. PF-CNFs were prepared, stabilization in air at 280 °C and then carbonized in N2 at 800, 1000, 1300 or 1500 °C. The PF-CNFs prepared at 1300 °C had abundant oxygen functional groups, large interlayer spaces and stable morphologies and when used as anodes in sodium-ion batteries, a reversible sodium intercalation capacity of 248 mAh g-1 was obtained with capacity retention ratio of 91% after 100 cycles at a current density of 100 mA g-1. This large capacity combined with the superior cycling performance indicates that fulvic acid-based carbon nanofibers are promising electrode materials for use in rechargeable sodium-ion batteries.

  10. Ionic liquid electrolytes with high sodium ion fraction for high-rate and long-life sodium secondary batteries

    Science.gov (United States)

    Chen, Chih-Yao; Kiko, Tomohiro; Hosokawa, Takafumi; Matsumoto, Kazuhiko; Nohira, Toshiyuki; Hagiwara, Rika

    2016-11-01

    Sodium secondary batteries are attracting considerably renewed interest as new battery systems owing to the high and uniform abundance and cost advantages of Na. However, their performance is still far from optimal as compared to the well-developed Li-ion technology. Herein, Na secondary batteries with unprecedented rate capability and a long life has been achieved by using a highly concentrated bis(fluorosulfonyl)amide anion (FSA-)-based ionic liquid electrolyte (3.3 mol dm-3 Na[FSA]) and a Na2FeP2O7 positive electrode, in a targeted operating temperature range from room to intermediate. Nearly full discharge capacity is obtained at 4000 mA g-1, and 79% of the capacity is retained at a discharge rate as high as 20000 mA g-1 at 363 K. Stable cycling (>300 cycles) with satisfactory coulombic efficiency (>99.5%) is found at an intermediate rate (100 mA g-1) over 298-363 K. A high-rate cycling test (1000 mA g-1) at 363 K reveals that the cell could retain 93% of its initial capacity after 1500 cycles.

  11. PSP toxin release from the cyanobacterium Raphidiopsis brookii D9 (Nostocales) can be induced by sodium and potassium ions.

    Science.gov (United States)

    Soto-Liebe, Katia; Méndez, Marco A; Fuenzalida, Loreto; Krock, Bernd; Cembella, Allan; Vásquez, Mónica

    2012-12-01

    Paralytic shellfish poisoning (PSP) toxins are a group of naturally occurring neurotoxic alkaloids produced among several genera of primarily freshwater cyanobacteria and marine dinoflagellates. Although saxitoxin (STX) and analogs are all potent Na(+) channel blockers in vertebrate cells, the functional role of these compounds for the toxigenic microorganisms is unknown. Based upon the known importance of monovalent cations (such as sodium) in the maintenance of cellular homeostasis and ion channel function, we examined the effect of high extracellular concentrations of these ions on growth, cellular integrity, toxin production and release to the external medium in the filamentous freshwater cyanobacterium, Raphidiopsis brookii D9; a gonyautoxins (GTX2/3) and STX producing toxigenic strain. We observed a toxin export in response to high (17 mM) NaCl and KCl concentrations in the growth medium that was not primarily related to osmotic stress effects, compared to the osmolyte mannitol. Addition of exogenous PSP toxins with the same compositional profile as the one produced by R. brookii D9 was able to partially mitigate this effect of high Na⁺ (17 mM). The PSP toxin biosynthetic gene cluster (sxt) in D9 has two genes (sxtF and sxtM) that encode for a MATE (multidrug and toxic compound extrusion) transporter. This protein family, represented by NorM in the bacterium Vibrio parahaemolyticus, confers resistance to multiple cationic toxic agents through Na⁺/drug antiporters. Conserved domains for Na⁺ and drug recognition have been described in NorM. For the D9 sxt cluster, the Na⁺ recognition domain is conserved in both SxtF and SxtM, but the drug recognition domain differs between them. These results suggest that PSP toxins are exported directly in response to the presence of monovalent cations (Na⁺, K⁺) at least at elevated concentrations. Thus, the presence of both genes in the sxt cluster from strain D9 can be explained as a selective recognition

  12. Reversible Sodium Ion Insertion in Single Crystalline Manganese Oxide Nanowires with Long Cycle Life

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yuliang; Xiao, Lifen; Wang, Wei; Choi, Daiwon; Nie, Zimin; Yu, Jianguo; Saraf, Laxmikant V.; Yang, Zhenguo; Liu, Jun

    2011-07-26

    Single crystalline Na4Mn9O18 nanowires were synthesized via pyrolysis of polyacrylate salt precursors prepared by in-situ polymerization of the metal salts and acrylate acid, followed by calcinations at an appropriate temperature to achieve good crystalline structure and uniform nanowire morphology with an average diameter of 50 nm. The Na4Mn9O18 nanowires have shown a high, reversible, and near theoretical sodium ion insertion capacity (128 mA h g-1 at 0.1C), excellent long cyclability (77% capacity retention for 1000 cycles at 0.5 C), along with good rate capability. Good capacity and charge-discharge stability are also observed for full cell experiments using a pyrolyzed carbon as the anode, therefore demonstrating the potential of these materials for sodium-ion batteries for large scale energy storage. Furthermore, this research shows that a good crystallinity and small particles are required to enhance the Na-ion diffusion and increase the stability of the electrode materials for long charge-discharge cycles.

  13. High extracellular potassium ion concentration attenuates the blockade action of ketanserin on Kvl.3 channels expressed in xenopus oocytes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Background Ketanserin (KT), a selective serotonin (5-HT) 2-receptor antagonist, reduces peripheral blood pressure by blocking the activation of peripheral 5-HT receptors. In this study electrophysiological method was used to investigate the effect of KT and potassium ion on Kv1.3 potassium channels and explore the role of blocker KT in the alteration of channel kinetics contributing to the potassium ion imbalances. Methods Kvl.3 channels were expressed in xenopus oocytes, and currents were measured using the two-microelectrode voltage-clamp technique. Results KCI made a left shift of activation and an inactivation curve of Kv1.3 current and accelerated the activation and inactivation time constant. High extracellular [K+] attenuated the blockade effect of KT on Kv1.3 channels. In the presence of KT and KCI the activation and inactivation time constants were not influenced significantly no matter what was administered first. KT did not significantly inhibit Kv1.3 current induced by tetraethylammonium (TEA). Conclusions KT is a weak blocker of Kv1.3 channels at different concentrations of extracellular potassium and binds to the intracellular side of the channel pore. The inhibitor KT of ion channels is not fully effective in clinical use because of high [K+]o and other electrolyte disorders.

  14. NALCN ion channels have alternative selectivity filters resembling calcium channels or sodium channels.

    Directory of Open Access Journals (Sweden)

    Adriano Senatore

    Full Text Available NALCN is a member of the family of ion channels with four homologous, repeat domains that include voltage-gated calcium and sodium channels. NALCN is a highly conserved gene from simple, extant multicellular organisms without nervous systems such as sponges and placozoans and mostly remains a single gene compared to the calcium and sodium channels which diversified into twenty genes in humans. The single NALCN gene has alternatively-spliced exons at exons 15 or exon 31 that splices in novel selectivity filter residues that resemble calcium channels (EEEE or sodium channels (EKEE or EEKE. NALCN channels with alternative calcium, (EEEE and sodium, (EKEE or EEKE -selective pores are conserved in simple bilaterally symmetrical animals like flatworms to non-chordate deuterostomes. The single NALCN gene is limited as a sodium channel with a lysine (K-containing pore in vertebrates, but originally NALCN was a calcium-like channel, and evolved to operate as both a calcium channel and sodium channel for different roles in many invertebrates. Expression patterns of NALCN-EKEE in pond snail, Lymnaea stagnalis suggest roles for NALCN in secretion, with an abundant expression in brain, and an up-regulation in secretory organs of sexually-mature adults such as albumen gland and prostate. NALCN-EEEE is equally abundant as NALCN-EKEE in snails, but is greater expressed in heart and other muscle tissue, and 50% less expressed in the brain than NALCN-EKEE. Transfected snail NALCN-EEEE and NALCN-EKEE channel isoforms express in HEK-293T cells. We were not able to distinguish potential NALCN currents from background, non-selective leak conductances in HEK293T cells. Native leak currents without expressing NALCN genes in HEK-293T cells are NMDG(+ impermeant and blockable with 10 µM Gd(3+ ions and are indistinguishable from the hallmark currents ascribed to mammalian NALCN currents expressed in vitro by Lu et al. in Cell. 2007 Apr 20;129(2:371-83.

  15. Immediate response of Ca2+ concentration in myocardial cells against oxidation stress by extracellular photosensitization reaction using Talaporfin sodium for the arrhythmia treatment application

    Science.gov (United States)

    Ogawa, Emiyu; Takahashi, Mei; Ito, Arisa; Arai, Tsunenori

    2014-02-01

    We studied the immediate response of myocardial cells by continuous observation using confocal microscope against oxidation stress by extracellular photosensitization reaction using Talaporfin sodium for tachyarrhythmia treatment application. Immediate response in order from several seconds to several minutes is required for the arrhythmia treatment since operators should judge the therapeutic effect during the tachyarrhythmia ablation procedure. To understand the immediate response of myocardial cells, we measured the intracellular Ca2+ concentration using fluo-4 AM during and after the extracellular photosensitization reaction. Talaporfin sodium concentration was varied 10-30 μg/ml. A red diode laser of 663 nm in wavelength was irradiated under the microscope with the radiant exposure of 40 J/cm2 and irradiance of 0.29 W/cm2. We observed the fluorescence image of fluo-4 AM each 400 ms during until 10 min after the photosensitization reaction. The myocardial cell beatings were stopped about 2 s after the beginning of the laser irradiation. The blebs were formed with the Ca2+ inflow. The intracellular Ca2+ was re-decreased after the bleb formation and then the cell necrosis was induced. The cell lethality 10 min after the laser irradiation was less than bleb formation ratio. The time response of the cell necrosis was shortened with the photosensitizer concentration increasing and the minimum average value was 209 s in the case of the 30 μg/ml in photosensitizer concentration and 40 J/cm2 in the radiant exposure. We think this extracellular photosensitization reaction may be applicable to tachyarrhythmia treatment in terms of its immediate response.

  16. Extracellular Linkers Completely Transplant the Voltage Dependence from Kv1.2 Ion Channels to Kv2.1.

    Science.gov (United States)

    Elinder, Fredrik; Madeja, Michael; Zeberg, Hugo; Århem, Peter

    2016-10-18

    The transmembrane voltage needed to open different voltage-gated K (Kv) channels differs by up to 50 mV from each other. In this study we test the hypothesis that the channels' voltage dependences to a large extent are set by charged amino-acid residues of the extracellular linkers of the Kv channels, which electrostatically affect the charged amino-acid residues of the voltage sensor S4. Extracellular cations shift the conductance-versus-voltage curve, G(V), by interfering with these extracellular charges. We have explored these issues by analyzing the effects of the divalent strontium ion (Sr(2+)) on the voltage dependence of the G(V) curves of wild-type and chimeric Kv channels expressed in Xenopus oocytes, using the voltage-clamp technique. Out of seven Kv channels, Kv1.2 was found to be most sensitive to Sr(2+) (50 mM shifted G(V) by +21.7 mV), and Kv2.1 to be the least sensitive (+7.8 mV). Experiments on 25 chimeras, constructed from Kv1.2 and Kv2.1, showed that the large Sr(2+)-induced G(V) shift of Kv1.2 can be transferred to Kv2.1 by exchanging the extracellular linker between S3 and S4 (L3/4) in combination with either the extracellular linker between S5 and the pore (L5/P) or that between the pore and S6 (LP/6). The effects of the linker substitutions were nonadditive, suggesting specific structural interactions. The free energy of these interactions was ∼20 kJ/mol, suggesting involvement of hydrophobic interactions and/or hydrogen bonds. Using principles from double-layer theory we derived an approximate linear equation (relating the voltage shifts to altered ionic strength), which proved to well match experimental data, suggesting that Sr(2+) acts on these channels mainly by screening surface charges. Taken together, these results highlight the extracellular surface potential at the voltage sensor as an important determinant of the channels' voltage dependence, making the extracellular linkers essential targets for evolutionary selection.

  17. Mechanism of Ion Permeation in Mammalian Voltage-Gated Sodium Channels.

    Directory of Open Access Journals (Sweden)

    Somayeh Mahdavi

    Full Text Available Recent determination of the crystal structures of bacterial voltage-gated sodium (NaV channels have raised hopes that modeling of the mammalian counterparts could soon be achieved. However, there are substantial differences between the pore domains of the bacterial and mammalian NaV channels, which necessitates careful validation of mammalian homology models constructed from the bacterial NaV structures. Such a validated homology model for the NaV1.4 channel was constructed recently using the extensive mutagenesis data available for binding of μ-conotoxins. Here we use this NaV1.4 model to study the ion permeation mechanism in mammalian NaV channels. Linking of the DEKA residues in the selectivity filter with residues in the neighboring domains is found to be important for keeping the permeation pathway open. Molecular dynamics simulations and potential of mean force calculations reveal that there is a binding site for a Na+ ion just inside the DEKA locus, and 1-2 Na+ ions can occupy the vestibule near the EEDD ring. These sites are separated by a low free energy barrier, suggesting that inward conduction occurs when a Na+ ion in the vestibule goes over the free energy barrier and pushes the Na+ ion in the filter to the intracellular cavity, consistent with the classical knock-on mechanism. The NaV1.4 model also provides a good description of the observed Na+/K+ selectivity.

  18. Efficient Storing Energy Harvested by Triboelectric Nanogenerators Using a Safe and Durable All-Solid-State Sodium-Ion Battery.

    Science.gov (United States)

    Hou, Huidan; Xu, Qingkai; Pang, Yaokun; Li, Lei; Wang, Jiulin; Zhang, Chi; Sun, Chunwen

    2017-08-01

    Storing energy harvested by triboelectric nanogenerators (TENGs) from ambient mechanical motion is still a great challenge for achieving low-cost and environmental benign power sources. Here, an all-solid-state Na-ion battery with safe and durable performance used for efficient storing pulsed energy harvested by the TENG is demonstrated. The solid-state sodium-ion batteries are charged by galvanostatic mode and pulse mode with the TENG, respectively. The all-solid-state sodium-ion battery displays excellent cyclic performance up to 1000 cycles with a capacity retention of about 85% even at a high charge and discharge current density of 48 mA g(-1). When charged by the TENG, an energy conversion efficiency of 62.3% is demonstrated. The integration of TENGs with the safe and durable all-solid-state sodium-ion batteries is potential for providing more stable power output for self-powered systems.

  19. Na2Ti6O13 thin films as anode for thin film sodium ion batteries

    Science.gov (United States)

    Rambabu, A.; Kishore, B.; Munichandraiah, N.; Krupanidhi, S. B.; Barpanda, P.

    2017-05-01

    The pulsed laser deposition was employed to produce Na2Ti6O13 (NTO) thin films, which were applied as an anode material for Sodium-Ion batteries (SIBs). X-ray diffraction made it clear that the film is crystalline in single phase. Morphology and elemental composition studies were done using FESEM. Grain size and surface roughness was measured from atomic force microscopy. The electrochemical measurements were performed at 0.5 - 3V range and it exhibited the initial discharge capacity was 49.7 µAh/μm-cm2 with coulombic efficiency 69.8%.

  20. Microanalyses of the hydroxyl—poly—calcium sodium phosphate coatings produced by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    LIUZhong-Yang; WANGChang-Xing; 等

    2002-01-01

    Thin calcium phosphate catings on titanium alloy substrates were prepared by Ar+ ion beam assisted deposition(IBAD) from hydroxyl-poly-calcium sodium phosphate(HPPA) target.The coatings were analyzed by XRD,FTIR,XPS,These analyses revealed that the as-deposited films were amorphous or no apparent crystallinity.No distinct absorption band of the hydroxyl group was observed in FTIR spectra of the coatings but new absorption bands were presented for CO3-2,The calcium to phosphorous ratio of these catings in different IBAD conditions varied from 0.46 to 3.36.

  1. Flexible Electrodes for Sodium-Ion Batteries: Recent Progress and Perspectives.

    Science.gov (United States)

    Wang, Heng-Guo; Li, Wang; Liu, Da-Peng; Feng, Xi-Lan; Wang, Jin; Yang, Xiao-Yang; Zhang, Xin-Bo; Zhu, Yujie; Zhang, Yu

    2017-08-21

    Sodium-ion batteries (SIBs) are considered as promising alternatives to lithium-ion batteries (LIBs) for large-scale electrical-energy-storage applications due to the wide availability and the low cost of Na resources. Along with the avenues of research on flexible LIBs, flexible SIBs are now being actively developed as one of the most promising power sources for the emerging field of flexible and wearable electronic devices. Here, the recent progress on flexible electrodes based on metal substrates, carbonaceous substrates (i.e., graphene, carbon cloth, and carbon nanofibers), and other materials, as well as their applications in flexible SIBs, are summarized. Also, some future research directions for constructing flexible SIBs are proposed, with the aim of providing inspiration to the further development of advanced flexible SIBs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. A theoretical and experimental study of calcium, iron, zinc, cadmium, and sodium ions absorption by aspartame.

    Science.gov (United States)

    Mahnam, Karim; Raisi, Fatame

    2017-03-01

    Aspartame (L-Aspartyl-L-phenylalanine methyl ester) is a sweet dipeptide used in some foods and beverages. Experimental studies show that aspartame causes osteoporosis and some illnesses, which are similar to those of copper and calcium deficiency. This raises the issue that aspartame in food may interact with cations and excrete them from the body. This study aimed to study aspartame interaction with calcium, zinc, iron, sodium, and cadmium ions via molecular dynamics simulation (MD) and spectroscopy. Following a 480-ns molecular dynamics simulation, it became clear that the aspartame is able to sequester Fe(2+), Ca(2+), Cd(2+), and Zn(2+) ions for a long time. Complexation led to increasing UV-Vis absorption spectra and emission spectra of the complexes. This study suggests a potential risk of cationic absorption of aspartame. This study suggests that purification of cadmium-polluted water by aspartame needs a more general risk assessment.

  3. Energetics of ion competition in the DEKA selectivity filter of neuronal sodium channels

    Directory of Open Access Journals (Sweden)

    D. Boda

    2015-03-01

    Full Text Available The energetics of ionic selectivity in the neuronal sodium channels is studied. A simple model constructed for the selectivity filter of the channel is used. The selectivity filter of this channel type contains aspartate (D, glutamate (E, lysine (K, and alanine (A residues (the DEKA locus. We use Grand Canonical Monte Carlo simulations to compute equilibrium binding selectivity in the selectivity filter and to obtain various terms of the excess chemical potential from a particle insertion procedure based on Widom's method. We show that K+ ions in competition with Na+ are efficiently excluded from the selectivity filter due to entropic hard sphere exclusion. The dielectric constant of protein has no effect on this selectivity. Ca2+ ions, on the other hand, are excluded from the filter due to a free energetic penalty which is enhanced by the low dielectric constant of protein.

  4. Reduced Graphene Oxide/Tin-Antimony Nanocomposites as Anode Materials for Advanced Sodium-Ion Batteries.

    Science.gov (United States)

    Ji, Liwen; Zhou, Weidong; Chabot, Victor; Yu, Aiping; Xiao, Xingcheng

    2015-11-11

    Reduced graphene oxides loaded with tin-antimony alloy (RGO-SnSb) nanocomposites were synthesized through a hydrothermal reaction and the subsequent thermal reduction treatments. Transmission electron microscope images confirm that SnSb nanoparticles with an average size of about 20-30 nm are uniformly dispersed on the RGO surfaces. When they were used as anodes for rechargeable sodium (Na)-ion batteries, these as-synthesized RGO-SnSb nanocomposite anodes delivered a high initial reversible capacity of 407 mAh g(-1), stable cyclic retention for more than 80 cycles and excellent cycle stability at ultra high charge/discharge rates up to 30C. The significantly improved performance of the synthesized RGO-SnSb nanocomposites as Na-ion battery anodes can be attributed to the synergetic effects of RGO-based flexible framework and the nanoscale dimension of the SnSb alloy particles (batteries.

  5. In operando PXRD study P2-NaxTMO2 cycled in a sodium ion battery

    DEFF Research Database (Denmark)

    Birgisson, Steinar; Shen, Yanbin; Christiansen, Troels Lindahl;

    Sodium ion batteries (SIB) are being considered as a cheaper and more environmentally friendly alternative to lithium ion batteries (LIB). Application of SIB is especially important in large scale electricity storage from renewable energy sources [1]. A mayor hindrance of the development of SIB...... for practical applications is that so far there are no known electrode materials with sufficiently good rate and cycling capability. Studying structural changes of electrode materials while the battery is being charged and discharged is important to gain a deeper understanding of processes affecting...... the electrode materials. This understanding can be used to optimize battery performance and understand decay mechanisms, which in turn will facilitate the development of electrode materials fit for practical application in SIB. Our research group has developed an in operando battery cell capable of following...

  6. Beyond Conventional Cathode Materials for Lithium-ion Batteries and Sodium-ion Batteries Nickel fluoride conversion materials and P2 type Sodium-ion intercalation cathodes

    Science.gov (United States)

    Lee, Dae Hoe

    The Li-ion battery is one of the most important rechargeable energy storage devices due to its high energy density, long cycle life, and reliable safety. Although the performances of Li-ion batteries have been improved dramatically, the limit in terms of the energy density still needs to be resolved to meet the growing demands for large-scale mobile devices. Choosing the cathode material is the most pivotal issue in achieving higher energy, since the energy density is directly correlated to the specific capacity of the cathode. Intercalation-based cathode materials have been widely utilized in commercial products; however they yield a limited capacity due to restricted crystallographic sites for Li-ions. In this thesis, the NiF2 and NiO doped NiF2/C conversion materials, which display substantially greater capacities, are intensively studied using various synchrotron X-ray techniques and magnetic measurements. The enhanced electronic conductivity of NiO doped NiF2/C is associated with a significant improvement in the reversible conversion reaction. While bimodal Ni nanoparticles are maintained for NiO doped NiF2/C upon the discharge, for pure NiF2 only smaller nanoparticles remain following the 2nd discharge. Based on the electronic conductivity, it is demonstrated that the size of Ni nanoparticles is associated with the conversion kinetics and consequently the reversibility. Although Li-ion batteries offer the highest energy density among all the secondary batteries, the amount of the reserves and the cost associated with the Li sources are still a concern. In the second part of the thesis, P2 type Na2/3[Ni1/3Mn2/3]O2 is investigated to understand the structural stability in the Na-ion batteries. Significantly improved battery performances are obtained by excluding the phase transformation region. In addition, the structural evolution of the P2-Na0.8[Li0.12Ni0.22Mn0.66]O 2 is tracked by in situ technique and revealed no phase transformation during the cycling. It

  7. Structure and further fragmentation of significant [a3 + Na - H]+ ions from sodium-cationized peptides.

    Science.gov (United States)

    Wang, Huixin; Wang, Bing; Wei, Zhonglin; Zhang, Hao; Guo, Xinhua

    2015-01-01

    A good understanding of gas-phase fragmentation chemistry of peptides is important for accurate protein identification. Additional product ions obtained by sodiated peptides can provide useful sequence information supplementary to protonated peptides and improve protein identification. In this work, we first demonstrate that the sodiated a3 ions are abundant in the tandem mass spectra of sodium-cationized peptides although observations of a3 ions have rarely been reported in protonated peptides. Quantum chemical calculations combined with tandem mass spectrometry are used to investigate this phenomenon by using a model tetrapeptide GGAG. Our results reveal that the most stable [a3 + Na - H](+) ion is present as a bidentate linear structure in which the sodium cation coordinates to the two backbone carbonyl oxygen atoms. Due to structural inflexibility, further fragmentation of the [a3 + Na - H](+) ion needs to overcome several relatively high energetic barriers to form [b2 + Na - H](+) ion with a diketopiperazine structure. As a result, low abundance of [b2 + Na - H](+) ion is detected at relatively high collision energy. In addition, our computational data also indicate that the common oxazolone pathway to generate [b2 + Na - H](+) from the [a3 + Na - H](+) ion is unlikely. The present work provides a mechanistic insight into how a sodium ion affects the fragmentation behaviors of peptides.

  8. Insights into the Effects of Zinc Doping on Structural Phase Transition of P2-Type Sodium Nickel Manganese Oxide Cathodes for High-Energy Sodium Ion Batteries.

    Science.gov (United States)

    Wu, Xuehang; Xu, Gui-Liang; Zhong, Guiming; Gong, Zhengliang; McDonald, Matthew J; Zheng, Shiyao; Fu, Riqiang; Chen, Zonghai; Amine, Khalil; Yang, Yong

    2016-08-31

    P2-type sodium nickel manganese oxide-based cathode materials with higher energy densities are prime candidates for applications in rechargeable sodium ion batteries. A systematic study combining in situ high energy X-ray diffraction (HEXRD), ex situ X-ray absorption fine spectroscopy (XAFS), transmission electron microscopy (TEM), and solid-state nuclear magnetic resonance (SS-NMR) techniques was carried out to gain a deep insight into the structural evolution of P2-Na0.66Ni0.33-xZnxMn0.67O2 (x = 0, 0.07) during cycling. In situ HEXRD and ex situ TEM measurements indicate that an irreversible phase transition occurs upon sodium insertion-extraction of Na0.66Ni0.33Mn0.67O2. Zinc doping of this system results in a high structural reversibility. XAFS measurements indicate that both materials are almost completely dependent on the Ni(4+)/Ni(3+)/Ni(2+) redox couple to provide charge/discharge capacity. SS-NMR measurements indicate that both reversible and irreversible migration of transition metal ions into the sodium layer occurs in the material at the fully charged state. The irreversible migration of transition metal ions triggers a structural distortion, leading to the observed capacity and voltage fading. Our results allow a new understanding of the importance of improving the stability of transition metal layers.

  9. Understanding the Size-Dependent Sodium Storage Properties of Na2C6O6-Based Organic Electrodes for Sodium-Ion Batteries.

    Science.gov (United States)

    Wang, Yaqun; Ding, Yu; Pan, Lijia; Shi, Ye; Yue, Zhuanghao; Shi, Yi; Yu, Guihua

    2016-05-11

    Organic electroactive materials represent a new generation of sustainable energy storage technology due to their unique features including environmental benignity, material sustainability, and highly tailorable properties. Here a carbonyl-based organic salt Na2C6O6, sodium rhodizonate (SR) dibasic, is systematically investigated for high-performance sodium-ion batteries. A combination of structural control, electrochemical analysis, and computational simulation show that rational morphological control can lead to significantly improved sodium storage performance. A facile antisolvent method was developed to synthesize microbulk, microrod, and nanorod structured SRs, which exhibit strong size-dependent sodium ion storage properties. The SR nanorod exhibited the best performance to deliver a reversible capacity of ∼190 mA h g(-1) at 0.1 C with over 90% retention after 100 cycles. At a high rate of 10 C, 50% of the capacity can be obtained due to enhanced reaction kinetics, and such high electrochemical activity maintains even at 80 °C. These results demonstrate a generic design route toward high-performance organic-based electrode materials for beyond Li-ion batteries. Using such a biomass-derived organic electrode material enables access to sustainable energy storage devices with low cost, high electrochemical performance and thermal stability.

  10. Centrifugally-spun carbon microfibers and porous carbon microfibers as anode materials for sodium-ion batteries

    Science.gov (United States)

    Dirican, Mahmut; Zhang, Xiangwu

    2016-09-01

    Natural abundance and low cost of sodium resources bring forward the sodium-ion batteries as a promising alternative to widely-used lithium-ion batteries. However, insufficient energy density and low cycling stability of current sodium-ion batteries hinder their practical use for next-generation smart power grid and stationary storage applications. Electrospun carbon microfibers have recently been introduced as a high-performance anode material for sodium-ion batteries. However, electrospinning is not feasible for mass production of carbon microfibers due to its complex processing condition, low production rate and high cost. Herein, we report centrifugal spinning, a high-rate and low-cost microfiber production method, as an alternative approach to electrospinning for carbon microfiber production and introduce centrifugally-spun carbon microfibers (CMFs) and porous carbon microfibers (PCMFs) as anode materials for sodium-ion batteries. Electrochemical performance results indicated that the highly porous nature of centrifugally-spun PCMFs led to increased Na+ storage capacity and improved cycling stability. The reversible capacity of centrifugally-spun PCMF anodes at the 200th cycle was 242 mAh g-1, which was much higher than that of centrifugally-spun CMFs (143 mAh g-1). The capacity retention and coulombic efficiency of the centrifugally-spun PCMF anodes were 89.0% and 99.9%, respectively, even at the 200th cycle.

  11. Nanostructured Black Phosphorus/Ketjenblack-Multiwalled Carbon Nanotubes Composite as High Performance Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Xu, Gui-Liang; Chen, Zonghai; Zhong, Gui-Ming; Liu, Yuzi; Yang, Yong; Ma, Tianyuan; Ren, Yang; Zuo, Xiaobing; Wu, Xue-Hang; Zhang, Xiaoyi; Amine, Khalil

    2016-06-08

    Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack-multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (∼1700 mAh g(-1) after 100 cycles at 1.3 A g(-1) based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries.

  12. Vanadium-based polyoxometalate as new material for sodium-ion battery anodes

    Science.gov (United States)

    Hartung, Steffen; Bucher, Nicolas; Chen, Han-Yi; Al-Oweini, Rami; Sreejith, Sivaramapanicker; Borah, Parijat; Yanli, Zhao; Kortz, Ulrich; Stimming, Ulrich; Hoster, Harry E.; Srinivasan, Madhavi

    2015-08-01

    Affordable energy storage is crucial for a variety of technologies. One option is sodium-ion batteries (NIBs) for which, however, suitable anode materials are still a problem. We report on the application of a promising new class of materials, polyoxometalates (POMs), as an anode in NIBs. Specifically, Na6[V10O28]·16H2O is being synthesized and characterized. Galvanostatic tests reveal a reversible capacity of approximately 276 mA h g-1 with an average discharge potential of 0.4 V vs. Na/Na+, as well as a high cycling stability. The underlying mechanism is rationalized to be an insertion of Na+ in between the [V10O28]6- anions rather than an intercalation into a crystal structure; the accompanying reduction of V+V to V+IV is confirmed by X-ray Photoelectron Spectroscopy. Finally, a working full-cell set-up is presented with the POM as the anode, substantiating the claim that Na6[V10O28]·16H2O is a promising option for future high-performing sodium-ion batteries.

  13. Optical planar waveguide in sodium-doped calcium barium niobate crystals by carbon ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jin-Hua, E-mail: zhaojinhuazjh@gmail.com [School of Science, Shandong Jianzhu University, Jinan 250101 (China); Qin, Xi-Feng; Wang, Feng-Xiang; Fu, Gang; Wang, Hui-Lin [School of Science, Shandong Jianzhu University, Jinan 250101 (China); Wang, Xue-Lin [School of Physics, Key Laboratory of Particle Physics and Particle Irradiation, Ministry of Education, and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China)

    2013-07-15

    There is great interest in niobate crystals which belong to the tetragonal tungsten bronze (TTB) families owing to their intriguing properties. As one representative of such crystals, CBN (calcium barium niobate) has attracted rapidly growing attention. Because it has a higher Curie temperature than SBN (strontium barium niobate), possesses outstanding ferroelectric and it possesses optical properties. In addition, doped with sodium, CBN will show a higher Curie temperature than pure CBN. We report on the fabrication and characterization of optical planar waveguide in x-cut sodium-doped calcium barium niobate crystal by using C ion implantation. The guided-mode properties at the wavelength of 633 and 1539 nm are investigated through prism-coupling measurements, respectively. By applying direct end-face coupling arrangement, the near-field optical intensity distribution of waveguide modes is measured at 633 nm. For comparison, the modal profile of the same guided mode is also numerically calculated by the finite difference beam-propagation method via computer software BeamPROP. The transmission spectra of the waveguide before and after ion implantation treatments were investigated also. Our experiment results reveal that the waveguide could propagate light with transverse magnetic polarized direction only and it is assumed that the polarization selectivity of CBN crystal may responsible for this phenomenon.

  14. Biologically derived melanin electrodes in aqueous sodium-ion energy storage devices.

    Science.gov (United States)

    Kim, Young Jo; Wu, Wei; Chun, Sang-Eun; Whitacre, Jay F; Bettinger, Christopher J

    2013-12-24

    Biodegradable electronics represents an attractive and emerging paradigm in medical devices by harnessing simultaneous advantages afforded by electronically active systems and obviating issues with chronic implants. Integrating practical energy sources that are compatible with the envisioned operation of transient devices is an unmet challenge for biodegradable electronics. Although high-performance energy storage systems offer a feasible solution, toxic materials and electrolytes present regulatory hurdles for use in temporary medical devices. Aqueous sodium-ion charge storage devices combined with biocompatible electrodes are ideal components to power next-generation biodegradable electronics. Here, we report the use of biologically derived organic electrodes composed of melanin pigments for use in energy storage devices. Melanins of natural (derived from Sepia officinalis) and synthetic origin are evaluated as anode materials in aqueous sodium-ion storage devices. Na(+)-loaded melanin anodes exhibit specific capacities of 30.4 ± 1.6 mAhg(-1). Full cells composed of natural melanin anodes and λ-MnO2 cathodes exhibit an initial potential of 1.03 ± 0.06 V with a maximum specific capacity of 16.1 ± 0.8 mAhg(-1). Natural melanin anodes exhibit higher specific capacities compared with synthetic melanins due to a combination of beneficial chemical, electrical, and physical properties exhibited by the former. Taken together, these results suggest that melanin pigments may serve as a naturally occurring biologically derived charge storage material to power certain types of medical devices.

  15. Sodium-ion supercapacitors based on nanoporous pyroproteins containing redox-active heteroatoms

    Science.gov (United States)

    Cho, Se Youn; Yoon, Hyeon Ji; Kim, Na Rae; Yun, Young Soo; Jin, Hyoung-Joon

    2016-10-01

    Nanostructured carbon-based materials fabricated via simple methods from renewable bio-resources have great potential in rechargeable energy storage systems. In this study, nanoporous pyroproteins containing a large amount of redox-active heteroatoms (H-NPs) were fabricated from silk fibroin by an in situ carbonization/activation method. The H-NPs have a large surface area of ∼3050 m2 g-1, which is mainly comprised of nanometer-scale pores. Also, these H-NPs have oxygen and nitrogen heteroatoms of 17.4 wt% and 2.9 wt%, respectively. Synergistic sodium ion storage behaviors originate from electrochemical double layer capacitance and pseudocapacitance, leading to very high electrochemical performances of H-NPs in aqueous and non-aqueous electrolyte systems. Sodium-ion supercapacitors (NISs) based on commercial graphite//H-NPs show a high specific power of ∼1900 W kg-1 at ∼77 Wh kg-1. Also, NISs based on commercial hard carbon//H-NPs exhibit a high specific energy of ∼217 Wh kg-1 at ∼42 W kg-1. In addition, outstanding cycling performances over 30,000 cycles are achieved for symmetric NISs.

  16. Electrochemical Performance of a V2O5 Cathode for a Sodium Ion Battery

    Science.gov (United States)

    Van Nghia, Nguyen; Long, Pham Duy; Tan, Ta Anh; Jafian, Samuel; Hung, I.-Ming

    2017-06-01

    In this paper, layered vanadium pentoxide (V2O5) is employed as a cathode material for a sodium ion battery. The V2O5 particle sizes range from 200 nm to 500 nm and the shapes of the aggregated V2O5 particles are non-homogeneous and irregular. The material exhibits a first discharge capacity of approximately 208.1 mAh g-1. The structure of V2O5 changes to a NaxV2O5 structure after Na+ insertion at the first discharge; the structure of NaxV2O5 remains stable␣during cycling. After 40 cycles, the discharge capacity retains 61.2% of the capacity of the second cycle. The capacity of V2O5 at a high charge/discharge current rate of 1.0 C is 49.1% of capacity at 0.1 C. Furthermore, the capacity returns to the initial value as the discharge rate returns to 0.1 C. The results of electrochemical performance tests indicate that V2O5 is a potential cathode material for sodium ion batteries.

  17. Bismuth Nanoparticles Embedded in Carbon Spheres as Anode Materials for Sodium/Lithium-Ion Batteries.

    Science.gov (United States)

    Yang, Fuhua; Yu, Fan; Zhang, Zhian; Zhang, Kai; Lai, Yanqing; Li, Jie

    2016-02-12

    Sodium-ion batteries (SIBs) are regarded as an attractive alternative to lithium-ion batteries (LIBs) for large-scale commercial applications, because of the abundant terrestrial reserves of sodium. Exporting suitable anode materials is the key to the development of SIBs and LIBs. In this contribution, we report on the fabrication of Bi@C microspheres using aerosol spray pyrolysis technique. When used as SIBs anode materials, the Bi@C microsphere delivered a high capacity of 123.5 mAh g(-1) after 100 cycles at 100 mA g(-1) . The rate performance is also impressive (specific capacities of 299, 252, 192, 141, and 90 mAh g(-1) are obtained under current densities of 0.1, 0.2, 0.5, 1, and 2 A g(-1) , respectively). Furthermore, the Bi@C microsphere also proved to be suitable LIB anode materials. The excellent electrochemical performance for both SIBs and LIBs can attributed to the Bi@C microsphere structure with Bi nanoparticles uniformly dispersed in carbon spheres. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Optimization of sodium extraction from soil by using a central composite design (CCD and determination of soil sodium content by ion selective electrodes

    Directory of Open Access Journals (Sweden)

    Sevinç Karadağ

    2016-04-01

    Full Text Available Rapid determination of sodium (Na ions in soil samples using ion selective electrodes (ISE was investigated in this study. The compatibility of ISEs with soil extraction solution is a challenging subject as various effects such as pH, ionic strength and other interferences have to be considered as well as efficiency of the extraction solution. Because almost every type of sodium salt is soluble in water, and the pH of water is suitable for ISE studies, it was chosen as the soil extractant. Firstly, the extraction parameters were optimized by using a central composite design (CCD, secondly thirty agricultural soil samples were extracted with water and the extracts were measured by Na-ISE in a previously developed flow system. The results were compared with ion chromatography (IC as the reference method, and the regression analysis between IC and ISE results yielded a high correlation (R² = 0.9408. It was concluded that, ion selective electrodes can be used with water as an extraction solution for rapid determination of sodium in soil samples.

  19. Chlorine ions but not sodium ions alter genome stability of Arabidopsis thaliana.

    Science.gov (United States)

    Boyko, Alex; Golubov, Andrey; Bilichak, Andriy; Kovalchuk, Igor

    2010-06-01

    Various environmental stresses influence plant genome stability. Most of these stresses, such as ionizing radiation, heavy metals and organic chemicals, represent potent DNA-damaging agents. Here, we show that exposure to NaCl, the stress that is not thought to cause direct DNA damage, results in an increase in the level of strand breaks and homologous recombination rates (RRs) in Arabidopsis thaliana plants. The effect of salt stress on the RR was found to be primarily associated with Cl(-) ions, since exposure of plants to Na(2)SO(4) did not increase the RR, whereas exposure to MgCl(2) resulted in an increase. Changes in the number of strand breaks and in the RR were also paralleled by transcriptional activation of AtRad51 and down-regulation of AtKu70. The progeny of exposed plants exhibited higher RRs, higher expression of AtRad51, lower expression of AtKu70, higher tolerance to salt and methyl methane sulfate (MMS) stresses, as well as a higher increase in RR upon further exposure to stress. Our experiments showed that NaCl is a genotoxic stress that leads to somatic and transgenerational changes in recombination rates, and these changes are primarily triggered by exposure to Cl(-) ions.

  20. Hydrophobic ion pairing of an insulin-sodium deoxycholate complex for oral delivery of insulin

    Directory of Open Access Journals (Sweden)

    Sun S

    2011-11-01

    Full Text Available Shaoping Sun1–3, Na Liang2, Yoshiaki Kawashima3, Dengning Xia2, Fude Cui21School of Chemistry and Material Science, Heilongjiang University, Harbin, 2School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, China; 3School of Pharmaceutical Science, Aichi Gakuin University, Nissin, JapanAbstract: Insulin was complexed with sodium deoxycholate to form an insulin-sodium deoxycholate complex (Ins-SD-Comp using an hydrophobic ion pairing method in aqueous phase to enhance the liposolubility of insulin. In order to obtain the maximal complexation efficiency, the molar ratio of sodium deoxycholate to insulin was found. The zeta potential method was used to confirm the optimal ratio for formation of Ins-SD-Comp. The structural characteristics of Ins-SD-Comp were assessed using the Fourier transform infrared method. The apparent partition coefficient of insulin increased upon the formation of Ins-SD-Comp. Based on the preliminary study, Ins-SD-Comp was encapsulated into poly(lactide-co-glycolide (PLGA nanoparticles using an emulsion solvent diffusion method. The maximal encapsulation efficiency of Ins-SD-Comp into PLGA nanoparticles was 93.6% ± 2.81%, drug loading was about 4.8% ± 0.32%, and the mean diameter of the nanoparticles was 278 ± 13 nm. Biological activity and in vivo results revealed that the bioactivity of insulin was not destroyed during the preparation process. Ins-SD-Comp-loaded PLGA nanoparticles have the potential to reduce serum glucose levels and increase the oral bioavailability of insulin.Keywords: insulin complex, sodium deoxycholate, nanoparticles, zeta potential, oral bioavailability

  1. Synthesis and investigation of novel cathode materials for sodium ion batteries

    Science.gov (United States)

    Sawicki, Monica

    Environmental pollution and eventual depletion of fossil fuels and lithium has increased the need for research towards alternative electrical energy storage systems. In this context, research in sodium ion batteries (NIBs) has become more prevalent since the price in lithium has increased due to its demand and reserve location. Sodium is an abundant resource that is low cost, and safe; plus its chemical properties are similar to that of Li which makes the transition into using Na chemistry for ion battery systems feasible. In this study, we report the effects of processing conditions on the electrochemical properties of Na-ion batteries made of the NaCrO2 cathode. NaCrO2 is synthesized via solid state reactions. The as-synthesized powder is then subjected to high-energy ball milling under different conditions which reduces particle size drastically and causes significant degradation of the specific capacity for NaCrO2. X-ray diffraction reveals that lattice distortion has taken place during high-energy ball milling and in turn affects the electrochemical performance of the cathode material. This study shows that a balance between reducing particle size and maintaining the layered structure is essential to obtain high specific capacity for the NaCrO2 cathode. In light of the requirements for grid scale energy storage: ultra-long cycle life (> 20,000 cycles and calendar life of 15 to 20 years), high round trip efficiency (> 90%), low cost, sufficient power capability, and safety; the need for a suitable cathode materials with excellent capacity retention such as Na2MnFe(CN)6 and K2MnFe(CN)6 will be investigated. Prussian blue (A[FeIIIFeII (CN)6]•xH2O, A=Na+ or K+ ) and its analogues have been investigated as an alkali ion host for use as a cathode material. Their structure (FCC) provides large ionic channels along the direction enabling facile insertion and extraction of alkali ions. This material is also capable of more than one Na ion insertion per unit formula

  2. Yolk-Shell Sn@C Eggette-like Nanostructure: Application in Lithium-Ion and Sodium-Ion Batteries.

    Science.gov (United States)

    Li, Site; Wang, Ziming; Liu, Jun; Yang, LinYu; Guo, Yue; Cheng, Lizi; Lei, Ming; Wang, Wenjun

    2016-08-03

    Yolk-shell carbon encapsulated tin (Sn@C) eggette-like compounds (SCE) have been synthesized by a facile method. The SCE structures consist of tin cores covered by carbon membrane networks with extra voids between the carbon shell and tin cores. The novel nanoarchitectures exhibit high electrochemical performance in both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). As anodes for LIBs, the SCE electrodes exhibit a specific capacity of ∼850 mA h g(-1) at 0.1 C (100 mA g(-1)) and high rate capability (∼450 mA h g(-1) remains) at high current densities up to 5 C (5000 mA g(-1)). For SIBs, the SCE electrodes show a specific capacity of ∼400 mA h g(-1) at 0.1 C and high rate capacity (∼150 mA h g(-1) remains) at high current densities up to 5 C (5000 mA g(-1)).

  3. Synthesis and characterizaton of inorganic materials for sodium-ion batteries

    Science.gov (United States)

    Shanmugam, Rengarajan

    Development of low-cost energy storage devices is critical for wide-scale implementation of intermittent renewable energy technologies and improving the electricity grid. Commercial devices remain prohibitively expensive or lack the performance specifications for a wider market reach. Na-ion batteries would perfectly suited for these large-scale applications as the raw materials (such as soda ash, salt, etc.) are plentiful, inexpensive and geographically unconstrained. However, extensive materials research on insertion electrodes is required for better understanding of the electrochemical and structural properties and engineering high performance Na-ion batteries. This thesis research involves exploratory study on new insertion materials with various crystallographic structure-types and extensive characterization of promising new inorganic compositions. Tunnel-type materials, sodium nickel phosphate-Na4Ni7(PO4)6, and sodium cobalt titanate- Na0.8Co0.4Ti1.6O4, were investigated to capitalize on the intrinsic structural stability offered by framework materials. Sol-gel and solid-state reaction synthetic techniques were employed for inorganic powder synthesis. Galvanostatic and potentiostatic testing confirm reversible sodium insertion/de-insertion reactions albeit with inadequate electrochemical characteristics (high voltage hysteresis> 1V). Subsequent efforts involved investigating layer-structured materials supporting fast ionic transport for better electrochemical performance. P2-sodium nickel titanate, Na2/3[Ni1/3Ti2/3]O2 (P2NT), with prismatic sodium co-ordination, was synthesized by solid-state technique. The 'bifunctional' oxide contains Ni2+/4+ and Ti4+/3+ redox couples with redox potentials of 3.6 V, 0.7 V vs. Na/Na+, respectively. This bifunctional approach would simplify electrode processing and provide cost reduction opportunities in battery manufacturing. The structural changes monitored using ex-situ XRD demonstrate a favorably broad solid

  4. Some anomalous effects of sodium ions on the electrophoretic mobility and heteroaggregation of microgel particles.

    Science.gov (United States)

    Routh, Alexander F; Vincent, Brian

    2004-05-15

    Experiments on the kinetics of heteroaggregation between oppositely charged particles, using both dynamic light scattering and turbidity methods, are reported. The negatively charged particles were cross-linked poly( [Formula: see text] -isopropylacrylamide) [PNIPAM] microgel particles, prepared using a carboxylic-acid-based initiator; these particles are swollen at room temperature. The positive particles were poly(4-vinylpyridine) [P4VP] particles, prepared using an amidinium-based initiator; such particles do not respond to temperature changes but do swell below pH approximately 4, where the pyridine moieties become protonated. As expected, the rate of heteroaggregation was shown to be largely independent of added salt concentration (up to approximately 20 mM), for a variety of alkali metal chlorides (MCl, where M = Li, Na, K, or Rb). However, an unexpected, significant decrease in the aggregation rate was observed at certain specific sodium chloride concentrations (typically at approximately 1 and also approximately 4 mM). Similar effects were not seen with the other alkali metal chloride salts. This strange effect was eventually attributed to the fact that the net charge on the positively charged P4VP particles had been reduced by the adsorption of (anionic) silicate species leached from the glassware container. Sodium silicates are known to be significantly more soluble than those of the other alkali metal ions, particularly at high pH. Moreover, P4VP particles dispersed in water, ostensibly at neutral pH, do buffer the aqueous medium to pH values around 9 or higher. This mechanism was confirmed by determining the electrophoretic mobility of the P4VP particles as a function of pH in the presence of the various alkali metal chloride salts. The mobility remained positive in 1 mM salt solutions over the pH range 3 to 11 for all the salts, except for sodium chloride; in that case the mobility reversed sign at alkaline pH values. A similar effect was observed for

  5. Cr2O5 as new cathode for rechargeable sodium ion batteries

    Science.gov (United States)

    Feng, Xu-Yong; Chien, Po-Hsiu; Rose, Alyssa M.; Zheng, Jin; Hung, Ivan; Gan, Zhehong; Hu, Yan-Yan

    2016-10-01

    Chromium oxide, Cr2O5, was synthesized by pyrolyzing CrO3 at 350 °C and employed as a new cathode in rechargeable sodium ion batteries. Cr2O5/Na rechargeable batteries delivered high specific capacities up to 310 mAh/g at a current density of C/16 (or 20 mA/g). High-resolution solid-state 23Na NMR both qualitatively and quantitatively revealed the reversible intercalation of Na ions into the bulk electrode and participation of Na ions in the formation of the solid-electrolyte interphase largely at low potentials. Amorphization of the electrode structure occurred during the first discharge revealed by both NMR and X-ray diffraction data. CrO3-catalyzed electrolyte degradation and loss in electronic conductivity led to gradual capacity fading. The specific capacity stabilized at >120 mAh/g after 50 charge-discharge cycles. Further improvement in electrochemical performance is possible via electrode surface modification, polymer binder incorporation, or designs of new morphologies.

  6. Sodium-ion hybrid electrolyte battery for sustainable energy storage applications

    Science.gov (United States)

    Senthilkumar, S. T.; Abirami, Mari; Kim, Junsoo; Go, Wooseok; Hwang, Soo Min; Kim, Youngsik

    2017-02-01

    Sustainable, safe, and low-cost energy storage systems are essential for large-scale electrical energy storage. Herein, we report a sodium (Na)-ion hybrid electrolyte battery with a replaceable cathode system, which is separated from the Na metal anode by a Na superionic conducting ceramic. By using a fast Na-ion-intercalating nickel hexacyanoferrate (NiHCF) cathode along with an eco-friendly seawater catholyte, we demonstrate good cycling performance with an average discharge voltage of 3.4 V and capacity retention >80% over 100 cycles and >60% over 200 cycle. Remarkably, such high capacity retention is observed for both the initial as well as replaced cathodes. Moreover, a Na-metal-free hybrid electrolyte battery containing hard carbon as the anode exhibits an energy density of ∼146 Wh kg-1 at a current density of 10 mA g-1, which is comparable to that of lead-acid batteries and much higher than that of conventional aqueous Na-ion batteries. These results pave the way for further advances in sustainable energy storage technology.

  7. Improving the cycling stability of Sn4P3 anode for sodium-ion battery

    Science.gov (United States)

    Wang, Wenhui; Zhang, Jiaolong; Yu, Denis Y. W.; Li, Quan

    2017-10-01

    Experimental results from electrochemical characterizations and ex-situ X-ray diffraction (XRD) of the Sn4P3 anode upon cycling reveal that Sn agglomeration from the Sn4P3 particles plays a major role in the fast capacity fading of the Sn4P3 anode for sodium-ion batteries. TiC is demonstrated to be an effective additive to enhance the cycle stability of Sn4P3 by suppressing Sn agglomeration during cycling. Sn4P3/30-wt%TiC composite delivers a stable capacity of 300 mAh g-1 or 700 Ah L-1 over 100 cycles at current density of 100 mA g-1. The high density TiC (4.93 g cm-3), as compared to conventional carbon based additives, makes it attractive for achieving higher volumetric capacity of the anode.

  8. Pre-sodiated nickel cobaltite for high-performance sodium-ion capacitors

    Science.gov (United States)

    Yang, Dongfang; Sun, Xiaoming; Lim, Kyungmi; Ranganathan Gaddam, Rohit; Ashok Kumar, Nanjundan; Kang, Kisuk; Zhao, Xiu Song

    2017-09-01

    Sodium-ion capacitors (NICs) are a hybrid energy storage system that store energy via both charge adsorption at the cathode/electrolyte interface and charge intercalation in the bulk of the anode, thereby possessing a higher energy density than supercapacitors and a higher power density than batteries. In this work, nickel cobaltite (NiCo2O4) hollow spheres with a chestnut shell morphology have been solvothermally synthesized and tested in a sodium half-cell. The NiCo2O4 material exhibits a reversible capacity of 313 mAh g-1 at 1 A g-1. Pre-sodiation of NiCo2O4 is found to significantly improve its energy density. A NIC fabricated with pre-sodiated NiCo2O4 as the anode and an activated carbon (AC) as the cathode delivers an energy density of 60 Wh kg-1 at the power density of 10,000 W kg-1. Ex-situ X-ray diffraction (XRD) and transmission electron microscopy (TEM) results reveal that NiCo2O4 is converted to metallic nickel and cobalt and Na2O phases during the pre-sodiation. The metallic nickel and cobalt phases are kinetically favourable for the electrolyte diffusion and electrochemical reactions, thus significantly improving the performance of the pre-sodiated NiCo2O4 electrode.

  9. Light-cured polymer electrolytes for safe, low-cost and sustainable sodium-ion batteries

    Science.gov (United States)

    Colò, Francesca; Bella, Federico; Nair, Jijeesh R.; Gerbaldi, Claudio

    2017-10-01

    In this work we present a very simple preparation procedure of a poly(ethylene oxide) (PEO)-based crosslinked polymer electrolyte (XPE) for application in sodium-ion batteries (NIBs). The polymer electrolyte, containing NaClO4 as Na+ source, is prepared by rapid, energy saving, solvent-free photopolymerization technique, in a single step. Thermal, mechanical, morphological and electrochemical properties of the resulting XPE are thoroughly investigated. The highly ionic conducting (>1 mS cm-1 at 25 °C) polymer electrolyte is used in a lab-scale sodium cell with nanostructured TiO2 working electrode. The obtained results in terms of ambient temperature cycling behaviour (stable specific capacity of about 250 mAh g-1 at 0.1 mA cm-2 and overall remarkable stability, for a quasi-solid state Na polymer cell, upon very long term cycling exceeding 1000 reversible cycles at 0.5 mA cm-2 corresponding to > 5000 h of continuous operation) demonstrate the promising prospects of this novel XPE to be implemented in the next-generation NIBs conceived for large-scale energy storage systems, such as those connected to photovoltaic and wind factories.

  10. An Empirical Model for Build-Up of Sodium and Calcium Ions in Small Scale Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    Subriyer Nasir

    2011-05-01

    Full Text Available A simple models for predicting build-up of solute on membrane surface were formulated in this paper. The experiments were conducted with secondary effluent, groundwater and simulated feed water in small-scale of RO with capacity of 2000 L/d. Feed water used in the experiments contained varying concentrations of sodium, calcium, combined sodium and calcium. In order to study the effect of sodium and calcium ions on membrane performance, experiments with ground water and secondary effluent wastewater were also performed. Build-up of salts on the membrane surface was calculated by measuring concentrations of sodium and calcium ions in feed water permeate and reject streams using Atomic Absorption Spectrophotometer (AAS. Multiple linear regression of natural logarithmic transformation was used to develop the model based on four main parameters that affect the build-up of solute in a small scale of RO namely applied pressure, permeate flux, membrane resistance, and feed concentration. Experimental data obtained in a small scale RO unit were used to develop the empirical model. The predicted values of theoretical build-up of sodium and calcium on membrane surface were found in agreement with experimental data. The deviation in the prediction of build-up of sodium and calcium were found to be 1.4 to 10.47 % and 1.12 to 4.46%, respectively.

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

    Science.gov (United States)

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

    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 conductivities were observed. As an example, “liquid-like” high conductivities (>1 mS cm−1) were obtained above 70 °C for solid-polymer electrolyte with a PEO to NaTCP molar ratio of 16:1. All presented salts showed high thermal stability and suitable windows of electrochemical stability between 3 and 5 V. These new anions open a new class of compounds with non-covalent structure for electrolytes system applications. PMID:28067301

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

    Science.gov (United States)

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

    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 conductivities were observed. As an example, “liquid-like” high conductivities (>1 mS cm‑1) were obtained above 70 °C for solid-polymer electrolyte with a PEO to NaTCP molar ratio of 16:1. All presented salts showed high thermal stability and suitable windows of electrochemical stability between 3 and 5 V. These new anions open a new class of compounds with non-covalent structure for electrolytes system applications.

  13. Insights into the Effects of Zinc Doping on Structural Phase Transition of P2-Type Sodium Nickel Manganese Oxide Cathodes for High-Energy Sodium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Xuehang; Xu, Gui-Liang; Zhong, Guiming; Gong, Zhengliang; McDonald, Matthew J.; Zheng, Shiyao; Fu, Riqiang; Chen, Zonghai; Amine, Khalil; Yang, Yong

    2016-08-31

    P2-type sodium nickel manganese oxide-based cathode materials with higher energy densities are prime candidates for applications in rechargeable sodium ion batteries. A systematic study combining in situ high energy X-ray diffraction (HEXRD), ex situ Xray absorption fine spectroscopy (XAFS), transmission electron microscopy (TEM), and solid-state nuclear magnetic resonance (SSNMR) techniques was carried out to gain a deep insight into the structural evolution of P2-Na0.66Ni0.33-xZnxMn0.67O2 (x = 0, 0.07) during cycling. In situ HEXRD and ex situ TEM measurements indicate that an irreversible phase transition occurs upon sodium insertion-extraction of Na0.66Ni0.33Mn0.67O2. Zinc doping of this system results in a high structural reversibility. XAFS measurements indicate that both materials are almost completely dependent on the Ni4+/Ni3+/ Ni2+ redox couple to provide charge/discharge capacity. SS-NMR measurements indicate that both reversible and irreversible migration of transition metal ions into the sodium layer occurs in the material at the fully charged state. The irreversible migration of transition metal ions triggers a structural distortion, leading to the observed capacity and voltage fading. Our results allow a new understanding of the importance of improving the stability of transition metal layers.

  14. Biomass carbon micro/nano-structures derived from ramie fibers and corncobs as anode materials for lithium-ion and sodium-ion batteries

    Science.gov (United States)

    Jiang, Qiang; Zhang, Zhenghao; Yin, Shengyu; Guo, Zaiping; Wang, Shiquan; Feng, Chuanqi

    2016-08-01

    Three-dimensional (3D) rod-like carbon micro-structures derived from natural ramie fibers and two-dimensional (2D) carbon nanosheets derived from corncobs have been fabricated by heat treatment at 700 °C under argon atomsphere. The structure and morphology of the as-obtained ramie fiber carbon (RFC) and corncob carbon (CC) were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) technique. The electrochemical performances of the biomass carbon-based anode in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) were investigated. When tested as anode material for lithium ion batteries, both the RFC microrods and CC nanosheets exhibited high capacity, excellent rate capability, and stable cyclability. The specific capacity were still as high as 489 and 606 mAhg-1 after 180 cycles when cycled at room temperature in a 3.0-0.01 V potential (vs. Li/Li+) window at current density of 100 mAg-1, respectively, which are much higher than that of graphite (375 mAhg-1) under the same current density. Although the anodes in sodium ion batteries showed poorer specific capability than that in lithium-ion batteries, they still achieve a reversible sodium intercalation capacity of 122 and 139 mAhg-1 with similar cycling stability. The feature of stable cycling performance makes the biomass carbon derived from natural ramie fibers and corncobs to be promising candidates as electrodes in rechargeable sodium-ion batteries and lithium-ion batteries.

  15. Biomass carbon micro/nano-structures derived from ramie fibers and corncobs as anode materials for lithium-ion and sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Qiang; Zhang, Zhenghao [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Yin, Shengyu [College of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan 430065 (China); Guo, Zaiping [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Institute for Superconducting & Electronic Materials, University of Wollongong, NSW 2522 (Australia); Wang, Shiquan [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Feng, Chuanqi, E-mail: cfeng@hubu.edu.cn [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China)

    2016-08-30

    Highlights: • Ramie fibers and corncobs are used as precursors to prepare the biomass carbons. • The ramie fiber carbon (RFC) took on morphology of 3D micro-rods. • The corncob carbon (CC) possessed a 2D nanosheets structure. • Both RFC and CC exhibited outstanding electrochemical performances in LIBs and SIBs systems. - Abstract: Three-dimensional (3D) rod-like carbon micro-structures derived from natural ramie fibers and two-dimensional (2D) carbon nanosheets derived from corncobs have been fabricated by heat treatment at 700 °C under argon atomsphere. The structure and morphology of the as-obtained ramie fiber carbon (RFC) and corncob carbon (CC) were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) technique. The electrochemical performances of the biomass carbon-based anode in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) were investigated. When tested as anode material for lithium ion batteries, both the RFC microrods and CC nanosheets exhibited high capacity, excellent rate capability, and stable cyclability. The specific capacity were still as high as 489 and 606 mAhg{sup −1} after 180 cycles when cycled at room temperature in a 3.0–0.01 V potential (vs. Li/Li{sup +}) window at current density of 100 mAg{sup −1}, respectively, which are much higher than that of graphite (375 mAhg{sup −1}) under the same current density. Although the anodes in sodium ion batteries showed poorer specific capability than that in lithium-ion batteries, they still achieve a reversible sodium intercalation capacity of 122 and 139 mAhg{sup −1} with similar cycling stability. The feature of stable cycling performance makes the biomass carbon derived from natural ramie fibers and corncobs to be promising candidates as electrodes in rechargeable sodium-ion batteries and lithium-ion batteries.

  16. A1Ao-ATP synthase of Methanobrevibacter ruminantium couples sodium ions for ATP synthesis under physiological conditions.

    Science.gov (United States)

    McMillan, Duncan G G; Ferguson, Scott A; Dey, Debjit; Schröder, Katja; Aung, Htin Lin; Carbone, Vincenzo; Attwood, Graeme T; Ronimus, Ron S; Meier, Thomas; Janssen, Peter H; Cook, Gregory M

    2011-11-18

    An unresolved question in the bioenergetics of methanogenic archaea is how the generation of proton-motive and sodium-motive forces during methane production is used to synthesize ATP by the membrane-bound A(1)A(o)-ATP synthase, with both proton- and sodium-coupled enzymes being reported in methanogens. To address this question, we investigated the biochemical characteristics of the A(1)A(o)-ATP synthase (MbbrA(1)A(o)) of Methanobrevibacter ruminantium M1, a predominant methanogen in the rumen. Growth of M. ruminantium M1 was inhibited by protonophores and sodium ionophores, demonstrating that both ion gradients were essential for growth. To study the role of these ions in ATP synthesis, the ahaHIKECFABD operon encoding the MbbrA(1)A(o) was expressed in Escherichia coli strain DK8 (Δatp) and purified yielding a 9-subunit protein with an SDS-stable c oligomer. Analysis of the c subunit amino acid sequence revealed that it consisted of four transmembrane helices, and each hairpin displayed a complete Na(+)-binding signature made up of identical amino acid residues. The purified MbbrA(1)A(o) was stimulated by sodium ions, and Na(+) provided pH-dependent protection against inhibition by dicyclohexylcarbodiimide but not tributyltin chloride. ATP synthesis in inverted membrane vesicles lacking sodium ions was driven by a membrane potential that was sensitive to cyanide m-chlorophenylhydrazone but not to monensin. ATP synthesis could not be driven by a chemical gradient of sodium ions unless a membrane potential was imposed. ATP synthesis under these conditions was sensitive to monensin but not cyanide m-chlorophenylhydrazone. These data suggest that the M. ruminantium M1 A(1)A(o)-ATP synthase exhibits all the properties of a sodium-coupled enzyme, but it is also able to use protons to drive ATP synthesis under conditions that favor proton coupling, such as low pH and low levels of sodium ions.

  17. Effects of Metal Ions on Viscosity of Aqueous Sodium Carboxylmethylcellulose Solution and Development of Dropping Ball Method on Viscosity

    Science.gov (United States)

    Set, Seng; Ford, David; Kita, Masakazu

    2015-01-01

    This research revealed that metal ions with different charges could significantly affect the viscosity of aqueous sodium carboxylmethylcellulose (CMC) solution. On the basis of an Ostwald viscometer, an improvised apparatus using a dropping ball for examining the viscosity of liquids/solutions has been developed. The results indicate that the…

  18. Charge–discharge properties of tin dioxide for sodium-ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jinsoo [Department of Materials and Energy Engineering, Kyungwoon University, 730 Gangdong-ro, Sandong-meon, Gumi-si, Gyeongbuk 730-739 (Korea, Republic of); Park, Jin-Woo; Han, Jeong-Hui [School of Materials Science and Engineering, RIGET, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Lee, Sang-Won [R and D 2 Team, COSMO AM and T CO., LTD., 315 Mokhaeng-dong, Chungju (Korea, Republic of); Lee, Ki-Young [Jeonyoung ECP, 637-1, Sunggok-dong, Danwon-gu, Ansan cilt, Kyunggi-do (Korea, Republic of); Ryu, Ho-Suk; Kim, Ki-Won [School of Materials Science and Engineering, RIGET, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Wang, Guoxiu [School of Chemistry and Forensic Science, University of Technology Sydney, Sydney, NSW 2007 (Australia); Ahn, Jou-Hyeon [Department of Chemical and Biological Engineering, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, RIGET, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of)

    2014-10-15

    Highlights: • The electrochemical reaction of SnO2 as an anode for Na-ion batteries was studied. • The SnO2 electrode delivered the initial discharge capacity of 747 mAh/g. • Alarge irreversible capacity (597 mAh/g)was observedin the first cycle. • The in-plain crack in the electrode caused the incompletereduction of SnO{sub 2}. - Abstract: Tin dioxide was investigated as an anode material for sodium-ion batteries. The Na/SnO{sub 2} cell delivered a first discharge capacity of 747 mAh/g, but the first charge capacity was 150 mAh/g. The irreversible capacity in the first cycle was examined through characterization by X-ray diffraction and scanning electron microscopy. X-ray diffraction analysis revealed that the SnO{sub 2} active material was not reduced fully to metallic Sn. Furrows and wrinkles were formed on the electrode surface owing to the volumetric expansion upon first discharge, which led to a deterioration of the electrode structure and a loss of electrical contact between the active materials. The analysis is summarized in the schematic drawing.

  19. Size and Composition Effects in Sb-Carbon Nanocomposites for Sodium-Ion Batteries.

    Science.gov (United States)

    Ramireddy, Thrinathreddy; Sharma, Neeraj; Xing, Tan; Chen, Ying; Leforestier, Jeremie; Glushenkov, Alexey M

    2016-11-09

    Sodium-ion batteries are in the spotlight as viable alternatives to lithium-ion batteries in stationary storage and power grid applications. Among possible anode materials, Sb is one of the interesting candidates due to a combination of battery-type potential plateaus in the charge-discharge profiles, high capacity (theoretical capacity of 660 mAh g(-1)), and demonstrated good cyclic stability. The influence of Sb particle size (particularly at the nanoscale range) and the composition of Sb-carbon composites on the electrode performance, stability, and charge storage mechanism is systematically evaluated here for the first time. A range of Sb-carbon nanocomposites with varied Sb particle size (between 50 and ∼1 nm) are studied. The control of the particle size is achieved via varying the carbon and Sb weight ratio in the precursors. The shape of charge-discharge profiles, hysteresis, and the difference in cyclic stabilities and rate performance are analyzed. The nanocomposite with the smallest particle size (∼1 nm) and the largest carbon content provides the most stable cyclic behavior and a better rate capability but suffers from an increased hysteresis between charge and discharge curves. In situ synchrotron X-ray diffraction experiments indicate that the storage mechanism in the Sb-carbon nanocomposites containing Sb nanoparticles is different from the electrodes with bulkier, micron-sized Sb particles, and the electrochemical reaction proceeds through a number of crystalline intermediates.

  20. Review on anionic redox for high-capacity lithium- and sodium-ion batteries

    Science.gov (United States)

    Zhao, Chenglong; Wang, Qidi; Lu, Yaxiang; Hu, Yong-Sheng; Li, Baohua; Chen, Liquan

    2017-05-01

    Rechargeable batteries, especially lithium-ion batteries, are now widely used as power sources for portable electronics and electric vehicles, but material innovations are still needed to satisfy the increasing demand for larger energy density. Recently, lithium- and sodium-rich electrode materials, including the A2MO3-family layered compounds (A  =  Li, Na; M  =  Mn4+, Ru4+, etc), have been extensively studied as potential high-capacity electrode materials for a cumulative cationic and anionic redox activity. Negatively charged oxide ions can potentially donate electrons to compensate for the absence of oxidable transition metals as a redox center to further increase the reversible capacity. Understanding and controlling the state-of-the-art anionic redox processes is pivotal for the design of advanced energy materials, highlighted in rechargeable batteries. Hence, experimental and theoretical approaches have been developed to consecutively study the diverting processes, states, and structures involved. In this review, we attempt to present a literature overview and provide insight into the reaction mechanism with respect to the anionic redox processes, proposing some opinions as target oriented. It is hoped that, through this discussion, the search for anionic redox electrode materials with high-capacity rechargeable batteries can be advanced, and practical applications realized as soon as possible.

  1. Influence of Humic Acid Complexation with Metal Ions on Extracellular Electron Transfer Activity.

    Science.gov (United States)

    Zhou, Shungui; Chen, Shanshan; Yuan, Yong; Lu, Qin

    2015-11-23

    Humic acids (HAs) can act as electron shuttles and mediate biogeochemical cycles, thereby influencing the transformation of nutrients and environmental pollutants. HAs commonly complex with metals in the environment, but few studies have focused on how these metals affect the roles of HAs in extracellular electron transfer (EET). In this study, HA-metal (HA-M) complexes (HA-Fe, HA-Cu, and HA-Al) were prepared and characterized. The electron shuttle capacities of HA-M complexes were experimentally evaluated through microbial Fe(III) reduction, biocurrent generation, and microbial azoreduction. The results show that the electron shuttle capacities of HAs were enhanced after complexation with Fe but were weakened when using Cu or Al. Density functional theory calculations were performed to explore the structural geometry of the HA-M complexes and revealed the best binding sites of the HAs to metals and the varied charge transfer rate constants (k). The EET activity of the HA-M complexes were in the order HA-Fe > HA-Cu > HA-Al. These findings have important implications for biogeochemical redox processes given the ubiquitous nature of both HAs and various metals in the environment.

  2. 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.

  3. Sodium concentration measurement during hemodialysis through ion-exchange resin and conductivity measure approach: in vitro experiments.

    Directory of Open Access Journals (Sweden)

    Andrea Tura

    Full Text Available Sodium measurement during hemodialysis treatment is important to preserve the patient from clinical events related to hypo- or hyper-natremia Usually, sodium measurement is performed through laboratory equipment which is typically expensive, and requires manual intervention. We propose a new method, based on conductivity measurement after treatment of dialysate solution through ion-exchange resin. To test this method, we performed in vitro experiments. We prepared 40 ml sodium chloride (NaCl samples at 280, 140, 70, 35, 17.5, 8.75, 4.375 mEq/l, and some "mixed samples", i.e., with added potassium chloride (KCl at different concentrations (4.375-17.5 mEq/l, to simulate the confounding factors in a conductivity-based sodium measurement. We measured the conductivity of all samples. Afterwards, each sample was treated for 1 min with 1 g of Dowex G-26 resin, and conductivity was measured again. On average, the difference in the conductivity between mixed samples and corresponding pure NaCl samples (at the same NaCl concentration was 20.9%. After treatment with the exchange resin, it was 14.7%, i.e., 42% lower. Similar experiments were performed with calcium chloride and magnesium chloride as confounding factors, with similar results. We also performed some experiments on actual dialysate solution during hemodialysis sessions in 15 patients, and found that the correlation between conductivity measures and sodium concentration improved after resin treatment (R=0.839 before treatment, R=0.924 after treatment, P<0.0001. We conclude that ion-exchange resin treatment coupled with conductivity measures may improve the measurement of sodium compared to conductivity measures alone, and may become a possible simple approach for continuous and automatic sodium measurement during hemodialysis.

  4. K+-Na+ ion-exchanged sodium magnesium aluminum germanate glass waveguide amplifier operating in the first telecommunications window

    Science.gov (United States)

    Yang, Dianlai; Zhang, Jie; Pun, Edwin Yue-Bun; Lin, Hai

    2010-12-01

    Potassium-sodium (K+-Na+) ion-exchanged multimode channel waveguide amplifiers have been fabricated based on Tm3+/Yb3+ codoped sodium magnesium aluminum germanate (NMAG) glass substrates. The normalized optical and relative gain coefficients of a 2.20 cm long device were identified to be 3.65 dB/cm and 1.58 dB/cm, respectively, at a signal wavelength of 810 nm under 457 mW 980 nm laser diode excitation. These are the highest values reported, and the results indicate that Tm3+/Yb3+ codoped NMAG glasses are an attractive material for optical amplification in the first telecommunications window.

  5. Combined sodium ion sensitivity in agonist binding and internalization of vasopressin V1b receptors.

    Science.gov (United States)

    Koshimizu, Taka-Aki; Kashiwazaki, Aki; Taniguchi, Junichi

    2016-05-03

    Reducing Na(+) in the extracellular environment may lead to two beneficial effects for increasing agonist binding to cell surface G-protein coupled receptors (GPCRs): reduction of Na(+)-mediated binding block and reduce of receptor internalization. However, such combined effects have not been explored. We used Chinese Hamster Ovary cells expressing vasopressin V1b receptors as a model to explore Na(+) sensitivity in agonist binding and receptor internalization. Under basal conditions, a large fraction of V1b receptors is located intracellularly, and a small fraction is in the plasma membrane. Decreases in external Na(+) increased cell surface [(3)H]AVP binding and decreased receptor internalization. Substitution of Na(+) by Cs(+) or NH4(+) inhibited agonist binding. To suppress receptor internalization, the concentration of NaCl, but not of CsCl, had to be less than 50 mM, due to the high sensitivity of the internalization machinery to Na(+) over Cs(+). Iso-osmotic supplementation of glucose or NH4Cl maintained internalization of the V1b receptor, even in a low-NaCl environment. Moreover, iodide ions, which acted as a counter anion, inhibited V1b agonist binding. In summary, we found external ionic conditions that could increase the presence of high-affinity state receptors at the cell surface with minimum internalization during agonist stimulations.

  6. PIGMENT CONTENT OF Chlorella vulgaris BEIJ. UNDER INFLUENCE OF THE SODIUM SELENITE AND METALS IONS

    Directory of Open Access Journals (Sweden)

    O. I.

    2016-02-01

    Full Text Available The aim of the research was to determine the conditions obtaining in the aquaculture of Chlorella vulgaris Beij. algosubstantion enriched with selenium and bioactive metals. For this purpose, the content of seaweed pigments studied by the action of sodium selenite in a concentration based on Se4+: 0.5, 5.0, 10.0 and 20.0 mg / dm3 for 1, 3 and 7 days and while exposed 10.0 mg Se4 +/dm3 and Zn2+, Mn2 +, Co2 +, Cu2 +, Fe3 + in concentrations of 5.0 mg/dm 3, 0.25, 0.002, 0.008 and 0.05 mg/dm3, respectively, within 7 days of culturing. The content of pigments was determined spectrophotometrically, the cellular walls were given off in the percoll gradient and investigated microscopically. The pigments content in Ch. vulgaris increase by 1,5–2,5 times in comparison with control sample under the influence of 10 mg Se(IV/dm3 with and without metal ions. In the same condition a ratio of chlorophylls a/b increased, that accompanied by the formation in cells of the second cell wall as the sign of successful adaptation process in the Chlorella cells under the influence of these factors. Thus, the cultivation of chlorella, enriched with selenium and bioactive metals, is possible within 7 days under the influence of 10 mg Se (IV/dm3 and mentioned concentration of these metal ions.

  7. High-density sodium and lithium ion battery anodes from banana peels.

    Science.gov (United States)

    Lotfabad, Elmira Memarzadeh; Ding, Jia; Cui, Kai; Kohandehghan, Alireza; Kalisvaart, W Peter; Hazelton, Michael; Mitlin, David

    2014-07-22

    Banana peel pseudographite (BPPG) offers superb dual functionality for sodium ion battery (NIB) and lithium ion battery (LIB) anodes. The materials possess low surface areas (19-217 m(2) g(-1)) and a relatively high electrode packing density (0.75 g cm(-3) vs ∼1 g cm(-3) for graphite). Tested against Na, BPPG delivers a gravimetric (and volumetric) capacity of 355 mAh g(-1) (by active material ∼700 mAh cm(-3), by electrode volume ∼270 mAh cm(-3)) after 10 cycles at 50 mA g(-1). A nearly flat ∼200 mAh g(-1) plateau that is below 0.1 V and a minimal charge/discharge voltage hysteresis make BPPG a direct electrochemical analogue to graphite but with Na. A charge capacity of 221 mAh g(-1) at 500 mA g(-1) is degraded by 7% after 600 cycles, while a capacity of 336 mAh g(-1) at 100 mAg(-1) is degraded by 11% after 300 cycles, in both cases with ∼100% cycling Coulombic efficiency. For LIB applications BPPG offers a gravimetric (volumetric) capacity of 1090 mAh g(-1) (by material ∼2200 mAh cm(-3), by electrode ∼900 mAh cm(-3)) at 50 mA g(-1). The reason that BPPG works so well for both NIBs and LIBs is that it uniquely contains three essential features: (a) dilated intergraphene spacing for Na intercalation at low voltages; (b) highly accessible near-surface nanopores for Li metal filling at low voltages; and (c) substantial defect content in the graphene planes for Li adsorption at higher voltages. The underpotential deposition. By contrast, the same analysis proves the presence of metallic Li in the pores, with intercalation being much less pronounced.

  8. Chemically Crushed Wood Cellulose Fiber towards High-Performance Sodium-Ion Batteries.

    Science.gov (United States)

    Shen, Fei; Zhu, Hongli; Luo, Wei; Wan, Jiayu; Zhou, Lihui; Dai, Jiaqi; Zhao, Bin; Han, Xiaogang; Fu, Kun; Hu, Liangbing

    2015-10-21

    Carbon materials have attracted great interest as an anode for sodium-ion batteries (SIBs) due to their high performance and low cost. Here, we studied natural wood fiber derived hard carbon anodes for SIBs considering the abundance and low cost of wood. We discovered that a thermal carbonization of wood fiber led to a porous carbon with a high specific surface area of 586 m(2) g(-1), while a pretreatment with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) could effectively decrease it to 126 m(2) g(-1). When evaluating them as anodes for SIBs, we observed that the low surface area carbon resulted in a high initial Coulombic efficiency of 72% compared to 25% of the high surface area carbon. More importantly, the low surface area carbon exhibits an excellent cycling stability that a desodiation capacity of 196 mAh g(-1) can be delivered over 200 cycles at a current density of 100 mA g(-1), indicating a promising anode for low-cost SIBs.

  9. Synthesis of calcium silicates by Pechini method and exchanging ions of sodium alginate-calcium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Garay, K.A.; Martinez-Luevanos, A.; Cruz-Ortiz, B.R.; Garcia-Cerda, L.A.; Lopez-Badillo, C.M.

    2016-07-01

    Calcium silicates samples were synthesized using tetraethyl orthosilicate (TEOS) and by Pechini methodology assisted with ion-exchange of sodium alginate, followed by a heat treatment of 800°C by two hours. A, B and C samples were obtained using 1.7×10−3M, 3.4×10−3M and 5.1×10−3M of TEOS, respectively, and without heat treatment; these samples were characterized by thermogravimetric analysis (TGA) and infrared spectroscopy with attenuated total reflectance (FTIR-ATR). Furthermore, samples A800, B800 and C800 obtained using a heat treatment of 800° by two hours were characterized by FTIR-ATR, absorption technique (BET), X-ray diffraction (XRD) and by scanning electron microscopy. The XRD patterns indicate that sample A800 contains olivine (Ca2SiO4) in orthorhombic phase and wollastonite-2M (CaSiO3); sample B800 showed the earlier phases and quartz (SiO2), whereas sample C800 contains wollastonite phases and larnite-2M (Ca2SiO4). (Author)

  10. Recovery Act - Demonstration of Sodium Ion Battery for Grid Level Applications

    Energy Technology Data Exchange (ETDEWEB)

    Wiley, Ted [Aquion Energy, Inc., Pittsburgh, PA (United States); Whitacre, Jay [Aquion Energy, Inc., Pittsburgh, PA (United States); Weber, Eric [Aquion Energy, Inc., Pittsburgh, PA (United States); Eshoo, Michael [Aquion Energy, Inc., Pittsburgh, PA (United States); Noland, James [Aquion Energy, Inc., Pittsburgh, PA (United States); Blackwood, David [Aquion Energy, Inc., Pittsburgh, PA (United States); Campbell, Williams [Aquion Energy, Inc., Pittsburgh, PA (United States); Sheen, Eric [Aquion Energy, Inc., Pittsburgh, PA (United States); Spears, Christopher [Aquion Energy, Inc., Pittsburgh, PA (United States); Smith, Christopher [Aquion Energy, Inc., Pittsburgh, PA (United States)

    2012-08-31

    Aquion Energy received a $5.179 million cooperative research agreement under the Department of Energy's Smart Grid Demonstration Program Demonstration of Promising Energy Storage Technologies (Program Area 2.5) of FOA DE-FOE-0000036. The main objective of this project was to demonstrate Aquion's low cost, grid-scale, ambient temperature sodium ion energy storage device. The centerpiece of the technology is a novel hybrid energy storage chemistry that has been proven in a laboratory environment. The objective was to translate these groundbreaking results from the small-batch, small-cell test environment to the pilot scale to enable significant numbers of multiple ampere-hour cells to be manufactured and assembled into test batteries. Aquion developed a proof of concept demonstration unit that showed similar performance and major cost improvement over existing technologies. Beyond minimizing cell and system cost, Aquion built a technology that is safe, environmentally benign and durable over many thousands of cycles as used in a variety of grid support roles.

  11. Assembly of SnSe Nanoparticles Confined in Graphene for Enhanced Sodium-Ion Storage Performance.

    Science.gov (United States)

    Yang, Xu; Zhang, Rongyu; Chen, Nan; Meng, Xing; Yang, Peilei; Wang, Chunzhong; Zhang, Yaoqing; Wei, Yingjin; Chen, Gang; Du, Fei

    2016-01-22

    Sodium-ion batteries (SIBs) have attracted much interest as a low-cost and environmentally benign energy storage system, but more attention is justifiably required to address the major technical issues relating to the anode materials to deliver high reversible capacity, superior rate capability, and stable cyclability. A SnSe/reduced graphene oxide (RGO) nanocomposite has been prepared by a facile ball-milling method, and its structural, morphological, and electrochemical properties have been characterized and compared with those of the bare SnSe material. Although the redox behavior of SnSe remains nearly unchanged upon the incorporation of RGO, its electrochemical performance is significantly enhanced, as reflected by a high specific capacity of 590 mA h g(-1) at 0.050 A g(-1) , a rate capability of 260 mA h g(-1) at 10 A g(-1) , and long-term stability over 120 cycles. This improvement may be attributed to the high electronic conductivity of RGO, which also serves as a matrix to buffer changes in volume and maintain the mechanical integrity of the electrode during (de)sodiation processes. In view of its excellent Na(+) storage performance, this SnSe/RGO nanocomposite has potential as an anode material for SIBs.

  12. Transition metal ion FRET uncovers K+ regulation of a neurotransmitter/sodium symporter

    Science.gov (United States)

    Billesbølle, Christian B.; Mortensen, Jonas S.; Sohail, Azmat; Schmidt, Solveig G.; Shi, Lei; Sitte, Harald H.; Gether, Ulrik; Loland, Claus J.

    2016-01-01

    Neurotransmitter/sodium symporters (NSSs) are responsible for Na+-dependent reuptake of neurotransmitters and represent key targets for antidepressants and psychostimulants. LeuT, a prokaryotic NSS protein, constitutes a primary structural model for these transporters. Here we show that K+ inhibits Na+-dependent binding of substrate to LeuT, promotes an outward-closed/inward-facing conformation of the transporter and increases uptake. To assess K+-induced conformational dynamics we measured fluorescence resonance energy transfer (FRET) between fluorescein site-specifically attached to inserted cysteines and Ni2+ bound to engineered di-histidine motifs (transition metal ion FRET). The measurements supported K+-induced closure of the transporter to the outside, which was counteracted by Na+ and substrate. Promoting an outward-open conformation of LeuT by mutation abolished the K+-effect. The K+-effect depended on an intact Na1 site and mutating the Na2 site potentiated K+ binding by facilitating transition to the inward-facing state. The data reveal an unrecognized ability of K+ to regulate the LeuT transport cycle. PMID:27678200

  13. Transition metal ion FRET uncovers K(+) regulation of a neurotransmitter/sodium symporter.

    Science.gov (United States)

    Billesbølle, Christian B; Mortensen, Jonas S; Sohail, Azmat; Schmidt, Solveig G; Shi, Lei; Sitte, Harald H; Gether, Ulrik; Loland, Claus J

    2016-09-28

    Neurotransmitter/sodium symporters (NSSs) are responsible for Na(+)-dependent reuptake of neurotransmitters and represent key targets for antidepressants and psychostimulants. LeuT, a prokaryotic NSS protein, constitutes a primary structural model for these transporters. Here we show that K(+) inhibits Na(+)-dependent binding of substrate to LeuT, promotes an outward-closed/inward-facing conformation of the transporter and increases uptake. To assess K(+)-induced conformational dynamics we measured fluorescence resonance energy transfer (FRET) between fluorescein site-specifically attached to inserted cysteines and Ni(2+) bound to engineered di-histidine motifs (transition metal ion FRET). The measurements supported K(+)-induced closure of the transporter to the outside, which was counteracted by Na(+) and substrate. Promoting an outward-open conformation of LeuT by mutation abolished the K(+)-effect. The K(+)-effect depended on an intact Na1 site and mutating the Na2 site potentiated K(+) binding by facilitating transition to the inward-facing state. The data reveal an unrecognized ability of K(+) to regulate the LeuT transport cycle.

  14. Nickel Hexacyanoferrate Nanoparticle Electrodes For Aqueous Sodium and Potassium Ion Batteries

    KAUST Repository

    Wessells, Colin D.

    2011-12-14

    The electrical power grid faces a growing need for large-scale energy storage over a wide range of time scales due to costly short-term transients, frequency regulation, and load balancing. The durability, high power, energy efficiency, and low cost needed for grid-scale storage pose substantial challenges for conventional battery technology.(1, 2)Here, we demonstrate insertion/extraction of sodium and potassium ions in a low-strain nickel hexacyanoferrate electrode material for at least five thousand deep cycles at high current densities in inexpensive aqueous electrolytes. Its open-framework structure allows retention of 66% of the initial capacity even at a very high (41.7C) rate. At low current densities, its round trip energy efficiency reaches 99%. This low-cost material is readily synthesized in bulk quantities. The long cycle life, high power, good energy efficiency, safety, and inexpensive production method make nickel hexacyanoferrate an attractive candidate for use in large-scale batteries to support the electrical grid. © 2011 American Chemical Society.

  15. Towards safer sodium-ion batteries via organic solvent/ionic liquid based hybrid electrolytes

    Science.gov (United States)

    Monti, Damien; Ponrouch, Alexandre; Palacín, M. Rosa; Johansson, Patrik

    2016-08-01

    Hybrid electrolytes aimed at application in sodium-ion batteries (SIB) consisting of an organic solvent mixture (EC:PC) and different ionic liquids (ILs); EMImTFSI, BMImTFSI, and Pyr13TFSI, and with the NaTFSI salt providing the Na+ charge carriers have here been extensively studied. The physico-chemical and electrochemical characterisation includes ionic conductivity, viscosity, density, cation coordination and solvation, various safety measures, and electrochemical stability window (ESW). Hybrid electrolytes with 10-50% of IL content were found to have ionic conductivities on par with comparable organic solvent based electrolytes, but with highly enhanced safety properties. A systematic Raman spectroscopy study of the cation coordination and solvation before and after electrolyte safety tests by ignition suggest that IL cations and TFSI remain stable when ignited while organic solvents are consumed. Finally, the solid electrolyte interphase (SEI) formed when using hybrid electrolytes has both better mechanical and electrochemical stability than the SEI derived from pure IL based electrolytes. For a half-cell with a hard carbon (HC) electrode and a hybrid electrolyte with a composition of 0.8 m NaTFSI in EC0.45:PC0.45:Pyr13TFSI0.10 encouraging results were obtained for IL based electrolytes - ca. 182 mAhg-1 at C/10 over 40 cycles.

  16. CuSbS2 as a negative electrode material for sodium ion batteries

    Science.gov (United States)

    Marino, C.; Block, T.; Pöttgen, R.; Villevieille, C.

    2017-02-01

    CuSbS2 was tested as a negative electrode material for sodium-ion batteries. The material synthesized by ball milling offers a specific charge of 730 mAh g-1, close to the theoretical value (751 mAh g-1), over a few cycles. The reaction mechanism was investigated by means of operando X-ray diffraction, 121Sb Mössbauer spectroscopy, and Cu K-edge X-ray absorption spectroscopy. These studies reveal a sodiation mechanism that involves an original conversion reaction in two steps, through the formation of a ternary phase, CuSb(1-x)S(2-y), as well as a NaxS alloy and Sb, followed by an alloying reaction involving the previously formed Sb. The desodiation process ends with the reformation of the ternary phase, CuSb(1-x‧)S(2-y‧), deficient in Sb and S; this phase is responsible for the good reversibility observed upon cycling.

  17. Layered SnS sodium ion battery anodes synthesized near room temperature

    KAUST Repository

    Xia, Chuan

    2017-08-10

    In this report, we demonstrate a simple chemical bath deposition approach for the synthesis of layered SnS nanosheets (typically 6 nm or ~10 layers thick) at very low temperature (40 °C). We successfully synthesized SnS/C hybrid electrodes using a solution-based carbon precursor coating with subsequent carbonization strategy. Our data showed that the ultrathin carbon shell was critical to the cycling stability of the SnS electrodes. As a result, the as-prepared binder-free SnS/C electrodes showed excellent performance as sodium ion battery anodes. Specifically, the SnS/C anodes delivered a reversible capacity as high as 792 mAh·g−1 after 100 cycles at a current density of 100 mA·g−1. They also had superior rate capability (431 mAh·g−1 at 3,000 mA·g−1) and stable long-term cycling performance under a high current density (345 mAh·g−1 after 500 cycles at 3 A·g−1). Our approach opens up a new route to synthesize SnS-based hybrid materials at low temperatures for energy storage and other applications. Our process will be particularly useful for chalcogenide matrix materials that are sensitive to high temperatures during solution synthesis.

  18. Helium ion microscopy of enamel crystallites and extracellular tooth enamel matrix

    Directory of Open Access Journals (Sweden)

    Felicitas B Bidlack

    2014-10-01

    Full Text Available An unresolved problem in tooth enamel studies has been to analyze simultaneously and with sufficient spatial resolution both mineral and organic phases in their three dimensional (3D organization in a given specimen. This study aims to address this need using high-resolution imaging to analyze the 3D structural organization of the enamel matrix, especially amelogenin, in relation to forming enamel crystals. Chemically fixed hemi-mandibles from wild type mice were embedded in LR White acrylic resin, polished and briefly etched to expose the organic matrix in developing tooth enamel. Full-length amelogenin was labeled with specific antibodies and 10 nm immuno-gold. This allowed us to use and compare two different high-resolution imaging techniques for the analysis of uncoated samples. Helium ion microscopy (HIM was applied to study the spatial organization of organic and mineral structures, while field emission scanning electron microscopy (FE-SEM in various modes, including backscattered electron detection, allowed us to discern the gold-labeled proteins. Wild type enamel in late secretory to early maturation stage reveals adjacent to ameloblasts a lengthwise parallel alignment of the enamel matrix proteins, including full-length amelogenin proteins, which then transitions into a more heterogeneous appearance with increasing distance from the mineralization front. The matrix adjacent to crystal bundles forms a smooth and lacey sheath, whereas between enamel prisms it is organized into spherical components that are interspersed with rod-shaped protein. These findings highlight first, that the heterogeneous organization of the enamel matrix can be visualized in mineralized en bloc samples. Second, our results illustrate that the combination of these techniques is a powerful approach to elucidate the 3D structural organization of organic matrix molecules in mineralizing tissue in nanometer resolution.

  19. Facile synthesis of carbon-mediated porous nanocrystallite anatase TiO2 for improved sodium insertion capabilities as an anode for sodium-ion batteries

    Science.gov (United States)

    Wu, Feng; Luo, Rui; Xie, Man; Li, Li; Zhang, Xiaoxiao; Zhao, Luzi; Zhou, Jiahui; Wang, KangKang; Chen, Renjie

    2017-09-01

    Porous carbon-mediated nanocrystallite anatase TiO2 composites are synthesized successfully via a simple dilatory hydrolysis-calcination method. The structural and morphological characterizations reveal that carbon-mediated TiO2 with a carbon content of 9.9 wt % (C2-TiO2) shows a combination of mesoporous and macroporous structures with a pore volume of 0.20 cm3 g-1 and surface area of 40.3 m2 g-1. Notably, C2-TiO2 delivered enhanced electrochemical performances of a high charge capacity of 259 mA h g-1 at 0.1 C and a high rate performance of 110 mA h g-1 after 150 cycles, even at 1 C. A significant decrease is also observed in the electrochemical impedance of the carbon-mediated samples, which explains superior electrochemical performance. Compared with the bare anatase TiO2 (B-TiO2), improved sodium storage capabilities of carbon-mediated samples are attributed to the participation of carbon to form a symbiotic structure with TiO2, which not only increases pore volume of the samples but serves as highly conductive network to provide a Na+ diffusion path during the insertion/de-insertion of sodium ions. All of these encouraging results suggest that carbon-mediated TiO2 has a great potential for improving sodium insertion capabilities with a facile and low-cost synthesis process.

  20. Trace heavy metal ions promoted extracellular electron transfer and power generation by Shewanella in microbial fuel cells.

    Science.gov (United States)

    Xu, Yu-Shang; Zheng, Tao; Yong, Xiao-Yu; Zhai, Dan-Dan; Si, Rong-Wei; Li, Bing; Yu, Yang-Yang; Yong, Yang-Chun

    2016-07-01

    Although microbial fuel cells (MFCs) is considered as one of the most promising technology for renewable energy harvesting, low power output still accounts one of the bottlenecks and limits its further development. In this work, it is found that Cu(2+) (0.1μgL(-1)-0.1mgL(-1)) or Cd(2+) (0.1μgL(-1)-1mgL(-1)) significantly improve the electricity generation in MFCs. The maximum power output achieved with trace level of Cu(2+) (∼6nM) or Cd(2+) (∼5nM) is 1.3 times and 1.6 times higher than that of the control, respectively. Further analysis verifies that addition of Cu(2+) or Cd(2+) effectively improves riboflavin production and bacteria attachment on the electrode, which enhances bacterial extracellular electron transfer (EET) in MFCs. These results unveil the mechanism for power output enhancement by Cu(2+) or Cd(2+) addition, and suggest that metal ion addition should be a promising strategy to enhance EET as well as power generation of MFCs.

  1. An ancient pathway combining carbon dioxide fixation with the generation and utilization of a sodium ion gradient for ATP synthesis.

    Directory of Open Access Journals (Sweden)

    Anja Poehlein

    Full Text Available Synthesis of acetate from carbon dioxide and molecular hydrogen is considered to be the first carbon assimilation pathway on earth. It combines carbon dioxide fixation into acetyl-CoA with the production of ATP via an energized cell membrane. How the pathway is coupled with the net synthesis of ATP has been an enigma. The anaerobic, acetogenic bacterium Acetobacterium woodii uses an ancient version of this pathway without cytochromes and quinones. It generates a sodium ion potential across the cell membrane by the sodium-motive ferredoxin:NAD oxidoreductase (Rnf. The genome sequence of A. woodii solves the enigma: it uncovers Rnf as the only ion-motive enzyme coupled to the pathway and unravels a metabolism designed to produce reduced ferredoxin and overcome energetic barriers by virtue of electron-bifurcating, soluble enzymes.

  2. Nitrogen-doped carbon/graphene hybrid anode material for sodium-ion batteries with excellent rate capability

    Science.gov (United States)

    Liu, Huan; Jia, Mengqiu; Cao, Bin; Chen, Renjie; Lv, Xinying; Tang, Renjie; Wu, Feng; Xu, Bin

    2016-07-01

    Nitrogen-doped carbon/graphene (NCG) hybrid materials were prepared by an in-situ polymerization and followed pyrolysis for sodium-ion batteries. The NCG has a large interlayer distance (0.360 nm) and a high nitrogen content of 7.54 at%, resulting in a high reversible sodium storage capacity of 336 mAh g-1 at 30 mA g-1. The NCG shows a sandwich-like structure, i.e. nitrogen-doped carbon nanosheets closely coated on both sides of graphene. The carbon nanosheets shorten the ion diffusion distance, while the sandwiched graphene with high electronic conductivity guarantees fast electron transport, making the NCG exhibit excellent rate capability (94 mAh g-1 at 5 A g-1). It also exhibits good cycle stability with a capacity retention of 89% after 200 cycles at 50 mA g-1.

  3. Preparation of Al(OH)3 by ion membrane electrolysis and precipitation of sodium aluminate solution with seeds

    Institute of Scientific and Technical Information of China (English)

    LI Yuan-gao; CHEN Qi-yuan; WANG Song-sen; YIN Zhou-lan; ZHANG Ping-min

    2008-01-01

    The preparation of Al(OH)3 by the ion exchange membrane electrolysis followed by the precipitation of sodium aluminate solution with seeds was made. During the process of ion membrane electrolysis, the sodium aluminate solution is rapidly acidified and the caustic ratio (aK) is decreased due to oxygen evolution in the anodic region. And the causticity of solution is increased due to hydrogen evolution in the cathode region, producing the high concentration of caustic soda solution. Regulating the acidity of the anodic solution by controlling the electric quantity in the electrolysis and subsequent decomposing the solution, Al(OH)3 could yield with very large rate and high efficiency. The experiments also indicate that the quality of aluminum hydroxide product is greatly affected by the impurity silicon.

  4. Conductivity study and fourier transform infrared (FTIR) characterization of methyl cellulose solid polymer electrolyte with sodium iodide conducting ion

    Energy Technology Data Exchange (ETDEWEB)

    Abiddin, Jamal Farghali Bin Zainal [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor D.E. (Malaysia); Ahmad, Azizah Hanom [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor D.E. (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor D.E. (Malaysia)

    2015-08-28

    Sodium ion (Na{sup +}) based solid polymer electrolyte (SPE) has been prepared using solution cast technique with distilled water as solvent and Methylcellulose (MC) as a polymer host. Methylcellulose polymer was chosen as the polymer host due to the abundance of lone pair electrons in the carbonyl and C-O-C constituents, which in turn provide multiple hopping sites for the Na{sup +} conducting ions. Variable compositions of sodium iodide (NaI) salt were prepared to investigate the optimum MC-NaI weight ratio. Results from Electrical Impedance Spectroscopy (EIS) technique show that pure methylcellulose has a low conductivity of 3.61 × 10{sup −11} S/cm.The conductivity increases as NaI content increases up to optimum NaIcomposition of 40 wt%, which yields an average conductivity of 2.70 × 10{sup −5} S/cm.

  5. Hierarchical porous nitrogen doped carbon derived from horn comb as anode for sodium-ion storage with high performance

    Science.gov (United States)

    Ou, Junke; Yang, Lin; Xi, Xianghui

    2017-01-01

    Horn comb, an abundant biomass waste, has been successfully converted into a hierarchical porous nitrogen doped carbon (HPNDC) via a simple and costeffective approach. Tested as anode for sodium ion batteries (SIBs), horn comb derived carbon shows good rate capability and cycling stability, delivering a high initial charge capacity of 400 mAh g-1 at 100 mA g-1, retaining a reversible capacity of 112 mAh g-1 at 5 A g-1, and exhibiting a capacity of 241 mAh g-1 at 100 mA g-1 after 100 cycles. These superior electrochemical performances can be ascribed to its unique hierarchical pore structure combined with appropriate nitrogen doping effects. We believe that our works will be helpful in promoting the development of high-rate and low-cost sodium ion batteries for large-scale energy storage systems. [Figure not available: see fulltext.

  6. An Aqueous Symmetric Sodium-Ion Battery with NASICON-Structured Na3 MnTi(PO4 )3.

    Science.gov (United States)

    Gao, Hongcai; Goodenough, John B

    2016-10-04

    A symmetric sodium-ion battery with an aqueous electrolyte is demonstrated; it utilizes the NASICON-structured Na3 MnTi(PO4 )3 as both the anode and the cathode. The NASICON-structured Na3 MnTi(PO4 )3 possesses two electrochemically active transition metals with the redox couples of Ti(4+) /Ti(3+) and Mn(3+) /Mn(2+) working on the anode and cathode sides, respectively. The symmetric cell based on this bipolar electrode material exhibits a well-defined voltage plateau centered at about 1.4 V in an aqueous electrolyte with a stable cycle performance and superior rate capability. The advent of aqueous symmetric sodium-ion battery with high safety and low cost may provide a solution for large-scale stationary energy storage.

  7. Accumulation and localization of sodium and potassium ions in maize plants on saline soil

    Directory of Open Access Journals (Sweden)

    S. N. Kabuzenko

    2013-02-01

    Full Text Available The goal of this work is studying the accumulation and distribution of Na+ and K+ in maize hybrids of different salt tolerance under conditions of the chloride salinity. The new corn hybrid Veselka MV (salt-tolerant and Odessa 375 MB (not salt-tolerant were studied. The plants grown in salt-free chernozem soil are control. In the experiment, sodium chloride was dissolved in the irrigation water to form the salinity of test soils up to concentrations of 0.25, 0.5, 0.75, and 1.0% of ovendry weight. Soil moisture in the pots was maintained at 60% of the full field water capacity, the air temperature was +25…+27 °C, and the light – 10 klux. Plant samples were dried in the oven under 70 °C. Then, the average sample of 10 specimens was thoroughly levigated in the porcelain pounder  and dispersed in distilled water at 100 °C. The ions were extracted, and the extracts were centrifuged for 20 min at 3000 rpm. The ions content in the cell sap was analysed. Plant samples (1 g were incubated 10 min in chloroform, dried carefully with filter paper, and then the cell sap was squeezed. 1 ml of clear top layer of the cell sap was dissolved in 10 ml of distilled water. Ions content was determined by the atomic absorption spectrophotometer ("Karl Zeiss", Germany. Salt-tolerant maize hybrid Veselka MW (14 days age is characterized by an increased content of Na+ in the root tissues in comparison with the above-ground parts. In Odessa 375 MB hybrid this regularity is less pronounced. With the increase of sodium chloride concentration in the soil the content of Na+ in the aerial parts of plants rises. That may be connected with the reduced role of a root barrier. The salt-tolerant hybrid has a higher content of Na+ in the roots as compared to the above-ground parts. The content of K+ was higher in the above-ground parts, which is more pronounced in the salt-tolerant hybrid Veselka MB. The decrease of K+ in cell sap of the root under saline conditions was

  8. Quantification of Carbohydrates and Related Materials Using Sodium Ion Adducts Produced by Matrix-Assisted Laser Desorption Ionization

    Science.gov (United States)

    Ahn, Sung Hee; Park, Kyung Man; Moon, Jeong Hee; Lee, Seong Hoon; Kim, Myung Soo

    2016-11-01

    The utility of sodium ion adducts produced by matrix-assisted laser desorption ionization for the quantification of analytes with multiple oxygen atoms was evaluated. Uses of homogeneous solid samples and temperature control allowed the acquisition of reproducible spectra. The method resulted in a direct proportionality between the ion abundance ratio I([A + Na]+)/I([M + Na]+) and the analyte concentration, which could be used as a calibration curve. This was demonstrated for carbohydrates, glycans, and polyether diols with dynamic range exceeding three orders of magnitude.

  9. A Spinel-integrated P2-type Layered Composite: High-rate Cathode for Sodium-ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianming; Yan, Pengfei; Kan, Wang Hay; Wang, Chong M.; Manthiram, Arumugam

    2016-01-14

    Sodium-ion batteries (SIB) are being intensively investigated, owing to the natural abundance and low cost of Na resources. However, the SIBs still suffer from poor rate capability due to the large ionic radius of Na+ ion and the significant kinetic barrier to Na+-ion transport. Here, we present an Fd-3m spinel-integrated P2-type layered composite (P2 + Fd-3m) material as a high-rate cathode for SIBs. The P2 + Fd-3m composite material Na0.50Ni1/6Co1/6Mn2/3O2 shows significantly enhanced discharge capacity, energy density, and rate capability as compared to the pure P2-type counterpart. The composite delivers a high capacity of 85 mA h g-1 when discharging at a very high current density of 1500 mA g-1 (10C rate) between 2.0 and 4.5 V, validating it as a promising cathode candidate for high-power SIBs. The superior performance is ascribed to the improved kinetics in the presence of the integrated-spinel phase, which facilitates fast electron transport to coordinate with the timely Na+-ion insertion/extraction. The findings of this work also shed light on the importance of developing lattice doping, surface coating, and electrolyte additives to further improve the structural and interfacial stability of P2-type cathode materials and fully realize their practical applications in sodium-ion batteries.

  10. Handheld Device Adapted to Smartphone Cameras for the Measurement of Sodium Ion Concentrations at Saliva-Relevant Levels via Fluorescence

    Directory of Open Access Journals (Sweden)

    Michelle Lipowicz

    2015-06-01

    Full Text Available The use of saliva sampling as a minimally-invasive means for drug testing and monitoring physiology is a subject of great interest to researchers and clinicians. This study describes a new optical method based on non-axially symmetric focusing of light using an oblate spheroid sample chamber. The device is simple, lightweight, low cost and is easily attached to several different brands/models of smartphones (Apple, Samsung, HTC and Nokia for the measurement of sodium ion levels at physiologically-relevant saliva concentrations. The sample and fluorescent reagent solutions are placed in a specially-designed, lightweight device that excludes ambient light and concentrates 470-nm excitation light, from a low-power photodiode, within the sample through non-axially-symmetric refraction. The study found that smartphone cameras and post-image processing quantitated sodium ion concentration in water over the range of 0.5–10 mM, yielding best-fit regressions of the data that agree well with a data regression of microplate luminometer results. The data suggest that fluorescence can be used for the measurement of salivary sodium ion concentrations in low-resource or point-of-care settings. With further fluorescent assay testing, the device may find application in a variety of enzymatic or chemical assays.

  11. High energy density sodium-ion capacitors through co-intercalation mechanism in diglyme-based electrolyte system

    Science.gov (United States)

    Han, Pengxian; Han, Xiaoqi; Yao, Jianhua; Zhang, Lixue; Cao, Xiaoyan; Huang, Changshui; Cui, Gunglei

    2015-11-01

    A novel sodium-ion capacitor (NIC) was assembled using graphitic mesocarbon microbead anode and activated carbon cathode in diglyme-based electrolyte. Charge/discharge tests indicate that sodium ions can reversibly co-intercalated with diglyme solvent into graphite anode and show good rate performance. The energy densities of the NICs are as high as 93.5 and 86.5 Wh kg-1 at 573 and 2832 W kg-1 (equal to 4 C and 50 C) in the voltage window at 1-4 V, respectively. By optimizing the voltage ranges, the capacity retention of the NIC at 20 C is 98.3% even after 3000 cycles. Such superior electrochemical performance should be attributed to the reversible intercalated/deintercalated reaction of sodium ions and the formation of ternary graphite intercalation compounds in diglyme-based electrolyte. The present work pioneers new realms of hybrid energy storage system with high energy density, high power density and long cycle life.

  12. Ultrafine Nb2O5 Nanocrystal Coating on Reduced Graphene Oxide as Anode Material for High Performance Sodium Ion Battery.

    Science.gov (United States)

    Yan, Litao; Chen, Gen; Sarker, Swagotom; Richins, Stephanie; Wang, Huiqiang; Xu, Weichuan; Rui, Xianhong; Luo, Hongmei

    2016-08-31

    Ultrafine niobium oxide nanocrystals/reduced graphene oxide (Nb2O5 NCs/rGO) was demonstrated as a promising anode material for sodium ion battery with high rate performance and high cycle durability. Nb2O5 NCs/rGO was synthesized by controllable hydrolysis of niobium ethoxide and followed by heat treatment at 450 °C in flowing forming gas. Transmission electron microscopy images showed that Nb2O5 NCs with average particle size of 3 nm were uniformly deposited on rGO sheets and voids among Nb2O5 NCs existed. The architecture of ultrafine Nb2O5 NCs anchored on a highly conductive rGO network can not only enhance charge transfer and buffer the volume change during sodiation/desodiation process but also provide more active surface area for sodium ion storage, resulting in superior rate and cycle performance. Ex situ XPS analysis revealed that the sodium ion storage mechanism in Nb2O5 could be accompanied by Nb(5+)/Nb(4+) redox reaction and the ultrafine Nb2O5 NCs provide more surface area to accomplish the redox reaction.

  13. Energetics of discrete selectivity bands and mutation-induced transitions in the calcium-sodium ion channels family

    CERN Document Server

    Kaufman, I; Tindjong, R; McClintock, P V E; Eisenberg, R S

    2013-01-01

    We use Brownian dynamics simulations to study the permeation properties of a generic electrostatic model of a biological ion channel as a function of the fixed charge Q_f at its selectivity filter. We reconcile the recently-discovered discrete calcium conduction bands M0 (Q_f=1e), M1 (3e), M2 (5e) with the set of sodium conduction bands L0 (0.5-0.7e), L1 (1.5-2e) thereby obtaining a completed pattern of conduction and selectivity bands v Q_f for the sodium-calcium channels family. An increase of Q_f leads to an increase of calcium selectivity: L0 (sodium selective, non-blocking channel) -> M0 (non-selective channel) -> L1 (sodium selective channel with divalent block) -> M1 (calcium selective channel exhibiting the anomalous mole fraction effect). We create a consistent identification scheme where the L1 band is identified with the eukaryotic (DEKA) sodium channel, and L0 (speculatively) with the bacterial NaChBac channel. The scheme created is able to account for the experimentally observed mutation-induced ...

  14. Sodium concentration measurement during hemodialysis through ion-exchange resin and conductivity measure approach: in vitro experiments.

    Science.gov (United States)

    Tura, Andrea; Sbrignadello, Stefano; Mambelli, Emanuele; Ravazzani, Paolo; Santoro, Antonio; Pacini, Giovanni

    2013-01-01

    Sodium measurement during hemodialysis treatment is important to preserve the patient from clinical events related to hypo- or hyper-natremia Usually, sodium measurement is performed through laboratory equipment which is typically expensive, and requires manual intervention. We propose a new method, based on conductivity measurement after treatment of dialysate solution through ion-exchange resin. To test this method, we performed in vitro experiments. We prepared 40 ml sodium chloride (NaCl) samples at 280, 140, 70, 35, 17.5, 8.75, 4.375 mEq/l, and some "mixed samples", i.e., with added potassium chloride (KCl) at different concentrations (4.375-17.5 mEq/l), to simulate the confounding factors in a conductivity-based sodium measurement. We measured the conductivity of all samples. Afterwards, each sample was treated for 1 min with 1 g of Dowex G-26 resin, and conductivity was measured again. On average, the difference in the conductivity between mixed samples and corresponding pure NaCl samples (at the same NaCl concentration) was 20.9%. After treatment with the exchange resin, it was 14.7%, i.e., 42% lower. Similar experiments were performed with calcium chloride and magnesium chloride as confounding factors, with similar results. We also performed some experiments on actual dialysate solution during hemodialysis sessions in 15 patients, and found that the correlation between conductivity measures and sodium concentration improved after resin treatment (R=0.839 before treatment, R=0.924 after treatment, Pconductivity measures may improve the measurement of sodium compared to conductivity measures alone, and may become a possible simple approach for continuous and automatic sodium measurement during hemodialysis.

  15. Comparison of electrochemical performances of olivine NaFePO4 in sodium-ion batteries and olivine LiFePO4 in lithium-ion batteries

    Science.gov (United States)

    Zhu, Yujie; Xu, Yunhua; Liu, Yihang; Luo, Chao; Wang, Chunsheng

    2012-12-01

    Carbon-coated olivine NaFePO4 (C-NaFePO4) spherical particles with a uniform diameter of ~80 nm are obtained by chemical delithiation and subsequent electrochemical sodiation of carbon-coated olivine LiFePO4 (C-LiFePO4), which is synthesized by a solvothermal method. The C-NaFePO4 electrodes are identical (particle size, particle size distribution, surface coating, and active material loading, etc.) to C-LiFePO4 except that Li ions in C-LiFePO4 are replaced by Na ions, making them ideal for comparison of thermodynamics and kinetics between C-NaFePO4 cathode in sodium-ion (Na-ion) batteries and C-LiFePO4 in lithium-ion (Li-ion) batteries. In this paper, the equilibrium potentials, reaction resistances, and diffusion coefficient of Na in C-NaFePO4 are systematically investigated by using the galvanostatic intermittent titration technique (GITT), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and compared to those of the well-known LiFePO4 cathodes in Li-ion batteries. Due to the lower diffusion coefficient of Na-ion and higher contact and charge transfer resistances in NaFePO4 cathodes, the rate performance of C-NaFePO4 in Na-ion batteries is much worse than that of C-LiFePO4 in Li-ion batteries. However, the cycling stability of C-NaFePO4 is almost comparable to C-LiFePO4 by retaining 90% of its capacity even after 100 charge-discharge cycles at a charge-discharge rate of 0.1 C.Carbon-coated olivine NaFePO4 (C-NaFePO4) spherical particles with a uniform diameter of ~80 nm are obtained by chemical delithiation and subsequent electrochemical sodiation of carbon-coated olivine LiFePO4 (C-LiFePO4), which is synthesized by a solvothermal method. The C-NaFePO4 electrodes are identical (particle size, particle size distribution, surface coating, and active material loading, etc.) to C-LiFePO4 except that Li ions in C-LiFePO4 are replaced by Na ions, making them ideal for comparison of thermodynamics and kinetics between C-NaFePO4 cathode in

  16. Effect of Sodium Tanshinone Ⅱ A Sulfonate on Phosphorylation of Extracellular Signal-regulated Kinase1/2 in Angiotensin Ⅱ-induced Hypertrophy of Myocardial Cells

    Institute of Scientific and Technical Information of China (English)

    LI Shu-sheng; FENG Jun; ZHENG Zhi; LIANG Qian-sheng

    2008-01-01

    Objective:To observe the effects of sodium tanshinone Ⅱ A sulfonate(STS)on angiotensin Ⅱ(Ang Ⅱ)-induced hypertrophy of myocardial cells through the expression of phosphorylated extracellular signal-regulated kinase(P-ERK1/2).Methods:In the primary culture of neonatal rat myocardial cells.the total protein content in myocardial cells was determined by coomassie brilliant blue and the protein synthesis rate was measured by[3H]-Leucine incorporation as indexes for hypertrophy of myocardial cells.The expression of p-ERK1/2 was determined using Western blot and immunofluorescence Iabeling.Results:(1)The totaI protein and protein synthesis rate increased significantly in contrast to the control group after the myocardial cells were stimulated by Ang Ⅱ (1 μmol/L)for 24 h;STS markedly inhibited the increment of the total protein level induced by Ang Ⅱ and the syntheses of protein.(2)After pretreatment of myocardial cells with Ang Ⅱ(1 μ mol/L)for 5 min,the p-ERK1/2 protein expression was increased,with the most obvious effect shown at about 10 min;pretreatment of myocardial cells with STS at different doses(2,10,50 μ mol/L)for 30 min resulted in obvious inhibition of the expression of p-ERK1/2 stimulated by Ang Ⅱ in a dose-dependent manner.(3)After the myocardial cells were stimulated by Ang Ⅱ(1 μ mol/L),the immunofluorescence of ERK1/2 rapidly appeared in the nucleus.The activation and translocation process of ERK1/2 induced by Ang Ⅱ was blocked distinctly by STS.Conclusion:STS inhibited the myocardial cell hypertrophy induced by Ang Ⅱ,and the mechanism may be associated with the inhibition of p-ERK1/2 expression.

  17. Comparison of electrochemical performances of olivine NaFePO4 in sodium-ion batteries and olivine LiFePO4 in lithium-ion batteries.

    Science.gov (United States)

    Zhu, Yujie; Xu, Yunhua; Liu, Yihang; Luo, Chao; Wang, Chunsheng

    2013-01-21

    Carbon-coated olivine NaFePO(4) (C-NaFePO(4)) spherical particles with a uniform diameter of ∼80 nm are obtained by chemical delithiation and subsequent electrochemical sodiation of carbon-coated olivine LiFePO(4) (C-LiFePO(4)), which is synthesized by a solvothermal method. The C-NaFePO(4) electrodes are identical (particle size, particle size distribution, surface coating, and active material loading, etc.) to C-LiFePO(4) except that Li ions in C-LiFePO(4) are replaced by Na ions, making them ideal for comparison of thermodynamics and kinetics between C-NaFePO(4) cathode in sodium-ion (Na-ion) batteries and C-LiFePO(4) in lithium-ion (Li-ion) batteries. In this paper, the equilibrium potentials, reaction resistances, and diffusion coefficient of Na in C-NaFePO(4) are systematically investigated by using the galvanostatic intermittent titration technique (GITT), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and compared to those of the well-known LiFePO(4) cathodes in Li-ion batteries. Due to the lower diffusion coefficient of Na-ion and higher contact and charge transfer resistances in NaFePO(4) cathodes, the rate performance of C-NaFePO(4) in Na-ion batteries is much worse than that of C-LiFePO(4) in Li-ion batteries. However, the cycling stability of C-NaFePO(4) is almost comparable to C-LiFePO(4) by retaining 90% of its capacity even after 100 charge-discharge cycles at a charge-discharge rate of 0.1 C.

  18. Tracking Sodium-Antimonide Phase Transformations in Sodium-Ion Anodes: Insights from Operando Pair Distribution Function Analysis and Solid-State NMR Spectroscopy.

    Science.gov (United States)

    Allan, Phoebe K; Griffin, John M; Darwiche, Ali; Borkiewicz, Olaf J; Wiaderek, Kamila M; Chapman, Karena W; Morris, Andrew J; Chupas, Peter J; Monconduit, Laure; Grey, Clare P

    2016-02-24

    Operando pair distribution function (PDF) analysis and ex situ (23)Na magic-angle spinning solid-state nuclear magnetic resonance (MAS ssNMR) spectroscopy are used to gain insight into the alloying mechanism of high-capacity antimony anodes for sodium-ion batteries. Subtraction of the PDF of crystalline NaxSb phases from the total PDF, an approach constrained by chemical phase information gained from (23)Na ssNMR in reference to relevant model compounds, identifies two previously uncharacterized intermediate species formed electrochemically; a-Na(3-x)Sb (x ≈ 0.4-0.5), a structure locally similar to crystalline Na3Sb (c-Na3Sb) but with significant numbers of sodium vacancies and a limited correlation length, and a-Na(1.7)Sb, a highly amorphous structure featuring some Sb-Sb bonding. The first sodiation breaks down the crystalline antimony to form first a-Na(3-x)Sb and, finally, crystalline Na3Sb. Desodiation results in the formation of an electrode formed of a composite of crystalline and amorphous antimony networks. We link the different reactivity of these networks to a series of sequential sodiation reactions manifesting as a cascade of processes observed in the electrochemical profile of subsequent cycles. The amorphous network reacts at higher voltages reforming a-Na(1.7)Sb, then a-Na(3-x)Sb, whereas lower potentials are required for the sodiation of crystalline antimony, which reacts to form a-Na(3-x)Sb without the formation of a-Na(1.7)Sb. a-Na(3-x)Sb is converted to crystalline Na3Sb at the end of the second discharge. We find no evidence of formation of NaSb. Variable temperature (23)Na NMR experiments reveal significant sodium mobility within c-Na3Sb; this is a possible contributing factor to the excellent rate performance of Sb anodes.

  19. Determination of sodium cromoglycate in human plasma by liquid chromatography-mass spectrometry in the turbo ion spray mode.

    Science.gov (United States)

    Ozou, M L; Girault, J; Malgouyat, J M; Pasquier, O

    2001-12-25

    A highly sensitivity liquid chromatography-tandem mass spectrometry method has been developed for the quantitation of sodium cromoglycate (SCG) in human plasma. The method was validated over a linear range of 0.100-50.0 ng/ml, using 13C4 sodium cromoglycate as the internal standard. Compounds were extracted from 1.0 ml of lithium heparin plasma by methanol elution of C18 solid-phase extraction cartridges. The dried residue was reconstituted with 100 microl of 0.01 N HCl. and 30 microl was injected onto the LC-MS-MS system. Chromatographic separation was achieved on a C8 (3.5 microm) column with an isocratic mobile phase of methanol-water-0.5 M ammonium acetate (35:64.8:0.2, v/v/v). The analytes were detected with a PE Sciex API 3000 mass spectrometer using turbo ion spray with positive ionization. Ions monitored in the multiple reaction monitoring (MRM) mode were m/z 469.2 (precursor ion) to m/z 245.1 (product ion) for SCG and m/z 473.2 (precursor ion) to m/z 247.1 (product ion) for 13C4 SCG (I.S.). The average recoveries of SCG and the I.S. from human plasma were 91 and 87%, respectively. The low limit of quantitation was 0.100 ng/ml. Results from a 4-day validation study demonstrated excellent precision (C.V.% values were between 1.9 and 6.5%) and accuracy (-5.4 to - 1.2%) across the calibration range of 0.100-50.0 ng/ml.

  20. Reconstituted voltage-sensitive sodium channel from Electrophorus electricus: chemical modifications that alter regulation of ion permeability.

    Science.gov (United States)

    Cooper, E C; Tomiko, S A; Agnew, W S

    1987-01-01

    At equilibrium, voltage-sensitive sodium channels normally are closed at all potentials. They open transiently in response to changes in membrane voltage or chronically under the influence of certain neurotoxins. Covalent modifications that result in chronic opening may help identify molecular domains involved in conductance regulation. Here, the purified sodium channel from electric eel electroplax, reconstituted in artificial liposomes, has been used to screen for such modifications. When the liposomes were treated with the alkaloid neurotoxin batrachotoxin, sodium-selective ion fluxes were produced, with permeability ratios PNa greater than PTl greater than PK greater than PRb greater than PCs. When the liposomes were treated with either of two oxidizing reagents (N-bromoacetamide or N-bromosuccinimide), or with Pronase or trypsin, ion-selective fluxes also were stimulated. These were blocked by tetrodotoxin and the anesthetic QX-314 in a manner suggesting that only modification of the cytoplasmic protein surface resulted in stimulation. Limited exposure to trypsin resulted in strong flux activation, with the concomitant appearance of peptide fragments with masses of approximately equal to 130, 70, and 38 kDa and fragments with masses of 45 and 24 kDa appearing later. We propose that characterization of these fragments may allow identification of channel domains important for inactivation gating. Images PMID:2442755

  1. Porous organic polymer/RGO composite as high performance cathode for half and full sodium ion batteries

    Science.gov (United States)

    Li, Aihua; Feng, Zhenyu; Sun, Yan; Shang, Limei; Xu, Liqiang

    2017-03-01

    Redox-active organic polymers are promising cathode electrodes owing to the advantages of open and flexible frame-works, renewability and environmental friendliness. Sodium salt of poly (2, 5-dihydroxy-p-benzoquinonyl sulfide)/RGO (Na2PDHBQS/RGO) composite has been fabricated via a convenient route and applied as a high performance and stable cathode for sodium ion batteries. The Na2PDHBQS/RGO was investigated in ether-based electrolyte, which demonstrated better electrochemical performances (228, 214, 203, 193, 172 and 147 mAh g-1 at 0.1, 0.2, 0.4, 0.8, 2 and 4C, respectively) than that in traditional ester-based ones. The high specific capacity, excellent cycle stability and reversibility of Na2PDHBQS/RGO may be attributed to the special porous structure, enhanced electronic conductivity by the introduction of RGO and fast sodium ion and electron diffusion rate in ether-based electrolyte. In addition, the Na2PDHBQS/RGO cathode has been assembled with disodium terephthalate (Na2TP) anode to compose a full cell for the first time, which presents an initial reversible capacity of 210 mAh g-1 at 0.1C.

  2. An Integrated Glucose Sensor with an All-Solid-State Sodium Ion-Selective Electrode for a Minimally Invasive Glucose Monitoring System

    Directory of Open Access Journals (Sweden)

    Junko Kojima

    2015-06-01

    Full Text Available We developed a minimally invasive glucose monitoring system that uses a microneedle to permeate the skin surface and a small hydrogel to accumulate interstitial fluid glucose. The measurement of glucose and sodium ion levels in the hydrogel is required for estimating glucose levels in blood; therefore, we developed a small, enzyme-fixed glucose sensor with a high-selectivity, all-solid-state, sodium ion-selective electrode (ISE integrated into its design. The glucose sensor immobilized glucose oxidase showed a good correlation between the glucose levels in the hydrogels and the reference glucose levels (r > 0.99, and exhibited a good precision (coefficient of variation = 2.9%, 0.6 mg/dL. In the design of the sodium ISEs, we used the insertion material Na0.33MnO2 as the inner contact layer and DD16C5 exhibiting high Na+/K+ selectivity as the ionophore. The developed sodium ISE exhibited high selectivity (\\( \\log \\,k^{pot}_{Na,K} = -2.8\\ and good potential stability. The sodium ISE could measure 0.4 mM (10−3.4 M sodium ion levels in the hydrogels containing 268 mM (10−0.57 M KCl. The small integrated sensor (ϕ < 10 mm detected glucose and sodium ions in hydrogels simultaneously within 1 min, and it exhibited sufficient performance for use as a minimally invasive glucose monitoring system.

  3. Fabrication of cubic spinel MnCo2O4 nanoparticles embedded in graphene sheets with their improved lithium-ion and sodium-ion storage properties

    Science.gov (United States)

    Chen, Chang; Liu, Borui; Ru, Qiang; Ma, Shaomeng; An, Bonan; Hou, Xianhua; Hu, Shejun

    2016-09-01

    Cubic Spinel MnCo2O4/graphene sheets (MCO/GS) nanocomposites are synthesized by a facile hydrothermal method with a subsequent annealing process. Nano-sized MnCo2O4 particles are evenly embedded in paper-like graphene sheets, possessing a unique nanoparticles-on-sheets hybrid nanostructure, with particle size around 20-50 nm. Owing to the special nanoparticles-on-sheets structures, MCO/GS nanocomposites have an outstanding electrochemical performance for rechargeable energy storage devices. As an anode material for lithium-ion batteries, MCO/GS electrodes exhibit high reversible discharge capacities (1350.4 mAh g-1 at the initial rate of 100 mA g-1), excellent rate capability (462.1 mAh g-1 at a current rate of 4000 mA g-1) and outstanding cycling performance (584.3 mAh g-1 at 2000 mA g-1 after 250 cycles). Meanwhile, as an anode material for sodium-ion batteries, MCO/GS electrodes also exhibit comparably promising electrochemical characteristics. Greatly improved electrochemical properties can be assigned to the special advantageous nanostructures. Besides, the existence of graphene sheets is beneficial to the transportation of ions/electrons during battery operation. The outstanding electrochemical performance demonstrates that the lithium/sodium storage capability of MCO/GS nanocomposites is highly promising for high-capacity batteries.

  4. TiO2 nanorods grown on carbon fiber cloth as binder-free electrode for sodium-ion batteries and flexible sodium-ion capacitors

    Science.gov (United States)

    Liu, Sainan; Luo, Zhigao; Tian, Gengyu; Zhu, Mengnan; Cai, Zhenyang; Pan, Anqiang; Liang, Shuquan

    2017-09-01

    Na-ion batteries (NIBs) and Na-ion capacitors (NICs) have tremendous potential in many large-scale energy storage applications. Here, NIBs based on TiO2 nanorods/carbon fiber cloth (TiO2/CFC) flexible anode materials are introduced. The as-prepared flexible anode exhibited a notable rate performance and high specific capacity of 148.7 mAh g-1 after 2000 cycles at 1 A g-1. Furthermore, we demonstrate a highly flexible NIC system employing the TiO2/CFC anode and carbon fibers (CFs) as the cathode material. The flexible TiO2/CFC//CFs NIC device achieved a high energy density of 73.8 Wh kg-1 and high power density of 13,750 W kg-1, as well as long-term cycling stability over 4000 cycles with a capacity retention of ∼90%.

  5. TRIPLICATE SODIUM IODIDE GAMMA RAY MONITORS FOR THE SMALL COLUMN ION EXCHANGE PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    Couture, A.

    2011-09-20

    This technical report contains recommendations from the Analytical Development (AD) organization of the Savannah River National Laboratory (SRNL) for a system of triplicate Sodium Iodide (NaI) detectors to be used to monitor Cesium-137 ({sup 137}Cs) content of the Decontaminated Salt Solution (DSS) output of the Small Column Ion Exchange (SCIX) process. These detectors need to be gain stabilized with respect to temperature shifts since they will be installed on top of Tank 41 at the Savannah River Site (SRS). This will be accomplished using NaI crystals doped with the alpha-emitting isotope, Americium-241({sup 241}Am). Two energy regions of the detector output will be monitored using single-channel analyzers (SCAs), the {sup 137}Cs full-energy {gamma}-ray peak and the {sup 241}Am alpha peak. The count rate in the gamma peak region will be proportional to the {sup 137}Cs content in the DSS output. The constant rate of alpha decay in the NaI crystal will be monitored and used as feedback to adjust the high voltage supply to the detector in response to temperature variation. An analysis of theoretical {sup 137}Cs breakthrough curves was used to estimate the gamma activity expected in the DSS output during a single iteration of the process. Count rates arising from the DSS and background sources were predicted using Microshield modeling software. The current plan for shielding the detectors within an enclosure with four-inch thick steel walls should allow the detectors to operate with the sensitivity required to perform these measurements. Calibration, testing, and maintenance requirements for the detector system are outlined as well. The purpose of SCIX is to remove and concentrate high-level radioisotopes from SRS salt waste resulting in two waste streams. The concentrated high-level waste containing {sup 137}Cs will be sent to the Defense Waste Processing Facility (DWPF) for vitrification and the low-level DSS will be sent to the Saltstone Production Facility (SPF

  6. RNAi-mediated knockdown of the voltage gated sodium ion channel TcNav causes mortality in Tribolium castaneum

    Science.gov (United States)

    Abd El Halim, Hesham M.; Alshukri, Baida M. H.; Ahmad, Munawar S.; Nakasu, Erich Y. T.; Awwad, Mohammed H.; Salama, Elham M.; Gatehouse, Angharad M. R.; Edwards, Martin G.

    2016-01-01

    The voltage-gated sodium ion channel (VGSC) belongs to the largest superfamily of ion channels. Since VGSCs play key roles in physiological processes they are major targets for effective insecticides. RNA interference (RNAi) is widely used to analyse gene function, but recently, it has shown potential to contribute to novel strategies for selectively controlling agricultural insect pests. The current study evaluates the delivery of dsRNA targeted to the sodium ion channel paralytic A (TcNav) gene in Tribolium castaneum as a viable means of controlling this insect pest. Delivery of TcNav dsRNA caused severe developmental arrest with larval mortalities up to 73% post injection of dsRNA. Injected larvae showed significant (p < 0.05) knockdown in gene expression between 30–60%. Expression was also significantly (p < 0.05) reduced in pupae following injection causing 30% and 42% knockdown for early and late pupal stages, respectively. Oral delivery of dsRNA caused dose-dependant mortalities of between 19 and 51.34%; this was accompanied by significant (p < 0.05) knockdown in gene expression following 3 days of continuous feeding. The majority of larvae injected with, or fed, dsRNA died during the final larval stage prior to pupation. This work provides evidence of a viable RNAi-based strategy for insect control. PMID:27411529

  7. Tin and Tin Compounds for Sodium Ion Battery Anodes: Phase Transformations and Performance.

    Science.gov (United States)

    Li, Zhi; Ding, Jia; Mitlin, David

    2015-06-16

    Sodium ion batteries (NIB, NAB, SIB) are attracting interest as a potentially lower cost alternative to lithium ion batteries (LIB), with readily available and geographically democratic reserves of the metal. Tin is one of most promising SIB anode materials, which alloys with up to 3.75 Na, leading to a charge storage capacity of 847 mAh g(-1). In this Account, we outline the state-of-the-art understanding regarding the sodiation-induced phase transformations and the associated performance in a range of Sn-based systems, treating metallic Sn and its alloys, tin oxide (SnO2), tin sulfide (SnS2/SnS), and tin phosphide (Sn4P3). We first detail what is known about the sodiation sequence in metallic Sn, highlighting the most recent insight into the reactions prior to the terminal equilibrium Na15Sn4 intermetallic. We explain why researchers argue that the equilibrium (phase diagram) series of phase transitions does not occur in this system, and rather why sodiation/desodiation proceeds through a series of metastable crystalline and amorphous structures. We also outline the recent modeling-based insight regarding how this phase transition profoundly influences the mechanical properties of the alloy, progressively changing the bonding and the near neighbor arrangement from "Sn-like" to "Na-like" in the process. We then go on to discuss the sodiation reactions in SnO2. We argue that while a substantial amount of experimental work already exists where the focus is on synthesis and testing of tin oxide-based nanocomposites, the exact sodiation sequence is just beginning to be understood. Unlike in Sn and Sn alloys, where capacities near the theoretical are reached at least early during cycling, SnO2 never quite achieves anything close to the 1398 mAh g(-1) that would be possible with a combination of fully reversible conversion and alloying reactions. We highlight recent work demonstrating that contrary to general expectations, it is the Sn to Na15Sn4 alloying reaction that

  8. Carbon- and Binder-Free NiCo2O4 Nanoneedle Array Electrode for Sodium-Ion Batteries: Electrochemical Performance and Insight into Sodium Storage Reaction

    Science.gov (United States)

    Lee, Jong-Won; Shin, Hyun-Sup; Lee, Chan-Woo; Jung, Kyu-Nam

    2016-02-01

    Sodium (Na)-ion batteries (NIBs) have attracted significant interest as an alternative chemistry to lithium (Li)-ion batteries for large-scale stationary energy storage systems. Discovering high-performance anode materials is a great challenge for the commercial success of NIB technology. Transition metal oxides with tailored nanoarchitectures have been considered as promising anodes for NIBs due to their high capacity. Here, we demonstrate the fabrication of a nanostructured oxide-only electrode, i.e., carbon- and binder-free NiCo2O4 nanoneedle array (NCO-NNA), and its feasibility as an anode for NIBs. Furthermore, we provide an in-depth experimental study of the Na storage reaction (sodiation and desodiation) in NCO-NNA. The NCO-NNA electrode is fabricated on a conducting substrate by a hydrothermal method with subsequent heat treatment. When tested in an electrochemical Na half-cell, the NCO-NNA electrode exhibits excellent Na storage capability: a charge capacity as high as 400 mAh g-1 is achieved at a current density of 50 mA g-1. It also shows a greatly improved cycle life (~215 mAh g-1 after 50 cycles) in comparison to a conventional powder-type electrode (~30 mAh g-1). However, the Na storage performance is still inferior to that of Li, which is mainly due to sluggish kinetics of sodiation-desodiation accompanied by severe volume change.

  9. High performance sodium-ion hybrid capacitor based on Na2Ti2O4(OH)2 nanostructures

    Science.gov (United States)

    Babu, Binson; Shaijumon, M. M.

    2017-06-01

    Hybrid Na-ion capacitors bridge the performance gap between Na-ion batteries and supercapacitors and offer excellent energy and power characteristics. However, designing efficient anode and cathode materials with improved kinetics and long cycle life is essential for practical implementation of this technology. Herein, layered sodium titanium oxide hydroxide, Na2Ti2O4(OH)2, synthesized through hydrothermal technique, is studied as efficient anode material for hybrid Na-ion capacitor. Half-cell electrochemical studies vs. Na/Na+ showed excellent performance for Na2Ti2O4(OH)2 electrode, with ∼57.2% of the total capacity (323.3 C g-1 at 1.0 mV s-1) dominated by capacitive behavior and the remaining due to Na-intercalation. The obtained values are in good agreement with Trasatti plots indicating the potential of this material as efficient anode for hybrid Na-ion capacitor. Further, a full cell Na-ion capacitor is fabricated with Na2Ti2O4(OH)2 as anode and chemically activated Rice Husk Derived Porous Carbon (RHDPC-KOH) as cathode by using organic electrolyte. The hybrid device, operated at a maximum cell voltage of 4 V, exhibits stable electrochemical performance with a maximum energy density of ∼65 Wh kg-1 (at 500 W kg-1, 0.20 A g-1) and with more than ∼ 93% capacitive retention after 3000 cycles.

  10. UV-exposed Bragg gratings for laser applications in silver-sodium ion-exchanged phosphate glass waveguides.

    Science.gov (United States)

    Yliniemi, Sanna; Albert, Jacques; Wang, Qing; Honkanen, Seppo

    2006-04-03

    High reflectivity Bragg gratings have been written by ArF excimer laser through a phase mask into IOG-1 hybrid phosphate glass. After grating exposure, a waveguide was fabricated by silver-sodium ion-exchange. Reflectivities around 80% at a wavelength of ~ 1535 nm were measured from the waveguide for both quasi-TE and -TM polarizations. Waveguide laser operation with the photowritten waveguide grating as another mirror was demonstrated. Output power of 3.8 mW with a pump power of 199 mW could be extracted from the laser configuration.

  11. A Biodegradable Polydopamine-Derived Electrode Material for High-Capacity and Long-Life Lithium-Ion and Sodium-Ion Batteries.

    Science.gov (United States)

    Sun, Tao; Li, Zong-Jun; Wang, Heng-Guo; Bao, Di; Meng, Fan-Lu; Zhang, Xin-Bo

    2016-08-26

    Polydopamine (PDA), which is biodegradable and is derived from naturally occurring products, can be employed as an electrode material, wherein controllable partial oxidization plays a key role in balancing the proportion of redox-active carbonyl groups and the structural stability and conductivity. Unexpectedly, the optimized PDA derivative endows lithium-ion batteries (LIBs) or sodium-ion batteries (SIBs) with superior electrochemical performances, including high capacities (1818 mAh g(-1) for LIBs and 500 mAh g(-1) for SIBs) and good stable cyclabilities (93 % capacity retention after 580 cycles for LIBs; 100 % capacity retention after 1024 cycles for SIBs), which are much better than those of their counterparts with conventional binders. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. "Electron/Ion Sponge"-Like V-Based Polyoxometalate: Toward High-Performance Cathode for Rechargeable Sodium Ion Batteries.

    Science.gov (United States)

    Liu, Jilei; Chen, Zhen; Chen, Shi; Zhang, Bowei; Wang, Jin; Wang, Huanhuan; Tian, Bingbing; Chen, Minghua; Fan, Xiaofeng; Huang, Yizhong; Sum, Tze Chien; Lin, Jianyi; Shen, Ze Xiang

    2017-07-25

    One key challenge facing room temperature Na-ion batteries lies in identifying earth-abundant, environmentally friendly and safe materials that can provide efficient Na(+) storage sites in Na-ion batteries. Herein, we report such a material, polyoxometalate Na2H8[MnV13O38] (NMV), with entirely different composition and structure from those cathode compounds reported before. Ex-situ XPS and FTIR analyses reveal that NMV cathode behaves like an "electron/Na-ion sponge", with 11 electrons/Na(+) acceptability per mole, which has a decisive contribution to the high capacity. The extraordinary structural features, evidenced by X-ray crystallographic analysis, of Na2H8[MnV13O38] with a flexible 2D lamellar network and 1D open channels provide diverse Na ion migration pathways, yielding good rate capability. First-principle calculations demonstrate that a super-reduced state, [MnV13O38](20-), is formed with slightly expanded size (ca. 7.5%) upon Na(+) insertion compared to the original [MnV13O38](9-). This "ion sponge" feature ensures the good cycling stability. Consequently, benefiting from the combinations of "electron/ion sponge" with diverse Na(+) diffusion channels, when revealed as the cathode materials for Na-ion batteries, Na2H8[MnV13O38]/G exhibits a high specific capacity (ca. 190 mA h/g at 0.1 C), associates with a good rate capability (130 mA h/g at 1 C), and a good capacity retention (81% at 0.2 C). Our results promote better understanding of the storage mechanism in polyoxometalate host, enrich the existing rechargeable SIBs cathode chemistry, and enlighten an exciting direction for exploring promising cathode materials for Na-ion batteries.

  13. A rationally designed dual role anode material for lithium-ion and sodium-ion batteries: case study of eco-friendly Fe3O4.

    Science.gov (United States)

    Hariharan, Srirama; Saravanan, Kuppan; Ramar, Vishwanathan; Balaya, Palani

    2013-02-28

    Identifying dual role electrode materials capable of storing both lithium and sodium are thought to be highly relevant, as these materials could find potential applications simultaneously in lithium and sodium ion batteries. In this regard, the concept of dual alkali storage is demonstrated in Fe(3)O(4) anode material undergoing conversion reaction. To enable improved storage, a rational active material and electrode design is proposed. Accordingly, the following features were simultaneously incorporated into the design: (i) an optimal particle size, (ii) a conducting matrix, (iii) adequately large active material surface area and (iv) strong electrode material-current collector integrity. Electrodes incorporating this rational design exhibit excellent high rate performance and impressive cyclability during lithium storage. For instance, Fe(3)O(4) electrodes deliver a charge capacity of 950 mAh g(-1) at 1.2 C (~2.6 times higher than graphite and 5.4 times higher than Li(4)Ti(5)O(12)). Further, these electrodes show no signs of capacity fade even up to 1100 cycles. Impressively, the cells could also be charged-discharged to 65% of their theoretical capacity in just 5 min or 12 C (11.11 A g(-1)). The rate performance and cyclability of lithium storage achieved here are amongst the highest reported values in the literature for the conversion reaction in Fe(3)O(4). Besides lithium storage, the dual role of this anode is shown by demonstrating its sodium storage ability by conversion reaction for the first time.

  14. Release of ATP from marginal cells in the cochlea of neonatal rats can be induced by changes in extracellular and intracellular ion concentrations.

    Directory of Open Access Journals (Sweden)

    Yating Peng

    Full Text Available BACKGROUND: Adenosine triphosphate (ATP plays an important role in the cochlea. However, the source of ATP and the mechanism by which it is released remain unclear. This study investigates the presence and release mechanism of ATP in vitro cultured marginal cells isolated from the stria vascularis of the cochlea in neonatal rats. METHODS: Sprague-Dawley rats aged 1-3 days old were used for isolation, in vitro culture, and purification of marginal cells. Cultured marginal cells were verified by flow cytometry. Vesicles containing ATP in these cells were identified by fluorescence staining. The bioluminescence assay was used for determination of ATP concentration in the extracellular fluid released by marginal cells. Assays for ATP concentration were performed when the ATP metabolism of cells was influenced, and ionic concentrations in intracellular and extracellular fluid were found to change. RESULTS: Evaluation of cultured marginal cells with flow cytometry revealed the percentage of fluorescently-labeled cells as 92.9% and 81.9%, for cytokeratin and vimentin, respectively. Quinacrine staining under fluorescence microscopy revealed numerous green, star-like spots in the cytoplasm of these cells. The release of ATP from marginal cells was influenced by changes in the concentration of intracellular and extracellular ions, namely extracellular K(+ and intra- and extracellular Ca(2+. Furthermore, changes in the concentration of intracellular Ca(2+ induced by the inhibition of the phospholipase signaling pathway also influence the release of ATP from marginal cells. CONCLUSION: We confirmed the presence and release of ATP from marginal cells of the stria vascularis. This is the first study to demonstrate that the release of ATP from such cells is associated with the state of the calcium pump, K(+ channel, and activity of enzymes related to the phosphoinositide signaling pathway, such as adenylate cyclase, phospholipase C, and phospholipase A(2.

  15. Tracking Sodium-Antimonide Phase Transformations in Sodium-Ion Anodes: Insights from Operando Pair Distribution Function Analysis and Solid-State NMR Spectroscopy

    Science.gov (United States)

    2016-01-01

    Operando pair distribution function (PDF) analysis and ex situ 23Na magic-angle spinning solid-state nuclear magnetic resonance (MAS ssNMR) spectroscopy are used to gain insight into the alloying mechanism of high-capacity antimony anodes for sodium-ion batteries. Subtraction of the PDF of crystalline NaxSb phases from the total PDF, an approach constrained by chemical phase information gained from 23Na ssNMR in reference to relevant model compounds, identifies two previously uncharacterized intermediate species formed electrochemically; a-Na3–xSb (x ≈ 0.4–0.5), a structure locally similar to crystalline Na3Sb (c-Na3Sb) but with significant numbers of sodium vacancies and a limited correlation length, and a-Na1.7Sb, a highly amorphous structure featuring some Sb–Sb bonding. The first sodiation breaks down the crystalline antimony to form first a-Na3–xSb and, finally, crystalline Na3Sb. Desodiation results in the formation of an electrode formed of a composite of crystalline and amorphous antimony networks. We link the different reactivity of these networks to a series of sequential sodiation reactions manifesting as a cascade of processes observed in the electrochemical profile of subsequent cycles. The amorphous network reacts at higher voltages reforming a-Na1.7Sb, then a-Na3–xSb, whereas lower potentials are required for the sodiation of crystalline antimony, which reacts to form a-Na3–xSb without the formation of a-Na1.7Sb. a-Na3–xSb is converted to crystalline Na3Sb at the end of the second discharge. We find no evidence of formation of NaSb. Variable temperature 23Na NMR experiments reveal significant sodium mobility within c-Na3Sb; this is a possible contributing factor to the excellent rate performance of Sb anodes. PMID:26824406

  16. Large-Area Carbon Nanosheets Doped with Phosphorus: A High-Performance Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Hou, Hongshuai; Shao, Lidong; Zhang, Yan; Zou, Guoqiang; Chen, Jun; Ji, Xiaobo

    2017-01-01

    Large-area phosphorus-doped carbon nanosheets (P-CNSs) are first obtained from carbon dots (CDs) through self-assembly driving from thermal treatment with Na catalysis. This is the first time to realize the conversion from 0D CDs to 2D nanosheets doped with phosphorus. The sodium storage behavior of phosphorus-doped carbon material is also investigated for the first time. As anode material for sodium-ion batteries (SIBs), P-CNSs exhibit superb performances for electrochemical storage of sodium. When cycled at 0.1 A g(-1), the P-CNSs electrode delivers a high reversible capacity of 328 mAh g(-1), even at a high current density of 20 A g(-1), a considerable capacity of 108 mAh g(-1) can still be maintained. Besides, this material also shows excellent cycling stability, at a current density of 5 A g(-1), the reversible capacity can still reach 149 mAh g(-1) after 5000 cycles. This work will provide significant value for the development of both carbon materials and SIBs anode materials.

  17. MoS2/cotton-derived carbon fibers with enhanced cyclic performance for sodium-ion batteries

    Science.gov (United States)

    Li, Xiang; Yang, Yan; Liu, Jiangwen; Ouyang, Liuzhang; Liu, Jun; Hu, Renzong; Yang, Lichun; Zhu, Min

    2017-08-01

    Carbon fibers derived from bio-template are low cost and environmental benign, therefore have attracted much attention in energy storage materials. In this work, we successfully fabricated MoS2/cotton-derived carbon fibers (MoS2/CDCFs) via hydrothermal route followed by carbonization process. In the composite of MoS2/CDCFs, MoS2 nanosheets vertically grow on the carbon fibers which offer fast ways for electron transfer and at the same time act as robust support to buffer the volume changes of MoS2 nanosheets during discharge/charge cycles. As anode materials for sodium-ion batteries, MoS2/CDCFs exhibit good rate performance and markedly enhanced cyclic stability due to the conductive support of CDCFs. At a current density of 0.1 A g-1, the MoS2/CDCFs-1 shows an initial reversible capacity of 504.9 mAh g-1, and maintains 444.5 mAh g-1 after 50 cycles. Even when the current density increases to 0.5 A g-1, it maintains 323.1 mAh g-1 after 150 cycles, which is much higher than the capacity retention of 149.6 mAh g-1 for the bare MoS2 nanosheets. The improved electrochemical performance verifies the effective strategy of using cotton as carbon source to construct hierarchical composites for sodium-ion batteries.

  18. Sb-AlC0.75-C composite anodes for high-performance sodium-ion batteries

    Science.gov (United States)

    Jung, Gyu Jin; Lee, Yongho; Mun, Yoo Seok; Kim, Hyeongwoo; Hur, Jaehyun; Kim, Tae Young; Suh, Kwang S.; Kim, Ji Hyeon; Lee, Daeho; Choi, Wonchang; Kim, Il Tae

    2017-02-01

    Antimony (Sb) nanoparticles dispersed in a hybrid matrix consisting of aluminum (Al) and carbon, AlC0.75-C were synthesized via one-step high-energy mechanical milling (HEMM) process and assessed as potential anode materials for use in sodium-ion batteries. The introduction of carbon during HEMM led to the formation of individual Sb nanoparticles dispersed in the AlC0.75-C matrix; in the absence of carbon during HEMM, an AlSb alloy was formed. The Sb-AlC0.75-C composite anodes demonstrated better cycling performance as well as higher rate capability compared to an AlSb anode; these improved properties could be due to the well-developed Sb phase, which acts as an electrochemically active nanocrystalline material in the AlC0.75/carbon conductive matrix. Furthermore, when fluoroethylene carbonate (FEC) was added to the electrolyte, the sodium-ion cells exhibited the best electrochemical performances, corresponding to a capacity retention of 83% at 100 cycles at 100 mA g-1 and a high rate capacity retention of 58% at 5000 mA g-1. In addition, the as-prepared Sb-AlC0.75-C composite has a high tap density; thus, its volumetric capacity was approximately three times that of carbon.

  19. Interconnected CoFe2O4-Polypyrrole Nanotubes as Anode Materials for High Performance Sodium Ion Batteries.

    Science.gov (United States)

    He, Qiming; Rui, Kun; Chen, Chunhua; Yang, Jianhua; Wen, Zhaoyin

    2017-10-10

    CoFe2O4-coated polypyrrole (PPy) nanotubes (CFO-PPy-NTs) with three-dimensional (3-D) interconnected networks have been prepared through a simple hydrothermal method. The application has been also studied for sodium ion batteries (SIBs). The finely crystallized CoFe2O4 nanoparticles (around 5 nm in size) are uniformly grown on the PPy nanotubes. When tested as anode materials for SIBs, the CFO-PPy-NT electrode maintains a discharge capacity of 400 mA h g(-1) and a stable Coulombic efficiency of 98% after 200 cycles at 100 mA g(-1). Even at a higher current density of 1000 mA g(-1), the composite can still retain a discharge capacity of 220 mA h g(-1) after 2000 cycles. The superior electrochemical performance could be mainly ascribed to the uniform distribution of CoFe2O4 on the 3-D matrix of PPy interconnected nanotubes, which favors the diffusion of sodium ions and electronic transportation and also buffers the large volumetric expansion during charge/discharge. Thereby our study suggests that such CFO-PPy-NTs have great potential as an anode material for SIBs.

  20. Achieving High-Energy-High-Power Density in a Flexible Quasi-Solid-State Sodium Ion Capacitor.

    Science.gov (United States)

    Li, Hongsen; Peng, Lele; Zhu, Yue; Zhang, Xiaogang; Yu, Guihua

    2016-09-14

    Simultaneous integration of high-energy output with high-power delivery is a major challenge for electrochemical energy storage systems, limiting dual fine attributes on a device. We introduce a quasi-solid-state sodium ion capacitor (NIC) based on a battery type urchin-like Na2Ti3O7 anode and a capacitor type peanut shell derived carbon cathode, using a sodium ion conducting gel polymer as electrolyte, achieving high-energy-high-power characteristics in solid state. Energy densities can reach 111.2 Wh kg(-1) at power density of 800 W kg(-1), and 33.2 Wh kg(-1) at power density of 11200 W kg(-1), which are among the best reported state-of-the-art NICs. The designed device also exhibits long-term cycling stability over 3000 cycles with capacity retention ∼86%. Furthermore, we demonstrate the assembly of a highly flexible quasi-solid-state NIC and it shows no obvious capacity loss under different bending conditions.

  1. In-Situ Formed Hierarchical Metal-Organic Flexible Cathode for High-Energy Sodium-Ion Batteries.

    Science.gov (United States)

    Huang, Ying; Fang, Chun; Zeng, Rui; Liu, Yaojun; Zhang, Wang; Wang, Yanjie; Liu, Qingju; Huang, Yunhui

    2017-09-10

    Metal-organic compounds are a family of electrode materials with structural diversity and excellent thermal stability for rechargeable batteries. Here, we fabricate a hierarchical nanocomposite with metal-organic cuprous tetracyanoquino- dimethane (CuTCNQ) in three-dimensional (3D) conductive carbon nanofibers (CNFs) network by in-situ growth, and evaluate it as flexible cathode for sodium-ion batteries (SIBs). CuTCNQ in such flexible composite electrode is able to exhibit a superhigh capacity of 252 mAh g-1 at 0.1 C and highly reversible stability for 1200 cycles within the voltage range of 2.5 - 4.1 V (vs. Na+/Na). A high specific energy of 762 Wh kg-1 is obtained with high average potential of 3.2 V (vs. Na+/Na). The in-situ formed electroactive metal-organic composites with tailored nanoarchitecture provide a promising alternative choice for high-performance cathode materials in sodium-ion batteries with high energy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Density Functional Theory Research into the Reduction Mechanism for the Solvent/Additive in a Sodium-Ion Battery.

    Science.gov (United States)

    Liu, Qi; Mu, Daobin; Wu, Borong; Wang, Lei; Gai, Liang; Wu, Feng

    2017-02-22

    The solid-electrolyte interface (SEI) film in a sodium-ion battery is closely related to capacity fading and cycling stability of the battery. However, there are few studies on the SEI film of sodium-ion batteries and the mechanism of SEI film formation is unclear. The mechanism for the reduction of ethylene carbonate (EC), propylene carbonate (PC), vinylene carbonate (VC), ethylene sulfite (ES), 1,3-propylene sulfite (PS), and fluorinated ethylene carbonate (FEC) is studied by DFT. The reaction activation energies, Gibbs free energies, enthalpies, and structures of the transition states are calculated. It is indicated that VC, ES, and PS additives in the electrolyte are all easier to form organic components in the anode SEI film by one-electron reduction. The priority of one-electron reduction to produce organic SEI components is in the order of VC>PC>EC; two-electron reduction to produce the inorganic Na2 CO3 component is different and follows the order of EC>PC>VC. Two-electron reduction for sulfites ES and PS to form inorganic Na2 SO3 is harder than that of carbonate ester reduction. It is also suggested that the one- and two-electron reductive decomposition pathway for FEC is more feasible to produce inorganic NaF components. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Tin anode for sodium-ion batteries using natural wood fiber as a mechanical buffer and electrolyte reservoir.

    Science.gov (United States)

    Zhu, Hongli; Jia, Zheng; Chen, Yuchen; Weadock, Nicholas; Wan, Jiayu; Vaaland, Oeyvind; Han, Xiaogang; Li, Teng; Hu, Liangbing

    2013-07-10

    Sodium (Na)-ion batteries offer an attractive option for low cost grid scale storage due to the abundance of Na. Tin (Sn) is touted as a high capacity anode for Na-ion batteries with a high theoretical capacity of 847 mAh/g, but it has several limitations such as large volume expansion with cycling, slow kinetics, and unstable solid electrolyte interphase (SEI) formation. In this article, we demonstrate that an anode consisting of a Sn thin film deposited on a hierarchical wood fiber substrate simultaneously addresses all the challenges associated with Sn anodes. The soft nature of wood fibers effectively releases the mechanical stresses associated with the sodiation process, and the mesoporous structure functions as an electrolyte reservoir that allows for ion transport through the outer and inner surface of the fiber. These properties are confirmed experimentally and computationally. A stable cycling performance of 400 cycles with an initial capacity of 339 mAh/g is demonstrated; a significant improvement over other reported Sn nanostructures. The soft and mesoporous wood fiber substrate can be utilized as a new platform for low cost Na-ion batteries.

  4. Electro-membrane reactor for separation and in situ ion substitution of glutamic acid from its sodium salt

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Mahendra; Tripathi, Bijay P. [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G. B. Marg, Bhavnagar 364002, Gujarat (India); Shahi, Vinod K. [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G. B. Marg, Bhavnagar 364002, Gujarat (India)], E-mail: vkshahi@csmcri.org

    2009-08-30

    An electro-membrane reactor with four compartments (EMR-4) (anolyte, catholyte and comp. 1 and 2) based on in-house-prepared cation- and anion-exchange membrane (CEM and AEM, respectively) was developed to achieve separation and recovery of glutamic acid (GAH) from its sodium salt by in situ ion substitution and acidification. The physicochemical and electrochemical properties of CEM and AEM were characterized and its suitability was assessed in operating environment. The separation of GA{sup -} from the mixture of nonionic organic compounds and further ion substitution was achieved by EMR-4. But the higher energy consumption (5.75 kWh/kg of GAH produced), low current efficiency (50.5%) and recovery of GAH (57.2%) in this process were main obstacles for the industrial exploration of the process. Latter, electro-membrane reactor with three compartments (EMR-3) (anolyte, catholyte and central compartment) was developed based on CEMs for only in situ ion substitution of GANa to achieve GAH, in which GA{sup -} was not allowed for electro-migration from its feed compartment. CE and recovery of GAH were close to 73% and 96% that indicate the suitability of the EMR-3 process for industrial application over the EMR-4. It was concluded that EMR-3 was efficient as compared to EMR-4 for separation and recovery of GAH from fermentation broth by in situ ion substitution in eco-friendly manner.

  5. Lithium and sodium ion capacitors with high energy and power densities based on carbons from recycled olive pits

    Science.gov (United States)

    Ajuria, Jon; Redondo, Edurne; Arnaiz, Maria; Mysyk, Roman; Rojo, Teófilo; Goikolea, Eider

    2017-08-01

    In this work, we are presenting both lithium and sodium ion capacitors (LIC and NIC) entirely based on electrodes designed from recycled olive pit bio-waste derived carbon materials. On the one hand, olive pits were pyrolized to obtain a low specific surface area semigraphitic hard carbon to be used as the ion intercalation (battery-type) negative electrode. On the other hand, the same hard carbon was chemically activated with KOH to obtain a high specific surface area activated carbon that was further used as the ion-adsorption (capacitor-type) positive electrode. Both electrodes were custom-made to be assembled in a hybrid cell to either build a LIC or NIC in the corresponding Li- and Na-based electrolytes. For comparison purposes, a symmetric EDLC supercapacitor cell using the same activated carbon in 1.5 M Et4NBF4/acetonitrile electrolyte was also built. Both LIC and NIC systems demonstrate remarkable energy and power density enhancement over its EDLC counterpart while showing good cycle life. This breakthrough offers the possibility to easily fabricate versatile hybrid ion capacitors, covering a wide variety of applications where different requirements are demanded.

  6. Biochemistry-directed hollow porous microspheres: bottom-up self-assembled polyanion-based cathodes for sodium ion batteries.

    Science.gov (United States)

    Lin, Bo; Li, Qiufeng; Liu, Baodong; Zhang, Sen; Deng, Chao

    2016-04-21

    Biochemistry-directed synthesis of functional nanomaterials has attracted great interest in energy storage, catalysis and other applications. The unique ability of biological systems to guide molecule self-assembling facilitates the construction of distinctive architectures with desirable physicochemical characteristics. Herein, we report a biochemistry-directed "bottom-up" approach to construct hollow porous microspheres of polyanion materials for sodium ion batteries. Two kinds of polyanions, i.e. Na3V2(PO4)3 and Na3.12Fe2.44(P2O7)2, are employed as cases in this study. The microalgae cell realizes the formation of a spherical "bottom" bio-precursor. Its tiny core is subjected to destruction and its tough shell tends to carbonize upon calcination, resulting in the hollow porous microspheres for the "top" product. The nanoscale crystals of the polyanion materials are tightly enwrapped by the highly-conductive framework in the hollow microsphere, resulting in the hierarchical nano-microstructure. The whole formation process is disclosed as a "bottom-up" mechanism. Moreover, the biochemistry-directed self-assembly process is confirmed to play a crucial role in the construction of the final architecture. Taking advantage of the well-defined hollow-microsphere architecture, the abundant interior voids and the highly-conductive framework, polyanion materials show favourable sodium-intercalation kinetics. Both materials are capable of high-rate long-term cycling. After five hundred cycles at 20 C and 10 C, Na3V2(PO4)3 and Na(3.12)Fe2.44(P2O7)2 retain 96.2% and 93.1% of the initial capacity, respectively. Therefore, the biochemistry-directed technique provides a low-cost, highly-efficient and widely applicable strategy to produce high-performance polyanion-based cathodes for sodium ion batteries.

  7. Conformational Dynamics on the Extracellular Side of LeuT Controlled by Na+ and K+ Ions and the Protonation State of Glu(290)

    DEFF Research Database (Denmark)

    Khelashvili, George; Schmidt, Solveig Gaarde; Shi, Lei

    2016-01-01

    the unoccupied Na2 site of dopamine transporter following the release of the Na2-bound Na+. Here we evaluate with computational simulations and experimental measurements of ion affinities under corresponding conditions, the consequences of K+ binding in the Na2 site of LeuT, a bacterial homolog of NSS, when both......, point to the Glu290 protonation state as a main determinant in the structural reconfiguration of the extracellular vestibule of LeuT in which a “water gate” opens through coordinated motions of residues Leu25, Tyr108, and Phe253. The resulting water channel enables the binding/dissociation of the Na...

  8. DETERMINATION OF SURFACTANT SODIUM LAURYL ETHER SULFATE BY ION PAIRING CHROMATOGRAPHY WITH SUPPRESSED CONDUCTIVITY DETECTION

    Science.gov (United States)

    A method for the determination of the anionic Steol CS-330 surfactant is described. CS-330 is a complex mixture of oligomers due to the various sizes of fatty alcohols and the number of moles of the ethoxylation. The main component of CS-330 is sodium lauryl ether sulfate (SLES)....

  9. Agglutination of human erythrocytes by the interaction of Zn(2+)ion with histidine-651 on the extracellular domain of band 3.

    Science.gov (United States)

    Kiyotake, Kento; Ochiai, Hideharu; Yamaguchi, Takeo

    2016-05-01

    Clustering of band 3, chloride/bicarbonate exchanger, has been reported in Zn(2+)-treated human erythrocytes. However, the agglutination of human erythrocytes is also induced by the interaction of Zn(2+)ion with histidine on band 3. Identification of histidine that interacts with Zn(2+)ion remains to be determined. The Zn(2+)-induced agglutination of human erythrocytes was unaffected by chymotrypsin cleavage of the small loop region containing His-547 in the extracellular domain of band 3. On the other hand, papain digestion of the large loop region containing His-651 in band 3 inhibited such Zn(2+)-induced agglutination. Moreover, Zn(2+)-induced erythrocyte agglutination was inhibited by the peptide (ARGWVIHPLG) containing His-651, but not by the peptide such as ARGWVIRPLG, which His-651 was substituted by arginine. Among 10 kinds of animal erythrocytes tested, interestingly, no agglutination by Zn(2+)ions was observed in cow cells only that the forth amino acid in the upstream from His-669 on the large loop of cow band 3 is aspartate (Asp-665) instead of glycine. As expected, the agglutination of human erythrocytes by Zn(2+) ions was inhibited in the presence of aspartate. These data indicate that the interaction of Zn(2+) ion with His-651 residue of band 3 plays an important role in the Zn(2+)-induced agglutination of human erythrocytes.

  10. Two-Dimensional Vanadium Carbide (MXene) as Positive Electrode for Sodium-Ion Capacitors.

    Science.gov (United States)

    Dall'Agnese, Yohan; Taberna, Pierre-Louis; Gogotsi, Yury; Simon, Patrice

    2015-06-18

    Ion capacitors store energy through intercalation of cations into an electrode at a faster rate than in batteries and within a larger potential window. These devices reach a higher energy density compared to electrochemical double layer capacitor. Li-ion capacitors are already produced commercially, but the development of Na-ion capacitors is hindered by lack of materials that would allow fast intercalation of Na-ions. Here we investigated the electrochemical behavior of 2D vanadium carbide, V2C, from the MXene family. We investigated the mechanism of Na intercalation by XRD and achieved capacitance of ∼100 F/g at 0.2 mV/s. We assembled a full cell with hard carbon as negative electrode, a known anode material for Na ion batteries, and achieved capacity of 50 mAh/g with a maximum cell voltage of 3.5 V.

  11. A 23Na Multiple-Quantum-Filtered NMR Study of the Effect of the Cytoskeleton Conformation on the Anisotropic Motion of Sodium Ions in Red Blood Cells

    Science.gov (United States)

    Knubovets, Tatyana; Shinar, Hadassah; Eliav, Uzi; Navon, Gil

    1996-01-01

    Recently, it has been shown that23Na double-quantum-filtered NMR spectroscopy can be used to detect anisotropic motion of bound sodium ions in biological systems. The technique is based on the formation of the second-rank tensor when the quadrupolar interaction is not averaged to zero. Using this method, anisotropic motion of bound sodium in human and dog red blood cells was detected, and the effect was shown to depend on the integrity of the membrane cytoskeleton. In the present study, multiple-quantum-filtered techniques were applied in combination with a quadrupolar echo to measure the transverse-relaxation times,T2fandT2s. Line fitting was performed to obtain the values of the residual quadrupolar interaction, which was measured for sodium in a variety of mammalian erythrocytes of different size, shape, rheological properties, and sodium concentrations. Human unsealed white ghosts were used to study sodium bound at the anisotropic sites on the inner side of the RBC membrane. Modulations of the conformation of the cytoskeleton by the variation of either the ionic strength or pH of the suspending medium caused drastic changes in both the residual quadrupolar interaction andT2fdue to changes in the fraction of bound sodium ions as well as changes in the structure of the binding sites. By combining the two spectroscopic parameters, structural change can be followed. The changes in the structure of the sodium anisotropic binding sites deduced by this method were found to correlate with known conformational changes of the membrane cytoskeleton. Variations of the medium pH affected both the fraction of bound sodium ions and the structure of the anisotropic binding sites. Sodium and potassium were shown to bind to the anisotropic binding sites with the same affinity.

  12. Two-Dimensional SnO Anodes with a Tunable Number of Atomic Layers for Sodium Ion Batteries

    KAUST Repository

    Zhang, Fan

    2017-01-18

    We have systematically changed the number of atomic layers stacked in 2D SnO nanosheet anodes and studied their sodium ion battery (SIB) performance. The results indicate that as the number of atomic SnO layers in a sheet decreases, both the capacity and cycling stability of the Na ion battery improve. The thinnest SnO nanosheet anodes (two to six SnO monolayers) exhibited the best performance. Specifically, an initial discharge and charge capacity of 1072 and 848 mAh g-1 were observed, respectively, at 0.1 A g-1. In addition, an impressive reversible capacity of 665 mAh g-1 after 100 cycles at 0.1 A g-1 and 452 mAh g-1 after 1000 cycles at a high current density of 1.0 A g-1 was observed, with excellent rate performance. As the average number of atomic layers in the anode sheets increased, the battery performance degraded significantly. For example, for the anode sheets with 10-20 atomic layers, only a reversible capacity of 389 mAh g-1 could be obtained after 100 cycles at 0.1 A g-1. Density functional theory calculations coupled with experimental results were used to elucidate the sodiation mechanism of the SnO nanosheets. This systematic study of monolayer-dependent physical and electrochemical properties of 2D anodes shows a promising pathway to engineering and mitigating volume changes in 2D anode materials for sodium ion batteries. It also demonstrates that ultrathin SnO nanosheets are promising SIB anode materials with high specific capacity, stable cyclability, and excellent rate performance.

  13. Interactions of drugs and toxins with permeant ions in potassium, sodium, and calcium channels.

    Science.gov (United States)

    Zhorov, B S

    2011-07-01

    Ion channels in cell membranes are targets for a multitude of ligands including naturally occurring toxins, illicit drugs, and medications used to manage pain and treat cardiovascular, neurological, autoimmune, and other health disorders. In the past decade, the x-ray crystallography revealed 3D structures of several ion channels in their open, closed, and inactivated states, shedding light on mechanisms of channel gating, ion permeation and selectivity. However, atomistic mechanisms of the channel modulation by ligands are poorly understood. Increasing evidence suggest that cationophilic groups in ion channels and in some ligands may simultaneously coordinate permeant cations, which form indispensible (but underappreciated) components of respective receptors. This review describes ternary ligand-metal-channel complexes predicted by means of computer-based molecular modeling. The models rationalize a large body of experimental data including paradoxes in structure-activity relationships, effects of mutations on the ligand action, sensitivity of the ligand action to the nature of current-carrying cations, and action of ligands that bind in the ion-permeation pathway but increase rather than decrease the current. Recent mutational and ligand-binding experiments designed to test the models have confirmed the ternary-complex concept providing new knowledge on physiological roles of metal ions and atomistic mechanisms of action of ion channel ligands.

  14. Cobalt- and Cadmium-Based Metal-Organic Frameworks as High-Performance Anodes for Sodium Ion Batteries and Lithium Ion Batteries.

    Science.gov (United States)

    Dong, Caifu; Xu, Liqiang

    2017-03-01

    Two multifunctional metal-organic frameworks (MOFs) with the same coordination mode, [Co(L)(H2O)]n·2nH2O [defined as "Co(L) MOF"] and [Cd(L)(H2O)]n·2nH2O [defined as "Cd(L) MOF"] (L = 5-aminoisophthalic acid) have been fabricated via a simple and versatile scalable solvothermal approach at 85 °C for 24 h. The relationship between the structure of the electrode materials (especially the coordination water and different metal ions) and the electrochemical properties of MOFs have been investigated for the first time. And then the possible electrochemical mechanisms of the electrodes have been studied and proposed. In addition, MOFs/RGO hybrid materials were prepared via ball milling, which demonstrated better electrochemical performances than those of individual Co(L) MOF and Cd(L) MOF. For example, when Co(L) MOF/RGO was applied as anode for sodium ion batteries (SIBs), it retained 206 mA h g(-1) after 330 cycles at 500 mA g(-1) and 1185 mA h g(-1) could be obtained after 50 cycles at 100 mA g(-1) for lithium-ion batteries (LIBs). The high-discharge capacity, excellent cyclic stability combined with the facile synthesis procedure enable Co(L) MOF- and Cd(L) MOF-based materials to be prospective anode materials for SIBs and LIBs.

  15. Influence of excess sodium ions on the specific surface area formation in a NiO-Al2O3 catalyst prepared by different methods

    Directory of Open Access Journals (Sweden)

    Lazić M.M.

    2008-01-01

    Full Text Available The influence of sodium ions on the specific surface area of a NiO-Al2O3 catalyst in dependence of nickel loading (5, 10, and 20 wt% Ni, temperature of heat treatment (400, 700 and 1100oC and the method of sample preparation was investigated. Low temperature nitrogen adsorption (LTNA, X-ray diffraction (XRD and scanning electron microscopy (SEM were applied for sample characterization. Dramatic differences in the specific surface area were registered between non-rinsed and rinsed Al2O3 and NiO-Al2O3 samples. The lagged sodium ions promote sintering of non-rinsed catalyst samples.

  16. Molten salt synthesis of sodium lithium titanium oxide anode material for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yin, S.Y., E-mail: yshy2004@hotmail.com [College of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan 430065 (China); Feng, C.Q. [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Wu, S.J.; Liu, H.L.; Ke, B.Q. [College of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan 430065 (China); Zhang, K.L. [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Chen, D.H. [College of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan 430065 (China); Hubei Key Laboratory for Catalysis and Material Science, College of Chemistry and Material Science, South Central University for Nationalities, Wuhan 430074, Hubei (China)

    2015-09-05

    Highlights: • Na{sub 2}Li{sub 2}Ti{sub 6}O{sub 12} has been successfully synthesized via a molten salt route. • Calcination temperature is an important effect on the component and microstructure of the product. • Pure phase Na{sub 2}Li{sub 2}Ti{sub 6}O{sub 12} could be obtained at 700 °C for 2 h. - Abstract: The sodium lithium titanium oxide with composition Na{sub 2}Li{sub 2}Ti{sub 6}O{sub 14} has been synthesized by a molten salt synthesis method using sodium chloride and potassium chloride mixture as a flux medium. Synthetic variables on the synthesis, such as sintering temperature, sintering time and the amount of lithium carbonate, were intensively investigated. Powder X-ray diffraction and scanning electron microscopy images of the reaction products indicates that pure phase sodium lithium titanium oxide has been obtained at 700 °C, and impure phase sodium hexatitanate with whiskers produced at higher temperature due to lithium evaporative losses. The results of cyclic voltammetry and discharge–charge tests demonstrate that the synthesized products prepared at various temperatures exhibited electrochemical diversities due to the difference of the components. And the sample obtained at 700 °C revealed highly reversible insertion and extraction of Li{sup +} and displayed a single potential plateau at around 1.3 V. The product obtained at 700 °C for 2 h exhibits good cycling properties and retains the specific capacity of 62 mAh g{sup −1} after 500 cycles.

  17. Free energy landscapes of sodium ions bound to DMPC-cholesterol membrane surfaces at infinite dilution.

    Science.gov (United States)

    Yang, Jing; Bonomi, Massimiliano; Calero, Carles; Martí, Jordi

    2016-04-07

    Exploring the free energy landscapes of metal cations on phospholipid membrane surfaces is important for the understanding of chemical and biological processes in cellular environments. Using metadynamics simulations we have performed systematic free energy calculations of sodium cations bound to DMPC phospholipid membranes with cholesterol concentration varying between 0% (cholesterol-free) and 50% (cholesterol-rich) at infinite dilution. The resulting free energy landscapes reveal the competition between binding of sodium to water and to lipid head groups. Moreover, the binding competitiveness of lipid head groups is diminished by cholesterol contents. As cholesterol concentration increases, the ionic affinity to membranes decreases. When cholesterol concentration is greater than 30%, the ionic binding is significantly reduced, which coincides with the phase transition point of DMPC-cholesterol membranes from a liquid-disordered phase to a liquid-ordered phase. We have also evaluated the contributions of different lipid head groups to the binding free energy separately. The DMPC's carbonyl group is the most favorable binding site for sodium, followed by DMPC's phosphate group and then the hydroxyl group of cholesterol.

  18. Synthesis and Electrochemical Performance of the Na3V2(PO4)3 Cathode for Sodium-Ion Batteries

    Science.gov (United States)

    Van Nghia, Nguyen; Jafian, Samuel; Hung, I.-Ming

    2016-05-01

    Rhombohedral Na3V2(PO4)3 with a Na+ superionic conductor structure was synthesized using a solid-state reaction method. Citric acid was used as a carbon resource for carbon-thermal reduction reaction to reduce the oxidation state of vanadium. The shape of Na3V2(PO4)3 particles is irregular and its average diameter is in the range 30-50 nm. The Na3V2(PO4)3 exhibits a superior cycling ability and rate capability. The discharge capacity retains 74.3% of the discharge capacity of its first cycle with coulombic efficiency of 99.3% after 100 cycles. The discharge capacity of Na3V2(PO4)3 at 10 C is 48.87 mAh g-1, which is 58.4% of the cell cycled at 0.1 C. Furthermore, the structure of Na3V2(PO4)3 is stable for a considerable amount of Na+ ions (2 mol of Na+ ions) insertion and extraction with only 0.42% difference of unit-cell volume between fully charged and discharged states. Na3V2(PO4)3 is a potential cathode material for sodium-ion battery applications.

  19. Potassium and sodium ions in the glycerinated skeletal muscle. Distribution changes induced by adenosine triphosphate and nondissociable anesthetic substances.

    Science.gov (United States)

    Dragomir, C T; Barbier, A; Ungureanu, D; Ionescu, V; Pausescu, E; Chirvasie, R; Ghitescu, D; Filipescu, G

    1975-01-01

    Investigation of the ionic behavior of glycerinated muscle fibers showed that the residual structures of this biologic cellular material, lacking functional membranes, are able to discriminate between alkaline ions. The characteristics of the ionic selectivity of the glycerinated fibers change with their functional state and with the presence in the medium of certain nonionic substances. Among the more important features of ionic distribution between the membrane-free fibers and the medium are the following: (1) There is evident adsorption of potassium on the fibers, in the absence of ATP. (2) This adsorption increases in contraction and decreases in relaxation. (3) At high ionic concentrations, in contrast to what occurs at low potassium concentrations, the glycerinated muscle prefers sodium to potassium, but even under these conditions both ions are accumulated in the fibers to far greater levels than in the medium. This strongly suggests a Donnan ionic equilibrium developing parallel to the adsorption process. (4) Nonionic substances of the general anesthetic group markedly alter the ionic selectivity of the glycerinated fibers, probably by their action on the water's physical state. A mechanism is proposed for the observed ionic adsorption specific of the muscle-a mechanism in which actin-myosin coupling plays the cardinal adsorption role. In the general interpretation of the data a synthetic concept is advanced according to which an entire set of processes and factors concurs with the distribution of ions between the muscle and the medium.

  20. Bio-derived hierarchically macro-meso-micro porous carbon anode for lithium/sodium ion batteries

    Science.gov (United States)

    Elizabeth, Indu; Singh, Bhanu Pratap; Trikha, Sunil; Gopukumar, Sukumaran

    2016-10-01

    Nitrogen doped hierarchically porous carbon derived from prawn shells have been efficiently synthesized through a simple, economically viable and environmentally benign approach. The prawn shell derived carbon (PSC) has high inherent nitrogen content (5.3%) and possesses a unique porous structure with the co-existence of macro, meso and micropores which can afford facile storage and transport channels for both Li and Na ions. PSC is well characterized using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Transmission electron Microscopy (TEM), High resolution TEM (HR-TEM) and X-ray photoelectron spectroscopy (XPS). Electron Paramagnetic Resonance (EPR) and Solid state-Nuclear Magnetic Resonance (NMR) studies have been conducted on pristine PSC and Li/Na interacted PSC. PSC as anode for Lithium ion batteries (LIBs) delivers superior electrochemical reversible specific capacity (740 mAh g-1 at 0.1 Ag-1 current density for 150 cycles) and high rate capability. When used as anode material for Sodium ion batteries (SIBs), PSC exhibits excellent reversible specific capacity of 325 mAh g-1 at 0.1 Ag-1 for 200 cycles and rate capability of 107 mAh g-1 at 2 Ag-1. Furthermore, this study demonstrates the employment of natural waste material as a potential anode for both LIB and SIB, which will definitively make a strike in the energy storage field.

  1. Lithium-sodium separation by ion-exchange. Particular study of a pulsed column; La separation lithium-sodium par echange d'ions. Etude particuliere d'une colonne a impulsions

    Energy Technology Data Exchange (ETDEWEB)

    Auvert, H. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1968-07-01

    A study is made of the operational conditions and constraints in the case of a moving-bed ion-exchange column subjected to pulses. The example chosen to illustrate its application concerns the lithium-sodium separation in a hydroxide medium (LiOH, NaOH). In the first part, the physico-chemical characteristics of the exchange and the kinetic characteristics of the exchange-reaction are considered. In the second part, the operation of the pulsed column is studied. Using the results obtained in the first part, the conditions required for study state operation are determined. When this is obtained, it is possible to calculate the height equivalent of the theoretical plate (HETP) of the installation. A study is also made of 'sliding', a phenomenon peculiar to pulsed columns. The results obtained show that it is possible, using laboratory tests, to determine the characteristics and the operational condition of a moving-bed ion-exchange column. (author) [French] On se propose d'etudier les conditions et les servitudes de fonctionnement d'une colonne d'echangeurs d'ions a lit mobile, fonctionnant par 'impulsions'. L'exemple d'application choisi est la separation lithium-sodium en milieu hydroxyde (LiOH, NaOH). Dans une premiere partie, on etudie successivement les caracteristiques physico-chimiques de l'echange envisage et les caracteristiques cinetiques de la reaction d'echange mise en oeuvre. Dans une seconde partie on etudie le fonctionnement de la colonne a impulsions. A partir des resultats acquis dans la premiere partie, on determine les conditions necessaires a l'obtention d'un regime permanent. Lorsque celui-ci est atteint en colonne, les performances obtenues permettent de calculer la hauteur equivalente a un plateau theorique (HEPT) de l'installation. On etudie par ailleurs l'influence du 'glissement', phenomene inherent au fonctionnement de la colonne a impulsions. L

  2. High-rate performance electrospun Na0.44MnO2 nanofibers as cathode material for sodium-ion batteries

    Science.gov (United States)

    Fu, Bi; Zhou, Xuan; Wang, Yaping

    2016-04-01

    Sodium-ion batteries (SIBs) are considered as one of the most promising candidates to replace lithium-ion batteries (LIBs), because of their similar electrochemical properties, and geographical limitations of lithium. However, searching for the appropriate cathode materials for SIBs that can accommodate structure change during the insertion and extraction of sodium ions is facing great challenges due to the relatively larger size of sodium ion. Na0.44MnO2 has recently attracted significant attention because its crystal structure exhibits two types of large channels formed by MnO6 octahedra and MnO5 square pyramids, which facilitate the transportation of sodium ions. However, suffering from the slow kinetics and structural degradation, its rate performance is still not satisfied. Here, we report the fabrication of two types of Na0.44MnO2 hierarchical structures by optimized electrospinning and controlled subsequent annealing process. One is nanofiber (NF) which demonstrates a superior rate performance with reversible specific capacity of 69.5 mAh g-1 at 10 C, attributed to its one-dimensional (1D) ultralong and continuous fibrous network structure; the other is nanorod (NR) which exhibits an excellent cyclic performance with reversible specific capacity of 120 mAh g-1 after 140 cycles, due to its large S-shaped tunnel structure with a single crystalline structure.

  3. Mesoporous Tin-Based Oxide Nanospheres/Reduced Graphene Composites as Advanced Anodes for Lithium-Ion Half/Full Cells and Sodium-Ion Batteries.

    Science.gov (United States)

    He, Yanyan; Li, Aihua; Dong, Caifu; Li, Chuanchuan; Xu, Liqiang

    2017-07-19

    The large volume variations of tin-based oxides hinder their extensive application in the field of lithium-ion batteries (LIBs). In this study, structure design, hybrid fabrication, and carbon-coating approaches have been simultaneously adopted to address these shortcomings. To this end, uniform mesoporous NiO/SnO2 @rGO, Ni-Sn oxide@rGO, and SnO2 @rGO nanosphere composites have been selectively fabricated. Among them, the obtained NiO/SnO2 @rGO composite exhibited a high capacity of 800 mAh g(-1) at 1000 mA g(-1) after 400 cycles. The electrochemical mechanism of NiO/SnO2 as an anode for LIBs has been preliminarily investigated by ex situ XRD pattern analysis. Furthermore, an NiO/SnO2 @rGO-LiCoO2 lithium-ion full cell showed a high capacity of 467.8 mAh g(-1) at 500 mA g(-1) after 100 cycles. Notably, the NiO/SnO2 @rGO composite also showed good performance when investigated as an anode for sodium-ion batteries (SIBs). It is believed that the unique mesoporous nanospherical framework, synergistic effects between the various components, and uniform rGO wrapping of NiO/SnO2 shorten the Li(+) ion diffusion pathways, maintain sufficient contact between the active material and the electrolyte, mitigate volume changes, and finally improve the electrical conductivity of the electrode. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Recent achievements on polyanion-type compounds for sodium-ion batteries: Syntheses, crystal chemistry and electrochemical performance

    Science.gov (United States)

    Guo, Sheng-Ping; Li, Jia-Chuang; Xu, Qian-Ting; Ma, Ze; Xue, Huai-Guo

    2017-09-01

    In the past several years, many efforts have been made to develop polyanion-type cathode materials for sodium ion batteries by chemists and material scientists. These materials are one of the main types of promising cathodes though the studies are still in their infancy. This paper reviews almost all the important advances of polyanion-type cathodes on their syntheses, crystal structures, morphologies, electrochemical performance and Na redox mechanisms. It specifically focuses on their crystal chemistry and electrochemical behaviors. The contents are divided into several categories according to their chemical compositions. After introduction of the synthetic methods, phosphates (ortho-, pyro- and fluoro-), silicates, sulfates, and mixed anions type cathodes are summarized and discussed successively.

  5. The relation between the structure and electrochemical performance of sodiated iron phosphate in sodium-ion batteries

    Science.gov (United States)

    Liu, Yao; Zhou, Yirong; Zhang, Junxi; Zhang, Shiming; Ren, Ping

    2016-05-01

    The structure and electrochemical performance of sodiated iron phosphate were investigated by means of X-ray diffraction, high-resolution transmission electron microscopy and electrochemical measurements. The results indicate that after the sodiation process, all FePO4 samples transform into the amorphous sodium iron phosphate and crystallite NaFePO4, namely triphylite NaFePO4 for amorphous FePO4 and maricite NaFePO4 for trigonal FePO4, respectively. The amorphous FePO4 samples show excellent electrochemical performance in terms of cyclic stability and discharge capacity, while trigonal FePO4 displays poor electrochemical performance. The outstanding electrochemical performance of amorphous FePO4 was attributed to the amorphous and triphylite NaFePO4 with high electrochemical activity. Those findings indicate that amorphous FePO4 can be transformed into active NaFePO4, which may have great potential as an electrode material for sodium-ion batteries.

  6. Probing kinetic drug binding mechanism in voltage-gated sodium ion channel: open state versus inactive state blockers.

    Science.gov (United States)

    Pal, Krishnendu; Gangopadhyay, Gautam

    2015-01-01

    The kinetics and nonequilibrium thermodynamics of open state and inactive state drug binding mechanisms have been studied here using different voltage protocols in sodium ion channel. We have found that for constant voltage protocol, open state block is more efficient in blocking ionic current than inactive state block. Kinetic effect comes through peak current for mexiletine as an open state blocker and in the tail part for lidocaine as an inactive state blocker. Although the inactivation of sodium channel is a free energy driven process, however, the two different kinds of drug affect the inactivation process in a different way as seen from thermodynamic analysis. In presence of open state drug block, the process initially for a long time remains entropy driven and then becomes free energy driven. However in presence of inactive state block, the process remains entirely entropy driven until the equilibrium is attained. For oscillating voltage protocol, the inactive state blocking is more efficient in damping the oscillation of ionic current. From the pulse train analysis it is found that inactive state blocking is less effective in restoring normal repolarisation and blocks peak ionic current. Pulse train protocol also shows that all the inactive states behave differently as one inactive state responds instantly to the test pulse in an opposite manner from the other two states.

  7. Long-term cycling stability of porous Sn anode for sodium-ion batteries

    Science.gov (United States)

    Kim, Changhyeon; Lee, Ki-Young; Kim, Icpyo; Park, Jinsoo; Cho, Gyubong; Kim, Ki-Won; Ahn, Jou-Hyeon; Ahn, Hyo-Jun

    2016-06-01

    A phase-inversion technique is introduced to produce a porous Sn anode for sodium batteries, which can accommodate volume changes during sodiation and desodiation. The Sn electrode shows two plateaus with a capacity of 1066 mAh g-1 during the first sodiation and four flat plateaus with a charge capacity of 674 mAh g-1 at the first desodiation process. During 500 cycles, the Sn electrode shows reversible capacity more than 519 mAh g-1 with Coulombic efficiency of nearly 99%. The Sn electrode with a porous structure is a possible solution to the electrode degradation.

  8. Quantification of sodium in ancient Roman glasses with ion beam analysis

    Energy Technology Data Exchange (ETDEWEB)

    Climent-Font, A. [Centro de Micro Analisis de Materiales, Universidad Autonoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Munoz-Martin, A. [Centro de Micro Analisis de Materiales, Universidad Autonoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Ynsa, M.D. [Centro de Micro Analisis de Materiales, Universidad Autonoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Fundacion Parque Cientifico de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Zucchiatti, A. [Istituto Nazionale di Fisica Nucleare, via Dodecaneso 33, 16146 Genova (Italy)], E-mail: zucc@ge.infn.it

    2008-02-15

    Concentrations of light elements (Na, Al, Si) in glass have been profiled by comparing the PIGE yields as a function of beam energy to those of a glass standard in combination with PIXE measurements which are used to determine the specific energy loss of protons in the unknown glasses. The technique has been tested on a known sample and applied to a few Roman natron glasses giving results compatible with the morphology of the archaeological samples, as deduced from microscopy. The results have suggested some considerations on the systematic use of the PIGE technique in the determination of bulk sodium concentration in ancient materials.

  9. Transition metal ion FRET uncovers K(+) regulation of a neurotransmitter/sodium symporter

    DEFF Research Database (Denmark)

    Billesbølle, Christian B; Mortensen, Jonas S; Sohail, Azmat

    2016-01-01

    Neurotransmitter/sodium symporters (NSSs) are responsible for Na(+)-dependent reuptake of neurotransmitters and represent key targets for antidepressants and psychostimulants. LeuT, a prokaryotic NSS protein, constitutes a primary structural model for these transporters. Here we show that K(+) in......(+)-effect. The K(+)-effect depended on an intact Na1 site and mutating the Na2 site potentiated K(+) binding by facilitating transition to the inward-facing state. The data reveal an unrecognized ability of K(+) to regulate the LeuT transport cycle....

  10. Structural and optical characteristics of Eu3+ ions in sodium-lead-zinc-lithium-borate glass system

    Science.gov (United States)

    Rajagukguk, J.; Kaewkhao, J.; Djamal, M.; Hidayat, R.; Suprijadi; Ruangtaweep, Y.

    2016-10-01

    Structural and optical properties of Eu3+-doped sodium-lead-zinc-lithium-borate glasses (65-x)B2O3sbnd 15Na2Osbnd 10PbOsbnd 5ZnOsbnd 5Li2Osbnd xEu2O3 (where x = 0, 0.05, 0.1, 0.5, 1.0, 2.0 and 4.0) have been measured and analyzed by varying the Eu3+ ion concentrations. The physical parameters such as polaron radius, field strength and inter nuclear distance have been determined from measurements of densities and refractive indices. The structural properties of the prepared borate glasses were analyzed based on X-ray diffraction (XRD) and FTIR instruments. The diffraction spectra show no characteristic peaks in these glasses, which indicates the amorphous nature of the glasses. The infrared spectrum of the Eu3+-doped sodium-lead-zinc-lithium-borate glass systems show three disparate regions for active absorption band around 830-860 cm-1, 1020-1040 cm-1 and 1170-1180 cm-1. The electronic transitions in the UV-vis and NIR regions are assigned to the 7F0 → 5D4, 7F0 → 5G2, 7F0 → 5L6, 7F0 → 5D3, 7F0 → 5D2, 7F0 → 5D1, 7F0 → 5D07F1 → 5D07F0 → 7F6 and 7F1 → 7F6 levels centered at 362 nm, 380 nm, 395 nm, 414 nm, 465 nm, 533 nm, 583 nm, 590 nm 2092 nm and 2202 nm respectively. Five transition bands of luminescence spectra have been observed by using an excited wavelength of 395 nm. The luminescence intensity ratio (R) of 5D0 → 7F2 (electric dipole) transition to 5D0 → 7F1 (magnetic dipole) transition has been determined to obtain the strength of the covalent/ionic bond between the Eu3+ ions and the surrounding ligands. Radiative life time and emission color of the glasses were estimated and compared with other literature data by varying Eu3+ concentrations. The experimental lifetime of the 5D0 level was found to increase with increasing Eu3+ ion content, suggesting higher non-radiative energy transfer among Eu3+ ions in the glasses.

  11. Changes in brain glucose use and extracellular ions associated with kainic acid-induced seizures: (/sup 14/C)-2-deoxyglucose and intracranial

    Energy Technology Data Exchange (ETDEWEB)

    Chastain, J.E Jr.

    1986-01-01

    The effect of kainic acid (KA) on brain glucose use with coadministration of diazepam, and the effect of KA on brain extracellular (K/sup +/), Ca/sup 2 +/), and (Na/sup +/) was investigated in rats by means of (/sup 14/C)-2-deoxyglucose (2-DG) and intracranial microdialysis, respectively. Also, the impact of intracranial microdialysis on brain regional metabolic function was studied. Co-treatment with KA and diazepam attenuated KA-induced 3 hr increases and prevented 48 hr decreases in glucose use within all structures measured, particularly the piriform cortex and amygdala. Hippocampal CA/sub 3/, CA/sub 4/, and CA/sub 1/-ventral were least affected by diazepam. The results suggest that diazepam suppresses KA seizure spread from its focus, proposed to be CA/sub 3/. KA-induced ions changes were studied by intracranial microdialysis. Dialysis fibers were implanted within the hippocampus or piriform cortex and perfused 24 hr later. Samples, collected before and after KA, were analyzed for (K/sup +/), (Ca/sup 2 +/), and (Na/sup +/). KA caused an early and prolonged increase in extracellular (K/sup +/) and a negligible decrease in (Ca/sup 2 +/) within the hippocampus. In the piriform cortex, both (K/sup +/) and (Na/sup +/) increase during a period of early seizure signs. The results indicate that ion homostatic control of ion levels is better maintained during parenteral KA-induced seizures than when the brain is activated locally or during ischemia/hypoxia. The effect of intracranial microdialysis was studied by means of 2-DG in control state and KA-induced seizure state. The results indicate that intracranial microdialysis alters brain metabolic function during KA-induced seizures, but not in the control state. At 3 hr post KA, seizure metabolic activity was enhanced within the piriform cortex, and attenuated within the hippocampus.

  12. Spent lithium-ion battery recycling - Reductive ammonia leaching of metals from cathode scrap by sodium sulphite.

    Science.gov (United States)

    Zheng, Xiaohong; Gao, Wenfang; Zhang, Xihua; He, Mingming; Lin, Xiao; Cao, Hongbin; Zhang, Yi; Sun, Zhi

    2017-02-01

    Recycling of spent lithium-ion batteries has attracted wide attention because of their high content of valuable and hazardous metals. One of the difficulties for effective metal recovery is the separation of different metals from the solution after leaching. In this research, a full hydrometallurgical process is developed to selectively recover valuable metals (Ni, Co and Li) from cathode scrap of spent lithium ion batteries. By introducing ammonia-ammonium sulphate as the leaching solution and sodium sulphite as the reductant, the total selectivity of Ni, Co and Li in the first-step leaching solution is more than 98.6% while it for Mn is only 1.36%. In detail understanding of the selective leaching process is carried out by investigating the effects of parameters such as leaching reagent composition, leaching time (0-480min), agitation speed (200-700rpm), pulp density (10-50g/L) and temperature (323-353K). It was found that Mn is primarily reduced from Mn(4+) into Mn(2+) into the solution as [Formula: see text] while it subsequently precipitates out into the residue in the form of (NH4)2Mn(SO3)2·H2O. Ni, Co and Li are leached and remain in the solution either as metallic ion or amine complexes. The optimised leaching conditions can be further obtained and the leaching kinetics is found to be chemical reaction control under current leaching conditions. As a result, this research is potentially beneficial for further optimisation of the spent lithium ion battery recycling process after incorporating with metal extraction from the leaching solution.

  13. Ion conduction and conformational flexibility of a bacterial voltage-gated sodium channel.

    Science.gov (United States)

    Boiteux, Céline; Vorobyov, Igor; Allen, Toby W

    2014-03-04

    Voltage-gated Na(+) channels play an essential role in electrical signaling in the nervous system and are key pharmacological targets for a range of disorders. The recent solution of X-ray structures for the bacterial channel NavAb has provided an opportunity to study functional mechanisms at the atomic level. This channel's selectivity filter exhibits an EEEE ring sequence, characteristic of mammalian Ca(2+), not Na(+), channels. This raises the fundamentally important question: just what makes a Na(+) channel conduct Na(+) ions? Here we explore ion permeation on multimicrosecond timescales using the purpose-built Anton supercomputer. We isolate the likely protonation states of the EEEE ring and observe a striking flexibility of the filter that demonstrates the necessity for extended simulations to study conduction in this channel. We construct free energy maps to reveal complex multi-ion conduction via knock-on and "pass-by" mechanisms, involving concerted ion and glutamate side chain movements. Simulations in mixed ionic solutions reveal relative energetics for Na(+), K(+), and Ca(2+) within the pore that are consistent with the modest selectivity seen experimentally. We have observed conformational changes in the pore domain leading to asymmetrical collapses of the activation gate, similar to proposed inactivated structures of NavAb, with helix bending involving conserved residues that are critical for slow inactivation. These structural changes are shown to regulate access to fenestrations suggested to be pathways for lipophilic drugs and provide deeper insight into the molecular mechanisms connecting drug activity and slow inactivation.

  14. Sputtering of sodium and potassium from nepheline: Secondary ion yields and velocity spectra

    Science.gov (United States)

    Martinez, R.; Langlinay, Th.; Ponciano, C. R.; da Silveira, E. F.; Palumbo, M. E.; Strazzulla, G.; Brucato, J. R.; Hijazi, H.; Agnihotri, A. N.; Boduch, P.; Cassimi, A.; Domaracka, A.; Ropars, F.; Rothard, H.

    2017-09-01

    Silicates are the dominant surface material of many Solar System objects, which are exposed to ion bombardment by solar wind ions and cosmic rays. Induced physico-chemical processes include sputtering which can contribute to the formation of an exosphere. We have measured sputtering yields and velocity spectra of secondary ions ejected from nepheline, an aluminosilicate thought to be a good analogue for Mercury's surface, as a laboratory approach to understand the evolution of silicate surfaces and the presence of Na and K vapor in the exosphere. Experiments were performed with highly charged ion beams (keV/u-MeV/u) delivered by GANIL using an imaging XY-TOF-SIMS device under UHV conditions. The fluence dependence of sputtering yields gives information about the evolution of surface stoichiometry during irradiation. From the energy distributions N(E) of sputtered particles, the fraction of particles which could escape from the gravitational field of Mercury, and of those falling back and possibly contributing to populate the exosphere can be roughly estimated.

  15. Ab Initio Prediction and Characterization of Mo2C Monolayer as Anodes for Lithium-Ion and Sodium-Ion Batteries.

    Science.gov (United States)

    Sun, Qilong; Dai, Ying; Ma, Yandong; Jing, Tao; Wei, Wei; Huang, Baibiao

    2016-03-17

    Identifying suitable electrodes materials with desirable electrochemical properties is urgently needed for the next generation of renewable energy technologies. Here we report an ideal candidate material, Mo2C monolayer, with not only required large capacity but also high stability and mobility by means of first-principles calculations. After ensuring its dynamical and thermal stabilities, various low energy Li and Na adsorption sites are identified, and the electric conductivity of the host material is also maintained. The calculated minor diffusion barriers imply a high mobility and cycling ability of Mo2C. In addition, the Li-adsorbed Mo2C monolayer possesses a high theoretical capacity of 526 mAh·g(-1) and a low average electrode potential of 0.14 eV. Besides, we find that the relatively low capability of Na-adsorbed Mo2C (132 mAh·g(-1)) arises from the proposed competition mechanism. These results highlight the promise of Mo2C monolayer as an appealing anode material for both lithium-ion and sodium-ion batteries.

  16. 3D Networked Tin Oxide/Graphene Aerogel with a Hierarchically Porous Architecture for High-Rate Performance Sodium-Ion Batteries.

    Science.gov (United States)

    Xie, Xiuqiang; Chen, Shuangqiang; Sun, Bing; Wang, Chengyin; Wang, Guoxiu

    2015-09-07

    Low-cost and sustainable sodium-ion batteries are regarded as a promising technology for large-scale energy storage and conversion. The development of high-rate anode materials is highly desirable for sodium-ion batteries. The optimization of mass transport and electron transfer is crucial in the discovery of electrode materials with good high-rate performances. Herein, we report the synthesis of 3 D interconnected SnO2 /graphene aerogels with a hierarchically porous structure as anode materials for sodium-ion batteries. The unique 3 D architecture was prepared by a facile in situ process, during which cross-linked 3 D conductive graphene networks with macro-/meso-sized hierarchical pores were formed and SnO2 nanoparticles were dispersed uniformly on the graphene surface simultaneously. Such a 3 D functional architecture not only facilitates the electrode-electrolyte interaction but also provides an efficient electron pathway within the graphene networks. When applied as anode materials in sodium-ion batteries, the as-prepared SnO2 /graphene aerogel exhibited high reversible capacity, improved cycling performance compared to SnO2 , and promising high-rate capability.

  17. Three-dimensional spider-web architecture assembled from Na₂Ti₃O₇ nanotubes as a high performance anode for a sodium-ion battery.

    Science.gov (United States)

    Zhang, Yuping; Guo, Lin; Yang, Shihe

    2014-11-21

    A Na2Ti3O7 nanotube-assembled three-dimensional spider-web architecture is synthesized using a hydrothermal method. The self-similar network architecture exhibits an excellent performance as an anode for a room temperature sodium ion battery without any additives (e.g. binder, conducting agent) for the first time.

  18. Membrane topology of the sodium ion-dependent citrate carrier of Klebsiella pneumoniae - Evidence for a new structural class of secondary transporters

    NARCIS (Netherlands)

    vanGeest, M; Lolkema, JS

    1996-01-01

    The predicted secondary structure model of the sodium ion-dependent citrate carrier of Klebsiella pneumoniae (CitS) presents the la-transmembrane helix motif observed for many secondary transporters, Biochemical evidence presented in this paper is not consistent with this model. N-terminal and C-ter

  19. Membrane Topology of the Sodium Ion-dependent Citrate Carrier of Klebsiella pneumoniae. Evidence for a New Structural Class of Secondary Transporters

    NARCIS (Netherlands)

    Geest, Marleen van; Lolkema, Juke S.

    1996-01-01

    The predicted secondary structure model of the sodium ion-dependent citrate carrier of Klebsiella pneumoniae (CitS) presents the 12-transmembrane helix motif observed for many secondary transporters. Biochemical evidence presented in this paper is not consistent with this model. N-terminal and C-ter

  20. Biochemistry-directed hollow porous microspheres: bottom-up self-assembled polyanion-based cathodes for sodium ion batteries

    Science.gov (United States)

    Lin, Bo; Li, Qiufeng; Liu, Baodong; Zhang, Sen; Deng, Chao

    2016-04-01

    Biochemistry-directed synthesis of functional nanomaterials has attracted great interest in energy storage, catalysis and other applications. The unique ability of biological systems to guide molecule self-assembling facilitates the construction of distinctive architectures with desirable physicochemical characteristics. Herein, we report a biochemistry-directed ``bottom-up'' approach to construct hollow porous microspheres of polyanion materials for sodium ion batteries. Two kinds of polyanions, i.e. Na3V2(PO4)3 and Na3.12Fe2.44(P2O7)2, are employed as cases in this study. The microalgae cell realizes the formation of a spherical ``bottom'' bio-precursor. Its tiny core is subjected to destruction and its tough shell tends to carbonize upon calcination, resulting in the hollow porous microspheres for the ``top'' product. The nanoscale crystals of the polyanion materials are tightly enwrapped by the highly-conductive framework in the hollow microsphere, resulting in the hierarchical nano-microstructure. The whole formation process is disclosed as a ``bottom-up'' mechanism. Moreover, the biochemistry-directed self-assembly process is confirmed to play a crucial role in the construction of the final architecture. Taking advantage of the well-defined hollow-microsphere architecture, the abundant interior voids and the highly-conductive framework, polyanion materials show favourable sodium-intercalation kinetics. Both materials are capable of high-rate long-term cycling. After five hundred cycles at 20 C and 10 C, Na3V2(PO4)3 and Na3.12Fe2.44(P2O7)2 retain 96.2% and 93.1% of the initial capacity, respectively. Therefore, the biochemistry-directed technique provides a low-cost, highly-efficient and widely applicable strategy to produce high-performance polyanion-based cathodes for sodium ion batteries.Biochemistry-directed synthesis of functional nanomaterials has attracted great interest in energy storage, catalysis and other applications. The unique ability of

  1. The central mechanism underlying hypertension: a review of the roles of sodium ions, epithelial sodium channels, the renin-angiotensin-aldosterone system, oxidative stress and endogenous digitalis in the brain.

    Science.gov (United States)

    Takahashi, Hakuo; Yoshika, Masamichi; Komiyama, Yutaka; Nishimura, Masato

    2011-11-01

    The central nervous system has a key role in regulating the circulatory system by modulating the sympathetic and parasympathetic nervous systems, pituitary hormone release, and the baroreceptor reflex. Digoxin- and ouabain-like immunoreactive materials were found >20 years ago in the hypothalamic nuclei. These factors appeared to localize to the paraventricular and supraoptic nuclei and the nerve fibers at the circumventricular organs and supposed to affect electrolyte balance and blood pressure. The turnover rate of these materials increases with increasing sodium intake. As intracerebroventricular injection of ouabain increases blood pressure via sympathetic activation, an endogenous digitalis-like factor (EDLF) was thought to regulate cardiovascular system-related functions in the brain, particularly after sodium loading. Experiments conducted mainly in rats revealed that the mechanism of action of ouabain in the brain involves sodium ions, epithelial sodium channels (ENaCs) and the renin-angiotensin-aldosterone system (RAAS), all of which are affected by sodium loading. Rats fed a high-sodium diet develop elevated sodium levels in their cerebrospinal fluid, which activates ENaCs. Activated ENaCs and/or increased intracellular sodium in neurons activate the RAAS; this releases EDLF in the brain, activating the sympathetic nervous system. The RAAS promotes oxidative stress in the brain, further activating the RAAS and augmenting sympathetic outflow. Angiotensin II and aldosterone of peripheral origin act in the brain to activate this cascade, increasing sympathetic outflow and leading to hypertension. Thus, the brain Na(+)-ENaC-RAAS-EDLF axis activates sympathetic outflow and has a crucial role in essential and secondary hypertension. This report provides an overview of the central mechanism underlying hypertension and discusses the use of antihypertensive agents.

  2. Conformational constraining of inactive and active States of a seven transmembrane receptor by metal ion site engineering in the extracellular end of transmembrane segment V

    DEFF Research Database (Denmark)

    Rosenkilde, Mette M; David, Ralf; Oerlecke, Ilka;

    2006-01-01

    The extracellular part of transmembrane segment V (TM-V) is expected to be involved in the activation process of 7TM receptors, but its role is far from clear. Here, we study the highly constitutively active CXC-chemokine receptor encoded by human herpesvirus 8 (ORF74-HHV8), in which a metal ion...... at concentrations >10 microM. The chemokine interaction with [R208H;R212H]-ORF74 was altered compared with wild-type ORF74-HHV8 with decreased agonist (CXCL1/GROalpha) potency (84-fold), affinity (5.8- and 136-fold in competition against agonist and inverse agonist, respectively), and binding capacity (B(max); 25....... The activating properties of Zn(II) were not due to a metal ion site between the ligand and the receptor because CXCL1/GROalpha analogs in which the putative metal-ion binding residues had been substituted-[H19A] and [H34A]-acted like wild-type CXCL1/GROalpha. Based on the complex action of Zn...

  3. Contribution of a Sodium Ion Gradient to Energy Conservation during Fermentation in the Cyanobacterium Arthrospira (Spirulina) maxima CS-328 ▿ †

    Science.gov (United States)

    Carrieri, Damian; Ananyev, Gennady; Lenz, Oliver; Bryant, Donald A.; Dismukes, G. Charles

    2011-01-01

    Sodium gradients in cyanobacteria play an important role in energy storage under photoautotrophic conditions but have not been well studied during autofermentative metabolism under the dark, anoxic conditions widely used to produce precursors to fuels. Here we demonstrate significant stress-induced acceleration of autofermentation of photosynthetically generated carbohydrates (glycogen and sugars) to form excreted organic acids, alcohols, and hydrogen gas by the halophilic, alkalophilic cyanobacterium Arthrospira (Spirulina) maxima CS-328. When suspended in potassium versus sodium phosphate buffers at the start of autofermentation to remove the sodium ion gradient, photoautotrophically grown cells catabolized more intracellular carbohydrates while producing 67% higher yields of hydrogen, acetate, and ethanol (and significant amounts of lactate) as fermentative products. A comparable acceleration of fermentative carbohydrate catabolism occurred upon dissipating the sodium gradient via addition of the sodium-channel blocker quinidine or the sodium-ionophore monensin but not upon dissipating the proton gradient with the proton-ionophore dinitrophenol (DNP). The data demonstrate that intracellular energy is stored via a sodium gradient during autofermentative metabolism and that, when this gradient is blocked, the blockage is compensated by increased energy conversion via carbohydrate catabolism. PMID:21890670

  4. Hetero-bimetallic Complex of a 2D Coordination Network Constructed by Sodium Ion and p-Sulfonatothiacalix[4]arene

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A 2D coordination polymer built by sodium ion and water-soluble p-sulfonato thiacalix(4)arene of trivalent yttrium complex [Na(H2O)2Y(H2O)6(DMF) (p-sulfonatothiaca lix(4)arene)]·9H2O is reported.The complex belongs to the monoclinic system, space group P21/c, with a =16.703(3),b = 17.819(4), c = 17.357(4)(A), β= 106.23(3)°,Z= 4,V= 4960.0(17)(A)3, Mr = 1304.08,Dc = 1.746 g/cm3,μ= 1.624 mm-1, F(000) = 2688, the final R = 0.0398 and wR = 0.1132 for 7534 observed reflections with I>2σ(I).One yttrium(Ⅲ) ion is coordinated by the thiacalixarene ligand via the sulfonato group, and also ligated by an oxygen atom of a DMF molecule occupying the cavity of thiacalixarene and six aqua ligands.

  5. Enhancing Sodium Ion Battery Performance by Strongly Binding Nanostructured Sb2S3 on Sulfur-Doped Graphene Sheets.

    Science.gov (United States)

    Xiong, Xunhui; Wang, Guanhua; Lin, Yuwei; Wang, Ying; Ou, Xing; Zheng, Fenghua; Yang, Chenghao; Wang, Jeng-Han; Liu, Meilin

    2016-12-27

    Sodium ion batteries (SIBs) have been considered a promising alternative to lithium ion batteries for large-scale energy storage. However, their inferior electrochemical performances, especially cyclability, become the major challenge for further development of SIBs. Large volume change and sluggish diffusion kinetics are generally considered to be responsible for the fast capacity degradation. Here we report the strong chemical bonding of nanostructured Sb2S3 on sulfur-doped graphene sheets (Sb2S3/SGS) that enables a stable capacity retention of 83% for 900 cycles with high capacities and excellent rate performances. To the best of our knowledge, the cycling performance of the Sb2S3/SGS composite is superior to those reported for any other Sb-based materials for SIBs. Computational calculations demonstrate that sulfur-doped graphene (SGS) has a stronger affinity for Sb2S3 and the discharge products than pure graphene, resulting in a robust composite architecture for outstanding cycling stability. Our study shows a feasible and effective way to solve the long-term cycling stability issue for SIBs.

  6. Niobium-doped titanium oxide anode and ionic liquid electrolyte for a safe sodium-ion battery

    Science.gov (United States)

    Usui, Hiroyuki; Domi, Yasuhiro; Shimizu, Masahiro; Imoto, Akinobu; Yamaguchi, Kazuki; Sakaguchi, Hiroki

    2016-10-01

    The anode properties of Nb-doped rutile TiO2 electrodes were investigated in an ionic liquid electrolyte comprised of N-methyl-N-propylpyrrolidinium cation and bis(fluorosulfonyl)amide anion for use in a safe Na-ion battery. Although the electrolyte's conductivity was lower than that of a conventional organic electrolyte at 30 °C, it showed high conductivity comparable to that of the organic electrolyte at 60 °C. The Nb-doped TiO2 electrode showed excellent cyclability in the ionic liquid electrolyte at 60 °C: a high capacity retention of 97% was observed even at the 350th cycle, which is comparable to value in the organic electrolyte (91%). In a non-flammability test in a closed system, no ignition was observed with the ionic liquid electrolyte even at 300 °C. These results indicate that combination of a Nb-doped TiO2 anode and ionic liquid electrolyte gives not only an excellent cyclability but also high safety for a Na-ion battery operating at a temperature below the sodium's melting point of 98 °C.

  7. Facile preparation of carbon wrapped copper telluride nanowires as high performance anodes for sodium and lithium ion batteries

    Science.gov (United States)

    Yu, Hong; Yang, Jun; Geng, Hongbo; Chao Li, Cheng

    2017-04-01

    Uniform carbon wrapped copper telluride nanowires were successfully prepared by using an in situ conversion reaction. The length of these nanowires is up to several micrometers and the width is around 30–40 nm. The unique one dimensional structure and the presence of conformal carbon coating of copper telluride greatly accommodate the large volumetric changes during cycling, significantly increase the electrical conductivity and reduce charge transfer resistance. The copper telluride nanowires show promising performance in a lithium ion battery with a discharge capacity of 130.2 mA h g‑1 at a high current density of 6.0 A g‑1 (26.74 C) and a stable cycling performance of 673.3 mA h g‑1 during the 60th cycle at 100 mA g‑1. When evaluated as anode material for a sodium ion battery, the copper telluride nanowires deliver a reversible capacity of 68.1 mA h g‑1 at 1.0 A g‑1 (∼4.46 C) and have a high capacity retention of 177.5 mA h g‑1 during the 500th cycle at 100 mA g‑1.

  8. Design and synthesis of hollow NiCo2O4 nanoboxes as anodes for lithium-ion and sodium-ion batteries.

    Science.gov (United States)

    Chen, Junfen; Ru, Qiang; Mo, Yudi; Hu, Shejun; Hou, Xianhua

    2016-07-28

    Hollow porous NiCo2O4-nanoboxes (NCO-NBs) were synthesized with zeolitic imidazolate framework-67 (ZIF-67) nanocrystals as the template followed by a subsequent annealing treatment. The structure and morphology of the NCO-NBs were characterized using X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. When tested as potential anode materials for lithium-ion batteries, these porous NCO-NBs with a well-defined hollow structure manifested enhanced performance of Li storage. The discharge capacity of the NCO-NBs remained 1080 mA h g(-1) after 150 cycles at a current rate of 500 mA g(-1) and 884 mA h g(-1) could be obtained at a current density of 2000 mA g(-1) after 200 cycles. Even when cycled at a high density of 8000 mA g(-1), a comparable capacity of 630 mA h g(-1) could be achieved. Meanwhile, the Na storage behavior of NCO-NBs as anode materials of sodium ion batteries (SIBs) was initially investigated and they exhibited a high initial discharge capacity of 826 mA h g(-1), and a moderate capacity retention of 328 mA h g(-1) was retained after 30 cycles. The improved electrochemical performance for NCO-NBs could be attributed to the hierarchical hollow structure and the desirable composition, which provide enough space to alleviate volume expansion during the Li(+)/Na(+) insertion/extraction process and facilitate rapid transport of ions and electrons.

  9. One-Step Synthesis of Titanium Oxyhydroxy-Fluoride Rods and Research on the Electrochemical Performance for Lithium-ion Batteries and Sodium-ion Batteries.

    Science.gov (United States)

    Li, Biao; Gao, Zhan; Wang, Dake; Hao, Qiaoyan; Wang, Yan; Wang, Yongkun; Tang, Kaibin

    2015-12-01

    Titanium oxyhydroxy-fluoride, TiO0.9(OH)0.9F1.2 · 0.59H2O rods with a hexagonal tungsten bronze (HTB) structure, was synthesized via a facile one-step solvothermal method. The structure, morphology, and component of the products were characterized by X-ray powder diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), ion chromatograph, energy-dispersive X-ray (EDX) analyses, and so on. Different rod morphologies which ranged from nanoscale to submicron scale were simply obtained by adjusting reaction conditions. With one-dimension channels for Li/Na intercalation/de-intercalation, the electrochemical performance of titanium oxyhydroxy-fluoride for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) was also studied. Electrochemical tests revealed that, for LIBs, titanium oxyhydroxy-fluoride exhibited a stabilized reversible capacity of 200 mAh g(-1) at 25 mA g(-1) up to 120 cycles in the electrode potential range of 3.0-1.2 V and 140 mAh g(-1) at 250 mA g(-1) up to 500 cycles, especially; for SIBs, a high capacity of 100 mAh g(-1) was maintained at 25 mA g(-1) after 115 cycles in the potential range of 2.9-0.5 V.

  10. Na+,K+-ATPase amino acids involved in transport of the 3rd sodium ion

    DEFF Research Database (Denmark)

    Holm, Rikke; Einholm, Anja P.; Toustrup-Jensen, Mads Schak

    856A and Q856E exhibit ~24-,~9- and ~4-fold reduction of Na+ affinity, respectively, relative to wt, and the Q856 mutants display wt-like interaction with K+ at the E2P sites, thus supporting the hypothesis that the channel containing D923/928 and Q856 is a transport pathway for the third Na+ ion. I...... α3 mutant D923N, which is associated with RDP [1]. D923 is located in the cytoplasmic half of transmembrane helix M8 in a putative transport channel between M5, M7, M8 and M10. The external K+ sites behaved wild type (wt)-like in the mutant, suggesting that D923 is associated with the third Na+ ion...... mutated C932 close to the proposed channel inlet. C932F reduced Na+ affinity ~73-fold. This fits into a model, where the bulky phenylalanine prevents Na+ from entering the channel....

  11. Virus enabled 3d nano-array electrodes for integrated Lithium/Sodium-ion microbatteries

    Science.gov (United States)

    Liu, Yihang

    Multilayers of functional materials (carbon/electrode/nickel) were hierarchically architectured over tobacco mosaic virus (TMV) templates that were genetically modified to self-assemble in a vertical manner on current-collectors for battery applications. The spaces formed between individual rods effectively accommodated the volume expansion and contraction of electrodes during charge/discharge, while surface carbon coating engineered over these nanorods further enhance the electronic conductivity. The microbattery based on self aligned nanoforests with precise arrangement of various auxiliary material layers including a central nanometric metal core as direct electronic pathway to current collector, can deliver high energy density and stable cycling stability. C/LiFePO4/Ni/TMV nanoforest cathodes for Li-ion batteries and C/Sn/Ni/TMV nanoforest anodes for Na-ion batteries were assembled using physical sputtering deposition. Both 3D nanoforest electrodes show exceptional cycling stability and rate capability.

  12. SnSe2 2D Anodes for Advanced Sodium Ion Batteries

    KAUST Repository

    Zhang, Fan

    2016-08-22

    A simple synthesis method to prepare pure SnSe2 nanosheet anodes for Na ion batteries is reported. The SnSe2 2D sheets achieve a stable and reversible specific capacity of 515 mA h g-1 after 100 cycles, with excellent rate performance. The sodiation and desodiation process in this anode material is shown to occur via a combination of conversion and alloying reactions.

  13. 钠离子电池正极材料的研究进展∗%The research progress of cathode material for sodium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    杨绍斌; 董伟; 沈丁; 王晓亮; 李思南; 王峰; 王阳; 孙闻

    2015-01-01

    钠离子电池与锂离子电池相比,具有钠资源储量丰富、价格低廉等优点,被认为是发展新能源、实现规模化储能极具潜力的二次电池。近年来钠离子电池成为人们研究的热点,相关报道也在逐年增加。综述了钠离子电池正极材料发展中典型化合物,如过渡金属氧化物、聚阴离子化合物等的研究进展,以及目前人们主要采用的纳米化、包覆、掺杂等几种有效的改性手段,并对正极材料未来的研究方向以及发展前景提出了展望。%Compared with lithium-ion batteries,sodium sodium-ion batteries has the resources was abundant, the price was low wait for an advantage,and was considered to be potential secondary battery of development new energy,realizing large-scale energy storage.Sodium-ion batteries in recent years become the research hot spot,the relevant report also increased year by year.This paper reviews development of the typical compounds in sodium-ion battery cathode material,such as transition metal oxides,polyanionic compounds;and the effec-tive modification methods adopting by people such as nano-technology,coating,cladding,etc.Then,the re-search direction and prospects for development of sodium-ion batteries are forecasted.

  14. ELUTION OF TUNGSTEN BY SODIUM COMPOUNDS AND ACCELERATION EFFECTS OF COEXISTENT COUNTER IONS IN MIXED ELUANT

    Institute of Scientific and Technical Information of China (English)

    WanLinsheng; DengZuoGuo

    1995-01-01

    The elution of WO42- ions by NaOH、NaNO3、NaCl and NH4Cl on strong basic anion exchange resins in quaternary ammonium form I and the adsorption properties after elution were studied.In addition,the elution curve,the permeation curve and the exchange capacities of operation were presented.The eluate containing tungsten with high content and excessive eluant of low content were obtained by employing the process of eluting using mixed solution of NaCl and NaOH.It′s possible to obtain Na2WO4·2H2O with high purity by evaporating and crystallizing the eluate.The results of mixed elution showed that the diffusion coefficients of Cl-、OH- and WO42- ions in solution or exchange agent varied due to the coexistence of counter ions and then the exchange velocity of WO42-→Cl- and WO42-→OH- was accelerated.

  15. Phase selection controlled by sodium ions in the synthesis of FAU/LTA composite zeolite

    Science.gov (United States)

    Hu, Linyan; Xie, Sujuan; Wang, Qingxia; Liu, Shenglin; Xu, Longya

    2009-01-01

    Zeolite faujasite (FAU), Linde type A (LTA) and FAU/LTA composite have been synthesized using tetramethylammonium cation (TMA +) as template, by adjusting only the concentration of Na + ions in the initial solution (1.00 Al2 O3 4.36 SiO2 : 2.39 (TMA)2 O : β Na2 O : 249.00H2 O). Na + ions alter the phase composition of the product more than TMA+ or OH- ions. When Na2 O concentration [Na2 O] increases from 0.024 to 0.168, the product gradually changes from pure FAU to pure LTA via the formation of FAU/LTA composite with increasing LTA fraction. Interestingly, the induction periods of FAU and LTA in the FAU/LTA composite zeolite ([Na2 O] is 0.072) are both 13 h, quite different from the induction periods of their individual pure phases—45 h for FAU and 4 h for LTA. During the crystallization, the LTA/(FAU + LTA) fraction in the composite zeolite decreases in a nearly linear fashion. Scanning electron microscopy, thermogravimetry and differential thermal analysis indicate some difference between the properties of the FAU/LTA composite zeolite and of the mechanical mixture.

  16. Phase selection controlled by sodium ions in the synthesis of FAU/LTA composite zeolite

    Directory of Open Access Journals (Sweden)

    Linyan Hu, Sujuan Xie, Qingxia Wang, Shenglin Liu and Longya Xu

    2009-01-01

    Full Text Available Zeolite faujasite (FAU, Linde type A (LTA and FAU/LTA composite have been synthesized using tetramethylammonium cation (TMA + as template, by adjusting only the concentration of Na + ions in the initial solution (1.00 Al2 O3 4.36 SiO2 : 2.39 (TMA2 O : β Na2 O : 249.00H2 O. Na + ions alter the phase composition of the product more than TMA+ or OH− ions. When Na2 O concentration [Na2 O] increases from 0.024 to 0.168, the product gradually changes from pure FAU to pure LTA via the formation of FAU/LTA composite with increasing LTA fraction. Interestingly, the induction periods of FAU and LTA in the FAU/LTA composite zeolite ([Na2 O] is 0.072 are both 13 h, quite different from the induction periods of their individual pure phases—45 h for FAU and 4 h for LTA. During the crystallization, the LTA/(FAU + LTA fraction in the composite zeolite decreases in a nearly linear fashion. Scanning electron microscopy, thermogravimetry and differential thermal analysis indicate some difference between the properties of the FAU/LTA composite zeolite and of the mechanical mixture.

  17. Pigments content in Сhlorella vulgaris under the influence of the sodium selenite and the ions of metals

    Directory of Open Access Journals (Sweden)

    O. I. Bodnar

    2016-01-01

    Full Text Available We investigated the content of pigments in Chlorella vulgaris Beij. (Chlorophyta under the influence of sodium selenite in concentrations based on Se4+ 0.5, 5.0, 10.0 and 20.0 mg/dm3 during one, three and seven days and under the influence of the simultaneous action of selenite in concentrations 10 mg Se4+/dm3 and ions of Zn2+, Mn2+, Co2+,Cu2+, Fe3+ in concentrations 5.00, 0.25, 0.05, 0.008 and 0.002 mg/dm3over seven days. This research was carried out to establish the conditions for obtaining algal lipidis substance enriched with selenium and biogenic metals in the aquaculture. The content of pigments was determined spectrophotometrically, the cellular walls were separatedby centrifuge in the percoll gradient and investigated microscopically. The pigments content in the Ch. vulgaris increased by 1.5–2.5 times in comparison with the control sample under the influence of 10 mg Se4+/dm3 with and without metal ions, in all variants of experimental influence due to binding of SeО32– with proteins and lipids. We found that selenium was included in all lipid fractions (triacylglycerols, dyacylglycerols, phospholipids, nonetherified fatty acids; the maximum amount of selenium-containing lipids wasrecorded in chloroplasts. The increase in the contents of carotenoids caused by the actions of experimental factors played an exceptional role in the mechanism of antioxidant protection that prevents destruction of chlorophyll and, accordingly, increases its amount in cells. Changes in the functioning of the photosynthetic apparatus of Ch. vulgaris affect the whole complex of metabolic transformation. Thus, the successful cultivation of chlorella, enriched with selenium and biogenic metals, is possible within seven days under the influence of 10 mg Se4+/dm3 and the above-mentioned concentration of metal ions.

  18. Microanalyses of the hydroxyl-poly-calcium sodium phosphate coatings produced by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Thin calcium phosphate coatings on titanium alloy substrates wereprepared by Ar+ ion beam assisted deposition (IBAD) from hydroxyl-poly-calciumsodium phosphate (HPPA) target. The coatings were analyzed by XRD, FTIR, XPS.These analyses revealed that the as-deposited films were amorphous or no apparentcrystallinity. No distinct absorption band of the hydroxyl group was observed in FTIRspectra of the coatings but new absorption bands were presented for CO3-2. Thecalcium to phosphorous ratio of these coatings in different IBAD conditions variedfrom 0.46 to 3.36.

  19. Structural features of ion transport and allosteric regulation in sodium-calcium exchanger (NCX proteins

    Directory of Open Access Journals (Sweden)

    Moshe eGiladi

    2016-02-01

    Full Text Available Na+/Ca2+ exchanger (NCX proteins extrude Ca2+ from the cell to maintain cellular homeostasis. Since NCX proteins contribute to numerous physiological and pathophysiological events, their pharmacological targeting has been desired for a long time. This intervention remains challenging owing to our poor understanding of the underlying structure-dynamic mechanisms. Recent structural studies have shed light on the structure-function relationships underlying the ion-transport and allosteric regulation of NCX. The crystal structure of an archaeal NCX (NCX_Mj along with molecular dynamic simulations and ion flux analyses, have assigned the ion binding sites for 3Na+ and 1Ca2+, which are being transported in separate steps. In contrast with NCX_Mj, eukaryotic NCXs contain the regulatory Ca2+-binding domains, CBD1 and CBD2, which affect the membrane embedded ion-transport domains over a distance of ~80 Å. The Ca2+-dependent regulation is ortholog, isoform and splice-variant dependent to meet physiological requirements, exhibiting either a positive, negative or no response to regulatory Ca2+. The crystal structures of the two-domain (CBD12 tandem have revealed a common mechanism involving a Ca2+-driven tethering of CBDs in diverse NCX variants. However, dissociation kinetics of occluded Ca2+ (entrapped at the two-domain interface depends on the alternative-splicing segment (at CBD2, thereby representing splicing-dependent dynamic coupling of CBDs. The HDX-MS, SAXS, NMR, FRET, equilibrium 45Ca2+ binding and stopped-flow techniques provided insights into the dynamic mechanisms of CBDs. Ca2+ binding to CBD1 results in a population shift, where more constraint conformational states become highly populated without global conformational changes in the alignment of CBDs. This mechanism is common among NCXs. Recent HDX-MS studies have demonstrated that the apo CBD1 and CBD2 are stabilized by interacting with each other, while Ca2+ binding to CBD1 rigidifies

  20. [Advanced Treatment of Effluent from Industrial Park Wastewater Treatment Plant by Ferrous Ion Activated Sodium Persulfate].

    Science.gov (United States)

    Zhu, Song-mei; Zhou, Zhen; Gu, Ling-yun; Jiang, Hai-tao; Ren, Jia-min; Wang, Luo-chun

    2016-01-15

    Fe(II) activated sodium persulfate (PS) technology was used for advanced treatment of effluent from industrial park wastewater treatment plant. Separate and combined effects of PS/COD, Fe(II)/PS and pH on COD and TOC removal were analyzed by the response surface methodology. Variations of organic substances before and after Fe(II)-PS oxidation were characterized by UV-Vis spectrometry, gel chromatography and three-dimensional fluorescence. PS/COD and Fe(II)/PS had significant effect on COD removal, while all the three factors had significant effect on TOC removal. The combined effect of PS/COD and pH had significant effect on COD removal. COD and TOC removal efficiencies reached 50.7% and 60.6% under optimized conditions of PS/COD 3.47, Fe(II)/PS 3.32 and pH 6.5. Fe(II)-PS oxidation converted macromolecular organic substances to small ones, and reduced contents of protein-, humic- and fulvic-like substances.

  1. Reinstating lead for high-loaded efficient negative electrode for rechargeable sodium-ion battery

    Science.gov (United States)

    Darwiche, Ali; Dugas, Romain; Fraisse, Bernard; Monconduit, Laure

    2016-02-01

    Due to its weight and toxicity, Pb is usually not considered as possible anode for Li- and Na-ion (NIBs) batteries. Nevertheless the toxicity is related to specific applications and its recycling is more than 99% which is one of the highest recycling rates on the planet where no other power source is utilized in more applications with such sustainability. For this reason, we have investigated micrometric lead particles as electrode for NIBs in an ether-based electrolyte (1 M NaPF6 in diglyme). The cyclability, coulombic efficiency and rate capability of lead were unexpected. A high loaded lead electrode with 98%wt of Pb and only 1% of carbon additive showed i) a capacity retention of 464 mA h/g after 50 cycles with only 1.5% of capacity loss, which represents a high volumetric capacity of 5289 mA h/cm3 due to the high density of Pb and ii) a very interesting capacity retention even at high current rate (1950 mA/g). In situ XRD study confirmed a sodiation-desodiation process in four steps. Preliminary tests in Pb//Na3V2(PO4)2F3 full cells showed promising results demonstrating that Pb could be a practical candidate for future high energy density Na-ion batteries with an efficient sodiated or non sodiated positive electrode.

  2. Nonequilibrium response of a voltage gated sodium ion channel and biophysical characterization of dynamic hysteresis.

    Science.gov (United States)

    Pal, Krishnendu; Das, Biswajit; Gangopadhyay, Gautam

    2017-02-21

    Here we have studied the dynamic as well as the non-equilibrium thermodynamic response properties of voltage-gated Na-ion channel. Using sinusoidally oscillating external voltage protocol we have both kinetically and energetically studied the non-equilibrium steady state properties of dynamic hysteresis in details. We have introduced a method of estimating the work done associated with the dynamic memory due to a cycle of oscillating voltage. We have quantitatively characterised the loop area of ionic current which gives information about the work done to sustain the dynamic memory only for ion conduction, while the loop area of total entropy production rate gives the estimate of work done for overall gating dynamics. The maximum dynamic memory of Na-channel not only depends on the frequency and amplitude but it also depends sensitively on the mean of the oscillating voltage and here we have shown how the system optimize the dynamic memory itself in the biophysical range of field parameters. The relation between the average ionic current with increasing frequency corresponds to the nature of the average dissipative work done at steady state. It is also important to understand that the utilization of the energy from the external field can not be directly obtained only from the measurement of ionic current but also requires nonequilibrium thermodynamic study.

  3. Investigations on spectral features of tungsten ions in sodium lead alumino borate glass system

    Science.gov (United States)

    Madhuri, V.; Kumar, J. Santhan; Rao, M. Subba; Cole, Sandhya

    2015-03-01

    Na2O-PbO-Al2O3-B2O3 (NPAB) glasses mixed with different concentrations of WO3 (ranging from 0 to 2.5 mol%) are synthesized by conventional melt quenching method. The samples are characterized by X-ray diffraction (XRD), optical absorption, Electron paramagnetic resonance (EPR) and Fourier transform infrared (FT-IR) spectroscopic techniques. Glass formation is confirmed by X-ray diffraction spectra. The optical absorption spectra of these glasses exhibited a predominant broad band peak at about 850-870 nm is identified due to dxy-dx2-y2 transition of W5+ ions. From the optical absorption spectral data, optical band gap (Eopt) and Urbach energy (ΔE) are evaluated. From EPR spectra the strength of the signal is increased and hyperfine splitting is resolved with increasing concentration of WO3 in the glass matrix. The FT-IR spectral studies have pointed out the existence of conventional BO3, BO4, B-O-B, PbO4, WO4 and WO6 structural units of these glasses. Various physical properties and optical basicity are also evaluated with respect to the concentration of WO3 ions.

  4. Highly stable linear carbonate-containing electrolytes with fluoroethylene carbonate for high-performance cathodes in sodium-ion batteries

    Science.gov (United States)

    Lee, Yongwon; Lee, Jaegi; Kim, Hyungsub; Kang, Kisuk; Choi, Nam-Soon

    2016-07-01

    Employing linear carbonates such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) as electrolyte solvents provides an opportunity to design appropriate electrolyte systems for high-performance sodium-ion batteries (SIBs). However, in practice, the use of linear carbonate-containing electrolytes is quite challenging because linear carbonates readily decompose at Na metal electrodes or sodiated anodes. One of the promising approaches is using an electrolyte additive to resolve the critical problems related to linear carbonates. Our investigation reveals that remarkable enhancement in electrochemical performance of Na4Fe3(PO4)2(P2O7) cathodes with linear carbonate-containing electrolytes is achieved by using a fluoroethylene carbonate (FEC) additive. Importantly, the initial Coulombic efficiency of the Na deposition/stripping on a stainless steel (SS) electrode is drastically improved from 16% to 90% by introducing the FEC additive into ethylene carbonate (EC)/propylene carbonate (PC)/DEC (5/3/2, v/v/v)/0.5 M NaClO4. The underlying mechanism of FEC at the electrode-electrolyte interface is clearly demonstrated by 13C nuclear magnetic resonance (NMR). In addition, the Na4Fe3(PO4)2(P2O7) cathode in EC/PC/DEC (5/3/2, v/v/v)/0.5 M sodium perchlorate (NaClO4) with FEC delivers a discharge capacity of 90.5 mAh g-1 at a current rate of C/2 and exhibits excellent capacity retention of 97.5% with high Coulombic efficiency of 99.6% after 300 cycles at 30 °C.

  5. Investigations on Poly (ethylene oxide) (PEO) - blend based solid polymer electrolytes for sodium ion batteries

    Science.gov (United States)

    Koduru, H. K.; Iliev, M. T.; Kondamareddy, K. K.; Karashanova, D.; Vlakhov, T.; Zhao, X.-Z.; Scaramuzza, N.

    2016-10-01

    Polymer blend electrolytes based on Polyethylene oxide (PEO) and polyvinyl pyrrolidone (PVP), complexed with NaIO4 salt and Graphene oxide (GO) are investigated in the present report. The electrolytes are prepared by a facile solution cast technique. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) are employed to study the influence of ion-polymer interactions on the micro structural properties of blend electrolytes. Measurements of electrical conductivity of the blend polymer complexes have been performed by using complex impedance spectroscopy in the frequency range 1 Hz - 1 MHz and within the temperature range 303 K - 343 K.A study on electrical conductivity properties of GO doped ‘salt complexed electrolyte’ systems is presented.

  6. Hard Carbon Fibers Pyrolyzed from Wool as High-Performance Anode for Sodium-Ion Batteries

    Science.gov (United States)

    Zhu, Xiaoming; Li, Qian; Qiu, Shen; Liu, Xiaoling; Xiao, Lifen; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2016-10-01

    In this paper, we first demonstrate that the wool from worn-out clothes can serve as a low-cost and easy-to-collect precursor to preparing high-performance hard carbons for Na-ion batteries. Morphological characterizations demonstrate that this wool-derived hard carbon presents well-defined and homogeneously dispersed fiber networks. X-ray diffraction results combined with high-resolution transmission electron microscopy analysis reveal that the interlayer space (d(002)) of the graphitic layers is 0.376 nm, sufficient for Na insertion into the stacked graphene layers. Electrochemical results show that the wool-derived hard carbon can deliver a high capacity of 303 mAh g-1 and excellent cycle stability over 80 cycles. This satisfactory electrochemical performance and easy synthetic procedure make it a promising anode material for practical SIBs.

  7. MCDHF Calculations and Beam-Foil EUV Spectra of Boron-Like Sodium Ions (Na VII

    Directory of Open Access Journals (Sweden)

    Per Jönsson

    2015-06-01

    Full Text Available Atomic data, such as wavelengths and line identifications, are necessary for many applications, especially in plasma diagnostics and for interpreting the spectra of distant astrophysical objects. The number of valence shell electrons increases the complexity of the computational problem. We have selected a five-electron ion, Na6+ (with the boron-like spectrum Na VII, for looking into the interplay of measurement and calculation. We summarize the available experimental work, perform our own extensive relativistic configuration interaction (RCI computations based on multi-configuration Dirac–Hartree–Fock (MCDHF wave functions, and compare the results to what is known of the level structure. We then discuss problems with databases that have begun to combine observations and computations.

  8. Distribution and mobility of phosphates and sodium ions in cheese by solid-state 31P and double-quantum filtered 23Na NMR spectroscopy.

    Science.gov (United States)

    Gobet, Mallory; Rondeau-Mouro, Corinne; Buchin, Solange; Le Quéré, Jean-Luc; Guichard, Elisabeth; Foucat, Loïc; Moreau, Céline

    2010-04-01

    The feasibility of solid-state magic angle spinning (MAS) (31)P nuclear magnetic resonance (NMR) spectroscopy and (23)Na NMR spectroscopy to investigate both phosphates and Na(+) ions distribution in semi-hard cheeses in a non-destructive way was studied. Two semi-hard cheeses of known composition were made with two different salt contents. (31)P Single-pulse excitation and cross-polarization MAS experiments allowed, for the first time, the identification and quantification of soluble and insoluble phosphates in the cheeses. The presence of a relatively 'mobile' fraction of colloidal phosphates was evidenced. The detection by (23)Na single-quantum NMR experiments of all the sodium ions in the cheeses was validated. The presence of a fraction of 'bound' sodium ions was evidenced by (23)Na double-quantum filtered NMR experiments. We demonstrated that NMR is a suitable tool to investigate both phosphates and Na(+) ions distributions in cheeses. The impact of the sodium content on the various phosphorus forms distribution was discussed and results demonstrated that NMR would be an important tool for the cheese industry for the processes controls.

  9. Multiangular Rod-Shaped Na0.44MnO2 as Cathode Materials with High Rate and Long Life for Sodium-Ion Batteries.

    Science.gov (United States)

    Liu, Qiannan; Hu, Zhe; Chen, Mingzhe; Gu, Qinfen; Dou, Yuhai; Sun, Ziqi; Chou, Shulei; Dou, Shi Xue

    2017-02-01

    The tunnel-structured Na0.44MnO2 is considered as a promising cathode material for sodium-ion batteries because of its unique three-dimensional crystal structure. Multiangular rod-shaped Na0.44MnO2 have been first synthesized via a reverse microemulsion method and investigated as high-rate and long-life cathode materials for Na-ion batteries. The microstructure and composition of prepared Na0.44MnO2 is highly related to the sintering temperature. This structure with suitable size increases the contact area between the material and the electrolyte and guarantees fast sodium-ion diffusion. The rods prepared at 850 °C maintain specific capacity of 72.8 mA h g(-1) and capacity retention of 99.6% after 2000 cycles at a high current density of 1000 mA g(-1). The as-designed multiangular Na0.44MnO2 provides new insight into the development of tunnel-type electrode materials and their application in rechargeable sodium-ion batteries.

  10. Origin of Enhanced Reactivity of a Microsolvated Nucleophile in Ion Pair SN2 Reactions: The Cases of Sodium p-Nitrophenoxide with Halomethanes in Acetone.

    Science.gov (United States)

    Li, Qiang-Gen; Xu, Ke; Ren, Yi

    2015-04-30

    In a kinetic experiment on the SN2 reaction of sodium p-nitrophenoxide with iodomethane in acetone-water mixed solvent, Humeres et al. (J. Org. Chem. 2001, 66, 1163) found that the reaction depends strongly on the medium, and the fastest rate constant was observed in pure acetone. The present work tries to explore why acetone can enhance the reactivity of the title reactions. Accordingly, we make a mechanistic study on the reactions of sodium p-nitrophenoxide with halomethanes (CH3X, X = Cl, Br, I) in acetone by using a supramolecular/continuum model at the PCM-MP2/6-311+G(d,p)//B3LYP/6-311+G(d,p) level, in which the ion pair nucleophile is microsolvated by one to three acetone molecules. We compared the reactivity of the microsolvated ion pair nucleophiles with solvent-free ion pair and anionic ones. Our results clearly reveal that the microsolvated ion pair nucleophile is favorable for the SN2 reactions; meanwhile, the origin of the enhanced reactivity induced by microsolvation of the nucleophile is discussed in terms of the geometries of transition state (TS) structures and activation strain model, suggesting that lower deformation energies and stronger interaction energies between the deformed reactants in the TS lead to the lower overall reaction barriers for the SN2 reaction of microsolvated sodium p-nitrophenoxide toward halomethanes in acetone.

  11. Development and validation of an ion-pair liquid chromatographic method for the quantitation of sodium cromoglycate in urine following inhalation.

    Science.gov (United States)

    Aswania, O A; Corlett, S A; Chrystyn, H

    1997-03-07

    An ion-pair liquid high-performance chromatography method with solid-phase extraction for measuring urinary concentrations of sodium cromoglycate following inhalation has been developed and validated. Sodium cromoglycate was extracted from urine on a 100-mg phenyl cartridge (Isolute, Jones Chromatography) and then quantified on a 25-cm C8 Spherisorb 5 microns stationary phase with a mobile phase of methanol-0.045 M phosphate buffer-0.05 M dodecyl triethyl ammonium phosphate (550:447.6:2.4, v/v) pH 2.3, at 0.85 ml min-1 using nedocromil sodium as an internal standard and UV detection at 238 nm. The inter- and intra-day reproducibilities were 8.33 and 13.63%, respectively, at 0.25 mg l-1. The limit of determination for sodium cromoglycate was 0.25 mg l-1 (with a signal-to-noise ratio of greater than 10:1). Following oral and inhaled administration of 20 mg of sodium cromoglycate to eight healthy volunteers, the mean and S.D. of sodium cromoglycate excreted in the urine at 0.5, 1 and 24 h post-dose were 0.02, 0.05 and 0.33%, and 0.16, 0.30 and 1.55% of the dose, respectively. The urinary recovery of sodium cromoglycate at 0.5 and 1 h following inhalation can therefore be used to compare the amount of drug reaching the respiratory tract using different sodium cromoglycate inhaled products or inhalation methods.

  12. Proline accumulation, ions dynamics and sodium root-shoot partition and compartmentation

    Directory of Open Access Journals (Sweden)

    Jesus Emanuel eBojorquez Quintal

    2014-11-01

    Full Text Available Despite its economic relevance, little is known about salt tolerance mechanisms in pepper plants. To address this question, we compared differences in responses to NaCl in two Capsicum chinense varieties: Rex (tolerant and Chichen-Itza (sensitive. Under salt stress (150 mM NaCl over 7 days roots of Rex variety accumulated 50 times more compatible solutes such as proline compared to Chichen-Itza. Mineral analysis indicated that Na+ is restricted to roots by preventing its transport to leaves. Fluorescence analysis suggested an efficient Na+ compartmentalization in vacuole-like structures and in small intracellular compartments in roots of Rex variety. At the same time, Na+ in Chichen-Itza plants was compartmentalized in the apoplast, suggesting substantial Na+ extrusion. Rex variety was found to retain more K+ in its roots under salt stress according to a mineral analysis and microelectrode ion flux estimation (MIFE. Vanadate-sensitive H+ efflux was higher in Chichen-Itza variety plants, suggesting a higher activity of the plasma membrane H+-ATPase, which fuels the extrusion of Na+, and, possibly, also the re-uptake of K+. Our results suggest a combination of stress tolerance mechanisms, in order to alleviate the salt-induced injury. Furthermore, Na+ extrusion to apoplast does not appear to be an efficient strategy for salt tolerance in pepper plants.

  13. Ultrafiltration by a compacted clay membrane-II. Sodium ion exclusion at various ionic strengths

    Science.gov (United States)

    Hanshaw, B.B.; Coplen, T.B.

    1973-01-01

    Several recent laboratory studies and field investigations have indicated that shales and compacted clay minerals behave as semipermeable membranes. One of the properties of semipermeable membranes is to retard or prevent the passage of charged ionic species through the membrane pores while allowing relatively free movement of uncharged species. This phenomenon is termed salt filtering, reverse osmosis, or ultrafiltration. This paper shows how one can proceed from the ion exchange capacity of clay minerals and, by means of Donnan membrane equilibrium concept and the Teorell-Meyer-Siever theory, develop a theory to explain why and to what extent ultrafiltration occurs when solutions of known concentration are forced to flow through a clay membrane. Reasonable agreement between theory and laboratory results were found. The concentration of the ultrafiltrate was always greater than predicted because of uncertainty in values of some parameters in the equations. Ultrafiltration phenomena may be responsible for the formation of some subsurface brines and mineral deposits. The effect should also be taken into consideration in any proposal for subsurface waste emplacement in an environment containing large quantities of clay minerals. ?? 1973.

  14. Passivation Layer and Cathodic Redox Reactions in Sodium-Ion Batteries Probed by HAXPES.

    Science.gov (United States)

    Doubaji, Siham; Philippe, Bertrand; Saadoune, Ismael; Gorgoi, Mihaela; Gustafsson, Torbjorn; Solhy, Abderrahim; Valvo, Mario; Rensmo, Håkan; Edström, Kristina

    2016-01-08

    The cathode material P2-Nax Co2/3 Mn2/9 Ni1/9 O2, which could be used in Na-ion batteries, was investigated through synchrotron-based hard X-ray photoelectron spectroscopy (HAXPES). Nondestructive analysis was made through the electrode/electrolyte interface of the first electrochemical cycle to ensure access to information not only on the active material, but also on the passivation layer formed at the electrode surface and referred to as the solid permeable interface (SPI). This investigation clearly shows the role of the SPI and the complexity of the redox reactions. Cobalt, nickel, and manganese are all electrochemically active upon cycling between 4.5 and 2.0 V; all are in the 4+ state at the end of charging. Reduction to Co(3+), Ni(3+), and Mn(3+) occurs upon discharging and, at low potential, there is partial reversible reduction to Co(2+) and Ni(2+). A thin layer of Na2 CO3 and NaF covers the pristine electrode and reversible dissolution/reformation of these compounds is observed during the first cycle. The salt degradation products in the SPI show a dependence on potential. Phosphates mainly form at the end of the charging cycle (4.5 V), whereas fluorophosphates are produced at the end of discharging (2.0 V).

  15. Heterogeneous WSx/WO₃ Thorn-Bush Nanofiber Electrodes for Sodium-Ion Batteries.

    Science.gov (United States)

    Ryu, Won-Hee; Wilson, Hope; Sohn, Sungwoo; Li, Jinyang; Tong, Xiao; Shaulsky, Evyatar; Schroers, Jan; Elimelech, Menachem; Taylor, André D

    2016-03-22

    Heterogeneous electrode materials with hierarchical architectures promise to enable considerable improvement in future energy storage devices. In this study, we report on a tailored synthetic strategy used to create heterogeneous tungsten sulfide/oxide core-shell nanofiber materials with vertically and randomly aligned thorn-bush features, and we evaluate them as potential anode materials for high-performance Na-ion batteries. The WSx (2 ≤ x ≤ 3, amorphous WS3 and crystalline WS2) nanofiber is successfully prepared by electrospinning and subsequent calcination in a reducing atmosphere. To prevent capacity degradation of the WSx anodes originating from sulfur dissolution, a facile post-thermal treatment in air is applied to form an oxide passivation surface. Interestingly, WO3 thorn bundles are randomly grown on the nanofiber stem, resulting from the surface conversion. We elucidate the evolving morphological and structural features of the nanofibers during post-thermal treatment. The heterogeneous thorn-bush nanofiber electrodes deliver a high second discharge capacity of 791 mAh g(-1) and improved cycle performance for 100 cycles compared to the pristine WSx nanofiber. We show that this hierarchical design is effective in reducing sulfur dissolution, as shown by cycling analysis with counter Na electrodes.

  16. Cu6Sn5-TiC-C nanocomposite anodes for high-performance sodium-ion batteries

    Science.gov (United States)

    Kim, Il Tae; Allcorn, Eric; Manthiram, Arumugam

    2015-05-01

    Cu6Sn5 alloy nanoparticles dispersed in a TiC and C conductive matrix have been developed via high energy mechanical milling (HEMM), and the resulting Cu6Sn5-TiC-C nanocomposite has been assessed as anodes for sodium-ion batteries. Composite anodes of Sn-C exhibit poor cyclic performance even with the introduction of 2 vol. % fluoroethylene carbonate (FEC) additive into the electrolyte. In contrast, Cu6Sn5-TiC-C nanocomposite anodes exhibit stable cycle life corresponding to a capacity retention of ∼80% at 40 cycles and high-rate performance with a capacity retention of ∼62% at 3000 mA g-1. These superior performance metrics is ascribed to the well-developed electrochemically active nanocrystalline material (Cu6Sn5) as well as a hybrid conductive matrix (TiC and C). The incorporation of 2 vol. % FEC additive into the electrolyte further improves the performance of Cu6Sn5-TiC-C nanocomposite to display a capacity retention of ∼94% at 250 cycles and high-rate capacity retention of ∼82% at 5000 mA g-1, which are attributed to the formation of a thin and stable SEI layer in presence of FEC.

  17. Nitrogen-Doped Yolk-Shell-Structured CoSe/C Dodecahedra for High-Performance Sodium Ion Batteries.

    Science.gov (United States)

    Zhang, Yifang; Pan, Anqiang; Ding, Lin; Zhou, Zilong; Wang, Yaping; Niu, Shaoyu; Liang, Shuquan; Cao, Guozhong

    2017-02-01

    In this work, nitrogen-doped, yolk-shell-structured CoSe/C mesoporous dodecahedra are successfully prepared by using cobalt-based metal-organic frameworks (ZIF-67) as sacrificial templates. The CoSe nanoparticles are in situ produced by reacting the cobalt species in the metal-organic frameworks with selenium (Se) powder, and the organic species are simultaneously converted into nitrogen-doped carbon material in an inert atmosphere at temperatures between 700 and 900 °C for 4 h. For the composite synthesized at 800 °C, the carbon framework has a relatively higher extent of graphitization, with high nitrogen content (17.65%). Furthermore, the CoSe nanoparticles, with a size of around 15 nm, are coherently confined in the mesoporous carbon framework. When evaluated as novel anode materials for sodium ion batteries, the CoSe/C composites exhibit high capacity and superior rate capability. The composite electrode delivers the specific capacities of 597.2 and 361.9 mA h g(-1) at 0.2 and 16 A g(-1), respectively.

  18. Preparation and physicochemical properties of surfactant-free emulsions using electrolytic-reduction ion water containing lithium magnesium sodium silicate.

    Science.gov (United States)

    Okajima, Masahiro; Wada, Yuko; Hosoya, Takashi; Hino, Fumio; Kitahara, Yoshiyasu; Shimokawa, Ken-ichi; Ishii, Fumiyoshi

    2013-04-01

    Surfactant-free emulsions by adding jojoba oil, squalane, olive oil, or glyceryl trioctanoate (medium chain fatty acid triglycerides, MCT) to electrolytic-reduction ion water containing lithium magnesium sodium silicate (GE-100) were prepared, and their physiochemical properties (thixotropy, zeta potential, and mean particle diameter) were evaluated. At an oil concentration of 10%, the zeta potential was ‒22.3 ‒ ‒26.8 mV, showing no marked differences among the emulsions of various types of oil, but the mean particle diameters in the olive oil emulsion (327 nm) and MCT emulsion (295 nm) were smaller than those in the other oil emulsions (452-471 nm). In addition, measurement of the hysteresis loop area of each type of emulsion revealed extremely high thixotropy of the emulsion containing MCT at a low concentration and the olive emulsion. Based on these results, since surfactants and antiseptic agents markedly damage sensitive skin tissue such as that with atopic dermatitis, surfactant- and antiseptic-free emulsions are expected to be new bases for drugs for external use.

  19. Chemical bonding between antimony and ionic liquid-derived nitrogen-doped carbon for sodium-ion battery anode

    Science.gov (United States)

    Xu, Xin; Si, Ling; Zhou, Xiaosi; Tu, Fengzhang; Zhu, Xiaoshu; Bao, Jianchun

    2017-05-01

    Antimony has received a great deal of attention as a promising anode material for sodium-ion batteries (SIBs) due to its high theoretical capacity of 660 mAh g-1. However, this application is significantly hampered by inherent large volume change and sluggish kinetics. To address these issues, an antimony-cyano-based ionic liquid-derived nitrogen-doped carbon (Sbsbnd CNC) hybrid is proposed and synthesized by ball-milling and subsequent pyrolysis treatment. As an anode material for SIBs, the as-synthesized Sbsbnd CNC hybrid delivers reversible capacities of 475 mAh g-1 at a current density of 100 mA g-1 and 203 mAh g-1 at 5000 mA g-1, and a 92.4% capacity retention based on the first-cycle capacity after 150 cycles at 100 mA g-1. Using ex situ X-ray photoelectron spectroscopy and elemental mapping techniques, we attribute the good structural integrity to the formation of Sbsbnd Nsbnd C bonds between Sb and the cyano-based ionic liquid-derived N-doped carbon matrix. Moreover, the presence of N-doped carbon network in the hybrid material serves as a robust protective cover and an electrical highway, buffering the substantial volume expansion of Sb nanoparticles and ensuring the fast electron transport for stable cycling operation.

  20. In Situ Binding Sb Nanospheres on Graphene via Oxygen Bonds as Superior Anode for Ultrafast Sodium-Ion Batteries.

    Science.gov (United States)

    Wan, Fang; Guo, Jin-Zhi; Zhang, Xiao-Hua; Zhang, Jing-Ping; Sun, Hai-Zhu; Yan, Qingyu; Han, Dong-Xue; Niu, Li; Wu, Xing-Long

    2016-03-01

    Graphene incorporation should be one effective strategy to develop advanced electrode materials for a sodium-ion battery (SIB). Herein, the micro/nanostructural Sb/graphene composite (Sb-O-G) is successfully prepared with the uniform Sb nanospheres (∼100 nm) bound on the graphene via oxygen bonds. It is revealed that the in-situ-constructed oxygen bonds play a significant role on enhancing Na-storage properties, especially the ultrafast charge/discharge capability. The oxygen-bond-enhanced Sb-O-G composite can deliver a high capacity of 220 mAh/g at an ultrahigh current density of 12 A/g, which is obviously superior to the similar Sb/G composite (130 mAh/g at 10 A/g) just without Sb-O-C bonds. It also exhibits the highest Na-storage capacity compared to Sb/G and pure Sb nanoparticles as well as the best cycling performance. More importantly, this Sb-O-G anode achieves ultrafast (120 C) energy storage in SIB full cells, which have already been shown to power a 26-bulb array and calculator. All of these superior performances originate from the structural stability of Sb-O-C bonds during Na uptake/release, which has been verified by ex situ X-ray photoelectron spectroscopies and infrared spectroscopies.

  1. Boron-Doped Anatase TiO2 as a High-Performance Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Wang, Baofeng; Zhao, Fei; Du, Guodong; Porter, Spencer; Liu, Yong; Zhang, Peng; Cheng, Zhenxiang; Liu, Hua Kun; Huang, Zhenguo

    2016-06-29

    Pristine and boron-doped anatase TiO2 were prepared via a facile sol-gel method and the hydrothermal method for application as anode materials in sodium-ion batteries (SIBs). The sol-gel method leads to agglomerated TiO2, whereas the hydrothermal method is conducive to the formation of highly crystalline and discrete nanoparticles. The structure, morphology, and electrochemical properties were studied. The crystal size of TiO2 with boron doping is smaller than that of the nondoped crystals, which indicates that the addition of boron can inhibit the crystal growth. The electrochemical measurements demonstrated that the reversible capacity of the B-doped TiO2 is higher than that for the pristine sample. B-doping also effectively enhances the rate performance. The capacity of the B-doped TiO2 could reach 150 mAh/g at the high current rate of 2C and the capacity decay is only about 8 mAh/g over 400 cycles. The remarkable performance could be attributed to the lattice expansion resulting from B doping and the shortened Li(+) diffusion distance due to the nanosize. These results indicate that B-doped TiO2 can be a good candidate for SIBs.

  2. Three dimensional nuclear magnetic resonance spectroscopic imaging of sodium ions using stochastic excitation and oscillating gradients

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, B.deB. [California Univ., Berkeley, CA (United States)]|[Lawrence Berkeley Lab., CA (United States)

    1994-12-01

    Nuclear magnetic resonance (NMR) spectroscopic imaging of {sup 23}Na holds promise as a non-invasive method of mapping Na{sup +} distributions, and for differentiating pools of Na{sup +} ions in biological tissues. However, due to NMR relaxation properties of {sup 23}Na in vivo, a large fraction of Na{sup +} is not visible with conventional NMR imaging methods. An alternate imaging method, based on stochastic excitation and oscillating gradients, has been developed which is well adapted to measuring nuclei with short T{sub 2}. Contemporary NMR imaging techniques have dead times of up to several hundred microseconds between excitation and sampling, comparable to the shortest in vivo {sup 23}Na T{sub 2} values, causing significant signal loss. An imaging strategy based on stochastic excitation has been developed which greatly reduces experiment dead time by reducing peak radiofrequency (RF) excitation power and using a novel RF circuit to speed probe recovery. Continuously oscillating gradients are used to eliminate transient eddy currents. Stochastic {sup 1}H and {sup 23}Na spectroscopic imaging experiments have been performed on a small animal system with dead times as low as 25{mu}s, permitting spectroscopic imaging with 100% visibility in vivo. As an additional benefit, the encoding time for a 32x32x32 spectroscopic image is under 30 seconds. The development and analysis of stochastic NMR imaging has been hampered by limitations of the existing phase demodulation reconstruction technique. Three dimensional imaging was impractical due to reconstruction time, and design and analysis of proposed experiments was limited by the mathematical intractability of the reconstruction method. A new reconstruction method for stochastic NMR based on Fourier interpolation has been formulated combining the advantage of a several hundredfold reduction in reconstruction time with a straightforward mathematical form.

  3. The impact of functionalized CNT in the network of sodium alginate-based nanocomposite beads on the removal of Co(II) ions from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Karkeh-abadi, Fatemeh [Department of Chemistry, University of Kashan, Kashan (Iran, Islamic Republic of); Saber-Samandari, Samaneh, E-mail: samaneh.saber@gmail.com [Department of Chemistry, Eastern Mediterranean University, Gazimagusa, TRNC via Mersin 10 (Turkey); Saber-Samandari, Saeed, E-mail: saeedss@aut.ac.ir [New Technologies Research Center, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2016-07-15

    Highlights: • The sodium alginate-hydroxyapatite-CNT nanocomposite beads were prepared. • Amide functionalized CNT imprinted in the network of sodium alginate containing HAp. • The prepared beads were used as adsorbents of cobalt ions from an aqueous solution. • The adsorption was fit with the Freundlich isotherm and second-order kinetic models. • The endothermic adsorption process is spontaneous and thermodynamically favorable. - Abstract: Significant efforts have been made to develop highly efficient adsorbents to remove radioactive Co(II) ion pollutants from medical and industrial wastewaters. In this study, amide group functionalized multi-walled carbon nanotube (CNT-CONH{sub 2}) imprinted in the network of sodium alginate containing hydroxyapatite, and new nanocomposite beads were synthesized. Then, they were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The prepared nanocomposite beads were used as an adsorbent of Co(II) ions from an aqueous solution. The presence and distribution of Co(II) ions in the surface of the nanocomposite beads was confirmed using FESEM, EDS and metal mapping analysis. The effect of various experimental conditions such as time, pH, and initial concentration of the adsorbate solution and temperature on the adsorption capacity of the nanocomposite beads were explored. The maximum Co(II) ions adsorption capacity of the prepared nanocomposite beads with the largest surface area of 163.4 m{sup 2} g{sup −1} was 347.8 mg g{sup −1} in the optimized condition. The adsorption mechanism followed a pseudo-second-order kinetic model. Furthermore, the Freundlich appears to produce better fit than the Langmuir adsorption isotherm. Finally, thermodynamic studies suggest that endothermic adsorption process of Co(II) ions is spontaneous and

  4. Layered nickel sulfide-reduced graphene oxide composites synthesized via microwave-assisted method as high performance anode materials of sodium-ion batteries

    Science.gov (United States)

    Qin, Wei; Chen, Taiqiang; Lu, Ting; Chua, Daniel H. C.; Pan, Likun

    2016-01-01

    Layered nickel sulfide (NS)-reduced graphene oxide (RGO) composites are prepared via a simple microwave-assisted method and subsequent annealing in N2/H2 atmosphere. A detailed array of characterization tools are used to study their morphology, structure and electrochemical performance. It was found that these composites exhibit significantly improved sodium-ion storage ability as compared with pure NS under galvanostatic cycling at a specific current of 100 mA g-1 in a potential limitation of 0.005-3.0 V. Furthermore, the composite with the RGO content of 35 wt.% achieves a high maximum reversible specific capacity of about 391.6 mAh g-1 at a specific current of 100 mA g-1 after 50 cycles. These results prove that NS-RGO composites are highly promising when applied directly as anode materials in sodium-ion batteries.

  5. Research progress in the sodium-ion battery cathode material%钠离子电池正极材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    徐硕炯; 张俊喜; 张世明

    2013-01-01

    Some main types of positive materials,including transition metal oxides,poly-anionic compounds for sodium-ion batterieswere discussed.Research progress in the sodium-ion battery cathode material was summarized through the thread of relation between structure and electrochemical performance of all kinds of cathode materials.%介绍了钠离子电池正极材料的几种主要类型,如过渡金属氧化物、聚阴离子化合物的研究进展.以各种正极材料的结构与电化学性能之间的关联为线索,综述了钠离子电池正极材料方面的研究进展.

  6. NaN3 addition, a strategy to overcome the problem of sodium deficiency in P2-Na0.67[Fe0.5Mn0.5]O2 cathode for sodium-ion battery

    Science.gov (United States)

    Martinez De Ilarduya, Jaione; Otaegui, Laida; López del Amo, Juan Miguel; Armand, Michel; Singh, Gurpreet

    2017-01-01

    Sodium-ion full cell with hard carbon as anode and a layered oxide cathode based on earth abundant elements i.e., Na0.67[Fe0.5Mn0.5]O2 is reported. The irreversible capacity of the negative electrode in the full cell configuration is compensated by the addition of a sacrificial salt such as NaN3 to the P2-Na0.67[Fe0.5Mn0.5]O2 cathode material. 60% increase in the reversible capacity is achieved with the addition of 10% of sodium azide in the composite cathode without compromise on the cycle life. Though, there is a limit in its use because of the capacity fade which can be observed with the further increase in NaN3 content. The quantification of sodium ions at the end of discharge (at 1 V) after 40 cycles by ex-situ X-ray diffraction and solid state nuclear magnetic resonance supports the electrochemical data. Scanning electron microscopy shows the effect of NaN3 on the electrode microstructure in terms of the porosity created by NaN3 decomposition.

  7. Confined Amorphous Red Phosphorus in MOF-Derived N-Doped Microporous Carbon as a Superior Anode for Sodium-Ion Battery.

    Science.gov (United States)

    Li, Weihan; Hu, Shuhe; Luo, Xiangyu; Li, Zhongling; Sun, Xizhen; Li, Minsi; Liu, Fanfan; Yu, Yan

    2017-04-01

    Red phosphorus (P) has attracted intense attention as promising anode material for high-energy density sodium-ion batteries (NIBs), owing to its high sodium storage theoretical capacity (2595 mAh g(-1) ). Nevertheless, natural insulating property and large volume variation of red P during cycling result in extremely low electrochemical activity, leading to poor electrochemical performance. Herein, the authors demonstrate a rational strategy to improve sodium storage performance of red P by confining nanosized amorphous red P into zeolitic imidazolate framework-8 (ZIF-8) -derived nitrogen-doped microporous carbon matrix (denoted as P@N-MPC). When used as anode for NIBs, the P@N-MPC composite displays a high reversible specific capacity of ≈600 mAh g(-1) at 0.15 A g(-1) and improved rate capacity (≈450 mAh g(-1) at 1 A g(-1) after 1000 cycles with an extremely low capacity fading rate of 0.02% per cycle). The superior sodium storage performance of the P@N-MPC is mainly attributed to the novel structure. The N-doped porous carbon with sub-1 nm micropore facilitates the rapid diffusion of organic electrolyte ions and improves the conductivity of the encapsulated red P. Furthermore, the porous carbon matrix can buffer the volume change of red P during repeat sodiation/desodiation process, keeping the structure intact after long cycle life. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Li4Ti5O12-TiO2 nanowire arrays constructed with stacked nanocrystals for high-rate lithium and sodium ion batteries

    Science.gov (United States)

    Gao, Lin; Wang, Lichuan; Dai, Sirui; Cao, Minglei; Zhong, Zhicheng; Shen, Yan; Wang, Mingkui

    2017-03-01

    This work reports on nanoparticle-stacked Li4Ti5O12-TiO2 nanowire arrays (SLTO) as anode for lithium and sodium ion battery (NIB). Our finding shows that the pseudocapacitive effect partly contributes to the performance for the NIBs based on the SLTO electrode due to a large size volume of Na+ ions. More importantly, the SLTO nanowires constituting of the nanoparticles efficiently shorten ion diffusion length, thereafter accelerate ion insertion/extraction reaction and improve the rate capability. For the SLTO electrode, a specific capacity of 199.7 mAh g-1 can be achieved in the LIBs at a current rate of 0.75 C (voltage range of 1.0-3.0 V) and a specific capacity of 94.2 mAh g-1 is obtained in the NIBs at a high current rate of 15 C (voltage range of 0.5-2.5 V). Most importantly, the sodium ion full battery based on SLTO as anode and Na3V2(PO4)3 as cathode materials shows stable cycling performance with tiny capacity degradation (90.1 mAh g-1) after 200 cycles at a current rate of 4 C (voltage range of 1.0-4.0 V), simultaneously possessing a high energy density of 136.5 Wh kg-1 at the power density of 312 W kg-1.

  9. Metal-organic framework derived porous CuO/Cu2O composite hollow octahedrons as high performance anode materials for sodium ion batteries.

    Science.gov (United States)

    Zhang, Xiaojie; Qin, Wei; Li, Dongsheng; Yan, Dong; Hu, Bingwen; Sun, Zhuo; Pan, Likun

    2015-11-25

    Porous CuO/Cu2O composite hollow octahedrons were synthesized simply by annealing Cu-based metal-organic framework templates. When evaluated as anode materials for sodium ion batteries, they exhibit a high maximum reversible capacity of 415 mA h g(-1) after 50 cycles at 50 mA g(-1) with excellent cycling stability and good rate capability.

  10. The Progress of Sodium-Ion Battery Anode Material%钠离子电池负极材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    张洁; 杨占旭

    2016-01-01

    Sodium ion batteries have attracted tremendous attentions due to its rich resources,low cost,high efficiency and good chemical stability,and can satisfy people's demand for energy in the new era,which are considered a top alternative to lithium-ion batteries.The research progress on sodium ion battery anode materials are reviewed in details in this paper, including carbon-based materials,low voltage metal phosphates,the sodium storage alloys,metal oxides,titanium-based materials,and other negative electrode materials.Then the characteristics of anode materials are discussed.Finally,some future directions for sodium-ion battery anode materials are pointed out.%钠离子电池具有资源丰富、成本低、效率高、化学性能稳定等优点,成为锂离子电池 的理想替代品.主要阐述了钠离子电池负极材料的研究进展,包括碳基负极材料、低电压金属磷酸盐负极材料、合金类储钠负极材料、金属氧化物负极材料、钛酸盐类负极材料及其他负极材料,并对各类负极材料的性能进行了评价,最后对钠离子电池负极材料的发展方向做出了展望.

  11. Recent Progress in Sodium-ion Battery Materials%钠离子电池关键材料研究进展

    Institute of Scientific and Technical Information of China (English)

    沈晓辉; 卲乐; 田占元

    2016-01-01

    钠离子电池作为一种电化学能量储存与转换装置,具有原料来源丰富和成本低的优势,近年来吸引了国内外研究者的广泛关注。钠离子电池关键材料和相关技术近几年发展迅速,取得了重要进展,研究体系不断丰富。文章对钠离子电池正极材料和负极材料最新研究进展进行了综述,探讨了电极材料目前所面临的主要问题及可能的解决方案,分析了钠离子电池未来的研究发展方向。%Sodium ion batteries (SIBs) receive signiifcant attention for electrochemical energy storage and conversion owing to the large abundance of sodium resources and its low cost. In recent years, the key materials and related technology of sodium ion batteries have developed rapidly and made signiifcant progress, related components have been enriched. The recent advancements of cathode and anode materials for sodium ion batteries are reviewed in details, which have signiifcant effects on the electrode performance. The main problems of these kinds of electrode materials are discussed and the probable strategies are proposed. Finally, the research directions of sodium ion batteries in the future are also forecasted.

  12. TRANSPORT OF CITRATE CATALYZED BY THE SODIUM-DEPENDENT CITRATE CARRIER OF KLEBSIELLA-PNEUMONIAE IS OBLIGATORILY COUPLED TO THE TRANSPORT OF 2 SODIUM-IONS

    NARCIS (Netherlands)

    LOLKEMA, JS; ENEQUIST, H; VANDERREST, ME

    1994-01-01

    Aerobically grown Escherichia coli GM48 harboring plasmid pKScitS that codes for the sodium-dependent citrate carrier from Klebsiella pneumoniae (CitS) allows initial-rate measurements of citrate uptake in whole cells. The cation stoichiometry and selectivity of CitS was studied using this experimen

  13. Transport of citrate catalyzed by the sodium-dependent citrate carrier of Klebsiella pneumoniae is obligatorily coupled to the transport of two sodium ions

    NARCIS (Netherlands)

    Lolkema, Juke S.; Enequist, Hans; Rest, Michel E. van der

    1994-01-01

    Aerobically grown Escherichia coli GM48 harboring plasmid pKScitS that codes for the sodium-dependent citrate carrier from Klebsiella pneumoniae (CitS) allows initial-rate measurements of citrate uptake in whole cells. The cation stoichiometry and selectivity of CitS was studied using this experimen

  14. A comparative study on the impact of different glymes and their derivatives as electrolyte solvents for graphite co-intercalation electrodes in lithium-ion and sodium-ion batteries.

    Science.gov (United States)

    Jache, Birte; Binder, Jan Oliver; Abe, Takeshi; Adelhelm, Philipp

    2016-06-07

    The abundance of sodium has recently sparked considerable interest in sodium-ion batteries (NIBs). Their similarity to conventional lithium-ion technology is obvious; however, the cell chemistry often significantly deviates. Graphite, although being the standard negative electrode in Li-ion batteries, is largely inactive for Na-ion storage in conventional non-aqueous carbonate-based electrolytes, for example. Very recently, it has been demonstrated that graphite can be activated for Na-ion storage in cells with ether-based electrolytes. The storage mechanism is based on co-intercalation of solvent molecules along with the Na-ions, forming ternary graphite intercalation compounds (t-GICs). This process is highly reversible but yet poorly understood. Here, we provide a comprehensive study on the formation and the stability of t-GICs. A series of ether solvents are being discussed: linear glymes with different chain lengths (mono-, di-, tri-, and tetraglyme), several derivatives with side groups as well as tetrahydrofuran (THF) as a cyclic ether and one crown ether. We show that the redox potentials shift depending on the ether chain length and mixing of ethers might enable tailoring of the redox behaviour. The inferior behaviour of triglyme is likely due to the less ideal ion coordination. Complementary experiments with lithium are made and demonstrate the superior behaviour of sodium. We find that the increase in graphene layer spacing during intercalation only slightly depends on the chain length and is in the range of 250%, and still mechanical stability is preserved. We further show the t-GICs possess chemical stability and demonstrate that the kinetically favoured charge transfer is probably due to the absence of a solid electrolyte interphase.

  15. 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.

  16. 离子色谱法测定肝素钠中草酸根的含量%Determination of Oxalic Ion in Heparin Sodium by Ion-chromatography

    Institute of Scientific and Technical Information of China (English)

    邓锋; 严全鸿

    2009-01-01

    Objective To establish a method to determine oxalic ion in heparin sodium, and to improve its quality control. Methods The oxalic ion in heparin sodium was determined by ion-chromatography, Results The linear coefficientcorrelation was 0.9998, and the recovery rate was 95.2%~99.7%. A total of 40 hatches of heparin sodium were tested. The content of oxalic ion in some of those batches was relatively high. Conclusion The method is simple and accurate.%目的 加强肝素钠的质量控制,建立草酸根检测方法.方法 采用离子色谱法对肝素钠中草酸根离子进行测定,并进行方法学验证.结果 线性相关系数r=0.9998,加样回收率为95.2%~99.7%,检测40批肝素钠原料发现部分草酸根离子含量较高.结论 本方法操作简单,结果准确,灵敏度高,可对肝素钠进行更进一步的质量控制.

  17. Review of Electrode Materials for Sodium Ion Batteries%钠离子电池电极材料研究进展

    Institute of Scientific and Technical Information of China (English)

    贾旭平; 陈梅

    2012-01-01

    钠是地球上储量较丰富的元素之一,与锂的化学性能类似,因此也可能适用于锂离子电池体系。钠离子电池相比锂离子电池有诸多优势,如成本低,安全性好,随着研究的深入,钠离子电池将越来越具有成本效益,并有望在未来取代锂离子电池而被广泛应用。介绍了钠离子电池正极材料、负极材料的最新研究进展,分析了该电池未来的研究发展方向。%Sodium is one of the more abundant elements on Earth and exhibits similar chemical properties to Li,indicating that Na chemistry could be applied to a similar battery system.Sodium ion batteries have various kinds of advantages,such as low cost,excellent safety,and etc.,which may take place of lithium ion batteries in the future based on successful development.The development of electrode materials of sodium ion batteries was reviewed,and its future development direction was proposed.

  18. Direct atomic-scale confirmation of three-phase storage mechanism in Li₄Ti₅O₁₂ anodes for room-temperature sodium-ion batteries.

    Science.gov (United States)

    Sun, Yang; Zhao, Liang; Pan, Huilin; Lu, Xia; Gu, Lin; Hu, Yong-Sheng; Li, Hong; Armand, Michel; Ikuhara, Yuichi; Chen, Liquan; Huang, Xuejie

    2013-01-01

    Room-temperature sodium-ion batteries attract increasing attention for large-scale energy storage applications in renewable energy and smart grid. However, the development of suitable anode materials remains a challenging issue. Here we demonstrate that the spinel Li4Ti5O12, well-known as a 'zero-strain' anode for lithium-ion batteries, can also store sodium, displaying an average storage voltage of 0.91 V. With an appropriate binder, the Li4Ti5O12 electrode delivers a reversible capacity of 155 mAh g(-1) and presents the best cyclability among all reported oxide-based anode materials. Density functional theory calculations predict a three-phase separation mechanism, 2Li4Ti5O12+6Na(+)+6e(-)↔Li7Ti5O12+Na6LiTi5O12, which has been confirmed through in situ synchrotron X-ray diffraction and advanced scanning transmission electron microscope imaging techniques. The three-phase separation reaction has never been seen in any insertion electrode materials for lithium- or sodium-ion batteries. Furthermore, interfacial structure is clearly resolved at an atomic scale in electrochemically sodiated Li4Ti5O12 for the first time via the advanced electron microscopy.

  19. Beneficial effect of boron in layered sodium-ion cathode materials - The example of Na2/3B0.11Mn0.89O2

    Science.gov (United States)

    Vaalma, Christoph; Buchholz, Daniel; Passerini, Stefano

    2017-10-01

    Sodium-ion batteries are regarded as a complementary drop-in technology to lithium-ion batteries because they promise lower cost and a higher degree of environmental friendliness. Among other reasons, these benefits come from the use of manganese-based materials, whose stabilization via cation substitution is intensively studied to improve the electrochemical performance. Although multiple elements have been considered as substituent, surprisingly, boron has not been reported for layered sodium-ion cathode materials up to date. Our investigation of layered Na2/3B0.11Mn0.89O2 reveals an unexpectedly good electrochemical performance, with charge and discharge capacities of more than 175 mAh g-1 at 10 mA g-1 and 135 mAh g-1 at 500 mA g-1. The measured capacities are among the highest ever reported for sodium-based layered oxides in the potential range of 4.0-2.0 V vs. Na/Na+.

  20. Determination methods of sodium ion in food%食品中钠离子含量检测方法综述

    Institute of Scientific and Technical Information of China (English)

    叶青; 李勤; 吕庆; 李柚; 龚雁

    2016-01-01

    钠是食品中重要的矿物质,可维持机体正常的渗透压和新陈代谢,可以维持体内酸碱的平衡,对人体有着非常重要的作用。但是如果钠摄入过多,又是高血压等慢性病的危险因素。钠离子还是中华人民共和国卫生部在2011年发布的GB 28050-2011《食品安全国家标准预包装食品营养标签通则》中规定的4种核心营养素之一,因此食品中钠的含量受到人们的广泛关注。食品中钠离子含量的测定对于保证人体健康有重要意义,也是目前国内研究的热点问题,目前有多种方法实现了对钠离子的准确定量检测,包括色谱法、原子吸收光谱法、滴定法等,各有优缺点。本文针对各种检验技术进行了详细的对比,对近年来食品中钠离子检测方法的研究进行了综述。%ABSTRACT:Sodium is an important mineral in food, which can maintain the body's normal osmotic pressure and metabolism as well as can maintain acid-base balance in the body, so it is very important for human health. If the intake of sodium is excessive, it will cause hypertension and other chronic diseases. Sodium is one of the 4 kinds of core nutrients in GB 28050-2011 National food safety standard-General nutrition labels standard for pre-packaged food published by the Ministry of Health of the PRC. Therefore, the content of sodium in foods gains widespread concerns. Determination of sodium ion is important for human health, also becomes the research focus. There are lots of methods for detection of sodium ion, and each method has advantages and disadvantages. This paper compared the different analytical methods and reviewed the recent researches of analytical methods of sodium ion in food.

  1. Extracellular calcium sensing and extracellular calcium signaling

    Science.gov (United States)

    Brown, E. M.; MacLeod, R. J.; O'Malley, B. W. (Principal Investigator)

    2001-01-01

    The cloning of a G protein-coupled extracellular Ca(2+) (Ca(o)(2+))-sensing receptor (CaR) has elucidated the molecular basis for many of the previously recognized effects of Ca(o)(2+) on tissues that maintain systemic Ca(o)(2+) homeostasis, especially parathyroid chief cells and several cells in the kidney. The availability of the cloned CaR enabled the development of DNA and antibody probes for identifying the CaR's mRNA and protein, respectively, within these and other tissues. It also permitted the identification of human diseases resulting from inactivating or activating mutations of the CaR gene and the subsequent generation of mice with targeted disruption of the CaR gene. The characteristic alterations in parathyroid and renal function in these patients and in the mice with "knockout" of the CaR gene have provided valuable information on the CaR's physiological roles in these tissues participating in mineral ion homeostasis. Nevertheless, relatively little is known about how the CaR regulates other tissues involved in systemic Ca(o)(2+) homeostasis, particularly bone and intestine. Moreover, there is evidence that additional Ca(o)(2+) sensors may exist in bone cells that mediate some or even all of the known effects of Ca(o)(2+) on these cells. Even more remains to be learned about the CaR's function in the rapidly growing list of cells that express it but are uninvolved in systemic Ca(o)(2+) metabolism. Available data suggest that the receptor serves numerous roles outside of systemic mineral ion homeostasis, ranging from the regulation of hormonal secretion and the activities of various ion channels to the longer term control of gene expression, programmed cell death (apoptosis), and cellular proliferation. In some cases, the CaR on these "nonhomeostatic" cells responds to local changes in Ca(o)(2+) taking place within compartments of the extracellular fluid (ECF) that communicate with the outside environment (e.g., the gastrointestinal tract). In others

  2. Pipe-Wire TiO2-Sn@Carbon Nanofibers Paper Anodes for Lithium and Sodium Ion Batteries.

    Science.gov (United States)

    Mao, Minglei; Yan, Feilong; Cui, Chunyu; Ma, Jianmin; Zhang, Ming; Wang, Taihong; Wang, Chunsheng

    2017-06-14

    Metallic tin has been considered as one of the most promising anode materials both for lithium (LIBs) and sodium ion battery (NIBs) because of a high theoretical capacity and an appropriate low discharge potential. However, Sn anodes suffer from a rapid capacity fading during cycling due to pulverization induced by severe volume changes. Here we innovatively synthesized pipe-wire TiO2-Sn@carbon nanofibers (TiO2-Sn@CNFs) via electrospinning and atomic layer deposition to suppress pulverization-induced capacity decay. In pipe-wire TiO2-Sn@CNFs paper, nano-Sn is uniformly dispersed in carbon nanofibers, which not only act as a buffer material to prevent pulverization, but also serve as a conductive matrix. In addition, TiO2 pipe as the protection shell outside of Sn@carbon nanofibers can restrain the volume variation to prevent Sn from aggregation and pulverization during cycling, thus increasing the Coulombic efficiency. The pipe-wire TiO2-Sn@CNFs show excellent electrochemical performance as anodes for both LIBs and NIBs. It exhibits a high and stable capacity of 643 mA h/g at 200 mA/g after 1100 cycles in LIBs and 413 mA h/g at 100 mA/g after 400 cycles in NIBs. These results would shed light on the practical application of Sn-based materials as a high capacity electrode with good cycling stability for next-generation LIBs and NIBs.

  3. Prolactin 177, prolactin 188, and extracellular osmolality independently regulate the gene expression of ion transport effectors in gill of Mozambique tilapia.

    Science.gov (United States)

    Inokuchi, Mayu; Breves, Jason P; Moriyama, Shunsuke; Watanabe, Soichi; Kaneko, Toyoji; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

    2015-11-15

    This study characterized the local effects of extracellular osmolality and prolactin (PRL) on branchial ionoregulatory function of a euryhaline teleost, Mozambique tilapia (Oreochromis mossambicus). First, gill filaments were dissected from freshwater (FW)-acclimated tilapia and incubated in four different osmolalities, 280, 330, 380, and 450 mosmol/kg H2O. The mRNA expression of Na(+)/K(+)-ATPase α1a (NKA α1a) and Na(+)/Cl(-) cotransporter (NCC) showed higher expression with decreasing media osmolalities, while Na(+)/K(+)/2Cl(-) cotransporter 1a (NKCC1a) and PRL receptor 2 (PRLR2) mRNA levels were upregulated by increases in media osmolality. We then incubated gill filaments in media containing ovine PRL (oPRL) and native tilapia PRLs (tPRL177 and tPRL188). oPRL and the two native tPRLs showed concentration-dependent effects on NCC, NKAα1a, and PRLR1 expression; Na(+)/H(+) exchanger 3 (NHE3) expression was increased by 24 h of incubation with tPRLs. Immunohistochemical observation showed that oPRL and both tPRLs maintained a high density of NCC- and NKA-immunoreactive ionocytes in cultured filaments. Furthermore, we found that tPRL177 and tPRL188 differentially induce expression of these ion transporters, according to incubation time. Together, these results provide evidence that ionocytes of Mozambique tilapia may function as osmoreceptors, as well as directly respond to PRL to modulate branchial ionoregulatory functions.

  4. SnO2 particles anchored on N-doped graphene surface as sodium-ion battery anode with enhanced electrochemical capability

    Science.gov (United States)

    Wang, Gui-Zhi; Feng, Jian-Min; Dong, Lei; Li, Xi-Fei; Li, De-Jun

    2017-02-01

    The small-size SnO2 particles uniformly dispersed on the nitrogen doping graphene nanocomposites (SnO2-N-GNS) have been successfully synthesized by a mild hydrothermal method with the precursors of graphene oxide, urea and SnCl4.5H2O. The phase (XRD, EDX and XPS) and morphology (SEM, TEM) analysis further confirm the obtained products. When the composite served as anode material in sodium ion batteries (SIBs), it delivers superior sodium storage performance with reversible discharge capacity of 294.4 mAh g-1 at a current density of 50 mA g-1 in the voltage range from 0.01-3 V after 50 discharge/charge cycles, which is much higher than that of SnO2-GNS (182.9 mAh g-1) and N-GNS (114.9 mAh g-1). Besides, the SnO2-N-GNS electrode also exhibits admirable rate stability with the discharge capacity of 206 mAh g-1 even at 800 mA g-1. More importantly, the SnO2-N-GNS shows lower internal resistance and larger sodium-ion diffusion coefficient. These enhanced electrochemical performances of SnO2-N-GNS are due to the N-doping defects and the homogeneous dispersion of SnO2 particles.

  5. 3D Interconnected Carbon Fiber Network-Enabled Ultralong Life Na3 V2 (PO4 )3 @Carbon Paper Cathode for Sodium-Ion Batteries.

    Science.gov (United States)

    Kretschmer, Katja; Sun, Bing; Zhang, Jinqiang; Xie, Xiuqiang; Liu, Hao; Wang, Guoxiu

    2017-03-01

    Sodium-ion batteries (NIBs) are an emerging technology, which can meet increasing demands for large-scale energy storage. One of the most promising cathode material candidates for sodium-ion batteries is Na3 V2 (PO4 )3 due to its high capacity, thermal stability, and sodium (Na) Superionic Conductor 3D (NASICON)-type framework. In this work, the authors have significantly improved electrochemical performance and cycling stability of Na3 V2 (PO4 )3 by introducing a 3D interconnected conductive network in the form of carbon fiber derived from ordinary paper towel. The free-standing Na3 V2 (PO4 )3 -carbon paper (Na3 V2 (PO4 )3 @CP) hybrid electrodes do not require a metallic current collector, polymeric binder, or conducting additives to function as a cathode material in an NIB system. The Na3 V2 (PO4 )3 @CP cathode demonstrates extraordinary long term cycling stability for 30 000 deep charge-discharge cycles at a current density of 2.5 mA cm(-2) . Such outstanding cycling stability can meet the stringent requirements for renewable energy storage.

  6. Porous CoFe2O4 nanocubes derived from metal-organic frameworks as high-performance anode for sodium ion batteries.

    Science.gov (United States)

    Zhang, Xiaojie; Li, Dongsheng; Zhu, Guang; Lu, Ting; Pan, Likun

    2017-08-01

    Recently sodium ion batteries (SIBs) as a new energy storage system have attracted enormous interests. Unfortunately, the development of high-performance electrode materials for SIBs is restricted owing to the large volume change during sodium insertion and extraction. In this work, porous CoFe2O4 nanocubes (PCFO-NCs) were prepared simply by annealing metal-organic frameworks and used as anode materials for SIBs. The PCFO-NCs exhibit a high initial Coulombic efficiency of 68.8% and a maximum reversible capacity of 360mAhg(-1) after 50 cycles at the current density of 50mAg(-1), as well as good rate capability and excellent cycling stability at high current density. The excellent electrochemical performance can be attributed the short diffusion distance of sodium ion due to the good interfacial contact between electrode and electrolyte, and the buffering of volume change during charge/discharge processes by the porous structure. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Free-standing electrodes composed of carbon-coated Li4Ti5O12 nanosheets and reduced graphene oxide for advanced sodium ion batteries

    Science.gov (United States)

    Xu, Guobao; Tian, Ye; Wei, Xiaolin; Yang, Liwen; Chu, Paul K.

    2017-01-01

    A free-standing electrode composed of carbon-coated Li4Ti5O12 nanosheets and reduced graphene oxide (designated as LTO-C/RGO) is fabricated for Na storage by modified vacuum filtration and subsequent annealing. In this process, graphene oxide with negative charges and LTO-C nanosheets with abundant charged ions are self-assembled into the nanocomposite based on the screening effect of electrostatic repulsion. The unique structure of the confined LTO-C nanosheets in a highly conductive interconnected RGO network not only promotes the reaction kinetics and structural stability of the electrodes during Na+ insertion/extraction, but also provides plenty of interfacial sites for Na+ adsorption giving rise to additional interfacial Na storage. The free-standing LTO-C/RGO anode for sodium ion battery exhibits a high capacity of 166 mAhg-1 at 1 C, good rate capability of 98.7 mAhg-1 at 5 C, and superior cyclic performance of 114 mAhg-1 at 2 C after 600 cycles. The materials boasting superior Na storage have large potential in high-performance sodium ion batteries in portable, flexible and wearable electronics.

  8. In Situ Grown Fe2O3 Single Crystallites on Reduced Graphene Oxide Nanosheets as High Performance Conversion Anode for Sodium-Ion Batteries.

    Science.gov (United States)

    Li, Ting; Qin, Aiqiong; Yang, Lanlan; Chen, Jie; Wang, Qiufan; Zhang, Daohong; Yang, Hanxi

    2017-06-14

    Electrochemical conversion reactions of metal oxides provide a new avenue to build high capacity anodes for sodium-ion batteries. However, the poor rate performance and cyclability of these conversion anodes remain a significant challenge for Na-ion battery applications because most of the conversion anodes suffer from sluggish kinetics and irreversible structural change during cycles. In this paper, we report an Fe2O3 single crystallites/reduced graphene oxide composite (Fe2O3/rGO), where the Fe2O3 single crystallites with a particle size of ∼300 nm were uniformly anchored on the rGO nanosheets, which provide a highly conductive framework to facilitate electron transport and a flexible matrix to buffer the volume change of the material during cycling. This Fe2O3/rGO composite anode shows a very high reversible capacity of 610 mAh g(-1) at 50 mA g(-1), a high Coulombic efficiency of 71% at the first cycle, and a strong cyclability with 82% capacity retention after 100 cycles, suggesting a potential feasibility for sodium-ion batteries. More significantly, the present work clearly illustrates that an electrochemical conversion anode can be made with high capacity utilization, strong rate capability, and stable cyclability through appropriately tailoring the lattice structure, particle size, and electronic conduction channels for a simple transition-metal oxide, thus offering abundant selections for development of low-cost and high-performance Na-storage electrodes.

  9. Rapid synthesis of three-dimensional network structure CuO as binder-free anode for high-rate sodium ion battery

    Science.gov (United States)

    Chen, Chengcheng; Dong, Yanying; Li, Songyue; Jiang, Zhuohan; Wang, Yijing; Jiao, Lifang; Yuan, Huatang

    2016-07-01

    We report on the preparation of the three dimensional (3D) network structure CuO by rapid and facile engraving method and their application as high rate anode for sodium ion battery. The CuO is rapidly synthesized by in-situ etched and oxidated the specified Cu foils within 15 min. It shows the 3D network architecture with flower-like nanosheets connected by nanowires, which provides the porous structure, short ion diffusion pathway and collaborative electronic transmission. Furthermore, the etched CuO can be directly used as anode for sodium ion battery without polymer additions or conductive agents. The electrodes exhibit excellent electrochemical performance with a high capacity of 680 mAh·g-1 at 50 mA g-1 and a reversible capacity of 280 mAh·g-1 at 1000 mA g-1. In addition, the electrochemical reaction and detail charge/discharge process are carefully explored to discover the conversion reaction routes and the recession reason. Thus, the 3D network structure CuO might open an insight for transition-metal oxides as energy storage materials.

  10. An electrochemical and structural study of highly uniform tin oxide nanowires fabricated by a novel, scalable solvoplasma technique as anode material for sodium ion batteries

    Science.gov (United States)

    Mukherjee, Santanu; Schuppert, Nicholas; Bates, Alex; Jasinski, Jacek; Hong, Jong-Eun; Choi, Moon Jong; Park, Sam

    2017-04-01

    A novel solvoplasma based technique was used to fabricate highly uniform SnO2 nanowires (NWs) for application as an anode in sodium-ion batteries (SIBs). This technique is scalable, rapid, and utilizes a rigorous cleaning process to produce very pure SnO2 NWs with enhanced porosity; which improves sodium-ion hosting and reaction kinetics. The batch of NWs obtained from the plasma process were named the ;as-made; sample and after cleaning the ;pure; sample. Structural characterization showed that the as-made sample has a K+ ion impurity which is absent in the pure samples. The pure samples have a higher maximum specific capacity, 400.71 mAhg-1, and Coulombic efficiency, 85%, compared to the as-made samples which have a maximum specific capacity of 174.69 mAhg-1 and Coulombic efficiency of 74% upon cycling. A study of the electrochemical impedance spectra showed that the as-made samples have a higher interfacial and diffusion resistance than the pure samples and resistances increased after 50 cycles of cell operation for both samples due to progressive electrode degradation. Specific energy vs specific power plots were employed to analyze the performance of the system with respect to the working conditions.

  11. Distinct interactions of Na{sup +} and Ca{sup 2+} ions with the selectivity filter of the bacterial sodium channel Na{sub V}Ab

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Song, E-mail: song.ke@univie.ac.at [Department of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, UZA 2, A-1090 Vienna (Austria); Zangerl, Eva-Maria, E-mail: a0509032@unet.univie.ac.at [Department of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, UZA 2, A-1090 Vienna (Austria); Stary-Weinzinger, Anna, E-mail: anna.stary@univie.ac.at [Department of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, UZA 2, A-1090 Vienna (Austria)

    2013-01-25

    Highlights: ► Ca{sup 2+} translocates slowly in the filter, due to lack of “loose” knock-on mechanism. ► Identification of a high affinity binding site in Na{sub V}Ab selectivity filter. ► Changes of EEEE locus triggered by electrostatic interactions with Ca{sup 2+} ions. -- Abstract: Rapid and selective ion transport is essential for the generation and regulation of electrical signaling pathways in living organisms. In this study, we use molecular dynamics simulations and free energy calculations to investigate how the bacterial sodium channel Na{sub V}Ab (Arcobacter butzleri) differentiates between Na{sup +} and Ca{sup 2+} ions. Multiple nanosecond molecular dynamics simulations revealed distinct binding patterns for these two cations in the selectivity filter and suggested a high affinity calcium binding site formed by backbone atoms of residues Leu-176 and Thr-175 (S{sub CEN}) in the sodium channel selectivity filter.

  12. Sodium dodecyl sulfate coated γ-alumina support modified by a new Schiff base for solid phase extraction and flame-AAS determination of lead and copper ions

    Directory of Open Access Journals (Sweden)

    Ardeshir Shokrollahi

    2013-01-01

    Full Text Available A simple and fast approach for solid phase extraction is herein described, and used to determine trace amounts of Pb2+ and Cu2+ metal ions. The solid phase support is sodium dodecyl sulfate (SDS-coated γ-alumina modified with bis(2-hydroxy acetophenone-1,6-hexanediimine (BHAH ligand. The adsorbed ions were stripped from the solid phase by 6 mL of 4 M nitric acid as eluent. The eluting solution was analyzed by flame atomic absorption spectrometry (FAAS. The sorption recovery of metal ions was investigated with regard to the effects of pH, amount of ligand, γ-alumina and surfactant and the amount and type of eluent. Complexation of BHAH with Pb2+ or Cu2+ ions was examined via spectrophotometry using the HypSpec program. The detection limit for Cu2+ was 7.9 µg L-1 with a relative standard deviation of 1.67%, while that for Pb2+ was 6.4 µg L-1 with a relative standard deviation of 1.64%. A preconcentration factor of 100 was achieved for these ions. The method was successfully applied to determine analyte concentrations in samples of liver, parsley, cabbage, and water.

  13. The effect of 100 MeV oxygen ion on electrical and optical properties of nonlinear optical l-alanine sodium nitrate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ahlam, M. A.; Prakash, A. P. Gnana [Department of Studies in Physics, University of Mysore, Mysore-570 006, Karnataka (India)

    2012-06-05

    Single crystals of nonlinear optical (NLO) L-alanine Sodium Nitrate (LASN) were grown by slow evaporation method. The grown crystals were irradiated by 100 MeV oxygen ions with the cumulative doses of 1Mrad, 6 Mrad and 10 Mrad. The dielectric properties, differential scanning calorimetry (DSC) and second harmonic generation (SHG) of the crystals were studied before and after irradiation. The dielectric constant was found to increase after irradiation. The DSC reveals that the melting point remains unaffected due to irradiation. The SHG efficiency of LASN was found to decrease with increase in radiation dose.

  14. The effect of 100 MeV oxygen ion on electrical and optical properties of nonlinear optical l-alanine sodium nitrate single crystals

    Science.gov (United States)

    Ahlam, M. A.; Prakash, A. P. Gnana

    2012-06-01

    Single crystals of nonlinear optical (NLO) L-alanine Sodium Nitrate (LASN) were grown by slow evaporation method. The grown crystals were irradiated by 100 MeV oxygen ions with the cumulative doses of 1Mrad, 6 Mrad and 10 Mrad. The dielectric properties, differential scanning calorimetry (DSC) and second harmonic generation (SHG) of the crystals were studied before and after irradiation. The dielectric constant was found to increase after irradiation. The DSC reveals that the melting point remains unaffected due to irradiation. The SHG efficiency of LASN was found to decrease with increase in radiation dose.

  15. Energy Storage: Nitrogen-Doped Ordered Mesoporous Anatase TiO2 Nanofibers as Anode Materials for High Performance Sodium-Ion Batteries (Small 26/2016).

    Science.gov (United States)

    Wu, Ying; Liu, Xiaowu; Yang, Zhenzhong; Gu, Lin; Yu, Yan

    2016-07-01

    On page 3522, Y. Yu and co-workers fabricate nitrogen-doped ordered mesoporous TiO2 nanofibers (denoted as N-MTO) by electrospinning and subsequent nitridation treatment. Nitrogen atoms are successfully doped into the TiO2 lattice, accompanied by the formation of Ti(3+) and oxygen vacancies, contributing to the improvement of electronic conductivity of TiO2 . When used as an anode for a sodium-ion battery, the N-MTO demonstrates excellent rate capability and superior long cycling performance.

  16. Changes in ion transport in inflammatory disease

    Directory of Open Access Journals (Sweden)

    Eisenhut Michael

    2006-03-01

    Full Text Available Abstract Ion transport is essential for maintenance of transmembranous and transcellular electric potential, fluid transport and cellular volume. Disturbance of ion transport has been associated with cellular dysfunction, intra and extracellular edema and abnormalities of epithelial surface liquid volume. There is increasing evidence that conditions characterized by an intense local or systemic inflammatory response are associated with abnormal ion transport. This abnormal ion transport has been involved in the pathogenesis of conditions like hypovolemia due to fluid losses, hyponatremia and hypokalemia in diarrhoeal diseases, electrolyte abnormalites in pyelonephritis of early infancy, septicemia induced pulmonary edema, and in hypersecretion and edema induced by inflammatory reactions of the mucosa of the upper respiratory tract. Components of membranous ion transport systems, which have been shown to undergo a change in function during an inflammatory response include the sodium potassium ATPase, the epithelial sodium channel, the Cystic Fibrosis Transmembrane Conductance Regulator and calcium activated chloride channels and the sodium potassium chloride co-transporter. Inflammatory mediators, which influence ion transport are tumor necrosis factor, gamma interferon, interleukins, transforming growth factor, leukotrienes and bradykinin. They trigger the release of specific messengers like prostaglandins, nitric oxide and histamine which alter ion transport system function through specific receptors, intracellular second messengers and protein kinases. This review summarizes data on in vivo measurements of changes in ion transport in acute inflammatory conditions and in vitro studies, which have explored the underlying mechanisms. Potential interventions directed at a correction of the observed abnormalities are discussed.

  17. The mechanism of the sodiation and desodiation in Super P carbon electrode for sodium-ion battery

    Science.gov (United States)

    Wu, Chun-Ming; Pan, Ping-I.; Cheng, Yin-Wei; Liu, Chuan-Pu; Chang, Chia-Chin; Avdeev, Maxim; Lin, Shih-kang

    2017-02-01

    The sodiation and desodiation of sodium (Na) into the Super-P carbon anode material were investigated using electrochemical analyses, high-resolution transmission electron microscopy (HRTEM), and neutron powder diffraction (NPD). In the sodiated Super-P carbon, sodium is stored both in the graphite interlayer space of carbon nano-particles and pores between the particles. Sodium metal clusters found in micro-pores between the carbon particles are responsible for the large irreversible capacity of the Super-P electrode. The graphite interlayer distance increases on sodiation from 3.57 Å to two distinct values of ∼3.84 and 4.41 Å. The mechanism of the process is discussed.

  18. A highly stable (SnOx-Sn)@few layered graphene composite anode of sodium-ion batteries synthesized by oxygen plasma assisted milling

    Science.gov (United States)

    Cheng, Deliang; Liu, Jiangwen; Li, Xiang; Hu, Renzong; Zeng, Meiqing; Yang, Lichun; Zhu, Min

    2017-05-01

    The (SnOx-Sn)@few layered graphene ((SnOx-Sn)@FLG) composite has been synthesized by oxygen plasma-assisted milling. Owing to the synergistic effect of rapid plasma heating and ball mill grinding, SnOx (1 ≤ x ≤ 2) nanoparticles generated from the reaction of Sn with oxygen are tightly wrapped by FLG nanosheets which are simultaneously exfoliated from expanded graphite, forming secondary micro granules. Inside the granules, the small size of the SnOx nanoparticles enables the fast kinetics for Na+ transfer. The in-situ formed FLG and residual Sn nanoparticles improve the electrical conductivity of the composite, meanwhile alleviate the aggregation of SnOx nanoparticles and relieve the volume change during the cycling, which is beneficial for the cyclic stability for the Na+ storage. As an anode material for sodium-ion batteries, the (SnOx-Sn)@FLG composite exhibits a high reversible capacity of 448 mAh g-1 at a current density of 100 mA g-1 in the first cycle, with 82.6% capacity retention after 250 cycles. Even when the current density increases to 1000 mA g-1, this composite retains 316.5 mAh g-1 after 250 cycles. With superior Na+ storage stability, the (SnOx-Sn)@FLG composite can be a promising anode material for high performance sodium-ion batteries.

  19. A Metal-Organic Compound as Cathode Material with Superhigh Capacity Achieved by Reversible Cationic and Anionic Redox Chemistry for High-Energy Sodium-Ion Batteries.

    Science.gov (United States)

    Fang, Chun; Huang, Ying; Yuan, Lixia; Liu, Yaojun; Chen, Weilun; Huang, Yangyang; Chen, Kongyao; Han, Jiantao; Liu, Qingju; Huang, Yunhui

    2017-06-06

    Although sodium-ion batteries (SIBs) are considered as alternatives to lithium-ion batteries (LIBs), the electrochemical performances, in particular the energy density, are much lower than LIBs. A metal-organic compound, cuprous 7,7,8,8-tetracyanoquinodimethane (CuTCNQ), is presented as a new kind of cathode material for SIBs. It consists of both cationic (Cu(II) ↔Cu(I) ) and anionic (TCNQ(0) ↔TCNQ(-) ↔ TCNQ(2-) ) reversible redox reactions, delivering a discharge capacity as high as 255 mAh g(-1) at a current density of 20 mA g(-1) . The synergistic effect of both redox-active metal cations and organic anions brings an electrochemical transfer of multiple electrons. The transformation of cupric ions to cuprous ions occurs at near 3.80 V vs. Na(+) /Na, while the full reduction of TCNQ(0) to TCNQ(-) happens at 3.00-3.30 V. The remarkably high voltage is attributed to the strong inductive effect of the four cyano groups. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Link between optical spectra, crystal-field parameters, and local environments of Eu3+ ions in Eu2O3-doped sodium disilicate glass

    Science.gov (United States)

    Qin, T.; Mountjoy, G.; Afify, N. D.; Reid, M. F.; Yeung, Y. Y.; Speghini, A.; Bettinelli, M.

    2011-09-01

    Rare-earth-doped glasses are key materials for optical technology due to the luminescent properties of 4fn ions. The crystal-field model describes the effect of local environment on transitions between 4f electrons. We present a detailed modeling study of the optical spectra of sodium disilicate glass, 33Na2O·67SiO2, doped with 0.2% and 1.0 mol% Eu2O3. This study uses very large molecular dynamics models with up to 100 Eu3+ ions, the superposition model for covalent and overlap effects on crystal-field parameters, and realistic values for homogeneous linewidth broadening. The simulated spectra are in reasonable agreement with experiment. The trends in 7FJ energy levels across different Eu3+ ion sites have been examined and a very detailed analysis is presented that looks at how features of the spectra are related to features of the local environment of Eu3+ ions. Increasing the crystal-field strength Stotal causes the 7F0 energy level to decrease and causes the splitting of 7FJ manifolds to increase, and this is due to increasing mixing of 4f wave functions. To a reasonable approximation the crystal-field strength components Sk depend on angular positions of ligands independently of distances to ligands. The former are seen to be more significant in determining Sk, which are closely related to the rotationally invariant bond-orientational order parameters Qk. The values of S2 are approximately linear in Q2, and the values of Q2 are higher for fivefold than sixfold coordinated rare-earth ions. These results can be of importance for efforts to enhance the local environment of rare-earth ions in oxide glasses for optical applications.

  1. A novel coordination polymer of 7-azaindole-3-carboxylic acid with sodium ions: crystal and molecular structures, vibrational spectra and DFT calculations

    Science.gov (United States)

    Morzyk-Ociepa, Barbara; Szmigiel, Ksenia; Petrus, Rafał; Turowska-Tyrk, Ilona; Michalska, Danuta

    2017-09-01

    A novel two-dimensional coordination polymer, catena-poly[(μ2-7-azaindole-3-carboxylato-O:N)-di-aqua-sodium], [Na(7AI3CAH)(H2O)2]n has been synthesized and investigated by a single crystal X-ray diffraction, vibrational spectroscopy and DFT calculations. The sodium complex crystallizes in the triclinic system, space group Pī with a = 7.2226 (4), b = 7.4342 (7), c = 8.8428 (8) Å, α = 103.568 (8), β = 93.425 (6), γ = 91.233 (6)°, V = 460.42 (7) A3 and Z = 2. The asymmetric unit contains two crystallographically independent, half occupied sodium cations surrounded by one 7AI3CAH anion and two water molecules. The O-deprotonated 7-azaindole-3-carboxylate ligand (7AI3CAH) bridges the adjacent Na ions via one oxygen atom of the carboxylate group and via the pyridine nitrogen atom of the 7-azaindole group, which is quite unusual. The sodium cations are six-coordinated in a distorted octahedral geometry, where two apical positions are occupied by two water molecules. Extensive intermolecular Nsbnd H⋯O and Osbnd H⋯O hydrogen bonds stabilize the crystal structure of the complex. The infrared and Raman spectra of [Na(7AI3CAH)(H2O)2]n were recorded in the solid state. The theoretical wavenumbers, infrared intensities, Raman scattering activities and Raman intensities were calculated at the B3LYP/6-311++G(d,p) level for a theoretical model of the title compound including an inter ligand Nsbnd H⋯O(aqua) interaction. A detailed vibrational assignment has been made on the basis of the calculated potential energy distribution.

  2. Coupled ion Binding and Structural Transitions Along the Transport Cycle of Glutamate Transporters

    Energy Technology Data Exchange (ETDEWEB)

    Verdon, Gregory [Weill Cornell Medical College, New York, NY (United States); Oh, SeCheol [Weill Cornell Medical College, New York, NY (United States); Serio, Ryan N. [Weill Cornell Medical College, New York, NY (United States); Boudker, Olga [Weill Cornell Medical College, New York, NY (United States)

    2014-05-19

    Membrane transporters that clear the neurotransmitter glutamate from synapses are driven by symport of sodium ions and counter-transport of a potassium ion. Previous crystal structures of a homologous archaeal sodium and aspartate symporter showed that a dedicated transport domain carries the substrate and ions across the membrane. We report new crystal structures of this homologue in ligand-free and ions-only bound outward- and inward-facing conformations. We then show that after ligand release, the apo transport domain adopts a compact and occluded conformation that can traverse the membrane, completing the transport cycle. Sodium binding primes the transport domain to accept its substrate and triggers extracellular gate opening, which prevents inward domain translocation until substrate binding takes place. Moreover, we describe a new cation-binding site ideally suited to bind a counter-transported ion. We suggest that potassium binding at this site stabilizes the translocation-competent conformation of the unloaded transport domain in mammalian homologues.

  3. LiMPO4 and derived NaMPO4 (M = Mn, Fe, Mg) with excellent electrochemical properties for lithium/sodium ion batteries

    Science.gov (United States)

    Zou, Bang-Kun; Shao, Yu; Qiang, Zi-Yue; Liao, Jia-Ying; Tang, Zhong-Feng; Chen, Chun-Hua

    2016-12-01

    A simple two-step solid-state-reaction process is adopted to synthesize carbon-coated Mg-doped Li(Mn,Fe)PO4 (LMMFP) nano-particles. As positive electrode materials for lithium-ion batteries, the carbon-coated LMMFP samples show excellent electrochemical properties in a temperature range from -20 to 55 °C. For example, LiMn0.48Fe0.5Mg0.02PO4 can deliver a capacity of 146.2 mAh g-1 at 3C rate and retain 95.3% after 450 cycles at 25 °C. It can also deliver 160.7 mAh g-1 at 1C and retain 97.7% after 100 cycles at 55 °C. Even at -20 °C, it gives a capacity of 109.5 mAh g-1 with an average discharge voltage of 3.37 V at 0.2C. In Na/LMMFP cells, the LMMFP electrodes can be electrochemically converted into Mg-doped Na(Mn,Fe)PO4 (NMMFP) electrodes for sodium-ion batteries (SIBs). Ex-situ XRD proves that the derived NMMFP have an olivine-type structure and can reversibly extract and insert sodium ions. For example, NaMn0.48Fe0.5Mg0.02PO4 can deliver a reversible specific capacity of 126.9 mAh g-1 after 30 cycles at 0.1C with an average discharge voltage of 3.1 V. This study opens up a new direction on exploring olivine-type SIB cathodes.

  4. Preparation, characterization and adsorption properties of a novel 3-aminopropyltriethoxysilane functionalized sodium alginate porous membrane adsorbent for Cr(III) ions.

    Science.gov (United States)

    Chen, Jian Hua; Xing, Hai Tao; Guo, Hong Xu; Li, Guo Ping; Weng, Wen; Hu, Shi Rong

    2013-03-15

    In this study, we prepared 3-aminopropyl-triethoxysilane (APTEOS) functionalized sodium alginate (SA) porous membrane adsorbent (APTEOS/SA) and tested its adsorption performance for removing of Cr(III) ions. The physico-chemical properties of the pristine and Cr(III) ions loaded APTEOS/SA were investigated by FT-IR, SEM-EDX, TG, AFM, and contact angle goniometer methods. To investigate the adsorption kinetics of Cr(III) ions onto this newly developed APTEOS/SA, we performed a batch of experiments under different adsorption conditions: solution pH, adsorbent dose, initial Cr(III) ion concentration, adsorption temperature, and contact time. The APTEOS/SA exhibited an encouraging uptake capacity of 90.0mg/g under suitable adsorption conditions. To study the mechanism of adsorption process, we examined the Lagergren pseudo-first-order and pseudo-second-order kinetic model, the intra-particular diffusion model, and the Crank model. Kinetics experiments indicated that the pseudo-first-order model displayed the best correlation with adsorption kinetics data. The Crank model showed that the intra-particle solute diffusion was the main rate-controlling step. Furthermore, our adsorption equilibrium data could be better described by the Freundlich equation. We also carried out consecutive adsorption-desorption experiments eight times to show that the APTEOS/SA has encouraging adsorption-desorption efficiencies. The results indicates that the prepared adsorbent is promising for using as an effective and economical adsorbent for Cr(III) ions removal.

  5. Effect of resin composites with sodium trimetaphosphate with or without fluoride on hardness, ion release and enamel demineralization.

    Science.gov (United States)

    Tiveron, Adelisa Rodolfo Ferreira; Delbem, Alberto Carlos Botazzo; Gaban, Gabriel; Sassaki, Kikue Takebayashi; Pedrini, Denise

    2013-08-01

    To evaluate the effect of the addition of sodium trimetaphosphate (TMP) with or without fluoride on enamel demineralization, and the hardness and release of fluoride and TMP of resin composites. Bovine enamel slabs (4 x 3 x 3 mm) were prepared and selected based on initial surface hardness (n = 96). Eight experimental resin composites were formulated, according to the combination of TMP and sodium fluoride (NaF): TMP/NaF-free (control), 1.6% sodium fluoride (NaF), and 1.5%, 14.1% and 36.8% TMP with and without 1.6% NaF. Resin composite specimens (n = 24) were attached to the enamel slabs with wax and the sets were subjected to pH cycling. Next, surface and cross-sectional hardness and fluoride content of enamel as well as fluoride and TMP release and hardness of the materials were evaluated. Data were statistically analyzed using ANOVA (P composites (P > 0.05), but higher than in the other materials (P < 0.05). The combination of 14.1% TMP and fluoride resulted in less demineralization, especially on lesion surface (P < 0.05). The presence of TMP increased fluoride release from the materials and reduced their hardness.

  6. [Unification of methods for determining the trace quantities of lead, zinc, sodium and potassium ions in the assessment of drinking water adn transfusion fluid quality].

    Science.gov (United States)

    Popkov, V A; Golovina, N V; Evgrafov, A A

    2001-01-01

    The results of long-term studies made by the Department of General Chemistry, I. M. Sechenov Moscow Medical Academy, that deals with unification of methods for determining some ions of metals (lead, zinc, sodium, and potassium) in the assessment of the quality of drinking water and transfusion fluids are summarized. A procedure was developed to determine the trace impurities of zinc, lead, and silver by atomic absorption spectrometry (AAS) by using sorption concentration. C-80-2-aminothiazole, a new sorbent synthesized at the Research Institute of Polymers, was used to detect these ions in the drinking water. With regards to the chosen optimal conditions, drinking water samples were analyzed via their direct spraying in the air-acetylene flame. The prior sorption concentration determined drinking water zinc and lead ions in the concentrations equal to or less than their permissible dose concentrations. The studies indicated that the used methods to determine the trace quantities of metals in the drinking water and aqueous solutions show a high sensitivity, rapidity, simplicity of sample preparation.

  7. The effect of core and lanthanide ion dopants in sodium fluoride-based nanocrystals on phagocytic activity of human blood leukocytes

    Science.gov (United States)

    Sojka, Bartlomiej; Liskova, Aurelia; Kuricova, Miroslava; Banski, Mateusz; Misiewicz, Jan; Dusinska, Maria; Horvathova, Mira; Ilavska, Silvia; Szabova, Michaela; Rollerova, Eva; Podhorodecki, Artur; Tulinska, Jana

    2017-02-01

    Sodium fluoride-based β-NaLnF4 nanoparticles (NPs) doped with lanthanide ions are promising materials for application as luminescent markers in bio-imaging. In this work, the effect of NPs doped with yttrium (Y), gadolinium (Gd), europium (Eu), thulium (Tm), ytterbium (Yb) and terbium (Tb) ions on phagocytic activity of monocytes and granulocytes and the respiratory burst was examined. The surface functionalization of <10-nm NPs was performed according to our variation of patent pending ligand exchange method that resulted in meso-2,3-dimercaptosuccinic acid (DMSA) molecules on their surface. Y-core-based NCs were doped with Eu ions, which enabled them to be excited with UV light wavelengths. Cultures of human peripheral blood ( n = 8) were in vitro treated with five different concentrations of eight NPs for 24 h. In summary, neither type of nanoparticles is found toxic with respect to conducted test; however, some cause toxic effects (they have statistically significant deviations compared to reference) in some selected doses tested. Both core types of NPs (Y-core and Gd-core) impaired the phagocytic activity of monocytes the strongest, having minimal or none whatsoever influence on granulocytes and respiratory burst of phagocytic cells. The lowest toxicity was observed in Gd-core, Yb, Tm dopants and near-infrared nanoparticles. Clear dose-dependent effect of NPs on phagocytic activity of leukocytes and respiratory burst of cells was observed for limited number of samples.

  8. Determination of sodium chloride in ion - exchange membrane caustic soda%离子膜碱中氯化钠的测定

    Institute of Scientific and Technical Information of China (English)

    宋昕; 孙士娟; 邱雪松

    2000-01-01

    The determination of sodium chloride in ion- exchange membrane caustic soda by potentiometry and by spectrophotometry are introduced, and the results obtained by the above two methods are compared. It is concluded that potentiometry is suitable to macro analysis with characteristics of simple operation, rapid analysis and accurate measurement.%介绍了用电位滴定法和分光光度法测定离子膜碱中氯化钠含量的方法,并对这2种方法的测试结果进行了比较。电位滴定法适用于常量分析,具有操作简便、分析速度快、测量结果准确等特点。

  9. Rydberg Matter clusters of alkali metal atoms: the link between meteoritic matter, polar mesosphere summer echoes (PMSE), sporadic sodium layers, polar mesospheric clouds (PMCs, NLCs), and ion chemistry

    CERN Document Server

    Olofson, Frans; Holmlid, Leif

    2010-01-01

    A material exists which links together the influx of meteoritic matter from interplanetary space, the polar mesosphere summer echoes (PMSE), the sporadic sodium layers, the polar mesospheric clouds (PMCs, NLCs), and the observed ion chemistry in the mesosphere. The evidence in these research fields is here analyzed and found to agree well with the properties of Rydberg Matter (RM). This material has been studied with numerous methods in the laboratory. Alkali atoms, mainly Na, reach the mesosphere in the form of interplanetary (meteoritic, cometary) dust. The planar RM clusters NaN usually contain N = 19, 37 or 61 atoms, and have the density of air at 90 km altitude where they float. The diameters of the clusters are 10-100 nm from laboratory high precision radio frequency spectroscopic studies. Such experiments show that RM clusters interact strongly with radar frequencies: this explains the radio frequency heating and reflection studies of PMSE layers. The clusters give the low temperature in the mesosphere...

  10. Spinel lithium titanate (Li4Ti5O12) as novel anode material for room-temperature sodium-ion battery

    Institute of Scientific and Technical Information of China (English)

    Zhao Liang; Pan Hui-Lin; Hu Yong-Sheng; Li Hong; Chen Li-Quan

    2012-01-01

    This is the first time that a novel anode material,spinel Li4Ti5O12 which is well known as a “zero-strain” anode material for lithium storage,has been introduced for sodium-ion battery.The Li4Ti5O12 shows an average Na storage voltage of about 1.0 V and a reversible capacity of about 145 mAh/g,thereby making it a promising anode for sodiumion battery.Ex-situ X-ray diffraction (XRD) is used to investigate the structure change in the Na insertion/deinsertion process.Based on this,a possible Na storage mechanism is proposed.

  11. Sodium-dependent pH regulation in active sea urchin sperm.

    Science.gov (United States)

    Bibring, T; Baxandall, J; Harter, C C

    1984-02-01

    Extracellular sodium ion is required for activation of motility and respiration in sea urchin sperm when semen is diluted in seawater. We have investigated the role of sodium ion in maintenance of sperm activity. Active sperm lose activity on transfer to sodium-free artificial seawater and can be reactivated with external Na+. Reactivation occurs in the range of Na+ concentration required for initial activation; ammonium can substitute for sodium in reactivation. Sperm withdrawn from sodium and sperm prior to activation share a characteristic morphology with straight or gently bent flagella. Activation of sperm by amines in the absence of Na+ is unstable. It is followed by a steady respiratory decline which is temporarily reversed by addition of more amine and stably reversed by addition of Na+. Measurements of intracellular pH indicate that the internal pH rises during amine activation. Internal reacidification occurs during the period of respiratory decline, and Na+ again elevates internal pH. Treatment with cyanide abolishes the reacidification, indicating that it depends on respiration. We conclude that the sodium requirement persists in active sperm; respiration-dependent production of H+ must be balanced by sodium-dependent H+ removal to maintain activity.

  12. Reversible conversion-alloying of Sb2O3 as a high-capacity, high-rate, and durable anode for sodium ion batteries.

    Science.gov (United States)

    Hu, Meijuan; Jiang, Yinzhu; Sun, Wenping; Wang, Hongtao; Jin, Chuanhong; Yan, Mi

    2014-11-12

    Sodium ion batteries are attracting ever-increasing attention for the applications in large/grid scale energy storage systems. However, the research on novel Na-storage electrode materials is still in its infancy, and the cycling stability, specific capacity, and rate capability of the reported electrode materials cannot satisfy the demands of practical applications. Herein, a high performance Sb(2)O(3) anode electrochemically reacted via the reversible conversion-alloying mechanism is demonstrated for the first time. The Sb(2)O(3) anode exhibits a high capacity of 550 mAh g(-1) at 0.05 A g(-1) and 265 mAh g(-1) at 5 A g(-1). A reversible capacity of 414 mAh g(-1) at 0.5 A g(-1) is achieved after 200 stable cycles. The synergistic effect involving conversion and alloying reactions promotes stabilizing the structure of the active material and accelerating the kinetics of the reaction. The mechanism may offer a well-balanced approach for sodium storage to create high capacity and cycle-stable anode materials.

  13. Development of an ion-pair reversed-phase HPLC method with indirect UV detection for determination of phosphates and phosphites as impurities in sodium risedronate.

    Science.gov (United States)

    Breuzovska, Katerina; Dimitrovska, Aneta; Kitanovski, Zoran; Petrusevska, Jelena; Ribarska, Jasmina Tonic; Jolevska, Suzana Trajkovic

    2010-01-01

    A method based on RP-HPLC with indirect UV detection was developed for the determination of phosphates and phosphites as impurities in sodium risedronate. RP separation of the phosphates and phosphites was achieved by adding tetrabutylammonium hydroxide as an ion-pairing agent in the mobile phase. Potassium hydrogen phthalate was added to the mobile phase as an ionic chromophore in order to obtain high background absorption of the mobile phase. Separation was performed on a C18 column using a mixture of pH 8.2 buffer (containing 0.5 mM tetrabutylammonium hydroxide and 1 mM phthalate) and acetonitrile (95 + 5, v/v) as the mobile phase, with indirect UV detection at 248 nm. The validation of the method included determination of specificity/selectivity, linearity, LOD, LOQ, accuracy, precision, and robustness. The LOD was 0.86 microg/mL for phosphates and 0.76 microg/mL for phosphites. The LOQ was 2.60 microg/mL for phosphates and 2.29 microg/mL for phosphites. The developed method is suitable for quantitative determination of phosphates and phosphites as impurities in QC of sodium risedronate.

  14. 电位滴定法测定烧碱中微量氯含量%The Determination of Chlorine Ion in Sodium Hydroxides Using Potentionetry Titrations

    Institute of Scientific and Technical Information of China (English)

    胡正梅; 张忠瑞

    2011-01-01

    The potentiometry titration can be used to determine the content of chlorine ion in sodium hydroxides. The pracess was that neutralize sodium hydroxides with excessive concentrated nitric acids, using the standard liquor of silver nitrate as the titrant,%采用电位滴定分析法测定烧碱中氯含量:以浓硝酸中和烧碱并过量,用硝酸银作标准溶液为滴定剂,在乙醇介质中,以Ag—Ag2S电极作指示电极,双液接型甘汞电极为参比电极进行电位滴定,根据电位突跃确定滴定终点,方法相对误差0.047%,相对标准偏差0.00025%;平均回收率为99.80%。

  15. Room-Temperature All-solid-state Rechargeable Sodium-ion Batteries with a Cl-doped Na3PS4 Superionic Conductor.

    Science.gov (United States)

    Chu, Iek-Heng; Kompella, Christopher S; Nguyen, Han; Zhu, Zhuoying; Hy, Sunny; Deng, Zhi; Meng, Ying Shirley; Ong, Shyue Ping

    2016-09-20

    All-solid-state sodium-ion batteries are promising candidates for large-scale energy storage applications. The key enabler for an all-solid-state architecture is a sodium solid electrolyte that exhibits high Na(+) conductivity at ambient temperatures, as well as excellent phase and electrochemical stability. In this work, we present a first-principles-guided discovery and synthesis of a novel Cl-doped tetragonal Na3PS4 (t-Na3-xPS4-xClx) solid electrolyte with a room-temperature Na(+) conductivity exceeding 1 mS cm(-1). We demonstrate that an all-solid-state TiS2/t-Na3-xPS4-xClx/Na cell utilizing this solid electrolyte can be cycled at room-temperature at a rate of C/10 with a capacity of about 80 mAh g(-1) over 10 cycles. We provide evidence from density functional theory calculations that this excellent electrochemical performance is not only due to the high Na(+) conductivity of the solid electrolyte, but also due to the effect that "salting" Na3PS4 has on the formation of an electronically insulating, ionically conducting solid electrolyte interphase.

  16. Determination of major sodium iodide symporter (NIS) inhibitors in drinking waters using ion chromatography with conductivity detector.

    Science.gov (United States)

    Cengiz, Mehmet Fatih; Bilgin, Ayse Kevser

    2016-02-20

    Goiter is an important health problem all over the world and iodine deficiency is its most common cause. Perchlorate, thiocyanate and nitrate (called as major NIS inhibitors) are known to competitively inhibit iodide uptake by the thyroid gland and thus, human exposure to major NIS inhibitors is a public health concern. In this study, an ion chromatographic method for the determination of most common NIS inhibitor ions in drinking waters was developed and validated. This is the first study where an analytical method is used for the determination of major NIS inhibitors in drinking water by an ion chromatography system in a single run. Chromatographic separations were achieved with an anion-exchange column and separated ions were identified by a conductivity detector. The method was found to be selective, linear, precise accurate and true for all of interested ions. The limits of the detections (LOD) were estimated at 0.003, 0.004 and 0.025mgL(-1) for perchlorate, thiocyanate and nitrate, respectively. Possible interference ions in drinking waters were examined for the best separation of NIS inhibitors. The excellent method validation data and proficiency test result (Z-score for nitrate: -0.1) of the FAPAS(®) suggested that the developed method could be applied for determination of NIS inhibitor residues in drinking waters. To evaluate the usefulness of the method, 75 drinking water samples from Antalya/Turkey were analyzed for NIS inhibitors. Perchlorate concentrations in the samples ranged from not detected (less than LOD) to 0.07±0.02mgL(-1) and the range of nitrate concentrations were found to be 3.60±0.01mgL(-1) and 47.42±0.40mgL(-1). No thiocyanate residues were detected in tested drinking water samples.

  17. Role of sodium ions in the vitrification process: glass matrix modification, slag structure depolymerization, and influence of metal immobilization.

    Science.gov (United States)

    Kuo, Yi-Ming

    2014-07-01

    This study investigates the role of Na ions, a common flux, in the vitrification process. Artificial glass systems composed of Al2O3, CaO, and SiO2 with various Na concentrations were melted at 1450 degrees C. The specimens were cooled by air cooling and water quenching and the metal mobility was evaluated using a sequential extraction procedure. The X-ray diffraction analysis and scanning electron microscopy observations showed that Na ions governed the air-cooled slag's structure. Na ions initially depolymerized CaSiO3-linked chains into CaSiO3 chains, and further cut them into shorter and nonuniform ones, making the slag structure amorphous. With even more Na ions, CaSiO3 chains were divided into single SiO4 tetrahedrons and formed Na-related crystals (Na2Ca3Si2O8 and NaAlSiO4). The phase distributions of Al, Cr, Cu Mn, and Ni showed that Na has a positive effect on the immobilization of heavy metals at suitable concentrations, but a negative effect when in excess amounts. Implications: Vitrification has been widely used to treat hazardous materials. The Na-bearing additives were often used as a flux to improve the melting process. This study described the role of Na played in the vitrification process. The Na ions acted as glass modifier and depolymerize the chain structure of slag. With adequate addition amount of Na ions, the immobilization of heavy metals was improved. The results provided much information about the crystalline phase variation, metal mobility, and surface characteristics while Na serves as a flux.

  18. O3-type NaNi0·33Li0·11Ti0·56O2-based electrode for symmetric sodium ion cell

    Science.gov (United States)

    Zhang, Shuming; Liu, Yu; Zhang, Na; Zhao, Kuan; Yang, Jianhua; He, Shiyang

    2016-10-01

    Layered materials Na0.67+3xNi0.33LixTi0.67-xO2 with Li-substitution as x = 0, 0.05 and 0.11 have been synthesized and investigated as "bi-functional" electrodes for symmetric sodium ion cells. The samples with lithium substitution up to 0.11 are confirmed to be a single phase without impurities and introducing lithium into the transition metal layer increases the interlayer space of the layered materials. It is found that O3-type NaNi0·33Li0·11Ti0·56O2 exhibits two electrochemical working windows, 0.4-0.8 V and 3.1-3.75 V, for sodium ion storage. The as-proposed material thus can be employed as both positive and negative electrodes. As positive electrode, it shows a high working voltage of ca. 3.75 V versus Na+/Na and an initial capacity of 91 mAh g-1 with 19% capacity loss after 100 cycles. When utilized as negative electrode, it delivers a low average voltage of ca. 0.65 V versus Na+/Na, along with a reversible capacity of 125 mAh g-1 and 76% capacity retention after 200 cycles. A symmetric full cell based on the O3-type NaNi0·33Li0·11Ti0·56O2 "bi-functional" electrode has been developed. The cell exhibits a high voltage of 3.1 V and an energy density of 100 W h kg-1 based on the total mass of active electrode materials.

  19. Research progress of anode material for sodium-ion batteries%钠离子电池负极材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    杨绍斌; 董伟; 沈丁; 李思南; 王中将; 张佳民; 孙闻; 张琴

    2016-01-01

    The research status of anode materials in recent years, such as carbons, alloys, metal oxides and soon,were summarized, the performance and storage mechanism of sodiumofthe materials reachedwere introduced. The main problems of these kinds of anode materialsand the solutionwere discussed.The research directions and prospects on anode materialswereforecasted, and thecarbon materials with large layer spacing and less surface area is the most promising candidate anode material for sodium ion battery,and titanate with good structure stability is potential anode materials. Designing and developingnew materials is an important future research field for sodium ion battery.%综述近年来国内外对于碳、合金、金属氧化物等负极材料的研究现状,重点介绍材料的性能以及储钠机理,探讨材料存在的主要问题和解决方法,对负极材料的研究方向以及前景进行展望,指出具有较大层间距和较小比表面积的碳材料是目前最有希望应用于钠离子电池的负极材料,结构稳定性较好的钛酸盐材料是极具潜力的负极材料,设计开发适合的离子电池自身特点的新材料是未来钠电子电池研究的重要方向。

  20. Preparation of NaV1-xAlxPO4F cathode materials for application of sodium-ion battery

    Institute of Scientific and Technical Information of China (English)

    LIU Zhi-ming; WANG Xian-you; WANG Ying; TANG An-ping; YANG Shun-yi; HE Liang-fu

    2008-01-01

    The effects of Al doping on the electrochemical properties of NaVPO4F as a cathode material for sodium-ion batteries were investigated. Al-doped NaV1-xAlxPO4F (x=0, 0.02) samples were prepared by a simple high temperature solid-state reaction involving VPO4 and NaF for the application of cathode material of sodium-ion batteries. The crystal structure and morphology of the material were studied by Flourier-infrared spectrometry(FT-IR), X-ray diffractometry(XRD) and scanning electron microscopy(SEM). The results show that NaV1-xAlxPO4F (x=0, 0.02) has a typical monoclinic structure. The effects of Al doping on the performance of the cathode material were analyzed in terms of the crystal structure, charge-discharge curves and cycle performance. It is found that NaV0.98Al0.02PO4F shows an improved cathodic behavior and discharge capacity retention compared with the undoped samples in the voltage range of 3.0-4.5 V. The electrodes prepared from NaV0.98Al0.02PO4F deliver an initial discharge capacity of 80.4 mA-h/g and an initial coulombic efficiency of 89.2%, and the capacity retention is 85% after 30th cycle. Though the Al-doped samples have lower initial capacities, they show better cycle performance than Al-free samples.

  1. Ion chromatography for the precise analysis of chloride and sodium in sweat for the diagnosis of cystic fibrosis

    NARCIS (Netherlands)

    Doorn, J.; Storteboom, T. T. R.; Mulder, A. M.; de Jong, W. H. A.; Rottier, B. L.; Kema, I. P.

    2015-01-01

    BACKGROUND: Measurement of chloride in sweat is an essential part of the diagnostic algorithm for cystic fibrosis. The lack in sensitivity and reproducibility of current methods led us to develop an ion chromatography/high-performance liquid chromatography (IC/HPLC) method, suitable for the analysis

  2. Determination of Sodium Thiocyanate Content in Milk by Ion Chromatography%离子色谱法测定乳品中硫氰酸钠含量

    Institute of Scientific and Technical Information of China (English)

    陈基耘

    2014-01-01

    采用离子色谱法测定乳品中硫氰酸钠的含量。样品用5 mL乙腈沉淀蛋白质,上清液过C18柱净化,所得的产物采用离子色谱法测定,外标法定量。结果表明,通过流动相以及前处理方法的改进,硫氰酸钠质量浓度在0.10~4.00 mg/L范围内与色谱峰面积呈良好的线性,相关系数r2=1,方法的检出限为0.01 mg/L。在牛奶样品中加入硫氰酸钠标准溶液进行回收试验,测得回收率为95.0%~101.0%,测定结果的相对标准准偏差为1.8%~2.8%(n=7)。该方法操作简便,能有效避免假阳性的发生,测定结果准确,适合于乳品中硫氰酸钠的检测。%Ion chromatography was applied to the determination of sodium thiocyanate content in milk. The sample was purified by protein precipitation and the C18 extraction column. Then the product was tested by ion chromatography and the concentration was quantified by external standard method. Through the improment of mobile phase and pretreatment method,the concentration of sodium thiocyanate was linear with peak area in the range of 0.10–4.00 mg/L,and the correlation coefficient was r2=1. The detection limit determination of the method was 0.01 mg/L. Test recovery experiment was made by standard addition method,and the recovery was 95.0%–101.0%. The relative standard deviation of the determination results was 1.8%–2.8% (n=7). This method has the advantages of simple operation,it can effectively avoid the occurrence of false positive so it is suitable for detection of sodium thiocyanate in milk.

  3. The evaluation of enzymatic method for the determination of serum sodium ion%酶法测定血清钠离子的评价

    Institute of Scientific and Technical Information of China (English)

    郭华

    2012-01-01

    Objective To evaluate the performance of enzymatic method for serum sodium ion determination. Methods The accuracy, precision, off cap stability, linearity, correlation with ion selective electrode method, recovery rate and anti-interference were evaluated by the reagent of enzymatic method for sodium ion determination. Results The coefficient of variation ( CV) was <2% . Calibration period reached 5 d. Accuracy met Randox's quality control. Linearity scope was 100-160mmol/L. Coefficient of correlation ( r ) was 0. 989 9, and enzymatic method was correlated well with ion selective electrode method. The recovery rate was 100. 9%. No interference appeared when bilirubin≤600 μmol/L, triglyceride ≤ 20 mmol/L, vitamin C≤0. 5 g/L, hemoglobin ≤ 10 g/L, ammonium ion ≤ 25 mmol/L,potassium ion≤10 mmol/L, magnesium ion ≤5 mmol/L,calcium ion≤5 mmol/L,zinc ion≤50 mmol/L and copper ion ≤ 50 mmol/L. Conclusions Enzymatic method meets clinical requirements with good repeatability, accuracy, stability, linearity and high anti-interference.%目的 评价酶法测定钠离子的性能.方法 评价血清钠离子酶法试剂的准确性、精密度、开盖稳定性、线性、与电极法的相关性、回收率及抗干扰性.结果 酶法测定钠离子的变异系数(CV)<2%,定标周期能够维持5 d,准确度满足朗道质控品要求,线性范围达到100~160 mmol/L,与电极法具有很好的相关性[相关系数(r)=0.989 9],回收率为100.9%,在胆红素≤600 μmol/L、甘油三酯≤20 mmol/L、维生素C≤0.5 g/L、血红蛋白≤10 g/L、铵离子≤25 mmol/L、钾离子≤10 mmol/L、镁离子≤5 mmol/L、钙离子≤5 mmol/L、锌离子≤50 mmol/L、铜离子≤50 mmol/L对钠离子测定无明显干扰.结论 钠离子酶法试剂有较好的重复性、准确性和稳定性,线性良好,抗干扰能力强,能满足临床使用要求.

  4. Preparation by ion exchange and structural simulation of a new hydrogen phosphate of sodium zirconium; Preparacion por intercambio ionico y simulacion estructural de un nuevo hidrogenofosfato de circonio sodio

    Energy Technology Data Exchange (ETDEWEB)

    Contreras R, A.; Fernandez V, S. M.; Ordonez R, E.; Perez A, M. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

    2008-07-01

    It is described the method of synthesis of the {tau}-Zr P and the obtaining of its sodium form by ion exchange, the simulation of crystalline model and their patterns of X-ray diffraction and comparison of these with other compounds reported in the literature. (Author)

  5. A quantitative approach to the determination of drug release from reverse-phase evaporation lipid vesicles. The influence of sodium ion-pair formation on warfarin partitioning and permeability

    NARCIS (Netherlands)

    Janssen, L.H.M.; Cools, A.A.

    1984-01-01

    The influence of sodium ion-pair formation on warfarin partitioning and permeability has been investigated using reverse-phase evaporation lipid vesicles. An experimental method for the isolation of the vesicles having known amounts of encapsulated drug has been described. The partitioning of warfar

  6. 钠盐浓度对厌氧产氢颗粒污泥从蔗糖中产氢的影响%Effect of Sodium Ion Concentration on Hydrogen Production from Sucrose by Anaerobic Hydrogen-producing Granular Sludge

    Institute of Scientific and Technical Information of China (English)

    郝小龙; 周明华; 俞汉青; 沈琴琴; 雷乐成

    2006-01-01

    This work evaluated the effects of sodium ion concentration, ranging from 0 to 16000mg·L-1(Na+), on the conversion of sucrose to hydrogen by a high-activity anaerobic hydrogen-producing granular sludge. At the optimum sodium ion concentration [1000-2000mg·L-1(Na+)] for hydrogen production at 37℃, the maximum sucrose degradation rate, the specific hydrogen production yield and the specific hydrogen production rate were 393.6-413.1mg·L-1·h-1, 28.04-28.97ml·g-1, 7.52-7.83ml·g-1·h-1, respectively. The specific production yields of propionate, butyrate and valerate decreased, with increasing sodium ion concentration, whereas the specific acetate production yield increased, meanwhile the specific production yields of ethanol and caproate were less than 55.3 and 12.6mg·g-1, respectively. The hybrid fermentation composition gradually developed from acetate, propionate and butyrate to acetate with the increase in sodium ion concentration.

  7. Template-free formation of carbon nanotube-supported cobalt sulfide@carbon hollow nanoparticles for stable and fast sodium ion storage

    Science.gov (United States)

    Han, Fei; Jun Tan, Clara Yi; Gao, Zhiqiang

    2017-01-01

    Carbon-coated cobalt sulfide (CoS) hollow nanoparticles on carbon nanotube (CNT) networks are synthesized by combining three simple approaches: direct growth of Co3O4 nanocrystals on the CNT backbones, chemical conversion of the Co3O4 nanocrystals to CoS hollow nanoparticles, and the spatial introduction of conformal surface modification by carbon. It is noteworthy that the CoS hollow nanoparticles with inner cavity of <50 nm and an average wall thickness of 6-8 nm are derived from a template-free method. Such a template-free-derived multifunctional nanostructure design achieves the amalgamation of the favorite traits of one-dimensional conducting networks, hollow nanoparticles, and surface modification, thus resulting in much enhanced charge transfer, ion transport, and upholding the integrity of the electrode and electrode/electrolyte interface. When applied the synthesized CoS-based material as anodes in sodium-ion batteries (SIBs), excellent performance is observed. For instance, a reversible specific capacity of 562 mAh g-1 at 100 mA g-1 and a capacity retention rate of 90% after 200 cycles at a higher current density of 500 mA g-1 are obtained. Moreover, a superior rate capability is observed with reversible specific capacities of 341 and 276 mAh g-1 at 2000 and at 5000 mA g-1, respectively.

  8. The influence of heavy metal ions, spermine and sodium nitroprusside on ATP-hydrolases of cell membranes of rat colon smooth muscle

    Directory of Open Access Journals (Sweden)

    A. A. Kaplia

    2016-08-01

    Full Text Available The specific features of functional lability of the rat colon smooth muscle (CSM АТР-hydrolases were studied. Na+,K+-AТРase activity is effectively inhibited by divalent ions of both transition (≥ 0,1 µM and nontransition (≥ 1 µM heavy metals in succession by efficiency: Cu2+ > Fe2+ ≥ Cd2+ (10 µM. Polyamine spermine (0,5-1,0 mM is a weak Na+,K+-AТРase inhibitor at saturation concentrations of ions and substrate. Sodium nitroprusside (1 mM as nitric oxide-generating compound exhibits weak Na+,K+-AТРase inhibition only after prolonged preincubation with membranes. Mg2+-АТР-hydrolase activity in all cases is much more resistant to studied agents. Considering the example of the CSM Na+,K+-AТРase it is assumed that enzyme has specific biochemical features that contribute to its role as a potential target and redox-sensor, mediating the pathological mechanisms of heavy metal intoxication and cell oxidative damage.

  9. Honeycomb-inspired design of ultrafine SnO2@C nanospheres embedded in carbon film as anode materials for high performance lithium- and sodium-ion battery

    Science.gov (United States)

    Ao, Xiang; Jiang, Jianjun; Ruan, Yunjun; Li, Zhishan; Zhang, Yi; Sun, Jianwu; Wang, Chundong

    2017-08-01

    Tin oxide (SnO2) has been considered as one of the most promising anodes for advanced rechargeable batteries due to its advantages such as high energy density, earth abundance and environmental friendly. However, its large volume change during the Li-Sn/Na-Sn alloying and de-alloying processes will result in a fast capacity degradation over a long term cycling. To solve this issue, in this work we design and synthesize a novel honeycomb-like composite composing of carbon encapsulated SnO2 nanospheres embedded in carbon film by using dual templates of SiO2 and NaCl. Using these composites as anodes both in lithium ion batteries and sodium-ion batteries, no discernable capacity degradation is observed over hundreds of long term cycles at both low current density (100 mA g-1) and high current density (500 mA g-1). Such a good cyclic stability and high delivered capacity have been attributed to the high conductivity of the supported carbon film and hollow encapsulated carbon shells, which not only provide enough space to accommodate the volume expansion but also prevent further aggregation of SnO2 nanoparticles upon cycling. By engineering electrodes of accommodating high volume expansion, we demonstrate a prototype to achieve high performance batteries, especially high-power batteries.

  10. Changes in Sodium, Calcium, and Magnesium Ion Concentrations That Inhibit Geobacillus Biofilms Have No Effect on Anoxybacillus flavithermus Biofilms.

    Science.gov (United States)

    Somerton, B; Lindsay, D; Palmer, J; Brooks, J; Flint, S

    2015-08-01

    This study investigated the effects of varied sodium, calcium, and magnesium concentrations in specialty milk formulations on biofilm formation by Geobacillus spp. and Anoxybacillus flavithermus. The numbers of attached viable cells (log CFU per square centimeter) after 6 to 18 h of biofilm formation by three dairy-derived strains of Geobacillus and three dairy-derived strains of A. flavithermus were compared in two commercial milk formulations. Milk formulation B had relatively high sodium and low calcium and magnesium concentrations compared with those of milk formulation A, but the two formulations had comparable fat, protein, and lactose concentrations. Biofilm formation by the three Geobacillus isolates was up to 4 log CFU cm(-2) lower in milk formulation B than in milk formulation A after 6 to 18 h, and the difference was often significant (P ≤ 0.05). However, no significant differences (P ≤ 0.05) were found when biofilm formations by the three A. flavithermus isolates were compared in milk formulations A and B. Supplementation of milk formulation A with 100 mM NaCl significantly decreased (P ≤ 0.05) Geobacillus biofilm formation after 6 to 10 h. Furthermore, supplementation of milk formulation B with 2 mM CaCl2 or 2 mM MgCl2 significantly increased (P ≤ 0.05) Geobacillus biofilm formation after 10 to 18 h. It was concluded that relatively high free Na(+) and low free Ca(2+) and Mg(2+) concentrations in milk formulations are collectively required to inhibit biofilm formation by Geobacillus spp., whereas biofilm formation by A. flavithermus is not impacted by typical cation concentration differences of milk formulations.

  11. Solid state synthesis of layered sodium manganese oxide for sodium-ion battery by in-situ high energy X-ray diffraction and X-ray absorption near edge spectroscopy

    Science.gov (United States)

    Ma, Tianyuan; Xu, Gui-Liang; Zeng, Xiaoqiao; Li, Yan; Ren, Yang; Sun, Chengjun; Heald, Steve M.; Jorne, Jacob; Amine, Khalil; Chen, Zonghai

    2017-02-01

    In situ high energy X-ray diffraction (HEXRD) and in situ X-ray absorption near edge spectroscopy (XANES) were carried out to understand the solid state synthesis of NaxMnO2, with particular interest on the synthesis of P2 type Na2/3MnO2. It was found that there were multi intermediate phases formed before NaMnO2 appeared at about 600 °C. And the final product after cooling process is a combination of O‧3 NaMnO2 with P2 Na2/3MnO2. A P2 type Na2/3MnO2 was synthesized at reduced temperature (600 °C). The influence of Na2CO3 impurity on the electrochemical performance of P2 Na2/3MnO2 was thoroughly investigated in our work. It was found that the content of Na2CO3 can be reduced by optimizing Na2CO3/MnCO3 ratio during the solid state reaction or other post treatment such as washing with water. We expected our results could provide a good guide for future development of high performance cathode materials for sodium-ion batteries.

  12. Disordered 3 D Multi-layer Graphene Anode Material from CO2 for Sodium-Ion Batteries.

    Science.gov (United States)

    Smith, Kassiopeia; Parrish, Riley; Wei, Wei; Liu, Yuzi; Li, Tao; Hu, Yun Hang; Xiong, Hui

    2016-06-22

    We report the application of disordered 3 D multi-layer graphene, synthesized directly from CO2 gas through a reaction with Li at 550 °C, as an anode for Na-ion batteries (SIBs) toward a sustainable and greener future. The material exhibited a reversible capacity of ∼190 mA h g(-1) with a Coulombic efficiency of 98.5 % at a current density of 15 mA g(-1) . The discharge capacity at higher potentials (>0.2 V vs. Na/Na(+) ) is ascribed to Na-ion adsorption at defect sites, whereas the capacity at low potentials (CO2 gas makes it attractive not only as an anode material for SIBs but also to mitigate CO2 emission.

  13. Dissecting ion-specific dielectric spectra of sodium-halide solutions into solvation water and ionic contributions

    Energy Technology Data Exchange (ETDEWEB)

    Rinne, Klaus F.; Netz, Roland R. [Fachbereich Physik, Freie Universität Berlin, 14195 Berlin (Germany); Gekle, Stephan [Physikalisches Institut, Universität Bayreuth, 95440 Bayreuth (Germany)

    2014-12-07

    Using extensive equilibrium molecular dynamics simulations we determine the dielectric spectra of aqueous solutions of NaF, NaCl, NaBr, and NaI. The ion-specific and concentration-dependent shifts of the static dielectric constants and the dielectric relaxation times match experimental results very well, which serves as a validation of the classical and non-polarizable ionic force fields used. The purely ionic contribution to the dielectric response is negligible, but determines the conductivity of the salt solutions. The ion-water cross correlation contribution is negative and reduces the total dielectric response by about 5%-10% for 1 M solutions. The dominating water dielectric response is decomposed into different water solvation shells and ion-pair configurations, by this the spectral blue shift and the dielectric decrement of salt solutions with increasing salt concentration is demonstrated to be primarily caused by first-solvation shell water. With rising salt concentration the simulated spectra show more pronounced deviations from a single-Debye form and can be well described by a Cole-Cole fit, in quantitative agreement with experiments. Our spectral decomposition into ionic and different water solvation shell contributions does not render the individual contributions more Debye-like, this suggests the non-Debye-like character of the dielectric spectra of salt solutions not to be due to the superposition of different elementary relaxation processes with different relaxation times. Rather, the non-Debye-like character is likely to be an inherent spectral signature of solvation water around ions.

  14. Dissecting ion-specific dielectric spectra of sodium-halide solutions into solvation water and ionic contributions

    Science.gov (United States)

    Rinne, Klaus F.; Gekle, Stephan; Netz, Roland R.

    2014-12-01

    Using extensive equilibrium molecular dynamics simulations we determine the dielectric spectra of aqueous solutions of NaF, NaCl, NaBr, and NaI. The ion-specific and concentration-dependent shifts of the static dielectric constants and the dielectric relaxation times match experimental results very well, which serves as a validation of the classical and non-polarizable ionic force fields used. The purely ionic contribution to the dielectric response is negligible, but determines the conductivity of the salt solutions. The ion-water cross correlation contribution is negative and reduces the total dielectric response by about 5%-10% for 1 M solutions. The dominating water dielectric response is decomposed into different water solvation shells and ion-pair configurations, by this the spectral blue shift and the dielectric decrement of salt solutions with increasing salt concentration is demonstrated to be primarily caused by first-solvation shell water. With rising salt concentration the simulated spectra show more pronounced deviations from a single-Debye form and can be well described by a Cole-Cole fit, in quantitative agreement with experiments. Our spectral decomposition into ionic and different water solvation shell contributions does not render the individual contributions more Debye-like, this suggests the non-Debye-like character of the dielectric spectra of salt solutions not to be due to the superposition of different elementary relaxation processes with different relaxation times. Rather, the non-Debye-like character is likely to be an inherent spectral signature of solvation water around ions.

  15. Energy conservation by oxidation of formate to carbon dioxide and hydrogen via a sodium ion current in a hyperthermophilic archaeon.

    Science.gov (United States)

    Lim, Jae Kyu; Mayer, Florian; Kang, Sung Gyun; Müller, Volker

    2014-08-05

    Thermococcus onnurineus NA1 is known to grow by the anaerobic oxidation of formate to CO2 and H2, a reaction that operates near thermodynamic equilibrium. Here we demonstrate that this reaction is coupled to ATP synthesis by a transmembrane ion current. Formate oxidation leads to H(+) translocation across the cytoplasmic membrane that then drives Na(+) translocation. The ion-translocating electron transfer system is rather simple, consisting of only a formate dehydrogenase module, a membrane-bound hydrogenase module, and a multisubunit Na(+)/H(+) antiporter module. The electrochemical Na(+) gradient established then drives ATP synthesis. These data give a mechanistic explanation for chemiosmotic energy conservation coupled to formate oxidation to CO2 and H2. Because it is discussed that the membrane-bound hydrogenase with the Na(+)/H(+) antiporter module are ancestors of complex I of mitochondrial and bacterial electron transport these data also shed light on the evolution of ion transport in complex I-like electron transport chains.

  16. Germanium as a Sodium Ion Battery Material: In Situ TEM Reveals Fast Sodiation Kinetics with High Capacity

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xiaotang; Adkins, Emily R.; He, Yang; Zhong, Li; Luo, Langli; Mao, Scott X.; Wang, Chong M.; Korgel, Brian A.

    2016-01-29

    Amorphous germanium (a-Ge) nanowires have great potential for application as anodes in Na-ion batteries. However, the Na-Ge reaction is much less studied and understood compared with other metal alloy anodes. Here, in situ transmission electron microscopy (TEM) is used to study the sodiation/desodiation behavior of a-Ge nanowires. Unexpectedly, our experiments revealed that a-Ge nanowires can be charged at a very fast rate and the final sodiation product, with over 300% volume expansion, is close to Na3Ge instead of NaGe which was considered as the ultimate sodiation state that Ge could achieve. Porous structure was observed in desodiation and, in contrast to delithiation, Na extraction is more likely to create pores in the nanowires due to the much larger radius of the Na ion. This porous structure has demonstrated excellent robustness upon cycling: it could recover flawlessly from the giant pores that were created during experimentation. These results show that the potential of a-Ge for Na-ion battery applications may have been previously underestimated.

  17. Ion Selectivity Mechanism in a Bacterial Pentameric Ligand-Gated Ion Channel

    Energy Technology Data Exchange (ETDEWEB)

    Fritsch, Sebastian M [ORNL; Ivanov, Ivaylo N [ORNL; Wang, Hailong [Mayo Clinic College of Medicine; Cheng, Xiaolin [ORNL

    2011-01-01

    The proton-gated ion channel from Gloeobacter violaceus (GLIC) is a prokaryotic homolog of the eukaryotic nicotinic acetylcholine receptor (nAChR) that responds to the binding of neurotransmitter acetylcholine and mediates fast signal transmission. Recent emergence of a high resolution crystal structure of GLIC captured in a potentially open state allowed detailed, atomic-level insight into ion conduction and selectivity mechanisms in these channels. Herein, we have examined the barriers to ion conduction and origins of ion selectivity in the GLIC channel by the construction of potential of mean force (PMF) profiles for sodium and chloride ions inside the transmembrane region. Our calculations reveal that the GLIC channel is open for a sodium ion to transport, but presents a ~10 kcal/mol free energy barrier for a chloride ion, which arises primarily from the unfavorable interactions with a ring of negatively charged glutamate residues (E-2 ) at the intracellular end and a ring of hydrophobic residues (I9 ) in the middle of the transmembrane domain. Our collective findings further suggest that the charge selection mechanism can, to a large extent, be attributed to the narrow intracellular end and a ring of glutamate residues in this position their strong negative electrostatics and ability to bind cations. By contrast, E19 at the extracellular entrance only plays a minor role in ion selectivity of GLIC. In addition to electrostatics, both ion hydration and protein dynamics are found to be crucial for ion conduction as well, which explains why a chloride ion experiences a much greater barrier than a sodium ion in the hydrophobic region of the pore.

  18. Mechanisms of sodium and potassium ions transfer facili-tated by dibenzo-15-crown-5 across the water / 1,2-dichloro-ethane interface using micropipettes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The transfer of sodium and potassium ions facilitated by dibenzo-15-crown-5 (DB15C5) has been studied at the micro-water/1,2-dichloroethane (water/DCE) interface supported at the tip of a micropipette. Cyclic voltammetric measurements were performed in two limiting conditions: the bulk concentration of Na+ or K+ in the aqueous phase is much higher than that of DB15C5 in the organic phase (DB15C5 diffusion controlled process) and the reverse condition (metal ion diffusion controlled process). The mechanisms of the facilitated Na+ transfer by DB15C5 are both transfer by interfacial complexation (TIC) with 1∶1 stoichiometry under these two conditions, and the corresponding association constants were determined at log β1 = 8.97 ( 0.05 or log β1 = 8.63 ( 0.03. However, the transfers of K+ facilitated by DB15C5 show different behavior. In the former case it is a TIC process and its stoichiometry is 1∶2, whereas in the latter case two peaks during the forward scan were observed, the first of which was confirmed as the formation of K+(DB15C5)2 at the interface by a TIC mechanism, while the second one may be another TIC process with 1∶1 stoichiometry in the more positive potential. The relevant association constants calculated for the complexed ion, K+(DB15C5)2, in the organic phase in two cases, logβ2, are 13.64 ( 0.03 and 11.34 ( 0.24, respectively.

  19. Structural characterization of layered Na0.5Co0.5Mn0.5O2 material as a promising cathode for sodium-ion batteries

    Science.gov (United States)

    Manikandan, Palanisamy; Heo, Seongwoo; Kim, Hyun Woo; Jeong, Hu Young; Lee, Eungje; Kim, Youngsik

    2017-09-01

    Layered Na0.5Co0.5Mn0.5O2 material is synthesized through a facile mixed hydroxy-carbonate route using (Co0.5Mn0.5)2(OH)2CO3 precursor and well characterized as a hexagonal layered structure under P63/mmc space group. The lattice parameters and unit cell volume (a = 2.8363 Å, c = 11.3152 Å and V = 78.83 Å3) are calculated by Rietveld refinement analysis. A flaky-bundle morphology is obtained to the layered Na0.5Co0.5Mn0.5O2 material with the hexagonal flake size ∼30 nm. Advanced transmission electron microscopic images are revealed the local structure of the layered Na0.5Co0.5Mn0.5O2 material with contrasting bright dots and faint dark dots corresponding to the Co/Mn and Na atoms. Two oxidation and reduction peaks are occurred in a cyclic voltammetric analysis corresponding to Co3+/Co4+ and Mn3+/Mn4+ redox processes. These reversible processes are attributed to the intercalation/de-intercalation of Na+ ions into the host structure of layered Na0.5Co0.5Mn0.5O2 material. Accordingly, the sodium cell is delivered the initial charge-discharge capacity 53/144 mAh g-1 at 0.5 C, which cycling studies are extended to rate capability test at 1 C, 3 C and 5C. Eventually, the Na-ion full-cell is yielded cathode charge-discharge capacity 55/52 mAh g-1 at 0.212 mA and exhibited as a high voltage cathode for Na-ion batteries.

  20. Neutral losses of sodium benzoate and benzoic acid in the fragmentation of the [M + Na](+) ions of methoxyfenozide and tebufenozide via intramolecular rearrangement in electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Chai, Yunfeng; Gao, Guanwei; Shen, Shanshan; Liu, Xin; Lu, Chengyin

    2017-02-15

    Electrospray ionization (ESI) tandem mass spectrometry can be applied to determine structural information about organic compounds. The [M + Na](+) ion is one of the major precursor ions in ESI mass spectrometry, but its fragmentation mechanism study is still insufficient. This study reveals the interesting fragmentation reactions of the [M + Na](+) ions of methoxyfenozide and tebufenozide. The fragmentations of the [M + Na](+) , [M + Li](+) , and [M + H](+) ions of methoxyfenozide and tebufenozide were studied using a hybrid quadrupole-orbitrap mass spectrometer and an ion trap mass spectrometer. A hydrogen/deuterium (H/D)-exchange experiment in the amide group of methoxyfenozide allowed for the confirmation of the fragmentation mechanism. Density functional theory (DFT) calculations were performed for a further understanding of the fragmentation mechanism of the [M + Na](+) ion of methoxyfenozide. Neutral losses of sodium benzoate and benzoic acid in the fragmentation of the [M + Na](+) ions of methoxyfenozide and tebufenozide were observed as the major fragmentation pathways. In contrast, similar fragmentations were not observed or minor pathways in the fragmentation of the [M + Li](+) and [M + H](+) ions of methoxyfenozide and tebufenozide. In addition, a minor product ion resulting from loss of NaOH was identified, which was the first reported example in the fragmentation of sodiated compounds in mass spectrometry. Losses of sodium benzoate and benzoic acid in the fragmentation of the [M + Na](+) ions of methoxyfenozide and tebufenozide are proposed to be formed through an intramolecular rearrangement reaction, which is supported by DFT calculations. An H/D-exchange experiment confirms that the carboxyl hydrogen of benzoic acid and the hydrogen of NaOH exclusively derive from the amide hydrogen of the precursor ion. This study enriches our knowledge on the Na(+) -induced fragmentation reactions. Copyright © 2016 John Wiley & Sons, Ltd

  1. Investigations of spherical Cu NPs in sodium lauryl sulphate with Tb{sup 3+} ions dispersed in PVA films

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Brijesh; Kaur, Gagandeep, E-mail: gagandeep_bhu@yahoo.com; Rai, S.B., E-mail: sbrai49@yahoo.co.in

    2016-03-15

    Highlights: • Cu NPs were prepared in SDS using 1064 nm laser radiation at fluence 37, 64 and 88 J/cm{sup 2}. • Spherical Cu NPs with average diameter varying between 10 and 50 nm atdifferent fluence. • PL of Tb3+ ions in PVA polymer film is maximum with Cu NPS at fluence 37 J/cm{sup 2}. • PVA films of Cu NPs displayed a highly temperature-dependent electrical conductivity. • These copper NPs embedded PVA films can be used as novel, low-cost sensor materials. - Abstract: Cu nanoparticles (NPs) have been prepared in SDS solution using 1064 nm laser radiation at different fluence 37 J/cm{sup 2}, 64 J/cm{sup 2} and 88 J/cm{sup 2} and structurally characterized. The TEM measurements reveal the presence of nanoparticles of spherical shape with different size. The size of the nanoparticles and their concentration increases with the increase of fluence.The effect of these Cu nanoparticles on the emissive properties of Tb{sup 3+} ion in polymer films has been studied. It is found that emission intensity of Tb{sup 3+} first increases and then deceases both with concentration of Cu NPs as well as with sizes. The PL intensity of Tb{sup 3+} ions is minimum for Cu NPs prepared with highest fluence. It has been explained in term of local field effect. This was also verified by life time measurements. These thin PVA films of copper nanoparticles displayed a highly temperature-dependent electrical conductivity with sensitivity at least comparable to commercial materials which suggest the use of these copper NPs embedded PVA films as novel, low-cost sensor materials.

  2. The vasodilator mechanisms of sodium metabisulfite on precontracted isolated aortic rings in rats: signal transduction pathways and ion channels.

    Science.gov (United States)

    Yang, Zhenhua; Zhang, Yuexia; Meng, Ziqiang

    2012-09-01

    Sodium metabisulfite (SMB) is most commonly used as a food additives, however few study was performed on the vasodilator effect of SMB. In the present paper, the vasodilator effects of SMB and roles of Ca(2+) and K(+) channels as well as the cGMP pathway on isolated rat aortic rings were studied. The results show that: (1) SMB could relax isolated aortic rings precontracted by norepinephrine in a concentration-dependent manner. The maximal endothelium-dependent vasorelaxation was approximately 20% whereas that not depending on the presence of the endothelium was more than 90%. (2) The vasorelaxant effects induced by 50 or 200 μM SMB were partially inhibited by iberiotoxin, NS-2028 or l-NNA. The vasorelaxation of 1000 μM SMB was partially inhibited by nifedipine or glibenclamide. The SMB induced vasorelaxation was partially inhibited by tetraethylammonium. These results led to the conclusions that the vasorelaxation of SMB at low concentrations (500 μM) was endothelium-independent and mediated by K(ATP) channel and L-type Ca(2+) channel. The maximal allowable concentration from China and the acceptable daily intake level from WHO of SMB as a food additive should be revised. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Collisional Ionization Equilibrium for Optically Thin Plasmas. I. Updated Recombination Rate Coefficients for Bare though Sodium-like Ions

    CERN Document Server

    Bryans, P; Gorczyca, T W; Laming, J M; Mitthumsiri, W; Savin, D W

    2006-01-01

    Reliably interpreting spectra from electron-ionized cosmic plasmas requires accurate ionization balance calculations for the plasma in question. However, much of the atomic data needed for these calculations have not been generated using modern theoretical methods and are often highly suspect. This translates directly into the reliability of the collisional ionization equilibrium (CIE) calculations. We make use of state-of-the-art calculations of dielectronic recombination (DR) rate coefficients for the hydrogenic through Na-like ions of all elements from He up to and including Zn. We also make use of state-of-the-art radiative recombination (RR) rate coefficient calculations for the bare through Na-like ions of all elements from H through to Zn. Here we present improved CIE calculations for temperatures from $10^4$ to $10^9$ K using our data and the recommended electron impact ionization data of \\citet{Mazz98a} for elements up to and including Ni and Mazzotta (private communication) for Cu and Zn. DR and RR ...

  4. Suppressing the chromium disproportionation reaction in O3-type layered cathode materials for high capacity sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Ming-Hui; Wang, Yong; Shadike, Zulipiya; Yue, Ji-Li; Hu, Enyuan; Bak, Seong-Min; Zhou, Yong-Ning; Yang, Xiao-Qing; Fu, Zheng-Wen

    2017-01-01

    Chromium-based layered cathode materials suffer from the irreversible disproportionation reaction of Cr4+ to Cr3+ and Cr6+, which hinders the reversible multi-electron redox of Cr ions in layered cathodes, and limits their capacity and reversibility. To address this problem, a novel O3-type layer-structured transition metal oxide of NaCr1/3Fe1/3Mn1/3O2 (NCFM) was designed and studied as a cathode material. A high reversible capacity of 186 mA h g-1 was achieved at a current rate of 0.05C in a voltage range of 1.5 to 4.2 V. X-ray diffraction revealed an O3 → (O3 + P3) → (P3 + O3'') → O3'' phase-transition pathway for NCFM during charge. X-ray absorption, X-ray photoelectron and electron energy-loss spectroscopy measurements revealed the electronic structure changes of NCFM during Na+ deintercalation/intercalation processes. It is confirmed that the disproportionation reaction of Cr4+ to Cr3+ and Cr6+ can be effectively suppressed by Fe3+ and Mn4+ substitution. These results demonstrated that the reversible multi-electron oxidation/reduction of Cr ions can be achieved in NCFM during charge and discharge accompanied by CrO6 octahedral distortion and recovery.

  5. Effect of external electric fields on the dielectronic recombination cross section of lithium and sodium like ions

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, D.C.; Pindzola, M.S.; Bottcher, C.

    1985-03-01

    The effect of external electric fields on the dielectronic recombination cross section associated with the 2s ..-->.. 2p excitation in the Li like ions B/sup 2 +/, C/sup 3 +/, O/sup 5 +/, and Fe/sup 23 +/, and the 3s ..-->.. 3p excitation in the Na like ions Mg/sup +/, S/sup 5 +/, Cl/sup 6 +/, and Fe/sup 15 +/ has been studied in the configuration-average, distorted-wave approximation. By applying the linear-Stark approximation to the doubly-excited 2pnl and 3pnl Rydberg states in the presence of an external electric field, we study the systematics of field mixing effects on dielectronic recombination and determine the maximum field enhancement of the dielectronic recombination cross section. We find that the magnitude of the field enhancement decreases as we move up an isoelectronic sequence and is of the order of a factor of two or three in highly-ionized systems. In addition, we show that dielectronic recombination transitions through doubly-excited states near threshold can produce large narrow peaks in the cross section at low energies, which are especially prominent in high stages of ionization, and are not affected by the electric field.

  6. Regulation of ion gradients across myocardial ischemic border zones: a biophysical modelling analysis.

    Directory of Open Access Journals (Sweden)

    Steven Niederer

    Full Text Available The myocardial ischemic border zone is associated with the initiation and sustenance of arrhythmias. The profile of ionic concentrations across the border zone play a significant role in determining cellular electrophysiology and conductivity, yet their spatial-temporal evolution and regulation are not well understood. To investigate the changes in ion concentrations that regulate cellular electrophysiology, a mathematical model of ion movement in the intra and extracellular space in the presence of ionic, potential and material property heterogeneities was developed. The model simulates the spatial and temporal evolution of concentrations of potassium, sodium, chloride, calcium, hydrogen and bicarbonate ions and carbon dioxide across an ischemic border zone. Ischemia was simulated by sodium-potassium pump inhibition, potassium channel activation and respiratory and metabolic acidosis. The model predicted significant disparities in the width of the border zone for each ionic species, with intracellular sodium and extracellular potassium having discordant gradients, facilitating multiple gradients in cellular properties across the border zone. Extracellular potassium was found to have the largest border zone and this was attributed to the voltage dependence of the potassium channels. The model also predicted the efflux of [Formula: see text] from the ischemic region due to electrogenic drift and diffusion within the intra and extracellular space, respectively, which contributed to [Formula: see text] depletion in the ischemic region.

  7. Sodium-level-sensitive sodium channel Na(x) is expressed in glial laminate processes in the sensory circumventricular organs.

    Science.gov (United States)

    Watanabe, Eiji; Hiyama, Takeshi Y; Shimizu, Hidetada; Kodama, Ryuji; Hayashi, Noriko; Miyata, Seiji; Yanagawa, Yuchio; Obata, Kunihiko; Noda, Masaharu

    2006-03-01

    Na(x) is an atypical sodium channel that is assumed to be a descendant of the voltage-gated sodium channel family. Our recent studies on the Na(x)-gene-targeting mouse revealed that Na(x) channel is localized to the circumventricular organs (CVOs), the central loci for the salt and water homeostasis in mammals, where the Na(x) channel serves as a sodium-level sensor of the body fluid. To understand the cellular mechanism by which the information sensed by Na(x) channels is transferred to the activity of the organs, we dissected the subcellular localization of Na(x) in the present study. Double-immunostaining and immunoelectron microscopic analyses revealed that Na(x) is exclusively localized to perineuronal lamellate processes extended from ependymal cells and astrocytes in the organs. In addition, glial cells isolated from the subfornical organ, one of the CVOs, were sensitive to an increase in the extracellular sodium level, as analyzed by an ion-imaging method. These results suggest that glial cells bearing the Na(x) channel are the first to sense a physiological increase in the level of sodium in the body fluid, and they regulate the neural activity of the CVOs by enveloping neurons. Close communication between inexcitable glial cells and excitable neural cells thus appears to be the basis of the central control of the salt homeostasis.

  8. Ion Association in Hydrothermal Sodium Sulfate Solutions Studied by Modulated FT-IR-Raman Spectroscopy and Molecular Dynamics.

    Science.gov (United States)

    Reimer, Joachim; Steele-MacInnis, Matthew; Wambach, Jörg M; Vogel, Frédéric

    2015-07-30

    Saline aqueous solutions at elevated pressures and temperatures play an important role in processes such as supercritical water oxidation (SCWO) and supercritical water gasification (SCWG), as well as in natural geochemical processes in Earth and planetary interiors. Some solutions exhibit a negative temperature coefficient of solubility at high temperatures, thereby leading to salt precipitation with increasing temperature. Using modulated FT-IR Raman spectroscopy and classical molecular dynamics simulations (MD), we studied the solute speciation in solutions of 10 wt % Na2SO4, at conditions close to the saturation limit. Our experiments reveal that ion pairing and cluster formation are favored as solid saturation is approached, and ionic clusters form prior to the precipitation of solid sulfate. The proportion of such clusters increases as the phase boundary is approached either by decreasing pressure or by increasing temperature in the vicinity of the three-phase (vapor-liquid-solid) curve.

  9. [Studies on the mechanism of action of vascular spasmolytics. 3. Effect of nitroprusside sodium, nitroglycerin, prenylamine and verapamil on the fluoride-induced contracture of the isolated coronary artery].

    Science.gov (United States)

    Fermum, R; Meisel, P; Klinner, U

    1977-01-01

    On isolated coronary arteries of cattle, nitroprusside-sodium, nitroglycerol, prenylamine, and verapamil were studied for their spasmolytic effects on a contracture induced by fluoride ions. With this contracture model, which is independent of extracellular calcium, nitroprosside-sodium and nitroglycerol showed strong spasmolytic action. Verapamil proved ineffective, and the effectiveness of prenylamine was strongly reduced. The results lend support to earlier findings suggesting that nitroglycerol and nitroprusside-sodium are endowed with a relaxation mechanism different from that of verapamil and analogously acting compounds.

  10. 烧伤回吸期持续性高钠高氯与侵袭性感染%Persistent High Level of Sodium and Chloride Ions and Invasive Infection in Resorption Phase Postburn

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    目的:探讨大面积烧伤患者持续性高钠高氯产生的原因及防治措施;动态监测大面积烧伤后血清Na+,Cl-的临床意义。方法:回顾性分析了7例严重烧伤后持续性高Na+高Cl-和61例严重烧伤后非持续性高Na+,高Cl-患者的临床特点。结果:7例严重烧伤后持续高Na+,高Cl-患者均有严重侵袭性感染;且高Na+出现愈早,上升愈快,则感染愈重,愈后愈差。结论:1.烧伤后持续性高Na+,高Cl-产生的原因是严重侵袭性感染。2.动态监测血清Na+Cl-对感染的评价及抗感染效果有积极意义。3.预防措施包括平稳渡过休克,保护创面,避免长途转运。治疗上一旦出现持续性高钠高氯,除对症治疗外,根本措施是创面处理及抗感染。%Objective: To investigate the cause persistent high level of sodium and chloride ions in serum and methods for its prevention and treatment. The clinical significance of dynamic monitoring of serum sodium and chloride ion levels in severe burn patients. Method: To make a review of 7 cases with persistent high serum sodium and chloride ion levels and 61 cases without. Results: All of the severe cases had invasive infection. The earlier the presence of high serum sodium and chloride ion levels, the more dangerous the case. Conclusion: 1. Persistent high serum sodium and chloride ion levels is caused by invasive infection. 2. Dynamic monitoring of serum sodium and chloride ion levels is of great clinical significance. 3. Prevention measures include: to tide over shock stage, to protect burn wounds, to avoid long distance transfer. 4. Treating measures include careful management of burn wounds, anti-infection and expectant treatment.

  11. Effect of Different Metal Ions on Mycelium Growth and Extracellular Polysaccharide in Medicinal Mushroom Phellinus igniarius%金属离子对桑黄菌丝体及胞外多糖含量的影响

    Institute of Scientific and Technical Information of China (English)

    高慧娟; 刘雨晴; 李娟辉; 董瑞丽; 王晓琴; 贺旭阳; 张万恒; 张芬琴

    2013-01-01

      筛选出促进桑黄菌丝体生物量和胞外多糖的金属离子。通过测定平板上菌丝体生长速度,液体发酵的菌丝体干重和胞外多糖含量,确定金属离子对桑黄生长的影响。在固体平板培养中,Mg2+、Fe2+、Ca2+对桑黄的生长速度具有明显的促进作用,Na+对菌丝生长速度无明显的促进作用,而在液体摇瓶发酵中,1、3 mg/mL Mg2+,0.9 mg/mL Fe2+,3、5、7 mg/mL Ca2+以及3 mg/mL Na+增加菌丝体干重量,较空白对照差异显著,是空白对照的5倍~8倍。在3 mg/mL K+和Na+,7 mg/mL Ca2+,0.7 mg/mL Fe2+,0.1 mg/mL Zn2+的培养基中桑黄分泌的胞外粗多糖含量分别为0.4760、0.7105、0.5200、0.4516和0.6820 g/100 mL,较空白对照显著差异。一定浓度的金属离子对桑黄菌丝体的生长和胞外多糖分泌有一定的促进作用。%To screen the different mineral ions for promoting the growth of mycelia and crude extracellular polysaccharide of hellinus igniarius. Impact of metal ions on the Santo effect on the growth of P. linteus was identified by determination of growth rate of Mycelia in solid surface culture method in medium with different metal ions, mycelia dry weight and crude extracellular polysaccharide obtained in shake -flsak fermentation. The results show that the medium with Mg2+,Fe2+,Ca2+could obviously promote the growth of the mycelia of P. inteus on plate cultivation, while the Na+has no obvious role.In medium with 1 mg/mL and 3 mg/mL Mg2+, 0.9 mg/mL Fe2+, 3,5 mg/mL and 7mg/mL Ca2+,and 3 mg/mLNa+,the dry weight of mycelia were 5-8 folds than that of control medium,In medium with 3 mg/mL K+and Na+, 7mg/mL Ca2+,0.7 mg/mL Fe2+and 0.1 mg/mL Zn2+, the contains of extracellular polysaccharide secreted by P.inteus were 0.476 0, 0.710 5, 0.520 0, 0.451 6 g/100 mL and 0.6820 g/100 mL,respecrively, the difference was significient compared with control medium. The different metal ions had the role of promoting the growth of

  12. Mechanistic Insight into the Stability of HfO2-Coated MoS2 Nanosheet Anodes for Sodium Ion Batteries

    KAUST Repository

    Ahmed, Bilal

    2015-06-01

    It is demonstrated for the first time that surface passivation of 2D nanosheets of MoS2 by an ultrathin and uniform layer of HfO2 can significantly improve the cyclic performance of sodium ion batteries. After 50 charge/discharge cycles, bare MoS2 and HfO2 coated MoS2 electrodes deliver the specific capacity of 435 and 636 mAh g-1, respectively, at current density of 100 mA g-1. These results imply that batteries using HfO2 coated MoS2 anodes retain 91% of the initial capacity; in contrast, bare MoS2 anodes retain only 63%. Also, HfO2 coated MoS2 anodes show one of the highest reported capacity values for MoS2. Cyclic voltammetry and X-ray photoelectron spectroscopy results suggest that HfO2 does not take part in electrochemical reaction. The mechanism of capacity retention with HfO2 coating is explained by ex situ transmission electron microscope imaging and electrical impedance spectroscopy. It is illustrated that HfO2 acts as a passivation layer at the anode/electrolyte interface and prevents structural degradation during charge/discharge process. Moreover, the amorphous nature of HfO2 allows facile diffusion of Na ions. These results clearly show the potential of HfO2 coated MoS2 anodes, which performance is significantly higher than previous reports where bulk MoS2 or composites of MoS2 with carbonaceous materials are used. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Hydrophobic sodium fluoride-based nanocrystals doped with lanthanide ions: assessment of in vitro toxicity to human blood lymphocytes and phagocytes.

    Science.gov (United States)

    Sojka, Bartlomiej; Kuricova, Miroslava; Liskova, Aurelia; Bartusova, Maria; Banski, Mateusz; Misiewicz, Jan; Dusinska, Maria; Horvathova, Mira; Jahnova, Eva; Ilavska, Silvia; Szabova, Michaela; Rollerova, Eva; Podhorodecki, Artur; Tulinska, Jana

    2014-11-01

    In vitro immunotoxicity of hydrophobic sodium fluoride-based nanocrystals (NCs) doped with lanthanide ions was examined in this study. Although there is already a significant amount of optical and structural data on NaYF4 NCs, data on safety assessment are missing. Therefore, peripheral whole blood from human volunteers was used to evaluate the effect of 25 and 30 nm hydrophobic NaYF4 NCs dissolved in cyclohexane (CH) on lymphocytes, and of 10 nm NaYF4 NCs on phagocytes. In the concentration range 0.12-75 µg cm(-2) (0.17-106 µg ml(-1) ), both 25 and 30nm NaYF4 NCs did not induce cytotoxicity when measured as incorporation of [(3) H]-thymidine into DNA. Assessment of lymphocyte function showed significant suppression of the proliferative activity of T-lymphocytes and T-dependent B-cell response in peripheral blood cultures (n = 7) stimulated in vitro with mitogens phytohemagglutinin (PHA) and pokeweed (PWM) (PHA > PWM). No clear dose-response effect was observed. Phagocytic activity and respiratory burst of leukocytes (n = 5-8) were generally less affected. A dose-dependent suppression of phagocytic activity of granulocytes in cultures treated with 25 nm NCs was observed (vs. medium control). A decrease in phagocytic activity of monocytes was found in cells exposed to higher doses of 10 and 30 nm NCs. The respiratory burst of phagocytes was significantly decreased by exposure to the middle dose of 30 nm NCs only. In conclusion, our results demonstrate immunotoxic effects of hydrophobic NaYF4 NCs doped with lanthanide ions to lymphocytes and to lesser extent to phagocytes. Further research needs to be done, particularly faze transfer of hydrophobic NCs to hydrophilic ones, to eliminate the solvent effect.

  14. Ultrafiltration by a compacted clay membrane. I - Oxygen and hydrogen isotopic fractionation. II - Sodium ion exclusion at various ionic strengths.

    Science.gov (United States)

    Coplen, T. B.; Hanshaw, B. B.

    1973-01-01

    Laboratory experiments were carried out to determine the magnitude of the isotopic fractionation of distilled water and of 0.01N NaCl forced to flow at ambient temperature under a hydraulic pressure drop of 100 bars across a montmorillonite disk compacted to a porosity of 35% by a pressure of 330 bars. The ultrafiltrates in both experiments were depleted in D by 2.5% and in O-18 by 0.8% relative to the residual solution. No additional isotopic fractionation due to a salt-filtering mechanism was observed at NaCl concentrations up to 0.01N. Adsorption is most likely the principal mechanism which produces isotopic fractionation, but molecular diffusion may play a minor role. The results suggest that oxygen and hydrogen isotopic fractionation of ground water during passage through compacted clayey sediments should be a common occurrence, in accord with published interpretations of isotopic data from the Illinois and Alberta basins. It is shown how it is possible to proceed from the ion exchange capacity of clay minerals and, by means of the Donnan membrane equilibrium concept and the Teorell-Meyer-Siever theory, develop a theory to explain why and to what extent ultrafiltration occurs when solutions of known concentration are forced to flow through a clay membrane.

  15. Bivalence Mn5O8 with hydroxylated interphase for high-voltage aqueous sodium-ion storage

    Science.gov (United States)

    Shan, Xiaoqiang; Charles, Daniel S.; Lei, Yinkai; Qiao, Ruimin; Wang, Guofeng; Yang, Wanli; Feygenson, Mikhail; Su, Dong; Teng, Xiaowei

    2016-11-01

    Aqueous electrochemical energy storage devices have attracted significant attention owing to their high safety, low cost and environmental friendliness. However, their applications have been limited by a narrow potential window (~1.23 V), beyond which the hydrogen and oxygen evolution reactions occur. Here we report the formation of layered Mn5O8 pseudocapacitor electrode material with a well-ordered hydroxylated interphase. A symmetric full cell using such electrodes demonstrates a stable potential window of 3.0 V in an aqueous electrolyte, as well as high energy and power performance, nearly 100% coulombic efficiency and 85% energy efficiency after 25,000 charge-discharge cycles. The interplay between hydroxylated interphase on the surface and the unique bivalence structure of Mn5O8 suppresses the gas evolution reactions, offers a two-electron charge transfer via Mn2+/Mn4+ redox couple, and provides facile pathway for Na-ion transport via intra-/inter-layer defects of Mn5O8.

  16. Bivalence Mn5O8 with hydroxylated interphase for high-voltage aqueous sodium-ion storage.

    Science.gov (United States)

    Shan, Xiaoqiang; Charles, Daniel S; Lei, Yinkai; Qiao, Ruimin; Wang, Guofeng; Yang, Wanli; Feygenson, Mikhail; Su, Dong; Teng, Xiaowei

    2016-11-15

    Aqueous electrochemical energy storage devices have attracted significant attention owing to their high safety, low cost and environmental friendliness. However, their applications have been limited by a narrow potential window (∼1.23 V), beyond which the hydrogen and oxygen evolution reactions occur. Here we report the formation of layered Mn5O8 pseudocapacitor electrode material with a well-ordered hydroxylated interphase. A symmetric full cell using such electrodes demonstrates a stable potential window of 3.0 V in an aqueous electrolyte, as well as high energy and power performance, nearly 100% coulombic efficiency and 85% energy efficiency after 25,000 charge-discharge cycles. The interplay between hydroxylated interphase on the surface and the unique bivalence structure of Mn5O8 suppresses the gas evolution reactions, offers a two-electron charge transfer via Mn(2+)/Mn(4+) redox couple, and provides facile pathway for Na-ion transport via intra-/inter-layer defects of Mn5O8.

  17. In situ X-ray diffraction characterization of NiSe2 as a promising anode material for sodium ion batteries

    Science.gov (United States)

    Ou, Xing; Li, Jiao; Zheng, Fenghua; Wu, Peng; Pan, Qichang; Xiong, Xunhui; Yang, Chenghao; Liu, Meilin

    2017-03-01

    Reduced graphene oxide (rGO) homogenously wrapped nickel diselenide (NiSe2/rGO) hybrid has been prepared by a facile one-spot hydrothermal method. When investigated as anode material for sodium ion batteries (SIBs), NiSe2/rGO hybrid delivers a high reversible capacity (433 mAh g-1 at 100 mA g-1), superior rate performance (406, 386, 366, 347 and 318 mAh g-1 at 200, 500, 1000, 2000 and 5000 mA g-1, respectively) and excellent cycling stability (a capacity retention of 346 mAh g-1 after 1000 cycles at 1000 mA g-1) within the 0.4-3.0 V voltage range. In situ XRD analysis and ex situ SEM/TEM measurement reveal that the high capacity of NiSe2/rGO is originated from the combined Na+ intercalation and conversion reactions. These results validate the impact of voltage range on electrochemical property, providing a new route to rationalize the limiting factors that affect the performance of NiSe2 anode material. The facile synthesis and superior electrochemical performance of the NiSe2/rGO hybrid render it a promising anode material for SIBs.

  18. Budding willow branches shaped Na3V2(PO4)3/C nanofibers synthesized via an electrospinning technique and used as cathode material for sodium ion batteries

    Science.gov (United States)

    Li, Hui; Bai, Ying; Wu, Feng; Li, Yu; Wu, Chuan

    2015-01-01

    Budding willow branches shaped Na3V2(PO4)3/C nanofibers were successfully synthesized by a simple electrospinning technique with Poly(vinyl pyrrilidone) (PVP). The Na3V2(PO4)3/C nanoparticles that anchored on the nanofibers surface seemed like the willow buds; the inner core of the nanofibers, which composed Na3V2(PO4)3, looked like willow twig and the uniform carbon layer was same with willow bark. Such special morphology played a vital role in improving cycle stability and rate capability of the electrode due to the conductive network built up by nanofibers. The Na3V2(PO4)3/C nanofibers cathode exhibited an initial specific capacity of 106.8 mAh g-1 at a current density of 0.2C, still stabling at 107.2 mAh g-1 after 125 cycles with excellent cycle stability. Moreover, a capacity retention of 95.7% was obtained when Na3V2(PO4)3/C nanofibers cycled stepwise from 0.2 to 2C. Good electrochemical performance should be ascribed to both the special morphology and preferential growth of the (113) plane. The simple synthesis technique and good electrochemical performance suggests that this material with the special shape of budding willow branches is a promising cathode for sodium ion batteries.

  19. Physicochemical studies on ion-pair amphiphiles: Solution and interfacial behaviour of systems derived from sodium dodecylsulfate and -alkyltrimethylammonium bromide homologues

    Indian Academy of Sciences (India)

    Kajari Maiti; Subhash C Bhattacharya; Satya P Moulik; Amiya K Panda

    2010-11-01

    Bulk and interfacial properties of ion-pair amphiphiles (IPA), formed between sodium dodecylsulfate (SDS) and -alkyltrimethylammonium bromide homologues (CTAB; = 10, 12, 14, 16, and 18), have been investigated. Different phases and aggregated states, formed in the ternary combinations of CTAB/SDS/H2O, have been identified and described. Equimolar mixture of IPAs in water yielded precipitates, in the form of coacervates. Aqueous solubility of isolated coacervates in presence and absence of additives like cholesterol and bile salts have been examined. The isolated coacervates have been characterized by 1H NMR, FTIR, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and polarization microscopic measurements. The coacervates have appeared in the shape of needle and complex flower-like aggregates. Surface pressure ()-area (A) isotherm of the coacervates at the air/water interface have been constructed and compared with the lipid 1,2-dipalmitoyl--glycero-3-phosphocholine (DPPC). Morphologies of the IPA monolayers at different surface pressures have been also examined by epifluorescence microscopy. The compressed interfacial monolayers have produced spherical (both regular and irregular) and fern-leaf like domains.

  20. Size-Tunable Olive-Like Anatase TiO2 Coated with Carbon as Superior Anode for Sodium-Ion Batteries.

    Science.gov (United States)

    Chen, Jun; Zhang, Yan; Zou, Guoqiang; Huang, Zhaodong; Li, Simin; Liao, Hanxiao; Wang, Jufeng; Hou, Hongshuai; Ji, Xiaobo

    2016-10-01

    Olive-shaped anatase TiO2 with tunable sizes in nanoscale are designed employing polyvinyl alcohol (PVA) as structure directing agents to exert dramatic impacts on structure shaping and size manipulation. Notably, the introduced PVA simultaneously serves as carbon sources, bringing about a homogenous carbon layer with intimate coupling interfaces for boosted electronic conductivity. Constructed from tiny crystalline grains, the uniformly dispersed carbon-coated TiO2 nano-olives (TOC) possess subtle loose structure internally for prompt Na(+) transportations. When utilized for sodium-ion storage, the size effects are increasingly significant at high charge-discharge rates, leading to the much superior rate performances of TOC with the smallest size. Bestowed by the improved Na(+) adsorption and diffusion kinetics together with the promoted electron transfer, it delivers a high specific capacity of 267 mAh g(-1) at 0.1 C (33.6 mA g(-1) ) and sustains 110 mAh g(-1) at a rather high rate of 20 C. Even after cycled at 10 C over 1000 cycles, a considerable capacity of 125 mAh g(-1) with a retention of 94.6% is still obtained, highlighting its marvelous long-term cyclability and high-rate capabilities. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Physicochemical properties of selectively oxidized 1-monolaurin from 2,2,6,6-tetramethyl-1-piperidinyl oxoammonium ion/sodium hypochlorite-mediated reaction.

    Science.gov (United States)

    Ahn, Seon Min; Lee, Hyong Joo; Kim, Sang Woo; Lee, Jaehwan; Chang, Pahn-Shick

    2009-04-08

    The primary alcohol group of 1-monolaurin (1-ML) was selectively oxidized using 2,2,6,6-tetramethyl-1-piperidine oxoammonium ion/sodium hypochlorite (NaOCl) without NaBr at two different conditions. The selective oxidation occurred more efficiently at 35 degrees C and 32.2 mmol of NaOCl than at 25 degrees C and 18.7 mmol of NaOCl. Regioselective oxidation of the primary alcohol without oxidation of a secondary alcohol was confirmed by a chemical shift at 175 ppm and no resonance between 198 and 205 ppm in (13)C NMR and the presence of a peak at 1560-1570 cm(-1) in IR spectra. The water solubility of oxidized 1-monolaurin (OML) was remarkably increased by 33.2 times as compared to that of 1-ML. Creaming velocities resulting from fat flocculation in a 0.2% level of OML and 1-ML were 0.16 and 1.13 mm/h, respectively, implying that OML showed higher efficiency and emulsion stability in preventing fat flocculation than 1-ML due to the selective oxidation of primary alcohol.

  2. TEM study of green rust sodium sulphate (GR{sub Na,SO4}) interacted with neptunyl ions (NpO{sub 2}{sup +})

    Energy Technology Data Exchange (ETDEWEB)

    Bach, David; Schild, Dieter; Geckeis, Horst [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. for Nuclear Waste Disposal; Christiansen, Bo C. [Copenhagen Univ. (Denmark). Nano-Science Center

    2014-07-01

    Green rust (GR) as sodium sulphate form, NaFe(II){sub 6}Fe(III){sub 3}(OH){sub 18}(SO{sub 4}){sub 2} . 12H{sub 2}O, is reacted with an aqueous solution of neptunyl ions (NpO{sub 2}{sup +}) and the resulting Np(IV) solid phase is investigated at a nanometer scale by different transmission electron microscopy (TEM) techniques, including high-resolution TEM (HRTEM), high-angle annular dark-field scanning TEM (HAADF-STEM), energy-dispersive X-ray spectroscopy (EDXS), and electron energy-loss spectroscopy (EELS). The aim of the analyses is to achieve insight into the potential immobilization mechanism for Np(V) in the context of safety assessment of a nuclear-waste repository. The neptunium is found to be immobilized at the edge of the green rust platelets, in a rim composed of nanocrystallites about 2-3.5 nm in size. The EELS results and more particularly the HRTEM findings are consistent with NpO{sub 2} crystallizing in a fluorite-type structure. Furthermore, the Np-O{sub 4,5} edges recorded by EELS at the Np(IV) phase are presented, expanding the EELS-data set currently available in the literature for Np. (orig.)

  3. Atomically thin Co3O4 nanosheet-coated stainless steel mesh with enhanced capacitive Na+ storage for high-performance sodium-ion batteries

    Science.gov (United States)

    Dou, Yuhai; Wang, Yunxiao; Tian, Dongliang; Xu, Jiantie; Zhang, Zhijia; Liu, Qiannan; Ruan, Boyang; Ma, Jianmin; Sun, Ziqi; Xue Dou, Shi

    2017-03-01

    Capacitive storage (e.g., double layer capacitance and pseudocapacitance) with Na+ stored mainly at the surface or interface of the active materials rather than inserted into the bulk crystal is an effective approach to achieve high rate capability and long cycle life in sodium-ion batteries (SIBs). Herein, atomically thin Co3O4 nanosheets are successfully synthesized and grown directly on the stainless steel mesh as an anode material for SIBs. This anode delivers a high average capacity of 509.2 mAh g-1 for the initial 20 cycles (excluding the first cycle) at 50 mA g-1, presents excellent rate capability with an average capacity of 427.0 mAh g-1 at 500 mA g-1, and exhibits high cycling stability, which significantly outperforms the electrode prepared from conventional Co3O4 nanostructures, the electrode prepared by conventional casting method, and previously reported Co3O4 electrodes. The superior electrochemical performance is mainly attributable to the atomic thickness of the Co3O4 nanosheets and the direct growth method in electrode processing, which lead to remarkably enhanced surface redox pseudocapacitance and interfacial double layer capacitance. This Na+ capacitive storage mechanism provides a promising strategy for the development of electrode materials with high energy and power densities and ultralong cycle life for SIBs.

  4. Graphitic Carbon-Coated FeSe2 Hollow Nanosphere-Decorated Reduced Graphene Oxide Hybrid Nanofibers as an Efficient Anode Material for Sodium Ion Batteries

    Science.gov (United States)

    Cho, Jung Sang; Lee, Jung-Kul; Kang, Yun Chan

    2016-04-01

    A novel one-dimensional nanohybrid comprised of conductive graphitic carbon (GC)-coated hollow FeSe2 nanospheres decorating reduced graphene oxide (rGO) nanofiber (hollow nanosphere FeSe2@GC-rGO) was designed as an efficient anode material for sodium ion batteries and synthesized by introducing the nanoscale Kirkendall effect into the electrospinning method. The electrospun nanofibers transformed into hollow nanosphere FeSe2@GC-rGO hybrid nanofibers through a Fe@GC-rGO intermediate. The discharge capacities of the bare FeSe2 nanofibers, nanorod FeSe2-rGO-amorphous carbon (AC) hybrid nanofibers, and hollow nanosphere FeSe2@GC-rGO hyrbid nanofibers at a current density of 1 A g-1 for the 150th cycle were 63, 302, and 412 mA h g-1, respectively, and their corresponding capacity retentions measured from the 2nd cycle were 11, 73, and 82%, respectively. The hollow nanosphere FeSe2@GC-rGO hybrid nanofibers delivered a high discharge capacity of 352 mA h g-1 even at an extremely high current density of 10 A g-1. The enhanced electrochemical properties of the hollow nanosphere FeSe2@GC-rGO composite nanofibers arose from the synergetic effects of the FeSe2 hollow morphology and highly conductive rGO matrix.

  5. Conversion of uniform graphene oxide/polypyrrole composites into functionalized 3D carbon nanosheet frameworks with superior supercapacitive and sodium-ion storage properties

    Science.gov (United States)

    Wang, Huanwen; Zhang, Yu; Sun, Wenping; Tan, Hui Teng; Franklin, Joseph B.; Guo, Yuanyuan; Fan, Haosen; Ulaganathan, Mani; Wu, Xing-Long; Luo, Zhong-Zhen; Madhavi, Srinivasan; Yan, Qingyu

    2016-03-01

    Two-dimensional (2D) graphene oxide/polypyrrole (GO/PPy) hybrid materials derived from in-situ polymerization are used as precursors for constructing functionalized three-dimensional (3D) porous nitrogen-doped carbon nanosheet frameworks (FT-PNCNFs) through a one-step activation strategy. In the formation process of FT-PNCNFs, PPY is directly converted into hierarchical porous nitrogen-doped carbon layers, while GO is simultaneously reduced to become electrically conductive. The complementary functions of individual components endow the FT-PNCNFs with excellent properties for both supercapacitors (SCs) and sodium ion batteries (SIBs) applications. When tested in symmetrical SC, the FT-PNCNFs demonstrate superior energy storage behaviour. At an extremely high scan rate of 3000 mV s-1, the cyclic voltammetry (CV) curve retains an inspiring quasi-rectangle shape in KOH solution. Meanwhile, high capacitances (∼247 F g-1 at 10 mV s-1; ∼146 F g-1 at 3000 mV s-1) and good cycling stability (∼95% retention after 8000 cycles) are achieved. In addition, an attractive SIB anode performance could be achieved. The FT-PNCNFs electrode delivers a reversible capacity of 187 mAh g-1 during 160th cycle at 100 mA g-1. Its reversible capacity retains 144 mAh g-1 after extending the number of cycles to 500 at 500 mA g-1.

  6. Reduced graphene oxide/carbon nanotubes sponge: A new high capacity and long life anode material for sodium-ion batteries

    Science.gov (United States)

    Yan, Dong; Xu, Xingtao; Lu, Ting; Hu, Bingwen; Chua, Daniel H. C.; Pan, Likun

    2016-06-01

    Reduced graphene oxide/carbon nanotubes (CNTs) sponge (GCNTS) is fabricated via a simple freeze drying of graphene oxide/CNTs mixed solution and subsequent thermal treatment in nitrogen atmosphere, and used as anodes for sodium-ion batteries (SIBs) for the first time. The morphology, structure and electrochemical performance of GCNTS are characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, nitrogen adsorption-desorption isotherms, galvanostatic charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The results show that GCNTS with 20 wt % CNTs has a highest charge capacity of 436 mA h g-1 after 100 cycles at a current density of 50 mA g-1 and even at a high current density of 10 A g-1, a capacity of 195 mA h g-1 is maintained after 7440 cycles. The high capacity, excellent rate performance and long life cycling enable the GCNTS to be a promising candidate for practical SIBs.

  7. Sodium diffusion in boroaluminosilicate glasses

    DEFF Research Database (Denmark)

    Smedskjaer, Morten M.; Zheng, Qiuju; Mauro, John C.

    2011-01-01

    of isothermal sodium diffusion in BAS glasses by ion exchange, inward diffusion, and tracer diffusion experiments. By varying the [SiO2]/[Al2O3] ratio of the glasses, different structural regimes of sodium behavior are accessed. We show that the mobility of the sodium ions decreases with increasing [SiO2]/[Al2O......3] ratio, revealing that sodium is more mobile when it acts as a charge compensator to stabilize network formers than when it acts as a creator of non-bridging oxygens on tetrahedrally-coordinated silicon and trigonal boron. The impacts of both the addition of iron and its redox state on the sodium...... be attributed to the fact that for sodium inward diffusion, the charge compensation for electron holes is a rather slow process that limits the rate of diffusion. (C) 2011 Elsevier B.V. All rights reserved....

  8. Metallic VS2 Monolayer Polytypes as Potential Sodium-Ion Battery Anode via ab Initio Random Structure Searching.

    Science.gov (United States)

    Putungan, Darwin Barayang; Lin, Shi-Hsin; Kuo, Jer-Lai

    2016-07-27

    We systematically investigated the potential of single-layer VS2 polytypes as Na-battery anode materials via density functional theory calculations. We found that sodiation tends to inhibit the 1H-to-1T structural phase transition, in contrast to lithiation-induced transition on monolayer MoS2. Thus, VS2 can have better structural stability in the cycles of charging and discharging. Diffussion of Na atom was found to be very fast on both polytypes, with very small diffusion barriers of 0.085 eV (1H) and 0.088 eV (1T). Ab initio random structure searching was performed in order to explore stable configurations of Na on VS2. Our search found that both the V top and the hexagonal center sites are preferred adsorption sites for Na, with the 1H phase showing a relatively stronger binding. Notably, our random structures search revealed that Na clusters can form as a stacked second layer at full Na concentration, which is not reported in earlier works wherein uniform, single-layer Na adsorption phases were assumed. With reasonably high specific energy capacity (232.91 and 116.45 mAh/g for 1H and 1T phases, respectively) and open-circuit voltage (1.30 and 1.42 V for 1H and 1T phases, respectively), VS2 is a promising alternative material for Na-ion battery anodes with great structural sturdiness. Finally, we have shown the capability of the ab initio random structure searching in the assessment of potential materials for energy storage applications.

  9. Troglitazone induced cytosolic acidification via extracellular signal-response kinase activation and mitochondrial depolarization: complex I proton pumping regulates ammoniagenesis in proximal tubule-like LLC-PK1 cells.

    Science.gov (United States)

    Oliver, Robert; Friday, Ellen; Turturro, Francesco; Welbourne, Tomas

    2008-01-01

    To determined the mechanism(s) through which troglitazone induces cytosolic acidification and glutamine-dependent ammoniagenesis in pig kidney derived LLC-PK1 cells. Acute experiments measured acid extrusion, acid production and simultaneous Extracellular Signal-Regulated Kinase activation. TRO-enhanced acid production was correlated with mitochondrial membrane potential and rotenone and 5-(N-ethyl-N-isopropyl) amiloride, were employed to test specifically the role of Complex I proton pumping. Chronic experiments correlated inhibitors of Complex I with prevention of TRO-increased ammoniagenesis and affects on glutamine metabolism. Exposure to TRO acutely activated Extracellular Signal-Regulated Kinase in a dose dependent manner associated with a fall in spontaneous cytosolic pH. Cytosolic acidosis was associated with both an increase in acid production and inhibition of sodium/hydrogen ion exchanger -mediated acid extrusion. Preventing TRO-induced Extracellular Signal-Regulated Kinase activation with Mitogen Activated Protein Kinase Kinase inhibitors blocked the increase in acid production, restored sodium/hydrogen ion exchanger-activity and prevented cytosolic acidification. Mechanistically, increased acid production was associated with a rapid mitochondrial depolarization and Complex I proton pumping. Blocking Extracellular Signal-Regulated Kinase activation prevented both the fall in Psim and the increased acid production suggesting that the former underlies the accelerated mitochondrial 'acid production'. Mitochondrial Complex I inhibitors EIPA and rotenone prevented increased acid production despite Extracellular Response Kinase activation and reduced sodium/hydrogen ion activity. Inhibition of Complex I prevented TRO's effects on glutamine metabolism. TRO induces cellular acidosis through Extracellular Signal-Regulated Kinase activation-associated acid production and impaired acid extrusion. Acutely, increased acid production reflects mitochondrial Complex I

  10. Synthesis and properties of the metallo-supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]·AgNO3: Ag+/Cu2+ ion exchange and effective antibacterial activity

    KAUST Repository

    Xu, Feng

    2014-01-01

    The commercial polymeric anhydride poly(methyl vinyl ether-alt-maleic anhydride) (PVM/MA) is converted by reaction with NaOH to give poly(methyl vinyl ether-alt-mono-sodium maleate) (PVM/Na-MA). By addition of AgNO 3-solution, the formation of the silver(i) supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]·AgNO 3 is reported. Freeze-dried samples of the hydrogel show a mesoporous network of polycarboxylate ligands that are crosslinked by silver(i) cations. In the intact hydrogel, ion-exchange studies are reported and it is shown that Ag+ ions can be exchanged by copper(ii) cations without disintegration of the hydrogel. The silver(i) hydrogel shows effective antibacterial activity and potential application as burn wound dressing. © the Partner Organisations 2014.

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

    Science.gov (United States)

    Luo, Qingyun; Yu, Bingjun; Liu, Youliang

    2005-09-01

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

  12. Effects of sodium chloride exposure on ion regulation in larvae (glochidia) of the freshwater mussel Lampsilis fasciola.

    Science.gov (United States)

    Nogueira, Lygia S; Bianchini, Adalto; Wood, Chris M; Loro, Vania L; Higgins, Sarah; Gillis, Patricia L

    2015-12-01

    The salinization of freshwater can have negative effects on ecosystem health, with heightened effects in salt-sensitive biota such as glochidia, the larvae of freshwater mussels. However, the toxicological mechanism underlying this sensitivity is unknown. Therefore, Lampsilis fasciola glochidia were exposed to NaCl (nominally 0.25 and 1.0 g/L) prepared in reconstituted moderately-hard water (control), as well as to a dilution of that water (1:4) with ultrapure reference water (diluted control). Unidirectional Na(+) influx (measured with (22)Na) was evaluated after 1, 3 and 48 h of exposure. In addition, unidirectional Cl(-) influx (measured with (36)Cl), whole-body ion (Cl(-) and Na(+)) concentrations, and glochidia viability (measured as the ability to close valves) were assessed after 48 h of exposure. Significantly reduced glochidia viability (56%) was observed after exposure to 1.0 g/L NaCl. Na(+) influx was significantly higher in glochidia exposed to both 0.25 and 1.0 g/L NaCl for 1h than in those kept under control conditions. After 3 and 48 h of exposure, differences in Na(+) influx rate between salt-exposed and control glochidia were generally reduced, indicating that larvae may be able to, at least temporarily, recover their ability to regulate Na(+) influx when exposed to elevated NaCl concentration. Compared to the moderately-hard water control, whole-body Na(+) and Cl(-) concentrations were relatively unchanged in glochidia exposed to 0.25 g/L NaCl, but were significantly elevated in glochidia exposed to 1.0 g/L NaCl and the diluted control. While Na(+) influx rate had recovered to the control level after 48 h of exposure to 1.0 g/L NaCl, Cl(-) influx rate remained elevated, being ~7-fold higher than the Na(+) influx rate. These findings suggest that the loss of viability observed when glochidia were exposed to a high NaCl concentration (1.0 g/L) could be caused by ionoregulatory disturbances mainly associated with an elevated Cl(-) influx.

  13. Vanadium Oxide Nanomaterials for Sodium-Ion Battery%钒氧化物纳米材料在钠离子电池中的应用

    Institute of Scientific and Technical Information of China (English)

    魏湫龙; 蒋周阳; 谭双双; 李启东; 麦立强

    2016-01-01

    Sodium-ion batteries (SIBs) as next-generation energy storage technology, especially for the large scale energy storage systems, have attracted recent attentions due to their abundant resource and low cost of sodium. It is important to develop high performance SIB cathodes and realize safe, efficient and commercialized applications. Vanadium oxides with various valence states, layered structures and compounds with multi-electron reaction exhibit a high storage capacity for SIBs. The design and optimization of vanadium oxide nanostructure can largely improve the electrochemical performance. This review summarizes recent development and their optimization strategies of vanadium oxide nanomaterials for SIBs. Combining with previous work by our group, we discuss the future directions in the application of vanadium oxides for high performance SIBs.%钠离子电池具有资源广、成本低等优势,是新一代储能技术,更是大规模储能的发展前沿与热点。为获得安全、高效、可商业化的钠离子电池,其正极材料的开发是研究者们面临的难题之一。钒氧化物具有多变的价态与化合物,通过多电子反应可获得高的存储容量,丰富的层状结构为高容量的钠离子存储提供了可能。通过对钒氧化物纳米结构的设计与优化可有效改善电极材料的储钠性能。本文主要综述了最近钒氧化物纳米结构的储钠机理与性能优化的研究进展,并结合本课题组的研究工作讨论了相关的发展方向。

  14. High-performance symmetric sodium-ion batteries using a new, bipolar O3-type material, Na 0.8 Ni 0.4 Ti 0.6 O 2

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Shaohua; Yu, Haijun; Liu, Pan; Ren, Yang; Zhang, Tao; Chen, Mingwei; Ishida, Masayoshi; Zhou, Haoshen

    2015-01-01

    Based on low-cost and rich resources, sodium-ion batteries have been regarded as a promising candidate for next-generation energy storage batteries in the large-scale energy applications of renewable energy and smart grids. However, there are some critical drawbacks limiting its application, such as safety and stability problems. In this work, a stable symmetric sodium-ion battery based on the bipolar, active O3-type material, Na0.8Ni0.4Ti0.6O2, is developed. This bipolar material shows a typical O3-type layered structure, containing two electrochemically active transition metals with redox couples of Ni4+/Ni2+ and Ti4+/Ti3+, respectively. This Na0.8Ni0.4Ti0.6O2-based symmetric cell exhibits a high average voltage of 2.8 V, a reversible discharge capacity of 85 mA h g(-1), 75% capacity retention after 150 cycles and good rate capability. This full symmetric cell will greatly contribute to the development of room-temperature sodium-ion batteries with a view towards safety, low cost and long life, and it will stimulate further research on symmetric cells using the same active materials as both cathode and anode.

  15. Sodium Test

    Science.gov (United States)

    ... low levels of cortisol, aldosterone and sex hormones ( Addison disease ) Drinking too much water as might occur during ... urinary sodium levels may indicate diuretic use or Addison disease. Sodium levels are often evaluated in relation to ...

  16. Sodium Phosphate

    Science.gov (United States)

    Sodium phosphate is used in adults 18 years of age or older to empty the colon (large intestine, bowel) ... view of the walls of the colon. Sodium phosphate is in a class of medications called saline ...

  17. Sodium Oxybate

    Science.gov (United States)

    Sodium oxybate is used to prevent attacks of cataplexy (episodes of muscle weakness that begin suddenly and ... urge to sleep during daily activities, and cataplexy). Sodium oxybate is in a class of medications called ...

  18. Determination of lutetium (III) hydrolysis constants in the middle of ion force 1M sodium chloride at 303 K; Determinacion de las constantes de hidrolisis del lutecio (III), en medio de fuerza ionica 1M de cloruro de sodio, a 303 K

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez R, M.; Solache R, M.J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Ramirez G, J.J.; Rojas H, A. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico D.F. (Mexico). Dept. de Quimica

    1997-07-01

    With the purpose to complete information about the lutetium (III) hydrolysis constants here is used the potentiometric method to determine those in the middle of ion force 1M sodium chloride at 303 K. (Author)

  19. Ion Chromatography Determination of Sodium Sulfate in Water Reducing Agent%离子色谱法测定减水剂中硫酸钠含量

    Institute of Scientific and Technical Information of China (English)

    杨学灵; 林瑛

    2012-01-01

    建立了离子色谱法测定减水剂中硫酸钠含量的方法。减水剂试样溶于水中,采用201×7(717)强碱性阴离子交换树脂去除溶液中的有机物,进样量为20μL。在Metrosep A SUPP 5-250型阴离子分离柱上,以3.2mmol/L Na2CO3和1.0mmol/L NaHCO3混合溶液作为淋洗液,抑制型电导检测,以0.6mL/min流量洗脱,按峰面积定量。方法检出限(3S/N)为0.05mg/L。用标准加入法,以实体为基体进行回收试验,测得回收率为96.3%~104.3%。%Ion chromatography was applied to the determination of sodium sulfate (as SO42) in water reducing agent. The water reducing agent was dissolved in water. 201×7(707) strongly basic anion exchange resin was used to remove organic substances from the sample solution. An aliquot (20 μL) of the eluate from 201×7(707) strongly basic anion exchange resin was taken for IC determination. The Metrosep A SUPP 5-250 column was used for separation, 3.2 mmol/L Na2CO3 and 1.0 mmol/L NaHCO3 solutions were used as mobile phase with flow-rate of 0.6 mL/min, and SO42- ion was determined by suppressed conductance detection through measuring values of peak area. Detection limit (3S/D) found was 0.05 mg/L. Values of recovery found by standard addition method were in the range from 96.3%- 104.3%.

  20. Diagnosis of drowning by summation of sodium, potassium and chloride ion levels in pleural effusion: differentiating between freshwater and seawater drowning and application to bathtub deaths.

    Science.gov (United States)

    Yajima, Daisuke; Saito, Hisako; Sato, Kaoru; Hayakawa, Mutsumi; Iwase, Hirotaro

    2013-12-10

    Although electrolyte analysis of pleural effusion at autopsy is useful for the diagnosis of water aspiration (i.e., drowning), the method of comparing each level of sodium (Na(+)), potassium (K(+)), and chloride (Cl(-)) ions does not clearly differentiate between freshwater drowning, seawater drowning, and non-drowning. Therefore, here we introduce the summation of Na(+), K(+), and Cl(-) levels, that is SUM(Na+K+Cl), as a modified diagnostic indicator. In 21 autopsy cases of freshwater drowning, 32 cases of seawater drowning, and 43 non-drowning controls (with pleural effusion), mean SUM(Na+K+Cl) differed significantly between the groups (188.8±33.2, 403.5±107.9, and 239.3±21.7 mEq/L, respectively). We defined a SUM(Na+K+Cl) cut-off value of 282.7 mEq/L as strongly suggestive of seawater aspiration. When these values were applied to the two drowning groups, 15 cases (71%) of freshwater drowning and 29 cases (91%) of seawater drowning were diagnosed correctly. This new approach may be more valid than previous methods in cases found >2 days after death or those with substantial pleural effusion (>100 mL). For an additional 15 bathtub deaths, mean SUM(Na+K+Cl) was 198.8±40.0 mEq/L, and in 14 of these cases (93%) the relationship between cause of death and SUM(Na+K+Cl) could be explained using this method. Forensic pathologists should not depend exclusively on chemical findings and should consider also typical pathological indicators of drowning. This new method may be useful as a supplementary diagnostic tool when used alongside consideration of the pathological findings.

  1. Exfoliated MoS2 Sheets and Reduced Graphene Oxide-An Excellent and Fast Anode for Sodium-ion Battery.

    Science.gov (United States)

    Sahu, Tuhin Subhra; Mitra, Sagar

    2015-07-28

    Three dimensional (3D) MoS2 nanoflowers are successfully synthesized by hydrothermal method. Further, a composite of as prepared MoS2 nanoflowers and rGO is constructed by simple ultrasonic exfoliation technique. The crystallography and morphological studies have been carried out by XRD, FE-SEM, TEM, HR-TEM and EDS etc. Here, XRD study revealed, a composite of exfoliated MoS2 with expanded spacing of (002) crystal plane and rGO can be prepared by simple 40 minute of ultrasonic treatment. While, FE-SEM and TEM studies depict, individual MoS2 nanoflowers with an average diameter of 200 nm are uniformly distributed throughout the rGO surface. When tested as sodium-ion batteries anode material by applying two different potential windows, the composite demonstrates a high reversible specific capacity of 575 mAhg(-1) at 100 mAg(-1) in between 0.01 V-2.6 V and 218 mAhg(-1) at 50 mAg(-1) when discharged in a potential range of 0.4 V-2.6 V. As per our concern, the results are one of the best obtained as compared to the earlier published one on MoS2 based SIB anode material and more importantly this material shows such an excellent reversible Na-storage capacity and good cycling stability without addition of any expensive additive stabilizer, like fluoroethylene carbonate (FEC), in comparison to those in current literature.

  2. Dehydrohalogenation and Dehydration Reactions of i-C3H7Br and i-C3H7OH by Sodium Ions Studied by Guided Ion Beam Techniques and Quantum Chemical Methods.

    Science.gov (United States)

    López, E; Lucas, J M; de Andrés, J; Albertí, M; Bofill, J M; Aguilar, A

    2016-07-14

    Dehydrohalogenation and dehydration reactions of gas-phase i-C3H7Br and i-C3H7OH molecules induced by collision with Na(+), all participants being in their electronic ground state, were studied experimentally in our laboratory using a radiofrequency-guided ion beam apparatus and covering the 0.10-10.00 eV center of mass (CM) energy range. In Na(+) + i-C3H7Br collisions the formation of [C3H6-Na](+) and [HBr-Na](+) by dehydrohalogenation was observed and quantified, as well as that of the ion-molecule adduct [Na-i-C3H7Br](+) together with its decomposition products C3H7(+) and NaBr. In Na(+) + i-C3H7OH collisions the dehydration product [H2O-Na](+) was also found, while [C3H6-Na](+) was hardly detected. Moreover, the [Na-i-C3H7OH](+) adduct formation as well as its decomposition into C3H7(+) and NaOH were also quantified. For all these processes, absolute reaction cross sections were measured as a function of the CM collision energy. From measured excitation functions, rate constants for the formation of [C3H6-Na](+), [HBr-Na](+), and [H2O-Na](+) at 303 K were obtained. Complementing the experiments, exhaustive ab initio structure calculations at the MP2 level of theory were performed, giving information on the most relevant features of the potential energy surfaces (PESs) where the dehydrohalogenation, dehydration, and decomposition reactions take place adiabatically for both collision systems. On these PESs different stationary points associated with potential energy minima and transition state barriers were characterized, and their connectivity was ensured using the intrinsic-reaction-coordinate method. The main topology features of the ab initio calculated PESs allowed a qualitative interpretation of the experimental data also exposing the role of the sodium ion as a catalyst in elimination reactions.

  3. Density functional theory of anode in sodium-ion batteries%钠离子电池负极材料密度泛函理论研究进展

    Institute of Scientific and Technical Information of China (English)

    杨绍斌; 李思南; 孙闻; 董伟; 沈丁

    2016-01-01

    近年来有关钠离子电池的理论计算和实验研究不断增多,其中第一性原理计算的应用及结果引起国内外学者的研究兴趣.综述了密度泛函理论在钠离子电池负极材料中应用的研究进展,主要包括结构模型、电极电势或电池电压、可逆容量、晶格膨胀及其弹性、钠的存在状态、钠离子的扩散行为和电子导电性.随着研究的逐步深入,通过密度泛函理论计算能够给出电极材料可逆储钠性能的系统解释,并在新材料结构和成分设计方面发挥更重要的作用.%In recent years,increasing researches of theoretical calculation and experimental about the sodium ion battery,the application of the first principle calculation and the results have attracted enormous interest of re-searchers.The density functional theory of anode materials in sodium-ion batteries has been reviewed in this pa-per,mainly including structure models of the anode materials,electrode potential or average voltage,reversible capacity,structure expansion and elasticity,existence state of sodium,behavior of ion diffusion and electronic conductivity.With the development of the density functional theory,a systematic explanation of reversible sodi-um storage behavior of the electrode materials will be given and a significant role will be played in design of structure and composition for the new materials.

  4. Chloride binding site of neurotransmitter sodium symporters.

    Science.gov (United States)

    Kantcheva, Adriana K; Quick, Matthias; Shi, Lei; Winther, Anne-Marie Lund; Stolzenberg, Sebastian; Weinstein, Harel; Javitch, Jonathan A; Nissen, Poul

    2013-05-21

    Neurotransmitter:sodium symporters (NSSs) play a critical role in signaling by reuptake of neurotransmitters. Eukaryotic NSSs are chloride-dependent, whereas prokaryotic NSS homologs like LeuT are chloride-independent but contain an acidic residue (Glu290 in LeuT) at a site where eukaryotic NSSs have a serine. The LeuT-E290S mutant displays chloride-dependent activity. We show that, in LeuT-E290S cocrystallized with bromide or chloride, the anion is coordinated by side chain hydroxyls from Tyr47, Ser290, and Thr254 and the side chain amide of Gln250. The bound anion and the nearby sodium ion in the Na1 site organize a connection between their coordinating residues and the extracellular gate of LeuT through a continuous H-bond network. The specific insights from the structures, combined with results from substrate binding studies and molecular dynamics simulations, reveal an anion-dependent occlusion mechanism for NSS and shed light on the functional role of chloride binding.

  5. Nature-Inspired Na2Ti3O7 Nanosheets-Formed Three-Dimensional Microflowers Architecture as a High-Performance Anode Material for Rechargeable Sodium-Ion Batteries.

    Science.gov (United States)

    Anwer, Shoaib; Huang, Yongxin; Liu, Jia; Liu, Jiajia; Xu, Meng; Wang, Ziheng; Chen, Renjie; Zhang, Jiatao; Wu, Feng

    2017-04-05

    Low cycling stability and poor rate performance are two of the distinctive drawbacks of most electrode materials for sodium-ion batteries (SIBs). Here, inspired by natural flower structures, we take advantage of the three-dimensional (3D) hierarchical flower-like stable microstructures formed by two-dimensional (2D) nanosheets to solve these problems. By precise control of the hydrothermal synthesis conditions, a novel three-dimensional (3D) flower-like architecture consisting of 2D Na2Ti3O7 nanosheets (Na-TNSs) has been successfully synthesized. The arbitrarily arranged but closely interlinked thin nanosheets in carnation-shaped 3D Na2Ti3O7 microflowers (Na-TMFs) originate a good network of electrically conductive paths in an electrode. Thus, Na-TMFs can get electrons from all directions and be fully utilized for sodium-ion insertion and extraction reactions, which can improve sodium storage properties with enhanced rate capability and super cycling performance. Furthermore, the large specific surface area provides a high capacity, which can be ascribed to the pseudo-capacitance effect. The wettability of the electrolyte was also improved by the porous and crumpled structure. The remarkably improved cycling performance and rate capability of Na-TMFs make a captivating case for its development as an advanced anode material for SIBs.

  6. 离子色谱法测定食品中防腐剂双乙酸钠的研究%The determination of preservative sodium diacetate in food by ion chromatography

    Institute of Scientific and Technical Information of China (English)

    赵娅鸿

    2011-01-01

    本文采用离子色谱法测定食品中的双乙酸钠含量,实验结果表明,该方法可准确测定食品中的双乙酸钠且有很好的线性关系,相关系数大于99%,最低检出限为 0.01mg/kg,加标回收率在 90.0%~108.0%之间,可用于食品中双乙酸钠的检测.%A new method for the determination of sodium hydrogen in several food by ion chromatography was studied.It is shown that the sodium hydrogen content was in a good linearity(r>99%).The lowest content sodium hydrogen determined was 0.01mg/kg.The recovery rate was 90.0%~108.0%.It can be applied to determine sodium hydrogen content in food.

  7. Skeletal muscle sodium channelopathies.

    Science.gov (United States)

    Nicole, Sophie; Fontaine, Bertrand

    2015-10-01

    This is an update on skeletal muscle sodium channelopathies since knowledge in the field have dramatically increased in the past years. The relationship between two phenotypes and SCN4A has been confirmed with additional cases that remain extremely rare: severe neonatal episodic laryngospasm mimicking encephalopathy, which should be actively searched for since patients respond well to sodium channel blockers; congenital myasthenic syndromes, which have the particularity to be the first recessive Nav1.4 channelopathy. Deep DNA sequencing suggests the contribution of other ion channels in the clinical expressivity of sodium channelopathies, which may be one of the factors modulating the latter. The increased knowledge of channel molecular structure, the quantity of sodium channel blockers, and the availability of preclinical models would permit a most personalized choice of medication for patients suffering from these debilitating neuromuscular diseases. Advances in the understanding of the molecular structure of voltage-gated sodium channels, as well as availability of preclinical models, would lead to improved medical care of patients suffering from skeletal muscle, as well as other sodium channelopathies.

  8. Synthetic ion transporters can induce apoptosis by facilitating chloride anion transport into cells.

    Science.gov (United States)

    Ko, Sung-Kyun; Kim, Sung Kuk; Share, Andrew; Lynch, Vincent M; Park, Jinhong; Namkung, Wan; Van Rossom, Wim; Busschaert, Nathalie; Gale, Philip A; Sessler, Jonathan L; Shin, Injae

    2014-10-01

    Anion transporters based on small molecules have received attention as therapeutic agents because of their potential to disrupt cellular ion homeostasis. However, a direct correlation between a change in cellular chloride anion concentration and cytotoxicity has not been established for synthetic ion carriers. Here we show that two pyridine diamide-strapped calix[4]pyrroles induce coupled chloride anion and sodium cation transport in both liposomal models and cells, and promote cell death by increasing intracellular chloride and sodium ion concentrations. Removing either ion from the extracellular media or blocking natural sodium channels with amiloride prevents this effect. Cell experiments show that the ion transporters induce the sodium chloride influx, which leads to an increased concentration of reactive oxygen species, release of cytochrome c from the mitochondria and apoptosis via caspase activation. However, they do not activate the caspase-independent apoptotic pathway associated with the apoptosis-inducing factor. Ion transporters, therefore, represent an attractive approach for regulating cellular processes that are normally controlled tightly by homeostasis.

  9. Electrochemical properties of a new nanocrystalline NaMn{sub 2}O{sub 4} cathode for rechargeable sodium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Moni Kanchan, E-mail: mkd16@pitt.edu [Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Center for Complex Engineered Multifunctional Materials, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Kuruba, Ramalinga [Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Jampani, Prashanth H. [Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Chung, Sung Jae [Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Saha, Partha [Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Epur, Rigved [Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Kadakia, Karan; Patel, Prasad [Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Gattu, Bharat [Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Manivannan, Ayyakkannu [US Department of Energy, National Energy Technology Laboratory, Morgantown, WV 26507 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Center for Complex Engineered Multifunctional Materials, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); School of Dental Medicine, University of Pittsburgh, PA 15261 (United States)

    2014-10-15

    Highlights: • Nanocrystalline NaMn{sub 2}O{sub 4} exhibiting a new crystalline form has been synthesized by high energy mechanical milling. • Mechanical milling for 20 h directly results in nanocrystalline NaMn{sub 2}O{sub 4}. • Thermally treated oxide shows ∼95 mAh/g capacity in the 2–4.5 V window. • Capacities from ∼75 to 95 mAh/g obtained with varying voltage windows. • Oxide exhibits 0.3%/cycle fade in capacity when cycled in the 2–4 V window. - Abstract: Nanocrystalline NaMn{sub 2}O{sub 4} with a crystallite size of ∼8–10 nm exhibiting a new close packed hexagonal crystalline form, different from the known stable orthorhombic (Pbam or Pmnm symmetry) or monoclinic structures common to the Na–Mn–O system, has been synthesized by a high energy mechano-chemical milling process (HEMM) using Na{sub 2}O{sub 2} and Mn{sub 2}O{sub 3} as starting materials. The newly synthesized structure of NaMn{sub 2}O{sub 4} has been studied as a cathode for sodium ion rechargeable batteries. The HEMM derived NaMn{sub 2}O{sub 4} shows a 1st cycle discharge capacity ∼75 mAh/g, ∼86 mAh/g and ∼95 mAh/g when cycled at a rate of ∼40 mA/g in the potential window ∼2.0–4.0 V, ∼2–4.2 V and ∼2–4.5 V, respectively. The nanostructured NaMn{sub 2}O{sub 4} shows a fade in capacity of 0.3% per cycle and a moderate rate capability when cycled in the potential window 2–4 V. However, electrolyte decomposition occurring during charging of the electrode above ∼3.8 V needs to be resolved in order utilize the full capacity of NaMn{sub 2}O{sub 4} as well as improve the stability of the electrode.

  10. Sodium and Food Sources

    Science.gov (United States)

    ... Sources Top 10 Sources of Sodium How to Reduce Sodium Sodium Reduction Resources for Everyone Sodium Reduction Fact ... in processed food [PDF-867K] and how to reduce sodium. Sodium Reduction Is Challenging Types of food matter: ...

  11. Sodium in diet

    Science.gov (United States)

    Diet - sodium (salt); Hyponatremia - sodium in diet; Hypernatremia - sodium in diet; Heart failure - sodium in diet ... The body uses sodium to control blood pressure and blood volume. Your body also needs sodium for your muscles and nerves to work ...

  12. Sodium Channel (Dys)Function and Cardiac Arrhythmias

    NARCIS (Netherlands)

    C.A. Remme; C.R. Bezzina

    2010-01-01

    P>Cardiac voltage-gated sodium channels are transmembrane proteins located in the cell membrane of cardiomyocytes. Influx of sodium ions through these ion channels is responsible for the initial fast upstroke of the cardiac action potential. This inward sodium current thus triggers the initiation an

  13. Comparison of potassium and sodium binding in vivo and in agarose samples using TQTPPI pulse sequence

    Science.gov (United States)

    Schepkin, Victor D.; Neubauer, Andreas; Nagel, Armin M.; Budinger, Thomas F.

    2017-04-01

    Potassium and sodium specific binding in vivo were explored at 21.1 T by triple quantum (TQ) magnetic resonance (MR) signals without filtration to achieve high sensitivities and precise quantifications. The pulse sequence used time proportional phase increments (TPPI). During simultaneous phase-time increments, it provided total single quantum (SQ) and TQ MR signals in the second dimension at single and triple quantum frequencies, respectively. The detection of both TQ and SQ signals was performed at identical experimental conditions and the resulting TQ signal equals 60 ± 3% of the SQ signal when all ions experience sufficient time for binding. In a rat head in vivo the TQ percentage relative to SQ for potassium is 41.5 ± 3% and for sodium is 16.1 ± 1%. These percentages were compared to the matching values in an agarose tissue model with MR relaxation times similar to those of mammalian brain tissue. The sodium TQ signal in agarose samples decreased in the presence of potassium, suggesting a competitive binding of potassium relative to sodium ions for the same binding sites. The TQTPPI signals correspond to almost two times more effective binding of potassium than sodium. In vivo, up to ∼69% of total potassium and ∼27% of total sodium can be regarded as bound or experiencing an association time in the range of several milliseconds. Experimental data analyses show that more than half of the in vivo total sodium TQ signal could be from extracellular space, which is an important factor for quantification of intracellular MR signals.

  14. Evolutionary primacy of sodium bioenergetics

    Directory of Open Access Journals (Sweden)

    Wolf Yuri I

    2008-04-01

    Full Text Available Abstract Background The F- and V-type ATPases are rotary molecular machines that couple translocation of protons or sodium ions across the membrane to the synthesis or hydrolysis of ATP. Both the F-type (found in most bacteria and eukaryotic mitochondria and chloroplasts and V-type (found in archaea, some bacteria, and eukaryotic vacuoles ATPases can translocate either protons or sodium ions. The prevalent proton-dependent ATPases are generally viewed as the primary form of the enzyme whereas the sodium-translocating ATPases of some prokaryotes are usually construed as an exotic adaptation to survival in extreme environments. Results We combine structural and phylogenetic analyses to clarify the evolutionary relation between the proton- and sodium-translocating ATPases. A comparison of the structures of the membrane-embedded oligomeric proteolipid rings of sodium-dependent F- and V-ATPases reveals nearly identical sets of amino acids involved in sodium binding. We show that the sodium-dependent ATPases are scattered among proton-dependent ATPases in both the F- and the V-branches of the phylogenetic tree. Conclusion Barring convergent emergence of the same set of ligands in several lineages, these findings indicate that the use of sodium gradient for ATP synthesis is the ancestral modality of membrane bioenergetics. Thus, a primitive, sodium-impermeable but proton-permeable cell membrane that harboured a set of sodium-transporting enzymes appears to have been the evolutionary predecessor of the more structurally demanding proton-tight membranes. The use of proton as the coupling ion appears to be a later innovation that emerged on several independent occasions. Reviewers This article was reviewed by J. Peter Gogarten, Martijn A. Huynen, and Igor B. Zhulin. For the full reviews, please go to the Reviewers' comments section.

  15. Layered P2-Na2/3Co1/2Ti1/2O2 as a high-performance cathode material for sodium-ion batteries

    Science.gov (United States)

    Sabi, Noha; Doubaji, Siham; Hashimoto, Kazuki; Komaba, Shinichi; Amine, Khalil; Solhy, Abderrahim; Manoun, Bouchaib; Bilal, Essaid; Saadoune, Ismael

    2017-02-01

    Layered oxides are regarded as promising cathode materials for sodium-ion batteries. We present Na2/3Co1/2Ti1/2O2 as a potential new cathode material for sodium-ion batteries. The crystal features and morphology of the pristine powder were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The cathode material is evaluated in galvanostatic charge-discharge and galvanostatic intermittent titration tests, as well as ex-situ X-ray diffraction analysis. Synthesized by a high-temperature solid state reaction, Na2/3Co1/2Ti1/2O2 crystallizes in P2-type structure with P63/mmc space group. The material presents reversible electrochemical behavior and delivers a specific discharge capacity of 100 mAh g-1 when tested in Na half cells between 2.0 and 4.2 V (vs. Na+/Na), with capacity retention of 98% after 50 cycles. Furthermore, the electrochemical cycling of this titanium-containing material evidenced a reduction of the potential jumps recorded in the NaxCoO2 parent phase, revealing a positive impact of Ti substitution for Co. The ex-situ XRD measurements confirmed the reversibility and stability of the material. No structural changes were observed in the XRD patterns, and the P2-type structure was stable during the charge/discharge process between 2.0 and 4.2 V vs. Na+/Na. These outcomes will contribute to the progress of developing low cost electrode materials for sodium-ion batteries.

  16. Hidden Sodium

    Centers for Disease Control (CDC) Podcasts

    2013-03-04

    In this podcast, learn about reducing sodium intake by knowing what to eat and the main sources of sodium in the diet. It's important for a healthy lifestyle.  Created: 3/4/2013 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 3/4/2013.

  17. Dietary sodium

    DEFF Research Database (Denmark)

    Graudal, Niels

    2015-01-01

    The 2013 Institute of Medicine (IOM) report "Sodium Intake in Populations: Assessment of Evidence" did not support the current recommendations of the IOM and the American Heart Association (AHA) to reduce daily dietary sodium intake to below 2,300 mg. The report concluded that the population...... Control (CDC), other public health advisory bodies, and major medical journals have continued to support the current policy of reducing dietary sodium.......-based health outcome evidence was not sufficient to define a safe upper intake level for sodium. Recent studies have extended this conclusion to show that a sodium intake below 2,300 mg/day is associated with increased mortality. In spite of this increasing body of evidence, the AHA, Centers for Disease...

  18. Gastrointestinal osmoreceptors and renal sodium excretion in humans

    DEFF Research Database (Denmark)

    Andersen, L J; Skram, Thomas Ulrik; Bestle, M H;

    2000-01-01

    The hypothesis that natriuresis can be induced by stimulation of gastrointestinal osmoreceptors was tested in eight supine subjects on constant sodium intake (150 mmol NaCl/day). A sodium load equivalent to the amount contained in 10% of measured extracellular volume was administered by a nasogas......The hypothesis that natriuresis can be induced by stimulation of gastrointestinal osmoreceptors was tested in eight supine subjects on constant sodium intake (150 mmol NaCl/day). A sodium load equivalent to the amount contained in 10% of measured extracellular volume was administered......-angiotensin system....

  19. Cardiac sodium channelopathies.

    Science.gov (United States)

    Amin, Ahmad S; Asghari-Roodsari, Alaleh; Tan, Hanno L

    2010-07-01

    Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (INa) during phase 0 of the cardiac action potential. The importance of INa for normal cardiac electrical activity is reflected by the high incidence of arrhythmias in cardiac sodium channelopathies, i.e., arrhythmogenic diseases in patients with mutations in SCN5A, the gene responsible for the pore-forming ion-conducting alpha-subunit, or in genes that encode the ancillary beta-subunits or regulatory proteins of the cardiac sodium channel. While clinical and genetic studies have laid the foundation for our understanding of cardiac sodium channelopathies by establishing links between arrhythmogenic diseases and mutations in genes that encode various subunits of the cardiac sodium channel, biophysical studies (particularly in heterologous expression systems and transgenic mouse models) have provided insights into the mechanisms by which INa dysfunction causes disease in such channelopathies. It is now recognized that mutations that increase INa delay cardiac repolarization, prolong action potential duration, and cause long QT syndrome, while mutations that reduce INa decrease cardiac excitability, reduce electrical conduction velocity, and induce Brugada syndrome, progressive cardiac conduction disease, sick sinus syndrome, or combinations thereof. Recently, mutation-induced INa dysfunction was also linked to dilated cardiomyopathy, atrial fibrillation, and sudden infant death syndrome. This review describes the structure and function of the cardiac sodium channel and its various subunits, summarizes major cardiac sodium channelopathies and the current knowledge concerning their genetic background and underlying molecular mechanisms, and discusses recent advances in the discovery of mutation-specific therapies in the management of these channelopathies.

  20. Determination of Sodium Chloride Content in Food(Ion chromatography)%食品中氯化钠含量的测定(离子色谱法)

    Institute of Scientific and Technical Information of China (English)

    刘庆

    2012-01-01

    Level of sodium chloride content in food was analyzed by using ion chromatography for the determination of anions in liquid sample.3.2mM Na_2CO_3+1.0mM NaHCO_3 were adopted as eluent solution,20~80mmol/L H_2SO_4 were adopted as suppression solution.Results showed that the detection limit of sodium chloride was 0.01%,the recovery was 95%.The method shows convenience,high accuracy,easy pretreatment,and can satisfy the analysis for sodium chloride in food.%利用离子色谱法测定样液中的阴离子含量,以3.2mM Na_2CO_3+1.0mM NaHCO_3为淋洗液,以20~80mmol/LH_2SO_4为抑制液,分析测定了食品中氯化钠的含量。结果表明,食品中氯化钠的检出限为0.01%,回收率达95%。该方法简便、快速、准确度高、前处理简单、能够满足食品中氯化钠的分析要求。

  1. Adsorption of toxic mercury(II) by an extracellular biopolymer poly(gamma-glutamic acid).

    Science.gov (United States)

    Inbaraj, B Stephen; Wang, J S; Lu, J F; Siao, F Y; Chen, B H

    2009-01-01

    Adsorption of mercury(II) by an extracellular biopolymer, poly(gamma-glutamic acid) (gamma-PGA), was studied as a function of pH, temperature, agitation time, ionic strength, light and heavy metal ions. An appreciable adsorption occurred at pH>3 and reached a maximum at pH 6. Isotherms were well predicted by Redlich-Peterson model with a dominating Freundlich behavior, implying the heterogeneous nature of mercury(II) adsorption. The adsorption followed an exothermic and spontaneous process with increased orderliness at solid/solution interface. The adsorption was rapid with 90% being attained within 5 min for a 80 mg/L mercury(II) solution, and the kinetic data were precisely described by pseudo second order model. Ionic strength due to added sodium salts reduced the mercury(II) binding with the coordinating ligands following the order: Cl(-) >SO(4)(2-) >NO(3)(-). Both light and heavy metal ions decreased mercury(II) binding by gamma-PGA, with calcium(II) ions showing a more pronounced effect than monovalent sodium and potassium ions, while the interfering heavy metal ions followed the order: Cu(2+) > Cd(2+) > Zn(2+). Distilled water adjusted to pH 2 using hydrochloric acid recovered 98.8% of mercury(II), and gamma-PGA reuse for five cycles of operation showed a loss of only 6.5%. IR spectra of gamma-PGA and Hg(II)-gamma-PGA revealed binding of mercury(II) with carboxylate and amide groups on gamma-PGA.

  2. The synthesis of Li(Cosbnd Mnsbnd Ni)O2 cathode material from spent-Li ion batteries and the proof of its functionality in aqueous lithium and sodium electrolytic solutions

    Science.gov (United States)

    Senćanski, Jelena; Bajuk-Bogdanović, Danica; Majstorović, Divna; Tchernychova, Elena; Papan, Jelena; Vujković, Milica

    2017-02-01

    Several spent Li-ion batteries were manually dismantled and their components were uncurled and separated. The chemical composition of each battery's component was determined by atomic absorption spectroscopy. Among several ways to separate cathode material from the collector, the alkali dissolution treatment was selected as the most effective one. After both complete separation and acid leaching steps, the co-precipitation method, followed by a thermal treatment (700 °C or 850 °C), was used to resynthesize cathode material LiCo0.415Mn0.435Ni0.15O2. Its structure and morphology were characterized by XRD, Raman spectroscopy and SEM-EDS methods. The electrochemical behavior of recycled cathode materials was examined by cyclic voltammetry and chronopotentiometry in both LiNO3 and NaNO3 aqueous solutions. High sodium storage capacity, amounting to 93 mAh g-1, was measured galvanostatically at a relatively high current of ∼100 mA g-1. Initial lithium intercalation capacity of ∼64 mAh g-1, was determined potentiodynamically at very high scan rate of 20 mV s-1 (∼40 C). Somewhat lower initial capacity of ∼30 mAh g-1, but much lower capacity fade on cycling, was found for sodium intercalation at the same scan rate. The differences in the Li and Na charge storage capability were explained in terms of ion rearrangement during charging/discharging processes.

  3. A new Ion-exchange Membrane Sodium Hypochlorite Generator for Disinfection in Disaster Areas%一种新型适合灾区消毒的离子膜电解次氯酸钠发生器

    Institute of Scientific and Technical Information of China (English)

    闫冠宇; 刘文朝; 李连香; 李含英

    2015-01-01

    Based on the ion-exchange membrane electrolytic process of chlor-alkali industry ,a new ion-exchange membrane sodium hy-pochlorite generator was developed in this paper .Results indicated that the new generator could produce sodium hypochlorite concen-tration higher than 8% with salt consumption fewer than 2 kilograms per kilogram available chlorine .This generator could solve the problem of chlorine leakage effectively in operation management and also suitable for water and environment disinfection in disaster areas .%借鉴氯碱工业离子膜法电解工艺,研发了一种可现场制备高浓度次氯酸钠溶液的发生器。所研发的次氯酸钠发生器盐耗低于2 kg/kg ,有效氯浓度可达8%,并有效解决了运行管理中氯气泄漏的问题。该次氯酸钠发生器可用于灾区饮用水消毒以及环境消毒,消毒剂按需生产,无需运输和储存,不存在后期处理困难的问题。

  4. Sodium - blood

    Science.gov (United States)

    ... gland problems such as Cushing syndrome or hyperaldosteronism Diabetes insipidus (type of diabetes in which kidneys are not able to conserve water) Too much salt or sodium bicarbonate in the diet Use of certain medicines, including corticosteroids, laxatives, lithium, ...

  5. Effects of valproate sodium on extracellular signal-regulated kinase 1/2 phosphorylation after hippocampal neuronal epileptiform discharge in rats%丙戊酸钠对大鼠海马神经元癫痫样放电后细胞外信号调节激酶磷酸化水平的影响

    Institute of Scientific and Technical Information of China (English)

    徐祖才; 王学峰; 雷显泽; 徐忠祥; 徐平

    2012-01-01

    目的 细胞外信号调节激酶(extracellular signal-regulated kinase 1/2,ERK1/2)参与癫痫的发生,但其与抗癫痫药物之间的关系不明确,文中旨在观察丙戊酸钠对大鼠海马神经元癫痫样放电后磷酸化ERK1/2(p-ERK1/2)的影响.方法 取24h内新生Wistar大鼠,雌雄不拘,迅速断头取脑.建立神经元癫痫样放电模型,将神经元分为空白对照组和丙戊酸钠组,量效实验中,于神经元癫痫样放电前30min时加入不同浓度的丙戊酸钠(50mg/L、75mg/L、100mg/L),运用免疫荧光技术测定p-ERK1/2在不同浓度时的表达;时效实验中,分别于癫痫样放电前30min,放电后0min、30min、2h和6h加入50mg/L丙戊酸钠,采用 Wester blot观察p-ERK1/2的变化.结果 量效实验中,不同浓度的丙戊酸钠均能降低ERK1/2的磷酸化水平,且无显著性差异.时效实验中,于放电前30min时加入丙戊酸钠对ERK1/2的磷酸化水平抑制最明显,与以后各时间点间都有显著性差异.结论 海马神经元癫痫样放电后ERK1/2被过度持久的激活,在早期小剂量有效浓度的丙戊酸钠能显著抑制此反应中ERK1/2的磷酸化水平.%Objective Extracellular signal-regulated kinase l/2(ERKl/2) plays a role in the occurrence of epilepsy , but the mechanism of the involvement of ERK1/2 and its association with antiepileptic drugs remain unclear . The aim of this study is to investi -gate the effects of valproate sodium on ERK 1/2 phosphorylation (p-ERKl/2) after hippocampal neuronal epileptiform discharge in rats. Methods The epileptiform discharge model of the neuron was established in female and male neonate Wistar rats by rapid de -capitation. The neurons were divided into a blank control and a valproate sodium group , the latter incubated with valproate sodium at 50, 75 and 100 mg/L 30 min before epileptiform discharge in the concentration response experiment, and the expression of p-ERKl/2 at different concentrations detected using

  6. Sol-gel synthesis of Na4Fe3(PO4)2(P2O7)/C nanocomposite for sodium ion batteries and new insights into microstructural evolution during sodium extraction

    Science.gov (United States)

    Wu, Xuehang; Zhong, Guiming; Tang, Zheng; Yang, Yong

    2016-09-01

    A mixed polyanionic Na4Fe3(PO4)2(P2O7)/C nanocomposite is synthesized via a sol-gel route. The phosphate raw material is transformed to the mixed phosphate-pyrophosphate with high phase purity via a self-condensation reaction at 500 °C. Na4Fe3(PO4)2(P2O7)/C can deliver an initial capacity of 110 mAh g-1 at 0.05C with the average discharge voltage approaching 3.1 V. The nanocomposite shows excellent rate capability because of the presence of an in-situ formed 3-D network of carbon. At 10 C rate, the nanocomposite delivers a discharge capacity of 78 mAh g-1 at 25 mAh °C and 82 mAh g-1 at 55 °C. The nanocomposite has a good long-term cycling stability, retaining 89% of the initial discharge capacity after 300 cycles. In-situ XRD results demonstrate that the sodium insertion/extraction process in Na4Fe3(PO4)2(P2O7) is an imperfect solid-solution reaction with an obvious local lattice distortion instead of an ideal solid-solution reaction. Using a solid-state NMR technique, it is further found that the sodium extraction from the Na1, Na3, and Na4 sites causes an obvious change in local structure. However, the local structure of Na2 remains unchanged, which may aid the stability of the host structure.

  7. AVL9130与FAT600钾钠氯离子电极仪对比分析%Comparison and analysis of potassium-sodium-chlorine AVL9130 and FAT600 ion electrode analyzer

    Institute of Scientific and Technical Information of China (English)

    许新春; 闫景刚; 王新尧; 董晨宇

    2013-01-01

    Objective: To evaluate the potassium - sodium - chlorine ion detection results obtained by two kinds of electrode analyzer, AVL9130 and FAT600. Methods: The venous blood was collected by coagulant negative pressure tube, then serum was separated by centrifugal machine for synchronic detection by AVL9130 and FAT600 for 20 times to observe the repeated results, including the levels of potassium ion, triglyceride and total protein. Results: By comparison, there was no obvious difference among the levels of potassium, sodium and chlorine in tested serum. While without FAT600 interference, the levels of potassium, sodium and chlorine showed positive correlation. Conclusion: The detection results of potassium, sodium and chlorine by AVL9130 and FAT600 showed positive correlation without obvious difference. Fibrinogen interference and clogging may easily occur with FAT600, so serum separation is very important for FAT600 to get the accuracy detection result.%目的:探讨两种钾钠氯电极仪对血清钾钠氯离子检测结果的评价.方法:用促凝剂负压管采集静脉血液,离心机分离血清,选取混合血清对AVL9130与FAT600两种离子仪平行20次同步检测,观察两者的重复结果.选取560份不同值血清样板(包括不同高低值钾离子、甘油三酯、总蛋白)对两仪器做平行对比观察.结果:两仪器混合血清样本比较,钾钠氯各值均无显著差异,两组不同值血清样本的相关检测排除FAT600干扰后,两组钾钠氯各值呈正相关.结论:两种仪器检测钾钠氯结果均无显著差异并成正相关,FAT600离子仪易发生纤维蛋白原干扰和堵孔,血清分离非常重要,尤其是FAT600对血清分离结果要求更重要.

  8. Fluid and sodium loss in whole-body-irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Geraci, J.P.; Jackson, K.L.; Mariano, M.S.

    1987-09-01

    Whole-body and organ fluid compartment sizes and plasma sodium concentrations were measured in conventional, GI decontaminated, bile duct ligated, and choledochostomized rats at different times after various doses of gamma radiation. In addition, sodium excretion was measured in rats receiving lethal intestinal radiation injury. After doses which were sublethal for 3-5 day intestinal death, transient decreases occurred in all the fluid compartments measured (i.e., total body water, extracellular fluid space, plasma volume). No recovery of these fluid compartments was observed in rats destined to die from intestinal radiation injury. The magnitude of the decreases in fluid compartment sizes was dose dependent and correlated temporally with the breakdown and recovery of the intestinal mucosa but was independent of the presence or absence of enteric bacteria or bile acids. Associated with the loss of fluid was an excess excretion of 0.83 meq of sodium between 48 and 84 h postirradiation. This represents approximately 60% of the sodium lost from the extracellular fluid space in these animals during this time. The remaining extracellular sodium loss was due to redistribution of sodium to other spaces. It is concluded that radiation-induced breakdown of the intestinal mucosa results in lethal losses of fluid and sodium as evidenced by significant decreases in total body water, extracellular fluid space, plasma volume, and plasma sodium concentration, with hemoconcentration. These changes are sufficient to reduce tissue perfusion leading to irreversible hypovolemic shock and death.

  9. Recommendation on mean molar activity coefficients and single ion activity coefficients of solutions for calibration of ion-selective electrodes for sodium, potassium and calcium determination (Reprinted from J Clin Chem Clin Biochem)

    NARCIS (Netherlands)

    Burnett, RW; Covington, AK; FoghAndersen, N; Kulpmann, WR; Maas, AHJ; MullerPlathe, O; SiggaardAndersen, O; VanKessel, A; Wimberley, PD; Zijlstra, WG

    1997-01-01

    In principle, flame photometry measures substance concentration, and ion-selective electrodes (ISEs) measure ion activity. However, the situation regarding the comparison of results from the two techniques when applied to blood plasma is complex. The problem can be approached experimentally from the

  10. The complete targeted profile of the organic acid intermediates of the citric acid cycle using a single stable isotope dilution analysis, sodium borodeuteride reduction and selected ion monitoring GC/MS.

    Science.gov (United States)

    Mamer, Orval; Gravel, Simon-Pierre; Choinière, Luc; Chénard, Valérie; St-Pierre, Julie; Avizonis, Daina

    2013-01-01

    The quantitative profiling of the organic acid intermediates of the citric acid cycle (CAC) presents a challenge due to the lack of commercially available internal standards for all of the organic acid intermediates. We developed an analytical method that enables the quantitation of all the organic acids in the CAC in a single stable isotope dilution GC/MS analysis with deuterium-labeled analogs used as internal standards. The unstable α-keto acids are rapidly reduced with sodium borodeuteride to the corresponding stable α-deutero-α-hydroxy acids and these, along with their unlabeled analogs and other CAC organic acid intermediates, are converted to their tert-butyldimethylsilyl derivatives. Selected ion monitoring is employed with electron ionization. We validated this method by treating an untransformed mouse mammary epithelial cell line with well-known mitochondrial toxins affecting the electron transport chain and ATP synthase, which resulted in profound perturbations of the concentration of CAC intermediates.

  11. 氯化钠对锂离子电池石墨负极的修饰改性%Modification of Graphite Anode for Li-ion Batteries by Sodium Chloride

    Institute of Scientific and Technical Information of China (English)

    周友元; 李新海; 郭华军; 王志兴; 杨勇; 朱文明

    2007-01-01

    The electrochemical performance of a graphite electrode for rechargeable lithium-ion batteries was improved by pretreatment of graphite powders with NaCl aqueous solutions. The procedure of the pretreatment was simple and easy. Graphite powders were dispersed in the aqueous solutions of sodium chloride, followed by stirring, heating and drying. The irreversible capacity at the initial cycle was suppressed by the modification. The sample modified with 1% NaCl had the best electrochemical performances with a reversible capacity of 364.8mAh·g-1, an irreversible capacity of 47.4 mAh·g-1, and an initial coulombic efficiency of 88.5%. The cycling stability of the Li/C cells with modified graphite as anodes was improved. The capacity retention ratio at the 30th cycle was up to 91.97%.

  12. Modifications induced in the structural and optical properties of bismuth sodium borosilicate glass thin films by 120 MeV Ag{sup 7+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Ravneet, E-mail: ravneet_383@yahoo.com [Department of Physics, Guru Nanak Dev University, Amritsar 143 005 (India); Singh, Surinder [Department of Physics, Guru Nanak Dev University, Amritsar 143 005 (India); Pandey, O.P. [School of Physics and Materials Science, Thapar University, Patiala 147 004 (India)

    2013-06-15

    The composition of the glass is Bi{sub 2}O{sub 3} (20%)–Na{sub 2}O (15%)–B{sub 2}O{sub 3} (50%)–SiO{sub 2} (15%) was prepared by conventional melt quench method. To study the effect of heavy ion irradiation on the glass network and structural units, thin films of the glass have been prepared by electron beam gun evaporation. The prepared films are irradiated using 120 MeV Ag{sup 7+} ions in the fluence range of 1 × 10{sup 12}–3 × 10{sup 13} ions cm{sup −2}. The optical and structural properties were investigated using UV–visible absorption spectroscopy and Fourier Transform Infrared (FTIR) spectroscopic techniques. A significant decrease in the band gap is observed after irradiation which is indicative of the fact that radiation has caused compaction in the glass structure.

  13. 离子膜法电解次氯酸钠发生方法运行效果试验研究%Research on the Operation Results of Ion-exchange Membrane Electrolytic Sodium Hypochlorite Generation Method

    Institute of Scientific and Technical Information of China (English)

    贾燕南; 鄢元波; 丁昆仑; 孙文海

    2016-01-01

    In this paper,laboratory tests are done under realizable operation conditions to observe the operation effects of membrane electrolytic sodium hypochlorite generation device,from three aspects:membrane material,the brine quality into the anode,the wa-ter quality into the cathode.At the same time,the effects on the operation results are studied whether the electrolyte is heated or not.Then,the current efficiency of the ion-exchange membrane cell changes over time is monitored.The results show that ion-ex-change membrane electrolytic sodium hypochlorite generation method has a good performance in chlorine concentration,salt con-sumption and power consumption.If the ion-exchange membrane recovering from the chlor-alkali industry is used,the ordinary brine water and tap water are respectively used as the anolyte and catholyte,the electrolysis performance does not change significantly. However,in the long-term operation,electrolyzer should be heated and pure water should be used as catholyte.At the same time, the ion-exchange membrane should be replaced at regular intervals.%通过实验室内测试研究了不同离子膜材料、阳(阴)极电解液质量以及电解液加热与否等多种运行条件下离子膜电解次氯酸钠装置的短期电解性能,并研究对比了3种运行条件下电解装置的长期运行效果。结果表明,离子膜法电解次氯酸钠发生方法在有效氯浓度、盐耗、电耗方面性能优异,采用氯碱行业回收离子膜,普通食盐水和自来水分别作为阳极液和阴极液情况下,电解性能并未发生显著变化;但长期运行时,建议阴极采用纯水,并对电解槽或电解液进行加热,同时需定期更换离子膜。

  14. Graphene-Wrapped Anatase TiO2 Nanofibers as High-Rate and Long-Cycle-Life Anode Material for Sodium Ion Batteries

    Science.gov (United States)

    Yeo, Yeolmae; Jung, Ji-Won; Park, Kyusung; Kim, Il-Doo

    2015-09-01

    Anatase TiO2 has been suggested as a potential sodium anode material, but the low electrical conductivity of TiO2 often limits the rate capability, resulting in poor electrochemical properties. To address this limitation, we propose graphene-wrapped anatase TiO2 nanofibers (rGO@TiO2 NFs) through an effective wrapping of reduced graphene oxide (rGO) sheets on electrospun TiO2 NFs. To provide strong electrostatic interaction between the graphene oxide (GO) sheets and the TiO2 NFs, poly(allylamine hydrochloride) (PAH) was used to induce a positively charged TiO2 surface by the immobilization of the -NH3+ group and to promote bonding with the negatively charged carboxylic acid (-COO-) and hydroxyl (-O-) groups on the GO. A sodium anode electrode using rGO@TiO2 NFs exhibited a significantly improved initial capacity of 217 mAh g-1, high capacity retention (85% after 200 cycles at 0.2C), and a high average Coulombic efficiency (99.7% from the second cycle to the 200th cycle), even at a 5C rate, compared to those of pristine TiO2 NFs. The improved electrochemical performances stem from highly conductive properties of the reduced GO which is effectively anchored to the TiO2 NFs.

  15. 离子色谱法测定食品中甜蜜素含量的研究%Study on Determination of the Content of Sodium CycIamate in Food by Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    辛若竹; 康鑫琦

    2015-01-01

    目的:建立离子色谱法测定食品中甜蜜素含量的分析方法。方法:不同基质的样品经相应方法提取和净化后,以 Dionex IonPacTMAS19(4 mm×250 mm)为分析柱,Dionex IonPacTMAG19(4 mm×50 mm)为保护柱,自动在线淋洗液发生器产生的高纯氢氧化钾溶液为淋洗液进行梯度淋洗,电导检测器检测,外标法定量。结果:该方法在0.50~10.0μg/mL 浓度有良好的线性关系,相关系数 r2为0.9997;不同种类食品中甜蜜素的加标回收率在92.7%~105.6%,相对标准偏差在0.08%~1.68%,方法检出限为0.15 mg/kg ,方法定量限为0.5 mg/kg。结论:该方法具有简便、快速、准确、灵敏度高、实用性强等优点,可用于固体、液体等不同形态不同基质食品中甜蜜素测定。%Obj ect:A method is developed for the determination of the content of sodium cyclamate in food by ion chromatography.Method:Samples of different matrix after corresponding extraction and purification methods,use Dionex IonPacTM AS19 (4 mm × 250 mm)as analytical column,Dionex IonPacTMAG19 (4 mm × 50 mm)as guard column,automatic on-line eluent generator to produce high-purity potassium hydroxide solution as eluent for gradient elution,conductance detector for detection and external standard method for quantitative analysis.Result:This method has a great linear relationship in the concentration range of 0.50~10.0μg/mL,the correlation coefficient r2 is 0.9997;the standard addition recoveries of sodium cyclamate in different kinds of foods are between 92.7%~105.6%,the relative standard deviations are in the range of 0.08%~1.68%,the method detection limit is 0.15 mg/kg,and the method quantitative limit is 0.5 mg/kg.Conclusion:This method is simple,rapid,accurate,with high sensitivity,strong practicability,etc.,it can be used to determine the content of sodium cyclamate in solid,liquid and other different morphological matrix of

  16. EFFECTS OF THE SODIUM-CHANNEL BLOCKER TETRODOTOXIN (TTX) ON CELLULAR ION HOMEOSTASIS IN RAT-BRAIN SUBJECTED TO COMPLETE ISCHEMIA

    NARCIS (Netherlands)

    XIE, YX; DENGLER, K; ZACHARIAS, E; WILFFERT, B; TEGTMEIER, F

    1994-01-01

    Anoxic depolarization (AD) and failure of the cellular ion homeostasis are suggested to play a key role in ischemia-induced neuronal death. Recent studies show that the blockade of Na+ influx significantly improved the neuronal outcome. In the present study, we investigated the effects of 10 mu M te

  17. Simultaneous determination of free calcium, magnesium, sodium and potassium ion concentrations in simulated milk ultrafiltrate and reconstituted skim milk using the Donnan Membrane Technique

    NARCIS (Netherlands)

    Gao, R.; Temminghoff, E.J.M.; Leeuwen, van H.P.; Valenberg, van H.J.F.; Eisner, M.D.; Boekel, van M.A.J.S.

    2009-01-01

    This study focused on determination of free Ca2+, Mg2+, Na+ and K+ concentrations in a series of CaCl2 solutions, simulated milk ultrafiltrate and reconstituted skim milk using a recently developed Donnan Membrane Technique (DMT). A calcium ion selective electrode was used to compare the DMT results

  18. Test Your Sodium Smarts

    Science.gov (United States)

    ... You may be surprised to learn how much sodium is in many foods. Sodium, including sodium chloride ... foods with little or no salt. Test your sodium smarts by answering these 10 questions about which ...

  19. NaF-M (M = Fe, Cu) Nanocomposites as Conversion Cathode Materials for Sodium Ion Batteries%NaF—M(M=Fe,Cu)钠离子电池转换正极材料的研究

    Institute of Scientific and Technical Information of China (English)

    李婷; 陈重学; 曹余良; 杨汉西

    2012-01-01

    NaF-M (M=Fe, Cu) nanocomposites were prepared by high-energy ball milling using TiN grind- ing nanoparticles and investigated as cathode materials for sodium ion batteries. The experimental results dem-onstrated that NaF-Fe and NaF-Cu nanocomposites can go through electrochemical conversion reaction with Na ^+ uptake or removal, delivering a reversible capacity of- 150 mAh·g^-1, even through a reversed conver-sion from initial discharged state to a charged state. These results reveal the possibility to realize a conversion reaction as long as NaF and elemental metal particles are intimately contacted to form active nanocomposites at nanodomain, which suggests a potential feasibility to use these nanocomposites as sodium-rich cathode materi-als for sodium ion batteries.%以纳米TiN为研磨剂,采用机械球磨技术制备了NaF—M(M=Fe,Cu)纳米复合物,探索了这类复合物作为钠离子电池转换正极材料的可能性.电化学测试表明,NaF—Fe和NaF—Cu纳米复合物电极在钠离子电解液中能实现与Na^+的逆向转换反应,其可逆放电容量达150mAh·g^-1以上,并具有较好的循环寿命.只要创造了适合相转变反应进行的微区结构,钠离子的转换反应也可以通过可逆的电化学转换反应实现,并从起始的富钠放电态直接充电至贫钠的荷电态.本工作为开发高容量钠离子电池正极材料提供了新途径.

  20. Extracellular Gd-CA

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Marckmann, Peter

    2008-01-01

    Until recently it was believed that extracellular gadolinium-based contrast agents were safe for both the kidneys and all other organs within the dose range up to 0.3 mmol/kg body weight. However, in 2006, it was demonstrated that some gadolinium-based contrast agents may trig the development of ...

  1. Low sodium diet (image)

    Science.gov (United States)

    ... for you. Look for these words on labels: low-sodium, sodium-free, no salt added, sodium-reduced, or ... for you. Look for these words on labels: low-sodium, sodium-free, no salt added, sodium-reduced, or ...

  2. Kinetics of wet sodium vapor complex plasma

    Science.gov (United States)

    Mishra, S. K.; Sodha, M. S.

    2014-04-01

    In this paper, we have investigated the kinetics of wet (partially condensed) Sodium vapor, which comprises of electrons, ions, neutral atoms, and Sodium droplets (i) in thermal equilibrium and (ii) when irradiated by light. The formulation includes the balance of charge over the droplets, number balance of the plasma constituents, and energy balance of the electrons. In order to evaluate the droplet charge, a phenomenon for de-charging of the droplets, viz., evaporation of positive Sodium ions from the surface has been considered in addition to electron emission and electron/ion accretion. The analysis has been utilized to evaluate the steady state parameters of such complex plasmas (i) in thermal equilibrium and (ii) when irradiated; the results have been graphically illustrated. As a significant outcome irradiated, Sodium droplets are seen to acquire large positive potential, with consequent enhancement in the electron density.

  3. Crystal structure of the sodium-potassium pump

    DEFF Research Database (Denmark)

    Morth, J Preben; Pedersen, Bjørn Panyella; Toustrup-Jensen, Mads S;

    2007-01-01

    The Na+,K+-ATPase generates electrochemical gradients for sodium and potassium that are vital to animal cells, exchanging three sodium ions for two potassium ions across the plasma membrane during each cycle of ATP hydrolysis. Here we present the X-ray crystal structure at 3.5 A resolution of the...

  4. First Introduction of NiSe2 to Anode Material for Sodium-Ion Batteries: A Hybrid of Graphene-Wrapped NiSe2/C Porous Nanofiber

    Science.gov (United States)

    Cho, Jung Sang; Lee, Seung Yeon; Kang, Yun Chan

    2016-03-01

    The first-ever study of nickel selenide materials as efficient anode materials for Na-ion rechargeable batteries is conducted using the electrospinning process. NiSe2-reduced graphene oxide (rGO)-C composite nanofibers are successfully prepared via electrospinning and a subsequent selenization process. The electrospun nanofibers giving rise to these porous-structured composite nanofibers with optimum amount of amorphous C are obtained from the polystyrene to polyacrylonitrile ratio of 1/4. These composite nanofibers also consist of uniformly distributed single-crystalline NiSe2 nanocrystals that have a mean size of 27 nm. In contrast, the densely structured bare NiSe2 nanofibers formed via selenization of the pure NiO nanofibers consist of large crystallites. The initial discharge capacities of the NiSe2-rGO-C composite and bare NiSe2 nanofibers at a current density of 200 mA g-1 are 717 and 755 mA h g-1, respectively. However, the respective 100th-cycle discharge capacities of the former and latter are 468 and 35 mA h g-1. Electrochemical impedance spectroscopy measurements reveal the structural stability of the composite nanofibers during repeated Na-ion insertion and extraction processes. The excellent Na-ion storage properties of these nanofibers are attributed to this structural stability.

  5. Extracellular electron transfer mechanisms between microorganisms and minerals

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Liang; Dong, Hailiang; Reguera, Gemma; Beyenal, Haluk; Lu, Anhuai; Liu, Juan; Yu, Han-Qing; Fredrickson, James K.

    2016-08-30

    Electrons can be transferred from microorganisms to multivalent metal ions that are associated with minerals and vice versa. As the microbial cell envelope is neither physically permeable to minerals nor electrically conductive, microorganisms have evolved strategies to exchange electrons with extracellular minerals. In this Review, we discuss the molecular mechanisms that underlie the ability of microorganisms to exchange electrons, such as c-type cytochromes and microbial nanowires, with extracellular minerals and with microorganisms of the same or different species. Microorganisms that have extracellular electron transfer capability can be used for biotechnological applications, including bioremediation, biomining and the production of biofuels and nanomaterials.

  6. Sodium-ion storage properties of nickel sulfide hollow nanospheres/reduced graphene oxide composite powders prepared by a spray drying process and the nanoscale Kirkendall effect

    Science.gov (United States)

    Park, G. D.; Cho, J. S.; Kang, Y. C.

    2015-10-01

    Spray-drying and the nanoscale Kirkendall diffusion process are used to prepare nickel sulfide hollow nanospheres/reduced graphene oxide (rGO) composite powders with excellent Na-ion storage properties. Metallic Ni nanopowder-decorated rGO powders, formed as intermediate products, are transformed into composite powders of nickel sulfide hollow nanospheres/rGO with mixed crystal structures of Ni3S2 and Ni9S8 phases by the sulfidation process under H2S gas. Nickel sulfide/rGO composite powders with the main crystal structure of Ni3S2 are also prepared as comparison samples by the direct sulfidation of nickel acetate-graphene oxide (GO) composite powders obtained by spray-drying. In electrochemical properties, the discharge capacities at the 150th cycle of the nickel sulfide/rGO composite powders prepared by sulfidation of the Ni/rGO composite and nickel acetate/GO composite powders at a current density of 0.3 A g-1 are 449 and 363 mA h g-1, respectively; their capacity retentions, calculated from the tenth cycle, are 100 and 87%. The nickel sulfide hollow nanospheres/rGO composite powders possess structural stability over repeated Na-ion insertion and extraction processes, and also show excellent rate performance for Na-ion storage.Spray-drying and the nanoscale Kirkendall diffusion process are used to prepare nickel sulfide hollow nanospheres/reduced graphene oxide (rGO) composite powders with excellent Na-ion storage properties. Metallic Ni nanopowder-decorated rGO powders, formed as intermediate products, are transformed into composite powders of nickel sulfide hollow nanospheres/rGO with mixed crystal structures of Ni3S2 and Ni9S8 phases by the sulfidation process under H2S gas. Nickel sulfide/rGO composite powders with the main crystal structure of Ni3S2 are also prepared as comparison samples by the direct sulfidation of nickel acetate-graphene oxide (GO) composite powders obtained by spray-drying. In electrochemical properties, the discharge capacities at the

  7. One-step hydrothermal synthesis and electrochemical performance of sodium-manganese-iron phosphate as cathode material for Li-ion batteries

    Science.gov (United States)

    Karegeya, Claude; Mahmoud, Abdelfattah; Vertruyen, Bénédicte; Hatert, Frédéric; Hermann, Raphaël P.; Cloots, Rudi; Boschini, Frédéric

    2017-09-01

    The sodium-manganese-iron phosphate Na2Mn1.5Fe1.5(PO4)3 (NMFP) with alluaudite structure was obtained by a one-step hydrothermal synthesis route. The physical properties and structure of this material were obtained through XRD and Mössbauer analyses. X-ray diffraction Rietveld refinements confirm a cationic distribution of Na+ and presence of vacancies in A(2)', Na+ and small amounts of Mn2+ in A(1), Mn2+ in M(1), 0.5 Mn2+ and Fe cations (Mn2+,Fe2+ and Fe3+) in M(2), leading to the structural formula Na2Mn(Mn0.5Fe1.5)(PO4)3. The particles morphology was investigated by SEM. Several reactions with different hydrothermal reaction times were attempted to design a suitable synthesis protocol of NMFP compound. The time of reaction was varied from 6 to 48 h at 220 °C. The pure phase of NMFP particles was firstly obtained when the hydrothermal reaction of NMFP precursors mixture was maintained at 220 °C for 6 h. When the reaction time was increased from 6 to 12, 24 and 48 h, the dandelion structure was destroyed in favor of NMFP micro-rods. The combination of NMFP (NMFP-6H, NMFP-12H, NMFP-24H and NMFP-48H) structure refinement and Mössbauer characterizations shows that the increase of the reaction time leads to the progressive increment of Fe(III) and the decrease of the crystal size. The electrochemical tests indicated that NMFP is a 3 V sodium intercalating cathode. The comparison of the discharge capacity evolution of studied NMFP electrode materials at C/5 current density shows different capacities of 48, 40, 34 and 34 mA h g-1 for NMFP-6H, NMFP-12H, NMFP-24H and NMFP-48H respectively. Interestingly, all samples show excellent capacity retention of about 99% during 50 cycles.

  8. Purification and characterization of a thermostable extracellular phytase from Bacillus licheniformis PFBL-03.

    Science.gov (United States)

    Fasimoye, Feyisola O; Olajuyigbe, Folasade M; Sanni, Morakinyo D

    2014-01-01

    Extracellular phytase from Bacillus licheniformis PFBL-03 was purified in three steps by using ammonium sulfate precipitation, ion-exchange chromatography on a DEAE Sephadex A-50 column, and gel filtration chromatography on Sephadex G-100. The single protein band on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) suggested that the enzyme was homogeneous. The molecular mass determined from SDS-PAGE was 36 kD. The enzyme yield was 10% while the purification fold was 39. The purified phytase exhibited optimum activity at 55°C and was able to retain 55% of its original activity after 60 min of incubation at 80°C. The purified enzyme had optimum pH of 6.0 and was stable over a pH range of 4.0 to 7.5. The kinetic parameters K(m) and V(max) of the purified phytase for sodium phytate were 4.7 mM and 49.01 µmol/min. The activity of the enzyme was enhanced in the presence of Ca²⁺ but completely inhibited by Fe²⁺, Mn²⁺, and Cu²⁺. The exhibited characteristics of the purified phytase from Bacillus licheniformis PFBL-03 show that the enzyme has potential for applications in the animal feed industry.

  9. Nanosized Na{sub 4}Fe(CN){sub 6}/C composite as a low-cost and high-rate cathode material for sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Jianfeng; Zhou, Min; Cao, Yuliang; Ai, Xinping; Yang, Hanxi [Hubei Key Laboratory of Electrochemical Power Sources, College of Chemistry and Molecular Science, Wuhan University (China)

    2012-04-15

    A Na{sub 4}Fe(CN){sub 6}/C nanocomposite prepared simply by ball-milling Na{sub 4}Fe(CN){sub 6} with carbon powder displays a full utilization of its one-electron redox capacity, excellent cyclability, and high rate capability as a Na-storage cathode, offering a promising possibility to develop environmentally benign and low-cost Na ion batteries for large-scale electric storage applications. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Microseconds simulations reveal a new sodium-binding site and the mechanism of sodium-coupled substrate uptake by LeuT.

    Science.gov (United States)

    Zomot, Elia; Gur, Mert; Bahar, Ivet

    2015-01-02

    The bacterial sodium-coupled leucine/alanine transporter LeuT is broadly used as a model system for studying the transport mechanism of neurotransmitters because of its structural and functional homology to mammalian transporters such as serotonin, dopamine, or norepinephrine transporters, and because of the resolution of its structure in different states. Although the binding sites (S1 for substrate, and Na1 and Na2 for two co-transported sodium ions) have been resolved, we still lack a mechanistic understanding of coupled Na(+)- and substrate-binding events. We present here results from extensive (>20 μs) unbiased molecular dynamics simulations generated using the latest computing technology. Simulations show that sodium binds initially the Na1 site, but not Na2, and, consistently, sodium unbinding/escape to the extracellular (EC) region first takes place at Na2, succeeded by Na1. Na2 diffusion back to the EC medium requires prior dissociation of substrate from S1. Significantly, Na(+) binding (and unbinding) consistently involves a transient binding to a newly discovered site, Na1″, near S1, as an intermediate state. A robust sequence of substrate uptake events coupled to sodium bindings and translocations between those sites assisted by hydration emerges from the simulations: (i) bindings of a first Na(+) to Na1″, translocation to Na1, a second Na(+) to vacated Na1″ and then to Na2, and substrate to S1; (ii) rotation of Phe(253) aromatic group to seclude the substrate from the EC region; and (iii) concerted tilting of TM1b and TM6a toward TM3 and TM8 to close the EC vestibule.

  11. A recombinant fusion protein containing a spider toxin specific for the insect voltage-gated sodium ion channel shows oral toxicity towards insects of different orders.

    Science.gov (United States)

    Yang, Sheng; Pyati, Prashant; Fitches, Elaine; Gatehouse, John A

    2014-04-01

    Recombinant fusion protein technology allows specific insecticidal protein and peptide toxins to display activity in orally-delivered biopesticides. The spider venom peptide δ-amaurobitoxin-PI1a, which targets insect voltage-gated sodium channels, was fused to the "carrier" snowdrop lectin (GNA) to confer oral toxicity. The toxin itself (PI1a) and an amaurobitoxin/GNA fusion protein (PI1a/GNA) were produced using the yeast Pichia pastoris as expression host. Although both proteins caused mortality when injected into cabbage moth (Mamestra brassicae) larvae, the PI1a/GNA fusion was approximately 6 times as effective as recombinant PI1a on a molar basis. PI1a alone was not orally active against cabbage moth larvae, but a single 30 μg dose of the PI1a/GNA fusion protein caused 100% larval mortality within 6 days when fed to 3rd instar larvae, and caused significant reductions in survival, growth and feeding in 4th - 6th instar larvae. Transport of fusion protein from gut contents to the haemolymph of cabbage moth larvae, and binding to the nerve chord, was shown by Western blotting. The PI1a/GNA fusion protein also caused mortality when delivered orally to dipteran (Musca domestica; housefly) and hemipteran (Acyrthosiphon pisum; pea aphid) insects, making it a promising candidate for development as a biopesticide.

  12. Comparison of adsorption equilibrium of fructose, glucose and sucrose on potassium gel-type and macroporous sodium ion-exchange resins.

    Science.gov (United States)

    Nobre, C; Santos, M J; Dominguez, A; Torres, D; Rocha, O; Peres, A M; Rocha, I; Ferreira, E C; Teixeira, J A; Rodrigues, L R

    2009-11-03

    Adsorption equilibrium of fructose, glucose and sucrose was evaluated on sulfonated poly(styrene-co-divinylbenzene) cation-exchange resins. Two types of resins were used: potassium (K+) gel-type and sodium (Na+) macroporous resins. Influence of the cation and effect of the resin structure on adsorption were studied. The adsorption isotherms were determined by the static method in batch mode for mono-component and multi-component sugar mixtures, at 25 and 40 degrees C, in a range of concentrations between 5 and 250 g L(-1). All adsorption isotherms were fitted by a linear model in this range of concentrations. Sugars were adsorbed in both resins by the following order: fructose > glucose > sucrose. Sucrose was more adsorbed in the Na+ macroporous resin, glucose was identically adsorbed, and fructose was more adsorbed in the K+ gel-type resin. Data obtained from the adsorption of multi-component mixtures as compared to the mono-component ones showed a competitive effect on the adsorption at 25 degrees C, and a synergetic effect at 40 degrees C. The temperature increase conducted to a decrease on the adsorption capacity for mono-component sugar mixtures, and to an increase for the multi-component mixtures. Based on the selectivity results, K+ gel-type resin seems to be the best choice for the separation of fructose, glucose and sucrose, at 25 degrees C.

  13. Clinical experience with pegaptanib sodium

    Directory of Open Access Journals (Sweden)

    Chiara Rosina

    2008-10-01

    Full Text Available Chiara Rosina, Ferdinando Bottoni, Giovanni StaurenghiLuigi Sacco Hospital, University of Milano, ItalyAbstract: Pegaptanib sodium (Macugen® blocks the extracellular vascular endothelial growth factor (VEGF isoform VEGF165, whose elevated levels are associated with the development of choroidal neovascularization (CNV. This selective inhibition prevents binding to the VEGF receptors and the development of the increased vascular permeability and the CNV associated with neovascular age-related degeneration (AMD. The VEGF Inhibition Study In Ocular Neovascularization (VISION demonstrated that pegaptanib sodium confers clinically meaningful benefit in the treatment of all angiographic subtypes of neovascular AMD. It also has a favorable safety profile after 1 and 2 years of continuous treatment, and recent data suggest that the agent has a disease-modifying effect. Post hoc analysis of VISION suggests that treatment benefit may be greatest in patients with early lesions, in whom 80% achieved the primary endpoint of <15 letters lost, 47% maintained visual acuity (VA, and 20% gained ≥15 letters of vision. Similarly, our own clinical experience indicates that pegaptanib sodium achieves better outcomes in early lesions than in established lesions, particularly in patients with previously untreated minimally classic and occult lesions in whom VA improvement and lesion size stabilization has been recorded. Observations indicate that pegaptanib sodium has a slower mode of action than unselective VEGF inhibitors, resulting in an average of 3–4 injections being required to stabilize VA and lesion size. Pegaptanib sodium has good efficacy and safety profiles and represents a good treatment option for patients with early CNV membranes associated with neovascular AMD.Keywords: vascular endothelial growth factor (VEGF, choroidal neovasularization (CNV, age-related macular degeneration (AMD, pegaptanib sodium, early lesions, visual acuity (VA

  14. Electrospun TiO2/C Nanofibers As a High-Capacity and Cycle-Stable Anode for Sodium-Ion Batteries.

    Science.gov (United States)

    Xiong, Ya; Qian, Jiangfeng; Cao, Yuliang; Ai, Xinping; Yang, Hanxi

    2016-07-06

    Nanosized TiO2 is now actively developed as a low-cost and potentially high capacity anode material of Na-ion batteries, but its poor capacity utilization and insufficient cyclability remains an obstacle for battery applications. To overcome these drawbacks, we synthesized electrospun TiO2/C nanofibers, where anatase TiO2 nanocrystals with a diameter of ∼12 nm were densely embedded in the conductive carbon fibers, thus preventing them from aggregating and attacking by electrolyte. Due to its abundant active surfaces of well-dispersed TiO2 nanocrytals and high electronic conductivity of the carbon matrix, the TiO2/C anode shows a high redox capacity of ∼302.4 mA h g(-1) and a high-rate capability of 164.9 mAh g(-1) at a very high current of 2000 mA g(-1). More significantly, this TiO2/C anode can be cycled with nearly 100% capacity retention over 1000 cycles, showing a sufficiently long cycle life for battery applications. The nanofibrous architecture of the TiO2/C composite and its superior electrochemical performance may provide new insights for development of better host materials for practical Na-ion batteries.

  15. Influence of Sodium Ion Concentration in Dialysate on Blood Pressure of Hemodialysis Patients%透析液钠离子浓度对血液透析患者血压的影响

    Institute of Scientific and Technical Information of China (English)

    赵茜芸; 郝丽

    2012-01-01

    Objective To discuss the influence of changing sodium ion concentration in dialysate on the blood pressure of maintenance hemodialysis patients. Methods All 30 maintenance hemodialysis patients with hypertension, who received hemodialysis from 2009 July to 2012 February in our blood purification center,were selected with administration of 3 months of dialysis treat-ment:140 mmol/L sodium ion concentration in dialysate( dialysis mode A) and 135 mmol/L respectively (dialysis mode B). A-dopting self-comparison method, the blood pressure of patients 3 months before and after the treatment was observed. Results Compared with the values before dialysis, the blood pressure of patients with dialysis mode B was improved significantly after the dialysis,and the difference was statistically significant(( = 10. 037,18. 139.P 0. 05). Conclusion The dialysis mode B was obviously superior to dialysis mode A. The lowering sodium ion concentration in dialysate can reduce the occurrence of hypertension in maintenance hemodialysis patients.%目的 探讨透析液钠离子浓度的改变对维持性血液透析患者血压的影响.方法 选择2009年7月-2012年2月在我院血液净化中心进行血液透析的30例维持性血液透析的高血压患者,分别给予透析液钠离子浓度为140mmoL/L(透析模式A)和透析液钠离子浓度为135 mmol/L(透析模式B)的透析模式各透析3个月,采用自身对照,观察患者前3个月和后3个月血压的变化.结果 通过6个月的观察发现,透析模式B的患者透析后与透析前比较,血压显著改善,差异有统计学意义(t=10.037、18.139,P<0.01);透析模式A的患者透析后与透析前比较,差异无统计学意义(t=-0.218、0.264,P>0.05).结论 透析模式B的血压控制显著优于透析模式A,降低透析液钠离子的浓度可以降低维持性血液透析高血压患者高血压的发生.

  16. Identification of a chloride ion binding site in Na+/Cl -dependent transporters.

    Science.gov (United States)

    Forrest, Lucy R; Tavoulari, Sotiria; Zhang, Yuan-Wei; Rudnick, Gary; Honig, Barry

    2007-07-31

    The recent determination of the crystal structure of the leucine transporter from Aquifex aeolicus (aaLeuT) has provided significant insights into the function of neurotransmitter:sodium symporters. Transport by aaLeuT is Cl(-) independent, whereas many neurotransmitter:sodium symporters from higher organisms depend on Cl(-) ions. However, the only Cl(-) ion identified in the aaLeuT structure interacts with nonconserved residues in extracellular loops, and thus the relevance of this binding site is unclear. Here, we use calculations of pK(A)s and homology modeling to predict the location of a functionally important Cl(-) binding site in serotonin transporter and other Cl(-)-dependent transporters. We validate our model through the site-directed mutagenesis of residues predicted to coordinate the Cl(-) ion and through the observation of sequence conservation patterns in other Cl(-)-dependent transporters. The proposed site is located midway across the membrane and is formed by residues from transmembrane helices 2, 6, and 7. It is close to the Na1 sodium binding site, thus providing an explanation for the coupling of Cl(-) and Na(+) ions during transport. Other implications of the model are also discussed.

  17. Characterization of barium titanate powder doped with sodium and potassium ions by using Rietveld refining; Caracterizacao do po de titanato de bario dopado com ions sodio e potasio com o refinamento de Rietveld

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, M.C.; Assis, J.T.; Pereira, F.R., E-mail: mcalixto@iprj.uerj.b [Universidade do Estado do Rio de Janeiro (IPRJ/UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico; Araujo, J.C. [Universidade do Estado do Rio de Janeiro (FFP/UERJ), Sao Goncalo, RJ (Brazil). Fac. de Formacao de Professores; Moreira, E.L.; Moraes, V.C.A.; Lopes, A.R. [Centro Brasileiro de Pesquisas Fisicas (CBPF/MCT), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    A solid-reaction synthesis of doped barium titanate was done by employing barium carbonates, sodium, potassium and titanium oxides with classic procedures. Rietveld refining of X ray diffraction data of perovskite samples with tetragonal symmetry was applying and show good agreement. Besides, the treatment performed from 600 deg C produces nanocrystals of barium titanate with average size of 33 nm. The presence of endothermic peaks related to BaTiO{sub 3} formation at relatively low temperatures was determined by thermal analysis. A pseudo-Voigt Thompson-Cox-Hastings function was used to fit the standard samples of barium titanate. The Rietveld method has showed be efficient to detect the influences of temperature and doping on barium titanate microstructures. (author)

  18. Characterization of Glycan Structures of Chondroitin Sulfate-Glycopeptides Facilitated by Sodium Ion-Pairing and Positive Mode LC-MS/MS

    Science.gov (United States)

    Nilsson, Jonas; Noborn, Fredrik; Gomez Toledo, Alejandro; Nasir, Waqas; Sihlbom, Carina; Larson, Göran

    2016-11-01

    Purification and liquid chromatography-tandem mass spectrometry (LC-MS/MS) characterization of glycopeptides, originating from protease digests of glycoproteins, enables site-specific analysis of protein N- and O-glycosylations. We have described a protocol to enrich, hydrolyze by chondroitinase ABC, and characterize chondroitin sulfate-containing glycopeptides (CS-glycopeptides) using positive mode LC-MS/MS. The CS-glycopeptides, originating from the Bikunin proteoglycan of human urine samples, had ΔHexAGalNAcGlcAGalGalXyl-O-Ser hexasaccharide structure and were further substituted with 0-3 sulfate and 0-1 phosphate groups. However, it was not possible to exactly pinpoint sulfate attachment residues, for protonated precursors, due to extensive fragmentation of sulfate groups using high-energy collision induced dissociation (HCD). To circumvent the well-recognized sulfate instability, we now introduced Na+ ions to form sodiated precursors, which protected sulfate groups from decomposition and facilitated the assignment of sulfate modifications. Sulfate groups were pinpointed to both Gal residues and to the GalNAc of the hexasaccharide structure. The intensities of protonated and sodiated saccharide oxonium ions were very prominent in the HCD-MS2 spectra, which provided complementary structural analysis of sulfate substituents of CS-glycopeptides. We have demonstrated a considerable heterogeneity of the bikunin CS linkage region. The realization of these structural variants should be beneficial in studies aimed at investigating the importance of the CS linkage region with regards to the biosynthesis of CS and potential interactions to CS binding proteins. Also, the combined use of protonated and sodiated precursors for positive mode HCD fragmentation analysis will likely become useful for additional classes of sulfated glycopeptides.

  19. Characterization of Glycan Structures of Chondroitin Sulfate-Glycopeptides Facilitated by Sodium Ion-Pairing and Positive Mode LC-MS/MS

    Science.gov (United States)

    Nilsson, Jonas; Noborn, Fredrik; Gomez Toledo, Alejandro; Nasir, Waqas; Sihlbom, Carina; Larson, Göran

    2017-02-01

    Purification and liquid chromatography-tandem mass spectrometry (LC-MS/MS) characterization of glycopeptides, originating from protease digests of glycoproteins, enables site-specific analysis of protein N- and O-glycosylations. We have described a protocol to enrich, hydrolyze by chondroitinase ABC, and characterize chondroitin sulfate-containing glycopeptides (CS-glycopeptides) using positive mode LC-MS/MS. The CS-glycopeptides, originating from the Bikunin proteoglycan of human urine samples, had ΔHexAGalNAcGlcAGalGalXyl- O-Ser hexasaccharide structure and were further substituted with 0-3 sulfate and 0-1 phosphate groups. However, it was not possible to exactly pinpoint sulfate attachment residues, for protonated precursors, due to extensive fragmentation of sulfate groups using high-energy collision induced dissociation (HCD). To circumvent the well-recognized sulfate instability, we now introduced Na+ ions to form sodiated precursors, which protected sulfate groups from decomposition and facilitated the assignment of sulfate modifications. Sulfate groups were pinpointed to both Gal residues and to the GalNAc of the hexasaccharide structure. The intensities of protonated and sodiated saccharide oxonium ions were very prominent in the HCD-MS2 spectra, which provided complementary structural analysis of sulfate substituents of CS-glycopeptides. We have demonstrated a considerable heterogeneity of the bikunin CS linkage region. The realization of these structural variants should be beneficial in studies aimed at investigating the importance of the CS linkage region with regards to the biosynthesis of CS and potential interactions to CS binding proteins. Also, the combined use of protonated and sodiated precursors for positive mode HCD fragmentation analysis will likely become useful for additional classes of sulfated glycopeptides.

  20. Novel pre-treatment of zeolite materials for the removal of sodium ions: potential materials for coal seam gas co-produced wastewater.

    Science.gov (United States)

    Santiago, Oscar; Walsh, Kerry; Kele, Ben; Gardner, Edward; Chapman, James

    2016-01-01

    Coal seam gas (CSG) is the extraction of methane gas that is desorbed from the coal seam and brought to the surface using a dewatering and depressurisation process within the saturated coalbed. The extracted water is often referred to as co-produced CSG water. In this study, co-produced water from the coal seam of the Bowen Basin (QLD, Australia) was characterised by high concentration levels of Na(+) (1156 mg/L), low concentrations of Ca(2+) (28.3 mg/L) and Mg(2+) (5.6 mg/L), high levels of salinity, which are expected to cause various environmental problems if released to land or waters. The potential treatment of co-produced water using locally sourced natural ion exchange (zeolite) material was assessed. The zeolite material was characterized for elemental composition and crystal structure. Natural, untreated zeolite demonstrated a capacity to adsorb Na(+) ions of 16.16 mEq/100 g, while a treated zeolite using NH4 (+) using a 1.0 M ammonium acetate (NH4C2H3O2) solution demonstrated an improved 136 % Na(+) capacity value of 38.28 mEq/100 g after 720 min of adsorption time. The theoretical exchange capacity of the natural zeolite was found to be 154 mEq/100 g. Reaction kinetics and diffusion models were used to determine the kinetic and diffusion parameters. Treated zeolite using a NH4 (+) pre-treatment represents an effective treatment to reduce Na(+) concentration in coal seam gas co-produced waters, supported by the measured and modelled kinetic rates and capacity.

  1. P2-type Na2/3Mn1-xAlxO2 cathode material for sodium-ion batteries: Al-doped enhanced electrochemical properties and studies on the electrode kinetics

    Science.gov (United States)

    Pang, Wei-Lin; Zhang, Xiao-Hua; Guo, Jin-Zhi; Li, Jin-Yue; Yan, Xin; Hou, Bao-Hua; Guan, Hong-Yu; Wu, Xing-Long

    2017-07-01

    Recently, sodium-ion batteries (SIBs) have been considered as the promising alternative for lithium-ion batteries. Although layered P2-type transition metal oxides are an important class of cathode materials for SIBs, there are still some hurdles for the practical applications, including low specific capacity as well as poor cycling and rate properties. In this study, the electrochemical properties of layered Mn-based oxides have been effectively improved via Al doping, which cannot only promote the formation of layered P2-type structure in the preparation processes but also stabilize the lattice during the successive Na-intercalation/deintercalation due to suppression of the Jahn-Teller distortion of Mn3+. Among the as-prepared series of Na2/3Mn1-xAlxO2 (x = 0, 1/18, 1/9, and 2/9), Na2/3Mn8/9Al1/9O2 with x = 1/9 exhibits the optimal doping effect with the best electrochemical properties, in terms of the highest specific capacity of 162.3 mA h g-1 at 0.1 C, the highest rate capability, and the best cycling stability in comparison to the undoped Na2/3MnO2 and the other two materials with different Al-doped contents. Both cyclic voltammetry at varied scan rates and galvanostatic intermittent titration technique disclose the optimal electrode kinetics (the highest Na-diffusion coefficient) of the best Na2/3Mn8/9Al1/9O2.

  2. XPS of fast-frozen hematite colloids in NaCl aqueous solutions: I. Evidence for the formation of multiple layers of hydrated sodium and chloride ions induced by the {001} basal plane

    Energy Technology Data Exchange (ETDEWEB)

    Shchukarev, Andrei; Boily, Jean F.; Felmy, Andrew R.

    2007-12-13

    The influence of the {001} basal plane of hematite on the composition of fast-frozen centrifuged wet pastes of hematite prepared at pH 4 and 9 and at ionic strengths of 0, 10 and 100 mM NaCl was investigated by x-ray photoelectron spectroscopy. Two hematite preparations consisted of micrometer-sized platelets with 42% (HEM-1) and 95% (HEM-8) of the surface terminated by the {001} basal plane. A third preparation of spherical shape with no recognizable crystal plane (HEM-control) was used as a control to these experiments. All hematite samples responded to changes in pH and ionic strength, showing that acid/base reactions of surface hydroxyl groups control the composition of the paste. The HEM-1 and HEM-8 sample exhibited divergent properties at the highest ionic strength (100 mM) with energy loss features in the Na 1s and Cl 2p spectra and an important water content. As the spectra were typical of hydrated Na+ and Cl- ions and that the surface concentrations were unusually large, the HEM-1 and HEM-8 samples are proposed to induce the formation of a three-dimensional distribution of these ions in the paste. The sodium, chloride and water content was also correlated to the fraction of the {001} basal plane present in the sample and provided evidence for an approximate stochiometric Na:Cl:H2O ratio of 1:1:2. The {001} basal plane of hematite is consequently proposeD to be the cause of this feature.

  3. High-Performance Olivine NaFePO4 Microsphere Cathode Synthesized by Aqueous Electrochemical Displacement Method for Sodium Ion Batteries.

    Science.gov (United States)

    Fang, Yongjin; Liu, Qi; Xiao, Lifen; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2015-08-19

    Olivine NaFePO4/C microsphere cathode is prepared by a facile aqueous electrochemical displacement method from LiFePO4/C precursor. The NaFePO4/C cathode shows a high discharge capacity of 111 mAh g(-1), excellent cycling stability with 90% capacity retention over 240 cycles at 0.1 C, and high rate capacity (46 mAh g(-1) at 2 C). The excellent electrochemical performance demonstrates that the aqueous electrochemical displacement method is an effective and promising way to prepare NaFePO4/C material for Na-based energy storage applications. Moreover, the Na2/3FePO4 intermediate is observed for the first time during the Na intercalation process through conventional electrochemical techniques, corroborating an identical two-step phase transition reaction both upon Na intercalation and deintercalation processes. The clarification of the electrochemical reaction mechanism of olivine NaFePO4 could inspire more attention on the investigation of this material for Na ion batteries.

  4. Graft copolymer based on (sodium alginate-g-acrylamide): Characterization and study of Water swelling capacity, metal ion sorption, flocculation and resistance to biodegradability.

    Science.gov (United States)

    Sand, Arpit; Vyas, Aparna; Gupta, A K

    2016-09-01

    Graft copolymer of alginate and acrylamide was synthesized by grafting acrylamide chains on to alginate by free radical polymerization using potassium bromate/thiourea redox system in an inert atmosphere. The reaction conditions for maximum grafting have been optimized by varying the reaction variables, including the concentration of acrylamide (3.0×10(2)-9.3×10(2)moldm(-3)), potassium bromate (8×10(-3)-16×10(-3)moldm(-3)), thiourea (1.6×10(-3)-4.8×10(-3)moldm(-3)), sulphuric acid (3.0×10(-3)-7×10(-3)moldm(-3)), alginate (0.6-1.6gdm(-3)) along with time duration (60-180min) and temperature (30-50°C). Water swelling capacity, metal ion sorption, flocculation and resistance to biodegradability studies of synthesized graft copolymer have been performed with respect to the parent polymer. The grafted polymers were characterized by FTIR spectroscopy and thermo gravimetric analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Sodium-ion-conducting polymer nanocomposite electrolyte of TiO2/PEO/PAN complexed with NaPF6

    Science.gov (United States)

    Bhatt, Chandni; Swaroop, Ram; Sharma, Parul Kumar; Sharma, A. L.

    2016-05-01

    A free standing transparent film of solid state polymer electrolyte based on PEO/PAN+NaPF6 with different compositions of nano sized TiO2 in weight percent (x = 0, 1, 2, 5, 10, 15, 20) is synthesized by using standard solution cast technique. The homogeneous surface of above polymer composition is examined by FESEM. The microscopic interaction among polymer, salt and nanoceramic filler has been analyzed by Fourier Transformed Infra-Red (FTIR) spectroscopy. The reduction of ion pair formation in polymeric separator is clearly observed on addition of nanofiller in the polymer salt complex film. Electrical conductivity has been recorded of the prepared polymeric separator which is of the order of ˜10-4 Scm-1 after addition of nanofiller (15% wt/wt) which support the FTIR results. Electrochemical potential window has been observed of the order of ˜6V by the cyclic voltammetry results. The observed data of the prepared separator are at par with the desirable value for device applications

  6. Study of methanol catalyzed reaction between sodium 1,2-naphthoquine-4-sulfonate and hydroxyl ion and its application in the determination of methanol

    Science.gov (United States)

    Li, Quanmin; Zhang, Huanhuan

    2008-11-01

    A novel and simple spectrophotometric method for the direct determination of methanol with 1,2-naphthoquinone-4-sulfonate (NQS) is developed in this paper. It is based on the fact that methanol can catalyze the reaction between 1,2-naphthoquinone-4-sulfonate and hydroxyl ion to form 2-hydroxy-1,4-naphthoquinone in buffer solution of pH 13.00. Beer's law is obeyed in a range of 0.26-15.8 mg/ml at the maximal absorption wavelength of 454 nm. The equation of linear regression is A = 0.01998 + 0.05944 C (mg/ml), with a linear regression correlation coefficient of 0.9977. The detection limit is 0.25 mg/ml (3 σ/ k), while R.S.D. is 2.0% and the recovery rate is in a range of 96.5-103%. The detailed mechanism for the formation of the products is proposed and discussed.

  7. Neutron diffraction and electrochemical studies of Na0.79(Co,Mn)O2 cathodes for sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Faith R [National Energy Technology Laboratory (NETL); Cheng, Yongqiang [ORNL; Feygenson, Mikhail [ORNL; Bridges, Craig A [ORNL; Moorhead-Rosenberg, Z [Oak Ridge National Laboratory (ORNL); Manthiram, Arumugam [University of Texas at Austin; Goodenough, J. B. [University of Texas at Austin; Paranthaman, Mariappan Parans [ORNL; Manivannan, A. [National Energy Technology Laboratory (NETL)

    2014-01-01

    Na0.79CoO2 and Na0.79Co0.7Mn0.3O2 with a layered hexagonal structure (P2-type) were synthesized by the Pechini process followed by heat treatment at elevated temperatures in order to achieve the crystalline phases. The samples were characterized with x-ray diffraction, neutron diffraction, magnetic measurements and electrochemical charge-discharge cycling. X-ray diffraction confirmed the P2 layered hexagonal structure after heat treatment at 900 C in air. Neutron diffraction patterns confirm Mn doping on Co sites without forming pronounced Mn-Co ordering. Cyclic voltammetry showed the oxidation and reduction peaks of Co and Mn, indicating the intercalation and de-intercalation behavior of the Na ions. A discharge capacity of 60 mAh/g was achieved for both the compositions, with the Na0.79Co0.70Mn0.3O2 composition showing a more stable discharge capacity up to 60 cycles.

  8. Extracellular Matrix Proteins

    Directory of Open Access Journals (Sweden)

    Linda Christian Carrijo-Carvalho

    2012-01-01

    Full Text Available Lipocalin family members have been implicated in development, regeneration, and pathological processes, but their roles are unclear. Interestingly, these proteins are found abundant in the venom of the Lonomia obliqua caterpillar. Lipocalins are β-barrel proteins, which have three conserved motifs in their amino acid sequence. One of these motifs was shown to be a sequence signature involved in cell modulation. The aim of this study is to investigate the effects of a synthetic peptide comprising the lipocalin sequence motif in fibroblasts. This peptide suppressed caspase 3 activity and upregulated Bcl-2 and Ki-67, but did not interfere with GPCR calcium mobilization. Fibroblast responses also involved increased expression of proinflammatory mediators. Increase of extracellular matrix proteins, such as collagen, fibronectin, and tenascin, was observed. Increase in collagen content was also observed in vivo. Results indicate that modulation effects displayed by lipocalins through this sequence motif involve cell survival, extracellular matrix remodeling, and cytokine signaling. Such effects can be related to the lipocalin roles in disease, development, and tissue repair.

  9. Concentration of serum sodium ion after extracorporeal circulation in open heart surgery.%体外循环心脏直视手术术后血清钠离子浓度的变化

    Institute of Scientific and Technical Information of China (English)

    苏泓洁; 孔令文; 向小勇; 赵兴吉; 都定元; 张为民; 谭远康; 卢仁福

    2011-01-01

    目的 分析体外循环心脏直视手术患者术后血清中钠离子的含量变化.方法 选取2008年8月至2010年8月在我院及重庆医科大学附属第一医院就诊行体外循环心脏直视手术的82例患者,检测这些患者术舌血清中钠离子浓度,并分析导致钠离子含量变化的原因.结果 术后有50例患者出现低钠血症(血清中钠离子的含量小于135 mmol/L,),低钠血症的发生率为61.1%(50/82),其中7例患者的低钠血症持续1~3 d,30例患者的低钠血症持续4~9 d,余13例患者的低钠血症的持续时间超过9 d.主动脉阻断时间与术后低钠血症的发生率正相关,术后多巴胺和硝普钠的给药时间与低钠血症的发生率负相关.结论 低钠血症的出现可能与手术创伤、手术对机体内分泌的刺激和体外循环有关.行体外循环心脏直视手术患者术后出现低钠血症的几率较高,纠正低钠血症有利于患者的术后恢复,临床上应注意纠正术后低钠血症.%Objective To detect the concentration of serum sodium ion after extracorporeal circulation in open heart surgery. Methods 82 patients who underwent extracorporeal circulation in open heart surgery from Aug,2008 to Aug, 2010, and the concentration of serum sodium ion after surgery was detected. Results 50 patients had hyponatremia after surgery, and the incidence of hyponatremia was 61.1% (50/82). 7 of 50 patients had hyponatremia less than 3 days; 30 of 50 patients had hyponatremia for 4 to 9 days; while the rest 13 patients had hyponatremia more than 9 days. The time length of aortic occlusion is positive correlated to hyponatremia, while the time length of dopamine and sodium nitroprusside using is negative correlated to hyponatremia. Conclusion Hyponatremia may be related to trauma of surgery, stimuli of hormonal system after surgery and extracorporeal circulation. The incidence of hyponatremia after extracorporeal circulation in open heart surgery is higher, and

  10. ALD TiO2-Coated Flower-like MoS2 Nanosheets on Carbon Cloth as Sodium Ion Battery Anode with Enhanced Cycling Stability and Rate Capability.

    Science.gov (United States)

    Ren, Weina; Zhou, Weiwei; Zhang, Haifeng; Cheng, Chuanwei

    2017-01-11

    We report the fabrication of 3D flower-like MoS2 nanosheets arrays on carbon cloth as a binder-free anode for sodium ion battery. Ultrathin and conformal TiO2 layers are used to modify the surface of MoS2 by atomic layer deposition. The electrochemical performance measurements demonstrate that the ALD TiO2 layer can improve the cycling stability and rate capability of MoS2. The MoS2 nanosheets with 0.5-nm TiO2 coating electrode show the highest initial discharge capacity of 1392 mA h g(-1) at 200 mA g(-1), which is increased by 53% compared with that of bare MoS2. After 150 cycles, the capacity retention rate of the TiO2-coated MoS2 achieves 75.8% of its second cycle's capacity at 200 mA h g(-1) in contrast to that of 59% of pure MoS2. Furthermore, the mechanism behind the experimental results is revealed by ex situ scanning electron microscope (SEM), X-ray powder diffraction (XRD), and electrochemical impedance spectroscopy (EIS) characterizations, which confirms that the ultrathin TiO2 modifications can prevent the structural degradation and the formation of SEI film of MoS2 electrode.

  11. Na 2 Ti 3 O 7 Nanoplatelets and Nanosheets Derived from a Modified Exfoliation Process for Use as a High-Capacity Sodium-Ion Negative Electrode

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Jesse S.; Doan-Nguyen, Vicky V. T.; Kim, Hyung-Seok; Muller, Guillaume A.; Serino, Andrew C.; Weiss, Paul S.; Dunn, Bruce S.

    2017-01-18

    Th