Sample records for electrolytic manganese dioxide

  1. Effects of current density on preparation of grainy electrolytic manganese dioxide

    GUO Hua-jun; ZHU Bing-quan; LI Xin-hai; ZHANG Xin-ming; WANG Zhi-xing; PENG Wen-jie; LIU Lu-ping


    Grainy electrolytic manganese dioxide was prepared by electrodeposition in a 0.9 mol/L MnSO4 and 2.5 mol/L H2SO4 solution. The structure, particle size and appearance of the grainy electrolytic manganese dioxide were determined by powder X-ray diffraction, laser particle size analysis and scanning electron micrographs measurements. Current density has important effects on cell voltage, anodic current efficiency and particle size of the grainy electrolytic manganese dioxide, and the optimum current density is 30 A/dm 2. The grainy electrolytic manganese dioxide electrodeposited under the optimum conditions consists of γ-MnO2 with an orthorhombic lattice structure; the grainy electrolytic manganese dioxide has a spherical or sphere-like appearance and a narrow particle size distribution with an average particle diameter of 7.237 μm.

  2. 78 FR 54269 - Electrolytic Manganese Dioxide From Australia and China; Institution of Five-Year Reviews


    ... COMMISSION Electrolytic Manganese Dioxide From Australia and China; Institution of Five-Year Reviews AGENCY... of merchandise that is within the scope of the five-year reviews, as defined by the Department of... seeking to appear in Commission five-year reviews are advised that they may appear in a review even if...

  3. Effect of crystal structure of manganese dioxide on response for electrolyte of ahydrogen sensor operative at room temperature

    Koyanaka, Hideki [Forward Science Laboratory Ltd, Oita, Japan; Ueda, Yoshikatsu [Kyoto University, Japan; Takeuchi, K [Tokyo University of Science, Oshamanbe Hokkaido, Japan; Kolesnikov, Alexander I [ORNL


    Sensoring properties of a hydrogen sensor that used electrolytes made of different crystal type manganese dioxides were compared. An electrolyte made of a manganese dioxide, which has a high purity of ramsdellite-type crystal structure, provided the best characteristics for the hydrogen sensor. To explain the sensor property, network model of oxygen-pairs to store protons with a weak covalent bond and to conduct protons along the network in the ideal crystal structure of ramsdellite manganese dioxide was proposed. The inter-atomic distance of those oxygen-pairs in the high purity of ramsdellite manganese dioxide was estimated between 2.57 and 2.60 A using inelastic neutron scattering measurements. The property of the hydrogen sensor supported the unique proton conduction based on the network model.

  4. Electrolytic Manganese Dioxide Coatings on High Aspect Ratio Micro-Pillar Arrays for 3D Thin Film Lithium Ion Batteries

    Yafa Zargouni


    Full Text Available In this work, we present the electrochemical deposition of manganese dioxide (MnO2 thin films on carbon-coated TiN/Si micro-pillars. The carbon buffer layer, grown by plasma enhanced chemical vapor deposition (PECVD, is used as a protective coating for the underlying TiN current collector from oxidation, during the film deposition, while improving the electrical conductivity of the stack. A conformal electrolytic MnO2 (EMD coating is successfully achieved on high aspect ratio C/TiN/Si pillar arrays by tailoring the deposition process. Lithiation/Delithiation cycling tests have been performed. Reversible insertion and extraction of Li+ through EMD structure are observed. The fabricated stack is thus considered as a good candidate not only for 3D micorbatteries but also for other energy storage applications.

  5. Synthesis and Characterization of Nanostructured Manganese Dioxide Used as Positive Electrode Material for Electrochemical Capacitor with Lithium Hydroxide Electrolyte

    YUAN,An-Bao; ZHOU,Min; WANG,Xiu-Ling; SUN,Zi-Hong; WANG,Yu-Qin


    A nanostructured manganese dioxide electrode material was prepared using a solid-reaction route starting with MnCl2·4H2O and NH4HCO3, and its electrochemical performance as a positive electrode for MnO2/activated carbon hybrid supercapacitor with 1 mol·L-1 LiOH electrolyte was reported. The material was proved to be a mixture of nanostructured γ-MnO2 and α-MnO2 containing some bound water in the structure, which was characterized by X-ray diffraction analysis, infrared spectrum analysis, and transmission electron microscope observation. Electrochemical properties of the MnO2 electrode and the MnO2/AC capacitor were investigated by cyclic voltammetry, ac impedance and galvanostatic charge/discharge methods. Experimental results showed that the MnO2 electrode exhibited faradaic pseudocapacitance behavior and higher specific capacitance in 1 mol·L-1 LiOH electrolyte. The MnO2/AC hybrid capacitor with 1 mol·L-1 LiOH electrolyte presented excellent rate charge/discharge ability and cyclic stability.

  6. Composition and recovery method for electrolytic manganese residue

    陶长元; 李明艳; 刘作华; 杜军


    According to the statistic analysis,the reserve of manganese in electrolytic manganese residue deposit is over 780 kt. The average contents of available manganese and ammonium reach 3.90% and 1.68% (mass fraction),respectively. Large amount of manganese compounds and ammonium sulfate are detruded without any treatment or recovery. The compositions of the main elements in electrolytic manganese residue were analyzed comprehensively based on the extensive research data. According to the new development of electrolytic manganese residue comprehensively used in recent years,a water washing residue-twice precipitation process was also proposed. The experimental results indicate that manganese dioxide silicon dioxide and calcium sulfate are presented as amorphous state in the manganese residues. The recovery rates of manganese and nitrogen reach up to 99.5% and 94.5 %,respectively. The recovery process can be easily implemented,environment-friendly and fitting for industrial production.

  7. Rechargeability of manganese dioxide/zinc cell using zinc sulfate electrolyte

    Askar, M.H. (National Research Centre, Dokki, Cairo (Egypt)); Abbas, H. (National Research Centre, Dokki, Cairo (Egypt)); Afifi, S.E. (National Research Centre, Dokki, Cairo (Egypt) Central Metallurgical Research and Development Inst., Tabbin, Cairo (Egypt))


    The charge/discharge of electrolytic [gamma]-MnO[sub 2] (EMD) in sulfate solution rather than chloride was investigated. Discharge potential-time curves at different conditions of current density, charging schemes and solutions were registered. The charge/discharge cycle can be repeated up to the 20th cycle with no significant change in the discharge behaviour. The charge/discharge products are characterized by X-ray diffraction pattern indicating recovery of [gamma]-MnO[sub 2] during charging process. The results are promising and encouraging. They are discussed in the light of recent views. (orig.)

  8. High Specific Capacitance of Polyaniline/Mesoporous Manganese Dioxide Composite Using KI-H2SO4 Electrolyte

    Zhongkai Hu


    Full Text Available The PANI/Mesoporous MnO2 composites were prepared through a simple one step method and we introduced the KI-H2SO4 solution as the electrolyte of PANI/MnO2 composites creatively. The characterization of structure, morphology, and composition are obtained by X-ray diffraction, Fourier transform infrared spectroscopy, thermal gravity analysis, Raman spectra, and scanning electron microscope. The electrochemical performances were investigated by constant-current charge–discharge, the voltammetry curve, and alternating current (AC impedance technique. The specific capacitance of composites is 1405 F/g, which is almost 10 times larger than MnO2 (158 F/g. We also find that the iodide concentration is closely related to the specific capacitance. Therefore, we explored the specific capacitance at different iodide concentration (0.05, 0.1, 0.2, 0.5, and 1 M, the results indicated that the specific capacitance reached a maximum value (1580 F/g at 0.5 mol/L. Additionally, the PANI/Mesoporous MnO2 composites not only exhibited a good ratio discharge property (857 F/g at high current density, but also revealed an excellent cycling stability after 500 cycles, which retained 90% of the original specific capacitance.


    Katzin, L.I.


    A method of obtaining U/sup 233/ is described. An aqueous solution of neutriln irradiated thoriunn is treated by forming tberein a precipitate of manganese dioxide which carries and thus separates the Pa/sup 233/ from the solution. The carrier precipitate so formed is then dissolved in an acidic solution containing a reducing agent sufficiently electronegative to reduce the tetravalent manganese to the divalent state. Further purification of the Pa/sup 233/ may be obtained by forming another manganese dioxide carrier precipitate and subsequently dissolving it. Ater a sufficient number of such cycles have brought the Pa/sup 233/ to the desired purity, the solution is aged, allowing the formation ot U/sup 233/ by radioaetive decay. A manganese dioxide precipitate is then formed in the U/sup 233/ containing solution. This precipitate carries down any remaining Pa/sup 233/ thus leaving the separated U/sup 233/solution, from whieh it may be easily recovered.

  10. 40 CFR 424.60 - Applicability; description of the electrolytic manganese products subcategory.


    ... electrolytic manganese products subcategory. 424.60 Section 424.60 Protection of Environment ENVIRONMENTAL... CATEGORY Electrolytic Manganese Products Subcategory § 424.60 Applicability; description of the electrolytic manganese products subcategory. The provisions of this subpart are applicable to...

  11. Manganese Dioxide with High Specific Surface Area for Alkaline Battery

    HUANG You-ju; LIN Yu-li; LI Wei-shan


    The authors reported a facile method for the synthesis of manganese dioxide without any template and catalyst at a low-temperature.The prepared sample was characterized with X-ray diffraction(XRD),scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET) surface analysis,Fourier transform infrared(FTIR) spectrometry,cyclic voltammetry,altemative current(AC) impedance test and battery discharge test.It is found that the prepared sample belongs to α-MnO2 and has a microsphere morphology and a large BET surface area.The electrochemical characterization indicates that the prepared sample displays a larger electrochemical capacitance than the commercial electrolytic manganese dioxides(EMD) in Na2SO4 solution,and exhibits larger discharge capacity than EMD,especially at a high rate discharge condition when it is used as cathode of alkaline Zn/MnO2 battery.

  12. Electrokinetic remediation of manganese and ammonia nitrogen from electrolytic manganese residue.

    Shu, Jiancheng; Liu, Renlong; Liu, Zuohua; Du, Jun; Tao, Changyuan


    Electrolytic manganese residue (EMR) is a solid waste found in filters after sulphuric acid leaching of manganese carbonate ore, which mainly contains manganese and ammonia nitrogen and seriously damages the ecological environment. This work demonstrated the use of electrokinetic (EK) remediation to remove ammonia nitrogen and manganese from EMR. The transport behavior of manganese and ammonia nitrogen from EMR during electrokinetics, Mn fractionation before and after EK treatment, the relationship between Mn fractionation and transport behavior, as well as the effects of electrolyte and pretreatment solutions on removal efficiency and energy consumption were investigated. The results indicated that the use of H2SO4 and Na2SO4 as electrolytes and pretreatment of EMR with citric acid and KCl can reduce energy consumption, and the removal efficiencies of manganese and ammonia nitrogen were 27.5 and 94.1 %, respectively. In these systems, electromigration and electroosmosis were the main mechanisms of manganese and ammonia nitrogen transport. Moreover, ammonia nitrogen in EMR reached the regulated level, and the concentration of manganese in EMR could be reduced from 455 to 37 mg/L. In general, the electrokinetic remediation of EMR is a promising technology in the future.

  13. Substantial increase in the price of electrolytic manganese as an alternative to nickel


    <正>A roaring price of nickel and a shortage of the raw material of electrolytic manganese have intensified the demand for electrolytic manganese in China. As an alternative to nickel, electrolytic manganese has been consumed at a quickened speed, which boosts the continuous increase in export quotation. On the third

  14. Selection and Use of Manganese Dioxide by Neanderthals

    Heyes, Peter J.; Anastasakis, Konstantinos; de Jong, Wiebren; van Hoesel, Annelies; Roebroeks, Wil; Soressi, Marie


    Several Mousterian sites in France have yielded large numbers of small black blocs. The usual interpretation is that these ‘manganese oxides’ were collected for their colouring properties and used in body decoration, potentially for symbolic expression. Neanderthals habitually used fire and if they needed black material for decoration, soot and charcoal were readily available, whereas obtaining manganese oxides would have incurred considerably higher costs. Compositional analyses lead us to infer that late Neanderthals at Pech-de-l’Azé I were deliberately selecting manganese dioxide. Combustion experiments and thermo-gravimetric measurements demonstrate that manganese dioxide reduces wood’s auto-ignition temperature and substantially increases the rate of char combustion, leading us to conclude that the most beneficial use for manganese dioxide was in fire-making. With archaeological evidence for fire places and the conversion of the manganese dioxide to powder, we argue that Neanderthals at Pech-de-l’Azé I used manganese dioxide in fire-making and produced fire on demand.

  15. Leaching of manganese from electrolytic manganese residue by electro-reduction.

    Shu, Jiancheng; Liu, Renlong; Liu, Zuohua; Chen, Hongliang; Tao, Changyuan


    In this study, an improved process for leaching manganese from electrolytic manganese residue (EMR) by electro-reduction was developed. The mechanisms of the electro-reduction leaching were investigated through X-ray diffraction, scanning electron microscopy, X-ray fluorescence, and Brunauer Emmett Teller. The results show that the electric field could change the surface charge distribution of EMR particles, and the high-valent manganese can be reduced by electric field. The leaching efficient of manganese reached 84.1% under the optimal leaching condition: 9.2 wt% H2SO4, current density of 25 mA/cm(2), solid-to-liquid ratio of 1:5, and leaching time for 1 h. It is 37.9% higher than that attained without an electric field. Meanwhile, the manganese content in EMR decreased from 2.57% to 0.48%.

  16. Enhanced electrochemical properties of cobalt doped manganese dioxide nanowires

    Kim, Byung Chul; Justin Raj, C.; Cho, Won-Je; Lee, Won-Gil [Department of Chemistry, Dongguk University-Seoul, Seoul 100-715 (Korea, Republic of); Jeong, Hyeon Taek [ARC Centre of Excellence for Electromaterials Science, IPRI, AIIM Facility, Innovation Campus, University of Wollongong, NSW 2522 (Australia); Yu, Kook Hyun, E-mail: [Department of Chemistry, Dongguk University-Seoul, Seoul 100-715 (Korea, Republic of)


    Highlights: • Cobalt doped MnO{sub 2} nanowires were synthesized by the hydrothermal method. • Supercapacitor properties of Co–MnO{sub 2} electrodes were studied. • Cobalt content enhanced the conductivity and specific capacitance of MnO{sub 2}. • 5% Co doped MnO{sub 2} electrode shows 415 F g{sup −1} with excellent cyclic stability. - Abstract: The various molar concentrations of cobalt doped manganese dioxide (Co–MnO{sub 2}) nanostructures were synthesized by an hydrothermal technique for electrochemical supercapacitor application. The X-ray diffraction analysis showed that the samples were composed of multiphase of MnO{sub 2} with dominant reflections of γ-MnO{sub 2} structure of crystallization. The morphological studies displayed the existence of MnO{sub 2} nanowires with the width of 10–20 nm and showing a good degree of crystallization. The electrochemical characterization was performed using cyclic voltammetry, galvanostatic charge/discharge test and impedance spectroscopy in 1 M Na{sub 2}SO{sub 4} aqueous electrolyte. All the samples exhibit a typical ideal capacitive behavior with an increasing order of specific capacitance values with respect to the increase in the concentration of cobalt ions up to a certain limit. The specific capacitance of 415 F g{sup −1} was delivered by 5% Co–MnO{sub 2} sample at 0.2 A g{sup −1} which was nearly double that of bare MnO{sub 2} electrode of 231 F g{sup −1}. Moreover, the Co–MnO{sub 2} electrode shows an excellent capacitance retention (97.3%) after 5000 charge and discharge cycles.

  17. New generation of the zinc - manganese dioxide cell

    Rogulski, Z.; Chotkowski, M.; Czerwinski, A. [Warsaw Univ., Warsaw (Poland). Dept. of Chemistry; Industrial Chemistry Research Inst., Warsaw (Poland)


    Zinc chloride and alkaline system cells are the 2 most popular types of zinc manganese dioxide cells. They offer excellent shelf life, high-temperature performance, low cost, and favourable charge density and electrode potential. They are also environmentally sound. However, zinc corrosion and the formation of electrochemically inactive products of manganese dioxide reduction are some of the main problems with the storage and operation of rechargeable alkaline manganese dioxide (RAM) batteries. Studies have shown that reticulated vitreous carbon (RVC) can be used as reactive mass carrier and the current collector in lead-acid batteries, zinc-carbon batteries, and secondary cells with NiOOH/Ni(OH){sub 2} cathodes. This paper demonstrated the behaviour of the primary zinc-carbon cell and a secondary battery system (Zn/ZnSO{sub 4}/MnO{sub 2}) with a new current collector. The commonly used graphic rod in the cell for the cathodic current collector was substituted by RVC. This modification enhanced all of the operational parameters of the cell, including voltage stability during discharge and electrical capacity of the cathode. In addition, the application of RVC as both anode and cathode active mass holders in the battery system made it possible to develop a new rechargeable battery system. 15 refs., 8 figs.

  18. Durable rechargeable zinc-air batteries with neutral electrolyte and manganese oxide catalyst

    Sumboja, Afriyanti; Ge, Xiaoming; Zheng, Guangyuan; Goh, F. W. Thomas; Hor, T. S. Andy; Zong, Yun; Liu, Zhaolin


    Neutral chloride-based electrolyte and directly grown manganese oxide on carbon paper are used as the electrolyte and air cathode respectively for rechargeable Zn-air batteries. Oxygen reduction and oxygen evolution reactions on manganese oxide show dependence of activities on the pH of the electrolyte. Zn-air batteries with chloride-based electrolyte and manganese oxide catalyst exhibit satisfactory voltage profile (discharge and charge voltage of 1 and 2 V at 1 mA cm-2) and excellent cycling stability (≈90 days of continuous cycle test), which is attributed to the reduced carbon corrosion on the air cathode and decreased carbonation in neutral electrolyte. This work describes a robust electrolyte system that improves the cycle life of rechargeable Zn-air batteries.

  19. The Capacitive Behaviors of Manganese Dioxide Thin-Film Electrochemical Capacitor Prototypes

    Suh Cem Pang


    Full Text Available We have documented the fabrication of manganese dioxide (MnO2 thin-film electrochemical capacitor (EC prototypes with dual-planar electrode configuration. These EC prototypes exhibited good capacitive behaviors in mild Na2SO4 aqueous electrolyte. Enhanced capacitive behaviors of EC prototypes were observed upon prolonged voltammetric cycling which could be associated with microstructural transformation of MnO2 thin-film electrodes from densely packed plate-like to irregular petal-like surface morphology. Effects of voltammetric scan rates, prolonged voltammetric cycling, electrolyte composition, and electrolyte concentration on the surface morphology of MnO2 thin-film electrodes, and associated capacitive behaviors of MnO2 thin-film EC prototypes were investigated by cyclic voltammetry (CV, electrochemical impedance spectroscopy (EIS, and galvanostatic charge/discharge (GCD techniques. Results of both CV and EIS indicated that thin-film MnO2 EC prototypes exhibited the highest specific capacitance of 327 F/g in 0.2 M Na2SO4 aqueous electrolyte. Being environmentally benign and cheap, MnO2 thin-film electrochemical capacitors have high potential utility as pulsed power sources, as well as load-leveling functions in various consumer electronic devices.

  20. Solvation dynamics in water confined within layered manganese dioxide

    Remsing, Richard C.; Klein, Michael L.


    The confined environment presented by layered transition metal oxides is conducive to a variety of chemical reactions. Despite intense interest in these materials, little is known regarding the microscopic details relevant to their catalytic activity. We characterize aspects of the dynamics governing a redox reaction in the interlayer environment between manganese dioxide sheets. The nonequilibrium solvation dynamics surrounding charge transfer between an ion and the surface are highly non-linear and exhibit long-time relaxation that is governed by collective dynamics. These dynamics are rationalized in terms of structural rearrangements, allowing connections to be made to more complex reactions in these materials.

  1. Preparation and Characterization of Self-Assembled Manganese Dioxide Thin Films

    Suh Cem Pang


    Full Text Available Thin films of manganese dioxide (MnO2 were prepared by self-assembly of MnO2 nanoparticles directly unto nickel-coated poly(ethylene terephthalate flexible films using the newly developed horizontal submersion process. The thickness of deposited thin films was controllable by the deposition duration. This horizontal submersion deposition process for thin-film deposition is relatively easy, simple, and cost effective. Effects of deposition duration and calcination temperatures on the microstructure and electrochemical properties of self-assembled MnO2 thin films were investigated. Optimized MnO2 thin films exhibited high charge capacity, good cycling reversibility, and stability in a mild aqueous electrolyte and are thus promising electrode materials for the fabrication of thin-film electrochemical capacitors.

  2. Use of hydrous titanium dioxide as potential sorbent for the removal of manganese from water

    Kamaraj, Ramakrishnan; Ganesan, Pandian; Vasudevan, Subramanyan


    This research article deals with an electrosynthesis of hydrous titanium dioxide by anodic dissolution of titanium sacrificial anodes and their application for the adsorption of manganese from aqueous solution...

  3. Sorption of arsenic on manganese dioxide synthesized by solid state reaction.

    Dalvi, Aditi A; Ajith, Nicy; Swain, Kallola K; Verma, Rakesh


    Arsenic in groundwater is a major concern in many parts of the world and suitable sorbents are required for removal of arsenic from ground water. Removal of arsenic from groundwater has been studied using manganese dioxide, synthesized by solid state reaction of manganese acetate with potassium permanganate. Manganese dioxide was characterized by X-ray diffraction (XRD), zeta potential, surface area, particle size measurements and thermal analysis. XRD measurement showed that the manganese dioxide had α-MnO2 structure. Sorption of As(III) and As(V) on manganese dioxide was studied by radiotracer technique using (76)As radio isotope. Arsenic removal efficiency for both As(III) and As(V) at concentration of 2 mg L(-1) was ∼99% in the pH range of 3-9. The sorption capacities for As(III) and As(V) were ∼60 mg g(-1). Kinetic studies showed that the equilibrium was reached within 30 s. Arsenic sorbed on manganese dioxide was present as As(V) irrespective of initial oxidation state. The presence of Ca(2+), Mg(2+), Cl(-) and SO4(2-) up to a concentration of 1000 mg L(-1) had no significant effect on arsenic sorption. The sorption of arsenic decreased significantly in the presence of phosphate and bicarbonate anions above 10 mg L(-1). Arsenic sorbed on manganese dioxide was desorbed by 0.1M NaOH. Arsenic was effectively removed by manganese dioxide from groundwater samples collected from arsenic contaminated areas of West Bengal, India.

  4. Adsorption of dimethylamine from aqueous solution by manganese dioxide.

    Yang, L; Chen, Z; Zhang, D; Liu, Y; Han, Y; Shen, J


    Removal of precursors of N-nitrosodimethylamine (NDMA), such as the most direct precursor dimethylamine (DMA), might be an effective method to control NDMA formation during practical water treatment process. Adsorption of DMA onto manganese dioxide (MnO₂) from aqueous solution has been investigated using batch experiments in this study. Results indicate that DMA adsorption is initially rapid (in the first 5 h) and the adsorption process reaches a steady state after 15 h. The adsorption isotherms are well described by the Freundlich models. The desorption shows an irreversibility of DMA adsorption onto MnO₂. The effects of temperature, pH, ionic strength, humic acid, and the presence of other secondary aliphatic amines on adsorption processes are also examined. According to the experimental results, the amount of DMA adsorbed increases with an increase of temperature from 288 to 308 K, and with a decrease of ionic strength from 1 to 10 mM. The maximum adsorption appeared at pH 7.0. However, the amount of DMA adsorbed onto MnO₂ does not show obvious difference in the presence of humic acid. According to the results, it suggests that the adsorption is primarily brought about by electrostatic interaction between DMA and MnO₂ surface.

  5. Immunosensor based on carbon nanotube/manganese dioxide electrochemical tags.

    Tu, Meng-Che; Chen, Han-Yi; Wang, Yuxi; Moochhala, Shabbir M; Alagappan, Palaniappan; Liedberg, Bo


    This article reports on carbon nanotube/manganese dioxide (CNT-MnO2) composites as electrochemical tags for non-enzymatic signal amplification in immunosensing. The synthesized CNT-MnO2 composites showed good electrochemical activity, electrical conductivity and stability. The electrochemical signal of CNT-MnO2 composites coated glassy carbon electrode (GCE) increased by nearly two orders of magnitude compared to bare GCE in hydrogen peroxide (H2O2) environment. CNT-MnO2 composite was subsequently validated as electrochemical tags for sensitive detection of α-fetoprotein (AFP), a tumor marker for diagnosing hepatocellular carcinoma. The electrochemical immunosensor demonstrated a linear response on a log-scale for AFP concentrations ranging from 0.2 to 100 ng mL(-1). The limit of detection (LOD) was estimated to be 40 pg mL(-1) (S/N=3) in PBS buffer. Further measurements using AFP spiked plasma samples revealed the applicability of fabricated CNT-MnO2 composites for clinical and diagnostic applications.

  6. Benzene conversion by manganese dioxide assisted silent discharge plasma

    LU Bin; JI Min; YU Xin; FENG Tao; YAO Shuiliang


    Non-thermal plasma technologies have shown their promising potential specially for the low concentration of volatile organic compound control in indoor air in recent years.But it is also high energy consuming.So,to improve the energy efficiency,adding catalysts which enhance the plasma chemical reactions to plasma reactors may be a good selection.Therefore,in this study the manganese dioxide assisted silent discharge plasma was developed for benzene conversion at a relatively high energy efficiency.The results show that MnO2 could promote complete oxidation of benzene with O2 and O3 produced in the plasma discharge zone.The energy efficiency of benzene conversion with MnO2 was two folds as much as that without catalysts.It was also found that the site of MnO2 in the reactor and the energy density had effects on benzene conversion.While the energy density was lower than 48 J/L,benzene conversion decreased with the increase in the distance between MnO2 bed and the plasma discharge zone.Whereas when the energy density was higher than 104 J/L,benzene conversion had an optimal value that was governed by the distance between MnO2 bed and the plasma discharge zone.The mechanism of benzene oxidation in plasma discharges and over MnO2 is discussed in detail.

  7. Alternative Anodes for the Electrolytic Reduction of Uranium Dioxide

    Merwin, Augustus

    Reprocessing of spent nuclear fuel is an essential step in closing the nuclear fuel cycle. In order to consume current stockpiles, ceramic uranium dioxide spent nuclear fuel will be subjected to an electrolytic reduction process. The current reduction process employs a platinum anode and a stainless steel alloy 316 cathode in a molten salt bath consisting of LiCl-2wt% Li 2O and occurs at 700°C. A major shortcoming of the existing process is the degradation of the platinum anode under the severely oxidizing conditions encountered during electrolytic reduction. This work investigates alternative anode materials for the electrolytic reduction of uranium oxide. The high temperature and extreme oxidizing conditions encountered in these studies necessitated a unique set of design constraints on the system. Thus, a customized experimental apparatus was designed and constructed. The electrochemical experiments were performed in an electrochemical reactor placed inside a furnace. This entire setup was housed inside a glove box, in order to maintain an inert atmosphere. This study investigates alternative anode materials through accelerated corrosion testing. Surface morphology was studied using scanning electron microscopy. Surface chemistry was characterized using energy dispersive spectroscopy and Raman spectroscopy. Electrochemical behavior of candidate materials was evaluated using potentiodynamic polarization characteristics. After narrowing the number of candidate electrode materials, ferrous stainless steel alloy 316, nickel based Inconel 718 and elemental tungsten were chosen for further investigation. Of these materials only tungsten was found to be sufficiently stable at the anodic potential required for electrolysis of uranium dioxide in molten salt. The tungsten anode and stainless steel alloy 316 cathode electrode system was studied at the required reduction potential for UO2 with varying lithium oxide concentrations. Electrochemical impedance spectroscopy

  8. Modification of Recycled Al-332 Alloy Using Manganese Dioxide

    Durowoju M.O.


    Full Text Available Aluminum and its alloys are commercially available materials for both domestic (cooking utensils, beverages can and industrial applications (automobile and aircraft structural parts. This study presented the effect of the use of manganese dioxide (MnO2, obtained from discarded dry cell batteries on the features and formation of pores in recycled pistons (Al-332 alloy. 3kg of recycled Al-332 alloy was obtained in form of ingot. 150 g of the ingot was re-melted and the molten alloy was treated with 2 to 12g of MnO2. The molten alloy was stirred gently for 1 minute, sand cast and normalized. Parts of the cast samples were used for microstructural analysis, tensile strength and hardness test following standard test procedures in accordance with ASTM E8M-91 standards (1992. The distribution of pores present in the cast alloys were studied using fractal analysis and spatial point pattern method (SPP. The hardness, tensile strength, average fractal dimensions and sphericities were related to the amount of MnO2. The micrographs revealed an absolute reduction in pores at 8gram addition of MnO2. Maximum hardness and tensile values of 50.8BHN and 65.01MN/m2 were obtained at 8 g addition of MnO2, above which there is decrease in properties of the material. The weighted average fractal dimension and sphericity for as-cast and sample treated with 8 g of MnO2 are 1.3276 and 0.3357; 1.0050 and 0.9918 respectively. Spatial point pattern revealed that the pores in the samples are randomly distributed

  9. Manganese dioxide graphite composite electrodes: application to the electroanalysis of hydrogen peroxide, ascorbic acid and nitrite.

    Langley, Cathryn E; Sljukić, Biljana; Banks, Craig E; Compton, Richard G


    The modification of carbon powder with manganese dioxide using a wet impregnation procedure with electrochemical characterisation of the modified powder is described. The process involves saturation of the carbon powder with manganese(II) nitrate followed by thermal treatment at ca. 773 K leading to formation of manganese(IV) oxide on the surface of the carbon powder. The construction of composite electrodes based on manganese dioxide modified carbon powder and epoxy resin is also described, including optimisation of the percentage of the modified carbon powder. Composite electrodes showed attractive performances for electroanalytical applications, proving to be suitable for the electrochemical detection of hydrogen peroxide, ascorbic acid and nitrite ions with limits of detection comparable to the detection limits achieved by other analytical techniques. The results obtained for detection of these analytes, together with composite electrodes flexible design and low cost offers potential application of composite electrodes in biosensors.

  10. Thermogravimetric Analysis and Kinetics on Reducing Low-Grade Manganese Dioxide Ore by Biomass

    Zhang, Honglei; Zhu, Guocai; Yan, Hong; Li, Tiancheng; Feng, Xiujuan


    Nonisothermal thermogravimetric analysis (TGA) was applied to evaluate rice straw, sawdust, wheat stalk, maize straw, and bamboo to explore their potential for reduction of manganese dioxide ore. Results from the biomass pyrolysis experiments showed that wood-based biomass materials, such as sawdust and bamboo, could produce more reductive agents, while herb-based biomass materials, such as rice straw, wheat stalk, and maize straw, had lower reaction temperatures. The peak temperatures for biomass reduction tests were 20 K to 50 K (20 °C to 50 °C) higher compared with the pyrolysis tests, and a clear shoulder at around 523 K (250 °C) could be observed. The effects of heating rate, biomass/manganese dioxide ore ratio, and different components of biomass were also investigated. An independent parallel first-order reaction kinetic model was used to calculate the values of activation energy and frequency factor for biomass pyrolysis and reduction of manganese dioxide ore. For better understanding the reduction process, kinetic parameters of independent behavior of manganese dioxide ore were also calculated by simple mathematical treatment. Finally, the isokinetic temperature T i and the rate constant k 0 for reduction of manganese oxide ore by reductive volatiles of biomass were derived according to the Arrhenius equation, which were determined to be 603 K (330 °C) and 108.99 min-1, respectively.

  11. The Mechanism on Biomass Reduction of Low-Grade Manganese Dioxide Ore

    Zhang, Honglei; Zhu, Guocai; Yan, Hong; Li, Tiancheng; Zhao, Yuna


    The mechanism on biomass reduction of low-grade manganese dioxide ore was studied by investigating influence factors on manganese recovery degree, such as the reaction temperature, time, biomass/ore ratio, compositions of biomass, nitrogen flow rate, and particle size of raw materials, and it was further identified through analysis of gas composition in the outlet gas, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) for the reduced sample. The results show that the reduction process involved mainly two steps: (1) The biomass was first pyrolyzed to release reductive volatiles and (2) manganese oxide ore was reacted with the reductive volatiles. By an analysis of gas composition in the outlet gas, it was also found that the ratio of biomass/ore had an important effect on the reduction mechanism. With a low biomass/ore ratio of 0.5:10, the reducing reaction of the reductive volatiles with manganese dioxide ore proceeded mainly in two stages: (1) The condensable volatiles (tar) released from biomass pyrolysis reacted with manganese oxide ore to produce reductive noncondensable gases such as hydrogen, carbon monoxide, and some light hydrocarbons; and (2) the small molecule gases further participated in the reduction. XRD pattern analysis on the reduced manganese dioxide ore revealed that the process of biomass reduction of manganese ore underwent in phases (MnO2 → Mn3O4 → MnO). The kinetics study showed the reduction process was controlled by a gas-solid reaction between biomass volatiles and manganese oxide ore with activation energy E of 53.64 kJ mol-1 and frequency factor A of 5.45 × 103 minutes-1.

  12. Dissection of the mechanism of manganese porphyrin-catalyzed chlorine dioxide generation.

    Umile, Thomas P; Wang, Dong; Groves, John T


    Chlorine dioxide, an industrially important biocide and bleach, is produced rapidly and efficiently from chlorite ion in the presence of water-soluble, manganese porphyrins and porphyrazines at neutral pH under mild conditions. The electron-deficient manganese(III) tetra-(N,N-dimethyl)imidazolium porphyrin (MnTDMImP), tetra-(N,N-dimethyl)benzimidazolium (MnTDMBImP) porphyrin, and manganese(III) tetra-N-methyl-2,3-pyridinoporphyrazine (MnTM23PyPz) were found to be the most efficient catalysts for this process. The more typical manganese tetra-4-N-methylpyridiumporphyrin (Mn-4-TMPyP) was much less effective. Rates for the best catalysts were in the range of 0.24-32 TO/s with MnTM23PyPz being the fastest. The kinetics of reactions of the various ClO(x) species (e.g., chlorite ion, hypochlorous acid, and chlorine dioxide) with authentic oxomanganese(IV) and dioxomanganese(V)MnTDMImP intermediates were studied by stopped-flow spectroscopy. Rate-limiting oxidation of the manganese(III) catalyst by chlorite ion via oxygen atom transfer is proposed to afford a trans-dioxomanganese(V) intermediate. Both trans-dioxomanganese(V)TDMImP and oxoaqua-manganese(IV)TDMImP oxidize chlorite ion by 1-electron, generating the product chlorine dioxide with bimolecular rate constants of 6.30 × 10(3) M(-1) s(-1) and 3.13 × 10(3) M(-1) s(-1), respectively, at pH 6.8. Chlorine dioxide was able to oxidize manganese(III)TDMImP to oxomanganese(IV) at a similar rate, establishing a redox steady-state equilibrium under turnover conditions. Hypochlorous acid (HOCl) produced during turnover was found to rapidly and reversibly react with manganese(III)TDMImP to give dioxoMn(V)TDMImP and chloride ion. The measured equilibrium constant for this reaction (K(eq) = 2.2 at pH 5.1) afforded a value for the oxoMn(V)/Mn(III) redox couple under catalytic conditions (E' = 1.35 V vs NHE). In subsequent processes, chlorine dioxide reacts with both oxomanganese(V) and oxomanganese(IV)TDMImP to afford chlorate

  13. Degradation of the solid electrolyte interphase induced by the deposition of manganese ions

    Shin, Hosop; Park, Jonghyun; Sastry, Ann Marie; Lu, Wei


    The deposition of manganese ions dissolved from the cathode onto the interface between the solid electrolyte interphase (SEI) and graphite causes severe capacity fading in manganese oxide-based cells. The evolution of the SEI layer containing these Mn compounds and the corresponding instability of the layer are thoroughly investigated by artificially introducing soluble Mn ions into a 1 mol L-1 LiPF6 electrolyte solution. Deposition of dissolved Mn ions induces an oxygen-rich SEI layer that results from increased electrolyte decomposition, accelerating SEI growth. The spatial distribution of Mn shows that dissolved Mn ions diffuse through the porous layer and are deposited mostly at the inorganic layer/graphite interface. The Mn compound deposited on the anode, identified as MnF2, originates from a metathesis reaction between LiF and dissolved Mn ion. It is confirmed that ion-exchange reaction occurs in the inorganic layer, converting SEI species to Mn compounds. Some of the Mn is observed inside the graphite; this may cause surface structural disordering in the graphite, limiting lithium-ion intercalation. The continuous reaction that occurs at the inorganic layer/graphite interfacial regions and the modification of the original SEI layer in the presence of Mn ions are critically related to capacity fade and impedance rise currently plaguing Li-ion cells.

  14. Theoretical Basis for the Separation of W and Mo with Manganese Dioxide: A Speciation-Based Approach

    Song, Yunfeng; Chen, Xingyu; Zhao, Zhongwei; Zhang, Jialiang; He, Lihua


    The separation of W and Mo has been a technical problem in extractive metallurgy. It is known that manganese nodule (mainly manganese oxides) can adsorb W efficiently in the thalassochemistry; if there exists a difference between the adsorption behaviors of W and Mo onto manganese dioxide, then W/Mo separation may be achieved using manganese dioxide. In this paper, the adsorption characteristics of W and Mo onto ``nascent'' manganese dioxide were studied under different pH, ionic strength, and different concentration. The results showed that the adsorption of W onto manganese dioxide was higher than Mo both in single-sorbate solution and mixed solution. Besides, ionic strength had no impact on the W and Mo adsorption, while pH significantly affected the W and Mo adsorption. The adsorption of W followed the Freundlich isotherm, indicating that the surface of manganese dioxide was heterogeneous. Speciation-based model was developed to describe the W and Mo adsorption onto manganese dioxide. This model can be well applicable for describing the adsorption behavior of W and Mo in a wide pH range of 2 to 12 and a wide surface loading range. Besides, the optimum pH range of W/Mo separation in mixed solution predicted by this model was 6 to 6.5, which agrees well with the experimental results, and the separation factor achieved the maximum value 7 at this optimum pH range. Such model offers an important insight into the adsorption mechanism of W and Mo onto manganese dioxide, and lays a theoretical foundation for the process of separating W and Mo with manganese dioxide.

  15. Selection and use of manganese dioxide by Neanderthals

    Heyes, P.J.; Anastasakis, K.; De Jong, W.; Van Hoesel, A.; Roebroeks, W.; Soressi, M.


    Several Mousterian sites in France have yielded large numbers of small black blocs. The usual interpretation is that these ‘manganese oxides’ were collected for their colouring properties and used in body decoration, potentially for symbolic expression. Neanderthals habitually used fire and if they

  16. Selection and use of manganese dioxide by Neanderthals

    Heyes, P.J.; Anastasakis, K.; De Jong, W.; Van Hoesel, A.; Roebroeks, W.; Soressi, M.


    Several Mousterian sites in France have yielded large numbers of small black blocs. The usual interpretation is that these ‘manganese oxides’ were collected for their colouring properties and used in body decoration, potentially for symbolic expression. Neanderthals habitually used fire and if they

  17. Manganese

    Manganese is a mineral that is found in several foods including nuts, legumes, seeds, tea, whole grains, ... body requires it to function properly. People use manganese as medicine. Manganese is used for prevention and ...

  18. On the Oxidation State of Manganese Ions in Li-Ion Battery Electrolyte Solutions.

    Banerjee, Anjan; Shilina, Yuliya; Ziv, Baruch; Ziegelbauer, Joseph M; Luski, Shalom; Aurbach, Doron; Halalay, Ion C


    We demonstrate herein that Mn(3+) and not Mn(2+), as commonly accepted, is the dominant dissolved manganese cation in LiPF6-based electrolyte solutions of Li-ion batteries with lithium manganate spinel positive and graphite negative electrodes chemistry. The Mn(3+) fractions in solution, derived from a combined analysis of electron paramagnetic resonance and inductively coupled plasma spectroscopy data, are ∼80% for either fully discharged (3.0 V hold) or fully charged (4.2 V hold) cells, and ∼60% for galvanostatically cycled cells. These findings agree with the average oxidation state of dissolved Mn ions determined from X-ray absorption near-edge spectroscopy data, as verified through a speciation diagram analysis. We also show that the fractions of Mn(3+) in the aprotic nonaqueous electrolyte solution are constant over the duration of our experiments and that disproportionation of Mn(3+) occurs at a very slow rate.

  19. Use of hydrous titanium dioxide as potential sorbent for the removal of manganese from water

    Ramakrishnan Kamaraj


    Full Text Available This research article deals with an electrosynthesis of hydrous titanium dioxide by anodic dissolution of titanium sacrificial anodes and their application for the adsorption of manganese from aqueous solution. Titanium sheet was used as the sacrificial anode and galvanized iron sheet was used as the cathode. The optimization of different experimental parameters like initial ion concentration, current density, pH, temperature, etc., on the removal efficiency of manganese was carried out. The maximum removal efficiency of 97.55 % was achieved at a current density of 0.08 A dm-2 and pH of 7.0. The Langmuir, Freundlich and Redlich Peterson isotherm models were applied to describe the equilibrium isotherms and the isotherm constants were determined. The adsorption of manganese preferably followed the Langmuir adsorption isotherm. The adsorption kinetics was modelled by first- and second- order rate models and the adsorption kinetic studies showed that the adsorption of manganese was best described using the second-order kinetic model. Thermodynamic parameters indicate that the adsorption of manganese on hydrous titanium dioxide was feasible, spontaneous and exothermic.

  20. Trimethylsilylcyclopentadiene as a novel electrolyte additive for high temperature application of lithium nickel manganese oxide cathode

    Tu, Wenqiang; Ye, Changchun; Yang, Xuerui; Xing, Lidan; Liao, Youhao; Liu, Xiang; Li, Weishan


    Electrolyte additives are necessary for the application of high potential cathode in high energy density lithium ion batteries, especially at elevated temperature. However, the electrolyte additives that can effectively suppress the dissolution of transition metal ions from cathode have seldom been developed up to date. In this work, we propose a novel electrolyte additive, trimethylsilylcyclopentadiene (SE), for high temperature application of a representative high potential cathode, lithium nickel manganese oxide (LiNi0.5Mn1.5O4). It is found that the dissolution of Mn and Ni from LiNi0.5Mn1.5O4 can be effectively suppressed by applying SE. With applying 0.25% SE, the dissolved amount of Mn and Ni is decreased by 97.4% and 98%, respectively, after 100 cycles at 55 °C. Correspondingly, the cyclic performance of LiNi0.5Mn1.5O4 is significantly improved. Physical characterizations and electrochemical measurements show that SE can be preferentially oxidized and generate a protective film on LiNi0.5Mn1.5O4. The resulting film inhibits the electrolyte decomposition and the transition metal ion dissolution.

  1. Vapor-Liquid-Solid Equilibria of Sulfur Dioxide in Aqueous Electrolyte Solutions

    Pereda, Selva; Thomsen, Kaj; Rasmussen, Peter


    The Extended UNIQUAC model for electrolyte systems, combined with the Soave-Redlich-Kwong equation of state is used to describe the complex vapor-liquid-solid equilibria of sulfur dioxide in electrolyte solutions. Model parameters based on 1500 experimental data points are presented. The paramete...

  2. Reuse of Anode Slime Generated by the Zinc Industry to Obtain a Liquor for Manufacturing Electrolytic Manganese

    Ayala, J.; Fernández, B.


    A hydrometallurgical process is proposed in this article to recover manganese from a zinc electrowinning residue. The article describes the digestion-leaching experiments, precipitation, and electrowinning assays to recover Mn from this residue. Anode slime is treated with sulfuric acidic in a furnace within a temperature range of 400-450°C, leached with water, and then filtered. The results show that the dissolution of manganese increases with increasing temperature in the digestion step. The recovery yield of manganese was higher than 90%. As manganese electrolysis requires an electrolyte free of Zn, Ni, Co, and Cu pollutants, the sulfuric acid liquor needs a purification step. Na2S is used to remove pollutants. The results obtained in this study have shown that the proposed process for the recovery of manganese from this type of residue is technically viable.

  3. Crystallization Characteristic of Glass-ceramic Made from Electrolytic Manganese Residue

    QIAN Jueshi; HOU Pengkun; WANG Zhi; QU Yanzhao


    Electrolytic manganese residue (EMR) is a waste from electrolytic manganese industry that contains high concentration of toxic substances.Since the EMR disposal in landfill sites has a serious environmental impact,new ways of EMR utilization are being sought.Considering the melting of EMR to a glass at high temperature was a relatively less energy-intensive process,EMR was first made into a base glass and then the ground base glass was heat-treated in a certain procedure to make a glass-ceramic and the crystallization process was studied.It was determined by X-ray diffraction (XRD) that the primary crystalline phases of the EMR glass-ceramic were diopside and anorthite,which formed the surface crystallization mechanism with a crystallization activation energy of 429 kJ/mol.Scanning electron microscopy (SEM)observation showed that a layer of small spherical particles with an average size of about 0.5 μm were covered on the glass matrix surface,and among them there were some big particles.The low melting temperature and crystallization activation energy make it promising to reuse EMR for glass-ceramic production.

  4. Reduction of Low-grade Manganese Dioxide Ore Pellets by Biomass Wheat Stalk

    Honglei ZHANG; Guocai ZHU; Hong YAN; Yuna ZHAO; Tiancheng LI; Xiujuan FENG


    An investigation on reducing low-grade manganese dioxide ore pellets was carried out by using wheat stalk as reductant.The main impact factors of reduction percent such as particle size,biomass/ore ratio,heating rate,nitrogen flow rate,temperature and time in reduction process were discussed.The morphology and component of manganese dioxide ore particle at different stages were also analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS).The results show the increase of the reduction temperature and time,biomass/ore ratio,and the decrease of particle size,heating rate and nitrogen flow rate can significantly enhance reduction efficiency.The reduction kinetic of the manganese ore is controlled by three-dimensional mass diffusion of gaseous reductive volatiles passing from the surface to the core of the ore particles.The activation energy E and frequency factor A were calculated to be 24.15 kJ.mol-1 and 166 min-1,respectively.Biomass pyrolysis volatiles adsorbed onto the surface of the ore particle leads to serious variation of the microstructures and chemical composition of the manganese ore particles.

  5. Manganese oxide/graphene oxide composites for high-energyaqueous asymmetric electrochemical capacitors

    Jafta, CJ


    Full Text Available A high-energy aqueous asymmetric electrochemical capacitor was developed using manganese diox-ide ( -MnO2)/graphene oxide (GO) nanocomposites. The nanostructured -MnO2was prepared frommicron-sized commercial electrolytic manganese dioxide (EMD) via...

  6. Mild and selective heterogeneous catalytic hydration of nitriles to amides by flowing through manganese dioxide.

    Battilocchio, Claudio; Hawkins, Joel M; Ley, Steven V


    A sustainable flow chemistry process for the hydration of nitriles, whereby an aqueous solution of the nitrile is passed through a column containing commercially available amorphous manganese dioxide, has been developed. The product is obtained simply by concentration of the output stream without any other workup steps. The protocol described is rapid, robust, reliable, and scalable, and it has been applied to a broad range of substrates, showing a high level of chemical tolerance.

  7. Plant extract-mediated biogenic synthesis of silver, manganese dioxide, silver-doped manganese dioxide nanoparticles and their antibacterial activity against food- and water-borne pathogens.

    Krishnaraj, Chandran; Ji, Byoung-Jun; Harper, Stacey L; Yun, Soon-Il


    Silver nanoparticles (AgNPs), manganese dioxide nanoparticles (MnO₂NPs) and silver-doped manganese dioxide nanoparticles (Ag-doped MnO₂NPs) were synthesized by simultaneous green chemistry reduction approach. Aqueous extract from the leaves of medicinally important plant Cucurbita pepo was used as reducing and capping agents. Various characterization techniques were carried out to affirm the formation of nanoparticles. HR-TEM analysis confirmed the size of nanoparticles in the range of 15-70 nm and also metal doping was confirmed through XRD and EDS analyses. FT-IR analysis confirmed that the presence of biomolecules in the aqueous leaves extract was responsible for nanoparticles synthesis. Further, the concentration of metals and their doping in the reaction mixture was achieved by ICP-MS. The growth curve and well diffusion study of synthesized nanoparticles were performed against food- and water-borne Gram-positive and Gram-negative bacterial pathogens. The mode of interaction of nanoparticles on bacterial cells was demonstrated through Bio-TEM analysis. Interestingly, AgNPs and Ag-doped MnO₂NPs showed better antibacterial activity against all the tested bacterial pathogens; however, MnO₂NPs alone did not show any antibacterial properties. Hence, AgNPs and Ag-doped MnO₂NPs synthesized from aqueous plant leaves extract may have important role in controlling various food spoilage caused by bacteria.

  8. Simultaneous removal of tetracycline hydrochloride and As(III) using poorly-crystalline manganese dioxide.

    Wang, Huawei; Zhang, Daoyong; Mou, Shuyong; Song, Wenjuan; Al-Misned, Fahad A; Golam Mortuza, M; Pan, Xiangliang


    Simultaneous removal of antibiotic tetracycline hydrochloride (TC) and As(III) by poorly-crystalline Mn dioxide was investigated. TC and As(III) can be effectively oxidized and removed by MnO2. High concentrations of TC and As(III) competed with each other for oxidation or adsorption sites on MnO2 and thus affected their removal efficiency. The intermediates and products of TC after reaction with poorly-crystalline manganese dioxide were identified by LC-ESI-MS (liquid chromatography-electrospray ionization-mass spectrometry), and the decomposition pathways of TC by MnO2 were proposed. This study is helpful for understanding the importance of environmental Mn dioxides in the decontamination of combined pollution by organic pollutants and metal(loid)s. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese from electrolytic manganese residue by air under calcium oxide assist.

    Chen, Hongliang; Liu, Renlong; Shu, Jiancheng; Li, Wensheng


    Leaching tests of electrolytic manganese residue (EMR) indicated that high contents of soluble manganese and ammonia-nitrogen posed a high environmental risk. This work reports the results of simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese by air under calcium oxide assist. The ammonia-nitrogen stripping rate increased with the dosage of CaO, the air flow rate and the temperature of EMR slurry. Stripped ammonia-nitrogen was absorbed by a solution of sulfuric acid and formed soluble (NH4)2SO4 and (NH4)3H(SO4)3. The major parameters that effected soluble manganese precipitation were the dosage of added CaO and the slurry temperature. Considering these two aspects, the efficient operation conditions should be conducted with 8 wt.% added CaO, 60°C, 800 mL min(-1) air flow rate and 60-min reaction time. Under these conditions 99.99% of the soluble manganese was precipitated as Mn3O4, which was confirmed by XRD and SEM-EDS analyses. In addition, the stripping rate of ammonia-nitrogen was 99.73%. Leaching tests showed the leached toxic substances concentrations of the treated EMR met the integrated wastewater discharge standard of China (GB8978-1996).

  10. Significantly improved cyclability of lithium manganese oxide under elevated temperature by an easily oxidized electrolyte additive

    Zhu, Yunmin; Rong, Haibo; Mai, Shaowei; Luo, Xueyi; Li, Xiaoping; Li, Weishan


    Spinel lithium manganese oxide, LiMn2O4, is a promising cathode for lithium ion battery in large-scale applications, because it possesses many advantages compared with currently used layered lithium cobalt oxide (LiCoO2) and olivine phosphate (LiFePO4), including naturally abundant resource, environmental friendliness and high and long work potential plateau. Its poor cyclability under high temperature, however, limits its application. In this work, we report a significant cyclability improvement of LiMn2O4 under elevated temperature by using dimethyl phenylphonite (DMPP) as an electrolyte additive. Charge/discharge tests demonstrate that the application of 0.5 wt.% DMPP yields a capacity retention improvement from 16% to 82% for LiMn2O4 after 200 cycles under 55 °C at 1 C (1C = 148 mAh g-1) between 3 and 4.5 V. Electrochemical and physical characterizations indicate that DMPP is electrochemically oxidized at the potential lower than that for lithium extraction, forming a protective cathode interphase on LiMn2O4, which suppresses the electrolyte decomposition and prevents LiMn2O4 from crystal destruction.

  11. Autogenous electrolyte, non-pyrolytically produced solid capacitor structure

    Sharp, D.J.; Armstrong, P.S.; Panitz, J.K.G.


    A solid electrolytic capacitor is described having a solid electrolyte comprising manganese dioxide dispersed in an aromatic polyamide capable of further cure to form polyimide linkages, the solid electrolyte being disposed between a first electrode made of valve metal covered by an anodic oxide film and a second electrode opposite the first electrode. The electrolyte autogenously produces water, oxygen, and hydroxyl groups which act as healing substances and is not itself produced pyrolytically. Reduction of the manganese dioxide and the water molecules released by formation of imide linkages result in substantially improved self-healing of anodic dielectric layer defects. 2 figs.

  12. Nanostructured Multilayer Composite Films of Manganese Dioxide/Nickel/Copper Sulfide Deposited on Polyethylene Terephthalate Supporting Substrate

    Awangku Nabil Syafiq Bin Awangku Metosen


    Full Text Available Nanostructured multilayer manganese dioxide/nickel/copper sulfide (MnO2/Ni/CuS composite films were successfully deposited onto supporting polyethylene terephthalate (PET substrate through the sequential deposition of CuS, Ni, and MnO2 thin films by chemical bath deposition, electrodeposition, and horizontal submersion deposition techniques, respectively. Deposition of each thin-film layer was optimized by varying deposition parameters and conditions associated with specific deposition technique. Both CuS and Ni thin films were optimized for their electrical conductivity whereas MnO2 thin film was optimized for its microstructure and charge capacity. The electrochemical properties of nanostructured multilayer MnO2/Ni/CuS composite films were evaluated by cyclic voltammetry as electrode materials of an electrochemical capacitor prototype in a dual-planar device configuration. Cyclic voltammogram in mild Na2SO4 aqueous electrolyte exhibited a featureless and almost rectangular shape which was indicative of the ideal capacitive behavior and high cycling reversibility of the electrochemical capacitor prototype. Nanostructured multilayer MnO2/Ni/CuS composite films on supporting polyethylene terephthalate (PET substrate could potentially be utilized as electrode materials for the fabrication of high performance electrochemical capacitors.

  13. Investigation of cathodic current collection in lithium/manganese dioxide cells by electrochemical impedance spectroscopy

    Merritt, D.R.; Schmidt, C.L. [Medtronic, Inc., Minneapolis, MN (United States)


    Contact impedance between pressed composite manganese dioxide cathodes and current collectors has been shown to play an important role in the overall impedance of primary Li/MnO{sub 2} cells. Specifically, this impedance is manifested by an arc in the complex-plane impedance plot, representative of a parallel resistive/capacitive combination, This paper presents the results of a systematic series of experiments designed to better define the relationship between cathodic current collector configuration and cell impedance. A refined equivalent circuit model of the Li/MnO{sub 2} cell is also presented.

  14. Anticlastogenic Effect of Redistilled Cow's Urine Distillate in Human Peripheral Lymphocytes Challenged With Manganese Dioxide and Hexavalent Chromium



    Objective To study the anticlastogenic effect of redistilled cow's urine distillate (RCUD) in human peripheral lymphocytes (HLC) challenged with manganese dioxide and hexavalent chromium. Methods The anticlastogenic activity of redistilled cow's urine distillate was studied in human polymorphonuclear leukocytes (HPNLs) and human peripheral lymphocytes in vitro challenged with manganese dioxide and hexavalent chromium as established genotoxicants and clastogens which could cause induction of DNA strand break, chromosomal aberration and micronucleus. Three different levels of RCUD: 1 μL/mL, 50 μL/mL and 100μL/mL, were used in the study. Results Manganese dioxide and hexavalent chromium caused statistically significant DNA strand break, chromosomal aberration and micronucleus formation, which could be protected by redistilled cow's urine distillate. Conclusion The redistilled cow's urine distillate posseses strong antigenotoxic and anticlastogenic properties against HPNLs and HLC treated with Cr+6 and MnO2. This property is mainly due to the antioxidants present in RCUD.

  15. Arsenic transformation and adsorption by iron hydroxide/manganese dioxide doped straw activated carbon

    Xiong, Ying; Tong, Qiang; Shan, Weijun; Xing, Zhiqiang; Wang, Yuejiao; Wen, Siqi; Lou, Zhenning


    Iron hydroxide/manganese dioxide doped straw activated carbon was synthesized for As(III) adsorption. The Fe-Mn-SAc adsorbent has two advantages, on the one hand, the straw active carbon has a large surface area (1360.99 m2 g-1) for FeOOH and MnO2 deposition, on the other hand, the manganese dioxide has oxidative property as a redox potential of (MnO2 + H+)/Mn2+, which could convert As(III) into As(V). Combined with the arsenic species after reacting with Fe-Mn-SAc, the As(III) transformation and adsorption mechanism was discussed. H2AsO4-oxidized from As(III) reacts with the Fe-Mn-SAc by electrostatic interaction, and unoxidized As(III) as H3AsO3 reacts with SAc and/or iron oxide surface by chelation effect. The adsorption was well-described by Langmuir isotherms model, and the adsorption capacity of As(III) was 75.82 mg g-1 at pH 3. Therefore, considering the straw as waste biomass material, the biosorbent (Fe-Mn-SAc) is promising to be exploited for applications in the treatment of industrial wastewaters containing a certain ratio of arsenic and germanium.

  16. Preparation of manganese dioxide loaded activated carbon adsorbents and their desulfurization performance

    Zhang, Jiaojing; Wang, Guojian; Wang, Wenyi; Song, Hua; Wang, Lu


    Manganese dioxide loaded activated carbon adsorbents (MnO2/AC) were prepared and characterized by N2 adsorption-desorption, BET method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometry (FT-IR) and scanning electron microscopy (SEM). Effects of preparation conditions and adsorption conditions on desulfurization performance of the adsorbents were studied in a fixed-bed adsorption apparatus. Experimental results show that the surface area and pore volume of MnO2/AC decreased compared with the unmodified activated carbon, but the adsorption capacity to H2S was improved greatly. A suitable H2S removal activity was obtained with manganese dioxide to activated carbon ratio of 1.1: 1 and the calcination temperature of 250°C. At the adsorption temperature of 40°C and gas flow rate of 20 mL/min, the H2S saturation capacity and H2S removal rate reached up to 713.25 mg/g and 89.9%, respectively.

  17. Fabrication of titanium dioxide nanotube arrays using organic electrolytes

    Yoriya, Sorachon

    This dissertation focuses on fabrication and improvement of morphological features of TiO2 nanotube arrays in the selected organic electrolytes including dimethyl sulfoxide (DMSO; see Chapter 4) and diethylene glycol (DEG; see Chapter 5). Using a polar dimethyl sulfoxide containing hydrofluoric acid, the vertically oriented TiO2 nanotube arrays with well controlled morphologies, i.e. tube lengths ranging from few microns up to 101 microm, pore diameters from 100 nm to 150 nm, and wall thicknesses from 15 nm to 50 nm were achieved. Various anodization variables including fluoride ion concentration, voltage, anodization time, water content, and reuse of the anodized electrolyte could be manipulated under proper conditions to control the nanotube array morphology. Anodization current behaviors associated with evolution of nanotube length were analyzed in order to clarify and better understand the formation mechanism of nanotubes grown in the organic electrolytes. Typically observed for DMSO electrolyte, the behavior that anodization current density gradually decreases with time is a reflection of a constant growth rate of nanotube arrays. Large fluctuation of anodization current was significantly observed probably due to the large change in electrolyte properties during anodization, when anodizing in high conductivity electrolytes such as using high HF concentration and reusing the anodized electrolyte as a second time. It is believed that the electrolyte properties such as conductivity and polarity play important role in affecting ion solvation and interactions in the solution consequently determining the formation of oxide film. Fabrication of the TiO2 nanotube array films was extended to study in the more viscous diethylene glycol (DEG) electrolyte. The arrayed nanotubes achieved from DEG electrolytes containing either HF or NH4 F are fully separated, freely self-standing structure with open pores and a wide variation of tube-to-tube spacing ranging from

  18. A Facile and Efficient Oxidation of (,(-Unsaturated Alcohols with Manganese Dioxide in Ionic Liquids under Mild Conditions

    Wei Liang BAO; Qiang WANG; Yun Fa ZHENG


    The oxidation of α,β-unsaturated primary and secondary alcohols to corresponding aldehydes and ketones by manganese dioxide in ionic liquids as a safe recyclable and accelerative reaction medium under mild conditions are described. The rate of the oxidation reaction is faster and the yield is higher than that with conventional procedures.

  19. Preparation of MnO2and calcium silicate hydrate from electrolytic manganese residue and evaluation of adsorption properties

    李昌新; 钟宏; 王帅; 薛建荣; 武芳芳; 张振宇


    Electrolytic manganese residue (EMR), a high volume byproduct resulting from the electrolytic manganese industry, was used as a cheap and abundant chemical source for preparing MnO2 and EMR-made calcium silicate hydrate (EMR-CSH). The MnO2 is successfully synthesized from the metal cations extracted from EMR, which can effectively recycle the manganese in the EMR. By the combination of XRD, SEM and EDX analysis, the as-prepared MnO2 is found to exhibit a single-phase with the purity of 90.3%. Furthermore, EMR-CSH is synthesized from EMR via hydrothermal method. Based on the detailed analyses using XRD, FT-IR, FE-SEM, EDX and BET surface area measurement, the product synthesized under the optimum conditions (pH 12.0 and 100 °C) is identified to be a calcium silicate hydrate with a specific surface area of 205 m2/g incorporating the slag-derived metals (Al and Mg) in its structure. The as-synthesized material shows good adsorption properties for removal of Mn2+ and phosphate ions diluted in water, making it a promising candidate for efficient bulk wastewater treatment. This conversion process, which enables us to fabricate two different kinds of valuable materials from EMR at low cost and through convenient preparation steps, is surely beneficial from the viewpoint of the chemical and economical use of EMR.

  20. Simultaneous recovery of zinc and manganese dioxide from household alkaline batteries through hydrometallurgical processing

    de Souza, Cleusa Cristina Bueno Martha; Tenório, Jorge Alberto Soares

    This paper describes the leaching experiments and the electrowinning tests to recover Zn and Mn from spent household alkaline batteries. After the dismantling of the batteries, the black powder was analyzed and found to contain 21 wt.% Zn and 45%wt. Mn. Therefore, it was considered that recovery of these metals would be interesting due to their relatively large amounts in this kind of waste. Batch laboratory experiments were carried out to develop an acid leaching procedure and to determine appropriate leaching conditions to maximize zinc extraction and to study the leaching behavior of Mn. An experimental study was undertaken to evaluate the feasibility of simultaneous recovery of zinc and particulate manganese dioxide using a laboratory cell. The results from these electrowinning experiments are also presented in this paper.

  1. High electrochemical properties of graphene nanoribbons-hybridized manganese dioxide as cathode material for lithium battery

    Huang, Xiangyue; Fan, Zihan; Lin, Cunli; Jia, Lina; Lin, Baiwei; Wang, Jiaqi; Hu, Xiaolin, E-mail:; Zhuang, Naifeng, E-mail: [Fuzhou University, College of Chemistry (China)


    Manganese dioxide crystallite and its composite hybridized with graphene nanoribbons (GNRs) are prepared by hydrothermal method. The effects of reaction temperature and time, surfactant, and reducing Mn resource are discussed. As the cathode material for Li battery, γ-MnO{sub 2} nanowire/nanorod hybridizing with (GNRs) (γ-MnO{sub 2}/GNRs) shows a higher discharge specific capacity than it covering with carbon nanotubes or graphene sheets. In addition, the discharge specific capacity of γ-MnO{sub 2}/GNRs is much higher than those of pure β-MnO{sub 2} and compact β-MnO{sub 2}/GNRs. The effects of crystal size, morphology, and GNR hybrid on the discharge specific capacity are discussed.

  2. The oxidative and adsorptive effectiveness of hydrous manganese dioxide for arsenite removal

    Liu Ruiping; Yuan Baoling; Li Xing; Xia Shengji; Yang Yanling; Li Guibai


    This study focuses on the effectiveness of hydrous manganese dioxides (δMnO2) removing arsenite (As(Ⅲ)) from aqueous solution. Effects of such factors as permanganate oxidation, pH, humic acid and Ca2+ on As removal and possible mechanisms involved in have been investigated. Permanganate oxidation increases As removal to a certain extent; the higher pH results in the formation of more easily adsorbed As species, contributing to higher As removal; humic acid occupies adsorbing sites and decreases ζ potential of δMnO2, therefore inhibiting As removal; Ca2+ facilitates As adsorption on δMnO2, mainly through increasing ζ potential and decreasing repulsive forces between As and surface sites. δMnO2 exhibits oxidative and adsorptive potential for As(Ⅲ), and may be employed as adsorbents or filter coating for As removal in water treatment process.

  3. Cathodic reduction of sulfur dioxide in nonaqueous electrolytes. The effect of solution composition on the diffusion coefficient of sulfur dioxide

    Shembel, E.M.; Ksenzhek, O.S.; Lituinova, V.I.; Lobach, G.A.


    The authors measured the diffusion coefficients of SO/sub 2/ in electrolytes based on propylene carbonate, acetonitrile, dimethylformamide and dimethylsulfoxide in order to estimate possible diffusion limitations with respect to SO/sub 2/ and to establish the influence exerted by the solvent type on the process. The diffusion coefficients were calculated from the limiting diffusion currents of steady-state polarization curves for sulfur dioxide reduction recorded at a gold microdisk electrode which had a diameter of 2 x 10/sup -3/ cm. In lithium salt solutions the potentiodynamic curves recorded at the microelectrode do not exhibit a limiting current but are characterized by a current maximum.

  4. Three-Man Solid Electrolyte Carbon Dioxide Electrolysis Breadboard

    Isenberg, Arnold O.


    The development of the Three-Man (2.2 lb CO2/man-day) Solid Electrolyte CO2 Electrolysis Breadboard consisted of a Phase 1 and 2 effort. The Phase 1 effort constituted fabrication of three electrolysis cell types and performing parametric testing, off-design testing, and cell life testing. The Phase 2 consisted of the preliminary design, incorporation of palladium (Pd) tubes for hydrogen separation from the electrolyzer cathode feed gases, design support testing, final design, fabrication, and performance testing of the breadboard system. The results of performance tests demonstrated that CO2 electrolysis in an oxygen reclamation system for long duration space-based habitats is feasible. Closure of the oxygen system loop, therefore, can be achieved by CO2 electrolysis. In a two step process the metabolic CO2 and H2O vapor are electrolyzed into O2, H2, and CO. The CO can subsequently be disproportionated into carbon and CO2 in a carbon deposition reactor and the CO2 in turn be recycled and electrolyzed for total O2 recovery. The development effort demonstrated electrolyzer system can be designed and built to operate safely and reliably and the incorporation of Pd tubes for hydrogen diffusion can be integrated safely with predictable performance.

  5. Cationic Effect on the Electrochemical Characteristics of the Hydrothermally Grown Manganese Dioxide

    Vernardou, D.; Kazas, A.; Apostolopoulou, M.; Katsarakis, N.; Koudoumas, E.


    Hydrothermal growth of manganese dioxide (MnO2) nanostructures was carried out on indium tin dioxide glass substrates at 95°C for 24 h to study the effect of cations such as K+, Li+, and Na+ on their properties. It was observed that presence of cations affected the MnO2 phase and morphology: amorphous MnO2 (no cations) showed columnar-like structure, ɛ-MnO2 (K+) presented nanowires, α-MnO2 (Na+) was composed of agglomerates of spherical nanoparticles, while β-MnO2 (Li+) consisted of spherical aggregates of nanoparticles. The different electrochemical performance depending on the structure is expected to be useful for application in Li-ion batteries. As-grown ɛ-MnO2 exhibited lower charge resistance and higher ionic diffusion rate, providing the electrode with enhanced specific discharge capacity of 910 mAh g-1 and capacity retention of 98% after 500 scans. Hence, K+ can support tunnel structures and stabilize the structure compared with the smaller cations Na+ and Li+.

  6. Non-heme manganese catalysts for on-demand production of chlorine dioxide in water and under mild conditions.

    Hicks, Scott D; Kim, Doyeon; Xiong, Silei; Medvedev, Grigori A; Caruthers, James; Hong, Seungwoo; Nam, Wonwoo; Abu-Omar, Mahdi M


    Two non-heme manganese complexes are used in the catalytic formation of chlorine dioxide from chlorite under ambient temperature at pH 5.00. The catalysts afford up to 1000 turnovers per hour and remain highly active in subsequent additions of chlorite. Kinetic and spectroscopic studies revealed a Mn(III)(OH) species as the dominant form under catalytic conditions. A Mn(III)(μ-O)Mn(IV) dinuclear species was observed by EPR spectroscopy, supporting the involvement of a putative Mn(IV)(O) species. First-order kinetic dependence on the manganese catalyst precludes the dinuclear species as the active form of the catalyst. Quantitative kinetic modeling enabled the deduction of a mechanism that accounts for all experimental observations. The chlorine dioxide producing cycle involves formation of a putative Mn(IV)(O), which undergoes PCET (proton coupled electron-transfer) reaction with chlorite to afford chlorine dioxide. The ClO2 product can be efficiently removed from the aqueous reaction mixture via purging with an inert gas, allowing for the preparation of pure chlorine dioxide for on-site use and further production of chlorine dioxide.

  7. 4-(Trifluoromethyl)-benzonitrile: A novel electrolyte additive for lithium nickel manganese oxide cathode of high voltage lithium ion battery

    Huang, Wenna; Xing, Lidan; Wang, Yating; Xu, Mengqing; Li, Weishan; Xie, Fengchao; Xia, Shengan


    In this work, 4-(Trifluoromethyl)-benzonitrile (4-TB) is used as a novel electrolyte additive for LiNi0.5Mn1.5O4 cathode of high voltage lithium ion battery. Charge-discharge tests show that the cyclic stability of LiNi0.5Mn1.5O4 is significantly improved by using 0.5 wt.% 4-TB. With using 4-TB, LiNi0.5Mn1.5O4 delivers an initial capacity of 133 mAh g-1 and maintains 121 mAh g-1 after 300 cycles with a capacity retention of 91%, compared to the 75% of that using base electrolyte (1 M LiPF6 in ethylene carbonate(EC)/dimethyl carbonate(DMC)). The results from linear sweep voltammetry, density functional theory calculations, electrochemical impedance spectroscopy, scanning electron microscope, energy dispersive spectroscopy, Fourier transform infrared, and inductively coupled plasma, indicate that 4-TB has lower oxidative stability than EC and DMC, and is preferentially oxidized on LiNi0.5Mn1.5O4 forming a low-impedance protective film, which prevents the subsequent oxidation decomposition of the electrolyte and suppresses the manganese dissolution from LiNi0.5Mn1.5O4.

  8. Lithium/Manganese Dioxide (Li/MnO(2)) Battery Performance Evaluation: Final Report

    Ingersoll, D.; Clark, N.H.


    In February 1997, under the auspices of the Product Realization Program, an initiative to develop performance models for lithium/manganese dioxide-based batteries began. As a part of this initiative, the performance characteristics of the cells under a variety of conditions were determined, both for model development and for model validation. As a direct result of this work, it became apparent that possible Defense Program (DP) uses for batteries based on this cell chemistry existed. A larger effort aimed at mapping the performance envelope of this chemistry was initiated in order to assess the practicality of this cell chemistry, not only for DP applications, but also for other uses. The work performed included an evaluation of the cell performance as a function of a number of variables, including cell size, manufacturer, current, pulse loads, constant current loads, safety, etc. In addition, the development of new evaluation techniques that would apply to any battery system, such as those related to reliability assessments began. This report describes the results of these evaluations.

  9. Flexible electrodes based on polypyrrole/manganese dioxide/polypropylene fibrous membrane composite for supercapacitor

    Jin Ming [Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Taiyuan 030006 (China); Han Gaoyi, E-mail: [Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Taiyuan 030006 (China); Chang Yunzhen; Zhao Hua; Zhang Huanyu [Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Taiyuan 030006 (China)


    Highlights: > PPy/MnO{sub 2}/polypropylene fibrous film (PPF) is prepared by polymerizing pyrrole in gas. > The morphology and conductivity are influenced strongly by the content of PPy/MnO{sub 2}. > Specific capacitance of the capacitor reaches 110 F g{sup -1} based on amount of PPy/MnO{sub 2}. - Abstract: The composites of polypyrrole/manganese dioxide/polypropylene fibrous films (PPy/MnO{sub 2}/PPF) have been prepared in situ through chemical oxidation polymerization by using the mixture of FeCl{sub 3}.6H{sub 2}O and MnO{sub 2} adsorbed on PPF as oxidant in the atmosphere of pyrrole vapor at room temperature. The morphologies and structures of the composites are investigated by using scanning electron microscope and X-ray diffraction spectroscopy. The properties of the capacitor cells assembled by the composites of PPy/MnO{sub 2}/PPF are evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy methods. The results reveal that the morphologies, conductivities and capacitance performance of the composites are influenced strongly by the content of MnO{sub 2} in the solution of oxidant. The capacitors assembled by PPy/MnO{sub 2}/PPF exhibit the property of quick charge/discharge, and the highest specific capacitance of about 110 F g{sup -1} is obtained when the PPy/MnO{sub 2} content in the composite is about 17.4%.

  10. Fully Converting Graphite into Graphene Oxide Hydrogels by Preoxidation with Impure Manganese Dioxide.

    Sun, Jiaojiao; Yang, Ningxin; Sun, Zhe; Zeng, Mengqi; Fu, Lei; Hu, Chengguo; Hu, Shengshui


    Potassium permanganate (KMnO4) has been proved to be an efficient oxidant for converting graphite into graphite oxide, but its slow diffusion in the interlayer of graphite seriously restricts the production of graphene oxide (GO). Here, we demonstrate that the preoxidation of graphite by impure manganese dioxide (MnO2) in a mixture of concentrated sulfuric acid (H2SO4) and phosphorus pentoxide (P2O5) can efficiently improve the synthesis of GO when KMnO4 is employed as the oxidant. The prepared honey-like GO hydrogels possess a high yield of single-layer sheets, large sizes (average lateral size up to 20 μm), wide ranges of stable dispersion concentrations (from dilute solutions, viscous hydrogels, to dry films), and good conductivity after reduction (~2.9 × 10(4) S/m). The mechanism for the improved synthesis of GO by impure MnO2 was explored. The enhanced exfoliation and oxidation of graphite by oxidative Mn ions (mainly Mn(3+)), which are synergistically produced by the reaction of impure MnO2 with H2SO4 and P2O5, are found to be responsible for the improved synthesis of such GO hydrogels. Particularly, preoxidized graphite (POG) can be partially dispersed in water with sonication, which allows the facile construction of flexible and highly conductive graphene nanosheet film electrodes with excellent electrochemical sensing properties.

  11. Removal of Pb(II) from aqueous solution by hydrous manganese dioxide: adsorption behavior and mechanism.

    Xu, Meng; Wang, Hongjie; Di, Lei; Qu, Dan; Zhai, Yujia; Wang, Yili


    Hydrous manganese dioxide (HMO) synthesized by redox of potassium permanganate and hydrogen peroxide was used as an adsorbent for Pb(II) removal. The specific surface area, pore volume and BJH pore diameter of the HMO were 79.31 m2/g, 0.07 cm3/g and 3.38 nm, respectively. The adsorption equilibrium at 298 K could be well described by the Langmuir isotherm equation with qmax value of 352.55 mg/g. The negative values of deltaG and the positive values of deltaH and deltaS indicated the adsorption process was spontaneous and endothermic. The pseudo second-order equation could best fit the adsorption data. The value of the calculated activation energy for Pb(II) adsorption onto the HMO was 38.23 kJ/mol. The uptake of Pb(II) by HMO was correlated with increasing surface hydroxyl group content and the main adsorbed speciation was PbOH+. The final chemical state of Pb(II) on the surface of HMO was similar to PbO. HMO was a promising candidate for Pb(II) removal from aqueous solution.

  12. Manganese dioxide-graphene nanocomposite film modified electrode as a sensitive voltammetric sensor of indomethacin detection

    Liu, Yuxia; Zhang, Zhenfa; Zhang, Cuizong; Huang, Wei; Liang, Caiyun; Peng, Jinyun [Guangxi Normal University for Nationalities, Chongzuo (China)


    Excess amount of analgesic and anti-inflammatory drug, such as indomethacin, often leads to serious gastrointestinal complications; therefore, amount of such active compound should be regulated in commercial drugs. This study proposes an efficient analytical technique to detect indomethacin selectively. We prepared and investigated electrochemical properties of a manganese dioxide-graphene nanocomposite film modified glassy carbon electrode (MnO{sub 2}-Gr/GCE). The behavior of the modified electrode as electrocatalyst towards indomethacin oxidation was also examined. The cyclic voltammetric results reveal that the electrocatalytic activity for the oxidation of indomethacin can significantly be enhanced on the MnO{sub 2}-Gr/GCE. Indomethacin exhibited a sensitive anodic peak at about 0.90 V at MnO{sub 2}-Gr/GCE. The data obtained from differential pulse voltammetry showed that the anodic peak currents were linearly dependent on the indomethacin concentrations in the range of 1.0 X 10{sup -7} to 2.5 X 10{sup -5} mol/L with a detection limit of 3.2 X 10{sup -8} mol/L (S/N = 3). Most importantly, the proposed method shows efficient and selective sensing of indomethacin in commercial harmaceutical formulations. This is the first report of a voltammetric sensor for indomethacin using MnO{sub 2}-Gr/GCE. We believe that this new method can be commercialized for routine applications in laboratories.

  13. Lithium carbonate as an electrolyte additive for enhancing the high-temperature performance of lithium manganese oxide spinel cathode

    Wang, Renheng [School of Metallurgy and Environment, Central South University, Changsha 410083 (China); Li, Xinhai, E-mail: [School of Metallurgy and Environment, Central South University, Changsha 410083 (China); Wang, Zhixing; Guo, Huajun [School of Metallurgy and Environment, Central South University, Changsha 410083 (China); Hou, Tao [Jiangxi Youli New Materials Co., Ltd, Pingxiang 337000 (China); Yan, Guochun; Huang, Bin [School of Metallurgy and Environment, Central South University, Changsha 410083 (China)


    Highlights: • The addition of Li{sub 2}CO{sub 3} to the electrolyte can suppress the contents of HF in the electrolyte. • The low self-discharge rate of the LiMn{sub 2}O{sub 4} cells with Li{sub 2}CO{sub 3} is lower than that of no additive. • The LiMn{sub 2}O{sub 4} cells with Li{sub 2}CO{sub 3} exhibit better rate capability and excellent cycle stability than that without Li{sub 2}CO{sub 3}. • A stable film can be formed on the LiMn{sub 2}O{sub 4} cathode using containing-Li{sub 2}CO{sub 3} electrolyte. - Abstract: The effect of lithium carbonate (Li{sub 2}CO{sub 3}) as an additive on the stability of the electrolyte and cycling performance of lithium manganese oxide spinel (LiMn{sub 2}O{sub 4}) batteries at elevated temperature was studied. The addition of Li{sub 2}CO{sub 3} to the electrolyte can suppress the capacity fading of LiMn{sub 2}O{sub 4} batteries. The linear sweep voltammetry (LSV) and the cyclic voltammetry (CV) indicate that Li{sub 2}CO{sub 3} has a lower oxidation potential in the mixed solvents of ethylene carbonate (EC), diethyl carbonate (DEC) and ethyl methyl carbonate (EMC), participating in the formation process of the stable cathode electrolyte interface (CEI) film. In addition, the results of electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrate that the stable CEI film of the cells with Li{sub 2}CO{sub 3} can be formed, which can effectively reduce the dissolution of Mn{sup 2+} from LiMn{sub 2}O{sub 4} into the electrolyte at elevated temperature. It is concluded that the addition of Li{sub 2}CO{sub 3} to a solution of 1 M LiPF{sub 6}–EC/EMC/DEC = 1/1/1 (weight ratio) may decrease solvent decomposition and change the structure of the passivation film on the LiMn{sub 2}O{sub 4} cathode.

  14. Preparation of Electrolytic Manganese Residue Composite Cementing Material%电解锰渣复合胶凝材料的研制

    王智; 高翠翠; 王庆珍


    Electrolytic manganese residue and calcined lime were used to stimulate the activity of the pozzolanic material of fly ash,and electrolytic manganese residue composite cementing material was researched and developed.The influence of electrolytic manganese residue and cement to composite cementing material was studied,and based on this,the optimal mix proportion was concluded.When the mass ratio of electrolytic manganese residue,fly ash,lime and cement was 50 ∶ 30 ∶ 10 ∶ 10,water to binder ratio was 0.55,28 d flexural,compressive strength of electrolytic manganese residue composite cementing material were 2.50 MPa,10.05 MPa.%利用电解锰渣和生石灰激发火山灰质材料粉煤灰的火山灰活性,制备电解锰渣复合胶凝材料.研究了电解锰渣和水泥对复合胶凝材料性能的影响,并在此基础上得出了最佳配合比,当电解锰渣复合胶凝材料中电解锰渣、粉煤灰、生石灰与水泥的质量比为50∶30∶ 10∶10,取水胶质量比为0.55,其28d抗折、抗压强度分别为2.50 MPa、10.05 MPa.

  15. The effect of the amount of electrolyte in the anode gel on the rechargeability of alkaline manganese dioxidezinc cells

    Sharma, Yatendra; Haynes, Alejandro; Binder, Leo; Kordesch, Karl

    The zinc-limited anode technology for rechargeable alkaline manganese dioxidezinc cells is well known. Attempts have been made to relate the rechargeability of these cells with the amount of electrolyte available in the anode gel. The rechargeability of the cells is found to increase with the amount of electrolyte up to 35 - 40% of the dry weight of the anode mass. Further increases in the amount of electrolyte were found to be detrimental to the rechargeability of the cells. Analysis of cathodes after running several cycles shows higher amounts of zinc in those from cells with greater amounts of electrolyte. This could be due to haeterolite formation in the cathode which poisons it thus explaining the reduced rechargeability with excess electrolyte.

  16. Research progress of chemical manganese dioxide%化学二氧化锰研究进展

    彭爱国; 贺周初; 肖伟; 丁雄磊; 庄新娟


    Research progress and present status of preparation and application of chemical manganese dioxide (CMD)were reviewed. Several common preparation methods, such as manganese carbonate thermal decomposition method, manganese nitrate thermal decomposition method, solution oxidation - reduction method, and nano - MnO2 preparing method, were introduced ,and advantages and disadvantages of these methods were analyzed. At present, the main industrial production methods of CMD are manganese carbonate thermal decomposition method ,manganese nitrate thermal decomposition method,and manganese sulfate-potassium permanganate oxidation-reduction method. Preparation and application of nano - MnO2 are important developing directions of CMD.%综述了化学二氧化锰的制备、应用等方面的研究进展和现状.介绍了几种常用的制备方法,包括:碳酸锰热分解法、硝酸锰热分解法、溶液氧化还原法,以及纳米二氧化锰的制备方法,并分析了这些制备方法的特点.目前化学二氧化锰的主要工业生产方法是碳酸锰热分解法、硝酸锰热分解法和硫酸锰-高锰酸钾氧化还原法.纳米二氧化锰的制备及其应用是未来化学二氧化锰研究的重要发展方向.

  17. Rhenium and manganese bipyridine tricarbonyl catalysts for the electrochemical reduction of carbon dioxide

    Sampson, Matthew Dean

    Electrocatalytic reduction of carbon dioxide (CO2) is a profoundly challenging problem that is of interest, not only as a means of counteracting unsustainable emissions of CO2, but also as a method for the development of renewable fuels. Rhenium and manganese bipyridine tricarbonyl complexes are among the most active and robust catalysts for proton-coupled CO 2 reduction to carbon monoxide (CO). X- ray Absorption Spectroscopy studies are reported to reveal the electronic ground state of the Re catalysts, which help explain origins for high selectivity for CO2 reduction over proton reduction. Stopped-flow mixing in tandem with rapid-scan IR spectroscopy is utilized to probe the direct reaction of the Re catalysts with CO 2, observing, for the first time, the binding of CO2 to these catalysts. Manganese bipyridine catalysts are desirable, in comparison with their Re analogs, due to the earth-abundance of Mn and the ability for these catalysts to operate at lower overpotentials. One distinct difference between these Mn catalysts and their Re counterparts is a high tendency for dimerization after one-electron reduction, which contributes to the potential necessary to access their active state and to limiting their catalytic activity. Synthetic modification of the bipyridine ligand (by adding bulky mesityl groups) is used to completely eliminate dimerization for these Mn complexes, allowing the active catalyst to be generated at a 300 mV more positive potential than in typically Mn bipyridine complexes. CO2 reactivities in the presence of weak Bronsted acids, strong Bronsted acids, and Lewis acids have been explored in order to encourage this bulky Mn catalyst to reduce CO2 at low overpotentials. Mechanistic tools, including IR-spectroelectrochemistry, are described to gain insight into these unique catalytic processes. In order to further enhance stability and facilitate product separation, the use of metal-organic frameworks (MOFs) is explored as a means of anchoring

  18. Significantly improving trace thallium removal from surface waters during coagulation enhanced by nanosized manganese dioxide.

    Huangfu, Xiaoliu; Ma, Chengxue; Ma, Jun; He, Qiang; Yang, Chun; Jiang, Jin; Wang, Yaan; Wu, Zhengsong


    Thallium (Tl) is an element of high toxicity and significant accumulation in human body. There is an urgent need for the development of appropriate strategies for trace Tl removal in drinking water treatment plants. In this study, the efficiency and mechanism of trace Tl (0.5 μg/L) removal by conventional coagulation enhanced by nanosized manganese dioxide (nMnO2) were explored in simulated water and two representative surface waters (a river water and a reservoir water obtained from Northeast China). Experimental results showed that nMnO2 significantly improve Tl(I) removal from selected waters. The removal efficiency was dramatically higher in the simulated water, demonstrating by less than 0.1 μg/L Tl residual. The enhancement of trace Tl removal in the surface waters decreased to a certain extent. Both adjusting water pH to alkaline condition and preoxidation of Tl(I) to Tl(III) benefit trace Tl removal from surface waters. Data also indicated that competitive cation of Ca(2+) decreased the efficiency of trace Tl removal, resulting from the reduction of Tl adsorption on nMnO2. Humic acid could largely low Tl removal efficiency during nMnO2 enhanced coagulation processes. Trace elemental Tl firstly adsorbed on nMnO2 and then removed accompanying with nMnO2 settling. The information obtained in the present study may provide a potential strategy for drinking water treatment plants threatened by trace Tl.

  19. Ytterbium-doped Q-switched fiber laser based upon manganese dioxide (MnOsub>2sub>) saturable absorber.

    Hattori, Haroldo T; Khaleque, Abdul; Liu, Liming; Greck, Michael R


    Manganese dioxide (MnOsub>2sub>) is an abundant material that is widely used in many devices, such as alkaline batteries. At infrared frequencies, MnOsub>2sub> is lossy and strongly absorbs light. These characteristics make MnOsub>2sub> a potential candidate as a low-cost saturable absorber in Q-switched lasers. In this paper, we examine the performance of MnOsub>2sub> as a saturable absorber in an ytterbium-doped Q-switched fiber laser: we show that it can produce pulses with durations ranging from 300 to 1800 ns.

  20. Development of a solid electrolyte carbon dioxide and water reduction system for oxygen recovery

    Elikan, L.; Morris, J. P.; Wu, C. K.


    A 1/4-man solid electrolyte oxygen regeneration system, consisting of an electrolyzer, a carbon deposition reactor, and palladium membranes for separating hydrogen, was operated continuously in a 180-day test. Oxygen recovery from the carbon dioxide-water feed was 95%. One percent of the oxygen was lost to vacuum with the hydrogen off-gas. In a space cabin, the remaining 4% would have been recycled to the cabin and recovered. None of the electrolysis cells used in the 180-day test failed. Electrolysis power rose 20% during the test; the average power was 283.5 watts/man. Crew time was limited to 18 min/day of which 12 min/day was used for removing carbon. The success achieved in operating the system can be attributed to an extensive component development program, which is described. Stability of operation, ease of control, and flexibility in feed composition were demonstrated by the life test.

  1. The use of renewable energy in the form of methane via electrolytic hydrogen generation using carbon dioxide as the feedstock

    Hashimoto, Koji; Kumagai, Naokazu; Izumiya, Koichi; Takano, Hiroyuki; Shinomiya, Hiroyuki; Sasaki, Yusuke; Yoshida, Tetsuya; Kato, Zenta


    The history reveals the continuous increase in world energy consumption and carbon emissions. For prevention of intolerable global warming and complete exhaustion of fossil fuels we need complete conversion from fossil fuel consumption to renewable energy. We have been performing the research and development of global carbon dioxide recycling for more than 25 years to supply renewable energy to the world in the form of methane produced by the reaction of carbon dioxide captured from chimney with hydrogen generated electrolytically using electricity generated by renewable energy. We created the cathode and anode for electrolytic hydrogen generation and the catalyst for carbon dioxide methanation by the reaction with hydrogen. The methane formation from renewable energy will be the most convenient and efficient key technology for the use of renewable energy by storage of intermittent and fluctuating electricity generated from renewable energy and by regeneration of stable electricity. Domestic and international cooperation of companies for industrialization is in progress.

  2. Preparation of Ceramic Tiles with Electrolytic Manganese and Waste Glass Admicture%利用电解锰渣-废玻璃制备陶瓷砖

    冉岚; 刘少友; 杨红芸; 张扬


    In order to solve the pollution of electrolytic manganese residue, the environment and improve the utilization of manganese slag, the preparation of ceramic tiles was studied by using electrolytic manganese and waste glass as the main raw material. The basic formulas were obtained in terms of the CaO-Al2O3-SiO2 termary system phase diagram, then they were optimized through a lot of experiments and the text of crystallization. The results indicated that the calcining temperature was 950℃electrolysis manganese when adding 32%electrolytic manganese and 10 g waste glass, the main crystals composition were quartz, cristobalite, mullite and anorthite, the shrinkage is 0.27%, it complied with the standard of GB/T 4100-2006 ceramic tiles.%为了解决电解锰渣对环境的污染,提高锰渣的利用率,研究了以电解锰渣-废玻璃为主要原料制备陶瓷砖。首先利用CaO-Al2O3-SiO2三相图获得初始配方,然后进行了大量的实验,并对产品的晶相进行分析,确定陶瓷砖的最优配方。结果证明,锰渣的添加量为32%,废玻璃含量为25%,煅烧温度为950℃,煅烧时间为30 min时,陶瓷坯的主晶相为石英、钙长石、莫来石和方石英,收缩率为0.27%,符合GB/T 4100-2006陶瓷砖的标准。

  3. 萃取分离电解锰阳极液中锰、镁离子试验研究%Separating of Manganese and Magnesium From Electrolytic Manganese Anode Solution Using P204

    皮露; 何克杰; 罗炎; 孙维义; 丁桑岚; 苏仕军


    电解锰过程中,阳极液中的镁离子在闭路循环中会逐渐积累,使电流效率下降,能耗增大,同时也影响电解锰产品质量。研究了用P204‐磺化煤油溶液萃取分离阳极液中的锰离子和镁离子,分别考察了 P204体积分数、有机相皂化率、水相p H、相比等参数对锰离子和镁离子萃取率的影响。结果表明,在溶液温度35℃、P204体积分数25%、有机相皂化率50%、水相p H=4.0,V o ∶V a =2∶1的最佳条件下,经4级逆流萃取,锰离子萃取率达99.5%,镁离子萃取率为31.8%。%In the process of electrolytic manganese ,the magnesium ions in anode solution will gradually accumulated in closed cycle to reduce current efficiency and increase energy consumption ,and affect the quality of electrolytic manganese product .The separation of manganese and magnesium from the electrolytic manganese anode solution using P204 in sulfonated kerosene was investigated .The influence of several parameters on the extraction rate of manganese and magnesium were examined , such as P204 volume fraction in organic phase ,saponification rate of the organic phase ,water phase pH ,the ratio of organic phase volume to water phase volume .The results suggest that under the conditions of temperature of 35 ℃ ,P204 volume fraction of 25% ,organic phase saponification rate of 50% ,water phase pH of 4 .0 ,Vo ∶Va = 2∶1 ,and four‐stages countercurrent extraction ,satisfactory extraction efficiency (99 .5% ) of manganese ion is achieved ,while the extraction of magnesium is approximately 31 .8% ,manganese ion and magnesium ion are effectively separated at a low cost .

  4. Reduction Kinetics of Manganese Dioxide by Geobacter Sulfurreducens and Associated Biofilm Morphology in a Flow-Through Reactor

    Berns, E.; Werth, C. J.; Valocchi, A. J.; Sanford, R. A.


    Biogeochemical interactions have been investigated extensively to characterize natural nutrient cycling and predict contaminant transport in surface and groundwater. Dissimilatory metal reducing bacteria, many of which form biofilms, play an important role in reducing a variety of metals in these systems. It has been shown that biofilm morphology is impacted by flow conditions, but there has been little work that explores how reduction kinetics change as a result of these different morphologies. Different flow rates may affect physical properties of the biofilm that influence the rate of substrate reduction. We introduce an approach to calculate changes in Monod kinetic parameters while simultaneously evaluating biofilm morphologies under different flow rates. A vertical, cylindrical flow cell with removable glass slide sections coated in manganese dioxide (electron acceptor) was used to grow a biofilm of Geobacter sulfurreducens with acetate as the electron donor under both high (50 mL/hr) and low (5 mL/h) flow rates. The removable sections allowed for visualization of the biofilm at different time points with a confocal microscope, and quantification of the biomass on the surface using a combination of a protein assay and image analysis. Data collected from the experiments was used to determine yield and specific growth rate at the different flow rates, and a simple numerical model was used to estimate the half saturation constant of manganese dioxide at both flow rates. A smaller half saturation constant was estimated at the higher flow rate, indicating that the biofilm was more efficient in the high flow system, but a strong correlation between morphology and the faster reduction rate was not observed. Monod kinetic parameters are important for the development of accurate nutrient cycling and contaminant transport models in natural environments, and understanding how they are impacted by flow will be important for the development of new, improved models.

  5. Formation mechanism of manganese compounds in acidic electrolytes of copper; Mecanismo de la formacion de compuestos de manganeso en electrolitos acidos

    Ipinza, J.; Ibanez, J. P.; Pagliero, A.; Vergara, F.


    The formation mechanism of manganese compounds in acidic electrolytes (180 g/l of H{sub 2}SO{sub 4}) was studied by potentiostatic experiments at 50 degree centigree. In the oxide layer on a PbCaSn anode, amorphous MnOOH was formed XRD showed that anodic slimes collected from the cell bottom after 3 h was made up of: {gamma}-MnO{sub 2} and {epsilon}-MnO{sub 2}. It was proved that the {epsilon} type oxide was formed by an electrochemical process and the {gamma} type oxide was formed by a pure chemical precipitation, the last one depends on the MnO{sub 4} concentration in the electrolyte. The electrochemical formation of MnOOH only depends on the concentrations of Mn''3+ in the electrolyte, and this amorphous compounds in the intermediate specie for generating {epsilon}-MnO{sub 2}. Fe''2+, in the presence of Mn''2+. inhibited the formation of both MnO{sub 2} oxides, and in the anode interface reduces PbO{sub 2} to PbSO{sub 4}, that reports in the anodic slime. furthermore, the presence of ferrous ion resulted in a better distribution of the manganese compounds and originates PbSO{sub 4} precipitates, which report on the slime. (Author) 25 refs.

  6. Manganese-catalysed autoxidation of dissolved sulfur dioxide in the atmospheric aqueous phase

    Berglund, Johan; Elding, Lars I.

    Autoxidation of SO 2(aq) in the presence of manganese(II) is one of the important pathways for sulfuric acid formation in atmospheric clouds and fogs. Recent experimental results indicating that the catalyzed reaction takes place via a complex free-radical mechanism are discussed. Previous literature is reviewed in the light of this mechanism. Under atmospheric conditions of low total concentrations of manganese(II) ( < 2 × 10 -5 M) and sulfur(IV) ( ≤ 10 -5 M) and 2.5 < pH < 5, the rate law for conversion of SO 2(aq) to SO 3(aq) is reduced to d[S(IV)]/d t = k[Mn(II)][S(IV)], where [S(IV)] denotes the total concentration. A value of the overall rate constant k of 1.4 × 10 3 M -1s -1 is recommended for use in atmospheric model calculations.

  7. Zirconium dioxide nanofilled poly(vinylidene fluoride-hexafluoropropylene) complexed with lithium trifluoromethanesulfonate as composite polymer electrolyte for electrochromic devices

    Puguan, John Marc C.; Chinnappan, Amutha [Department of Energy and Biotechnology, Energy and Environment Fusion Technology Center, Myongji University, Yongin, Gyeonggi-do 449-728 (Korea, Republic of); Kostjuk, Sergei V. [Research Institute for Physical Chemical Problems, Belarusian State University, Minsk 220030 (Belarus); Kim, Hern, E-mail: [Department of Energy and Biotechnology, Energy and Environment Fusion Technology Center, Myongji University, Yongin, Gyeonggi-do 449-728 (Korea, Republic of)


    Highlights: • Successful synthesis of electrolyte by blending PVdF-HFP, ZrO{sub 2} and LiCF{sub 3}SO{sub 3}. • ZrO{sub 2} increased electrolyte conductivity by two orders of magnitude. • ZrO{sub 2} doubled bulk mechanical strength of electrolyte in terms of Young’s modulus. • Electrolytes gave a optimum optical transmittance of 52.6%. - Abstract: Poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) polymer electrolyte containing zirconium dioxide nanocrystals (ZrO{sub 2}-NC) and lithium trifluoromethanesulfonate (LiCF{sub 3}SO{sub 3}) has been synthesized using the conventional solution casting method. The addition of ZrO2-NC into the polymeric substrate gave remarkable properties in terms of the electrolyte’s ionic conductivity as well as its bulk mechanical strength. The enhanced amorphicity of the polymeric substrate due to ZrO{sub 2} and the nanofiller’s high dielectric constant make an excellent combination to increase the ionic conductivity (above 10{sup −4} S cm{sup −1}). Increasing the nanofiller content raises the ionic conductivity of the electrolyte by two orders of magnitude of which the optimum is 2.65 × 10{sup −4} S cm{sup −1} at 13.04 wt% ZrO{sub 2}-NC loading. Also, the Young’s modulus, an indicator of electrolyte’s mechanical stability, dramatically increased to 207 MPa upon loading 13.04 wt% ZrO{sub 2}-NC. Using UV–vis spectroscopy, the electrolytes with 13.04% ZrO{sub 2}-NC scanned from 200–800 nm wavelengths exhibited a maximum optical transmittance of 52.6% at 10 μm film thickness. The enhanced conductivity, high mechanical strength and reasonable optical transmittance shown by our composite polymer electrolyte make an excellent electrolyte for future energy saving smart windows such as electrochromic devices.

  8. Freestanding manganese dioxide nanosheet network grown on nickel/polyvinylidene fluoride coaxial fiber membrane as anode materials for high performance lithium ion batteries

    Zhang, Yan; Luo, Zhongping; Xiao, Qizhen; Sun, Tianlei; Lei, Gangtie; Li, Zhaohui; Li, Xiaojing


    A novel manganese dioxide (MnO2) nanosheet network grown on nickel/polyvinylidene fluoride (Ni/PVDF) coaxial fiber membrane is successfully fabricated by a three-step route: the polyvinylidene fluoride fiber membrane is prepared by electrospinning method, and then the Ni(shell)/PVDF(core) coaxial fiber membrane with core-shell structure can be obtained by the electroless deposition, and finally the manganese dioxide nanosheet network grown on Ni/PVDF coaxial fiber membrane can be achieved by using a simple hydrothermal treatment. This as-prepared binder-free and flexible composite membrane is directly used as anode for lithium ion batteries. The excellent electrochemical performance of the composite membrane can be attributed to the unique combinative effects of nanosized MnO2 network and conductive Ni/PVDF fiber matrix as well as the porous structure of composite fiber membrane.

  9. Manganese dioxide as a new cathode catalyst in microbial fuel cells

    Li, Xiang; Hu, Boxun; Suib, Steven; Lei, Yu; Li, Baikun

    This study focused on manganese oxides with a cryptomelane-type octahedral molecular sieve (OMS-2) structure to replace platinum as a cathode catalyst in microbial fuel cells (MFCs). Undoped (ud-OSM-2) and three catalysts doped with cobalt (Co-OMS-2), copper (Cu-OMS-2), and cerium (Ce-OMS-2) to enhance their catalytic performances were investigated. The novel OMS-2 cathodes were examined in granular activated carbon MFC (GACMFC) with sodium acetate as the anode reagent and oxygen in air as the cathode reagent. The results showed that after 400 h of operation, the Co-OMS-2 and Cu-OMS-2 exhibited good catalytic performance in an oxygen reduction reaction (ORR). The voltage of the Co-OMS-2 GACMFC was 217 mV, and the power density was 180 mW m -2. The voltage of the Cu-OMS-2 GACMFC was 214 mV and the power density was 165 mW m -2. The internal resistance (R in) of the OMS-2 GACMFCs (18 ± 1 Ω) was similar to that of the platinum GACMFCs (17 Ω). Furthermore, the degradation rates of organic substrates in the OMS-2 GACMFCs were twice those in the platinum GACMFCs, which enhance their wastewater treatment efficiencies. This study indicated that using OMS-2 manganese oxides to replace platinum as a cathodic catalyst enhances power generation, increases contaminant removal, and substantially reduces the cost of MFCs.

  10. Rechargeability and economic aspects of alkaline zinc-manganese dioxide cells for electrical storage and load leveling

    Ingale, ND; Gallaway, JW; Nyce, M; Couzis, A; Banerjee, S


    Batteries based on manganese dioxide (MnO2) cathodes are good candidates for grid-scale electrical energy storage, as MnO2 is low-cost, relatively energy dense, safe, water-compatible, and non-toxic. Alkaline Zn-MnO2 cells, if cycled at reduced depth of discharge (DOD), have been found to achieve substantial cycle life with battery costs projected to be in the range of $100 to 150 per kWh (delivered). Commercialization of rechargeable Zn-MnO2 batteries has in the past been hampered due to poor cycle life. In view of this, the work reported here focuses on the long-term rechargeability of prismatic MnO2 cathodes at reduced DOD when exposed to the effects of Zn anodes and with no additives or specialty materials. Over 3000 cycles is shown to be obtainable at 10% DOD with energy efficiency >80%. The causes of capacity fade during long-term cycling are also investigated and appear to be mainly due to the formation of irreversible manganese oxides in the cathode. Analysis of the data indicates that capacity loss is rapid in the first 250 cycles, followed by a regime of stability that can last for thousands of cycles. A model has been developed that captures the behavior of the cells investigated using measured state of charge (SOC) data as input. An approximate economic analysis is also presented to evaluate the economic viability of Zn-MnO2 batteries based on the experiments reported here. (C) 2014 Elsevier B.V. All rights reserved.

  11. Globally sustainable manganese metal production and use.

    Hagelstein, Karen


    The "cradle to grave" concept of managing chemicals and wastes has been a descriptive analogy of proper environmental stewardship since the 1970s. The concept incorporates environmentally sustainable product choices-such as metal alloys utilized steel products which civilization is dependent upon. Manganese consumption is related to the increasing production of raw steel and upgrading ferroalloys. Nonferrous applications of manganese include production of dry-cell batteries, plant fertilizer components, animal feed and colorant for bricks. The manganese ore (high grade 35% manganese) production world wide is about 6 million ton/year and electrolytic manganese metal demand is about 0.7 million ton/year. The total manganese demand is consumed globally by industries including construction (23%), machinery (14%), and transportation (11%). Manganese is recycled within scrap of iron and steel, a small amount is recycled within aluminum used beverage cans. Recycling rate is 37% and efficiency is estimated as 53% [Roskill Metals and Minerals Reports, January 13, 2005. Manganese Report: rapid rise in output caused by Chinese crude steel production. Available from:]. Environmentally sustainable management choices include identifying raw material chemistry, utilizing clean production processes, minimizing waste generation, recycling materials, controlling occupational exposures, and collecting representative environmental data. This paper will discuss two electrolytically produced manganese metals, the metal production differences, and environmental impacts cited to date. The two electrolytic manganese processes differ due to the addition of sulfur dioxide or selenium dioxide. Adverse environmental impacts due to use of selenium dioxide methodology include increased water consumption and order of magnitude greater solid waste generation per ton of metal processed. The use of high grade manganese ores in the electrolytic process also

  12. Preparation, Characterization and NO-CO Redox Reaction Studies over Palladium and Rhodium Oxides Supported on Manganese Dioxide

    M.S. Fal Desai


    Full Text Available The catalytic activity of PdO/MnO2 and Rh2O3/MnO2 is investigated for NO-CO redox reaction. Supported catalysts are prepared by wet impregnation method. Among the tested catalysts, PdO/MnO2 shows higher activity for this reaction. Active metal dispersion on MnO2 enhances the selectivity for N2 over N2O in this reaction. The XRD substantiate the formation of MnO2 monophasic phase. SEM images show the formation of elongated particles. TEM images indicate nano-size rod-like morphologies. An increase in the catalytic activity is observed on supported Pd and Rh oxides on MnO2. Temperature programed desorption studies with NO and CO are undertaken to investigate the catalytic surface studies. © 2015 BCREC UNDIP. All rights reservedReceived: 22nd November 2014; Revised: 31st December 2014; Accepted: 2nd January 2015How to Cite: Fal Desai, M.S., Kunkalekar, R.K., Salker, A.V. (2015. Preparation, Characterization and NO-CO Redox Reaction Studies over Palladium and Rhodium Oxides Supported on Manganese Dioxide. Bulletin of Chemical Reaction Engineering & Catalysis, 10 (1: 98-103. (doi:10.9767/bcrec.10.1.7802.98-103Permalink/DOI: 

  13. Removal of Pb(Ⅱ) from aqueous solution by hydrous manganese dioxide:Adsorption behavior and mechanism

    Meng Xu; Hongjie Wang; Di Lei; Dan Qu; Yujia Zhai; Yili Wang


    Hydrous manganese dioxide (HMO) synthesized by redox of potassium permanganate and hydrogen peroxide was used as an adsorbent for Pb(Ⅱ) removal.The specific surface area,pore volume and BJH pore diameter of the HMO were 79.31 m2/g,0.07 cm3/g and 3.38 nm,respectively.The adsorption equilibrium at 298 K could be well described by the Langmuir isotherm equation with qmax value of 352.55 mg/g.The negative values of AG and the positive values of AH and AS indicated the adsorption process was spontaneous and endothermic.The pseudo second-order equation could best fit the adsorption data.The value of the calculated activation energy for Pb(Ⅱ) adsorption onto the HMO was 38.23 KJ/mol.The uptake of Pb(Ⅱ) by HMO was correlated with increasing surface hydroxyl group content and the main adsorbed speciation was PbOH+.The final chemical state of Pb(Ⅱ) on the surface of HMO was similar to PbO.HMO was a promising candidate for Pb(Ⅱ) removal from aqueous solution.

  14. 3D hierarchical flower-like nickel ferrite/manganese dioxide toward lead (II) removal from aqueous water.

    Xiang, Bo; Ling, Dong; Lou, Han; Gu, Hongbo


    A functionalized magnetic nickel ferrite/manganese dioxide (NiFe2O4/MnO2) with 3D hierarchical flower-like and core-shell structure was synthesized by a facile hydrothermal approach and applied for the removal of Pb(II) ions from aqueous solutions. Batch adsorption experiments were conducted to study the effect of solution pH, initial Pb(II) concentration, and dose of absorbents on the Pb(II) removal by NiFe2O4/MnO2. The NiFe2O4/MnO2 nanocomposites showed the fast Pb(II) adsorption performance with the maximum adsorption capacity of 85.78mgg(-1). The adsorption kinetics of Pb(II) onto NiFe2O4/MnO2 obeyed a pseudo-second-order model. The isothermal experimental results indicated that the Langmuir model was fitted better than the Freundlich model, illustrating a monolayer adsorption process for Pb(II) onto NiFe2O4/MnO2. Meanwhile, the NiFe2O4/MnO2 was easily separated from the solution by an external magnet within a short period of time and still exhibited almost 80% removal capacity after six regenerations. The NiFe2O4/MnO2 is expected to be a new promising adsorbent for heavy metal removal.

  15. Preparation of graphene oxide-manganese dioxide for highly efficient adsorption and separation of Th(IV)/U(VI).

    Pan, Ning; Li, Long; Ding, Jie; Li, Shengke; Wang, Ruibing; Jin, Yongdong; Wang, Xiangke; Xia, Chuanqin


    Manganese dioxide decorated graphene oxide (GOM) was prepared via fixation of crystallographic MnO2 (α, γ) on the surface of graphene oxide (GO) and was explored as an adsorbent material for simultaneous removal of thorium/uranium ions from aqueous solutions. In single component systems (Th(IV) or U(VI)), the α-GOM2 (the weight ratio of GO/α-MnO2 of 2) exhibited higher maximum adsorption capacities toward both Th(IV) (497.5mg/g) and U(VI) (185.2 mg/g) than those of GO. In the binary component system (Th(IV)/U(VI)), the saturated adsorption capacity of Th(IV) (408.8 mg/g)/U(VI) (66.8 mg/g) on α-GOM2 was also higher than those on GO. Based on the analysis of various data, it was proposed that the adsorption process may involve four types of molecular interactions including coordination, electrostatic interaction, cation-pi interaction, and Lewis acid-base interaction between Th(IV)/U(VI) and α-GOM2. Finally, the Th(IV)/U(VI) ions on α-GOM2 can be separated by a two-stage desorption process with Na2CO3/EDTA. Those results displayed that the α-GOM2 may be utilized as an potential adsorbent for removing and separating Th(IV)/U(VI) ions from aqueous solutions.

  16. Enhanced coagulation with in situ manganese dioxide on removal of humic acid in micro-polluted water.

    Zeng, Yubin; Zeng, Ziyang; Wang, Junlin


    The morphology and surface characteristics of manganese dioxide (MnO₂) formed in situ, which was prepared through the oxidation of MnSO₄using KMnO₄, were studied. The effects of factors including the form of MnO₂, dosage, pH, dosing sequence of in situ MnO₂on the enhanced coagulation were systematically evaluated. The results of analysis by the UV254 and permanganate index CODMn methods indicated that humic acid removal increased from 9.2 and 2.5% to 55.0 and 38.9%, when 10 mg/L of the in situ MnO₂ was added in the presence of 2 mg/L of polyaluminum sulfate. The studies of orthogonal experiment revealed that coagulation was most affected by the pH, whereas the dosage of in situ MnO₂and slow stirring duration exhibited a weaker effect. At a pH value of 4.0, in situ MnO₂dosage of 10 mg/L, slow stir over 40 min, and the total solids content was 20 mg/L, the humic acid removal by UV254 and CODMn methods reached 71.2 and 61.2%. These results indicated that the presence of in situ MnO₂enhanced the coagulation and removal of humic acid from water.

  17. Electrochemical characterization of nano V, Ti doped MnO2 in primary lithium manganese dioxide batteries with high rate

    Sun, Yang; Wang, Shengping; Dai, Yu; Lei, Xinrong


    The nano-sized γ-MnO2 precursor is synthesized using a room temperature, liquid-phase reaction route with the assistance of ultrasonic waves. The MnO2 precursor as an electrode material in lithium manganese dioxide primary batteries displays a low capacity of 140mAhg-1 (45.5% for the theoretical capacity of MnO2) at 20mAg-1. Therefore, the doped MnO2 with cationic V or/and Ti are prepared at high temperature. After the heat treatment, the γ phase precursor powder gradually converts into the β-MnO2 and exhibits a higher specific surface area with a larger pore volume and pore size, providing significantly more electrochemically active sites for the redox reaction. The doped MnO2 matrix has advantage of the ideal lattice parameters and the higher conductivity, resulting in an enhancement of the Li+ diffusion kinetics in the tunnel structure. Especially for co-doped MnO2 with V and Ti, the modified material shows an outstanding electrochemical capacity of 190mAhg-1 (61.7% for the theoretical capacity) at 20mAg-1 and 169mAhg-1 for a higher power output of 100mAg-1.

  18. Study of a QCM Dimethyl Methylphosphonate Sensor Based on a ZnO-Modified Nanowire-Structured Manganese Dioxide Film

    Guang Li


    Full Text Available Sensitive, selective and fast detection of chemical warfare agents is necessary for anti-terrorism purposes. In our search for functional materials sensitive to dimethyl methylphosphonate (DMMP, a simulant of sarin and other toxic organophosphorus compounds, we found that zinc oxide (ZnO modification potentially enhances the absorption of DMMP on a manganese dioxide (MnO2 surface. The adsorption behavior of DMMP was evaluated through the detection of tiny organophosphonate compounds with quartz crystal microbalance (QCM sensors coated with ZnO-modified MnO2 nanofibers and pure MnO2 nanofibers. Experimental results indicated that the QCM sensor coated with ZnO-modified nanostructured MnO2 film exhibited much higher sensitivity and better selectivity in comparison with the one coated with pure MnO2 nanofiber film. Therefore, the DMMP sensor developed with this composite nanostructured material should possess excellent selectivity and reasonable sensitivity towards the tiny gaseous DMMP species.

  19. 用电气石提高二氧化锰电极的电容性能%Improving capacitance performance of manganese dioxide electrode by tourmaline

    杨帆; 季辰辰; 卫华; 包淑娟


    将具有特殊吸附特性的电气石与二氧化锰(MnO2)物理混合,制得电气石-MnO2电极。通过XRD、SEM对样品与电气石进行形貌与结构分析,用循环伏安、恒流充放电测试研究材料的电化学性能。当MnO2的质量为10 mg、电气石质量为12.5 mg时,电极在1 mol/L Na2 SO4中,以0.25 A/g的电流在-0.1~0.7 V放电,比电容可达347.0 F/g;电气石还可改善电极的循环稳定性,经过400次循环,电极的电容保持率可提高到90%。%Tourmaline with special adsorption characteristic was mixed with manganese dioxide (MnO2 )to prepare tourmaline-MnO2 electrode. The morphology and microstructure of samples and tourmaline were examined by SEM and XRD. Electrochemical performance of as-prepared samples was studied by cyclic voltammetry(CV)and galvanostatic charge/discharge. The specific capac-itance of 347.0 F/g was achieved in 1 mol/L Na2 SO4 electrolyte at the current density of 0.25 A/g and under the potential window of -0.1 ~0.7 V with a certain proportion(mMnO2 =10 mg,mDQ =12.5 mg). The cycle stability of electrode was improved by tour-maline,after 400 cycles,the capacitance retention of electrode was raised to 90%.

  20. Electrodeposited manganese dioxide nanostructures on electro-etched carbon fibers: High performance materials for supercapacitor applications

    Kazemi, Sayed Habib, E-mail: [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Center for Research in Climate Change and Global Warming (CRCC), Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Maghami, Mostafa Ghaem [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Kiani, Mohammad Ali [Chemistry and Chemical Engineering Research Center of Iran, P.O. Box 14335-186, Tehran (Iran, Islamic Republic of)


    Highlights: • We report a facile method for fabrication of MnO{sub 2} nanostructures on electro-etched carbon fiber. • MnO{sub 2}-ECF electrode shows outstanding supercapacitive behavior even at high discharge rates. • Exceptional cycle stability was achieved for MnO{sub 2}-ECF electrode. • The coulombic efficiency of MnO{sub 2}-ECF electrode is nearly 100%. - Abstract: In this article we introduce a facile, low cost and additive/template free method to fabricate high-rate electrochemical capacitors. Manganese oxide nanostructures were electrodeposited on electro-etched carbon fiber substrate by applying a constant anodic current. Nanostructured MnO{sub 2} on electro-etched carbon fiber was characterized by scanning electron microscopy, X-ray diffraction and energy dispersive X-ray analysis. The electrochemical behavior of MnO{sub 2} electro-etched carbon fiber electrode was investigated by electrochemical techniques including cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. A maximum specific capacitance of 728.5 F g{sup −1} was achieved at a scan rate of 5 mV s{sup −1} for MnO{sub 2} electro-etched carbon fiber electrode. Also, this electrode showed exceptional cycle stability, suggesting that it can be considered as a good candidate for supercapacitor electrodes.

  1. Preparation of Microporous Polypropylene/Titanium Dioxide Composite Membranes with Enhanced Electrolyte Uptake Capability via Melt Extruding and Stretching

    Shan Wang


    Full Text Available In this work, a blending strategy based on compounding the hydrophilic titanium dioxide (TiO2 particles with the host polypropylene (PP pellets, followed by the common membrane manufacture process of melt extruding/annealing/stretching, was used to improve the polarity and thus electrolyte uptake capability of the PP-based microporous membranes. The influence of the TiO2 particles on the crystallinity and crystalline orientation of the PP matrix was studied using differential scanning calorimetry (DSC, X-ray diffraction (XRD, and infrared dichroic methods. The results showed that the TiO2 incorporation has little influence on the oriented lamellar structure of the PP-based composite films. Investigations of the deformation behavior indicated that both the lamellar separation and interfacial debonding occurred when the PP/TiO2 composite films were subjected to uniaxial tensile stress. The scanning electron microscopy (SEM observations verified that two forms of micropores were generated in the stretched PP/TiO2 composite membranes. Compared to the virgin PP membrane, the PP/TiO2 composite membranes especially at high TiO2 loadings showed significant improvements in terms of water vapor permeability, polarity, and electrolyte uptake capability. The electrolyte uptake of the PP/TiO2 composite membrane with 40 wt % TiO2 was 104%, which had almost doubled compared with that of the virgin PP membrane.

  2. Effects of electrode distance and nature of electrolyte on the diameter of titanium dioxide nanotube

    Abbasi, S., E-mail:; Mohamed, N. M., E-mail:; Singh, B. S. M., E-mail: [Department of Fundamental and Applied Sciences Unviersiti Teknologi PETRONAS, 31750, Bandar Seri Iskandar (Malaysia); Abbasi, S. H., E-mail: [SABIC Plastic Application Development Center, Riyadh Technovalley, Riyadh (Saudi Arabia)


    The titanium nanotubes were synthesized using viscous electrolytes consisting of ethylene glycol and non-viscous electrolytes consisting of aqueous solution of hydrofluoric acid. Sodium fluoride and ammonium fluoride were utilized as the source of fluorine ions. The samples were then characterized by field emission scanning electron microscope (FE-SEM). Their morphologies were investigated under different anodic potentials and various electrolyte compositions. It was found out that nanotubes can be obtained in fluoride ions and morphology is dependent on various parameters like anodic potential, time, electrolyte composition and the effects by varying the distance between the electrodes on the morphology was also investigated. It was found that by altering the distance between the electrodes, change in the diameter and the porosity was observed.

  3. Manganese(III) Schiff base complexes: chemistry relevant to the copolymerization of epoxides and carbon dioxide.

    Darensbourg, Donald J; Frantz, Eric B


    Schiff base complexes of the form (acacen)Mn(III)X (acacen = N,N'-bis(acetylacetone)-1,2-ethylenediimine), where X = OAc, Cl, or N(3), have been evaluated for their ability to couple CO(2) and cyclohexene oxide in the presence of a variety of cocatalysts to provide cyclic or polycarbonates. These complexes proved to be ineffective at catalyzing this process; however, valuable information related to the coordination chemistry of these manganese Schiff bases was elucidated. Of importance, mechanistic findings as revealed by comprehensive studies involving structurally related (salen)CrX and (salen)CoX complexes strongly support the requirement of six-coordinate metal species for the effective copolymerization of CO(2) and epoxides. In the case of these Mn(III) complexes, it was determined that in chloroform or toluene solution a five-coordinate species was greatly favored over a six-coordinate species even in the presence of 20 equiv or more of various Lewis bases. Significantly epoxide monomers such as propylene oxide and cyclohexene oxide displayed no tendency to bind to these (acacen)MnX derivatives, even when used as solvents. Only in the case of excessive quantities of heterocyclic amines such as pyridine, DMAP, and DBU was spectral evidence of a six-coordinate Mn derivative observed in solution. X-ray crystal structures are provided for many of the complexes involved in this study, including the one-dimensional polymeric structures of [(acacen)MnOAc x 2H(2)O](n), [(acacen)MnN(3)](n) (mu(1,3)-N(3)), and a rare mixed bridging species [(acacen)MnN(3)](n) (mu(1,3)-N(3)/mu(1,1)-N(3)). In addition, a structure was obtained in which the unit cell contains both a (acacen)MnN(3)(DMAP) and a (acacen)MnN(3) species.

  4. Impact of interactions between metal oxides to oxidative reactivity of manganese dioxide.

    Taujale, Saru; Zhang, Huichun


    Manganese oxides typically exist as mixtures with other metal oxides in soil-water environments; however, information is only available on their redox activity as single oxides. To bridge this gap, we examined three binary oxide mixtures containing MnO(2) and a secondary metal oxide (Al(2)O(3), SiO(2) or TiO(2)). The goal was to understand how these secondary oxides affect the oxidative reactivity of MnO(2). SEM images suggest significant heteroaggregation between Al(2)O(3) and MnO(2) and to a lesser extent between SiO(2)/TiO(2) and MnO(2). Using triclosan and chlorophene as probe compounds, pseudofirst-order kinetic results showed that Al(2)O(3) had the strongest inhibitory effect on MnO(2) reactivity, followed by SiO(2) and then TiO(2). Al(3+) ion or soluble SiO(2) had comparable inhibitory effects as Al(2)O(3) or SiO(2), indicating the dominant inhibitory mechanism was surface complexation/precipitation of Al/Si species on MnO(2) surfaces. TiO(2) inhibited MnO(2) reactivity only when a limited amount of triclosan was present. Due to strong adsorption and slow desorption of triclosan by TiO(2), precursor-complex formation between triclosan and MnO(2) was much slower and likely became the new rate-limiting step (as opposed to electron transfer in all other cases). These mechanisms can also explain the observed adsorption behavior of triclosan by the binary oxide mixtures and single oxides.

  5. Effects of Heat Treatment on the Physical and Electrochemical Properties of Clew-like Manganese Dioxide%热处理对线团状二氧化锰结构及其电化学性质的影响

    万传云; 刘裕


    The clew-like manganese dioxide nanostructures composed of interleaving nanoplates were successfully prepared by adding 8 L dilute potassium permanganate solution(0.015 mol·L-1) to 8 L dilute manganese chloride solution(0.01 mol·L-1) with the dropping rate of 20 mL·min-1under a stirring condition.The effects of heat treatments on the physical and electrochemical properties of the obtained manganese dioxide were studied using X-ray diffraction(XRD),scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET) surface area measurement,cyclic voltametry(CV),electrochemical impedance spectroscopy(EIS) and constant current charge-discharge method.The pore size of the obtained clew-like manganese dioxide was ca.6.5 nm and its distribution was uniform.The results of physical characterization showed that heat treatment could adjust the microstructure of manganese dioxide.The increase of the treating temperature induced the decrease of the specific surface area and the amount of the micropores while the mean pore size increased with the increase of the treating temperature.The MnO2particles remained amorphous below 300 ℃.The cyclic voltametry measurements indicated that all the amorphous MnO2 samples have characteristic of the ideal pesudocapacitor.The impedance spectroscopy tests showed that a suitable treating temperature could promote the ability of faradic charger-transfer and the diffusion of ion on the interface between the active material particles and electrolyte.Though the MnO2 sample treated at 200 ℃ did not have the highest specific surface area,it had the lowest faradic charger-transfer resistance and the highest specific capacitance,which was 210.6 F·g-1 at the scan rate of 2 mV·s-1 in 1 mol·L-1 Na2SO4 solution.The constant charge-discharge curves of this sample are approximately symmetrical and linear for both charge and discharge portions,which indicated this sample had an ideal capacitive characterization.The cycling

  6. Ternary nanocomposite of polyaniline/manganese dioxide/titanium nitride nanowire array for supercapacitor electrode

    Xia, Chi; Xie, Yibing, E-mail:; Du, Hongxiu; Wang, Wei [Southeast University, School of Chemistry and Chemical Engineering (China)


    The electroactive polyaniline (PANI) and manganese oxide (MnO{sub 2}) were integrated with titanium nitride (TiN) nanowire array (NWA) to form PANI/MnO{sub 2}/TiN ternary nanocomposite for supercapacitor application. TiN NWA was prepared via a seed-assisted hydrothermal synthesis and ammonia nitridization process. The electroactive MnO{sub 2} and PANI was layer-by-layer coated on TiN NWA to form heterogeneous coaxial structure through a stepwise electrodeposition process. Scanning electron micrographs revealed that the well-separated TiN NWA was composed of well-distributed nanowires with diameters in the range of 10–30 nm and a total length of 1.5 μm. A villiform MnO{sub 2} layer with a thickness of 10–20 nm covered on TiN NWA to form MnO{sub 2}/TiN NWA composite. The coral-like PANI layer with thicknesses in the range of 20–50 nm covered on the above MnO{sub 2}/TiN NWA to form PANI/MnO{sub 2}/TiN NWA. Electrochemical measurements showed that a high specific capacitance of 674 F g{sup −1} at a current density of 1 A g{sup −1} (based on total mass of PANI/MnO{sub 2}) was obtained for PANI/MnO{sub 2}/TiN NWA ternary nanocomposite, which was much higher than that of PANI/MnO{sub 2}/carbon-cloth composites reported previously. This ternary nanocomposite also showed a good rate and cycling stability. Moreover, in comparison with PANI/TiN NWA or MnO{sub 2}/TiN NWA, the specific capacitance of PANI/MnO{sub 2}/TiN NWA was obviously enhanced due to the extra pseudocapacitance contribution and the effective surface area of coral-like PANI layer, showing the advantage of manipulating the heterogeneous coaxial configuration between PANI and MnO{sub 2} for fundamentally improved capacitive performance. These results demonstrated that PANI/MnO{sub 2}/TiN NWA ternary nanocomposite was a promising candidate electrode material for supercapacitor application.

  7. Carbon spheres-assisted strategy to prepare mesoporous manganese dioxide for supercapacitor applications

    Li Siheng [State Key Laboratory of Electroanalytical Chemistry, and Jilin Provincial Key Laboratory of Advanced Low-carbon Chemical Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin St., Changchun 130022 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Qi Li, E-mail: [State Key Laboratory of Electroanalytical Chemistry, and Jilin Provincial Key Laboratory of Advanced Low-carbon Chemical Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin St., Changchun 130022 (China); Lu Lehui; Wang Hongyu [State Key Laboratory of Electroanalytical Chemistry, and Jilin Provincial Key Laboratory of Advanced Low-carbon Chemical Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin St., Changchun 130022 (China)


    Mesoporous MnO{sub 2} microstructures with large specific surface area have been successfully synthesized by an in-situ redox precipitation method in the presence of colloidal carbon spheres. The samples of them had much higher specific surface area, pore size and pore volume than those obtained via routes without carbon spheres. The morphology, chemical compositions and porous nature of products were fully characterized. Electrochemical measurements showed that these mesoporous MnO{sub 2} could function well when used as positive electrode materials for supercapacitor. Ideal electrochemical capacitive performances and cyclic stability after 2000 galvanostatic charge-discharge cycles could be observed in 1 M neutral Na{sub 2}SO{sub 4} aqueous electrolyte with a working voltage of 1.7 V. - Graphical Abstract: Mesoporous MnO{sub 2} microstructures with large S{sub BET} were successfully synthesized by in-situ redox precipitation method in the presence of colloidal carbon spheres. Electrochemical measurements showed that these mesoporous MnO{sub 2} could be well used as electrode materials for supercapacitor. Highlights: Black-Right-Pointing-Pointer Mesoporous MnO{sub 2} was prepared by in-situ redox method assisted by carbon spheres. Black-Right-Pointing-Pointer S{sub BET}, pore size and volume were higher than MnO{sub 2} obtained without carbon spheres. Black-Right-Pointing-Pointer They could function well when used as electrode materials for supercapacitor. Black-Right-Pointing-Pointer Ideal capacitive behaviors and long cycling life showed after 2000 charge-discharge.

  8. Improving cyclic stability of lithium nickel manganese oxide cathode at elevated temperature by using dimethyl phenylphosphonite as electrolyte additive

    Mai, Shaowei; Xu, Mengqing; Liao, Xiaolin; Xing, Lidan; Li, Weishan


    A novel electrolyte additive, dimethyl phenylphosphonite (DMPP), is reported in this paper to be able to improve significantly the cyclic stability of LiNi0.5Mn1.5O4 cathode of high voltage lithium ion battery at elevated temperature. When experiencing charge/discharge cycling at 50 °C with 1C (1C = 146.7 mAh g-1) rate in a standard (STD) electrolyte (1.0 M LiPF6 in ethylene carbonate (EC)/dimethyl carbonate (DMC), EC/DMC = 1/2 in volume), LiNi0.5Mn1.5O4 suffers serious discharge capacity decaying, with a capacity retention of 42% after 100 cycles. With adding 0.5% DMPP into the STD electrolyte, the capacity retention is increased to 91%. This improvement can be ascribed to the preferential oxidation of DMPP to the STD electrolyte and the subsequent formation of a protective film on LiNi0.5Mn1.5O4, which suppresses the electrolyte decomposition and protects LiNi0.5Mn1.5O4 from destruction. Theoretical calculations together with voltammetric analyses demonstrate the preferential oxidation of DMPP and the consequent suppression of electrolyte decomposition, while the observations from scanning electron microscopy, X-ray photoelectronic spectroscopy and Fourier transform infrared spectroscopy confirm the protection that DMPP provides for LiNi0.5Mn1.5O4.

  9. Ultra-sensitive and selective NH3 room temperature gas sensing induced by manganese-doped titanium dioxide nanoparticles.

    Tshabalala, Zamaswazi P; Shingange, Katekani; Cummings, Franscious R; Ntwaeaborwa, Odireleng M; Mhlongo, Gugu H; Motaung, David E


    The study of the fabrication of ultra-high sensitive and selective room temperature ammonia (NH3) and nitrogen dioxide (NO2) gas sensors remains an important scientific challenge in the gas sensing field. This is motivated by their harmful impact on the human health and environment. Therefore, herein, we report for the first time on the gas sensing properties of TiO2 nanoparticles doped with various concentrations of manganese (Mn) (1.0, 1.5, 2.0, 2.5 and 3.0mol.% presented as S1, S2, S3, S4 and S5, respectively), synthesized using hydrothermal method. Structural analyses showed that both undoped and Mn-doped TiO2 crystallized in tetragonal phases. Optical studies revealed that the Mn doped TiO2 nanoparticles have enhanced UV→Vis emission with a broad shoulder at 540nm, signifying induced defects by substituting Ti(4+) ions with Mn(2+). The X-ray photoelectron spectroscopy and the electron paramagnetic resonance studies revealed the presence of Ti(3+) and singly ionized oxygen vacancies in both pure and Mn doped TiO2 nanoparticles. Additionally, a hyperfine split due to Mn(2+) ferromagnetic ordering was observed, confirming incorporation of Mn ions into the lattice sites. The sensitivity, selectivity, operating temperature, and response-recovery times were thoroughly evaluated according to the alteration in the materials electrical resistance in the presence of the target gases. Gas sensing studies showed that Mn(2+) doped on the TiO2 surface improved the NH3 sensing performance in terms of response, sensitivity and selectivity. The S1 sensing material revealed higher sensitivity of 127.39 at 20 ppm NH3 gas. The sensing mechanism towards NH3 gas is also proposed. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Method for Determination of Neptunium in Large-Sized Urine Samples Using Manganese Dioxide Coprecipitation and 242Pu as Yield Tracer

    Qiao, Jixin; Hou, Xiaolin; Roos, Per


    A novel method for bioassay of large volumes of human urine samples using manganese dioxide coprecipitation for preconcentration was developed for rapid determination of 237Np. 242Pu was utilized as a nonisotopic tracer to monitor the chemical yield of 237Np. A sequential injection extraction...... to 100% and high separation capacity of processing up to 5 L of human urine samples. The MnO2 coprecipitation process is simple and straightforward in which a batch (8–12) of samples can be pretreated within 4 h (i.e.,

  11. High catalytic activity of anatase titanium dioxide for decomposition of electrolyte solution in lithium ion battery

    Liu, Ming; He, Yan-Bing; Lv, Wei; Zhang, Chen; Du, Hongda; Li, Baohua; Yang, Quan-Hong; Kang, Feiyu


    It has been indicated that anatase TiO2 is a promising anode material for lithium ion power battery from many previous researches. Whereas, in this work, we find that the anatase TiO2, when used as an anode for lithium ion battery, has high catalytic activity to initiate the decarboxylation reaction of electrolyte solution, resulting in the large generation of sole gaseous component, CO2. The ROLi species and the new phase of flake-like Li2TiF6 material are the main reaction products between anatase TiO2 and LiPF6 based electrolyte solution. This work provides important and urgent information that the surface chemistry of anatase TiO2 used as the anode material of lithium ion battery must be modified to suppress its catalytic activity for the decomposition of solvents.

  12. Triethylborate as an electrolyte additive for high voltage layered lithium nickel cobalt manganese oxide cathode of lithium ion battery

    Wang, Zaisheng; Xing, Lidan; Li, JianHui; Xu, Mengqing; Li, Weishan


    Triethylborate (TEB) is used as an electrolyte additive to improve the electrochemical performances of LiNi1/3Co1/3Mn1/3O2 (LNCM) upon cycling at 4.5 V vs. Li/Li+. Charge/discharge tests demonstrate that the cyclic stability of LNCM at room and elevated temperature can be improved effectively by TEB. With addition of 10 wt. % TEB into STD electrolyte (1.0 M LiPF6/EC:EMC:DEC), LNCM achieves a capacity retention of 99.8% after 150 cycles and 94.7% after 120 cycles at room and elevated temperature, respectively, comparing to that of 68.9% and 68.8% of STD electrolyte. In addition, 10 wt. % TEB also improves the rate capability of LNCM at room temperature. Physical and electrochemical characterizations from XRD, SEM, TEM, XPS, ICP-MS, LSV, CA, and EIS reveal that the preferential oxidative reaction of TEB generates a thin, uniform and low interfacial resistance film on the LNCM surface. This film not only suppresses the subsequent decomposition of STD electrolyte, but also prevents the dissolution of transition metal ions from LNCM, resulting in improved cyclic stability and rate capability of LNCM.

  13. Integrin-mediated osteoblastic adhesion on a porous manganese-incorporated TiO2 coating prepared by plasma electrolytic oxidation.

    Zhang, Zhenxiang; Gu, Beibei; Zhu, Wei; Zhu, Lixian


    This study was conducted to evaluate the bioactivity of manganese-incorporated TiO2 (Mn-TiO2) coating prepared on titanium (Ti) plate by plasma electrolytic oxidation (PEO) technique in Ca-, P- and Mn-containing electrolytes. The surface topography, phase and element compositions of the coatings were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometry (EDS), respectively. The adhesion of osteoblast-like MG63 cells onto Ti, TiO2 and Mn-TiO2 surfaces was evaluated, and the signal transduction pathway involved was confirmed by the sequential expression of the genes for integrins β1, β3, α1 and α3, focal adhesion kinase (FAK), and the extracellular regulated kinases (ERKs), including ERK1 and ERK2. The results obtained indicated that Mn was successfully incorporated into the porous nanostructured TiO2 coating, and did not alter the surface topography or the phase composition of the coating. The adhesion of the MG63 cells onto the Mn-incorporated TiO2 coating was significantly enhanced compared with that on the Mn-free TiO2 coating and the pure Ti plates. In addition, the enhanced cell adhesion on the Mn-TiO2 coatings may have been mediated by the binding of the integrin subunits, β1 and α1, and the subsequent signal transduction pathway, involving FAK and ERK2. The study indicated that the novel Mn-TiO2 coating has potential for orthopedic implant applications, and that further investigations are required.

  14. A study of alternative methods for reclaiming oxygen from carbon dioxide and water by a solid-electrolyte process for spacecraft applications


    Two alternative technical approaches were studied for application of an electrochemical process using a solid oxide electrolyte (zirconia stabilized by yttria or scandia) to oxygen reclamation from carbon dioxide and water, for spacecraft life support systems. Among the topics considered are the advisability of proceeding to engineering prototype development and fabrication of a full scale model for the system concept, the optimum choice of method or approach to be carried into prototype development, and the technical problem areas which exist.

  15. Studies on effects of superiority strains on bioleaching of Mn from electrolytic manganese residues%优势菌种浸取电解锰渣中锰的影响因素研究

    黄华军; 李小明; 曹建兵; 张忠辉; 李焕利; 方丽; 杨慧; 杨麒; 刘精今


    采用电解锰废渣中分离出的一种锰抗性强的微生物Fusarium sp.浸取电解锰渣中的锰。研究了不同矿浆浓度、微生物生长活动、锰渣和培养基等对锰浸取效率的影响。结果表明,接种体积比为2%(v/v)时,矿浆浓度(m/v)对锰浸取效率影响显著,矿浆浓度过低(〈2%)或者过高(〉10%)对锰浸取效率都有不利影响。矿浆浓度为10%时锰浸取效率最高,达80%以上;微生物的生长活动对浸取过程有显著的影响;而锰渣的存在则能在一定程度上影响溶液的pH,进而影响锰浸取效率;培养基对锰浸取效率的贡献达50%左右。%The micro-organism named Fusarium sp.,which was separated from electrolytic manganese residues,has strong resistance of manganese.A series of microbioleaching experiments were performed using Fusarium extract manganese from electrolytic manganese residues.The effects of different factors such as pulp density,microbial growth and activity,electrolytic manganese residues and culture medium on the Mn bioleaching efficiency were studied.The results showed that the pulp densities had a significant influence on the Mn bioleaching efficiency when the inoculation volume ratio was 2%.The Mn bioleaching efficiency was inhibited when the pulp densities were too low(〈2%) or too high(〉10%).The highest Mn bioleaching efficiency was obtained when the pulp density was 10%,and it reached more than 80%;microbial growth and activity had a significant impact on bioleaching process.The existence of electrolytic manganese residues affected the pH of the solution to some extent,thereby affecting the Mn bioleaching efficiency.The contribution of culture medium to Mn bioleaching efficiency was about 50%.

  16. 容量法快速测定锰矿中二氧化硅含量%Determination of Silicon Dioxide Content in Manganese Ore by Volumetric Method

    张慤; 邓军华; 王一凌; 王翠艳; 曲月华


    At present, fluoride potassium silicate Volumetric method analysis silica content in manganese ore has not reported, through experiments optimized the parameters of fluoride potassium silicate Volumetric method: melt-like way, sample weight, volume of acidified et. It can complete the rapid determination of silicon dioxide content in manganese ore. Measurement Results consistent with the certified value and the analysis to satisfy the GB/T 1509 - 2006 permission deviation request, The relative standard deviation of measurement results are less than 1 % .%目前利用氟硅酸钾容量法测定锰矿中二氧化硅含量还没有报道.采用硅氟酸钾容量法,通过称样量、融样方式、酸化体积等条件进行优化实验,实现了容量法快速测定锰矿中二氧化硅的含量.实验数据的相对标准偏差小于1%.测量值与认定值一致,测量结果满足GB/T 1509-2006《锰矿石 硅含量的测定 高氯酸脱水重量法》允许差的要求.

  17. A Liquid Inorganic Electrolyte Showing an Unusually High Lithium Ion Transference Number: A Concentrated Solution of LiAlCl4 in Sulfur Dioxide

    Martin Winter


    Full Text Available We report on studies of an inorganic electrolyte: LiAlCl4 in liquid sulfur dioxide. Concentrated solutions show a very high conductivity when compared with typical electrolytes for lithium ion batteries that are based on organic solvents. Our investigations include conductivity measurements and measurements of transference numbers via nuclear magnetic resonance (NMR and by a classical direct method, Hittorf’s method. For the use of Hittorf’s method, it is necessary to measure the concentration of the electrolyte in a selected cell compartment before and after electrochemical polarization very precisely. This task was finally performed by potentiometric titration after hydrolysis of the salt. The Haven ratio was determined to estimate the association behavior of this very concentrated electrolyte solution. The measured unusually high transference number of the lithium cation of the studied most concentrated solution, a molten solvate LiAlCl4 × 1.6SO2, makes this electrolyte a promising alternative for lithium ion cells with high power ability.

  18. Study on the recycling of manganese dioxide in process of hydroquinone production by aniline oxidation%苯胺氧化制对苯二酚中二氧化锰的回收利用

    谭世语; 罗婷; 朱必珏


    苯胺氧化法生产对苯二酚的二氧化锰废水经熟石灰除杂,用氨水调pH至碱性,用双氧水氧化,硫酸精制得到二氧化锰固体粉末.最佳回收条件为:双氧水用量为64%(占废液体积),反应液pH为10.0,反应温度为25 ℃,反应时间为1 h,二氧化锰的回收率可达到80%,采用回收的二氧化锰氧化苯胺可使对苯醌的收率从72.48%提高到83.90%.%The recycling of manganese dioxide in wastewater generated in the process of hydroquinone production by aniline oxidation was studied by using orthogonal experiments. The optimum conditions were obtained as follows: volume ratio of hydrogen peroxide to waste water 0. 64 :1 ;pH 10. 0; reaction time 1 h; reaction temperature 25 ℃. Under the optimum conditions, the recovery rate of manganese dioxide can be as high as 80%. Moreover, the comparison experiments showed that the yield of p-benzoquinone increased from 72.84% to 83.90% by using recycled manganese dioxide.

  19. Low frequency sonochemical synthesis of nanoporous amorphous manganese dioxide (MnO{sub 2}) and adsorption of remazol reactive dye

    Hasan, Siti Zubaidah; Yusop, Muhammad Rahimi; Othman, Mohamed Rozali, E-mail: [School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia)


    Nanoporous amorphous-MnO{sub 2} was synthesized by sonochemical process (sonication) on the solid manganese (II) acetate tetrahydrate (Mn(CH{sub 3}COO){sub 2}.4H{sub 2}O) in 0.1 M KMnO{sub 4}. The product was characterized by X-ray diffraction (XRD), morphology of the material was scanned by Field Emission Scanning Electron Microscopy (FE-SEM) and absorptions of MnO{sub 2} bonding was characterized by Fourier Transform Infra-Red Spectrometer (FT-IR). Remazol reactive dye or Red 3BS, was used in the adsorption study using nanoporous amorphous-MnO{sub 2}. In batch experiment, 10 ppm of Remazol reactive dye was used and experiment was carried out at room temperature. Adsorption of Remazol dye on 0.2g synthesized nanoporous amorphous-MnO{sub 2} showed 99 – 100% decolorization.

  20. Determination of manganese dioxide in pyrolusite by iodometric method%碘量法测定软锰矿中的二氧化锰

    彭洪; 黄连军; 邹琪; 金家胜; 陈明


    Under the conditions of mixed acid medium (sulf uric acid and phosphoric acid) and excess potassium iodide, manganese dioxide in pyrolusite reacted with potassium iodide, quantitative iodine was precipitated,and the precipitated iodine was titrated with the standard solution of sodium thiosul-fate. The measured results were consistent with the standard value,and the relative standard deviation was less than 0. 11%. This method is simple, rapid, accurate and reliable, with satisfactory results, suitable for the analysis of production process.%在硫磷混合酸介质中、碘化钾过量的条件下,软锰矿中的二氧化锰与碘化钾作用定量析出碘,析出的碘可用硫代硫酸钠标准溶液滴定测定.测定结果与标准值完全一致,相对标准偏差<0.11%.该方法操作简便,快速,准确可靠,结果满意,适用于生产过程分析.

  1. Rational design of hierarchically porous birnessite-type manganese dioxides nanosheets on different one-dimensional titania-based nanowires for high performance supercapacitors

    Zhang, Yu Xin


    A facile and large-scale strategy of mesoporous birnessite-type manganese dioxide (MnO2) nanosheets on one-dimension (1D) H2Ti 3O7 and anatase/TiO2 (B) nanowires (NWs) is developed for high performance supercapacitors. The morphological characteristics of MnO2 nanoflakes on H2Ti 3O7 and anatase/TiO2 (B) NWs could be rationally designed with various characteristics (e.g., the sheet thickness, surface area). Interestingly, the MnO2/TiO2 NWs exhibit a more optimized electrochemical performance with specific capacitance of 120 F g-1 at current density of 0.1 A g-1 (based on MnO 2 + TiO2) than MnO2/H2Ti 3O7 NWs. An asymmetric supercapacitor of MnO 2/TiO2//activated graphene (AG) yields a better energy density of 29.8 Wh kg-1 than MnO2/H2Ti 3O7//AG asymmetric supercapacitor, while maintaining desirable cycling stability. Indeed, the pseudocapacitive difference is related to the substrates, unique structure and surface area. Especially, the anatase/TiO2 (B) mixed-phase system can provide good electronic conductivity and high utilization of MnO2 nanosheets. © 2014 Elsevier B.V. All rights reserved.

  2. Electrodeposition of manganese dioxide in three-dimensional poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)-polyaniline for supercapacitor

    Liu, Feng-Jiin [Department of Chemical Engineering, National United University, 1 Lien Da, Kung-Ching Li, Miao-Li (China)


    The preparation of composites of precise metal oxides/conducting polymers is important in studies of supercapacitors. In this work, a three-dimensional matrix of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)-polyaniline (PEDOT-PSS-PANI) was prepared by interfacial polymerization of ANI into PEDOT-PSS. Conductivity was enhanced by incorporating of PANI into PEDOT-PSS because of the decrease in the distance for electron shuttling along the conjugated polymeric chain. Composite electrodes were prepared by the electrodeposition of manganese dioxide (MnO{sub 2}) in a PEDOT-PSS-PANI three-dimensional matrix. The electrodes were characterized by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry techniques. The results show a significant improvement in the specific capacitance of the composite electrode. For PEDOT-PSS the specific capacitance was of 0.23 F g{sup -1}, while PEDOT-PSS-PANI and PEDOT-PSS-PANI-MnO{sub 2} displayed values of 6.7 and 61.5 F g{sup -1}, respectively. When only considering the MnO{sub 2} mass, the composite had the specific capacitance of 372 F g{sup -1}. The composite also had an excellent cyclic performance. (author)

  3. Gold nanorod-based poly(lactic-co-glycolic acid) with manganese dioxide core-shell structured multifunctional nanoplatform for cancer theranostic applications.

    Wang, Lei; Li, Dong; Hao, Yongwei; Niu, Mengya; Hu, Yujie; Zhao, Hongjuan; Chang, Junbiao; Zhang, Zhenzhong; Zhang, Yun


    Recently, photothermal therapy has become a promising strategy in tumor treatment. However, the therapeutic effect was seriously hampered by the low tissue penetration of laser. Therefore, in this study, radiofrequency (RF) with better tissue penetration was used for tumor hyperthermia. First, one type of gold nanorods (AuNRs) suitable for RF hyperthermia was selected. Then, poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with AuNRs and docetaxel (DTX) (PLGA/AuNR/DTX) NPs were constructed. Finally, manganese dioxide (MnO2) ultrathin nanofilms were coated on the surfaces of PLGA/AuNR/DTX NPs by the reduction of KMnO4 to construct the PLGA/AuNR/DTX@MnO2 drug delivery system. This drug delivery system can not only be used for the combined therapy of chemotherapy and RF hyperthermia but can also produce Mn(2+) to enable magnetic resonance imaging. Furthermore, the RF hyperthermia and the degradation of MnO2 can significantly promote the controlled drug release in a tumor region. The in vitro and in vivo results suggested that the PLGA/AuNR/DTX@MnO2 multifunctional drug delivery system is a promising nanoplatform for effective cancer theranostic applications.

  4. Rational design of hierarchically porous birnessite-type manganese dioxides nanosheets on different one-dimensional titania-based nanowires for high performance supercapacitors

    Zhang, Yu Xin; Kuang, Min; Hao, Xiao Dong; Liu, Yan; Huang, Ming; Guo, Xiao Long; Yan, Jing; Han, Gen Quan; Li, Jing


    A facile and large-scale strategy of mesoporous birnessite-type manganese dioxide (MnO2) nanosheets on one-dimension (1D) H2Ti3O7 and anatase/TiO2 (B) nanowires (NWs) is developed for high performance supercapacitors. The morphological characteristics of MnO2 nanoflakes on H2Ti3O7 and anatase/TiO2 (B) NWs could be rationally designed with various characteristics (e.g., the sheet thickness, surface area). Interestingly, the MnO2/TiO2 NWs exhibit a more optimized electrochemical performance with specific capacitance of 120 F g-1 at current density of 0.1 A g-1 (based on MnO2 + TiO2) than MnO2/H2Ti3O7 NWs. An asymmetric supercapacitor of MnO2/TiO2//activated graphene (AG) yields a better energy density of 29.8 Wh kg-1 than MnO2/H2Ti3O7//AG asymmetric supercapacitor, while maintaining desirable cycling stability. Indeed, the pseudocapacitive difference is related to the substrates, unique structure and surface area. Especially, the anatase/TiO2 (B) mixed-phase system can provide good electronic conductivity and high utilization of MnO2 nanosheets.

  5. Phase Behaviour, Thermodynamics and Kinetics of Clathrate Hydrate Systems of Carbon Dioxide in Presence of Tetrahydrofuran and Electrolytes

    Mohamad Sabil, K. Bin


    In view of the possibilities for new development of carbon dioxide hydrate processes, this study focused on experimental measurements to obtain fundamental insight into the phase behaviour and the kinetic of formation of carbon dioxide hydrate forming systems. These data are essential for the develo

  6. Performance evaluation of titanium dioxide based dye-sensitized solar cells under the influence of anodization steps, nanotube length and ionic liquid-free redox electrolyte solvents

    Cheong, Y. L.; Beh, K. P.; Yam, F. K.; Hassan, Z.


    In this work, highly ordered titanium dioxide (TiO2) nanotube (NT) arrays were synthesized on titanium foil using electrochemical anodization method. The morphological aspects of the nanotubes based on different anodization duration and number of anodization steps (maximum two) have been investigated. The nanotube arrays subsequently used as photoanode in a dye-sensitized solar cell (DSSC) assembly. The studies on the effects of different solvents for triiodide/iodide redox electrolyte and NT length towards the performance of DSSC were conducted. It is known that electrolyte solvent can significantly affect the photovoltaic conversion efficiency. It is noteworthy that longer NT length tends to yield higher efficiency due to better dye adsorption. However, when the NTs exceeded certain length the efficiency decreases instead. Meanwhile, a comparison of DSSC performance based on number of anodization steps on titanium was performed. Highly ordered NT arrays could be obtained using two-steps anodization, which proved to have positive effects on the DSSC performance. The highest photovoltaic conversion efficiency in this work is 2.04%, achieved by two-step anodization. The corresponding average nanotubes length was ˜18 μm, with acetonitrile (ACN) as the redox electrolyte solvent.

  7. Development of 3D Urchin-Shaped Coaxial Manganese Dioxide@Polyaniline (MnO2@PANI) Composite and Self-Assembled 3D Pillared Graphene Foam for Asymmetric All-Solid-State Flexible Supercapacitor Application.

    Ghosh, Kalyan; Yue, Chee Yoon; Sk, Md Moniruzzaman; Jena, Rajeeb Kumar


    We have fabricated high-energy-density all-solid-state flexible asymmetric supercapacitor by using a facile novel 3D hollow urchin-shaped coaxial manganese dioxide@polyaniline (MnO2@PANI) composite as positive electrode and 3D graphene foam (GF) as negative electrode materials with polyvinyl alcohol (PVA)/KOH gel electrolyte. The coaxial MnO2@PANI composite was fabricated by hydrothermal route followed by oxidation without use of an external oxidant. The formation mechanism of the 3D hollow MnO2@PANI composite occurs first by nucleation and growth of the MnO2 crystal species via dissolution-recrystallization and oriented attachment mechanisms followed by the oxidation of aniline monomers on the MnO2 crystalline template. The self-assembled 3D graphene block was synthesized by hydrothermal route using vitamin C as a reducing agent. The microstructures of the composites are analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The morphology is characterized by field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), which clearly showed the formation of urchin-shaped coaxial MnO2@PANI composite. The electrochemical studies are explored by cyclic voltammetry, electrochemical impedance spectrometry, and cyclic charge-discharge tests. The symmetric all-solid-state flexible MnO2@PANI//MnO2@PANI and GF//GF supercapacitors exhibit the specific capacitance of 129.2 and 82.1 F g(-1) at 0.5 A/g current density, respectively. The solid-state asymmetric supercapacitor shows higher energy density (37 Wh kg(-1)) with respect to the solid-state symmetric supercapacitors MnO2@PANI//MnO2@PANI and GF//GF, where the obtained energy density are found to be 17.9 and 11.4 Wh kg(-1), respectively, at 0.5 A/g current density. Surprisingly, the asymmetric supercapacitor shows a high energy density of 22.3 Wh kg(-1) at a high current density of 5 A g(-1). The solid-state asymmetric supercapacitor shows a



  9. Sensoring hydrogen gas concentration using electrolyte made of proton

    Ueda, Yoshikatsu [Kyoto University, Japan; Kolesnikov, Alexander I [ORNL; Koyanaka, Hideki [Kyoto University, Japan


    Hydrogen gas promises to be a major clean fuel in the near future. Thus, sensors that can measure the concentrations of hydrogen gas over a wide dynamic range (e.g., 1 99.9%) are in demand for the production, storage, and utilization of hydrogen gas. However, it is difficult to directly measure hydrogen gas concentrations greater than 10% using conventional sensor [1 11]. We report a simple sensor using an electrolyte made of proton conductive manganese dioxide that enables in situmeasurements of hydrogen gas concentration over a wide range of 0.1 99.9% at room temperature.

  10. Simultaneous removal of ammonia nitrogen and manganese from wastewater using nitrite by electrochemical method.

    Shu, Jiancheng; Liu, Renlong; Liu, Zuohua; Qiu, Jiang; Chen, Hongliang; Tao, Changyuan


    In this work, nitrite was developed to simultaneously remove manganese and ammonia nitrogen from wastewater by the electrochemical method. The characteristics of electrolytic reaction were observed via cyclic voltammograms. Moreover, the mole ratio of nitrite and ammonia nitrogen, voltage, and initial pH value, which affected the removal efficiency of ammonia nitrogen and manganese, were investigated. The results showed that the concentration of ammonia nitrogen in wastewater could be reduced from 120.2 to 6.0 mg L(-1), and manganese could be simultaneously removed from 302.4 to 1.5 mg L(-1) at initial pH of 8.0, the mole ratios of nitrite and ammonia nitrogen of 1.5:1, and voltage of 20 V direct current electrolysis for 4.0 h. XRD analysis showed that manganese dioxide was deposited on the anode, and manganese was mainly removed in the form of manganese hydroxide precipitation in the cathode chamber.

  11. Supercritical carbon dioxide extraction of electrolyte from spent lithium ion batteries and its characterization by gas chromatography with chemical ionization

    Mönnighoff, Xaver; Friesen, Alex; Konersmann, Benedikt; Horsthemke, Fabian; Grützke, Martin; Winter, Martin; Nowak, Sascha


    The aging products of the electrolyte from a commercially available state-of-the-art 18650-type cell were investigated. During long term cycling a huge difference in their performance and lifetime at different temperatures was observed. By interpretation of a strong capacity fading of cells cycled at 20 °C compared to cells cycled at 45 °C a temperature depending aging mechanism was determined. To investigate the influence of the electrolyte on this fading, the electrolyte was extracted by supercritical fluid extraction (SFE) and then analyzed by gas chromatography (GC) with electron impact (EI) ionization and mass selective detection. To obtain more information with regard to the identification of unknown decomposition products further analysis with positive chemical ionization (PCI) and negative chemical ionization (NCI) was performed. 17 different volatile organic aging products were detected and identified. So far, seven of them were not yet known in literature and several formation pathways were postulated taking previously published literature into account.

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

    Pennathur, Sumita; Kristensen, Jesper; Crumrine, Andrew


    conductance for low salt concentrations, we identify a minimum conductance value before saturation at a value independent of salt concentration in the dilute limit. Our model self-consistently couples chemical equilibrium models of the silica wall and the electrolyte bulk, and is parameterized by only...

  13. Improvement in the Capacity and Safety of Lithium/Inorganic Electrolyte Sulfur Dioxide Rechargeable Cells. Phase 2.


    to 0.56g. Common electrode area ("standard" form): 58.1 cm 2 Cell void volume, all components present except electrolyte: about 4.0 ml, measured as...was cell 37-57-1, which was underfilled because of difficulty in adequately crimping the fill tube. We therefore did not test more cells which had not

  14. Research Progress on Manganese Dioxide Electrode Materials for Electrochemical Capacitors%电化学电容器中二氧化锰电极材料研究进展

    李四横; 刘庆鹤; 齐力; 逯乐慧; 王宏宇


    本文在简介MnO2电极材料的性质和特点基础上,重点介绍近5年来国内外有关MnO2电极材料在合成及电化学电容器应用领域中的最新进展,及未来可能的发展方向.%Based on presenting the intrinsic characteristics of manganese dioxide electrode materials,the research progress of preparation and its application for electrochemical capacitor were introduced in this article. Moreover, the future development trend is prospected.

  15. Cause and Measures of High Copper Content in Electrolyzing Manganese Dioxide Process%电解二氧化锰生产中铜含量偏高的原因分析及措施



    针对电解二氧化锰生产中产品和电解废液中铜含量偏高的问题,分析其原因,提出相应的改进措施,使铜含量控制在一个较低的水平,产品质量大大提高。%Analyze the cause of the high copper content in both the product and the electrolysis waste water in the electrolyzing manganese dioxide process ,propose the improvement measures .The copper content is controlled to a lower level ,the product quality is greatly improved .

  16. 聚苯乙烯/二氧化锰复合微球的合成与表征%Synthesis and characterization of polystyrene/β-manganese dioxide organic/inorganic composite microspheres

    张艳萍; 钱建华; 刘琳; 王莉丽; 王晓旭


    Uniform polystyrene/β-manganese dioxide organic/inorganic composite microspheres were prepared by an easy and economical approach.Monodispersed sulfonated polystyrene(PS) microspheres were used as templates as well as the core of the composite microspheres,the shell layers were consist of close accumulated manganese dioxide nanorods and obtained through a hydrothermal reaction of Mn (CH3COO)2 and ammonium persulfate ((NH4)2S2O8) at 140℃.Scanning electron microscopy(SEM) and transmission electron microscopy(TEM)studies show that the as-obtained products consist of large scale composite microspheres.A possible mechanism for the formation of composite microspheres is also proposed in the paper.%本文利用聚苯乙烯微球为模板水热合成了聚苯乙烯/二氧化锰有机无机复合微球.复合微球核层为聚苯乙烯微球,壳层是由大量的二氧化锰纳米棒紧密堆积形成的.利用扫描电子显微镜及透射电子显微镜表征可以看出产物含有大量的复合微球,对于可能的反应机理进行了讨论.

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

    Pennathur, Sumita; Kristensen, Jesper; Crumrine, Andrew


    Nanochannel ion transport is known to be governed by surface charge at low ionic concentrations. In this talk, we show that this surface charge is dominated by hydronium ions arising from dissolution of ambient atmospheric carbon dioxide. By refining the electrokinetic model of the nanochannel...... the surface reaction equilibrium constant for silica/hydronium reactions. The model describes our experimental data with aqueous potassium chloride solutions in 165-nm-high silica nanochannels well, and furthermore, by comparing model predictions with measurements in bulk and in nanochannels with hydrochloric...

  18. Standard Gibbs energy of formation of tellurium dioxide measurement by a solid-oxide electrolyte EMF technique

    Aspiala, M., E-mail:; Sukhomlinov, D., E-mail:; Taskinen, P., E-mail:


    Highlights: • An improved experimental apparatus and new data analysis method have been applied. • Galvanic cells including solid zirconia electrolyte were measured accurately. • Δ{sub f}G° values for TeO{sub 2} have been determined in wide temperature range. • Third law plots for S{sub 298}{sup °} and ΔH{sub 298}{sup °} of TeO{sub 2} were produced using the experimentally observed values. - Abstract: The standard Gibbs energy of formation of TeO{sub 2} in the temperature range 369–795 °C was measured by the EMF method involving solid-oxide electrolyte galvanic cells of the type: (−)Pt, Ir, Te(s, l), TeO{sub 2}(s, l)|YSZ|O{sub 2}, Pt(+), where YSZ denotes stabilized zirconia with 8.5 mass percent of yttrium oxide. The standard Gibbs energies of formation obtained from the above cells are linear functions of temperature as: Δ{sub f}G° (kJ/mol) = −317.09 + 0.180 T (K) ± 0.307 (642–722.15 K) both phasess are solid. Δ{sub f}G° (kJ/mol) = −318.01 + 0.181 T (K) ± 0.308 (722.15–1005.8 K) Te – liquid; TeO{sub 2} – solid. Δ{sub f}G° (kJ/mol) = −256.26 + 0.120 T (K) ± 0.226 (1005.8–1068 K) both phases are liquid.

  19. High energy density capacitor using coal tar pitch derived nanoporous carbon/MnO{sub 2} electrodes in aqueous electrolytes

    Tomko, Timothy [Energy and Mineral Engineering, University Park, PA 16802 (United States); Rajagopalan, Ramakrishnan; Lanagan, Michael [Materials Research Institute, University Park, PA 16802 (United States); Foley, Henry C. [Department of Chemical Engineering, University Park, PA 16802 (United States)


    Asymmetric aqueous electrochemical capacitors with energy densities as high as 22 Wh kg{sup -1}, power densities of 11 kW kg{sup -1} and a cell voltage of 2 V were fabricated using cost effective, high surface carbon derived from coal tar pitch and manganese dioxide. The narrow pore size distribution of the activated carbon (mean pore size {proportional_to}0.8 nm) resulted in strong electroadsorption of protons making them suitable for use as negative electrodes. Amorphous manganese dioxide anodes were synthesized by chemical precipitation method with high specific capacitance (300 F g{sup -1}) in aqueous electrolytes containing bivalent cations. The fabricated capacitors demonstrated excellent cyclability with no signs of capacitance fading even after 1000 cycles. (author)

  20. Beneficial effect of propane sultone and tris(trimethylsilyl) borate as electrolyte additives on the cycling stability of the lithium rich nickel manganese cobalt (NMC) oxide

    Birrozzi, Agnese; Laszczynski, Nina; Hekmatfar, Maral; von Zamory, Jan; Giffin, Guinevere A.; Passerini, Stefano


    This study reports the investigation of several compounds as electrolyte additives for Li[Li0.2Mn0.56 Ni0.16 Co0.08]O2 (a.k.a lithium rich NMC) cathode material. Among the compounds investigated via electrochemical and ex-situ analytical techniques, i.e. XRD, XPS and RAMAN spectroscopy, only 1,3-propane sultone and tris(trimethylsilyl) borate show a beneficial effect on the capacity retention and coulombic efficiency of the layered cathode. The results suggest that the improved capacity retention of the cells containing the two above-mentioned additives mainly originates from their participation in the formation of the cathode passive layer, which prevents the dissolution of the metals from the cathode material. Additionally, the borate additive reduces the lithium consumption upon the passive layer formation thus leaving a higher amount of lithium available in the electrolyte. Graphite/Li[Li0.2Mn0.56 Ni0.16 Co0.08]O2 cells containing the borate additive in the electrolyte showed 85% capacity retention after 485 cycles, confirming the feasibility of its employment for practical applications.


    Dhanus Suryaman


    Full Text Available To shorten the biological treating time and to examine the effect of electrolytes in a model water on the photocatalytic treatment, the combined biological-photocatalytic treatment was evaluated for removal of a mixture (total: 100 mg L-1, each: 25 mg L-1 of 2-chlorophenol (2-CP, 2,4-dichlorophenol (2,4-DCP, 2,4,5-trichlorophenol (2,4,5-TCP, and pentachlorophenol (PCP in tap water. The mineralization of the four phenols was performed by a flow (biological treatment-circulative flow (photocatalytic treatment operation under black light and sunlight irradiations. After a large portion of biodegradable 2-CP and 2,4-DCP, and around half amount of slightly biodegradable 2,4,5-TCP were removed by the biological treatment, the remained three chlorophenols, biorecalcitrant PCP, and  biodegradation products were completely removed by the subsequent photocatalytic treatment. The combined treatment significantly shortened the degradation time only the biotreatment. High circulative flow rate (600 mL min-1 enabled for TiO2 particles to completely suspend in a tubular photoreactor and resulted in high removals of chlorophenols and TOC. Sunlight irradiation was successfully used and the saving of the electric energy of black light was possible. Since TiO2 particles in the tap water spontaneously sedimented on standing after the photocatalytic treatment, the combined system can be operated by integrating it with the TiO2 separation.   Keywords: photocatalysis, titanium dioxide, biodegradation, pollutant, wastewater

  2. Mineral resource of the month: manganese

    Corathers, Lisa


    Manganese is a silver-colored metal resembling iron and often found in conjunction with iron. The earliest-known human use of manganese compounds was in the Stone Age, when early humans used manganese dioxide as pigments in cave paintings. In ancient Rome and Egypt, people started using it to color or remove the color from glass - a practice that continued to modern times. Today, manganese is predominantly used in metallurgical applications as an alloying addition, particularly in steel and cast iron production. Steel and cast iron together provide the largest market for manganese (historically 85 to 90 percent), but it is also alloyed with nonferrous metals such as aluminum and copper. Its importance to steel cannot be overstated, as almost all types of steel contain manganese and could not exist without it.


    孙洋洲; 姚沛


    介绍了以钛基体二氧化铅作为阳极,电解氯酸钠合成高氯酸钠的过程。考察了电解温度、电解液初始氯酸钠浓度及氯化钠浓度对电流效率的影响。得出了电解反应的最佳条件。%A process of electrolytic synthesis of sodium perchlorate from sodium chlorate solution by lead dioxide anode based titanium metal is introduced. The influence of temperature,the concentration of sodium chlorate and the concentration of sodium chloride on the current efficiency is investigated, and the optimum conditions of the electrolytic process are also obtained.

  4. Carbon Nanotube/Graphene Supercapacitors Containing Manganese Oxide Nanoparticles


    electrolytes : 0.5 M K2SO4, 1 M sodium chloride (NaCl), and 1 M calcium chloride (CaCl2). The qualitative CV behavior of the three electrolytes can be seen...Carbon Nanotube/ Graphene Supercapacitors Containing Manganese Oxide Nanoparticles by Matthew Ervin, Vinay Raju, Mary Hendrickson, and...Laboratory Adelphi, MD 20783-1197 ARL-TR-6289 December 2012 Carbon Nanotube/ Graphene Supercapacitors Containing Manganese Oxide

  5. 二氧化锰对石煤钒矿酸性浸出的影响%Effect of Manganese Dioxide on Acid Leaching of Vanadium from Stone Coal

    颜文斌; 胡蓝双; 高峰; 华骏; 何新波


    采用湘西地区的石煤钒矿为研究对象,石煤中+3,+4,+5价钒分布分别为75.67%,17.85%和6.48%,硅酸盐含量较高,属高硅石煤矿.在传统直接酸浸工艺的基础上,添加少量氧化剂二氧化锰,考察了二氧化锰的用量、液固比、浸出温度、浸出时间、硫酸体积浓度等因素对钒浸出率的影响.单因素实验和正交试验结果表明:加入少量二氧化锰能协同H+破坏石煤结构,大大提高石煤中钒的浸出率;在二氧化锰用量为2%、液固比为1:1、浸出时间为13 h、硫酸体积浓度为25%和浸出温度为95℃的条件下,钒浸出率达到97.2%,其中硫酸体积浓度对石煤湿法提钒影响最大.和直接酸浸工艺相比,钒的浸出率提高40%以上;与传统的钠化焙烧工艺相比,钒的浸出率提高40%以上,完全消除了焙烧过程中所产生的烟气污染;本实验采用氧化酸浸提钒技术,不经焙烧过程,不产生烟气污染,节约能源,且能大幅度提高钒的浸出率,实现资源的充分利用,具有较好的应用前景.%The valence state distribution of +3, + 4, +5 V in stone coal from Xiangxi region were 75.67% 17. 85% and 6. 48% , respectively. Silicate content was higher, it belonged to high silica stone coal mine. Based on the traditional direct acid leaching technology, a small amount manganese dioxide as oxidant was added. Effects of manganese dioxide dosage, liquid-solid ratio, leaching temperature, leaching time, sulfuric acid volume concentration were investigated by single factor experiment and orthogonal test. The results showed that manganese dioxide could coordinate with hydrogen ions to damage the structure of the stone coal and increase significantly the leaching rate of vanadium, and the leaching rate could reach 97. 24% under the extraction conditions of oxidant dosage of 2% , liquid-solid ratio of 1: 1, leaching time of 13 h, sulfuric acid volume concentration of 25% , leaching temperature of 95

  6. Synthesis and electrochemical properties of nanostructure manganese dioxide by fluid phase method%纳米MnO2的液相法制备及电化学性能研究



    以过硫酸钾(K2s2O8)和硫酸锰(MnSO4· H2O)为反应起始原料,采用液相法制备出了纳米MnO2.采用X射线衍射(XRD)和扫描电镜(SEM)对样品进行结构与形貌分析,并通过循环伏安、恒电流充放电对二氧化锰进行电化学性能测试.研究结果表明,采用液相沉淀法,在pH等于1.0,反应温度为60℃,反应时间为22 h的条件下制备出的二氧化锰为纯四方晶系α-MnO2.循环伏安测试表明二氧化锰在较小的扫描速率下有较好的电容性能.恒电流充放电测试表明二氧化锰有良好的电容性能.%In this paper, using MnSO4·H2O and K2S2O8 as reactants, MnO2was synthesized by fluid phase method. The products were characterized by XRD, FTIR and SEM, the electrochemical properties of the materials were investigated by cyclic voltammetry, impedance and current charge/discharge measurements. The results show that under the condition pH=1.0, 0=60 ℃ and t =22 h, the pure nanostructure α-MnO2 of system can be synthesized. In cyclic voltammetric tests, the results show that manganese dioxide in smaller scanning speed conditions have better capacitance performance. The constant current charging and discharging experiments show that the manganese dioxide has good capacitance characteristics.

  7. Size-Dependent Toxicity of Dioxide Manganese Particles on DNA Damage in Hela Cells%二氧化锰颗粒对Hela细胞DNA损伤的尺度依赖性毒作用

    毛彩霞; 杨光涛; 乔永康; 李岩; 袭著革; 杨旭


    A comparison was made for the size-dependent DNA damage induced by both nano dioxide manganese particles(Nano-MnO2)and normal size dioxide manganese particles(Nor-MnO2).Hela cells were exposed to different concentrations of both Nano-MnO2 and Nor-MnO2(0,100,200,400μg·mL-1),respectively.The DNA damage of Hela cells was measIIred by the comet assay after 24h Mno2-cultivated.Results showed that the Tail DNA%and Tail Momem were both significantly increased after exposed to both Nano-MnO2 and Nor-MnO2 when compared with the control(p<0.01 for all). At the same concenuation level,Nano-MnO2 could induce more serious DNA damage than Nor-Mn02(p<0.01 for all). The results suggested that Nano-MnO2 shollld have more serious toxic effect regarding to DNA damage of the Hela cells than that of Nor-Mno2.%为了观察二氧化锰颗粒物所致的尺度依赖性DNA损伤作用,将纳米尺度二氧化锰颗粒物(Nano-MnO2)和常规尺度二氧化锰颗粒物(Nor-MnO2)所致的DNA损伤进行了对比研究.将Hela细胞分别暴露于不同浓度(0、100、200、400μtg·mL-1)的Nano-MnO2和Nor-MnO2中,染毒24h,采用彗星实验检测Hela细胞的DNA损伤水平.结果表明:与对照组相比,Nano-MnO2和Nor·MnO2均可使彗尾DNA百分比(砌DNA%)和尾矩(Tail Moment)显著增加(P<0.01);而在同一浓度水平上,Nano-MnO2所致的DNA损伤则比Nor-MnO2所致的DNA损伤更为严重(p<0.01).结果提示:二氧化锰颗粒对Hela细胞DNA损伤具有尺度依赖性毒作用,纳米尺度比常规尺度二氧化锰颗粒毒作用更强烈.

  8. Treatment of ammonia nitrogen in electrolytic manganese wastewater using ion exchange method%电解锰废水中氨氮的离子交换法处理研究

    孙瑾; 羊依金; 雷弢; 郑梦桃; 信欣; 谭显东; 胡俊


    Using 001×7 cation exchange resin to remove ammonia nitrogen in electrolytic manganese wastewa-ter, and then, regenerated the resin which had achieved breakthrough point. The adsorption effect of ion exchange columns with different resin bed volume flow rates on ammonia nitrogen and its adsorption performance after the regeneration were investigated. The results showed that, when the resin bed volume flow rates were 3.75, 2.50 and 1.88 BV/h respectively, the breakthrough points of those ion exchange columns were 7.04, 11.42 and 14.81 h respectively;when the regenerated liquid flow rate was 5.0 BV/h, complete desorption of ammonia nitrogen could be obtained economically and effectively, which need 150 min. It could be seen that, three groups of ion ex-change columns all had stable and effective adsorption performance even after 8 times of adsorption-regeneration.%采用001×7阳离子交换树脂去除电解锰废水中的氨氮,并对达到氨氮穿透点的树脂进行再生后重吸附,考察不同床体积流量的离子交换柱对氨氮的吸附效果以及再生后重吸附的性能。结果表明,床体积流量分别为3.75、2.50、1.88 BV/h时,离子交换柱穿透时间点分别为7.04、11.42、14.81 h;再生液流速为5.0 BV/h时能经济有效地完成氨氮解吸,解析完全所需时间为150 min;3组离子交换柱经过8次吸附-再生,性能稳定有效。

  9. Construction of composite electrodes comprising manganese dioxide nanoparticles distributed in polyaniline-poly(4-styrene sulfonic acid-co-maleic acid) for electrochemical supercapacitor

    Liu, Feng-Jiin; Hsu, Tsui-Fen [Department of Chemical Engineering, National United University, 1, Lien Da, Kung-Ching Li, Miao-Li 36003 (China); Yang, Chien-Hsin [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811 (China)


    This work demonstrated a novel and simple route for preparing a composite comprising of manganese oxide (MnO{sub 2}) nanoparticles and polyaniline (PANI) doped poly(4-styrene sulfonic acid-co-maleic acid) (PSSMA) by ''electrochemical doping-deposition''. The PANI-PSSMA-MnO{sub 2} composite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). SEM images revealed a uniform dispersion of MnO{sub 2} nanoparticles in the porous structure of PANI-PSSMA structure. XRD measurements showed the distortion of the crystal structure of {beta}-MnO{sub 2} after deposition of MnO{sub 2} in PANI-PSSMA structure. Thus, the XRD pattern of PANI was predominating. Cyclic voltammetry and chronopotentiometry were employed in 0.5 M Na{sub 2}SO{sub 4} to evaluate the capacitor properties. The results showed a significant improvement in the specific capacitance of the composite electrode. The specific capacitance of PANI-PSSMA-MnO{sub 2} (50.4 F g{sup -1}) had improvement values of 172% compared to that of PANI (18.5 F g{sup -1}). When only the MnO{sub 2} mass was considered, the composite had a specific capacitance of 556 F g{sup -1}. (author)

  10. Role for Outer Membrane Cytochromes OmcA and OmcB of Shewanella putrefaciens MR-1 in Reduction of Manganese Dioxide

    Myers, Judith M.; Myers, Charles R.


    Shewanella putrefaciens MR-1 can use a wide variety of terminal electron acceptors for anaerobic respiration, including certain insoluble manganese and iron oxides. To examine whether the outer membrane (OM) cytochromes of MR-1 play a role in Mn(IV) and Fe(III) reduction, mutants lacking the OM cytochrome OmcA or OmcB were isolated by gene replacement. Southern blotting and PCR confirmed replacement of the omcA and omcB genes, respectively, and reverse transcription-PCR analysis demonstrated loss of the respective mRNAs, whereas mRNAs for upstream and downstream genes were retained. The omcA mutant (OMCA1) resembled MR-1 in its growth on trimethylamine N-oxide (TMAO), dimethyl sulfoxide, nitrate, fumarate, thiosulfate, and tetrathionate and its reduction of nitrate, nitrite, ferric citrate, FeOOH, and anthraquinone-2,6-disulfonic acid. Similarly, the omcB mutant (OMCB1) grew on fumarate, nitrate, TMAO, and thiosulfate and reduced ferric citrate and FeOOH. However, OMCA1 and OMCB1 were 45 and 75% slower than MR-1, respectively, at reducing MnO2. OMCA1 lacked only OmcA. While OMCB1 lacked OmcB, other OM cytochromes were also missing or markedly depressed. The total cytochrome content of the OM of OMCB1 was less than 15% of that of MR-1. Western blots demonstrated that OMCB1 still synthesized OmcA, but most of it was localized in the cytoplasmic membrane and soluble fractions rather than in the OM. OMCB1 had therefore lost the ability to properly localize multiple OM cytochromes to the OM. Together, the results suggest that the OM cytochromes of MR-1 participate in the reduction of Mn(IV) but are not required for the reduction of Fe(III) or other electron acceptors. PMID:11133454

  11. Suppressing Manganese Dissolution from Lithium Manganese Oxide Spinel Cathodes with Single-Layer Graphene

    Jaber-Ansari, Laila; Puntambekar, Kanan P.; Kim, Soo; Aykol, Muratahan; Luo, Langli; Wu, Jinsong; Myers, Benjamin D.; Iddir, Hakim; Russell, John T.; Saldana, Spencer J.; Kumar, Rajan; Thackeray, Michael M.; Curtiss, Larry A.; Dravid, Vinayak P.; Wolverton, Christopher M.; Hersam, Mark C.


    Spinel-structured LiMn 2 O 4 (LMO) is a desirable cathode material for Li-ion batteries due to its low cost, abundance, and high power capability. However, LMO suffers from limited cycle life that is triggered by manganese dissolution into the electrolyte during electrochemical cycling. Here, it is shown that single-layer graphene coatings suppress manganese dissolution, thus enhancing the performance and lifetime of LMO cathodes. Relative to lithium cells with uncoated LMO cathodes, cells with graphene-coated LMO cathodes provide improved capacity retention with enhanced cycling stability. X-ray photoelectron spectroscopy reveals that graphene coatings inhibit manganese depletion from the LMO surface. Additionally, transmission electron microscopy demonstrates that a stable solid electrolyte interphase is formed on graphene, which screens the LMO from direct contact with the electrolyte. Density functional theory calculations provide two mechanisms for the role of graphene in the suppression of manganese dissolution. First, common defects in single-layer graphene are found to allow the transport of lithium while concurrently acting as barriers for manganese diffusion. Second, graphene can chemically interact with Mn 3+ at the LMO electrode surface, promoting an oxidation state change to Mn 4+ , which suppresses dissolution.

  12. Removal of Rhodamine B in water with nano layered manganese dioxide%纳米层状二氧化锰去除水中罗丹明B的效能研究

    孙宏; 张泽; 宋坤


    采用环己醇还原高锰酸钾制备纳米二氧化锰,通过扫描电镜(SEM)、激光粒度仪和傅里叶变换红外光谱(FTIR)对纳米二氧化锰进行了形貌和结构表征。采用静态吸附试验,研究了溶液pH、吸附剂用量、染料初始质量浓度和吸附时间等因素对二氧化锰吸附罗丹明B(RhB)染料的影响。结果表明:制得的MnO2为纳米层状颗粒,粒径主要分布在230~477 nm,表面存在大量活性—OH,对RhB的吸附迅速有效,适合处理染料废水。%Nano layered manganese dioxide was successful y prepared through reduction of potassium permanganate by cyclohexanol. The morphology and structure of product was characterized by scanning elec⁃tron microscope (SEM), laser granulometer and Fourier transform infrared spectroscopy (FTIR). The effects of solution pH, sorbent dosage, the initial concentration of Rhodamine B and adsorption time on the adsorption were investigated through static adsorption. The results indicated that the prepared MnO2 was nano layered particles with 230~477 nm of particle size distribution, and there were many active —OH groups on its sur⁃face. The adsorbent was found to adsorb Rhodamine B rapidly and effectively, which was suited for treatment of dyeing wastewater.

  13. Manganese nodules

    Hein, James R.; Harff, Jan; Petersen, Sven; Thiede, Jorn


    The existence of manganese (Mn) nodules (Fig. 1) has been known since the late 1800s when they were collected during the Challenger expedition of 1873–1876. However, it was not until after WWII that nodules were further studied in detail for their ability to adsorb metals from seawater. Many of the early studies did not distinguish Mn nodules from Mn crusts. Economic interest in Mn nodules began in the late 1950s and early 1960s when John Mero finished his Ph.D. thesis on this subject, which was published...

  14. Fabrication of Titanium dioxide nanotube photo-electrodes in different electrolyte mixtures and the impacts on their characteristics and photo-catalytic abilities under visible light

    Thabit Mohamed


    Full Text Available TiO2 nanotube arrays were fabricated using electrochemical anodization of titanium foils, where different types of electrolytes were tested to determine conceptual choice for nanotubes fabrication. These electrolytes are 1M (NH42SO4 containing 0.5% wt NH4F, 1M Na2SO4 containing 0.5% wt NH4F, 1M NaF containing 0.5% wt (NH42SO4 and a mixture of water: ethylene glycol 1:9 containing 0.5% wt NH4F. The foils were marked as EG type (Ethylene Glycol, AS type (Ammonium sulfate, SS type (sodium sulfate and SF type (sodium fluoride. The photocatalytic capabilities and characterization of the fabricated NTAs were analyzed using SEM, XRD, and DRS. The degradation ratio of designated organic pollutants (Rhodamine B was analyzed. The obtained results have proven that foils fabricated using Ethylene glycol have significant photocatalytic abilities, with a degradation ratio of EG-SS-SF-AS types being 80% to 85%, 70% to 80%, 70% to 75% and 52% to 55%, respectively.

  15. Manganese Countries

    Maria Sousa Galito


    Full Text Available Cheickna Bounajim Cissé wrote an article in Mars 2013 in the Journal Les Afriques N. º 237, suggesting a new acronym, MANGANESE, for the nine African countries: Morocco, Angola, Namibia, Ghana, Algeria, Nigeria, Egypt, South Africa and Ethiopia. According to Cissé, this group of African nations will be the fastest growing states in the region over the next few years. The purpose of this article is to test the pertinence of the acronym, discuss the credibility and reliability of the future prospects of these countries by comparing selected socioeconomic and sociopolitical indicators based on the latest global rankings and trends. Likewise, the potential of Cissé's claim will be assessed, especially in relationship to drug trafficking and terrorism that may put their recent sustainability in danger now and in the future.

  16. Nanostructured electrolytes for stable lithium electrodeposition in secondary batteries.

    Tu, Zhengyuan; Nath, Pooja; Lu, Yingying; Tikekar, Mukul D; Archer, Lynden A


    Secondary batteries based on lithium are the most important energy storage technology for contemporary portable devices. The lithium ion battery (LIB) in widespread commercial use today is a compromise technology. It compromises high energy, high power, and design flexibility for long cell operating lifetimes and safety. Materials science, transport phenomena, and electrochemistry in the electrodes and electrolyte that constitute such batteries are areas of active study worldwide because significant improvements in storage capacity and cell lifetime are required to meet new demands, including the electrification of transportation and for powering emerging autonomous aircraft and robotics technologies. By replacing the carbonaceous host material used as the anode in an LIB with metallic lithium, rechargeable lithium metal batteries (LMBs) with higher storage capacity and compatibility with low-cost, high-energy, unlithiated cathodes such as sulfur, manganese dioxide, carbon dioxide, and oxygen become possible. Large-scale, commercial deployment of LMBs are today limited by safety concerns associated with unstable electrodeposition and lithium dendrite formation during cell recharge. LMBs are also limited by low cell operating lifetimes due to parasitic chemical reactions between the electrode and electrolyte. These concerns are greater in rechargeable batteries that utilize other, more earth abundant metals such as sodium and to some extent even aluminum. Inspired by early theoretical works, various strategies have been proposed for alleviating dendrite proliferation in LMBs. A commonly held view among these early studies is that a high modulus, solid-state electrolyte that facilitates fast ion transport, is nonflammable, and presents a strong-enough physical barrier to dendrite growth is a requirement for any commercial LMB. Unfortunately, poor room-temperature ionic conductivity, challenging processing, and the high cost of ceramic electrolytes that meet the

  17. Nanostructured Electrolytes for Stable Lithium Electrodeposition in Secondary Batteries

    Tu, Zhengyuan


    © 2015 American Chemical Society. ConspectusSecondary batteries based on lithium are the most important energy storage technology for contemporary portable devices. The lithium ion battery (LIB) in widespread commercial use today is a compromise technology. It compromises high energy, high power, and design flexibility for long cell operating lifetimes and safety. Materials science, transport phenomena, and electrochemistry in the electrodes and electrolyte that constitute such batteries are areas of active study worldwide because significant improvements in storage capacity and cell lifetime are required to meet new demands, including the electrification of transportation and for powering emerging autonomous aircraft and robotics technologies. By replacing the carbonaceous host material used as the anode in an LIB with metallic lithium, rechargeable lithium metal batteries (LMBs) with higher storage capacity and compatibility with low-cost, high-energy, unlithiated cathodes such as sulfur, manganese dioxide, carbon dioxide, and oxygen become possible. Large-scale, commercial deployment of LMBs are today limited by safety concerns associated with unstable electrodeposition and lithium dendrite formation during cell recharge. LMBs are also limited by low cell operating lifetimes due to parasitic chemical reactions between the electrode and electrolyte. These concerns are greater in rechargeable batteries that utilize other, more earth abundant metals such as sodium and to some extent even aluminum.Inspired by early theoretical works, various strategies have been proposed for alleviating dendrite proliferation in LMBs. A commonly held view among these early studies is that a high modulus, solid-state electrolyte that facilitates fast ion transport, is nonflammable, and presents a strong-enough physical barrier to dendrite growth is a requirement for any commercial LMB. Unfortunately, poor room-temperature ionic conductivity, challenging processing, and the high cost

  18. Degradation and Removal of Suifadiazine from Waters by a Novel Polymer-supported Hydrous Manganese Dioxide(HMO)%新型树脂基水合锰氧化物对水体中磺胺嘧啶的降解去除

    高俊; 盛光遥; 邱宇平


    以大孔强碱阴离子交换树脂D201为载体,采用离子交换和氧化还原方法制备了一种新型树脂基水合锰氧化物材料HMO-201.考察了不同pH、离子强度和溶解性有机质(DOM)含量条件下,该材料对水体中磺胺嘧啶(SD)的去除能力.HPLC-MS分析表明,SD的高效去除是通过HMO-201的降解而非吸附方式实现的.实验结果表明,pH为1.0时HMO-201在120 min内对0.01 mmol/L SD的去除效率为99.9%,反应符合表观一级动力学模型;体系的离子强度和DOM含量变化对SD的去除效率均无显著影响.模拟环境离子强度和DOM浓度,连续10批次实验中SD废水的去除效率在240 min内均大于99%;HMO-201的柱动态降解装置连续处理SD溶液2000床体积,依然未检出SD.表明HMO-201材料具有较稳定的重复利用性,对环境中普遍存在的磺胺类抗生素药物具有着高效的降解去除效果,具有广泛的应用前景.%A new polymer-supported hydrous manganese dioxide (HMO-201) was prepared by impregnating HMO onto a porous polystyrene anion exchange resin(D201) through ion exchange, oxidation and reduction. The removal of sulfadiazine(SD) by HMO-201 was evaluated as a function of solution pH, background electrolyte NaCl and dissolved organic matter( DOM). HPLC-MS results showed that the removal of SD by HMO-201 was due to degradation rather than adsorption. The results indicated that the removal of 0. 01 mmol/L SD reached 99. 9% at pH = 1.0 within 120 min. The SD degradation followed the pseudo-first-order kinetics. SD removal efficiency was little affected by ionic strength and DOM. With simulated SD wastewater containing NaCl and DOM, SD removal efficiency remained above 99% within 240 min for up to ten batches of continuous operation. Fixed-bed column experiment results of HMO-201 showed that SD remained undetected after 2000 bed volume simulated SD wastewater was passed through the column. HMO-201 was effective for the removal of sulfonamide

  19. Manganese nodules

    Hein, James R.; Harff, Jan; Petersen, Sven; Thiede, Jorn


    The existence of manganese (Mn) nodules (Figure 1) has been known since the late 1800s when they were collected during the Challenger expedition of 1873–1876. However, it was not until after WWII that nodules were further studied in detail for their ability to adsorb metals from seawater. Many of the early studies did not distinguish Mn nodules from Mn crusts. Economic interest in Mn nodules began in the late 1950s and early 1960s when John Mero finished his Ph.D. thesis on this subject, which was published in the journal Economic Geology (Mero, 1962) and later as a book (Mero, 1965). By the mid-1970s, large consortia had formed to search for and mine Mn nodules that occur between the Clarion and Clipperton fracture zones (CCZ) in the NE Pacific (Figure 2). This is still the area considered of greatest economic potential in the global ocean because of high nickel (Ni), copper (Cu), and Mn contents and the dense distribution of nodules in the area. While the mining of nodules was fully expected to begin in the late 1970s or early 1980s, this never occurred due to a downturn in the price of metals on the global market. Since then, many research cruises have been undertaken to study the CCZ nodules, and now 15 contracts for exploration sites have been given or are pending by the International Seabed Authority (ISA). Many books and science journal articles have been published summarizing the early work (e.g., Baturin, 1988; Halbach et al., 1988), and research has continued to the present day (e.g., ISA, 1999; ISA, 2010). Although the initial attraction for nodules was their high Ni, Cu, and Mn contents, subsequent work has shown that nodules host large quantities of other critical metals needed for high-tech, green-tech, and energy applications (Hein et al., 2013; Hein and Koschinsky, 2014).

  20. Manganese Oxidation State Assignment for Manganese Catalase.

    Beal, Nathan J; O'Malley, Patrick J


    The oxidation state assignment of the manganese ions present in the superoxidized manganese (III/IV) catalase active site is determined by comparing experimental and broken symmetry density functional theory calculated (14)N, (17)O, and (1)H hyperfine couplings. Experimental results have been interpreted to indicate that the substrate water is coordinated to the Mn(III) ion. However, by calculating hyperfine couplings for both scenarios we show that water is coordinated to the Mn(IV) ion and that the assigned oxidation states of the two manganese ions present in the site are the opposite of that previously proposed based on experimental measurements alone.

  1. Reducing carbon dioxide to products

    Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A


    A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

  2. Differences analysis of minerals compositions and toxicity characteristics between the fresh electrolytic manganese residue and the stockpiling residue%新鲜电解锰渣和长期堆存渣的矿物成分和毒性特征的差异分析



    The objective of this work was to analyze and compare the contents of heavy metals,miner-als compositions and leached toxic substances from the fresh electrolytic manganese residue and the stockpiling residue. The results indicated that the content of Mn from the fresh residue was greater than from the stockpiling residue. The both residues mainly contained SiO2 ,calcium sulfates embodying dif-ferent crystal waters,ammonium salts and manganese salts,etc. The minerals forF eS2 ,MnSO4 ·H2 O, ( NH4 )2 SO4 disappeared in the stockpiling residue. The toxic pollutants were Mn and NH4+ -N in the leaching solutions of the both residues. The contents and leaching amounts of Mn and NH4+ -N in the stockpiling residue were lesser than in the fresh residue,which revealed that the dissolutions of Mn and NH4+ -N occurred at the stockpiling process of the electrolytic manganese residue( EMR). The con-tents of Mn and NH4+ -N in the EMR percolating water were 1776. 8mg/L,1225. 8mg/L,respective-ly,and 355 times,49 times as many as the requirement values of the GB8978-2002 standard. This study could provide a reference for the harmless treatment of EMR.%以电解锰渣为研究对象,对比分析了新鲜电解锰渣和长期堆存渣的重金属含量、矿物成分、浸出毒性等的特征和差异.结果表明:新鲜渣中Mn的含量高于堆存渣.两种渣的矿物成分主要包括SiO2、含不同结晶水的硫酸钙以及铵盐、锰盐等.堆存渣与新鲜渣的矿物成分相比,不含FeS2、MnSO4·H2 O、(NH4)2 SO4等矿物;电解锰渣浸出液中毒性污染物主要是Mn和NH4+-N.堆存渣中Mn和NH4+-N的含量、浸出量均低于新鲜渣,说明在电解锰渣堆存过程中,Mn、NH4+-N不断从渣中溶出.电解锰渣渗滤液中Mn和NH4+-N的含量分别为1776.8mg/L、1225.8mg/L,分别是污水排放标准GB8978-2002的355倍、49倍.该研究为电解锰渣无害化处置提供参考.

  3. Lanthanum Doped Manganese Dioxide/Carbon Nanotube Composite Electrodes for Electrochemical Supercapacitors%镧掺杂的二氧化锰/碳纳米管电化学超级电容器复合电极

    薛荣; 阎景旺; 田颖; 衣宝廉


    Although higher specific capacitances have been achieved for manganese dioxide/multi-walled carbon nanotubes (MnO2/MWCNTs),the low conductivity of MnO2 is still the main obstacle in increasing its loading or film thickness.Another problem is that the cycling stability of MnO2/MWCNTs is much lower than that of activated carbon electrodes.Therefore,this new type of electrode material is still limited in application until now.In this paper,lanthanum doped MnO2/MWCNTs composites were prepared by an in situ redox method.The surface morphology and phase structure of the as-prepared samples were investigated by transmission electron microscopy (TEM),scanning electron microscopy (SEM),X-ray diffraction (XRD),and Fourier transform infrared (FTIR) spectrometry.The electrochemical properties were investigated by cyclic voltammetry (CV),galvanostatic charge/discharge,and electrochemical impedance spectroscopy (EIS).The La-doped MnO2 could be formed on the MWCNTs by the reduction of MnO-4.The resistance of the composite electrodes decreased because La doping increases the number of imperfections in the MnO2 lattice,which improves the electrical conductivity and the electrochemical activity of the electrode.La doping is,therefore,an effective way to overcome the intrinsic low electric conductivity of MnO2,which facilitates an increase in the loading or the film thickness of MnO2 without increasing electrode resistance.The major effect of La doping is a significant improvement in the charge/discharge cycling performance of a symmetric electrochemical supercapacitor with electrodes composed of MnO2/MWCNTs.The specific capacitance of the composite electrodes was improved by La doping.%尽管在二氧化锰/多壁碳纳米管(MnO2/MWCNTs)上获得了较高的比电容,低电导率仍是制约MnO2担载量或膜厚度提高的主要障碍.另一个问题是MnO2/MWCNTs的循环稳定性远低于活性炭.所以截止到目前这一新型材料的应用仍然受到很大的限制.本

  4. Electrolytes Test

    ... mean? High or low electrolyte levels can be caused by several conditions and diseases. Generally, they are affected by how much is consumed in the diet and absorbed by the body, the amount of water in a person's body, and the amount eliminated ...

  5. Carbon dioxide sensor

    Dutta, Prabir K. (Worthington, OH); Lee, Inhee (Columbus, OH); Akbar, Sheikh A. (Hilliard, OH)


    The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

  6. Preparation of manganese sulfate from low-grade manganese carbonate ores by sulfuric acid leaching

    Qing-quan Lin; Guo-hua Gu; Hui Wang; Ren-feng Zhu; You-cai Liu; and Jian-gang Fu


    In this study, a method for preparing pure manganese sulfate from low-grade ores with a granule mean size of 0.47 mm by direct acid leaching was developed. The effects of the types of leaching agents, sulfuric acid concentration, reaction temperature, and agitation rate on the leaching efficiency of manganese were investigated. We observed that sulfuric acid used as a leaching agent provides a similar leach-ing efficiency of manganese and superior selectivity against calcium compared to hydrochloric acid. The optimal leaching conditions in sul-furic acid media were determined; under the optimal conditions, the leaching efficiencies of Mn and Ca were 92.42% and 9.61%, respec-tively. Moreover, the kinetics of manganese leaching indicated that the leaching follows the diffusion-controlled model with an apparent ac-tivation energy of 12.28 kJ·mol−1. The purification conditions of the leaching solution were also discussed. The results show that manganese dioxide is a suitable oxidant of ferrous ions and sodium dimethyldithiocarbamate is an effective precipitant of heavy metals. Finally, through chemical analysis and X-ray diffraction analysis, the obtained product was determined to contain 98% of MnSO4·H2O.

  7. Investigation of solid polymer electrolyte gas sensor with different electrochemical techniques

    Strzelczyk, A.; Jasinski, G.; Chachulski, B.


    In this work solid polymer electrolyte (SPE) amperometric sulphur dioxide sensor is investigated. Nafion was used as a membrane electrode and 1M sulphuric acid as an internal electrolyte. Sensor response to sulphur dioxide was measured. Besides traditional constant voltage amperometry also different electrochemical techniques were used. Results obtained by these methods are compared.

  8. Electrochemical energy storage in montmorillonite K10 clay based composite as supercapacitor using ionic liquid electrolyte.

    Maiti, Sandipan; Pramanik, Atin; Chattopadhyay, Shreyasi; De, Goutam; Mahanty, Sourindra


    Exploring new electrode materials is the key to realize high performance energy storage devices for effective utilization of renewable energy. Natural clays with layered structure and high surface area are prospective materials for electrical double layer capacitors (EDLC). In this work, a novel hybrid composite based on acid-leached montmorillonite (K10), multi-walled carbon nanotube (MWCNT) and manganese dioxide (MnO2) was prepared and its electrochemical properties were investigated by fabricating two-electrode asymmetric supercapacitor cells against activated carbon (AC) using 1.0M tetraethylammonium tetrafluroborate (Et4NBF4) in acetonitrile (AN) as electrolyte. The asymmetric supercapacitors, capable of operating in a wide potential window of 0.0-2.7V, showed a high energy density of 171Whkg(-1) at a power density of ∼1.98kWkg(-1). Such high EDLC performance could possibly be linked to the acid-base interaction of K10 through its surface hydroxyl groups with the tetraethylammonium cation [(C2H5)4N(+) or TEA(+)] of the ionic liquid electrolyte. Even at a very high power density of 96.4kWkg(-1), the cells could still deliver an energy density of 91.1Whkg(-1) exhibiting an outstanding rate capability. The present study demonstrates for the first time, the excellent potential of clay-based composites for high power energy storage device applications.

  9. Hot coal gas desulfurization with manganese-based sorbents

    Lynch, D.; Hepworth, M.T.


    The focus of work being performed on Hot Coal Gas Desulfurization is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies at the US Steel Fundamental Research Laboratories in Monroeville, PA, by E.T. Turkdogan indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}/O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese higher temperatures than zinc ferrite or zinc titanate. This presentation gives the thermodynamic background for consideration of manganese-based sorbents as an alternative to zinc ferrite. To date the work which has been in progress for nine months is limited at this stage to thermogravimetric testing of four formulations of manganese-alumina sorbents to determine the optimum conditions of pelletization and induration to produce reactive pellets.

  10. Methanogenesis from wastewater stimulated by addition of elemental manganese.

    Qiao, Sen; Tian, Tian; Qi, Benyu; Zhou, Jiti


    This study presents a novel procedure for accelerating methanogenesis from wastewater by adding elemental manganese into the anaerobic digestion system. The results indicated that elemental manganese effectively enhanced both the methane yield and the production rate. Compared to the control test without elemental manganese, the total methane yield and production rate with 4 g/L manganese addition increased 3.4-fold (from 0.89 ± 0.03 to 2.99 ± 0.37 M/gVSS within 120 h) and 4.4-fold (from 6.2 ± 0.1 to 27.2 ± 2.2 mM/gVSS/h), respectively. Besides, more acetate consumption and less propionate generation were observed during the methanogenesis with manganese. Further studies demonstrated that the elemental manganese served as electron donors for the methanogenesis from carbon dioxide, and the final proportion of methane in the total generated gas with 4 g/L manganese addition reached 96.9%, which was 2.1-fold than that of the control (46.6%).

  11. In Situ Engineering of the Electrode-Electrolyte Interface for Stabilized Overlithiated Cathodes

    Evans, Tyler [Department of Mechanical Engineering, University of Colorado at Boulder, Boulder CO 80309 USA; SiILion, Inc., Broomfield CO 80020 USA; Piper, Daniela Molina [SiILion, Inc., Broomfield CO 80020 USA; Sun, Huaxing [Department of Chemistry, University of Colorado at Boulder, Boulder CO 80309 USA; Porcelli, Timothy [Department of Chemistry, University of Colorado at Boulder, Boulder CO 80309 USA; Kim, Seul Cham [Department of Material Science and Engineering, Seoul National University, Seoul 151-742 South Korea; Han, Sang Sub [Department of Material Science and Engineering, Seoul National University, Seoul 151-742 South Korea; Choi, Yong Seok [Department of Material Science and Engineering, Seoul National University, Seoul 151-742 South Korea; Tian, Chixia [Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley CA 94720 USA; Nordlund, Dennis [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park CA 94025 USA; Doeff, Marca M. [Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley CA 94720 USA; Ban, Chunmei [Center of Chemical and Materials Science, National Renewable Energy Laboratory, Golden CO 80401 USA; Cho, Sung-Jin [Joint School of Nanoscience and Nanoengineering, North Carolina A& T State University, Greensboro NC 27411 USA; Oh, Kyu Hwan [Department of Material Science and Engineering, Seoul National University, Seoul 151-742 South Korea; Lee, Se-Hee [Department of Mechanical Engineering, University of Colorado at Boulder, Boulder CO 80309 USA


    The first-ever demonstration of stabilized Si/lithium-manganese-rich full cells, capable of retaining >90% energy over early cycling and >90% capacity over more than 750 cycles at the 1C rate (100% depth-of-discharge), is made through the utilization of a modified ionic liquid electrolyte capable of forming a favorable cathode-electrolyte interface.

  12. Improvement in grade of minerals using simultaneous Bio-oxidation of invisible gold concentrate and deep-sea manganese crust

    Myung, EunJi; Cho, Kang Hee; Kim, Hyun Soo; Park, Cheon Young


    Many sulfides of metal such as galena, sphalerite, chalcopyrite, and pyrite, are semiconductors. When two kinds of such minerals contact each other in an electrolyte, a galvanic couple, where the mineral of lower rest potential as anode, and that of higher rest potential as cathode forms. Manganese dioxide is also a semiconductor with much higher rest potential than all sulfides mentioned above, so that a galvanic couple in which both the minerals would dissolve simultaneously can form, when it contacts with any of the sulfides. The aim of this study was to investigate the improvement in grade of minerals using the simultaneous bio-oxidation of deep-sea manganese crust and invisible gold concentrate. The samples(deep-sea manganese crust and invisible gold concentrate) were characterized by chemical and XRD analysis. The primary components of the invisible gold concentrate was pyrite and quartz and the deep-sea manganese crust was amorphous material, as detected using XRD. The result of chemical analysis showed that Au, Ag, Te contents in the invisible gold concentrate 130.2, 954.1 and 1,043.6 mg/kg, respectively. and that Mn, Ni, Co contents in the deep-sea manganese crust 19,501.5, 151.9, 400.4 mg/kg, respectively. In order to increase the bacteria's tolerance of heavy metals, the bacteria using bio-oxidation experiments were repeatedly subcultured in an Cu adaptation-medium containing of 382.98 mg/l for 20 periods of 21 days. The improvement in grade of samples of in present adapted bacteria condition was greater than another conditions(control and in present non-adapted bacteria). The Au-Ag-Te contents in the invisible gold concentrate was enhanced in the order of physical oxidation, simultaneous/non-adaptive bio-oxidation, adaptive/bio-oxidation, simultaneous/adaptive bio-oxidation. If the bacteria is adapted to heavy metal ions and an optimization of conditions is found in future bio-oxidation-leaching processes. Acknowledgment : "This research was supported

  13. 石墨烯/二氧化锰/聚3,4-乙烯二氧噻吩三相复合电极的制备及电化学性能%Preparation and electrochemical properties of three-phase composite electrode from graphene/manganese dioxide/poly(3,4-ethylenedioxy thiophene)

    李金龙; 徐建华; 熊平; 杨文耀; 张辉; 陈燕; 杨亚杰


    采用水性溶液为电解液,在石墨烯表面用恒电位法依次制备二氧化锰和聚3,4-乙烯二氧噻吩层,得到石墨烯/二氧化锰/聚3,4-乙烯二氧噻吩三相复合电极.扫描电镜表征三相复合电极的形貌特征及复合结构;通过恒流充放电、循环伏安、交流阻抗等电化学测试方法研究三相复合电极的电化学性能.结果表明,石墨烯呈现独有的褶皱状结构,二氧化锰由不规则的纳米片交织而成,聚3,4-乙烯二氧噻吩由纳米范围粒子聚合而成,三相电极呈现层状复合结构;在1.0 A/g的充放电电流下得到的比容值为165 F/g,经过500次充放电循环后,容量保持率达到80%,具有较好的稳定性,同时,该三相复合电极还表现出很好的充放电可逆性和阻抗性能.%Three-phase composite electrode composed of graphene,manganese dioxide,and poly(3,4-ethylened-ioxythiophene)was obtained by potentiostatic method.The manganese dioxide and poly(3,4-ethylenedioxythio-phene)layers are prepared on the surface of graphene,with aqueous solution as electrode.The morphology characteristics and the composite structure of the three-phase composite electrode are characterized with scan-ning electron microscope (SEM).The electrochemical properties of composite electrode are measured by con-stant current charge-discharge,cyclic voltammetry,and alternating current impendence (AC impedance)meth-ods.The results show that the grapheme was special fold structure,the manganese dioxide was irregular nanosheets,the poly(3,4-ethylenedioxythiophene)was aggregated by nanoparticles,the three-phase composite electrode was layered composite structure.The specific volume was 1 65 F/g under 1.0 A/g charge-discharge current.The capacity maintains 80% after 500 charge-discharge cycles which show good stability.The three-phase composite electrode presents very good discharge reversibility and impedance-resistant.

  14. Electrolytic fixer.



    Interest in the recovery of silver from radiographic film generates a need to understand the operating procedures of recovery units utilizing the electrolytic fixer principle. Tailing or terminal units and recirculation units using electrolysis are evaluated. Difficulties encountered in the number of Coulombs applied to a specific amount of fixer are discussed. Reduction of sulfiding as a result of electrolysis and variations in film volumes are noted. The quantity and quality of silver collected can be improved by being aware of alterations in chemical activity used in a silver recovery program.

  15. Air Manganese Study

    In November 2011 US EPA researchers conducted a health study of airborne manganese exposure in East Liverpool, Ohio. This Web site discusses preliminary results of the study and provides background and other related information.

  16. Multi-layered proton-conducting electrolyte

    Lee, Tae H.; Dorris, Stephen E.; Balachandran, Uthamalingam


    The present invention provides a multilayer anode/electrolyte assembly comprising a porous anode substrate and a layered solid electrolyte in contact therewith. The layered solid electrolyte includes a first dense layer of yttrium-doped barium zirconate (BZY), optionally including another metal besides Y, Ba, and Zr (e.g., a lanthanide metal such as Pr) on one surface thereof, a second dense layer of yttrium-doped barium cerate (BCY), and an interfacial layer between and contacting the BZY and BCY layers. The interfacial layer comprises a solid solution of the BZY and BCY electrolytes. The porous anode substrate comprises at least one porous ceramic material that is stable to carbon dioxide and water (e.g., porous BZY), as well as an electrically conductive metal and/or metal oxide (e.g., Ni, NiO, and the like).

  17. [Function and disease in manganese].

    Kimura, Mieko


    Manganese is a metal that has been known named a Greek word "Magnesia" meaning magnesia nigra from Roman Empire. Manganese provide the wide range of metablic function and the multiple abnomalities from its deficiency or toxicity. In 1931, the essentiality of manganese was demonstrated with the authoritative poor growth and declined reproduction in its deficiency. Manganese deficiency has been recognized in a number of species and its signs are impaired growth, impaired reproduction, ataxia, skeletal abnormalities and disorders in lipid and carbohydrate metabolism. Manganese toxicity is also acknowledged as health hazard for animals and humans. Here manganese nutrition, metabolism and metabolic function are summarized.

  18. Synthesis of single crystal manganese oxide octahedral molecular sieve (OMS) nanostructures with tunable tunnels and shapes.

    Li, Wei-Na; Yuan, Jikang; Gomez-Mower, Sinue; Sithambaram, Shantakumar; Suib, Steven L


    A new and facile route is reported to manipulate the self-assembly synthesis of hierarchically ordered Rb-OMS-2 and pyrolusite with an interesting flowerlike morphology by a direct and mild reaction between rubidium chromateand manganese sulfate without any organic templates. The crystal forms, morphologies, and tunnel sizes of the obtained OMS materials can be controlled. A mechanism for the growth of manganese dioxides with flowerlike architectures was proposed. The obtained products exhibit potential for use in catalysis and other applications.

  19. The Composite Effect of Nanometer MnO2 Mixed with the Electrolytic MnO2


    The nanometer MnO2 has outstanding electrochemical performance theoretically, but it is not suitable for actual utilization, which may result in capacity decrease and resource waste. In this study we have utilized the characterizations of the nanometer material, synthesized a type of nanometer α-MnO2 through KMnO4 and KNO3 with hydrothermal method, and mixed the products into micron electrolytic manganese dioxide (EMD) to enhance the electrochemical performance of the electrode.The cyclic voltammogram and galvanostatical discharge measurements of the samples were investigated. It is found that the 50% nanometer MnO2 mixed electrode has the best electrochemical performance. The electrochemical performance improvement mechanism of the sample nanometer MnO2 mixed into micron EMD was discussed. With the existence of electrolyte, the nanometer MnO2 particles filled into the interspaces of the micron EMD particles, the mass and charge transfer conditions of the electrode reaction were improved, and the electrode polarization was diminished.

  20. Development of novel strategies for enhancing the cycle life of lithium solid polymer electrolyte batteries. Final report

    Macdonald, Digby D.; Urquidi-Macdonald, Mirna; Allcock, Harry; Engelhard, George; Bomberger, N.; Gao, L.; Olmeijer, D.


    Lithium/solid polymer electrolyte (Li/SPE) secondary batteries are under intense development as power sources for portable electronic devices as well as electric vehicles. These batteries offer high specific energy, high energy density, very low self-discharge rates, and flexibility in packaging; however, problems have inhibited their introduction into the marketplace. This report summarizes findings to examine processes that occur with Li/SPE secondary batteries upon cyclic charging/discharging. The report includes a detailed analysis of the impedance measured on the Li/SPE/IC and IC/SPE/IC systems. The SPE was a derivative of methoxyethoxyethoxyphosphazene (MEEP) with lithium triflate salt as the electrolyte, while the intercalated cathodes (IC) comprised mixtures of manganese dioxide, carbon powder, and MEEP as a binder. Studies on symmetrical Li/SPE/Li laminates show that cycling results in a significant expansion of the structure over the first few tens of cycles; however, no corresponding increase in the impedance was noted. The cycle life of the intercalation cathode was found to be very sensitive to the method of fabrication. Results indicate that the cycle life is due to the failure of the IC, not to the failure of the lithium/SPE interface. A pattern recognition neural network was developed to predict the cycle life of a battery from the charge/discharge characteristics.

  1. Manganese As a Metal Accumulator

    Manganese deposits in water distribution systems accumulate metals, radionuclides and oxyanions by a combination of surface complexation, adsorption and solid substitution, as well as a combination of oxidation followed by manganese reduction and sorption of the oxidized constitu...

  2. Manganese As a Metal Accumulator

    Manganese deposits in water distribution systems accumulate metals, radionuclides and oxyanions by a combination of surface complexation, adsorption and solid substitution, as well as a combination of oxidation followed by manganese reduction and sorption of the oxidized constitu...

  3. Occupational exposure to manganese.

    Sarić, M; Markićević, A; Hrustić, O


    The relationship between the degree of exposure and biological effects of manganese was studied in a group of 369 workers employed in the production of ferroalloys. Two other groups of workers, from an electrode plant and from an aluminium rolling mill, served as controls. Mean manganese concentrations at work places where ferroalloys were produced varied from 0-301 to 20-442 mg/m3. The exposure level of the two control groups was from 2 to 30 microgram/m3 and from 0-05 to 0-07 microgram/m3, in the electrode plant and rolling mill respectively. Sixty-two (16-8%) manganese alloy workers showed some signs of neurological impairment. These signs were noticeably less in the two control groups (5-8% and 0%) than in the occupationally exposed group. Subjective symptoms, which are nonspecific but may be symptoms of subclinical manganism, were not markedly different in the three groups. However, in the manganese alloy workers some of the subjective symptoms occurred more frequently in heavier smokers than in light smokers or nonsmokers. Heavier smokers engaged in manganese alloy production showed some of the subjective symptoms more often than heavier smokers from the control groups.

  4. Anodic growth of titanium dioxide nanostructures


    Disclosed is a method of producing nanostructures of titanium dioxide (TiO 2 ) by anodisation of titanium (Ti) in an electrochemical cell, comprising the steps of: immersing a non-conducting substrate coated with a layer of titanium, defined as the anode, in an electrolyte solution...... an electrical contact to the layer of titanium on the anode, where the electrical contact is made in the electrolyte solution...

  5. Some geological problems of bedded manganese ore deposits. Sojo mangankosho no chishitsugakuteki shomondai

    Momoi, H. (Ehime University, Ehime (Japan). Faculty of Science)


    This paper summarizes the bedded manganese ore deposits in Japan and in the world. Chert-hosted bedded manganese ore deposits in the Chichibu terrane and similar terranes of the inner zone of Southwest Japan are characterized by numerous small deposits composed of rhodochrosite and manganese silicate ores. They are Triassic to Middle Jurassic in age. The deposits in Japan are, together with those of Coast Ranges in western part of North America, typical in the mobile belts of the world. On the other hand, giant bedded manganese deposits represented by Nikopol, South Ukraine and Groote Eylandt, Australia, occur in the inner parts of stable continents and in platforms and consist of manganese dioxide and rhodochrosite. The deposits in mobile belts and those in stable continents are very contrasting in the scale of deposits, distribution, ore, age, depositional environment and other features. 85 refs., 2 figs., 3 tabs.

  6. Manganese in silicon carbide

    Linnarsson, M. K.; Hallén, A.


    Structural disorder and relocation of implanted Mn in semi-insulating 4H-SiC has been studied. Subsequent heat treatment of Mn implanted samples has been performed in the temperature range 1400-2000 °C. The depth distribution of manganese is recorded by secondary ion mass spectrometry. Rutherford backscattering spectrometry has been employed for characterization of crystal disorder. Ocular inspection of color changes of heat-treated samples indicates that a large portion of the damage has been annealed. However, Rutherford backscattering shows that after heat treatment, most disorder from the implantation remains. Less disorder is observed in the [0 0 0 1] channel direction compared to [ 1 1 2¯ 3] channel direction. A substantial rearrangement of manganese is observed in the implanted region. No pronounced manganese diffusion deeper into the sample is recorded.

  7. Manganese in silicon carbide

    Linnarsson, M.K., E-mail: [Royal Institute of Technology, School of Information and Communication Technology, P.O. Box E229, SE-16440 Kista-Stockhom (Sweden); Hallen, A. [Royal Institute of Technology, School of Information and Communication Technology, P.O. Box E229, SE-16440 Kista-Stockhom (Sweden)


    Structural disorder and relocation of implanted Mn in semi-insulating 4H-SiC has been studied. Subsequent heat treatment of Mn implanted samples has been performed in the temperature range 1400-2000 Degree-Sign C. The depth distribution of manganese is recorded by secondary ion mass spectrometry. Rutherford backscattering spectrometry has been employed for characterization of crystal disorder. Ocular inspection of color changes of heat-treated samples indicates that a large portion of the damage has been annealed. However, Rutherford backscattering shows that after heat treatment, most disorder from the implantation remains. Less disorder is observed in the [0 0 0 1] channel direction compared to [112{sup Macron }3] channel direction. A substantial rearrangement of manganese is observed in the implanted region. No pronounced manganese diffusion deeper into the sample is recorded.

  8. The corrosive nature of manganese in drinking water

    Alvarez-Bastida, C. [Centro Interamericano de Recursos del Agua, Facultad de Ingeniería, Universidad Autónoma del Estado de México, Carretera Toluca-Ixtlahuaca, Km. 14.5, C.P. 50200, Toluca, Estado de México (Mexico); Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón y Tollocan s/n, C.P. 50000, Toluca, Estado de México (Mexico); Martínez-Miranda, V.; Vázquez-Mejía, G. [Centro Interamericano de Recursos del Agua, Facultad de Ingeniería, Universidad Autónoma del Estado de México, Carretera Toluca-Ixtlahuaca, Km. 14.5, C.P. 50200, Toluca, Estado de México (Mexico); Solache-Ríos, M., E-mail: [Departamento de Química, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Col. Escandón, Delegación Miguel Hidalgo, C.P. 11801 México, D.F. (Mexico); Fonseca-Montes de Oca, G. [Centro Interamericano de Recursos del Agua, Facultad de Ingeniería, Universidad Autónoma del Estado de México, Carretera Toluca-Ixtlahuaca, Km. 14.5, C.P. 50200, Toluca, Estado de México (Mexico); Trujillo-Flores, E. [Facultad de Ingeniería, Universidad Autónoma del Estado de México, Cerro de Coatepec s/n, Ciudad Universitaria, C.P. 50130, Toluca, Estado de México (Mexico)


    Corrosion problems having to do with drinking water distribution systems are related to many processes and factors and two of them are ionic acidity and carbon dioxide, which were considered in this work. The corrosion character of water is determined by the corrosion indexes of Langelier, Ryznar, Larson, and Mojmir. The results show that pipes made of different materials, such as plastics or metals, are affected by corrosion, causing manganese to be deposited on materials and dissolved in water. The deterioration of the materials, the degree of corrosion, and the deposited corrosion products were determined by X-ray diffraction and Scanning Electron Microscopy. High levels of manganese and nitrate ions in water may cause serious damage to the health of consumers of water. Three wells were examined, one of them presented a high content of manganese; the others had high levels of nitrate ions, which increased the acidity of the water and, therefore, the amount of corrosion of the materials in the distribution systems. - Highlights: ► Corrosion of distribution systems affects the quality of drinking water. ► Corrosion in water distribution systems is related to acidity and carbon dioxide. ► Pipes are corroded and manganese is deposited on pipes and dissolved in water. ► The deterioration of the pipes and the corrosion products were determined. ► Nitrate ions increase the acidity of water in the wells.

  9. An Insoluble Titanium-Lead Anode for Sulfate Electrolytes

    Ferdman, Alla


    The project is devoted to the development of novel insoluble anodes for copper electrowinning and electrolytic manganese dioxide (EMD) production. The anodes are made of titanium-lead composite material produced by techniques of powder metallurgy, compaction of titanium powder, sintering and subsequent lead infiltration. The titanium-lead anode combines beneficial electrochemical behavior of a lead anode with high mechanical properties and corrosion resistance of a titanium anode. In the titanium-lead anode, the titanium stabilizes the lead, preventing it from spalling, and the lead sheathes the titanium, protecting it from passivation. Interconnections between manufacturing process, structure, composition and properties of the titanium-lead composite material were investigated. The material containing 20-30 vol.% of lead had optimal combination of mechanical and electrochemical properties. Optimal process parameters to manufacture the anodes were identified. Prototypes having optimized composition and structure were produced for testing in operating conditions of copper electrowinning and EMD production. Bench-scale, mini-pilot scale and pilot scale tests were performed. The test anodes were of both a plate design and a flow-through cylindrical design. The cylindrical anodes were composed of cylinders containing titanium inner rods and fitting over titanium-lead bushings. The cylindrical design allows the electrolyte to flow through the anode, which enhances diffusion of the electrolyte reactants. The cylindrical anodes demonstrate higher mass transport capabilities and increased electrical efficiency compared to the plate anodes. Copper electrowinning represents the primary target market for the titanium-lead anode. A full-size cylindrical anode performance in copper electrowinning conditions was monitored over a year. The test anode to cathode voltage was stable in the 1.8 to 2.0 volt range. Copper cathode morphology was very smooth and uniform. There was no

  10. Manganese dipyridoxyl diphosphate:

    H, Brurok; Ardenkjær-Larsen, Jan Henrik; G, Hansson


    Manganese dipyridoxyl diphosphate (MnDPDP) is a contrast agent for magnetic resonance imaging (MRI) of the liver. Aims of the study were to examine if MnDPDP possesses superoxide dismutase (SOD) mimetic activity in vitro, and if antioxidant protection can be demonstrated in an ex vivo rat heart...

  11. Manganese deficiency in plants

    Schmidt, Sidsel Birkelund; Jensen, Poul Erik; Husted, Søren


    Manganese (Mn) is an essential plant micronutrient with an indispensable function as a catalyst in the oxygen-evolving complex (OEC) of photosystem II (PSII). Even so, Mn deficiency frequently occurs without visual leaf symptoms, thereby masking the distribution and dimension of the problem...

  12. Role of manganese in protection against oxidative stress under iron starvation in cyanobacterium Anabaena 7120.

    Kaushik, Manish Singh; Srivastava, Meenakshi; Verma, Ekta; Mishra, Arun Kumar


    The cyanobacterium Anabaena sp. PCC 7120 was grown in presence and absence of iron to decipher the role of manganese in protection against the oxidative stress under iron starvation and growth, manganese uptake kinetics, antioxidative enzymes, lipid peroxidation, electrolyte leakage, thiol content, total peroxide, proline and NADH content was investigated. Manganese supported the growth of cyanobacterium Anabaena 7120 under iron deprived conditions where maximum uptake rate of manganese was observed with lower K(m) and higher V(max) values. Antioxidative enzymes were also found to be elevated in iron-starved conditions. Estimation of lipid peroxidation and electrolyte leakage depicted the role of manganese in stabilizing the integrity of the membrane which was considered as the prime target of oxygen free radicals in oxidative stress. The levels of total peroxide, thiol, proline and NADH content, which are the representative of oxidative stress response in Anabaena 7120, were also showed increasing trends in iron starvation. Hence, the results discerned, clearly suggested the role of manganese in protection against the oxidative stress in cyanobacterium Anabaena 7120 under iron starvation either due to its antioxidative properties or involvement as cofactor in a number of antioxidative enzymes.

  13. Manganese, Metallogenium, and Martian Microfossils

    Stein, L. Y.; Nealson, K. H.


    Manganese could easily be considered an abundant element in the Martian regolith, assuming that the composition of martian meteorites reflects the composition of the planet. Mineralogical analyses of 5 SNC meteorites have revealed an average manganese oxide concentration of 0.48%, relative to the 0.1% concentration of manganese found in the Earth's crust. On the Earth, the accumulation of manganese oxides in oceans, soils, rocks, sedimentary ores, fresh water systems, and hydrothermal vents can be largely attributed to microbial activity. Manganese is also a required trace nutrient for most life forms and participates in many critical enzymatic reactions such as photosynthesis. The wide-spread process of bacterial manganese cycling on Earth suggests that manganese is an important element to both geology and biology. Furthermore, there is evidence that bacteria can be fossilized within manganese ores, implying that manganese beds may be good repositories for preserved biomarkers. A particular genus of bacteria, known historically as Metallogenium, can form star-shaped manganese oxide minerals (called metallogenium) through the action of manganese oxide precipitation along its surface. Fossilized structures that resemble metallogenium have been found in Precambrian sedimentary formations and in Cretaceous-Paleogene cherts. The Cretaceous-Paleogene formations are highly enriched in manganese and have concentrations of trace elements (Fe, Zn, Cu, and Co) similar to modern-day manganese oxide deposits in marine environments. The appearance of metallogenium-like fossils associated with manganese deposits suggests that bacteria may be preserved within the minerals that they form. Additional information is contained in the original extended abstract.

  14. Extraction of Carbon Dioxide and Hydrogen from Seawater By an Electrolytic Cation Exchange Module (E-CEM) Part V: E-CEM Effluent Discharge Composition as aFunction of Electrode Water Composition


    Cation Exchange Module (E-CEM) Part V: E-CEM Effluent Discharge Composition as a Function of Electrode Water Composition August 1, 2017 Approved for...Electrolytic Cation Exchange Module (E-CEM) Part V: E-CEM Effluent Discharge Composition as a Function of Electrode Water Composition Heather D. Willauer...regulate E-CEM effluent discharge water composition with respect to pH and chlorine content. This report details the results of two separate

  15. Rechargable xLi{sub 2}MnO{sub 3}·(1 − x)Li{sub 4/3}Mn{sub 5/3}O{sub 4} electrode nanocomposite material as a modification product of chemical manganese dioxide by lithium additives

    Sokolsky, Georgii V., E-mail: [National University of Food Technologies, Volodymyrska st., 70, 01033 Kyiv (Ukraine); National Aviation University, Cosmonaut Komarov Avenue 1, 04058 Kiev 58 (Ukraine); Ivanov, Sergiy V. [National University of Food Technologies, Volodymyrska st., 70, 01033 Kyiv (Ukraine); Boldyrev, Eudgene I.; Ivanova, Natalya D. [Institute of General and Inorganic Chemistry of Ukrainian National Academy of Science, Palladin Avenue 32-34, 252680 Kiev 142 (Ukraine); Kiporenko, Oksana Ya. [The Ukrainian Physics and Mathematics Lyceum, Akademika Glushkova Avenue 6, 03680, Kyiv (Ukraine)


    Highlights: • Li-ion battery cathode preparation procedure included MnO{sub 2} modification by Li-salts with subsequent heat treatment. • Li{sub 4}Mn{sub 5}O{sub 12}, Li{sub 2}MnO{sub 3,} and Li-rich phases form active nanocomposite cathode. • Heat treatment mode is of crucial importance for rechargeability. • Cathode material capacity is 150 mA h g{sup −1} within 2.5–4.5 V. - Abstract: Relatively simple preparation procedure of rechargeable Li-ion battery cathode material via manganese dioxide treatment with Li-containing additive and subsequent calcination has been demonstrated. X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, and atomic force microscopy study were characterisation methods of modification products. Pyrolusite, Li{sub 0.3}MnO{sub 2}, layered Li{sub 2}MnO{sub 3}, and spinel Li{sub 4}Mn{sub 5}O{sub 12} phases were revealed as products of initial ramsdellite phase transformations at temperatures of heat treatment ranging from 360 °C to 600 °C. Optimal temperature of final heat treatment from the point of view of rechargeability and discharge characteristics was 450 °C. Samples heat-treated at 450 °C are characterized by the unique combination of Li{sub 4/3}Mn{sub 5/3}O{sub 4} and Li{sub 2}MnO{sub 3} phase components due to their structural integration, a significant degree of disordering, and sizes of nanocrystallites with Li diffusion path, which is the most favourable for reversibility. The prepared nanocomposite cathode material delivers a capacity of 150 mA h g{sup −1} within 2.5–4.5 V at 0.1 mA discharge.

  16. 21 CFR 184.1449 - Manganese citrate.


    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Manganese citrate. 184.1449 Section 184.1449 Food... Specific Substances Affirmed as GRAS § 184.1449 Manganese citrate. (a) Manganese citrate (Mn3(C6H5O7)2, CAS... manganese carbonate from manganese sulfate and sodium carbonate solutions. The filtered and...

  17. Manganese in Madison's drinking water.

    Schlenker, Thomas; Hausbeck, John; Sorsa, Kirsti


    Public concern over events of manganese-discolored drinking water and the potential for adverse health effects from exposure to excess manganese reached a high level in 2005. In response, Public Health Madison Dane County, together with the Madison Water Utility, conceived and implemented a public health/water utility strategy to quantify the extent of the manganese problem, determine the potential for adverse human health effects, and communicate these findings to the community. This strategy included five basic parts: taking an inventory of wells and their manganese levels, correlating manganese concentration with turbidity, determining the prevalence and distribution of excess manganese in Madison households, reviewing the available scientific literature, and effectively communicating our findings to the community. The year-long public health/water utility strategy successfully resolved the crisis of confidence in the safety of Madison's drinking water.

  18. Impact resistant electrolytes

    Veith, Gabriel M.; Armstrong, Beth L.; Tenhaeff, Wyatt E.; Dudney, Nancy J.


    A passively impact resistant composite electrolyte composition includes an electrolyte solvent, up to 2M of an electrolyte salt, and shear thickening ceramic particles having a polydispersity index of no greater than 0.1, an average particle size of in a range of 50 nm to 1 .mu.m, and an absolute zeta potential of greater than .+-.40 mV.

  19. Improved method generates more chlorine dioxide

    Jordan, R.W.; Kosinski, A.J.; Baker, R.J.


    The addition of acid can greatly improve the chlorine-chlorite process and enhance the use of chlorine dioxide as an alternative to chlorine for disinfection. The process is economical for use in taste and odor control, and for manganese, oxidation. The maximum yield is obtained using no excess chlorine, and the amount of unreacted sodium chlorite and chlorine in the product stream is reduced. (1 diagram, 4 graphs, 9 references)

  20. Asymmetric supercapacitors based on functional electrospun carbon nanofiber/manganese oxide electrodes with high power density and energy density

    Lin, Sheng-Chi; Lu, Yi-Ting; Chien, Yu-An; Wang, Jeng-An; You, Ting-Hsuan; Wang, Yu-Sheng; Lin, Chih-Wen; Ma, Chen-Chi M.; Hu, Chi-Chang


    Carbon nanofibers modified with carboxyl groups (CNF-COOH) possessing good wettability and high porosity are homogeneously deposited with amorphous manganese dioxide (amorphous MnO2) by potentiodynamic deposition for asymmetric super-capacitors (ASCs). The potential-cycling in 1 M H2SO4 successfully enhances the hydrophilicity of carbonized polymer nanofibers and facilitates the access of electrolytes within the CNF-COOH matrix. This modification favors the deposition of amorphous MnO2 and improves its electrochemical utilization. In this composite, MnO2 homogeneously dispersed onto CNF-COOH provides desirable pseudocapacitance and the CNF-COOH network works as the electron conductor. The composite of CNF-COOH@MnO2-20 shows a high specific capacitance of 415 F g-1 at 5 mV s-1. The capacitance retention of this composite is 94% in a 10,000-cycle test. An ASC cell consisting of this composite and activated carbon as positive and negative electrodes can be reversibly charged/discharged to a cell voltage of 2.0 V in 1 M Na2SO4 and 4 mM NaHCO3 with specific energy and power of 36.7 Wh kg-1 and 354.9 W kg-1, respectively. This ASC also shows excellent cell capacitance retention (8% decay) in the 2V, 10,000-cycle stability test, revealing superior performance.

  1. Nanoporous polymer electrolyte

    Elliott, Brian [Wheat Ridge, CO; Nguyen, Vinh [Wheat Ridge, CO


    A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

  2. Role of Manganese Deposition on Graphite in the Capacity Fading of Lithium Ion Batteries

    Vissers, Daniel R.; Chen, Zonghai; Shao, Yuyan; Engelhard, Mark H.; Das, Ujjal; Redfern, Paul C.; Curtiss, Larry A.; Pan, Baofei; Liu, Jun; Amine, Khalil


    Lithium-ion batteries utilizing manganese based cathodes have received considerable interest in recent years for their lower cost and favorable environmental friendliness relative to their cobalt counterparts. However, Li-ion batteries using manganese based cathodes and graphite anodes suffer from severe capacity fading at higher operating temperature. In this article, we report on an astute investigation into how the dissolution of manganese impacts the capacity fading within the Li-ion batteries. Our investigation reveals that the manganese dissolves from the cathode, transports to the graphite electrode, and deposits onto the outer surface of the inner most solid electrolyte interphase (SEI) layer which is known to be a mixture of inorganic salts (e.g. Li2CO3, LiF, and Li2O). In this location, the manganese facilitates the reduction of the electrolyte and the subsequent formation of lithium containing products on the graphite which removes lithium ions from the normal operation of the cell and thereby induces the severe capacity fade.

  3. 21 CFR 184.1452 - Manganese gluconate.


    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Manganese gluconate. 184.1452 Section 184.1452 Food... Specific Substances Affirmed as GRAS § 184.1452 Manganese gluconate. (a) Manganese gluconate (C12H22MnO14... manganese carbonate with gluconic acid in aqueous medium and then crystallizing the product. (b)...

  4. 21 CFR 184.1461 - Manganese sulfate.


    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Manganese sulfate. 184.1461 Section 184.1461 Food... Specific Substances Affirmed as GRAS § 184.1461 Manganese sulfate. (a) Manganese sulfate (MnSO4·H2O, CAS... manganese compounds with sulfuric acid. It is also obtained as a byproduct in the manufacture...

  5. Manganese regulates expression of manganese peroxidase by Phanerochaete chrysosporium.

    Brown, J A; Glenn, J K; Gold, M H


    The appearance of manganese peroxidase (MnP) activity in nitrogen-limited cultures of Phanerochaete chrysosporium is dependent on the presence of manganese. Cultures grown in the absence of Mn developed normally and produced normal levels of the secondary metabolite veratryl alcohol but produced no MnP activity. Immunoblot analysis indicated that appearance of MnP protein in the extracellular medium was also dependent on the presence of Mn. Intracellular MnP protein was detectable only in cel...

  6. Structure and morphological properties of clinoptilolite modified by manganese dioxide

    Vadim V. Korablev


    Full Text Available The chemical composition and morphological properties of сlinoptilolite-bearing materials modified by MnО2 have been studied using modern physical methods. Scanning electron microscopy, X-ray spectral microanalysis and optical reflection microscopy were applied. It was experimentally shown that MnО2-modified samples with high and low Si/Al ratios differed in such parameters as the layer thickness, the surface concentration, the degree of particle-surface dealumination, and also in morphological peculiarities of the MnО2-phase. This phase in the samples with high Si/Al ratios exhibited the structure formed by nanorods of 10–20nm in diameter and 500–700nm in length. These nanorods are intermeshed in the net which is cross-linked with the surface of clinoptilolite particles. The MnО2-modification of the samples was established to result in improving their mechanical and chemical strength as compared with the initial forms.

  7. Structure and morphological properties of clinoptilolite modified by manganese dioxide

    Korablev, Vadim V.; Chechevichkin, Aleksey V.; Irina K. Boricheva; Vyacheslav V. Samonin


    The chemical composition and morphological properties of сlinoptilolite-bearing materials modified by MnО2 have been studied using modern physical methods. Scanning electron microscopy, X-ray spectral microanalysis and optical reflection microscopy were applied. It was experimentally shown that MnО2-modified samples with high and low Si/Al ratios differed in such parameters as the layer thickness, the surface concentration, the degree of particle-surface dealumination, and also in morphologic...




  9. Preparation and electrochemical characterization of manganese dioxide-zirconia nanorods

    Muthuchudarkodi, R. R.; Vedhi, C.


    MnO2-ZrO2 nanorods were prepared by wet chemical method by mixing the solutions of MnSO4 and ZrOCl2 varying in the range (0.05-0.45 M) in aqueous NaOH at an elevated temperature. The morphologies of the synthesized products are characterized by scanning electron microscopy and transmission electron microscopy (TEM). X-ray diffraction (XRD) and energy-dispersive spectroscopic measurements were also employed for the characterization of the nanostructures. The synthesized nanoparticles were also characterized by ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy, electrochemical impedance and cyclic voltammetric studies. The morphological studies of the nanoparticles revealed particle distribution with uniform rod-like structure. Energy-dispersive analysis indicated the presence of Mn, Zr and O. The nanostructures of the product were characterized by TEM studies and the mixed rod and granular structure that was found clearly indicated the presence of MnO2-ZrO2 mixed oxide. The size of the synthesized nanorod was found to be 20 nm. From XRD studies the size of the nanorods was found to be in the range 39-56 nm calculated by Debye-Scherrer's formula. Thermal stability of the nanorods was characterized by thermogravimetric and differential scanning colorimetric analysis. Cyclic voltammetric studies exhibit good adherent behavior on electrode surface and good electroactivity at a pH value of 1.0.

  10. Towards Prognostics of Electrolytic Capacitors

    National Aeronautics and Space Administration — A remaining useful life prediction algorithm and degradation model for electrolytic capacitors is presented. Electrolytic capacitors are used in several applications...

  11. Electrodeposition of Manganese-Nickel Oxide Films on a Graphite Sheet for Electrochemical Capacitor Applications

    Hae-Min Lee


    Full Text Available Manganese-nickel (Mn-Ni oxide films were electrodeposited on a graphite sheet in a bath consisting of manganese acetate and nickel chloride, and the structural, morphological, and electrochemical properties of these films were investigated. The electrodeposited Mn-Ni oxide films had porous structures covered with nanofibers. The X-ray diffractometer pattern revealed the presence of separate manganese oxide (g-MnO2 and nickel oxide (NiO in the films. The electrodeposited Mn-Ni oxide electrode exhibited a specific capacitance of 424 F/g in Na2SO4 electrolyte. This electrode maintained 86% of its initial specific capacitance over 2000 cycles of the charge-discharge operation, showing good cycling stability.

  12. Regeneration of oxygen from carbon dioxide and water.

    Weissbart, J.; Smart, W. H.; Wydeven, T.


    In a closed ecological system it is necessary to reclaim most of the oxygen required for breathing from respired carbon dioxide and the remainder from waste water. One of the advanced physicochemical systems being developed for generating oxygen in manned spacecraft is the solid electrolyte-electrolysis system. The solid electrolyte system consists of two basic units, an electrolyzer and a carbon monoxide disproportionator. The electrolyzer can reclaim oxygen from both carbon dioxide and water. Electrolyzer preparation and assembly are discussed together with questions of reactor design and electrolyzer performance data.

  13. Regeneration of oxygen from carbon dioxide and water.

    Weissbart, J.; Smart, W. H.; Wydeven, T.


    In a closed ecological system it is necessary to reclaim most of the oxygen required for breathing from respired carbon dioxide and the remainder from waste water. One of the advanced physicochemical systems being developed for generating oxygen in manned spacecraft is the solid electrolyte-electrolysis system. The solid electrolyte system consists of two basic units, an electrolyzer and a carbon monoxide disproportionator. The electrolyzer can reclaim oxygen from both carbon dioxide and water. Electrolyzer preparation and assembly are discussed together with questions of reactor design and electrolyzer performance data.

  14. Electrolyte for batteries with regenerative solid electrolyte interface

    Xiao, Jie; Lu, Dongping; Shao, Yuyan; Bennett, Wendy D.; Graff, Gordon L.; Liu, Jun; Zhang, Ji-Guang


    An energy storage device comprising: an anode; and a solute-containing electrolyte composition wherein the solute concentration in the electrolyte composition is sufficiently high to form a regenerative solid electrolyte interface layer on a surface of the anode only during charging of the energy storage device, wherein the regenerative layer comprises at least one solute or solvated solute from the electrolyte composition.

  15. 24-epibrassinolide mitigates the adverse effects of manganese induced toxicity through improved antioxidant system and photosynthetic attributes in Brassica juncea.

    Fariduddin, Qazi; Ahmed, Mumtaz; Mir, Bilal A; Yusuf, Mohammad; Khan, Tanveer A


    The objective of this study was to establish relationship between manganese-induced toxicity and antioxidant system response in Brassica juncea plants and also to investigate whether brassinosteroids activate antioxidant system to confer tolerance to the plants affected with manganese induced oxidative stress. Brassica juncea plants were administered with 3, 6, or 9 mM manganese at 10-day stage for 3 days. At 31-day stage, the seedlings were sprayed with deionized water (control) or 10(-8) M of 24-epibrassinolide, and plants were harvested at 45-day stage to assess growth, leaf gas-exchange traits, and biochemical parameters. The manganese treatments diminished growth along with photosynthetic attributes and carbonic anhydrase activity in the concentration-dependent manner, whereas it enhanced lipid peroxidation, electrolyte leakage, accumulation of H2O2 as well as proline, and various antioxidant enzymes in the leaves of Brassica juncea which were more pronounced at higher concentrations of manganese. However, the follow-up application of 24-epibrassinolide to the manganese stressed plants improved growth, water relations, and photosynthesis and further enhanced the various antioxidant enzymes viz. catalase, peroxidase, and superoxide dismutase and content of proline. The elevated level of antioxidant enzymes as well as proline could have conferred tolerance to the manganese-stressed plants resulting in improved growth and photosynthetic attributes.

  16. Characterization of plasma electrolytic oxide formed onAZ91 Mg alloy in KMnO4 electrolyte

    Duck-Young HWANG; Ki-Ryong SHIN; Bongyoung YOO; Dong-Heon LEE; Deok-Yong PARK; Dong-Hyuk SHIN


    The aim of this work is to investigate microstructure, corrosion resistance characteristics and nanohardness of the oxide layer on AZ91 Mg alloy by applying different voltage with KMnO4 contained solution. There are lots of closed pores that are filled with another oxide compound compared with the typical surface morphology with pore coated until 350 V of coating voltage. The thickness of oxide layer increases with increasing coating voltage. The oxide layer formed on AZ91 Mg alloy in electrolyte with potassium permanganate consists of MgO and Mn2O3. Corrosion potential of the oxide layer on AZ91 Mg alloy obtained at different plasma electrolytic oxidation(PEO) reaction stages increases with increasing coating voltage. The corrosion resistance of AZ91 Mg alloy depends on the existence of the manganese oxide in the oxide layer. The inner barrier layer composed of the MgO and Mn2O3 may serve as diffusion barrier to enhance the corrosion resistance and may partially explain the excellent anti-corrosion performance in corrosion test. Nanohardness values increase with increasing coating voltage. The increase in the nanohardness may be due to the effect of manganese oxide in the oxide layer on AZ91 Mg alloy coated from electrolyte containing KMnO4.

  17. The corrosive nature of manganese in drinking water.

    Alvarez-Bastida, C; Martínez-Miranda, V; Vázquez-Mejía, G; Solache-Ríos, M; Fonseca-Montes de Oca, G; Trujillo-Flores, E


    Corrosion problems having to do with drinking water distribution systems are related to many processes and factors and two of them are ionic acidity and carbon dioxide, which were considered in this work. The corrosion character of water is determined by the corrosion indexes of Langelier, Ryznar, Larson, and Mojmir. The results show that pipes made of different materials, such as plastics or metals, are affected by corrosion, causing manganese to be deposited on materials and dissolved in water. The deterioration of the materials, the degree of corrosion, and the deposited corrosion products were determined by X-ray diffraction and Scanning Electron Microscopy. High levels of manganese and nitrate ions in water may cause serious damage to the health of consumers of water. Three wells were examined, one of them presented a high content of manganese; the others had high levels of nitrate ions, which increased the acidity of the water and, therefore, the amount of corrosion of the materials in the distribution systems. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Electrolytic oxidation of anthracite

    Senftle, F.E.; Patton, K.M.; Heard, I.


    An anthracite slurry can be oxidized only with difficulty by electrolytic methods in which aqueous electrolytes are used if the slurry is confined to the region of the anode by a porous pot or diaphragm. However, it can be easily oxidized if the anthracite itself is used as the anode. No porous pot or diaphragm is needed. Oxidative consumption of the coal to alkali-soluble compounds is found to proceed preferentially at the edges of the aromatic planes. An oxidation model is proposed in which the chief oxidants are molecular and radical species formed by the electrolytic decomposition of water at the coal surface-electrolyte interface. The oxidation reactions proposed account for the opening of the aromatic rings and the subsequent formation of carboxylic acids. The model also explains the observed anisotropic oxidation and the need for the porous pot or diaphragm used in previous studies of the oxidation of coal slurries. ?? 1981.

  19. Solid electrolytic fuel cell

    Sakai, Masayasu; Yamauchi, Yasuhiro; Kamisaka, Mitsuo; Notomi, Kei.


    Concerning a solid electrolytic fuel cell with a gas permeable substrate pipe, a fuel electrode installed on this substrate pipe and an air electrode which is laminated on this fuel electrode with the electrolyte in between, the existing fuel cell of this kind uses crystals of CaMnO3, etc. for the material of the air electrode, but its electric resistance is big and in order to avert this, it is necessary to make the film thickness of the air electrode big. However, in such a case, the entry of the air into its inside worsens and the cell performance cannot develop satisfactorily. In view of the above, in order to obtain a high performance solid electrolytic fuel cell which can improve electric conductivity without damaging diffusion rate of the air, this invention proposes with regard to the aforementioned solid electrolytic fuel cell to install a heat resistant and conductive member inside the above air electrode. 6 figs.

  20. Polymer electrolyte reviews. 1

    Mac Callum, J.R.; Vincent, C.A.


    The development of polymer electrolytes which have potential applications in battery technology has resulted in an escalation of research into the synthesis of new macromolecular supports and the mechanisms of ionic transport within the solid matrix. Investigation of the properties of polymer electrolytes has brought together polymer chemists and electrochemists, and the understanding of the solubility and transport of electrolytes in organic polymers is now developing from this pooled experience. This book deals with experimental, theoretical and applied aspects of solid solutions of electrolytes used in coordinating polymer matrices. Attention is focused on the synthesis and properties of these new materials, the mechanisms of conduction processes and practical applications, especially with regard to battery technology.

  1. Nanoscale Organic Hybrid Electrolytes

    Nugent, Jennifer L.


    Nanoscale organic hybrid electrolytes are composed of organic-inorganic hybrid nanostructures, each with a metal oxide or metallic nanoparticle core densely grafted with an ion-conducting polyethylene glycol corona - doped with lithium salt. These materials form novel solvent-free hybrid electrolytes that are particle-rich, soft glasses at room temperature; yet manifest high ionic conductivity and good electrochemical stability above 5V. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Nonequilibrium Thermodynamic Model of Manganese Carbonate Oxidation

    郝瑞霞; 彭省临


    Manganese carbonate can be converted to many kinds of manganese oxides when it is aerated in air and oxygen.Pure manganese carbonate can be changed into Mn3O4 and γ-MnOOH,and manganese carbonate ore can be converted to MnO2 under the air-aerating and oxygen-aerating circumstances.The oxidation process of manganese carbonate is a changing process of mineral association,and is also a converting process of valence of manganese itself.Not only equilibrium stat,but also nonequilibrium state are involved in this whole process,This process is an irreversible heterogeneous complex reaction,and oberys the nonequilibrium thermodynamic model,The oxidation rate of manganese cabonate is controlled by many factors,especially nonmanganese metallic ions which play an important role in the oxidation process of manganese carbonate.

  3. Selective determination of chlorine dioxide using gas diffusion flow injection analysis

    Hollowell, D.A.; Pacey, G.E.; Gordon, G.


    An automated absorbance technique for the determination of aqueous chlorine dioxide has been developed by utilizing gas diffusion flow injection analysis. A gas diffusion membrane is used to separate the donor (sampling) stream from the acceptor (detecting) stream. The absorbance of chlorine dioxide is monitored at 359 nm. The first method uses distilled water as the acceptor stream and gives a detection limit of 0.25 mg/L chlorine dioxide. This system is over 550 times more selective for chlorine dioxide than chlorine. To further minimize chlorine interference, oxalic acid is used in the acceptor stream. The detection limit for this system is 0.45 mg/L chlorine dioxide. This second system is over 5400 times more selective for chlorine dioxide than chlorine. Both methods show excellent selectivity for chlorine dioxide over iron and manganese compounds, as well as other oxychlorinated compounds such as chlorite and perchlorate ions. 18 references, 7 figures, 3 tables.

  4. Manganese depresses rat heart muscle respiration

    It has previously been reported that moderately high dietary manganese (Mn) in combination with marginal magnesium (Mg) resulted in ultrastructural damage to heart mitochondria. Manganese may replace Mg in biological functions, including the role of enzyme cofactor. Manganese may accumulate and subs...

  5. 21 CFR 582.5458 - Manganese hypophosphite.


    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Manganese hypophosphite. 582.5458 Section 582.5458 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5458 Manganese hypophosphite. (a) Product. Manganese hypophosphite. (b) Conditions of...

  6. 21 CFR 582.5446 - Manganese chloride.


    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Manganese chloride. 582.5446 Section 582.5446 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5446 Manganese chloride. (a) Product. Manganese chloride. (b) Conditions of use....

  7. 21 CFR 582.5452 - Manganese gluconate.


    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Manganese gluconate. 582.5452 Section 582.5452 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5452 Manganese gluconate. (a) Product. Manganese gluconate. (b) Conditions of use....

  8. 21 CFR 582.5461 - Manganese sulfate.


    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Manganese sulfate. 582.5461 Section 582.5461 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5461 Manganese sulfate. (a) Product. Manganese sulfate. (b) Conditions of use....

  9. 21 CFR 73.2775 - Manganese violet.


    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Manganese violet. 73.2775 Section 73.2775 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive manganese violet is a violet pigment obtained by reacting phosphoric acid, ammonium...

  10. 21 CFR 582.5455 - Manganese glycerophosphate.


    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Manganese glycerophosphate. 582.5455 Section 582.5455 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5455 Manganese glycerophosphate. (a) Product. Manganese glycerophosphate....

  11. 21 CFR 582.5449 - Manganese citrate.


    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Manganese citrate. 582.5449 Section 582.5449 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5449 Manganese citrate. (a) Product. Manganese citrate. (b) Conditions of use....

  12. Research on Frequency and Temperature Characteristics of Chip Organic Tantalum Solid Electrolytic Capacitor%片式有机固体钽电解电容器频率及温度特性研究

    马腾双; 陆胜; 龙道学


    Ferric p-toluenesulfonate as oxidant, using chemical oxidation method, the conductive polymer poly 3,4-vinyl dioxythiophene (PEDT) with high conductive was synthesized on the surface of the dielectric layer on the valve metal tantalum porous sintered compact. And replacing the traditional manganese dioxide with the PEDT as cathode electrolyte to make organic tantalum solid electrolytic capacitors, frequency and temperature characteristics of these organic tantalum solid electrolytic capacitors were studied. The results showed that the equivalent series resistance (ESR) value of the tantalum electrolytic capacitor with PEDT as cathode electrolyte decreased to1/3 or less of traditional inorganic solid tantalum electrolytic capacitor ESR value, and have stable frequency characteristics and temperature characteristics, meet the modern high-frequency switching power supply filter circuit specific requirements.%以对甲苯磺酸铁为氧化剂,采用化学氧化法在阀金属钽多孔体表面电介质层上合成了具有优异导电性能的导电聚合物聚3,4-乙烯基二氧噻吩(PEDT)。并以PEDT为阴极电解质取代传统的阴极电解质二氧化锰制备有机固体钽电解电容器,对有机固体钽电解电容器的频率及温度特性进行研究。结果表明,以PEDT为阴极电解质的钽电解电容器,其等效串联电阻(ESR)值降低至传统无机固体钽电解电容器ESR值的1/3以下,具有稳定的频率特性和温度特性,能够满足现代高频开关电源滤波电路的特殊要求。


    Thunaes, A.; Rabbits, F.T.; Hester, K.D.; Smith, H.W.


    A process is described for extracting uranlum from uranium containing material, such as a low grade pitchblende ore, or mill taillngs, where at least part of the uraniunn is in the +4 oxidation state. After comminuting and magnetically removing any entrained lron particles the general material is made up as an aqueous slurry containing added ferric and manganese salts and treated with sulfur dioxide and aeration to an extent sufficient to form a proportion of oxysulfur acids to give a pH of about 1 to 2 but insufficient to cause excessive removal of the sulfur dioxide gas. After separating from the solids, the leach solution is adjusted to a pH of about 1.25, then treated with metallic iron in the presence of a precipitant such as a soluble phosphate, arsonate, or fluoride.

  14. Water Quality Impacts of Pure Chlorine Dioxide Pretreatment at the Roanoke County (Virginia) Water Treatment Plant

    Ellenberger, Christine Spada


    WATER QUALITY IMPACTS OF PURE CHLORINE DIOXIDE PRETREATMENT AT THE ROANOKE COUNTY (VIRGINIA) WATER TREATMENT PLANT by Christine S. Ellenberger Dr. Robert C. Hoehn, Chairman (ABSTRACT) Chlorine dioxide (ClO2) was included in the Spring Hollow Water Treatment Plant (Roanoke County, Virginia) to oxidize manganese and iron, prevent tastes and odors, and avoid the formation of excessive halogenated disinfection by-products. A state-of-the-art, gas:solid ClO2 generation system ...

  15. Manganese in dwarf spheroidal galaxies

    North, P.; Cescutti, G.; Jablonka, P.; Hill, V.; Shetrone, M.; Letarte, B.; Lemasle, B.; Venn, K. A.; Battaglia, G.; Tolstoy, E.; Irwin, M. J.; Primas, F.; Francois, P.

    We provide manganese abundances (corrected for the effect of the hyperfine structure) for a large number of stars in the dwarf spheroidal galaxies Sculptor and Fornax, and for a smaller number in the Carina and Sextans dSph galaxies. Abundances had already been determined for a number of other

  16. Gel electrolytes and electrodes

    Fleischmann, Sven; Bunte, Christine; Mikhaylik, Yuriy V.; Viner, Veronika G.


    Gel electrolytes, especially gel electrolytes for electrochemical cells, are generally described. In some embodiments, the gel electrolyte layers comprise components a) to c). Component a) may be at least one layer of at least one polymer comprising polymerized units of: a1) at least one monomer containing an ethylenically unsaturated unit and an amido group and a2) at least one crosslinker. Component b) may be at least one conducting salt and component c) may be at least one solvent. Electrodes may comprise the components a), d) and e), wherein component a) may be at least one layer of at least one polymer as described herein. Component d) may be at least one electroactive layer and component e) may be at least one ceramic layer. Furthermore, electrochemical cells comprising component a) which may be at least one layer of at least one polymer as described herein, are also provided.

  17. Seebeck effect in electrolytes.

    Chikina, I; Shikin, V; Varlamov, A A


    We study Seebeck effect in liquid electrolytes, starting from its simple neutral analog--thermodiffusion (so-called Ludwig-Soret or Soret effect). It is observed that when two or more subsystems of mobile particles are subjected to the temperature gradient, various types of them respond to it differently. In the case when these fractions, with different mobility parameters (Soret coefficients), are oppositely charged (a case typical for electrolytes), the nonhomogeneous internal electric field is generated. The latter field prevents these fractions from space separation and determines the intensity of the appearing Seebeck effect.

  18. Multichannel discharge between jet electrolyte cathode and jet electrolyte anode

    Shakirova, E. F.; Gaitsin, Al. F.; Son, E. E.


    We present the results of an experimental study of multichannel discharge between a jet electrolyte cathode and jet electrolyte anode within a wide range of parameters. We pioneer the reveal of the burning particularities and characteristics of multichannel discharge with jet electrolyte and droplet

  19. Synthesis, characterization, optical and sensing property of manganese oxide nanoparticles

    Manigandan, R.; Suresh, R.; Giribabu, K.; Vijayalakshmi, L.; Stephen, A.; Narayanan, V.


    Manganese oxide nanoparticles were prepared by thermal decomposition of manganese oxalate. Manganese oxalate was synthesized by reacting 1:1 mole ratio of manganese acetate and ammonium oxalate along with sodium dodecyl sulfate (SDS). The structural characterization of manganese oxalate and manganese oxide nanoparticles was analyzed by XRD. The XRD spectrum confirms the crystal structure of the manganese oxide and manganese oxalate. In addition, the average grain size, lattice parameter values were also calculated using XRD spectrum. Moreover, the diffraction peaks were broadened due to the smaller size of the particle. The band gap of manganese oxide was calculated from optical absorption, which was carried out by DRS UV-Visible spectroscopy. The morphology of manganese oxide nanoparticles was analyzed by SEM images. The FT-IR analysis confirms the formation of the manganese oxide from manganese oxalate nanoparticles. The electrochemical sensing behavior of manganese oxide nanoparticles were investigated using hydrogen peroxide by cyclic voltammetry.

  20. Foaming-electrolyte fuel cell

    Nanis, L.; Saunders, A. P.


    Foam structure feeds fuel gas solution into electrolyte. Fuel gas reacts at static, three-phase interface between fuel gas, electrolyte, and electrode material. The foam forms an electrical contact between main body of electrolyte and the electrode, and aids in removal of by-products of the chemical reaction.

  1. Gel polymer electrolytes for batteries

    Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William


    Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at C.

  2. Spectroscopic characterization of manganese minerals

    Lakshmi Reddy, S.; Padma Suvarna, K.; Udayabhaska Reddy, G.; Endo, Tamio; Frost, R. L.


    Manganese minerals ardenite, alleghanyite and leucopoenicite originated from Madhya Pradesh, India, Nagano prefecture Japan, Sussex Country and Parker Shaft Franklin, Sussex Country, New Jersey respectively are used in the present work. In these minerals manganese is the major constituent and iron if present is in traces only. An EPR study of on all of the above samples confirms the presence of Mn(II) with g around 2.0. Optical absorption spectrum of the mineral alleghanyite indicates that Mn(II) is present in two different octahedral sites and in leucophoenicite Mn(II) is also in octahedral geometry. Ardenite mineral gives only a few Mn(II) bands. NIR results of the minerals ardenite, leucophoenicite and alleghanyite are due to hydroxyl and silicate anions which confirming the formulae of the minerals.

  3. Spectroscopic characterization of manganese minerals.

    Lakshmi Reddy, S; Padma Suvarna, K; Udayabhaska Reddy, G; Endo, Tamio; Frost, R L


    Manganese minerals ardenite, alleghanyite and leucopoenicite originated from Madhya Pradesh, India, Nagano prefecture Japan, Sussex Country and Parker Shaft Franklin, Sussex Country, New Jersey respectively are used in the present work. In these minerals manganese is the major constituent and iron if present is in traces only. An EPR study of on all of the above samples confirms the presence of Mn(II) with g around 2.0. Optical absorption spectrum of the mineral alleghanyite indicates that Mn(II) is present in two different octahedral sites and in leucophoenicite Mn(II) is also in octahedral geometry. Ardenite mineral gives only a few Mn(II) bands. NIR results of the minerals ardenite, leucophoenicite and alleghanyite are due to hydroxyl and silicate anions which confirming the formulae of the minerals. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. 钾锰氧化物:电化学控制合成及其电容器性质%Potassium Manganese Oxides: Electrochemically Controlled Synthesis and Capacitor Properties

    冯良东; 石建军; 姜立萍; 朱俊杰


    Potassium manganese oxides were prepared by cathodic deposition from aqueous KMnO4 solution on an indium tin oxide slide. The products were characterized by XRD, XPS and SEM techniques. The as-prepared products were potassium manganese oxides with different manganese valence states. The component, morphology and size of the products could be controlled through adjusting the preparation parameters such as deposition potential, deposition time and acidity of the electrolyte. The results show that the deposition of potassium manganese oxide from aqueous KMnO4 is a pH value dependent procedure. Due to the facilitating of intercalation and deintercalation of cations, the specific capacitance of the products deposited for 500 s is higher than that indicate that the reversibility and performance of these potassium manganese oxides are also changed with the deposition time.

  5. Manganese Research Health Project (MHRP)


    of a GLP compliant micronucleus assay in mice according to the OECD Guideline for the Testing of Chemicals, OECD 474: Mammalian Erythrocyte... Micronucleus Test . Experimental Design The basic experimental design used at ILS and proposed for the definitive in vivo micronucleus assay in manganese...regimen, would be expected to produce lethality”. The limit dose for the in vivo micronucleus assay based on OECD 474 is 2000 mg/kg and testing in a



    Keywords: Amino acids, dissociation constant, potentiometry, stability constant. INTRODUCTION ... constants of manganese (II) amino acid complexes using potentiometer. .... Principles of Biochemistry Third Edition,. Worth publishers, 41 ...

  7. Electrolytes for advanced batteries

    Blomgren, G.E. [Energizer, Westlake, OH (United States)


    The choices of the components of the electrolyte phase for advanced batteries (lithium and lithium ion batteries) are very sensitive to the electrodes which are used. There are also a number of other requirements for the electrolyte phase, which depend on the cell design and the materials chosen for the battery. The difficulty of choice is compounded when the cell is a rechargeable one. This paper looks at each of these requirements and the degree to which they are met for lithium and lithium ion batteries. The discussion is broken into sections on anode or negative electrode stability requirements, cathode or positive electrode stability requirements, conductivity needs, viscosity and wetting requirements. The effects of these properties and interactions on the performance of batteries are also discussed. (orig.)

  8. Nanoporous hybrid electrolytes

    Schaefer, Jennifer L.


    Oligomer-suspended SiO2-polyethylene glycol nanoparticles are studied as porous media electrolytes. At SiO2 volume fractions, , bracketing a critical value y ≈ 0.29, the suspensions jam and their mechanical modulus increase by more than seven orders. For >y, the mean pore diameter is close to the anion size, yet the ionic conductivity remains surprisingly high and can be understood, at all , using a simple effective medium model proposed by Maxwell. SiO 2-polyethylene glycol hybrid electrolytes are also reported to manifest attractive electrochemical stability windows (0.3-6.3 V) and to reach a steady-state interfacial impedance when in contact with metallic lithium. © 2010 The Royal Society of Chemistry.

  9. Electrochemical polymer electrolyte membranes

    Fang, Jianhua; Wilkinson, David P


    Electrochemical Polymer Electrolyte Membranes covers PEMs from fundamentals to applications, describing their structure, properties, characterization, synthesis, and use in electrochemical energy storage and solar energy conversion technologies. Featuring chapters authored by leading experts from academia and industry, this authoritative text: Discusses cutting-edge methodologies in PEM material selection and fabricationPoints out important challenges in developing PEMs and recommends mitigation strategies to improve PEM performanceAnalyzes the cur

  10. Electrolyte Concentrates Treat Dehydration


    Wellness Brands Inc. of Boulder, Colorado, exclusively licensed a unique electrolyte concentrate formula developed by Ames Research Center to treat and prevent dehydration in astronauts returning to Earth. Marketed as The Right Stuff, the company's NASA-derived formula is an ideal measure for athletes looking to combat dehydration and boost performance. Wellness Brands also plans to expand with products that make use of the formula's effective hydration properties to help treat conditions including heat stroke, altitude sickness, jet lag, and disease.

  11. Battles with Iron: Manganese in Oxidative Stress Protection*

    Aguirre, J. Dafhne; Culotta, Valeria C.


    The redox-active metal manganese plays a key role in cellular adaptation to oxidative stress. As a cofactor for manganese superoxide dismutase or through formation of non-proteinaceous manganese antioxidants, this metal can combat oxidative damage without deleterious side effects of Fenton chemistry. In either case, the antioxidant properties of manganese are vulnerable to iron. Cellular pools of iron can outcompete manganese for binding to manganese superoxide dismutase, and through Fenton chemistry, iron may counteract the benefits of non-proteinaceous manganese antioxidants. In this minireview, we highlight ways in which cells maximize the efficacy of manganese as an antioxidant in the midst of pro-oxidant iron. PMID:22247543

  12. Electrolyte materials - Issues and challenges

    Balbuena, Perla B. [Department of Chemical Engineering, and Department of Materials Science and Engineering, Texas A and M University, College Station, Texas, 77843 (United States)


    Electrolytes are vital components of an electrochemical energy storage device. They are usually composed of a solvent or mixture of solvents and a salt or a mixture of salts which provide the appropriate environment for ionic conduction. One of the main issues associated with the selection of a proper electrolyte is that its electronic properties have to be such that allow a wide electrochemical window - defined as the voltage range in which the electrolyte is not oxidized or reduced - suitable to the battery operating voltage. In addition, electrolytes must have high ionic conductivity and negligible electronic conductivity, be chemically stable with respect to the other battery components, have low flammability, and low cost. Weak stability of the electrolyte against oxidation or reduction leads to the formation of a solid-electrolyte interphase (SEI) layer at the surface of the cathode and anode respectively. Depending on the materials of the electrolyte and those of the electrode, the SEI layer may be composed by combinations of organic and inorganic species, and it may exert a passivating role. In this paper we discuss the current status of knowledge about electrolyte materials, including non-aqueous liquids, ionic liquids, solid ceramic and polymer electrolytes. We also review the basic knowledge about the SEI layer formation, and challenges for a rational design of stable electrolytes.

  13. Preparation and capacitive properties of lithium manganese oxide intercalation compound

    Tian, Fang; Xie, Yibing, E-mail: [Southeast University, School of Chemistry and Chemical Engineering (China)


    Lithium manganese oxide intercalation compound (Li{sub 0.7}MnO{sub 2}) supported on titanium nitride nanotube array (TiN NTA) was applied as cathode electrode material for lithium-ion supercapacitor application. Li{sub 0.7}MnO{sub 2}/TiN NTA was fabricated through electrochemical deposition and simultaneous intercalation process using TiN NTA as a substrate, Mn(CH{sub 3}COO){sub 2} as manganese source, and Li{sub 2}SO{sub 4} as lithium source. The morphology and microstructure of the Li{sub 0.7}MnO{sub 2}/TiN NTA were characterized by scanning electron microscopy and X-ray diffraction analysis. The electrochemical performance of the Li{sub 0.7}MnO{sub 2}/TiN NTA was investigated by electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge/discharge measurements. Li{sub 0.7}MnO{sub 2}/TiN NTA exhibited higher capacitive performance in Li{sub 2}SO{sub 4} electrolyte solution rather than that in Na{sub 2}SO{sub 4} electrolyte solution, which was due to the different intercalation effects of lithium-ion and sodium-ion. The specific capacitance was improved from 503.3 F g{sup −1} for MnO{sub 2}/TiN NTA to 595.0 F g{sup −1} for Li{sub 0.7}MnO{sub 2}/TiN NTA at a current density of 2 A g{sup −1} in 1.0 M Li{sub 2}SO{sub 4} electrolyte solution, which was due to the intercalation of lithium-ion for Li{sub 0.7}MnO{sub 2}. Li{sub 0.7}MnO{sub 2}/TiN NTA also kept 90.4 % capacity retention after 1000 cycles, presenting a good cycling stability. An all-solid-state lithium-ion supercapacitor was fabricated and showed an energy density of 82.5 Wh kg{sup −1} and a power density of 10.0 kW kg{sup −1}.

  14. Thermal properties of nonstoichiometry uranium dioxide

    Kavazauri, R.; Pokrovskiy, S. A.; Baranov, V. G.; Tenishev, A. V.


    In this paper, was developed a method of oxidation pure uranium dioxide to a predetermined deviation from the stoichiometry. Oxidation was carried out using the thermogravimetric method on NETZSCH STA 409 CD with a solid electrolyte galvanic cell for controlling the oxygen potential of the environment. 4 samples uranium oxide were obtained with a different ratio of oxygen-to-metal: O / U = 2.002, O / U = 2.005, O / U = 2.015, O / U = 2.033. For the obtained samples were determined basic thermal characteristics of the heat capacity, thermal diffusivity, thermal conductivity. The error of heat capacity determination is equal to 5%. Thermal diffusivity and thermal conductivity of the samples decreased with increasing deviation from stoichiometry. For the sample with O / M = 2.033, difference of both values with those of stoichiometric uranium dioxide is close to 50%.

  15. Control of bacterial iron homeostasis by manganese

    Puri, Sumant; Hohle, Thomas H.; O'Brian, Mark R.


    Perception and response to nutritional iron availability by bacteria are essential to control cellular iron homeostasis. The Irr protein from Bradyrhizobium japonicum senses iron through the status of heme biosynthesis to globally regulate iron-dependent gene expression. Heme binds directly to Irr to trigger its degradation. Here, we show that severe manganese limitation created by growth of a Mn2+ transport mutant in manganese-limited media resulted in a cellular iron deficiency. In wild-type cells, Irr levels were attenuated under manganese limitation, resulting in reduced promoter occupancy of target genes and altered iron-dependent gene expression. Irr levels were high regardless of manganese availability in a heme-deficient mutant, indicating that manganese normally affects heme-dependent degradation of Irr. Manganese altered the secondary structure of Irr in vitro and inhibited binding of heme to the protein. We propose that manganese limitation destabilizes Irr under low-iron conditions by lowering the threshold of heme that can trigger Irr degradation. The findings implicate a mechanism for the control of iron homeostasis by manganese in a bacterium. PMID:20498065

  16. Electric battery cell, system and method. [ambient temperature, dithionite salt in electrolyte

    Schwartz, R.E.


    An ambient-temperature electric cell of primary and secondary nature, characterized by the use of the dithionite salt of an active (alkali or an alkaline earth) metal as the charging agent, is described along with processes for manufacturing and for operating it. The dithionite salt is dissolved and suspended in an anhydrous electrolyte comprised of a suitable solvent, which may also contain another salt of the same active metal and may be saturated with sulfur dioxide. To form the cell, a sealed and evacuated enclosure having a negative electrode and a positive current-gathering electrode is filled with the electrolyte and subjected to a charging current sufficient to plate the active metal onto the negative electrode, while the positive electrode is saturated with sulfur dioxide. In the case of a secondary cell, the dithionite produced upon discharge is available as a partially dissolved and suspended salt in the electrolyte. Such availability may be enhanced by a system for forced circulation of the electrolyte. In the case of a primary cell, the final cell potential and discharge characteristics may be enhanced by replacing the dithionite electrolyte with other anhydrous electrolyte solutions (e.g., sulfuryl chloride or thionyl chloride) once the lithium has been plated out. The cell is characterized by extremely low internal resistance, long shelf life, and excellent performance over a wide temperature range. 72 claims.

  17. Preparation of Manganese Oxide Nanobelts

    Jisen WANG; Jinquan SUN; Ying BAO; Xiufang BIAN


    Oriented nanobelts of manganese oxide have been firstly and successfully prepared by a microemulsion techniqueunder controlled circumstances. The samples were characterized by X-ray diffraction (XRD), transmission electronmicroscope (TEM). Influences of sodium chloride and annealed temperature on the synthesis of Mn3O4 nanobeltswere investigated. It was found that NaCl is the key factor to synthesize oriented Mn3O4 nanobelts and 827 K isoptimum temperature to produce fine nanobelts. Oriented growth mechanism of Mn3O4 nanobelts was discussed.

  18. Reagent removal of manganese from ground water

    Brayalovsky, G.; Migalaty, E.; Naschetnikova, O.


    The study is aimed at the technology development of treating drinking water from ground waters with high manganese content and oxidizability. Current technologies, physical/chemical mechanisms and factors affecting in ground treatment efficiency are reviewed. Research has been conducted on manganese compound removal from ground waters with high manganese content (5 ppm) and oxidizability. The studies were carried out on granular sorbent industrial ODM-2F filters (0.7-1.5 mm fraction). It was determined that conventional reagent oxidization technologies followed by filtration do not allow us to obtain the manganese content below 0.1 ppm when treating ground waters with high oxidizability. The innovative oxidation-based manganese removal technology with continuous introduction of reaction catalytic agent is suggested. This technology is effective in alkalization up to pH 8.8-9. Potassium permanganate was used as a catalytic agent, sodium hypochlorite was an oxidizer and cauistic soda served an alkalifying agent.

  19. RNASeq in C. elegans Following Manganese Exposure.

    Parmalee, Nancy L; Maqbool, Shahina B; Ye, Bin; Calder, Brent; Bowman, Aaron B; Aschner, Michael


    Manganese is a metal that is required for optimal biological functioning of organisms. Absorption, cellular import and export, and excretion of manganese are all tightly regulated. While some genes involved in regulation, such as DMT-1 and ferroportin, are known, it is presumed that many more are involved and as yet unknown. Excessive exposure to manganese, usually in industrial settings such as mining or welding, can lead to neurotoxicity and a condition known as manganism that closely resembles Parkinson's disease. Elucidating transcriptional changes following manganese exposure could lead to the development of biomarkers for exposure. This unit presents a protocol for RNA sequencing in the worm Caenorhabditis elegans to assay for transcriptional changes following exposure to manganese. This protocol is adaptable to any environmental exposure in C. elegans. The protocol results in counts of gene transcripts in control versus exposed conditions and a ranked list of differentially expressed genes for further study.



    A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various thermopl......A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes...... electrolyte membrane by hot-press. The fuel cell can operate at temperatures up to at least 200 °C with hydrogen-rich fuel containing high ratios of carbon monoxide such as 3 vol% carbon monoxide or more, compared to the carbon monoxide tolerance of 10-20 ppm level for Nafion$m(3)-based polymer electrolyte...

  1. Solid state electrolyte systems

    Pederson, L.R.; Armstrong, B.L.; Armstrong, T.R. [Pacific Northwest Lab., Richland, WA (United States)] [and others


    Lanthanum gallates are a new family of solid electrolytes that exhibit high ionic conductivity and are stable to high temperatures. Compositions have been developed that are as much as a factor of two more conductive than yttria-stabilized zirconia at a given temperature, through partial replacement of lanthanum by calcium, strontium, and/or barium and through partial replacement of gallium by magnesium. Oxide powders were prepared using combustion synthesis techniques developed in this laboratory; these were sintered to >95% of theoretical density and consisted of a single crystalline phase. Electrical conductivities, electron and ion transference numbers, thermal expansion, and phase behavior were evaluated as a function of temperature and oxygen partial pressure. A key advantage of the use of lanthanum gallate electrolytes in solid oxide fuel cells is that the temperature of operation may be lowered to perhaps 800 C, yet provide approximately the same power density as zirconia-based cells operating at 1000 C. Ceramic electrolytes that conduct both oxygen ions and electrons are potentially useful to passively separate pure oxygen from an air source at low cost. In such materials, an oxygen ion flux in one direction is charge-compensated by an opposing electron flux. The authors have examined a wide range of mixed ion and electron conducting perovskite ceramics in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, where M = Sr, Ca, and Ba, and N = Pr, Mn, Ni, Cu, Ti, and Al, as well as mixed conducting brownmillerite ceramics, and have characterized oxygen permeation behavior, defect chemistry, structural and phase stability, and performance as cathodes.

  2. Chemical and structural changes in manganese-doped yttria-stabilized zirconia studied by electron energy loss spectroscopy combined with electron diffraction

    Appel, C.C.; Botton, G.A.; Horsewell, A.


    Solid solution of manganese in yttria-stabilized zirconia (YSZ) may occur in the electrolyte of solid oxide fuel cells. Possible changes in valence, coordination, and site occupancy of Mn in YSZ are of interest. Also, subsequent structural modification of the cubic YSZ, as well as the possible...... ordering of vacancies, has important consequences for the ionic conductivity, Electron energy loss spectroscopy was used to measure the O K and the Mn L edge of Mn in solid solution in a zirconia host lattice. The ratio Mn L-3/L-2 was determined for some manganese oxides and for Mn in solid solution...

  3. Manganese oxide octahedral molecular sieves as insertion electrodes for rechargeable Mg batteries

    Rasul, Shahid


    Magnesium has been inserted electrochemically into manganese oxide octahedral molecular sieves (OMS-5 MnO2) at room temperature. Discharge/charge profiles show that a large amount of Mg, i.e., 0.37 Mg/Mn can be inserted electrochemically using 1 M Mg(ClO4)2/AN electrolyte when OMS-5 is prepared in presence of acetylene black. X-ray diffraction analysis and discharge/charge profiles verify that a solid state solution reaction takes place upon Mg insertion into the host lattice with concurrent reduction of Mn4+ to Mn2+. However, upon each reduction of Mn by Mg insertion and resultant dissolution into electrolyte, decrease in the active compound occurs consequently. A low intrinsic electronic conductivity of OMS-5 was suggested to play a vital role in Mg insertion into the host. © 2013 Elsevier Ltd.

  4. Iron and manganese removal by using manganese ore constructed wetlands in the reclamation of steel wastewater.

    Xu, Jing-Cheng; Chen, Gu; Huang, Xiang-Feng; Li, Guang-Ming; Liu, Jia; Yang, Na; Gao, Sai-Nan


    To reclaim treated steel wastewater as cooling water, manganese ore constructed wetland was proposed in this study for the removal of iron and manganese. In lab-scale wetlands, the performance of manganese ore wetland was found to be more stable and excellent than that of conventional gravel constructed wetland. The iron and manganese concentration in the former was below 0.05 mg/L at hydraulic retention time of 2-5 days when their influent concentrations were in the range of 0.16-2.24 mg/L and 0.11-2.23 mg/L, respectively. Moreover, its removals for COD, turbidity, ammonia nitrogen and total phosphorus were 55%, 90%, 67% and 93%, respectively, superior to the corresponding removals in the gravel wetland (31%, 86%, 58% and 78%, respectively). The good performance of manganese ore was ascribed to the enhanced biological manganese removal with the aid of manganese oxide surface and the smaller size of the medium. The presence of biological manganese oxidation was proven by the facts of good manganese removal in wetlands at chemical unfavorable conditions (such as ORP and pH) and the isolation of manganese oxidizing strains from the wetlands. Similar iron and manganese removal was later observed in a pilot-scale gravel-manganese-ore constructed wetland, even though the manganese ore portion in total volume was reduced from 100% (in the lab-scale) to only 4% (in the pilot-scale) for the sake of cost-saving. The quality of the polished wastewater not only satisfied the requirement for cooling water but also suitable as make-up water for other purposes.

  5. Revision of the Export Tax Rebate Policy for Manganese


    <正>According to a newly released circular by the Finance Ministry and the State Administration of Taxation, the export tax rebate policy for the manganese products under the tax code No. 811100100 is eliminated as from August 1, 2005. These products mainly include un-wrought manganese, manganese scrap and manganese powder.

  6. Geochemical Characteristics of Sinian Manganese Deposits in China


    Sinian is one of the main periods of the formation of manganese deposits in China. Sinian manganese deposits are mainly hosted in carbon-rich black shale and siliceous shale formed during the Sinian interglacial period. The composition of manganese ore is simple. The main ore mineral is manganiferous carbonates. The grade of manganese ore is about 16- 25%, with Mn/Fe>5 and P/Mn=0.006- 0.14. Based on the tectonic setting and geological and geochemical characteristics of manganese deposits, this paper discusses the process of migration and concentration of manganese and ore-forming conditions of Sinian manganese deposits in China.

  7. Gelled Electrolytes For Lithium Batteries

    Nagasubramanian, Ganesan; Attia, Alan; Halpert, Gerald


    Gelled polymer electrolyte consists of polyacrylonitrile (PAN), LiBF4, and propylene carbonate (PC). Thin films of electrolyte found to exhibit stable bulk conductivities of order of 10 to the negative 3rd power S/cm at room temperature. Used in thinfilm rechargeable lithium batteries having energy densities near 150 W h/kg.

  8. Study of characteristics of a new-type lead dioxide anode for electrowinning of Zinc. 4. ; Application of a new-type lead dioxide electrode to electrowinning. Aen denkai saishu ni okeru shingata nisanka namari yokyoku no tokusei no kenkyu. 4. ; Shingata nisanka namari denkyoku no denkai seiren eno oyo

    Fukazawa, A.; Ueda, M.; Watanabe, A.; Hagimori, K.; Numasaki, T.; Kusano, K. (National Chemical Laboratory for Industry, Tsukuba, (Japan) Toho Zinc Co. Ltd., Tokyo, (Japan))


    A new-type of lead dioxide electrode was tried as an anode for electrowinning of zinc, and the results were reported in comparison with the conventional lead alloy electrode which contains about 1% of silver. The new-type electrode gave electrolytic zinc with a lower level of lead contamination, and no stabilization was required. It had a high resistance to chlorine corrosion, chlorine was effectively removed, and no crust manganese was found. Furthermore, it showed a high current efficiency in electrowinning of zinc, resistance in a high current density, and a higher anodic overpotential as well as a higher bath potential. On the other hand, it is believed that the new-type electrode may be more suitable for use in the zinc electrowinning process when the alloy electrode can not be used, e. g., electrowinning of pure zinc which is scarcely contaminated by lead, electrowinning from a bath with a large amount of chlorine, or electrowinning at a high current density. These merits are more than increased electric power cast which is due to the use of the new-type electrode. 13 refs., 5 figs., 2 tabs.



    A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes....... With the thermally resistant polymer, e.g., polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled with an acid doped solid...

  10. [Tongue play and manganese deficiency in dairy cattle].

    Karatzias, H; Roubies, N; Polizopoulou, Z; Papasteriades, A


    The present paper discusses "tongue rolling" observed in dairy cattle farms of a region in northern Greece associated with manganese deficiency. In these animals total body manganese status was evaluated by determining hair, as well as feed manganese content. Cows exhibiting tongue rolling had significantly lower hair manganese content, compared to non-tongue rolling control animals from other farms; in addition, feedstuff analysis demonstrated that manganese and inorganic phosphorus intake of affected cows was also significantly lower.


    Soldin, OP; Aschner, M.


    Manganese (Mn) is an essential trace nutrient that is potentially toxic at high levels of exposure. As a constituent of numerous enzymes and a cofactor, manganese plays an important role in a number of physiologic processes in mammals. The manganese-containing enzyme, manganese superoxide dismutase (Mn-SOD), is the principal antioxidant enzyme which neutralizes the toxic effects of reactive oxygen species. Other manganese-containing enzymes include oxidoreductases, transferases, hydrolases, l...

  12. Manganese oxide nanoparticles, methods and applications

    Abruna, Hector D.; Gao, Jie; Lowe, Michael A.


    Manganese oxide nanoparticles having a chemical composition that includes Mn.sub.3O.sub.4, a sponge like morphology and a particle size from about 65 to about 95 nanometers may be formed by calcining a manganese hydroxide material at a temperature from about 200 to about 400 degrees centigrade for a time period from about 1 to about 20 hours in an oxygen containing environment. The particular manganese oxide nanoparticles with the foregoing physical features may be used within a battery component, and in particular an anode within a lithium battery to provide enhanced performance.

  13. Tetrahydrofuran-promoted clathrate hydrate phase equilibria of CO{sub 2} in aqueous electrolyte solutions

    Sabil, K.M.; Roman, V.R. [Delft Univ. of Technology, Delft (Netherlands). Physical Chemistry and Molecular Thermodynamics; Witkamp, G.J.; Peters, C.J. [Delft Univ. of Technology, Delft, (Netherlands). Laboratory of Process Equipment, Mechanical, Maritime and Materials Engineering


    The phase behavior of a system consisting of carbon dioxide (CO{sub 2}) hydrates is of significant importance for many industrial and natural processes. Carbon dioxide and water are part of natural gas streams and they are also found in oil reservoirs during enhanced oil recovery. Formation of hydrate in these cases may cause problems during production and processing. Alternatively, carbon dioxide hydrate formation may be desirable since it can facilitate separation processes, freezing and refrigeration processes and sequestration of CO{sub 2}. The need for phase equilibrium data of systems, particularly electrolyte solutions containing CO{sub 2} are therefore needed. This paper presented a study that attempted to measure the hydrate equilibrium condition for quaternary system consisting of CO{sub 2}, tetrahydrofuran (THF), an electrolyte and water. The purpose of the study was to examine the competing effect of tetrahydrofuran and an electrolyte on the phase behavior of CO{sub 2} hydrates when both were simultaneously present in a system at hydrate forming condition and to compare the effect of different salts inhibition on tetrahydrofuran-promoted CO{sub 2} hydrate. Six different electrolytes were utilized, including sodium chloride, calcium chloride, magnesium chloride, potassium bromide, sodium fluoride and sodium bromide. It was concluded that the inhibiting effect among the cations increased with increasing charge of the cation and its radius. It was also found that the inhibiting effect of the anions decreased with a decrease on their ion radius. 12 refs., 4 figs.

  14. Room temperature magnesium electrorefining by using non-aqueous electrolyte

    Park, Jesik; Jung, Yeojin; Kusumah, Priyandi; Dilasari, Bonita; Ku, Heesuk; Kim, Hansu; Kwon, Kyungjung; Lee, Churl Kyoung


    The increasing usage of magnesium inevitably leads to a fast increase in magnesium scrap, and magnesium recycling appears extremely beneficial for cost reduction, preservation of natural resources and protection of the environment. Magnesium refining for the recovery of high purity magnesium from metal scrap alloy (AZ31B composed of magnesium, aluminum, zinc, manganese and copper) at room temperature is investigated with a non-aqueous electrolyte (tetrahydrofuran with ethyl magnesium bromide). A high purity (99.999%) of electrorefined magneisum with a smooth and dense surface is obtained after potentiostatic electrolysis with an applied voltage of 2 V. The selective dissolution of magnesium from magnesium alloy is possible by applying an adequate potential considering the tolerable impurity level in electrorefined magnesium and processing time. The purity estimation method suggested in this study can be useful in evaluating the maximum content of impurity elements.

  15. Electrolytes and thermoregulation

    Nielsen, B.; Greenleaf, J. E.


    The influence of ions on temperature is studied for cases where the changes in ionic concentrations are induced by direct infusion or injection of electrolyte solutions into the cerebral ventricles or into specific areas of brain tissue; intravenous infusion or injection; eating food or drinking solutions of different ionic composition; and heat or exercise dehydration. It is shown that introduction of Na(+) and Ca(++) into the cerebral ventricles or into the venous system affects temperature regulation. It appears that the specific action of these ions is different from their osmotic effects. It is unlikely that their action is localized to the thermoregulatory centers in the brain. The infusion experiments demonstrate that the changes in sodium balance occurring during exercise and heat stress are large enough to affect sweat gland function and vasomotor activity.

  16. Neurotoxicity of manganese oxide nanomaterials

    Stefanescu, Diana M.; Khoshnan, Ali; Patterson, Paul H.; Hering, Janet G.


    Manganese (Mn) toxicity in humans has been observed as manganism, a disease that resembles Parkinson's disease. The mechanism of Mn toxicity and the chemical forms that may be responsible for its neurotoxicity are not well understood. We examined the toxicity of Mn oxide nanomaterials in a neuronal precursor cell model, using the MTS assay to evaluate mitochondrial function in living cells and the LDH assay to quantify the release of the enzyme lactate dehydrogenase as a result of damage to the cell membrane. Both assays show that the toxicity of Mn is dependent on the type of Mn oxide nanomaterial and its concentration as well as on the state of cell differentiation. Following exposure to Mn oxide nanomaterials, reactive oxygen species (ROS) are generated, and flow cytometry experiments suggest that cell death occurred through apoptosis. During exposure to Mn oxide nanomaterials, increased levels of the transcription factor NF-κB (which mediates the cellular inflammatory response) were observed.

  17. Manganese-based Permanent Magnets

    Ian Baker


    Full Text Available There is a significant gap between the energy product, BH, where B is the magnetic flux density and H is the magnetic field strength, of both the traditional ferrite and AlNiCo permanent magnets of less than 10 MGOe and that of the rare earth magnets of greater than 30 MGOe. This is a gap that Mn-based magnets could potentially, inexpensively, fill. This Special Issue presents work on the development of both types of manganese permanent magnets. Some of the challenges involved in the development of these magnets include improving the compounds’ energy product, increasing the thermal stability of these metastable compounds, and producing them in quantity as a bulk material.[...

  18. The carbon dioxide cycle

    James, P.B.; Hansen, G.B.; Titus, T.N.


    The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor. ?? 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  19. Carbon Dioxide Absorbents


    carbondioxide content of the solution was then determined. A gas mixture containing 2.6% carbon dioxide and 97.4% nitrogen was prepared in the...which carbon dioxide is removed by heat0 Since this step is usually carried out by "steam stripping ", that is, contacting the solution at its boiling...required to produce the steam required for stripping the carbon dioxide from the s olution. The method ueed in this investigation for determining the

  20. Manganese ferrite thin films Part II: Properties

    Hulscher, W.S.


    Some properties of evaporated manganese ferrite thin films are investigated, e.g. resistivity, magnetization reversal, Curie temperature, Faraday rotation and optical absorption. The properties are partly related to the partial oxygen pressure present during a preceding annealing process.

  1. Manganese Oxidation by Bacteria: Biogeochemical Aspects

    Sujith, P.P.; LokaBharathi, P.A.

    Manganese is an essential trace metal that is not as readily oxidizable like iron. Several bacterial groups posses the ability to oxidize Mn effectively competing with chemical oxidation. The oxides of Mn are the strongest of the oxidants, next...

  2. Manganese: Its Speciation, Pollution and Microbial Mitigation

    Arvind Sinha; Sunil Kumar Khare


    Manganese is known to be one of the essential trace elements and has plenty of applications. Inspite of its essential nature, concerns are arising due to its toxic nature at higher concentration. Several methods of removing manganese from environment have been proposed during the last few decades. However, the most favourable option based on cost-effectiveness, performance, and simplicity is still under investigation. The current review summarizes updated information on various technical aspe...

  3. Photopolymerized Electrolytes For Electrochromic Devices

    Cogan, Stuart; Rauh, R. David


    Thin ion-conducting electrolyte films for use in electrochromic devices now fabricated relatively easily and quickly with any of class of improved formulations containing ultraviolet-polymerizable components. Formulations are liquids in their monomeric forms and self-supporting, transparent solids in their polymeric forms. Thin solid electrolytes form quickly and easily between electrode-bearing substrates. Film thus polymerized acts not only as solid electrolyte but also as glue holding laminate together: feature simplifies fabrication by reducing need for sealants and additional mechanical supports.

  4. Organic electrolytes for sodium batteries

    Vestergaard, B.


    A summary of earlier given status reports in connection with the project on organic electrolytes for sodium batteries is presented. The aim of the investigations was to develop new room temperature molten salts electrolytes mainly with radical substituted heterocyclic organic chlorides mixed with aluminum chloride. The new electrolytes should have an ionic conductivity comparable with MEIC1:AlCl3 or better. A computer model program MOPAC (Molecular Orbital Package) was to be included to calculate theoretically reduction potentials for a variety of organic cations. Furthermore, MOPAC could be utilized to predict the electron densities, and then give a prediction of the stability of the organic cation.

  5. High temperature stable Li-ion battery separators based on polyetherimides with improved electrolyte compatibility

    l'Abee, Roy; DaRosa, Fabien; Armstrong, Mark J.; Hantel, Moritz M.; Mourzagh, Djamel


    We report (electro-)chemically stable, high temperature resistant and fast wetting Li-ion battery separators produced through a phase inversion process using novel polyetherimides (PEI) based on bisphenol-aceton diphthalic anhydride (BPADA) and para-phenylenediamine (pPD). In contrast to previous studies using PEI based on BPADA and meta-phenylenediamine (mPD), the separators reported herein show limited swelling in electrolytes and do not require fillers to render sufficient mechanical strength and ionic conductivity. In this work, the produced 15-25 μm thick PEI-pPD separators show excellent electrolyte compatibility, proven by low degrees of swelling in electrolyte solvents, low contact angles, fast electrolyte wicking and high electrolyte uptake. The separators cover a tunable range of morphologies and properties, leading to a wide range of ionic conductivities as studied by Electrochemical Impedance Spectroscopy (EIS). Dynamic Mechanical Analysis (DMA) demonstrated dimensional stability up to 220 °C. Finally, single layer graphite/lithium nickel manganese cobalt oxide (NMC) pouch cells were assembled using this novel PEI-pPD separator, showing an excellent capacity retention of 89.3% after 1000 1C/2C cycles, with a mean Coulombic efficiency of 99.77% and limited resistance build-up. We conclude that PEI-pPD is a promising new material candidate for high performance separators.

  6. An electrolyte CPA equation of state for mixed solvent electrolytes

    Maribo-Mogensen, Bjørn; Thomsen, Kaj; Kontogeorgis, Georgios M.


    that the predictive capabilities could be improved through the development of an electrolyte equation of state. In this work, the Cubic Plus Association (CPA) Equation of State is extended to handle mixtures containing electrolytes by including the electrostatic contributions from the Debye-Hückel and Born terms...... depression. Finally, the model is applied to predict VLE, LLE, and SLE in aqueous salt mixtures as well as in mixed solvents....

  7. Autonomic function in manganese alloy workers

    Barrington, W.W.; Angle, C.R.; Willcockson, N.K.; Padula, M.A. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Korn, T.


    The observation of orthostatic hypotension in an index case of manganese toxicity lead to this prospective attempt to evaluate cardiovascular autonomic function and cognitive and emotional neurotoxicity in eight manganese alloy welders and machinists. The subjects consisted of a convenience sample consisting of an index case of manganese dementia, his four co-workers in a frog shop for gouging, welding, and grinding repair of high manganese railway track and a convenience sample of three mild steel welders with lesser manganese exposure also referred because of cognitive or autonomic symptoms. Frog shop air manganese samples 9.6--10 years before and 1.2--3.4 years after the diagnosis of the index case exceeded 1.0 mg/m{sup 3} in 29% and 0.2 mg/m{sup 3} in 62%. Twenty-four-hour electrocardiographic (Holter) monitoring was used to determine the temporal variability of the heartrate (RR{prime} interval) and the rates of change at low frequency and high frequency. MMPI and MCMI personality assessment and short-term memory, figure copy, controlled oral word association, and symbol digit tests were used.

  8. Non-aqueous electrolytes for electrochemical cells

    Zhang, Zhengcheng; Dong, Jian; Amine, Khalil


    An electrolyte electrochemical device includes an anodic material and an electrolyte, the electrolyte including an organosilicon solvent, a salt, and a hybrid additiving having a first and a second compound, the hybrid additive configured to form a solid electrolyte interphase film on the anodic material upon application of a potential to the electrochemical device.

  9. Thin film passivation of laser generated 3D micro patterns in lithium manganese oxide cathodes

    Pröll, J.; Kohler, R.; Bruns, M.; Oberst, V.; Weidler, P. G.; Heißler, S.; Kübel, C.; Scherer, T.; Prang, R.; Seifert, H. J.; Pfleging, W.


    The increasing need for long-life lithium-ion batteries requires the further development of electrode materials. Especially on the cathode side new materials or material composites are needed to increase the cycle lifetime. On the one hand, spinel-type lithium manganese oxide is a promising candidate to be used as cathode material due to its non-toxicity, low cost and good thermal stability. On the other hand, the spinel structure suffers from change in the oxidation state of manganese during cycling which is also accompanied by loss of active material into the liquid electrolyte. The general trend is to enhance the active surface area of the cathode in order to increase lithium-ion mobility through the electrode/electrolyte interface, while an enhanced surface area will also promote chemical degradation. In this work, laser microstructuring of lithium manganese oxide thin films was applied in a first step to increase the active surface area. This was done by using 248 nm excimer laser radiation and chromium/quartz mask imaging techniques. In a second step, high power diode laser-annealing operating at a wavelength of 940 nm was used for forming a cubic spinel-like battery phase. This was verified by means of Raman spectroscopy and cyclic voltammetric measurements. In a last step, the laser patterned thin films were coated with indium tin oxide (ITO) layers with a thickness of 10 nm to 50 nm. The influence of the 3D surface topography as well as the ITO thickness on the electrochemical performance was studied by cyclic voltammetry. Post-mortem studies were carried out by using scanning electron microscopy and focused ion beam analysis.

  10. ЕЛЕКТРОХІМІЧНИЙ СИНТЕЗ ДІОКСИДУ МАНГАНУ В ПРИСУТНОСТІ ІОНІВ Fe2+ ТА Co2+ Electrochemical synthesis of manganese dioxide in the presence of ions Fe2+ and Co2+ Электрохимический синтез диоксида марганца в присутствии ионов Fe2+ и Co2+

    О.В. Кобилінська


    Full Text Available  Зразки діоксиду мангану отримано методом анодного осадження із фторвмісних електролітів на основі сульфату мангану у присутності домішок іонів двовалентних заліза або кобальту. Отримані продукти характеризувалися методами ААС та ДТА. Проаналізовано вплив домішок іонів заліза і кобальту на хімічний склад отриманих зразків Manganese dioxide samples have been prepared by the anode deposition from fluoride containing electrolytes based on manganese sulphate at the presence of additives of iron(II, cobalt(II ions. Obtained materials were characterised with AAS and DTA. The influence of doping by ions of iron(II and cobalt(II on the chemical composition of the samples obtained has been analysed.  Образцы диоксида марганца получены методом анодного осаждения из фторсодержащих электролитов на основе сульфата марганца в присутствии примесей ионов двухвалентных железа или кобальта. Полученные продукты характеризовались методами ААС и ДТА. Проанализировано влияние примесей ионов железа и кобальта на химический состав полученных образцов.

  11. Composite solid polymer electrolyte membranes

    Formato, Richard M. (Shrewsbury, MA); Kovar, Robert F. (Wrentham, MA); Osenar, Paul (Watertown, MA); Landrau, Nelson (Marlborough, MA); Rubin, Leslie S. (Newton, MA)


    The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.

  12. Biogeochemical cycling of manganese in Oneida Lake, New York: whole lake studies of manganese

    Aguilar, C.; Nealson, K. H.


    Oneida Lake, New York is a eutrophic freshwater lake known for its abundant manganese nodules and a dynamic manganese cycle. Temporal and spatial distribution of soluble and particulate manganese in the water column of the lake were analyzed over a 3-year period and correlated with other variables such as oxygen, pH, and temperature. Only data from 1988 are shown. Manganese is removed from the water column in the spring via conversion to particulate form and deposited in the bottom sediments. This removal is due to biological factors, as the lake Eh/pH conditions alone can not account for the oxidation of the soluble manganese Mn(II). During the summer months the manganese from microbial reduction moves from the sediments to the water column. In periods of stratification the soluble Mn(II) builds up to concentrations of 20 micromoles or more in the bottom waters. When mixing occurs, the soluble Mn(II) is rapidly removed via oxidation. This cycle occurs more than once during the summer, with each manganese atom probably being used several times for the oxidation of organic carbon. At the end of the fall, whole lake concentrations of manganese stabilize, and remain at about 1 micromole until the following summer, when the cycle begins again. Inputs and outflows from the lake indicate that the active Mn cycle is primarily internal, with a small accumulation each year into ferromanganese nodules located in the oxic zones of the lake.

  13. Manganese exposure in foundry furnacemen and scrap recycling workers

    Lander, F; Kristiansen, J; Lauritsen, Jens


    Cast iron products are alloyed with small quantities of manganese, and foundry furnacemen are potentially exposed to manganese during tapping and handling of smelts. Manganese is a neurotoxic substance that accumulates in the central nervous system, where it may cause a neurological disorder...... that bears many similarities to Parkinson's disease. The aim of the study was to investigate the sources and levels of manganese exposure in foundry furnacemen by a combined measuring of blood-manganese (B-Mn) and manganese in ambient air (air-Mn)....

  14. Carbon Dioxide and Climate.

    Brewer, Peter G.


    The amount of carbon dioxide in the atmosphere is increasing at a rate that could cause significant warming of the Earth's climate in the not too distant future. Oceanographers are studying the role of the ocean as a source of carbon dioxide and as a sink for the gas. (Author/BB)

  15. Carbon Dioxide Fountain

    Kang, Seong-Joo; Ryu, Eun-Hee


    This article presents the development of a carbon dioxide fountain. The advantages of the carbon dioxide fountain are that it is odorless and uses consumer chemicals. This experiment also is a nice visual experiment that allows students to see evidence of a gaseous reagent being consumed when a pressure sensor is available. (Contains 3 figures.)…

  16. Autonomic function in manganese alloy workers.

    Barrington, W W; Angle, C R; Willcockson, N K; Padula, M A; Korn, T


    The observation of orthostatic hypotension in an index case of manganese toxicity lead to this prospective attempt to evaluate cardiovascular autonomic function and cognitive and emotional neurotoxicity in eight manganese alloy welders and machinists. The subjects consisted of a convenience sample consisting of an index case of manganese dementia, his four co-workers in a "frog shop" for gouging, welding, and grinding repair of high manganese railway track and a convenience sample of three mild steel welders with lesser manganese exposure also referred because of cognitive or autonomic symptoms. Frog shop air manganese samples 9.6-10 years before and 1.2-3.4 years after the diagnosis of the index case exceeded 1.0 mg/m3 in 29% and 0.2 mg/m3 in 62%. Twenty-four-hour electrocardiographic (Holter) monitoring was used to determine the temporal variability of the heartrate (RR' interval) and the rates of change at low frequency (0.04-0.15 Hz) and high frequency (0.15-0.40 Hz). MMPI and MCMI personality assessment and short-term memory, figure copy, controlled oral word association, and symbol digit tests were used. The five frog shop workers had abnormal sympathovagal balance with decreased high frequency variability (increased ln LF/ln HF). Seven of the eight workers had symptoms of autonomic dysfunction and significantly decreased heart rate variability (rMSSD) but these did not distinguish the relative exposure. Mood or affect was disturbed in all with associated changes in short-term memory and attention in four of the subjects. There were no significant correlations with serum or urine manganese. Power spectrum analysis of 24-h ambulatory ECG indicating a decrease in parasympathetic high frequency activation of heart rate variability may provide a sensitive index of central autonomic dysfunction reflecting increased exposure to manganese, although the contribution of exposures to solvents and other metals cannot be excluded. Neurotoxicity due to the gouging

  17. Spinel-structured surface layers for facile Li ion transport and improved chemical stability of lithium manganese oxide spinel

    Lee, Hae Ri; Seo, Hyo Ree; Lee, Boeun; Cho, Byung Won; Lee, Kwan-Young; Oh, Si Hyoung


    Li-ion conducting spinel-structured oxide layer with a manganese oxidation state close to being tetravalent was prepared on aluminum-doped lithium manganese oxide spinel for improving the electrochemical performances at the elevated temperatures. This nanoscale surface layer provides a good ionic conduction path for lithium ion transport to the core and also serves as an excellent chemical barrier for protecting the high-capacity core material from manganese dissolution into the electrolyte. In this work, a simple wet process was employed to prepare thin LiAlMnO4 and LiMg0.5Mn1.5O4 layers on the surface of LiAl0.1Mn1.9O4. X-ray absorption studies revealed an oxidation state close to tetravalent manganese on the surface layer of coated materials. Materials with these surface coating layers exhibited excellent capacity retentions superior to the bare material, without undermining the lithium ion transport characteristics and the high rate performances.

  18. Microstructural aspects of manganese metal during its electrodeposition from sulphate solutions in the presence of quaternary amines

    Padhy, Subrat Kumar [CSIR – Institute of Minerals and Materials Technology, Council of Scientific and Industrial Research, Bhubaneswar 751013 (India); Academy of Scientific and Innovative Research, CSIR Campus, CSIR Road, Taramani, Chennai 600 113 (India); Patnaik, P. [CSIR – Institute of Minerals and Materials Technology, Council of Scientific and Industrial Research, Bhubaneswar 751013 (India); Tripathy, B.C., E-mail: [CSIR – Institute of Minerals and Materials Technology, Council of Scientific and Industrial Research, Bhubaneswar 751013 (India); Academy of Scientific and Innovative Research, CSIR Campus, CSIR Road, Taramani, Chennai 600 113 (India); Bhattacharya, I.N. [CSIR – Institute of Minerals and Materials Technology, Council of Scientific and Industrial Research, Bhubaneswar 751013 (India)


    Graphical abstract: - Highlights: • Quaternary amines produced smooth and bright manganese electrodeposits. • TEABr produced smooth and bright deposits with euhedral shaped crystals. • TBABr produced dendritic deposits with elongated poly-nodular crystals. • All the quaternary amines behaved as cathode polarisers. • TEABr was found to be the most efficient organic additive. - Abstract: In the present study investigation was made on the electrodeposition of manganese from sulphate solutions in the presence of quaternary amines TEABr, TPABr and TBABr. The concentrations of these additives were varied over a relatively broad range to evaluate their effect on the deposit morphology and preferred crystal orientations of the electrodeposited metal. TEABr resulted in bright and smooth manganese electrodeposits giving euhedral shape to the crystals with distinct triple junction points. TPABr also showed similar results at lower concentrations. However, TBABr resulted in the formation of dendritic growths with elongated poly-nodular crystals similar to that of Paragorgia corals having uniform multistep growths. The presence of these quaternary amines in the electrolyte causes polarisation of the cathode. TBABr being the strongest cathode polariser adsorbs strongly on the cathode resulting in poor deposit quality. TEABr was found to be the most efficient additive producing the desired quality manganese electrodeposit.

  19. Manganese in dwarf spheroidal galaxies

    North, P; Jablonka, P; Hill, V; Shetrone, M; Letarte, B; Lemasle, B; Venn, K A; Battaglia, G; Tolstoy, E; Irwin, M J; Primas, F; Francois, P


    We provide manganese abundances (corrected for the effect of the hyperfine structure) for a large number of stars in the dwarf spheroidal galaxies Sculptor and Fornax, and for a smaller number in the Carina and Sextans dSph galaxies. Abundances had already been determined for a number of other elements in these galaxies, including alpha and iron-peak ones, which allowed us to build [Mn/Fe] and [Mn/alpha] versus [Fe/H] diagrams. The Mn abundances imply sub-solar [Mn/Fe] ratios for the stars in all four galaxies examined. In Sculptor, [Mn/Fe] stays roughly constant between [Fe/H]\\sim -1.8 and -1.4 and decreases at higher iron abundance. In Fornax, [Mn/Fe] does not vary in any significant way with [Fe/H]. The relation between [Mn/alpha] and [Fe/H] for the dSph galaxies is clearly systematically offset from that for the Milky Way, which reflects the different star formation histories of the respective galaxies. The [Mn/alpha] behavior can be interpreted as a result of the metal-dependent Mn yields of type II and ...

  20. Fluid and Electrolyte Nutrition

    Lane, Helen W.; Smith, Scott M.; Leach, Carolyn S.; Rice, Barbara L.


    Studies of fluid and electrolyte homeostasis have been completed since the early human space flight programs, with comprehensive research completed on the Spacelab Life Sciences missions SLS-1 and SLS-2 flights, and more recently on the Mir 18 mission. This work documented the known shifts in fluids, the decrease in total blood volume, and indications of reduced thirst. Data from these flights was used to evaluate the nutritional needs for water, sodium, and potassium. Interpretations of the data are confounded by the inadequate energy intakes routinely observed during space flight. This in turn results in reduced fluid intake, as food provides approximately 70% water intake. Subsequently, body weight, lean body mass, total body water, and total body potassium may decrease. Given these issues, there is evidence to support a minimum required water intake of 2 L per day. Data from previous Shuttle flights indicated that water intake is 2285 +/- 715 ml/day (mean +/- SD, n=26). There are no indications that sodium intake or homeostasis is compromised during space flight. The normal or low aldosterone and urinary sodium levels suggest adequate sodium intake (4047 +/- 902 mg/day, n=26). Because excessive sodium intake is associated with hypercalciuria, the recommended maximum amount of sodium intake during flight is 3500 mg/day (i.e., similar to the Recommended Dietary Allowance, RDA). Potassium metabolism appears to be more complex. Data indicate loss of body potassium related to muscle atrophy and low dietary intake (2407 +/- 548 mg/day, n=26). Although possibly related to measurement error, the elevations in blood potassium suggest alterations in potassium homeostasis. The space RDA for minimum potassium intake is 3500 mg/day. With the documented inadequate intakes, efforts are being made to increase dietary consumption of potassium.

  1. Manganese and acute paranoid psychosis: A case report

    W.M.A. Verhoeven (Wim); J.I.M. Egger (Jos); H.J. Kuijpers (Harold)


    textabstractIntroduction: Manganese regulates many enzymes and is essential for normal development and body function. Chronic manganese intoxication has an insidious and progressive course and usually starts with complaints of headache, fatigue, sleep disturbances, irritability and emotional instabi

  2. Manganese and acute paranoid psychosis: a case report

    Verhoeven, W.M.A.; Egger, J.I.M.; Kuijpers, H.J.H.


    Introduction Manganese regulates many enzymes and is essential for normal development and body function. Chronic manganese intoxication has an insidious and progressive course and usually starts with complaints of headache, fatigue, sleep disturbances, irritability and emotional instability. Later,

  3. 高锰硅合金品级率途径的探讨%A Research on Improving Manganese Silicon Alloy Grade Rate

    杨忠姚; 朱仕林; 唐继洪


    就如何采取有效措施提高锰硅合金品级率进行了论述,提出了提高混合锰矿二氧化硅含量,以贵州焦作为主要还原剂,采用升锰料批、升硅料批对产品质量波动进行及时调整的途径.%How to take the effective action to raise the manganese silicon alloy percentage of product to carry on the elaboration is an interesting talk, in which we have proposed the enhancement mix manganese of ore silicon dioxide content. We have in the meantime taken Cuizhou Jiaozuo as the main reducing agent, by rising the manganese materials, the silicon material to be approved to the product quality fluctuation in the prompt adjustment.

  4. Morphology and Crystallinity-controlled Synthesis of Manganese Cobalt Oxide/Manganese Dioxides Hierarchical Nanostructures for High-Performance Supercapacitors

    Fei; Li; Gang; Li; Hao; Chen; Jia; Qi; Jia; Fan; Dong; Yao; Bo; Hu; Zheng; Guo; Shang; 张育新


    We demonstrate a novel preparative strategy for the well-controlled MnCo2O4.5@MnO2 hierarchical nanostructures.Bothδ-MnO2 nanosheets andα-MnO2 nanorods can uniformly decorate the surface of MnCo2O4.5nanowires to form core-shell heterostructures.Detailed electrochemical characterization reveals that MnCo2O4.5@δ-MnO2 pattern exhibits not only high specific capacitance of 357.5 F g-1at a scan rate of 0.5 A g-1,but also good cycle stability(97%capacitance retention after 1000 cycles at a scan rate of 5 A g-1),which make it have a promising application as a supercapacitor electrode material.

  5. Integrated pyrolucite fluidized bed-membrane hybrid process for improved iron and manganese control in drinking water.

    Dashtban Kenari, Seyedeh Laleh; Barbeau, Benoit


    Newly developed ceramic membrane technologies offer numerous advantages over the conventional polymeric membranes. This work proposes a new configuration, an integrated pyrolucite fluidized bed (PFB)-ceramic MF/UF hybrid process, for improved iron and manganese control in drinking water. A pilot-scale study was undertaken to evaluate the performance of this process with respect to iron and manganese control as well as membrane fouling. In addition, the fouling of commercially available ceramic membranes in conventional preoxidation-MF/UF process was compared with the hybrid process configuration. In this regard, a series of experiments were conducted under different influent water quality and operating conditions. Fouling mechanisms and reversibility were analyzed using blocking law and resistance-in-series models. The results evidenced that the flux rate and the concentration of calcium and humic acids in the feed water have a substantial impact on the filtration behavior of both membranes. The model for constant flux compressible cake formation well described the rise in transmembrane pressure. The compressibility of the filter cake substantially increased in the presence of 2 mg/L humic acids. The presence of calcium ions caused significant aggregation of manganese dioxide and humic acid which severely impacted the extent of membrane fouling. The PFB pretreatment properly alleviated membrane fouling by removing more than 75% and 95% of iron and manganese, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Manganese determination om minerals by activation analysis, using the californium-252 as a neutron source; Determinacao de manganes em minerios, por analise por ativacao, usando californio-252 como fonte de neutrons

    Cardoso, Antonio


    Neutron Activation Analysis, using a Californium-252 neutron source, has been applied for the determination of manganese in ores such as pyrolusite, rodonite (manganese silicate)' and blending used in dry-batteries The favorable nuclear properties of manganese, such as high thermal neutron cross-section for the reaction {sup 55}Mn (n.gamma){sup 56} Mn, high concentration of manganese in the matrix and short half - life of {sup 56}Mn, are an ideal combination for non-destructive analysis of manganese in ores. Samples and standards of manganese dioxide were irradiated for about 20 minutes, followed by a 4 to 15 minutes decay and counted in a single channel pulse-height discrimination using a NaI(Tl) scintillation detector. Counting time was equal to 10 minutes. The interference of nuclear reactions {sup 56}Fe(n,p){sup 56}Mn and {sup 59} Co (n, {alpha}){sup 56} were studied, as well as problems in connection with neutron shadowing during irradiation, gamma-rays attenuation during counting and influence of granulometry of samples. One sample,was also analysed by wet-chemical method (sodium bismuthate) in order to compare results. As a whole, i t was shown that the analytical method of neutron activation for manganese in ores and blending, is a method simple, rapid and with good precision and accuracy. (author)

  7. 40 CFR 721.10003 - Manganese heterocyclic tetraamine complex (generic).


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Manganese heterocyclic tetraamine... Specific Chemical Substances § 721.10003 Manganese heterocyclic tetraamine complex (generic). (a) Chemical... as manganese heterocyclic tetraamine complex (PMNs P-98-625/626/627/628/629 and P-00-614/617)...

  8. 40 CFR 721.10011 - Barium calcium manganese strontium oxide.


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Barium calcium manganese strontium... Specific Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a) Chemical substance... manganese strontium oxide (PMN P-00-1124; CAS No. 359427-90-0) is subject to reporting under this...

  9. Essentiality, Toxicity and Uncertainty in the Risk Assessment of Manganese

    Risk assessments of manganese by inhalation or oral routes of exposure typically acknowledge the duality of manganese as an essential element at low doses and a toxic metal at high doses. Previously, however, risk assessors were unable to describe manganese pharmacokinetics quant...

  10. Developing New Electrolytes for Advanced Li-ion Batteries

    McOwen, Dennis Wayne

    synthesized for this investigation: dilithium 1,2,5-thiadiazolidine-3,4-dione-1,1-dioxide (Li2TDD), lithium ethyl N-trifluoroacetylcarbamate (LiETAC), lithium hexafluoroisopropoxide (LiHFI), lithium pentafluorophenolate (LiPFPO), and lithium 2-trifluoromethyl-4,5-dicyanoimidazolide (LiTDI). Using crystalline solvate structure analysis and electrolyte solvation numbers, each of these lithium salts were compared to more well-characterized lithium salts, such as LiPF6 and LiBF4. From this study, links between anion structural characteristics and the anion...Li+ cation interactions (i.e., ionic association strength) were made. From the screening of the five lithium salts that were synthesized, LiTDI was determined to be a promising candidate for Li-ion battery electrolytes. Further characterization of carbonate- and mixed carbonate-LiTDI electrolytes (e.g., ionic conductivity) confirmed this to be the case. Coin cells containing LiTDI or LiPF6 electrolytes showed that cells with either electrolyte could deliver nearly identical power density at 25 °C. Additionally, thermogravimetric analysis (TGA) and NMR suggested that the LiTDI salt and carbonate-LiTDI electrolytes are thermally stable up to at least 60 °C. Further supporting this finding, coin cells cycled at 60 °C with LiPF6 lost significantly more capacity than those with LiTDI. Therefore, LiTDI is a prime candidate for the complete replacement of LiPF6 to significantly increase Li-ion battery tolerance to heat, improving the safety characteristics. In addition to searching for new lithium salts, the effect of lithium salt concentration on electrolyte physicochemical properties was investigated. This radically different approach to modifying electrolyte properties determined that amorphous, highly concentrated carbonate-lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) electrolytes have drastically different behavior than more dilute electrolytes. For example, the thermal stability and anodic stability vs. a Pt

  11. Anion exchange polymer electrolytes

    Kim, Yu Seung; Kim, Dae Sik; Lee, Kwan-Soo


    Solid anion exchange polymer electrolytes and compositions comprising chemical compounds comprising a polymeric core, a spacer A, and a guanidine base, wherein said chemical compound is uniformly dispersed in a suitable solvent and has the structure: ##STR00001## wherein: i) A is a spacer having the structure O, S, SO.sub.2, --NH--, --N(CH.sub.2).sub.n, wherein n=1-10, --(CH.sub.2).sub.n--CH.sub.3--, wherein n=1-10, SO.sub.2-Ph, CO-Ph, ##STR00002## wherein R.sub.5, R.sub.6, R.sub.7 and R.sub.8 each are independently --H, --NH.sub.2, F, Cl, Br, CN, or a C.sub.1-C.sub.6 alkyl group, or any combination of thereof; ii) R.sub.9, R.sub.10, R.sub.11, R.sub.12, or R.sub.13 each independently are --H, --CH.sub.3, --NH.sub.2, --NO, --CH.sub.nCH.sub.3 where n=1-6, HC.dbd.O--, NH.sub.2C.dbd.O--, --CH.sub.nCOOH where n=1-6, --(CH.sub.2).sub.n--C(NH.sub.2)--COOH where n=1-6, --CH--(COOH)--CH.sub.2--COOH, --CH.sub.2--CH(O--CH.sub.2CH.sub.3).sub.2, --(C.dbd.S)--NH.sub.2, --(C.dbd.NH)--N--(CH.sub.2).sub.nCH.sub.3, where n=0-6, --NH--(C.dbd.S)--SH, --CH.sub.2--(C.dbd.O)--O--C(CH.sub.3).sub.3, --O--(CH.sub.2).sub.n--CH--(NH.sub.2)--COOH, where n=1-6, --(CH.sub.2).sub.n--CH.dbd.CH wherein n=1-6, --(CH.sub.2).sub.n--CH--CN wherein n=1-6, an aromatic group such as a phenyl, benzyl, phenoxy, methylbenzyl, nitrogen-substituted benzyl or phenyl groups, a halide, or halide-substituted methyl groups; and iii) wherein the composition is suitable for use in a membrane electrode assembly.

  12. Basic investigation into the production of oxygen in a solid electrolyte process

    Richter, R.


    Mission analyses indicated that by extracting oxygen from the Martian atmosphere, which consists primarily of carbon dioxide, the launch mass of a spacecraft can be reduced by such an amount that samples from the planet can be returned to earth. The solid electrolyte process for producing O2 from CO2 was investigated. A model of the thermodynamic and electrochemical processes in the electrolyte cell was postulated, thereby establishing the parameters influencing the effectiveness and efficiency of an in situ O2 production system. The major operating parameters were investigated over a wide range of temperature and pressure. Operating limits imposed by the solid electrolyte material, 8% yttria stabilized zirconia, were determined as a function of the operating temperature.

  13. Semiconductor electrolyte photovoltaic energy converter

    Anderson, W. W.; Anderson, L. B.


    Feasibility and practicality of a solar cell consisting of a semiconductor surface in contact with an electrolyte are evaluated. Basic components and processes are detailed for photovoltaic energy conversion at the surface of an n-type semiconductor in contact with an electrolyte which is oxidizing to conduction band electrons. Characteristics of single crystal CdS, GaAs, CdSe, CdTe and thin film CdS in contact with aqueous and methanol based electrolytes are studied and open circuit voltages are measured from Mott-Schottky plots and open circuit photo voltages. Quantum efficiencies for short circuit photo currents of a CdS crystal and a 20 micrometer film are shown together with electrical and photovoltaic properties. Highest photon irradiances are observed with the GaAs cell.

  14. Diabetes mellitus and electrolyte disorders

    Liamis, George; Liberopoulos, Evangelos; Barkas, Fotios; Elisaf, Moses


    Diabetic patients frequently develop a constellation of electrolyte disorders. These disturbances are particularly common in decompensated diabetics, especially in the context of diabetic ketoacidosis or nonketotic hyperglycemic hyperosmolar syndrome. These patients are markedly potassium-, magnesium- and phosphate-depleted. Diabetes mellitus (DM) is linked to both hypo- and hyper-natremia reflecting the coexistence of hyperglycemia-related mechanisms, which tend to change serum sodium to opposite directions. The most important causal factor of chronic hyperkalemia in diabetic individuals is the syndrome of hyporeninemic hypoaldosteronism. Impaired renal function, potassium-sparing drugs, hypertonicity and insulin deficiency are also involved in the development of hyperkalemia. This article provides an overview of the electrolyte disturbances occurring in DM and describes the underlying mechanisms. This insight should pave the way for pathophysiology-directed therapy, thus contributing to the avoidance of the several deleterious effects associated with electrolyte disorders and their treatment. PMID:25325058

  15. Kinetics of Nitrogen Diffusion in Granular Manganese

    ZHANG Jin-zhu; XU Chu-shao; ZHAO Yue-ping


    The kinetics and the influence of time on granular manganese nitriding were studied by means of a vacuum resistance furnace, X-ray diffraction technique, and LECO TC-436 oxygen/nitrogen determinator. The longer the nitriding time, the more the nitrogen pickup. Except for a trace of oxide MnO that developed, the metal manganese could thoroughly be nitrided to form Mn4N and a little ζ-phase (the stoichiometric components as Mn2N) with the nitriding time lasting. A kinetic model is developed to reveal the nitriding situation and agrees well with the experimental results.

  16. Electrolyte effects on the surface chemistry and cellular response of anodized titanium

    Ohtsu, Naofumi, E-mail: [Instrumental Analysis Center, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Kozuka, Taro; Hirano, Mitsuhiro [Instrumental Analysis Center, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Arai, Hirofumi [Department of Biotechnology and Environmental Chemistry, Kitami Institute of Technology, Kitami, Hokkaido 090-8507 (Japan)


    Highlights: • Ti samples were anodized using various electrolytes. • Anodization decreased carbon adsorption, improving hydrophilicity. • Improved hydrophilicity led to improved cellular attachment. • Only one electrolyte showed any heteroatom incorporation into the TiO{sub 2} layer. • Choice of electrolyte played no role on the effects of anodization. - Abstract: Anodic oxidation of titanium (Ti) material is used to enhance biocompatibility, yet the effects of various electrolytes on surface characteristics and cellular behavior have not been completely elucidated. To investigate this topic, oxide layers were produced on Ti substrates by anodizing them in aqueous electrolytes of (NH{sub 4}){sub 2}O·5B{sub 2}O{sub 3}, (NH{sub 4}){sub 2}SO{sub 4}, or (NH{sub 4}){sub 3}PO{sub 4}, after which their surface characteristics and cellular responses were examined. Overall, no surface differences between the electrolytes were visually observed. X-ray photoelectron spectroscopy (XPS) revealed that the anodized surfaces are composed of titanium dioxide (TiO{sub 2}), while incorporation from electrolyte was only observed for (NH{sub 4}){sub 3}PO{sub 4}. Surface adsorption of carbon contaminants during sterilization was suppressed by anodization, leading to lower water contact angles. The attachment of MC3T3-E1 osteoblast-like cells was also improved by anodization, as evidenced by visibly enlarged pseudopods. This improved attachment performance is likely due to TiO{sub 2} formation. Overall, electrolyte selection showed no effect on either surface chemistry or cellular response of Ti materials.

  17. Electrochemical device for converting carbon dioxide to a reaction product

    Masel, Richard I.; Chen, Qingmei; Liu, Zengcai; Kutz, Robert


    An electrochemical device converts carbon dioxide to a reaction product. The device includes an anode and a cathode, each comprising a quantity of catalyst. The anode and cathode each has reactant introduced thereto. A polymer electrolyte membrane is interposed between the anode and the cathode. At least a portion of the cathode catalyst is directly exposed to gaseous carbon dioxide during electrolysis. The average current density at the membrane is at least 20 mA/cm.sup.2, measured as the area of the cathode gas diffusion layer that is covered by catalyst, and CO selectivity is at least 50% at a cell potential of 3.0 V. In some embodiments, the polymer electrolyte membrane comprises a polymer in which a constituent monomer is (p-vinylbenzyl)-R, where R is selected from the group consisting of imidazoliums, pyridiniums and phosphoniums. In some embodiments, the polymer electrolyte membrane is a Helper Membrane comprising a polymer containing an imidazolium ligand, a pyridinium ligand, or a phosphonium ligand.

  18. Single- and double-ion type cross-linked polysiloxane solid electrolytes for lithium cells

    Tsutsumi, Hiromori; Yamamoto, Masahiro; Morita, Masayuki; Matsuda, Yoshiharu; Nakamura, Takashi; Asai, Hiroyuki

    Polymeric solid electrolytes, that have poly(dimethylsiloxane) (PMS) backbone and cross-linked network, were applied to a rechargeable lithium battery system. Single- (PMS-Li) and double-ion type (PMS-LiClO 4) electrolytes were prepared from the same prepolymers. Lithium electrode in the both electrolytes showed reversible stripping and deposition of lithium. Intercalation and deintercalation processes of lithium ion between lithium-manganese composite oxide (Li xMnO 2) electrode and the electrolytes were also confirmed by cyclic voltammetry, however, peak current decreased with several cycles in both cases. The model cell, Li/PMS-Li/Li xMnO 2 cell had 1.4 mA h g -1 (per 1 g of active material, current density: 3.77 μA cm -2), and the Li/PMS-LiClO 4/Li xMnO 2 cell had 1.6 mA h g -1 (current density: 75.3 μA cm -2).

  19. Single- and double-ion type cross-linked polysiloxane solid electrolytes for lithium cells

    Tsutsumi, Hiromori; Yamamoto, Masahiro; Morita, Masayuki; Matsuda, Yoshiharu (Dept. of Applied Chemistry and Chemical Engineering, Faculty of Engineering, Yamaguchi Univ., Ube (Japan)); Nakamura, Takashi; Asai, Hiroyuki (Dow Corning Toray Silicone Co. Ltd., Ichihara (Japan))


    Polymeric solid electrolytes, that have poly(dimethylsiloxane) (PMS) backbone and cross-linked network, were applied to a rechargeable lithium battery system. Single- (PMS-Li) and double-ion type (PMS-LiClO[sub 4]) electrolytes were prepared from the same prepolymers. Lithium electrode in the both electrolytes showed reversible stripping and deposition of lithium. Intercalation and deintercalation processes of lithium ion between lithium-manganese composite oxide (Li[sub x]MnO[sub 2]) electrode and the electrolytes were also confirmed by cyclic voltammetry, however, peak current decreased with several cycles in both cases. The model cell, Li/PMS-Li/Li[sub x]MnO[sub 2] cell had 1.4 mA h g[sup -1] (per 1 g of active material, current density: 3.77 [mu]A cm[sup -2]), and the Li/PMS-LiClO[sub 4]/Li[sub x]MnO[sub 2] cell had 1.6 mA h g[sup -1] (current density: 75.3 [mu]A cm[sup -2]). (orig.).

  20. Thermoelectricity in confined liquid electrolytes

    Dietzel, Mathias


    The electric field in an extended phase of a liquid electrolyte exposed to a temperature gradient is attributed to different thermophoretic mobilities of the ion species. As shown herein, such Soret-type ion thermodiffusion is not required to induce thermoelectricity even in the simplest electrolyte if it is confined between charged walls. The space charge of the electric double layer leads to selective ion diffusion driven by a temperature-dependent electrophoretic ion mobility, which -for narrow channels- may cause thermo-voltages larger in magnitude than for the classical Soret equilibrium.

  1. The photocatalytic and cytotoxic effects of titanium dioxide particles used in sunscreen

    Rampaul, Ashti

    Titanium dioxide nanoparticles are used in sunscreens to reflect UV radiation from the skin. However, titanium dioxide as anatase and rutile crystal forms is a well-known photocatalyst. The nanoparticles are surface coated with inert inorganic oxides such as silica and alumina or organics such as organosilanes or silicone polymers and more recently, have been doped with manganese oxide. These modifications to the titanium dioxide particles are purported to prevent the production of harmful reactive oxygen species. A range of sunscreens was tested with crystal form and modification type identified via XRD, Raman Spectroscopy, XPS and SSNMR. The particle modification and crystal form determined whether the particles were inert or rapidly degraded methylene blue dye, and killed or protected cultured human epithelium cells. Novel solid state Electron Paramagnetic Resonance analysis showed that the greatest amount of superoxide anions was formed during UVA irradiation of the mixed anatase and rutile crystal forms coated with an organosilane. These particles also degraded methylene blue at a similar rate to Degussa P25, a standard uncoated titanium dioxide powder and produced an increase in UVA induced apoptosis of human keratinocytes. Double Stranded Breaks were observed extensively in cells exposed to UVA irradiated mixed anatase and rutile titanium dioxide with organosilane. A new apoptotic-like cell death mechanism may have been recognised during the UVA irradiation of animal and human cells in the presence of titanium dioxide. This research concludes that mixed anatase and rutile crystal forms of titanium dioxide coated with organosilane or dimethicone may not be safe to use in sunscreen lotions. A less harmful alternative for sunscreen formulations is the manganese doped rutile particles or the alumina coated rutile powders, both of which exhibited a protective effect on cultured epithelial cells.

  2. Ferroportin is a manganese-responsive protein that decreases manganese cytotoxicity and accumulation

    Yin, Zhaobao; Jiang, Haiyan; Lee, Eun-Sook Y; Ni, Mingwei; Erikson, Keith M; Milatovic, Dejan; Bowman, Aaron B; Aschner, Michael


    Although manganese (Mn) is an essential trace element for human development and growth, chronic exposure to excessive Mn levels can result in psychiatric and motor disturbances, referred to as manganism...

  3. Evaluation of electrolyte imbalance among tuberculosis patients ...

    Adebimpe Wasiu Olalekan


    Feb 24, 2015 ... electrolyte and acid-base derangements frequently encountered in AIDS and TB, have ..... tuberculosis. Electrolyte and acid-base balance monitoring in ... National Agency for the Control of HIV/AIDS NACA. Preva- lence of ...

  4. Polymer Electrolytes for Lithium/Sulfur Batteries

    The Nam Long Doan


    Full Text Available This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes.

  5. Electrocatalytic Reduction of Carbon Dioxide to Methane

    Sammells, Anthony F.; Spiegel, Ella F.


    A room-temperature electrocatalytic process that effects the overall chemical reaction CO2 + 2H2O yields CH4 + 2O2 has been investigated as a means of removing carbon dioxide from air and restoring oxygen to the air. The process was originally intended for use in a spacecraft life-support system, in which the methane would be vented to outer space. The process may also have potential utility in terrestrial applications in which either or both of the methane and oxygen produced might be utilized or vented to the atmosphere. A typical cell used to implement the process includes a polymer solid-electrolyte membrane, onto which are deposited cathode and anode films. The cathode film is catalytic for electrolytic reduction of CO2 at low overpotential. The anode film is typically made of platinum. When CO2 is circulated past the cathode, water is circulated past the anode, and a suitable potential is applied, the anode half-cell reaction is 4H2O yields 2O2 + 8H(+) + 8e(-). The H(+) ions travel through the membrane to the cathode, where they participate in the half-cell reaction CO2 + 8H(+) + 8e(-) yields CH4 + 2H2O.

  6. Manganese ore tailing: optimization of acid leaching conditions and recovery of soluble manganese.

    Santos, Olívia de Souza Heleno; Carvalho, Cornélio de Freitas; Silva, Gilmare Antônia da; Santos, Cláudio Gouvêa Dos


    Manganese recovery from industrial ore processing waste by means of leaching with sulfuric acid was the objective of this study. Experimental conditions were optimized by multivariate experimental design approaches. In order to study the factors affecting leaching, a screening step was used involving a full factorial design with central point for three variables in two levels (2(3)). The three variables studied were leaching time, concentration of sulfuric acid and sample amount. The three factors screened were shown to be relevant and therefore a Doehlert design was applied to determine the best working conditions for leaching and to build the response surface. By applying the best leaching conditions, the concentrations of 12.80 and 13.64 %w/w of manganese for the global sample and for the fraction -44 + 37 μm, respectively, were found. Microbeads of chitosan were tested for removal of leachate acidity and recovering of soluble manganese. Manganese recovery from the leachate was 95.4%. Upon drying the leachate, a solid containing mostly manganese sulfate was obtained, showing that the proposed optimized method is efficient for manganese recovery from ore tailings.

  7. Crystallization and spectroscopic studies of manganese malonate

    Varghese Mathew; Jochan Joseph; Sabu Jacob; K E Abraham


    The preparation of manganese malonate crystals by gel method and its spectroscopic studies are reported. X-ray diffraction (XRD) pattern reveals the crystalline nature. The FTIR and FT Raman spectra of the crystals are recorded and the vibrational assignments are given with possible explanations. Diffuse reflectance spectroscopy (DRS) is used to measure the bandgap (g) of the material.

  8. Mixed iron-manganese oxide nanoparticles

    Lai, Jriuan; Shafi, Kurikka V.P.M.; Ulman, Abraham; Loos, Katja; Yang, Nan-Loh; Cui, Min-Hui; Vogt, Thomas; Estournès, Claude; Locke, Dave C.


    Designing nanoparticles for practical applications requires knowledge and control of how their desired properties relate to their composition and structure. Here, we present a detailed systematic study of mixed iron-manganese oxide nanoparticles, showing that ultrasonication provides the high-energy

  9. Manganese superoxide dismutase and breast cancer recurrence

    Cronin-Fenton, Deirdre P; Christensen, Mariann; Lash, Timothy L


    BACKGROUND: Manganese superoxide dismutase (MnSOD) inhibits oxidative damage and cancer therapy effectiveness. A polymorphism in its encoding gene (SOD2: Val16Ala rs4880) may confer poorer breast cancer survival, but data are inconsistent. We examined the association of SOD2 genotype and breast...

  10. Manganese homeostasis in the nervous system.

    Chen, Pan; Chakraborty, Sudipta; Mukhopadhyay, Somshuvra; Lee, Eunsook; Paoliello, Monica M B; Bowman, Aaron B; Aschner, Michael


    Manganese (Mn) is an essential heavy metal that is naturally found in the environment. Daily intake through dietary sources provides the necessary amount required for several key physiological processes, including antioxidant defense, energy metabolism, immune function and others. However, overexposure from environmental sources can result in a condition known as manganism that features symptomatology similar to Parkinson's disease (PD). This disorder presents with debilitating motor and cognitive deficits that arise from a neurodegenerative process. In order to maintain a balance between its essentiality and neurotoxicity, several mechanisms exist to properly buffer cellular Mn levels. These include transporters involved in Mn uptake, and newly discovered Mn efflux mechanisms. This review will focus on current studies related to mechanisms underlying Mn import and export, primarily the Mn transporters, and their function and roles in Mn-induced neurotoxicity. Though and essential metal, overexposure to manganese may result in neurodegenerative disease analogous to Parkinson's disease. Manganese homeostasis is tightly regulated by transporters, including transmembrane importers (divalent metal transporter 1, transferrin and its receptor, zinc transporters ZIP8 and Zip14, dopamine transporter, calcium channels, choline transporters and citrate transporters) and exporters (ferroportin and SLC30A10), as well as the intracellular trafficking proteins (SPCA1 and ATP12A2). A manganese-specific sensor, GPP130, has been identified, which affords means for monitoring intracellular levels of this metal.


    The ubiquitous element, manganese (Mn), is an essential nutrient, but toxic at excessive exposure levels. Therefore, the US EPA set guideline levels for Mn exposure through inhalation (reference concentration-RfC=0.05 ?g/m3) and ingestion (reference dose-RfD=0.14 mg/kg/day (10 mg...

  12. Electrolytes for magnesium electrochemical cells

    Burrell, Anthony K.; Sa, Niya; Proffit, Danielle Lee; Lipson, Albert; Liao, Chen; Vaughey, John T.; Ingram, Brian J.


    An electrochemical cell includes a high voltage cathode configured to operate at 1.5 volts or greater; an anode including Mg.sup.0; and an electrolyte including an ether solvent and a magnesium salt; wherein: a concentration of the magnesium salt in the ether is 1 M or greater.

  13. Soil manganese enrichment from industrial inputs: a gastropod perspective.

    Despina-Maria Bordean

    Full Text Available Manganese is one of the most abundant metal in natural environments and serves as an essential microelement for all living systems. However, the enrichment of soil with manganese resulting from industrial inputs may threaten terrestrial ecosystems. Several studies have demonstrated harmful effects of manganese exposure by cutaneous contact and/or by soil ingestion to a wide range of soil invertebrates. The link between soil manganese and land snails has never been made although these invertebrates routinely come in contact with the upper soil horizons through cutaneous contact, egg-laying, and feeding activities in soil. Therefore, we have investigated the direct transfer of manganese from soils to snails and assessed its toxicity at background concentrations in the soil. Juvenile Cantareus aspersus snails were caged under semi-field conditions and exposed first, for a period of 30 days, to a series of soil manganese concentrations, and then, for a second period of 30 days, to soils with higher manganese concentrations. Manganese levels were measured in the snail hepatopancreas, foot, and shell. The snail survival and shell growth were used to assess the lethal and sublethal effects of manganese exposure. The transfer of manganese from soil to snails occurred independently of food ingestion, but had no consistent effect on either the snail survival or shell growth. The hepatopancreas was the best biomarker of manganese exposure, whereas the shell did not serve as a long-term sink for this metal. The kinetics of manganese retention in the hepatopancreas of snails previously exposed to manganese-spiked soils was significantly influenced by a new exposure event. The results of this study reveal the importance of land snails for manganese cycling in terrestrial biotopes and suggest that the direct transfer from soils to snails should be considered when precisely assessing the impact of anthropogenic Mn releases on soil ecosystems.

  14. Soil Manganese Enrichment from Industrial Inputs: A Gastropod Perspective

    Bordean, Despina-Maria; Nica, Dragos V.; Harmanescu, Monica; Banatean-Dunea, Ionut; Gergen, Iosif I.


    Manganese is one of the most abundant metal in natural environments and serves as an essential microelement for all living systems. However, the enrichment of soil with manganese resulting from industrial inputs may threaten terrestrial ecosystems. Several studies have demonstrated harmful effects of manganese exposure by cutaneous contact and/or by soil ingestion to a wide range of soil invertebrates. The link between soil manganese and land snails has never been made although these invertebrates routinely come in contact with the upper soil horizons through cutaneous contact, egg-laying, and feeding activities in soil. Therefore, we have investigated the direct transfer of manganese from soils to snails and assessed its toxicity at background concentrations in the soil. Juvenile Cantareus aspersus snails were caged under semi-field conditions and exposed first, for a period of 30 days, to a series of soil manganese concentrations, and then, for a second period of 30 days, to soils with higher manganese concentrations. Manganese levels were measured in the snail hepatopancreas, foot, and shell. The snail survival and shell growth were used to assess the lethal and sublethal effects of manganese exposure. The transfer of manganese from soil to snails occurred independently of food ingestion, but had no consistent effect on either the snail survival or shell growth. The hepatopancreas was the best biomarker of manganese exposure, whereas the shell did not serve as a long-term sink for this metal. The kinetics of manganese retention in the hepatopancreas of snails previously exposed to manganese-spiked soils was significantly influenced by a new exposure event. The results of this study reveal the importance of land snails for manganese cycling in terrestrial biotopes and suggest that the direct transfer from soils to snails should be considered when precisely assessing the impact of anthropogenic Mn releases on soil ecosystems. PMID:24454856

  15. Manganese modified zeolite silicalite-1 as polysulphide sorbent in lithium sulphur batteries

    Lapornik, Vida; Novak Tusar, Natasa; Ristic, Alenka; Chellappan, Rajesh Kumar; Foix, Dominique; Dedryvère, Rémi; Gaberscek, Miran; Dominko, Robert


    Discharge/charge process of classical lithium sulphur battery proceeds through intermediate polysulphides which are soluble in classical electrolyte systems. Due to concentration gradient soluble polysulphides easily diffuse/migrate out from cathode composite forming non-uniform distribution of the sulphur within cathode. Eventually polysulphides can be completely reduced on the metallic lithium anode. In this work we compare the sorption properties of manganese modified zeolite silicalite-1 (MnS-1) with a cathode composite containing SBA-15 additive and a cathode composite without additive. Careful analysis using XPS and FIB microscopy equipped with EDX show improved retention of polysulphide species within cathode composite in the case of MnS-1 zeolite as an additive. Interestingly, the amount of sulphur species detected by XPS on the metallic lithium is very similar regardless on cathode composite we use. Finally, similar cycling behaviour can be observed if MnS-1 zeolite is used as an interlayer between composite cathode and separator.

  16. Selective chlorine dioxide determination using gas-diffusion flow injection analysis with chemiluminescent detection

    Hollowell, D.A.; Gord, J.R.; Gordon, G.; Pacey, G.E.


    An automated chemiluminescent technique has been developed utilizing the advantages of gas-diffusion flow injection analysis. A gas-diffusion membrane separates the donor (sampling) stream from the acceptor (detecting) stream and removes ionic interferences. A novel chemiluminescence flow-through detector cell is used to measure the concentration of chlorine dioxide as a function of the intensity of the chemiluminescence produced from its reaction with luminol. The chemiluminescent reagent merges with the analyte directly in front of the photomultiplier tube in order to maximize the sensitivity of the system. The detection limit for chlorine dioxide is approximately 5 ppb. The method is over 1500 times more selective for chlorine dioxide than for chlorine on a mole basis. This method eliminates interference from iron and manganese compounds, as well as other oxychlorinated compounds such as chlorite ion and chlorate ion.

  17. Efficient Electrolytes for Lithium-Sulfur Batteries

    Natarajan eAngulakshmi


    Full Text Available This review article mainly encompasses on the state-of-the-art electrolytes for lithium–sulfur batteries. Different strategies have been employed to address the issues of lithium-sulfur batteries across the world. One among them is identification of electrolytes and optimization of their properties for the applications in lithium-sulfur batteries. The electrolytes for lithium-sulfur batteries are broadly classified as (i non-aqueous liquid electrolytes, (ii ionic liquids, (iii solid polymer and (iv glass-ceramic electrolytes. This article presents the properties, advantages and limitations of each type of electrolytes. Also the importance of electrolyte additives on the electrochemical performance of Li-S cells is discussed.

  18. Metallic tin quantum sheets confined in graphene toward high-efficiency carbon dioxide electroreduction

    Lei, Fengcai; Liu, Wei; Sun, Yongfu; Xu, Jiaqi; Liu, Katong; Liang, Liang; Yao, Tao; Pan, Bicai; Wei, Shiqiang; Xie, Yi


    Ultrathin metal layers can be highly active carbon dioxide electroreduction catalysts, but may also be prone to oxidation. Here we construct a model of graphene confined ultrathin layers of highly reactive metals, taking the synthetic highly reactive tin quantum sheets confined in graphene as an example. The higher electrochemical active area ensures 9 times larger carbon dioxide adsorption capacity relative to bulk tin, while the highly-conductive graphene favours rate-determining electron transfer from carbon dioxide to its radical anion. The lowered tin-tin coordination numbers, revealed by X-ray absorption fine structure spectroscopy, enable tin quantum sheets confined in graphene to efficiently stabilize the carbon dioxide radical anion, verified by 0.13 volts lowered potential of hydroxyl ion adsorption compared with bulk tin. Hence, the tin quantum sheets confined in graphene show enhanced electrocatalytic activity and stability. This work may provide a promising lead for designing efficient and robust catalysts for electrolytic fuel synthesis.

  19. Facile hydrothermal preparation of titanium dioxide decorated reduced graphene oxide nanocomposite

    Chang, Betty Yea Sze; Huang, Nay Ming; An’amt, Mohd Nor; Marlinda, Abdul Rahman; Norazriena, Yusoff; Muhamad, Muhamad Rasat; Harrison, Ian; Lim, Hong Ngee; Chia, Chin Hua


    A simple single-stage approach, based on the hydrothermal technique, has been introduced to synthesize reduced graphene oxide/titanium dioxide nanocomposites. The titanium dioxide nanoparticles are formed at the same time as the graphene oxide is reduced to graphene. The triethanolamine used in the process has two roles. It acts as a reducing agent for the graphene oxide as well as a capping agent, allowing the formation of titanium dioxide nanoparticles with a narrow size distribution (~20 nm). Transmission electron micrographs show that the nanoparticles are uniformly distributed on the reduced graphene oxide nanosheet. Thermogravimetric analysis shows the nanocomposites have an enhanced thermal stability over the original components. The potential applications for this technology were demonstrated by the use of a reduced graphene oxide/titanium dioxide nanocomposite-modified glassy carbon electrode, which enhanced the electrochemical performance compared to a conventional glassy carbon electrode when interacting with mercury(II) ions in potassium chloride electrolyte. PMID:22848166



  1. Effects of vitamin E on serum enzymes and electrolytes in hypercholesterolemia.

    Prasad, Kailash


    It is not known if vitamin E in hyperlipidemia and hypercholesterolemia of longer duration has any beneficial or adverse effects on electrolytes, and liver and kidney function. The objectives of this study are to determine (i) if long duration of mild hypercholesterolemia has any adverse effects on serum electrolytes, glucose and enzymes related to liver and kidney functions; (ii) if vitamin E has any effects on serum electrolytes, glucose and enzymes related to liver and kidney function in hypercholesterolemia. Blood samples were collected from the rabbits before and at various intervals during administration of a high cholesterol diet (0.25%) for 2 and 4 months, and while on a high cholesterol diet with vitamin E following a high cholesterol diet. Measurements of serum total cholesterol (TC), glucose, aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), albumin, creatinine, electrolytes [sodium (Na), potassium (K), chloride (Cl), and carbon dioxide (CO2)] were made. High cholesterol diet for 2 months produced hypercholesterolemia which was associated with reductions in serum glucose, unaltered serum electrolytes, ALT, ALP, GGT, albumin and creatinine, and increased levels of AST. Hypercholesterolemia for 4 months had effects similar to hypercholesterolemia for 2 months except it lowered serum ALP. Vitamin E did not affect any of the parameters except serum glucose and Cl, which decreased compared to the values at month 2. Hypercholesterolemia for short and long term does not have adverse effects on liver or kidney function, and serum electrolytes. Vitamin E during hypercholesterolemia does not affect serum electrolytes or liver and kidney function.

  2. Structure and Properties of Cast Near-Congruent Copper-Manganese Alloys

    Chaput, Kevin; Trumble, Kevin P.


    Microstructure development in the casting of copper-manganese alloys based on the congruent point at 34.6 wt pct Mn and 1146 K (873 °C) has been studied. The alloys were prepared by induction melting of electrolytic Cu and Mn in clay-graphite crucibles in open air. Under conventional casting conditions, the alloys exhibit fine cellular (non-dendritic) solidification morphology with a distinct absence of solidification shrinkage microporosity, and they maintain these attributes over a composition range of approximately 3 wt pct Mn about the congruent point. The high Mn concentration in the alloy admits carbon into solution in the melt, resulting in formation of manganese carbide Mn7C3 particles having two different forms (globular and angular) in the cast microstructure. The Mn carbide was eliminated or controlled to low levels by melting in an alumina or a silicon carbide crucible, or in a clay-graphite crucible at lower temperatures. Microstructure development in casting the alloy was analyzed in terms of the available phase diagrams and thermochemical data. Hardness and tensile testing indicated a potent solid solution strengthening effect of Mn and high ductility in the as-cast condition, with additional hardness (strength) when the alloy contains the Mn carbide phase.

  3. Growth of anatase titanium dioxide nanotubes via anodization

    Ed Adrian Dilla


    Full Text Available In this work, titanium dioxide nanotubes were grown via anodization of sputtered titanium thin films using different anodization parameters in order to formulate a method of producing long anatase titanium dioxide nanotubes intended for solar cell applications. The morphological features of the nanotubes grown via anodization were explored using a Philips XL30 Field Emission Scanning Electron Microscope. Furthermore, the grown nanotubes were also subjected to X-ray diffraction and Raman spectroscopy in order to investigate the effect of the predominant crystal orientation of the parent titanium thin film on the crystal phase of the nanotubes. After optimizing the anodization parameters, nanotubes with anatase TiO2 crystal phase and tube length more than 2 microns was produced from parent titanium thin films with predominant Ti(010 crystal orientation and using ammonium fluoride in ethylene glycol as an electrolyte with a working voltage equal to 60V during 1-hour anodization runs.

  4. Electrochromic Device with Polymer Electrolyte

    Solovyev, Andrey A.; Zakharov, Alexander N.; Rabotkin, Sergey V.; Kovsharov, Nikolay F.


    In this study a solid-state electrochromic device (ECD) comprised of a WO3 and Prussian blue (Fe4[Fe(CN)6]3) thin film couple with a Li+-conducting solid polymer electrolyte is discussed. WO3 was deposited on K-Glass substrate by magnetron sputtering method, while Prussian blue layer was formed on the same substrate by electrodeposition method. The parameters of the electrochromic device K-Glass/WO3/Li+-electrolyte/PB/K-Glass, such as change of transmittance, response time and stability were successfully tested using coupled optoelectrochemical methods. The device was colored or bleached by the application of +2 V or -2 V, respectively. Light modulation with transmittance variation of up to 59% and coloration efficiency of 43 cm2/C at a wavelength of 550 nm were obtained. Numerous switching of the ECD over 1200 cycles without the observation of significant degradation has been demonstrated.

  5. Composite electrode/electrolyte structure

    Visco, Steven J.; Jacobson, Craig P.; DeJonghe, Lutgard C.


    Provided is an electrode fabricated from highly electronically conductive materials such as metals, metal alloys, or electronically conductive ceramics. The electronic conductivity of the electrode substrate is maximized. Onto this electrode in the green state, a green ionic (e.g., electrolyte) film is deposited and the assembly is co-fired at a temperature suitable to fully densify the film while the substrate retains porosity. Subsequently, a catalytic material is added to the electrode structure by infiltration of a metal salt and subsequent low temperature firing. The invention allows for an electrode with high electronic conductivity and sufficient catalytic activity to achieve high power density in ionic (electrochemical) devices such as fuel cells and electrolytic gas separation systems.

  6. Electrolyte leakage as an indicator

    ahmad nezami


    Full Text Available In order to evaluate the electrolyte leakage as an indicator of freezing injury in colza (Brassica napus L. genotypes under controlled conditions, a trial carried out at the green house of College of Agriculture, Ferdowsi University of Mashhad. In this study 10 rapeseed genotypes, with 5 temperatures (0, -4, -8, -12 and -16 °C on subplot and acclimation and non acclimation on main plot were evaluated on RCD factorial split plot with two replications. Plants were kept until 3-5 leaf stage in green house condition with 23/16 2 °C (day/night and natural photoperiod. Pots were subjected to acclimation (for three weeks or non acclimation that plants immediately frozen.For acclimation treatment after three weeks freezing was done in thermogradient freezer. The cell membrane integrity was measured through electrolyte leakage and the lethal temperature 50 (LT50 of samples also were determined. There were significant differences (p

  7. New Polymer Electrolyte Cell Systems

    Smyrl, William H.; Owens, Boone B.; Mann, Kent; Pappenfus, T.; Henderson, W.


    PAPERS PUBLISHED: 1. Pappenfus, Ted M.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; Smyrl, William H. Complexes of Lithium Imide Salts with Tetraglyme and Their Polyelectrolyte Composite Materials. Journal of the Electrochemical Society (2004), 15 1 (2), A209-A2 15. 2. Pappenfus, Ted M.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; Smyrl, William H. Ionic-liquidlpolymer electrolyte composite materials for electrochemical device applications. Polymeric Materials Science and Engineering (2003), 88 302. 3. Pappenfus, Ted R.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; and Smyrl, William H. Ionic Conductivity of a poly(vinylpyridinium)/Silver Iodide Solid Polymer Electrolyte System. Solid State Ionics (in press 2004). 4. Pappenfus Ted M.; Mann, Kent R; Smyrl, William H. Polyelectrolyte Composite Materials with LiPFs and Tetraglyme. Electrochemical and Solid State Letters, (2004), 7(8), A254.

  8. Manganese Abnormity in Holocene Sediments of the Bohai Sea


    Manganese abnormity has been observed in the Holocene sediments of the mud area of Bohai Sea. On the basis of grain size, chemical composition, heavy mineral content and accelerator mass spectrometry (AMS) 14C dating of foraminifer, relationships between manganese abnormity and sedimentation rates, material source, hydrodynamic conditions are probed. Manganese abnormity occurred during the Middle Holocene when sea level and sedimentation rates were higher than those at present. Sedimentary hiatus was not observed when material sources and hydrodynamic conditions were quite similar. Compared with the former period, the latter period showed a decrease in reduction environment and an inclination toward oxidation environment with high manganese content, whereas provenance and hydrodynamic conditions showed only a slight change. From the above observations, it can be concluded that correlation among manganese abnormity, material source, and hydrodynamic conditions is not obvious. Redox environment seems to be the key factor for manganese enrichment, which is mainly related to marine authigenic process.

  9. Microfluidic platform for studying the electrochemical reduction of carbon dioxide

    Whipple, Devin Talmage

    Diminishing supplies of conventional energy sources and growing concern over greenhouse gas emissions present significant challenges to supplying the world's rapidly increasing demand for energy. The electrochemical reduction of carbon dioxide has the potential to address many of these issues by providing a means of storing electricity in chemical form. Storing electrical energy as chemicals is beneficial for leveling the output of clean, but intermittent renewable energy sources such as wind and solar. Electrical energy stored as chemicals can also be used as carbon neutral fuels for portable applications allowing petroleum derived fuels in the transportation sector to be replaced by more environmentally friendly energy sources. However, to be a viable technology, the electrochemical reduction of carbon dioxide needs to have both high current densities and energetic efficiencies (Chapter 1). Although many researchers have studied the electrochemical reduction of CO2 including parameters such as catalysts, electrolytes and temperature, further investigation is needed to improve the understanding of this process and optimize the performance (Chapter 2). This dissertation reports the development and validation of a microfluidic reactor for the electrochemical reduction of CO2 (Chapter 3). The design uses a flowing liquid electrolyte instead of the typical polymer electrolyte membrane. In addition to other benefits, this flowing electrolyte gives the reactor great flexibility, allowing independent analysis of each electrode and the testing of a wide variety of conditions. In this work, the microfluidic reactor has been used in the following areas: • Comparison of different metal catalysts for the reduction of CO2 to formic acid and carbon monoxide (Chapter 4). • Investigation of the effects of the electrolyte pH on the reduction of CO2 to formic acid and carbon monoxide (Chapter 5). • Study of amine based electrolytes for lowering the overpotentials for CO2

  10. Spin dependent calculation of calcium manganese oxide

    Rathod, Ruchi; Kansara, Shivam; Gupta, Sanjeev K.; Sonvane, Yogesh


    Particularly interesting as candidates for technological applications are the manganese perovskites with AMnO3 formula. In this paper, we investigated the ground states properties of the CaMnO3 perovskite oxide. Our structural properties are given using GGA in the aim to introduce the exchange correlation potential using density functional calculation. Generally, the perovskites materials of ABO3-type are well known with their anti/ferroelectric, piezoelectric and anti/ferromagnetism properties applied in remarkable technological studies.

  11. Manganese concentration in human saliva using NAA

    Lewgoy, Hugo R., E-mail: [Universidade Bandeirante Anhanguera (UNIBAN), Sao Paulo, SP (Brazil); Zamboni, Cibele B.; Medeiros, Ilca M.M.A.; Medeiros, Jose A.G. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)


    In this investigation the Manganese levels in human whole saliva were determined using Neutron Activation Analysis (NAA) technique for the proposition of an indicative interval. The measurements were performed considering gender and lifestyle factors of Brazilian inhabitants (non-smokers, non-drinkers and no history of toxicological exposure). The results emphasize that the indicative interval is statistically different by gender. These data are useful for identifying or preventing some diseases in the Brazilian population. (author)

  12. Ionic Liquid based polymer electrolytes for electrochemical sensors

    Jakub Altšmíd


    Full Text Available Amperometric NO2 printed sensor with a new type of solid polymer electrolyte and a carbon working electrode has been developed. The electrolytes based on 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonylimide [EMIM][N(Tf2], 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][CF3SO3] and 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] ionic liquids were immobilized in poly(vinylidene fluoride matrix [PVDF]. The analyte, gaseous nitrogen dioxide, was detected by reduction at -500 mV vs. platinum pseudoreference electrode. The sensors showed a linear behavior in the whole tested range, i.e., 0 - 5 ppm and their sensitivities were in order of 0.3 x∙10-6 A/ppm. The sensor sensitivity was influenced by the electric conductivity of printing formulation; the higher the conductivity, the higher the sensor sensitivity. The rise/recovery times were in order of tens of seconds. The use of  screen printing technology and platinum pseudoreference electrode simplify the sensor fabrication and it does not have any negative effect on the sensor stability.DOI:

  13. Influence of the Applied Potential and Temperature on the Electrodeposition of the Lead Dioxide

    Taha Yaseen Khalaf


    Full Text Available The excellent specifications of electrodes coated with lead dioxide material make it of great importance in the industry. So it was suggested this study, which includes electrodeposition of lead dioxide on graphite substrate, knowing that the electrodeposition of lead dioxide on graphite studied earlier in different ways. In this work the deposition process for lead dioxide conducted using electrolytic solution containing lead nitrate concentration 0.72 M with the addition of some other material to the solution, such as copper nitrate, nickel nitrate, sodium fluoride and cetyl trimethyl ammonium bromide, but only in very small concentrations. As for the operating conditions, the effect of change potential and temperature as well as the time on the deposition process was studied. The results shown at the end of the experiments that the change in the applied potential to the cell and electrolytic solution temperature had the greatest influence on the cell current, anodic current density, anodic overpotential and the amount of lead dioxide deposited on the anode.

  14. Directed vapor deposition of lithium manganese oxide films

    Jin, Sang-Wan

    Electron beam evaporation and sputtering techniques are used to fabricate multilayered thin film structures. However, these techniques suffer several drawbacks resulting from (i) the complex chemistries of the lithiated oxide layers used for the cathode and electrolyte, (ii) the need for precise microstructure control in systems with many metastable phases, and (iii) the low deposition rate and poor material utilization efficiency, which slows the application of this energy storage approach. This dissertation has investigated the use of a novel electron-beam directed vapor deposition (EB-DVD) method for the synthesis of thin film batteries. The dissertation focuses upon the cathode layer of a representative Li-ion thin film battery system and investigates in detail the deposition of lithium manganese oxide films. Many phases with offering various electrochemical performance exist in the Li-Mn-O system and the thesis also investigates the use of processing conditions to control the structure and composition of these cathode layers. In the EB-DVD approach, a high voltage electron beam is used to evaporate a source material in the throat of a nozzle that forms a coaxial transonic gas jet around the vapor. The gas jet entrains and transports the vapor to a substrate where the deposition occurs. Directed simulation of Monte Carlo (DSMC) methods indicated that the vapor plume could be matched to a substrate diameter, and the deposition rate (and vapor utilization efficiency) therefore controlled by adjusting the pressure ratio up and downstream of the nozzle opening in the deposition chamber, and by varying the gas jet density and speed. The highest deposition rates were obtained with a high pressure ratio and the gas jet density. These observations are found to be consistent with the experimental results. Deposition rates up to 16 nm/s could be achieved using the most effective gas entrainment conditions identified by DSMC calculation. This was about a factor of ten


    J. Habibah; J. Khairiah; Ismail, B.S.; M.D. Kadderi


    Manganese speciation in selected agricultural soils of Peninsular Malaysia is discussed in this study. Manganese concentration in the Easily Leacheable and Ion Exchangeable (ELFE), Acid Reducible (AR), Organic Oxidizable (OO) and Resistant (RR) fractions of soils developed on weathered rocks, soils of mixed nature, alluvium and peat deposits are described. The total manganese concentration in soils developed on weathered rocks was found to be higher than that in soils of mixed nature, alluviu...

  16. Manganese oxide nanowires, films, and membranes and methods of making

    Suib, Steven Lawrence [Storrs, CT; Yuan, Jikang [Storrs, CT


    Nanowires, films, and membranes comprising ordered porous manganese oxide-based octahedral molecular sieves and methods of making the same are disclosed. A method for forming nanowires includes hydrothermally treating a chemical precursor composition in a hydrothermal treating solvent to form the nanowires, wherein the chemical precursor composition comprises a source of manganese cations and a source of counter cations, and wherein the nanowires comprise ordered porous manganese oxide-based octahedral molecular sieves.

  17. Manganese-induced turnover of TMEM165.

    Potelle, Sven; Dulary, Eudoxie; Climer, Leslie; Duvet, Sandrine; Morelle, Willy; Vicogne, Dorothée; Lebredonchel, Elodie; Houdou, Marine; Spriet, Corentin; Krzewinski-Recchi, Marie-Ange; Peanne, Romain; Klein, André; de Bettignies, Geoffroy; Morsomme, Pierre; Matthijs, Gert; Marquardt, Thorsten; Lupashin, Vladimir; Foulquier, François


    TMEM165 deficiencies lead to one of the congenital disorders of glycosylation (CDG), a group of inherited diseases where the glycosylation process is altered. We recently demonstrated that the Golgi glycosylation defect due to TMEM165 deficiency resulted from a Golgi manganese homeostasis defect and that Mn(2+) supplementation was sufficient to rescue normal glycosylation. In the present paper, we highlight TMEM165 as a novel Golgi protein sensitive to manganese. When cells were exposed to high Mn(2+) concentrations, TMEM165 was degraded in lysosomes. Remarkably, while the variant R126H was sensitive upon manganese exposure, the variant E108G, recently identified in a novel TMEM165-CDG patient, was found to be insensitive. We also showed that the E108G mutation did not abolish the function of TMEM165 in Golgi glycosylation. Altogether, the present study identified the Golgi protein TMEM165 as a novel Mn(2+)-sensitive protein in mammalian cells and pointed to the crucial importance of the glutamic acid (E108) in the cytosolic ELGDK motif in Mn(2+)-induced degradation of TMEM165. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  18. Manganese abundances in Galactic bulge red giants

    Barbuy, B; Zoccali, M; Minniti, D; Renzini, A; Ortolani, S; Gomez, A; Trevisan, M; Dutra, N


    Manganese is mainly produced in type II SNe during explosive silicon burning, in incomplete Si-burning regions, and depends on several nucleosynthesis environment conditions, such as mass cut beween the matter ejected and falling back onto the remnant, electron and neutron excesses, mixing fallback, and explosion energy. Manganese is also produced in type Ia SNe. The aim of this work is the study of abundances of the iron-peak element Mn in 56 bulge giants, among which 13 are red clump stars. Four bulge fields along the minor axis are inspected. The study of abundances of Mn-over-Fe as a function of metallicity in the Galactic bulge may shed light on its production mechanisms. High-resolution spectra were obtained using the FLAMES+UVES spectrograph on the Very Large Telescope. The spectra were obtained within a program to observe 800 stars using the GIRAFFE spectrograph, together with the present UVES spectra. We aim at identifying the chemical evolution of manganese, as a function of metallicity, in the Gala...

  19. Manganese deposition in drinking water distribution systems.

    Gerke, Tammie L; Little, Brenda J; Barry Maynard, J


    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn(3+) and Mn(4+)) and hollandite (Mn(2+) and Mn(4+)), and a Mn silicate, braunite (Mn(2+) and Mn(4+)), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality.

  20. Manganese deposition in drinking water distribution systems

    Gerke, Tammie L., E-mail: [Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013 (United States); Little, Brenda J., E-mail: [Naval Research Laboratory, Stennis Space Center, MS 39529 (United States); Barry Maynard, J., E-mail: [Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013 (United States)


    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn{sup 3+} and Mn{sup 4+}) and hollandite (Mn{sup 2+} and Mn{sup 4+}), and a Mn silicate, braunite (Mn{sup 2+} and Mn{sup 4+}), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality. - Highlights: • Oxidation and deposition of Mn deposits in drinking water distribution pipes • In-situ synchrotron-based μ-XANES and μ-XRF mapping • Toxic metal sorption in Mn deposits.

  1. Fabrication and Performance of Zirconia Electrolysis Cells for Cabon Dioxide Reduction for Mars In Situ Resource Utilization Applications

    Minh, N. Q.; Chung, B. W.; Doshi, R.; Lear, G. R.; Montgomery, K.; Ong, E. T.


    Use of the Martian atmosphere (95% CO2) to produce oxygen (for propellant and life support) can significantly lower the required launch mass and dramatically reduce the total cost for Mars missions. Zirconia electrolysis cells are one of the technologies being considered for oxygen generation from carbon dioxide in Mars In Situ Resource Utilization (ISRU) production plants. The attractive features of the zirconia cell for this application include simple operation and lightweight, low volume system. A zirconia electrolysis cell is an all-solid state device, based on oxygen-ion conducting zirconia electrolytes, that electrochemically reduces carbon dioxide to oxygen and carbon monoxide. The cell consists of two porous electrodes (the anode and cathode) separated by a dense zirconia electrolyte. Typical zirconia cells contain an electrolyte layer which is 200 to 400 micrometer thick. The electrical conductivity requirement for the electrolyte necessitates an operating temperature of 9000 to 10000C. Recently, the fabrication of zirconia cells by the tape calendering has been evaluated. This fabrication process provides a simple means of making cells having very thin electrolytes (5 to 30 micrometers). Thin zirconia electrolytes reduce cell ohmic losses, permitting efficient operation at lower temperatures (8000C or below). Thus, tape-calendered cells provides not only the potential of low temperature operation but also the flexibility in operating temperatures. This paper describes the fabrication of zirconia cells by the tape calendering method and discusses the performance results obtained to date.

  2. Response of electrochemical oxygen sensors to inert gas-air and carbon dioxide-air mixtures: measurements and mathematical modelling.

    Walsh, P T; Gant, S E; Dowker, K P; Batt, R


    Electrochemical oxygen gas sensors are widely used for monitoring the state of inertisation of flammable atmospheres and to warn of asphyxiation risks. It is well established but not widely known by users of such oxygen sensors that the response of the sensor is affected by the nature of the diluent gas responsible for the decrease in ambient oxygen concentration. The present work investigates the response of electrochemical sensors, with either acid or alkaline electrolytes, to gas mixtures comprising air with enhanced levels of nitrogen, carbon dioxide, argon or helium. The measurements indicate that both types of sensors over-read the oxygen concentrations when atmospheres contain high levels of helium. Sensors with alkaline electrolytes are also shown to underestimate the severity of the hazard in atmospheres containing high levels of carbon dioxide. This deviation is greater for alkaline electrolyte sensors compared to acid electrolyte sensors. A Computational Fluid Dynamics (CFD) model is developed to predict the response of an alkaline electrolyte, electrochemical gas sensor. Differences between predicted and measured sensor responses are less than 10% in relative terms for nearly all of the gas mixtures tested, and in many cases less than 5%. Extending the model to simulate responses of sensors with acid electrolytes would be straightforward.

  3. Sulfuric acid leaching of mechanically activated manganese carbonate ore

    Kenan Yıldız


    Full Text Available Acidic leaching of mechanically activated manganese ore from Denizli – Tavas was investigated. The ore was activated mechanically in a planetary mill and the amorphisation in manganese structure was analyzed with X-ray diffraction. The parameters in acidic leaching of the ore were milling time, acid concentration and time. All experiments were performed at 25°C with solid to liquid ratio: 1/10. The activation procedure led to amorphization and structural disordering in manganese ore and accelerated the dissolution of manganese in acidic media.

  4. A survey of neurobehavioral symptoms of welders exposed to manganese

    H Hassani


    Conclusion: Welders’ exposure to manganese and its potential health effects should be evaluated periodically and effective control measures should be applied in order to to prevent neurobehavioral symptoms.

  5. Manganese-enhanced magnetic resonance microscopy of mineralization

    Chesnick, I.E.; Todorov, T.I.; Centeno, J.A.; Newbury, D.E.; Small, J.A.; Potter, K.


    Paramagnetic manganese (II) can be employed as a calcium surrogate to sensitize magnetic resonance microscopy (MRM) to the processing of calcium during bone formation. At high doses, osteoblasts can take up sufficient quantities of manganese, resulting in marked changes in water proton T1, T2 and magnetization transfer ratio values compared to those for untreated cells. Accordingly, inductively coupled plasma mass spectrometry (ICP-MS) results confirm that the manganese content of treated cell pellets was 10-fold higher than that for untreated cell pellets. To establish that manganese is processed like calcium and deposited as bone, calvaria from the skull of embryonic chicks were grown in culture medium supplemented with 1 mM MnCl2 and 3 mM CaCl2. A banding pattern of high and low T2 values, consistent with mineral deposits with high and low levels of manganese, was observed radiating from the calvarial ridge. The results of ICP-MS studies confirm that manganese-treated calvaria take up increasing amounts of manganese with time in culture. Finally, elemental mapping studies with electron probe microanalysis confirmed local variations in the manganese content of bone newly deposited on the calvarial surface. This is the first reported use of manganese-enhanced MRM to study the process whereby calcium is taken up by osteoblasts cells and deposited as bone. ?? 2007 Elsevier Inc. All rights reserved.

  6. Synthesis and Crystal Structure of a New Manganese Complex

    WANG Jian; LIU Ping; CHEN Yun


    @@ In order to study the relationship between the manganese ion and the biological coordination agent, the role ofmanganese ion in the active sites and the structure of the active sites in the manganese enzymes, small molecule complexes are often applied to modeling the structure and the properties of reaction in the active centers. In this pa per, we will report the synthesis and crystal structure of a new manganese(Ⅱ) complex, catena[ aqua-(p-methoxybenzoato- O, O′ ) - (p-methoxybenzoato- O )- (2,2′-bipyridine)-manganese (Ⅱ) ] (p-methoxybenzoic acid). The crystal structure was confirmeded by X-ray crystallography analysis.

  7. Restoration of growth by manganese in a mutant strain of Escherichia coli lacking most known iron and manganese uptake systems

    Taudte, Nadine; German, Nadezhda; Zhu, Yong-Guan


    The interplay of manganese and iron homeostasis and oxidative stress in Escherichia coli can give important insights into survival of bacteria in the phagosome and under differing iron or manganese bioavailabilities. Here, we characterized a mutant strain devoid of all know iron/manganese......-uptake systems relevant for growth in defined medium. Based on these results an exit strategy enabling the cell to cope with iron depletion and use of manganese as an alternative for iron could be shown. Such a strategy would also explain why E. coli harbors some iron- or manganese-dependent iso......-enzymes such as superoxide dismutases or ribonucleotide reductases. The benefits for gaining a means for survival would be bought with the cost of less efficient metabolism as indicated in our experiments by lower cell densities with manganese than with iron. In addition, this strain was extremely sensitive to the metalloid...

  8. Nanostructured manganese oxides as highly active water oxidation catalysts: a boost from manganese precursor chemistry.

    Menezes, Prashanth W; Indra, Arindam; Littlewood, Patrick; Schwarze, Michael; Göbel, Caren; Schomäcker, Reinhard; Driess, Matthias


    We present a facile synthesis of bioinspired manganese oxides for chemical and photocatalytic water oxidation, starting from a reliable and versatile manganese(II) oxalate single-source precursor (SSP) accessible through an inverse micellar molecular approach. Strikingly, thermal decomposition of the latter precursor in various environments (air, nitrogen, and vacuum) led to the three different mineral phases of bixbyite (Mn2 O3 ), hausmannite (Mn3 O4 ), and manganosite (MnO). Initial chemical water oxidation experiments using ceric ammonium nitrate (CAN) gave the maximum catalytic activity for Mn2 O3 and MnO whereas Mn3 O4 had a limited activity. The substantial increase in the catalytic activity of MnO in chemical water oxidation was demonstrated by the fact that a phase transformation occurs at the surface from nanocrystalline MnO into an amorphous MnOx (1water oxidation in the presence of [Ru(bpy)3 ](2+) (bpy=2,2'-bipyridine) as a sensitizer and peroxodisulfate as an electron acceptor was carried out for all three manganese oxides including the newly formed amorphous MnOx . Both Mn2 O3 and the amorphous MnOx exhibit tremendous enhancement in oxygen evolution during photocatalysis and are much higher in comparison to so far known bioinspired manganese oxides and calcium-manganese oxides. Also, for the first time, a new approach for the representation of activities of water oxidation catalysts has been proposed by determining the amount of accessible manganese centers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. [Early Detection of Manganese Intoxication Based on Occupational History and T1-weighted MRI].

    Fukutake, Toshio; Yano, Hajime; Kushida, Ryutaro; Sunada, Yoshihide


    Manganese regulates many enzymes and is essential for normal cell function. Chronic manganese intoxication has an insidious and progressive course terminating to atypical parkinsonism with little therapeutic efficacy. For subjects with chronic manganese exposure such as welders, manganese intoxication can be detected early based on the presence of hyperintensity in the globus pallidus on T(1)-weighted MRI and abnormally high urinary excretion of manganese with a chelating agent even in cases of normal serum/urine level of manganese.

  10. VERTEX: manganese transport through oxygen minima

    Martin, John H.; Knauer, George A.


    Manganese transport through a well-developed oxygen minimum was studied off central Mexico (18°N, 108°W) in October-November 1981 as part of the VERTEX (Vertical Transport and Exchange) research program. Refractory, leachable and dissolved Mn fractions associated with particulates caught in traps set at eight depths (120-1950 m) were analyzed. Particles entering the oxygen minimum had relatively large Mn loads; however, as the particulates sank further into the minimum, total Mn fluxes steadily decreased from 190 nmol m -2 day -1 at 120 m to 36 nmol m -2 day -1 at 400 m. Manganese fluxes then steadily increased in the remaining 800-1950 m, reaching rates of up to 230 nmol m -2 day -1 at 1950 m. Manganese concentrations were also measured in the water column. Dissolved Mn levels Rate-of-change estimates based on trap flux data yield regeneration rates of up to 0.44 nmol kg -1 yr -1 in the upper oxygen minimum (120-200 m). However, only 30% of the dissolved Mn in the oxygen minimum appears to be from sinking particulate regeneration; the other 70% probably results from continental-slope-release-horizontal-transport processes. Dissolved Mn scavenges back onto particles as oxygen levels begin to increase with depth. Scavenging rates ranging from -0.03 to -0.09 nmol kg -1 yr -1 were observed at depths from 700 to 1950 m. These scavenging rates result in Mn residence times of 16-19 years, and scavenging rate constants on the order of 0.057 yr -1. Manganese removal via scavenging on sinking particles below the oxygen minimum is balanced by Mn released along continental boundaries and transported horizontally via advective-diffusive processes. Manganese appears to be very weakly associated with particulates. Nevertheless, the amounts of Mn involved with sinking biogenic particles are large, and the resulting fluxes are on the same order of magnitude as those necessary to explain the excess Mn accumulating on the sea floor. The overall behavior of Mn observed in this, and

  11. Electrolytic hydrogen fuel production with solid polymer electrolyte technology.

    Titterington, W. A.; Fickett, A. P.


    A water electrolysis technology based on a solid polymer electrolyte (SPE) concept is presented for applicability to large-scale hydrogen production in a future energy system. High cell current density operation is selected for the application, and supporting cell test performance data are presented. Demonstrated cell life data are included to support the adaptability of the SPE system to large-size hydrogen generation utility plants as needed for bulk energy storage or transmission. The inherent system advantages of the acid SPE electrolysis technology are explained. System performance predictions are made through the year 2000, along with plant capital and operating cost projections.

  12. Nanocomposite polymer electrolyte for rechargeable magnesium batteries

    Shao, Yuyan; Rajput, Nav Nidhi; Hu, Jian Z.; Hu, Mary Y.; Liu, Tianbiao L.; Wei, Zhehao; Gu, Meng; Deng, Xuchu; Xu, Suochang; Han, Kee Sung; Wang, Jiulin; Nie, Zimin; Li, Guosheng; Zavadil, K.; Xiao, Jie; Wang, Chong M.; Henderson, Wesley A.; Zhang, Jiguang; Wang, Yong; Mueller, Karl T.; Persson, Kristin A.; Liu, Jun


    Nanocomposite polymer electrolytes present new opportunities for rechargeable magnesium batteries. However, few polymer electrolytes have demonstrated reversible Mg deposition/dissolution and those that have still contain volatile liquids such as tetrahydrofuran (THF). In this work, we report a nanocomposite polymer electrolyte based on poly(ethylene oxide) (PEO), Mg(BH4)2 and MgO nanoparticles for rechargeable Mg batteries. Cells with this electrolyte have a high coulombic efficiency of 98% for Mg plating/stripping and a high cycling stability. Through combined experiment-modeling investigations, a correlation between improved solvation of the salt and solvent chain length, chelation and oxygen denticity is established. Following the same trend, the nanocomposite polymer electrolyte is inferred to enhance the dissociation of the salt Mg(BH4)2 and thus improve the electrochemical performance. The insights and design metrics thus obtained may be used in nanocomposite electrolytes for other multivalent systems.

  13. Electrolyte Additives for Phosphoric Acid Fuel Cells

    Gang, Xiao; Hjuler, H.A.; Olsen, C.A.


    Electrochemical characteristics of a series of modified phosphoric acid electrolytes containing fluorinated car on compounds and silicone fluids as additives are presented. When used in phosphoric acid fuel cells, the modified electrolytes improve the performance due to the enhanced oxygen...... reduction rate. Among useful additives we found potassium perfluorohexanesulfonate (C6F13SO3K), potassium nonafluorobutanesulfonate (C4F9SO3K), perfluorotributylamine [(C4F9)3N], and polymethylsiloxanes [(-Si(CH3)2O-)n]. The wettability of the electrodes by the modified electrolytes also is discussed......, as a fuel-cell performance with the modified electrolytes. Specific conductivity measurements of some of the modified phosphoric acid electrolytes are reported. At a given temperature, the conductivity of the C4F9SO3K-modified electrolyte decreases with an increasing amount of the additive; the conductivity...

  14. Adsorption of Zn2+ from solutions on manganese oxide obtained via ozone precipitation reaction

    Contreras-Bustos Roberto


    Full Text Available Synthesis via ozone precipitation reaction was used to obtain manganese dioxide (OMD and it was probed as an adsorbent for zinc ions. Adsorption was followed along shaking time and increasing ratio [NO3−] / [Zn2+], and isotherms were obtained at different pH values and in the presence of several anions (chloride, nitrate, sulphate, and acetate. It was found that adsorption equilibrium is fast and follows the pseudo-second order model (qe = 34 ±1 mg/g and K = 0.07 ±0.01 g/mg h. Isotherms were fitted to Langmuir, Freundlich, and Langmuir-Freundlich models, and the best fitting was found with the last one. The process is dependent on pH and the efficiency increases from pH 1 to 4. The ratio [NO3−] / [Zn2+] up to 3 does not seem to change the behaviour of the process. Regarding the anions, the efficiency of Zn(II adsorption occurs according to: acetate > nitrate and sulphate > chloride. Manganese oxide obtained via ozonization is an excellent adsorbent for zinc ions.

  15. Inorganic-organic electrolyte materials for energy applications

    Fei, Shih-To

    emphasizes the flammability studies. Chapter 4 expands the application of the ethyleneoxy phosphazene system to dye sensitized solar cell systems, and uses this material as a model for the study of electrode-electrolyte interfaces. We report here the results of our study on polymer electrolyte infiltration and its effect on dye-sensitized solar cells. In-depth studies have been made to compare the effects of different cell assembly procedures on the electrochemical properties as well as infiltration of electrolytes into various electrode designs. The first part of the study is based on the use of thermoplastic phosphazene electrolytes and how the overall fabrication procedure affects electrochemical performance, and the second is the use of cross-section microscopy to characterize the degree of electrolyte infiltration into various nanostructured titanium dioxide electrode surfaces. The results of this study should eventually improve the efficiency and longevity of thermally stable polymer dye solar cell systems. In Chapter 5 the effect of pendant polymer design on methanol fuel cell membrane performance was investigated. A synthetic method is described to produce a proton conductive polymer membrane with a polynorbornane backbone and inorganic-organic cyclic phosphazene pendent groups that bear sulfonic acid units. This hybrid polymer combines the inherent hydrophobicity and flexibility of the organic polymer with the tuning advantages of the cyclic phosphazene to produce a membrane with high proton conductivity and low methanol crossover at room temperature. The ion exchange capacity (IEC), the water swelling behavior of the polymer, and the effect of gamma radiation crosslinking were studied, together with the proton conductivity and methanol permeability of these materials. A typical membrane had an IEC of 0.329 mmolg-1 and had water swelling of 50 wt%. The maximum proton conductivity of 1.13x10 -4 Scm-1 at room temperature is less than values reported for some

  16. Manganese Catalyzed C-H Halogenation.

    Liu, Wei; Groves, John T


    The remarkable aliphatic C-H hydroxylations catalyzed by the heme-containing enzyme, cytochrome P450, have attracted sustained attention for more than four decades. The effectiveness of P450 enzymes as highly selective biocatalysts for a wide range of oxygenation reactions of complex substrates has driven chemists to develop synthetic metalloporphyrin model compounds that mimic P450 reactivity. Among various known metalloporphyrins, manganese derivatives have received considerable attention since they have been shown to be versatile and powerful mediators for alkane hydroxylation and olefin epoxidation. Mechanistic studies have shown that the key intermediates of the manganese porphyrin-catalyzed oxygenation reactions include oxo- and dioxomanganese(V) species that transfer an oxygen atom to the substrate through a hydrogen abstraction/oxygen recombination pathway known as the oxygen rebound mechanism. Application of manganese porphyrins has been largely restricted to catalysis of oxygenation reactions until recently, however, due to ultrafast oxygen transfer rates. In this Account, we discuss recently developed carbon-halogen bond formation, including fluorination reactions catalyzed by manganese porphyrins and related salen species. We found that biphasic sodium hypochlorite/manganese porphyrin systems can efficiently and selectively convert even unactivated aliphatic C-H bonds to C-Cl bonds. An understanding of this novel reactivity derived from results obtained for the oxidation of the mechanistically diagnostic substrate and radical clock, norcarane. Significantly, the oxygen rebound rate in Mn-mediated hydroxylation is highly correlated with the nature of the trans-axial ligands bound to the manganese center (L-Mn(V)═O). Based on the ability of fluoride ion to decelerate the oxygen rebound step, we envisaged that a relatively long-lived substrate radical could be trapped by a Mn-F fluorine source, effecting carbon-fluorine bond formation. Indeed, this idea

  17. Chemical stability of γ-butyrolactone-based electrolytes for aluminum electrolytic capacitors

    Ue, Makoto; Takeda, Masayuki; Suzuki, Yoko; Mori, Shoichiro

    γ-Butyrolactone-based electrolytes have been used as the operating electrolytes for aluminum electrolytic capacitors. The chemical stability of these electrolytes at elevated temperatures has been examined by monitoring the decrease in their electrolytic conductivities. The deteriorated electrolytes were analyzed by gas and liquid chromatography and the conductivity decrease was directly correlated with the loss of acid components. In quaternary ammonium hydrogen maleate/γ-butyrolactone electrolytes, the maleate anion decomposed by decarboxylation resulting in a complex polymer containing polyester and polyacrylate structures. Quaternary ammonium benzoate/γ-butyrolactoneelectrolytes decomposed by SN2 reactions giving alkyi benzoates and trialkylamines. The deterioration of the carboxylate salt/γ-butyrolactone electrolytes was accelerated by electrolysis.

  18. Investigation of electrolyte electric discharge characteristics

    Kirko, D. L.; Savjolov, A. S.


    The most important electrical characteristics of electrolyte electric discharge were investigated. The electric burning discharge was obtained with the help of different electrolytes. The spectral composition of the electric discharge electromagnetic radiation was determined, the plasma temperature was determined. The spectrum of the electric discharge high-frequency oscillations was calculated in the region v=10 kHz-80 MHz. The most appropriate modes of the electric burning discharge in different electrolytes were proposed.

  19. Solid electrolytes general principles, characterization, materials, applications

    Hagenmuller, Paul


    Solid Electrolytes: General Principles, Characterization, Materials, Applications presents specific theories and experimental methods in the field of superionic conductors. It discusses that high ionic conductivity in solids requires specific structural and energetic conditions. It addresses the problems involved in the study and use of solid electrolytes. Some of the topics covered in the book are the introduction to the theory of solid electrolytes; macroscopic evidence for liquid nature; structural models; kinetic models; crystal structures and fast ionic conduction; interstitial motion in

  20. Fuel cell assembly with electrolyte transport

    Chi, Chang V.


    A fuel cell assembly wherein electrolyte for filling the fuel cell matrix is carried via a transport system comprising a first passage means for conveying electrolyte through a first plate and communicating with a groove in a second plate at a first point, the first and second plates together sandwiching the matrix, and second passage means acting to carry electrolyte exclusively through the second plate and communicating with the groove at a second point exclusive of the first point.

  1. Solid-oxide fuel cell electrolyte

    Bloom, I.D.; Hash, M.C.; Krumpelt, M.


    This invention is comprised of a solid-oxide electrolyte operable at between 600{degrees}C and 800{degrees}C and a method of producing the solid-oxide electrolyte. The solid-oxide electrolyte comprises a combination of a compound having a weak metal-oxygen interactions with a compound having stronger metal-oxygen interactions whereby the resulting combination has both strong and weak metal-oxygen interaction properties.

  2. Novel Electrolytes for Lithium Ion Batteries

    Lucht, Brett L. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Chemistry


    We have been investigating three primary areas related to lithium ion battery electrolytes. First, we have been investigating the thermal stability of novel electrolytes for lithium ion batteries, in particular borate based salts. Second, we have been investigating novel additives to improve the calendar life of lithium ion batteries. Third, we have been investigating the thermal decomposition reactions of electrolytes for lithium-oxygen batteries.

  3. Influence of gaseous atmosphere during a thermal process for recovery of manganese and zinc from spent batteries

    Belardi, G.; Medici, F.; Piga, L.


    The aim of the work is the recovery by thermal treatment of manganese and zinc from a mixture of zinc-carbon and alkaline spent batteries, due to the different phase change temperatures of the metals. Activated charcoal, as a reductant of the zinc-bearing phases to metallic Zn, was added to the mixture that was heated in different atmospheres (air, nitrogen, carbon dioxide) at different temperatures and residence times. Characterization of the mixture and of the residues of thermal treatment was carried out by chemical analysis, thermogravimetric and differential thermal analysis, scanning electron microscope and X-ray diffraction and allowed to understand the mechanisms of reduction of zinc and to interpret the formation of different compounds during the process. Results show that recovery of 99% of Zn (grade 96%) at 1200 °C and 97% of Zn (grade 99%) at 1000 °C, are achieved in N2 at 30 min residence time. Recovery of Mn at 1200 °C and 30 min residence time was around 90-100% (90% grade). These products are suitable, after refining, for production of new batteries or higher value-added products. The residue of the treatment, enriched in manganese oxide, could be used in the production of iron-manganese alloys.

  4. Rebalancing electrolytes in redox flow battery systems

    Chang, On Kok; Pham, Ai Quoc


    Embodiments of redox flow battery rebalancing systems include a system for reacting an unbalanced flow battery electrolyte with a rebalance electrolyte in a first reaction cell. In some embodiments, the rebalance electrolyte may contain ferrous iron (Fe.sup.2+) which may be oxidized to ferric iron (Fe.sup.3+) in the first reaction cell. The reducing ability of the rebalance reactant may be restored in a second rebalance cell that is configured to reduce the ferric iron in the rebalance electrolyte back into ferrous iron through a reaction with metallic iron.

  5. [FTIR investigation of new polymer solid electrolytes].

    Yang, Shu-ting; Chen, Hong-jun; Dong, Hong-yu; Jia, Jun-hua; Cao, Zhao-xia


    The conductivity of the porous polymer solid electrolyte blended with PVDF and PMMA, which was made by a micro-wave hot-cross-linking method, reached 2.05 x 10(-3) S x cm(-1) at room temperature. The polymer solid electrolyte was analyzed and investigated by FTIR. The results show that the PVDF, PMMA and LiClO4 in the polymer solid electrolyte were not simply blended, but certain kind of effect existed which was strengthened only when the polymer solid electrolyte came into being.

  6. Electrodeposition of Fe powder from acid electrolytes



    Full Text Available Polarization characteristics of the electrodeposition processes of Fe powders from sulfate and chloride electrolytes and the morphology of the obtained powders were investigated. The morphology depended on the anion presence in the electrolyte but not on the current density in the investigated range. A characteristic feature of the dendritic powder with cauliflower endings obtained from sulfate electrolyte is the presence of cone-like cavities and the crystallite morphology of the powders surface. On the other hand, Fe powders electrodeposited from chloride electrolyte appear in the form of agglomerates. A soap solution treatment applied as a method of washing and drying provides good protection from oxidation of the powders.

  7. Drug delivery device including electrolytic pump

    Foulds, Ian G.


    Systems and methods are provided for a drug delivery device and use of the device for drug delivery. In various aspects, the drug delivery device combines a “solid drug in reservoir” (SDR) system with an electrolytic pump. In various aspects an improved electrolytic pump is provided including, in particular, an improved electrolytic pump for use with a drug delivery device, for example an implantable drug delivery device. A catalytic reformer can be incorporated in a periodically pulsed electrolytic pump to provide stable pumping performance and reduced actuation cycle.




    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  9. Role of Amorphous Manganese Oxide in Nitrogen Loss



    Studies have been made,by 15N-tracer technique on nitrogen loss resulting from adding amorphous manganese oxide to NH4+-N medium under anaerobic conditions.The fact that the total nitrogen recovery was decreased and that 15NO2,15N2O,15N14NO,15NO,15N2 and 15N14N were emitted has proved that,like amorphous iron oxide,amorphous manganese oxide can also act as an electron acceptor in the oxidation of NH4+-N under anaerobic conditions and give rise to nitrogen loss.This once again illustrates another mechanism by which the loss of ammonium nitrogen in paddy soils is brought about by amorphous iron and manganese oxides.The quantity of nitrogen loss by amorphous manganese oxide increased with an increase in the amount of amorphous manganese oxide added and lessened with time of its aging.The nitrogen loss resulting from amorphous manganese oxide was less than that from amorphous iron oxide.And the nitrogen loss resulting from amorphous manganese oxide was less than that from amorphous iron oxide.And the nitrogen loss by cooperation of amorphous manganese oxide and microorganisms (soil suspension) was larger than that by amorphous manganese oxide alone.In the system,nitrogen loss was associated with the specific surface ares and oxidation-reduction of amorphous manganese oxide.However,their quantitative relationship and the exact reaction processes of nitrogen loss induced by amorphous manganese oxide remain to be further studied.

  10. Electrolytic Passivation of Nitinol Shape Memory Alloy in Different Electrolytes

    SU Xiang-dong; WANG Tian-min; HAO Wei-chang; HE Li


    The corrosion behavior of the nitinol alloy was studied in various corrosion media of different Cl- ion concentrations. The results demonstrate that the Cl- ion concentration has significant influences on the corrosion behavior of the nitinol alloy. In order to enhance the corrosion resistance, protective films were generated on the surface of the nitinol alloy by means of the electrochemical passivation method, for which five different electrolytic solutions were investigated. The surface analysis indicates full growth of all samples passivated in the different electrolytic solutions with layers, however, showing different morphological features. Without any defects like micro-cracks and pores, the surface of the samples passivated in the molybdate solution turns out smoother and denser than those passivated in other solutions. It is shown that the electro-chemical passivation will reduce Ni content but increase Ti content in the surface, reaching the Mole ratio of Ti:Ni = 9.01:1 on the outermost surface. Potentiodynamic polarization test demonstrates that the samples electrochemically passivated in the molybdate solution present a significant increase in breakdown potential due to titanium enrichment on the outermost surface.

  11. Interfacial behavior of polymer electrolytes

    Kerr, John; Kerr, John B.; Han, Yong Bong; Liu, Gao; Reeder, Craig; Xie, Jiangbing; Sun, Xiaoguang


    Evidence is presented concerning the effect of surfaces on the segmental motion of PEO-based polymer electrolytes in lithium batteries. For dry systems with no moisture the effect of surfaces of nano-particle fillers is to inhibit the segmental motion and to reduce the lithium ion transport. These effects also occur at the surfaces in composite electrodes that contain considerable quantities of carbon black nano-particles for electronic connection. The problem of reduced polymer mobility is compounded by the generation of salt concentration gradients within the composite electrode. Highly concentrated polymer electrolytes have reduced transport properties due to the increased ionic cross-linking. Combined with the interfacial interactions this leads to the generation of low mobility electrolyte layers within the electrode and to loss of capacity and power capability. It is shown that even with planar lithium metal electrodes the concentration gradients can significantly impact the interfacial impedance. The interfacial impedance of lithium/PEO-LiTFSI cells varies depending upon the time elapsed since current was turned off after polarization. The behavior is consistent with relaxation of the salt concentration gradients and indicates that a portion of the interfacial impedance usually attributed to the SEI layer is due to concentrated salt solutions next to the electrode surfaces that are very resistive. These resistive layers may undergo actual phase changes in a non-uniform manner and the possible role of the reduced mobility polymer layers in dendrite initiation and growth is also explored. It is concluded that PEO and ethylene oxide-based polymers are less than ideal with respect to this interfacial behavior.

  12. Chlorine dioxide and hemodialysis

    Smith, R.P. (Dartmouth Coll., Hanover, NH (USA). Dept. of Pharmacology and Toxicology)


    Because it has little or no tendency to generate carcinogenic trihalomethanes such as chloroform, chlorine dioxide is an attractive alternative to chlorine for drinking water disinfection. There are, however, concerns about its acute toxicity, and the toxic effects of its by-products, chlorite and chlorate. The human experience with chlorine dioxide in both controlled, prospective studies and in actual use situations in community water supplies have as yet failed to reveal adverse health effects. The EPA has recommended standards of 0.06 mg/L for chlorine dioxide and standards of 0.007 mg/L for chlorite and chlorate in drinking water. Among groups who may be at special risk from oxychlorines in drinking water are patients who must undergro chronic extracorporeal hemodialysis. Although even units for home hemodialysis are supposed to be equipped with devices which effectively remove oxychlorines, there is a always a possibility of operator error or equipment failure. When the equipment is adequately maintained, it is likely that dialysis patients will have more intensive exposures from drinking water than from dialysis fluids despite the much larger volumes of water that are involved in dialysis. This paper discusses a hemodialysis and the standards and effects of oxychlorines. 90 refs., 2 tabs.

  13. Molecular identification of indigenous manganese solubilising bacterial biodiversity from manganese mining deposits.

    Ghosh, Shreya; Mohanty, Sansuta; Nayak, Sanghamitra; Sukla, Lala B; Das, Alok P


    Manganese (Mn) ranks twelfth among the most exuberant metal present in the earth's crust and finds its imperative application in the manufacturing steel, chemical, tannery, glass, and battery industries. Solubilisation of Mn can be performed by several bacterial strains which are useful in developing environmental friendly solutions for mining activities. The present investigation aims to isolate and characterize Mn solubilising bacteria from low grade ores from Sanindipur Manganese mine of Sundargh district in Odisha state of India. Four morphologically distinct bacterial strains showing visible growth on Mn supplemented plates were isolated. Mn solubilising ability of the bacterial strains was assessed by visualizing the lightening of the medium appearing around the growing colonies. Three isolates were gram negative and rod shaped while the remaining one was gram positive, coccobacilli. Molecular identification of the isolates was carried out by 16S rRNA sequencing and the bacterial isolates were taxonomically classified as Bacillus anthrasis MSB 2, Acinetobacter sp. MSB 5, Lysinibacillus sp. MSB 11, and Bacillus sp. MMR-1 using BLAST algorithm. The sequences were deposited in NCBI GenBank with the accession number KP635223, KP635224, KP635225 and JQ936966, respectively. Manganese solubilisation efficiency of 40, 96, 97.5 and 48.5% were achieved by MMR-1, MSB 2, MSB 5 and MSB 11 respectively. The efficiency of Mn solubilisation is suggested with the help of a pH variation study. The results are discussed in relation to the possible mechanisms involved in Manganese solubilisation efficiency of bacterial isolates.

  14. Manganese Loading and Photosystem II Stability are Key Components of Manganese Efficiency in Plants

    Schmidt, Sidsel Birkelund

    Manganese (Mn) deficiency constitutes a major plant nutritional problem in commercial crop production of winter cereals. In plants, Mn has an indispensable role in the oxygen evolving complex (OEC) of photosystem II (PSII). Hence, the consequences of Mn deficiency are reduced plant growth...


    Guanli Xu; Lina Xu; Shunlong Pan; Guangzhi Song


    The effect of polyethyleneimine (PEI) concentration on the properties of titanium dioxide (TiO2) suspensions is studied with or without the addition of an electrolyte (barium acetate). Measurements of the apparent viscosity and the stability of TiO2 suspensions showed that PEI is an effective dispersant for TiO2 particles in suspension in the absence of an electrolyte, not only reducing the viscosity of the suspension but also increasing its stability. In the presence of an electrolyte, however, small quantities of polyethyleneimine could neither disperse the TiO2 particles nor decrease the viscosity of the TiO2 suspensions; only PEI concentrations beyond saturation adsorption could perceptively improve the stability of TiO2 suspensions.

  16. Combined Electron Paramagnetic Resonance and Atomic Absorption Spectroscopy/Inductively Coupled Plasma Analysis As Diagnostics for Soluble Manganese Species from Mn-Based Positive Electrode Materials in Li-ion Cells.

    Shilina, Yuliya; Ziv, Baruch; Meir, Aviv; Banerjee, Anjan; Ruthstein, Sharon; Luski, Shalom; Aurbach, Doron; Halalay, Ion C


    Manganese dissolution from positive electrodes significantly reduces the durability of lithium-ion batteries. Knowledge of dissolution rates and oxidation states of manganese ions is essential for designing effective mitigation measures for this problem. We show that electron paramagnetic resonance (EPR) combined with atomic absorption spectroscopy (AAS) or inductively coupled plasma (ICP) can determine both manganese dissolution rates and relative Mn(3+) amounts, by comparing the correlation between EPR and AAS/ICP data for Mn(2+) standards with that for samples containing manganese cations dissolved from active materials (LiMn2O4 (LMO) and LiNi(0.5)Mn(1.5)O4 (LNMO)) into the same electrolyte solution. We show that Mn(3+), and not Mn(2+), is the dominant species dissolved from LMO, while Mn(2+) is predominant for LNMO. Although the dissolution rate of LMO varies significantly for the two investigated materials, due to particle morphology and the presence of Cr in one of them, the Mn speciation appears independent of such details. Thus, the relative abundance of dissolved manganese ions in various oxidation states depends mainly on the overall chemical identity of the active material (LMO vs LNMO). We demonstrate the relevance of our methodology for practical batteries with data for graphite-LMO cells after high-temperature cycling or stand at 4.2 V.

  17. Adsorptive removal of manganese, arsenic and iron from groundwater

    Buamah, R.


    Arsenic, manganese and iron in drinking water at concentrations exceeding recommended guideline values pose health risks and aesthetic defects. Batch and pilot experiments on manganese adsorption equilibrium and kinetics using iron-oxide coated sand (IOCS), Aquamandix and other media have been

  18. Adsorptive removal of manganese, arsenic and iron from groundwater

    Buamah, R.


    Arsenic, manganese and iron in drinking water at concentrations exceeding recommended guideline values pose health risks and aesthetic defects. Batch and pilot experiments on manganese adsorption equilibrium and kinetics using iron-oxide coated sand (IOCS), Aquamandix and other media have been inve

  19. Plasma electrolytic oxidation of AMCs

    Morgenstern, R.; Sieber, M.; Lampke, T.


    Aluminum Matrix Composites (AMCs) consisting of high-strength alloys and ceramic reinforcement phases exhibit a high potential for security relevant lightweight components due to their high specific mechanical properties. However, their application as tribologically stressed components is limited because of their susceptibility against fatigue wear and delamination wear. Oxide ceramic protective coatings produced by plasma electrolytic oxidation (PEO) can solve these problems and extend the possible applications of AMCs. The substrate material was powder metallurgically processed using alloy EN AW 2017 and SiC or Al2O3 particles. The influence of material properties like particle type, size and volume fraction on coating characteristics is clarified within this work. An alkaline silicate electrolyte was used to produce PEO coatings with technically relevant thicknesses under bipolar-pulsed current conditions. Coating properties were evaluated with regard to morphology, chemical composition, hardness and wear resistance. The particle type proved to have the most significant effect on the coating properties. Whereas compactness and thickness are not deteriorated by the incorporation of thermodynamically stable alumina particles, the decomposition of silica particles during the PEO processes causes an increase of the porosity. The higher silica particle content decreases also the coating thickness and hardness, which leads in particular to reduction of the wear resistance of the PEO coatings. Finally, different approaches for the reduction of the coating porosity of silica reinforced AMCs are discussed.

  20. Plasma electrolytic oxidation of metals

    Stojadinović Stevan


    Full Text Available In this lecture results of the investigation of plasma electrolytic oxidation (PEO process on some metals (aluminum, titanium, tantalum, magnesium, and zirconium were presented. Whole process involves anodizing metals above the dielectric breakdown voltage where numerous micro-discharges are generated continuously over the coating surface. For the characterization of PEO process optical emission spectroscopy and real-time imaging were used. These investigations enabled the determination of electron temperature, electron number density, spatial density of micro-discharges, the active surface covered by micro-discharges, and dimensional distribution of micro-discharges at various stages of PEO process. Special attention was focused on the results of the study of the morphology, chemical, and phase composition of oxide layers obtained by PEO process on aluminum, tantalum, and titanium in electrolytes containing tungsten. Physicochemical methodes: atomic force microscopy (AFM, scanning electron microscopy (SEM-EDS, x-ray diffraction (XRD, x-ray photoelectron spectroscopy (XPS, and Raman spectroscopy served as tools for examining obtained oxide coatings. Also, the application of the obtained oxide coatings, especially the application of TiO2/WO3 coatings in photocatalysis, were discussed.

  1. An analysis of the thermal decomposition reactions of organic electrolytes used in lithium-ion batteries

    Campion, Christopher Lawrence

    The thermal decomposition of LiPF6 in solution with carbonate solvents has been investigated. The thermal dissociation of LiPF6 into LiF and PF5 is known. In solution, PF 5 reacts with carbonates to form a variety of decomposition products including: carbon dioxide (CO2), ethers (R2O), alkylfluorides (RF), phosphorus oxyfluoride (OPF3), and fluorophosphates (OPF 2OR, OPF(OR)2), assignment of structure is supported by Nuclear Magnetic Resonance (NMR) spectroscopy and Gas Chromatography with Mass Selective Detection (GC-MS). Similar decomposition products are observed during the thermal decomposition of carbonate solutions of LiPF6. Since solutions of LiPF6 are widely used as Li-ion battery electrolytes, there is interest among battery manufacturers and researchers as to the thermal decomposition of this electrolyte. Here we describe the structural and mechanistic investigations of the thermal decomposition of lithium-ion battery electrolytes. The electrolyte undergoes autocatalytic decomposition reactions at moderately elevated temperatures (80--100°C) to produce a large number of decomposition products. Results indicate that the thermal decomposition reactions are suppressed by the electrode, particularly the cathode, or intended stabilizing additives.

  2. Identification and Characterization of a Putative Manganese Export Protein in Vibrio cholerae.

    Fisher, Carolyn R; Wyckoff, Elizabeth E; Peng, Eric D; Payne, Shelley M


    Manganese plays an important role in the cellular physiology and metabolism of bacterial species, including the human pathogen Vibrio cholerae The intracellular level of manganese ions is controlled through coordinated regulation of the import and export of this element. We have identified a putative manganese exporter (VC0022), named mneA (manganese exporter A), which is highly conserved among Vibrio spp. An mneA mutant exhibited sensitivity to manganese but not to other cations. Under high-manganese conditions, the mneA mutant showed an almost 50-fold increase in intracellular manganese levels and reduced intracellular iron relative to those of its wild-type parent, suggesting that the mutant's manganese sensitivity is due to the accumulation of toxic levels of manganese and reduced iron. Expression of mneA suppressed the manganese-sensitive phenotype of an Escherichia coli strain carrying a mutation in the nonhomologous manganese export gene, mntP, further supporting a manganese export function for V. cholerae MneA. The level of mneA mRNA was induced approximately 2.5-fold after addition of manganese to the medium, indicating regulation of this gene by manganese. This study offers the first insights into understanding manganese homeostasis in this important pathogen. Bacterial cells control intracellular metal concentrations by coordinating acquisition in metal-limited environments with export in metal-excess environments. We identified a putative manganese export protein, MneA, in Vibrio cholerae An mneA mutant was sensitive to manganese, and this effect was specific to manganese. The mneA mutant accumulated high levels of intracellular manganese with a concomitant decrease in intracellular iron levels when grown in manganese-supplemented medium. Expression of mneA in trans suppressed the manganese sensitivity of an E. coli mntP mutant. This study is the first to investigate manganese export in V. cholerae. Copyright © 2016, American Society for Microbiology

  3. Biodistribution and PET Imaging of pharmacokinetics of manganese in mice using Manganese-52.

    Wooten, A Lake; Aweda, Tolulope A; Lewis, Benjamin C; Gross, Rebecca B; Lapi, Suzanne E


    Manganese is essential to life, and humans typically absorb sufficient quantities of this element from a normal healthy diet; however, chronic, elevated ingestion or inhalation of manganese can be neurotoxic, potentially leading to manganism. Although imaging of large amounts of accumulated Mn(II) is possible by MRI, quantitative measurement of the biodistribution of manganese, particularly at the trace level, can be challenging. In this study, we produced the positron-emitting radionuclide 52Mn (t1/2 = 5.6 d) by proton bombardment (EpManganese is known to cross the blood-brain barrier, as confirmed in our studies following IV injection (0.86%ID/g, 1 d p.i.) and following inhalation of aerosol, (0.31%ID/g, 1 d p.i.). Uptake in salivary gland and pancreas were observed at 1 d p.i. (0.5 and 0.8%ID/g), but to a much greater degree from IV injection (6.8 and 10%ID/g). In a separate study, mice received IV injection of an imaging dose of [52Mn]MnCl2, followed by in vivo imaging by positron emission tomography (PET) and ex vivo biodistribution. The results from this study supported many of the results from the biodistribution-only studies. In this work, we have confirmed results in the literature and contributed new results for the biodistribution of inhaled radiomanganese for several organs. Our results could serve as supporting information for environmental and occupational regulations, for designing PET studies utilizing 52Mn, and/or for predicting the biodistribution of manganese-based MR contrast agents.

  4. Reaction products of chlorine dioxide.

    Stevens, A A


    Inspection of the available literature reveals that a detailed investigation of the aqueous organic chemistry of chlorine dioxide and systematic identification of products formed during water disinfection has not been considered. This must be done before an informed assessment can be made of the relative safety of using chlorine dioxide as a disinfectant alternative to chlorine. Although trihalomethanes are generally not formed by the action of chlorine dioxide, the products of chlorine dioxi...

  5. Reaction products of chlorine dioxide.

    Stevens, A. A.


    Inspection of the available literature reveals that a detailed investigation of the aqueous organic chemistry of chlorine dioxide and systematic identification of products formed during water disinfection has not been considered. This must be done before an informed assessment can be made of the relative safety of using chlorine dioxide as a disinfectant alternative to chlorine. Although trihalomethanes are generally not formed by the action of chlorine dioxide, the products of chlorine dioxi...

  6. Moderate-temperature operable SO2 gas sensor based on Zr4+ ion conducting solid electrolyte

    Y. Uneme


    Full Text Available A solid electrolyte type sulfur dioxide (SO2 gas sensor that can operate at moderate temperatures was fabricated using Zr4+ ion conducting Zr39/40TaP2.9W0.1O12 solid electrolyte with 0.7La2O2SO4 − 0.3(0.8Li2SO4 + 0.2K2SO4 having a large surface area and Zr metal as the auxiliary sensing electrode and reference electrode, respectively. Since the present sensor showed a quantitative, reproducible and rapid response which obeys the theoretical Nernst relationship even at 400 °C, it is a potential on site SO2 gas sensing tool operable at moderate temperatures around 400 °C.

  7. Manganese accumulation in the brain: MR imaging

    Uchino, A.; Nomiyama, K.; Takase, Y.; Nakazono, T.; Nojiri, J.; Kudo, S. [Saga Medical School, Department of Radiology, Saga (Japan); Noguchi, T. [Kyushu University, Department of Clinical Radiology, Graduate School of Medicine, Fukuoka (Japan)


    Manganese (Mn) accumulation in the brain is detected as symmetrical high signal intensity in the globus pallidi on T1-weighted MR images without an abnormal signal on T2-weighted images. In this review, we present several cases of Mn accumulation in the brain due to acquired or congenital diseases of the abdomen including hepatic cirrhosis with a portosystemic shunt, congenital biliary atresia, primary biliary cirrhosis, congenital intrahepatic portosystemic shunt without liver dysfunction, Rendu-Osler-Weber syndrome with a diffuse intrahepatic portosystemic shunt, and patent ductus venosus. Other causes of Mn accumulation in the brain are Mn overload from total parenteral nutrition and welding-related Mn intoxication. (orig.)

  8. Preparation of highly efficient manganese catalase mimics.

    Triller, Michael U; Hsieh, Wen-Yuan; Pecoraro, Vincent L; Rompel, Annette; Krebs, Bernt


    The series of compounds [Mn(bpia)(mu-OAc)](2)(ClO(4))(2) (1), [Mn(2)(bpia)(2)(muO)(mu-OAc)](ClO(4))(3).CH(3)CN (2), [Mn(bpia)(mu-O)](2)(ClO(4))(2)(PF(6)).2CH(3)CN (3), [Mn(bpia)(Cl)(2)](ClO)(4) (4), and [(Mn(bpia)(Cl))(2)(mu-O)](ClO(4))(2).2CH(3)CN (5) (bpia = bis(picolyl)(N-methylimidazol-2-yl)amine) represents a structural, spectroscopic, and functional model system for manganese catalases. Compounds 3 and 5 have been synthesized from 2 via bulk electrolysis and ligand exchange, respectively. All complexes have been structurally characterized by X-ray crystallography and by UV-vis and EPR spectroscopies. The different bridging ligands including the rare mono-mu-oxo and mono-mu-oxo-mono-mu-carboxylato motifs lead to a variation of the Mn-Mn separation across the four binuclear compounds of 1.50 A (Mn(2)(II,II) = 4.128 A, Mn(2)(III,III) = 3.5326 and 3.2533 A, Mn(2)(III,IV) = 2.624 A). Complexes 1, 2, and 3 are mimics for the Mn(2)(II,II), the Mn(2)(III,III), and the Mn(2)(III,IV) oxidation states of the native enzyme. UV-vis spectra of these compounds show similarities to those of the corresponding oxidation states of manganese catalase from Thermus thermophilus and Lactobacillus plantarum. Compound 2 exhibits a rare example of a Jahn-Teller compression. While complexes 1 and 3 are efficient catalysts for the disproportionation of hydrogen peroxide and contain an N(4)O(2) donor set, 4 and 5 show no catalase activity. These complexes have an N(4)Cl(2) and N(4)OCl donor set, respectively, and serve as mimics for halide inhibited manganese catalases. Cyclovoltammetric data show that the substitution of oxygen donor atoms with chloride causes a shift of redox potentials to more positive values. To our knowledge, complex 1 is the most efficient binuclear functional manganese catalase mimic exhibiting saturation kinetics to date.

  9. Toxicity of manganese metallodrugs toward Danio rerio.

    Arndt, Anderson; Borella, Maria Inês; Espósito, Breno Pannia


    Manganese is an essential metal which can be neurotoxic in some instances. As Mn-based metallodrugs are ever more prevalent in clinical practice, concern regarding the toxic effects of Mn discharges to water bodies on the biota prompted us to study the physicochemical parameters of these complexes and to assess their acute toxicity toward adult Danio rerio individuals, particularly in terms of brain tissue damage. Our results show that the Mn(III)-salen acetate complex EUK108 is toxic, which can be rationalized in terms of its lipophilicity, stability and redox activity.

  10. Thermoelectric properties of higher manganese silicides

    Tseng, Yu-Chih; Venkataraman, Vijay Shankar; Kee, Hae-Young


    Higher manganese silicides (HMS) are promising thermoelectric materials that may be broadly deployable because of the abundance of the constituent elements and their non-toxic nature. We study the thermoelectric properties of HMS using density functional theory calculations and tight-binding models to fit these calculations. We estimate charge carrier density and mobility, and compare with experimental data. Theoretically obtained thermal and electrical conductivities, and the Seebeck coefficients are presented. Possible scattering mechanisms and relations to figure of merit are also discussed. NSERC CREATE - HEATER Program.

  11. Organic/inorganic nanocomposite polymer electrolyte

    Li Qi; Shao Jun Dong


    The organic/inorganic nanocomposites polymer electrolytes were designed and synthesized. The organic/inorganic nanocom posites membrane materials and their lithium salt complexes have been found thermally stable below 200 ℃. The conductivity of the organic/inorganic nanocomposites polymer electrolytes prepared at room temperature was at magnitude range of 10-6 S/cm.

  12. Polymeric electrolytes for ambient temperature lithium batteries

    Farrington, G. C.


    During this reporting period a number of novel solid polymer electrolytes formed by salts of multivalent cations and polyethylene oxide (PEO) have been prepared and characterized. These materials are of interest not only because of their potential ionic conductivities, but also because some of them may have electronic conductivity and oxidizing power which would be useful for novel electrode materials in all-solid-state batteries. Two broad classes of materials were investigated: PEO solutions of Zn(2), Cd(2), and Pb(2), all of which are potential electrolytes for solid-state batteries, and PEO solutions of transition metal salts, which are of interest as possible cathode materials. Mixed compositions containing both divalent cations and lithium ions were also prepared. Electrolytes formed with small, highly-polarizing ions, such as Mg(2) and Ca(2), are essentially pure anion conductors. Electrolytes containing Zn(2) behave similarly, unless they are hydrated, in which case the Zn(2) ions are quite mobile. Electrolytes formed with larger, more polarizable cations, such as Pb(2) and Cd(2), conduct both anions and cations. Solutions of salts of transition metal cations form a third group of electrolytes. Of the electrolytes investigated so far, those formed with Ni(++) salts are the most unusual. It appears as if the transport number of Ni(2) and the electrolyte conductivity can be greatly enhanced by controlling the hydration and dehydration of the polymer.

  13. The charge transport in polymeric gel electrolytes

    Reiche, A


    The aim of the present thesis consisted in the study of the charge transport in gel electrolytes, which were obtained by photopolymerization of oligo(ethylene glycol) sub n -dimethacrylates with n=3, 9, and 23, and the survey of structure and property relations for the optimization of the electrolyte composition. The pressure dependence of the electric conductivity was measured. (HSI)

  14. Microporous polymer electrolyte based on PVDF-PEO

    LI Jian; XI Jingyu; SONG Qing; TANG Xiaozhen


    @@ Since Wright et al.[1] found that the complex of PEO/alkali metals salt had the ability of ionic conductivity in 1973, in-depth studies have been carried out about various polymer electrolytes, which were applied to replacing the liquid electrolytes in lithium ion battery[2,3]. At present, polymer electrolytes mainly include three kinds: dry polymer electrolytes, gel polymer electrolytes and microporous polymer electrolytes.

  15. A novel three-dimensional manganese dioxide electrode for high performance supercapacitors

    Kong, Shuying; Cheng, Kui; Gao, Yinyi; Ouyang, Tian; Ye, Ke; Wang, Guiling; Cao, Dianxue


    Development of MnO2 based electrode materials for supercapacitor application with high comprehensive electrochemical performance, such as high capacitance, superior reversibility, excellent stability, and good rate capability, is still a tremendous challenge. In this work, a distinctive interwoven three-dimensional (3D) structure electrode with ultra-thin 2D graphene nanosheet decorated on the surface of 1D C/TiC nanowire array is built as the support to immobilize MnO2 nanoflakes (MnO2-Graphene nanosheet-C/TiC nanowire array, denoted as MGCT). Compared with the normal 1D core/shell structure, this novel 3D architecture can dramatically not only increase the surface area for MnO2 loading but also facilitate the ion and electron transfer. The electrochemical performance of the as-prepared 3D MnO2 electrode is evaluated by cyclic voltammetrys, galvanostatic charging-discharging tests and electrochemical impedance spectroscopy, high specific capacitance (856 F g-1 at 2 A g-1), good rate capability (69.1% capacitance retention at 40 A g-1vs 2 A g-1), superior reversibility, and cycling stability (85.7% capacitance retention after 10,000 cycles at 10 A g-1) are obtained, suggesting that this novel structure can offer a new and appropriate idea for obtaining high-performance supercapacitor electrode materials.

  16. Molybdenum-Doped Manganese Dioxide for Use in Low Temperature Battery Cathodes


    as described earlier (1) 1.5g of a 85-15 oxide - graphite mix was pasted with 0.7 ml binder solution (5g carboxymethylcellulose *, TB-253, dissolved...short phrases that characterize a document and could be helpful in cataloging the document. Key words should be selected so that no security

  17. Ammonium vanadate@polypyrrole@manganese dioxide nanowire arrays with enhanced reversible lithium storage

    Wang, Chang; Liu, Hui; Jiang, Ming; Wang, Yingde; Liu, Ruina; Luo, Zhiping; Liu, Xiaoqing; Xu, Weilin; Xiong, Chuanxi; Fang, Dong


    Design and fabrication of novel optimized electrode materials are important for the development of new batteries for energy storage applications. Herein, we report on a hierarchical bulk electrode material with a tailored nanostructure that which consists of three components: a NH4V4O10 nanowire as an active skeleton, an intermediate polymer layer (polypyrrole, PPy), and a metal oxide layer (MnO2) as the outside shell. The NH4V4O10-PPy-MnO2 nanowires exhibit present higher capacitance than that of the simple NH4V4O10-PPy core@shell or NH4V4O10 nanowires. The structure of double shells of combined PPy and MnO2 is a key factor in enhancing their electrochemical performance including high specific capacitance and excellent cycling stability. Our V-based core@shell@shell structure can serve as freestanding, compressible electrodes for various energy devices.

  18. Monodispersed fabrication and dielectric studies on ethylenediamine passivated α-manganese dioxide nanorods

    Joseph, A. Martin [Research and Development Centre, Bharathiar University, Coimbatore, Tamilnadu (India); Kumar, R. Thilak, E-mail: [Periyar Arts College, Cuddalore-607001, Tamilnadu (India)


    Highlights: • Monodispersed ethylenediamine (EDA) passivated α-MnO{sub 2} nanorods were fabricated by inexpensive wet chemical method. • FTIR analysis indicated that surface passivation is strongly influenced by the introduction of the organic ligand. • XRD and HR-SEM revealed the structure and morphology of the fabricated α-MnO{sub 2} nanorods with an average size of about 40 × 200 nm. • Dielectric studies pointed out that the fabricated α-MnO{sub 2} is semiconducting in nature with resistivity, ρ = 1.46 to 5.76 × 10{sup 3} Ωcm. • The optical energy gap for the fabricated α-MnO{sub 2} nanorods is found to be around 1.37 eV. - Abstract: In this present work, pure α-MnO{sub 2} nanorods were fabricated by the reduction of 0.2 m/L of KMnO{sub 4} with 0.2 m/L of Na{sub 2}S{sub 2}O{sub 3}·5H{sub 2}O and by passivating with the organic ligand Ethylenediamine (EDA). The structural, functional, morphological and chemical composition of the nanorods were investigated by X-Ray Diffractometer (XRD), Fourier Transform Infrared Spectrometer (FTIR), High Resolution Scanning Electron Microscope (HR-SEM) and Energy Dispersive X-Ray Spectrometry (EDX). The XRD analysis indicated high crystalline nature of the product and FTIR confirmed the contribution of the organic ligand in surface passivation. HR-SEM image revealed the morphology of the α-MnO{sub 2} nanorods with an average size of about 40 × 200 nm. EDX confirmed the presence of Mn and O in the material. UV–visible spectrophotometery was used to determine the absorption behavior of the nanorods and an indirect band gap of 1.37 eV was acquired by Taucplot. Dielectric studies were carried out using Broadband Dielectric Spectrometer(BDS) and the resistivity was found to be around the semiconductor range (ρ = 1.46 to 5.76 × 10{sup 3} Ωcm).

  19. A bird nest-like manganese dioxide and its application as electrode in supercapacitors

    Fen; Ran; Huili; Fan; Lingren; Wang; Lei; Zhao; Yongtao; Tan; Xuanxuan; Zhang; Lingbin; Kong; Long; Kang


    A novel bird nest-like nanostructured MnO2(BNNS-MnO2) was prepared by a facile and cost-effective strategy. Their structures and morphologies were characterized by field emission scanning electron microscopy, transmission electron microscopy and powder X-ray diffraction. Capacitive behaviors were investigated by cyclic voltammetry and galvanostatic charge-discharge. The obtained nano-MnO2 possesses a well designed loose-assembled hierarchical nanoarchitecture with an appropriate crystallinity which gives rise to excellent performances as an electrode material for supercapacitors. A maximum specific capacitance of 917 F/g has been obtained at a current density of 5 mA/cm2 in 6 mol/L KOH aqueous solution, and a specific capacitance of 210 F/g has been maintained for 500 cycles. As the low cost of MnSO4 and KCr2O7 and the low reaction temperature, the present method avoids the requirements for complicated operations, time/energy-consuming and expensive reagents, and perhaps is ready for the industrialization of nano-MnO2 production.

  20. Manganese Oxide-Surface Modified Titanium(IV Dioxide as Environmental Catalyst

    Hiroaki Tada


    Full Text Available The purpose of this study is to present an “environmental catalyst” possessing both thermocatalytic activity and visible-light activity for the decomposition of organic pollutants. Molecule-sized MnOx clusters are highly dispersed on the surface of TiO2 (anatase/rutile = 4/1 w/w, P-25, Degussa by the chemisorption-calcination cycle technique using Mn(acac3 complex as a precursor (MnOx/TiO2. The thermo- and photo-catalytic activities of MnOx/TiO2 were studied for the degradation of 2-naphthol used as a model water pollutant. In contrast to the FeOx/TiO2 system, MnOx/TiO2 exhibits high thermocatalytic activity exceeding those of bulk β-β-MnO2 and Mn2O3. Also, visible-light activity is induced by the surface modification of TiO2 with MnOx clusters, whereas its UV-light activity decreases.

  1. Manganese Dioxide nanosheet suspension: A novel absorbent for Cadmium(II) contamination in waterbody.

    Peng, Liang; Zeng, Qingru; Tie, Boqing; Lei, Ming; Yang, Jiao; Luo, Si; Song, Zhengguo


    A MnO2 nanosheet (MnO2-NS) suspension was prepared from tetramethylammonium hydroxide (TMA⋅OH), H2O2, and MnCl2⋅4H2O, and its efficiency for Cd(II) removal from aqueous solutions was investigated. The maximum adsorption capacity of the MnO2-NS for Cd(II) was evaluated to be about 348 mg/g, which is thus far the highest value reported for MnO2 at pH 6.0. This high adsorption capacity is attributed to efficient ion exchange. X-ray photoelectron spectroscopy (XPS) revealed that Cd(II) was adsorbed on MnO2 as CdO and Cd(OH)2. After Cd(II) adsorption, the suspended MnO2-NS aggregated and precipitated within 5.0 min from solution. Therefore, dispersive MnO2-NS can be used to remove Cd(II) from wastewater rapidly and with high efficiency.

  2. Aqueous manganese dioxide ink for paper-based capacitive energy storage devices.

    Qian, Jiasheng; Jin, Huanyu; Chen, Bolei; Lin, Mei; Lu, Wei; Tang, Wing Man; Xiong, Wei; Chan, Lai Wa Helen; Lau, Shu Ping; Yuan, Jikang


    We report a simple approach based on a chemical reduction method to synthesize aqueous inorganic ink comprised of hexagonal MnO2 nanosheets. The MnO2 ink exhibits long-term stability and continuous thin films can be formed on various substrates without using any binder. To obtain a flexible electrode for capacitive energy storage, the MnO2 ink was printed onto commercially available A4 paper pretreated with multiwalled carbon nanotubes. The electrode exhibited a maximum specific capacitance of 1035 F g(-1) (91.7 mF cm(-2)). Paper-based symmetric and asymmetric capacitors were assembled, which gave a maximum specific energy density of 25.3 Wh kg(-1) and a power density of 81 kW kg(-1). The device could maintain a 98.9% capacitance retention over 10 000 cycles at 4 A g(-1). The MnO2 ink could be a versatile candidate for large-scale production of flexible and printable electronic devices for energy storage and conversion.

  3. Control of Manganese Dioxide Particles Resulting From In Situ Chemical Oxidation Using Permanganate


    1-dimensional 2-D 2-dimensional 3-D 3-dimensional AA atomic absorption spectroscopy Amax maximum absorbance (418nm measurements) C... Atomic absorption (AA) spectroscopy analyses for Mn content were made of the aqueous filtrate, the DI water extract, the barium chloride extract, and...chemistry with electrode APHA 1998 MnO4- Spectrophotometry at 525 nm with Hach DR/4000 APHA 1998 TCE H.P. 6890 Capillary GC-ECD/FID US EPA 1986, 1990

  4. Accurate state of charge assessment of lithium-manganese dioxide primary batteries

    Manane, Yassine; Yazami, Rachid


    A new method for state of charge (SOC) assessment of Li/MnO2 primary batteries is disclosed. The method is based on thermodynamics data measurements and processing. Entropy 'ΔS' and enthalpy 'ΔH' data are collected during intermittent discharge process and tentatively linked to SOC. Using Li/MnO2 cell sets from two different manufacturers, we found a linear relationship between SOC, ΔS and ΔH; i. e. SOC = α+βΔS+λΔH. In the equation α, β and λ coefficients are manufacturer dependent. This result has been assigned to the physical chemical characteristics MnO2, which vary according the cathode material synthesis conditions specific to each manufacturer. The SOC assessment method was initially developed by us for rechargeable lithium ion battery systems. It surprisingly applies to primary batteries too despite cathode processes are irreversible in nature. It is suggested the method may extend to online SOC assessment owing to an imbedded chip, which collects and processes voltage and temperature data to convert them into thermodynamics data. The method can also be used to characterize MnO2 materials from the thermodynamics properties perspective and to trace Li/MnO2 cell manufacturer.

  5. Oxidation of pyrite and iron sulfide by manganese dioxide in marine sediments

    Schippers, A.; Jørgensen, BB


    in the presence of MnO2. At the iron sulfide surface, Fe(III) is reduced to Fe(II) which is reoxidized to Fe(III) by MnO2. Thus, an Fe(II)/Fe(III) shuttle should transport electrons between the surfaces of the two solid compounds. Copyright (C) 2001 Elsevier Science Ltd....... in the sediment. FeS2 and iron sulfide (FeS) were oxidized chemically at pH 8 by MnO2 but not by nitrate or amorphic Fe(III) oxide. Elemental sulfur and sulfate were the only products of FeS oxidation, whereas FeS2 was oxidized to a variety of sulfur compounds, mainly sulfate plus intermediates......) for total dissolved S and total dissolved Fe, respectively. Since these values are in the same range as previously published rates for the oxidation of FeS2 by Fe(II), and since Fe(III) is a well-known oxidant for FeS2 even at circumneutral pH, Fe(III) is assumed also to be the oxidant for FeS and FeS2...

  6. Diffusion abnormalities of the globi pallidi in manganese neurotoxicity

    McKinney, Alexander M.; Filice, Ross W.; Teksam, Mehmet; Casey, Sean; Truwit, Charles; Clark, H. Brent; Woon, Carolyn; Liu, Hai Ying [Department of Radiology, Medical School, Box 292, 420 Delaware Street S.E., 55455, Minneapolis, MN (United States)


    Manganese is an essential trace metal required for normal central nervous system function, which is toxic when in excess amounts in serum. Manganese neurotoxicity has been demonstrated in patients with chronic liver/biliary failure where an inability to excrete manganese via the biliary system causes increased serum levels, and in patients on total parenteral nutrition (TPN), occupational/inhalational exposure, or other source of excess exogenous manganese. Manganese has been well described in the literature to deposit selectively in the globi pallidi and to induce focal neurotoxicity. We present a case of a 53-year-old woman who presented for a brain MR 3 weeks after liver transplant due to progressively decreasing level of consciousness. The patient had severe liver failure by liver function tests and bilirubin levels, and had also been receiving TPN since the transplant. The MR demonstrated symmetric hyperintensity on T1-weighted images in the globi pallidi. Apparent diffusion coefficient (ADC) map indicated restricted diffusion in the globi pallidi bilaterally. The patient eventually succumbed to systemic aspergillosis 3 days after the MR. The serum manganese level was 195 mcg/l (micrograms per liter) on postmortem exam (over 20 times the upper limits of normal). The patient was presumed to have suffered from manganese neurotoxicity since elevated serum manganese levels have been shown in the literature to correlate with hyperintensity on T1-weighted images, neurotoxicity symptoms, and focal concentration of manganese in the globi pallidi. Neuropathologic sectioning of the globi pallidi at autopsy was also consistent with manganese neurotoxicity. (orig.)

  7. Reduction of ripening time of full-scale manganese removal filters with manganese oxide-coated media

    Bruins, J.H.; Petrusevski, B.; Slokar, Y.M.; Huysman, K.; Joris, K.; Kruithof, J.C.; Kennedy, M.D.


    Effective manganese removal by conventional aeration-filtration with virgin filter media requires a long ripening time. The aim of this study was to assess the potential of manganese oxide-coated media to shorten the ripening time of filters with virgin media, under practical conditions. A full

  8. Reduction of ripening time of full-scale manganese removal filters with manganese oxide-coated media

    Bruins, J.H.; Petrusevski, B.; Slokar, Y.M.; Huysman, K.; Joris, K.; Kruithof, J.C.; Kennedy, M.D.


    Effective manganese removal by conventional aeration-filtration with virgin filter media requires a long ripening time. The aim of this study was to assess the potential of manganese oxide-coated media to shorten the ripening time of filters with virgin media, under practical conditions. A full scal

  9. Proton Conducting Polymer Electrolytes and Its Applications

    S. Selvasekarapandian; G. Hirankumar; R. Baskaran; M.S. Bhuvaneswari


    @@ 1Introduction Proton conducting solid polymer electrolytes have been extensively studied due to their potential applications in electrochemical devices such as batteries, super capacitors, electrochromic windows, sensors etc[1,2]Many researchers have studied the behaviour of inorganic based polymer electrolytes as proton conductors and their applications in solid state devices at room temperature[3]. But, inorganic acid doped electrolytes have some serious disadvantages like corrosion towards the electrode and hazardous. Hence, there is need for searching new electrolyte which is stable towards the electrode. It has been reported that the ammonium salts which behaves like alkali metal salt are good dopant to the polymer matrix[4, 5] for the development of proton conducting polymer electrolyte. The proton conductors based on poly (ethylene oxide)[6], poly (ethylene succinate)[7], poly (ethylene glycol)[8], as host matrix doped with ammonium salt have already been reported.

  10. Solid polymer electrolyte from phosphorylated chitosan

    Fauzi, Iqbal, E-mail:; Arcana, I Made, E-mail: [Inorganic and Physical Chemistry Research Groups, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)


    Recently, the need of secondary battery application continues to increase. The secondary battery which using a liquid electrolyte was indicated had some weakness. A solid polymer electrolyte is an alternative electrolytes membrane which developed in order to replace the liquid electrolyte type. In the present study, the effect of phosphorylation on to polymer electrolyte membrane which synthesized from chitosan and lithium perchlorate salts was investigated. The effect of the component’s composition respectively on the properties of polymer electrolyte, was carried out by analyzed of it’s characterization such as functional groups, ion conductivity, and thermal properties. The mechanical properties i.e tensile resistance and the morphology structure of membrane surface were determined. The phosphorylation processing of polymer electrolyte membrane of chitosan and lithium perchlorate was conducted by immersing with phosphoric acid for 2 hours, and then irradiated on a microwave for 60 seconds. The degree of deacetylation of chitosan derived from shrimp shells was obtained around 75.4%. Relative molecular mass of chitosan was obtained by viscometry method is 796,792 g/mol. The ionic conductivity of chitosan membrane was increase from 6.33 × 10{sup −6} S/cm up to 6.01 × 10{sup −4} S/cm after adding by 15 % solution of lithium perchlorate. After phosphorylation, the ionic conductivity of phosphorylated lithium chitosan membrane was observed 1.37 × 10{sup −3} S/cm, while the tensile resistance of 40.2 MPa with a better thermal resistance. On the strength of electrolyte membrane properties, this polymer electrolyte membrane was suggested had one potential used for polymer electrolyte in field of lithium battery applications.

  11. Iron and manganese removal from drinking water

    Daniela-Elena Pascu


    Full Text Available The purpose of the present study is to find a suitable method for removal of iron and manganese from ground water, considering bothlocal economical and environmental aspects. Ground water is a highly important source of drinking water in Romania. Ground water is naturally pure from bacteria at a 25 m depth or more. However, solved metals may occur and if the levels are too high, the water is not drinkable. Different processes, such as electrochemical and combined electrochemical-adsorption methods have been applied to determine metals content in accordance to reports of National Water Agency from Romania (ANAR. Every water source contains dissolved or particulate compounds. The concentrations of these compounds can affect health, productivity, compliance requirements, or serviceability and cannot be economically removed by conventional filtration means. In this study, we made a comparison between the electrochemical and adsorption methods (using membranes. Both methods have been used to evaluate the efficiency of iron and manganese removal at various times and temperatures. We used two membrane types: composite and cellulose, respectively. Different approaches, including lowering the initial current density and increasing the initial pH were applied. Reaction kinetics was achieved using mathematical models: Jura and Temkin.

  12. Preparation and Characterization of Manganese Ferrite Aluminates

    R. L. Dhiman


    Full Text Available Aluminum doped manganese ferrites MnAlxFe2−xO4 with 0.0≤x≤1.0 have been prepared by the double ceramic route. The formation of mixed spinel phase has been confirmed by X-ray diffraction analysis. The unit cell parameter `aO' is found to decrease linearly with aluminum concentration due to smaller ionic radius of aluminum. The cation distributions were estimated from X-ray diffraction intensities of various planes. The theoretical lattice parameter, X-ray density, oxygen positional parameter, ionic radii, jump length, and bonds and edges lengths of the tetrahedral (A and octahedral (B sites were determined. 57Fe Mössbauer spectra recorded at room temperature were fitted with two sextets corresponding to Fe3+ ions at A- and B-sites. In the present ferrite system, the area ratio of Fe3+ ions at the A- and B-sites determined from the spectral analysis of Mössbauer spectra gives evidence that Al3+ ions replace iron ions at B-sites. This change in the site preference reflects an abrupt change in magnetic hyperfine fields at A- and B-sites as aluminum concentration increases, which has been explained on the basis of supertransferred hyperfine field. On the basis of estimated cation distribution, it is concluded that aluminum doped manganese ferrites exhibit a 55% normal spinel structure.

  13. Environmental Exposure to Manganese in Air: Associations ...

    BACKGROUND: Manganese (Mn) inhalation has been associated with neuropsychological and neurological sequelae in exposed workers. Few environmental epidemiologic studies have examined the potentialy neurotoxic effects of Mn exposure in ambient air on motor function and hand tremor in adult community residents. Mn exposed residents were recruited in two Ohio towns: Marietta, a town near a ferro-manganese smelter, and East Liverpool, a town adjacent to a facility processing, crushing, screening, and packaging Mn products.METHODS: Chronic (≥10years) exposure to ambient air Mn in adult residents and effects on neuropsychological and neurological outcomes were investigated. Participants from Marietta (n=100) and East Liverpool (n=86) were combined for analyses. AERMOD dispersion modeling of fixed-site outdoor air monitoring data estimated Mn inhalation over a ten year period. Adult Mn­ exposed residents' psychomotor ability was assessed using Finger Tapping, Hand Dynamometer, Grooved Pegbcard, and the Computerized Adaptive Testing System (CATSYS) Tremor system.Bayesian structural equation modeling was used to assess associations between air-Mn and motor function and tremor .RESULTS: Air-Mn exposure was significantly correlated in bivariate analyses with the tremor test (CATSYS) for intensity, center frequency and harmonic index. The Bayesian path analysis model showed associations of air-Mn with the CATSYS non-dominant center frequency and harmonic ind

  14. Down-regulation of a manganese transporter in the face of metal toxicity.

    Jensen, Laran T; Carroll, Mark C; Hall, Matthew D; Harvey, Christopher J; Beese, Sara E; Culotta, Valeria C


    The yeast Smf1p Nramp manganese transporter is posttranslationally regulated by environmental manganese. Smf1p is stabilized at the cell surface with manganese starvation, but is largely degraded in the vacuole with physiological manganese through a mechanism involving the Rsp5p adaptor complex Bsd2p/Tre1p/Tre2p. We now describe an additional level of Smf1p regulation that occurs with toxicity from manganese, but not other essential metals. This regulation is largely Smf1p-specific. As with physiological manganese, toxic manganese triggers vacuolar degradation of Smf1p by trafficking through the multivesicular body. However, regulation by toxic manganese does not involve Bsd2p/Tre1p/Tre2p. Toxic manganese triggers both endocytosis of cell surface Smf1p and vacuolar targeting of intracellular Smf1p through the exocytic pathway. Notably, the kinetics of vacuolar targeting for Smf1p are relatively slow with toxic manganese and require prolonged exposures to the metal. Down-regulation of Smf1p by toxic manganese does not require transport activity of Smf1p, whereas such transport activity is needed for Smf1p regulation by manganese starvation. Furthermore, the responses to manganese starvation and manganese toxicity involve separate cellular compartments. We provide evidence that manganese starvation is sensed within the lumen of the secretory pathway, whereas manganese toxicity is sensed within an extra-Golgi/cytosolic compartment of the cell.

  15. Early Postnatal Blood Manganese Levels and Children’s Neurodevelopment

    Henn, Birgit Claus; Ettinger, Adrienne S.; Schwartz, Joel; Téllez-Rojo, Martha María; Lamadrid-Figueroa, Héctor; Hernández-Avila, Mauricio; Schnaas, Lourdes; Amarasiriwardena, Chitra; Bellinger, David C.; Hu, Howard; Wright, Robert O.


    Background Recent evidence suggests that low-level environmental exposure to manganese adversely affects child growth and neurodevelopment. Previous studies have addressed the effects of prenatal exposure, but little is known about developmental effects of early postnatal exposure. Methods We studied 448 children born in Mexico City from 1997 through 2000, using a longitudinal study to investigate neurotoxic effects of early life manganese exposure. Archived blood samples, collected from children at 12 and 24 months of age, were analyzed for manganese levels using inductively-coupled plasma mass spectrometry. Mental and psychomotor development were scored using Bayley Scales of Infant Development at 6-month intervals between 12 and 36 months of age. Results At 12 months of age, the mean (SD) blood manganese level was 24.3 (4.5) μg/l and the median was 23.7 μg/l; at 24 months, these values were 21.1 (6.2) μg/l and 20.3 μg/l, respectively. Twelve- and 24-month manganese concentrations were correlated (Spearman correlation = 0.55) and levels declined over time (β = −5.7 [95% CI = −6.2 to −5.1]). We observed an inverted U-shaped association between 12-month blood manganese and concurrent mental development scores (compared with the middle 3 manganese quintiles, for the lowest manganese quintile, β = −3.3 [−6.0 to −0.7] and for the highest manganese quintile, β = −2.8 [−5.5 to −0.2]). This 12-month manganese effect was apparent but diminished with mental development scores at later ages. The 24-month manganese levels were not associated with neurodevelopment. Conclusions These results suggest a possible biphasic dose-response relationship between early-life manganese exposure at lower exposure levels and infant neurodevelopment. The data are consistent with manganese as both an essential nutrient and a toxicant. PMID:20549838

  16. Production of Manganese Oxide Nanoparticles by Shewanella Species

    Farooqui, Saad M.; White, Alan R.


    ABSTRACT Several species of the bacterial genus Shewanella are well-known dissimilatory reducers of manganese under anaerobic conditions. In fact, Shewanella oneidensis is one of the most well studied of all metal-reducing bacteria. In the current study, a number of Shewanella strains were tested for manganese-oxidizing capacity under aerobic conditions. All were able to oxidize Mn(II) and to produce solid dark brown manganese oxides. Shewanella loihica strain PV-4 was the strongest oxidizer, producing oxides at a rate of 20.3 mg/liter/day and oxidizing Mn(II) concentrations of up to 9 mM. In contrast, S. oneidensis MR-1 was the weakest oxidizer tested, producing oxides at 4.4 mg/liter/day and oxidizing up to 4 mM Mn(II). Analysis of products from the strongest oxidizers, i.e., S. loihica PV-4 and Shewanella putrefaciens CN-32, revealed finely grained, nanosize, poorly crystalline oxide particles with identical Mn oxidation states of 3.86. The biogenic manganese oxide products could be subsequently reduced within 2 days by all of the Shewanella strains when culture conditions were made anoxic and an appropriate nutrient (lactate) was added. While Shewanella species were detected previously as part of manganese-oxidizing consortia in natural environments, the current study has clearly shown manganese-reducing Shewanella species bacteria that are able to oxidize manganese in aerobic cultures. IMPORTANCE Members of the genus Shewanella are well known as dissimilatory manganese-reducing bacteria. This study shows that a number of species from Shewanella are also capable of manganese oxidation under aerobic conditions. Characterization of the products of the two most efficient oxidizers, S. loihica and S. putrefaciens, revealed finely grained, nanosize oxide particles. With a change in culture conditions, the manganese oxide products could be subsequently reduced by the same bacteria. The ability of Shewanella species both to oxidize and to reduce manganese indicates


    Harlan U. Anderson


    This project has three main goals: Thin Films Studies, Preparation of Graded Porous Substrates and Basic Electrical Characterization and Testing of Planar Single Cells. During this time period substantial progress has been made in developing low temperature deposition techniques to produce dense, nanocrystalline yttrium-stabilized zirconia films on both dense oxide and polymer substrates. Progress has been made in the preparation and characterization of thin electrolytes and porous LSM substrates. Both of these tasks are essentially on or ahead of schedule. In our proposal, we suggested that the ZrO{sub 2}/Sc system needed to be considered as a candidate as a thin electrolyte. This was because microcrystalline ZrO{sub 2}/Sc has a significantly higher ionic conductivity than YSZ, particularly at the lower temperatures. As a result, some 0.5 micron thick film of ZrO{sub 2}/16% Sc on an alumina substrate (grain size 20nm) was prepared and the electrical conductivity measured as a function of temperature and oxygen activity. The Sc doped ZrO{sub 2} certainly has a higher conductivity that either 20nm or 2400nm YSZ, however, electronic conductivity dominates the conductivity for oxygen activities below 10{sup -15}. Whereas for YSZ, electronic conductivity is not a problem until the oxygen activity decreases below 10{sup -25}. These initial results show that the ionic conductivity of 20nm YSZ and 20nm ZrO{sub 2}/16% Sc are essentially the same and the enhanced conductivity which is observed for Sc doping in microcrystalline specimens is not observed for the same composition when it is nanocrystalline. In addition they show that the electronic conductivity of Sc doped ZrO{sub 2} is at least two orders of magnitude higher than that observed for YSZ. The conclusion one reaches is that for 0.5 to 1 micron thick nanocrystalline films, Sc doping of ZrO{sub 2} has no benefits compared to YSZ. As a result, electrolyte films of ZrO{sub 2}/Sc should not be considered as candidates

  18. Photobiological hydrogen production and carbon dioxide sequestration

    Berberoglu, Halil

    Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of

  19. Efficacy and Safety Evaluation of a Chlorine Dioxide Solution.

    Ma, Jui-Wen; Huang, Bin-Syuan; Hsu, Chu-Wei; Peng, Chun-Wei; Cheng, Ming-Long; Kao, Jung-Yie; Way, Tzong-Der; Yin, Hao-Chang; Wang, Shan-Shue


    In this study, a chlorine dioxide solution (UC-1) composed of chlorine dioxide was produced using an electrolytic method and subsequently purified using a membrane. UC-1 was determined to contain 2000 ppm of gaseous chlorine dioxide in water. The efficacy and safety of UC-1 were evaluated. The antimicrobial activity was more than 98.2% reduction when UC-1 concentrations were 5 and 20 ppm for bacteria and fungi, respectively. The half maximal inhibitory concentrations (IC50) of H1N1, influenza virus B/TW/71718/04, and EV71 were 84.65 ± 0.64, 95.91 ± 11.61, and 46.39 ± 1.97 ppm, respectively. A 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test revealed that the cell viability of mouse lung fibroblast L929 cells was 93.7% at a 200 ppm UC-1 concentration that is over that anticipated in routine use. Moreover, 50 ppm UC-1 showed no significant symptoms in a rabbit ocular irritation test. In an inhalation toxicity test, treatment with 20 ppm UC-1 for 24 h showed no abnormality and no mortality in clinical symptoms and normal functioning of the lung and other organs. A ClO₂ concentration of up to 40 ppm in drinking water did not show any toxicity in a subchronic oral toxicity test. Herein, UC-1 showed favorable disinfection activity and a higher safety profile tendency than in previous reports.

  20. Carbon dioxide and climate


    Scientific and public interest in greenhouse gases, climate warming, and global change virtually exploded in 1988. The Department's focused research on atmospheric CO{sub 2} contributed sound and timely scientific information to the many questions produced by the groundswell of interest and concern. Research projects summarized in this document provided the data base that made timely responses possible, and the contributions from participating scientists are genuinely appreciated. In the past year, the core CO{sub 2} research has continued to improve the scientific knowledge needed to project future atmospheric CO{sub 2} concentrations, to estimate climate sensitivity, and to assess the responses of vegetation to rising concentrations of CO{sub 2} and to climate change. The Carbon Dioxide Research Program's goal is to develop sound scientific information for policy formulation and governmental action in response to changes of atmospheric CO{sub 2}. The Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1990 and gives a brief overview of objectives, organization, and accomplishments.

  1. Photosynthetic water oxidation: insights from manganese model chemistry.

    Young, Karin J; Brennan, Bradley J; Tagore, Ranitendranath; Brudvig, Gary W


    Catalysts for light-driven water oxidation are a critical component for development of solar fuels technology. The multielectron redox chemistry required for this process has been successfully deployed on a global scale in natural photosynthesis by green plants and cyanobacteria using photosystem II (PSII). PSII employs a conserved, cuboidal Mn4CaOX cluster called the O2-evolving complex (OEC) that offers inspiration for artificial O2-evolution catalysts. In this Account, we describe our work on manganese model chemistry relevant to PSII, particularly the functional model [Mn(III/IV)2(terpy)2(μ-O)2(OH2)2](NO3)3 complex (terpy = 2,2';6',2″-terpyridine), a mixed-valent di-μ-oxo Mn dimer with two terminal aqua ligands. In the presence of oxo-donor oxidants such as HSO5(-), this complex evolves O2 by two pathways, one of which incorporates solvent water in an O-O bond-forming reaction. Deactivation pathways of this catalyst include comproportionation to form an inactive Mn(IV)Mn(IV) dimer and also degradation to MnO2, a consequence of ligand loss when the oxidation state of the complex is reduced to labile Mn(II) upon release of O2. The catalyst's versatility has been shown by its continued catalytic activity after direct binding to the semiconductor titanium dioxide. In addition, after binding to the surface of TiO2 via a chromophoric linker, the catalyst can be oxidized by a photoinduced electron-transfer mechanism, mimicking the natural PSII process. Model oxomanganese complexes have also aided in interpreting biophysical and computational studies on PSII. In particular, the μ-oxo exchange rates of the Mn-terpy dimer have been instrumental in establishing that the time scale for μ-oxo exchange of high-valent oxomanganese complexes with terminal water ligands is slower than O2 evolution in the natural photosynthetic system. Furthermore, computational studies on the Mn-terpy dimer and the OEC point to similar Mn(IV)-oxyl intermediates in the O-O bond

  2. Reaction products of chlorine dioxide.

    Stevens, A A


    Inspection of the available literature reveals that a detailed investigation of the aqueous organic chemistry of chlorine dioxide and systematic identification of products formed during water disinfection has not been considered. This must be done before an informed assessment can be made of the relative safety of using chlorine dioxide as a disinfectant alternative to chlorine. Although trihalomethanes are generally not formed by the action of chlorine dioxide, the products of chlorine dioxide treatment of organic materials are oxidized species, some of which also contain chlorine. The relative amounts of species types may depend on the amount of chlorine dioxide residual maintained and the concentration and nature of the organic material present in the source water. The trend toward lower concentrations of chlorinated by-products with increasing ClO2 concentration, which was observed with phenols, has not been observed with natural humic materials as measured by the organic halogen parameter. Organic halogen concentrations have been shown to increase with increasing chlorine dioxide dose, but are much lower than those observed when chlorine is applied. Aldehydes have been detected as apparent by-products of chlorine dioxide oxidation reactions in a surface water that is a drinking water source. Some other nonchlorinated products of chlorine dioxide treatment may be quinones and epoxides. The extent of formation of these moieties within the macromolecular humic structure is also still unknown. PMID:7151750

  3. Manganese carbonates as possible biogenic relics in Archean settings

    Rincón-Tomás, Blanca; Khonsari, Bahar; Mühlen, Dominik; Wickbold, Christian; Schäfer, Nadine; Hause-Reitner, Dorothea; Hoppert, Michael; Reitner, Joachim


    Carbonate minerals such as dolomite, kutnahorite or rhodochrosite are frequently, but not exclusively generated by microbial processes. In recent anoxic sediments, Mn(II)carbonate minerals (e.g. rhodochrosite, kutnahorite) derive mainly from the reduction of Mn(IV) compounds by anaerobic respiration. The formation of huge manganese-rich (carbonate) deposits requires effective manganese redox cycling in an oxygenated atmosphere. However, putative anaerobic pathways such as microbial nitrate-dependent manganese oxidation, anoxygenic photosynthesis and oxidation in ultraviolet light may facilitate manganese cycling even in an early Archean environment, without the availability of oxygen. In addition, manganese carbonates precipitate by microbially induced processes without change of the oxidation state, e.g. by pH shift. Hence, there are several ways how these minerals could have been formed biogenically and deposited in Precambrian sediments. We will summarize microbially induced manganese carbonate deposition in the presence and absence of atmospheric oxygen and we will make some considerations about the biogenic deposition of manganese carbonates in early Archean settings.

  4. Potential Role of Epigenetic Mechanism in Manganese Induced Neurotoxicity

    Tarale, Prashant; Chakrabarti, Tapan; Sivanesan, Saravanadevi; Naoghare, Pravin; Bafana, Amit; Krishnamurthi, Kannan


    Manganese is a vital nutrient and is maintained at an optimal level (2.5–5 mg/day) in human body. Chronic exposure to manganese is associated with neurotoxicity and correlated with the development of various neurological disorders such as Parkinson's disease. Oxidative stress mediated apoptotic cell death has been well established mechanism in manganese induced toxicity. Oxidative stress has a potential to alter the epigenetic mechanism of gene regulation. Epigenetic insight of manganese neurotoxicity in context of its correlation with the development of parkinsonism is poorly understood. Parkinson's disease is characterized by the α-synuclein aggregation in the form of Lewy bodies in neuronal cells. Recent findings illustrate that manganese can cause overexpression of α-synuclein. α-Synuclein acts epigenetically via interaction with histone proteins in regulating apoptosis. α-Synuclein also causes global DNA hypomethylation through sequestration of DNA methyltransferase in cytoplasm. An individual genetic difference may also have an influence on epigenetic susceptibility to manganese neurotoxicity and the development of Parkinson's disease. This review presents the current state of findings in relation to role of epigenetic mechanism in manganese induced neurotoxicity, with a special emphasis on the development of Parkinson's disease. PMID:27314012

  5. New electrolytes and electrolyte additives to improve the low temperature performance of lithium-ion batteries

    Yang, Xiao-Qing


    In this program, two different approaches were undertaken to improve the role of electrolyte at low temperature performance - through the improvement in (i) ionic conductivity and (ii) interfacial behavior. Several different types of electrolytes were prepared to examine the feasibil.ity of using these new electrolytes in rechargeable lithium-ion cells in the temperature range of +40°C to -40°C. The feasibility studies include (a) conductivity measurements of the electrolytes, (b) impedance measurements of lithium-ion cells using the screened electrolytes with di.fferent electrochemical history such as [(i) fresh cells prior to formation cycles, (ii) after first charge, and (iii) after first discharge], (c) electrical performance of the cells at room temperatures, and (d) charge discharge behavior at various low temperatures. Among the different types of electrolytes investigated in Phase I and Phase II of this SBIR project, carbonate-based LiPF6 electrolytes with the proposed additives and the low viscous ester as a third component to the carbonate-based LiPF6 electrolytes show promising results at low temperatures. The latter electrolytes deliver over 80% of room temperature capacity at -20{degrees}C when the lithium-ion cells containing these electrolytes were charged at -20 °C. Also, there was no lithium plating when the lithium­-ion cells using C-C composite anode and LiPF{sub 6} in EC/EMC/MP electrolyte were charged at -20{degrees}C at C/5 rate. The studies of ionic conductivity and AC impedance of these new electrolytes, as well as the charge discharge characteristics of lithium-ion cells using these new electrolytes at various low temperatures provide new findings: The reduced capacity and power capability, as well as the problem of lithium plating at low temperatures charging of lithium-ion cells are primarily due to slow the lithium-ion intercalation/de-intercalation kinetics in the carbon structure.

  6. Polymer electrolytes, problems, prospects, and promises

    Nagasubramanian, G.; Boone, D.


    Ionically conducting polymer electrolytes have generated, in recent years, wide-spread interest as candidate materials for a number of applications including high energy density and power lithium batteries. In the early 70s the first measurements of ionic conductivity in polyethylene oxide (PEO)-salt complexes were carried out. However, Armand was the first one to realize potential of these complexes (polymer-salt complexes) as practical ionically conducting materials for use as electrolytes in lithium batteries. Subsequent research efforts identified the limitations and constraints of the polymer electrolytes. These limitations include poor ionic conductivity at RT (< 10{sup {minus}8} S/cm), low cation transport number (<0.2) etc. Several different approaches have been made to improving the ionic conductivity of the polymer electrolytes while retaining the flexibility, processibility, ease of handling and relatively low impact on the environment that polymers inherently possess. This paper- reviews evolution of polymer electrolytes from conventional PEO-LiX slat complexes to the more conducting polyphosphazene and copolymers, gelled electrolytes etc. We also review the various chemical approaches including modifying PEO to synthesizing complicated polymer architecture. In addition, we discuss effect of various lithium salts on the conductivity of PEO-based polymers. Charge/discharge and cycle life data of polymer cells containing oxide and chalcogenide cathodes and lithium (Li) anode are reviewed. Finally, future research directions to improve the electrolyte properties are discussed.

  7. Effect of manganese on the secretion of manganese-peroxidase by the basidiomycete Ceriporiopsis subvermispora.

    Mancilla, Rodrigo A; Canessa, Paulo; Manubens, Augusto; Vicuña, Rafael


    The ligninolytic machinery of the widely used model fungus Ceriporiopsis subvermispora includes the enzymes manganese-peroxidase (MnP) and laccase (Lcs). In this work the effect of Mn(II) on the secretion of MnP was studied. Cultures grown in the absence of Mn(II) showed high levels of mnp transcripts. However, almost no MnP enzyme was detected in the extracellular medium, either by enzymatic activity assays or Western blot hybridizations. In the corresponding mycelia, immuno-electron microscopy experiments showed high levels of MnP enzyme within intracellular compartments. These results suggest that in addition to its well-known effect on transcription regulation of mnp genes, manganese influences secretion of MnP to the extracellular medium. Experiments carried out in the presence of cycloheximide confirmed that the metal is required to secrete MnP already synthesized and retained within the cell.

  8. Reserve, flowing electrolyte, high rate lithium battery

    Puskar, M.; Harris, P.

    Flowing electrolyte Li/SOCl2 tests in single cell and multicell bipolar fixtures have been conducted, and measurements are presented for electrolyte flow rates, inlet and outlet temperatures, fixture temperatures at several points, and the pressure drop across the fixture. Reserve lithium batteries with flowing thionyl-chloride electrolytes are found to be capable of very high energy densities with usable voltages and capacities at current densities as high as 500 mA/sq cm. At this current density, a battery stack 10 inches in diameter is shown to produce over 60 kW of power while maintaining a safe operating temperature.

  9. Electrolytic orthoborate salts for lithium batteries

    Angell, Charles Austen; Xu, Wu


    Orthoborate salts suitable for use as electrolytes in lithium batteries and methods for making the electrolyte salts are provided. The electrolytic salts have one of the formulae (I). In this formula anionic orthoborate groups are capped with two bidentate chelating groups, Y1 and Y2. Certain preferred chelating groups are dibasic acid residues, most preferably oxalyl, malonyl and succinyl, disulfonic acid residues, sulfoacetic acid residues and halo-substituted alkylenes. The salts are soluble in non-aqueous solvents and polymeric gels and are useful components of lithium batteries in electrochemical devices.

  10. Iron, zinc, and manganese distribution in mature soybean seeds

    Cvitanich, Cristina; Przybyłowicz, Wojciech J; Mesjasz-Przybyłowicz, Jolanta


    to reveal the distribution of iron, zinc, manganese and phosphorus within soybean seeds. We show that high concentrations of iron accumulate in the seed coats of mature soybean seeds. This iron accounted for 20 to 40% of the total seed iron. Furthermore, manganese and iron accumulated in close proximity...... to each other in the provascular tissue of the soybean radicle. No regions with increased accumulation of iron, zinc, or manganese were observed in the cotyledons. The concentrations of both phosphorus and zinc were higher in the radicle compared to the cotyledons, and zinc accumulated primarily near...

  11. Hydrothermal Manganese Mineralization Near the Samoan Hotspot

    Hein, J. R.; Staudigel, H.; Koppers, A.; Hart, S. R.; Dunham, R.


    The thickest beds of hydrothermal manganese oxides recovered to date from the global ocean were collected from a volcanic cone in the south Pacific. In April 2005, samples were dredged aboard the R.V. Kilo Moana from a volcanic cone on the lower flank of Tulaga seamount (about 2,700 m water depth; 14° 39.222' S; 170° 1.730' W), located 115 km SW of Vailulu'u, the volcanically and hydrothermally active center of the Samoan hotspot. Additional hydrothermal manganese samples were collected off Ofu Island (dredge Alia 107), 72 km to the WSW of Vailulu'u. Manganese-oxide beds up to 9 cm thick are composed of birnessite and 10 Å manganates. Some layers consist of Mn-oxide columnar structures 4 cm long and 1 cm wide, which have not been described previously. The mean Mn and Fe contents of 18 samples are 51 weight percent and 0.76 weight percent, respectively. Elevated concentrations of Li (mean 0.11 wt. percent) are indicators of a hydrothermal origin, and distinguishes these samples, along with the high Mn and low Fe contents, from hydrogenetic Fe-Mn crusts. Other enriched elements include Ba (mean 0.14 percent), Cu (249 ppm), Mo (451 ppm), Ni (400 ppm), Zn (394 ppm), V (214 ppm), and W (132 ppm). Chondrite-normalized REE patterns show large negative Ce anomalies and LREE enrichments, both characteristic of hydrothermal Mn deposits. Small negative Eu anomalies are not typical of hydrothermal deposits and can be explained either by the absence of leaching of plagioclase by the hydrothermal fluids or by the precipitation of Eu-rich minerals, such as barite and anhydrite, at depth. The high base-metal contents indicate that sulfides are not forming deeper in the hydrothermal system or that such deposits are being leached by the ascending fluids. Textures of the thickest Mn deposits indicate that the Mn oxides formed below the seabed from ascending fluids during multiple phases of waxing and waning hydrothermal pulses. The deposits were later exposed at the seafloor by

  12. Manganese abundances in Galactic bulge red giants

    Barbuy, B.; Hill, V.; Zoccali, M.; Minniti, D.; Renzini, A.; Ortolani, S.; Gómez, A.; Trevisan, M.; Dutra, N.


    Context. Manganese is mainly produced in type II SNe during explosive silicon burning, in incomplete Si-burning regions, and depends on several nucleosynthesis environment conditions, such as mass cut between the matter ejected and falling back onto the remnant, electron and neutron excesses, mixing fallback, and explosion energy. Manganese is also produced in type Ia SNe. Aims: The aim of this work is the study of abundances of the iron-peak element Mn in 56 bulge giants, among which 13 are red clump stars. Four bulge fields along the minor axis are inspected. The study of abundances of Mn-over-Fe as a function of metallicity in the Galactic bulge may shed light on its production mechanisms. Methods: High-resolution spectra were obtained using the FLAMES+UVES spectrograph on the Very Large Telescope. The spectra were obtained within a program to observe 800 stars using the GIRAFFE spectrograph, together with the present UVES spectra. Results: We aim at identifying the chemical evolution of manganese, as a function of metallicity, in the Galactic bulge. We find [Mn/Fe] ~ -0.7 at [Fe/H] ~ -1.3, increasing to a solar value at metallicities close to solar, and showing a spread around - 0.7 ≲ [Fe/H] ≲ -0.2, in good agreement with other work on Mn in bulge stars. There is also good agreement with chemical evolution models. We find no clear difference in the behaviour of the four bulge fields. Whereas [Mn/Fe] vs. [Fe/H] could be identified with the behaviour of the thick disc stars, [Mn/O] vs. [O/H] has a behaviour running parallel, at higher metallicities, compared to thick disc stars, indicating that the bulge enrichment might have proceeded differently from that of the thick disc. Observations collected at the European Southern Observatory, Paranal, Chile (ESO programmes 71.B-0617A, 73.B0074A, and GTO 71.B-0196).Tables 1-6 and Figs. 1-6 are available in electronic form at

  13. Correlation between airborne manganese concentration at the workstations in the iron foundry and manganese concentration in workers' blood.

    Mirmohammadi, Seyedtaghi; Moghaddasi, Yosef; Yazdani, Jamshid; Yousefinejad, Razyeh; Esfandyari, Yahya; Gorgani, Mohsen; Habibpour, Manijeh


    Manganese (Mn) used as raw material for melting process in the ferrous foundry is considered as hazardous neurotoxic substance because it accumulates in the central nervous system and may cause neurological disorders. The furnace-men and melting department workers are potentially exposed to manganese particles or fume in the workplace. The objective of the research has been to investigate the sources and levels of manganese exposure in the foundry by correlation of blood-manganese (B-Mn) and air-manganese (air-Mn) measurement. Air-Mn and Mn of blood serum were measured involving workers who worked in a big-sized foundry during 1 year. The standard method of the Occupational Safety and Health Administration (OSHA) ID-121 was used for air and blood assessment and atomic absorption spectroscopy (AAS) was carried out for air and blood sample analysis. The air sampling results have revealed that there is a high exposure to manganese (4.5 mg/m3) in the workplace as compared to the National Institute for Occupational Safety and Health's (NIOSH) time weighted average (the reference time-weighted average (TWA) = 1 mg/m3). The average blood serum Mn concentration was 2.745 μg/l for subjects working for shorter than 3 months and 274.85 μg/l for subjects working 3-12 months. Against the research hypothesis there was no correlation between the air-Mn concentration and the B-Mn (serum) level of manganese in the serum of the exposed subjects. It may be due to short time of air sampling of manganese airborne particles, and a real-time monitoring of airborne manganese particles is suggested for any future study. Med Pr 2017;68(4):449-458.

  14. Correlation between airborne manganese concentration at the workstations in the iron foundry and manganese concentration in workers’ blood

    Seyedtaghi Mirmohammadi


    Full Text Available Background: Manganese (Mn used as raw material for melting process in the ferrous foundry is considered as hazardous neurotoxic substance because it accumulates in the central nervous system and may cause neurological disorders. The furnace-men and melting department workers are potentially exposed to manganese particles or fume in the workplace. The objective of the research has been to investigate the sources and levels of manganese exposure in the foundry by correlation of blood-manganese (B-Mn and air-manganese (air-Mn measurement. Material and Methods: Air-Mn and Mn of blood serum were measured involving workers who worked in a big-sized foundry during 1 year. The standard method of the Occupational Safety and Health Administration (OSHA ID-121 was used for air and blood assessment and atomic absorption spectroscopy (AAS was carried out for air and blood sample analysis. Results: The air sampling results have revealed that there is a high exposure to manganese (4.5 mg/m3 in the workplace as compared to the National Institute for Occupational Safety and Health’s (NIOSH time weighted average (the reference time-weighted average (TWA = 1 mg/m3. The average blood serum Mn concentration was 2.745 μg/l for subjects working for shorter than 3 months and 274.85 μg/l for subjects working 3–12 months. Conclusions: Against the research hypothesis there was no correlation between the air-Mn concentration and the B-Mn (serum level of manganese in the serum of the exposed subjects. It may be due to short time of air sampling of manganese airborne particles, and a real-time monitoring of airborne manganese particles is suggested for any future study. Med Pr 2017;68(4:449–458

  15. Manganese inhibits poly(ADP-ribosyl)ation in human cells: a possible mechanism behind manganese-induced toxicity?

    Bornhorst, Julia; Ebert, Franziska; Hartwig, Andrea; Michalke, Bernhard; Schwerdtle, Tanja


    For humans manganese is both an essential trace element and, at higher doses, a toxic metal. Due to the ubiquitous occurrence of manganese in foodstuff, in industrial countries daily dietary uptake is higher as compared to the estimated daily requirement. Therefore manganese deficiency is extremely rare. In contrast chronic manganese toxicity, affecting primarily the central nervous system, is more prevalent. Thus manganese occupational and dietary overexposure has been shown to cause progressive, permanent, neurodegenerative damage, resulting in syndromes similar to idiopathic Parkinson's disease. To date modes of manganese neurotoxic action are poorly understood and in most studies oxidative stress is postulated as the underlying mechanism. The present study searched on the cellular level for a molecular mechanism behind manganese-induced neurotoxicity and investigated bioavailability, cytotoxicity and genotoxicity of MnCl(2), as well as its impact on the DNA damage response in human cells (HeLa S3) in culture. Whereas up to 10 µM MnCl(2) showed no induction of DNA strand breaks after 24 h incubation, manganese strongly inhibited H(2)O(2)-stimulated poly(ADP-ribosyl)ation at low, completely non-cytotoxic, for certain human exposure, relevant concentrations starting at 1 µM. Thereby inhibition of this essential DNA damage response signalling reaction was not due to a reduced gene expression or protein level of the responsible polymerase PARP-1. Taken together, the results indicate that manganese, under conditions of either overload due to high exposure or disturbed homeostasis, can disturb the cellular response to DNA strand breaks, which has been shown before (S. Katyal and P. J. McKinnon, Mech. Ageing Dev., 2008, 129, 483-491) to result in neurological diseases.

  16. Towards a high open-circuit voltage by co-additives in electrolyte for high-efficiency dye-sensitized solar cells

    Sun, Xun; Li, Yafeng; Mao, Haijuan; Dou, Jie; Wei, Mingdeng


    The co-additives of benzimidazole and 2-ethylimidazole in electrolyte have an obvious effect on the performance of dye-sensitized solar cells due to their good coordination ability of titanium dioxide, which could affect the energy levels and charge transfer process. Through a balance of the concentrations, the best efficiency of 7.93% with a high open-circuit voltage of 0.817 V is achieved for a cell fabricated with the electrolyte contains benzimidazole and 2-ehtylimidazole by a molar ratio of 9.5/0.5.

  17. Forecasting carbon dioxide emissions.

    Zhao, Xiaobing; Du, Ding


    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy.

  18. Uranium dioxide electrolysis

    Willit, James L [Batavia, IL; Ackerman, John P [Prescott, AZ; Williamson, Mark A [Naperville, IL


    This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

  19. Dermal administration of manganese porphyrin by iontophoresis.

    Ito, Fuminori; Imamura, Shinya; Asayama, Shoichiro; Kanamura, Kiyoshi; Kawakami, Hiroyoshi


    The present study describes a technique for dermal administration of cationic manganese porphyrin (Mn-porphyrin), an antioxidant with superoxide dismutase (SOD) activity, in hairless mouse. In general, the stratum corneum on the surface of the skin represents a barrier to passive diffusion of therapeutic agents by standard dermal administration. The present study investigated whether, dermal administration of Mn-porphyrin solution using iontophoresis, the electrical dermal administration technique, could overcome this barrier. We visually confirmed that Mn-porphyrin had penetrated to the reverse side of the hairless mouse skin after iontophoresis for a short period. With prolonged iontophoresis, the ratio of detectable Mn-porphyrin solution on the reverse side of the hairless mouse skin increased. In the future, this technique could provide an innovative approach for delivery of this antioxidant in intractable disease.

  20. Method of dosing electrolyte in a sealed storage battery

    Boldin, R.V.; Akbulatova, A.D.; Mel' nikova, T.A.; Perugina, T.P.


    A method is proposed for dosing electrolyte in a sealed storage battery by weighing the storage battery before pouring in the electrolyte, pouring in the electrolyte, forming, removing the surplus electrolyte, repeated weighing, calculation for the difference in the weight of the quantity of the remaining electrolyte and correction for the weight of the quantity of electrolyte according to theoretical calculations. In order to improve accuracy after repeated weighing, a measurement is made of the magnitude of free gas space of the storage battery and a volume of electrolyte is added until it reaches 90-95% of the degree of filling of the pores included in the volume of the gas space.

  1. Ultrafiltration of a polymer-electrolyte mixture

    Vonk, P; Noordman, T.R; Schippers, D; Tilstra, B; Wesselingh, J.A


    We present a mathematical model to describe the ultrafiltration behaviour of polymer-electrolyte mixtures. The model combines the proper thermodynamic forces (pressure, chemical potential and electrical potential differences) with multicomponent diffusion theory. The model is verified with experimen

  2. Electrolytic tiltmeters inside magnetic fields: Some observations

    Alberdi, J. [CIEMAT, Madrid (Spain); Arce, P. [CIEMAT, Madrid (Spain); Barcala, J.M. [CIEMAT, Madrid (Spain); Calvo, E. [CIEMAT, Madrid (Spain); Ferrando, A. [CIEMAT, Madrid (Spain)]. E-mail:; Josa, M.I. [CIEMAT, Madrid (Spain); Luque, J.M. [CIEMAT, Madrid (Spain); Molinero, A. [CIEMAT, Madrid (Spain); Navarrete, J. [CIEMAT, Madrid (Spain); Oller, J.C. [CIEMAT, Madrid (Spain); Yuste, C. [CIEMAT, Madrid (Spain); Calderon, A. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Garcia-Moral, L.A. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Gomez, G. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Gonzalez-Sanchez, F.J. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Martinez-Rivero, C. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Matorras, F. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Rodrigo, T. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Ruiz-Arbol, P. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Scodellaro, L. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Sobron, M. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Vila, I. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Virto, A.L. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain)


    We present observations of the electrolytic clinometers behaviour inside magnetic field environments introducing phenomenological expressions to account for the measured output voltage variations as functions of field gradients and field strengths.

  3. Electrolytic silver ion cell sterilizes water supply

    Albright, C. F.; Gillerman, J. B.


    Electrolytic water sterilizer controls microbial contamination in manned spacecraft. Individual sterilizer cells are self-contained and require no external power or control. The sterilizer generates silver ions which do not impart an unpleasant taste to water.

  4. Highly Quantitative Electrochemical Characterization of Non-Aqueous Electrolytes & Solid Electrolyte Interphases

    Sergiy V. Sazhin; Kevin L. Gering; Mason K. Harrup; Harry W. Rollins


    The methods to measure solid electrolyte interphase (SEI) electrochemical properties and SEI formation capability of non-aqueous electrolyte solutions are not adequately addressed in the literature. And yet, there is a strong demand in new electrolyte generations that promote stabilized SEIs and have an influence to resolve safety, calendar life and other limitations of Li-ion batteries. To fill this gap, in situ electrochemical approach with new descriptive criteria for highly quantitative characterization of SEI and electrolytes is proposed. These criteria are: SEI formation capacity, SEI corrosion rate, SEI maintenance rate, and SEI kinetic stability. These criteria are associated with battery parameters like irreversible capacity, self-discharge, shelf-life, power, etc. Therefore, they are especially useful for electrolyte development and standard fast screening, allowing a skillful approach to narrow down the search for the best electrolyte. The characterization protocol also allows retrieving information on interfacial resistance for SEI layers and the electrochemical window of electrolytes, the other important metrics of characterization. The method validation was done on electrolyte blends containing phosphazenes, developed at Idaho National Laboratory, as 1.2M LiPF6 [80 % EC-MEC (2:8) (v/v) + 20% Phosphazene variety] (v/v), which were targeted for safer electrolyte variations.

  5. A comparative study of gel polymer electrolytes based on PVDF-HFP and liquid electrolytes, containing imidazolinium ionic liquids of different carbon chain lengths in DSSCs

    Suryanarayanan, Vembu [Department of Chemical Engineering, National Taiwan University, Taipei 10617 (China); Lee, Kun-Mu [Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617 (China); Ho, Wen-Hsien; Chen, Hung-Chang [Department of Product Development, Taiwan Textile Research Institute, Tucheng 23674 (China); Ho, Kuo-Chuan [Department of Chemical Engineering, National Taiwan University, Taipei 10617 (China); Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617 (China)


    The photoelectrochemical characteristics of titanium dioxide (TiO{sub 2})-based dye-sensitized solar cells (DSSCs) containing gel polymer electrolyte (GPE) and organic liquid electrolyte (OLE) were studied in detail. GPE was prepared by adding poly(vinyidene fluoride-co-hexafluoro propylene) (PVDF-HFP) to imidazolinium ionic liquids (IILs) of the type, 1-methyl-3-alkyl imidazolinium iodides (alkyl is C{sub n}H{sub 2n+1}, where n=3-10) in methoxy propionitrile (MPN) and the OLE contained the above molten salt in MPN. The IILs were synthesized in the laboratory and characterized by {sup 1}H nuclear magnetic resonance spectroscopy (NMR). The conductivities ({sigma}) of both GPE and OLE decrease with increase in chain length (n) of the alkyl group of IILs; however, the effect is more drastic in the former case. The performance of the DSSCs containing OLE increases with the increase in alkyl chain length of IIL from C3 to C7, whereas, there is a linear decrease in the efficiency of the DSSCs incorporated with GPE containing IIL of alkyl chain length from C3 to C10. The change in short circuit current density (J{sub SC}) determines the cell efficiency as the V{sub OC} of the DSSCs remains almost the same with increase of alkyl chain length of IILs for both the electrolytes. The change in J{sub SC} values and the consistency of the V{sub OC} of the DSSCs for both the electrolytes may be explained on the basis of increase in viscosity of IILs from C3 to C10 and the dominating role of the 4-tertiary butyl pyridine (TBP), respectively, on the phenomenon of charge recombination. (author)

  6. Multiple-membrane multiple-electrolyte redox flow battery design

    Yan, Yushan; Gu, Shuang; Gong, Ke


    A redox flow battery is provided. The redox flow battery involves multiple-membrane (at least one cation exchange membrane and at least one anion exchange membrane), multiple-electrolyte (one electrolyte in contact with the negative electrode, one electrolyte in contact with the positive electrode, and at least one electrolyte disposed between the two membranes) as the basic characteristic, such as a double-membrane, triple electrolyte (DMTE) configuration or a triple-membrane, quadruple electrolyte (TMQE) configuration. The cation exchange membrane is used to separate the negative or positive electrolyte and the middle electrolyte, and the anion exchange membrane is used to separate the middle electrolyte and the positive or negative electrolyte.

  7. Modeling Electrolytically Top-Gated Graphene

    Mišković ZL


    Full Text Available Abstract We investigate doping of a single-layer graphene in the presence of electrolytic top gating. The interfacial phenomenon is modeled using a modified Poisson–Boltzmann equation for an aqueous solution of simple salt. We demonstrate both the sensitivity of graphene’s doping levels to the salt concentration and the importance of quantum capacitance that arises due to the smallness of the Debye screening length in the electrolyte.

  8. Handheld Microneedle-Based Electrolyte Sensing Platform.

    Miller, Philip R. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Rivas, Rhiana [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Johnson, David [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Edwards, Thayne L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Koskelo, Markku [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Shawa, Luay [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Brener, Igal [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Chavez, Victor H. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Polsky, Ronen [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)


    Sandia National Laboratories will provide technical assistance, within time and budget, to Requester on testing and analyzing a microneedle-based electrolyte sensing platform. Hollow microneedles will be fabricated at Sandia and integrated with a fluidic chip using plastic laminate prototyping technology available at Sandia. In connection with commercial ion selective electrodes the sensing platform will be tested for detection of electrolytes (sodium and/or potassium) within physiological relevant concent ration ranges.

  9. Review: electrolytes for electrochemical energy storage

    Xia, Lin; Yu, Linpo; Hu, Di; Chen, George Z.


    An electrolyte is a key component of electrochemical energy storage (EES) devices and its properties greatly affect the energy capacity, rate performance, cyclability and safety of all EES devices. This article offers a critical review of the recent progress and challenges in electrolyte research and development, particularly for supercapacitors and supercapatteries, rechargeable batteries (such as lithium-ion and sodium-ion batteries), and redox flow batteries (including fuel cells in a broa...

  10. Gastroprotective Properties of Manganese Chloride on Acetic Acid ...

    Dr Olaleye

    factors causes ulcer, gastric acid secretion still remains an important factor in ... acid hyper secretion can also cause problems such as ... and many diseases including osteoporosis, ..... amount of manganese delivered in children's parenteral.

  11. Status and Role of Manganese in the Environment

    RK Kamble


    Full Text Available Manganese is the second most abundant heavy metal, and in frequency list of elements it occupies 12th place. The Earth’s core contains about 1.5% manganese. According to Indian Standards for Drinking water (IS 10500:2012 manganese concentration in drinking water is 0.1 ppm (acceptable limit and 0.3 ppm as permissible limit. An attempt has been made to record the presence of manganese in different environmental matrices such as air, water, soil, food, its effects on plants, animals including human beings. DOI: International Journal of Environment Vol.3(3 2014: 222-234

  12. Manganese, Iron, and sulfur cycling in Louisiana continental shelf sediments

    Sulfate reduction is considered the primary pathway for organic carbon remineralization on the northern Gulf of Mexico Louisiana continental shelf (LCS) where bottom waters are seasonally hypoxic, yet limited information is available on the importance of iron and manganese cyclin...

  13. Sorbents based on xerogels of zirconium, aluminum and manganese oxyhydroxides

    R.V. Smotraiev; E.O. Sorochkina; А.V. Dzuba; Y.D. Galivets


    ...: The aim of this work is to determine the impact of aluminum and manganese ions additives on surface and sorption properties of zirconium oxyhydroxide based sorbents during their production process...

  14. Manganese Concentrations In Hair and Fingernail of Some Kano ...


    sonic bath and on drying were stored in small plastic tubes ... using three different washing methods. Distilled ..... Derivation of manganese safe an adequate daily intakes. In .... Nuclear Chemistry 236(1-2):25-28. ... Hazardous Waste Site.

  15. India's manganese nodule mine site in the Central Indian Ocean

    Banakar, V.K.

    This commentary highlights the activities of massive exploration programme for manganese nodule deposits in the Central Indian Basin located 5 km below the ocean surface and India's claim for mine site development and registration with UNCLOS...

  16. Manganese nodules in the Exclusive Economic Zone of Mauritius

    Nath, B.N.; ShyamPrasad, M.

    The distribution of manganese nodules in the Exclusive Economic Zone of the island nation Mauritius was delineated during cruise SK-35 of ORV Sagar Kanya in 1987. The areas surveyed included Saya de Malha and Nazareth Banks, the Cargados Carajos...

  17. Manganese, Iron, and sulfur cycling in Louisiana continental shelf sediments

    Sulfate reduction is considered the primary pathway for organic carbon remineralization on the northern Gulf of Mexico Louisiana continental shelf (LCS) where bottom waters are seasonally hypoxic, yet limited information is available on the importance of iron and manganese cyclin...

  18. By lithology Zbruch deposits (Lower Sarmatian Nikopol manganese ore Basin

    Bogdanovich V.V.


    Full Text Available Based on lithologic-paleogeographic study Zbruch layers of Nikopol manganese ore Basin sediments described lithological and genetic types of rocks and facies conditions of formation of deposits.

  19. Wedge wetting by electrolyte solutions

    Mußotter, Maximilian; Bier, Markus


    The wetting of a charged wedgelike wall by an electrolyte solution is investigated by means of classical density functional theory. As in other studies on wedge wetting, this geometry is considered as the most simple deviation from a planar substrate, and it serves as a first step toward more complex confinements of fluids. By focusing on fluids containing ions and surface charges, features of real systems are covered that are not accessible within the vast majority of previous theoretical studies concentrating on simple fluids in contact with uncharged wedges. In particular, the filling transition of charged wedges is necessarily of first order, because wetting transitions of charged substrates are of first order and the barrier in the effective interface potential persists below the wetting transition of a planar wall; hence, critical filling transitions are not expected to occur for ionic systems. The dependence of the critical opening angle on the surface charge, as well as the dependence of the filling height, of the wedge adsorption, and of the line tension on the opening angle and on the surface charge are analyzed in detail.

  20. Assessing manganese nanostructures based carbon nanotubes composite for the highly sensitive determination of vitamin C in pharmaceutical formulation.

    Hameed, Sadaf; Munawar, Anam; Khan, Waheed S; Mujahid, Adnan; Ihsan, Ayesha; Rehman, Asma; Ahmed, Ishaq; Bajwa, Sadia Z


    This work is the first report describing the development of a novel three dimensional manganese nanostructures based carbon nanotubes (CNTs-Mn NPs) composite, for the determination of ascorbic acid (vitamin C) in pharmaceutical formulation. Carbon nanotubes (CNTs) were used as a conductive skeleton to anchor highly electrolytic manganese nanoparticles (Mn NPs), which were prepared by a hydrothermal method. Scanning electron microscopy and atomic force microscopy revealed the presence of Mn Nps of 20-25nm, anchored along the whole length of CNTs, in the form of patches having a diameter of 50-500nm. Fourier transform infrared spectroscopy confirmed the surface modification of CNTs by amine groups, whereas dynamic light scattering established the presence of positive charge on the prepared nanocomposite. The binding events were studied by monitoring cyclic voltammetry signals and the developed nanosensor exhibited highly sensitive response, demonstrating improved electrochemical activity towards ascorbic acid. Linear dependence of the peak current on the square root of scan rates (R(2)=0.9785), demonstrated that the oxidation of ascorbic acid by the designed nanostructures is a diffusion control mechanism. Furthermore, linear range was found to be 0.06-4.0×10(-3)M, and nanosensor displayed an excellent detection limit of 0.1µM (S/N=3). This developed nanosensor was successfully applied for the determination of vitamin C in pharmaceutical formulation. Besides, the results of the present study indicate that such a sensing platform may offer a different pathway to utilize manganese nanoparticles based CNTs composite for the determination of other bio-molecules as well.

  1. Boron Clusters as Highly Stable Magnesium-Battery Electrolytes**

    Carter, Tyler J; Mohtadi, Rana; Arthur, Timothy S; Mizuno, Fuminori; Zhang, Ruigang; Shirai, Soichi; Kampf, Jeff W


    Boron clusters are proposed as a new concept for the design of magnesium-battery electrolytes that are magnesium-battery-compatible, highly stable, and noncorrosive. A novel carborane-based electrolyte incorporating an unprecedented magnesium-centered complex anion is reported and shown to perform well as a magnesium-battery electrolyte. This finding opens a new approach towards the design of electrolytes whose likelihood of meeting the challenging design targets for magnesium-battery electrolytes is very high. PMID:24519845

  2. Synthesis and characterization of cathode, anode and electrolyte materials for rechargeable lithium batteries

    Yang, Shoufeng

    Two new classes of cathode materials were studied: iron phosphate/sulfate materials and layered manganese oxides, both of which are low cost and had shown some potential. The first class of materials have poor conductivity and cyclability. I studied a number of methods for increasing the conductivity, and determined that grinding the material with carbon black was as effective as special in-situ coatings. The optimum carbon loading was determined to be between 6 and 15 wt%. Too much carbon reduces the volumetric energy density, whereas too little significantly increased cell polarization (reduced the rate of reaction). The kinetic and thermodynamic stability of LiFePO 4 was also studied and it was determined that over discharge protection will be needed as irreversible Li3PO4 can be formed at low potentials. A novel hydrothermal synthesis method was developed, but the significant level of Fe on the Li site reduces the reaction rate too much. In the case of the layered manganese oxide, cation substitution with Co and Ni is found to be effective in avoiding Jahn-Teller effects and improving electrochemistry. A wide range of tin compounds have been suggested as lithium storage media for advanced anode materials, as tin can store over 4 Li per Sn atom. Lithium hexafluorophosphate, LiPF6, is presently the salt of choice for LiCoO2 batteries, but it is expensive and dissolves some manganese compounds. The lithium bis(oxolato)borate (BOB) salt was recently reported, and I made a study of its use in cells with the LiFePO4 cathode and the tin anode. During its synthesis, it became clear that LiBOB is very reactive with many solvents, and these complexes were characterized to better understand this new material. In LiBOB the lithium is five coordinated, an unstable configuration for the lithium ion so that water and many other solvents rapidly react to make a six coordination. Only in the case of ethylene carbonate was the lithium found to be four coordinated. The Li

  3. Lithium-Air Batteries with Hybrid Electrolytes.

    He, Ping; Zhang, Tao; Jiang, Jie; Zhou, Haoshen


    During the past decade, Li-air batteries with hybrid electrolytes have attracted a great deal of attention because of their exceptionally high capacity. Introducing aqueous solutions and ceramic lithium superionic conductors to Li-air batteries can circumvent some of the drawbacks of conventional Li-O2 batteries such as decomposition of organic electrolytes, corrosion of Li metal from humidity, and insoluble discharge product blocking the air electrode. The performance of this smart design battery depends essentially on the property and structure of the cell components (i.e., hybrid electrolyte, Li anode, and air cathode). In recent years, extensive efforts toward aqueous electrolyte-based Li-air batteries have been dedicated to developing the high catalytic activity of the cathode as well as enhancing the conductivity and stability of the hybrid electrolyte. Herein, the progress of all aspects of Li-air batteries with hybrid electrolytes is reviewed. Moreover, some suggestions and concepts for tailored design that are expected to promote research in this field are provided.

  4. Photo-catalytic Degradation and Sorption of Radio-cobalt from EDTA-Co Complexes Using Manganese Oxide Materials - 12220

    Koivula, Risto; Harjula, Risto [University of Helsinki, P.O.Box 55, FI-00014 Helsinki (Finland); Tusa, Esko [Fortum Power and Heat Oy P.O.Box 100, 00048 FORTUM (Finland)


    oxide were very promising for the treatment of EDTA complexed Co solutions. The better performance values and cheaper production cost of manganese oxide, compared to titanium dioxide, is so big driving force that further studies on the material are evident. The possibilities for continuous treatment, instead of the fluidized bed -type batch experiment are investigated and the effects of other compounds affecting the de-complexation of Co-EDTA are further studied. (authors)

  5. Oxygen toxicity in Streptococcus mutans: manganese, iron and superoxide dismutase

    Martin, M.E.; Strachan, R.C.; Aranha, H.; Evans, S.L.; Salin, M.L.; Welch, B.; Arceneaux, J.E.L.; Byers, B.R.


    When cultured anaerobically in a chemically defined medium that was treated with Chelex-100 to lower its trace metal content, Streptococcus mutans OMZ176 had no apparent requirement for manganese or iron. Manganese or iron was necessary for aerobic cultivation in deep static cultures. During continuous aerobic cultivation in a stirred chemostat, iron did not support the growth rate achieved with manganese. Since the dissolved oxygen level in the chemostat cultures was higher than the final level in the static cultures, manganese may be required for growth at elevated levels. In medium supplemented with manganese, cells grown anaerobically contained a low level of superoxide dismutase (SOD) activity; aerobic cultivation increased SOD activity at least threefold. In iron-supplemented medium, cells grown anaerobically also had low SOD activity; aerobic incubation resulted in little increase in SOD activity. Polyacrylamide gel electrophoresis of the cell extracts revealed a major band and a minor band of SOD activity in the cells grown with manganese; however, cells grown with iron contained a single band of SOD activity with an R/sub f/ value similar to that of the major band found in cells grown with manganese. None of the SOD activity bands were abolished by the inclusion of 2 mM hydrogen peroxide in the SOD activity strain. S. mutans may not produce a separate iron-containing SOD but may insert either iron or manganese into an apo-SOD protein. Alternatively, iron may function in another activity (not SOD) that augments the defense against oxygen toxicity at low SOD levels. 28 references, 3 figures, 1 table.

  6. Iron and manganese contamination: sources, adverse effects and control methods.

    Satyanarayana, Y V V; Saraf, Renu


    This article discusses the problem of iron and manganese contamination, the adverse effects and available control methods. The presence of iron and manganese in water causes serious commercial and health problems. Various treatment methods are available to treat water contaminated with these elements. However, catalytic media is an excellent choice particularly increasing given the preference for non-chemical water treatment. INDION ISR and BIRM are the most popularly used synthetically manufactured catalytic media.

  7. Study on Manganese Balance in Zinc Hydrometallurgy Factory System%湿法炼锌厂系统锰平衡的研究

    孙国记; 段宏志; 李志强


    Based on the production practice of zinc hydrometallurgy production , Through analyzing the change of manga-nese-bearing zinc hydrometallurgy process , it is pointed out in the high manganese condition that short-term measures should be taken to reduce acid zinc ratio with the reduction of manganese powder at the same time , and in the long run measures should be taken to solve the problem of effective open circuit for accumulated impurities from old electrolytic zinc plant system .Combined with change in the impurities in zinc leaching residues during the second washing , the balance of manganese in system was summarized .%本文根据生产实践,以分析系统含锰变化时锌湿法生产情况为出发点,指出高锰时短期应采取降低酸锌比同时配合减少锰粉加入量的技术措施,长远应考虑如何解决老电解锌厂系统内累积杂质有效开路的问题,并结合锌浸出渣二次洗涤前后杂质变化,总结系统锰的平衡。

  8. Electrochemical performance of nanostructured spinel LiMn 2O 4 in different aqueous electrolytes

    Tian, Lei; Yuan, Anbao

    A nanostructured spinel LiMn 2O 4 electrode material was prepared via a room-temperature solid-state grinding reaction route starting with hydrated lithium acetate (LiAc·2H 2O), manganese acetate (MnAc 2·4H 2O) and citric acid (C 6H 8O 7·H 2O) raw materials, followed by calcination of the precursor at 500 °C. The material was characterized by X-ray diffraction (XRD) and transmission electron microscope techniques. The electrochemical performance of the LiMn 2O 4 electrodes in 2 M Li 2SO 4, 1 M LiNO 3, 5 M LiNO 3 and 9 M LiNO 3 aqueous electrolytes was studied using cyclic voltammetry, ac impedance and galvanostatic charge/discharge methods. The LiMn 2O 4 electrode in 5 M LiNO 3 electrolyte exhibited good electrochemical performance in terms of specific capacity, rate dischargeability and charge/discharge cyclability, as evidenced by the charge/discharge results.

  9. Magnesium-dependent processes are targets of bacterial manganese toxicity

    Hohle, Thomas H.; O’Brian, Mark R.


    A Bradyrhizobium japonicum mutant defective in the gene encoding the high affinity Mn2+ transporter MntH has a severe growth phenotype under manganese limitation. Here, we isolated suppressor mutants of an mntH strain that grew under manganese limitation, and activities of high affinity Mn2+ transport and Mn2+-dependent enzymes were partially rescued. The suppressor strains harbor gain-of-function mutations in the gene encoding the Mg2+ channel MgtE. The MgtE variants likely allow Mn2+ entry via loss of a gating mechanism that normally holds the transporter in the closed state when cellular Mg2+ levels are high. Both MgtE-dependent and -independent suppressor phenotypes were recapitulated by magnesium-limited growth of the mntH strain. Growth studies of wild type cells suggest that manganese is toxic to cells when environmental magnesium is low. Moreover, extracellular manganese and magnesium levels were manipulated to inhibit growth without substantially altering the intracellular content of either metal, implying that manganese toxicity depends on its cellular distribution rather than the absolute concentration. Mg2+-dependent enzyme activities were found to be inhibited or stimulated by Mn2+. We conclude that Mn2+ can occupy Mg2+-binding sites in cells, and suggest that Mg2+-dependent processes are targets of manganese toxicity. PMID:24975873

  10. Spatial and temporal variations of manganese concentrations in drinking water.

    Barbeau, Benoit; Carrière, Annie; Bouchard, Maryse F


    The objective of this study was to assess the variability of manganese concentrations in drinking water (daily, seasonal, spatial) for eight communities who participated in an epidemiological study on neurotoxic effects associated with exposure to manganese in drinking water. We also assessed the performance of residential point-of-use and point-of-entry devices (POE) for reducing manganese concentrations in water. While the total Mn concentrations measured during this study were highly variable depending on the location (manganese concentration for 4 out of 5 sampling locations. The efficiency of reverse osmosis and ion exchange for total Mn removal was consistently high while activated carbon provided variable results. The four POE greensand filters investigated all increased (29 to 199%) manganese concentration, indicating deficient operation and/or maintenance practices. Manganese concentrations in the distribution system were equal or lower than at the inlet, indicating that sampling at the inlet of the distribution system is conservative. The decline in total Mn concentration was linked to higher water residence time in the distribution system.

  11. Permanganate-based synthesis of manganese oxide nanoparticles in ferritin

    Olsen, Cameron R.; Smith, Trevor J.; Embley, Jacob S.; Maxfield, Jake H.; Hansen, Kameron R.; Peterson, J. Ryan; Henrichsen, Andrew M.; Erickson, Stephen D.; Buck, David C.; Colton, John S.; Watt, Richard K.


    This paper investigates the comproportionation reaction of MnII with {{{{MnO}}}4}- as a route for manganese oxide nanoparticle synthesis in the protein ferritin. We report that {{{{MnO}}}4}- serves as the electron acceptor and reacts with MnII in the presence of apoferritin to form manganese oxide cores inside the protein shell. Manganese loading into ferritin was studied under acidic, neutral, and basic conditions and the ratios of MnII and permanganate were varied at each pH. The manganese-containing ferritin samples were characterized by transmission electron microscopy, UV/Vis absorption, and by measuring the band gap energies for each sample. Manganese cores were deposited inside ferritin under both the acidic and basic conditions. All resulting manganese ferritin samples were found to be indirect band gap materials with band gap energies ranging from 1.01 to 1.34 eV. An increased UV/Vis absorption around 370 nm was observed for samples formed under acidic conditions, suggestive of MnO2 formation inside ferritin.

  12. Low copper and high manganese levels in prion protein plaques

    Johnson, Christopher J.; Gilbert, P.U.P.A.; Abrecth, Mike; Baldwin, Katherine L.; Russell, Robin E.; Pedersen, Joel A.; McKenzie, Debbie


    Accumulation of aggregates rich in an abnormally folded form of the prion protein characterize the neurodegeneration caused by transmissible spongiform encephalopathies (TSEs). The molecular triggers of plaque formation and neurodegeneration remain unknown, but analyses of TSE-infected brain homogenates and preparations enriched for abnormal prion protein suggest that reduced levels of copper and increased levels of manganese are associated with disease. The objectives of this study were to: (1) assess copper and manganese levels in healthy and TSE-infected Syrian hamster brain homogenates; (2) determine if the distribution of these metals can be mapped in TSE-infected brain tissue using X-ray photoelectron emission microscopy (X-PEEM) with synchrotron radiation; and (3) use X-PEEM to assess the relative amounts of copper and manganese in prion plaques in situ. In agreement with studies of other TSEs and species, we found reduced brain levels of copper and increased levels of manganese associated with disease in our hamster model. We also found that the in situ levels of these metals in brainstem were sufficient to image by X-PEEM. Using immunolabeled prion plaques in directly adjacent tissue sections to identify regions to image by X-PEEM, we found a statistically significant relationship of copper-manganese dysregulation in prion plaques: copper was depleted whereas manganese was enriched. These data provide evidence for prion plaques altering local transition metal distribution in the TSE-infected central nervous system.

  13. Magnesium-dependent processes are targets of bacterial manganese toxicity.

    Hohle, Thomas H; O'Brian, Mark R


    A Bradyrhizobium japonicum mutant defective in the gene encoding the high-affinity Mn(2+) transporter MntH has a severe growth phenotype under manganese limitation. Here, we isolated suppressor mutants of an mntH strain that grew under manganese limitation, and activities of high-affinity Mn(2+) transport and Mn(2+) -dependent enzymes were partially rescued. The suppressor strains harbour gain-of-function mutations in the gene encoding the Mg(2+) channel MgtE. The MgtE variants likely allow Mn(2+) entry via loss of a gating mechanism that normally holds the transporter in the closed state when cellular Mg(2+) levels are high. Both MgtE-dependent and MgtE-independent suppressor phenotypes were recapitulated by magnesium-limited growth of the mntH strain. Growth studies of wild-type cells suggest that manganese is toxic to cells when environmental magnesium is low. Moreover, extracellular manganese and magnesium levels were manipulated to inhibit growth without substantially altering the intracellular content of either metal, implying that manganese toxicity depends on its cellular distribution rather than the absolute concentration. Mg(2+) -dependent enzyme activities were found to be inhibited or stimulated by Mn(2+) . We conclude that Mn(2+) can occupy Mg(2+) binding sites in cells, and suggest that Mg(2+) -dependent processes are targets of manganese toxicity.

  14. Failure of manganese to protect from Shiga toxin.

    Marsha A Gaston

    Full Text Available Shiga toxin (Stx, the main virulence factor of Shiga toxin producing Escherichia coli, is a major public health threat, causing hemorrhagic colitis and hemolytic uremic syndrome. Currently, there are no approved therapeutics for these infections; however manganese has been reported to provide protection from the Stx1 variant isolated from Shigella dysenteriae (Stx1-S both in vitro and in vivo. We investigated the efficacy of manganese protection from Stx1-S and the more potent Stx2a isoform, using experimental systems well-established for studying Stx: in vitro responses of Vero monkey kidney cells, and in vivo toxicity to CD-1 outbred mice. Manganese treatment at the reported therapeutic concentration was toxic to Vero cells in culture and to CD-1 mice. At lower manganese concentrations that were better tolerated, we observed no protection from Stx1-S or Stx2a toxicity. The ability of manganese to prevent the effects of Stx may be particular to certain cell lines, mouse strains, or may only be manifested at high, potentially toxic manganese concentrations.

  15. Failure of manganese to protect from Shiga toxin.

    Gaston, Marsha A; Pellino, Christine A; Weiss, Alison A


    Shiga toxin (Stx), the main virulence factor of Shiga toxin producing Escherichia coli, is a major public health threat, causing hemorrhagic colitis and hemolytic uremic syndrome. Currently, there are no approved therapeutics for these infections; however manganese has been reported to provide protection from the Stx1 variant isolated from Shigella dysenteriae (Stx1-S) both in vitro and in vivo. We investigated the efficacy of manganese protection from Stx1-S and the more potent Stx2a isoform, using experimental systems well-established for studying Stx: in vitro responses of Vero monkey kidney cells, and in vivo toxicity to CD-1 outbred mice. Manganese treatment at the reported therapeutic concentration was toxic to Vero cells in culture and to CD-1 mice. At lower manganese concentrations that were better tolerated, we observed no protection from Stx1-S or Stx2a toxicity. The ability of manganese to prevent the effects of Stx may be particular to certain cell lines, mouse strains, or may only be manifested at high, potentially toxic manganese concentrations.

  16. 沉钒母液中锰离子制备电解金属锰的实验研究%An Experimental Study on Preparation of EMM from Manganese Ion in Mother Liquor

    陶长元; 伍锡斌; 彭毅; 张兴然; 舒建成; 彭浩; 陈燕; 刘作华


    提钒废水中含有钒、锰、铁、镁、钙、磷等多种元素,其中锰离子浓度达到10~16 g/L。实验以硫酸亚铁为还原剂,通过在酸性低浓度含锰废水中加入浓氨水调节 pH 值,使钒、铁、磷等离子沉积在渣相中。在除杂后的溶液中加入电解添加剂 SeO2和硫酸铵,确保电解液能满足正常电解要求。实验能够使酸性含锰废水中钒、铁、磷均低于特定的工艺要求指标0.01 g/L,电解金属锰达到DJMnDII 级,电耗能维持在6900 kW·h /t 锰以下,电流效率也能达到54.44%以上,阳极液中锰离子低于5 g/L。%We know that vanadium extraction wastewater contains vanadium,manganese,iron,magnesium, calcium,phosphorus and other elements.This paper,with ferrous sulfate as reducing agent in acid waste water,it contains low concentration manganese to adjust pH value by concentrating ammonia solution,including adding the right amount of active carbon powder,as can make the vanadium,iron,phosphorus deposition in the slag phase. Adding a certain amount of additive SeO2 ,the ammonium sulfate to the solution after removal of impurity to ensure that the electrolytic solution can meet the requirement of normal electrolysis.In this study,the process route can make acid waste water in vanadium.And iron and phosphorus are lower than the specific process requirements of 0.01 g/L.It can reduce the maximum degree of loss of manganese ion in solution.Electrolysis manganese metal elemental can not only reach industry standard in the general level DJMnD level to control the tons of electrolytic manganese power consumption,it is also maintained in the 6 900 kW·h.Manganese cathode current efficiency can reach more than 54.44% to reasonably control the manganese ion in the anode solution in 5 g/L.

  17. Multifunctional nanosheets based on folic acid modified manganese oxide for tumor-targeting theranostic application

    Hao, Yongwei; Wang, Lei; Zhang, Bingxiang; Zhao, Hongjuan; Niu, Mengya; Hu, Yujie; Zheng, Cuixia; Zhang, Hongling; Chang, Junbiao; Zhang, Zhenzhong; Zhang, Yun


    It is highly desirable to develop smart nanocarriers with stimuli-responsive drug-releasing and diagnostic-imaging functions for cancer theranostics. Herein, we develop a reduction and pH dual-responsive tumor theranostic platform based on degradable manganese dioxide (MnO2) nanosheets. The MnO2 nanosheets with a size of 20-60 nm were first synthesized and modified with (3-Aminopropyl) trimethoxysilane (APTMS) to get amine-functionalized MnO2, and then functionalized by NH2-PEG2000-COOH (PEG). The tumor-targeting group, folic acid (FA), was finally conjugated with the PEGylated MnO2 nanosheets. Then, doxorubicin (DOX), a chemotherapeutic agent, was loaded onto the modified nanosheets through a physical adsorption, which was designated as MnO2-PEG-FA/DOX. The prepared MnO2-PEG-FA/DOX nanosheets with good biocompatibility can not only efficiently deliver DOX to tumor cells in vitro and in vivo, leading to enhanced anti-tumor efficiency, but can also respond to a slightly acidic environment and high concentration of reduced glutathione (GSH), which caused degradation of MnO2 into manganese ions enabling magnetic resonance imaging (MRI). The longitudinal relaxation rate r 1 was 2.26 mM-1 s-1 at pH 5.0 containing 2 mM GSH. These reduction and pH dual-responsive biodegradable nanosheets combining efficient MRI and chemotherapy provide a novel and promising platform for tumor-targeting theranostic application.

  18. Aspects of carbon dioxide utilization

    Omae, Iwao [Omae Research Laboratories, 335-23 Mizuno, Sayama, Saitama 350-1317 (Japan)


    Carbon dioxide reacts with hydrogen, alcohols, acetals, epoxides, amines, carbon-carbon unsaturated compounds, etc. in supercritical carbon dioxide or in other solvents in the presence of metal compounds as catalysts. The products of these reactions are formic acid, formic acid esters, formamides, methanol, dimethyl carbonate, alkylene carbonates, carbamic acid esters, lactones, carboxylic acids, polycarbonate (bisphenol-based engineering polymer), aliphatic polycarbonates, etc. Especially, the productions of formic acid, formic acid methyl ester and dimethylformamide with a ruthenium catalyst; dimethyl carbonate and urethanes with a dialkyltin catalyst; 2-pyrone with a nickel-phosphine catalyst; diphenyl carbonate with a lead phenoxide catalyst; the alternating copolymerization of carbon dioxide and epoxides with a zinc catalyst has attracted attentions as the industrial utilizations of carbon dioxide. The further development of these production processes is expected. (author)

  19. Carbon Dioxide Flux Measurement Systems

    Oak Ridge National Laboratory — The Southern Great Plains (SGP) carbon dioxide flux (CO2 flux) measurement systems provide half-hour average fluxes of CO2, H2O (latent heat), and sensible heat. The...

  20. Recuperative supercritical carbon dioxide cycle

    Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A


    A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.