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Sample records for conductometry

  1. Nonfaradaic nanoporous electrochemistry for conductometry at high electrolyte concentration.

    Science.gov (United States)

    Bae, Je Hyun; Kang, Chung Mu; Choi, Hyoungseon; Kim, Beom Jin; Jang, Woohyuk; Lim, Sung Yul; Kim, Hee Chan; Chung, Taek Dong

    2015-02-17

    Nanoporous electrified surfaces create a unique nonfaradaic electrochemical behavior that is sensitively influenced by pore size, morphology, ionic strength, and electric field modulation. Here, we report the contributions of ion concentration and applied ac frequency to the electrode impedance through an electrical double layer overlap and ion transport along the nanopores. Nanoporous Pt with uniform pore size and geometry (L2-ePt) responded more sensitively to conductivity changes in aqueous solutions than Pt black with poor uniformity despite similar real surface areas and enabled the previously difficult quantitative conductometry measurements at high electrolyte concentrations. The nanopores of L2-ePt were more effective in reducing the electrode impedance and exhibited superior linear responses to not only flat Pt but also Pt black, leading to successful conductometric detection in ion chromatography without ion suppressors and at high ionic strengths.

  2. General Chemistry Students' Conceptual Understanding and Language Fluency: Acid-Base Neutralization and Conductometry

    Science.gov (United States)

    Nyachwaya, James M.

    2016-01-01

    The objective of this study was to examine college general chemistry students' conceptual understanding and language fluency in the context of the topic of acids and bases. 115 students worked in groups of 2-4 to complete an activity on conductometry, where they were given a scenario in which a titration of sodium hydroxide solution and dilute…

  3. Modification of Rat Lung Decellularization Protocol Based on Dynamic Conductometry of Working Solution.

    Science.gov (United States)

    Kuevda, E V; Gubareva, E A; Gumenyuk, I S; Sotnichenko, A S; Gilevich, I V; Nakokhov, R Z; Rusinova, T V; Yudina, T G; Red'ko, A N; Alekseenko, S N

    2017-03-01

    We modified the protocol of obtaining of biological scaffolds of rat lungs based on dynamic recording of specific resistivity of working detergent solution (conductometry) during perfusion decellularization. Termination of sodium deoxycholate exposure after attaining ionic equilibrium plateau did not impair the quality of decellularization and preserved structural matrix components, which was confirmed by morphological analysis and quantitative assay of residual DNA.

  4. Study of interactions between hyaluronan and cationic surfactants by means of calorimetry, turbidimetry, potentiometry and conductometry.

    Science.gov (United States)

    Krouská, J; Pekař, M; Klučáková, M; Šarac, B; Bešter-Rogač, M

    2017-02-10

    The thermodynamics of the micelle formation of the cationic surfactants tetradecyltrimethylammonium bromide (TTAB) and cetyltrimethylammonium bromide (CTAB) with and without the addition of hyaluronan of two molecular weights was studied in aqueous solution by titration calorimetry. Macroscopic phase separation, which was detected by calorimetry and also by conductometry, occurs when charges on the surfactant and hyaluronan are balanced. In contrast, turbidimetry and potentiometry showed hyaluronan-surfactant interactions at very low surfactant concentrations. The observed differences between systems prepared with CTAB and TTAB indicate that besides the electrostatic interactions, which probably predominate, hydrophobic effects also play a significant role in hyaluronan interactions with cationic surfactants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. "Reagent-free" L-asparaginase activity assay based on CD spectroscopy and conductometry.

    Science.gov (United States)

    Kudryashova, Elena V; Sukhoverkov, Kirill V

    2016-02-01

    A new method to determine the catalytic parameters of L-asparaginase using circular dichroism spectroscopy (CD spectroscopy) has been developed. The assay is based on the difference in CD signal between the substrate (L-asparagine) and the product (L-aspartic acid) of enzymatic reaction. CD spectroscopy, being a direct method, enables continuous measurement, and thus differentiates from multistage and laborious approach based on Nessler's method, and overcomes limitations of conjugated enzymatic reaction methods. In this work, we show robust measurements of L-asparaginase activity in conjugates with PEG-chitosan copolymers, which otherwise would not have been possible. The main limitation associated with the CD method is that the analysis should be performed at substrate saturation conditions (V max regime). For K M measurement, the conductometry method is suggested, which can serve as a complimentary method to CD spectroscopy. The activity assay based on CD spectroscopy and conductometry was successfully implicated to examine the catalytic parameters of L-asparaginase conjugates with chitosan and its derivatives, and for optimization of the molecular architecture and composition of such conjugates for improving biocatalytic properties of the enzyme in the physiological conditions. The approach developed is potentially applicable to other enzymatic reactions where the spectroscopic properties of substrate and product do not enable direct measurement with absorption or fluorescence spectroscopy. This may include a number of amino acid or glycoside-transforming enzymes.

  6. Estimation of AOT and SDS CMC in a methanol using conductometry, viscometry and pyrene fluorescence spectroscopy methods

    Science.gov (United States)

    Mitsionis, Anastasios I.; Vaimakis, Tiverios C.

    2012-09-01

    Critical micelle concentration (CMC) of two anionic surfactants in methanol was estimated using conductometry, viscometry and pyrene fluorescence spectroscopy methods. The surfactants used, were sodium bis(2-ethylhexyl) sulfosuccinate (Aerosol-OT, AOT) and sodium dodecyl sulfate (SDS) dispersed in pure methanol. The CMC determination was evaluated in room temperature. The results have shown nearly similar concentrations.

  7. Effect of counterions on properties of micelles formed by alkylpyridinium surfactants .1. Conductometry and H-1-NMR chemical shifts

    NARCIS (Netherlands)

    Bijma, K; Engberts, J.B.F.N.

    1997-01-01

    This paper delineates the influence of counterions on the aggregation behavior of 1-methyl-4-n-dodecylpyridinium surfactants, using conductometry and H-1-NMR spectroscopy. Three types of counterions have been studied: (i) halides, (ii) alkanesulfonates, and (iii) aromatic counterions. The critical.

  8. Effect of counterions on properties of micelles formed by alkylpyridinium surfactants .1. Conductometry and H-1-NMR chemical shifts

    OpenAIRE

    Bijma, K; Engberts, J.B.F.N.

    1997-01-01

    This paper delineates the influence of counterions on the aggregation behavior of 1-methyl-4-n-dodecylpyridinium surfactants, using conductometry and H-1-NMR spectroscopy. Three types of counterions have been studied: (i) halides, (ii) alkanesulfonates, and (iii) aromatic counterions. The critical. micelle concentration is found to decrease with increasing counterion size and increasing counterion hydrophobicity, whereas the degree of counterion binding increases. The aggregation behavior of ...

  9. APPLICATION FEATURES OF SPATIAL CONDUCTOMETRY SENSORS IN MODELLING OF COOLANT FLOW MIXING IN NUCLEAR POWER UNIT EQUIPMENT

    Directory of Open Access Journals (Sweden)

    A. A. Barinov

    2016-01-01

    Full Text Available Coolant flow mixing processes with different temperatures and concentrations of diluted additives widely known in nuclear power units operation. In some cases these processes make essential impact on the resource and behavior of the nuclear unit during transient and emergency situations. The aim of the study was creation of measurement system and test facility to carry out basic tests and to embed spatial conductometry method in investigation practice of turbulent coolant flows. In the course of investigation measurement system with sensors and experimental facility was designed, several first tests were carried out. A special attention was dedicated to calibration and clarification of conductometry sensor application methodologies in studies of turbulent flow characteristics. Investigations involved method of electrically contrast tracer jet with concurrent flow in closed channel of round crosssection. The measurements include both averaged and unsteady realizations of measurement signal. Experimental data processing shows good agreement with other tests acquired from another measurement systems based on different physical principles. Calibration functions were acquired, methodical basis of spatial conductometry measurement system application was created. Gathered experience of spatial sensor application made it possible to formulate the principles of further investigation that involve large-scale models of nuclear unit equipment. Spatial wire-mesh sensors proved to be a perspective type of eddy resolving measurement devices.

  10. Thermal Scanning Conductometry (TSC) as a General Method for Studying and Controlling the Phase Behavior of Conductive Physical Gels.

    Science.gov (United States)

    Bielejewski, Michal

    2018-01-23

    The thermal scanning conductometry protocol is a new approach in studying ionic gels based on low molecular weight gelators. The method is designed to follow the dynamically changing state of the ionogels, and to deliver more information and details about the subtle change of conductive properties with an increase or decrease in the temperature. Moreover, the method allows the performance of long term (i.e. days, weeks) measurements at a constant temperature to investigate the stability and durability of the system and the aging effects. The main advantage of the TSC method over classical conductometry is the ability to perform measurements during the gelation process, which was impossible with the classical method due to temperature stabilization, which usually takes a long time before the individual measurement. It is a well-known fact that to obtain the physical gel phase, the cooling stage must be fast; moreover, depending on the cooling rate, different microstructures can be achieved. The TSC method can be performed with any cooling/heating rate that can be assured by the external temperature system. In our case, we can achieve linear temperature change rates between 0.1 and approximately 10 °C/min. The thermal scanning conductometry is designed to work in cycles, continuously changing between heating and cooling stages. Such an approach allows study of the reproducibility of the thermally reversible gel-sol phase transition. Moreover, it allows the performance of different experimental protocols on the same sample, which can be refreshed to initial state (if necessary) without removal from the measuring cell. Therefore, the measurements can be performed faster, in a more efficient way, and with much higher reproducibility and accuracy. Additionally, the TSC method can be also used as a tool to manufacture the ionogels with targeted properties, like microstructure, with an instant characterization of conductive properties.

  11. The determination of levofloxacin by flow injection analysis using UV detection, potentiometry, and conductometry in pharmaceutical preparations.

    Science.gov (United States)

    Altiokka, G; Atkosar, Z; Can, N O

    2002-10-15

    A flow injection analysis (FIA) using UV detection, potentiometry and conductometry for levofloxacin (LVF) are described in this study. The best solvent system was found to consist of 0.2 M acetate buffer at pH 3 having 10% MeOH. A flow rate of 1 ml min(-1) was pumped and active material was detected at 288 nm. The detection limit (LOD) and limit of quantification (LOQ) for FIA were calculated to be 3 x 10(-7) M (S/N = 3) and 1 x 10(-7) M (S/N = 10), respectively. In the analysis of tablets, the RSD values were found to be 0.83, 0.98 and 0.99 for FIA, potentiometric and conductometric methods, respectively. Copyright 2002 Elsevier Science B.V.

  12. Determination of dissociation constants or propionic acid and lactic acid (2-hydroxypropionic acid) by potentiometry and conductometry

    International Nuclear Information System (INIS)

    Saeeduddin; Khanzada, A.W.K.

    2004-01-01

    Dissociation constants of propionic acid and 2-hydroxypropionic acid (lactic acid) have been studied at different temperatures between 25 to 50 deg. C interval. Propionic acid is analyzed by conductometry while 2-hydroxypropionic acid is analyzed by potentiometry. Both investigated compounds are symmetrical carboxylic acids having same length of carbon chain but are markedly different in ionic behavior. We were interested to see how the hydroxyl group (-OH) induction in propionic acid affects on pKa values of 2-hydroxypropionic acid. We observed that as temperature increases pKa values increase. The increase is observed for both the investigated compounds. PKa values of 2-hydroxypropionic acid are lower as compared to propionic acid because of electron withdrawing (-OH). (author)

  13. Study on complex formation of dicyclohexyl-18-crown-6 with Mg2+, Ca2+ and Sr2+ in acetonitrile-water binary mixtures by conductometry

    OpenAIRE

    Mallika Sanyal

    2017-01-01

    The complexation reactions between Mg2+, Ca2+ and Sr2+ cations and dicyclohexyl-18-crown-6 (DCH 18C6) have been studied in acetonitrile–water binary mixtures at different temperatures by conductometry. The formation constants of the resulting 1:1 (M:L) complexes for all the three cations were determined from computer fitting of the molar conductance versus mole ratio data. The results show that the selectivity order of DCH 18C6 for the metal cations in the acetonitrile-water binary solvent at...

  14. High performance conductometry

    International Nuclear Information System (INIS)

    Saha, B.

    2000-01-01

    Inexpensive but high performance systems have emerged progressively for basic and applied measurements in physical and analytical chemistry on one hand, and for on-line monitoring and leak detection in plants and facilities on the other. Salient features of the developments will be presented with specific examples

  15. Conductometry of electrolyte solutions

    Science.gov (United States)

    Safonova, Lyubov P.; Kolker, Arkadii M.

    1992-09-01

    A review is given of the theories of the electrical conductance of electrolyte solutions of different ionic strengths and concentrations, and of the models of ion association. An analysis is made of the methods for mathematical processing of experimental conductometric data. An account is provided of various theories describing the dependence of the limiting value of the ionic electrical conductance on the properties of the solute and solvent. The bibliography includes 115 references.

  16. Direct Detection of the Ion Pair to Free Ions Transformation upon Complexation with an Ion Receptor in Non‐Polar Solvents by using Conductometry

    Science.gov (United States)

    Iseda, Kazuya

    2018-01-01

    Abstract In this study, we performed conductometry in various organic solvents to directly detect the transformation from tetrabutylammonium chloride (TBACl) ion‐pair salt to the free ions through complexation with meso‐octamethylcalix[4]pyrrole (CP), which is a well‐known receptor for chloride anions. In the presence of CP, the conductivity of TBACl increases in various non‐polar solvents, indicating that complexation with CP enhances the ionic dissociation of TBACl in such non‐polar solvents. In other words, CP recognizes chloride as an ion‐paired salt as well as a free anion in non‐polar solvents. Additionally, the TBA(CP–Cl) complex exhibited a considerably lower ion‐pairing constant (K ip) than TBACl in non‐polar solvents, resulting in enhanced conductivity. Based on these findings, we can conclude that complexation of an anion with a hydrophobic anion receptor will be useful for creating functional and stimuli‐responsive soft materials in organic solvents using coulombic forces. PMID:29610717

  17. Direct Detection of the Ion Pair to Free Ions Transformation upon Complexation with an Ion Receptor in Non-Polar Solvents by using Conductometry.

    Science.gov (United States)

    Iseda, Kazuya; Kokado, Kenta; Sada, Kazuki

    2018-03-01

    In this study, we performed conductometry in various organic solvents to directly detect the transformation from tetrabutylammonium chloride ( TBACl ) ion-pair salt to the free ions through complexation with meso -octamethylcalix[4]pyrrole ( CP ), which is a well-known receptor for chloride anions. In the presence of CP , the conductivity of TBACl increases in various non-polar solvents, indicating that complexation with CP enhances the ionic dissociation of TBACl in such non-polar solvents. In other words, CP recognizes chloride as an ion-paired salt as well as a free anion in non-polar solvents. Additionally, the TBA(CP - Cl ) complex exhibited a considerably lower ion-pairing constant ( K ip ) than TBACl in non-polar solvents, resulting in enhanced conductivity. Based on these findings, we can conclude that complexation of an anion with a hydrophobic anion receptor will be useful for creating functional and stimuli-responsive soft materials in organic solvents using coulombic forces.

  18. Synthesis, characterization, X-ray crystal structure and conductometry studying of a number of new Schiff base complexes; a new example of binuclear square pyramidal geometry of Cu(II) complex bridged with an oxo group

    Science.gov (United States)

    Golbedaghi, Reza; Alavipour, Ehsan

    2015-11-01

    Three new binuclear Cu(II), Mn(II), Co(II) complexes [Cu2(L) (ClO4)](ClO4)2 (1), [Mn2(L) (ClO4)](ClO4)2 (2), and [Co2(L) (ClO4)](ClO4)2 (3), {L = 1,3-bis(2-((Z)-(2-aminopropylimino)methyl)phenoxy)propan-2-ol} have been synthesized. Single crystal X-ray structure analysis of complex 1 showed that the complex is binuclear and all nitrogen and oxygen atoms of ligand (N4O3) are coordinated to two Cu(II) center ions. In addition, the crystal structure studying shows, a perchlorate ion has been bridged to the Cu(II) metal centers. However, two distorted square pyramidal Cu(II) ions are bridged asymmetrically by a perchlorate ion and oxygen of hydroxyl group of Schiff base ligand. In addition, the conductometry behaviors of all complexes were studied in acetonitrile solution.

  19. Contactless or High Frequency Conductometry or Oscillometry of Electrolytes

    OpenAIRE

    Kiumars Ghowsi; Hosein Ghowsi

    2013-01-01

    Circuit models are used to express the behavior of the conductometric cells in the radio frequency to microwave region .The capacitive cell has two era classic era and modern era as a detector for Capillary Zone Electrophoresis . Capacitive Cell where electrodes are outside the Cells and frequency of the electric signal is in the cell the radio frequency range is modeled. Both microscopic phenomena occurring at radio frequencies in electrolytes and macroscopic phenomena the circuit model for ...

  20. HEC influence on cement hydration measured by conductometry

    OpenAIRE

    Pourchez , Jérémie; Grosseau , Philippe; Guyonnet , René; Ruot , Bertrand

    2006-01-01

    International audience; Cellulose ethers are of universal use in factory-made mortars, though their influences on mortar properties at a molecular scale are poorly understood. Recent studies dealt with the influence of hydroxyethylmethyl cellulose (HEMC) and hydroxypropylmethyl cellulose (HPMC) molecular parameters on cement hydration. It was concluded that the degree of substitution is the most relevant factor on cement hydration kinetics, contrary to the molecular weight. Nevertheless, the ...

  1. The self-association of acebutolol: Conductometry and light scattering

    Science.gov (United States)

    Ruso, Juan M.; López-Fontán, José L.; Prieto, Gerardo; Sarmiento, Félix

    2003-04-01

    The association characteristics of an amphiphilic beta-blocker drug, acebutolol hydrochloride, in aqueous solution containing high concentrations of electrolyte and at different temperatures have been examined by static and dynamic light scattering and electrical conductivity. Time averaged light scattering measurements on aqueous solutions of acebutolol at 298.15 K in the presence of added electrolyte (0.4-1.0 mol kg-1 NaCl) have shown discontinuities which reflect the appearance of aggregates. The critical micelle concentration, aggregation numbers, effective micelle charges, and degree of micellar ionization were calculated. Dynamic light scattering has shown an increase in micellar size with increase in concentration of added electrolyte. Data have been interpreted using the DLVO theory to quantify the interaction between the drug aggregates and the colloidal stability. Critical micelle concentrations in water have been calculated from conductivity measurements over the temperature range 288.15-313.15 K. The variation in critical concentration with temperature passes through a minimum close to 294 K. Thermodynamic parameters of aggregate formation (ΔGm0,ΔHm0,ΔSm0) were obtained from a variation of the mass action model applicable to systems of low aggregation number.

  2. The interactions between ionic surfactants and phosphatidylcholine vesicles: Conductometry

    Science.gov (United States)

    Tsao, Heng-Kwong; Tseng, Wen Liang

    2001-11-01

    The interaction between ionic surfactants and phosphatidylcholine vesicles, which are prepared without addition of buffer and salt, is investigated by conductivity measurements. On the basis of the vesicle acting as a trap of charge carriers, the bilayer/aqueous phase partition coefficient K and the surfactant/lipid molar ratio Re of nine surfactants are determined. The thermodynamic consistency is satisfied by the measured parameters. The effects of the alkyl chain length (C10-C16) and ionic head group are then studied. The inverse partition coefficient K-1 is linearly related to the critical micelle concentration. The solubilizing ability Reb is a consequence of the competition between the surfactant incorporation into the bilayer and the formation of micelles. Consequently, the K parameter rises whereas the Reb parameter declines as the chain length is increased. The influence due to addition of salt is also discussed.

  3. In-line bulk supersaturation measurement by electrical conductometry in KDP crystal growth from aqueous solution

    Science.gov (United States)

    Bordui, P. F.; Loiacono, G. M.

    1984-07-01

    A method is presented for in-line bulk supersaturation measurement in crystal growth from aqueous solution. The method is based on a computer-controlled concentration measurement exploiting an experimentally predetermined cross-correlation between the concentration, electrical conductivity, and temperature of the growth solution. The method was applied to Holden crystallization of potassium dihydrogen phosphate (KDP). An extensive conductivity-temperature-concentration data base was generated for this system over a temperature range of 31 to 41°C. The method yielded continous, automated bulk supersaturation output accurate to within ±0.05 g KDP100 g water (±0.15% relative supersaturation).

  4. High resolution conductometry for isotopic assay of deuterium in mixtures of heavy water and light water

    International Nuclear Information System (INIS)

    Ananthanarayanan, R.; Sahoo, P.; Murali, N.

    2014-01-01

    A PC based high resolution conductivity monitoring technique has been deployed for determination of isotopic purity of heavy water in samples containing heavy water and light water mixtures using pulsating sensor based conductivity monitoring instrument. The technique involves accurate determination of conductivities of a series of specially treated heavy water and light water mixtures of various compositions at a constant solution temperature. The shift in conductivity (Δκ), which is the difference between conductivities of composite mixture after and before the formation of a typical complex compound (boric acid–mannitol complex in this case), shows a smooth and reproducible decreasing trend with increase in percentage composition of heavy water. This relation, which is obtained by appropriate calibration, is used in the software program for direct display of isotopic purity of heavy water. The technique is examined for determination of percentage composition of heavy water in the entire range of concentration (0-100 %) with reasonable precision (relative standard deviation, RSD ≤1.5 %). About 1 mL of sample is required for each analysis and analysis is completed within a couple of minutes after pretreatment of sample. The accuracy in measurement is ≤1.75 %. (author)

  5. Erythrocyte swelling and membrane hole formation in hypotonic media as studied by conductometry.

    Science.gov (United States)

    Pribush, A; Meyerstein, D; Hatskelzon, L; Kozlov, V; Levi, I; Meyerstein, N

    2013-02-01

    Hypoosmotic swelling of erythrocytes and the formation of membrane holes were studied by measuring the dc conductance (G). In accordance with the theoretical predictions, these processes are manifested by a decrease in G followed by its increase. Thus, unlike the conventional osmotic fragility test, the proposed methodological approach allows investigations of both the kinetics of swelling and the erythrocyte fragility. It is shown that the initial rate of swelling and the equilibrium size of the cells are affected by the tonicity of a hypotonic solution and the membrane rheological properties. Because the rupture of biological membranes is a stochastic process, a time-dependent increase in the conductance follows an integral distribution function of the membrane lifetime. The main conclusion which stems from reported results is that information about rheological properties of red blood cell (RBC) membranes and the resistivity of RBCs to a certain osmotic shock may be extracted from conductance signals.

  6. Evaluation of Amount of Blood in Dry Blood Spots: Ring-Disk Electrode Conductometry.

    Science.gov (United States)

    Kadjo, Akinde F; Stamos, Brian N; Shelor, C Phillip; Berg, Jordan M; Blount, Benjamin C; Dasgupta, Purnendu K

    2016-06-21

    A fixed area punch in dried blood spot (DBS) analysis is assumed to contain a fixed amount of blood, but the amount actually depends on a number of factors. The presently preferred approach is to normalize the measurement with respect to the sodium level, measured by atomic spectrometry. Instead of sodium levels, we propose electrical conductivity of the extract as an equivalent nondestructive measure. A dip-type small diameter ring-disk electrode (RDE) is ideal for very small volumes. However, the conductance (G) measured by an RDE depends on the depth (D) of the liquid below the probe. There is no established way of computing the specific conductance (σ) of the solution from G. Using a COMSOL Multiphysics model, we were able to obtain excellent agreement between the measured and the model predicted conductance as a function of D. Using simulations over a large range of dimensions, we provide a spreadsheet-based calculator where the RDE dimensions are the input parameters and the procedure determines the 99% of the infinite depth conductance (G99) and the depth D99 at which this is reached. For typical small diameter probes (outer electrode diameter ∼ <2 mm), D99 is small enough for dip-type measurements in extract volumes of ∼100 μL. We demonstrate the use of such probes with DBS extracts. In a small group of 12 volunteers (age 20-66), the specific conductance of 100 μL aqueous extracts of 2 μL of spotted blood showed a variance of 17.9%. For a given subject, methanol extracts of DBS spots nominally containing 8 and 4 μL of blood differed by a factor of 1.8-1.9 in the chromatographically determined values of sulfate and chloride (a minor and major constituent, respectively). The values normalized with respect to the conductance of the extracts differed by ∼1%. For serum associated analytes, normalization of the analyte value by the extract conductance can thus greatly reduce errors from variations in the spotted blood volume/unit area.

  7. Development of an Automated Diffusion Scrubber-Conductometry System for Measuring Atmospheric Ammonia

    International Nuclear Information System (INIS)

    Lee, Bok Young; Lee, Chong Keun; Lee, Dong Soo

    2011-01-01

    A semi-continuous and automated method for quantifying atmospheric ammonia at the parts per billion level has been developed. The instrument consists of a high efficiency diffusion scrubber, an electrolytic on-line anion exchange device, and a conductivity detector. Water soluble gases in sampled air diffuse through the porous membrane and are absorbed in an absorbing solution. Interferences are eliminated by using an anion exchange devises. The electrical conductivity of the solution is measured without chromatographic separation. The collection efficiency was over 99%. Over the 0-200 ppbv concentration range, the calibration was linear with r"2 = 0.99. The lower limit of detection was 0.09 ppbv. A parallel analysis of Seoul air over several days using this method and a diffusion scrubber coupled to an ion chromatography system showed acceptable agreement, r"2 = 0.940 (n = 686). This method can be applied for ambient air monitoring of ammonia

  8. Conductometry and Size Characterization of Polypyrrole Nanoparticles Produced by Ball Milling

    OpenAIRE

    Abbasi, Abdul Malik Rehan; Marsalkova, Miroslava; Militky, Jiri

    2013-01-01

    Polypyrrole (PPy), one of the most extensively investigated conducting polymers, has attracted a great deal of interest because of its good electrical conductivity, environmental stability, and easy synthesis. PPy films were produced by polymerization of pyrrole and tosylate (TsO−) as dopants in the presence of oxidant FeCl3 and polyethylene glycol (Mw 8000) at −5°C for 48 h. High energy milling was carried out at 850 rpm in the dry media with the balls of 10 mm. Particles were then character...

  9. CONDUCTOMETRY BIOTESTING AS APPLIED TO VALUATION OF THE PRO- AND ANTIBACTERIAL PROPERTIES OF CATOLITES AND ANOLITES

    Directory of Open Access Journals (Sweden)

    V. S. Sibirtsev

    2016-05-01

    Full Text Available The paper deals with technique of the electrical conductivity biotesting as applied to the analysis of pro- and antibacterial activity of catolit and anolit solutions. The tested preparations were received by 25 minute electrolysis processing of 1% NaCl water solution (in cathode space and 1% Na2SO4 water solution (in anode space at 7 A amperage and 28 V voltage. The submitted technique is based on the analysis of change dynamics of impedance electrical conductivity of researched samples, caused by metabolic processes, realized by tested microorganisms in analyzed samples. Application of this technique enabled to show that makeup anolit solution, beginning from concentration equal to 1 vol. %, has a bacteriostatic effect on liquid culture medium with Escherichia coli in the quantity of 104 live cells on 1 ml. At anolit solution concentration more than 5 vol.% its action on the same microorganismes becomes bactericidal. At the same time, makeup catolit solution activates microorganismes vital activity as early as from concentration equal to 5 vol.%. Thus, it is shown, that electrical conductivity biotesting is a sensitive laboratory tool, granting accessible, convenient and informative way to a researcher for valuation of properties of various pro- and anti-infective preparations, as well as the other physico-chemical systems (including rather complex concerning structure and dynamics of its change, capable to act on microorganismes vital activity.

  10. Studies on Rapidly Frozen Suspensions of Yeast Cells by Differential Thermal Analysis and Conductometry

    Science.gov (United States)

    Mazur, Peter

    1963-01-01

    Few, if any, yeast cells survived rapid cooling to -196°C and subsequent slow warming. After rapid freezing, the suspensions absorbed latent heat of fusion between -15° and 0°C during warming, and the relation between the amount of heat absorbed and the concentration of cells was the same as that in equivalent KCl solutions, indicating that frozen suspensions behave thermally like frozen solutions. The amount of heat absorbed was such that more than 80 per cent of the intracellular solution had to be frozen. The conductometric behavior of frozen suspensions showed that cell solutes were still inside the cells and surrounded by an intact cell membrane at the time heat was being absorbed. Two models are consistent with these findings. The first assumes that intracellular freezing has taken place; the second that all freezable water has left the cells and frozen externally. The latter model is ruled out because rapidly cooled cells do not shrink by an amount equal to the volume of water that would have to be withdrawn to prevent internal freezing. PMID:13934216

  11. Development of an Automated Diffusion Scrubber-Conductometry System for Measuring Atmospheric Ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bok Young; Lee, Chong Keun; Lee, Dong Soo [Yonsei University, Seoul (Korea, Republic of)

    2011-06-15

    A semi-continuous and automated method for quantifying atmospheric ammonia at the parts per billion level has been developed. The instrument consists of a high efficiency diffusion scrubber, an electrolytic on-line anion exchange device, and a conductivity detector. Water soluble gases in sampled air diffuse through the porous membrane and are absorbed in an absorbing solution. Interferences are eliminated by using an anion exchange devises. The electrical conductivity of the solution is measured without chromatographic separation. The collection efficiency was over 99%. Over the 0-200 ppbv concentration range, the calibration was linear with r{sup 2} = 0.99. The lower limit of detection was 0.09 ppbv. A parallel analysis of Seoul air over several days using this method and a diffusion scrubber coupled to an ion chromatography system showed acceptable agreement, r{sup 2} = 0.940 (n = 686). This method can be applied for ambient air monitoring of ammonia.

  12. Measurement of acid dissociation constants of weak acids by cation exchange and conductometry

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, P.K.; Nara, Osamu (Texas Tech Univ., Lubbock (USA))

    1990-06-01

    A simple strategy is presented for the determination of acid dissociation constants based on the measurement of conductance of a known concentration of the acid and/or the conductance of a solution of its fully or partially neutralized alkali-metal salts. For an n-protic acid, 2n conductance measurements are minimally necessary. In the simplest case of a typical monoprotic acid, the conductance of its alkali salt solution is measured before and after passage through an H{sup +}-form exchanger. From these data both the pK{sub a} of the acid and the equivalent conductance of the anion can be computed. The underlying equations are rigorously solved for monoprotic acids and some diprotic acid systems. For other diprotic and multiprotic acid systems, initial estimates are obtained by making approximations; the complete data set is then subjected to multiparametric fitting. The method does not require pH measurements; conductance can generally be measured accurately at low enough ionic strengths to obviate the need for major activity correction. Several experimental measurements are presented and excellent agreement with literature pK{sub a} values is observed. The reliability of the equivalent conductance values computed in this fashion is limited, however.

  13. Thermodynamic and Interfacial Properties of DTABr/CTABr Mixed Surfactant Systems in Ethanolamine/Water Mixtures: A Conductometry Study

    OpenAIRE

    Esan, Olaseni Segun; Osundiya, Medinat Olubunmi; Aboluwoye, Christopher Olumuyiwa; Olanrewaju, Owoyomi; Ige, Jide

    2013-01-01

    Mixed-micelle formation in the binary mixtures of dodecyltrimethylammonium bromide (DTABr) and cetyltrimethylammonium bromide (CTABr) surfactants in water-ethanolamine mixed solvent systems has been studied by conductometric method in the temperature range of 298.1 to 313.1 K at 5 K intervals. It was observed that the presence of ethanolamine forced the formation of mixed micelle to lower total surfactant concentration than in water only. The synergistic interaction was quantitatively investi...

  14. Laser based thermo-conductometry as an approach to determine ribbon solid fraction off-line and in-line.

    Science.gov (United States)

    Wiedey, Raphael; Šibanc, Rok; Kleinebudde, Peter

    2018-06-06

    Ribbon solid fraction is one of the most important quality attributes during roll compaction/dry granulation. Accurate and precise determination is challenging and no in-line measurement tool has been generally accepted, yet. In this study, a new analytical tool with potential off-line as well as in-line applicability is described. It is based on the thermo-conductivity of the compacted material, which is known to depend on the solid fraction. A laser diode was used to punctually heat the ribbon and the heat propagation monitored by infrared thermography. After performing a Gaussian fit of the transverse ribbon profile, the scale parameter σ showed correlation to ribbon solid fraction in off-line as well as in-line studies. Accurate predictions of the solid fraction were possible for a relevant range of process settings. Drug stability was not affected, as could be demonstrated for the model drug nifedipine. The application of this technique was limited when using certain fillers and working at higher roll speeds. This study showed the potentials of this new technique and is a starting point for additional work that has to be done to overcome these challenges. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Stability constants for some divalent metal ion/crown ether complexes in methanol determined by polarography and conductometry

    NARCIS (Netherlands)

    Chen, L.; Bos, M.; Grootenhuis, P.D.J.; Christenhusz, A.; Hoogendam, E.; Reinhoudt, David; van der Linden, W.E.

    1987-01-01

    Stability constants in methanol at 25.0°C were evaluated for the complexes of the divalent cations Ca2+, Ni2+, Zn2+, Pb2+, Mg2+, Co2+ and Cu2+ with the macrocyclic polyethers 15-crown-5 (15C5), 18-crown-6 (18C6), dicyclohexyl-18-crown-6 (DC18C6) and dibenzo-24-crown-8 (DB24C8). The log K values of

  16. Characterization of the binding of multivalent ions to modified pluronic micelles by isothermal titration calorimetry and modified conductometry

    NARCIS (Netherlands)

    Nispen, van S.F.G.M.; Custers, J.P.A.; Broeke, van den L.J.P.; Keurentjes, J.T.F.

    2010-01-01

    CAE surfactants (carboxylic acid end-standing triblock copolymers of poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide)) are amphiphiles that are able to bind multivalent cations thermoreversibly; a property that can be used to develop new environmentally friendly separation and ion

  17. Comparative Investigation of the Ionicity of Aprotic and Protic Ionic Liquids in Molecular Solvents by using Conductometry and NMR Spectroscopy.

    Science.gov (United States)

    Thawarkar, Sachin; Khupse, Nageshwar D; Kumar, Anil

    2016-04-04

    Electrical conductivity (σ), viscosity (η), and self-diffusion coefficient (D) measurements of binary mixtures of aprotic and protic imidazolium-based ionic liquids with water, dimethyl sulfoxide, and ethylene glycol were measured from 293.15 to 323.15 K. The temperature dependence study reveals typical Arrhenius behavior. The ionicities of aprotic ionic liquids were observed to be higher than those of protic ionic liquids in these solvents. The aprotic ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, [bmIm][BF4 ], displays 100 % ionicity in both water and ethylene glycol. The protic ionic liquids in both water and ethylene glycol are classed as good ionic candidates, whereas in DMSO they are classed as having a poor ionic nature. The solvation dynamics of the ionic species of the ionic liquids are illustrated on the basis of the (1) H NMR chemical shifts of the ionic liquids. The self-diffusion coefficients D of the cation and anion of [HmIm][CH3 COO] in D2 O and in [D6 ]DMSO are determined by using (1) H nuclei with pulsed field gradient spin-echo NMR spectroscopy. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Molecular interactions in a surfactant-water-polyacrylamide system, according to densimetry, viscometry, conductometry, and spectroscopy data

    Science.gov (United States)

    Harutyunyan, R. S.

    2013-08-01

    Molecular interactions in a surfactant-polyacrylamide-water system are investigated. It is established that the interactions affect such physicochemical parameters of the system as viscosity, density, surface tension, conductivity, and critical micelle concentration. It is shown that in a polyacrylamide-water system, raising the polyacrylamide concentration to 0.02% causes conformational changes in its macromolecule.

  19. Determination of the Critical Micelle Concentration of Neutral and Ionic Surfactants with Fluorometry, Conductometry, and Surface Tension-A Method Comparison.

    Science.gov (United States)

    Scholz, Norman; Behnke, Thomas; Resch-Genger, Ute

    2018-01-01

    Micelles are of increasing importance as versatile carriers for hydrophobic substances and nanoprobes for a wide range of pharmaceutical, diagnostic, medical, and therapeutic applications. A key parameter indicating the formation and stability of micelles is the critical micelle concentration (CMC). In this respect, we determined the CMC of common anionic, cationic, and non-ionic surfactants fluorometrically using different fluorescent probes and fluorescence parameters for signal detection and compared the results with conductometric and surface tension measurements. Based upon these results, requirements, advantages, and pitfalls of each method are discussed. Our study underlines the versatility of fluorometric methods that do not impose specific requirements on surfactants and are especially suited for the quantification of very low CMC values. Conductivity and surface tension measurements yield smaller uncertainties particularly for high CMC values, yet are more time- and substance consuming and not suitable for every surfactant.

  20. A thermodynamic study of complexation process between N, N'-dipyridoxylidene(1,4-butanediamine) and Cd2+ in some binary mixed solvents using conductometry

    Science.gov (United States)

    Ebrahimpoor, Sonia; Khoshnood, Razieh Sanavi; Beyramabadi, S. Ali

    2016-12-01

    Complexation of the Cd2+ ion with N, N'-dipyridoxylidene(1,4-butanediamine) Schiff base was studied in pure solvents including acetonitrile (AN), ethanol (EtOH), methanol (MeOH), tetrahydrofuran (THF), dimethylformamide (DMF), water (H2O), and various binary solvent mixtures of acetonitrile-ethanol (AN-EtOH), acetonitrile-methanol (AN-MeOH), acetonitrile-tetrahydrofuran (AN-THF), acetonitrile-dimethylformamide (AN-DMF), and acetonitrile-water (AN-H2O) systems at different temperatures using the conductometric method. The conductance data show that the stoichiometry of complex is 1: 1 [ML] in all solvent systems. A non-linear behavior was observed for changes of log K f of [Cd( N, N'-dipyridoxylidene(1,4-butanediamine)] complex versus the composition of the binary mixed solvents, which was explained in terms of solvent-solvent interactions. The results show that the thermodynamics of complexation reaction is affected by the nature and composition of the mixed solvents.

  1. Determination of the molecular complexation constant between alprostadil and alpha-cyclodextrin by conductometry: implications for a freeze-dried formulation.

    Science.gov (United States)

    Sheehy, Philip M; Ramstad, Tore

    2005-10-04

    The binding constant between alprostadil (PGE1) and alpha-cyclodextrin (alpha-CD) was determined at four temperatures using conductance measurements. Alpha-cyclodextrin is an excipient material in Caverject dual chamber syringe (DCS) that was added to enhance stability. The binding constant was used to calculate the amount of PGE1 free upon reconstitution and injection, since only the free drug is clinically active. The conductivity measurement is based on a decrease in specific conductance as alprostadil is titrated with alpha-CD. The change in conductivity was plotted versus free ligand concentration (alpha-CD) to generate a binding curve. As the value of the binding constant proved to be dependent on substrate concentration, it is really a pseudo binding constant. A value of 742+/-60 M(-1) was obtained for a 0.5 mM solution of alprostadil at 27 degrees C and a value of 550+/-52 M(-1) at 37 degrees C. These results compare favorably to values previously obtained by NMR and capillary electrophoresis. Calculation of the fraction PGE1 free upon reconstitution and injection show it to approach the desired outcome of one. Hence, the amount of drug delivered by Caverject DCS is nominally equivalent to that delivered by Caverject S. Po., a predecessor product that contains no alpha-cyclodextrin.

  2. Ionic association and solvation of the ionic liquid 1-hexyl-3-methylimidazolium chloride in molecular solvents revealed by vapor pressure osmometry, conductometry, volumetry, and acoustic measurements.

    Science.gov (United States)

    Sadeghi, Rahmat; Ebrahimi, Nosaibah

    2011-11-17

    A systematic study of osmotic coefficient, conductivity, volumetric and acoustic properties of solutions of ionic liquid 1-hexyl-3-methylimidazolium chloride ([C(6)mim][Cl]) in various molecular solvents has been made at different temperatures in order to study of ionic association and solvation behavior of [C(6)mim][Cl] in different solutions. Precise measurements on electrical conductances of solutions of [C(6)mim][Cl] in water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and acetonitrile at 293.15, 298.15, and 303.15 K are reported and analyzed with Barthel's low-concentration chemical model (lcCM) to obtain the limiting molar conductivities and association constants of this ionic liquid in the investigated solvents. Strong ion pairing was found for the ionic liquid in 2-propanol, 1-butanol, and 1-propanol, whereas ion association in acetonitrile, methanol and ethanol is rather weak and in water the ionic liquid is fully dissociated. In the second part of this work, the apparent molar volumes and isentropic compressibilities of [C(6)mim][Cl] in water, methanol, ethanol, acetonitrile, 1-propanol, 2-propanol, and 1-butanol are obtained at the 288.15-313.15 K temperature range at 5 K intervals at atmospheric pressure from the precise measurements of density and sound velocity. The infinite dilution apparent molar volume and isentropic compressibility values of the free ions and ion pairs of [C(6)mim][Cl] in the investigated solvents as well as the excess molar volume of the investigated solutions are determined and their variations with temperature and type of solvents are also studied. Finally, the experimental measurements of osmotic coefficient at 318.15 K for binary solutions of [C(6)mim][Cl] in water, methanol, ethanol, 2-propanol, and acetonitrile are taken using the vapor pressure osmometry (VPO) method and from which the values of the solvent activity, vapor pressure, activity coefficients, and Gibbs free energies are calculated. The results are interpreted in terms of ion association, ion-dipole interactions, and structural factors of the ionic liquid and investigated organic solvents. The ionic liquid is solvated to a different extent by the molecular solvents, and ionic association is affected significantly by ionic solvation.

  3. Ferutinin as a Ca(2+) complexone: lipid bilayers, conductometry, FT-IR, NMR studies and DFT-B3LYP calculations.

    Science.gov (United States)

    Dubis, A; Zamaraeva, M V; Siergiejczyk, L; Charishnikova, O; Shlyonsky, V

    2015-10-07

    Calcium ionophoretic properties of ferutinin were re-evaluated in solvent-containing bilayer lipid membranes. The slopes of conductance-concentration curves suggest that in the presence of a solvent in the membrane the majority of complexes appear to consist of a single terpenoid molecule bound to one Ca ion. By contrast, the stoichiometry of ferutinin-Ca(2+) complexes in acetone determined using the conductometric method was 2 : 1. While the cation-cation selectivity of ferutinin did not change, the cation-anion selectivity slightly decreased in solvent containing membranes. FT-IR and NMR data together with DFT calculations at the B3LYP/6-31G(d) level of theory indicate that in the absence of Ca ions ferutinin molecules are hydrogen-bonded at the phenol hydroxyl groups. The variations of absorption assigned to -OH and -C-O stretching mode suggest that ferutinin interacts strongly with Ca ions via the hydroxyl group of ferutinol and carboxyl oxygen of the complex ether bond. The coordination through the carbonyl group of ferutinin was demonstrated by theoretical calculations. Taken together, ferutinin molecules form H-bonded dimers, while complexation of Ca(2+) by ferutinin ruptures this hydrogen bond due to spatial re-orientation of the ferutinin molecules from parallel to antiparallel alignment.

  4. Automatic Analyzers and Signal Indicators of Toxic and Dangerously Explosive Substances in Air,

    Science.gov (United States)

    1980-01-09

    of air are used also thermo- conductometry and electroconductometric methods. The thermo- conductometry method of analysis is based on a change of the... conductometry gas analyzers is very limited and is reduced in essence to the analysis of two-component mixtures or multicomponent ones, all whose...differs. Rain disadvantage in tae tnormo- conductometry gas analyzers - increased sensitivity to a change in the ambient conditions, in consequence of

  5. Study of complex formation process between 4′-nitrobenzo-18-crown-6 and yttrium(III cation in some binary mixed non-aqueous solvents using the conductometry method

    Directory of Open Access Journals (Sweden)

    Mahboobeh Vafi

    2017-07-01

    Full Text Available The complexation reaction between Y3+ cation and macrocyclic ligand, 4′-nitrobenzo-18-crown-6 (4′NB18C6, was studied in acetonitrile–methanol (AN–MeOH, acetonitrile–1,2-dichloroethane (AN–DCE, acetonitrile–dimethylformamide (AN–DMF and acetonitrile–ethylacetate (AN–EtOAc binary mixed solvent solutions at different temperatures using the conductometric method. The conductance data show that in most cases, the stoichiometry of the complex formed between 4′NB18C6 and Y3+ cation is 1:1 [M:L], but in the case of AN-DCE binary solution (mol% DCE = 50 at 15, 25 and 35 °C, a 2:1 [M2:L] and also a 2:2 [M2:L2] complexes are formed in solution. The results show that the stoichiometry of the complex formed between 4′NB18C6 and Y3+ cation changes with the composition of the mixed solvents and even with temperature. The stability constant of the 1:1 complex was determined using a computer program, GENPLOT. The stability order of (4′NB18C6.Y3+ complex in pure studied solvents at 25 °C was found to be: EtOAc > AN > MeOH > DMF and in the case of the mixed solvent solutions with 25 mol percent of AN at 25 °C was: AN-DCE > AN-EtOAc > AN-MeOH ∼ AN-DMF. The values of stability constant (logKf of (4′NB18C6.Y3+ complex which were obtained from conductometric data, show that the stability of the complex is not only affected by the nature and composition of the solvent system, but it is also influenced by the temperature. In all cases, a non-linear behavior is observed for changes of logKf of the (4′NB18C6.Y3+ complex versus the composition of the binary mixed solvents. The values of standard thermodynamic quantities (ΔH°c and ΔS°c for the complexation process which were obtained from temperature dependence of the stability constant of (4′NB18C6.Y3+ complex, show that depending on the solvent system, in most cases, the complex is enthalpy and also entropy stabilized, but in some cases, it is stabilized or destabilized from these view points.

  6. Phase behavior and micellar properties of carboxylic acid end group modified pluronic surfactants

    NARCIS (Netherlands)

    Custers, J.P.A.; Broeke, van den L.J.P.; Keurentjes, J.T.F.

    2007-01-01

    The micellar behavior of three different carboxylic acid end standing (CAE) surfactants has been characterized using conductometry, differential scanning calorimetry, isothermal titration calorimetry, and dynamic light scattering. The CAE surfactants are modified high molecular weight Pluronic

  7. De hoogfrequentconductometrie met uitwendige electroden en enkele toepassingen in de farmacie

    NARCIS (Netherlands)

    Hannema, Harmen Ids

    1968-01-01

    In this thesis an investigation of high-frequency conductometry is described . The purpose of the investigation was to deepen the theoretical basis of the method and to obtain a better insight into the possibilities of the practical application.....

  8. Stabilization of chromium salt in ordinary portland cement

    Indian Academy of Sciences (India)

    Ordinary Portland cement (OPC) samples containing the chromium salt have been investigated using differential microcalorimetry, conductometry and Fourier transform infrared spectroscopic analysis. The effect of chromium on OPC hydration was evaluated by continuous observing of early hydration.

  9. Bezkontaktní měření vodivosti mělkých částí geologického prostředí

    OpenAIRE

    Podolník, Jan

    2014-01-01

    The task is focused on the issue of contactless conductometry for shallow parts of geological medium and it consists of two connected parts, search and experimental. The first part includes fundamental theoretical principles of contactless conductivity measurement, summary of presently manufactured electromagnetic devices (ground conductivity meters) and finally it presents the potentialities of using conductometry for detection and monitoring of contaminants. The basis of the second part com...

  10. Electrochemical analysis

    International Nuclear Information System (INIS)

    Hwang, Hun

    2007-02-01

    This book explains potentiometry, voltametry, amperometry and basic conception of conductometry with eleven chapters. It gives the specific descriptions on electrochemical cell and its mode, basic conception of electrochemical analysis on oxidation-reduction reaction, standard electrode potential, formal potential, faradaic current and faradaic process, mass transfer and overvoltage, potentiometry and indirect potentiometry, polarography with TAST, normal pulse and deferential pulse, voltammetry, conductometry and conductometric titration.

  11. Poly(vinylidene fluoride)-based ion track membranes with different pore diameters and shapes. SEM observations and conductometric analysis

    International Nuclear Information System (INIS)

    Nuryanthi, Nunung; Yamaki, Tetsuya; Koshikawa, Hiroshi; Asano, Masaharu; Enomoto, Kazuyuki; Sawada, Shin-ichi; Maekawa, Yasunari; Voss, Kay-Obbe; Trautmann, Christina; Neumann, Reinhard

    2010-01-01

    Poly(vinylidene fluoride) (PVDF) membranes with conical and cylindrical nanopores were prepared in a controlled manner by the ion-track technique, which involved heavy-ion beam irradiation and subsequent alkaline etching. The etching behavior mainly depended on the energy deposition of the ion beams, and thus its depth distribution, estimated by theoretical simulation, was successfully applied to control the shapes and diameters of the etched pores. Scanning electron microscopy (SEM) and electrolytic conductometry provided an insight into the critical experimental parameters. Interestingly, applying a higher voltage to the conductometry cell promoted track etching up to breakthrough probably because electrophoretic migration of the dissolved products occurred out of each pore. (author)

  12. Molecular complexes of tungsten oxotetrachloride with azomethins. Molekulyarnye kompleksy oksotetrakhlorida vol'frama s azometinami

    Energy Technology Data Exchange (ETDEWEB)

    Abramenko, Yu V; Garnovskij, A D; Abramenko, V A; Medvedeva, T E [Rostovskij-na-Donu Gosudarstvennyj Univ., Rostov-na-Donu (Russian Federation). Nauchno-Issledovatel' skij Inst. Fizicheskoj i Organicheskoj Khimii

    1992-09-01

    Series of new molecular complexes of tungsten oxotetrachloride with benza- and salicylalimines of equimolar compositions obtained. Substances are studied using element analysis, IR spectroscopy and conductometry. Octahedral structure of complexes with central atom coordination of benzalaniline molecules via azomethin nitrogen atom, and salicylalimines - via carbonyl oxygen atom of quinoid tantometric form of ligand is assumed.

  13. Regularities in the association of polymethacrylic acid with benzethonium chloride in aqueous solutions

    Science.gov (United States)

    Tugay, A. V.; Zakordonskiy, V. P.

    2006-06-01

    The association of cationogenic benzethonium chloride with polymethacrylic acid in aqueous solutions was studied by nephelometry, conductometry, tensiometry, viscometry, and pH-metry. The critical concentrations of aggregation and polymer saturation with the surface-active substance were determined. A model describing processes in such systems step by step was suggested.

  14. Association constants of telluronium salts

    International Nuclear Information System (INIS)

    Kovach, N.A.; Rivkin, B.B.; Sadekov, T.D.; Shvajka, O.P.

    1996-01-01

    Association constants in acetonitrile of triphenyl telluronium salts, which are dilute electrolytes, are determined through the conductometry method. Satisfactory correlation dependence of constants of interion association and threshold molar electroconductivity on the Litvinenko-Popov constants for depositing groups is identified. 6 refs

  15. Different-ligand boron complexes with gluconate-ions and pentaerythritol and gluconatoborates with B-O-B bridge bond. Raznoligandnye kompleksy bora s glyukonat-ionami i pentaehritritom i glyukonatoboraty s mostikovoj V-O-V svyaz'yu

    Energy Technology Data Exchange (ETDEWEB)

    Tel' zhenskaya, P N; Shvarts, E M; Vitola, I M [AN Latvijskoj SSR, Riga (USSR). Inst. Neorganicheskoj Khimii

    1990-01-01

    Borogluconates differing in structure of the complex dimeric borogluconate ion from the described earlier have been synthesized. The results of physicochemical measurements (chemical and thermal analysis, IR-spectroscopy, titration according to Fisher, conductometry) allowed to propose formulas for the studied compounds.

  16. Different-ligand boron complexes with gluconate-ions and pentaerythritol and gluconatoborates with B-O-B bridge bond

    International Nuclear Information System (INIS)

    Tel'zhenskaya, P.N.; Shvarts, E.M.; Vitola, I.M.

    1990-01-01

    Borogluconates differing in structure of the complex dimeric borogluconate ion from the described earlier have been synthesized. The results of physicochemical measurements (chemical and thermal analysis, IR-spectroscopy, titration according to Fisher, conductometry) allowed to propose formulas for the studied compounds

  17. Determination of diffusion coefficients for sulfide ions in solid electrolytes on the basis of BaSm2S4 and CaGd2S4

    International Nuclear Information System (INIS)

    Yurlov, I.S.; Ushakova, Yu.N.; Medvedeva, O.V.; Kalinina, L.A.; Shirokova, G.I.; Ananchenko, B.A.

    2007-01-01

    Coefficients of self-diffusion and coefficients of diffusion of the sulfur ion in solid electrolytes BaSm 2 S 4 and CaGd 2 S 4 are determined with recourse to methods of conductometry and potentiostatic chronoamperometry. A vacancy mechanism for the defect formation in solid solutions on the basis of barium thiosamarate and calcium thiogadolynate is proposed [ru

  18. Sodium benzyl(monoethanol)ammonium bis(gluconatoborate). Bis(glyukonatoborat) natriya-benzil(monoehtanol)ammoniya

    Energy Technology Data Exchange (ETDEWEB)

    Tel' zhenskaya, P N; Shvarts, E M; Vitola, I M [AN Latvijskoj SSR, Riga (USSR). Inst. Neorganicheskoj Khimii

    1990-01-01

    Boron compounds with gluconic acid and monoethanol- and benzylamines are synthesized and investigated by physicochemical methods (IR-spectroscopy, thermal decomposition, conductometry, Fischer titration). Tetracoordinated boron has two free hydroxyl groups, dimer of boron-gluconate anion is held by hydrogen bonds, sodium ions and ammonium protonated salts are cations.

  19. Shewanella putrefaciens adhesion and biofilm formation on food processing surfaces

    DEFF Research Database (Denmark)

    Bagge, Dorthe; Hjelm, M.; Johansen, C.

    2001-01-01

    Laboratory model systems were developed for studying Shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. S. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. S. putrefaciens bacteria suspended in buf...... from surfaces, and indirect conductometry and found this combination sufficient to quantify bacteria on surfaces...

  20. Properties of LiBF[sub 4] and LiAsF[sub 6] solutions in mixtures of tetrahydrofuran and 2-methyltetrahydrofuran. Svojstva rastvorov LiBF[sub 4] i LiAsF[sub 6] v smesyakh tetragidrofurana i 2-metiltetragidrofurana

    Energy Technology Data Exchange (ETDEWEB)

    Plakhotnik, A V; Tovmash, N F; Mishustin, A I; Kokunov, Yu V [AN SSSR, Moscow (Russian Federation). Inst. Obshchej i Neorganicheskoj Khimii

    1993-01-01

    Solutions of lithium tetrafluoroborate and hexafluoroarsenate in mixtures of tetrahydrofuran and 2-methyltetrahydrofuran were studies by the methods of conductometry, densimetry, viscosimetry and measurement of spin-lattice relaxation rate on [sup 7]Li nuclei. Considerable ifluence of anion nature was ascertained. Assumptions are made on the presence of cooperative interaction involving formation of the structures from solvent molecules and salt ions.

  1. Properties of LiBF4 and LiAsF6 solutions in mixtures of tetrahydrofuran and 2-methyltetrahydrofuran

    International Nuclear Information System (INIS)

    Plakhotnik, A.V.; Tovmash, N.F.; Mishustin, A.I.; Kokunov, Yu.V.

    1993-01-01

    Solutions of lithium tetrafluoroborate and hexafluoroarsenate in mixtures of tetrahydrofuran and 2-methyltetrahydrofuran were studies by the methods of conductometry, densimetry, viscosimetry and measurement of spin-lattice relaxation rate on 7 Li nuclei. Considerable ifluence of anion nature was ascertained. Assumptions are made on the presence of cooperative interaction involving formation of the structures from solvent molecules and salt ions

  2. Water-soluble resorcin[4]arene based cavitands

    NARCIS (Netherlands)

    Grote gansey, M.H.B.; Grote Gansey, Marcel H.B.; Bakker, Frank K.G.; Feiters, Martinus C.; Geurts, Hubertus P.M.; Verboom, Willem; Reinhoudt, David

    1998-01-01

    Water-soluble resorcin[4]arene based cavitands were obtained in good yields by reaction of bromomethylcavitands with pyridine. Their solubility was determined by conductometry. The behaviour in water depends on the alkyl chain length; the methylcavitand does not aggregate, whereas the pentyl- and

  3. Complexing properties of some carbamoylmethylphosphine oxides and methylenediphosphine dioxides with respect to alkali metal cations and the effect of abnormal aryl strengthening

    International Nuclear Information System (INIS)

    Evreinov, V.I.; Safronova, Z.V.; Yarkevich, A.N.; Kharitonov, A.V.; Bondarenko, N.A.; Tsvetkov, E.N.

    1999-01-01

    By the method of conductometry in anhydrous tetrahydrofuran at 25 Deg C stability constants of alkali metal (M = Li, Na, K) cation complexes with certain phosphinoxides have been determined. Abnormal aryl strengthening is first of all pronounced in the cation complexes with tetraphenyldiphosphine dioxide [ru

  4. Thermal transformations of oxohalide complexes of rhenium(5) and molybdenum(5) with diazo-18-crown-6 in solid phase. Termicheskie prevrashcheniya oksogalogenidnykh kompleksov reniya(5) i molibdena(5) s diaza-18-kraun-6 v tverdoj faze

    Energy Technology Data Exchange (ETDEWEB)

    Ashurova, N Kh; Yakubov, K G [Tadzhikskij Gosudarstvennyj Univ., Dushanbe (Tajikistan)

    1992-11-01

    Methods for synthesis and separation in solid state of the rhenium(5) and molybdenum(5) onium complexes with diaza-18-crown-6(L), the content of which according to the data of elementary analysis, IRS in the close and remote areas, thermogravimetry, conductometry and potentiometry corresponds to the (H[sub 2]L)[EOX[sub 5

  5. Sodium benzyl(monoethanol)ammonium bis(gluconatoborate)

    International Nuclear Information System (INIS)

    Tel'zhenskaya, P.N.; Shvarts, E.M.; Vitola, I.M.

    1990-01-01

    Boron compounds with gluconic acid and monoethanol- and benzylamines are synthesized and investigated by physicochemical methods (IR-spectroscopy, thermal decomposition, conductometry, Fischer titration). Tetracoordinated boron has two free hydroxyl groups, dimer of boron-gluconate anion is held by hydrogen bonds, sodium ions and ammonium protonated salts are cations

  6. Physicochemical analysis of zinc and cadmium ions interaction with unithiol; Fiziko-khimicheskij analiz vzaimodejstviya ionov tsinka i kadmiya s unitiolom v vodykh rastvorakh

    Energy Technology Data Exchange (ETDEWEB)

    Dubinina, L K; Shejkkh, M A; Ospanov, Kh K; Gemanova, L N [Kazakhskij Gosudarstvennyj Univ., Alma-Ata (Kazakhstan)

    1995-01-01

    Zinc and cadmium interaction with sodium 2,3-dimercaptopropane sulfonate in aqueous solution is studied by means of physicochemical analysis techniques (pH-metry, conductometry, viscosimetry, volumetry). Cadmium is determined to form 1:1 and 1:2 composition complex compounds. Formation constants of complex ions are determined. Mechanism of interaction of initial reagents is suggested. 7 refs.; 1 fig.

  7. The mechanism of interaction of polymethacrylic acid with sodium dodecylbenzenesulfonate in aqueous solutions

    Science.gov (United States)

    Sachko, A. V.; Zakordonskii, V. P.; Voloshinovskii, A. S.; Golod, T. Yu.

    2009-07-01

    A complex of physicochemical methods (light scattering, potentiometry, conductometry, viscometry, tensiometry, and fluorescence spectroscopy) were used to show the possibility of formation of intermolecular associates/complexes in systems with likely charged components. The driving forces of such interactions were analyzed and a possible scheme of complex formation between polymethacrylic acid and sodium dodecylbenzenesulfonate was suggested.

  8. Self-assembly in mixtures of sodium alkyl sulfates and alkyltrimethylammonium bromides : Aggregation behavior and catalytic properties

    NARCIS (Netherlands)

    Talhout, Reinskje; Engberts, BFN

    1997-01-01

    Two aqueous mixtures of cationic and anionic surfactants have been studied by means of conductometry, transmission electron microscopy, and microcalorimetry. Their catalytic effects on the decarboxylation of the kinetic probe 6-nitrobenzisoxazole-3-carboxylate (6-NBIC) were also examined in some

  9. Specification analysis of plutonium fuels for non-metallic impurities. I. Estimation of carbon

    Energy Technology Data Exchange (ETDEWEB)

    Rizvi, G H; Sethuraman, P R; Venkataramana, P; Natarajan, P R

    1975-01-01

    An analytical method for the estimation of carbon in plutonium samples in the range of 10-400 ..mu..g by conductometry has been developed. In the first step of the method, the entire carbon in sample is converted into CO/sub 2/ which in the second step is completely absorbed in barium hydroxide solution in conductivity of the solution.

  10. Molecular complexes of tungsten oxotetrachloride with azomethins

    International Nuclear Information System (INIS)

    Abramenko, Yu.V.; Garnovskij, A.D.; Abramenko, V.A.; Medvedeva, T.E.

    1992-01-01

    Series of new molecular complexes of tungsten oxotetrachloride with benza- and salicylalimines of equimolar compositions obtained. Substances are studied using element analysis, IR spectroscopy and conductometry. Octahedral structure of complexes with central atom coordination of benzalaniline molecules via azomethin nitrogen atom, and salicylalimines - via carbonyl oxygen atom of quinoid tantometric form of ligand is assumed

  11. Concentration dependence of the partial volume, viscosity, and electric conductivity of solutions of lithium salts in aliphatic alcohols

    International Nuclear Information System (INIS)

    Eliseeva, O.V.; Golubev, V.V.

    2003-01-01

    Concentration dependence of partial volumes, electric conductivity and viscosity of lithium nitrate and chloride solutions in methanol, propanol, isopropanol, butanol, isobutanol, pentanol and isopentanol at 298.15 K were studied by the methods of densimetry, conductometry and viscosimetry. Structural specific features of the solutions studied are discussed on the basis of the calculated volumetric characteristics of the substance dissolved and solvent [ru

  12. Association constants of telluronium salts; Konstanty assotsiatsii telluronievykh solej

    Energy Technology Data Exchange (ETDEWEB)

    Kovach, N A; Rivkin, B B; Sadekov, T D; Shvajka, O P

    1997-12-31

    Association constants in acetonitrile of triphenyl telluronium salts, which are dilute electrolytes, are determined through the conductometry method. Satisfactory correlation dependence of constants of interion association and threshold molar electroconductivity on the Litvinenko-Popov constants for depositing groups is identified. 6 refs.

  13. Ternary mixtures of alkyltriphenylphosphonium bromides (C12 TPB ...

    Indian Academy of Sciences (India)

    Administrator

    Critical Micellar Concentrations (CMCs) by conductometry, but their ternary mixtures produce single ... efficiently quenched pyrene fluorescence; the performances of the homologues in this respect were assessed. Keywords ..... The shape of the amphiphile aggregates ..... Haque M E, Das A R and Moulik S P 1999 J. Colloid.

  14. Specification analysis of plutonium fuels for non-metallic impurities. I - estimation of carbon

    International Nuclear Information System (INIS)

    Rizvi, G.H.; Sethuraman, P.R.; Venkataramana, P.; Natarajan, P.R.

    1975-01-01

    An analytical method for the estimation of carbon in plutonium samples in the range of 10-400 μg by conductometry has been developed. In the first step of the method, the entire carbon in sample is converted into CO 2 which in the second step is completely absorbed in barium hydroxide solution in conductivity of the solution. (M.G.B.)

  15. Ion track etching revisited: II. Electronic properties of aged tracks in polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Hernandez, G. M.; Cruz, S. A.; Garcia-Arellano, H.; Vacík, Jiří; Hnatowicz, Vladimír; Kiv, A.; Alfonta, L.

    2018-01-01

    Roč. 173, 1-2 (2018), s. 148-164 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : polymers * ion tracks * etching * conductometry * rectification * phase shift Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 0.443, year: 2016

  16. SHORT COMMUNICATION INVESTIGATION OF 1-ALKANOLS IN ...

    African Journals Online (AJOL)

    Preferred Customer

    The results indicate that even longer chain alkanols prefer interfacial ... investigation of surfactant-dye aggregates by conductometry and spectroscopic analysis [8-11]. The present study ... The negative value of k reflects a decrease in CMC. This is .... Hoiland, H.; Blokhus, A.M. Handbook of Surface and Colloid Chemistry.

  17. Effect of [gamma]-irradiation on latent tracks of polyethylene terephthalate (PET) film

    Science.gov (United States)

    Hiroki, A.; Asano, M.; Yamaki, T.; Yoshida, M.

    2005-04-01

    The pre-treatment effect of γ-irradiation on latent tracks of polyethylene terephthalate (PET) films bombarded with swift heavy ions was investigated by electric conductometry and scanning electron microscope (SEM) observation. The Xe-ion bombarded PET films were etched for 6 h in 0.2 M NaOH aqueous solution at 70 °C to prepare track-etched membranes. As γ-irradiation doses increased in the range of 0-160 kGy, the surface pore diameter obtained by SEM observation decreased while that obtained by conductometry became large. This inconsistent result between the two methods was due to an increase in the crosslinked region in the latent tracks caused by γ-irradiation.

  18. Instrumental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Jae; Seo, Seong Gyu

    1995-03-15

    This textbook deals with instrumental analysis, which consists of nine chapters. It has Introduction of analysis chemistry, the process of analysis and types and form of the analysis, Electrochemistry on basic theory, potentiometry and conductometry, electromagnetic radiant rays and optical components on introduction and application, Ultraviolet rays and Visible spectrophotometry, Atomic absorption spectrophotometry on introduction, flame emission spectrometry and plasma emission spectrometry. The others like infrared spectrophotometry, X-rays spectrophotometry and mass spectrometry, chromatography and the other instrumental analysis like radiochemistry.

  19. Study into complexing of anhydrous uranyl chloride with organic o-bases in nonaqueous media. Interaction with aliphatic sulfoxides

    Energy Technology Data Exchange (ETDEWEB)

    Kobets, L V; Buchikhin, E P; Klyshevich, R P; Belyachis, G F

    1982-01-01

    The methods of spectrophotometry, conductometry and calorimetry have been used to investigate interaction of uranyl chloride with dimethyl, diamil, dioctyl sulfoxides in the nonaqueous acetone media. Existence of complexes with 1:1, 1:2, 1:3 composition for dimethyl sulfoxide and with 1:1, 1:2 composition for diamil-, dioctyl sulfoxides is revealed. The constants of formation and dissociation of these complexes are calculated; the enthalpies of their formation in acetone are determined.

  20. German standard methods for the examination of water, waste water and sludge: General measurements of effects and substances (group H), determination of total organic carbon (TOC) (H 3)

    International Nuclear Information System (INIS)

    1982-01-01

    The following method for the determination of the total organic bound carbon is proposed. The carbon of the organic compounds is oxidized to carbon dioxide. There are three oxidation possibilities. Combustion, oxidation with proper oxidation agents in the solution and oxidation by irradiation of ultraviolette light. The resulting carbon dioxide or the possible reduction product methane are analysed with the following measuring instruments: Infrared spectroscopy, acidimetry, coulometry, conductometry, CO 2 sensitive electrodes, heat conductivity detection and flame ionisation detection. (VG) [de

  1. Preparation and characterization of TRIS(1,10-phenanthroline) technetium(III)

    International Nuclear Information System (INIS)

    Kremer, C.; Kremer, E.

    1993-01-01

    The [Tc(phen) 3 ] (PF 6 ) 3 complex has been synthesized by ligand substitution on [Tc(tu) 6 ] 3+ . The reaction proceeds quickly in aqueous solution. A pure compound is obtained with 40% yield. It was characterized by Tc elemental analysis, cerimetric titration, conductometry and electrophoresis. The corresponding spectroscopic properties (UV, Vis, IR and NMR) are also reported and discussed. (author) 16 refs.; 3 tabs

  2. Ruthenium (3) coordination compounds with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid

    International Nuclear Information System (INIS)

    Ezerskaya, N.A.; Buj Kuang Ki; Shubochkin, L.K.

    1987-01-01

    In the process of interaction of K 2 Ru(H 2 O)Cl 5 with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid (H 8 EDTP) Ru 3 mono-, bi- and trinuclear complexonates are synthesized. On the basis of IR and X-ray electron spectroscopy and potentiometry suppositions are made on the way of ligand (EDTP, Cl - , H 2 O) coordination. Ru 3 complexonates are characterized using spectrophotometry, polarography, conductometry. Thermal decomposition of the complexonates is studied

  3. Products of the reaction between methylene iodide and tertiary arsines

    International Nuclear Information System (INIS)

    Gigauri, R.D.; Arabuli, L.G.; Machaidze, Z.I.; Rusiya, M.Sh.

    2005-01-01

    Iodides of iodomethylenetrialkyl(aryl) arsonium were synthesized with high yields as a result of interaction between methylene iodide and tertiary arsines. Exchange reactions of the iodides prepared with lead(II) nitrate in water-alcohol solutions gave rise to formation of iodomethylenetrialkyl(aryl) arsonium nitrates. All the products prepared were characterized by data of elementary analysis, IR spectroscopy, conductometry and melting points measurements [ru

  4. Superamphiphilic nanocontainers based on the resorcinarene - Cationic surfactant system: Synergetic self-assembling behavior

    Science.gov (United States)

    Gaynanova, Gulnara A.; Bekmukhametova, Alina M.; Kashapov, Ruslan R.; Ziganshina, Albina Yu.; Zakharova, Lucia Ya.

    2016-05-01

    Self-organization in the mixed system based on water-soluble aminomethylated calix[4]arene with sulfonatoethyl groups at the lower rim and classical cationic surfactant cetyltrimethylammonium bromide has been studied by the methods of tensiometry, conductometry, spectrophotometry, dynamic and electrophoretic light scattering. The values of the critical association concentration, the size and zeta potential values, and the solubilization capacity of mixed aggregates toward the hydrophobic probe (Sudan I) were determined.

  5. Study of some features of coordination polymerization of α-oxides by the example of forming U(4) alkoxyhalides

    International Nuclear Information System (INIS)

    Khvostik, G.M.; Minevich, V.Ya.; Shupik, A.N.

    1985-01-01

    The interaction of uranium tetrachloride with α-oxides in THF has been studied by NMR and conductometry methods. The opening of the oxide cycle under the action of UCl 4 is shown. The formation of the coordinational bond between the oxygen atom of the polyester clain and the catalytic centre is found to result in retardation of the reactions of the chain propagation. The general scheme of the reactions of interaction of UCl 4 with oxides is proposed

  6. Studies on preparation of some alkaloid complexes and solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, A A

    1990-12-31

    Describes the various methods available in the literature for the determination of different classes of alkaloids spectrochemical (e.g.spectrophotometry and colorimetry, fluorimetry and phosphorimetry, nephelometry and reiractometry), electrochemical (e.g. polarography, amperometry, conductometry, coulometry and potentiometry), volumetric (e.q. acid-base, iodometry , bromimetry , oxidimetry, complexometry and precipitation ) and miscellaneous methods (e.g.gasliquid chromatography, gravimetry, thermometry and rediometry ) has been discussed. 31 tabs; 29 figs; 402 refs.

  7. Analytical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Seong

    1993-02-15

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  8. Study into complexing of anhydrous uranyl chloride with organic o-bases in nonaqueous media. Interaction with aliphatic sulfoxides

    International Nuclear Information System (INIS)

    Kobets, L.V.; Buchikhin, E.P.; Klyshevich, R.P.; Belyachis, G.F.

    1982-01-01

    The methods of spectrophotometry, conductometry and calorimetry have been used to investigate interaction of uranyl chloride with dimethyl, diamil, dioctyl sulfoxides in the nonaqueous acetone media. Existence of complexes with 1:1, 1:2, 1:3 composition for dimethyl sulfoxide and with 1:1, 1:2 composition for diamil-, dioctyl sulfoxides is revealed. The constants of formation and dissociation of these complexes are calculated; the enthalpies of their formation in acetone are determined

  9. Rhenium(5) and molybdenum(5) complexes with 4',4[sup (]5[sup )]-divaleryldibenzo-18-crown-6. Kompleksnye soedineniya reniya(5) i molibdena(5) s 4',4[sup (]5[sup )]-divalerildibenzo-18-kraun-6

    Energy Technology Data Exchange (ETDEWEB)

    Ashurova, N Kh; Yakubov, K G; Tashmukhamedova, A K; Basitova, S M [Tadzhikskij Gosudarstvennyj Univ., Dushanbe (Tajikistan)

    1993-02-01

    Methods for synthesizing oxohalide complexes of rhenium and molybdenum with +5 oxidation degree with 4',4[sup (5)]-divaleryldibenzo-18-crown-6 were developed. Content and composition of prepared compounds were investigated by the methods of element analysis, crystal optics, conductometry, IR spectroscopy in the near and far regions, thermogravimetry. Oxidation degree of the complex-forming metal was determined. It was established that composition of the compounds coressponded to the general formula MOLX [sub [center dot

  10. Instrumental analysis

    International Nuclear Information System (INIS)

    Kim, Seung Jae; Seo, Seong Gyu

    1995-03-01

    This textbook deals with instrumental analysis, which consists of nine chapters. It has Introduction of analysis chemistry, the process of analysis and types and form of the analysis, Electrochemistry on basic theory, potentiometry and conductometry, electromagnetic radiant rays and optical components on introduction and application, Ultraviolet rays and Visible spectrophotometry, Atomic absorption spectrophotometry on introduction, flame emission spectrometry and plasma emission spectrometry. The others like infrared spectrophotometry, X-rays spectrophotometry and mass spectrometry, chromatography and the other instrumental analysis like radiochemistry.

  11. Instrumental analysis

    International Nuclear Information System (INIS)

    Jae, Myeong Gi; Lee, Won Seong; Kim, Ha Hyeok

    1989-02-01

    This book give description of electronic engineering such as circuit element and device, circuit analysis and logic digital circuit, the method of electrochemistry like conductometry, potentiometry and current measuring, spectro chemical analysis with electromagnetic radiant rays, optical components, absorption spectroscopy, X-ray analysis, atomic absorption spectrometry and reference, chromatography like gas-chromatography and liquid-chromatography and automated analysis on control system evaluation of automated analysis and automated analysis system and reference.

  12. Rhenium (5) and molybdenum (5) complexes with 4',4''(5'')-ditretbutyldibenzo-24-crown-8. Kompleksnye soedineniya reniya (5) i molibdena (5) s 4',4''(5'')-ditretbutildibenzo-24-kraun-8

    Energy Technology Data Exchange (ETDEWEB)

    Ashurova, N Kh; Yakubov, K G; Basitova, S M; Tashmukhamedova, A K; Sajfullina, N Zh [Tadzhikskij Gosudarstvennyj Univ., Dushanbe (USSR)

    1989-10-01

    Rhenium and molybdenum complexes in +5 oxidation degree with 4',4''(5'')-ditretbutyldibenzo-24-crown-8 (L) are synthesized with 75-95 % yield. Composition and structure of compounds produced are investigated using element analysis, conductometry, IR spectroscopy, thermogravimetry methods. Oxidation degree of complexer metal is determined. It is ascertained that the compound composition corresponds to the MOLX{sub 3} formula, where M-Re, Mo; X-Cl{sup -}, Br{sup -}.

  13. Instrumental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jae, Myeong Gi; Lee, Won Seong; Kim, Ha Hyeok

    1989-02-15

    This book give description of electronic engineering such as circuit element and device, circuit analysis and logic digital circuit, the method of electrochemistry like conductometry, potentiometry and current measuring, spectro chemical analysis with electromagnetic radiant rays, optical components, absorption spectroscopy, X-ray analysis, atomic absorption spectrometry and reference, chromatography like gas-chromatography and liquid-chromatography and automated analysis on control system evaluation of automated analysis and automated analysis system and reference.

  14. Detection of radiation processing in onions

    International Nuclear Information System (INIS)

    Duchacek, V.

    1985-01-01

    Two breeds of onions were used for irradiation. Both breeds were divided into two parts - the first was irradiated with a dose of 80 Gy and the second served as a control. The two parts were stored under the same conditions. Conductometry, liquid chromatography and spectrophotometry were used for detecting the radiation processing of the onions. Only from the spectrophotometric determination of 2-desoxysaccharides it was possible to safely distinguish irradiated onions from non-irradiated controls throughout storage time. (E.S.)

  15. Rhenium (5) and molybdenum (5) complexes with 4',4''(5'')-ditretbutyldibenzo-24-crown-8

    International Nuclear Information System (INIS)

    Ashurova, N.Kh.; Yakubov, K.G.; Basitova, S.M.; Tashmukhamedova, A.K.; Sajfullina, N.Zh.

    1989-01-01

    Rhenium and molybdenum complexes in +5 oxidation degree with 4',4''(5'')-ditretbutyldibenzo-24-crown-8 (L) are synthesized with 75-95 % yield. Composition and structure of compounds produced are investigated using element analysis, conductometry, IR spectroscopy, thermogravimetry methods. Oxidation degree of complexer metal is determined. It is ascertained that the compound composition corresponds to the MOLX 3 formula, where M-Re, Mo; X-Cl - , Br -

  16. Studies on preparation of some alkaloid complexes and solvent extraction

    International Nuclear Information System (INIS)

    Mohamed, A.A.

    1989-01-01

    Describes the various methods available in the literature for the determination of different classes of alkaloids spectrochemical (e.g.spectrophotometry and colorimetry, fluorimetry and phosphorimetry, nephelometry and reiractometry), electrochemical (e.g. polarography, amperometry, conductometry, coulometry and potentiometry), volumetric (e.q. acid-base, iodometry , bromimetry , oxidimetry, complexometry and precipitation ) and miscellaneous methods (e.g.gasliquid chromatography, gravimetry, thermometry and rediometry ) has been discussed

  17. Features of melting of indium monohalides

    Energy Technology Data Exchange (ETDEWEB)

    Dmitriev, V S; Smirniv, V A [AN SSSR, Chernogolovka. Inst. Fiziki Tverdogo Tela

    1980-12-01

    The character of InCl, InBr and InI melting is investigated by the methods of DTA, calorimetry, conductometry and chemical analysis. Partial decomposition of monohalogenides during melting according to the reactions of disproportionation is shown. The presence of disproportionation products (In/sup 0/ and In/sup 3 +/) is manifested in the properties of solid monohalogenides, prepared by the crystallization from melt, in their photosensitivity and electroconductivity.

  18. Analytical chemistry

    International Nuclear Information System (INIS)

    Choi, Jae Seong

    1993-02-01

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  19. Thermal decomposition of rhenium (5) complexes with 1,2,4-triazole

    International Nuclear Information System (INIS)

    Amindzhanov, A.A.; Gagieva, S.Ch.; Kotegov, K.V.

    1991-01-01

    Processes of thermal decomposition of rhenium (5) complexes with 1,2,4-triazole were studied. Thermolysis products were identified on the basis of data of the element analysis, IR spectra, conductometry and other methods. It is ascertained that at the first stage of thermolysis of hydroxyl-containing monomer complexes removal of water molecules occurs, and at the second one - dimerization process with formation of Re-O-Re group. It is shown that the nature of halide ion practically does not affect the temperature of the start of intensive thermal decomposition of the complexes

  20. Electric-surface characteristics and stability of type K coal suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Baichenko, A A; Baran, A A; Mitina, N S; Kocherga, I I

    1987-07-01

    Investigates with the help of potentiometric titration, electrophoresis and conductometry the structure of double electric layer and aggregation stability of type K coal suspension at the Berezovsk preparation plant (Kuzbassugol' association). Discusses tests carried out with coal which was preliminarily crushed, sieved, crushed again in colloid mills, elutriated and separated into sedimento-stable fractions. Data obtained indicate that coal suspensions represent typical ion-stabilized dispersions, coagulation of which by electrolytes can be depicted within the framework of lyophobic colloid stability theory. Addition of double-charged gegenions considerably reduces electrokinetic potential while addition of triple-charged gegenions results in surface recharging. 10 refs.

  1. Transport of Zn(OH)4(-2) ions across a polyolefin microporous membrane

    Science.gov (United States)

    Krejci, Ivan; Vanysek, Peter; Trojanek, Antonin

    1993-04-01

    Transport of ZN(OH)4(2-) ions through modified microporous polypropylene membranes (Celgard 3401, 350140) was studied using polarography and conductometry. Soluble Nafion as an ion exchange modifying agent was applied to the membrane by several techniques. The influence of Nafion and a surfactant on transport of zinc ions through the membrane was studied. A relationship between membrane impedance and the rate of Zn(OH)4(2-) transport was found. The found correlation between conductivity, ion permeability and Nafion coverage suggests a suitable technique of membrane preparation to obtain desired zinc ion barrier properties.

  2. Influence of complexing on physicochemical properties of polymer-salt solutions. Vliyanie kompleksoobrazovaniya na fiziko-khimicheskie svojstva polimerno-solevykh rastvorov

    Energy Technology Data Exchange (ETDEWEB)

    Ostroushko, A A; Yushkova, S M; Koridze, N V; Skobkoreva, N V; Zhuravleva, L I; Palitskaya, T A; Antropova, S V; Ostroushko, I P [Ural' skij Gosudarstvennyj Univ., Sverdlovsk (Russian Federation) AN SSSR, Moscow (Russian Federation). Inst. Obshchej i Neorganicheskoj Khimii

    1993-06-01

    Using the methods of spectrophotometry, viscosimetry, conductometry the influence of salt-polymer complexing processes on physicochemical prperties of aqueous solutions of yttrium, barium, copper nitrates and formates with polyvinyl alcohol was studied. Change of dynamic viscosity, specific electric conductivity of solutions in the process of complexing was shown. Thermal effects of salt-polymer interaction were measured. It is shown that decrease of transition temperature of polymer to plastic state in films, temperature and effective activation energy of salt decomposition is also connected with complexing. Effective values of surface tension on the boundary with air are measured. Coefficients of cation diffusion in polymer-salt solutions are estimated.

  3. On composition and thermal degradation of basic zirconium sulfates

    Energy Technology Data Exchange (ETDEWEB)

    Grizik, A A; Nekhamkin, L G; Kondrashova, I A; Serebrennikov, E L; Kerina, V P

    1988-02-01

    Methods of potentiometric titration, conductometry and thermal gravimetric analysis are used to study composition and properties of basic zirconium sulfates (BZS) obtained under different conditions of precipitation from aqueous solutions. Three X-ray amorphous phases of BZR with mole ratio SO/sub 4//sup 2-/:Zr, being 0.60+-0.03; 0.37+-0.04 and 0.176+-0.005, are identified. Different character of thermal decomposition of these phases in the process of zirconium dioxide preparation from BZS is confirmed.

  4. Reaction of pyridine-N-oxides with halogens; Vzaimodejstvie piridin-N-oksidov s galogenami

    Energy Technology Data Exchange (ETDEWEB)

    Kanibolotskij, A L; Mikhzajlov, V A; Savelova, V A [AN Ukrainskoj SSR, Donetsk (Ukraine). Inst. Fiziko-Organicheskoj Khimii i Uglekhimii

    1994-12-31

    By the methods of conductometry, NMR and IR spectroscopy it has been ascertained that interaction of pyridine-N-oxides with bromine, iodine and interhalides (ICl and IBr) gives rise to the formation of crystal complexes of 1:1 composition. The complexes mentioned are of presumably ionic structure: [RC{sub 5}H{sub 4}N-O...X...O-NC{sub 5}H{sub 4}R]{sup +}[Y-X-Y]{sup -},where X,Y = Cl,Br,I.

  5. Study of lanthanum nitrate-sodium tetrametaphosphate-water system

    International Nuclear Information System (INIS)

    Emel'yanov, O.V.; Bojko, K.M.

    1978-01-01

    The system La(NO 3 ) 3 -Na 4 P 4 O 12 -H 2 O has been studied using the solubility method, pH- and conductometry. Found are subsequent formation of the main phases of alternate composition and neutral salt La 4 (P 4 O 12 ) 3 , which is solved in Na 4 P 4 O 12 excess which is a result of complex formation. The soluble complexes of the composition Na 5 [La(P 4 O 12 ) 2 ] are obtained. The extracted complexes are investigated using the methods of paper chromatography, thermography roentgenography and IR-spectroscopy

  6. Reactions of vanadium(5) with aluminium(3) in weakly acid aqueous solutions; Vzaimodejstvie mezhdu vanadiem(5) i alyhminiem(3) v slabokislykh vodnykh rastvorakh

    Energy Technology Data Exchange (ETDEWEB)

    Ditrikh, I V; Makhno, A Ya [Donetskij Gosudarstvennyj Univ., Donetsk (Ukraine)

    1997-12-31

    Conditions of vanadium(5) heteropolycompounds formation in aqueous solutions containing aluminium(3) have been studied. By the methods of potentiometry and conductometry in solutions of Al(NO{sub 3}){sub 3}-NaVO{sub 3} salt mixture the formation of complexes with the ratios [Al{sup 3+}]:[V{sup 5+}]=1:3, 1:6 and 1:12 has been ascertained. A salt of gross formula 3NaO {center_dot} (Al{sub 2}){sub 3} {center_dot} 12V{sub 2}O{sub 5} {center_dot} 67H{sub 2}O has been isolated. 3 refs.; 2 figs.

  7. Influence of complexing on physicochemical properties of polymer-salt solutions

    International Nuclear Information System (INIS)

    Ostroushko, A.A.; Yushkova, S.M.; Koridze, N.V.; Skobkoreva, N.V.; Zhuravleva, L.I.; Palitskaya, T.A.; Antropova, S.V.; Ostroushko, I.P.; AN SSSR, Moscow

    1993-01-01

    Using the methods of spectrophotometry, viscosimetry, conductometry the influence of salt-polymer complexing processes on physicochemical prperties of aqueous solutions of yttrium, barium, copper nitrates and formates with polyvinyl alcohol was studied. Change of dynamic viscosity, specific electric conductivity of solutions in the process of complexing was shown. Thermal effects of salt-polymer interaction were measured. It is shown that decrease of transition temperature of polymer to plastic state in films, temperature and effective activation energy of salt decomposition is also connected with complexing. Effective values of surface tension on the boundary with air are measured. Coefficients of cation diffusion in polymer-salt solutions are estimated

  8. Pulse radiolysis in model studies toward radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Sonntag, C Von; Bothe, E; Ulanski, P; Deeble, D J [Max-Planck-Institut fuer Strahlenchemie, Muelheim an der Ruhr (Germany)

    1995-10-01

    Using the pulse radiolysis technique, the OH-radical-induced reactions of poly(vinyl alcohol) PVAL, poly(acrylic acid) PAA, poly(methyacrylic acid) PMA, and hyaluronic acid have been investigated in dilute aqueos solution. The reactions of the free-radical intermediates were followed by UV-spectroscopy and low-angle laser light-scattering; the scission of the charged polymers was also monitored by conductometry. For more detailed product studies, model systems such as 2,4-dihydroxypentane (for PVAL) and 2,4-dimethyl glutaric acid (for PAA) was also investigated. (author).

  9. A study of the complex formation of bivalent lanthanides with tetraphenylborate-ion in organic solvents. Izuchenie kompleksoobrazovaniya dvukhvalentnykh lantanoidov s tetrafenilborat-ionom v organicheskikh rastvoritelyakh

    Energy Technology Data Exchange (ETDEWEB)

    Veleshko, I E; Mikheev, N B; Kulyukhin, S A

    1992-01-01

    Interaction of bivalent lanthanides with tetraphenylborate-ion (BPh[sub 4][sup -]) in solutions of CH[sub 3]CN and C[sub 2]H[sub 5]OH was studied by the methods of cocrystallization, conductometry and spectrophotometry.It is shown that no complexing between Ln[sup 2+] and BPh[sub 4][sup -] takes place in ethanol, wheras in CH[sub 3]CN formation of second sphere complexes of the composition [Ln(CH[sub 3]CN)[sub n

  10. Ruthenium (3) coordination compounds with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Ezerskaya, N A; Ki, Buj Kuang; Shubochkin, L K

    1987-12-01

    In the process of interaction of K/sub 2/Ru(H/sub 2/O)Cl/sub 5/ with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid (H/sub 8/EDTP) Ru/sup 3/ mono-, bi- and trinuclear complexonates are synthesized. On the basis of IR and X-ray electron spectroscopy and potentiometry suppositions are made on the way of ligand (EDTP, Cl/sup -/, H/sub 2/O) coordination. Ru/sup 3/ complexonates are characterized using spectrophotometry, polarography, conductometry. Thermal decomposition of the complexonates is studied.

  11. Association of ions in LiPF{sub 6} solutions in propylencarbonate and {gamma}-butyrolactone; Assotsiatsiya ionov v rastvorakh LiPF{sub 6} v propilenkarbonate i {gamma}-butirolaktone

    Energy Technology Data Exchange (ETDEWEB)

    Plakhotnik, V N; Sukhaya, E M; Mishustin, A I

    1995-10-01

    Lithium hexafluorophosphate solutions in propylencarbonate and {gamma}-butyrolactone are investigated in a wide ranges of concentrations and temperatures using conductometry, viscosimetry, densimetry methods and measurements of lithium-7 nucleus spin-lattice relaxation rates. Absence of correlations between solution conductivity and ionization ability of solvents, which is conditioned by the prevailing viscosity effect, is shown. Notable effect of ion-dipole interaction on the formation of Li{sup +} ion electric field gradient is ascertained within the framework of ion association model. 15 refs.; 2 figs.; 1 tab.

  12. Interaction of sodium monoborate and boric acid with some mono- and disaccharides in aqueous solutions (from data on isomolar solutions method)

    International Nuclear Information System (INIS)

    Shvarts, E.M.; Ignash, R.T.; Belousova, R.G.

    2000-01-01

    Interaction of sodium monoborate Na[B(OH) 4 ] and boric acid with D-glucose, D-fructose, D-saccharose and D-lactose in aqueous solution depending on the solution total concentration is studied through the method of isomolar solutions with application of conductometry and polarimetry. It is shown by the D-glucose and D-fructose examples that the method of isomolar solutions leads to results compatible with the data obtained by other methods and it may be applied to other saccharides [ru

  13. Kinetics and mechanism of hydrolysis of scandium sulfate

    International Nuclear Information System (INIS)

    Koshchej, E.V.; Stryapkov, A.V.; Podosenov, D.E.; Makarov, G.V.; Razdobreev, D.A.

    1998-01-01

    The Sc 2 (SO 4 ) 3 -H 2 SO 4 -H 2 O system is studied through the methods of pH-potentiometry, conductometry and turbidimetry at 298 and 318 K and ion force 0.01, 0.1 and 1.0. The hydrolysis mechanism including the processes in the system homogenous and heterogeneous constituents. The hydrolysis rates of scandium salts and their dependences on OH-ions concentration, solution ions force and temperature are found; the constants of the processes rate with participation of OH - and SO 4 2- ions and constants of the solid phase formation rate are calculated [ru

  14. Electrical properties and structure of glasses in the Ba(PO3)2-MF2 systems, where M = Mg, Ca, Sr, Ba

    International Nuclear Information System (INIS)

    Sokolov, I.A.; Tarlakov, Yu.P.; Murin, I.V.; Pronkin, A.A.

    2000-01-01

    Using the methods of conductometry and IR spectroscopy the concentrational dependences of electric conductivity are studied, the nature of current carriers is determined, the concentrational dependence of transfer numbers is ascertained and structural changes in glasses of the system Ba(PO 3 ) 2 -MF 2 (M = Mg, Ca, Sr, Ba), depending on MF 2 content, are considered. It is shown that F - ions take part in electric current transfer. Influence of crystallochemical nature of alkaline-earth cations on physicochemical properties and structure of the glasses studied is analyzed [ru

  15. Rhenium(V) complexes with sulfur-containing amino acids

    International Nuclear Information System (INIS)

    Gagieva, S.Ch.; Tautieva, M.A.; Tsaloev, A.T.; Galimov, Yu.B.; Gagieva, L.Ch.; Belyaeva, T.N.

    2007-01-01

    Rhenium(V) complexes with 2-amino-4-(methylthio)butanoic acid (methionine, Met) and 2-amino-3-sulfopropionic acid (cysteine, Cys) have been synthesized. Depending on the initial reagent ratio, the resulting complexes contain one or two ligand molecules. On heating the compounds with one amino acid molecule, two hydrogen halide molecules are removed at 128-132 deg C to form a molecular complex. The composition, structure, and thermal stability of the complexes have been studied by elemental analysis, conductometry, IR spectroscopy, NMR, and mass spectrometry [ru

  16. Cation mobility in H+/Na+ ion exchange products of acid tantalum and zirconium phosphates

    International Nuclear Information System (INIS)

    Tarnopol'skij, V.A.; Yaroslavtsev, A.B.

    2000-01-01

    Ionic conductivity of Na + /H + exchange products on acid zirconium phosphate with different substitution degree and on acid tantalum phosphate, where ion exchange occurs via formation of a continuous series of solid solutions, was studied by the method of conductometry. It was ascertained that ionic conductivity decreases monotonously with growth in substitution degree of H + for Na + in acid tantalum phosphate. Anomalous increase in ionic conductivity of ion exchange products on acid zirconium phosphate with a low substitution degree has been detected for the first time. Formation of a double electric layer with a high concentration of cationic defects on the interface surface is the reason for increase in ionic conductivity [ru

  17. On composition and thermal degradation of basic zirconium sulfates

    International Nuclear Information System (INIS)

    Grizik, A.A.; Nekhamkin, L.G.; Kondrashova, I.A.; Serebrennikov, E.L.; Kerina, V.P.

    1988-01-01

    Methods of potentiometric titration, conductometry and thermal gravimetric analysis are used to study composition and properties of basic zirconium sulfates (BZS) obtained under different conditions of precipitation from aqueous solutions. Three X-ray amorphous phases of BZR with mole ratio SO 4 2- :Zr, being 0.60±0.03; 0.37±0.04 and 0.176±0.005, are identified. Different character of thermal decomposition of these phases in the process of zirconium dioxide preparation from BZS is confirmed

  18. Thermodynamic aspects of polymer–surfactant interactions: Gemini (16-5-16-PVP-water system

    Directory of Open Access Journals (Sweden)

    Naved Azum

    2016-11-01

    Full Text Available The interaction between polyvinylpyrrolidone (PVP and gemini surfactant (16-5-16 in aqueous solution has been analyzed using conductometry. From conductivity data the critical aggregation concentration (cac, critical micelle concentration (cmc, the effective degree of counter-ion binding (β at different temperatures were obtained. The thermodynamic parameters, i.e., Gibbs energy of aggregation and micellization, standard enthalpy of aggregation, and standard entropy of aggregation of surfactant/polymer system were estimated, employing pseudophase separation model. The negative values of Gibbs energy and standard enthalpy suggest that the surfactant/polymer aggregation process is spontaneous and exothermic respectively.

  19. Peculiarity of counterion - polyion interactions in aqueous solutions of copolymers of acrylamide with cadmium acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Myagchenkov, V A; Kurenkov, V F; Akhmed' yanova, R A [Kazanskij Khimiko-Tekhnologicheskij Inst. (USSR)

    1984-02-01

    Binding of Cd/sup 2 +/ ions in aqueous solutions of statistical copolymers of acrylamide with cadmium acrylate with different content of ionogenic groups in copolymers was investigated by polarography, conductometry, viscometry and dialysis. It is shown that the degree of binding of Cd/sup 2 +/ ions increases with increasing of the content of ionogenic groups in the copolymer and with decreasing of ionic strength of the solution. The values of the degree of binding of Cd/sup 2 +/ ions obtained by polarography and dialysis show satisfactory agreement.

  20. Thermal decomposition of rhenium (5) complexes with 1,2,4-triazole. Termicheskoe razlozhenie kompleksov reniya (5) s 1,2,4-triazolom

    Energy Technology Data Exchange (ETDEWEB)

    Amindzhanov, A A; Gagieva, S Ch; Kotegov, K V [Tadzhikskij Gosudarstvennyj Univ., Dushanbe (Tajikistan)

    1991-01-01

    Processes of thermal decomposition of rhenium (5) complexes with 1,2,4-triazole were studied. Thermolysis products were identified on the basis of data of the element analysis, IR spectra, conductometry and other methods. It is ascertained that at the first stage of thermolysis of hydroxyl-containing monomer complexes removal of water molecules occurs, and at the second one - dimerization process with formation of Re-O-Re group. It is shown that the nature of halide ion practically does not affect the temperature of the start of intensive thermal decomposition of the complexes.

  1. Magnetic coupling between liquid 3He and a solid state substrate: a new approach

    Science.gov (United States)

    Klochkov, Alexander V.; Naletov, Vladimir V.; Tayurskii, Dmitrii A.; Tagirov, Murat S.; Suzuki, Haruhiko

    2000-07-01

    We suggest a new approach for solving the long-standing problem of a magnetic coupling between liquid 3He and a solid state substrate at temperatures above the Fermi temperature. The approach is based on our previous careful investigations of the physical state of a solid substrate by means of several experimental methods (EPR, NMR, conductometry, and magnetization measurements). The developed approach allows, first, to get more detailed information about the magnetic coupling phenomenon by varying the repetition time in pulse NMR investigations of liquid 3He in contact with the solid state substrate and, second, to compare the obtained dependences and the data of NMR-cryoporometry and AFM-microscopy.

  2. Interaction of cadmium and indium nitrate mixture with sodium tungstate in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Belousova, E E; Krivobok, V I; Gruba, A I [Donetskij Gosudarstvennyj Univ. (Ukrainian SSR)

    1982-01-01

    The interaction of the mixture of cadmium and indium nitrates with sodium tungstate in aqueous solution is studied using the methods of ''residual concentrations'', pH potentiometry and conductometry. Independent of the ratio of components in the initial solution a mixture of coprecipitated normal tungstates of cadmium and indium is formed in the system. Heat treatment of the precipitates at 800 deg C for 50 hrs with subsequent hardening results in the formation of solid solutions on the basis of normal cadmium and indium tungstates.

  3. 15-year-activity of Electron Linear Accelerator Laboratory

    International Nuclear Information System (INIS)

    Karolczak, S.

    1999-01-01

    The purchase of the Russian Electron Linear Accelerator ELU-6E by Institute of Radiation Technique of Lodz Technical University in 1978 started the activity of the ELA Laboratory. The accelerator itself and many additional scientific equipment designed and built during past 15 years have became the basic investigation tool for the ITR now. The most important measuring systems based on electron beam as irradiation source are: pulse radiolysis system with detection in IR, UV and visible region of the spectra, radiation induced conductometry, Faraday chamber and computerized data acquisition and processing system

  4. Determination of stability constants of K and Cs nitrate complex with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions

    International Nuclear Information System (INIS)

    Myasoedova, T.G.; Ponomareva, A.V.; Zagorets, P.A.; Filippov, E.A.

    1984-01-01

    Total stability constants of K and Cs nitrate complexes with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions were determined by the method of low-frequency contact conductometry. Clearly defined K/Cs selectivity is observed for the system with dibenzo-18-crown-6. It is shown that lgβ depends on permittivity of the solvent. The decrease of permittivity of isopropanol aqueous solutions results in reduction of K/Cs selectivity of DB18C6

  5. A study of heterogeneous systems which retard the processes of motor oil aging. VI. The effect of the composition of the oil medium on its electric conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Zhdanov, V V; Ashkinazi, L A; Chkalov, V A; Filanovskiy, B K; Grilikhes, M S; Nikolayenko, A V; Poray-Koshits, A B; Ravdel, A A

    1982-01-01

    A method of contact conductometry is used to study the effect of the composition of an oil medium on its electric conductivity and the factors to which this parameter is the most sensitive was determined. It is shown that the electric conductivity is a sensitive parameter, which reacts to a change in the water content in the oil, the length of operation in an internal combustion engine, to the volume of additives in the base oil and to the acid and base properties of the oil medium.

  6. Films of double oxides of zirconium and iron

    International Nuclear Information System (INIS)

    Kozik, V.V.; Borilo, L.P.; Shul'pekov, A.M.

    2000-01-01

    Films of double oxides of zirconium and iron were prepared by the method of precipitation from film-forming alcohol solutions of zirconium oxychloride and iron chloride with subsequent thermal treatment. Using the methods of X-ray phase and differential thermal analyses, conductometry and optical spectroscopy, basic chemical processes occurring in the film-forming solutions and during thermal treatment are studied alongside with phase composition and optical characteristics of the films prepared. The composition-property diagrams of the given system in a thin-film state are plotted [ru

  7. Solvent effect on the rate and equilibrium of reaction between 10-phenylphenoxarsine and methyl iodide

    International Nuclear Information System (INIS)

    Gavrilov, V.I.; Gumerov, N.S.; Rakhmatullin, R.R.

    1990-01-01

    Effect of solvent nature on nucleophilic capacity of three-coordinated arsenic and the equilibrium state of 10-phenylphenoxarsine (PA) reaction with methyl iodide are studied. Kinetic investigations are carried out by the conductometry at 24,35,45 deg C. It is established that quaternization of PA with methyl iodide when substituting a solvent (ketone for alcohol) increases 3-14 times with simultaneous growth of the activation energy value. When transforming from aprotic solvents to protic ones PA interaction equilibrium with methyl iodide shifts to the side of arsonic salt formation

  8. Study of some features of coordination polymerization of. cap alpha. -oxides by the example of forming U(4) alkoxyhalides

    Energy Technology Data Exchange (ETDEWEB)

    Khvostik, G M; Minevich, V Ya; Shupik, A N

    1985-10-01

    The interaction of uranium tetrachloride with ..cap alpha..-oxides in THF has been studied by NMR and conductometry methods. The opening of the oxide cycle under the action of UCl/sub 4/ is shown. The formation of the coordinational bond between the oxygen atom of the polyester clain and the catalytic centre is found to result in retardation of the reactions of the chain propagation. The general scheme of the reactions of interaction of UCl/sub 4/ with oxides is proposed.

  9. Selectivity in inter polymer complexation involving phenolic copolymer, poly electrolytes, non-ionic polymers and transition metal ions

    International Nuclear Information System (INIS)

    Vasheghani Farahani, B.; Hosseinpour Rajabi, F.

    2006-01-01

    Selectivity in inter polymer complex formation involving a typical four-component phenolic copolymer (ρ-chloro phenol-ρ-aminophenol-ρ-toluidine-ρ-cresol- HCHO copolymer), poly electrolytes such as polyethylene imine and polyacrylic acid, a non-ionic homopolymer polyvinyl pyrrolidone, and some transition metal ions (e.g., Cu (II), Ni (11)) have been studied in dimethylformamide-methanol solvents mixture. The coordinating groups of phenolic copolymer form complexes through hydrogen bonding and ion-dipole interactions. The different stages of interactions have been studied by several experimental techniques, e.g., viscometry, potentiometry and conductometry. Some schemes have been suggested to explain the mode of interaction between these components

  10. Thermal transformations of oxohalide complexes of rhenium(5) and molybdenum(5) with diazo-18-crown-6 in solid phase

    International Nuclear Information System (INIS)

    Ashurova, N.Kh.; Yakubov, K.G.

    1992-01-01

    Methods for synthesis and separation in solid state of the rhenium(5) and molybdenum(5) onium complexes with diaza-18-crown-6(L), the content of which according to the data of elementary analysis, IRS in the close and remote areas, thermogravimetry, conductometry and potentiometry corresponds to the (H 2 L)[EOX 5 ], where E = Re, Mo; X = Cl - , Br - . Thermotransformation of onium compounds is studied by methods of thermal methods (TG-DTG-DTA combined study). Their avility to be affected by solid-phase dehydrohalogenization, e.i. anderson regrouping. The thermolysis products, corresponding to the general formula (EOLX 3 ), are separated and studied

  11. Sulfide-conducting solid electrolytes

    International Nuclear Information System (INIS)

    Kalinina, L.A.; Shirokova, G.I.; Murin, I.V.; Ushakova, Yu.N.; Fominykh, E.G.; Lyalina, M.Yu.

    2000-01-01

    Feasibility of sulfide transfer in phases on the basis of BaZrS 3 and MLn 2 S 4 ( M = Ca, Ba; Ln = La, Y, Tm, Nd, Sm, Pr) is considered. Solid solution regions on the basis of ternary compounds are determined. Systematic study of the phases is carried out making use of the methods of conductometry, emf in chemical concentration chains without/with transfer, potentiostatic chronoamperometry. Possible mechanism of defect formation during successive alloying of ternary sulfides by binary ones in suggested [ru

  12. Proton mobility on the surface of some acid salt crystal hydrates

    International Nuclear Information System (INIS)

    Yaroslavtsev, A.B.; Mirak'yan, A.L.; Chuvaev, V.F.; Sokolova, L.N.

    1997-01-01

    Mobility of proton-containing groupings on the surface of Zr(HPO 4 ) 2 xH 2 O and InH(SO 4 ) 2 x4H 2 O crystals of different dispersion has been studied by 1 H NMR and conductometry methods. It is shown that translational mobility of proton-containing groupings on the surface is much greater than in the sample bulk. A ratio describing the dependence of protonic conductivity on particle sizes of the compounds considered is suggested and its applicability is demonstrated. An increase in conductivity with a decrease in anion proton-accepting ability is pointed out

  13. The self-organization and functional activity of binary system based on erucyl amidopropyl betaine - alkylated polyethyleneimine

    Science.gov (United States)

    Gaynanova, Gulnara A.; Valiakhmetova, Alsu R.; Kuryashov, Dmitry A.; Kudryashova, Yuliana R.; Lukashenko, Svetlana S.; Syakaev, Victor V.; Latypov, Shamil K.; Bukharov, Sergey V.; Bashkirtseva, Natalia Yu.; Zakharova, Lucia Ya.

    2013-11-01

    The self-organization in individual and binary aqueous solutions of a zwitterionic surfactant erucyl amidopropyl betaine and alkylated polyethyleneimine is carried out with a wide range of physical and chemical methods, including tensiometry, conductometry, dynamic light scattering, pH-metry, spectrophotometry, and fluorescence spectroscopy. The data obtained strongly support the formation of nanosized aggregates in the systems and provide information on their structure and probable morphological transitions. High solubilization capacity and data on the contact angle showed a possibility of the application of these systems as nanocontainers or oil wetting agents in the oil recovery.

  14. Reactions of vanadium(5) with aluminium(3) in weakly acid aqueous solutions

    International Nuclear Information System (INIS)

    Ditrikh, I.V.; Makhno, A.Ya.

    1996-01-01

    Conditions of vanadium(5) heteropolycompounds formation in aqueous solutions containing aluminium(3) have been studied. By the methods of potentiometry and conductometry in solutions of Al(NO 3 ) 3 -NaVO 3 salt mixture the formation of complexes with the ratios [Al 3+ ]:[V 5+ ]=1:3, 1:6 and 1:12 has been ascertained. A salt of gross formula 3NaO · Al 2 ) 3 · 12V 2 O 5 · 67H 2 O has been isolated. 3 refs.; 2 figs

  15. Effect of a lanthanide ion on the micellation and self-organization of lyotropic liquid crystal systems

    International Nuclear Information System (INIS)

    Selivanova, N.M.; Osipova, V.V.; Galyametdinov, Yu.G.

    2006-01-01

    Lanthanide-containing lyotropic liquid-crystalline systems were synthesized and their phase behavior, as well as the micellar behavior of aqueous solutions of decaethylene glycol monodecyl ether in the absence and presence of a lanthanide ion, were studied. Tensimetry and conductometry were used to determine the critical micellation concentration, and the values obtained by these methods were found to be in close agreement with each other. Polarization microscopy observations showed that, in concentrated aqueous solutions, ordered lyotropic mesophases arise. The parameters of the phase transitions in the systems under study were determined. The mesophase obtained was demonstrated to have a 2D hexagonal supramolecular structure [ru

  16. Synthesis and physicochemical characterization of rhenium (V) complexes with bisbenzoylthiosemicarbazones

    International Nuclear Information System (INIS)

    Gagieva, S.Ch.; Gutnova, N.A.; Tsaloev, A.T.; Khubulov, A.B.; Arutyunyants, A.A.; Galimov, Yu.B.

    2003-01-01

    Rhenium (V) complexing with mono- and bis-benzoylthiosemicarbazones is studied in dependence on hydrohalic acids concentration changes. It is determined that in media with high concentration of hydrohalic acids (6 mol/l HCl, 7 mol/l HBr) in dependence on reaction conditions stable complexes with bi- and tridentate coordination of thiosemicarbazone are formed. In the case of hydrohalic acid concentration decreasing stable binuclear and oxohydroxycomplexes are formed. Composition and structure of the compounds obtained are determined by the methods of element analysis, IR spectroscopy, conductometry. Thermal investigations of the compounds obtained are done [ru

  17. Oxovanadium (iv) complexes with n/o- and o-donor ligands: their synthesis, characterization, semiempirical study and alkaline phosphatase activity (abstract)

    International Nuclear Information System (INIS)

    Munawar, K.S.; Ali, S.; Khan, A.N.

    2011-01-01

    Various N/O- and O-donor ligands and their oxovanadium complexes have been synthesized and characterized by different techniques such as FTIR, elemental analysis, thermogravimetery and conductometry. The IR data show the bidentate nature of the ligands and reveals hexa-coordinated geometry in the solid state which is also confirmed by semi-empirical study. Conductance measurements reveal the non-electrolytic nature of the complexes. These complexes have been checked for their alkaline phosphatase activity in the presence and absence of inhibitor which shows that by the addition of inhibitor the activity of enzyme decreases and at higher concentration it is completely inhibited. (author)

  18. Adsorption and catalytic properties of skeleton nickel alloyed by tantalum

    Energy Technology Data Exchange (ETDEWEB)

    Erzhanova, M S; Sokol' skii, D V; Popov, N I; Kondratenko, V I

    1977-02-01

    Adsorption properties are studied of Ni-Ta-catalysts composed of 20-50% Ni, 0-30% Ta, 50% Al with respect to hydrogen; their activity in a number of reactions has been tested. The adsorption capacity is characterized with respect to H/sub 2/ by the methods of thermodesorption and conductometry. It is shown that three forms to hydrogen (..beta.., ..gamma.., sigma) adsorb onto the surface of the alloyed catalysts, whose desorption peaks overlap because of their high mobility and interchangeability. Variation of activity, selectivity and isomerizing capacity of the catalysts correlates with the content of a weakly adsorbed mobile form of H/sub 2/.

  19. The physicochemical properties of the low-temperature ionic liquid silver bromide-1-butyl-3-methylimidazolium bromide

    Science.gov (United States)

    Grishina, E. P.; Ramenskaya, L. M.; Pimenova, A. M.

    2009-11-01

    The physicochemical properties of the low-temperature ionic liquid based on 1-butyl-3-methylimidazolium bromide (BMImBr) and silver bromide were studied. Differential scanning calorimetry, Fourier transform IR spectroscopy, densimetry, viscometry, and conductometry measurements were performed to determine the dependences of the parameters under study on the concentration of AgBr. It was shown that the temperature and concentration behavior of the physicochemical properties of BMImBr-AgBr melts characterized the interaction between the system components with the formation of complex particles.

  20. Formation of CdS thin films in a chemical bath environment under the action of an external magnetic field

    International Nuclear Information System (INIS)

    Vaskes-Luna, Kh.G.; Zekhe, A.; Nhukhil'o-Garsiya, M.P.; Starostenko, O.

    2000-01-01

    The effect of external magnetic field on obtaining thin CdS films on glass sub layers through the method of chemical deposition from the cadmium chloride aqueous solution is studied. The intensity and direction of the magnetic field during deposition obviously affect the number of physical properties of polycrystalline films: thickness, grain size and optical quality. The films characteristics are studied through an atomic-power microscope, light absorption spectroscopy and conductometry in darkness. The results obtained are interpreted on the basis of notions on the cadmium and sulfur specific interaction in the chemical bath with a magnetic field [ru

  1. Rhenium(5) and molybdenum(5) complexes with 4',4(5)-divaleryldibenzo-18-crown-6

    International Nuclear Information System (INIS)

    Ashurova, N.Kh.; Yakubov, K.G.; Tashmukhamedova, A.K.; Basitova, S.M.

    1993-01-01

    Methods for synthesizing oxohalide complexes of rhenium and molybdenum with +5 oxidation degree with 4',4 (5) -divaleryldibenzo-18-crown-6 were developed. Content and composition of prepared compounds were investigated by the methods of element analysis, crystal optics, conductometry, IR spectroscopy in the near and far regions, thermogravimetry. Oxidation degree of the complex-forming metal was determined. It was established that composition of the compounds coressponded to the general formula MOLX · H 2 O, where M - Re, Mo; L -4',4 (5) -divaleryldibenzo-18-crown-6; X -Cl - , Br -

  2. Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC. Crystal structure of [Cu(PLITSC−HH2O]Br•H2O

    Directory of Open Access Journals (Sweden)

    Leovac Vukadin M.

    2014-01-01

    Full Text Available The synthesis and structural characterization of a square-planar copper(II complex with pyridoxal S-methylisothiosemicarbazone (PLITSC of the formula [Cu(PLITSC−HH2O]Br•H2O (1 as the first Cu(II complex with monoanionic form of this ligand were described. Complex 1 together with two previously synthesized complexes [Cu(PLITSCBr2] (2 and [Cu(PLITSCBr(MeOH]Br (3 were characterized by elemental analysis, IR and electronic spectra and also by the methods of thermal analysis, conductometry and magnetochemistry. [Projekat Pokrajisnkog sekretarijata za nauku i tehnoloski razvoj Vojvodine i Ministarstva nauke Republike Srbije, br. 172014

  3. Solvent effect on the rate and equilibrium of reaction between 10-phenylphenoxarsine and methyl iodide. Vliyanie rastvoritelya na skorost' i ravnovesie reaktsii 10-fenilfenoksarsina s iodistym metilom

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, V I; Gumerov, N S; Rakhmatullin, R R [Kazanskij Khimiko-Tekhnologicheskij Inst., Kazan (USSR)

    1990-02-01

    Effect of solvent nature on nucleophilic capacity of three-coordinated arsenic and the equilibrium state of 10-phenylphenoxarsine (PA) reaction with methyl iodide are studied. Kinetic investigations are carried out by the conductometry at 24,35,45 deg C. It is established that quaternization of PA with methyl iodide when substituting a solvent (ketone for alcohol) increases 3-14 times with simultaneous growth of the activation energy value. When transforming from aprotic solvents to protic ones PA interaction equilibrium with methyl iodide shifts to the side of arsonic salt formation.

  4. Electrochemical and visco metric studies on some copolymer/ homopolymer poly electrolytes and transition metal ion interaction

    International Nuclear Information System (INIS)

    Rajabi, F. H.; Frahani, B. V.

    2003-01-01

    Some random three-component copolymers have been prepared by condensing of formaldehyde with various aromatic amines. The compositions of the copolymers have been determined by known methods. selective complexation of copolymers have been carried out with PAA, PEI, PVP and some transition metal ions (e.g., Cu 2+ )by adding the components in various sequences. The relative complexation ability of different -NH 2 groups, associated with the various comonomer units, has been interpreted in terms of the these complexes has been studied by conductometry. potentiometry and viscometry techniques. A scheme has presented to explain the mode of interaction of the various components

  5. A continuous-flow denuder for the measurement of ambient concentrations and surface-exchange fluxes of ammonia

    Science.gov (United States)

    Wyers, G. P.; Otjes, R. P.; Slanina, J.

    A new diffusion denuder is described for the continuous measurement of atmospheric ammonia. Ammonia is collected in an absorption solution in a rotating denuder, separated from interfering compounds by diffusion through a semi-permeable membrane and detected by conductometry. The method is free from interferences by other atmospheric gases, with the exception of volatile amines. The detection limit is 6 ng m -3 for a 30-min integration time. This compact instrument is fully automated and suited for routine deployment in field studies. The precision is sufficiently high for micrometeorological studies of air-surface exchange of ammonia.

  6. Effect of partial oxygen pressure on physicochemical properties of Kh18N10T steel at isothermal oxidation

    International Nuclear Information System (INIS)

    Alekseev, V.N.; Oshe, E.K.; Fokin, M.N.; Bogdanova, S.V.; Loskutov, A.I.

    1990-01-01

    Auger-electron spectroscopy, photoelectric polarization, conductometry methods have been used to analyze chemical and defect composition of surface oxide layers, formed on stainless steel Kh18N10T in vacuum (10 -9 - 10 -2 torr) and at temperatures 593-673 K. The boundary conditions of manifestation of extermal behaviour of the dependence of the surface oxide growth rate at isothermal oxidation of this steel are determined. The relation between passivation properties of the surface oxide and the magnitude of the edge angle of the surface wetting with molten tin is revealed

  7. Determination of stability constants of K and Cs nitrate complex with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Myasoedova, T G; Ponomareva, A V; Zagorets, P A; Filippov, E A [Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR)

    1984-08-01

    Total stability constants of K and Cs nitrate complexes with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions were determined by the method of low-frequency contact conductometry. Clearly defined K/Cs selectivity is observed for the system with dibenzo-18-crown-6. It is shown that lg..beta.. depends on permittivity of the solvent. The decrease of permittivity of isopropanol aqueous solutions results in reduction of K/Cs selectivity of DB18C6.

  8. Investigation into interaction of mixture of zinc and neodymium nitrates with sodium tungstates in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rozantsev, G M; Krivobok, V I [Donetskij Gosudarstvennyj Univ. (Ukrainian SSR)

    1978-09-01

    The methods of residual concentrations, pH-potentiometry, and conductometry have been used for studying interaction between the mixture of zinc and neodymium nitrates with sodium tungstate in aqueous solutions. It has been established that independent of the ratio between the components the reaction product is a mixture of simultaneously precipitated zinc and neodymium orthotungstates. Thermal treatment of such mixtures at 650-700 deg C for 40 h and subsequent hardening yields solid solution of the structure ..cap alpha..-Eu/sub 2/(WO/sub 4/)/sub 3/ within the concentration range 85-100 mol % of Nd/sub 2/(WO/sub 4/)/sub 3/.

  9. Effect of partial oxygen pressure on physicochemical properties of Kh18N10T steel at isothermal oxidation. Vliyanie partsial'nogo davleniya kisloroda na fiziko-khimicheskie svojstva poverkhnosti stali Kh18N10T pri izotermicheskom okislenii

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, V N; Oshe, E K; Fokin, M N; Bogdanova, S V; Loskutov, A I [AN SSSR, Moscow (USSR). Inst. Fizicheskoj Khimii

    1990-10-01

    Auger-electron spectroscopy, photoelectric polarization, conductometry methods have been used to analyze chemical and defect composition of surface oxide layers, formed on stainless steel Kh18N10T in vacuum (10{sup -9} - 10{sup -2} torr) and at temperatures 593-673 K. The boundary conditions of manifestation of extermal behaviour of the dependence of the surface oxide growth rate at isothermal oxidation of this steel are determined. The relation between passivation properties of the surface oxide and the magnitude of the edge angle of the surface wetting with molten tin is revealed.

  10. Fundamentals of electrochemical detection techniques for CE and MCE.

    Science.gov (United States)

    Kubán, Pavel; Hauser, Peter C

    2009-10-01

    The electroanalytical techniques of amperometry, conductometry and potentiometry match well with the instrumental simplicity of CE. Indeed, all three detection approaches have been reported for electrophoretic separations. However, the characteristics of the three methods are quite distinct and these are not related to the optical methods more commonly employed. A detailed discussion of the underlying principles of each is given. The issue of possible effects of the separation voltage on the electrochemical detection techniques is considered in depth, and approaches to the elimination of such interferences are also discussed for each case.

  11. Kinetics of the oxidation of hydrogen sulfite by hydrogen peroxide in aqueous solution:. ionic strength effects and temperature dependence

    Science.gov (United States)

    Maaß, Frank; Elias, Horst; Wannowius, Klaus J.

    Conductometry was used to study the kinetics of the oxidation of hydrogen sulfite, HSO -3, by hydrogen peroxide in aqueous non-buffered solution at the low concentration level of 10 -5-10 -6 M, typically found in cloud water. The kinetic data confirm that the rate law reported for the pH range 3-6 at higher concentration levels, rate= kH·[H +]·[HSO -3]·[H 2O 2], is valid at the low concentration level and at low ionic strength Ic. At 298 K and Ic=1.5×10 -4 M, third-order rate constant kH was found to be kH=(9.1±0.5)×10 7 M -2 s -1. The temperature dependence of kH led to an activation energy of Ea=29.7±0.9 kJ mol -1. The effect of the ionic strength (adjusted with NaCl) on rate constant kH was studied in the range Ic=2×10 -4-5.0 M at pH=4.5-5.2 by conductometry and stopped-flow spectrophotometry. The dependence of kH on Ic can be described with a semi-empirical relationship, which is useful for the purpose of comparison and extrapolation. The kinetic data obtained are critically compared with those reported earlier.

  12. Structure and dynamics of humic substances and model poly-electrolytes in solution

    International Nuclear Information System (INIS)

    Roger, G.

    2010-09-01

    In the frame of a study about the feasibility of an underground storage of radioactive wastes, we focused on the role of degraded natural organic matter in the eventual transport of radionuclides in the environment. We are more interested by the determination of electro kinetic properties of these humic substances rather than the description of speciation reaction already widely discussed in the literature. We chose to determine the size and the charge of these humic substances thanks to an original method: high precision conductometry. This technique, associated to a suited transport theory, allows to describe the mobility of charged species in solution when taking into account the pairs interactions. We have participated in the development of this transport theory and we use it in order to determine the size and the charge of humic substances and a reference polyelectrolyte in different conditions of pH and ionic strength. All these experimental results obtained by conductometry were correlated with other experimental and theoretical methods: Atomic Force Microscopy, dynamic light scattering, laser zeta-metry and Monte-Carlo simulations. The obtained results confirm the generally admitted idea that humic substances are nano-metric entities having complexing properties towards cations and that can aggregate to form supra molecular structures. The effect of the ions present in the environment (sodium, calcium, magnesium) has been investigated. Finally the complexation of europium (which is considered as a good analogue of americium 241) has also been analysed by square wave voltammetry. (author)

  13. Conductometric investigation of salt-free solutions of polyriboguanylic acid. Issledovanie bessolevykh rastvorov poliriboguanilovoj kisloty metodom konduktometrii

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, A G; Davydova, O V; Kargov, S I [Moskovskij Gosudarstvennyj Univ., Moscow (Russian Federation). Khimicheskij Fakul' tet

    1993-08-01

    Salt-free solutions of various ionic forms of polyriboguanylic acid (poly(G)) were studied by the methods of conductometry and spectroscopy of annular dichroism. The Manning approach was employed to calculate transport characteristics and structural parameters of poly(G) on the basis of spectra permit putting poly(G) salts in two groups: the first one comprising NH[sub 4][sup +]-, Rb[sup +]-, K[sup +]-, Na[sup +]-, the second one - Cs[sup +]-, and Li[sup +]-poly(G). The assumption is made that Li[sup +] and Cs[sup +] ions, bound with concrete groups of polyanion in a specific way, can promote formation of a stable structure different from the one observed in the presence of the first group counterions. 25 refs., 3 figs.

  14. Chemical and radiolytical solvent degradation in the Purex process

    International Nuclear Information System (INIS)

    Stieglitz, L.; Becker, R.

    1985-01-01

    The state of the art of chemical and radiolytical solvent degradation is described. For the hydrolysis of tributylphosphate TBP->HDBP->H 2 MBP->H 3 PO 4 values are given for the individual constants in a temperature range from 23 to 90 0 C. Radiolytic yields were measured for HDBP as 80 mg/Wh, for H 2 MBP as 2 mg/Wh, and for H 3 PO 4 as 5 mg/Wh. Experimental results on the degradation products of the diluent are summarized and their influence on the process is discussed. Long chain acid phosphates and acid TBP oligomeres were identified as responsible for the retention of fission products. Techniques such as polarography, infrared spectrometry and electrolytic conductometry are applied to estimate concentrations of degradation products down to 10 -5 mol/l. (orig.) [de

  15. Conductometric investigation of salt-free solutions of polyriboguanylic acid

    International Nuclear Information System (INIS)

    Kozlov, A.G.; Davydova, O.V.; Kargov, S.I.

    1993-01-01

    Salt-free solutions of various ionic forms of polyriboguanylic acid (poly(G)) were studied by the methods of conductometry and spectroscopy of annular dichroism. The Manning approach was employed to calculate transport characteristics and structural parameters of poly(G) on the basis of spectra permit putting poly(G) salts in two groups: the first one comprising NH 4 + -, Rb + -, K + -, Na + -, the second one - Cs + -, and Li + -poly(G). The assumption is made that Li + and Cs + ions, bound with concrete groups of polyanion in a specific way, can promote formation of a stable structure different from the one observed in the presence of the first group counterions. 25 refs., 3 figs

  16. New hydride compounds of 1,4-diazabicyclo[2.2.2]octane and its dication with borine and tetrahydridoborate anion and products of their transformations

    International Nuclear Information System (INIS)

    Shevchenko, Yu.N.; Yashina, N.I.; Markova, O.Z.; Trachevskij, V.V.

    1996-01-01

    New compounds [dabcoH 2 ](BH 4 ) 2 , dabco(BH 3 ) 2 2H 2 , [dabco(BH 3 ) 2 H 2 ] n have been synthesized by means of interaction between dihydrochloride of 1,4-diazobicyclo[2.2.2] octane (dabco) and NaBH 4 in the medium of nonaqueous solvents (glyme, diglyme, tetrahydrofuran, dimethylsulfoxide) and identified by the methods of element analysis, conductometry, 1 H, 11 B, 14 N NMR, IR spectroscopy and thermal analysis. A mechanism is suggested and the conditions are defined for mutual transformations of the compounds studied. Their ability to bind reversibly molecular hydrogen has been revealed for the first time. 19 refs.; 3 figs.; 1 tab

  17. Studies on the rare earth complexes with pyridine derivatives and their N-oxide(II) - Synthesis and properties of fluorescent solid complexes of samarium, europium, gadolium and terbium chlorides with 2,2'-bipyridine-N,N'-dioxide

    International Nuclear Information System (INIS)

    Minyu, T.; Ning, T.; Yingli, Z.; Jiyuan, B.

    1985-01-01

    The solid complexes of rare earth nitrates perchlorates and thiocyanates with 2,2'-bipyridine-N,N'-dioxide (bipyO/sub 2/) have been reported. However, the corresponding complexes of other rear earth chlorides have not been investigated except lanthanum, cerium and yttrium. As an extension of our previous work on the synthesis of complexes of praseodymium and neodymium chlorides wiht bipoyO/sub 2/, the authors have now prepared fluorescent solid complexes of samarium, europium, gadolium and terbium chlorides with biphyO/sub 2/, using methanol as a reaction medium. The new synthesized compounds have been identified by means of elemental analysis, infrared spectrometry, conductometry, differential thermal analysis (DTA), thermogravimetry (TG) and X-ray powder diffraction

  18. OH radical induced depolymerization of poly(methacrylic acid)

    Science.gov (United States)

    Ulanski, Piotr; Bothe, Eberhard; von Sonntag, Clemens

    1999-05-01

    Hydroxyl radicals (generated pulse radiolytically in dilute N 2O-saturated aqueous solutions) react with poly(methacrylic acid) producing two kinds of radicals. The primary radical is converted into a secondary one by H-abstraction ( k=3.5 × 10 2 s -1) as monitored by changes in the UV spectrum. Subsequently, the secondary radicals undergo chain scission ( k=1.8 s -1 at pH 7-9). This process has been followed both by spectrophotometry as well as by conductometry. In competition with the bimolecular decay of the radicals the ensuing end-chain radicals undergo efficient depolymerization resulting in the release of monomer. Since the lifetime of the radicals is much longer at high pH, where the polymer attains a rod-like conformation, depolymerization is most efficient in basic solution.

  19. COORDINATION COMPOUNDS OF 3D-METALS ACETYLACETONATES WITH THIOSEMICARBAZIDE

    Directory of Open Access Journals (Sweden)

    T. V. Koksharova

    2015-03-01

    Full Text Available Coordination Compounds of 3d-Metals acetylacetonates with Thiosemicarbazide were synthesized. Their physical and chemical properties and structure were studied by conductometry, IR spectroscopy, electronic spectroscopy, magnetochemistry and thermo-gravimetricstudies. The complexes compositions correspond to the formulas Co(L2(Acac and M(L(Acac, where M = Cu, Ni, Zn, HL is thiosemicarbazide, HAcac is acetylacetone. All of them are nonelectrolytes. Thiosemicarbazide is deprotonated and coordinated through the nitrogen and sulphur atoms with the formation of four-membered ring in all cases. Acetylacetonate co-ordination mode does not change at acetylacetonates with Thiosemicarbazide interaction. Copper(II and nickel(II complexes have square-planar structure, and cobalt(III complex is octahedral.

  20. Electric conductivity of solid solutions of the Na3-2xMxPO4 (M=Cd, Pb) systems

    International Nuclear Information System (INIS)

    Shekhtman, G.Sh.; Burmakin, E.I.; Smirnov, N.B.; Esina, N.O.

    2002-01-01

    Electric conductivity, phase composition and conductivity character in the system Na 3-2x Cd x PO 4 in the temperature range of 300-750 deg C were studied by the methods of conductometry, X-ray phase and thermal analyses. It was ascertained that maximum values of electric conductivity (6.25x10 -3 S/cm at 300 deg C) are observed near upper concentration boundaries (x ≅ 0.4) of monophase regions in γ-solid solutions. Conductivity of the solid electrolytes studied is of cocationic character. The values of activation energies of Na + and Cd 2+ cation jumping over in solid electrolytes Na 2.7 Cd 0.15 PO 4 are 38.7 and 43.6 kJ/mol respectively according to the NMR data [ru

  1. Investigation of electric conductivity, viscosity and density of LiBF4-1,3-dioxolane system in homogeneity region

    International Nuclear Information System (INIS)

    Plakhotnik, V.N.; Tovmash, N.F.; Mishustin, A.N.; Dam'e, V.N.

    1987-01-01

    Solutions of lithium tetrafluoborate in 1,3-dioxolane (DOL) in temperature range and concentrations limiting the homogeneity region from the side of salt crystallization and formation of polymer structures from -30 deg to +25 deg and from 10 -6 to 1.4 mol/l. are investigated using methods of conductometry, densimetry, viscosimetry and by measuring time of spinlattice 7 Li nuclei relaxation. The dissociation constant of LiBF 4 in DOL (pK D =4.9±0.2 at 25 deg) is determined. Comparison with systems based on 1,2-dimethoxyethane and tetrahydrofurane studied earlier is carried out. Suppositions concerning considerable contribution of ion molecular structures with participation of salt ions and solvent molecules to electric conductivity are stated, and it agrees with the data on measurements of velocities of spin-lattice relaxation of 7 Li nuclei

  2. Thermodynamics of micelle formation in a water-alcohol solution of sodium tetradecyl sulfate

    Science.gov (United States)

    Shilova, S. V.; Tret'yakova, A. Ya.; Barabanov, V. P.

    2016-01-01

    The effects of addition of ethanol and propan-1-ol on sodium tetradecyl sulfate micelle formation in an aqueous solution are studied via microprobe fluorescence microscopy and conductometry. The critical micelle concentration, quantitative characteristics of micelles, and thermodynamic parameters of micelle formation are determined. Addition of 5-15 vol % of ethanol or 5-10 vol % of propan-1-ol is shown to result in a lower critical micelle concentration than in the aqueous solution, and in the formation of mixed spherical micelles whose sizes and aggregation numbers are less than those for the systems without alcohol. The contribution from the enthalpy factor to the free energy of sodium tetradecyl sulfate micelle formation is found to dominate in mixed solvents, in contrast to aqueous solutions.

  3. The acidic functional groups of humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shanxiang, Li; Shuhe, Sun; Zhai Zongxi, Wu Qihu

    1983-09-01

    The acidic functional groups content, pK value, DELTAH and DELTAS of humic acid (HA) and nitro-humic acid (NHA) were determined by potentiometry, conductometry and calorimetric titration. The thermodynamic parameters of carboxylic groups and phenolic hydroxyl groups of humic acid are similar to that of simple hydroxy-benzoic acid. The configuration sites of acidic functional groups in humic acid from different coals are different. The carbonyl groups on aromatic rings are probably ortho to phenolic -OH for HA and NHA extracted from Huangxian's brown coal and Japanese lignite, while those from Lingshi's weathered coal are not. The weak -COOH groups of the latter possess higher chemical activity. The -COOH content in HA increases, phenolic -OH group decreases and the chemical acidity of acidic functional groups increases when HA is oxidized by nitric acid. (14 refs.)

  4. Controlled ion track etching

    Science.gov (United States)

    George, J.; Irkens, M.; Neumann, S.; Scherer, U. W.; Srivastava, A.; Sinha, D.; Fink, D.

    2006-03-01

    It is a common practice since long to follow the ion track-etching process in thin foils via conductometry, i.e . by measurement of the electrical current which passes through the etched track, once the track breakthrough condition has been achieved. The major disadvantage of this approach, namely the absence of any major detectable signal before breakthrough, can be avoided by examining the track-etching process capacitively. This method allows one to define precisely not only the breakthrough point before it is reached, but also the length of any non-transient track. Combining both capacitive and conductive etching allows one to control the etching process perfectly. Examples and possible applications are given.

  5. Influence of Salt Stress on Growth and Frost Resistance of Three Winter Cereals

    Science.gov (United States)

    Matuszak-Slamani, Renata; Brzóstowicz, Aleksander

    2015-04-01

    This paper presents results of a study on the influence of 0-150 mmol NaCl dm-3 Hoagland solution on growth, chlorophyll content, photosynthesis and frost resistance of seedlings of three winter cereals: wheat - cv. Almari, rye - cv. Amilo, and triticale - cv. Tornado. Sodium chloride at 25 mmol dm-3 caused better growth of wheat shoots and roots, both of fresh and dry matter. Higher concentrations of NaCl in the medium decreased the biomass of the tested seedlings. The influence of NaCl on the chlorophyll content in the seedlings varied. The conductometry method showed that the resistance of the cell walls of wheat and rye to low temperature decreased in the presence of NaCl in the growth medium. Luminescence has shown that seedlings that grew in NaCl-containing medium indicated an impediment of electron flow at a lower temperature than the control plants.

  6. Investigation of electric conductivity, viscosity and density of LiBF/sub 4/-1,3-dioxolane system in homogeneity region

    Energy Technology Data Exchange (ETDEWEB)

    Plakhotnik, V N; Tovmash, N F; Mishustin, A N; Dam' e, V N

    1987-01-01

    Solutions of lithium tetrafluoborate in 1,3-dioxolane (DOL) in temperature range and concentrations limiting the homogeneity region from the side of salt crystallization and formation of polymer structures from -30 deg to +25 deg and from 10/sup -6/ to 1.4 mol/l. are investigated using methods of conductometry, densimetry, viscosimetry and by measuring time of spinlattice /sup 7/Li nuclei relaxation. The dissociation constant of LiBF/sub 4/ in DOL (pK/sub D/=4.9+-0.2 at 25 deg) is determined. Comparison with systems based on 1,2-dimethoxyethane and tetrahydrofurane studied earlier is carried out. Suppositions concerning considerable contribution of ion molecular structures with participation of salt ions and solvent molecules to electric conductivity are stated, and it agrees with the data on measurements of velocities of spin-lattice relaxation of /sup 7/Li nuclei.

  7. Chemical and radiolytical solvent degradation in the Purex process

    Energy Technology Data Exchange (ETDEWEB)

    Stieglitz, L; Becker, R

    1985-01-01

    The state of the art of chemical and radiolytical solvent degradation is described. For the hydrolysis of tributylphosphate TBP->HDBP->H/sub 2/MBP->H/sub 3/PO/sub 4/ values are given for the individual constants in a temperature range from 23 to 90/sup 0/C. Radiolytic yields were measured for HDBP as 80 mg/Wh, for H/sub 2/MBP as 2 mg/Wh, and for H/sub 3/PO/sub 4/ as 5 mg/Wh. Experimental results on the degradation products of the diluent are summarized and their influence on the process is discussed. Long chain acid phosphates and acid TBP oligomeres were identified as responsible for the retention of fission products. Techniques such as polarography, infrared spectrometry and electrolytic conductometry are applied to estimate concentrations of degradation products down to 10/sup -5/ mol/l.

  8. Study of interaction in systems of MoCl/sub 5/-MeCl/sub 2/ (Me - Sn, Zn, Cd, Hg) - a solvent

    Energy Technology Data Exchange (ETDEWEB)

    Golub, A M; Trachevskii, V V; Ul' ko, N V [Kievskij Gosudarstvennyj Univ. (Ukrainian SSR)

    1978-04-01

    Interaction of Mo(5) with dichlorides of tin, zinc, cadmium and mercury in organic solvents was studied by preparative methods, by electron, epr, infrared spectrometry and by conductometry. A polynuclear diamagnetic compound with Mo(5):Sn(2) ratio of 2:1 formed in acetone. A coordination polynuclear compound of (MoOCl/sub 3/)/sub 2/xSnCl/sub 2/x2CH/sub 3/CN was isolated from acetonitrile. It is shown that formation of solvate-chloride and solvate complexes of Mo(5) in solvents depends both on the solvating capacity of the solvent and on stability of the MeCl/sup -3/ (Me is Sn, Zn, Cd, Hg) chloride complex, which grows in the Zn < Sn < Cd < Hg series.

  9. 18-Crown-6-polyether complexing with iodine

    International Nuclear Information System (INIS)

    Borovikov, Yu.Ya.

    1988-01-01

    Using the methods of dielectrometry, conductometry, calorimetry, UV, NMR and IR spectroscopy, 18-Crown-6-polyether complexing with iodine in chlorobenzene, benzotrifluoride, 1,2 dichloroethane is investigated. At the first stage external complexes (1) of the composition 1:1 (dipole momentum μ=7 D) is formed, which gradually regroups into internal complex (2) of the compositon 4:1. The time of 1 transition into 2 is inversely proportional to dielectric permeability of the medium. Enthalpy of 1 formation is close to 8.3 kcal/mol, which is 2,5 times higher than in cyclohexane solutions. Complex 1 is molecular, 2 is salt-like. Formation enthalpy of complex 2 of the components is not high, in dichlaroethane it is centrally symmetric and nonpolar, in chlorobenzene and benzotrifluoride-highly polar. In solid phase complex of the composition 1:2 is formed

  10. Ion track etching revisited: I. Correlations between track parameters in aged polymers

    Science.gov (United States)

    Fink, D.; Muñoz H., G.; García A., H.; Vacik, J.; Hnatowicz, V.; Kiv, A.; Alfonta, L.

    2018-04-01

    Some yet poorly understood problems of etching of pristine and swift heavy ion track-irradiated aged polymers were treated, by applying conductometry across the irradiated foils during etching. The onset times of etchant penetration across pristine foils, and the onset times of the different etched track regimes in irradiated foils were determined for polymers of various proveniences, fluences and ages, as well as their corresponding etching speeds. From the results, correlations of the parameters with each other were deduced. The normalization of these parameters enables one to compare irradiated polymer foils of different origin and treatment with one another. In a number of cases, also polymeric gel formation and swelling occur which influence the track etching behaviour. The polymer degradation during aging influences the track etching parameters, which differ from each other on both sides of the foils. With increasing sample age, these differences increase.

  11. Sodium dodecyl benzene sulphonate mediated tautomerism of Eriochrome Black-T: Effect of charge transfer interaction

    Science.gov (United States)

    Ghosh, Sumit

    2010-11-01

    Interaction between anionic surfactant, sodium dodecyl benzene sulphonate, (SDBS) and an anionic dye Eriochrome Black-T, (EBT) has been investigated by visible spectroscopy, conductometry, dynamic light scattering and zeta potential measurements. Spectral changes of EBT observed on addition of SDBS indicate formation of quinone-hydrazone tautomer at pH 7.0, whereas in absence of SDBS this change appears at pH ˜ 9.45. However, at pH 7.0 this change in tautomerism is not observed in presence of sodium dodecyl sulphate (SDS). Experimental results indicate presence of charge transfer interaction between less stable quinone-hydrazone tautomer of EBT and SDBS molecules, which is confirmed using Benesi-Hildebrand and Scott equations.

  12. Acid-base properties of complexes of 3 group elements with tetra-4-tert. butylphthalocyanine. [Elements: Al, Ga, In, Sc

    Energy Technology Data Exchange (ETDEWEB)

    Borovkov, N Yu; Akopov, A S

    1987-01-01

    Step-like constants of pKn complex ionization of In and Sc with tetra-4-tert.butylphthalocyanine in CH/sub 3/COOH-H/sub 2/SO/sub 4/ and B-CH/sub 3/COOH-H/sub 2/SO/sub 4/, where B is antipyrine or urea are determined. They have the next values at n equalling 1, 2, 3, 4: +2.70+-0.30; -0.26+-0.09; -3.70+-0.20; -6.10+-0.20 for HOIn phthalocyanine substituted correspondingly. Effect of the methane atom nature on the basicity of phthalocyanine nitrogen mesonic atoms is considered. Using the conductometry method, it is established that phthalocyanines in concentrated H/sub 2/SO/sub 4/ form both completely protonated shapes and contact ion pairs.

  13. ADMET Polymerization Activities of Electrochemically Reduced W-Based Active Species for Ge- and Sn-Containing Dienes

    Science.gov (United States)

    Imamoglu, Yavuz; Aydogdu, Cemil; Karabulut, Solmaz; Düz, Bülent

    In the last 20 years metal atom-containing polymers have become important classes of polymers [1]. Properties like high thermic stability, electric, and photo conductometry make them very interesting for producing films, fibers, and coating [2]. Many of these compounds can be synthesized by conventional methods [3]. For producing metal-containing polymers anionic, cationic, and radicalic polymerizations were used [4-6]. Metal-containing polymers were also synthesized via acyclic diene metathesis (ADMET) polymerization that is facilitated by Schrock’s molybdenum alkylidene, or Grubbs’ ruthenium carbene catalyst [7-9]. In 1979, Gilet and coworkers succeeded in synthesizing metathetically active species from electrochemical reduction of WCl6 and MoCl5 [10,11]. In the light of these works, we have showed that electrochemically generated tungsten-based active species (WCl6-e--Al-CH2Cl2) catalyzes various metathesis-related reactions [12-16].

  14. Charging and Screening in Nonpolar Solutions of Nonionizable Surfactants

    Science.gov (United States)

    Behrens, Sven

    2010-03-01

    Nonpolar liquids do not easily accommodate electric charges, but surfactant additives are often found to dramatically increase the solution conductivity and promote surface charging of suspended colloid particles. Such surfactant-mediated electrostatic effects have been associated with equilibrium charge fluctuations among reverse surfactant micelles and in some cases with the statistically rare ionization of individual surfactant molecules. Here we present experimental evidence that even surfactants without any ionizable group can mediate charging and charge screening in nonpolar oils, and that they can do so at surfactant concentrations well below the critical micelle concentration (cmc). Precision conductometry, light scattering, and Karl-Fischer titration of sorbitan oleate solutions in hexane, paired with electrophoretic mobility measurements on suspended polymer particles, reveal a distinctly electrostatic action of the surfactant. We interpret our observations in terms of a charge fluctuation model and argue that the observed charging processes are likely facilitated, but not limited, by the presence of ionizable impurities.

  15. New hydride compounds of 1,4-diazabicyclo[2.2.2]octane and its dication with borine and tetrahydridoborate anion and products of their transformations; Novye gidridnye soedineniya 1,4-diazabitsiklo[2.2.2]oktana i ego dikationa s borinom i tetergidridoborat-anionom i produkty ikh prevrashcheniya

    Energy Technology Data Exchange (ETDEWEB)

    Shevchenko, Yu N; Yashina, N I; Markova, O Z; Trachevskij, V V

    1997-12-31

    New compounds [dabcoH{sub 2}](BH{sub 4}){sub 2}, dabco(BH{sub 3}){sub 2}2H{sub 2}, [dabco(BH{sub 3}){sub 2}H{sub 2}]{sub n} have been synthesized by means of interaction between dihydrochloride of 1,4-diazobicyclo[2.2.2] octane (dabco) and NaBH{sub 4} in the medium of nonaqueous solvents (glyme, diglyme, tetrahydrofuran, dimethylsulfoxide) and identified by the methods of element analysis, conductometry, {sup 1}H, {sup 11}B, {sup 14}N NMR, IR spectroscopy and thermal analysis. A mechanism is suggested and the conditions are defined for mutual transformations of the compounds studied. Their ability to bind reversibly molecular hydrogen has been revealed for the first time. 19 refs.; 3 figs.; 1 tab.

  16. On the conditions of preparation of hydrated rare earth orthovanadates

    Energy Technology Data Exchange (ETDEWEB)

    Nakhodnova, A P; Belousova, E E; Shuba, Yu I; Zaslavskij, L V

    1988-10-01

    The properties of Ln(NO/sub 3/)/sub 3/-Na/sub 3/VO/sub 4/-H/sub 2/O solution series, where Ln is Er, Ho, Eu are investigated by the methods of residual concentrations, conductometry and potentiometry. It is found that at equivalent ratios of the initial components LnVO/sub 4/xmH/sub 2/O hydrated orthovanadates are formed. Deviations towards excess of rare earths or vanadium result in contamination of the compounds by products of side reactions. According to the data on X-ray phase analysis, hydrated erbium, holmium, europium orthovanadates have the zirconium crystal structure typical for anhydrous compounds. It is shown that hydrate water, being a component of orthovanadates, can be referred to adsorbed and interlayer water.

  17. Fe(II) and Co (II) complexes of (4-(4-bromophenyl)-[2,2'-bipyridine]-6-carboxylic acid) synthesis, characterization and electrochromic studies

    International Nuclear Information System (INIS)

    Saba, A.; Maqsood, Z.T.; Wasim, A.A.; Basha, F.Z.

    2017-01-01

    In this study novel complexes of substituted bipyridine (4-(4-bromophenyl)-[2,2'-bipyridine]-6-carboxylic acid) with Fe/sup +2/ and Co/sup +2/ were synthesized and characterized by different physical, analytical and spectral techniques which includes /sup 1/ H-NMR, MALDI-MS, FTIR, UV-VIS Spectrophotometry, CHN analysis and conductometry. Mole ratio method revealed that both complexes satisfied ML2 stoichiometry. Other characterization studies showed that substituted bipyridine acted as a tridentate ligand, with two pyridine N and one carboxylic O atom as binding sites per ligand molecule. The complexes were found octahedral, neutral and possessed fairly high molar absorptivities in visible region. Electrochromic studies revealed that Fe (II) complex had relatively good electrochromic properties with a reversible color change from blue to pale yellow. Co (II) complex, however, did not show significant electrochromic properties in the visible region. (author)

  18. Microchannel conductivity measurements in microchip for on line monitoring of dephosphorylation rates of organic phosphates using paramagnetic-beads linked alkaline phosphatase.

    Science.gov (United States)

    Kechadi, Mohammed; Sotta, Bruno; Gamby, Jean

    2015-01-01

    This paper presents the use of polymer coated microelectrodes for the realtime conductivity monitoring in a microchannel photoablated through the polymer without contact. Based on this strategy, a small conductometry sensor has been developed to record in time conductivity variation when an enzymatic reaction occurs through the channel. The rate constant determination, k2, for the dephosphorylation of organic phosphate-alkaline phosphatase-superparamagnetic beads complex using chemically different substrates such as adenosine monoesterphosphate, adenosine diphosphate and adenosine triphosphate was taken as an example to demonstrate selectivity and sensivity of the detection scheme. The k2 value measured for each adenosine phosphate decreases from 39 to 30 s(-1) in proportion with the number (3, 2 and 1) of attached phosphate moiety, thus emphasizing the steric hindrance effect on kinetics. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. 18-Crown-6-polyether complexing with iodine

    Energy Technology Data Exchange (ETDEWEB)

    Borovikov, Yu Ya [AN Ukrainskoj SSR, Kiev (Ukrainian SSR). Inst. Organicheskoj Khimii

    1988-01-01

    Using the methods of dielectrometry, conductometry, calorimetry, UV, NMR and IR spectroscopy, 18-Crown-6-polyether complexing with iodine in chlorobenzene, benzotrifluoride, 1,2 dichloroethane is investigated. At the first stage external complexes (1) of the composition 1:1 (dipole momentum {mu}=7 D) is formed, which gradually regroups into internal complex (2) of the compositon 4:1. The time of 1 transition into 2 is inversely proportional to dielectric permeability of the medium. Enthalpy of 1 formation is close to 8.3 kcal/mol, which is 2,5 times higher than in cyclohexane solutions. Complex 1 is molecular, 2 is salt-like. Formation enthalpy of complex 2 of the components is not high, in dichlaroethane it is centrally symmetric and nonpolar, in chlorobenzene and benzotrifluoride-highly polar. In solid phase complex of the composition 1:2 is formed.

  20. Investigation of rare elements by electrochemical methods

    International Nuclear Information System (INIS)

    Zarinskij, V.A.

    1988-01-01

    The use of electrochemical methods for the study of complexing, separation of rare element mixtures, their preparation in lower oxidation states, and also for the development of highly sensitive methods of the element determination, is considered in the review. Voltammetric methods of Pt, Au, Re determination are considered, as well as Re preparation in oxidation states +5, +3 by electrolytic methods. The possibility to use electrodialysis methods for purification of insoluble compounds of rare earths (RE) from impurities, and for separation of Re and Mo with simultaneous purification of Re from K and other elements is shown. The application of high-frequency conductometry to analytic chemistry and to the study of Th, In, RE complexing and kinetics of the reactions is considered

  1. Theory of space-charge polarization for determining ionic constants of electrolytic solutions

    Science.gov (United States)

    Sawada, Atsushi

    2007-06-01

    A theoretical expression of the complex dielectric constant attributed to space-charge polarization has been derived under an electric field calculated using Poisson's equation considering the effects of bound charges on ions. The frequency dependence of the complex dielectric constant of chlorobenzene solutions doped with tetrabutylammonium tetraphenylborate (TBATPB) has been analyzed using the theoretical expression, and the impact of the bound charges on the complex dielectric constant has been clarified quantitatively in comparison with a theory that does not consider the effect of the bound charges. The Stokes radius of TBA +(=TPB-) determined by the present theory shows a good agreement with that determined by conductometry in the past; hence, the present theory should be applicable to the direct determination of the mobility of ion species in an electrolytic solution without the need to measure ionic limiting equivalent conductance and transport number.

  2. Solvation effect on decomposition rate of 10-methyl-10-phenylphenoxarsonium iodide in some alcohols and ketones

    International Nuclear Information System (INIS)

    Gavrilov, V.I.; Gumerov, N.S.; Rakhmatullin, R.R.

    1989-01-01

    By the method of conductometry decomposition kinetics of 10-methyl-10phenylphenoxarsonium iodide in methanol, ethanol, 2-propanol, 1-butanol, 1-pentanol and methyl ethyl ketone at initial concentration of the salt 0.00024-0.003 mol/l, is studied. It is shown that at the temperatures up to 80-95 deg C practically no decomposition of arsonium salt in methanol and ethanol is observed. With an increase in the length of alcohol alkyl radical the decomposition rate increases. The values of activation enrgy both for alcohols and ketone are approximately the same. At the same time, decomposition rate in alcohol proved much slower than in ketone, which is related to iodide-ion solvation in protic solvents

  3. Application of chemical dosemeters during the irradiation of agricultural products

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, A; Stenger, V; Foeldiak, G [Magyar Tudomanyos Akademia, Budapest. Izotopintezete

    1983-09-01

    The joint recommedation by the FAO, WHO and IAEA in 1981 proposed the unrestricted permission of food irradiation under the dose value of 10 kGy (1 Mrd). The chemical dosemeters presented in the paper cover the dose range of 30 Gy to 1 MGy for use to food irradiation safety measurements. The Fricke dosemeter was used in the 50-400 Gy range at radappertization operations of onion, poppy and potato. The alcoholic chlorobenzene dosemeter with oscillometric analysis was applied successfully at low (0.4-4 kGy) ranges, primarily for irradiation dose monitoring of fruits, vegetables, refrigerated poultry etc. The conductometry could be used for dosimetry in the range of 60 Gy to 1 MGy.

  4. Determination of impurities in uranium--niobium (7.5%)--zirconium (2.5%) alloy

    Energy Technology Data Exchange (ETDEWEB)

    Arragon, Y

    1973-10-01

    The determination of 11 impurities in uranium--niobium-- zirconium alloys was studied. Elements of which the alloy is composed are considered and information is given on the determination of niobium by niobic acid precipitation. Selective elimination of the three components is discussed. Two liquid-liquid extractions are used. The nioblum is separated by methylisobutylketone in a hydrochloric --hydrofluoric medium and the zirconium and uranium by tributyl phosphate in a nitric medium. The determination of trace elements using electrochemical methods is discussed. Anodic re-dissolution polarography or square wave polarography enabled six elements (cadmium, copper, lead, zinc, bismuth, and thallium) to be determined in a carbonate medium together with aluminium in tetraethylammonium perchlorate, molybdenum in nitric acid, ammonium nitrate, and tungsten in hydrochloric acid with added double sodium and potassium tartrate. Fluorine was determined using ionometric techniques with a specific electrode and carbon was titrated by conductometry after combustion of the sample in an oxygen current. (auth)

  5. Solubility of Gliclazide and Ion-Molecular Interactions with Aminopropanol in Aqueous Solutions

    Science.gov (United States)

    Hamdan, Imad I.; El-Sabawi, Dina; Abu-Dahab, Rana

    2018-01-01

    A new salt of gliclazide (GZD) was prepared and was shown to have a significantly higher aqueous solubility at physiological pH together with superior dissolution profiles in comparison to GZD employing an organic amino-alcohol base. Characterization by NMR, IR, DSC, conductometry and HPLC techniques concluded that an ion pair salt is formed between acidic GZD and basic aminopropanol (AMP). In addition to the presence of about 5% tightly bound water, hydrogen bonds appeared to form extensively between GZD, AMP and water molecules. Unlike many of solubility enhancing approaches, the salt did not hamper the permeability of GZD as shown by transport through Caco-2 cells model. In vivo studies on rats confirmed that the blood glucose lowering effect of GZD-AMP was significantly higher and more rapid compared to parent GZD indicating an enhanced overall performance of the prepared salt.

  6. Viability and vigour of ageing winter wheat grains

    Directory of Open Access Journals (Sweden)

    Stanisław Grzesiuk

    2014-01-01

    Full Text Available The viability and vigour of ageing winter wheat caryopses of the cvs. Grana and Jana were tested. Viability was determined on the basis of germination capacity and rate, and vigour on the basis of the over-all activity of hydrogenases in the sprouts, exudate conductometry, analysis of sprout growth, oxygen uptake and mitochondrial protein content in the sprouts. What is called energy (or rate of germination and over-all dehydrogenase activity in embryos and sprouts and the electroconductivity of exudates were found to be very good measures of the vigour of ageing caryopses. The latter two indices of vigour should be determined at a strictly defined moment of swelling and germination. Good measures of caryopse vigour are also respiration during swelling and at the beginning of germination and mitochondrial protein content in the sprouts or seedlings. There is a high correlation between the vigour of ageing grain and its bioenergetic indices.

  7. Investigation into complexing of anhydrons uranyl chloride with organic o-bases in nonaqueous media. Reaction with neutral organic phosphorus compounds

    International Nuclear Information System (INIS)

    Kobets, L.V.; Buchikhin, E.P.; Klyshevich, R.P.; Belyachis, G.F.

    1983-01-01

    The methods of spectrophotometry, conductometry and calorimetry have been used to investigate the uranylchloride inter ction with tributylphosphate, di-iso-amyl, dioctyl ethers of methylphosphonic acid, trioctylphosphinoxid and hexamethylphosphortriamide in anhydrous acetone medium. The existence of complexes of 1:1 and 1:2 composition is found, constants of formation and dissociation for these substances are calculated and enthalpies of their formation in acetone are determined. The dependence of equivalent electric conductivity of complexes on their concentration in acetone is studied. The analysis of the data obtained proves a regular growth of both complex formation constants and enthalpies of interaction with the growth of the value of donor number of bases. Dissociation constants of complexes do not practically depend on donor properties of phosphorogranic bases studied with the exception of HMFTA. This is most probably connected with the effect of steric factors, rather than the growth of basisity of compound

  8. Synthesis and characterization of ligational behavior of curcumin drug towards some transition metal ions: Chelation effect on their thermal stability and biological activity

    Science.gov (United States)

    Refat, Moamen S.

    2013-03-01

    Complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with curcumin ligand as antitumor activity were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV-Vis, IR, Raman, ESR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a monobasic bidentate ligand towards the central metal ion with an oxygen's donor atoms sequence of both sbnd OH and Cdbnd O groups under keto-enol structure. From the microanalytical data, the stoichiometry of the complexes 1:2 (metal:ligand) was found. The ligand and their metal complexes were screened for antibacterial activity against Escherichia Coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa and fungicidal activity against Aspergillus flavus and Candida albicans.

  9. Electrochemical measurements on a droplet using gold microelectrodes

    Science.gov (United States)

    Jenabi, Amin; Souri, Asma; Rastkhadiv, Ali

    2016-03-01

    Facile methods of ion recognition are important for the fabrication of electronic tongue systems. In this work, we demonstrate performing pulsed conductometry on microliter electrolyte droplets dropped on gold microelectrodes vapor deposited on soda lime glass slides. A droplet is dropped between two microelectrodes when a voltage waveform from a preprogramed power supply is applied on them. The temporal variation of the electric current passing through the droplet is recorded, digitized and stored. The obtained data are compared with the database formed out of the previous experiences for the classification of the sample electrolytes. It is shown that the shape of the voltage waveform is the important parameter of the process. We devised a method for the optimization of the voltage waveform profile for obtaining the maximum of discriminating information from the recorded current variations.

  10. Electrical conductivity of solutions of copper(II) nitrate crystalohydrate in dimethyl sulfoxide

    Science.gov (United States)

    Mamyrbekova, Aigul K.; Mamitova, A. D.; Mamyrbekova, Aizhan K.

    2016-06-01

    Conductometry is used to investigate the electric conductivity of Cu(NO3)2 ṡ 3H2O solutions in dimethyl sulfoxide in the 0.01-2.82 M range of concentrations and at temperatures of 288-318 K. The limiting molar conductivity of the electrolyte and the mobility of Cu2+ and NO 3 - ions, the effective coefficients of diffusion of copper(II) ions and nitrate ions, and the degree and constant of electrolytic dissociation are calculated for different temperatures from the experimental results. It is established that solutions containing 0.1-0.6 M copper nitrate trihydrate in DMSO having low viscosity and high electrical conductivity can be used in electrochemical deposition.

  11. Study of lanthanum nitrate-sodium tetrametaphosphate-water system

    Energy Technology Data Exchange (ETDEWEB)

    Emel' yanov, O V; Boiko, K M [Kievskii Gosudarstvennyj Univ. (Ukrainian SSR)

    1978-10-01

    The system La(NO/sub 3/)/sub 3/-Na/sub 4/P/sub 4/O/sub 12/-H/sub 2/O has been studied using the solubility method, pH- and conductometry. Found are subsequent formation of the main phases of alternate composition and neutral salt La/sub 4/(P/sub 4/O/sub 12/)/sub 3/, which is solved in Na/sub 4/P/sub 4/O/sub 12/ excess which is a result of complex formation. The soluble complexes of the composition Na/sub 5/(La(P/sub 4/O/sub 12/)/sub 2/) are obtained. The extracted complexes are investigated using the methods of paper chromatography, thermography roentgenography and IR-spectroscopy.

  12. Investigation into complexing of anhydrons uranyl chloride with organic o-bases in nonaqueous media. Reaction with neutral organic phosphorus compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kobets, L V; Buchikhin, E P; Klyshevich, R P; Belyachis, G F

    1983-01-01

    The methods of spectrophotometry, conductometry and calorimetry have been used to investigate the uranylchloride interaction with tributylphosphate, di-iso-amyl, dioctyl ethers of methylphosphonic acid, trioctylphosphinoxide and hexamethylphosphortriamide in anhydrous acetone medium. The existence of complexes of 1:1 and 1:2 composition is found, constants of formation and dissociation for these substances are calculated and enthalpies of their formation in acetone are determined. The dependence of equivalent electric conductivity of complexes on their concentration in acetone is studied. The analysis of the data obtained proves a regular growth of both complex formation constants and enthalpies of interaction with the growth of the value of donor number of bases. Dissociation constants of complexes do not practically depend on donor properties of phosphorogranic bases studied with the exception of HMFTA. This is most probably connected with the effect of steric factors, rather than the growth of basisity of compound.

  13. Etching behavior of poly (vinylidene fluoride) thin films irradiated with ion beams. Effect of irradiated ions and pretreatment

    International Nuclear Information System (INIS)

    Yamaki, Tetsuya; Rohani, Rosiah; Koshikawa, Hiroshi; Takahashi, Shuichi; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari; Voss, Kay-Obbe; Neumann, Reinhard

    2008-01-01

    Poly (vinylidene fluoride) thin films irradiated with four kinds of ion beams were exposed to a 9M KOH aqueous solution after their storage in air for 30 or 90 days at different temperatures. According to the conductometry, the heating at 120degC was found to enhance the etch rate in the latent track without changing that in the bulk, thereby enabling us to obtain very high etching sensitivity for the preparation of nano-sized through-pores. The formation of hydroperoxides during this pretreatment should facilitate the introduction of the etching agent to improve etchability. Additionally, the irradiation of higher-LET ions, causing each track to contain more activated sites (like radicals), was preferable to achieve high sensitivity of the etching. (author)

  14. Solvation effect on decomposition rate of 10-methyl-10-phenylphenoxarsonium iodide in some alcohols and ketones

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, V I; Gumerov, N S; Rakhmatullin, R R [Kazanskij Khimiko-Tekhnologicheskij Inst., Kazan (USSR)

    1989-03-01

    By the method of conductometry decomposition kinetics of 10-methyl-10phenylphenoxarsonium iodide in methanol, ethanol, 2-propanol, 1-butanol, 1-pentanol and methyl ethyl ketone at initial concentration of the salt 0.00024-0.003 mol/l, is studied. It is shown that at the temperatures up to 80-95 deg C practically no decomposition of arsonium salt in methanol and ethanol is observed. With an increase in the length of alcohol alkyl radical the decomposition rate increases. The values of activation enrgy both for alcohols and ketone are approximately the same. At the same time, decomposition rate in alcohol proved much slower than in ketone, which is related to iodide-ion solvation in protic solvents.

  15. Thermodynamic properties of amphiphilic antidepressant drug citalopram HBr

    International Nuclear Information System (INIS)

    Usman, M.; Khan, A.

    2010-01-01

    Association characteristics of antidepressant during Citalopram hydrobromide in water Have been examined and its thermodynamic parameters have been calculated using tensiometery and conductometry. The critical micelle concentration (cmc) was determined by surface tension measurement at 30 deg. C and Surface activity was studied by measuring surface parameters i.e. surface pressure, JI, surface excess concentration, area per molecule of drug and standard Gibbs free energy of adsorption, delta G. The electrical conductivity was measured as a function of concentration at various temperatures and cmc was calculated in the temperature range 20-50 deg. C. Thermodynamic parameters i.e. standard free energy of micellization, delta G standard enthalpy of micellization, delta H/sub m/ and standard entropy of micellization, delta S/sub m/ were calculated from cmc value using closed association model. (author)

  16. BENZYLIDENESALICYLOYLHYDRAZINATO- N,OTIN(IV] (R = OCH3, Br, N(CH32 AND THEIR ANTI-INFLAMMATORY ACTIVITY

    Directory of Open Access Journals (Sweden)

    N. V. Shmatkova

    2014-11-01

    Full Text Available The complexes [SnCl4(2-OH-HB-4R-b] ·CH3CN (R = 4-OCH3 (І, 4-Br(II were obtained by interaction of SnCl4 with salicyloylhydrazones 4–R- benzaldehydes (2-OH-HB-4R-b in acetonitrile. The composition and structure (O(C=O-N(CH=N – the coordination of ligand’s amide form were established by element analysis methods, conductometry, thermogravimetry and IR spectroscopy. It was studied the anti-inflammatory activity of (I, II and previously synthesized, structurally characterized [SnCl4(2-OH-HB-4R-b∙H] (R=N (CH32 (III in model of aseptic carrageenan induced swelling, and it is shown that compound (II demonstrates the highest activity.

  17. Redox reactions in rare earth chloride molten electrolytes

    International Nuclear Information System (INIS)

    Khokhlov, V.A.; Novoselova, A.V.; Nikolaeva, E.V.; Tkacheva, O.Yu.; Salyulev, A.B.

    2007-01-01

    Rare earth (REM, Ln) solutions in chloride melts including MCI+LnCl 3 mixtures, where M - alkali metals, were investigated by potentiometry, voltammetry, conductometry in wide concentration and temperature intervals. Findings present complete and trusty information on the valent state of rare earths, structure and composition of complex ions affecting essentially on properties of electrolytes. It is demonstrated that the coexistence of rare earth ions with different oxidation level formed as a result of possible redox reactions: 2Ln 3+ + Ln ↔3Ln 2+ , Ln 2+ + Ln↔2Ln + and nM + + Ln↔nM + Ln n+ appears sharply in thermodynamic and transport properties of molten Ln-LnCl 3 and Ln-LnCl 3 -MCl systems [ru

  18. Electrochemically driven emulsion inversion

    Science.gov (United States)

    Johans, Christoffer; Kontturi, Kyösti

    2007-09-01

    It is shown that emulsions stabilized by ionic surfactants can be inverted by controlling the electrical potential across the oil-water interface. The potential dependent partitioning of sodium dodecyl sulfate (SDS) was studied by cyclic voltammetry at the 1,2-dichlorobenzene|water interface. In the emulsion the potential control was achieved by using a potential-determining salt. The inversion of a 1,2-dichlorobenzene-in-water (O/W) emulsion stabilized by SDS was followed by conductometry as a function of added tetrapropylammonium chloride. A sudden drop in conductivity was observed, indicating the change of the continuous phase from water to 1,2-dichlorobenzene, i.e. a water-in-1,2-dichlorobenzene emulsion was formed. The inversion potential is well in accordance with that predicted by the hydrophilic-lipophilic deviation if the interfacial potential is appropriately accounted for.

  19. Transition metal complexes with oxygen donor ligands: a synthesis, spectral, thermal and antimicrobial study

    Directory of Open Access Journals (Sweden)

    VAIBHAV N. PATANGE

    2008-10-01

    Full Text Available Transition metal complexes of chalcones derived from the conden¬sation of 3-acetyl-6-methyl-2H-pyran-2,4(3H-dione (dehydroacetic acid and p-methoxybenzaldehyde (HL1 or p-nitrobenzaldehyde (HL2 were synthesized and characterized by elemental analysis, conductometry, thermal analysis, magnetic measurements, IR, 1H-NMR, UV–Vis spectroscopy and a microbial study. From the analytical and thermal data, the stoichiometry of the complexes was found to be 1:2 (metal:ligand. The molar conductance data revealed that all the metal chelates were non-electrolytes. The thermal stability of the complexes was studied by thermogravimetry and the decomposition schemes of the complexes are given. The ligands and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli, and fungicidal activity against Aspergillus flavus, Curvularia lunata and Penicillium notatum.

  20. Synthesis and properties of compounds (Ln(NO/sub 3/)/sub 2/(OP(N(CH/sub 3/)/sub 2/)/sub 3/)/sub 4/)B(C/sub 6/H/sub 5/)/sub 4/ (Ln=Y,La, Ce-Lu)

    Energy Technology Data Exchange (ETDEWEB)

    Skopenko, V V; Zub, Yu L; Matishinets, I M [Kievskij Gosudarstvennyj Univ. (Ukrainian SSR)

    1984-01-01

    From acetone solutions with the yield 75-80% compounds of the composition (Ln(NO/sub 3/)/sub 2/(OP(Nx(CN/sub 3/)/sub 2/)/sub 3/))B(C/sub 6/H/sub 5/)/sub 4/ (Ln=Y, La, Ce-Lu) have been separated. Comparing diffractograms the existence of two isostructural series with morphotropic transition at the Nd/Sm boundary has been established. Using the data of conductometry and IR spectroscopy it has been shown that the cation coordination number of the central atom is eight: four O atoms from two bidentate-cyclic nitrate groups and four O atoms from four monodentate phosphineoxide ligands. Measurement of electric conductivity of the substances separated in nitromethane has shown that the value lambdasub(M) varies inconsiderably from the value 48 Ohm/sup -1/xcm/sup 2/xmol/sup -1/.

  1. On the conditions of preparation of hydrated rare earth orthovanadates

    International Nuclear Information System (INIS)

    Nakhodnova, A.P.; Belousova, E.E.; Shuba, Yu.I.; Zaslavskij, L.V.

    1988-01-01

    The properties of Ln(NO 3 ) 3 -Na 3 VO 4 -H 2 O solution series, where Ln is Er, Ho, Eu are investigated by the methods of residual concentrations, conductometry and potentiometry. It is found that at equivalent ratios of the initial components LnVO 4 xmH 2 O hydrated orthovanadates are formed. Deviations towards excess of rare earths or vanadium result in contamination of the compounds by products of side reactions. According to the data on X-ray phase analysis, hydrated erbium, holmium, europium orthovanadates have the zirconium crystal structure typical for anhydrous compounds. It is shown that hydrate water, being a component of orthovanadates, can be referred to adsorbed and interlayer water

  2. Lanthanide recognition: A Ho3+ potentiometric membrane sensor as a probe for determination of terazosin

    International Nuclear Information System (INIS)

    Ganjali, Mohammad Reza; Shams, Haniyeh; Faridbod, Farnoush; Hajiaghababaei, Leila; Norouzi, Parviz

    2009-01-01

    In this study, complexation of N'-(1-pyridin-2-ylmethylene)-2-furohydrazide (NFH) with some metal ions was investigated by conductometry and spectroscopy. Then, a Ho 3+ potentiometric membrane sensor was prepared based on the highly selective complexation between this ionophore and Ho 3+ . These new ionophores are more selective than the previously reported ones. In this work, for the first time, the proposed sensor was applied in indirect determination of the terazocine in its pharmaceutical formulation. The interest in constructing lanthanide sensors arises because they have similar ionic radii to calcium, but a higher charge density, which allows them to be used as probes to find the interactions between Ca 2+ and biologically important molecules.

  3. IR-spectroscopic study and electrical properties of glasses in the Ba(PO3)2-Ba(Hal)2 systems

    International Nuclear Information System (INIS)

    Sokolov, I.A.; Tarlakov, Yu.P.; Murin, I.V.; Pronkin, A.A.

    2000-01-01

    Temperature-concentration dependence of electric conductivity of glasses in the systems Ba(PO 3 ) 2 -Ba(Hal) 2 , where Hal = Cl, Br, I, is studied by the method of conductometry, the numbers of iodide-ions transfer are determined and their concentration dependence is found. Data of IR spectroscopy permitted ascertained participation of halide ions in formation of anionic constituent of the glass structure at the expense of bridge bonds formation, as well as formation of structural-chemical units of [(Hal) - Ba 2+ O - POO 2/2 ] type, their dissociation giving rise to formation of halide ions their dissociation giving rise to formation of halide ions taking part in electric current transfer [ru

  4. Electrochemical measurements on a droplet using gold microelectrodes

    International Nuclear Information System (INIS)

    Jenabi, Amin; Souri, Asma; Rastkhadiv, Ali

    2016-01-01

    Facile methods of ion recognition are important for the fabrication of electronic tongue systems. In this work, we demonstrate performing pulsed conductometry on microliter electrolyte droplets dropped on gold microelectrodes vapor deposited on soda lime glass slides. A droplet is dropped between two microelectrodes when a voltage waveform from a preprogramed power supply is applied on them. The temporal variation of the electric current passing through the droplet is recorded, digitized and stored. The obtained data are compared with the database formed out of the previous experiences for the classification of the sample electrolytes. It is shown that the shape of the voltage waveform is the important parameter of the process. We devised a method for the optimization of the voltage waveform profile for obtaining the maximum of discriminating information from the recorded current variations. (paper)

  5. Synthesis and some properties of hydrogen phosphites M3(H2PO3)3, where M = Ga, V, Fe, or In

    International Nuclear Information System (INIS)

    Zakharova, B.S.; Tarnopol'skij, V.A.; Chudinova, N.N.

    2001-01-01

    The conditions on production and the properties of the acid phosphites M 3 (H 2 PO 3 ) 3 (M = Ga, V, Fe, In) are demonstrated. The compounds were investigated by X-ray diffraction, thermal gravimetric analysis, IR spectroscopy and conductometry. Interaction of M 2 O 3 (M = Ga, V, Fe, In) with the melt of phosphorous acid was studied in the P : M = 1. 5 : 1 - 10 : 1 interval of compositions. The lattice parameters are given, the hypothesis on the available of superstructure in the M 3 (H 2 PO 3 ) 3 compounds is corroborated. From the measurements the proton conductivity in vanadium and indium phosphites is comprised of 2.5 x 10 -5 and 1.9 x 10 8- S/cm correspondingly. Acid vanadium and indium phosphites are behaved similarly during heating. The limit of thermal stability of the acid phosphites V(H 2 PO 3 ) 3 , V(H 2 PO 3 ) 3 grows [ru

  6. Toxicity assessment using different bioassays and microbial biosensors.

    Science.gov (United States)

    Hassan, Sedky H A; Van Ginkel, Steven W; Hussein, Mohamed A M; Abskharon, Romany; Oh, Sang-Eun

    2016-01-01

    Toxicity assessment of water streams, wastewater, and contaminated sediments, is a very important part of environmental pollution monitoring. Evaluation of biological effects using a rapid, sensitive and cost effective method can indicate specific information on ecotoxicity assessment. Recently, different biological assays for toxicity assessment based on higher and lower organisms such as fish, invertebrates, plants and algal cells, and microbial bioassays have been used. This review focuses on microbial biosensors as an analytical device for environmental, food, and biomedical applications. Different techniques which are commonly used in microbial biosensing include amperometry, potentiometry, conductometry, voltammetry, microbial fuel cells, fluorescence, bioluminescence, and colorimetry. Examples of the use of different microbial biosensors in assessing a variety of environments are summarized. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Interaction between cobalt-containing materials and solid electrolyte on the basis of lanthanum gallate

    International Nuclear Information System (INIS)

    Bronin, D.I.; Kuzin, B.L.; Sokolova, Yu.V.; Polyakova, N.V.

    2000-01-01

    High-temperature interaction of solid electrolyte La 0.88 Sr 0.12 Mg 0.18 Ga 0.82 O 3-α with material of oxygen electrode La 0.7 Sr 0.3 CoO 3-δ (LSC) and with Co 3 O 4 and its influence on electrochemical activity of oxygen electrodes made of LSO and Pt were studied using the methods of X-ray microanalysis, conductometry and impedance-spectroscopy. It was ascertained that the surface of the solid electrolyte contacting LSC or Co 3 O 4 at a temperature of 1100 Deg C and higher is enriched by cobalt. Electric conductivity of the electrolyte layer modified by cobalt is noticeably higher than that of the initial one. Electrochemical activity of oxygen electrodes made of LSC is 1-2 ordered higher than the one characteristic of platinum electrode [ru

  8. The α-chymotrypsin and its hydrophobic derivatives in inverse micelles

    International Nuclear Information System (INIS)

    Pitre, Franck

    1993-01-01

    The α-chymotrypsin is among the most used enzymes, notably and particularly in medicine for therapeutic treatments as well as in biochemistry to determine the amine acid sequence of proteins. This research thesis addresses the study of interactions between a micro-emulsion system and an enzymatic system, and more particularly the behaviour of α-chymotrypsin in AOT inverse micelles. After a brief description of the inverse micellar system and of previously obtained results on the solubilisation of α-chymotrypsin in inverse micelles, the author reports the study of the inverse micellar phase in presence of α-chymotrypsin at the vicinity of the maximum solubility. Various techniques are used for this purpose: UV-visible absorption spectrophotometry, conductometry, and X ray scattering. Then, the author describes the chemical modification of α-chymotrypsin, and reports the study of structural as well as reaction modifications introduced during the solubilisation of α-chymotrypsin modified in inverse micelles [fr

  9. Redox reactions in rare earth chloride molten electrolytes; Okislitel'no-vosstanovitel'nye reaktsii v rasplavlennykh ehlektrolitakh, soderzhashchikh khloridy redkozemel'nykh metallov

    Energy Technology Data Exchange (ETDEWEB)

    Khokhlov, V A; Novoselova, A V; Nikolaeva, E V; Tkacheva, O Yu; Salyulev, A B [Inst. Vysokotemperaturnoj Ehlektrokhimii UrO RAN, Ekaterinburg (Russian Federation)

    2007-08-15

    Rare earth (REM, Ln) solutions in chloride melts including MCI+LnCl{sub 3} mixtures, where M - alkali metals, were investigated by potentiometry, voltammetry, conductometry in wide concentration and temperature intervals. Findings present complete and trusty information on the valent state of rare earths, structure and composition of complex ions affecting essentially on properties of electrolytes. It is demonstrated that the coexistence of rare earth ions with different oxidation level formed as a result of possible redox reactions: 2Ln{sup 3+} + Ln {r_reversible}3Ln{sup 2+}, Ln{sup 2+} + Ln{r_reversible}2Ln{sup +} and nM{sup +} + Ln{r_reversible}nM + Ln{sup n+} appears sharply in thermodynamic and transport properties of molten Ln-LnCl{sub 3} and Ln-LnCl{sub 3}-MCl systems.

  10. The development of quantitative determination method of organic acids in complex poly herbal extraction

    Directory of Open Access Journals (Sweden)

    I. L. Dyachok

    2016-08-01

    Full Text Available Aim. The development of sensible, economical and expressive method of quantitative determination of organic acids in complex poly herbal extraction counted on izovaleric acid with the use of digital technologies. Materials and methods. Model complex poly herbal extraction of sedative action was chosen as a research object. Extraction is composed of these medical plants: Valeriana officinalis L., Crataégus, Melissa officinalis L., Hypericum, Mentha piperita L., Húmulus lúpulus, Viburnum. Based on chemical composition of plant components, we consider that main pharmacologically active compounds, which can be found in complex poly herbal extraction are: polyphenolic substances (flavonoids, which are contained in Crataégus, Viburnum, Hypericum, Mentha piperita L., Húmulus lúpulus; also organic acids, including izovaleric acid, which are contained in Valeriana officinalis L., Mentha piperita L., Melissa officinalis L., Viburnum; the aminoacid are contained in Valeriana officinalis L. For the determination of organic acids content in low concentration we applied instrumental method of analysis, namely conductometry titration which consisted in the dependences of water solution conductivity of complex poly herbal extraction on composition of organic acids. Result. The got analytical dependences, which describes tangent lines to the conductometry curve before and after the point of equivalence, allow to determine the volume of solution expended on titration and carry out procedure of quantitative determination of organic acids in the digital mode. Conclusion. The proposed method enables to determine the point of equivalence and carry out quantitative determination of organic acids counted on izovaleric acid with the use of digital technologies, that allows to computerize the method on the whole.

  11. Facilitatory effect of AC-iontophoresis of lidocaine hydrochloride on the permeability of human enamel and dentine in extracted teeth.

    Science.gov (United States)

    Ikeda, Hideharu; Suda, Hideaki

    2013-04-01

    The objectives of the present study were to quantitatively evaluate chemical permeability through human enamel/dentine using conductometry and to clarify if alternating current (AC) iontophoresis facilitates such permeability. Electrical impedance of different concentrations of lidocaine hydrochloride was measured using a bipolar platinum impedance probe. A quadratic curve closely fitted to the response functions between conductance and lidocaine hydrochloride. For analysis of the passage of lidocaine hydrochloride through human enamel/dentine, eight premolars that were extracted for orthodontic treatment were sectioned at the cemento-enamel junction. The tooth crowns were held between two chambers with a double O-ring. The enamel-side chamber was filled with lidocaine hydrochloride, and the pulp-side chamber was filled with extrapure water. Two platinum plate electrodes were set at the end of each chamber to pass alternating current. A simulated interstitial pulp pressure was applied to the pulp-side chamber. The change in the concentration of lidocaine hydrochloride in the pulp-side chamber was measured every 2min using a platinum recording probe positioned at the centre of the pulp-side chamber. Passive entry without iontophoresis was used as a control. The level of lidocaine hydrochloride that passed through enamel/dentine against the dentinal fluid flow increased with time. Electrical conductance (G, mho) correlated closely to the concentration (x, mmol/L) of lidocaine hydrochloride (G=2.16x(2)+0.0289x+0.000376, r(2)=0.999). Lidocaine hydrochloride can pass through enamel/dentine. Conductometry showed that the level of lidocaine hydrochloride that passed through enamel/dentine was increased by AC iontophoresis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Pulse radiolysis in model studies toward radiation processing

    Science.gov (United States)

    Von Sonntag, C.; Bothe, E.; Ulanski, P.; Deeble, D. J.

    1995-02-01

    Using the pulse radiolysis technique, the OH-radical-induced reactions of poly(vinyl alcohol) PVAL, poly(acrylic acid) PAA, poly(methacrylic acid) PMA, and hyaluronic acid have been investigated in dilute aqueous solution. The reactions of the free-radical intermediates were followed by UV-spectroscopy and low-angle laser light-scattering; the scission of the charged polymers was also monitored by conductometry. For more detailed product studies, model systems such as 2,4-dihydroxypentane (for PVAL) and 2,4-dimethyl glutaric acid (for PAA) was also investigated. With PVA, OH-radicals react predominantly by abstraction of an H-atom in α-position to the hydroxyl group (70%). The observed bimolecular decay rate constant of the PVAL-radicals decreases with time. This has been interpreted as being due to an initially fast decay of proximate radicals and a decrease of the probability of such encounters with time. Intramolecular crosslinking (loop formation) predominates at high doses per pulse. In the presence of O 2, peroxyl radicals are formed which in the case of the α-hydroxyperoxyl radicals can eliminate HO 2-radicals in competition with bimolecular decay processes which lead to a fragmentation of the polymer. In PAA, radicals both in α-position (characterized by an absorption near 300 nm) and in β-position to the carboxylate groups are formed in an approximately 1:2 ratio. The lifetime of the radicals increases with increasing electrolytic dissociation of the polymer. The β-radicals undergo a slow (intra- as well as intermolecular) H-abstraction yielding α-radicals, in competition to crosslinking and scission reactions. In PMA only β-radicals are formed. Their fragmentation has been followed by conductometry. In hyaluronic acid, considerable fragmeentation is observed even in the absence of oxygen which, in fact, has some protective effect against this process. Thus free-radical attack on this important biopolymer makes it especially vulnerable with respect

  13. The Evaluation of Real Time Milk Analyse Result Reliability in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Oto Hanuš

    2016-01-01

    Full Text Available The good result reliability of regular analyzes of milk composition could improve the health monitoring of dairy cows and herd management. The aim of this study was the analysis of measurement of abilities and properties of RT (Real Time system (AfiLab = AfiMilk (NIR measurement unit (near infrared spectroscopy and electrical conductivity (C of milk by conductometry + AfiFarm (calibration and interpretation software for the analysis of individual milk samples (IMSs. There were 2 × 30 IMSs in the experiment. The reference values (RVs of milk components and properties (fat (F, proteins (P, lactose (L, C and the somatic cell count (SCC were determined by conventional (direct and indirect: conductometry (C; infrared spectroscopy 1 with the filter technology and 2 with the Fourier transformations (F, P, L; fluoro-opto-electronic cell counting (SCC in the film on the rotation disc (1 and by flow cytometry (2 methods. AfiLab method (alternative showed less close relationships as compared to the RVs as relationships between reference methods. This was expected. However, these relationships (r were mostly significant: F from .597 to .738 (P ≤ 0.01 and ≤ 0.001; P from .284 to .787 (P > 0.05 and P ≤ 0.001; C .773 (P ≤ 0.001. Correlations (r were not significant (P > 0.05: L from −.013 to .194; SCC from −.148 to −.133. Variability of the RVs explained the following percentages of variability in AfiLab results: F to 54.4 %; P to 61.9 %; L only 3.8 %; C to 59.7 %. Explanatory power (reliability of AfiLab results to the animal is increasing with the regularity of their measurements (principle of real time application. Correlation values r (x minus 1.64 × sd for confidence interval (one-sided at a level of 95 % can be used for an alternative method in assessing the calibration quality. These limits are F 0.564, P 0.784 and C 0.715 and can be essential with the further implementation of this advanced technology of dairy herd management.

  14. Dimethyl sulfoxide complexing with iodine

    Energy Technology Data Exchange (ETDEWEB)

    Borovikov, Yu Ya; Serguchev, Yu A; Staninets, V I

    1986-01-01

    Dielectrometry, conductometry, IR-spectroscopy are used to study dimethyl sulfoxide complexing with iodine in binary system and in CCl/sub 4/, C/sub 6/H/sub 6/, C/sub 6/H/sub 5/Cl, C/sub 6/H/sub 5/CF/sub 3/, 1, 2-dichloroethane solutions. Complexes of 1:1 composition are formed in solutions, in the binary system of 2:1 and 2:2 composition. I/sub 2/ molecules add to oxygen atoms. In CCl/sub 4/ and in binary system gradual transformation of so called external charge transfer complexes (CTC-1) to internal ones (CTC-2) that are described by the 1st order reaction kinetic equations is observed. On dissolution of CTC of 2:2 composition they disproportionate into two CTC molecules 1:1. Enthalpy of forming CTC-1 1:1 is approximately 4 kcal/mol, CTC-2 1:1 - 8, CTC-1 2:1 - 8 kcal/mol.

  15. Radiolysis of poly(acrylic acid) in aqueous solution

    Science.gov (United States)

    Ulanski, Piotr; Bothe, Eberhard; Hildenbrand, Knut; Rosiak, Janusz M.; von Sonntag, Clemens

    1995-02-01

    Poly(acrylic acid), PAA, reacts with OH-radicals yielding -CHCH(CO 2H)- (β-radicals) and -CH 2C(CO 2H)- (α-radicals) in a ratio of approximately 2:1. This estimate is based on pulse radiolysis data where the absorption spectrum of the PAA-radicals was compared with the spectra of α-radicals from model systems. The β-radicals convert slowly into α-radicals ( k = 0.7 s -1 at pH 10). This process has also been observed by ESR. At PAA-concentrations of 10 -2 mol dm -3 chain scission dominates over other competing reactions except at low pH. The rate of chain scission was followed by pulse conductometry and in the pH range 7-9 k = 4 × 10 -2s -1 was observed. Oxygen reacts with PAA-radicals with k = 3.1 × 10 8 dm 3 mol -1 s -1 at pH 3.5 and k = 1.0 × 10 8 dm 3 mol -1 s -1 at pH 10. The corresponding peroxyl radicals undergo slow intramolecular H-transfer yielding a UV-absorbing product whose properties are that of 1,3-diketones.

  16. A novel, rapid and automated conductometric method to evaluate surfactant-cells interactions by means of critical micellar concentration analysis.

    Science.gov (United States)

    Tiecco, Matteo; Corte, Laura; Roscini, Luca; Colabella, Claudia; Germani, Raimondo; Cardinali, Gianluigi

    2014-07-25

    Conductometry is widely used to determine critical micellar concentration and micellar aggregates surface properties of amphiphiles. Current conductivity experiments of surfactant solutions are typically carried out by manual pipetting, yielding some tens reading points within a couple of hours. In order to study the properties of surfactant-cells interactions, each amphiphile must be tested in different conditions against several types of cells. This calls for complex experimental designs making the application of current methods seriously time consuming, especially because long experiments risk to determine alterations of cells, independently of the surfactant action. In this paper we present a novel, accurate and rapid automated procedure to obtain conductometric curves with several hundreds reading points within tens of minutes. The method was validated with surfactant solutions alone and in combination with Saccharomyces cerevisiae cells. An easy-to use R script, calculates conductometric parameters and their statistical significance with a graphic interface to visualize data and results. The validations showed that indeed the procedure works in the same manner with surfactant alone or in combination with cells, yielding around 1000 reading points within 20 min and with high accuracy, as determined by the regression analysis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Interface interactions in benzophenone doped by multiwalled carbon nanotubes

    Science.gov (United States)

    Lebovka, N. I.; Goncharuk, A.; Melnyk, V. I.; Puchkovska, G. A.

    2009-08-01

    The interface interactions were studied by methods of conductometry, low-temperature phosphorescence and differential scanning calorimetry (DSC) in multiwalled carbon nanotubes (MWCNT) and benzophenone (BP) composite. The concentration of MWCNTs was varied within 0-1 wt%. A percolative threshold was found at MWCNT concentrations exceeding 0.1 wt%. The integration of MWCNTs caused melting temperature increase (≈3 K for 1 wt% of MWCNTs). The effect of positive thermal resistively coefficient, as well as substantial hysteretic behaviour of electrical conductivity σ in a heating-cooling cycle, was observed near the melting point of BP ( T m=321.5 K). The activation-type temperature behaviour of electrical conductivity was observed in the temperature range of supercooled BP. The activation energy was decreasing with increase of MWCNT concentration. The observed nonlinear dependencies of electrical conductivity σ vs. applied voltage U reflect the transport mechanism of the charge carriers through amorphous interface films formed near the surface of the MWCNTs. The thermal shifts of phosphorescence spectra measured within the temperature range 5-200 K evidence existence of such interface films of amorphous BP with width of the order of 0.1 μm.

  18. Synthesis of thiadiazolobenzamide via cyclization of thioxothiourea and its Ni and Pd complexes

    Directory of Open Access Journals (Sweden)

    Adhami Forogh

    2012-01-01

    Full Text Available In this study, the new compound, N-(3-methyl-4- oxo[1,3,4]thiadiazolo[2,3-c][1,2,4]triazin-7-yl benzamide, could be obtained via two different reactions: 1 reaction of 4-amino-6-Methyl-3- (Methylsulfanyl-1,2,4-triazin-5-one with benzoyl isothiocyanate under removal of methylmercaptane, 2 reaction of 4-amino-6-Methyl-3-thioxo- 1,2,4-triazin-5-one with benzoyl isothiocyanate under elimination of hydrogen sulfide. In both reactions a new bond between sulfur and nitrogen atoms was formed and a five-membered ring was created. The oxo thiadiazolo benzamide was characterized by IR-, 1HNMR- and 13CNMR spectroscopy as well as by Mass spectrometry. X-ray crystallography was used to shed light on the structure of this new compound. Two new complexes could be generated by coordination of oxo thiadiazolo benzamide to Pd(II and Ni(II ions. These complexes have been analyzed by IR-, 1HNMR- and 13CNMR spectroscopy, conductometry and Thermal gravimetry (TGA. Theoretical QM Calculation GIAO has also been applied to predict the structure of the Pd complex.

  19. Adsorption of dissymmetric cationic gemini surfactants at silica/water interface

    Science.gov (United States)

    Sun, Yuhai; Feng, Yujun; Dong, Hongwei; Chen, Zhi

    2007-05-01

    Adsorption of a series of cationic gemini surfactants 12-2- m ( m = 8, 12, 16) on the surface of silica was investigated. The critical micelle concentrations, cmcs, of cationic gemini surfactants in the initial solutions and in the supernatants were measured by conductometry and tensiometer. The changes in cmc values indicate that the ion exchanges take place between polar groups of gemini surfactants adsorbed and ions bound on the surface of silica. The adsorption isotherms of cationic gemini surfactants were obtained by a solution depletion method. Based on the driving force, the adsorption includes two steps, one of which is ion exchange, and the other is hydrophobic interaction. In each step, the tendency of surfactant molecules in the solution to form aggregates or to be adsorbed on the silica varies with their structures. The maximum adsorption amount of gemini surfactants on the silica, τmax, decreases as increasing in the length of one alkyl chain, m, from 8, 12 to 16. So the results show that the adsorption behaviors of gemini surfactants are closely related to the dissymmetry of gemini molecules.

  20. Some aspects of surfactant action mechanism in the organic reagents - metal ions systems

    Energy Technology Data Exchange (ETDEWEB)

    Chernova, R K; Shtykov, S N; Beloliptseva, G M; Sukhova, L K; Amelin, V G; Kulapina, E G [Saratovskij Gosudarstvennyj Univ. (USSR)

    1984-06-01

    Results are reviewed of investigations into the interaction of ions of Mo(6), W, Zr, Be, Sc, Nb, Ta, J, rare earths, a. o. with organic reagents of triphenylmethane class in the 8M H/sub 2/SO/sub 4/-pH14 acidity range and the 1x10/sup -3/-5x10/sup -6/ M concentration range both in the presence and absence of different surfactant type (cetylpyridine, methyltrimethylammonium, synthanols, etc). Three types of effects, determining enhancement of the sensitivity and selectivity of reactions jn the Me-R-surfactant systems, were determined: an increase in the number of coordinated ligands, the activating effect of cation surfactants resulting in a potential complexing in acid media, multicenter interaction of polydentate ligands both via chelating groups and auxochrome groups in the presence of cation surfactants. Protolytic and flotation properties of ionic associates are considered. The observed effects are explained from the viewpoint of electrostatic and hydrophobic interactions in the R-surfactant systems, observed by the methods of NMR, polarography amperometry, conductometry. A possible use of the investigated M-R-surfactant systems as complexonometric indicators was evaluated. A possibility was shown of using them for direct titrimetric determination of hundredth milligram portions of Cu, Ga, In and Sc at a titrant concentratjon of less than 0.01 M. It follows from the estimation of basic optical parameters of the Me-R-surfactant systems that detection.

  1. Study of Sr sup 2+ and Eu sup 2+ complexing with 18-crown-6 in aqueous-ethanolic solutions. Izuchenie kompleksoobrazovaniya Sr sup 2+ i Eu sup 2+ s 18-kraun-6 v vodno-ehtanol'nykh rastvorakh

    Energy Technology Data Exchange (ETDEWEB)

    Kulyukhin, S A; Majorov, A V; Kamenskaya, A N; Mikheev, N B

    1989-01-01

    Using cocrystallization and conductometry methods Sr{sup 2+} and Eu{sup 2+} complexing with 18-crown-6 in aqueous-ethanolic solutions at (H{sub 2}O)=10 mol/l is studied. Stability constants of Sr{sup 2+} and Eu{sup 2+} complexes with 18-crown-6 in C{sub 2}H{sub 5}OH, for which lg{beta} is equal to (4.76{plus minus}0.12) and (4.72{plus minus}0.13) respectively, are determined. Comparison of the investigated elements features during complexing with 18-crown-6 in aqueous and aqueous-ethanolic solutions is carried out. It is shown that both in water and in C{sub 2}H{sub 5}OH -10 mol/l H{sub 2}O system under Sr{sup 2+} and Eu{sup 2+} complexing with 18-crown-6 the differences in properties of these elements are not detected.

  2. Investigation of complexing in solutions of salt mixture In(NO3)3-NaVO3

    International Nuclear Information System (INIS)

    Nakhodnova, A.N.; Listratenko, I.V.

    1987-01-01

    Spectrophotometry, conductometry and pH-metry are used to investigate properties and composition of the solid phases of isomolar series of In(NO 3 ) 3 -NaVO 3 salt mixture solutions and series of solutions having constant concentration of one of the components and varied of the other. Results of investigation are presented. It is stated that in the investigated solution series in weakly acid media HPA with the ratios [In 3+ ]:[V 5+ ] being equal to 11:1, 6:1, and 1:9, are formed. Composition of the complexes is mainly defined by the ratio of the components in In(NO 3 ) 3 and NaVO 3 salt mixture solutions and the medium acidity. Compounds of Na 2 OxIn 2 O 3 x2.5V 2 O 5 x8.5H 2 O and Cs 2 OxIn 2 O 3 x6V 2 O 5 x6.5H 2 O empirical formulae are separated. Results of IR spectroscopy, derivatography and X-ray phase analysis of the corresponding salts are presented

  3. Investigation into complexing in Re/sup 7/-H/sub 3/O/sup +/-SO/sub 4//sup 2 -/-H/sub 2/O system

    Energy Technology Data Exchange (ETDEWEB)

    Sinyakova, G S [AN Latvijskoj SSR, Riga. Inst. Neorganicheskoj Khimii

    1979-10-01

    Using the methods of spectrophotometry and conductometry it is shown, that in the ReO/sub 4//sup -/-H/sub 3/O/sup +/-SO/sub 4//sup 2 -/-H/sub 2/O system interaction between rhenium (7) and sulfuric acid takes place in a wide concentration range. In low-acid solutions at pH 2.0-0.9 rhenium(7) complex with proton is formed at the ratio of 1:1 with lgK/sub 1/=3.30+-0.02. In 1-10 mol. sulfuric acid observed is consecutive complexing at the rhenium(7) - sulfuric acid ratio in the complex of 1:1 and 1:2 respectively with lgK/sub 2/=0.93+-0.13 and lgK/sub 3/=0.34+-0.03. At the background of concentrated perchloric acid rhenium (7) and sodium sulfate form two complex compounds at rhenium (7) - sodium sulfate ratio of 1:1 and 1:2 with lgK/sub 1/=1.86+-0.02 and lgK/sub 2/=2.35+-0.03.

  4. Novel Zinc(II Complexes [Zn(atc-Et2] and [Zn(atc-Ph2]: In Vitro and in Vivo Antiproliferative Studies

    Directory of Open Access Journals (Sweden)

    Erica de O. Lopes

    2016-05-01

    Full Text Available Cisplatin and its derivatives are the main metallodrugs used in cancer therapy. However, low selectivity, toxicity and drug resistance are associated with their use. The zinc(II (ZnII thiosemicarbazone complexes [Zn(atc-Et2] (1 and [Zn(atc-Ph2] (2 (atc-R: monovalent anion of 2-acetylpyridine N4-R-thiosemicarbazone were synthesized and fully characterized in the solid state and in solution via elemental analysis, Fourier transform infrared (FTIR, ultraviolet-visible (UV-Vis and proton nuclear magnetic resonance (1H NMR spectroscopy, conductometry and single-crystal X-ray diffraction. The cytotoxicity of these complexes was evaluated in the HepG2, HeLa, MDA-MB-231, K-562, DU 145 and MRC-5 cancer cell lines. The strongest antiproliferative results were observed in MDA-MB-231 and HepG2 cells, in which these complexes displayed significant selective toxicity (3.1 and 3.6, respectively compared with their effects on normal MRC-5 cells. In vivo studies were performed using an alternative model (Artemia salina L. to assure the safety of these complexes, and the results were confirmed using a conventional model (BALB/c mice. Finally, tests of oral bioavailability showed maximum plasma concentrations of 3029.50 µg/L and 1191.95 µg/L for complexes 1 and 2, respectively. According to all obtained results, both compounds could be considered as prospective antiproliferative agents that warrant further research.

  5. Investigation into complexing in Re7-H3O+-SO42--H2O system

    International Nuclear Information System (INIS)

    Sinyakova, G.S.

    1979-01-01

    Using the methods of spectrophotometry and conductometry it is shown, that in the ReO 4 - -H 3 O + -SO 4 2- -H 2 O system interaction between rhenium (7) and sulfuric acid takes place in a wide concentration range. In low-acid solutions at pH 2.0-0.9 rhenium(7) complex with proton is formed at the ratio of 1:1 with lgK 1 =3.30+-0.02. In 1-10 mol. sulfuric acid observed is consecutive complexing at the rhenium(7) - sulfuric acid ratio in the complex of 1:1 and 1:2 respectively with lgK 2 =0.93+-0.13 and lgK 3 =0.34+-0.03. At the background of concentrated perchloric acid rhenium (7) and sodium sulfate form two complex compounds at rhenium (7) - sodium sulfate ratio of 1:1 and 1:2 with lgK 1 =1.86+-0.02 and lgK 2 =2.35+-0.03

  6. Analisis dan Pemanfaatan Unsur Belerang dan Salinitas Lumpur Bledug Kuwu di Desa Kuwu, Kecamatan Kradenan, Kabupaten Grobongan, Jawa Tengah

    Directory of Open Access Journals (Sweden)

    Sepridawati Siregar

    2016-05-01

    Full Text Available This study was conducted to determine the levels of elemental sulfur and salinity of the mud Bledug Kuwu. The research area has a subsurface lithology bedding rock mud, sand stone and rocks submerged in saltwater, brackish water and sea water. Bledug Kuwu is a phenomenon of volcanic mud. Around Kuwu found several indications of an ancient sea that connect up to the east, that is to Cepu and westward to the region Boja and Cirebon. Judging from geological formations, estimated Kuwu to Cepu was once the sea. The ancient sea stretching from Bledug Kuwu region to the southwest that is to Sangiran and also to Boyolali. Bledug Kuwu mud has a high sulfur and salt contents, evidenced from the results of laboratory analysis where the average concentration of sulfur 62,883 x102 mg/Kg with UV-vis spectrophotometry method and the average of salinity 57,15 mg/L by the Conductometry method. From the analysis, Bledug Kuwu mud can be used for tourism and an additional income for the local community. the mud of Bledug kuwu has high content of sulfur can be used as a treatment especially for skin diseases and salinity can be used for making salt.

  7. Radiolysis of uracil in oxygenated aqueous solutions. A study by product analysis and pulse radiolysis. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schuchnmann, M N; Sonntag, C von [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany, F.R.). Inst. fuer Strahlenchemie

    1983-10-01

    Hydroxyl radicals are generated by the radiolysis of N/sub 2/O-O/sub 2/ (4:1 v/v)-saturated aqueous solutions of uracil. They add to the 5,6-double bond of the substrate. These radicals are converted by oxygen into the corresponding peroxyl radicals (I) and (II), respectively. Peroxyl radical (I) undergoes a base-induced O/sub 2//sup -/ elimination. As an intermediate 5-hydroxyisopyrimidine is formed which rearranges into isobarbituric acid and adds water forming 5,6-dihydro-5,6-dihydroxyuracil. Competing with this base-induced reaction of radical (I) there is a bimolecular decay of radicals (I) and (II). These processes become predominant at low pH. For this reason a strong pH dependence of G (products) is observed. The major products are (G values at pH 3 and 10 in parentheses) 5,6-dihydroxy-5,6-dihydrouracil (1.1; 2.4), isobarbituric acid (0; 1.2), N-formyl-5-hydroxyhydantoin (1.6; 0.2), 5-hydroxybarbituric acid (0.9; 0.2). 5-Hydroxybarbituric acid is formed in its keto form. Its deprotonation has been followed by pulse conductometry. Details of the reaction mechanism, e.g. the involvement of oxyl radicals in the bimolecular decay of (I) and (II), are discussed.

  8. Chemistry of ice: Migration of ions and gases by directional freezing of water

    Directory of Open Access Journals (Sweden)

    Umer Shafique

    2016-09-01

    Full Text Available Redistribution of anions and cations creates an electrical imbalance in ice grown from electrolyte solutions. Movement of acidic and basic ions in cooling solutions can permanently change the pH of frozen and unfrozen parts of the system, largely. The extent of pH change associated with freezing is determined by solute concentration and the extent of cooling. In the present work, redistribution of hydrogen, hydroxyl, carbonate, and bicarbonate ions was studied during directional freezing in batch aqueous systems. Controlled freezing was employed vertically as well as radially in acidic and basic solutions. In each case, the ions substantially migrated along with moving freezing front. Conductometry and pH-metry were employed to monitor the moving ions. Besides, some other experiments were carried out with molecular gases, such as oxygen, carbon dioxide, and chlorine and an azeotropic mixture like water–ethanol. Findings can be used to understand possible changes that can occur in preserving materials by freezing.

  9. Effects of surfactant micelles on viscosity and conductivity of poly(ethylene glycol) solutions

    Science.gov (United States)

    Wang, Shun-Cheng; Wei, Tzu-Chien; Chen, Wun-Bin; Tsao, Heng-Kwong

    2004-03-01

    The neutral polymer-micelle interaction is investigated for various surfactants by viscometry and electrical conductometry. In order to exclude the well-known necklace scenario, we consider aqueous solutions of low molecular weight poly(ethylene glycol) (2-20)×103, whose radial size is comparable to or smaller than micelles. The single-tail surfactants consist of anionic, cationic, and nonionic head groups. It is found that the viscosity of the polymer solution may be increased several times by micelles if weak attraction between a polymer segment and a surfactant exists, ɛ

  10. Synthesis, characterization and thermal study of some transition metal complexes of an asymmetrical tetradentate Schiff base ligand

    Directory of Open Access Journals (Sweden)

    ACHUT S. MUNDE

    2010-03-01

    Full Text Available Complexes of Cu(II, Ni(II, Co(II, Mn(II and Fe(III with an asymmetric tetradentate Schiff base ligand derived from dehydroacetic acid, 4-methyl-o-phenylenediamine and salicylic aldehyde were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV–Vis, IR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a dibasic tetadentate ligand towards the central metal ion with an ONNO donor atoms sequence. From the microanalytical data, the stoichiometry of the complexes 1:1 (metal:ligand was found. The physico-chemical data suggested square planar geometry for the Cu(II and Ni(II complexes and octahedral geometry for the Co(II, Mn(II and Fe(III complexes. The thermal behaviour (TGA/DTA of the complexes was studied and kinetic parameters were determined by Horowitz–Metzger and Coats–Redfern methods. The powder X-ray diffraction data suggested a monoclinic crystal system for the Co(II, Mn(II and Fe(III complexes. The ligand and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli and fungicidal activity against Aspergillus niger and Trichoderma viride.

  11. Double tungstates of metals of scandium and ammonium subgroups

    Energy Technology Data Exchange (ETDEWEB)

    Maksin, V I [AN Ukrainskoj SSR, Kiev. Inst. Kolloidnoj Khimii i Khimii Vody

    1980-06-01

    The methods of pH-potentiometry, conductometry, determination of residual concentrations of liquid phases and precipitations, selected by chemical analysis have been used for investigation R(NO/sub 3/)/sub 3/-(NH/sub 4/)/sub 2/WO/sub 2/-H/sub 2/O systems, (where R=Sc, Y, La). The formation of double tungstates NH/sub 4/R(WO/sub 4/)/sub 2/xnH/sub 2/O is established. The NH/sub 4/Sc(WO/sub 4/)/sub 2/x4.5H/sub 2/O, NH/sub 4/Yx(WO/sub 4/)/sub 2/x3H/sub 2/O, NH/sub 4/La(WO/sub 4/)/sub 2/x1.5H/sub 2/O compounds are synthesized in individual form. Precipitation conditions (pH, concentration ratio) and composition of the solid phase are determined. The behaviour of synthesized slats at thermolysis up to 880 deg C is studied. Physicochemical properties (color, solubility of the simple and double tungstates of scandium, yttrium and lanthanum with ammonium) is studied. IR spectra and X-ray diffraction analysis give idea about double salts structural transformations.

  12. Synthesis, crystal structure, fluorescence and electrochemical studies of a new tridentate Schiff base ligand and its nickel(II) and palladium(II) complexes

    Science.gov (United States)

    Shafaatian, Bita; Soleymanpour, Ahmad; Kholghi Oskouei, Nasim; Notash, Behrouz; Rezvani, Seyyed Ahmad

    2014-07-01

    A new unsymmetrical tridentate Schiff base ligand was derived from the 1:1 M condensation of ortho-vanillin with 2-mercaptoethylamine. Nickel and palladium complexes were obtained by the reaction of the tridentate Schiff base ligand with nickel(II) acetate tetrahydrate and palladium(II) acetate in 2:1 M ratio. In nickel and palladium complexes the ligand was coordinated to metals via the imine N and enolic O atoms. The S groups of Schiff bases were not coordinated to the metals and S-S coupling was occured. The complexes have been found to possess 1:2 Metal:Ligand stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The complexes exhibited octahedral coordination geometry. The emission spectra of the ligand and its complexes were studied in methanol. Electrochemical properties of the ligand and its metal complexes were investigated in the CH3CN solvent at the 100 mV s-1 scan rate. The ligand and metal complexes showed both reversible and quasi-reversible processes at this scan rate. The Schiff base and its complexes have been characterized by IR, 1H NMR, UV/Vis, elemental analyses and conductometry. The crystal structure of nickel complex has been determined by single crystal X-ray diffraction.

  13. Process measuring techniques applying in-line and on-line analyzers. Betriebsmesstechnik unter Einsatz von in-line und on-line Analysatoren

    Energy Technology Data Exchange (ETDEWEB)

    Oehme, F; Jola, M

    1982-01-01

    The measurement and control of classical physical parameters such as pressure, temperature etc, is frequently not sufficient now for optimum process control in chemistry and associated fields. Only the use of inline and online analysers makes it possible to maintain the narrow limits of chemical reaction conditions. This ABC pocket book should help the user to select the best from the large number of available methods of measurement. Using 120 alphabetically arranged key words with many cross-references, it has a well-thought-out treatment of basic measurements and descriptions of apparatus, and on the other hand, it contains selected typical examples of applications. Width rather than depth of information is aimed at. The electrochemical methods discussed are potentiometry (pH value, redox potential, direct potentiometry with ion selective electrodes), conductometry (measurement of conductivity) and voltammetry (polarography, ammetry). Photometry, the measurement of density, the refractive index, surface tension and viscosity are described. From the large number of applications, the examples of textile processing, the cellulose and paper industry, the surface treatment of materials and petrochemicals are discussed. Special attention is paid to the treatment of service water, drinking water and boiler feed water. In connection with questions of work and environmental protection, emission control and the treatment of domestic and industrial waste water are described. With 119 figs.

  14. Study of complex formation of 5,5'-(2 E, 2' E)-2,2'-(ethane-1,2-diylidene)bis(hydrazine-1-yl-2-ylidene)bis(4-amino-4H-1,2,4-triazole-3-thiol) (HYT) macrocyclic ligand with Cd2+ cation in non-aqueous solution by spectroscopic and conductometric methods

    Science.gov (United States)

    Mallaekeh, Hassan; Shams, Alireza; Shaker, Mohammad; Bahramzadeh, Ehsan; Arefi, Donya

    2014-12-01

    In this paper the complexation reaction of the 5,5'-(2 E,2' E)-2,2'-(ethane-1,2-diylidene)bis(hydrazine-1-yl-2-ylidene)bis(4-amino-4H-1,2,4-triazole-3-thiol) ligand (HYT) with Cd2+ education was studied in some binary mixtures of methanol (MeOH), n-propanol (PrOH) and dimethyl-formamide (DMF) at different temperatures using the conductometry and spectrophotometry. The stability constants of the complex was determined using a GENPLOT computer program. The conductance data and absorbance-mole ratio plots show that in all solvent systems, the stoichiometry of the complex formed between (HYT) and Cd2+ cation is 1: 1. The obtained results show that the stability of (HYT)-Cd complex is sensitive to the mixed solvents composition. The values of thermodynamic parameters (Δ G ∘, Δ H ∘, and Δ S ∘) for formation of (HYT)-Cd complex were obtained from temperature dependence of the stability constant using the van't Hoff plots. The results show that in most cases, the complex are enthalpy destabilized but entropy stabilized and the complex formation is affected by pH, time, temperature and the nature of the solvent.

  15. The Role of Concentration and Solvent Character in the Molecular Organization of Humic Acids

    Directory of Open Access Journals (Sweden)

    Martina Klučáková

    2016-10-01

    Full Text Available The molecular organization of humic acids in different aqueous solutions was studied over a wide concentration range (0.01–10 g·dm−3. Solutions of humic acids were prepared in three different media: NaOH, NaCl, and NaOH neutralized by HCl after dissolution of the humic sample. Potentiometry, conductometry, densitometry, and high resolution ultrasound spectrometry were used in order to investigate conformational changes in the humic systems. The molecular organization of humic acids in the studied systems could be divided into three concentration ranges. The rearrangements were observed at concentrations of ~0.02 g·dm−3 and ~1 g·dm−3. The first “switch-over point” was connected with changes in the hydration shells of humic particles resulting in changes in their elasticity. The compressibility of water in the hydration shells is less than the compressibility of bulk water. The transfer of hydration water into bulk water increased the total compressibility of the solution, reducing the ultrasonic velocity. The aggregation of humic particles and the formation of rigid structures in systems with concentrations higher than 1 g·dm−3 was detected.

  16. Synthesis, spectral, thermal and biological studies of transition metal complexes of 4-hydroxy-3-[3-(4-hydroxyphenyl-acryloyl]-6-methyl-2H-pyran-2-one

    Directory of Open Access Journals (Sweden)

    BALASAHEB R. ARBAD

    2011-09-01

    Full Text Available The solid complexes of Mn(II, Fe(III, Co(II, Ni(II, and Cu(II with 4-hydroxy-3-[(2E-3-(4-hydroxyphenylprop-2-enoyl]-6-methyl-2H-pyran-2-one, derived from 3-acetyl-6-methyl-2H-pyran-2,4(3H-dione (dehydroacetic acid and 4-hydroxybenzaldehyde, were synthesized and characterized by elemental analysis, conductometry, thermal analysis, magnetic measurements, IR, 1H-NMR and UV–Vis spectroscopy and a biological study. From the analytical and spectral data, the stoichiometry of the complexes was found to be 1:2 (metal:ligand. The physico–chemical data suggest a distorted octahedral geometry for the Cu(II complexes and an octahedral geometry for all the other complexes. The thermal decomposition of all the complexes was studied by the TG–DTA method. The synthesized ligand and its metal complexes were screened for their in vitro antibacterial activity against Gram-negative (Escherichia coli and Gram-positive (Staphylococcus aureus bacterial strains and for in vitro antifungal activity against Aspergillus flavus, Curvularia lunata and Penicillium notatum. The results of these studies showed the metal complexes to be more antibacterial/antifungal against one or more species as compared with the non-complexed ligand.

  17. Internal electric fields of electrolytic solutions induced by space-charge polarization

    Science.gov (United States)

    Sawada, Atsushi

    2006-10-01

    The dielectric dispersion of electrolytic solutions prepared using chlorobenzene as a solvent and tetrabutylammonium tetraphenylborate as a solute is analyzed in terms of space-charge polarization in order to derive the ionic constants, and the Stokes radius obtained is discussed in comparison with the values that have been measured by conductometry. A homogeneous internal electric field is assumed for simplicity in the analysis of the space-charge polarization. The justification of the approximation by the homogeneous field is discussed from two points of view: one is the accuracy of the Stokes radius value observed and the other is the effect of bound charges on electrodes in which they level the highly inhomogeneous field, which has been believed in the past. In order to investigate the actual electric field, numerical calculations based on the Poisson equation are carried out by considering the influence of the bound charges. The variation of the number of bound charges with time is clarified by determining the relaxation function of the dielectric constant attributed to the space-charge polarization. Finally, a technique based on a two-field approximation, where homogeneous and hyperbolic fields are independently applied in relevant frequency ranges, is introduced to analyze the space-charge polarization of the electrolytic solutions, and further improvement of the accuracy in the determination of the Stokes radius is achieved.

  18. Kinetics on the reaction of substituted quinolines and p-substituted benzoylchlorides under various pressures

    International Nuclear Information System (INIS)

    Kim, Young Cheul; Lim, Jong Wan; Choi, Sung Yong; Kim, Se Kyong

    1999-01-01

    The reaction rates of substituted quinolines(6-CH 3 C 9 H 7 N, C 9 H 7 N) with p-substituted benzoylchlorides(p-CH 3 , p-H, p-NO 2 ) have been measured by conductometry in acetonitrile, and the rate constants are determined at various temperatures (10,15, 20, 25 .deg. C) and pressures(1, 200, 500, 1000bar). From the values of rate constants, the activation parameters(Ea, ΔV ≠ , ΔS ≠ , and ΔG ≠ ) and the pressure dependence of Hammett ρ values were determined. The rate constants increase as a function of temperatures and pressures, and are further increase by introduction the electron donor substituents in nucleophile(p-CH 3 ) or electron acceptor(p-NO 2 ) substituents in substrate. The activation volume, and the activation entropy are all negative. Hammett ρ values are also negative for nucleophile (ρ X ) and positive for the substrate (ρ Y ) over the pressure range studied. The results of kinetic studies for pressure and substituent show that these reactions proceed in typical S N 2 reaction mechanism and 'associative S N 2' in which bond formation favored with increasing pressures

  19. Investigation into isomolar series of Al(NO3)3, Na3VO4 solution mixture and composition of solid phases

    International Nuclear Information System (INIS)

    Chernysh, L.F.; Nakhodnova, A.P.; Makarova, R.A.

    1979-01-01

    Conducted is investigation of properties of isomolar series of aluminium nitrate and sodiUm vanadate solutions at pH of the latter 12.5; 10.0; 7.0 and the temperature of 25 deg C using the methods of pH-metry, conductometry, ''seeming'' volume of precipitations, residual concentration of aluminium and vanadium. It is shown, that the composition property diagram of the system investigated does not reflect the true composition of solid-phase products of the reaction, which depends on the component ratio in solution. Bottom phases of isomolar series are mainly heterogeneous. At the excess of sodium vanadate solution and its high pH values conditions for the basic salt formation are created. At pH of the Na 3 VO 4 solution of 12.5 and 10.0 and Al(NO 3 ) 3 : Na 3 VO 4 ratios 4:6 and 3:7 respectively obtained are the basic aluminium vanadates of the (AlOH) 3 (VO 4 ) 2 x 7.5H 2 O and (AlOH) 2 V 2 O 7 x5H 2 O composition, some of their physicochemical properties being investigated

  20. Thermodynamic Study of the Complexation of p-Isopropylcalix[6]arene with Cs+ Cation in Dimethylsulfoxide-Acetonitrile Binary Media

    Directory of Open Access Journals (Sweden)

    Gholam Hossein Rounaghi

    2011-09-01

    Full Text Available The complexation reactions between the macrocyclic ionophore, p-isopropylcalix[6]arene and Cs+ cation were studied in dimethylsulfoxide–acetonitrile (DMSO-AN binary non-aqueous solvents at different temperatures using a conductometry method. The conductance data show that the stoichiometry of the (p-isopropylcalix[6]-arene·Cs+ complex in all binary mixed solvents is 1:1. The stability of the complexes is affected by the composition of the binary solvent media and a non-linear behavior was observed for changes of log Kf of the complex versus the composition of the binary mixed solvents. The thermodynamic parameters (DH°c and DS°c for formation of (p-isopropyl-calix[6]arene·Cs+ complex were obtained from temperature dependence of the stability constant and the obtained results show that the (p-isopropylcalix[6]arene·Cs+ complex is enthalpy destabilized, but entropy stabilized, and the values of the mentioned parameters are affected strongly by the nature and composition of the binary mixed solvents.

  1. Synthesis, characterization, spectroscopic and theoretical studies of new zinc(II), copper(II) and nickel(II) complexes based on imine ligand containing 2-aminothiophenol moiety

    Science.gov (United States)

    Shafaatian, Bita; Mousavi, S. Sedighe; Afshari, Sadegh

    2016-11-01

    New dimer complexes of zinc(II), copper(II) and nickel(II) were synthesized using the Schiff base ligand which was formed by the condensation of 2-aminothiophenol and 2-hydroxy-5-methyl benzaldehyde. This tridentate Schiff base ligand was coordinated to the metal ions through the NSO donor atoms. In order to prevent the oxidation of the thiole group during the formation of Schiff base and its complexes, all of the reactions were carried out under an inert atmosphere of argon. The X-ray structure of the Schiff base ligand showed that in the crystalline form the SH groups were oxidized to produce a disulfide Schiff base as a new double Schiff base ligand. The molar conductivity values of the complexes in dichloromethane implied the presence of non-electrolyte species. The fluorescence properties of the Schiff base ligand and its complexes were also studied in dichloromethane. The products were characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis, and conductometry. The crystal structure of the double Schiff base was determined by single crystal X-ray diffraction. Furthermore, the density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d,p) level of theory for the determination of the optimized structures of Schiff base complexes.

  2. Identification of solution products of lanthanoid (3) diethyldithiocarbamatohexamethyl phosphotriamide compounds from IR, electron and sup 1 H, sup 13 C, sup 31 P NMR absorption spectra. Identifikatsiya produktov rastvoreniya diehtilditiokarbamatogeksametil fosfotriamidnykh soedinenij lantanoidov (3) po IK, ehlektronnym i YaMR sup 1 H, sup 13 C, sup 31 P spektram pogloshcheniya

    Energy Technology Data Exchange (ETDEWEB)

    Skopenko, V V; Savost' yanova, A F; Trachevskij, V V; Gorbalyuk, A D; Sukhan, T A [Kievskij Gosudarstvennyj Univ., Kiev (Ukrainian SSR)

    1991-01-01

    By the methods of conductometry, IR, electron and {sup 1}H, {sup 13}C, {sup 31}P NMR spectroscopy nonaqueous solutions of the compounds (La(S{sub 2}CNEt{sub 2})Hmpa{sub 5})(BPh{sub 4}){sub 2}, Hmpa=OP(NMe{sub 2}){sub 3}; (Ln(S{sub 2}CNEt{sub 2}){sub 2}Hmpa{sub 3})BPh{sub 4}, Ln=Y, La-Lu; (Ln(S{sub 2}CNEt{sub 2}){sub 3}Hmpa{sub 2}), Ln=La-Gd, have been investigated. It is ascertained that bis-dithiocarbamate compounds are dissolved in all the studied solvents with preservation of composition and structure of lanthanide (3) inner coordination sphere. Tris-dithiocarbamates in nonaqueous solutions are subjected to reactions of ligand redistribution according to schemes depending on the solvent nature. In the process of dissolving of lanthanum monodithiocarbamate bond isomerization of dithiocarbamate groups occurs, which is pronounced in splitting of {sup 1}H and {sup 13}C NMR signals.

  3. Simultaneous and rapid determination of caffeine and taurine in energy drinks by MEKC in a short capillary with dual contactless conductivity/photometry detection.

    Science.gov (United States)

    Vochyánová, Blanka; Opekar, František; Tůma, Petr

    2014-06-01

    A method has been developed for the simultaneous determination of taurine and caffeine using a laboratory-made instrument enabling separation analysis in a short 10.5 cm capillary. The substances are detected using a contactless conductometry/ultraviolet (UV) photometry detector that enables recording both signals at one place in the capillary. The separation of caffeine and taurine was performed using the MEKC technique in a BGE with the composition 40 mM CHES, 15 mM NaOH, and 50 mM SDS, pH 9.36. Under these conditions, the migration time of caffeine is 43 s and of taurine 60 s; LOD for caffeine is 4 mg/L using photometric detection and LOD for taurine is 24 mg/L using contactless conductometric detection. The standard addition method was used for determination in Red Bull energy drink of caffeine 317 mg/L and taurine 3860 mg/L; the contents in Kamikaze drink were 468 mg/L caffeine and 4110 mg/L taurine. The determined values are in good agreement with the declared contents of these substances. RSD does not exceed 3%. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Influence of packaging and conditions of storaging on content of mineral water Guber-Srebrenica

    Directory of Open Access Journals (Sweden)

    Blagojević Dragana D.

    2008-01-01

    Full Text Available Mineral waters are found in nature in greater depths most often in reduction conditions, so after surfacing their content alters in contact with oxygen, which is caused by oxidation of certain components. Due to this, efforts were made to make these waters more stabile so they could be used after certain time. This work monitors the stability of Guber (Argentaria-Srebrenica water exposed to light and with addition of ascorbic acid. The methods of analysis and the parameters analyzed are: gravimetric (SO2-4, suspended solids, total dry residue at 180°C, conductometry (electric conductivity, volumetric (Al3+, spectrometric (SiO2 and atomic-absorption spectrophotometry (Fe2+, Mg2+, Mn2+, Zn2+, K+, Ca2+, Na+ i Cu2+. Obtained results of water analysis, after retaining water in PET (polyethylentereftalate and glass bottles, in certain time intervals, show that significant changes of concentration of Fe2+, Al3+, K+, Ca2+, pH value and electric conductivity occurred. Concentration of iron Fe2+ has been slightly changed after 120 days, in sample stabilized with 0,2 g ascorbic acid, while concentrations of Al and K+ were changing the same as without adding of stabilizer. Samples of water in glass packaging without added stabilizer are less stable compared to samples which were retained in PET packaging.

  5. Determination by Small-angle X-ray Scattering of Pore Size Distribution in Nanoporous Track-etched Polycarbonate Membranes

    Science.gov (United States)

    Jonas, A. M.; Legras, R.; Ferain, E.

    1998-03-01

    Nanoporous track-etched membranes with narrow pore size distributions and average pore size diameters tunable from 100 to 1000 Åare produced by the chemical etching of latent tracks in polymer films after irradiation by a beam of accelerated heavy ions. Nanoporous membranes are used for highly demanding filtration purposes, or as templates to obtain metallic or polymeric nanowires (L. Piraux et al., Nucl. Instr. Meth. Phys. Res. 1997, B131, 357). Such applications call for developments in nanopore size characterization techniques. In this respect, we report on the characterization by small-angle X-ray scattering (SAXS) of nanopore size distribution (nPSD) in polycarbonate track-etched membranes. The obtention of nPSD requires inverting an ill-conditioned inhomogeneous equation. We present different numerical routes to overcome the amplification of experimental errors in the resulting solutions, including a regularization technique allowing to obtain the nPSD without a priori knowledge of its shape. The effect of deviations from cylindrical pore shape on the resulting distributions are analyzed. Finally, SAXS results are compared to results obtained by electron microscopy and conductometry.

  6. Conductance Studies on Complex Formation between c-Methylcalix[4]resorcinarene and Titanium (III in Acetonitrile-H2O Binary Solutions

    Directory of Open Access Journals (Sweden)

    Naghmeh Saadati

    2013-09-01

    Full Text Available Calixresorcinarenes have proved to be unique molecules for molecular recognition via hydrogen bonding, hydrophobic and ionic interactions with suitable substrates such as cations. The study of the interactions involved in the complexation of different cations with calixresorcinarenes in solvent mixtures is important for a better understanding of the mechanism of biological transport, molecular recognition, and other analytical applications. This article summarizes different aspects of the complexes of the Ti3+ metal cation with c-methylcalix[4]resorcinarene (CMCR as studied by conductometry in acetonitrile (AN–water (H2O binary mixtures at different temperatures. Conductance data show that the metal cation/ligand (ML stoichiometry of the complexes in solution is 1:1 in all cases. Non-linear behaviour was observed for the variation of logKf of the complexes vs. the composition of the binary solvent mixtures. Selectivity of CMCR for the Ti3+ cation is sensitive to solvent composition; in some cases and at certain compositions of the mixed solvent systems, the selectivity order is changed. Values of thermodynamic parameters (, for formation of the CMCR–Ti3+ complexes in AN–H2O binary systems were obtained from the temperature dependence of stability constants, and the results show that the thermodynamics of complexation reactions are affected by the nature and composition of the mixed solvents.

  7. Frequency-dependent electrodeformation of giant phospholipid vesicles in AC electric field

    Science.gov (United States)

    2010-01-01

    A model of vesicle electrodeformation is described which obtains a parametrized vesicle shape by minimizing the sum of the membrane bending energy and the energy due to the electric field. Both the vesicle membrane and the aqueous media inside and outside the vesicle are treated as leaky dielectrics, and the vesicle itself is modeled as a nearly spherical shape enclosed within a thin membrane. It is demonstrated (a) that the model achieves a good quantitative agreement with the experimentally determined prolate-to-oblate transition frequencies in the kilohertz range and (b) that the model can explain a phase diagram of shapes of giant phospholipid vesicles with respect to two parameters: the frequency of the applied alternating current electric field and the ratio of the electrical conductivities of the aqueous media inside and outside the vesicle, explored in a recent paper (S. Aranda et al., Biophys J 95:L19–L21, 2008). A possible use of the frequency-dependent shape transitions of phospholipid vesicles in conductometry of microliter samples is discussed. PMID:21886342

  8. Integration and enhancement of low-level signals from air-pollution monitoring sensors

    Energy Technology Data Exchange (ETDEWEB)

    Dowd, G F; Dubois, L; Monkman, J L

    1975-09-01

    In this paper, we have demonstrated how signal enhancement techniques would be advantageous in the low-level analysis of air pollutants. We have further shown what type of signal-to-noise gain may be expected from an off-the-shelf, inexpensive run-of-the-mill mercury monitor. As long as an evoked response time constant is introduced into the measuring system, noise of a random nature may be reduced to such an extent that trace signals, buried deep in the electrical background, may be reliably measured. If we couple this type of analysis to a multi-parameter mercury analyzer, contributing factors may be evaluated. This will result in a more efficient system application. We have also reported a manner in which evoked response time is related to instrument onset time. However, there are other methods for obtaining an evoked response. Of note is the use of wavelength in the enhancement of spectrophotometric signals. In additional work now being carried out in our laboratory, there are indications that it is possible to relate this type of processing to SO/sub 2/ analyzing systems using conductometry. (auth)

  9. Kinetics on the reaction of 6-chloroquinoline and p-substituted benzoylchlorides under high pressures

    International Nuclear Information System (INIS)

    Kim, Eung Ryul; Lim, Jong Wan; Kim, Se Kyong; Ko, Young Shin

    2002-01-01

    The reactions rates of substituted 6-chloroquinoline, with p-substituted benzoyichlorides (p-CH 3 , p-H, p-NO 2 ) have been measured by conductometry in acetonitrile, and the rate constants are determined at various temperatures (10,15,20,25 .deg. C) and pressures (1, 200, 500, 1000 bar). From the values of rate constants, the activation parameters (Ea, ΔV ≠ , ΔH ≠ , ΔS ≠ , and ΔG ≠ ) and the pressure dependence of Hammett ρ values were determined. The rate constants increased with increasing temperatures and pressures, and are further increased to introduction to the electron donor substituents in substrate (p-NO 2 ) with 6-chloroquinoline. When, the activation volume and the activation entropy are all negative. And the Hammett ρ values are positive for the substrate over the pressure and temperature range studied. The results of kinetic studies for pressure and substituent show that thease reactions proceed in typical S N 2 reaction mechanism and 'associative S N 2' in bond formation favored with increasing pressures

  10. New complexes of silver (I) with N-hydroxy-succinimide

    Science.gov (United States)

    Sibiescu, Doina; Mîţǎ, Carmen; Vizitiu, Mihaela; Crudu, Andra Manuela

    2016-12-01

    Over the last period of time silver was considerably studied due to its lower resistivity. In the field of materials science, silver was used in applications such as: microelectronics components of high - temperature superconductiviting materials, bactericidal coatings and others domains. This study presents the process of obtaining and characterization the new complexes of silver (I) with Nhydroxy- succinimide. In the process of obtaining the new complex compounds in aqous solution, first we have to look at conductometry and UV-Vis absorbtion spectroscopy in order to determine the molar ratio silver : N-hydroxysuccinimide and the stability constants. The obtained solid coordination compounds were characterized by elemental analysis, IR spectroscopy and also was investigated of their thermostability. The X-ray powder diffraction reflects that the complexes compounds of silver (I) with N-hydroxysuccinimide are amorphous. In our further studies we want to determine if the new synthetized compounds will present the same or improuved properties as in the above mentioned silver characteristics.

  11. Behaviors of nitrato complexes of nitrosylruthenium in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, S [Radia Industry Co. Ltd., Takasaki (Japan)

    1979-11-01

    Nitrato nitrosylruthenium complexes (RuNO(NO/sub 3/)sub(x)(H/sub 2/O)sub(5-x))sup((3-x)+) readily dissociate in aqueous solutions with decrease in pH and increase in electrical conductivity of the solutions. This study aimed to elucidate the behaviours of dissociation of the complexes with time. The change in the amount of undissociated complexes was determined with time. The results indicated that the dissociation was a multi-order reaction involving both protolysis and hydrolysis. The protolysis completed in relatively short period within (several tens of minutes), but it depended on the concentration of the complexes in the solution. The completion of the protolysis and the formation of the resulting dissociation products were observed by absorption spectrometry. The dissociation products, which were assumed as aquohydroxy complexes, underwent the successive step-wise dissociation for a prolonged period as revealed by pH measurements. The rate constants involved in the step-wise dissociation, process were obtained. The degree of dissociation and dissociation constant of the complexes were measured by conductometry.

  12. Some aspects of surfactant action mechanism in the organic reagents - metal ions systems

    International Nuclear Information System (INIS)

    Chernova, R.K.; Shtykov, S.N.; Beloliptseva, G.M.; Sukhova, L.K.; Amelin, V.G.; Kulapina, E.G.

    1984-01-01

    Results are reviewed of investigations into the interaction of ions of Mo(6), W, Zr, Be, Sc, Nb, Ta, J, rare earths, a. o. with organic reagents of triphenylmethane class in the 8M H 2 SO 4 -pH14 acidity range and the 1x10 -3 -5x10 -6 M concentration range both in the presence and absence of different surfactant type (cetylpyridine, methyltrimethylammonium, synthanols, etc). Three types of effects, determining enhancement of the sensitivity and selectivity of reactions jn the Me-R-surfactant systems, were determined: an increase in the number of coordinated ligands, the activating effect of cation surfactants resulting in a potential complexing in acid media, multicenter interaction of polydentate ligands both via chelating groups and auxochrome groups in the presence of cation surfactants. Protolytic and flotation properties of ionic associates are considered. The observed effects are explained from the viewpoint of electrostatic and hydrophobic interactions in the R-surfactant systems, observed by the methods of NMR, polarography amperometry, conductometry. A possible use of the investigated M-R-surfactant systems as complexonometric indicators was evaluated. A possibility was shown of using them for direct titrimetric determination of hundredth milligram portions of Cu, Ga, In and Sc at a titrant concentratjon of less than 0.01 M. It follows from the estimation of basic optical parameters of the Me-R-surfactant systems that detection

  13. Investigation into isomolar series of Al(NO/sub 3/)/sub 3/, Na/sub 3/VO/sub 4/ solution mixture and composition of solid phases

    Energy Technology Data Exchange (ETDEWEB)

    Chernysh, L F; Nakhodnova, A P; Makarova, R A [Donetskij Gosudarstvennyj Univ. (Ukrainian SSR)

    1979-11-01

    Conducted is investigation of properties of isomolar series of aluminium nitrate and sodium vanadate solutions at pH of the latter 12.5; 10.0; 7.0 and the temperature of 25 deg C using the methods of pH-metry, conductometry, ''seeming'' volume of precipitations, residual concentration of aluminium and vanadium. It is shown, that the composition property diagram of the system investigated does not reflect the true composition of solid-phase products of the reaction, which depends on the component ratio in solution. Bottom phases of isomolar series are mainly heterogeneous. At the excess of sodium vanadate solution and its high pH values conditions for the basic salt formation are created. At pH of the Na/sub 3/VO/sub 4/ solution of 12.5 and 10.0 and Al(NO/sub 3/)/sub 3/: Na/sub 3/VO/sub 4/ ratios 4:6 and 3:7 respectively obtained are the basic aluminium vanadates of the (AlOH)/sub 3/(VO/sub 4/)/sub 2/x 7.5H/sub 2/O and (AlOH)/sub 2/V/sub 2/O/sub 7/x5H/sub 2/O composition, some of their physicochemical properties being investigated.

  14. Partition thermodynamics of ionic surfactants between phosphatidylcholine vesicle and water phases

    Science.gov (United States)

    Chu, Shin-Chi; Hung, Chia-Hui; Wang, Shun-Cheng; Tsao, Heng-Kwong

    2003-08-01

    The partition of ionic surfactants (sodium alkyl sulfate and alkyl trimethyl ammonium bromide) between phosphatidylcholine vesicles and aqueous phase is investigated by simple conductometry under different temperatures. The experimental results can be well represented by the proposed regular solution theory and the thermodynamic parameters satisfy the thermodynamic consistency. The deviation from ideal partition is manifested through the effective interaction energy between lipid and surfactant wb, which is O(kT) large. It is found that wb rises as the alkyl chain is decreased for a specified head group. This is attributed to significant mismatch of chain lengths between surfactant and lipid molecules. The partition coefficient K declines with increasing temperature. The energy barrier from bilayer to aqueous phase, Δμ/kT∝ln K, is in the range of 16-26 kJ/mol. As the alkyl chain length is decreased for a given head group, Δμ is lowered by 1.3-1.5 kJ/mol per methylene group. Two independent analyses are employed to confirm this result. Using the thermodynamic parameters determined from experiments, the internal energy, entropy, and free energy of the partition process can be derived. Partition is essentially driven by the internal energy gain. The solubilizing ability, which is represented by the maximum surfactant-lipid ratio in the bilayer, Reb also decreases in accord with the K parameter. It is because the change in temperature influences the surfactant incorporation into the bilayer more than the formation of micelles.

  15. The interactions between lipase and pyridinium ligands investigated by electrochemical and spectrophotometric methods

    Directory of Open Access Journals (Sweden)

    Simona Patriche

    2016-04-01

    Full Text Available The interaction between pyridinium ligands derived from 4,4’-bipyridine (N,N’-bis(p-bromophenacyl-4,4’-bipyridinium dibromide – Lr and (N,N’-bis(p-bromophenacyl-1,2-bis (4-pyridyl ethane dibromide – Lm with lipase enzyme was evaluated. The stability of the pyridinium ligands, having an essential role in biological systems, in 0.1 M KNO3 as supporting electrolyte is influenced by the lipase concentration added. The pH and conductometry measurements in aqueous solution suggest a rapid ionic exchange process. The behavior of pyridinium ligands in the presence of lipase is investigated by cyclic voltammetry and UV/Vis spectroscopy, which indicated bindings and changes from the interaction between them. The voltammograms recorded on the glassy carbon electrode showed a more intense electronic transfer for the Lr interaction with lipase compared to Lm, which is due to the absence of mobile ethylene groups from Lr structure.

  16. Radiolysis of poly(acrylic acid) in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Ulanski, P [Max-Planck-Institut fuer Strahlenchemie, Muelheim an der Ruhr (Germany); [Politechnika Lodzka, Lodz (Poland); Bothe, E; Hildenbrand, K; Sonntag, C von [Max-Planck-Institut fuer Strahlenchemie, Muelheim an der Ruhr (Germany); Rosiak, J M [Politechnika Lodzka, Lodz (Poland)

    1995-10-01

    Poly(acrylic acid), PAA, reacts with OH-radicals yielding -CH-CH(CO{sub 2}H)- ({beta}-radicals) and -CH{sub 2}-C(CO{sub 2}H)-({alpha}-radicals) in a ratio of approximately 2:1. This estimate is based on pulse radiolysis data where the absorption spectrum of the PAA-radicals was compared with the spectra of {alpha}-radicals from model systems. The {beta}-radicals convert slowly into {alpha}-radicals (k = 0.7s {sup -1} at pH 10). This process has also been observed by ESR. At PAA-concentrations of 10{sup -2} mol dm{sup -3} chain scission dominates over other competing reactions except at low pH. The rate of chain scission was followed by pulse conductometry and in the pH range 7-9 k = 4 x 10{sup -2}s{sup -1} was observed. Oxygen reacts with PAA-radicals with k = 3.1 x 10{sup 8} dm{sup 3} mol{sup -1} s{sup -1} at pH 3.5 and k = 1.0 x 10{sup 8} dm{sup 3} mol{sup -1} s{sup -1} at pH 10. The corresponding peroxyl radicals undergo slow intramolecular H-transfer yielding a UV-absorbing product whose properties are that of 1,3-diketones. (Author).

  17. Behaviors of nitrato complexes of nitrosylruthenium in aqueous solutions

    International Nuclear Information System (INIS)

    Sugimoto, Senichi

    1979-01-01

    Nitrato nitrosylruthenium complexes [RuNO(NO 3 )sub(x)(H 2 O)sub(5-x)]sup((3-x)+) readily dissociate in aqueous solutions with decrease in pH and increase in electrical conductivity of the solutions. This study aimed to elucidate the behaviours of dissociation of the complexes with time. The change in the amount of undissociated complexes was determined with time. The results indicated that the dissociation was a multi-order reaction involving both protolysis and hydrolysis. The protolysis completed in relatively short period within (several tens of minutes), but it depended on the concentration of the complexes in the solution. The completion of the protolysis and the formation of the resulting dissociation products were observed by absorption spectrometry. The dissociation products, which were assumed as aquohydroxy complexes, underwent the successive step-wise dissociation for a prolonged period as revealed by pH measurements. The rate constants involved in the step-wise dissociation, process were obtained. The degree of dissociation and dissociation constant of the complexes were measured by conductometry. (author)

  18. Investigation of complexing in solutions of salt mixture In(NO/sub 3/)/sub 3/-NaVO/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Nakhodnova, A N; Listratenko, I V

    1987-05-01

    Spectrophotometry, conductometry and pH-metry are used to investigate properties and composition of the solid phases of isomolar series of In(NO/sub 3/)/sub 3/-NaVO/sub 3/ salt mixture solutions and series of solutions having constant concentration of one of the components and varied of the other. Results of investigation are presented. It is stated that in the investigated solution series in weakly acid media HPA with the ratios (In/sup 3+/):(V/sup 5+/) being equal to 11:1, 6:1, and 1:9, are formed. Composition of the complexes is mainly defined by the ratio of the components in In(NO/sub 3/)/sub 3/ and NaVO/sub 3/ salt mixture solutions and the medium acidity. Compounds of Na/sub 2/OxIn/sub 2/O/sub 3/x2.5V/sub 2/O/sub 5/x8.5H/sub 2/O and Cs/sub 2/OxIn/sub 2/O/sub 3/x6V/sub 2/O/sub 5/x6.5H/sub 2/O empirical formulae are separated. Results of IR spectroscopy, derivatography and X-ray phase analysis of the corresponding salts are presented.

  19. The radiolysis of uracil in oxygenated aqueous solutions. A study by product analysis and pulse radiolysis

    International Nuclear Information System (INIS)

    Schuchnmann, M.N.; Sonntag, C. von

    1983-01-01

    Hydroxyl radicals are generated by the radiolysis of N 2 O-O 2 (4:1 v/v)-saturated aqueous solutions of uracil. They add to the 5,6-double bond of the substrate. These radicals are converted by oxygen into the corresponding peroxyl radicals (I) and (II), respectively. Peroxyl radical (I) undergoes a base-induced O 2 - elimination. As an intermediate 5-hydroxyisopyrimidine is formed which rearranges into isobarbituric acid and adds water forming 5,6-dihydro-5,6-dihydroxyuracil. Competing with this base-induced reaction of radical (I) there is a bimolecular decay of radicals (I) and (II). These processes become predominant at low pH. For this reason a strong pH dependence of G (products) is observed. The major products are (G values at pH 3 and 10 in parentheses) 5,6-dihydroxy-5,6-dihydrouracil (1.1; 2.4), isobarbituric acid (0; 1.2), N-formyl-5-hydroxyhydantoin (1.6; 0.2), 5-hydroxybarbituric acid (0.9; 0.2). 5-Hydroxybarbituric acid is formed in its keto form. Its deprotonation has been followed by pulse conductometry. Details of the reaction mechanism, e.g. the involvement of oxyl radicals in the bimolecular decay of (I) and (II), are discussed. (author)

  20. Synthesis, spectroscopy and biological investigations of manganese(III) Schiff base complexes derived from heterocyclic β-diketone with various primary amine and 2,2'-bipyridyl

    Science.gov (United States)

    Surati, Kiran R.

    2011-06-01

    The mixed ligand mononuclear complex [Mn(bipy)(HPMFP)(OAc)]ClO 4 was synthesized by reaction of Mn(OAc) 3·2H 2O with HPMFP and 2,2'-bipyridyl. The corresponding Schiff base complexes were prepared by condensation of [Mn(bipy)(HPMFP)(OAc)]ClO 4 with ethylenediamine, ethanolamine and glycine (where HPMFP = 1-phenyl-3methyl-4-formyl-2-pyrazolin-5one, bipy = 2,2'-bipyridyl). All the compounds have been characterized by elemental analysis, magnetic susceptibility, conductometry measurements and 1H and 13C NMR, FT-IR, mass spectrometry. Electronic spectral and magnetic susceptibility measurements indicate square pyramidal geometry around manganese(III) ion. The thermal stabilities, activation energy E*, entropy change Δ S*, enthalpy change Δ H* and heat capacity of thermal degradation for these complexes were determined by TGA and DSC. The in vitro antibacterial and antifungal activity of four coordination compounds and ligand HPMFP were investigated. In vitro activates of Bacillus subtillis (MTCC-619), Staphylococcus aureus (MTCC-96), Escherichia coli (MTCC-722) and Klebsiella pneumonia (MTCC-109) bacteria and the fungus Candida albicans (ATCC-90028) were determined. All the compounds showed good antimicrobial activity. The antimicrobial activities increased as formation of Schiff base.

  1. Synthesis, characterization, single crystal X-ray determination, fluorescence and electrochemical studies of new dinuclear nickel(II) and oxovanadium(IV) complexes containing double Schiff base ligands

    Science.gov (United States)

    Shafaatian, Bita; Ozbakzaei, Zahra; Notash, Behrouz; Rezvani, S. Ahmad

    2015-04-01

    A series of new bimetallic complexes of nickel(II) and vanadium(IV) have been synthesized by the reaction of the new double bidentate Schiff base ligands with nickel acetate and vanadyl acetylacetonate in 1:1 M ratio. In nickel and also vanadyl complexes the ligands were coordinated to the metals via the imine N and enolic O atoms. The complexes have been found to possess 1:1 metals to ligands stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The nickel and vanadyl complexes exhibited distorted square planar and square pyramidal coordination geometries, respectively. The emission spectra of the ligands and their complexes were studied in methanol. Electrochemical properties of the ligands and their metal complexes were also investigated in DMSO solvent at 150 mV s-1 scan rate. The ligands and metal complexes showed both quasi-reversible and irreversible processes at this scan rate. The Schiff bases and their complexes have been characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis and conductometry. The crystal structure of the nickel complex has been determined by single crystal X-ray diffraction.

  2. Preparation of microcapsules by complex coacervation of gum Arabic and chitosan.

    Science.gov (United States)

    Butstraen, Chloé; Salaün, Fabien

    2014-01-01

    Gum Arabic-chitosan microcapsules containing a commercially available blend of triglycerides (Miglyol 812 N) as core phase were synthesized by complex coacervation. This study was conducted to clarify the influence of different parameters on the encapsulation process, i.e. during the emulsion formation steps and during the shell formation, using conductometry, zeta potential, surface and interface tension measurement and Fourier-transform infrared spectroscopy. By carefully analyzing the influencing factors including phase volume ratio, stirring rate and time, pH, reaction time, biopolymer ratio and crosslinking effect, the optimum synthetic conditions were found out. For the emulsion step, the optimum phase volume ratio chosen was 0.10 and an emulsion time of 15 min at 11,000 rpm was selected. The results also indicated that the optimum formation of these complexes appears at a pH value of 3.6 and a weight ratio of chitosan to gum Arabic mixtures of 0.25. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Synthesis, characterization and reactivity of nitrite and nitrosyl derivates of phosphane complexes of tetraamminrethenium (II)

    International Nuclear Information System (INIS)

    Souza Santos, L. de.

    1988-01-01

    The substitution reaction: trans-[Ru(NH 3 ) 4 P(III) (H 2 O)] 2+ + NO - 2 K 1 K -1 trans-[Ru(NH 3 ) 4 P(III) (NO 2 ) + + H 2 O. The reaction product has been isolated as trans-[Ru(NH 3 ) 4 P(III) (NO 2 )] (PF 6 ) and characterized by using electronic and infrared spectroscopies and cyclic voltammetry, microanalysis and conductometry techniques. This nitrite complex can be converted into the nitrosyl complex in solution by adding H + , according to: trans-[Ru(NH 3 ) 4 P(III) (NO 2 )] + + 2H + →sup (K)1 trans-[Ru(NH 3 ) 4 P(III) (NO)] 3+ + H 2 O which can be converted back to the nitrite derivative by adding alkali: trans-[Ru(NH 3 ) 4 P(III) (NO)] 3+ + 2 OH - →sup (K)-1 trans-[Ru(NH 3 ) 4 P(III) (NO 2 )] + + H 2 O. The nitrosyl complexes have been synthesized by reaction of NO with trans-[Ru(NH 3 ) 4 P(III) ( 2 O)] 2+ or by reacting the nitrite derivative in acidic solutions, and characterized by eletronic and infrared spetroscopies, cyclic voltametry, microanalysis, eletron paramagnetic resonance (E.P.R.) and nuclear magnetic resonance (N.M.R.) techniques. E.P.R. and N.M.R. data suggest that these complexes are diamagnetic and better formulated as Ru(II)-NO + . (author) [pt

  4. Thermodynamic and structural of the water - dodecane - bis(ethyl-2-hexyl) phosphoric acid and its sodium salt

    International Nuclear Information System (INIS)

    Lovera, Jacqueline

    1985-01-01

    This research thesis reports the study of the appearance and disappearance of the 'third phase' obtained during the salification of the bis(ethyl-2 hexyl) phosphoric acid (HDEHP) diluted in dodecane, by sodium aqueous solutions. After a large bibliographical study on the properties of the intervening compounds (extraction of metallic cation by the acid, parameters influencing the 'third phase' appearance, surfactant properties, direct and inverse micelles, formation of para-crystalline phases), the author presents chemical experimental methods: liquid-liquid extraction tests, tests by the synthetic way, preparation of reactants, dosing method, methods of chemical analysis). Then, she reports and discusses experimental results in terms of determination of phase diagrams at 25 C, of composition by weight of the third phase, of influence of the apolar diluent, and of influence of the electrolyte. Physical experimental methods are then presented (differential calorimetric analysis, NMR, small angle X-ray scattering, light scattering, polarised light microscopy, constrained phase microscopy, photography, infrared spectroscopy, conductometry, transmission electron micrography, volumetric mass measurements, surface and interface tension measurements, viscoelasticity measurements) and their results are discussed and interpreted [fr

  5. Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine; Etude de la selectivite de molecules extractantes polyazotees dans la complexation des actinides (III) et des lanthanides (III) en solution dans la pyridine anhydre

    Energy Technology Data Exchange (ETDEWEB)

    Riviere, Ch

    2000-10-05

    The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

  6. Potentiometric and Conductometric Study of Aqueous Solutions of Lithium and Sodium Salts of Poly(thiophen-3-ylacetic acid).

    Science.gov (United States)

    Hostnik, Gregor; Vlachy, Vojko; Bondarev, Dmitrij; Jiří, Vohlídal; Cerar, Janez

    2012-09-01

    The title polymer, PTAA, practically free of ester groups was obtained by oxidative polymerization of methyl thiophen-3-ylacetate and subsequent basic hydrolysis of primary polymer. Poly(thiophen-3-ylacetic acid) has been thoroughly characterized by NMR, IR, Raman, and UV/Vis spectroscopy. The polyacid behavior during neutralization titrations with lithium and sodium hydroxides, carried out under nitrogen atmosphere, has been studied by conductometry and potentiometry. Henderson-Hasselbach plots of potentiometric titration curves show a break point at pH around 6, where the curve slope drops from 1.8 (at lower pH) to a value from 1.05 to 1.3 (at higher pH values). The UV/Vis spectra monitored during back titration show: (i) monotonous decrease of both λmax and εmax as pH decreases, (ii) the presence of the isosbestic point at 401 nm that can be ascribed to conformational transition of PTAA chains, and (iii) absence of the isosbestic point at 392 nm reported previously by other authors.

  7. Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine

    International Nuclear Information System (INIS)

    Riviere, Ch.

    2000-01-01

    The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

  8. Critical micelle concentration of surfactants in aqueous buffered and unbuffered systems

    International Nuclear Information System (INIS)

    Fuguet, Elisabet; Rafols, Clara; Roses, Marti; Bosch, Elisabeth

    2005-01-01

    Critical micelle concentration (CMC) of sodium dodecyl sulphate (SDS), lithium perfluorooctanesulfonate (LPFOS), hexadecyltrimethylammonium bromide (HTAB), tetradecyltrimethylammonium bromide (TTAB), and sodium cholate (SC), surfactants commonly used as pseudostationary phases in micellar electrokinetic chromatography (MEKC), have been determined by means of three different methods: MEKC, spectrophotometry, and conductometry. Determinations have been performed in water, and also in different concentrations of phosphate buffer at pH 7.0. CMC values ranging from 8.08 (water) to 1.99 (50 mM phosphate buffer) mM for SDS, from 7.16 (water) to 2,81 (30 mM phosphate buffer) mM for LPFOS, from 3.77 (water) to 1.93 (20 mM phosphate buffer) mM for TTAB, from 0.91 (water) to ∼0.34 (20 mM phosphate buffer) for HTAB, and around 13 mM (20 mM phosphate buffer) for SC, are obtained. The effect of the electrolyte concentration on the CMC, as well as the linear relationship between the electrolyte counter-ion concentration and the CMC are discussed. This linear relationship provides an easy way for users to estimate the CMC of a MEKC system, at a given electrolyte concentration. A comparison between experimental methods, as well as a discussion about the suitability of a given method for the determination of the CMC for a given surfactant system is also provided

  9. Complexation of f elements by tripodal ligands containing aromatic nitrogens. Application to the selective extraction of actinides(III)

    International Nuclear Information System (INIS)

    Wietzke, Raphael

    1999-01-01

    This work initiates a research project, whose aim is the actinides(lll)/lanthanides(III) separation by liquid-liquid extraction. We were interested in the study of the coordination chemistry of lanthanides(III) and uranium(III) (uranium(III) as model for the actinides(III)), with the aim to show differences between the two families and to better understand the coordination properties involved in the extraction process. We studied the lanthanide(III) and uranium(III) complexation with tripodal ligands containing aromatic nitrogens. Several tripodal ligands were synthesized varying the type and the number of the donor atoms. The lanthanide(III) complexes have been characterized in the solid state and in solution (by several techniques: "1H NMR, ESMS, luminescence, UV spectrophotometry, conductometry). Differences in the coordination were found depending on the nature of the donor atoms. The new ligands, tris(2-pyrazinylmethyl)amine (tpza) et tris(N,N-diethyl-2-carbamoyl-6- pyridylmethyl)amine (tpaa), have shown a selectivity for the actinides(III) with promising results in liquid-liquid extraction. The comparison between the lanthanum(III) and uranium(III) complexes with the ligand tpza showed differences in the bonding nature, which could be attributed to a covalent contribution to the metal-ligand bond. (author) [fr

  10. Cellular properties of slug flow in vertical co-current gas-liquid flow: slug-churn transition

    International Nuclear Information System (INIS)

    Lusseyran, Francois

    1990-01-01

    This research thesis reports the study and description of the structure of a slug flow regime in a co-current vertical cylindrical duct, and the characterization and prediction of its transition towards a slug-churn (de-structured) regime. Flow physical mechanisms highlighted by the measurement of two important dynamics variables (wall friction and thickness of liquid films) are related to hypotheses of cellular models. The author first proposes an overview of slug flow regimes: theoretical steady and one-dimensional analysis, mass assessment equations of cellular models, application to the assessment of the flow rate and of the thickness of the film surrounding the gas slug. In the second part, the author addresses the slug flow regime transition towards the slug-churn regime: assessment of the evolution of flow dynamic properties, use of average wall friction analysis to obtain a relevant transition criterion. The third part presents experimental conditions, and measurement methods: conductometry for thickness measurement, polarography for wall friction measurement, and gas phase detection by using an optic barrier or optic fibres [fr

  11. Comprehensive study of tartrazine/cationic surfactant interaction.

    Science.gov (United States)

    Shahir, Afshin Asadzadeh; Javadian, Soheila; Razavizadeh, Bi Bi Marzieh; Gharibi, Hussein

    2011-12-15

    Interaction of a food dye, tartrazine, with some cationic conventional and gemini surfactants, tetradecyltrimethylammonium bromide (TTAB), N,N'-ditetradecyl-N,N,N',N'-tetramethyl-N,N'-butanediyl-diammonium dibromide (14,4,14), and N,N'-didodecyl-N,N,N',N'-tetramethyl-N,N'-butanediyl-diammonium dibromide (12,4,12), were first investigated comprehensively employing conductometry, tensiometry, and UV-visible spectroscopy. Tartrazine was found to behave in the same manner as aromatic counterions. The formation of ion pairs reflected as a considerable increase of the surfactant efficiency in tensiometry plots and their stoichiometry were determined by Job's method of continuous variations. For the tartrazine/TTAB system, nonionic DS(3), ionic DS(2-), and/or DS(2)(-) ion pairs, their small premicelles, and tartrazine-rich micelles were constituted as well as dye-containing TTAB-rich micelles. Insoluble J-aggregates of DS(-) ion pairs and cylindrical surfactant-rich micelles were also formed in tartrazine/gemini surfactant systems and recognized by transmission electron microscopy. The zeta potential and the size of the aggregates were determined using dynamic light scattering and confirmed the suggested models for the processes happening in each system. Cyclic voltammetry was applied successfully to track all of these species using tartrazine's own reduction peak current for the first time.

  12. Free radical transfer in polymers

    International Nuclear Information System (INIS)

    Sonntag, C. von; Bothe, E.; Ulanski, P.

    1998-01-01

    For the present study of free-radical transfer in polymers pulse radiolysis and product studies have been carried out in aqueous solutions using thus far only the water-soluble polymers polyacrylic acid, polymethacrylic acid and polyvinyl alcohol. When OH radicals, generated in the radiolysis of N 2 O-saturated aqueous solutions, react with polymers the lifetime of the polymer radical thus created very much depends on the number of radicals per polymer chain. When there are a large number of radicals per chain their bimolecular decay may be faster than the corresponding (diffusion controlled) decay of monomeric radicals, but when the macromolecule contains only few or even just one radical their lifetime is considerably prolonged. Highly charged polymers such as polyacrylic acid at high pH attain a rod-like conformation which again favors a long lifetime of the radicals. Under such conditions, radical transfer reactions can occur. For example, in polyacrylic acid OH radicals generate two kinds of radicals side by side. The radical in β-position to the carboxylate group converts into the thermodynamically more stable α-radicals by an H-transfer reaction as can be followed by spectrophotometry. Besides radical transfer reactions β-fragmentation reactions occur causing chain scission. Such reactions can be followed in a pulse radiolysis experiment by conductometry, because counter ions are released upon chain scission. Such a process is especially effective in the case of polymethacrylic acid, where it results in a chain depolymerization. An intramolecular H-abstraction is also observed in the γ-radiolysis of polyacrylic acid with the corresponding peroxyl radicals. This causes a chain reaction to occur. The resulting hydroperoxides are unstable and decarboxylate given rise to acetylacetone-like products. In polyvinyl alcohol the peroxyl radicals in α-position to the alcohol function undergo HO 2 -elimination. This prevents a scission of the polymer chain in the

  13. Spectroscopic (IR, NMR) and conductometric characterization of lithium aluminum hydride - crown ethers complexes [Li{sup +}-C E](A I H{sub 4})- with C E=syn-isomers of DC 18-C-6 in benzene solutions; Caracterisation par spectrometrie (IR, RMN) et conductimetrie des complexes entre le tetrahydrualuminate de lithium LiAIH{sub 4} et l`ether-couronne DC 18-C-6* (isomeres cis-anti-cis et cis-syn-cis) en solution dans le benzene (*2,3,11,12-dicyclohexano-1,4,7,10,13,16-hexacyclooctadecane)

    Energy Technology Data Exchange (ETDEWEB)

    Bastide, J P; Ezzemouri, K; Carre, J; Bouamrane, A; Claudy, P [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France); Frange, B [Faculte des Sciences, 21 - Dijon (France)

    1996-03-01

    [Li{sup +}-C E](AIH{sub 4}){sup -} complexes with C E = syn and anti-isomers of the crown ether DC 18-C-6 have been characterized in benzene solutions by IR (infrared spectroscopy), NMR (nuclear magnetic resonance) and conductometry (at 298 K). The properties of these complexes are closely related to those of the cation [Li{sup +}-C E]. For the anti-isomer, no distortion of the macrocycle was noticed after complexation, the Li{sup +} trapped cation is coordinated with four oxygen atoms of the cavity, and the complex exhibits a covalent behavior. Electrical conductivity of the benzene solution is concentration independent and has a very low mean value ({lambda} = 0,06 {omega}{sup -1}.cm{sup 2}.mol{sup -1}). The macrocycle of the syn-isomer is drastically distorted after complexation. A tridimensional cavity is formed, in which the Li{sup +} trapped cation is coordinated with six oxygen atoms. As a consequence, the species exhibits a high degree of ionic character due to the stretching of the Li{sup +}---(AIH{sub 4}){sup -} bond. Electrical conductivity is enhanced for dilute solutions (x 10 at C 0,01 mol.L{sup -1}). The regular tetrahedral symmetry of (AIH{sub 4}){sup -} anion is retained in the molecular structure of the two complexes. Benzene solutions of [Li-+-syn-DC 18-C-6](AIH{sub 4}){sup -} appear to be the first example of free-(AIH{sub 4}){sup -} anions in a non-polar organic medium. (authors). 22 refs., 3 figs., 4 tabs.

  14. Radiolysis of aqueous solutions of nucleosides halogenated at the sugar moiety

    Energy Technology Data Exchange (ETDEWEB)

    Hissung, A; Isildar, M; von Sonntag, C [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany, F.R.). Inst. fuer Strahlenforschung; Witzel, H [Biochemisches Institut der Westfaelischen Wilhelms-Universitaet, Muenster, West Germany

    1981-02-01

    The pulse radiolysis of aqueous solutions of nucleosides halogenated at the sugar moiety (2'-bromo-2'-deoxyuridine 4, 3'-deoxy-3'-iodothymidine 5, 5'-deoxy-5'-iodouridine 6) has been studied. G(Hal) were determined by conductometry varying the experimental conditions (pH, saturation with Ar, N/sub 2/O or air, addition of t-butanol). The results indicate that solvated electrons both add to the nucleobases and eliminate halogen ions from the halogenated sugar moiety. In the case of 4(and possibly of 5) the radical anion of the base transfers (k approximately 10/sup 5/s/sup -1/) an electron to the sugar-bound halogen atom thus cleaving the C-Hal bond. In competition with this reaction there is a protonation of the radical anion of the base by protons and by water. For the latter reaction constant of k = 5 x 10/sup 3/ M/sup -1/s/sup -1/ was estimated. Compound 4 has also been investigated by product analysis after 60-Co-..gamma..-irradiation. In aerated solutions erythrose is formed with a G-value of 0.12. Its precursor radical is the 2'-radical generated from 4 by dissociative electron capture which reacts with O/sub 2/ to the corresponding peroxyl radical. Erythrose is formed after a sequence of reactions, one of which involves the scission of the C-1'-C-2'bond. Under this condition G(HBr) as measured by pulse radiolysis is 0.8. Thus erythrose is formed in 15 per cent yield with respect to its precursor radical. This result is of importance in assessing the precursor radical of a similar product observed in irradiated DNA.

  15. Biomass of active microorganisms is not limited only by available carbon in the rhizosphere

    Science.gov (United States)

    Gilmullina, Aliia

    2017-04-01

    Microbial activity is generally limited by carbon (C) availability. The easily available substrate release by roots creates so called "hotspots" in the rhizosphere that drives microbial activity removing C limitation. We simulated a gradient of root exudates by glucose addition at different concentrations to stimulate the activation of microbial biomass (MB). Glucose was added at the rates lower than MB (5, 10, 25 and 50%) and at the rates similar or higher than MB (100, 150, 200, 250, 300 and 400%). During incubation CO2 efflux was measured by conductometry, the size of active MB and specific growth rate were estimated by substrate-induced growth response method. We tested a hypothesis that glucose addition exceeding 100% MB is able to activate major fraction of soil microbial community. Addition of glucose at concentrations higher than 5% decreased specific growth rate, demonstrating the shift of microbial community from r-strategy to K-strategy. The percentage of active MB grew up by the increase of glucose concentration. The treatment with glucose at 100% presented a dramatic shift in the activation of MB up to 14%. Contrary to our hypothesis, further increase in glucose rate caused moderate stimulation of active MB up to 22% of total MB. Furthermore, glucose addition above 200% did not increase the fraction of active biomass indicating glucose oversaturation and possible limitation by other nutrients. The results suggest that despite the fact that C is the most important limitation factor, limitless C supply is not able to activate MB up to 100%. Thus, if the rhizosphere is limited by nutrients, the fraction of active biomass remains at low level despite an excess of available C.

  16. DEVELOPMENT AND ADAPTATION OF VORTEX REALIZABLE MEASUREMENT SYSTEM FOR BENCHMARK TEST WITH LARGE SCALE MODEL OF NUCLEAR REACTOR

    Directory of Open Access Journals (Sweden)

    S. M. Dmitriev

    2017-01-01

    Full Text Available The last decades development of applied calculation methods of nuclear reactor thermal and hydraulic processes are marked by the rapid growth of the High Performance Computing (HPC, which contribute to the active introduction of Computational Fluid Dynamics (CFD. The use of such programs to justify technical and economic parameters and especially the safety of nuclear reactors requires comprehensive verification of mathematical models and CFD programs. The aim of the work was the development and adaptation of a measuring system having the characteristics necessary for its application in the verification test (experimental facility. It’s main objective is to study the processes of coolant flow mixing with different physical properties (for example, the concentration of dissolved impurities inside a large-scale reactor model. The basic method used for registration of the spatial concentration field in the mixing area is the method of spatial conductometry. In the course of the work, a measurement complex, including spatial conductometric sensors, a system of secondary converters and software, was created. Methods of calibration and normalization of measurement results are developed. Averaged concentration fields, nonstationary realizations of the measured local conductivity were obtained during the first experimental series, spectral and statistical analysis of the realizations were carried out.The acquired data are compared with pretest CFD-calculations performed in the ANSYS CFX program. A joint analysis of the obtained results made it possible to identify the main regularities of the process under study, and to demonstrate the capabilities of the designed measuring system to receive the experimental data of the «CFD-quality» required for verification.The carried out adaptation of spatial sensors allows to conduct a more extensive program of experimental tests, on the basis of which a databank and necessary generalizations will be created

  17. Synthesis, spectral, crystallography and thermal investigations of novel Schiff base complexes of manganese (III) derived from heterocyclic β-diketone with aromatic and aliphatic diamine

    Science.gov (United States)

    Surati, Kiran R.; Thaker, B. T.

    2010-01-01

    The Schiff base tetradentate ligands N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H 2L 1), N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H 2L 2), N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H 2L 3) and N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H 2L 4) were prepared from the reaction between 5-oxo-3-methyl-1-p-tolyl-1H-pyrazole-4-carbaldehyde or 4-(4-formyl-5-oxo-3-methyl-pyrazol-1-yl)-benzenesulfonic acid and o-phenylenediamine or ethylenediamine. And these are characterized by elemental analysis, FT-IR, 1H NMR and GC-MS. The corresponding Schiff base complexes of Mn(III) were prepared by condensation of [Mn 3(μ 3-O)(OAc) 6(H 2O) 3]·3H 2O with ligands H 2L 1, H 2L 2, H 2L 3 and H 2L 4. All these complexes have been characterized by elemental analysis, magnetic susceptibility, X-ray crystallography, conductometry measurement, FT-IR, electronic spectra and mass (FAB) spectrometry. Thermal behaviour of the complexes has been studied by TGA, DTA and DSC. Electronic spectra and magnetic susceptibility measurements indicate octahedral stereochemistry of manganese (III) complexes, while non-electrolytic behaviour complexes indicate the absence of counter ion.

  18. Biomimetic routes to nanoscale-toughened oxide ceramics

    Science.gov (United States)

    Deschaume, Olivier

    In this work, a novel anion exchange technique has been developed and optimised in order to prepare extra-pure, hydroxide-free solutions of aluminium polyoxocations (A113 and A130) as well as for the preparation of nanosized, highly monodisperse aluminium hydroxide particles in the particle size range 20-200nm. In order for the evolution and composition of the resulting systems to be monitored, an array of characterisation techniques including 27A1 NMR, dynamic light scattering, po-tentiometry, conductometry and UV-Vis spectroscopy, have been implemented and complemented with successful data treatment strategies. The quantitative data obtained indicates that the static anion exchange method is a soft, environmentally friendly, low-cost, energy-saving and convenient procedure for the preparation of Al- containing model systems. The A1 species obtained can be used for high-precision model studies on A1 speciation, and serve as nanosize precursors to a variety of Al-containing materials. The use of these pure A1 precursors has a clear advantage in materials synthesis arising from an improved understanding and better control of A1 speciation. In a second development of the project, the model systems have been used in a nanotectonic approach to biomimetic materials synthesis, with possible applications to the optimisation of Al-containing materials such as ceramics or composite films. Bearing this aim in mind, the interactions of the prepared aluminium species with the model protein BSA and a bioelastomer, elastin, were monitored and the resulting composite materials characterised. The methodology developed for the synthesis and characterisation of pure A1 species and A1 species/biomolecule systems is a robust base for further studies spanning research fields such as Chemistry, Biology or Environmental sciences, and possess a large potential for application to industrial products and processes.

  19. Copper(I), silver(I) and gold(I) halide complexes with the dithioformamidinium dihalides

    Science.gov (United States)

    Peyronel, Giorgio; Malavasi, Wanda; Pignedoli, Anna

    Some copper(I), silver(I) and gold(I) halide complexes with the dithioformamidinium dihalides (Tu 2X 2) were prepared and studied by infrared spectroscopy and conductometry: 3CuX.2Tu 2X 2(XCl,I), CuBr.Tu 2Br 2, 4CuBr.3.5Tu 2Br 2.MeOH, 2CuBr.Tu 2Br 2.0.66EtOH, 3CuI.2Tu 2I 2, 2AgCl.2.5Tu 2Cl 2, 3AgCl.2Tu 2Cl 2.0.5EtOH, 3AgCl.Tu 2Cl 2, 2AgBr.2Tu 2Br 2.0.5Tu 2(NO 3) 2.H 2O, AgBr.Tu 2Br 2, 4AgBr.Tu 2Br 2, 4AgI.0.5Tu 2I 2.EtOH, AuCl.1.5Tu 2Cl 2, 4AuCl.3.5Tu 2Cl 2.2DMF, AuBr.4Tu 2Br 2, AuBr.2Tu 2Br 2.1.5DMF, AuI.5Tu 2I 2, AuI.Tu 2I 2. A decrease of the ν(NH), δ(NH 2) and ν(CN 2) frequencies and an increase of the ν(CS) frequencies indicate an N-coordination of the dithioformamidinium cation to the metal ions; ν(MN) and ν(MX) frequencies are tentatively assigned in the far-infrared spectra.

  20. Stabilizing effect of epoxidized sunflower oil as a secondary stabilizer for Ca/Hg stabilized PVC

    Directory of Open Access Journals (Sweden)

    2008-01-01

    Full Text Available Unsaturated triglyceride oil sunflower was epoxidized and characterized by chemical and spectroscopic methods. Epoxidized sunflower oil (ESO was used as an organic thermal co-stabilizer for rigid poly(vinyl chloride (PVC in the presence of tricalcium dicitrate (Ca3(C6H5O72 and mercury (II acetate (Hg(CH3COO2. The thermo-oxidative degradation of PVC was studied in the presence of these ternary stabilizer systems at 170, 180, 190 and 200°C in N2 atmosphere. The effects of metal carboxylate combination Ca/Hg in the absence and in the presence of epoxidized sunflower oil on static heat treatment of PVC have been studied. The formation of polyene sequences was investigated by UV-visible and FT-IR spectroscopy and by comparing viscosity data obtained in the presence and in the absence of the additives. It was found that the additives retard the rate of degradation and reduce the extent of polymer chain scission associated with the thermal degradation of poly(vinyl chloride. Synergistic effects were found when stabilizer was blended in 50:50 weight ratios with either. It was found that ESO exerted a stabilizing effect on the degradation of PVC. The activation energy for degraded PVC in absence of stabilizers was 38.6 kJ•mol–1 and in the presence of Ca/Hg and Ca/Hg/ESO were 53.3 and 64.7 kJ•mol–1 respectively. In order of compare the efficiency of the epoxidized sunflower oil with these metal soap stabilizers, thermal stabilities were evaluated on the basis of evolved hydrogen chloride determined by conductometry technique and degree of discoloration are discussed.

  1. Study of complexation process between 4'-nitrobenzo-15-crown-5 and yttrium(III) cation in binary mixed non-aqueous solvents using conductometric method

    Science.gov (United States)

    Habibi, N.; Rounaghi, G. H.; Mohajeri, M.

    2012-12-01

    The complexation reaction of macrocyclic ligand (4'-nitrobenzo-15C5) with Y3+ cation was studied in acetonitrile-methanol (AN-MeOH), acetonitrile-ethanol (AN-EtOH), acetonitrile-dimethylformamide (AN-DMF) and ethylacetate-methanol (EtOAc-MeOH) binary mixtures at different temperatures using conductometry method. The conductivity data show that in all solvent systems, the stoichiometry of the complex formed between 4'-nitrobenzo-15C5 and Y3+ cation is 1: 1 (ML). The stability order of (4'-nitrobenzo-15C5). Y3+ complex in pure non-aqueous solvents at 25°C was found to be: EtOAc > EtOH > AN ≈ DMF > MeOH, and in the case of most compositions of the binary mixed solvents at 25°C it was: AN≈MeOH ≈ AN-EtOH > AN-DMF > EtOAc-MeOH. But the results indicate that the sequence of the stability of the complex in the binary mixed solutions changes with temperature. A non-linear behavior was observed for changes of log K f of (4'-nitrobenzo-15C5 · Y3+) complex versus the composition of the binary mixed solvents, which was explained in terms of solvent-solvent interactions and also the hetero-selective solvation of the species involved in the complexation reaction. The values of thermodynamic parameters (Δ H {c/ℴ} and Δ S {c/ℴ}) for formation of the complex were obtained from temperature dependent of the stability constant using the van't Hoff plots. The results represent that in most cases, the complex is both enthalpy and entropy stabilized and the values and also the sign of thermodynamic parameters are influenced by the nature and composition of the mixed solvents.

  2. DEVELOPMENT OF RAPID TECHNIQUE FOR DETERMINATION OF THE TOTAL MINERALIZATION OF NATURAL WATERS

    Directory of Open Access Journals (Sweden)

    T. A. Kuchmenko

    2015-01-01

    Full Text Available A new approach has been proposed for rapid and easy evaluation of a indicator of quality and properties of natural water - soluble salt content (mineralization. The method of quartz crystal microbalance is employed at load of the mass-sensitive resonator electrode (BAW-type with investigated water. The degree of correlation between the various indicators related to the contents of salts and insoluble compounds and the level of mineralization obtained by the standard method (gravimetry has been studied. A procedure for salt weighing by single sensor at unilateral load with small sample of natural water has been developed. The optimal conditions for measurement is established using the design of experiment by model 23 . The possibilities of quartz crystal microbalance for determination of non-volatile compounds in the water are described. The calibration of piezosensor is produced by standard solution NaCl (c = 1.000 g / dm3 at optimal conditions of experiment. The adequacy and accuracy of proposed technique is assessed by the correlation between the results of quartz crystal microbalance and conductometry. The correlation between indicators of mineralization established by quartz crystal microbalance and gravimetry is found. It has been obtained an equation that can be used to calculate the standard indicator of the mineralization by the results of a quartz crystal microbalance using single sensor. The approaches to enhance the analytical capabilities of the developed technique for water with low and high mineralization are proposed. The metrological characteristics of quartz crystal microbalance of insoluble compounds in natural water are estimated. A new technique of determination of the mass concentration of the dry residue in water with a conductivity of 0.2 mS or above has been developed, which can be used for rapid analysis of the water at nonlaboratory conditions and in the laboratory for rapid obtaining the information about a sample.

  3. Template synthesis, characterization and antimicrobial activity of some new complexes with isonicotinoyl hydrazone ligands

    Directory of Open Access Journals (Sweden)

    LIVIU MITU

    2009-09-01

    Full Text Available Complexes of Cu(II, Ni(II, Co(II with the 9-anthraldehyde iso-nicotinoyl hydrazone ligand (HL1 and the 3,5-di-tert-butyl-4-hydroxy-benzaldehyde isonicotinoyl hydrazone ligand (H2L2 were synthesized by the template method. The complexes were characterized by analytical analysis, IR, UV-Vis and ESR spectroscopy, magnetic measurements, conductometry and thermal analysis and the two ligands by 1H-NMR spectroscopy. From the elemental analysis, 1:2 (metal:ligand stoichiometry for the complexes of Cu(II, Ni(II with the ligands HL1 and H2L2 and 1:1 (metal:ligand stoichiometry for the complex of Co(II with the ligand HL1 are proposed. The molar conductance data showed that the complexes are non-electrolytes. The magnetic susceptibility results coupled with the electronic and ESR spectra suggested a distorted octahedral geometry for the complexes Ni(II/HL1, Ni(II/H2L2 and Cu(II/H2L2, a tetrahedral stereochemistry for the complex Cu/HL1 and a square-planar geometry for the complex Co/HL1. The IR spectra demonstrated the bidentate coordination of the ligands HL1 and H2L2 by the O=C amide oxygen and the azomethine nitrogen, as well as monodentate coordination of the ligand HL1 by the azomethine nitrogen in the Cu(IIcomplex. The antibacterial activity of the ligands and their metallic complexes were tested against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae.

  4. Shewanella putrefaciens Adhesion and Biofilm Formation on Food Processing Surfaces

    Science.gov (United States)

    Bagge, Dorthe; Hjelm, Mette; Johansen, Charlotte; Huber, Ingrid; Gram, Lone

    2001-01-01

    Laboratory model systems were developed for studying Shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. S. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. S. putrefaciens bacteria suspended in buffer adhered readily to stainless steel surfaces. Maximum numbers of adherent bacteria per square centimeter were reached in 8 h at 25°C and reflected the cell density in suspension. Numbers of adhering bacteria from a suspension containing 108 CFU/ml were much lower in a laminar flow system (modified Robbins device) (reaching 102 CFU/cm2) than in a batch system (reaching 107 CFU/cm2), and maximum numbers were reached after 24 h. When nutrients were supplied, S. putrefaciens grew in biofilms with layers of bacteria. The rate of biofilm formation and the thickness of the film were not dependent on the availability of carbohydrate (lactate or glucose) or on iron starvation. The number of S. putrefaciens bacteria on the surface was partly influenced by the presence of other bacteria (Pseudomonas fluorescens) which reduced the numbers of S. putrefaciens bacteria in the biofilm. Numbers of bacteria on the surface must be quantified to evaluate the influence of environmental factors on adhesion and biofilm formation. We used a combination of fluorescence microscopy (4′,6′-diamidino-2-phenylindole staining and in situ hybridization, for mixed-culture studies), ultrasonic removal of bacteria from surfaces, and indirect conductometry and found this combination sufficient to quantify bacteria on surfaces. PMID:11319118

  5. Effect of variation in the glass-former network structure on the relaxation properties of conductive Ag+ ions in AgI-based fast ion conducting glasses

    Science.gov (United States)

    Hanaya, Minoru; Nakayama, Michiko; Hatate, Atsuo; Oguni, Masaharu

    1995-08-01

    Heat capacities and ac conductivities of AgI-based fast ion conducting glasses of AgI-Ag2O-P2O5 and AgI-Ag2O-B2O3 systems with different P-O or B-O network structures but with the same AgI concentration of 1.55×104 mol m-3 were measured in the temperature range 14-400 K and in the temperature and frequency ranges 100-200 K and 10 Hz-1 MHz, respectively. The β-glass transition due to a freezing-in of the rearrangement of Ag+ ions was observed by adiabatic calorimetry for the glasses in the liquid-nitrogen temperature region, and the conductometry was suggested to see the same mode of Ag+-ion motion as the calorimetry. It was found that the development of the network structure of the glass former at constant AgI concentration resulted in the decrease of the β-glass transition temperature and the activation energy for the diffusional motion of Ag+ ions and in the increase of the heat-capacity jump associated with the glass transition. The results support the amorphous AgI aggregate model for the structure of the conductive region in the glasses with relatively high AgI compositions, indicating that Ag+-ion conductivity is mainly dominated by the degree of development of the AgI aggregate region dependent on the glass-former network structure as well as the AgI composition.

  6. Radiolysis of aqueous solutions of nucleosides halogenated at the sugar moiety

    International Nuclear Information System (INIS)

    Hissung, A.; Isildar, M.; Sonntag, C. von; Witzel, H.

    1981-01-01

    The pulse radiolysis of aqueous solutions of nucleosides halogenated at the sugar moiety (2'-bromo-2'-deoxyuridine 4, 3'-deoxy-3'-iodothymidine 5, 5'-deoxy-5'-iodouridine 6) has been studied. G(Hal) were determined by conductometry varying the experimental conditions (pH, saturation with Ar, N 2 O or air, addition of t-butanol). The results indicate that solvated electrons both add to the nucleobases and eliminate halogen ions from the halogenated sugar moiety. In the case of 4(and possibly of 5) the radical anion of the base transfers (k approximately 10 5 s -1 ) an electron to the sugar-bound halogen atom thus cleaving the C-Hal bond. In competition with this reaction there is a protonation of the radical anion of the base by protons and by water. For the latter reaction constant of k = 5 x 10 3 M -1 s -1 was estimated. Compound 4 has also been investigated by product analysis after 60-Co-γ-irradiation. In aerated solutions erythrose is formed with a G-value of 0.12. Its precursor radical is the 2'-radical generated from 4 by dissociative electron capture which reacts with O 2 to the corresponding peroxyl radical. Erythrose is formed after a sequence of reactions, one of which involves the scission of the C-1'-C-2'bond. Under this condition G(HBr) as measured by pulse radiolysis is 0.8. Thus erythrose is formed in 15 per cent yield with respect to its precursor radical. This result is of importance in assessing the precursor radical of a similar product observed in irradiated DNA. (author)

  7. Characterization of carrier states in CuWO₄ thin-films at elevated temperatures using conductometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Carlos M., E-mail: carlosmiguelgg@yahoo.com [Energy Mining and Environment Portfolio, National Research Council of Canada, 1200 Montreal Road, Ottawa, Ontario, Canada, K1A 0R6 (Canada); Dunford, Jeffrey L.; Du, Xiaomei; Post, Michael L. [Energy Mining and Environment Portfolio, National Research Council of Canada, 1200 Montreal Road, Ottawa, Ontario, Canada, K1A 0R6 (Canada)

    2013-05-01

    CuWO₄ thin-films were deposited by pulsed laser deposition onto an insulating substrate. The temperature dependence of the electronic conductivity of CuWO₄ thin-films was determined over 100–500 °C temperature range in a synthetic air atmosphere. Additionally, variations of conductivity at 300 °C and 500 °C have been measured for oxygen partial pressures (0.1 atmconductometry. • The determination of the apparent activation energy of conduction with temperature is outlined. • Temperature and O₂ concentration effects on the oxygen states was established. • For the ranges of temperature studied, the identified operating oxygen states were O₂⁻ and O⁻.

  8. Various methods for determination of the degree of N-acetylation of chitin and chitosan: a review.

    Science.gov (United States)

    Kasaai, Mohammad R

    2009-03-11

    Chitin, chitosan, and their derivatives have been identified as versatile biopolymers for a broad range of agriculture and food applications. Up to now, several methods have been developed to determine degree of N-acetylation, DA, for chitin and chitosan. In this article, an effort has been made to review the available literature information on the DA determination. These methods are classified into three categories: (1) spectroscopy (IR, (1)H NMR, (13)C NMR, (15)N NMR, and UV); (2) conventional (various types of titration, conductometry, potentiometry, ninhydrin assay, adsorption of free amino groups of chitosan by pictric acid); (3) destructive (elemental analysis, acid or enzymatic hydrolysis of chitin/chitosan and followed by the DA measurement by colorimetry or high performance liquid chromatography, pyrolysis-gas chromatography, and thermal analysis using differential scanning calorimetry) methods. These methods have been compared for their performances and limitations as well as their advantages and disadvantages. The use of IR and NMR spectroscopy methods provides a number of advantages. They do not need long-term procedures to prepare samples, and they provide information on the chemical structure. (1)H NMR and UV techniques are more sensitive than IR, (13)C NMR, and (15)N NMR spectroscopy. The IR technique is mostly used for a qualitative evaluation and comparison studies. Conventional methods are not applicable for highly acetylated chitin. The results of the latter methods are affected by ionic strength of the solvent, pH, and temperature of solution. In destructive methods, longer times are needed for the measurements compared to spectroscopy and conventional methods, but they are applicable for the entire range of the DA.

  9. Synthesis, spectral, crystallography and thermal investigations of novel Schiff base complexes of manganese (III) derived from heterocyclic beta-diketone with aromatic and aliphatic diamine.

    Science.gov (United States)

    Surati, Kiran R; Thaker, B T

    2010-01-01

    The Schiff base tetradentate ligands N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(1)), N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(2)), N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(3)) and N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(4)) were prepared from the reaction between 5-oxo-3-methyl-1-p-tolyl-1H-pyrazole-4-carbaldehyde or 4-(4-formyl-5-oxo-3-methyl-pyrazol-1-yl)-benzenesulfonic acid and o-phenylenediamine or ethylenediamine. And these are characterized by elemental analysis, FT-IR, (1)H NMR and GC-MS. The corresponding Schiff base complexes of Mn(III) were prepared by condensation of [Mn(3)(mu(3)-O)(OAc)(6)(H(2)O)(3)].3H(2)O with ligands H(2)L(1), H(2)L(2), H(2)L(3) and H(2)L(4). All these complexes have been characterized by elemental analysis, magnetic susceptibility, X-ray crystallography, conductometry measurement, FT-IR, electronic spectra and mass (FAB) spectrometry. Thermal behaviour of the complexes has been studied by TGA, DTA and DSC. Electronic spectra and magnetic susceptibility measurements indicate octahedral stereochemistry of manganese (III) complexes, while non-electrolytic behaviour complexes indicate the absence of counter ion. Copyright 2009. Published by Elsevier B.V.

  10. Multicomponent transport in membranes for redox flow batteries

    Science.gov (United States)

    Monroe, Charles

    2015-03-01

    Redox flow batteries (RFBs) incorporate separator membranes, which ideally prevent mixing of electrochemically active species while permitting crossover of inactive supporting ions. Understanding crossover and membrane selectivity may require multicomponent transport models that account for solute/solute interactions within the membrane, as well as solute/membrane interactions. Application of the Onsager-Stefan-Maxwell formalism allows one to account for all the dissipative phenomena that may accompany component fluxes through RFB membranes. The magnitudes of dissipative interactions (diffusional drag forces) are quantified by matching experimentally established concentration transients with theory. Such transients can be measured non-invasively using DC conductometry, but the accuracy of this method requires precise characterization of the bulk RFB electrolytes. Aqueous solutions containing both vanadyl sulfate (VOSO4) and sulfuric acid (H2SO4) are relevant to RFB technology. One of the first precise characterizations of aqueous vanadyl sulfate has been implemented and will be reported. To assess the viability of a separator for vanadium RFB applications with cell-level simulations, it is critical to understand the tendencies of various classes of membranes to absorb (uptake) active species, and to know the relative rates of active-species and supporting-electrolyte diffusion. It is also of practical interest to investigate the simultaneous diffusion of active species and supports, because interactions between solutes may ultimately affect the charge efficiency and power efficiency of the RFB system as a whole. A novel implementation of Barnes's classical model of dialysis-cell diffusion [Physics 5:1 (1934) 4-8] is developed to measure the binary diffusion coefficients and sorption equilibria for single solutes (VOSO4 or H2SO4) in porous membranes and cation-exchange membranes. With the binary diffusion and uptake measurement in hand, a computer simulation that

  11. СOMPLEXES OF Sn(IV WITH ISONICOTINOYLHYDRAZONES OF AROMATIC ALDEHYDES. SYNTHESIS, CHARACTERIZATION, EFFECT ON THE GROWTH OF Mycobacterium Tuberculosis

    Directory of Open Access Journals (Sweden)

    N. V. Shmatkova

    2017-12-01

    Full Text Available Сomplexes[SnCl4(R-Ib∙Н], where R=H (1, 4-Br (2, 4-NO2(3, 2-OCH3(4, 4-OCH3(5, -ОC7H15(6,were synthesized by interaction of SnCl4 with isonicotinoylhydrazones of R-benzoic aldehydes (R-HIb in acetonitrile and complex [SnCl3(2-OH-Inf∙Н](9 – by interaction of SnCl4with 2-OH- naphthaldehydeisonicotinoylhydrazone (2-OH-H2Inf. In (1-6 bidentateO(C-O–N(N=CH-coordination of the enol form of the ligand is realized and the coordination node {SnCl4ON}– is formed, and in (9 the enol form remains, but the composition of the node changes – {SnCl3O2N}– due to O(C-O–N(N=CH–О(Ph-O- tridentate coordination.The compounds were characterized by the methods of elemental analysis, mass spectrometry, conductometry, thermogravimetry. Their structure was established by comparing the mass- and IR spectra (1-6 and (9 with previously obtained and X-ray structurally characterized complexes [SnCl4(R-Ib∙Н]∙CH3CN (R=4-N(CH32(7 and [SnCl3(R-Ib∙Н]∙2CH3CN (R=2-OH(8with bi- (7 and tridentate coordination (8 of isonicotinoylhydrazones, respectively. It is shown that (1-6 and (9 are complex compounds of the zwitterionic type: the negative charge on the coordination nodes of tin(IVis delocalized by the oxyazine fragment N=C–O, and the positive charge – by the protonation of the vacant pyridine nitrogen atomof hydrazide fragment. The influence of the composition of the coordination node of complexes (1-9, as well as the nature and position of the substituents (R in their molecules on the activity against Mycobacteriumtuberculosis was determined. It was found that the effect of complexes with tridentate hydrazones (8 and (9 on the growth of pathogen is lower (MIC = 12.5 and 25 μM/ml, respectively compared with bidentatehydrazones (MIC (1-7 = 0,8 – 6,25 μM/ml, among which [SnCl4(2-OCH3-Ib∙Н] (4  stand out (MIC = 0.8 μM/ml.

  12. Improvement of ionic conductivity and performance of quasi-solid-state dye sensitized solar cell using PEO/PMMA gel electrolyte

    International Nuclear Information System (INIS)

    Aram, E.; Ehsani, M.; Khonakdar, H.A.

    2015-01-01

    Graphical abstract: Reduced interfacial resistance of a quasi-solid-state dye sensitized solar cell with PEO/PMMA blend gel electrolytes. - Highlights: • A new polymer gel electrolyte containing PEO/PMMA was developed for DSSCs. • Optimization of polymer gel electrolyte was done for dye sensitized solar cell. • The best ionic conductivity was found in PEO/PMMA blend with 10/90 w/w composition. • The DSSC with the PEO/PMMA based electrolyte showed good photovoltaic performance. • Significant stability improvement for quasi-solid state DSSC was obtained. - Abstract: Polymer blend gel electrolytes based on polyethylene oxide (PEO) and poly(methyl methacrylate) (PMMA) as host polymers with various weight ratios, LiI/I 2 as redox couple in electrolyte and 4-tert-butyl pyridine as additive were prepared by solution method. The introduction of PMMA in the PEO gel electrolyte reduced the degree of crystallinity of PEO, which was confirmed by differential scanning calorimetry (DSC). Complexation and ionic conductivity as a function of temperature were investigated with Fourier transform infrared and ionic conductometry, respectively. A good correlation was found between the degree of crystallinity and ionic conductivity. The reduction in crystallinity, governed by blending ratio, led to improvement of ionic conductivity. The best ionic conductivity was attained in PEO/PMMA blend with 10/90 w/w composition. The performance of a quasi-solid-state dye sensitized solar cell using the optimized polymer gel electrolyte was investigated. The optimized system of high ionic conductivity of 7 mS cm −1 , with fill factor of 0.59, short-circuit density of 11.11 mA cm −2 , open-circuit voltage of 0.75 V and the conversion efficiency of 4.9% under air mass 1.5 irradiation (100 mW cm −2 ) was obtained. The long-term stability of the dye-sensitized solar cell (DSSC) during 600 h was improved by using PEO/PMMA gel electrolyte relative to a liquid type electrolyte

  13. Cost-Effective, Insitu Field Measurements for Determining the Water Retention Quantification onBehavior of Individual Right-of-Way Bioswales

    Science.gov (United States)

    Wang, S.; McGillis, W. R.; Hu, R.; Culligan, P. J.

    2017-12-01

    Green infrastructure (GI) interventions, such as right-of-way bioswales, are being implemented in many urban areas, including New York City, to help mitigate the negative impacts of stormwater runoff. To understand the storm water retention capacity of bioswales, hydrological models, at scales ranging from the tributary area of a single right-of-way bioswale to an entire watershed, are often invoked. The validation and calibration of these models is, however, currently hampered by lack of extensive field measurements that quantify bioswale stormwater retention behaviors for different storm sizes and bioswale configurations. To overcome this problem, three field methods to quantify the water retention capacity of individual bioswales were developed. The methods are potentially applicable to other applications concerned with quantifying flow regimes in urban area. Precise measurements with high time resolutions and low environmental impacts are desired for gauging the hydraulic performance of bioswales, and similar GI configurations. To satisfy these requirements, an in-field measurement method was developed which involved the deployment of acoustic water-level sensors to measure the upstream and downstream water levels of flow into and out of a bioswale located in the Bronx areas of New York City. The measurements were made during several individual storm events. To provide reference flow rates to enable accurate calibration of the acoustic water level measurements, two other conductometry-based methods, which made use of YSI sensors and injected calcium chloride solutions, were also developed and deployed simultaneously with the water level measurements. The suite of data gathered by these methods enabled the development of a relationship between stage-discharge and rainfall intensity, which was then used to obtain the upstream and downstream hydrographs for the individual bioswale for the different storm events. This presentation will describe in detail the

  14. Cellular properties of slug flow in vertical co-current gas-liquid flow: slug-churn transition; Caracteristiques cellulaires du regime a poches en ecoulement gaz-liquide co-courant vertical. Transition vers le regime destructure

    Energy Technology Data Exchange (ETDEWEB)

    Lusseyran, Francois

    1990-12-13

    This research thesis reports the study and description of the structure of a slug flow regime in a co-current vertical cylindrical duct, and the characterization and prediction of its transition towards a slug-churn (de-structured) regime. Flow physical mechanisms highlighted by the measurement of two important dynamics variables (wall friction and thickness of liquid films) are related to hypotheses of cellular models. The author first proposes an overview of slug flow regimes: theoretical steady and one-dimensional analysis, mass assessment equations of cellular models, application to the assessment of the flow rate and of the thickness of the film surrounding the gas slug. In the second part, the author addresses the slug flow regime transition towards the slug-churn regime: assessment of the evolution of flow dynamic properties, use of average wall friction analysis to obtain a relevant transition criterion. The third part presents experimental conditions, and measurement methods: conductometry for thickness measurement, polarography for wall friction measurement, and gas phase detection by using an optic barrier or optic fibres [French] Les ecoulements gaz-liquide en conduite verticale presentent quatre configurations ou regimes d'ecoulement. Ce travail porte sur le regime a poches et sur la transition vers la configuration qui lui succede: le regime destructure (churn flow). Les mesures sont effectuees a 200D du point d'injection du gaz, dans une conduite de 12.2 mm de diametre et pour le couple de fluides eau-azote. Les deux principales grandeurs mesurees en fonction des flux d'entree sont: le frottement parietal instantane (methode electrochimique) et l'epaisseur de film instantanee (methode conductimetrique). Une detection optique simultanee de la presence des phases permet un traitement conditionnel de la base de donnees. Les caracteristiques de la cellule moyenne representative de chaque point de fonctionnement en sont deduites: longueur de la cellule

  15. The study of new complex compounds of Ni (II) and Co (II) with N- hydroxy-succinimide and their potential applications as sensors

    Science.gov (United States)

    Sibiescu, Doina; Tutulea, Mihaela-Dana; Mîţă, Carmen; Stan, Corneliu; Roţca, Ioan; Vizitiu, Mihaela

    2010-11-01

    In this paper, the study of obtaining new coordination compounds of Ni (II) and Co(II) using as ligand, N-hydroxy-succinimide, was presented. Also, the stability constants of these compounds in aqueous medium were determined. The obtaining conditions and the stability of the new compounds were accomplished in aqueous solutions using characteristic methods for coordination compounds: pH-metry, conductometry and UV-VIS absorption spectroscopy. The combination ratios and the stability constants were determined with methods characteristic for studies in solutions. From experimental data resulted that the combination ratio of central metallic atoms with the ligand N-hydroxy-succinimide was: 1:1 and respectively 1:2. In the experiments were used salts of NiCl2.6H2O and CoCl2.6H2O. The optimal domain of pH stability of the studied compounds is limited between 5.74 - 5.86 for Co- N-hydroxy-succinimide (for molar ratio 1:1 and 1:2) and respectively 5.69 - 5.87 for Ni-N-hydroxysuccinimide( for molar ratio 1:1 and 1:2, too). It is important to mention that these compounds were used with very good results in determination of wastewaters from textile, metallurgical, chemical and food industry. Complexion reactions with this ligand are very sensitive for the cations in this paper mentioned. Therefore it is used most often with success in analytical chemistry and also it is posibil to use as sensors. The new complex compounds has electronics transitions at λ = 517 nm for both complexes Co-N-hydroxy-succinimide at molar ratio 1:1 and 1:2 and also at the same λ = 397nm for Ni-N-hydroxysuccinimide at molar ratio 1:1 and 1:2. These complexes compounds was separated and recrystallized from aqueous solution. From the spectrophotometric data it was determined the type and the nature of the electronics transitions by Dq parameters.

  16. Synthesis, characterization and thermal behavior of antibacterial and antifungal active zinc complexes of bis (3(4-dimethylaminophenyl)-allylidene-1,2-diaminoethane

    Energy Technology Data Exchange (ETDEWEB)

    Montazerozohori, Morteza, E-mail: mmzohori@mail.yu.ac.ir [Department of Chemistry, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Zahedi, Saeedeh [Department of Chemistry, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Naghiha, Asghar [Department of Animal Sciences, Faculty of Agriculture, Yasouj University, Yasouj (Iran, Islamic Republic of); Zohour, Mostafa Montazer [Genetics of Non-Communicable Disease Research Center, Zahedan University of Medical Sciences, Zahedan (Iran, Islamic Republic of)

    2014-02-01

    In this work, synthesis of a new series of zinc halide/pseudohalide complexes of a bidentate Schiff base ligand entitled as bis (3-(4-dimethylaminophenyl)-allylidene)-1,2-diaminoethane(L) is described. The ligand and its zinc complexes were characterized by various techniques such as elemental analysis, FT-IR, UV–visible, {sup 1}H and {sup 13}C NMR spectra, cyclic voltammetry, and conductometry. Accordingly ZnLX{sub 2} (X = Cl{sup −}, Br{sup −}, I{sup −}, SCN{sup −} and N{sub 3}{sup −}) was suggested as molecular formula of the complexes. Redox behaviors of ligand and its zinc complexes were investigated by cyclic voltammetry method. Furthermore, the ligand and its zinc halide/pseudohalide complexes were tested for their in vitro antibacterial activities against two gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Also in vitro antifungal activities of them against Candida albicans and Aspergillus niger were investigated. The results indicated that all compounds are antibacterial and antifungal active. Thermal behaviors of ligand and its zinc complexes were studied from room temperature to 1100 °C under argon atmosphere. It was found that the ligand and zinc iodide are decomposed completely via three and four steps respectively while other zinc complexes leave out the metal or organometallic compounds as final residuals after 3–4 decomposition steps at above temperature range. Moreover evaluation of some thermo-kinetic parameters such as activation energy (∆E{sup ⁎}), enthalpy (∆H{sup ⁎}), entropy (∆S{sup ⁎}) and Gibbs free energy change (∆G{sup ⁎}) of the thermal decomposition steps were performed based on the Coats–Redfern relation. - Highlights: • Some novel complexes of Zn(II) with a bidentate Schiff base ligand have been synthesized. • Redox behavior of ligand and zinc complexes was investigated by cyclic voltammetry. • The

  17. Anion exchanger and the resistance against thermal haemolysis.

    Science.gov (United States)

    Ivanov, I T; Zheleva, A; Zlatanov, I

    2011-01-01

    4,4'-Diiso-thiocyanato stilbene-2,2'-disulphonic acid (DIDS) is a membrane-impermeable, highly specific covalent inhibitor and powerful thermal stabiliser of the anion exchanger (AE1), the major integral protein of erythrocyte membrane (EM). Suspensions of control and DIDS-treated (15 µM, pH 8.2) human erythrocytes were heated from 20° to 70°C using various but constant heating rates (1-8°C/min). The cellular electrolyte leakage exhibited a sigmoidal response to temperature as detected by conductometry. The critical midpoint temperature of leakage, T(mo), extrapolated to low heating rate (0.5°C/min) was used as a measure for EM thermostability. T(mo) was greater for DIDS-treated erythrocytes, 63.2° ± 0.3°C, than for intact erythrocytes, 60.7° ± 0.2°C. The time, t(1/2), for 50% haemolysis of erythrocytes, exposed to 53°C was used as a measure for the resistance of erythrocytes against thermal haemolysis. The t(1/2) was also greater for DIDS-treated erythrocytes, 63 ± 3 min, than for intact erythrocytes, 38 ± 2 min. The fluorescent label N-(3-pyrenyl)maleimide and EPR spin label 3-maleimido-proxyl, covalently bound to sulphydryl groups of major EM proteins, were used to monitor the changes in molecular motions during transient heating. Both labels reported an intensification of the motional dynamics at the denaturation temperatures of spectrin (50°C) and AE1 (67°C), and, surprisingly, immobilisation of a major EM protein, presumably the AE1, at T(mo). The above results are interpreted in favour of the possible involvement of a predenaturational rearrangement of AE1 copies in the EM thermostability and the resistance against thermal haemolysis.

  18. Improvement of ionic conductivity and performance of quasi-solid-state dye sensitized solar cell using PEO/PMMA gel electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Aram, E. [Iran Polymer and Petrochemical Institute, 14965/115 Tehran (Iran, Islamic Republic of); Ehsani, M., E-mail: m.ehsani@ippi.ac.ir [Iran Polymer and Petrochemical Institute, 14965/115 Tehran (Iran, Islamic Republic of); Khonakdar, H.A. [Iran Polymer and Petrochemical Institute, 14965/115 Tehran (Iran, Islamic Republic of); Leibniz Institute of Polymer Research, D-01067 Dresden (Germany)

    2015-09-10

    Graphical abstract: Reduced interfacial resistance of a quasi-solid-state dye sensitized solar cell with PEO/PMMA blend gel electrolytes. - Highlights: • A new polymer gel electrolyte containing PEO/PMMA was developed for DSSCs. • Optimization of polymer gel electrolyte was done for dye sensitized solar cell. • The best ionic conductivity was found in PEO/PMMA blend with 10/90 w/w composition. • The DSSC with the PEO/PMMA based electrolyte showed good photovoltaic performance. • Significant stability improvement for quasi-solid state DSSC was obtained. - Abstract: Polymer blend gel electrolytes based on polyethylene oxide (PEO) and poly(methyl methacrylate) (PMMA) as host polymers with various weight ratios, LiI/I{sub 2} as redox couple in electrolyte and 4-tert-butyl pyridine as additive were prepared by solution method. The introduction of PMMA in the PEO gel electrolyte reduced the degree of crystallinity of PEO, which was confirmed by differential scanning calorimetry (DSC). Complexation and ionic conductivity as a function of temperature were investigated with Fourier transform infrared and ionic conductometry, respectively. A good correlation was found between the degree of crystallinity and ionic conductivity. The reduction in crystallinity, governed by blending ratio, led to improvement of ionic conductivity. The best ionic conductivity was attained in PEO/PMMA blend with 10/90 w/w composition. The performance of a quasi-solid-state dye sensitized solar cell using the optimized polymer gel electrolyte was investigated. The optimized system of high ionic conductivity of 7 mS cm{sup −1}, with fill factor of 0.59, short-circuit density of 11.11 mA cm{sup −2}, open-circuit voltage of 0.75 V and the conversion efficiency of 4.9% under air mass 1.5 irradiation (100 mW cm{sup −2}) was obtained. The long-term stability of the dye-sensitized solar cell (DSSC) during 600 h was improved by using PEO/PMMA gel electrolyte relative to a liquid type

  19. Solidification of metallic aluminum on magnesium phosphate cements

    International Nuclear Information System (INIS)

    Lahalle, Hugo

    2016-01-01

    This work deals with the stabilization/solidification of radioactive waste using cement. More particularly, it aims at assessing the chemical compatibility between metallic aluminum and mortars based on magnesium phosphate cement. The physical and chemical processes leading to setting and hardening of the cement are first investigated. X-ray diffraction (XRD), thermogravimetry (TGA) and nuclear magnetic resonance spectroscopy ("3"1P and "1"1B MAS-NMR) are first used to characterize the solid phases formed during hydration, while inductively coupled plasma atomic emission spectroscopy analysis (ICP-AES), electrical conductometry and pH measurements provide information on the pore solution composition. Then, the corrosion of metallic aluminum in magnesium phosphate mortars is studied by monitoring the equilibrium potential and by electrochemical impedance spectroscopy (EIS). Magnesium phosphate cement is prepared from a mix of magnesium oxide (MgO) and potassium dihydrogen orthophosphate (KH_2PO_4). In the presence of water, hydration occurs according to a dissolution - precipitation process. The main hydrate is K-struvite (MgKPO_4.6H_2O). Its precipitation is preceded by that of two transient phases: phosphorrosslerite (MgHPO_4.7H_2O) and Mg_2KH(PO_4)_2.15H_2O. Boric acid retards cement hydration by delaying the formation of cement hydrates. Two processes may be involved in this retardation: the initial precipitation of amorphous or poorly crystallized minerals containing boron and phosphorus atoms, and/or the stabilization of cations (Mg"2"+, K"+) in solution. As compared with a Portland cement-based matrix, corrosion of aluminum is strongly limited in magnesium phosphate mortar. The pore solution pH is close to neutrality and falls within the passivation domain of aluminum. Corrosion depends on several parameters: it is promoted by a water-to-cement ratio (w/c) significantly higher than the chemical water demand of cement (w/c = 0.51), and by the addition of boric

  20. Synthesis, characterization and thermal behavior of antibacterial and antifungal active zinc complexes of bis (3(4-dimethylaminophenyl)-allylidene-1,2-diaminoethane

    International Nuclear Information System (INIS)

    Montazerozohori, Morteza; Zahedi, Saeedeh; Naghiha, Asghar; Zohour, Mostafa Montazer

    2014-01-01

    In this work, synthesis of a new series of zinc halide/pseudohalide complexes of a bidentate Schiff base ligand entitled as bis (3-(4-dimethylaminophenyl)-allylidene)-1,2-diaminoethane(L) is described. The ligand and its zinc complexes were characterized by various techniques such as elemental analysis, FT-IR, UV–visible, 1 H and 13 C NMR spectra, cyclic voltammetry, and conductometry. Accordingly ZnLX 2 (X = Cl − , Br − , I − , SCN − and N 3 − ) was suggested as molecular formula of the complexes. Redox behaviors of ligand and its zinc complexes were investigated by cyclic voltammetry method. Furthermore, the ligand and its zinc halide/pseudohalide complexes were tested for their in vitro antibacterial activities against two gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Also in vitro antifungal activities of them against Candida albicans and Aspergillus niger were investigated. The results indicated that all compounds are antibacterial and antifungal active. Thermal behaviors of ligand and its zinc complexes were studied from room temperature to 1100 °C under argon atmosphere. It was found that the ligand and zinc iodide are decomposed completely via three and four steps respectively while other zinc complexes leave out the metal or organometallic compounds as final residuals after 3–4 decomposition steps at above temperature range. Moreover evaluation of some thermo-kinetic parameters such as activation energy (∆E ⁎ ), enthalpy (∆H ⁎ ), entropy (∆S ⁎ ) and Gibbs free energy change (∆G ⁎ ) of the thermal decomposition steps were performed based on the Coats–Redfern relation. - Highlights: • Some novel complexes of Zn(II) with a bidentate Schiff base ligand have been synthesized. • Redox behavior of ligand and zinc complexes was investigated by cyclic voltammetry. • The ligand and its zinc complexes are antibacterial and

  1. The α-chymotrypsin and its hydrophobic derivatives in inverse micelles; L'α-chymotrypsine et ses derives hydrophobes en micelles inverses

    Energy Technology Data Exchange (ETDEWEB)

    Pitre, Franck

    1993-01-29

    The α-chymotrypsin is among the most used enzymes, notably and particularly in medicine for therapeutic treatments as well as in biochemistry to determine the amine acid sequence of proteins. This research thesis addresses the study of interactions between a micro-emulsion system and an enzymatic system, and more particularly the behaviour of α-chymotrypsin in AOT inverse micelles. After a brief description of the inverse micellar system and of previously obtained results on the solubilisation of α-chymotrypsin in inverse micelles, the author reports the study of the inverse micellar phase in presence of α-chymotrypsin at the vicinity of the maximum solubility. Various techniques are used for this purpose: UV-visible absorption spectrophotometry, conductometry, and X ray scattering. Then, the author describes the chemical modification of α-chymotrypsin, and reports the study of structural as well as reaction modifications introduced during the solubilisation of α-chymotrypsin modified in inverse micelles [French] L'α-chymotrypsine compte parmi les enzymes les plus utilisees dans le monde. Elle est employee tout aussi bien en medecine pour des actions therapeutiques qu'en biochimie afin de determiner entre autre la sequence en acides amines des proteines a etudier. Son succes provient en partie du fait qu'elle hydrolyse avec efficacite un grand nombre de liaisons peptidiques. Les micelles inverses sont un milieu adequat pour permettre l'hydrolyse de molecules relativement hydrophobes par l'α-chymotrypsine. Elle peut ainsi fonctionner dans un milieu tres fortement organique sans etre denaturee. Nous avons montre d'une part que l'α-chymotrypsine se localise au coeur de la micelle inverse sans contact permanent avec les molecules tensioactives. La solubilisation de l'α-chymotrypsine n'a aucune influence sur la taille, pour des micelles dont le rayon est superieur a celui de l'enzyme, et sur le potentiel d'interaction intermicellaire et ceci meme pour des

  2. Thermodynamic and structural of the water - dodecane - bis(ethyl-2-hexyl) phosphoric acid and its sodium salt; Etude thermodynamique et structurale du systeme: eau - dodecane - acide bis(ethyl-2 hexyl) phosphorique et de son sel de sodium

    Energy Technology Data Exchange (ETDEWEB)

    Lovera, Jacqueline

    1985-12-20

    This research thesis reports the study of the appearance and disappearance of the 'third phase' obtained during the salification of the bis(ethyl-2 hexyl) phosphoric acid (HDEHP) diluted in dodecane, by sodium aqueous solutions. After a large bibliographical study on the properties of the intervening compounds (extraction of metallic cation by the acid, parameters influencing the 'third phase' appearance, surfactant properties, direct and inverse micelles, formation of para-crystalline phases), the author presents chemical experimental methods: liquid-liquid extraction tests, tests by the synthetic way, preparation of reactants, dosing method, methods of chemical analysis). Then, she reports and discusses experimental results in terms of determination of phase diagrams at 25 C, of composition by weight of the third phase, of influence of the apolar diluent, and of influence of the electrolyte. Physical experimental methods are then presented (differential calorimetric analysis, NMR, small angle X-ray scattering, light scattering, polarised light microscopy, constrained phase microscopy, photography, infrared spectroscopy, conductometry, transmission electron micrography, volumetric mass measurements, surface and interface tension measurements, viscoelasticity measurements) and their results are discussed and interpreted [French] Nous etudions l'apparition et la disparition de la 'troisieme phase' obtenue lors de la salification de l'acide bis(ethyl-2 hexyl) phosphorique - HDEHP - dilue dans le dodecane, par des solutions aqueuses de soude. Nous obtenons cinq resultats experimentaux essentiels: a - dans le systeme etudie, la troisieme phase n'apparait qu'au dela de la salification. La phase qui apparait est une phase aqueuse de soude diluee, se separant de la phase organique en equilibre avec le dodecane presente a la salification exacte. b - la disparition de la troisieme phase s'effectue par recombinaison des deux phases organiques: la 'phase organique lourde

  3. Shadow corrosion phenomenon. An out-of-pile study on electrochemical effects

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Nadine

    2017-04-28

    galvanic current could be decreased by a CrN coating layer on Inconel 718. Objectives including a deeper knowledge about the corrosion mechanism with its influencing parameters and driving forces by studying Shadow Corrosion with out-of-pile autoclave experiments are listed in chapter 4. A further aim was to test the effectiveness of a possible spacer coating to reduce the corrosion or even to prevent the reactor plant components against Shadow Corrosion. Chapter 5 gives an overview of the experimental part with a description of the materials and chemicals, like Zircaloy and Inconel 718, as well as the specimen preparation techniques, such as etching, pre-oxidation or coating with CrN. Moreover, the three experimental test set-ups used to simulate the different conditions as a function of temperature and water chemistry parameters are depicted. The electrochemical measuring methods including electrochemical corrosion potential (ECP), galvanic corrosion (GC), electrochemical impe-dance spectroscopy (EIS) and conductometry are described. Further methods for surface analyses comprising microscopy, scanning electron microscopy (SEM), focused ion beam (FIB), transmission electron microscopy (TEM), ellipsometry, ion coupled plasma optical emission spectroscopy (ICP-OES) and spectrophotometry are presented. Results and corresponding discussions are summarized in chapter 6, which is divided into three subchapters. Chapter 6.1 deals with electrochemical parameters, like electrochemical corrosion potential, galvanic potential, and galvanic current as well as parameters obtained from electrochemical impedance spectroscopy as a function of different water chemistry parameters. The focus was on the concentration of hydrogen peroxide, the presence of impurities in the form of nitrate, and the exposure to UV-light. Furthermore, surface analyses via the focused ion beam technique and the transmission electron microscopy were gathered to visualize the oxide layer structure, composition

  4. Shadow corrosion phenomenon. An out-of-pile study on electrochemical effects

    International Nuclear Information System (INIS)

    Weber, Nadine

    2017-01-01

    N coating layer on Inconel 718. Objectives including a deeper knowledge about the corrosion mechanism with its influencing parameters and driving forces by studying Shadow Corrosion with out-of-pile autoclave experiments are listed in chapter 4. A further aim was to test the effectiveness of a possible spacer coating to reduce the corrosion or even to prevent the reactor plant components against Shadow Corrosion. Chapter 5 gives an overview of the experimental part with a description of the materials and chemicals, like Zircaloy and Inconel 718, as well as the specimen preparation techniques, such as etching, pre-oxidation or coating with CrN. Moreover, the three experimental test set-ups used to simulate the different conditions as a function of temperature and water chemistry parameters are depicted. The electrochemical measuring methods including electrochemical corrosion potential (ECP), galvanic corrosion (GC), electrochemical impe-dance spectroscopy (EIS) and conductometry are described. Further methods for surface analyses comprising microscopy, scanning electron microscopy (SEM), focused ion beam (FIB), transmission electron microscopy (TEM), ellipsometry, ion coupled plasma optical emission spectroscopy (ICP-OES) and spectrophotometry are presented. Results and corresponding discussions are summarized in chapter 6, which is divided into three subchapters. Chapter 6.1 deals with electrochemical parameters, like electrochemical corrosion potential, galvanic potential, and galvanic current as well as parameters obtained from electrochemical impedance spectroscopy as a function of different water chemistry parameters. The focus was on the concentration of hydrogen peroxide, the presence of impurities in the form of nitrate, and the exposure to UV-light. Furthermore, surface analyses via the focused ion beam technique and the transmission electron microscopy were gathered to visualize the oxide layer structure, composition, and thickness after exposure to oxygenated