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Sample records for solution composition nacl

  1. Corrosion Behaviour of Heat - Treated Al-6063/ SiCp Composites Immersed in 5 wt% NaCl Solution

    Directory of Open Access Journals (Sweden)

    Kenneth ALANEME

    2011-06-01

    Full Text Available The influence of SiC volume percent and temper conditions (namely, as-cast, solutionized, and artificial age hardening at 180°C and 195°C on the corrosion behaviour of Al (6063 composites and its monolithic alloy immersed in 5wt% NaCl solution has been investigated. Al (6063 - SiC particulate composites containing 6, 12 and 15 volume percent SiC were produced by premixing the SiC particles with borax additive and then adopting two step stir casting. Mass loss and corrosion rate measurements were utilized as criteria for evaluating the corrosion behaviour of the composites. The results show that the corrosion susceptibility of the Al (6063 - SiCp composites was higher than that of the monolithic alloy, and for most cases the corrosion rate of the composites increased with increase in volume percent of SiC. However, it was discovered that the nature of the passive films formed on the composites was sufficiently stable to reduce significantly the corrosion rate of the composites after 13days of immersion. This trend was observed to be consistent for all heat-treatment conditions utilized.

  2. Corrosion behavior and pitting susceptibility of in-situ Ti-based metallic glass matrix composites in 3.5 wt.% NaCl solutions

    Science.gov (United States)

    Xu, K. K.; Lan, A. D.; Yang, H. J.; Han, P. D.; Qiao, J. W.

    2017-11-01

    The Ti62Zr12V13Cu4Be9, Ti58Zr16V10Cu4Be12, Ti46Zr20V12Cu5Be17, and Ti40Zr24V12Cu5Be19 metallic glass matrix composites (MGMCs) were prepared by copper mould casting. The corrosion resistance and the pitting susceptibility of Ti-based MGMCs were tested on their cross-sectional areas in 3.5 wt.% NaCl solutions by potentiodynamic polarization measurements. The composites with lower Ti contents (Ti40Zr24V12Cu5Be19 and Ti46Zr20V12Cu5Be17) exhibit a low resistance to the chloride induced pitting and local corrosion. The preferential dissolution of amorphous matrix is explained by the high chemical reactivity of beryllium element compared to that of stable dendrites and by the detected lower Ti and V contents. However, fairly good passivity was found in the composite with higher Ti contents (Ti62Zr12V13Cu4Be9). XPS measurements revealed that protective Ti-enriched oxide film was formed on the composite surface, additionally, lower content of beryllium element in amorphous matrix hinder the selective corrosion of amorphous matrix. The assessment of experimental observation leads to a proposed corrosion mechanism involving selective dissolution of amorphous matrix and chloride induced pitting process.

  3. Corrosion behaviour of groundnut shell ash and silicon carbide hybrid reinforced Al-Mg-Si alloy matrix composites in 3.5% NaCl and 0.3M H2SO4 solutions

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo ALANEME

    2015-05-01

    Full Text Available The corrosion behaviour of Al-Mg-Si alloy based composites reinforced with groundnut shell ash (GSA and silicon carbide (SiC was investigated. The aim is to assess the corrosion properties of Al-Mg-Si alloy based hybrid reinforced composites developed using different mix ratios of GSA (a cheaply processed agro waste derivative which served as partial replacement for SiC and SiC as reinforcing materials. GSA and SiC mixed in weight ratios 0:1, 1:3, 1:1, 3:1, and 1:0 were utilized to prepare 6 and 10 wt% of the reinforcing phase with Al‐Mg‐Si alloy as matrix using two‐step stir casting method. Mass loss and corrosion rate measurement was used to study the corrosion behaviour of the produced composites in 3.5% NaCl and 0.3M H2SO4 solutions. The results show that the Al-Mg-Si alloy based composites containing 6 and 10 wt% GSA and SiC in varied weight ratios were resistant to corrosion in 3.5% NaCl solution. The composites were however more susceptible to corrosion in 0.3M H2SO4 solution (in comparison with the 3.5% NaCl solution. It was noted that the Al-Mg-Si/6 wt% GSA-SiC hybrid composite grades containing GSA and SiC in weight ratio 1:3 and 3:1 respectively exhibited superior corrosion resistance in the 0.3M H2SO4 solution compared to other composites produced for this series. In the case of the Al-Mg-Si/10 wt% GSA-SiC hybrid composite grades, the corrosion resistance was relatively superior for the composites containing a greater weight ratio of GSA (75% and 100% in 0.3M H2SO4 solution.

  4. Manipulating Single Microdroplets of NaCl Solutions

    DEFF Research Database (Denmark)

    Utoft, Anders; Kinoshita, Koji; Bitterfield, Deborah

    2018-01-01

    fraction of S = 1.9, the saturation concentration of NaCl in aqueous solution as measured with nanograms of material (5.5 ± 0.1 M), the diffusion coefficient for water in octanol, D = (1.96 ± 0.10) × 10−6 cm2/s, and the effect of the solvent’s activity on dissolution kinetics. It is further shown...... growth are affected by changing the bathing medium from octanol to decane. A much slower loss of water-solvent and concomitant slower up-concentration of the NaCl solute resulted in a lower tendency to nucleate and slower crystal growth because much less excess material was available at the onset...... of nucleation in the decane system as compared to the octanol system. Thus, the crystal structure is reported to be dendritic for NaCl solution microdroplets dissolving rapidly and nucleating violently in octanol, while they are formed as single cubic crystals in a gentler way for solution-dissolution in decane...

  5. Passivity of alloy C-22 in NaCl solutions

    International Nuclear Information System (INIS)

    Rodriguez, Martin A.; Carranza, Ricardo M.

    2004-01-01

    Alloy C-22 has been proposed as the corrosion resistant barrier of high-level waste nuclear containers. This alloy must be resistant to corrosion in multi-ionic solutions for a period of time as long as 10,000 years. The aim of the present work was to study the corrosion behavior of alloy C-22 in NaCl solutions. General and crevice corrosion were studied by means of electrochemical techniques. Open circuit potential was measured over the time, electrochemical impedance spectroscopy (EIS) measurements were carried out at open circuit and passivity potentials, as well as cyclic potentiodynamic polarization curves. Corrosion rates obtained by EIS measurements were acceptable for a waste nuclear container ( P ) values increased with open circuit potential and polarization time at constant potential. This was attributed to an increase in oxide film thickness and its aging respectively. The passive oxide form on alloy C-22 at the studied conditions presented a n-type semiconductor behavior in the passive potential range. Repassivation potential values (E R1 ) were determined for alloy C-22 at the studied conditions using PCA probes. (author) [es

  6. Ultrasonic cavitation erosion of Ti in 0.35% NaCl solution with bubbling oxygen and nitrogen.

    Science.gov (United States)

    Li, D G; Wang, J D; Chen, D R; Liang, P

    2015-09-01

    The influences of oxygen and nitrogen on the ultrasonic cavitation erosion of Ti in 0.35%NaCl solution at room temperature, were investigated using a magnetostrictive-induced ultrasonic cavitation erosion (CE) facility and scanning electron microscopy (SEM). The roles of oxygen and nitrogen in the composition and the electronic property of the passive film on Ti, were studied by Mott-Schottky plot and X-ray photoelectron spectroscopy (XPS). The results showed that the mass loss of Ti in 0.35%NaCl solution increased with increasing cavitation time. Bubbling oxygen can evidently increase the resistance of ultrasonic cavitation erosion comparing with bubbling nitrogen. XPS results showed that the thickness of the passive film on Ti in 0.35%NaCl solution in the case of bubbling oxygen for 3 weeks, was about 7 nm, and the passive film was mainly composed of TiO2 with an anatase structure. While TiO2 with a rutile structure was found to be the major component of the passive film on Ti in 0.35%NaCl solution in the case of bubbling nitrogen for 3 weeks, and the film thickness was 5 nm. The results extracted from Mott-Schottky plot showed that the passive film on Ti in the case of bubbling oxygen had more donor density than the passive film on Ti in the case of bubbling nitrogen. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2015-12-01

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

  8. Study on the spectrum of photonic crystal cavity and its application in measuring the concentration of NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yun [Nanjing Agricultural Univ., Nanjing (China). Dept. of Physics; Wuxi Institute of Commerce, Wuxi (China). School of Electromechanical Technology; Xie, Xun; Hao, Jiong-Ju; Yang, Hong-Wei [Nanjing Agricultural Univ., Nanjing (China). Dept. of Physics; Yang, Ze-Kun [Lanzhou Univ. (China). School of Information Science and Engineering; Xu, Zhi-Gang [Nanjing Agricultural Univ., Nanjing (China). College of Agriculture

    2017-07-01

    In this article, we propose an approach to measure solution concentrations by using photonic crystal cavities. Based on the experimental data, the refractive index of a NaCl solution is proportional to the concentration. Filling the proposed photonic crystal cavity with a NaCl solution, we calculate the spectral transmission using the transfer matrix method. We found that the cavity transmittance was proportional to the refractive index of the NaCl solution, and thus we obtained a linear relationship between cavity transmittance and the concentration of the NaCl solution. The formula was found by fitting the simulation results with experimental data. Such a formula can be applied to the measurement of an unknown concentration of NaCl solution utilizing a photonic crystal cavity.

  9. Phase equilibria of hydrogen sulfide and carbon dioxide simple hydrates in the presence of methanol, (methanol + NaCl) and (ethylene glycol + NaCl) aqueous solutions

    International Nuclear Information System (INIS)

    Mohammadi, Amir H.; Richon, Dominique

    2012-01-01

    Highlights: → Dissociation conditions of H 2 S or CO 2 hydrate + inhibitor aqueous solution are reported. → Methanol, methanol + NaCl and EG + NaCl aqueous solutions are considered as inhibitors. → Comparisons are made between our experimental data and the corresponding literature data. - Abstract: This work aims at reporting the dissociation pressures of hydrogen sulfide and carbon dioxide simple hydrates in the presence of methanol, (methanol + NaCl) and (ethylene glycol + NaCl) aqueous solutions at different temperatures and various concentrations of inhibitor in aqueous solution. The equilibrium results were generated using an isochoric pressure-search method. These values are compared with some selected experimental data from the literature on the dissociation conditions of hydrogen sulfide and carbon dioxide simple hydrates in the presence of pure water to show the inhibition effects of the above mentioned aqueous solutions. Comparisons are finally made between our experimental values and the corresponding literature data. Some disagreements among the literature data and our data are found.

  10. Supercooling of aqueous NaCl and KCl solutions under acoustic levitation.

    Science.gov (United States)

    Lü, Y J; Wei, B

    2006-10-14

    The supercooling capability of aqueous NaCl and KCl solutions is investigated at containerless state by using acoustic levitation method. The supercooling of water is obviously enhanced by the alkali metal ions and increases linearly with the augmentation of concentrations. Furthermore, the supercooling depends on the nature of ions and is 2-3 K larger for NaCl solution than that for KCl solution in the present concentration range: Molecular dynamics simulations are performed to reveal the intrinsic correlation between supercoolability and microstructure. The translational and orientational order parameters are applied to quantitatively demonstrate the effect of ionic concentration on the hydrogen-bond network and ice melting point. The disrupted hydrogen-bond structure determines essentially the concentration dependence of supercooling. On the other hand, the introduced acoustic pressure suppresses the increase of supercooling by promoting the growth and coalescence of microbubbles, the effective nucleation catalysts, in water. However, the dissolved ions can weaken this effect, and moreover the degree varies with the ion type. This results in the different supercoolability for NaCl and KCl solutions under the acoustic levitation conditions.

  11. Cephradine as corrosion inhibitor for copper in 0.9% NaCl solution

    Science.gov (United States)

    Tasić, Žaklina Z.; Petrović Mihajlović, Marija B.; Radovanović, Milan B.; Simonović, Ana T.; Antonijević, Milan M.

    2018-05-01

    The effect of (6R,7R)-7-[[(2R)-2-amino-2-cyclohexa-1,4-dien-1-ylacetyl]amino]-3-methyl-8-oxo-5-thia-1-azobicyclo[4.2.0]oct-2-ene-2-carboxylic acid (cephradine) on corrosion behavior of copper in 0.9% NaCl solution was investigated. The electrochemical methods including the open circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy measurements, scanning electron microscopy with energy dispersive X-ray spectroscopy and quantum chemical calculations were used for this investigation. According to the results obtained by potentiodynamic polarization, cephradine acts as mixed type inhibitor. Also, the results obtained by electrochemical impedance spectroscopy indicate that cephradine provides good copper protection in 0.9% NaCl solution. The inhibition efficiency of cephradine increases with increasing its concentration. The scanning electron microscopy with energy dispersive X-ray spectroscopy confirms that a protective layer is formed on the copper surface due to the adsorption of cephradine on the active sites on the copper surface. Adsorption of cephradine in 0.9% NaCl solution follows the Langmuir adsorption isotherm. Quantum chemical calculations are in agreement with results obtained by electrochemical measurements.

  12. Effect of applied voltage and initial concentration to desalting NaCl solution using electrodialysis

    International Nuclear Information System (INIS)

    Boubakri, Ali; Gzara, Lassaad; Dhahbi, Mahmoud; Bouguecha, Salah

    2009-01-01

    The desalination process of electrodialysis is one of membrane separation that competes with reverse osmosis for desalination of brackish water and seawater. In this work water desalination using a laboratory electrodialysis was performed and evaluated to desalting aqueous solutions containing 5000, 10000 and 20000 mg/L NaCl at different applied potential (10, 15 and 20 V) and at a constant flow rate of 3 L/min. Nine electrodialysis runs were performed. The results showed that the increasing of applied potential and decreasing of NaCl concentration have an important effect to enhance the electrodialysis performance. The efficiencies of each experiment were evaluated as function of specific power consumption with the electrical energy consumed in electrodialysis stack. It was obtained that the specific power consumption increased when the salt concentration and applied voltage increased. A laboratory electrodialysis stack containing fifteen cation exchange membranes and fifteen anion exchange membranes of 0,716 m 2 total effective area was used.

  13. Forward flux sampling calculation of homogeneous nucleation rates from aqueous NaCl solutions.

    Science.gov (United States)

    Jiang, Hao; Haji-Akbari, Amir; Debenedetti, Pablo G; Panagiotopoulos, Athanassios Z

    2018-01-28

    We used molecular dynamics simulations and the path sampling technique known as forward flux sampling to study homogeneous nucleation of NaCl crystals from supersaturated aqueous solutions at 298 K and 1 bar. Nucleation rates were obtained for a range of salt concentrations for the Joung-Cheatham NaCl force field combined with the Extended Simple Point Charge (SPC/E) water model. The calculated nucleation rates are significantly lower than the available experimental measurements. The estimates for the nucleation rates in this work do not rely on classical nucleation theory, but the pathways observed in the simulations suggest that the nucleation process is better described by classical nucleation theory than an alternative interpretation based on Ostwald's step rule, in contrast to some prior simulations of related models. In addition to the size of NaCl nucleus, we find that the crystallinity of a nascent cluster plays an important role in the nucleation process. Nuclei with high crystallinity were found to have higher growth probability and longer lifetimes, possibly because they are less exposed to hydration water.

  14. Evaluation of the corrosion behavior of the al-356 alloy in NaCl solutions

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    Mauricio Vásquez Rendón

    2011-01-01

    Full Text Available Cellular metals are a new class of materials with promising applications and a unique combination of physical, chemical and mechanical properties. The Al-356 alloy is used to manufacture metal foams from NaCl preforms. Despite the usefulness of these materials, their performance may be affected by corrosion due to residual salt. This paper reports the study of the behavior of the Al-356 alloy in chloride solutions by electrochemical techniques in rotating disk electrode. The cathodic reaction of oxygen reduction is the crucial stage of process dissolution of the material, which shows that is the oxygen transport which limits the corrosion process.

  15. Corrosion monitoring of the AA2024 alloy in NaCl solutions by electrochemical noise measurements

    International Nuclear Information System (INIS)

    Aballe, A.; Bethencourt, M.; Botana, F.J.; Marcos, M.; Rodriguez-Chacon, M.A.

    1998-01-01

    The behaviour of the AA2024 alloy against corrosion in 3.5% NaCl solution has been monitored. In this environment the alloy can be easily damaged under small anodic polarizations. Linear Polarization, electrochemical impedance, spectroscopy and electrochemical noise measurement have been used as experimental techniques. Data from ENM have been analyzed using statistical parameters and Chaos Theory. The results here obtained suggest that ENM is particularly useful to monitored systems that can be modified using other electrochemical techniques. (Author) 11 refs

  16. Crevice corrosion resistance of high alloyed materials in 3.5 % NaCl solution

    International Nuclear Information System (INIS)

    Alar, Vesna; Stojanovic, Ivan; Simunovic, Vinko

    2014-01-01

    The effects of applied torque on the corrosion behaviour of W.-Nr. 1.4404 and 1.4462 stainless steels and W.-Nr. 2.4605 and 2.4858 nickel alloys with crevices were investigated using the cyclic potentiodynamic polarization method. Crevice corrosion (material-to-polytetrafluoroethylene) was tested in 3.5 % NaCl solution at 22 C. The corroded surface was examined using scanning electron microscopy. The results indicate similar trends in susceptibility to crevice corrosion with increasing torque. Among the four specimens, the W.-Nr. 1.4404 is the most susceptible to crevice corrosion. (orig.)

  17. Study on the deterioration process of a chromium-free conversion coating on AZ91D magnesium alloy in NaCl solution

    International Nuclear Information System (INIS)

    Zhao Ming; Wu Shusen; An Ping; Luo Jirong

    2006-01-01

    The morphology of a chromium-free conversion coating for AZ91D magnesium alloy was observed with an Atomic Force Microscopy. The results showed the uniform conversion coating has a relatively smooth appearance with shallow valleys. The EDX results indicated that the compositions of the coating were mainly compounds of Mg, Al, Mn, P, Ca and O. The XRD result showed that the coating contained amorphous materials and a small quantity of crystalline compound. The pitting product of the coating in NaCl water solution mainly composed of Mg, Cl, Mn, P, Ca and O. The corrosion behavior of the samples in NaCl solution was also studied by electrochemical impedance spectroscopy (EIS), which was characterized by one capacitive loop and one inductive loop. Based upon study on both a mathematical model for Faradic admittance of coating in NaCl solution and EIS, it could be considered that the inductive loop was caused by the adsorption of Cl anion and the appearance of pitting corrosion. A degradation mechanism of the coating in NaCl solution is set forth: dissolution velocity of the Cl - adsorption regions of the coating is higher than those non-adsorption regions, for Cl - anions are selective adsorption at some regions of coating surface. When the adsorption regions of coating layer are penetrated by dissolution, the pitting comes into being. The degradation mechanism of conversion coating and the mathematical model are consistent with the EIS results, polarization measurement results and coating's corrosion test results

  18. Manipulating Single Microdroplets of NaCl Solutions: Solvent Dissolution, Microcrystallization, and Crystal Morphology

    DEFF Research Database (Denmark)

    Utoft, Anders; Kinoshita, Koji; Bitterfield, Deborah

    2018-01-01

    that the same Epstein−Plesset (EP) model, which was originally developed for diffusion-controlled dissolution and uptake of gas, and successfully applied to liquid-in-liquid dissolution, can now also be applied to describe the diffusion-controlled uptake of water from a water-saturated environment using...... of nucleation in the decane system as compared to the octanol system. Thus, the crystal structure is reported to be dendritic for NaCl solution microdroplets dissolving rapidly and nucleating violently in octanol, while they are formed as single cubic crystals in a gentler way for solution-dissolution in decane....... These new techniques and analyses can now also be used for any other system where all relevant parameters are known. An example of this is control of drug/hydrogel/emulsion particle size change due to solvent uptake....

  19. Stress corrosion cracking of 350 maraging steel in 3.5 Wt. % NaCl solution

    International Nuclear Information System (INIS)

    Hussain, I.; Hussain, T.; Tauqir, A.; Hashmi, F.H.; Khan, A.Q.

    1993-01-01

    Stress corrosion behavior of 350 maraging steel in 3.5 wt.% NaCl solution was investigated. The results suggest that the steel is susceptible to stress corrosion cracking as the time to failure was always considerably shorter, as compared to those in air at the same stress level. The fracture mode was nearly intergranular and occasionally transgranular. There was no definite trend for the different modes of failure. The strain rate effect was also considered and the results show that the stress corrosion cracks were absent at strain rate high than 1.97 x 10/sup -4/S/sup -1/ and lower than 1.29 x 10/sup -7/S/sup -1/. The critical strain rate range was found to be between 6.4 x 10/sup -7/ to 3.24 x10/sup -5/S /sup -1/. (author)

  20. Thermodiffusive behaviour of NaCl and KCl aqueous solutions a model for the Na-K pump

    International Nuclear Information System (INIS)

    Gaeta, F.S.; Mita, D.G.; Perna, G.; Scala, G.

    1975-01-01

    In NaCl and KCl aqueous nonisothermal solutions K + inverts its sense of migration within the physiological concentration range; Na + behaves similarly at much lower concentrations. These findings are discussed in relation to solute induced modifications of water structure and of their influence on thermal diffusion. A possible evolutionary model of a thermodiffusive mechanism for the sodium potassium pump is also suggested

  1. Composite coatings of titanium-aluminum nitride for steel against corrosion induced by solid NaCl deposit and water vapor at 600 °C

    Directory of Open Access Journals (Sweden)

    M.S. Li

    2004-03-01

    Full Text Available Composite coatings (Ti,AlN with different Al content were deposited on a wrought martensite steel 1Cr11Ni2W2MoV by reactive multi-arc ion plating. With the addition of Al to the coatings, the crystallographic structure of them changed from B1 NaCl to B4 ZnS, the relevant hardness and adhesive strength firstly increased then decreased and their oxidation-resistance was also dramatically improved. It was indicated that the introduction of Al was beneficial to (Ti,AlN coatings against corrosion induced by NaCl(s in wet oxygen at 600 °C as well as wet corrosion in NaCl solution at ambient temperature.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, P. [Dipartimento di Matematica e Fisica, Università Roma Tre, Via della Vasca Navale 84, I-00146 Rome, Italy and INFN, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); Corradini, D.; Rovere, M., E-mail: rovere@fis.uniroma3.it [Dipartimento di Matematica e Fisica, Università Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy)

    2013-11-28

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

  3. Corrosion behaviour of Mg-Cu and Mg-Mo composites in 3.5% NaCl

    International Nuclear Information System (INIS)

    Budruk Abhijeet, S.; Balasubramaniam, R.; Gupta, M.

    2008-01-01

    The corrosion behaviour of pure magnesium, Mg-Cu (0.3, 0.6, and 1 vol.%) and Mg-Mo (0.1, 0.3, and 0.6 vol.%) composites has been studied in 3.5% NaCl solution by weight loss and polarisation methods. Corrosion rates determined by weight loss method were considerably higher than that determined by polarisation method. The corrosion rate increased with increasing volume fraction of reinforcement in Mg-Cu and Mg-Mo composites. At the same volume fraction of reinforcement, molybdenum reinforced composite corroded faster than copper reinforced composite. The galvanic current density between Mg-Cu and Mg-Mo couples has been experimentally measured using zero resistance ammeter technique. The experimentally observed galvanic current densities were in close agreement with those obtained using mixed potential theory analysis. SEM observation of corroded samples confirmed microgalvanic activity at the matrix/reinforcement interfaces. The poor corrosion resistance of composites has been attributed to microgalvanic effects between the matrix and reinforcements and inferior quality of surface films

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

    Science.gov (United States)

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

    2016-04-01

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

  5. In situ AFM study on barite (0 0 1) surface dissolution in NaCl solutions at 30 °C

    International Nuclear Information System (INIS)

    Kuwahara, Yoshihiro; Makio, Masato

    2014-01-01

    Highlights: • We examined barite surface dissolution behavior in NaCl solutions by AFM. • Step retreat and step splitting behavior changed with the NaCl concentration. • Etch pit formation and development differed in each NaCl solution. • Step retreat and etch pit growth rates increased with the NaCl concentration. • We assessed the effects of temperature and NaCl concentration on these rates. - Abstract: This paper reports in situ observations on barite (0 0 1) surface dissolution behavior in 0.1–0.001 M NaCl solutions at 30 °C using atomic force microscopy (AFM). The step retreating on barite (0 0 1) surfaces changed with increasing NaCl solution concentrations. In solutions with a higher NaCl concentration (⩾0.01 M), many steps showed curved or irregular fronts during the later experimental stage, while almost all steps in solutions with a lower NaCl concentration exhibited straight or angular fronts, even during the late stage. The splitting phenomenon of the initial 〈h k 0〉 one-layer steps (7.2 Å) into two half-layer steps (3.6 Å) occurred in all NaCl solutions, while that of the initial [0 1 0] one-layer steps observed only in the 0.1 M NaCl solution. The step retreat rates increased with an increasing NaCl solution concentration. We observed triangular etch pit and deep etch pit formation in all NaCl solutions, which tended to form late in solutions with lower NaCl concentrations. The deep etch pit morphology changed with increasing NaCl solution concentrations. A hexagonal form elongated in the [0 1 0] direction was bounded by the {1 0 0}, {3 1 0}, and (0 0 1) faces in a 0.001 M NaCl solution, and a rhombic form was bounded by the {5 1 0} and (0 0 1) faces in 0.01 M and 0.1 M NaCl solutions. An intermediate form was observed in a 0.005 M NaCl solution, which was defined by {1 0 0}, a curved face tangent to the [0 1 0] direction, {3 1 0}, and (0 0 1) faces: the intermediate form appeared between the hexagonal and rhombic forms in

  6. Effects of prior cold work on corrosion and corrosive wear of copper in HNO3 and NaCl solutions

    International Nuclear Information System (INIS)

    Yin Songbo; Li, D.Y.

    2005-01-01

    Effects of prior cold work on corrosion and corrosive wear behavior of copper in 0.1 M HNO 3 and 3.5% NaCl solutions, respectively, were investigated using electrochemical tests, electron work function measurements, and sliding corrosive wear tests with and without cathodic protection. Optical microscope and SEM were employed to examine the microstructure and worn surfaces. It was shown that, in general, the prior cold work raised the corrosion rate, but the effect differed in different corrosive media. In both the solutions, pure mechanical wear decreased with an increase in cold work. The prior cold work had a significant influence on the corrosive wear of copper, depending on the corrosive solution and the applied load. In the 0.1 M HNO 3 solution, the ratio of the wear loss caused by corrosion-wear synergism to the total wear loss increased with the cold work and became saturated when the cold work reached a certain level. In the 3.5% NaCl solution, however, this ratio decreased initially and then became relatively stable with respect to the cold work. It was observed that wear of copper in the 3.5% NaCl solution was larger than that in 0.1 M HNO 3 solution, although copper showed lower corrosion rate in the former solution. The experimental observations and the possible mechanisms involved are discussed

  7. Corrosion electrochemical behaviors of silane coating coated magnesium alloy in NaCl solution containing cerium nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Luo, F.; Li, Q.; Zhong, X.K.; Gao, H.; Dai, Y.; Chen, F.N. [School of Chemistry and Chemical Engineering, Southwest University Chongqing (China)

    2012-02-15

    Sol-gel coatings cannot provide adequate corrosion protection for metal/alloys in the corrosive environments due to their high crack-forming potential. This paper demonstrates the possibility to employ cerium nitrate as inhibitor to decrease the corrosion development of sol-gel-based silane coating on the magnesium alloy in NaCl solution. Cerium nitrate was added into the NaCl solution where the silane coating coated magnesium alloy was immersed. Scanning electron microscopy (SEM) was used to examine surface morphology of the silane coating coated magnesium alloy immersed in NaCl solutions doped and undoped with cerium nitrate. The corrosion electrochemical behaviors were investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests. The results showed that the introduction of cerium nitrate into NaCl solution could effectively inhibit the corrosion of the silane coating coated magnesium alloy. Moreover, the influence of concentration of cerium nitrate on the corrosion inhibition and the possible inhibiting mechanism were also discussed in detail. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Electrochemical corrosion response of a low carbon heat treated steel in a NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Osorio, W.R.; Peixoto, L.C.; Garcia, L.R.; Garcia, A. [Department of Materials Engineering, State University of Campinas, SP (Brazil)

    2009-10-15

    Dual-phase (DP) steels are produced from a specific heat treatment procedure and have recently emerged as a potential class of engineering materials for a number of structural and automobile applications. Such steels have high strength-to-weight ratio and reasonable formability. The present study aims to investigate the effects of four different and conventional heat treatments (i.e., hot rolling, normalizing, annealing, and intercritical annealing) on the resulting microstructural patterns and on the electrochemical corrosion behavior. Electrochemical impedance spectroscopy (EIS) and Tafel plots were carried out on heat treated steel samples in a 0.5 M NaCl solution at 25 C with neutral pH. An equivalent circuit analysis was also used to provide quantitative support for the discussions. The normalizing and the annealing heat treatments have provided the highest and the lowest corrosion resistances, respectively. The intercritical annealing and as-received (hot rolled) low carbon steel samples have shown similar corrosion behavior. Although a deleterious effect on the corrosion resistance has been verified for DP steel due to the residual stress from the martensite formation, it combines good mechanical properties with intermediate electrochemical corrosion resistance. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  9. Electrokinetic properties of tantalum oxide deposited on model substrate in NaCl and LiCl solutions

    International Nuclear Information System (INIS)

    Sidorova, M.P.; Bogdanova, N.F.; Ermakova, L.Eh.; Bobrov, P.V.

    1997-01-01

    Electrokinetic characteristics of tantalum oxide have been studied using a model system - a plane-parallel capillary in chloride solutions containing monocharge (H + , Na + , Li + ) counterions in a wide range of pH and concentrations. It is shown that position of isoelectric point (IEP) of Ta 2 O 5 depends on concentration and type of counterion, moreover, the dependence is not explained in the framework of classical notions of the influence of counterion specific adsorption on IEP position. Electrokinetic potential of Ta 2 O-5 surface at the background of diluted LiCl solutions is higher in its absolute value, than at the background of NaCl solutions according to direct lyotropic series. The results of measurements of the capillary resistance dependence on pH at the background of NaCl and LiCl solutions 10 -3 -10 -1 M are used for the calculation of efficiency and specific surface conductivity factors

  10. Swelling/deswelling of polyacrylamide gels in aqueous NaCl solution

    Indian Academy of Sciences (India)

    Swelling kinetics of water-swollen polyacrylamide (PAAm) hydrogels (WSG) was investigated in various ... parameter, χ, were calculated and found to decrease with increase in [NaCl]. Collective ..... in other words, increase in hydrophilicity.

  11. NaCl stress-induced changes in the essential oil quality and abietane diterpene yield and composition in common sage

    Directory of Open Access Journals (Sweden)

    Taieb Tounekti

    2015-09-01

    Full Text Available Aim: The purpose of this study was to evaluate how increasing NaCl salinity in the medium can affects the essential oils (EOs composition and phenolic diterpene content and yield in leaves of Salvia officinalis L. The protective role of such compounds against NaCl stress was also argued with regard to some physiological characteristics of the plant (water and ionic relations as well as the leaf gas exchanges. Materials and Methods: Potted plants were exposed to increasing NaCl concentrations (0, 50, 75 and 100 mM for 4 weeks during July 2012. Replicates from each treatment were harvested after 0, 2, 3 and 4 weeks of adding salt to perform physiological measurements and biochemical analysis. Results: Sage EOs were rich in manool, viridiflorol, camphor, and borneol. Irrigation with a solution containing 100 mM NaCl for 4 weeks increased considerably 1.8-cineole, camphor and beta-thujone concentrations, whereas lower concentrations (50 and 75 mM had no effects. On the contrary, borneol and viridiflorol concentrations decreased significantly under the former treatment, while manool and total fatty acid concentrations were not affected. Leaf extracts contained also several diterpenes such as carnosic acid (CA, carnosol (CAR and 12- and #1054;-methoxy carnosic acid (MCA. The concentrations and total contents of CA and MCA increased after 3 weeks of irrigation with 75 or 100 mM NaCl. The 50 mM NaCl had no effect on these diterpenes. Our results suggest a protective role for CA against salinity stress. Conclusion: This study may provide ways to manipulate the concentration and yield of some phenolic diterpenes and EOs in sage. In fact soil salinity may favour a directional production of particular components of interest. [J Intercult Ethnopharmacol 2015; 4(3.000: 208-216

  12. Effect of tonicity on 22NaCl solution uptake by rabbit eye in vivo and in vitro

    International Nuclear Information System (INIS)

    Obenberger, J.; Bartosova, D.; Babicky, A.

    1979-01-01

    Solutions of 22 NaCl in saline or distilled water differ with respect to their ocular uptake. Studies were performed on eyes of living rabbits as well on the enucleated rabbit eyes. Chromatographic paper strips (15x2 mm) were soaked in both solutions, stretched over the cornea and left in contact for 1 min. Radioactivities of paper strips and rabbit eyes were measured and the ocular uptake of 22 Na was expressed as percentual values of the total radioactivities contained in the paper strips before their application to the corneal surface. Values of the ocular uptake of 22 NaCl solved in distilled water exceeded more than twice the values found in experiments where 22 Na solution in saline was used. The use of carrier-free 22 NaCl solutions in distilled water is recommended for the method measuring the ocular uptake hydrodynamics on basis of ocular 22 Na clearance. Uptake of 22 Na in enucleated eyes was twenty-five per cent higher in comparison with the eyes of living rabitts. (author)

  13. Terahertz reflection spectroscopy of aqueous NaCl and LiCl solutions

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd; Merbold, Hannes

    2010-01-01

    frequencies. Whereas both the real and imaginary part of the permittivity of NaCl increases with concentration,we see that the imaginary part of the permittivity of LiCl (related to the absorption)decreases with increasing salt concentration. We relate these changes to the behavior...

  14. Corrosion mitigation of J55 steel in 3.5% NaCl solution by a macrocyclic inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ambrish [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Chengdu, Sichuan 610500 (China); Department of Chemistry, LFTS, Lovely Professional University, Phagwara, Punjab 144402 (India); Lin, Yuanhua, E-mail: yhlin28@163.com [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Chengdu, Sichuan 610500 (China); Obot, I.B. [Centre of Research Excellence in Corrosion, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Ebenso, Eno E. [Department of Chemistry, School of Mathematical & Physical Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735 (South Africa); Material Science Innovation & Modelling (MaSIM) Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735 (South Africa); Ansari, K.R.; Quraishi, M.A. [Department of Applied Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, Uttar Pradesh (India)

    2015-11-30

    Graphical abstract: SECM studies revealed decrease of steady current in the presence of inhibitor while it increased for 3.5% NaCl solution that acted as the conductor. - Highlights: • J55 steel protection in 3.5% NaCl solution saturated with CO{sub 2} by HPT. • Potentiodynamic polarization curves reveal that the actions of HPT are mixed type. • The adsorption of HPT obeys the Langmuir adsorption isotherm. • Scanning electrochemical microscopy is used to discuss the insulated and conductive surface. - Abstract: 1,2,4,7,9,10-Hexaazacyclo-pentadeca-10,15-dien-3,5,6,8-tetraone (HPT) a macrocyclic compound has been studied using electrochemical methods and scanning electrochemical microscopy (SECM) techniques. The R{sub ct} values increased and C{sub dl} values decreased with the increase in concentration of the inhibitor. The corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO{sub 2} by polarization studies revealed that HPT acted as a mixed type inhibitor. The adsorption of HPT on the J55 steel surface obeyed the Langmuir adsorption isotherm. The thermodynamic parameters (K{sub ads}, ΔG°{sub ads}) were also computed and discussed.

  15. Corrosion mitigation of J55 steel in 3.5% NaCl solution by a macrocyclic inhibitor

    International Nuclear Information System (INIS)

    Singh, Ambrish; Lin, Yuanhua; Obot, I.B.; Ebenso, Eno E.; Ansari, K.R.; Quraishi, M.A.

    2015-01-01

    Graphical abstract: SECM studies revealed decrease of steady current in the presence of inhibitor while it increased for 3.5% NaCl solution that acted as the conductor. - Highlights: • J55 steel protection in 3.5% NaCl solution saturated with CO 2 by HPT. • Potentiodynamic polarization curves reveal that the actions of HPT are mixed type. • The adsorption of HPT obeys the Langmuir adsorption isotherm. • Scanning electrochemical microscopy is used to discuss the insulated and conductive surface. - Abstract: 1,2,4,7,9,10-Hexaazacyclo-pentadeca-10,15-dien-3,5,6,8-tetraone (HPT) a macrocyclic compound has been studied using electrochemical methods and scanning electrochemical microscopy (SECM) techniques. The R ct values increased and C dl values decreased with the increase in concentration of the inhibitor. The corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO 2 by polarization studies revealed that HPT acted as a mixed type inhibitor. The adsorption of HPT on the J55 steel surface obeyed the Langmuir adsorption isotherm. The thermodynamic parameters (K ads , ΔG° ads ) were also computed and discussed.

  16. Corrosion behavior of novel imitation-gold copper alloy with rare earth in 3.5% NaCl solution

    International Nuclear Information System (INIS)

    Chen, J.L.; Li, Z.; Zhu, A.Y.; Luo, L.Y.; Liang, J.

    2012-01-01

    Highlights: → The design alloy has better anti-tarnish property than that of H7211 alloy during salt-spray test. → The corrosion rate of design alloy is much lower than that of H7211 alloy as immersed in NaCl solution. → In the low frequency region, the capacitive behavior normally faded and diffusion process had a key role. → In the medium frequency region, the Bode pattern showed a capacitive behavior. -- Abstract: A novel imitation-gold copper alloy with rare earth was designed and prepared. The corrosion behavior of the alloy immersed in 3.5% NaCl solution and its anti-tarnish property in the salt spray for different days has been studied. The designed alloy (CuZnAlNiMeRe) has more excellent anti-tarnish property and lower corrosion rate than those of currency coinage materials of H7211 alloy (used in China). A uniform and compact of corrosion film has been formed after the designed alloy immersed in 3.5% NaCl solution. The corrosion current densities I corr of the alloy decreased while the polarization resistance R p increased with time. The capacitance of the corrosion product film C film of the alloy decreased while the charge transfer resistance R ct . The Warburg diffusion impedance W R and the resistance of the equivalent circuit R increased with time.

  17. Effects of dilute aqueous NaCl solution on caffeine aggregation

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Bhanita; Paul, Sandip, E-mail: sandipp@iitg.ernet.in [Department of Chemistry, Indian Institute of Technology, Guwahati 781039, Assam (India)

    2013-11-21

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

  18. Effects of dilute aqueous NaCl solution on caffeine aggregation

    International Nuclear Information System (INIS)

    Sharma, Bhanita; Paul, Sandip

    2013-01-01

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

  19. Ultrasound degradation of xanthan polymer in aqueous solution: Its scission mechanism and the effect of NaCl incorporation.

    Science.gov (United States)

    Saleh, H M; Annuar, M S M; Simarani, K

    2017-11-01

    Degradation of xanthan polymer in aqueous solution by ultrasonic irradiation was investigated. The effects of selected variables i.e. sonication intensity, irradiation time, concentration of xanthan gum and molar concentration of NaCl in solution were studied. Combined approach of full factorial design and conventional one-factor-at-a-time was applied to obtain optimum degradation at sonication power intensity of 11.5Wcm -2 , irradiation time 120min and 0.1gL -1 xanthan in a salt-free solution. Molecular weight reduction of xanthan gum under sonication was described by an exponential decay function with higher rate constant for polymer degradation in the salt free solution. The limiting molecular weight where fragments no longer undergo scission was determined from the function. The incorporation of NaCl in xanthan solution resulted in a lower limiting molecular weight. The ultrasound-mediated degradation of aqueous xanthan polymer chain agreed with a random scission model. Side chain of xanthan polymer is proposed to be the primary site of scission action. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Long Term Corrosion Experiment of Steel Rebar in Fly Ash-Based Geopolymer Concrete in NaCl Solution

    OpenAIRE

    Asmara, Y. P.; Siregar, J. P.; Tezara, C.; Nurlisa, Wan; Jamiluddin, J.

    2016-01-01

    This research focuses on an experimental investigation to identify the effects of fly ash on the electrochemical process of concrete during the curing time. A rebar was analysed using potentiostat to measure the rest potential, polarization diagram, and corrosion rate. Water-to-cement ratio and amount of fly ash were varied. After being cured for 24 hours at a temperature of 65°C, the samples were immersed in 3.5% of NaCl solution for 365 days for electrochemical measurement. Measurements of ...

  1. Corrosion control of copper in 3.5 wt.% NaCl Solution by Domperidone: Experimental and Theoretical Study

    International Nuclear Information System (INIS)

    Wang, Dan; Xiang, Bin; Liang, Yuanpeng; Song, Shan; Liu, Chao

    2014-01-01

    Highlights: • Domperidone has good inhibition effect for copper in 3.5 wt.% NaCl solution. • Domperidone acts as an anodic type inhibitor. • The SEM and AFM analyses support the weight loss, polarization, and EIS data. • Molecular dynamics (MD) method simulates the adsorption model of domperidone on Cu surface. • The adsorption of domperidone on copper surface obeys Langmuir adsorption isotherm. - Abstract: Inhibition of copper corrosion in 3.5 wt.% NaCl solution by domperidone was investigated by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The experimental results revealed that domperidone was an anodic inhibitor with a maximum achievable inhibition efficiency of 94.2%. The results of SEM and AFM studies further confirmed the inhibition action of domperidone. Quantum chemical calculation and the molecular dynamics (MD) simulation showed that the domperidone molecule could be adsorbed on copper surface through the imidazolidinone ring, benzene ring and N atom of hexaheterocyclic. Adsorption of domperidone was found to follow the Langmuir adsorption isotherm

  2. Influence of immersion freezing in NaCl solutions and of frozen storage on the viscoelastic behavior of mozzarella cheese.

    Science.gov (United States)

    Ribero, G G; Rubiolo, A C; Zorrilla, S E

    2007-06-01

    The freezing of Mozzarella cheese by immersion in NaCl solutions may be an innovative procedure for the dairy industry because it combines conveniently salting and freezing processes. In this work, the influence of this type of freezing method and of the frozen storage of samples on the viscoelastic behavior of Mozzarella cheese was studied. Slabs (2 x 10 x 10 cm(3)) were immersed in 23% w/w NaCl solutions (control samples: 4 degrees C, 90 min; frozen samples: -15 degrees C, 180 min). Half of the frozen samples were immediately thawed at 4 degrees C . The other half was stored at -20 degrees C for 2 mo and then was thawed at 4 degrees C (frozen-stored samples). Samples were stored at 4 degrees C and assayed at 1, 7, 14, 20, 27, 34, and 41 d. Rheological tests were carried out in oscillatory mode (parallel-plate geometry, diameter: 20 mm, gap: 1 mm, frequency: 1 Hz). Strain sweeps were run (0.001 immersion freezing of Mozzarella cheese affects some of the studied parameters, the differences observed between frozen and frozen-stored samples with control samples were small. Therefore, it was considered that the immersion freezing might be useful for the manufacture and commercialization of Mozzarella cheese.

  3. Slow positron beam study of corrosion behavior of AM60B magnesium alloy in NaCl solution

    International Nuclear Information System (INIS)

    Yang, W.; Zhu, Z.J.; Wang, J.J.; Wu, Y.C.; Zhai, T.; Song, G.-L.

    2016-01-01

    Highlights: • Positron annihilation is a sensitive tool to characterize the corrosion layer. • The interfacial voids promoted the formation of Mg(OH) 2 corrosion layer. • Mg(OH) 2 precipitated during early corrosion stage provided a temporary protection. - Abstract: The corrosion behavior of super vacuum die-cast AM60B magnesium alloys immersed in a 5 wt% NaCl solution was investigated by slow positron beam technique, XRD, XPS, SEM and potentiodynamic polarization tests. The XRD and XPS results indicated that Mg(OH) 2 was main corrosion product in the salt solution. With prolonging the immersion time, a significant decrease of Doppler-broadened annihilation line-width parameter near the surface after corrosion was observed and interpreted that the pre-existing interfacial voids between oxide film and matrix might promote the formation of Mg(OH) 2 corrosion layer. Polarization tests found that Mg(OH) 2 could provide a temporary protection.

  4. Effect of pH and chloride on the micro-mechanism of pitting corrosion for high strength pipeline steel in aerated NaCl solutions

    International Nuclear Information System (INIS)

    Wang, Yafei; Cheng, Guangxu; Wu, Wei; Qiao, Qiao; Li, Yun; Li, Xiufeng

    2015-01-01

    Highlights: • Pitting behavior of X80 steel in aerated NaCl solutions is studied systematically. • Unique large pit morphology is observed in neutral/acidic NaCl solutions. • In low pH solutions, pit will propagate in the horizontal direction, leading to the shallow shape of pitting morphology; in high pH solutions, the pit sizes are much smaller. • Film growth, which is dependent on the pH and chloride concentration, has great influence on the cathodic reaction by affecting oxygen diffusion process. - Abstract: The pitting corrosion mechanism of high strength pipeline steel in aerated NaCl solutions with different pH and chloride content was investigated, using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). The pitting behavior in alkaline solutions was found to be significantly different from that in neutral and acidic solutions. Electrochemical results and SEM images indicate that the product film formed on the steel surface results in different corrosion behavior in an alkaline solution. SEM images show that pH and chloride concentration in the bulk solution have a great influence on the pitting morphology. Unique large pit morphology due to corrosion in neutral/acidic solutions with 0.05 mol/L NaCl was observed. The relationship between solution pH and the effect of chloride concentration is also discussed

  5. Aqueous solutions of proline and NaCl studied by differential scanning calorimetry at subzero temperatures

    DEFF Research Database (Denmark)

    Rasmussen, Peter Have; Jørgensen, Bo; Nielsen, Jette

    1997-01-01

    The hydration properties of proline are studied by differential scanning calorimetry (DSC) in aqueous solutions during freezing to -60 degrees C and subsequent heating to +20 degrees C. The concentration of proline in the freeze concentrated solution was estimated to approximately 50 wt% (w/w) in...... plants and insects living under water stress conditions is discussed. (C) 1997 Elsevier Science B.V....

  6. COMPOSITE SOLUTIONS IN RAILROAD ENGINEERING

    Directory of Open Access Journals (Sweden)

    Panfilova Marina Ivanovna

    2012-10-01

    Full Text Available Present-day methods of recovery of used wooden railway ties, including burial, chemical neutralization, gasification and subsequent burning, utilization in the capacity of composite materials, are expensive and unsafe for the environment. The authors propose a new method of their utilization. Ash generated in the course of their burning may replace a portion of cement in composite solutions and act as an additive to grouting mortars designated for the filling of the annulus space of manifold tunnels. The chemical composition of the ash was identified by the x-ray method applied to three samples taken during various periods of time from out of a dry-type dust collector. The level of human health/environmental hazard of the ash is based on its chemical composition. Changes in the rheological properties of composite solutions that contained concrete fractions, various ratios of ash, and 5% of liquid glass were studied in the course of the research. The experiments have proven that in the event of replacement of 20% of cement by ash, the strength of the composite solution is approximately the same as the one of the benchmark sample; therefore, this ash content ratio is deemed acceptable. The finding demonstrate that the ash has no toxic effect, and the ecological safety of this solution is thus confirmed. The authors have proven that 20% of cement may be replaced by the ash generated in the course of burning of waste railway ties.

  7. Corrosion mechanism of Al, Al–Zn and Al–Zn–Sn alloys in 3 wt.% NaCl solution

    International Nuclear Information System (INIS)

    Khireche, S.; Boughrara, D.; Kadri, A.; Hamadou, L.; Benbrahim, N.

    2014-01-01

    Highlights: • We elaborate Al–5Zn–xSn sacrificial anodes (x = 0.1%, 0.2% and 0.4%). • Increasing Sn amount does activate Al alloys. • The anode dissolution in NaCl initiates at precipitations where Sn is enriched. • Sn enhances uniform attack on the surface of the Al alloy. • Al–Zn–Sn anodes perform better than the Al–Zn anode. - Abstract: The effect of zinc and tin addition to pure aluminum was investigated in 3 wt.% NaCl solution. The corrosion behavior of the elaborated samples (Al, Al–Zn and Al–Zn–Sn) was studied by open circuit potential, Tafel plot and electrochemical impedance spectroscopy. For the microstructure characterization, Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy were used. The aluminum activation increases in the following order: Al < Al–5Zn < Al–5Zn–0.1Sn < Al–5Zn–0.2Sn < Al–5Zn–0.4Sn. The impedance measurements and the microscopic observations confirmed the great activity of Al–Zn and Al–Zn–Sn compared to pure Al. The segregation at the grain boundaries leads to intergranular corrosion

  8. Effect of substrate temperature on corrosion performance of nitrogen doped amorphous carbon thin films in NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Khun, N.W. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Liu, E., E-mail: MEJLiu@ntu.edu.s [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2009-07-01

    Nitrogen doped amorphous carbon (a-C:N) thin films were deposited on p-Si substrates by DC magnetron sputtering at varying substrate temperature from room temperature (RT) to 300 {sup o}C. The bonding structure, surface morphology and adhesion strength of the a-C:N films were investigated by using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM) and micro-scratch testing. The corrosion behavior of the a-C:N films was evaluated by potentiodynamic polarization test in a 0.6 M NaCl solution. The results indicated that the corrosion resistance of the films depended on the sp{sup 3}-bonded cross-link structure that was significantly affected by the substrate temperature.

  9. Corrosion behavior of aluminum doped diamond-like carbon thin films in NaCl aqueous solution.

    Science.gov (United States)

    Khun, N W; Liu, E

    2010-07-01

    Aluminum doped diamond-like carbon (DLC:Al) thin films were deposited on n-Si(100) substrates by co-sputtering a graphite target under a fixed DC power (650 W) and an aluminum target under varying DC power (10-90 W) at room temperature. The structure, adhesion strength and surface morphology of the DLC:Al films were characterized by X-ray photoelectron spectroscopy (XPS), micro-scratch testing and atomic force microscopy (AFM), respectively. The corrosion performance of the DLC:Al films was investigated by means of potentiodynamic polarization testing in a 0.6 M NaCl aqueous solution. The results showed that the polarization resistance of the DLC:Al films increased from about 18 to 30.7 k(omega) though the corrosion potentials of the films shifted to more negative values with increased Al content in the films.

  10. Effect of substrate temperature on corrosion performance of nitrogen doped amorphous carbon thin films in NaCl solution

    International Nuclear Information System (INIS)

    Khun, N.W.; Liu, E.

    2009-01-01

    Nitrogen doped amorphous carbon (a-C:N) thin films were deposited on p-Si substrates by DC magnetron sputtering at varying substrate temperature from room temperature (RT) to 300 o C. The bonding structure, surface morphology and adhesion strength of the a-C:N films were investigated by using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM) and micro-scratch testing. The corrosion behavior of the a-C:N films was evaluated by potentiodynamic polarization test in a 0.6 M NaCl solution. The results indicated that the corrosion resistance of the films depended on the sp 3 -bonded cross-link structure that was significantly affected by the substrate temperature.

  11. Pitting resistance and mechanism of TiN-coated Inconel 600 in 100 C NaCl solution

    International Nuclear Information System (INIS)

    In, C.B.; Kim, J.S.; Chun, S.S.; Lee, W.J.

    1995-01-01

    TiN films were deposited on Inconel 600 by PACVD method using a gaseous mixture of TiCl 4 , N 2 , H 2 and Ar, and their pitting resistance and mechanism in 100 C NaCl solution were investigated. Anodic polarization measurement of TiN-coated Inconel 600 was compared with that of bare Inconel 600. TiN-coated Inconel 600 has a higher E np and a lower pit depth than bare Inconel 600. It also shows a smaller pit aspect ratio due to the concentration of the corrosion in the Inconel 600 contacted with the TiN film. When the Inconel 600 has a rough surface, E np decreases and the pit density increases to a great extent. However, E corr , pit depth and pit aspect ratio are not affected. ((orig.))

  12. Experimental study of formation and dynamics of cavitation bubbles and acoustic flows in NaCl, KCl water solutions

    Science.gov (United States)

    Rybkin, K. A.; Bratukhin, Yu. K.; Lyubimova, T. P.; Fatallov, O.; Filippov, L. O.

    2017-07-01

    The acoustic flows and the phenomena associated with them arising under the action of ultrasound of different power on distilled water and aqueous solutions of a mixture of NaCl and KCl salts of various concentrations are studied experimentally. It is found that in the distilled water, under the action of ultrasound, the appearance of inertial and non-inertial cavitation bubbles takes place, then the formation of stable clusters, the distance between which depends on the power of the ultrasound source is observed. Experiments show that an increase in the mass concentration of salts in water leads to the decrease in the average diameter of the arising inertial cavitation bubbles and to the gradual decrease in their number, up to an almost complete disappearance at nearly 13% of the concentration of the salt mixture in the water.

  13. Corrosion Behavior of Cu40Zn in Sulfide-Polluted 3.5% NaCl Solution

    Science.gov (United States)

    Song, Q. N.; Xu, N.; Bao, Y. F.; Jiang, Y. F.; Gu, W.; Yang, Z.; Zheng, Y. G.; Qiao, Y. X.

    2017-10-01

    The corrosion behavior of a duplex-phase brass Cu40Zn in clean and sulfide-polluted 3.5% NaCl solutions was investigated by conducting electrochemical and gravimetric measurements. The corrosion product films were analyzed by scanning electron microscopy, energy-dispersive spectroscopy and x-ray diffraction. The presence of sulfide shifted the corrosion potential of Cu40Zn toward a more negative value by 100 mV and increased the mass loss rate by a factor of 1.257 compared with the result in the clean solution. The corrosion product film in the clean solution was thin and compact; it mainly consisted of oxides, such as ZnO and Cu2O. By contrast, the film in the sulfide-polluted solution was thick and porous. It mainly contained sulfides and zinc hydroxide chloride (i.e., Zn5(OH)8Cl2·H2O). The presence of sulfide ions accelerated the corrosion damage of Cu40Zn by hindering the formation of protective oxides and promoting the formation of a defective film which consisted of sulfides and hydroxide chlorides.

  14. Acid-base behavior of the gaspeite (NiCO3(s)) surface in NaCl solutions.

    Science.gov (United States)

    Villegas-Jiménez, Adrián; Mucci, Alfonso; Pokrovsky, Oleg S; Schott, Jacques

    2010-08-03

    Gaspeite is a low reactivity, rhombohedral carbonate mineral and a suitable surrogate to investigate the surface properties of other more ubiquitous carbonate minerals, such as calcite, in aqueous solutions. In this study, the acid-base properties of the gaspeite surface were investigated over a pH range of 5 to 10 in NaCl solutions (0.001, 0.01, and 0.1 M) at near ambient conditions (25 +/- 3 degrees C and 1 atm) by means of conventional acidimetric and alkalimetric titration techniques and microelectrophoresis. Over the entire experimental pH range, surface protonation and electrokinetic mobility are strongly affected by the background electrolyte, leading to a significant decrease of the pH of zero net proton charge (PZNPC) and the pH of isoelectric point (pH(iep)) at increasing NaCl concentrations. This challenges the conventional idea that carbonate mineral surfaces are chemically inert to background electrolyte ions. Multiple sets of surface complexation reactions (i.e., ionization and ion adsorption) were formulated within the framework of three electrostatic models (CCM, BSM, and TLM) and their ability to simulate proton adsorption and electrokinetic data was evaluated. A one-site, 3-pK, constant capacitance surface complexation model (SCM) reproduces the proton adsorption data at all ionic strengths and qualitatively predicts the electrokinetic behavior of gaspeite suspensions. Nevertheless, the strong ionic strength dependence exhibited by the optimized SCM parameters reveals that the influence of the background electrolyte on the surface reactivity of gaspeite is not fully accounted for by conventional electrostatic and surface complexation models and suggests that future refinements to the underlying theories are warranted.

  15. Inhibitory effect of konjac glucomanan on pitting corrosion of AA5052 aluminium alloy in NaCl solution.

    Science.gov (United States)

    Zhang, Kegui; Yang, Wenzhong; Xu, Bin; Chen, Yun; Yin, Xiaoshuang; Liu, Ying; Zuo, Huanzhen

    2018-05-01

    A natural carbohydrate polymer, konjac glucomanan, has been extracted from commercial product and studied as a green corrosion inhibitor for AA5052 aluminium alloy in 3.5 wt% NaCl solution by high-performance gel permeation chromatography (GPC), thermo gravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectra, electrochemical measurement and surface characterization techniques. The results of GPC measurements suggest the weight-average molecular weight and the number-average molecular weight of KGM with 98.2% purity are 1.61 × 10 5  g/mol and 1.54 × 10 5  g/mol, respectively. Potentiodynamic polarization curves show konjac glucomanan behaves as a mixed-type inhibitor with dominant anodic effect and that its maximum efficiency at 200 ppm is 94%. Electrochemical impedance spectroscopy (EIS) studies reveal the resistance of oxide film is approximately two orders of magnitude greater than the resistance of adsorbed inhibitor layer and that they both increase with KGM concentration. Moreover, in-situ electrochemical noise (EN) detection demonstrates that the growth and propagation stages of the pitting corrosion germinating on metal surface are blocked by polysaccharide additive, which is confirmed by the surface analysis of aluminium alloy using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and Raman spectroscopy. At last, it is found that the addition of KGM makes it harder for water droplet containing NaCl to wet the metallic substrate. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Effect of silicon carbide addition on the corrosion behavior of powder metallurgy Cu−30Zn brass in a 3.5 wt% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Almomani, Mohammed Ali, E-mail: maalmomani7@just.edu.jo [Department of Industrial Engineering, Jordan University of Science and Technology, P. O. Box 3030, Irbid 22110 (Jordan); Tyfour, Wa' il Radwan, E-mail: wrtyfou@just.edu.jo [Department of Industrial Engineering, Jordan University of Science and Technology, P. O. Box 3030, Irbid 22110 (Jordan); Nemrat, Mohammed Hani, E-mail: mohammednemrat@yahoo.com [Department of Mechanical Engineering, Institute of Applied Technology, Abu Dhabi (United Arab Emirates)

    2016-09-15

    A study was made to evaluate the corrosion behavior when Cu−30Zn alloy is reinforced with different weight fractions of silicon carbide (SiC) particles in a simulated sea solution (3.5 wt% NaCl aqueous solution). The composites were produced via powder metallurgy (PM) route. For the sake of comparison, the corrosion behaviors of unreinforced and reinforced alloy were examined. Electrochemical measurements (potentiodynamic testing) showed that the corrosion rate of the composites decreased with increase of SiC weight percentages, as a result of weak microgalvanic couple between reinforcement particles and Cu−30Zn matrix, and the low possibility of intermetallic phases formation. ANOVA test indicated that the variations of corrosion rate of the composites upon changing weight percentages of SiC particles are statistically significant. Polarization curves showed that the passive film tends to be less stable, and the potential difference between passivation and free corrosion points increased with increase of SiC weight percentages, as SiC cathodically protect the matrix material by sacrificial anodic dissolution of crevice regions about reinforcement particles. Scanning Electron Microscope (SEM) images of the sample's surfaces before and after testing are in agreement with the electrochemical results. - Highlights: • Effect of adding SiC on both uniform and localized corrosion of Cu−30Zn alloy is studied. • Reinforcing Cu−30Zn with nonconductive SiC particles decreases its tendency to uniform and localized corrosion. • Reinforcement particles cathodically protect the matrix material, and retard pit propagation to the matrix.

  17. NaCl leached sustainable porous flexible Fe3O4 decorated RGO-polyaniline/PVDF composite for durable application against electromagnetic pollution

    Directory of Open Access Journals (Sweden)

    R. Bera

    2017-05-01

    Full Text Available To avoid the interference of electromagnetic radiation from other devices, an electronic device needs to be fabricated with flexible and light weight electromagnetic interference (EMI shielding materials with high efficiency. According, highly flexible porous poly(vinylidene fluoride (PVDF/PFR (Fe3O4 decorated polyaniline/RGO composite composite was prepared through solution blending of PVDF with pre-synthesized PFR conductive composite that involves in-situ oxidative polymerization of aniline in the presence of reduced graphene oxide (RGO using FeCl3 as oxidant. The porous morphology of the composite was created by leaching out of mixed NaCl from the composite. Polyaniline and RGO were mutually decorated by chemically in-situ synthesized ferrosoferric oxide (Fe3O4 using the Fe source of FeCl3. A homogeneous dispersion of PFR in insulated PVDF matrix resulted in a highly electrical conductive composite (PVDF-PFR material through formation of three dimensional continuous conductive networks of polyaniline-RGO in the matrix phase. The composite shows an outstanding EMI shielding effectiveness (EMI SE property due to the porous structure and the presence of conductive network and ferromagnetic Fe3O4 nanoparticles. The PVDF-PFR composite (0.5 mm thickness depicts a great permittivity and permeability value and achieve high EMI SE value (≈–28.18 dB and conductivity value of ≈1.10·10–1 S·cm–1 at very low loading (5 wt% of RGO.

  18. A comparative corrosion behavior of Mg, AZ31 and AZ91 alloys in 3.5% NaCl solution

    Directory of Open Access Journals (Sweden)

    I.B. Singh

    2015-06-01

    Full Text Available The corrosion behavior of Mg, AZ31 and AZ91 has been evaluated in 3.5% NaCl solution using weight loss, electrochemical polarization and impedance measurements. Corrosion rate derived from the weight losses demonstrated the occurrence of steeply fast corrosion reaction on AZ91 alloy after three hours of immersion, indicating the start of galvanic corrosion. An increase of corrosion rate with immersion time was also observed for AZ31 but with lesser extent than AZ91 alloy. Whereas Mg metals showed a decrease of corrosion rate with immersion time, suggesting the formation of a protective layer on their surfaces. In contrast, the corrosion current density (Icorr derived from the Tafel plots, exhibited their corrosion resistances in order of Mg > AZ91 > AZ31. Electrochemical charge transfer resistance (Rct and double layer capacitance measured by electrochemical impedance spectroscopy (EIS, are well in accordance with the measured Icorr. EIS measurements with time and microstructural examination of the corroded and uncorroded samples are helpful in elucidation of results measured by electrochemical polarization.

  19. Inhibition of Corrosion of Carbon Steel in 3.5% NaCl Solution by Myrmecodia Pendans Extract

    Directory of Open Access Journals (Sweden)

    Atria Pradityana

    2016-01-01

    Full Text Available Inhibitor is a substance that is added to the corrosive media to inhibit corrosion rate. Organic inhibitors are preferred to inorganic ones since they are environmentally friendly. One of the organic compounds which is rarely reported as a corrosion inhibitor is Myrmecodia Pendans. The organic compounds can be adsorbed on the metal surface and block the active surface to reduce the rate of corrosion. In this study, the used pipe was carbon steel API 5L Grade B with 3.5% NaCl solution as the corrosion medium. The objective of this research was to analyze the inhibition mechanism Myrmecodia Pendans towards carbon steel in a corrosion medium. Concentration variations of extract Myrmecodia Pendans were 0–500 ppm. Fourier Transform Infrared (FTIR was used for chemical characterization of Myrmecodia Pendans. Polarization and Electrochemical Impedance Spectroscopy (EIS were used to measure the corrosion rate and behaviour. From the electrochemical measurements, it was found that the addition of 400 mg/L inhibitor gave the highest inhibition efficiency. Myrmecodia Pendans acted as a corrosion inhibitor by forming a thin layer on the metal surface.

  20. Long Term Corrosion Experiment of Steel Rebar in Fly Ash-Based Geopolymer Concrete in NaCl Solution

    Directory of Open Access Journals (Sweden)

    Y. P. Asmara

    2016-01-01

    Full Text Available This research focuses on an experimental investigation to identify the effects of fly ash on the electrochemical process of concrete during the curing time. A rebar was analysed using potentiostat to measure the rest potential, polarization diagram, and corrosion rate. Water-to-cement ratio and amount of fly ash were varied. After being cured for 24 hours at a temperature of 65°C, the samples were immersed in 3.5% of NaCl solution for 365 days for electrochemical measurement. Measurements of the half-cell potential and corrosion current density indicated that the fly ash has significant effects on corrosion behaviour of concrete. Although fly ash tends to create passivity on anodic current, it increases corrosion rate. The corrosion potential of this concrete mixture decreases compared to concrete without fly ash. From the result, it can be summarized that concrete mixture with 70% of OPC (Ordinary Portland Cement and 30% fly ash has shown the best corrosion resistance.

  1. Curcuminoid Compounds Isolated from Curcuma domestica Val. as Corrosion Inhibitor Towards Carbon Steel in 1 % NaCl Solution

    International Nuclear Information System (INIS)

    Kandias, D.; Bundjali, B.; Wahyuningrum, D.

    2011-01-01

    The corrosion inhibitor of carbon steel in 1 % NaCl solution by curcuminoids has been studied at 27 degree Celsius using weight loss and electrochemical method. The determination of corrosion inhibition efficiency (% eff) utilising weight loss method at the concentration of 80 ppm showed the best result of 78.70 % for third isolated fraction. Further determination utilising Tafel method showed the following results: raw pure extract of curcuminoid gave 89.88 % at 50 ppm; the first isolated fraction gave 46.50 % at 80 ppm; the second isolated fraction gave 44.83 % at 30 ppm; and the third isolated fraction gave 92.44 % at 70 ppm. Based on the analysis of Tafel extrapolation curve, the raw pure extract and the third fraction of curcuminoid acted as anodic inhibitor, whereas the first and the second fraction performed as cathodic inhibitors. The evaluations of synergism parameter (S θ ) indicate that the enhancement in inhibition efficiency towards raw pure extract was caused by the presence of second and third fractions as cathodic and anodic inhibitors. The contribution of steric hindrance of methoxy groups in curcuminoid structure causes the decrease in curcuminoid activity to be adsorbed on the electrode (carbon steel) surface. (author)

  2. Simulation of NaCl and KCl mass transfer during salting of Prato cheese in brine with agitation: a numerical solution

    Directory of Open Access Journals (Sweden)

    E. Bona

    2007-09-01

    Full Text Available The association of dietary NaCl with arterial hypertension has led to a reduction in the levels of this salt in cheeses. For salting, KCl has been used as a partial substitute for NaCl, which cannot be completely substituted without affecting product acceptability. In this study a sensorially adequate saline solution (NaCl/KCl was simultaneously diffused during salting of Prato cheese in brine with agitation. The simultaneous multicomponent diffusion during the process was modeled with Fick’s second generalized law. The system of partial differential equations formed was solved by the finite element method (FEM. In the experimental data concentration the deviation for NaCl was of 7.3% and for KCl of 5.4%, both of which were considered acceptable. The simulation of salt diffusion will allow control and modulation of salt content in Prato cheese, permitting the prediction of final content from initial conditions.

  3. Plasma glucose level in elective surgical patients administered with 5% dextrose in 0.45% NaCl in comparison with those receiving lactated Ringer's solution.

    Science.gov (United States)

    Saringcarinkul, Ananchanok; Kotrawera, Kriengsak

    2009-09-01

    To determine the effect of dextrose containing solution (5% dextrose in 0.45% NaCl) compared to non-dextrose containing solution (lactated Ringer's solution) on plasma glucose level in elective surgical patients. A prospective randomized double-blind control trial was conducted on 60 patients aged 18-60, with ASA physical status I to II, who were scheduled for elective surgery at Maharaj Nakorn Chiang Mai Hospital, Thailand between October; 2007 and September; 2008. The patients received either lactated Ringer's solution (Group L), or 5% dextrose in 0.45% NaCl (Group D) in the morning of the operation day. Blood glucose levels were determined before intravenous fluid administration (T0), at the beginning (T1), after the 1st hr (T2), and at the end of surgery (T3). Mean duration of preoperative fast was almost 11 hrs in both groups; however, none of the patients had preoperative hypoglycemia. The blood sugar levels were significantly higher in the patients receiving 5% dextrose solution compared to the patients receiving lactated Ringer's solution at the beginning, after the 1st hr and at the end of surgery (p-value = 0.06, 0.018 and 0.036 respectively). There were some patients having hyperglycemia after receiving 5% dextrose in 0.45% NaCl during surgery. However, none of the average plasma glucose values in either group was considered as hyperglycemia. Though they fasted many hours before surgery, no patients were found to have hypoglycemia. The large volume of lactate Ringer's solution had minimal effect on the blood sugar levels compared to the levels in 5% dextrose in 0.45% NaCl group. Therefore, lactate Ringer's solution is probably the alternative choice of intravenous fluid for perioperative maintenance and can be used as replacement in healthy patients undergoing elective surgery.

  4. Electrochemical Behavior of Sn-9Zn- xTi Lead-Free Solders in Neutral 0.5M NaCl Solution

    Science.gov (United States)

    Wang, Zhenghong; Chen, Chuantong; Jiu, Jinting; Nagao, Shijo; Nogi, Masaya; Koga, Hirotaka; Zhang, Hao; Zhang, Gong; Suganuma, Katsuaki

    2018-05-01

    Electrochemical techniques were employed to study the electrochemical corrosion behavior of Sn-9Zn- xTi ( x = 0, 0.05, 0.1, 0.2 wt.%) lead-free solders in neutral 0.5M NaCl solution, aiming to figure out the effect of Ti content on the corrosion properties of Sn-9Zn, providing information for the composition design of Sn-Zn-based lead-free solders from the perspective of corrosion. EIS results reveal that Ti addition was involved in the corrosion product layer and changed electrochemical interface behavior from charge transfer control process to diffusion control process. The trace amount of Ti addition (0.05 wt.%) can refine the microstructure and improve the corrosion resistance of Sn-9Zn solder, evidenced by much lower corrosion current density ( i corr) and much higher total resistance ( R t). Excess Ti addition (over 0.1 wt.%) led to the formation of Ti-containing IMCs, which were confirmed as Sn3Ti2 and Sn5Ti6, deteriorating the corrosion resistance of Sn-9Zn- xTi solders. The main corrosion products were confirmed as Sn3O(OH)2Cl2 mixed with small amount of chlorine/oxide Sn compounds.

  5. Effects of laser remelting on microstructures and immersion corrosion performance of arc sprayed Al coating in 3.5% NaCl solution

    Science.gov (United States)

    Sun, Ze; Zhang, Donghui; Yan, Baoxu; Kong, Dejun

    2018-02-01

    An arc sprayed aluminum (Al) coating on S355 steel was processed using a laser remelting (LR). The microstructures, chemical element composition, and phases of the obtained Al coating were analyzed using a field mission scanning electronic microscope (FESEM), energy dispersive spectrometer (EDS), and X-ray diffractometer (XRD), respectively, and the residual stresses were measured using an X-ray diffraction stress tester. The immersion corrosion tests and potentiodynamic polarization of Al coating in 3.5% NaCl solution were performed to investigate the effects of LR on its immersion corrosion behaviors, and the corrosion mechanism of Al coating was also discussed. The results show that the arc sprayed Al coating is composed of Al phase, while that by LR is composed of Al-Fe and AlO4FeO6 phases, and the porosities and cracks in the arc sprayed Al coating are eliminated by LR, The residual stress of arc sprayed Al coating is -5.6 ± 18 MPa, while that after LR is 137.9 ± 12 MPa, which deduces the immersion corrosion resistance of Al coating. The corrosion mechanism of arc sprayed Al coating is pitting corrosion and crevice corrosion, while that by LR is uniform corrosion and pitting corrosion. The corrosion potential of arc sprayed Al coating by LR shifts positively, which improves its immersion corrosion resistance.

  6. Photoelectrochemical response and corrosion behavior of CdS/TiO2 nanocomposite films in an aerated 0.5 M NaCl solution

    Science.gov (United States)

    Boonserm, Aleena; Kruehong, Chaiyaput; Seithtanabutara, Varinrumpai; Artnaseaw, Apichart; Kwakhong, Panomkorn

    2017-10-01

    This research aimed to investigate the photoelectrochemical response and corrosion behavior of CdS/TiO2 nanocomposite films using electrochemical measurements in an aerated 0.5 M NaCl solution under white light illumination. The CdS/TiO2 nanocomposite films were prepared by chemical bath deposition technique in a solution of cadmium and sulfide ions. The high resolution images of CdS/TiO2 nanocomposite films were provided by field emission scanning electron microscope. Theirs chemical identification and quantitative compositional information, crystallinity and actual chemical compounds formed were determined by energy dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The results indicated that the photoelectrochemical activity of the films depended strongly on CdS content. From the preparation of CdS/TiO2 nanocomposite films by 5, 10 and 15 dipping cycles in the chemical solutions, the best photoelectrochemical response was revealed by the 10 dipping cycles-prepared film. Galvanic couple testing demonstrated that the photoelectrochemical response of the film decreased continuously compared to that of anodized nanoporous TiO2 substrate which described by photocorrosion of CdS nanoparticles. In addition, chloride-ion attack also induced pitting corrosion leading to fluctuation and deterioration of photoelectrochemical response. CdO2 and Cd(OH)2 depositions were found as the main photocorrosion products on collapsed nanostructured-surface. The relevance between photoelectrochemical response and corrosion behavior of CdS/TiO2 nanocomposite film was discussed in detail.

  7. Effect of Different Welding Processes on Electrochemical and Corrosion Behavior of Pure Nickel in 1 M NaCl Solution

    Directory of Open Access Journals (Sweden)

    Xijing Wang

    2017-11-01

    Full Text Available A plasma arc welding (PAW-tungsten inert gas (TIG hybrid welding process is proposed to weld pure nickel. In PAW-TIG welding, the arc of the PAW was first to be ignited, then TIG was ignited, while in PAW welding, only the PAW arc was launched. This paper investigated the effect of different welding processes on electrochemical and corrosion performance of between a pure nickel joint and a base metal in an aerated 1 M NaCl solution, respectively. The average grain size of the joint fabricated by PAW welding (denoted as JP joint is 463.57 μm, the joint fabricated by PAW-TIG welding(denoted as JP-T joint is 547.32 μm, and the base metal (BM is 47.32 μm. In this work, the passivity behaviors of samples were characterized for two welding processes by electrochemical impedance spectroscopy (EIS, open circuit potential versus immersion time (OCP-t, and the potentiodynamic polarization plots. EIS spectra, attained with different immersion times, were analyzed and fitted by an equivalent electrical circuit. Photomicrographs of BM, JP, and JP-T were also taken with a scanning electron microscope (SEM to reveal the morphological structure of the pit surfaces. Electrochemical tests show that the sequence of the corrosion resistance is BM > JP > JP-T. The size and quantity of the hemispherical corrosion pits of all samples are different. The corrosion morphology observations found a consistency with the consequence of the electrochemical measurements. The results show that an increase of the grain dimensions due to different heat treatments decreased the pure nickel stability to pitting corrosion.

  8. Corrosion resistance and durability of superhydrophobic surface formed on magnesium alloy coated with nanostructured cerium oxide film and fluoroalkylsilane molecules in corrosive NaCl aqueous solution.

    Science.gov (United States)

    Ishizaki, Takahiro; Masuda, Yoshitake; Sakamoto, Michiru

    2011-04-19

    The corrosion resistant performance and durability of the superhydrophobic surface on magnesium alloy coated with nanostructured cerium oxide film and fluoroalkylsilane molecules in corrosive NaCl aqueous solution were investigated using electrochemical and contact angle measurements. The durability of the superhydrophobic surface in corrosive 5 wt% NaCl aqueous solution was elucidated. The corrosion resistant performance of the superhydrophobic surface formed on magnesium alloy was estimated by electrochemical impedance spectroscopy (EIS) measurements. The EIS measurements and appropriate equivalent circuit models revealed that the superhydrophobic surface considerably improved the corrosion resistant performance of magnesium alloy AZ31. American Society for Testing and Materials (ASTM) standard D 3359-02 cross cut tape test was performed to investigate the adhesion of the superhydrophobic film to the magnesium alloy surface. The corrosion formation mechanism of the superhydrophobic surface formed on the magnesium alloy was also proposed. © 2011 American Chemical Society

  9. Effect of NaCl Solution Spraying on Fatigue Lives of Smooth and Slit Specimens of 0.37% Carbon Steel

    Science.gov (United States)

    Makabe, Chobin; Ferdous, Md. Shafiul; Shimabukuro, Akimichi; Murdani, Anggit

    2017-07-01

    The fatigue crack initiation life and growth rate are affected by experimental conditions. A corrosive environment can be created in a laboratory by means of dropping salt water onto the specimen surface, spraying chloride mist into the experimental chamber, etc. In the case of smooth specimens of some metals, fatigue life is shortened and the fatigue limit disappears under such corrosive experimental conditions. In this study, the effects of intermittent spraying of 3% NaCl solution-mist on corrosion fatigue behavior were investigated. The material used was 0.37% carbon steel. This is called JIS S35C in Japan. Spraying of 3% NaCl solution-mist attacked the surface layer of the specimen. It is well known that the pitting, oxidation-reduction reaction, etc. affect the fatigue strength of metals in a corrosive environment. We carried out corrosion fatigue tests with smooth specimens, holed specimens and slit specimens. Then the effects of such specimen geometry on the fatigue strength were investigated when the NaCl solution-mist was sprayed onto the specimen surface. In the case of lower stress amplitude application in slit specimens, the fatigue life in a corrosive atmosphere was longer than that in the open air. It is discussed that the behavior is related to the crack closure which happens when the oxide builds up and clogs the crack or slit.

  10. Effect of temperature and ionic strength on volumetric and acoustic properties of solutions of urea alkyl derivatives in aqueous NaCl

    International Nuclear Information System (INIS)

    Krakowiak, Joanna; Wawer, Jarosław

    2015-01-01

    Highlights: • Urea and its alkyl derivatives in aqueous NaCl solutions were studied. • The density and the speed of sound were measured for presented systems. • The strongest impact of NaCl on obtained quantities is noticed for apparent molar compression. • Bigger hydrophobic character of the solute results in bigger changes of calculated quantities with concentration. • The geometry of the solute is a crucial condition for hydrophobic hydration to happen. - Abstract: The present work was undertaken to study volumetric and acoustic properties for diluted solutions of tetramethylurea in pure water and for urea, n-propylurea, n-butylurea and tetramethylurea in 0.5 or 1 mol · dm −3 aqueous solutions of sodium chloride. This paper presents measured values of densities and sound velocities at T = (288.15, 298.15 and 308.15) K. From these data the apparent molar volumes, V Φ , adiabatic compressibilities, κ S , and apparent molar adiabatic compressions, K S,Φ , were obtained. The values of apparent molar volumes for infinite dilution and limited apparent adiabatic compressions were calculated from extrapolation of the concentration dependence. Further, the corresponding transfer data as well as hydration number of urea and its derivatives in the studied systems were estimated. The obtained parameters are discussed in terms of various solute-solvent and solute-cosolute interactions

  11. MAPK-mediated regulation of growth and essential oil composition in a salt-tolerant peppermint (Mentha piperita L.) under NaCl stress.

    Science.gov (United States)

    Li, Zhe; Wang, Wenwen; Li, Guilong; Guo, Kai; Harvey, Paul; Chen, Quan; Zhao, Zhongjuan; Wei, Yanli; Li, Jishun; Yang, Hetong

    2016-11-01

    Peppermint (Mentha × piperita L.) is an important and commonly used flavoring agent worldwide, and salinity is a major stress that limits plant growth and reduces crop productivity. This work demonstrated the metabolic responses of essential oil production including the yield and component composition, gene expression, enzyme activity, and protein activation in a salt-tolerant peppermint Keyuan-1 with respect to NaCl stress. Our results showed that Keyuan-1 maintained normal growth and kept higher yield and content of essential oils under NaCl stress than wild-type (WT) peppermint.Gas chromatography-mass spectrometry (GC-MS) and qPCR results showed that compared to WT seedlings, a 150-mM NaCl stress exerted no obvious changes in essential oil composition, transcriptional level of enzymes related to essential oil metabolism, and activity of pulegone reductase (Pr) in Keyuan-1 peppermint which preserved the higher amount of menthol and menthone as well as the lower content of menthofuran upon the 150-mM NaCl stress. Furthermore, it was noticed that a mitogen-activated protein kinase (MAPK) protein exhibited a time-dependent activation in the Keyuan-1 peppermint and primarily involved in the modulation of the essential oil metabolism in the transcript and enzyme levels during the 12-day treatment of 150 mM NaCl. In all, our data elucidated the effect of NaCl on metabolic responses of essential oil production, and demonstrated the MAPK-dependent regulation mechanism of essential oil biosynthesis in the salt-tolerant peppermint, providing scientific basis for the economic and ecological utilization of peppermint in saline land.

  12. Radiation inactivation of angiotensin-converting enzyme in solutions. Communication 3. The effect of NaCl

    International Nuclear Information System (INIS)

    Orlova, M.A.; Kost, O.A.; Nikol'skaya, I.I.; Troshina, N.N.; Binevskij, P.V.

    1999-01-01

    The effect of 0-0.15 M NaCl on the dose response of angiotensin-converting enzyme is described. The data represented at three-dimensional surfaces demonstrate the existence of special areas where definite mechanisms of dose response are predominant. In acidic and alkaline media, the regions of high values of enzyme activation can be emphasized; moreover, the oscillations of enzyme activity can also be detected. At pH 7.5, when angiotensin-converting enzyme conformation is less rigid, activation peaks on the three-dimensional surface are less pronounced indicating the decreasing effect of NaCl on dose response at this pH value [ru

  13. Effect of pH on corrosion behavior of CuCrZr in solution without and with NaCl

    Energy Technology Data Exchange (ETDEWEB)

    Kwok, C.T.; Wong, P.K. [Department of Electromechanical Engineering, University of Macau (China); Man, H.C. [Department of Industrial and Systems Engineering, Hong Kong Polytechnic University (Hong Kong); Cheng, F.T., E-mail: apaftche@polyu.edu.h [Department of Applied Physics, Hong Kong Polytechnic University (Hong Kong)

    2009-10-01

    CuCrZr is a high copper alloy widely used as electrical and thermal conducting material, especially in heat exchangers in nuclear reactors. In this respect, the physical and fatigue properties of CuCrZr have been extensively studied. The electrochemical behavior of CuCrZr, on the other hand, has not been adequately investigated. In the present study, the effect of pH on the corrosion behavior of CuCrZr in aqueous solutions without and with chloride (0.6 M NaCl) was studied. The pH of the solutions is found to exert significant influence on the corrosion behavior of CuCrZr. In acidic solutions without chloride, the corrosion of CuCrZr is ascribed to active dissolution with soluble products. In neutral and alkaline solutions without NaCl, the presence of oxides on the surface of CuCrZr leads to a noble shift in corrosion potential and passivation results in increased corrosion resistance. In chloride solutions at various pH values, the chloride ions influence the formation of the surface layers and the anodic dissolution process during polarization. At high pH, CuCrZr shows significant passivity and high corrosion resistance due to the growth of Cu{sub 2}O/Cu(OH) film which hinders further dissolution whereas at low pH the corrosion resistance is lowered due to active dissolution of Cu.

  14. Effect of pH on corrosion behavior of CuCrZr in solution without and with NaCl

    International Nuclear Information System (INIS)

    Kwok, C.T.; Wong, P.K.; Man, H.C.; Cheng, F.T.

    2009-01-01

    CuCrZr is a high copper alloy widely used as electrical and thermal conducting material, especially in heat exchangers in nuclear reactors. In this respect, the physical and fatigue properties of CuCrZr have been extensively studied. The electrochemical behavior of CuCrZr, on the other hand, has not been adequately investigated. In the present study, the effect of pH on the corrosion behavior of CuCrZr in aqueous solutions without and with chloride (0.6 M NaCl) was studied. The pH of the solutions is found to exert significant influence on the corrosion behavior of CuCrZr. In acidic solutions without chloride, the corrosion of CuCrZr is ascribed to active dissolution with soluble products. In neutral and alkaline solutions without NaCl, the presence of oxides on the surface of CuCrZr leads to a noble shift in corrosion potential and passivation results in increased corrosion resistance. In chloride solutions at various pH values, the chloride ions influence the formation of the surface layers and the anodic dissolution process during polarization. At high pH, CuCrZr shows significant passivity and high corrosion resistance due to the growth of Cu 2 O/Cu(OH) film which hinders further dissolution whereas at low pH the corrosion resistance is lowered due to active dissolution of Cu.

  15. Solubility and hydrolysis of Np(V) in dilute to concentrated alkaline NaCl solutions. Formation of Na-Np(V)-OH solid phases at 22 C

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Vladimir G. [Lomonosov Moscow State Univ. (Russian Federation). Dept. of Chemistry; Fellhauer, David; Gaona, Xavier; Dardenne, Kathy; Rothe, Joerg; Altmaier, Marcus [Karlsruhe Institute of Technology (Germany). Inst. for Nuclear Waste Disposal; Kalmykov, Stepan N. [Lomonosov Moscow State Univ. (Russian Federation). Dept. of Chemistry; NRC Kurchatov Institute, Moscow (Russian Federation)

    2017-03-01

    The solubility of Np(V) was investigated at T=22±2 C in alkaline NaCl solutions of different ionic strength (0.1-5.0 M). The solid phases controlling the solubility at different -log{sub 10} m{sub H{sup +}}(pH{sub m}) and NaCl concentration were characterized by XRD, quantitative chemical analysis, SEM-EDS and XAFS (both XANES and EXAFS). Aqueous phases in equilibrium with Np(V) solids were investigated for selected samples within 8.9≤pH{sub m}≤10.3 by UV-vis/NIR absorption spectroscopy. In 0.1 M NaCl, the experimental solubility of the initial greenish NpO{sub 2}OH(am) solid phase is in good agreement with previous results obtained in NaClO{sub 4} solutions, and is consistent with model calculations for fresh NpO{sub 2}OH(am) using the thermodynamic data selection in NEA-TDB. Below pH{sub m}∝11.5 and for all NaCl concentrations studied, Np concentration in equilibrium with the solid phase remained constant during the timeframe of this study (∝2 years). This observation is in contrast to the aging of the initial NpO{sub 2}OH(am) into a more crystalline modification with the same stoichiometry, NpO{sub 2}OH(am, aged), as reported in previous studies for concentrated NaClO{sub 4} and NaCl. Instead, the greenish NpO{sub 2}OH(am) transforms into a white solid phase in those systems with [NaCl]≥1.0 M and pH{sub m}≥11.5, and into two different pinkish phases above pH{sub m}∝13.2. The solid phase transformation is accompanied by a drop in Np solubility of 0.5-2 log{sub 10}-units (depending upon NaCl concentration). XANES analyses of green, white and pink phases confirm the predominance of Np(V) in all cases. Quantitative chemical analysis shows the incorporation of Na{sup +} in the original NpO{sub 2}OH(am) material, with Na:Np ≤ 0.3 for the greenish solids and 0.8 ≤ Na:Np ≤ 1.6 for the white and pinkish phases. XRD data confirms the amorphous character of the greenish phase, whereas white and pink solids show well-defined but discrepant XRD patterns

  16. Corrosion Resistance Behavior of Single-Layer Cathodic Arc PVD Nitride-Base Coatings in 1M HCl and 3.5 pct NaCl Solutions

    Science.gov (United States)

    Adesina, Akeem Yusuf; Gasem, Zuhair M.; Madhan Kumar, Arumugam

    2017-04-01

    The electrochemical behavior of single-layer TiN, CrN, CrAlN, and TiAlN coatings on 304 stainless steel substrate, deposited using state-of-the-art and industrial size cathodic arc PVD machine, were evaluated in 1M HCl and 3.5 pct NaCl solutions. The corrosion behavior of the blank and coated substrates was analyzed by electrochemical impedance spectroscopy (EIS), linear polarization resistance, and potentiodynamic polarization. Bond-coat layers of pure-Ti, pure-Cr, alloyed-CrAl, and alloyed-TiAl for TiN, CrN, CrAlN, and TiAlN coatings were, respectively, first deposited for improved coating adhesion before the actual coating. The average coating thickness was about 1.80 µm. Results showed that the corrosion potentials ( E corr) of the coated substrates were shifted to more noble values which indicated improvement of the coated substrate resistance to corrosion susceptibility. The corrosion current densities were lower for all coated substrates as compared to the blank substrate. Similarly, EIS parameters showed that these coatings possessed improved resistance to defects and pores in similar solution compared to the same nitride coatings developed by magnetron sputtering. The charge transfer resistance ( R ct) can be ranked in the following order: TiAlN > CrN > TiN > CrAlN in both media except in NaCl solution where R ct of TiN is lowest. While the pore resistance ( R po) followed the order: CrAlN > CrN > TiAlN > TiN in HCl solution and TiAlN > CrN > CrAlN > TiN in NaCl solution. It is found that TiAlN coating has the highest protective efficiencies of 79 and 99 pct in 1M HCl and 3.5 pct NaCl, respectively. SEM analysis of the corroded substrates in both media was also presented.

  17. Inhibition effect of 4-amino-antipyrine on the corrosion of copper in 3 wt.% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Hong Song; Chen Wen; Luo Hongqun [Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Li Nianbing, E-mail: linb@swu.edu.cn [Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer 4-Amino-antipyrine (AAP) has inhibition behaviour for copper corrosion in 3.0 wt.% NaCl. Black-Right-Pointing-Pointer AAP acted as a mixed-type inhibitor with anodic predominance. Black-Right-Pointing-Pointer Adsorption of AAP on the copper surface obeys the Langmuir isotherm. Black-Right-Pointing-Pointer Quantum chemical calculations were applied to explain the experimental results. - Abstract: The effect of 4-amino-antipyrine (AAP) on the corrosion of copper in 3.0 wt.% NaCl was investigated using weight loss, potentiodynamic polarisation, and electrochemical impedance spectroscopy. The results revealed that AAP acts as a mixed-type inhibitor with more pronounced effect on anodic domain and the inhibition efficiency decreases with increasing the temperature. The adsorption of AAP was found to obey the Langmuir isotherm. Surface characterisation was performed using scanning electron microscope and Fourier transform infrared spectrometer. Quantum chemical calculations show that AAP has large negative charge in nitrogen and oxygen atoms, which facilitates the adsorption of AAP on the copper surface.

  18. Synergic effects in the extraction of paracetamol from aqueous NaCl solution by the binary mixtures of diethyl ether and low molecular weight primary alcohols

    Science.gov (United States)

    Nikolić, G. M.; Živković, J. V.; Atanasković, D. S.; Nikolić, M. G.

    2013-12-01

    Liquid-liquid extraction of paracetamol from aqueous NaCl solutions was performed with diethyl ether, 1-propanol, 1-butanol, isobutanol, 1-pentanol, and binary mixtures diethyl ether/1-propanol, diethyl ether/1-butanol, and diethyl ether/isobutanol. Among the pure solvents investigated in this study best extraction efficacy was obtained with 1-butanol. Synergic effects in the extraction with binary mixtures was investigated and compared with some other systems used for the extraction of poorly extractable compounds. Results obtained in this study may be of both fundamental and practical importance.

  19. Effect of Magnesium Hydride on the Corrosion Behavior of Pure Magnesium in 0.1 M NaCl Solution

    OpenAIRE

    Xu, Shanna; Dong, Junhua; Ke, Wei

    2010-01-01

    The effect of magnesium hydride on the corrosion behavior of pure magnesium in 0.1 M NaCl solution was investigated using the gas collection method, potentiostatic current decay test, and in situ Raman spectrum. The formation of magnesium hydride (MgH2, Mg2H4) was observed at the cathodic region. Applying anodic potential leads to decomposition of magnesium hydride. Magnesium hydride plays an important role on the negative difference effect (NDE) in both the cathodic and anodic regions.

  20. Effect of Magnesium Hydride on the Corrosion Behavior of Pure Magnesium in 0.1 M NaCl Solution

    Directory of Open Access Journals (Sweden)

    Shanna Xu

    2010-01-01

    Full Text Available The effect of magnesium hydride on the corrosion behavior of pure magnesium in 0.1 M NaCl solution was investigated using the gas collection method, potentiostatic current decay test, and in situ Raman spectrum. The formation of magnesium hydride (MgH2, Mg2H4 was observed at the cathodic region. Applying anodic potential leads to decomposition of magnesium hydride. Magnesium hydride plays an important role on the negative difference effect (NDE in both the cathodic and anodic regions.

  1. Evolution of the corrosion process of AA 2024-T3 in an alkaline NaCl solution with sodium dodecylbenzenesulfonate and lanthanum chloride inhibitors

    International Nuclear Information System (INIS)

    Zhou, Biner; Wang, Yishan; Zuo, Yu

    2015-01-01

    Highlights: • Inhibition effect of LaCl 3 and SDBS for AA 2024 in NaCl solution (pH 10) was studied. • At the beginning the active polarization behavior of the alloy changed to passivation. • The passive behavior gradually disappeared with time and pitting happened at S-phases. • The compounded inhibitors showed good inhibition but cannot totally inhibit pitting. • The adsorption of SDBS played the key role for inhibition to the corrosion process. - Abstract: The evolution of the corrosion process of AA 2024-T3 in 0.58 g L −1 NaCl solution (pH 10) with sodium dodecylbenzenesulfonate (SDBS) and lanthanum chloride inhibitors was studied with electrochemical and surface analysis methods. With the addition of the compounded LaCl 3 and SDBS inhibitors, in the early stage the polarization behavior of AA 2024-T3 changed from active corrosion to passivation, and both the general corrosion and pitting corrosion were inhibited. However, with the immersion time extended, the passive behavior gradually disappeared and pitting happened at the Cu-rich phases. After 24 h immersion, the compounded inhibitors still showed good inhibition for general corrosion, but the polarization curve again presented the characteristic similar to active polarization. The compounded inhibitors also inhibited the pitting corrosion to some extent. The acting mechanism of the inhibitors SDBS and La 3 Cl on the corrosion process of AA 2024-T3 in the test solution was discussed.

  2. The 4D evolution of porosity during ongoing pressure-solution processes in NaCl using x-ray microtomography

    Science.gov (United States)

    Macente, Alice; Fusseis, Florian; Butler, Ian; Tudisco, Erika; Hall, Stephen; Andò, Edward

    2016-04-01

    Pressure-solution creep is a common deformation mechanism in the upper crust. It represents a mass transfer via dissolution-reprecipitation that critically affects the hydraulic properties of rocks. Successful management of safe radioactive storage sites in rock-salt deposits critically depends on an accurate knowledge of the hydro-mechanical behaviour of salt deposits. Despite numerous lab experiments that have been conducted, many aspects of pressure-solution are still poorly understood. There is little knowledge about the spatio-temporal evolution of porosity and permeability during pressure-solution creep. While rates of pressure-solution creep in silicates and carbonates are slow, which makes laboratory investigations of these materials impractical, compaction experiments have demonstrated that NaCl samples deform sufficiently fast to study pressure-solution creep in a lab environment at room temperature and modest loads. We present results from novel experiments that quantify the 4-dimensional (three spatial dimensions plus time) evolution of pressure-solution processes using in-situ x-ray microtomography. Our experiments are performed in custom made x-ray transparent presses. 5 mm diameter NaCl powder samples with a grain size of 250-300 μm are loaded dry into the press and pre-compacted to produce a starting aggregated material. The sample is then flooded with saturated NaCl solution and loaded uniaxially by means of a pneumatic actuator to a constant uniaxial stress. Different sample mixtures were tested, as well as different uniaxial loads. The resulting deformation of the samples is documented in 3-dimensional microtomographic datasets, acquired at regular time intervals. Image analysis allowed characterization of the microstructural evolution of the NaCl grains and the spatio-temporal distribution of porosity during ongoing mechanical and chemical compaction. The microtomography data have also been analysed with 3D Digital Image Correlation (3D-DIC or

  3. Flexible electromagnetic wave sensor operating at GHz frequencies for instantaneous concentration measurements of NaCl, KCl, MnCl2 and CuCl solutions

    International Nuclear Information System (INIS)

    Korostynska, O; Ortoneda-Pedrola, M; Mason, A; Al-Shamma'a, A I

    2014-01-01

    A novel electromagnetic wave sensor operating at GHz frequencies for real-time chlorides concentration analysis is reported. The sensor response to deionized water, NaCl, KCl, MnCl 2  and CuCl solutions at various concentrations was tested. The sensing element, in the form of a silver pattern antenna that emits an electromagnetic field, was printed on a polyimide flexible laminate substrate to form a sensor to suit a broad range of applications, where a sensor could be placed in water reservoirs or fluid-carrying pipes for continuous analysis. The developed system confirmed the viability of using microwaves for real-time chloride solutions monitoring as the reflected signals represented by S 11  parameters were unique with clearly observed shifts in the resonant frequencies and amplitude changes when placed in direct contact with 20 µl of each solution. (paper)

  4. Molecular dynamics study of structure and vibrational spectra at zwitterionoic lipid/aqueous KCl, NaCl, and CaCl2 solution interfaces

    Science.gov (United States)

    Ishiyama, Tatsuya; Shirai, Shinnosuke; Okumura, Tomoaki; Morita, Akihiro

    2018-06-01

    Molecular dynamics (MD) simulations of KCl, NaCl, and CaCl2 solution/dipalmytoylphosphatidylcholine lipid interfaces were performed to analyze heterodyne-detected vibrational sum frequency generation (HD-VSFG) spectra in relation to the interfacial water structure. The present MD simulation well reproduces the experimental spectra and elucidates a specific cation effect on the interfacial structure. The K+, Na+, and Ca2+ cation species penetrate in the lipid layer more than the anions in this order, due to the electrostatic interaction with negative polar groups of lipid, and the electric double layer between the cations and anions cancels the intrinsic orientation of water at the water/lipid interface. These mechanisms explain the HD-VSFG spectrum of the water/lipid interface and its spectral perturbation by adding the ions. The lipid monolayer reverses the order of surface preference of the cations at the solution/lipid interface from that at the solution/air interface.

  5. Corrosion Prevention of Steel Reinforcement in 7.5% NaCl Solution using Pure Magnesium Anode

    Science.gov (United States)

    Iyer Murthy, Yogesh; Gandhi, Sumit; Kumar, Abhishek

    2018-03-01

    The current work investigates the performance of pure Magnesium on corrosion prevention of steel reinforcements by way of sacrificial anoding. Two set of six steel reinforcements were tested for half-cell potential, weight loss, anode efficiency and tensile strength for each of the sacrificial anodes in a high chloride atmosphere of 7.5% NaCl in tap water. Significant reduction in weight of anode was observed during the initial 12 days. The reduction in weight of steel reinforcements tied with anodes was found to be negligible, while that of reinforcements without anodes was significantly higher. Five distinct zones of corrosion were observed during the test. The tensile strength of steel cathodically protected by Mg alloy anodes was found less affected. It could be concluded that pure Mg anode provides an effective way of corrosion mitigation.

  6. Investigation of electrochemical corrosion behavior in a 3.5 wt.% NaCl solution of boronized dual-phase steel

    International Nuclear Information System (INIS)

    Kayali, Yusuf; Anaturk, Bilal

    2013-01-01

    Highlights: ► Corrosion behaviors in a 3.5% NaCl solution of boronized Dual-Phase (DP) steels were examined. ► The martensite ratio increased with an increase in the intercritical annealing temperature. ► The corrosion resistance decreased with increase of the martensite ratio. ► The boride layer increased the corrosion resistance of DP steel 2–3-fold. ► The superior properties of DP steel as well as poor corrosion properties were improved by the boriding process. - Abstract: In this study, corrosion behaviors of boronized and non-boronized dual-phase steel were investigated with Tafel extrapolation and linear polarization methods in a 3.5 wt.% NaCl solution. Microstructure analyses show that the boride layer on the dual-phase steel surface had a flat and saw smooth morphology. It was detected by X-ray diffraction (XRD) analysis that the boride layer contained FeB and Fe 2 B phases. The amount of martensite increases with an increase in the intercritical annealing temperature. Both the amount of martensite and the morphology of the phase constituents have an influence on the corrosion behavior of dual-phase steel. A higher corrosion tendency was observed with an increased amount of martensite. The corrosion resistance of boronized dual-phase steel is higher compared with that of dual-phase steel

  7. Corrosion Behavior in 3.5% NaCl Solutions of γ-TiAl Processed by Electron Beam Melting Process

    Directory of Open Access Journals (Sweden)

    Asiful Hossain Seikh

    2015-12-01

    Full Text Available In this work, the corrosion behavior of γ-TiAl alloy produced by electron beam melting (EBM process in 3.5% NaCl solution was reported. The study has been performed using potentiodynamic polarization resistance and electrochemical impedance spectroscopy techniques and complemented by scanning electron microscopy investigations. All measurements were carried out after different periods of alloy exposure in the chloride solutions and at different temperatures. The results showed that the EBM produced γ-TiAl alloy has excellent corrosion resistance confirmed by the high values of polarization resistance and the low values of corrosion current and corrosion rate. With increase in immersion time, the corrosion potential moved to a higher positive value with a decrease in corrosion current and corrosion rate, which suggests an improvement in corrosion resistance. On the other hand, the increase of temperature was found to significantly increase the corrosion of the processed γ-TiAl alloy.

  8. Study in aqueous solution of the praseodymium inclusion in β-cyclodextrin in 2 M of NaCl

    International Nuclear Information System (INIS)

    De la Cruz M, N.

    2013-01-01

    In the fission of uranium to produce electricity, generated between the fission products which are the lanthanides and actinides that at any given time may come into contact with aqueous media, because of this, praseodymium was including in the β-cyclodextrin in order to increase the solubility and stability of praseodymium by forming inclusion complexes Praseodymium-β-cyclodextrin (Pr-β-Cd). The inclusion study was conducted in a proportion of praseodymium and β-cyclodextrin. Infrared spectra, Raman and X-ray diffraction showed the presence of praseodymium and β-cyclodextrin in the inclusion complex, in both proportions. The analysis by scanning electron microscopy confirmed the inclusion of praseodymium in βcyclodextrin. In general, the results of characterization obtained by these techniques show the formation of the inclusion complex. Furthermore, the behaviour of praseodymium inclusion in the β-cyclodextrin was studied in 2 M NaCl at 303 K and free-CO 2 conditions. For this reason, we used two methods: spectrophotometric and potentiometric titration direct of praseodymium-β-cyclodextrin, the data were treated graphically and with the program SUPERQUAD, respectively. The values obtained for praseodymium by spectrophotometric method was: log β 1 = -8.75 calculated graphically and with the potentiometric method, using program SUPERQUAD were logβ 1,OH = -8.73 ± 0.01 logβ 1,2OH = -18.27 ± 0.16 and logβ 1,3OH = -26.44 ± 0.02 obtained simultaneously. (Author)

  9. Effect of bismuth and silver on the corrosion behavior of Sn-9Zn alloy in NaCl 3 wt.% solution

    Energy Technology Data Exchange (ETDEWEB)

    Ahmido, A. [Laboratory of Chimie Physique General, Faculty of Sciences, University Med V Agdal, Av. Ibn Battouta, B.P. 1014, M-10000 Rabat (Morocco); Laboratory of Spectroscopy Infra Rouge, Faculty of Sciences, University Med V Agdal, Av. Ibn Battouta, B.P. 1014, M-10000 Rabat (Morocco); Sabbar, A. [Laboratory of Chimie Physique General, Faculty of Sciences, University Med V Agdal, Av. Ibn Battouta, B.P. 1014, M-10000 Rabat (Morocco); Zouihri, H.; Dakhsi, K. [UATRS, CNRST, Angle Allal Fassi, FAR, BP 8027, Hay Riad, Rabat (Morocco); Guedira, F. [Laboratory of Chimie Physique General, Faculty of Sciences, University Med V Agdal, Av. Ibn Battouta, B.P. 1014, M-10000 Rabat (Morocco); Serghini-Idrissi, M. [Laboratory of Spectroscopy Infra Rouge, Faculty of Sciences, University Med V Agdal, Av. Ibn Battouta, B.P. 1014, M-10000 Rabat (Morocco); El Hajjaji, S., E-mail: selhajjaji@hotmail.com [Laboratory of Spectroscopy Infra Rouge, Faculty of Sciences, University Med V Agdal, Av. Ibn Battouta, B.P. 1014, M-10000 Rabat (Morocco)

    2011-08-15

    Highlights: > Sn-9Zn-xAg-yBi as alternative for Sn-Pb solder. > Effect of silver (Ag) and bismuth (Bi) on the corrosion resistance of Sn-9Zn alloy in NaCl 3 wt%. > Bi and Ag lead to the increase of corrosion rate. > EDS and XRD analyses confirmed the oxide of zinc (ZnO and Zn5(OH){sub 8}Cl{sub 2}H{sub 2}O) as the major corrosion product. - Abstract: The effect of silver (Ag) and bismuth (Bi) on the corrosion resistance of Sn-9Zn alloy in NaCl 3 wt.% solution was investigated using electrochemical techniques. The results showed that the addition of Bi and Ag lead to the increase of corrosion rate and the corrosion potential E{sub corr} is shifted towards less noble values. After immersion, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive of spectroscopy (EDS) analysis of the corroded alloy surface revealed the nature of corrosion products. EDS and XRD analyses confirmed the oxide of zinc (ZnO and Zn{sub 5}(OH){sub 8}Cl{sub 2}H{sub 2}O) as the major corrosion product formed on the outer surface of in the tested three solder alloys.

  10. Evaluation of Salt Tolerance (NaCl in Tunisian Chili Pepper (Capsicum frutescens L. on Growth, Mineral Analysis and Solutes Synthesis

    Directory of Open Access Journals (Sweden)

    Zhani, Kaouther

    2013-02-01

    Full Text Available Every year, more and more land becomes non-productive due to salinity which adversely affects the productivity and quality of most crops that is why salinity becomes a concern to be studied more to understand the mechanisms included and select the tolerant genotypes. In this context, this investigation was carried out to study the impact of NaCl on growth, mineral analysis and solutes synthesis in five Tunisian chili pepper (Capsicum frutescens L. cultivars: Tebourba (Tb, Somaa (Sm, Korba (Kb, Awald Haffouzz (Aw and Souk jedid (Sj. Thus, an experiment took place under greenhouse at Higher Institute of Agronomy, Chott Meriem, Tunisia and stress was induced during two months in water by NaCl (0, 2, 4, 6, 8, 10 and 12 g/l. Results showed that increasing salinity stress, for all cultivars, decreases the height and biomass (dry and fresh weight of plant in addition to the relative water content. Also, a decline in K+ and Ca2+ amounts in roots and K+/Na+ ratio was recorded. However, Na+ content in roots and the biosynthesis of soluble sugars and soluble proteins in leaves increased. Awlad Haffouzz and Korba cultivars succefully tolerated highest salinity level by accumulating more K+, Ca2+ in roots and containing the highest concentrations of soluble sugars and soluble protein in their leaves contrary to Souk jedid cultivar, considered as the sensitive cultivar.

  11. Dynamics of cognitive disturbances in rats with acute cerebral ischemia on the background of introduction of 0.9 % solution NaCl

    Directory of Open Access Journals (Sweden)

    Андрій Ігорович Семененко

    2015-06-01

    Full Text Available For today there are no clear recommendations on infusion therapy at the disease and injuries of brain, and infusion preparations are commonly used empirically. Within the framework of the complex study of an influence of the different infusion remedies on brain at an experimental ischemia of brain, an aim of this work is to investigate how the 0,9 % solution of NaCl influences on the dynamics of cognitive functions and neurological status of the rats with an acute cerebral ischemia at the course medical introduction into an animal organism.Methods. Experiments were carried out on 60 white rats-males. An acute disturbance of cerebral blood circulation (ADCBC was modeled by means of the two-sided dressing of internal carotid arteries. The 0,9 % solution of NаСІ was injected intravenously in catheterized thigh vein 2,5 ml/kg 2 times/day (5 ml/kg for a day. The first introduction was carried out in 30 minutes after ADCBC and then every day in 12 hours during 7 days. The control groups consist of intact rats that received 0,9 % NаСІ and animals with a model ischemia without treatment.Neurological deficiency in animals was defined on the scale stroke-index McGrow C. P. The dynamics of position-finding activity was assessed in experiment “an open field”. An assessment of animal capacity to training and memorization of an aversive stimulus was studied in the test of conditioned response of passive avoidance. The results were processed using the program StatPlus 2009.Results. The study showed that bilateral carotid occlusion in rats without treatment is followed not only by the high animal lethality but also by the development of a hard neurological symptomatology and then by essential disturbance of mnestic functions in animals that survived during the recovery period of model insult (р<0,01.The study of lethality dynamics, neurological status, behavioral responses in rats with ADCBC on the model of bilateral carotid occlusion showed that the

  12. pH effect on pit potential and protection potential of stainless steels AISI-304, 310 and 316 in NaCl solution

    International Nuclear Information System (INIS)

    Cabral, U.Q.; Sathler, L.; Mariano Neto, F.

    1973-06-01

    For three austenitic stainless steels, AISI 304, 310 and 316, the pH influence on the rupture, protection and corrosion potentials was studied in a 0,5N NACl solution. The pit potentials determined by the chronogalvonometric method, are pH independent within the acid range. They showed a rough linear variation within the basic range having a maximum corresponding to the pH value of 8.8. The electrochemical hysteresis method, employed for determining the protection potential, presented a total pH independence for the AISI 316. The other steels showed a small dependence within the basic range but with a tendency for the protection potential to become slightly more active with increasing pH, within the acid range. It was also noted for the three steels studied that the corrosion potental became more active with increasing pH, within the basic range [pt

  13. The effect of some metallurgical factors on the corrosion behaviour of austenitic stainless steels in 3% NaCl aqueous solutions

    International Nuclear Information System (INIS)

    El-Sayed, A.A.; Morsy, S.M.; El-Raghy, S.M.

    1979-01-01

    The effect of cold work and subsequent heat treatment on the corrosion behaviour of austenitic stainless steels in 3% NaCl aqueous solutions was studied. Cold work was found to increase the corrosion rate, and heat treatment at 1050 C followed by water-quenching was found reduce to the rate of attack. The increase in the corrosion rate accompanied with a shift in the less noble direction of the steady state potential, an increase in the exchange current density and a decrease in the value of the activation energy. The results indicated that the corrosion potentials are less noble than the critical potentials for pitting, and they are discussed in terms of a simple dissolution process. A correlation is made between the corrosion rate, as expresses in weight loss, and the electrode properties of the corroding material

  14. A surface complexation model of YREE sorption on Ulva lactuca in 0.05-5.0 M NaCl solutions

    Science.gov (United States)

    Zoll, Alison M.; Schijf, Johan

    2012-11-01

    We present distribution coefficients, log iKS, for the sorption of yttrium and the rare earth elements (YREEs) on BCR-279, a dehydrated tissue homogenate of a marine macroalga, Ulva lactuca, resembling materials featured in chemical engineering studies aimed at designing renewable biosorbents. Sorption experiments were conducted in NaCl solutions of different ionic strength (0.05, 0.5, and 5.0 M) at T = 25 °C over the pH range 2.7-8.5. Distribution coefficients based on separation of the dissolved and particulate phase by conventional filtration (3 kDa) using an existing pH-dependent model. Colloid-corrected values were renormalized to free-cation concentrations by accounting for YREE hydrolysis and chloride complexation. At each ionic strength, the pH dependence of the renormalized values is accurately described with a non-electrostatic surface complexation model (SCM) that incorporates YREE binding to three monoprotic functional groups, previously characterized by alkalimetric titration, as well as binding of YREE-hydroxide complexes (MOH2+) to the least acidic one (pKa ∼ 9.5). In non-linear regressions of the distribution coefficients as a function of pH, each pKa was fixed at its reported value, while stability constants of the four YREE surface complexes were used as adjustable parameters. Data for a single fresh U. lactuca specimen in 0.5 M NaCl show generally the same pH-dependent behavior but a lower degree of sorption and were excluded from the regressions. Good linear free-energy relations (LFERs) between stability constants of the YREE-acetate and YREE-hydroxide solution complex and surface complexes with the first and third functional group, respectively, support their prior tentative identifications as carboxyl and phenol. A similar confirmation for the second group is precluded by insufficient knowledge of the stability of YREE-phosphate complexes and a perceived lack of YREE binding in 0.05 M NaCl; this issue awaits further study. The results

  15. Study of the corrosion behavior and the corrosion films formed on the surfaces of Mg–xSn alloys in 3.5 wt.% NaCl solution

    International Nuclear Information System (INIS)

    Wang, Jingfeng; Li, Yang; Huang, Song; Zhou, Xiaoen

    2014-01-01

    Highlights: • Corrosion of four cast Mg–xSn alloys in 3.5 wt.% NaCl solution was investigated. • Both Mg(OH) 2 /SnO 2 corrosion product film and Mg(OH) 2 /MgSnO 3 clusters formed on Mg–1.5Sn. • Compact Mg(OH) 2 /MgSnO 3 film suppressed the cathodic effect of the impurity inclusions. • Mg–xSn (x = 0.5, 1.0, 2.0 wt.%) alloys only formed loose Mg(OH) 2 /SnO 2 corrosion product film. - Abstract: The corrosion behavior and the corrosion films formed on the surfaces of Mg–xSn (x = 0.5, 1.0, 1.5, and 2.0 wt.%) alloys in 3.5 wt.% NaCl solution were investigated by immersion tests, electrochemical measurements, corrosion morphology observations, and X-ray diffraction analysis. Immersion tests and electrochemical measurements illustrated that the best corrosion resistance was reported for the Mg–1.5Sn alloy. Both Mg(OH) 2 /SnO 2 corrosion product film and Mg(OH) 2 /MgSnO 3 clusters formed on Mg–1.5Sn alloy surface. Mg(OH) 2 /MgSnO 3 clusters were compact and suppressed the cathodic effect of the impurity inclusions greatly. The Mg–xSn (x = 0.5, 1.0, and 2.0 wt.%) alloys only formed loose Mg(OH) 2 /SnO 2 corrosion product film during the corrosion process

  16. Effect of Laser Remelting on Friction-Wear Behaviors of Cold Sprayed Al Coatings in 3.5% NaCl Solution

    Directory of Open Access Journals (Sweden)

    Zhang Jing

    2018-02-01

    Full Text Available A cold sprayed Al coating on S355 structural steel was processed using a laser remelting (LR. The surface and cross-section morphologies, chemical compositions, and phases of as-obtained Al coating before and after LR were analyzed using a scanning electronic microscope (SEM, energy dispersive spectrometer (EDS, and X-ray diffractometer (XRD, respectively, and their hardness was measured using a micro-hardness tester. The friction-wear behaviors of Al coating before and after LR in 3.5% NaCl solution were conducted to simulate the sand and gravel scouring on its surface in seawater, the effects of wear loads and speeds on the tribological properties of Al coating were analyzed, and the wear mechanisms under different wear loads and speeds were also discussed. The results show that the Al coating after LR is primarily composed of an Al phase and its hardness is 104.66 HV, increasing 54.70 HV than the cold sprayed Al coating. The average coefficient of friction (COF of cold sprayed Al coating at the wear load of 0.5, 1.0 and 1.5 N is 0.285, 0.239, and 0.435, respectively, while that after LR is 0.243, 0.227, and 0.327, respectively, decreased by 14.73%, 5.02% and 24.83% compared to the cold sprayed Al coating. The wear rate of cold sprayed Al coating at the wear load of 0.5, 1.0 and 1.5 N is 1.60 × 10−4, 2.36 × 10−4, and 2.40 × 10−4 mm3/m·N, respectively, while that after LR is 1.59 × 10−4, 1.70 × 10−4, and 1.94 × 10–4 mm3/m·N, respectively, decreased by 1%, 32%, and 23%, respectively, indicating that LR has high anti-friction performance. Under the wear load action of 1.0 N, the average COF of laser remelted Al coating at the wear speeds of 300, 400 and 500 times/min is 0.294, 0.279, and 0.239, respectively, and the corresponding wear rate is 1.06 × 10−4, 1.24 × 10−4, and 1.70 × 10−4 mm3/m·N, respectively. The wear mechanism of cold sprayed Al coating is primarily corrosion wear at the loads of 0.5 and 1.0 N, and

  17. Corrosion study of API 5L x-series pipeline steels in 3.5% NaCl solution under varying conditions

    International Nuclear Information System (INIS)

    Shahid, M.; Qureshi, M.I.; Farooq, M.U.; Khan, M.I.

    2003-01-01

    Pipelines provide convenient and efficient means for mass transportation of variety of fluids, such as oil and gas, over varying distances. In the last two decades or so, pipeline designers focused mainly on the usage of larger sizes and higher operating pressures for achieving higher transportation efficiency. This has been accomplished through the provision of steels with progressive increase in yield strength coupled with good weldability and sufficient toughness to restrict crack propagation. In addition to higher strength and toughness, developing pipeline technologies have required improved resistance to corrosion, which has been tried with specific alloy additions and special control over non-metallic inclusions. Corrosion investigations were carried out on various grades of pipeline steels (API 5L X-46, X-52, X-56, X-60 and X- 70) under varying environmental conditions. This paper describes the results pertaining to corrosion behavior of the steels in 3.5% NaCl solutions in stagnant, turbulent and deaerated conditions. It was found that all grades corrode in this solution and their corrosion potentials and corrosion currents are in close vicinity of each other. Turbulent solutions, however, have shown an increase in corrosion rates whereas deaeration has revealed a relative decrease in aggressivity of the electrolyte. (author)

  18. Stress Corrosion Cracking Behavior of Multipass TIG-Welded AA2219 Aluminum Alloy in 3.5 wt pct NaCl Solution

    Science.gov (United States)

    Venugopal, A.; Sreekumar, K.; Raja, V. S.

    2012-09-01

    The stress corrosion cracking (SCC) behavior of the AA2219 aluminum alloy in the single-pass (SP) and multipass (MP) welded conditions was examined and compared with that of the base metal (BM) in 3.5 wt pct NaCl solution using a slow-strain-rate technique (SSRT). The reduction in ductility was used as a parameter to evaluate the SCC susceptibility of both the BM and welded joints. The results showed that the ductility ratio ( ɛ NaCl/( ɛ air) was 0.97 and 0.96, respectively, for the BM and MP welded joint, and the same was marginally reduced to 0.9 for the SP welded joint. The fractographic examination of the failed samples revealed a typical ductile cracking morphology for all the base and welded joints, indicating the good environmental cracking resistance of this alloy under all welded conditions. To understand the decrease in the ductility of the SP welded joint, preexposure SSRT followed by microstructural observations were made, which showed that the decrease in ductility ratio of the SP welded joint was caused by the electrochemical pitting that assisted the nucleation of cracks in the form of corrosion induced mechanical cracking rather than true SCC failure of the alloy. The microstructural examination and polarization tests demonstrated a clear grain boundary (GB) sensitization of the PMZ, resulting in severe galvanic corrosion of the SP weld joint, which initiated the necessary conditions for the localized corrosion and cracking along the PMZ. The absence of PMZ and a refined fusion zone (FZ) structure because of the lesser heat input and postweld heating effect improved the galvanic corrosion resistance of the MP welded joint greatly, and thus, failure occurred along the FZ.

  19. Corrosion behaviour of nanometre sized cerium oxide and titanium oxide incorporated aluminium in NaCl solution

    International Nuclear Information System (INIS)

    Ashraf, P. Muhamed; Edwin, Leela

    2013-01-01

    Highlights: ► Corrosion resistant aluminium incorporated with nano oxides of cerium and titanium. ► 0.2% nano CeO 2 and 0.05% nano TiO 2 showed increased corrosion resistance. ► Nano TiO 2 concentration influenced the optimum performance of the material. ► Comparison of Micro and nano CeO 2 and TiO 2 aluminium showed the latter is best. - Abstract: The study highlights the development of an aluminium matrix composite by incorporating mixture of nanometre sized cerium oxide and titanium oxide in pure aluminium and its corrosion resistance in marine environment. The mixed nanometre sized oxides incorporated aluminium exhibited improved microstructure and excellent corrosion resistance. Corrosion resistance depends on the concentration of nanometre sized titanium oxide. Electrochemical characteristics improved several folds in nanometre sized mixed oxides incorporated aluminium than micrometre sized oxides incorporated aluminium.

  20. Bentonite swelling pressure in strong NaCl solutions. Correlation of model calculations to experimentally determined data

    International Nuclear Information System (INIS)

    Karnland, O.

    1998-01-01

    A number of quite different quantitative models concerning swelling pressure in bentonite clay have been proposed. This report discusses a number of models which possibly can be used also for saline conditions. A discrepancy between calculated and measured values was noticed for all models at brine conditions. In general the models predicted a too low swelling pressure compared to what was experimentally found. An osmotic component in the clay/water system is proposed in order to improve the previous conservative use of the thermodynamic model. Calculations of this osmotic component is proposed to be made by use of the clay cation exchange capacity and Donnan equilibrium. Calculations made by this approach showed considerably better correlation to literature laboratory data, compared to calculations made by the previous conservative use of the thermodynamic model. A few verifying laboratory tests were made and are briefly described in the report. The improved model predicts a substantial bentonite swelling pressure also in a saturated sodium chloride solution if the density of the system is sufficiently high. This means in practice that the buffer in a KBS-3 repository will give rise to an acceptable swelling pressure, but that the positive effects of mixing bentonite into a backfill material will be lost if the system is exposed to brines. (orig.)

  1. Bentonite swelling pressure in strong NaCl solutions. Correlation between model calculations and experimentally determined data

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, O. [Clay Technology, Lund (Sweden)

    1997-12-01

    A number of quite different quantitative models concerning swelling pressure in bentonite clay have been proposed by different researchers over the years. The present report examines some of the models which possibly may be used also for saline conditions. A discrepancy between calculated and measured values was noticed for all models at brine conditions. In general the models predicted a too low swelling pressure compared to what was experimentally found. An osmotic component in the clay/water system is proposed in order to improve the previous conservative use of the thermodynamic model. Calculations of this osmotic component is proposed to be made by use of the clay cation exchange capacity and Donnan equilibrium. Calculations made by this approach showed considerably better correlation to literature laboratory data, compared to calculations made by the previous conservative use of the thermodynamic model. A few verifying laboratory tests were made and are briefly described in the report. The improved thermodynamic model predicts substantial bentonite swelling pressures also in saturated sodium chloride solution if the density of the system is high enough. In practice, the model predicts a substantial swelling pressure for the buffer in a KBS-3 repository if the system is exposed to brines, but the positive effects of mixing bentonite into a backfill material will be lost, since the available compaction technique does not give a sufficiently high bentonite density 37 refs, 15 figs

  2. Bentonite swelling pressure in strong NaCl solutions. Correlation of model calculations to experimentally determined data

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, O. [Clay Technology, Lund (Sweden)

    1998-01-01

    A number of quite different quantitative models concerning swelling pressure in bentonite clay have been proposed. This report discusses a number of models which possibly can be used also for saline conditions. A discrepancy between calculated and measured values was noticed for all models at brine conditions. In general the models predicted a too low swelling pressure compared to what was experimentally found. An osmotic component in the clay/water system is proposed in order to improve the previous conservative use of the thermodynamic model. Calculations of this osmotic component is proposed to be made by use of the clay cation exchange capacity and Donnan equilibrium. Calculations made by this approach showed considerably better correlation to literature laboratory data, compared to calculations made by the previous conservative use of the thermodynamic model. A few verifying laboratory tests were made and are briefly described in the report. The improved model predicts a substantial bentonite swelling pressure also in a saturated sodium chloride solution if the density of the system is sufficiently high. This means in practice that the buffer in a KBS-3 repository will give rise to an acceptable swelling pressure, but that the positive effects of mixing bentonite into a backfill material will be lost if the system is exposed to brines. (orig.). 14 refs.

  3. Bentonite swelling pressure in strong NaCl solutions. Correlation between model calculations and experimentally determined data

    International Nuclear Information System (INIS)

    Karnland, O.

    1997-12-01

    A number of quite different quantitative models concerning swelling pressure in bentonite clay have been proposed by different researchers over the years. The present report examines some of the models which possibly may be used also for saline conditions. A discrepancy between calculated and measured values was noticed for all models at brine conditions. In general the models predicted a too low swelling pressure compared to what was experimentally found. An osmotic component in the clay/water system is proposed in order to improve the previous conservative use of the thermodynamic model. Calculations of this osmotic component is proposed to be made by use of the clay cation exchange capacity and Donnan equilibrium. Calculations made by this approach showed considerably better correlation to literature laboratory data, compared to calculations made by the previous conservative use of the thermodynamic model. A few verifying laboratory tests were made and are briefly described in the report. The improved thermodynamic model predicts substantial bentonite swelling pressures also in saturated sodium chloride solution if the density of the system is high enough. In practice, the model predicts a substantial swelling pressure for the buffer in a KBS-3 repository if the system is exposed to brines, but the positive effects of mixing bentonite into a backfill material will be lost, since the available compaction technique does not give a sufficiently high bentonite density

  4. Corrosion protection of AISI 1018 steel using Co-doped TiO_2/polypyrrole nanocomposites in 3.5% NaCl solution

    International Nuclear Information System (INIS)

    Ladan, Magaji; Basirun, Wan Jeffrey; Kazi, Salim Newaz; Rahman, Fariza Abdul

    2017-01-01

    A polypyrrole nanocomposites (PPy NTCs) have been effectively synthesized in the presence of TiO_2 and Co-doped TiO_2 nanoparticles (NPs) by an in situ chemical oxidative polymerization. Field Emission Scanning Electron Microscopy and Transmission Electron Microscopy revealed a tube shape structure of the PPy. The TEM results confirmed that the nanocomposite size of Co-doped TiO_2/PPy NTCs was smaller than TiO_2/PPy NTCs thereby increasing the interaction between the PPy nanotube and the AISI steel surface. The corrosion performance of the coatings was evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements in 3.5% NaCl solution. The EIS results show that the log |Z| of AISI 1018 coated with Co-doped TiO_2/PPy NTCs and TiO_2/PPy NTCs reached about 8.2 and 6.0 respectively after 30 days of exposure in 3.5% NaCl solution. This is likely due to the increased surface area of the PPy synthesized in the presence of Co-doped TiO_2 NPs. The EIS results are confirmed by the potentiodynamic polarization and open circuit potential values of the Co-doped TiO_2/PPy which indicated little changes between 1 and 30 days of exposure which confirms the protection ability of this coating. . It is evident that the presence of Co-doped TiO_2 NPs can enhance the resistance against corrosion at the steel/electrolyte interface. - Highlights: • Polymerization of pyrrole monomer in the presence of Co-doped TiO_2 decreases the size of the polypyrrole nanotube (PPy NT). • The corrosion protection increases with the increase in PPy NT dispersion. • The corrosion resistance of steel coated with Co-doped TiO_2/PPy NTCs is considerably higher. • TiO_2/PPy with Co doping reduces the charge transfer across the electrolyte/AISI 1018 steel interface.

  5. Corrosion protection of AISI 1018 steel using Co-doped TiO{sub 2}/polypyrrole nanocomposites in 3.5% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Ladan, Magaji, E-mail: ladanmagaji@yahoo.com [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, 50603 (Malaysia); Department of Pure and Industrial Chemistry, Bayero University Kano (Nigeria); Basirun, Wan Jeffrey, E-mail: jeff@um.edu.my [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, 50603 (Malaysia); Institute of Nanotechnology and Catalysis (NanoCat), University of Malaya, Kuala Lumpur, 50603 (Malaysia); Kazi, Salim Newaz; Rahman, Fariza Abdul [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, 50603 (Malaysia)

    2017-05-01

    A polypyrrole nanocomposites (PPy NTCs) have been effectively synthesized in the presence of TiO{sub 2} and Co-doped TiO{sub 2} nanoparticles (NPs) by an in situ chemical oxidative polymerization. Field Emission Scanning Electron Microscopy and Transmission Electron Microscopy revealed a tube shape structure of the PPy. The TEM results confirmed that the nanocomposite size of Co-doped TiO{sub 2}/PPy NTCs was smaller than TiO{sub 2}/PPy NTCs thereby increasing the interaction between the PPy nanotube and the AISI steel surface. The corrosion performance of the coatings was evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements in 3.5% NaCl solution. The EIS results show that the log |Z| of AISI 1018 coated with Co-doped TiO{sub 2}/PPy NTCs and TiO{sub 2}/PPy NTCs reached about 8.2 and 6.0 respectively after 30 days of exposure in 3.5% NaCl solution. This is likely due to the increased surface area of the PPy synthesized in the presence of Co-doped TiO{sub 2} NPs. The EIS results are confirmed by the potentiodynamic polarization and open circuit potential values of the Co-doped TiO{sub 2}/PPy which indicated little changes between 1 and 30 days of exposure which confirms the protection ability of this coating. . It is evident that the presence of Co-doped TiO{sub 2} NPs can enhance the resistance against corrosion at the steel/electrolyte interface. - Highlights: • Polymerization of pyrrole monomer in the presence of Co-doped TiO{sub 2} decreases the size of the polypyrrole nanotube (PPy NT). • The corrosion protection increases with the increase in PPy NT dispersion. • The corrosion resistance of steel coated with Co-doped TiO{sub 2}/PPy NTCs is considerably higher. • TiO{sub 2}/PPy with Co doping reduces the charge transfer across the electrolyte/AISI 1018 steel interface.

  6. Intergranular Pressure Solution in Nacl: Grain-To-Grain Contact Experiments under the Optical Microscope Dissolution sous contrainte dans NaCl : expériences de contact grain à grain sous microscope optique

    Directory of Open Access Journals (Sweden)

    Spiers C. J.

    2006-12-01

    effective diffusivity varying with contact force and on-going convergence. The results agree broadly with those of previous compaction creep experiments performed using wet halite powder. Discrepancies with other workers results for single-contact dissolution experiments can be explained in terms of differences in experimental configuration and competition between driving forces. La dissolution sous contrainte (IPS - Intergranular Pressure Solution représente un mécanisme de lithification, de compaction et de déformation à l'échelle géologique pour une large gamme de roches. Les études expérimentales d'IPS réalisées sur des agrégats de quartz n'ont pas été couronnées de succès en raison d'un taux faible d'IPS, et les expériences IPS réalisées en utilisant une halite saturée comme analogue de roche (Spiers et Schutjens, 1990 ; Hickman et Evans, 1991 ont laissé des incertitudes quant au détail des mécanismes IPS et à la structure/saturation au contact du grain dans ce matériau. La présente étude fait état de quatre expériences de dissolution de contact réalisées sous microscope optique afin d'étudier le mécanisme et la cinétique de l'IPS pour des contacts simples halite/halite et halite/verre, chargés en eau salée (température ambiante. Des forces normales de contact dans la gamme de 1,0 à 2,6 N ont été appliquées en présence d'eau salée saturée en NaCl, induisant des pressions de 0,8 à 7,4 MPa. Des pertes de masse et des convergences - fonction du temps - ont été observées pour tous les contacts. Dans tous les cas, le fait de charger le contact (ou d'augmenter la charge sur le contact a conduit à la formation immédiate d'une morphologie de contact rugueuse, composée d'un motif d'îles et de canaux, contrôlé par des caractéristiques cristallographiques, à l'échelle de quelques microns. Cette microstructure non équilibrée a évolué dans le temps vers une face de contact optiquement plate. Le processus de convergence

  7. Redox behavior of Tc(VII)/Tc(IV) under various reducing conditions in 0.1 M NaCl solutions

    International Nuclear Information System (INIS)

    Kobayashi, T.; Gaona, X.; Altmaier, M.; Scheinost, A.C.; Fellhauer, D.; European Commission Joint Research Centre, Karlsruhe

    2013-01-01

    Redox behaviour of Tc(VII)/Tc(IV) was investigated in 0.1 M NaCl solutions containing different reducing agents in the pH range 2 to 13 at 22 C under inert Ar atmosphere. In several samples, the 1 x 10 -5 mol/dm 3 (M) initially added TcO 4 - was reduced to form a Tc(IV) oxide solid phase with low solubility. The observed Tc redox transformation processes are systematized according to E h -pH conditions in solution, indicating that a borderline for the reduction of Tc(VII) to Tc(IV), TcO 4 - + 3e - + 4H + TcO 2 . xH 2 O(coll, hyd) + (2-x)H 2 O exists, independent of the reducing chemical system. This experimentally derived borderline is about 100 mV lower than the equilibrium line calculated from the reported standard redox potential of TcO 2 . 1.6H 2 O(s). This behaviour can be related to the existence of more soluble solid phase modifications, i.e. nanoparticulate Tc(IV) oxide species TcO 2 . xH 2 O(coll, hyd). The reaction kinetics likewise correlate to the redox potential measured in solution. Slow reduction of Tc(VII) to Tc(IV) was observed when the redox potential in the system was slightly below the above mentioned reduction borderline. Fast reduction was observed in the systems far below the borderline, but also in those systems containing Fe(II) solids, suggesting a specific surface mediated effect in the reduction process. EXAFS analysis on two magnetite samples indicate reduced Tc(IV) species which do not remain adsorbed at the reactive mineral surface and are incorporated in the magnetite structure. (orig.)

  8. Anti-corrosion film formed on HAl77-2 copper alloy surface by aliphatic polyamine in 3 wt.% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yinzhe; Yang, Dong; Zhang, Daquan, E-mail: zhdq@sh163.net; Wang, Yizhen; Gao, Lixin

    2017-01-15

    Highlights: • Properties of ADDD meet environment-friendly requirements. • ADDD’s inhibition efficiency is better than BTA at the low concentration. • ADDD adsorbs on the copper alloy surface by via the N atom in its amino group using flat mode. - Abstract: The corrosion inhibition of a polyamine compound, N-(4-amino-2, 3-dimethylbutyl)-2, 3-dimethylbutane-1, 4-diamine (ADDD), was investigated for HAl77-2 copper alloy in 3 wt.% NaCl solution. Electrochemical measurements, scanning electron microscopy (SEM), atomic force microscope (AFM) and Fourier transform infrared spectroscopy (FT-IR) techniques were employed for this research. The results show that ADDD strongly suppresses the corrosion of HAl77-2 alloy. The inhibition efficiency of ADDD is 98.6% at 0.5 mM, which is better than benzotriazole (BTAH) at the same concentration. Polarization curves indicate that ADDD is an anodic type inhibitor. Surface analysis suggests that a protective film is formed via the interaction of ADDD and copper. FT-IR reveals that the inhibition mechanism of ADDD is dominated by chemisorption onto the copper alloy surface to form an inhibition film. Furthermore, quantum chemical calculation and molecular dynamics (MD) simulations methods show that ADDD adsorbs on HAl77-2 surface via amino group in its molecule.

  9. Interaction of inhibitors with corrosion scale formed on N80 steel in CO{sub 2}-saturated NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D. [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Hubei Key Laboratory of Materials Chemistry and Service Failure, Wuhan (China); School of Chemical Engineering and Pharmacy, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology, Wuhan (China); Qiu, Y.B.; Guo, X.P. [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Hubei Key Laboratory of Materials Chemistry and Service Failure, Wuhan (China); Tomoe, Y.; Bando, K. [Japan Oil, Gas and Metals National Corporation, The Former Japan National Oil Corporation, Hamada, Mihama-ku, Chiba-City, Chiba (Japan)

    2011-12-15

    The performance of the selected inhibitors, including thioglycolic acid (TGA), diethylenetriamine (DETA), and naphthene acid imidazolines (IM), on the bare surface of N80 steel and its scaled surface pre-corroded in CO{sub 2}-saturated 1%NaCl solution was investigated by weight-loss method, electrochemical measurements using rotating cylinder electrode and surface analytical methods (SEM, XRD, and EPMA). The results indicate that there is a remarkable difference in inhibition efficiency of inhibitors on the N80 steel with and without pre-corrosion scale. The synergistic effect between inhibitors and corrosion scale not only depends on the size of inhibitor molecules, but also depends on the interaction of the inhibitor with the corrosion scale. It shows that IM and DETA have a good positive synergistic effect with the corrosion scale formed on N80 steel, although DETA has no inhibition efficiency for bare N80 steel, which can easily enter into the apertures of the corrosion scale, and block the active sites on the metal surface and the diffusion routeways of the reactant so as to depress the corrosion of the substrate metal. While TGA shows excellent inhibition efficiency on bare N80 steel, but it has an antagonistic effect with the corrosion scale although it has a small molecular weight as well as DETA, because TGA can dissolve corrosion scale and break its integrality and protectiveness performance. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Titration of poly(dA-dT) . poly(dA-dT) in solution at variable NaCl concentration.

    Science.gov (United States)

    Airoldi, Marta; Boicelli, C Andrea; Cadoni, Fabio; Gennaro, Giuseppe; Giomini, Marcello; Giuliani, Anna M; Giustini, Mauro

    2004-10-05

    CD and uv absorption data showed that high molecular weight poly(dA-dT) . poly(dA-dT), at 298 K, undergoes an acid-induced transition from B-double helix to random coil in NaCl solutions of different concentrations, ranging from 0.005 to 0.600M. Similarly, titration of the polynucleotide with a strong base causes duplex-to-single strands transition. The base- and acid-induced transitions were both reversible by back-titration (with an acid or, respectively, with a base): the apparent pKa were the same in both directions. However, the number of protons per titratable site (adenine N1) required to reach half-denaturation was in great excess over the stoichiometric value; to a much larger extent, the same effect was observed also for the deprotonation of the N3H sites of thymine. Moreover, in the basic denaturation experiments, at low salt concentrations ([NaCl]acid than calculated was needed to back-titrate the base excess to half-denaturation. Both effects could be qualitatively justified on the basis of the counterion condensation theory of polyelectrolytes and considering the energy barrier created by the negatively charged phosphodiester groups to the penetration of the OH- ions inside the double helix and the screening effect of the Na+ ions on such charges, in the deprotonation experiments.

  11. Corrosion Behavior of High Pressure Die Cast Al-Ni and Al-Ni-Ca Alloys in 3.5% NaCl Solution

    Energy Technology Data Exchange (ETDEWEB)

    Arthanari, Srinivasan; Jang, Jae Cheol; Shin, Kwang Seon [Seoul National University, Seoul (Korea, Republic of)

    2017-06-15

    In this investigation corrosion behavior of newly developed high-pressure die cast Al-Ni (N15) and Al-Ni-Ca (NX1503) alloys was studied in 3.5% NaCl solution. The electrochemical corrosion behavior was evaluated using open circuit potential (OCP) measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. Potentiodynamic polarization results validated that NX1503 alloy exhibited lower corrosion current density (i{sub corr}) value (5.969 μA/cm{sup 2}) compared to N15 (7.387 μA/cm{sup 2}). EIS-Bode plots revealed a higher impedance (|Z|) value and maximum phase angle value for NX1503 than N15 alloy. Equivalent circuit curve fitting analysis revealed that surface layer (R{sub 1}) and charge transfer resistance (R{sub ct}) values of NX1503 alloy was higher compared to N15 alloy. Immersion corrosion studies were also conducted for alloys using fishing line specimen arrangement to simultaneously measure corrosion rates from weight loss (P{sub W}) and hydrogen volume (P{sub H}) after 72 hours and NX1503 alloy had lower corrosion rate compared to N15 alloy. The addition of Ca to N15 alloy significantly reduced the Al{sub 3}Ni intermetallic phase and further grain refinement may be attributed for reduction in the corrosion rate.

  12. Synergism between cerium nitrate and sodium dodecylbenzenesulfonate on corrosion of AA5052 aluminium alloy in 3 wt.% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jie; Wang, Dapeng; Gao, Lixin; Zhang, Daquan, E-mail: zhdq@sh163.net

    2016-12-15

    Highlights: • Effectively prevent corrosion of AA5052 alloy by using the mixture of cerium nitrate and sodium dodecylbenzenesulfonate. • Synergistic mechanism of the combination of cerium nitrate and sodium dodecylbenzenesulfonate. • Structure of the complex formed between cerium ions and dodecylbenzenesulfonate. • The optimal adsorption model of dodecylbenzenesulfonate on the Al{sub 2}O{sub 3} and CeO{sub 2} surface. - Abstract: The synergistic inhibition effect of rare earth cerium nitrate and sodium dodecylbenzenesulfonate (DBS) on corrosion of AA5052 aluminium alloy in 3 wt.% NaCl solution was investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curve, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). The results show that the single cerium nitrate or DBS has a limited inhibition effect against corrosion of AA5052 alloy. The combination cerium ions with DBS produced strong synergistic effect on corrosion inhibition for AA5052 alloy and rendered a negaitve shift of the corrosion potential. The formation of the complex of Al(DBS){sub 3} and Ce(DBS){sub 3} stabilized the passive film of Al{sub 2}O{sub 3} and CeO{sub 2}, retarding both the cathodic and anodic processes of AA5052 alloy corrosion reaction significantly.

  13. Investigation on localized corrosion of 304 stainless steel joints brazed using Sn-plated Ag alloy filler in NaCl aqueous solution

    Science.gov (United States)

    Wang, Xingxing; Li, Shuai; Peng, Jin

    2018-03-01

    Novel AgCuZnSn filler metal with high Sn contents was prepared from BAg50CuZn filler metal by a process of electroplating and thermal diffusion, and the prepared filler metal was applied to induction brazing of 304 stainless steel. The corrosion behavior of the brazed joints was evaluated based on localized corrosion analysis, the morphology of the joints were analyzed by SEM after immersion in a 3.5 vol% NaCl aqueous solution. The results indicated that corrosion groove occurred near the interface between the stainless steel base metal and the brazing seam. A wide range of defects such as holes and cracks appeared on the surface of the base metal, while the brazing seam zone almost no corrosion defects occur. With the increase of corrosion time, the corrosion rates of both the brazing seam and the base metal first exhibited an increasing trend, followed by a decreasing trend, and the corrosion rate of the base metal was slightly greater than that of the brazing seam. The corrosion potential of the brazing seam and 304 stainless steel were -0.7758 V and -0.7863 V, respectively.

  14. The Electrochemical Stability in NaCl Solution of Nanotubes and Nanochannels Elaborated on a New Ti-20Zr-5Ta-2Ag Alloy

    Directory of Open Access Journals (Sweden)

    Claudiu Constantin Manole

    2015-01-01

    Full Text Available Nanotubular and nanochannels structures were fabricated via anodizing on a new alloy Ti-20Zr-8Ta-2Ag. A continuous coating of connected tubes/channels can be observed in the SEM micrographs forming tubular structures with diameters in hundreds of nm, as well as smaller tubes, with diameters in tens of nm. In the case of nanochannels structure, the diameters are smaller and wall thicknesses significantly thinner than in nanotubes. Wettability measurements indicate a decrease of contact angles in both cases of nanotubes and nanochannels, but the increase of hydrophilic character is more significant in the case of nanochannels. The Tafel procedure and electrochemical impedance spectroscopy tests performed in NaCl 0.9% solution indicate a better stability for the nanostructured surfaces compared to untreated alloy, the surface with nanochannels offering higher corrosion resistance. Spectral UV-VIS determination has confirmed Ag metallic presence, opening the door for applications not only in tissue engineering but for water splitting and the photoreduction of CO2 as well.

  15. Corrosion behavior of magnesium-graphene composites in sodium chloride solutions

    Directory of Open Access Journals (Sweden)

    Muhammad Rashad

    2017-09-01

    Full Text Available Coating of graphene and graphene/polymer composites on metals improves the corrosion resistance of metal substrates. On other hand, graphene embedded inside metal (especially Mg matrices increases or decreases corrosion, is a crucial factor and must be explored. In present study, electrochemical behaviors of magnesium alloys (AZ31 and AZ61 and their composites reinforced with graphene nanoplatelets (GNPs were carried out in 3.5% NaCl solution by polarization method. The surface morphology of composites before and after corrosion tests were analyzed using scanning electron microscopy. Experimental results revealed that presence of graphene nanoplatelets in different matrices decrease corrosion resistance of composites. This may be attributed to presence of graphene nanoplatelets which activates the corrosion of magnesium/alloys due to the occurrence of galvanic corrosion and this effect increases with increasing graphene nanoplatelets content. Further, an appropriate model describing the corrosion mechanism was proposed.

  16. Experimental Determination of Lead Interactions with Citrate and EDTA in NaCl and MgCl2 Solutions to High Ionic Strength and Its Applications.

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Yongliang [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Kirkes, Leslie Dawn [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Westfall, Terry [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Marrs, Cassandra [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Knox, Jandi [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Burton, Heather Lynn [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group

    2017-09-01

    For this study, the interactions of lead with citrate and ethylenediaminetetraacetate (EDTA) are investigated based on solubility measurements as a function of ionic strength at room temperature (22.5 ± 0.5°C) in NaCl and MgCl2 solutions. The formation constants (log β10 ) for Pb[C3H5O(COO)3]– (abbreviated as PbCitrate) and Pb[(CH2COO)2N(CH2)2N(CH2COO)2)]2– (abbreviated as PbEDTA2–) Pb2+ + [C3H5O(COO)3]3– = Pb[C3H5O(COO)3] (1) Pb2+ + (CH2COO)2N(CH2)2N(CH2COO)2)4- = Pb[(CH2COO)2N(CH2)2N(CH2COO)2)]2– (2) are evaluated as 7.28 ± 0.18 (2σ) and 20.00 ± 0.20 (2σ), respectively, with a set of Pitzer parameters describing the specific interactions in NaCl and MgCl2 media. Based on these parameters, the interactions of lead with citrate and EDTA in various low temperature environments can be accurately modelled.

  17. Effects of Proteoliposome Composition and Draw Solution Types on Separation Performance of Aquaporin-Based Proteoliposomes

    DEFF Research Database (Denmark)

    Zhao, Yang; Vararattanavech, Ardcharaporn; Li, Xuesong

    2013-01-01

    Escherichia coli cells, and their separation properties were characterized by stopped-flow measurements. The current study systematically investigated the effect of proteoliposome composition (lipid type, protein-to-lipid ratio (PLR), and the addition of cholesterol) on water permeability and NaCl retention......Aquaporins are a large family of water transport proteins in cell membranes. Their high water permeability and solute rejection make them potential building blocks for high-performance biomimetic membranes for desalination. In the current study, proteoliposomes were prepared using AquaporinZ from...

  18. Corrosion behavior of aluminum-alumina composites in aerated 3.5 percent chloride solution

    Science.gov (United States)

    Acevedo Hurtado, Paul Omar

    Aluminum based metal matrix composites are finding many applications in engineering. Of these Al-Al2O3 composites appear to have promise in a number of defense applications because of their mechanical properties. However, their corrosion behavior remains suspect, especially in marine environments. While efforts are being made to improve the corrosion resistance of Al-Al2O3 composites, the mechanism of corrosion is not well known. In this study, the corrosion behavior of powder metallurgy processed Al-Cu alloy reinforced with 10, 15, 20 and 25 vol. % Al2O3 particles (XT 1129, XT 2009, XT 2048, XT 2031) was evaluated in aerated 3.5% NaCl solution using microstructural and electrochemical measurements. AA1100-O and AA2024T4 monolithic alloys were also studied for comparison purposes. The composites and unreinforced alloys were subjected to potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) testing. Addition of 25 vol. % Al2O 3 to the base alloys was found to increase its corrosion resistance considerably. Microstructural studies revealed the presence of intermetallic Al2Cu particles in these composites that appeared to play an important role in the observations. Pitting potential for these composites was near corrosion potential values, and repassivation potential was below the corresponding corrosion potential, indicating that these materials begin to corrode spontaneously as soon as they come in contact with the 3.5 % NaCl solution. EIS measurements indicate the occurrence of adsorption/diffusion phenomena at the interface of the composites which ultimately initiate localized or pitting corrosion. Polarization resistance values were extracted from the EIS data for all the materials tested. Electrically equivalent circuits are proposed to describe and substantiate the corrosive processes occurring in these Al-Al2O 3 composite materials.

  19. The effect of hydrogen and gamma radiation on the oxidation of UO2 in 0.1 mol*(dm)-3 NaCl solution

    International Nuclear Information System (INIS)

    King, F.; Quinn, M.J.; Miller, N.H.

    1999-11-01

    High partial pressures of H 2 may develop in an underground nuclear fuel waste disposal vault as a result of radiolysis of groundwater or corrosion of steel container components. The presence of H 2 could suppress the oxidation and subsequent dissolution of used fuel by creating reducing conditions near the fuel surface. A series of experiments has been performed to determine the extent of oxidation of UO 2 due to γ-radiolysis in the presence of H 2 . A H 2 partial pressure of 5 MPa was used to simulate the maximum possible pressure of H 2 in a disposal vault located at a depth of 500 m. Experiments were also performed with an Ar overpressure for comparison. Deaerated 0.1 mol·(dm) -3 NaCl was used to simulate the groundwater. The extent of oxidation was determined by monitoring the corrosion potential of UO 2 electrodes, by cathodically stripping the oxidized layer from the electrode at the end of the test, and by determining the ratio of U(VI) to U(IV) species on the surface of a UO 2 disc exposed to the same solution by X-ray photoelectron spectroscopy. The presence of H 2 is found to have two effects on the oxidation of UO 2 in the presence of y-radiation. Not only does H 2 prevent oxidation of the UO 2 by radiolytic oxidants but it also produces more reducing conditions than those observed with either H 2 or Ar atmospheres in the absence of irradiation. It is suggested that radiolytically produced reductants participate in homogeneous reactions in solution with radiolytic oxidants and in heterogeneous reactions on the UO 2 surface, most likely at reactive grain-boundary sites

  20. Thermodynamics of geothermal brines. I. Thermodynamic properties of vapor-saturated NaCl (aq) solutions from 0-300 {sup 0}C

    Energy Technology Data Exchange (ETDEWEB)

    Silvester, L.F.; Pitzer, K.S.

    1976-01-01

    Osmotic and activity coefficient data, enthalpy data, and heat capacity data on aqueous sodium chloride solutions from various sources have been fitted to a thirteen parameter equation. The equation reproduces the osmotic coefficient data to +-0.005 over the composition range 0-6M and temperature range 0-300{sup 0}C, enthalpy data to +-5-10 cal/mole for compositions of 0-5M at temperatures from 25-100{sup 0}C, and heat capacity data to +-0.5 cal/{sup 0}K for compositions of 0-2M at temperatures from 25-200{sup 0}C. Tabulated values of the total Gibbs energy, enthalpy, and heat capacity, plus partial molal and excess thermodynamic quantities of sodium chloride solutions for compositions of 0-6M at 25{sup 0}C intervals from 0-300{sup 0}C are given along with the same quantities in graphical form for compositions of 0-6M at temperatures of 100-350{sup 0}C.

  1. Porphyrins as Corrosion Inhibitors for N80 Steel in 3.5% NaCl Solution: Electrochemical, Quantum Chemical, QSAR and Monte Carlo Simulations Studies

    Directory of Open Access Journals (Sweden)

    Ambrish Singh

    2015-08-01

    Full Text Available The inhibition of the corrosion of N80 steel in 3.5 wt. % NaCl solution saturated with CO2 by four porphyrins, namely 5,10,15,20-tetrakis(4-hydroxyphenyl-21H,23H-porphyrin (HPTB, 5,10,15,20-tetra(4-pyridyl-21H,23H-porphyrin (T4PP, 4,4′,4″,4‴-(porphyrin-5,10,15,20-tetrayltetrakis(benzoic acid (THP and 5,10,15,20-tetraphenyl-21H,23H-porphyrin (TPP was studied using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization, scanning electrochemical microscopy (SECM and scanning electron microscopy (SEM techniques. The results showed that the inhibition efficiency, η% increases with increasing concentration of the inhibitors. The EIS results revealed that the N80 steel surface with adsorbed porphyrins exhibited non-ideal capacitive behaviour with reduced charge transfer activity. Potentiodynamic polarization measurements indicated that the studied porphyrins acted as mixed type inhibitors. The SECM results confirmed the adsorption of the porphyrins on N80 steel thereby forming a relatively insulated surface. The SEM also confirmed the formation of protective films of the porphyrins on N80 steel surface thereby protecting the surface from direct acid attack. Quantum chemical calculations, quantitative structure activity relationship (QSAR were also carried out on the studied porphyrins and the results showed that the corrosion inhibition performances of the porphyrins could be related to their EHOMO, ELUMO, ω, and μ values. Monte Carlo simulation studies showed that THP has the highest adsorption energy, while T4PP has the least adsorption energy in agreement with the values of σ from quantum chemical calculations.

  2. Study in aqueous solution of the praseodymium inclusion in β-cyclodextrin in 2 M of NaCl; Estudio en solucion acuosa de la inclusion del praseodimio en la β-ciclodextrina en 2 M de NaCl

    Energy Technology Data Exchange (ETDEWEB)

    De la Cruz M, N.

    2013-07-01

    In the fission of uranium to produce electricity, generated between the fission products which are the lanthanides and actinides that at any given time may come into contact with aqueous media, because of this, praseodymium was including in the β-cyclodextrin in order to increase the solubility and stability of praseodymium by forming inclusion complexes Praseodymium-β-cyclodextrin (Pr-β-Cd). The inclusion study was conducted in a proportion of praseodymium and β-cyclodextrin. Infrared spectra, Raman and X-ray diffraction showed the presence of praseodymium and β-cyclodextrin in the inclusion complex, in both proportions. The analysis by scanning electron microscopy confirmed the inclusion of praseodymium in βcyclodextrin. In general, the results of characterization obtained by these techniques show the formation of the inclusion complex. Furthermore, the behaviour of praseodymium inclusion in the β-cyclodextrin was studied in 2 M NaCl at 303 K and free-CO{sub 2} conditions. For this reason, we used two methods: spectrophotometric and potentiometric titration direct of praseodymium-β-cyclodextrin, the data were treated graphically and with the program SUPERQUAD, respectively. The values obtained for praseodymium by spectrophotometric method was: log β{sub 1}= -8.75 calculated graphically and with the potentiometric method, using program SUPERQUAD were logβ{sub 1,OH}= -8.73 ± 0.01 logβ{sub 1,2OH}= -18.27 ± 0.16 and logβ{sub 1,3OH}= -26.44 ± 0.02 obtained simultaneously. (Author)

  3. Partial molar volumes of L-alanine, DL-serine, DL-threonine, L-histidine, glycine, and glycylglycine in water, NaCl, and DMSO aqueous solutions at T 298.15 K

    International Nuclear Information System (INIS)

    Yuan Quan; Li Zhifen; Wang Baohuai

    2006-01-01

    The apparent molar volumes of L-alanine, DL-serine, DL-threonine, L-histidine, glycine, and glycylglycine in water and in the aqueous solutions of NaCl and DMSO with various concentrations at T = 298.15 K have been measured by the precise vibrating-tube digital densimeter. The calculated partial molar volumes at infinite dilution have been used to obtain corresponding transfer volumes from water to various solutions. The experimental results show that the standard partial molar volumes of the above amino acids and peptide at the dilute DMSO aqueous solutions are very close to those in water. However, the volumes show several types of variations with the increase of the concentrations of DMSO due to different types of side chain of amino acids, which should be discussed specifically. The NaCl changes considerably the infinite dilution standard partial molar volumes of the above amino acids and peptide in the aqueous solutions. The infinite dilution standard partial molar volumes of the each amino acids and peptide increase with the concentrations of NaCl. The experimental results have been rationalized by a cosphere overlap model

  4. Corrosion performance of SiCsubp/6061 Al metal matrix composites in sodium chloride solution

    International Nuclear Information System (INIS)

    Mohmad Soib bin Selamat

    1995-01-01

    The corrosion performance of silicon carbide particle/aluminium metal matrix composites (SiCsubp/Al) were studied in sodium chloride solution by means of electrochemical, microscopic, gravimetric and analytical techniques. The materials under investigation were compocasting processed 6061 Al reinforced with increasing amounts of SiC particles. Potentiostatic polarization tests were done in 0.1M NaCl solutions that were aerated or deaerated to observe overall corrosion behaviour. It was seen that the corrosion potentials did not vary greatly in relation to the amounts of SiCsubp reinforcement. Corrosion tests showed that the degree of corrosion increased with increasing SiCsubp content. SEM analysis technique was used to study the corroded samples and the pitting morphology. By TEM, no intermetallic layer was found at SiC/Al interface. A model for pitting process was proposed

  5. In situ observation of initial rust formation process on carbon steel under Na2SO4 and NaCl solution films with wet/dry cycles using synchrotron radiation X-rays

    International Nuclear Information System (INIS)

    Yamashita, M.; Konishi, H.; Kozakura, T.; Mizuki, J.; Uchida, H.

    2005-01-01

    Atmospheric corrosion of steel proceeds under thin electrolyte film formed by rain and dew condensation followed by wet and dry cycles. It is said that rust layer formed on steel as a result of atmospheric corrosion strongly affects the corrosion behavior of steel. The effect of environmental corrosiveness on the formation process and structure of the rust layer is, however, not clear to date. In this study, in situ observation of the rusting process of a carbon steel covered with a thin film of Na 2 SO 4 or NaCl solution was performed under a wet/dry repeating condition by X-ray diffraction spectroscopy with white X-rays obtained from synchrotron radiation. The present in situ experiments successfully detected initial process of the rust formation. In the early cycles, the rust constituents were not well crystallized yet, but the presence of Fe(OH) 2 and Fe(OH) 3 was confirmed. In the subsequent cycles, two different solutions resulted in difference in preferential phase of the rust constituents. α-FeOOH was preferentially formed in the case of the Na 2 SO 4 solution film, whereas β-FeOOH appeared only under the NaCl solution film

  6. Corrosion behavior of Mg–5Al based magnesium alloy with 1 wt.% Sn, Mn and Zn additions in 3.5 wt.% NaCl solution

    Directory of Open Access Journals (Sweden)

    Nguyen Dang Nam

    2014-06-01

    Full Text Available The corrosion properties of four Mg–5Al alloys with M-alloying elements (tin, manganese and zinc in a 3.5 wt.% NaCl solution were examined using electrochemical tests and surface analyses. The electrochemical results indicated that the addition of 1 wt.% M metal decreased the corrosion rate and hydrogen evolution rate of the Mg–5Al specimens. Moreover, the addition of 1Zn resulted in having the best corrosion resistance due to the interaction of Zn oxide with Mg and Al oxides which acted as a corrosion barrier.

  7. Corrosion behavior of TiN, TiAlN, TiAlSiN thin films deposited on tool steel in the 3.5 wt.% NaCl solution

    International Nuclear Information System (INIS)

    Yoo, Yun Ha; Le, Diem Phuong; Kim, Jung Gu; Kim, Sun Kyu; Vinh, Pham Van

    2008-01-01

    TiN, TiAlN and TiAlSiN hard coatings were deposited onto AISI H13 tool steel by cathodic arc plasma method. X-ray diffraction (XRD) analysis confirmed that incorporation of Al and Si into TiN led to refinement of microstructure. From the results of potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) test conducted in an aerated 3.5% NaCl solution, the TiAlSiN film showed the best corrosion resistance with the lowest corrosion current density and porosity, the highest protective efficiency and total resistance (pore resistance plus charge transfer resistance)

  8. Experimental study of evaporation of distilled water and 10% NaCl and СaCl2 aqueous salt solutions droplets under their free falling on a heated surface

    Directory of Open Access Journals (Sweden)

    Feoktistov D.V.

    2017-01-01

    Full Text Available The paper presents the experimental results of evaporation of distilled water and 10% aqueous salt solutions of NaCl and СaCl2 droplets under their free falling on a heated surface. It is proved that it is more expedient to conduct the experimental research in this field according to classical multifactorial experiment. Laser treatment of surfaces is found to increase the evaporation rate and to biases the point of boiling crisis in the region of lower surface temperatures. In this case, in the conditions of boiling crisis the frequency of contact of a droplet with a heated surface will decrease.

  9. Effect of Repair Welding on Electrochemical Corrosion and Stress Corrosion Cracking Behavior of TIG Welded AA2219 Aluminum Alloy in 3.5 Wt Pct NaCl Solution

    Science.gov (United States)

    Venugopal, A.; Sreekumar, K.; Raja, V. S.

    2010-12-01

    The stress corrosion cracking (SCC) behavior of AA2219 aluminum alloy in the as-welded (AW) and repair-welded (RW) conditions was examined and compared with that of the base metal (BM) in 3.5 wt pct NaCl solution using the slow strain rate technique (SSRT). The reduction in ductility was used as a parameter to evaluate the SCC susceptibility of both BM and welded joints. The results show that the ductility ratio ( ɛ NaCl/( ɛ air)) of the BM was close to one (0.97) and reduced to 0.9 for the AW joint. This value further reduced to 0.77 after carrying out one repair welding operation. However, the RW specimen exhibited higher ductility than the single-weld specimens even in 3.5 wt pct NaCl solution. SSRT results obtained using pre-exposed samples followed by post-test metallographic observations clearly showed localized pitting corrosion along the partially melted zone (PMZ), signifying that the reduction in ductility ratio of both the AW and RW joints was more due to mechanical overload failure, caused by the localized corrosion and a consequent reduction in specimen thickness, than due to SCC. Also, the RW joint exhibited higher ductility than the AW joint both in air and the environment, although SCC index (SI) for the former is lower than that of the latter. Fractographic examination of the failed samples, in general, revealed a typical ductile cracking morphology for all the base and welded joints, indicating the good environmental cracking resistance of this alloy. Microstructural examination and polarization tests further demonstrate grain boundary melting along the PMZ, and that provided the necessary electrochemical condition for the preferential cracking on that zone of the weldment.

  10. AES depth profiles in Mo-coated 304L stainless steel achieved by RF-magnetron sputtering and influence of Mo on the corrosion in 3.5% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Saidi, D. [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Zaid, B., E-mail: zaidbachir@yahoo.com [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Souami, N. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Saoula, N. [Division des Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées CDTA, Cité du 20 août 1956, Baba Hassan, BP n 17, Alger (Algeria); Siad, M. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Si Ahmed, A. [Im2np, UMR 7334 CNRS, Aix-Marseille Université, 13397 Marseille Cedex 20 (France); Biberian, J.P. [CINaM, UMR 7525 CNRS, Aix Marseille Université, 13288 Marseille Cedex 9 (France)

    2015-10-05

    Highlights: • Mo coating of 304L stainless steel is achieved via RF-magnetron sputtering. • The AES depth profiles before and after annealing in air (at 973 K) are analyzed. • The corrosions in NaCl solution of bare and Mo-coated samples are compared. • Mo-coated steels exhibit better corrosion behaviors. • The positive action of Mo oxide via its semi-conducting properties is deduced. - Abstract: Molybdenum-coated 304L stainless steel samples, fabricated by RF-magnetron sputtering, are characterized by Auger Electron Spectroscopy (AES) before and after annealing in air at 973 K. The electrochemical parameters of bare and coated materials, in NaCl 3.5% water solution at 298 K, are derived from the potentiodynamic polarization curves. The corrosion current of Mo-coated samples (before and after annealing) is significantly lower than that of its bare counterpart. The information gained from the AES depth profiles leads us to infer that the positive action of molybdenum on the corrosion behavior may be attributed to the changes induced by the semi-conducting properties of Mo oxide in the passive film.

  11. Effect of Nd on the corrosion behaviour of AM50 and AZ91D magnesium alloys in 3.5 wt.% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Arrabal, R., E-mail: raularrabal@quim.ucm.es [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Pardo, A.; Merino, M.C.; Mohedano, M.; Casajus, P. [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Paucar, K. [Gabinete de Corrosion, Facultad de Ingenieria Quimica y Textil, Universidad Nacional de Ingenieria, Cod. Postal 25, Lima (Peru); Garces, G. [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Nd addition modified the microstructure of AM50 and AZ91D magnesium alloys. Black-Right-Pointing-Pointer Volume of {beta}-Mg{sub 17}Al{sub 12} phase was reduced and Al{sub 2}Nd/Al-Mn-Nd particles were formed. Black-Right-Pointing-Pointer Nd-containing intermetallics revealed lower potential than Al-Mn inclusions. Black-Right-Pointing-Pointer 0.7-0.8 wt.% Nd reduced the corrosion rate of AM50 and AZ91D alloys by 90%. - Abstract: The corrosion performance of AM50 and AZ91D alloys containing up to 1.5 wt.% Nd was investigated by electrochemical and gravimetric measurements in 3.5 wt.% NaCl at 22 Degree-Sign C. The alloys were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and surface potential maps. In Nd-containing alloys, formation of Al{sub 2}Nd and Al-Mn-Nd intermetallic compounds reduced the volume fraction and modified the morphology of the {beta}-Mg{sub 17}Al{sub 12} phase. The addition of Nd improved the corrosion resistance of the alloys due to increased passivity of the surface film and suppression of micro-galvanic couples.

  12. Investigation of Corrosion Behavior of Ti/TiN Multilayers on Al7075 Deposited by High-Vacuum Magnetron Sputtering in 3.5% NaCl Solution

    Science.gov (United States)

    Molavi, Esfandiar; Shanaghi, Ali; Chu, Paul K.

    2018-04-01

    Although Al 7075 has many favorable mechanical properties such as the large strength-to-weight ratio, the relatively poor corrosion resistance has restricted industrial applications. In this work, Ti/TiN as hard multilayered and nanostructured coatings are deposited on the relatively soft Al 7075 structure by high-vacuum radio-frequency magnetron sputtering and the phase, structure, and morphology are investigated in details. The corrosion behavior is evaluated by electrochemical impedance spectroscopy in 3.5% NaCl at a pH of 7.5 for 1, 6, 12, 24, 36, 48, 60, and 72 h. At time points of 1, 6, 12, and 24 h, primary oxide layers and double layers are formed, but the corrosive medium penetrates the primary titanium nitride columnar structure. At longer time points of 24, 36, 48, 60, and 72 h, formation of stronger oxide and double layers leads to better corrosion resistance which is 14.8 times better than that observed from the uncoated substrate after immersion for 36 h. According to R ct, the corrosion resistances of the short and long immersion groups are 808.5-1984 and 808.5-1248 kΩ cm2, respectively, thereby confirming the effectiveness of the Ti/TiN coating against corrosion in comparison with the corrosion resistance of 84.3 kΩ cm2 observed from the uncoated Al 7075. The smallest corrosion resistance of 808.5 kΩ cm2 observed at the time point of 24 h is 9.6 times that of the uncoated substrate.

  13. Direct measurement of CO2 solubility and pH in NaCl hydrothermal solutions by combining in-situ potentiometry and Raman spectroscopy up to 280 °C and 150 bar

    Science.gov (United States)

    Truche, Laurent; Bazarkina, Elena F.; Berger, Gilles; Caumon, Marie-Camille; Bessaque, Gilles; Dubessy, Jean

    2016-03-01

    The in-situ monitoring of aqueous solution chemistry at elevated temperatures and pressures is a major challenge in geochemistry. Here, we combined for the first time in-situ Raman spectroscopy for concentration measurements and potentiometry for pH measurement in a single hydrothermal cell equipped with sampling systems and operating under controlled conditions of temperature and pressure. Dissolved CO2 concentration and pH were measured at temperatures up to 280 °C and pressures up to 150 bar in the H2O-CO2 and H2O-CO2-NaCl systems. A Pitzer specific-ion-interaction aqueous model was developed and confirmed the accuracy and consistency of the measurements, at least up to 250 °C. The revised Pitzer parameters for the H2O-CO2-NaCl system were formatted for the Phreeqc geochemical software. Significant changes with respect to the Pitzer.dat database currently associated with Phreeqc were observed. The new model parameters are now available for further applications. The Raman and pH probes tested here may also be applied to field monitoring of hydrothermal springs, geothermal wells, and oil and gas boreholes.

  14. Effect of the dopamine D1-like receptor antagonist SCH 23390 on the microstructure of ingestive behaviour in water-deprived rats licking for water and NaCl solutions.

    Science.gov (United States)

    Galistu, Adriana; D'Aquila, Paolo S

    2012-01-18

    The analysis of licking microstructure provides measures, size and number of licking bouts, which might reveal, respectively, reward evaluation and behavioural activation. Based on the different effects of the dopamine D1-like and D2-like receptor antagonists SCH 23390 and raclopride on licking for sucrose, in particular the failure of the former to reduce bout size and the ability of the latter to induce a within-session decrement of bout number resembling either reward devaluation or neuroleptics on instrumental responding, we suggested that activation of reward-associated responses depends on dopamine D1-like receptor stimulation, and its level is updated on the basis of a dopamine D2-like receptor-mediated reward evaluation. Consistent results were obtained in a study examining the effect of dopamine D2-like receptor antagonism in rats licking for NaCl solutions and water. In this study, we examined the effects of the dopamine D1-like receptor antagonist SCH 23390 (0, 10, 20 and 40 μg/kg) on the microstructure of licking for water and sodium chloride solutions (0.075 M, 0.15 M, 0.3 M) in 12 h water deprived rats. Rats were exposed to each solution for 60 s either after the first lick or after 3 min that the animals were placed in the chambers. Bout size, but not bout number, was decreased at the highest NaCl concentration. SCH 23390 produced a decrease of bout number and of lick number mainly due to the decreased number of subjects engaging in licking behaviour, and failed to reduce bout size for Na Cl and water at a dose which increased the latency to the 1st lick but did not affect the intra-bout lick rate. In agreement with previous observations, these results suggest that dopamine D1-like receptors play an important role in the activation of reward-oriented responses. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Electrical Conductivity and Chemical Composition of Soil Solution: Comparison of Solution Samplers in Tropical Soils

    Directory of Open Access Journals (Sweden)

    Davi Lopes do Carmo

    2016-01-01

    Full Text Available ABSTRACT Soil solution samplers may have the same working principle, but they differ in relation to chemical and physical characteristics, cost and handling, and these aspects exert influence on the chemical composition of the soil solution obtained. This study was carried out to evaluate, over time, the chemical composition of solutions extracted by Suolo Acqua, with the hydrophilic membrane (HM as a standard, using soils with contrasting characteristics, and to determine the relationship between electrical conductivity (EC and concentration of ions and pH of soil solution samples. This study was carried out under laboratory conditions, using three soils samples with different clay and organic matter (OM contents. Soil solution contents of F−, Cl−, NO−3, Br−, SO42−, Na+, NH4+, K+, Mg2+, Ca2+, were analyzed, as well as inorganic, organic, and total C contents, pH, and EC, in four successive sampling times. Soil solution chemical composition extracted by the Suolo Acqua sampler is similar to that collected by the HM, but the Suolo Acqua extracted more Na+ and soluble organic C than the HM solution. Solution EC, cation and anion concentrations, and soluble C levels are higher in the soil with greater clay and OM contents (Latossolo and Cambissolo in this case. Soil solution composition varied over time, with considerable changes in pH, EC, and nutrient concentrations, especially associated with soil OM. Thus, single and isolated sampling of the soil solution must be avoided, otherwise composition of the soil solution may not be correctly evaluated. Soil solution EC was regulated by pH, as well as the sum of cation and anion concentrations, and the C contents determined in the soil liquid phase.

  16. Volumetric properties of ascorbic acid (vitamin C) and thiamine hydrochloride (vitamin B1) in dilute HCl and in aqueous NaCl solutions at (283.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K

    International Nuclear Information System (INIS)

    Ayranci, Guler; Sahin, Melike; Ayranci, Erol

    2007-01-01

    Apparent molar volumes and apparent molar isentropic compressibilities of ascorbic acid (vitamin C) and thiamine hydrochloride (vitamin B 1 ) were determined from accurately measured density and sound velocity data in water and in aqueous NaCl solutions at (283.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K. These volume and compressibility data were extrapolated to zero concentration using suitable empirical or theoretical equations to determine the corresponding infinite dilution values. Apparent molar expansibilities at infinite dilution were determined from slopes of apparent molar volume vs. temperature plots. Ionization of both ascorbic acid and thiamine hydrochloride were suppressed using sufficiently acidic solutions. Apparent molar volumes at infinite dilution for ascorbic acid and thiamine hydrochloride were found to increase with temperature in acidic solutions and in the presence of co-solute, NaCl. Apparent molar expansibility at infinite dilution were found to be constant over the temperature range studied and were all positive, indicating the hydrophilic character of the two vitamins studied in water and in the presence of co-solute, NaCl. Apparent molar isentropic compressibilities of ascorbic acid at infinite dilution were positive in water and in the presence of co-solute, NaCl, at low molalities. Those of thiamine hydrochloride at infinitive dilution were all negative, consistent with its ionic nature. Transfer apparent molar volumes of vitamins at infinite dilution from water solutions to NaCl solutions at various temperatures were determined. The results were interpreted in terms of complex vitamin-water-co-solute (NaCl) interactions

  17. Regularities of radium coprecipitation with barium sulfate from salt solutions

    International Nuclear Information System (INIS)

    Kudryavskij, Yu.P.; Rakhimova, O.V.

    2007-01-01

    Coprecipitation of radium with barium sulfate from highly concentrated NaCl solutions is studied, including the effects of the initial solution composition, alkaline reagent (CaO, NaOH), supporting electrolyte (NaCl) concentration, and pH. The process is promoted by high NaCl concentration in the initial solution, which is due to structural transformation and change in the sorption activity of the BaSO 4 precipitate in salt solutions. The results obtained were applied to recovery of radium from process solutions during the development and introduction of improved procedure for disinfection and decontamination of waste yielded by chlorination of loparite concentrates [ru

  18. Yttrium 3-(4-nitrophenyl)-2-propenoate used as inhibitor against copper alloy corrosion in 0.1 M NaCl solution

    International Nuclear Information System (INIS)

    Nam, Nguyen Dang; Thang, Vo Quoc; Hoai, Nguyen To; Hien, Pham Van

    2016-01-01

    Highlights: • Yttrium 3-(4-nitrophenyl)-2-propenoate has been studied as an effective corrosion inhibitor for copper. • A high inhibition performance is attributed to the forming protective inhibiting deposits. • Yttrium 3-(4-nitrophenyl)-2-propenoate mitigates corrosion by promoting random distribution of minor anodes. - Abstract: Yttrium 3-(4-nitrophenyl)-2-propenoate has been studied as an effective corrosion inhibitor for copper alloy in 0.1 M chloride solution. The results show that the surface of copper alloy coupons exposed to solutions containing 0.45 mM yttrium 3-(4-nitrophenyl)-2-propenoate had no signs of corrosion attack due to protective film formation, whereas the surface of copper alloy coupons exposed to non-inhibitor and lower concentrations of yttrium 3-(4-nitrophenyl)-2-propenoate containing solutions were severely corroded. A high inhibition performance is attributed to the forming protective inhibiting deposits that slow down the electrochemical corrosion reactions and mitigate corrosion by promoting random distribution of minor anodes.

  19. Experimental determination of the H2O + 15 wt% NaCl and H2O + 25 wt% NaCl liquidi to 1.4 GPa

    Science.gov (United States)

    Valenti, P.; Schmidt, C.

    2009-12-01

    The binary H2O+NaCl is one of the most important model systems for chloridic fluids in many geologic environments such as the Earth’s crust, upper mantle, and subducting slabs, and is also applicable to extraterrestrial icy planetary bodies (e.g., Manning 2004, Zolensky et al., 1999). The knowledge on phase equilibria and PVTx properties of this system is still fragmentary at high pressures, e.g., very little has been reported on liquidi at compositions Daniel 2008). In this study, we investigated the liquidus of 15 and 25 wt% NaCl solutions at pressures up to 1.4 GPa. The experiments were performed using a hydrothermal diamond-anvil cell (Bassett et al. 1993) modified for Raman spectroscopy and accurate temperature measurements. A quartz chip, halite, and water were loaded into the sample chamber, which also contained a small trapped air bubble (10 vol%) when it was sealed. The actual salinity was then determined from measurement of the vapor-saturated liquidus temperature. The sample chamber was then compressed until the bubble disappeared. After freezing, phase transitions occurring with increasing temperature were observed optically, and the pressure was determined from the frequency shift of the 464 cm-1 Raman line of quartz (Schmidt and Ziemann 2000). The sample chamber was then compressed further, and the experiment was repeated at various bulk densities until a pressure of ~1.4 GPa was attained. At some conditions, Raman spectra were acquired for identification of the phase assemblage. The solution always crystallized to a single phase upon cooling above ~0.15 GPa at 25 wt% NaCl and above ~1 GPa at 15 wt% NaCl. Raman spectra in the OH stretching region indicate that this phase contains or is a NaCl hydrate other than hydrohalite, probably in solid solution with ice. Melting of this phase produced liquid and hydrohalite and/or ice VI. Ice VI was the last solid that dissolved upon heating, between 1100 MPa, 3 °C and 1370 MPa, 17 °C for 15 wt% NaCl and at

  20. The chemistry of Pu in concentrated aqueous NaCl solution: Effects of alpha self-radiolysis and the interaction between hypochlorite and dioxoplutonium(VI)

    Energy Technology Data Exchange (ETDEWEB)

    Pashalidis, I. (Inst. fuer Radiochemie, TU Muenchen, Garching (Germany)); Kim, J.I. (Inst. fuer Radiochemie, TU Muenchen, Garching (Germany) Inst. fuer Nukleare Entsorgungstechnik, Kernforschungszentrum Karlsruhe (Germany)); Lierse, C. (Inst. fuer Radiochemie, TU Muenchen, Garching (Germany)); Sullivan, J.C. (Chemistry Div., Argonne National Lab., IL (United States))

    1993-01-01

    The reactions between dioxoplutonium(VI) and hypochlorite in aqueous solution produce the species PuO[sub 2](OH)(ClO) and PuO[sub 2](ClO)[sub 2]. The results of spectrophotometric observations are presented and the data used to calculate values of log K=14.0 at pH=6.7 and 14.5 at pH=8.4 for the former complex and a value of 10.3 for the latter. The possible participation of 6d orbitals in these reactions is noted. (orig.)

  1. The influence of the surface distribution of Al6(MnFe) intermetallic on the electrochemical response of AA5083 aluminium alloy in NaCl solutions

    International Nuclear Information System (INIS)

    Bethencourt, M.; Botana, F.J.; Calvino, J.J.; Perez, J.; Rodriguez, M.A.; Marcos, M.

    1998-01-01

    In this paper the behaviour against pitting corrosion of different samples of AA5083 aluminium alloy has been studied. A correlation between the microstructure of the samples and their susceptibility to pitting has been established. Metallographic analysis combined with SEM and EDS techniques have allowed us to detect three intermetallic compounds in the samples. The particle size distribution and surface density of each intermetallic phase have been evaluated for the three AA5083 alloy samples coming from different suppliers. Significant differences in the microstructure of the three samples have been found. Full immersion test carried out in 3.5% aerated aqueous solutions showed that pitting starts at the locations of the Al 6 (MnFe) intermetallic particles. As a consequence of this, the samples with higher Al 6 (MnFe) content showed a higher pit density on its surface. The results of cyclic polarisation tests showed also a good correlation with the microstructural parameters. (orig.)

  2. Features of solid solutions composition in magnesium with yttrium alloys

    International Nuclear Information System (INIS)

    Drits, M.E.; Rokhlin, L.L.; Tarytina, I.E.

    1983-01-01

    Additional data on features of yttrium solid solutions composition in magnesium in the course of their decomposition investigation in the case of aging are obtianed. The investigation has been carried out on the base of a binary magnesium-yttrium alloy the composition of which has been close to maximum solubility (at eutectic temperature) and magnesium-yttrium alloys additionally doped with zinc. It is shown that higher yttrium solubility in solid magnesium than it has been expected, issueing from the difference in atomic radii of these metals indicates electron yttrium-magnesium atoms interaction. In oversaturated magnesium-yttrium solid solutions at earlier decomposition stages Mg 3 Cd type ordering is observed. At aging temperatures up to 250 deg C and long exposures corresponding to highest strengthening in oversaturated magnesium yttrium solid solutions a rhombic crystal lattice phase with three symmetric orientations is formed

  3. Preparation of Cu–Ni–Fe alloy coating and its evaluation on corrosion behavior in 3.5% NaCl solution

    International Nuclear Information System (INIS)

    Zhou, Qiongyu; Jiang, Jibo; Zhong, Qingdong; Wang, Yi; Li, Ke; Liu, Huijuan

    2013-01-01

    Highlights: ► An uniform Cu–Ni–Fe alloy coating constituted of homogenous γ-phases was prepared on the surface of low-carbon steel. ► The increase of Ni has a significant promotion to produce a uniform and homogenous Cu–Ni–Fe alloy coating. ► Electrochemical test results indicated the excellent corrosion resistance of the coating with high Ni content. ► EIS test and results demonstrated the surface homogeneity or compactness of the coating with high Ni content. -- Abstract: In this paper, an attempt had been made to prepare a Cu–Ni–Fe alloy coating for improving the corrosion resistance of the low-carbon steel. The surface heat treatment of coated low-carbon steel was performed at 1000 °C for 3 h under hydrogen atmosphere. The structure and microstructure of coatings was separately analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The corrosion resistance of the samples was evaluated by potentiodynamic polarization (Tafel) and electrochemical impedance spectroscopy (EIS). Results indicated that a compact alloy coating was formed on the surface of low-carbon steel and the Ni content had a prodigious impact to the microstructure, composition and structure of Cu–Ni–Fe alloy coating. Apart from that, significant improvements in corrosion resistance were achieved by using the Cu–Ni–Fe alloy coating, which constituting of homogeneous γ-phases

  4. Electrochemical corrosion behavior of acid treated strip cast AM50 and AZX310 magnesium alloys in 3.5 wt.% NaCl solution

    Directory of Open Access Journals (Sweden)

    Srinivasan Arthanari

    2017-09-01

    Full Text Available The influence of acid treatments on the surface morphology and electrochemical corrosion behavior of strip-cast AM50 and AZX310 alloys have been studied in the present investigation. The alloys were acid treated using H3PO4 (AT-1, HF (AT-2 and HNO3 (AT-3 for different treatment durations viz., 60, 300 and 600 s. The acid treatments produced a surface layer consisting of corresponding magnesium salts of the acids and were confirmed from the X-ray diffraction (XRD, scanning electron microscopy (SEM and energy dispersive X-ray analysis (EDAX. AT-1 treatment produced cracked and network porous morphology for AM50 and AZX310 alloys respectively and AT-3 treatment exhibited dense creaked surface layer formation while AT-2 does not produce any significant change in the morphology. Polarization studies revealed that, the acid treatment significantly altered the corrosion process by altering anodic and cathodic reaction rates of AM50 and AZX310 alloys. The HNO3 (AT-3 treatment was effective compared to other treatments to control the corrosion rate in the studied treatment conditions. The surface morphology and chemical composition of surface layer produced during the treatment was correlated to explain the corrosion results.

  5. The use of morinda citrifolia as a green corrosion inhibitor for low carbon steel in 3.5% NaCl solution

    Science.gov (United States)

    Kusumastuti, Rahayu; Pramana, Rakhmad Indra; Soedarsono, Johny W.

    2017-03-01

    The effect and mechanism of green corrosion inhibitor of Morinda Citrifolia (Noni) toward low carbon steel material has been researched. The general background is to develop the cheap and eco-friendly corrosion inhibitor based on components taken from tropical plants that grow +in Indonesia. This research aims to determine the effectiveness of the use of the extracts of noni as green corrosion inhibitor of carbon steel material in aggressive environment. The medium applied for this experiment is 3.5% natrium chloride solution. The variation of the concentration and immersion time duration has been applied as the experimental parameters. All the work was done at room temperature. The corrosion rate was measured by electrochemical polarization method with CMS 600-Gamry instruments and weight loss. The adsorption of inhibitor into the metal surface, which induced bonding formation after immersion was observed by using FTIR method. Inhibition mechanism was observed by polarization curves and fitted by the Langmuir adsorption models. The experimental results show that the higher concentration of inhibitor increasing the inhibition effect. The optimum inhibition is obtained at 3 ppm noni fruit extract, after immersion for about 288 hours. The corrosion rates obtained was 1.385 mpy, with the inhibitor efficiency of 76.92%. The monolayer film is formed coating the surface material as a result of mixed type corrosion inhibitor behavior of Noni. It can be concluded that this green inhibitor is effective to be used for low carbon steel material.

  6. Fixation of potentially lethal radiation damage by post-irradiation exposure of Chinese hamster cells to 0.5 M or 1.5 M NaCl solutions

    International Nuclear Information System (INIS)

    Raaphorst, G.P.; Dewey, W.C.

    1979-01-01

    The effect of 0.05 M and 1.5 M NaCl treatments on CHO cells during and after irradiation has been examined. Treatment with either hypotonic or hypertonic salt solutions during and after irradiation resulted in the fixation of radiation damage which would otherwise not be expressed. The half time for fixation was 4 to 5 min, and the increased expression of the potentially lethal damage by anisotonic solutions was mainly characterized by large decreases in the shoulder of the survival curve, as well as by decreases in Dsub(o). Fixation of radiation damage at 37 0 C occurred to a much greater extent for the hypertonic treatment than for the hypotonic treatment and was greater at 37 0 C than at 20 0 C. Although both the hypotonic and hypertonic treatments during and after irradiation reduced or eliminated the repair of sublethal and potentially lethal damage, treatment during irradiation only, radiosensitized the cells when the treatment was hypotonic, and radioprotected the cells when the treatment was hypertonic. These observations are discussed in relation to salt treatments and different temperatures altering competition between repair and fixation of potentially lethal lesions, the number of which depends on the particular salt treatment at the time of irradiation. (author)

  7. Response of duplex Cr(N)/S and Cr(C)/S coatings on 316L stainless steel to tribocorrosion in 0.89% NaCl solution under plastic contact conditions.

    Science.gov (United States)

    Sun, Y; Dearnley, P A; Mallia, Bertram

    2017-08-01

    Two duplex coatings, Cr(N)/S and Cr(C)/S, were deposited on 316 L stainless steel by magnetron sputtering. The effectiveness of these duplex coatings in improving the tribocorrosion behavior of medical alloys under elastic contact conditions has been demonstrated in a recent publication. The present work focused on the response of these duplex coatings to tribocorrosion under plastic contact conditions. Tribocorrosion tests were conducted in 0.89% NaCl solution at 37°C at an initial contact pressure of 740 MPa and under unidirectional sliding conditions for sliding duration up to 24 h. The results showed that during sliding in the corrosive solution, the duplex coatings were plastically deformed into the substrate to a depth about 1 μm. The Cr(C)/S duplex coating had sufficient ductility to accommodate the deformation without cracking, such that it was worn through gradually, leading to the gradual increase in open circuit potential (OCP) and coefficient of friction (COF). On the other hand, the Cr(N)/S duplex coating suffered from cracking at all tested potentials, leading to coating blistering after prolonged sliding at OCP and stable pit formation in the substrate beneath the coating at applied anodic potentials. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1503-1513, 2017. © 2016 Wiley Periodicals, Inc.

  8. Uncertainty in geochemical modelling of CO2 and calcite dissolution in NaCl solutions due to different modelling codes and thermodynamic databases

    International Nuclear Information System (INIS)

    Haase, Christoph; Dethlefsen, Frank; Ebert, Markus; Dahmke, Andreas

    2013-01-01

    Highlights: • CO 2 and calcite dissolution is calculated. • The codes PHREEQC, Geochemist’s Workbench, EQ3/6, and FactSage are used. • Comparison with Duan and Li (2008) shows lowest deviation using phreeqc.dat and wateq4f.dat. • Using Pitzer databases does not improve accurate calculations. • Uncertainty in dissolved CO 2 is largest using the geochemical models. - Abstract: A prognosis of the geochemical effects of CO 2 storage induced by the injection of CO 2 into geologic reservoirs or by CO 2 leakage into the overlaying formations can be performed by numerical modelling (non-invasive) and field experiments. Until now the research has been focused on the geochemical processes of the CO 2 reacting with the minerals of the storage formation, which mostly consists of quartzitic sandstones. Regarding the safety assessment the reactions between the CO 2 and the overlaying formations in the case of a CO 2 leakage are of equal importance as the reactions in the storage formation. In particular, limestone formations can react very sensitively to CO 2 intrusion. The thermodynamic parameters necessary to model these reactions are not determined explicitly through experiments at the total range of temperature and pressure conditions and are thus extrapolated by the simulation code. The differences in the calculated results lead to different calcite and CO 2 solubilities and can influence the safety issues. This uncertainty study is performed by comparing the computed results, applying the geochemical modelling software codes The Geochemist’s Workbench, EQ3/6, PHREEQC and FactSage/ChemApp and their thermodynamic databases. The input parameters (1) total concentration of the solution, (2) temperature and (3) fugacity are varied within typical values for CO 2 reservoirs, overlaying formations and close-to-surface aquifers. The most sensitive input parameter in the system H 2 O–CO 2 –NaCl–CaCO 3 for the calculated range of dissolved calcite and CO 2 is the

  9. Method for the preparation of cellulose acetate flat sheet composite membranes for forward osmosis—Desalination using MgSO4 draw solution

    KAUST Repository

    Sairam, M.; Sereewatthanawut, E.; Li, K.; Bismarck, A.; Livingston, A.G.

    2011-01-01

    A lab scale method for the preparation of defect free flat sheet composite membranes for forward osmosis (FO) has been developed. Membranes containing a thin layer of cellulose acetate (CA) cast on a nylon fabric of 50μm thick were prepared by phase inversion in water. Cellulose acetate (CA) membranes with an overall thickness of 70-80μm have been prepared with lactic acid, maleic acid and zinc chloride as pore forming agents, at different annealing temperatures, for forward osmosis. These membranes have been tested in the desalination of saline feeds (35g·L-1 of NaCl) using magnesium sulphate solution (150g·L-1) as the draw solution. The water flux, and rejection of NaCl, were compared with those of commercially available membranes tested under the same FO conditions. The commercially available FO membrane from Hydration Technologies Inc, OR (M1) has a permeability of 0.13L·h-1·m-2·bar-1 with a NaCl rejection of 97% when tested with 150g·L-1 of MgSO4 in the draw solution. Another commercially available membrane for FO from Hydration Technologies Inc, OR, M2 has a water permeability of 0.014L·h-1·m-2·bar-1 with NaCl rejection of 100%. The flux and rejection of the CA membranes prepared in this work are found to be dependent on the nature of the pore forming agent, and annealing temperature. Impregnation of an inorganic filler, sodium montmorrillonite in CA membranes and coating of CA membranes with hydrophilic PVA did not enhance the flux of base CA membranes. Cellulose acetate membranes cast from dope solutions containing acetone/isopropanol and lactic acid, maleic acid and zinc chloride as pore forming agents have water permeabilities of 0.13, 0.09 and 0.68L·h-1·m-2·bar-1 respectively, with NaCl rejections of 97.7, 99.3 and 88% when annealed at 50°C. CA membranes prepared with zinc chloride as a pore forming agent have good permeability of 0.27L·h-1·m-2·bar-1 with a NaCl rejection of 95% when annealed at 70°C. © 2011.

  10. Method for the preparation of cellulose acetate flat sheet composite membranes for forward osmosis—Desalination using MgSO4 draw solution

    KAUST Repository

    Sairam, M.

    2011-06-01

    A lab scale method for the preparation of defect free flat sheet composite membranes for forward osmosis (FO) has been developed. Membranes containing a thin layer of cellulose acetate (CA) cast on a nylon fabric of 50μm thick were prepared by phase inversion in water. Cellulose acetate (CA) membranes with an overall thickness of 70-80μm have been prepared with lactic acid, maleic acid and zinc chloride as pore forming agents, at different annealing temperatures, for forward osmosis. These membranes have been tested in the desalination of saline feeds (35g·L-1 of NaCl) using magnesium sulphate solution (150g·L-1) as the draw solution. The water flux, and rejection of NaCl, were compared with those of commercially available membranes tested under the same FO conditions. The commercially available FO membrane from Hydration Technologies Inc, OR (M1) has a permeability of 0.13L·h-1·m-2·bar-1 with a NaCl rejection of 97% when tested with 150g·L-1 of MgSO4 in the draw solution. Another commercially available membrane for FO from Hydration Technologies Inc, OR, M2 has a water permeability of 0.014L·h-1·m-2·bar-1 with NaCl rejection of 100%. The flux and rejection of the CA membranes prepared in this work are found to be dependent on the nature of the pore forming agent, and annealing temperature. Impregnation of an inorganic filler, sodium montmorrillonite in CA membranes and coating of CA membranes with hydrophilic PVA did not enhance the flux of base CA membranes. Cellulose acetate membranes cast from dope solutions containing acetone/isopropanol and lactic acid, maleic acid and zinc chloride as pore forming agents have water permeabilities of 0.13, 0.09 and 0.68L·h-1·m-2·bar-1 respectively, with NaCl rejections of 97.7, 99.3 and 88% when annealed at 50°C. CA membranes prepared with zinc chloride as a pore forming agent have good permeability of 0.27L·h-1·m-2·bar-1 with a NaCl rejection of 95% when annealed at 70°C. © 2011.

  11. Electrochemical corrosion behaviour of lead-free Sn-8.5 Zn-X Ag-0.1 Al-0.5 Ga solder in 3.5% NaCl solution

    International Nuclear Information System (INIS)

    Mohanty, Udit Surya; Lin, K.-L.

    2005-01-01

    The electrochemical corrosion behaviour of Pb-free Sn-8.5 Zn-X Ag-0.1 Al-0.5 Ga solder in 3.5% NaCl solution was investigated by using potentiodynamic polarization methods, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) analysis. The results obtained from polarization studies showed that an increase in the Ag content from 0.1 to 1.5 wt% decreased the corrosion current density (I corr ) and shifted the corrosion potential (E corr ) towards more noble values. These changes were also reflected in the linear polarization resistance (LPR), corrosion rate, anodic Tafel slope (b A ) and the cathodic Tafel slope (b c ) values, respectively. Passivation behaviour was noted in the Sn-Zn-X Ag-Al-Ga solders with Ag content > 0.1 wt%. The oxides and hydroxides of zinc were responsible for the formation of passive film. Presence of Ag atoms in the oxide layer also improved the passivation behaviour of solders to a certain extent. X-ray photoelectron spectroscopy revealed that two different oxygen species were formed on the surface films, one was assigned to OH - in Zn(OH) 2 and the other to O 2 - in ZnO. XPS depth profile results revealed that the two species had different depth distribution in the films. SEM and EDX analyses confirmed SnCl 2 as the major corrosion product formed after the electrochemical experiments

  12. SAE 1045 steel/WC-Co/Ni-Cu-Ni/SAE 1045 steel joints prepared by dynamic diffusion bonding: Microelectrochemical studies in 0.6 M NaCl solution

    International Nuclear Information System (INIS)

    Andreatta, Francesco; Matesanz, Laura; Akita, Adriano H.; Paussa, Luca; Fedrizzi, Lorenzo; Fugivara, Cecilio S.; Gomez de Salazar, Jose M.; Benedetti, Assis V.

    2009-01-01

    Corrosion of SAE 1045 steel/WC-Co/Ni-Cu-Ni/SAE 1045 steel interfaces was investigated in 0.6 M NaCl solution using an electrochemical microcell, which enables local electrochemical characterization at the micrometer scale. Two pieces of steel, one with a WC-Co coating covered with Ni (12 μm) and Cu (5 μm) layers, and the other with a Ni (15 μm) layer, were welded by dynamic diffusion bonding. A WC-Co coating was applied to the steel by the high velocity oxygen-fuel process, and Ni-Cu and Ni layers by electroplating. Polarization curves were recorded using an electrochemical microcell. Different regions of welded samples were investigated, including steel, cermet coating, and steel/cermet and steel/Ni-Cu-Ni/cermet interfaces. Optical and electronic microscopes were employed to study the corroded regions. Potentiodynamic polarization curves obtained using the microcell revealed that the base metal was more susceptible to corrosion than the cermet. In addition, cermet steel/cermet and steel/Ni-Cu-Ni/cermet joints exhibited different breakdown potentials. Steel was strongly corroded in the regions adjacent to the interfaces, while the cermet was less corroded. Iron oxides/hydroxides and chloride salts were the main corrosion products of steel. After removal of the superficial layer of corrosion products, iron oxides were mainly observed. Chloride ions were detected mainly on a copper-enriched layer placed between two Ni-enriched layers.

  13. In-Situ Electrochemical Corrosion Behavior of Nickel-Base 718 Alloy Under Various CO2 Partial Pressures at 150 and 205 °C in NaCl Solution

    Science.gov (United States)

    Zhang, Yubi; Zhao, Yongtao; Tang, An; Yang, Wenjie; Li, Enzuo

    2018-03-01

    The electrochemical corrosion behavior of nickel-base alloy 718 was investigated using electrochemical impedance spectroscopy and potentiodynamic polarization techniques at various partial pressures of CO2 (P_{{{CO}2 }} s) in a 25 wt% NaCl solution at 150 and 205 °C. The passive films composed of FeCO3 exhibit good corrosion resistance with a feature of Warburg impedance, Tafel plots show a complete passivation and the anodic reactions was dominated by a diffusion process at low P_{{{CO}2 }} s (1.8-9.8 MPa) at 150 °C. While numerous dented corrosion areas appeared on the sample surface for the P_{{{CO}2 }} of 11.6 MPa at 205 °C, the Tafel plot with three anodic peaks and the Nyquist diagram with an atrophied impedance arc were present. This dented corrosion attribute to the synergistic effects of stress, temperature, P_{{{CO}2 }} and Cl-, the temperature and stress could play crucial roles on the corrosion of the alloy 718.

  14. Compositional Solution Space Quantification for Probabilistic Software Analysis

    Science.gov (United States)

    Borges, Mateus; Pasareanu, Corina S.; Filieri, Antonio; d'Amorim, Marcelo; Visser, Willem

    2014-01-01

    Probabilistic software analysis aims at quantifying how likely a target event is to occur during program execution. Current approaches rely on symbolic execution to identify the conditions to reach the target event and try to quantify the fraction of the input domain satisfying these conditions. Precise quantification is usually limited to linear constraints, while only approximate solutions can be provided in general through statistical approaches. However, statistical approaches may fail to converge to an acceptable accuracy within a reasonable time. We present a compositional statistical approach for the efficient quantification of solution spaces for arbitrarily complex constraints over bounded floating-point domains. The approach leverages interval constraint propagation to improve the accuracy of the estimation by focusing the sampling on the regions of the input domain containing the sought solutions. Preliminary experiments show significant improvement on previous approaches both in results accuracy and analysis time.

  15. Transparent megahertz circuits from solution-processed composite thin films.

    Science.gov (United States)

    Liu, Xingqiang; Wan, Da; Wu, Yun; Xiao, Xiangheng; Guo, Shishang; Jiang, Changzhong; Li, Jinchai; Chen, Tangsheng; Duan, Xiangfeng; Fan, Zhiyong; Liao, Lei

    2016-04-21

    Solution-processed amorphous oxide semiconductors have attracted considerable interest in large-area transparent electronics. However, due to its relative low carrier mobility (∼10 cm(2) V(-1) s(-1)), the demonstrated circuit performance has been limited to 800 kHz or less. Herein, we report solution-processed high-speed thin-film transistors (TFTs) and integrated circuits with an operation frequency beyond the megahertz region on 4 inch glass. The TFTs can be fabricated from an amorphous indium gallium zinc oxide/single-walled carbon nanotube (a-IGZO/SWNT) composite thin film with high yield and high carrier mobility of >70 cm(2) V(-1) s(-1). On-chip microwave measurements demonstrate that these TFTs can deliver an unprecedented operation frequency in solution-processed semiconductors, including an extrinsic cut-off frequency (f(T) = 102 MHz) and a maximum oscillation frequency (f(max) = 122 MHz). Ring oscillators further demonstrated an oscillation frequency of 4.13 MHz, for the first time, realizing megahertz circuit operation from solution-processed semiconductors. Our studies represent an important step toward high-speed solution-processed thin film electronics.

  16. The influence of solution composition and grain boundaries on the replacement of calcite by dolomite

    Science.gov (United States)

    Moraila Martinez, Teresita de Jesus; Putnis, Christine V.; Putnis, Andrew

    2016-04-01

    Dolomite formation is a mineral replacement reaction that affects extensive rock volumes and comprises a large fraction of oil and gas reservoirs [1,2]. The most accepted hypothesis is the 'dolomitization' of limestone by Mg-rich fluids [3]. The objective of this research is to study the replacement mechanism of calcite by dolomite, the role of grain boundaries, highlighted by Etschmann et al. (2014), and the possible influence of solutions in dolomite formation under the presence of ions that are normally in crustal aqueous fluids. To accomplish this purpose, we performed hydrothermal experiments using Carrara marble cubes of ~1.5 mm size and 7-9 mg weight as starting material, reacted with 1M (Mg,Ca)Cl2 aqueous solutions, with Mg/Ca ratios of 3 and 5 at 200°C, for different reaction times. Additional experiments were performed adding 1mM of Na2SO4, NaCl or NaF to the previous solutions. After the reaction, the product phases were identified using Raman spectroscopy, X-Ray powder diffraction (XRD), electron microprobe analysis (EMPA), and the textural evolution was studied by scanning electron microscopy (SEM). Samples reacted with aqueous solutions resulted in the replacements of the calcite rock into magnesite and dolomite. The amount and type of reaction strongly depends on the Mg/Ca ratio. Samples reacted with a Mg/Ca ratio of 5 resulted in an almost complete replacement reaction and more favorable for magnesite formation than for dolomite. When the Mg/Ca ratio was 3 dolomite formed but the replacement was located in the core of the sample. We show that grain boundaries are very important for the infiltration of solution and the progress of a replacement reaction, acting as fluid pathways. Solution composition controls the nature of the replacement product. Acknowledgment: This work is funded within a Marie Curie EU Initial Training Network- CO2-React. 1. Etschmann B., Brugger J., Pearce M.A., Ta C., Brautigan D., Jung M., Pring A. (2014). Grain boundaries as

  17. The effect of NaCl substitution by KCl on telemea cheese properties

    Directory of Open Access Journals (Sweden)

    Mihai ANGHELOIU

    2016-12-01

    Full Text Available The effect of partial or total substitution of sodium chloride by potassium chloride on the chemical composition, texture profile and sensory properties of Telemea cheese during 28 days of ripening at 4°C was evaluated in the current study. Telemea cheese was ripened in 4 different brine solutions (20%, wt/wt made from different NaCl:KCl ratios as follows: (NaCl (A, KCl (B, 1NaCl:1KCl (C and 1NaCl:2KCl (D. The physicochemical properties of Telemea cheese (dry matter, fat, protein, ash, pH, total nitrogen (TN, water soluble nitrogen (WSN and ripening degree values were determined after 1, 7, 14, 21 and 28 days of ripening. Dry matter, pH and ripening degree values were significantly (p < 0.05 affected during ripening. The results of this study indicated that replacing 66% NaCl with KCl influenced the texture profile and sensorial characteristics of Telemea cheese.

  18. Electron scattering in graphene with adsorbed NaCl nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Drabińska, Aneta, E-mail: Aneta.Drabinska@fuw.edu.pl; Kaźmierczak, Piotr; Bożek, Rafał; Karpierz, Ewelina; Wysmołek, Andrzej; Kamińska, Maria [Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw (Poland); Wołoś, Agnieszka [Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw (Poland); Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Pasternak, Iwona; Strupiński, Włodek [Institute of Electronic Materials Technology, Wólczyńska 133, 01-919 Warsaw (Poland); Krajewska, Aleksandra [Institute of Electronic Materials Technology, Wólczyńska 133, 01-919 Warsaw (Poland); Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland)

    2015-01-07

    In this work, the results of contactless magnetoconductance and Raman spectroscopy measurements performed for a graphene sample after its immersion in NaCl solution were presented. The properties of the immersed sample were compared with those of a non-immersed reference sample. Atomic force microscopy and electron spin resonance experiments confirmed the deposition of NaCl nanoparticles on the graphene surface. A weak localization signal observed using contactless magnetoconductance showed the reduction of the coherence length after NaCl treatment of graphene. Temperature dependence of the coherence length indicated a change from ballistic to diffusive regime in electron transport after NaCl treatment. The main inelastic scattering process was of the electron-electron type but the major reason for the reduction of the coherence length at low temperatures was additional, temperature independent, inelastic scattering. We associate it with spin flip scattering, caused by NaCl nanoparticles present on the graphene surface. Raman spectroscopy showed an increase in the D and D′ bands intensities for graphene after its immersion in NaCl solution. An analysis of the D, D′, and G bands intensities proved that this additional scattering is related to the decoration of vacancies and grain boundaries with NaCl nanoparticles, as well as generation of new on-site defects as a result of the decoration of the graphene surface with NaCl nanoparticles. The observed energy shifts of 2D and G bands indicated that NaCl deposition on the graphene surface did not change carrier concentration, but reduced compressive biaxial strain in the graphene layer.

  19. Electron scattering in graphene with adsorbed NaCl nanoparticles

    International Nuclear Information System (INIS)

    Drabińska, Aneta; Kaźmierczak, Piotr; Bożek, Rafał; Karpierz, Ewelina; Wysmołek, Andrzej; Kamińska, Maria; Wołoś, Agnieszka; Pasternak, Iwona; Strupiński, Włodek; Krajewska, Aleksandra

    2015-01-01

    In this work, the results of contactless magnetoconductance and Raman spectroscopy measurements performed for a graphene sample after its immersion in NaCl solution were presented. The properties of the immersed sample were compared with those of a non-immersed reference sample. Atomic force microscopy and electron spin resonance experiments confirmed the deposition of NaCl nanoparticles on the graphene surface. A weak localization signal observed using contactless magnetoconductance showed the reduction of the coherence length after NaCl treatment of graphene. Temperature dependence of the coherence length indicated a change from ballistic to diffusive regime in electron transport after NaCl treatment. The main inelastic scattering process was of the electron-electron type but the major reason for the reduction of the coherence length at low temperatures was additional, temperature independent, inelastic scattering. We associate it with spin flip scattering, caused by NaCl nanoparticles present on the graphene surface. Raman spectroscopy showed an increase in the D and D′ bands intensities for graphene after its immersion in NaCl solution. An analysis of the D, D′, and G bands intensities proved that this additional scattering is related to the decoration of vacancies and grain boundaries with NaCl nanoparticles, as well as generation of new on-site defects as a result of the decoration of the graphene surface with NaCl nanoparticles. The observed energy shifts of 2D and G bands indicated that NaCl deposition on the graphene surface did not change carrier concentration, but reduced compressive biaxial strain in the graphene layer

  20. Excellent enhancement of corrosion properties of Fe–9Al–30Mn–1.8C alloy in 3.5% NaCl and 10% HCl aqueous solutions using gas nitriding treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yung-Chang; Lin, Chih-Lung; Chao, Chuen-Guang; Liu, Tzeng-Feng, E-mail: Lewischen815@gmail.com

    2015-06-05

    Highlights: • The FeAlMnC alloy was gas-nitrided to simultaneously achieve the aging effect. • Anti-corrosion components AlN, Fe{sub 3}N and Fe{sub 4}N were identified by using GIXRD method. • The present nitrided alloy showed a great improvement in corrosion resistance. • The nitrided sample showed an excellent coherence between nitrided layer and matrix. • The nitrided and then stretched sample maintained satisfactory corrosion behavior. - Abstract: The as-quenched Fe–9.0Al–30Mn–1.8C (in wt.%) alloy gas nitrided at 550 °C for 4 h show excellent corrosion resistance investigated in 3.5% NaCl and 10% HCl solutions. Owing to the high corrosion resistance components, the gas-nitrided layer consists mainly of AlN with a slight amount of Fe{sub 3}N and Fe{sub 4}N identified by grazing incidence X-ray diffraction technique. Therefore, the pitting potential and corrosion potential of the nitrided sample are +1860 mV and +30 mV, respectively. Surprisingly, it is worthy to be pointed out that the nitrided and then tensile-tested alloy reveals very shallow in fracture depth and the excellent lattice coherence is shown between the nitrided layer and the substrate. Moreover, due to the extremely high nitrogen concentration (about 17–18 wt.%) at stretched surface, the corrosion resistance of present gas-nitrided and then tensile-tested alloy is superior to those optimally gas-nitrided or plasma-nitrided high-strength alloy steels, as well as martensitic stainless steels. The nitrided and then stretched alloy still retains a satisfactory corrosion resistance (E{sub pit} = +890 mV; E{sub corr} = +10 mV). Furthermore, only nanoscale-size pits were observed on the corroded surface after being immersed in 10% HCl for 24 h.

  1. Separating NaCl and AlCl3·6H2O Crystals from Acidic Solution Assisted by the Non-Equilibrium Phase Diagram of AlCl3-NaCl-H2O(-HCl Salt-Water System at 353.15 K

    Directory of Open Access Journals (Sweden)

    Huaigang Cheng

    2017-08-01

    Full Text Available Extracting AlCl3·6H2O from acid leaching solution through crystallization is one of the key processes to extracting aluminum from fly ash, coal gangue and other industrial solid wastes. However, the obtained products usually have low purity and a key problem is the lack of accurate data for phase equilibrium. This paper presented the non-equilibrium phase diagrams of AlCl3-NaCl-H2O (HCl salt-water systems under continuous heating and evaporation conditions, which were the main components of the acid leaching solution obtained through a sodium-assisted activation hydrochloric acid leaching process. The ternary system was of a simple eutonic type under different acidities. There were three crystalline regions; the crystalline regions of AlCl3·6H2O, NaCl and the mixture AlCl3·6H2O/NaCl, respectively. The phase diagram was used to optimize the crystallization process of AlCl3·6H2O and NaCl. A process was designed to evaporate and remove NaCl at the first stage of the evaporation process, and then continue to evaporate and crystallize AlCl3·6H2O after solid-liquid separation. The purities of the final salt products were 99.12% for NaCl and up to 97.35% for AlCl3·6H2O, respectively.

  2. Reaction of metal oxides with molten mixtures NaPO3+NaCl

    International Nuclear Information System (INIS)

    Kovarskaya, E.N.; Mityakhina, V.S.; Rodionov, Yu.I.; Silin, M.Yu.

    1988-01-01

    By methods of solubility determination and paper chromatography it is shown, that Fe 2 O 3 solution in NaPO 3 +NaCl melts in the air relizes due to its chemical interaction with solvent resulting in formation of iron and sodium binary di- and monophosphates depending on melt-solvent initial composition, its attainment of equilibrium state and experiment temperature. It is established, that oxides increased solubility in melts with NaCl initial content ∼30 mol.% is specified by sodium tri- and tricyclophosphates presence in the melts. On this basis of NGR-spectroscopy data the presence of iron, europium, tin and sodium binary di- and monophosphates in some chloride-polyphosphate melts is confirmed

  3. Derivative spectrophotometry applied to solutions of complex composition

    International Nuclear Information System (INIS)

    Perfil'ev, V.A.

    1986-01-01

    The authors consider not only the basic principles of derivative spectrophotometry but also survey the data on its use in research on the properties of materials, the compositions of compounds, and the structures of complex chemical systems. Recording methods by which derivative spectra can be generated include descriptions of electronic differentiation, computer spectrum differentiation, wavelength modulation, and the two-way derivative method. A section on the advantages of derivative spectrophotometry presents a discussion on features enabling one to determine various substances from their characteristic absorption spectra without performing complicated operations to isolate or separate the components. Other topics include research on the structures of substances and metal-ion complexing in solutions, derivative spectrophotometry in gas analysis, gas determination, and determining organic and compounds

  4. Osmotic and ionic effects of NaCl and Na2SO4 salinity on Phragmites australis

    DEFF Research Database (Denmark)

    Pagter, Majken; Bragato, Claudia; Malagoli, Mario

    2009-01-01

    Osmotic and ion-specific effects of NaCl and Na2SO4 on Phragmites australis (Cav.) Trin ex. Steud. were investigated in a laboratory experiment by examining effects of iso-osmotic solutions of NaCl and Na2SO4 on growth, osmolality of cell sap, proline content, elemental composition and gas exchange....... Plants were supplied with a control standard nutrient solution (Ψ = -0.09 MPa) or solutions of NaCl or Na2SO4 at water potentials of -0.50, -1.09 or -1.74 MPa. Salt treatments increased root concentrations of Na and S or Cl, whereas P. australis had efficient mechanisms for exclusion of Na and S...... and partly Cl ions from the leaves. Incomplete exclusion of Cl from the leaves may affect aboveground biomass production, which was significantly more reduced by NaCl than Na2SO4. Stomatal conductance was negatively influenced by decreasing water potentials caused by NaCl or Na2SO4, implying that a non...

  5. Microstructure and adhesion strength of Sn-9Zn-1.5Ag-xBi (x = 0 wt% and 2 wt%)/Cu after electrochemical polarization in a 3.5 wt% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.-L. [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China); Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Chen, Y.-R.; Chang, K.-M. [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China); Liu, C.-Y.; Hon, M.-H. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Wang, M.-C. [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shihchuan 1st Road, Kaohsiung 80728, Taiwan (China)], E-mail: mcwang@kmu.edu.tw

    2008-08-11

    The microstructure and adhesion strength of the Sn-9Zn-1.5Ag-xBi (x = 0 wt% and 2 wt%)/Cu interface after electrochemical polarization have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and pull-off testing. The equilibrium potentials of Sn-9Zn-1.5Ag/Cu and Sn-9Zn-1.5Ag-2Bi/Cu are -1.31 V{sub sce} and -1.22 V{sub sce}, respectively, indicating that Sn-9Zn-1.5Ag-2Bi/Cu has a better corrosion resistance than that of Sn-9Zn-1.5Ag/Cu. The intermetallic compounds of Cu{sub 6}Sn{sub 5}, Cu{sub 5}Zn{sub 8} and Ag{sub 3}Sn are formed at the soldered interface between the Sn-9Zn-1.5Ag-xBi solder alloy and the Cu substrate. The scallop-shaped Cu{sub 6}Sn{sub 5} is close to the Cu substrate and the scallop-shaped Cu{sub 5}Zn{sub 8} is found at the interface in the solder matrix after soldering at 250 deg. C for 10 s. The corrosion products are ZnCl{sub 2}, SnCl{sub 2} and ZnO. On the other hand, pits are also formed on the surface of both solder alloys. The interfacial adhesion strength of the Sn-9Zn-1.5Ag/Cu and Sn-9Zn-1.5Ag-2Bi/Cu decreases from 8.27 {+-} 0.56 MPa and 12.67 {+-} 0.45 MPa to 4.78 {+-} 0.45 MPa and 8.14 {+-} 0.38 MPa, respectively, after electrochemical polarization in a 3.5 wt% NaCl solution. The fracture path of the Sn-9Zn-1.5Ag-2Bi/Cu is along the solder alloy/ZnO and solder/Cu{sub 6}Sn{sub 5} interfaces.

  6. Finite element based composite solution for neutron transport problems

    International Nuclear Information System (INIS)

    Mirza, A.N.; Mirza, N.M.

    1995-01-01

    A finite element treatment for solving neutron transport problems is presented. The employs region-wise discontinuous finite elements for the spatial representation of the neutron angular flux, while spherical harmonics are used for directional dependence. Composite solutions has been obtained by using different orders of angular approximations in different parts of a system. The method has been successfully implemented for one dimensional slab and two dimensional rectangular geometry problems. An overall reduction in the number of nodal coefficients (more than 60% in some cases as compared to conventional schemes) has been achieved without loss of accuracy with better utilization of computational resources. The method also provides an efficient way of handling physically difficult situations such as treatment of voids in duct problems and sharply changing angular flux. It is observed that a great wealth of information about the spatial and directional dependence of the angular flux is obtained much more quickly as compared to Monte Carlo method, where most of the information in restricted to the locality of immediate interest. (author)

  7. Reactions of metal oxides with molten NaPO3 + NaCl mixtures

    International Nuclear Information System (INIS)

    Kovarskaya, E.N.; Mityakhina, V.S.; Rodionov, Yu.I.; Silin, M.Yu.

    1988-01-01

    We consider the dissolution mechanism for iron (III), europium(III), and tin(IV) oxides in molten NaPO 3 + NaCl that are responsible for the peak solubilities. We chose Fe 2 O 3 as the basic material since this occurs in large amounts around damaged metal structures in rock salt mines in a proposed zone for storing vitrified radioactive wastes. Solubility measurement and paper chromatography show that Fe 2 O 3 dissolves in molten NaPO 3 + NaCl in air by reaction with the solvent to give double iron and sodium diphosphates and monophosphates in accordance with the initial solution-in-the-melt composition, the degree of equilibration, and the temperature. The elevated solubilities for initial NaCl contents close to 30 mole % are due to sodium triphosphates and tricyclophosphates present in these melts. Moessbauer spectroscopy confirms that double iron, europium and tin diphosphates and monophosphates containing sodium occur in these chloride-polyphosphate melts

  8. Facilitated transport of Cu with hydroxyapatite nanoparticles in saturated sand: Effects of solution ionic strength and composition

    Science.gov (United States)

    Column experiments were conducted to investigate the facilitated transport of Cu in association with hydroxyapatite nanoparticles (nHAP) in water-saturated quartz sand at different solution concentrations of NaCl (0 to 100 mM) or CaCl2 (0.1 to 1.0 mM). The experimental breakthrough curves and retent...

  9. Composition and method for solution mining of uranium ores

    International Nuclear Information System (INIS)

    Lawes, B.C.; Watts, J.C.

    1981-01-01

    It has been found that, in the solution mining of uranium ores using ammonium carbonate solutions containing hydrogen peroxide or ozone as an oxidant, the tendency of the formation being treated to become less permeable during the leaching process can be overcome by including in the leaching solution a very small concentration of sodium silicate

  10. Corrosion of Dental Au-Ag-Cu-Pd Alloys in 0.9 % Sodium Chloride Solution

    International Nuclear Information System (INIS)

    Chiba, Atsushi; Kusayanagi, Yukiharu

    2005-01-01

    Two Au-Ag-Cu-Pd dental casting alloys (Au:12% and 20%) used. The test solutions used 0.9 % NaCl solution (isotonic sodium chloride solution), 0.9 % NaCl solution containing 1 % lactic acid, and 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol dm -3 Na 2 S. The surface of two samples in three sample solutions was not natural discoloration during one year. The alloy containing 12 % gold was easily alloyed and the composition was uniform comparing with the alloy containing 20 % gold. The rest potentials have not a little effect after three months. The kinds of metals could not definitely from the oxidation and reduction waves of metal on the cyclic voltammograms. The dissolutions of gold and palladium were 12 % Au sample in the 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol dm -3 Na 2 S. The pH of solution had an affect on dissolution of copper, and sulfur ion had an affect on dissolution of silver. The copper dissolved amount from 20 % gold sample was about 26 times comparing with that of 12 % gold sample in the 0.9 % solution containing 1 % lactic acid. Corrosion products were silver chloride and copper chloride in NaCl solution, and silver sulfide and copper sulfide in NaCl solution containing Na 2 S

  11. Non-Catalytic Self Healing Composite Material Solution, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Fiber reinforce polymer (FRP) composite materials are seeing increasing use in the construction of a wide variety of aerospace structures. However, uncertainties...

  12. Separation of radio cesium from PUREX feed solution by sorption on composite ammonium molybdo phosphate (AMP)

    International Nuclear Information System (INIS)

    Singh, I.J.; Achuthan, P.V.; Jain, S.; Janardanan, C.; Gopalakrishnan, V.; Wattal, P.K.; Ramanujam, A.

    2001-01-01

    Composite AMP exchanger was developed and evaluated for separation of radio cesium from dissolver solutions of PUREX process using a column experiment. The composite shows excellent sorption of radio cesium from dissolver solutions without any loss of plutonium and uranium. The removal of radio cesium from dissolver solutions will help in lowering the degradation of tri-n-butyl phosphate (TBP) in the solvent extraction process and will also help in reducing the radiation related problems. (author)

  13. Self-healing composites: in-situ repair solutions

    NARCIS (Netherlands)

    Coope, T.S.; Luterbacher, R.; Turkenburg, D.H.; Fischer, H.R.; Bond, I.P.

    2015-01-01

    Realising self-healing composites in a commercial environment remains a challenge for the transport sector. Herein, this research considers the design envelope and the implications of embedding self-healing agents into commercially relevant fibre reinforced polymer (FRP) composite applications. A

  14. Effect of composition on the electrochemical behavior of austenitic stainless steel in Ringer's solution

    International Nuclear Information System (INIS)

    Bandy, R.; Cahoon, J.R.

    1977-01-01

    Potentiodynamic cyclic polarization tests on Type 316L stainless steel, a common orthopedic implant alloy, in Ringer's solution show considerable hysteresis and a protection potential more active than the open circuit corrosion potential. This implies that chances of repassivation of actively growing pits in this alloy are limited. Tests in Ringer's solution containing hydrochloric acid show that the open circuit potential of Type 316L steel in this solution may exceed in the noble direction the critical pitting potential in the same solution. This signifies that spontaneous breakdown of passivity may occur in a bulk environment which grossly simulates the electrochemical environment within a crevice. Alloying elements such as Mo, Ni, Cr, all improve the corrosion resistance of Type 316L stainless steel in that the critical pitting potential shifts in the noble direction in the alloys having any of the three alloying elements in a higher proportion than in Type 316L steel. Polarization tests in Ringer's solution on a 20% Cr, 25% Ni, 4.5% Mo, 1.5% Cu austenitic stainless steel, having Mo, Cr, and Ni--all in higher proportions than in Type 316L steel, does not show any critical pitting potential or hysteresis at potentials below that for dissociation of water. However, test in 4% NaCl solution at 60 C, a more aggressive chloride environment than Ringer'ssolution, reveals considerable hysteresis and a very active protection potential, indicating that this behavior is a common feature of austenitic stainless steel in sufficiently aggressive, chloride media

  15. In situ composition measurements of Bunsen reaction solution by radiation probes

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Shinji; Nagaya, Yasunobu [Japan Atomic Energy Agency (Japan)

    2010-07-01

    Measuring equipments are integral to chemical process controls. A stable hydrogen production by the Iodine-Sulfur thermochemical water-splitting process is relatively difficult because of lack of existing in situ composition measurement techniques for multiple components and corrosive solution. Composition regulations of Bunsen reaction solution is particularly important, since a closed cycle system provided with this process causes that the many streams with different composition return to this section. Accordingly Bunsen solution becomes changeable composition. Radiation probes have a potential for applications to determine this multiple component solution while the non-contact approach avoids the corrosive issues. Moreover the probes have features of the promptness, contact-less and sequential use. Laboratory scale experiments to evaluate these possibilities of the measurement were conducted with use of simulated Bunsen solution, HIx solution and H{sub 2}SO{sub 4} solution, containing HI, I2, H{sub 2}SO{sub 4} and H{sub 2}O and sealed radiation sources. Radiations were counted, which were interacted with the solutions in various compositions around room temperature contained in vessels. For HIx solution, the obtained counting rates were correlated with hydrogen volume concentrations; moreover, the application of the Monte Carlo method suggests possibilities that the detector responses for HIx solution by the radiation probes are predictable. For H{sub 2}SO{sub 4} solution, iodine atoms had significant influences on the relationship between output values of two gamma-ray density meters, cesium source as higher energy and barium source as lower energy. This results suggest that the neutron ray probe, the gamma-ray probes of both lower energy and higher energy have possibilities to determine the composition of Bunsen solution of HIx and H{sub 2}SO{sub 4} solutions. (orig.)

  16. Quantitative relationship between adsorbed amount of solute and solvent composition

    International Nuclear Information System (INIS)

    Wang Yan; Geng Xindu; Zebolsky, Don M.

    2003-01-01

    A new adsorption isotherm that relates the amount of solute adsorbed to the solvent concentration is proposed. The new equation is derived from Geng and Shi's stoichiometric displacement model for adsorption (SDM-A). The obtained equation may be simplified to an expression containing two parameters. The equation with two parameters, valid for low concentrations of solute, is a logarithmically linear relationship. The intercept contains a thermodynamic equilibrium constant of the solute displacing solvent from the adsorbent. The slope is the negative value of the stoichiometric displacement parameter (Z), the average total number of solvent molecules displaced from an active site on the adsorbent and from the solute. Tests with a homologous series of aromatic alcohols by frontal analysis in reversed phase liquid chromatography demonstrate that experimental results fit the equation well

  17. A Local Composition Model for Paraffinic Solid Solutions

    DEFF Research Database (Denmark)

    Coutinho, A.P. João; Knudsen, Kim; Andersen, Simon Ivar

    1996-01-01

    The description of the solid-phase non-ideality remains the main obstacle in modelling the solid-liquid equilibrium of hydrocarbons. A theoretical model, based on the local composition concept, is developed for the orthorhombic phase of n-alkanes and tested against experimental data for binary sy...... systems. It is shown that it can adequately predict the experimental phase behaviour of paraffinic mixtures. This work extends the applicability of local composition models to the solid phase. Copyright (C) 1996 Elsevier Science Ltd....

  18. Kinetin Reversal of NaCl Effects

    Science.gov (United States)

    Katz, Adriana; Dehan, Klara; Itai, Chanan

    1978-01-01

    Leaf discs of Nicotiana rustica L. were floated on NaCl in the presence of kinetin or abscisic acid. On the 5th day 14CO2 fixation, [3H]leucine incorporation, stomatal conductance, and chlorophyll content were determined. Kinetin either partially or completely reversed the inhibitory effects of NaCl while ABA had no effect. PMID:16660618

  19. Effect of a New Surface Treatment Solution on the Bond Strength of Composite to Enamel

    Science.gov (United States)

    2016-06-01

    Bond Strength of Composite to Enamel " is appropriately acknowledged and, beyond brief excerpts, is with the permission of the copyright owner...Solution on the Bond Strength of Composite to Enamel ABSTRACT Clean & Boost (Apex Dental Materials) is a novel surface treatment solution...designed to be used in place of phosphoric acid to increase the bond strength of self-etch adhesives to enamel and more effectively remove contaminants

  20. Probabilistic Compositional Models: solution of an equivalence problem

    Czech Academy of Sciences Publication Activity Database

    Kratochvíl, Václav

    2013-01-01

    Roč. 54, č. 5 (2013), s. 590-601 ISSN 0888-613X R&D Projects: GA ČR GA13-20012S Institutional support: RVO:67985556 Keywords : Probabilistic model * Compositional model * Independence * Equivalence Subject RIV: BA - General Mathematics Impact factor: 1.977, year: 2013 http://library.utia.cas.cz/separaty/2013/MTR/kratochvil-0391079.pdf

  1. Analytical solution for heat conduction problem in composite slab and its implementation in constructal solution for cooling of electronics

    International Nuclear Information System (INIS)

    Kuddusi, Luetfullah; Denton, Jesse C.

    2007-01-01

    The constructal solution for cooling of electronics requires solution of a fundamental heat conduction problem in a composite slab composed of a heat generating slab and a thin strip of high conductivity material that is responsible for discharging the generated heat to a heat sink located at one end of the strip. The fundamental 2D heat conduction problem is solved analytically by applying an integral transform method. The analytical solution is then employed in a constructal solution, following Bejan, for cooling of electronics. The temperature and heat flux distributions of the elemental heat generating slabs are assumed to be the same as those of the analytical solution in all the elemental volumes and the high conductivity strips distributed in the different constructs. Although the analytical solution of the fundamental 2D heat conduction problem improves the accuracy of the distributions in the elemental slabs, the results following Bejan's strategy do not affirm the accuracy of Bejan's constructal solution itself as applied to this problem of cooling of electronics. Several different strategies are possible for developing a constructal solution to this problem as is indicated

  2. Influence of soil solution cation composition on boron adsorption by soils

    Science.gov (United States)

    Boron (B) adsorption on five arid-zone soil samples from California was investigated as a function of solution pH (4-10) and cation composition (Na, Ca, or Mg). Boron adsorption increased with increasing solution pH, reached an adsorption maximum near pH 9, and decreased with further increases with...

  3. Glass composition and solution speciation effects on stage III dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Trivelpiece, Cory L. [Pennsylvania State Univ., University Park, PA (United States); Rice, Jarret A. [Pennsylvania State Univ., University Park, PA (United States); Pantano, Carlo G. [Pennsylvania State Univ., University Park, PA (United States)

    2017-10-03

    To understand and mitigate the onset of Stage III corrosion of multicomponent oxides waste glasses. Stage III refers to a resumption of the high initial rate of glass dissolution in some glass samples that have otherwise exhibited dissolution at the much lower residual rate for a long time (Stage II). Although the onset of Stage III is known to occur concurrently with the precipitation of particular alteration products, the root cause of the transition is still unknown. Certain glass compositions (notably AFCI) and high pH environmental conditions are also associated with this observed transition.

  4. Glass composition and solution speciation effects on stage III dissolution

    International Nuclear Information System (INIS)

    Trivelpiece, Cory L.; Rice, Jarret A.; Pantano, Carlo G.

    2017-01-01

    To understand and mitigate the onset of Stage III corrosion of multicomponent oxides waste glasses. Stage III refers to a resumption of the high initial rate of glass dissolution in some glass samples that have otherwise exhibited dissolution at the much lower residual rate for a long time (Stage II). Although the onset of Stage III is known to occur concurrently with the precipitation of particular alteration products, the root cause of the transition is still unknown. Certain glass compositions (notably AFCI) and high pH environmental conditions are also associated with this observed transition.

  5. Investigation of Different Colloidal Porous Silicon Solutions and Their Composite Solid Matrix Rods by Optical Techniques

    Science.gov (United States)

    Khan, M. Naziruddin; Aldalbahi, Ali; Almohammedi, Abdullah

    2018-03-01

    Colloidal porous silicon (PSi) in different solvents was synthesized by simple chemical etching. Colloidal solutions were then prepared using different quantities of silicon wafer pieces (Pcs) and chloroplatinic (Pt) acid in catalyst solution. The effect on the properties of the colloidal solutions and composite rods were investigated using various optical characterization techniques. Absorption and photoluminescence (PL) intensity of the colloidal PSi solutions are observed to depend on the quantity of wafer Pcs, the Pt-solution, and the porosity formation on the wafer surface. The morphological structure of the PSi in a solvent and the solid-rod environments were studied using field-emission scanning electron microscopy (FE-SEM) and were observed to have different structures. A mono-oriented structure of PSi exists in tetrahydrofuran, which has stereo orientation in dioxane and dimethylsulfoxide (approximately 5-8 nm as confirmed using high resolution transmission electron microscopy). Subsequently, some colloidal PSi solutions were directly embedded in three types of sol-gel-based matrices, silica, ormosils (or organically modified silica) and polymer, which easily generated solid rods. Spontaneous emission (SE) of the PSi solutions and their composite rods were examined using a high power picosecond 355 nm laser source. The emitted PL and SE signals of the colloidal PSi solutions were dependent on the Pt volume, nature of the solvent, quantity of Si wafer piece, and pumping energy. The response of SE signals from the PSi composites rods is an interesting phenomenon, and such nanocomposites may be used for future research on light amplification.

  6. Composition and performance of thin film CdSe electrodeposited from selenosulfite solution

    International Nuclear Information System (INIS)

    Szabo, J.P.; Simms, D.; Cocivera, M.

    1985-01-01

    Cathodic electrodeposition of thin film CdSe from aqueous selenosulfite solution has been studied as function of solution composition and electrode potential. The Cd/Se ratio has been analyzed using polarography and Rutherford backscattering spectroscopy. Polarography gives a compostion averaged over the whole film (2cm 2 ) while RBS gives local surface composition (1 mm 2 ). The average Cd/Se ratio is 1.1, but some variation was found to occur across the surface of film (0.82 to 1.2)

  7. Synthesis of a magnetic composite resin and its cobalt removal characteristics in aqueous solution

    International Nuclear Information System (INIS)

    Kim, Young Kyun; Lee, Kun Jai

    2001-01-01

    A series of stepwise procedures to prepare a new organic-inorganic composite magnetic resin with phenolsulphonic-formaldehyde and freshly formed iron ferrite was established, based upon wet-and-neutralization method for synthesizing iron ferrite and pearl-polymerization method for synthesizing rigid bead-type composite resin. The ion exchange and sorption characteristics of the composite resin prepared by the above method at various conditions were experimentally disclosed. The composite resin prepared shows stably high removal efficiency to Co(II) species in aqueous solution in a wide range of solution pH. The overall isotherm is qualitatively explained by the generalized adsorption isotherm concept proposed by McKinley. The standard enthalpy change derived from van't Hoff equation conforms to the typical range for chemisorption or ion exchange. The selectivity of the PSF-F (phenolsulphonic formaldehyde-iron ferrite) composite resin to Co(II) species and other competing chemicals (i.e. Na 2 EDTA, Ca(II) and Na) was compared. It is anticipated that the composite resin can also be used for column-operation with process-control by applying external magnetic field, since the rigid bead-type composite resin shows magnetic-susceptibility due to its paramagnetic inorganic constituent (i.e. iron ferrite). (author)

  8. Importance of waste composition for Life Cycle Assessment of waste management solutions

    DEFF Research Database (Denmark)

    Bisinella, Valentina; Götze, Ramona; Conradsen, Knut

    2017-01-01

    The composition of waste materials has fundamental influence on environmental emissions associated with waste treatment, recycling and disposal, and may play an important role also for the Life Cycle Assessment (LCA) of waste management solutions. However, very few assessments include effects...... of the waste composition and waste LCAs often rely on poorly justified data from secondary sources. This study systematically quantifiesy the influence and uncertainty on LCA results associated with selection of waste composition data. Three archetypal waste management scenarios were modelled with the waste...... LCA model EASETECH based on detailed waste composition data from the literature. The influence from waste composition data on the LCA results was quantified with a step-wise Global Sensitivity Analysis (GSA) approach involving contribution, sensitivity, uncertainty and discernibility analyses...

  9. Effect of NaCl and KCl on irradiated diploid yeast cells

    International Nuclear Information System (INIS)

    Amirtaev, K.G.; Lobachevskij, P.N.; Lyu Gvan Son

    1984-01-01

    Irradiated dipload yeast Saccharomyces cerevisiae kept in NaCl and KCl solutions died more readily than nonirradiated cells: the death rate was a functaon of radiation Jose and temperature of exposure. It was suggested that the radiation-induced injury to mass cell structures was responsible for the death rate. It was shown that the postirradiataon recovery of cells from radiation damages proceeded in KCl solution two-three times slower than mn water, and it was inhibited completely in NaCl solution

  10. Chemical composition and Zn bioavailability of the soil solution extracted from Zn amended variable charge soils.

    Science.gov (United States)

    Zampella, Mariavittoria; Adamo, Paola

    2010-01-01

    A study on variable charge soils (volcanic Italian and podzolic Scottish soils) was performed to investigate the influence of soil properties on the chemical composition of soil solution. Zinc speciation, bioavailability and toxicity in the soil solution were examined. The soils were spiked with increasing amounts of Zn (0, 100, 200, 400 and 1000 mg/kg) and the soil solutions were extracted using rhizon soil moisture samplers. The pH, total organic carbon (TOC), base cations, anions, total Zn and free Zn2+ in soil solution were analysed. A rapid bioassay with the luminescent bacterium Escherichia coli HB101 pUCD607 was performed to assess Zn toxicity. The influence of soil type and Zn treatments on the chemical composition of soil solution and on Zn toxicity was considered and discussed. Different trends of total and free Zn concentrations, base cations desorption and luminescence of E. coli HB101 pUCD607 were observed. The soil solution extracted from the volcanic soils had very low total and free Zn concentrations and showed specific Zn2+/Ca2+ exchange. The soil solution from the podzolic soil had much higher total and free Zn concentrations and showed no evidence of specific Zn2+/Ca2+ exchange. In comparison with the subalkaline volcanic soils, the acidic podzol showed enhanced levels of toxic free Zn2+ and consequently stronger effects on E. coli viability.

  11. Functional porous composites by blending with solution-processable molecular pores.

    Science.gov (United States)

    Jiang, S; Chen, L; Briggs, M E; Hasell, T; Cooper, A I

    2016-05-25

    We present a simple method for rendering non-porous materials porous by solution co-processing with organic cage molecules. This method can be used both for small functional molecules and for polymers, thus creating porous composites by molecular blending, rather than the more traditional approach of supporting functional molecules on pre-frabricated porous supports.

  12. Enhanced adsorptive degradation of Congo red in aqueous solutions using polyaniline/Fe0 composite nanofibers

    CSIR Research Space (South Africa)

    Bhaumik, M

    2015-01-01

    Full Text Available In this study, a simple approach was described for the fabrication of composite nanofibers (CNFs) of polyaniline/Fe0 (PANI/Fe0) using a template-free method for the reductive degradation and removal of Congo red (CR) from aqueous solutions. The PANI...

  13. SANS studies of solutions and molecular composites prepared from cellulose tricarbanilate

    CERN Document Server

    Alava, C; Cameron, J D; Cowie, J M G; Vaqueiro, P; Möller, A; Triolo, A

    2002-01-01

    We report on SANS measurements carried out on the instrument SANS1 (V4) at the BENSC facility on solutions and composites of cellulose tricarbanilate (CTC). This cellulose derivative exhibits lyotropic behaviour in methylacrylate (MA). The SANS data indicate that in the isotropic liquid state (up to 25% wt CTC in MA) the CTC chains behave like rods of mass per unit length (M/L). In the liquid crystalline (LC) phase (at and above 35% wt CTC in MA), the Q dependence varies from Q sup - sup 1 to Q sup - sup 4 , probably as a result of self-assembling of the CTC chains. The general aim of our work is to prepare molecular composites, i.e. miscible blends of rigid-rod and flexible-coil polymers, from CTC solutions in polymerizable media. To establish the degree of homogeneity of the composites, we performed SANS measurements on UV-cured CTC/MA solutions. Here, we compare the SANS data of CTC/monomer solutions with those of the corresponding composites. (orig.)

  14. Composite Transport Model and Water and Solute Transport across Plant Roots: An Update

    Directory of Open Access Journals (Sweden)

    Yangmin X. Kim

    2018-02-01

    Full Text Available The present review examines recent experimental findings in root transport phenomena in terms of the composite transport model (CTM. It has been a well-accepted conceptual model to explain the complex water and solute flows across the root that has been related to the composite anatomical structure. There are three parallel pathways involved in the transport of water and solutes in roots – apoplast, symplast, and transcellular paths. The role of aquaporins (AQPs, which facilitate water flows through the transcellular path, and root apoplast is examined in terms of the CTM. The contribution of the plasma membrane bound AQPs for the overall water transport in the whole plant level was varying depending on the plant species, age of roots with varying developmental stages of apoplastic barriers, and driving forces (hydrostatic vs. osmotic. Many studies have demonstrated that the apoplastic barriers, such as Casparian bands in the primary anticlinal walls and suberin lamellae in the secondary cell walls, in the endo- and exodermis are not perfect barriers and unable to completely block the transport of water and some solute transport into the stele. Recent research on water and solute transport of roots with and without exodermis triggered the importance of the extension of conventional CTM adding resistances that arrange in series (epidermis, exodermis, mid-cortex, endodermis, and pericycle. The extension of the model may answer current questions about the applicability of CTM for composite water and solute transport of roots that contain complex anatomical structures with heterogeneous cell layers.

  15. Composite Transport Model and Water and Solute Transport across Plant Roots: An Update.

    Science.gov (United States)

    Kim, Yangmin X; Ranathunge, Kosala; Lee, Seulbi; Lee, Yejin; Lee, Deogbae; Sung, Jwakyung

    2018-01-01

    The present review examines recent experimental findings in root transport phenomena in terms of the composite transport model (CTM). It has been a well-accepted conceptual model to explain the complex water and solute flows across the root that has been related to the composite anatomical structure. There are three parallel pathways involved in the transport of water and solutes in roots - apoplast, symplast, and transcellular paths. The role of aquaporins (AQPs), which facilitate water flows through the transcellular path, and root apoplast is examined in terms of the CTM. The contribution of the plasma membrane bound AQPs for the overall water transport in the whole plant level was varying depending on the plant species, age of roots with varying developmental stages of apoplastic barriers, and driving forces (hydrostatic vs. osmotic). Many studies have demonstrated that the apoplastic barriers, such as Casparian bands in the primary anticlinal walls and suberin lamellae in the secondary cell walls, in the endo- and exodermis are not perfect barriers and unable to completely block the transport of water and some solute transport into the stele. Recent research on water and solute transport of roots with and without exodermis triggered the importance of the extension of conventional CTM adding resistances that arrange in series (epidermis, exodermis, mid-cortex, endodermis, and pericycle). The extension of the model may answer current questions about the applicability of CTM for composite water and solute transport of roots that contain complex anatomical structures with heterogeneous cell layers.

  16. Removal of Congo red dye from aqueous solutions using a halloysite-magnetite-based composite.

    Science.gov (United States)

    Ferrarini, F; Bonetto, L R; Crespo, Janaina S; Giovanela, M

    2016-01-01

    Adsorption has been considered as one of the most effective methods to remove dyes from aqueous solutions due to its ease of operation, high efficiency and wide adaptability. In view of all these aspects, this study aimed to evaluate the adsorption capacity of a halloysite-magnetite-based composite in the removal of Congo red dye from aqueous solutions. The effects of stirring rate, pH, initial dye concentration and contact time were investigated. The results revealed that the adsorption kinetics followed the pseudo-second-order model, and equilibrium was well represented by the Brunauer-Emmett-Teller isotherm. The thermodynamic data showed that dye adsorption onto the composite was spontaneous and endothermic and occurred by physisorption. Finally, the composite could also be regenerated at least four times by calcination and was shown to be a promising adsorbent for the removal of this dye.

  17. Application of artificial neural network and adaptive neuro-fuzzy inference system to investigate corrosion rate of zirconium-based nano-ceramic layer on galvanized steel in 3.5% NaCl solution

    International Nuclear Information System (INIS)

    Mousavifard, S.M.; Attar, M.M.; Ghanbari, A.; Dadgar, M.

    2015-01-01

    Highlights: • Film formation of Zr-based conversion coating under different conditions was investigated. • We study the effect of some parameters on anticorrosion performance of conversion coating. • Optimization of processing conditions for surface treatment of galvanized steel was obtained. • Modeling and predicting corrosion current density of treated surfaces was performed using ANN and ANFIS. - Abstract: A nano-ceramic Zr-based conversion solution was prepared and optimization of Zr concentration, pH, temperature and immersion time for the treatment of hot-dip galvanized steel (HDG) was performed. SEM microscopy was utilized to investigate the microstructure and film formation of the layer and the anticorrosion performance of conversion coating was studied using polarization test. Artificial intelligence systems (ANN and ANFIS) were applied on the data obtained from polarization test and the models for predicting corrosion current density values were attained. The outcome of these models showed proper predictability of the methods. The influence of input parameters was discussed and the optimized conditions for Zr-based conversion layer formation on the galvanized steel were obtained as follows: pH 3.8–4.5, Zr concentration of about 100 ppm, ambient temperature and immersion time of about 90 s

  18. Application of artificial neural network and adaptive neuro-fuzzy inference system to investigate corrosion rate of zirconium-based nano-ceramic layer on galvanized steel in 3.5% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Mousavifard, S.M. [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Attar, M.M., E-mail: attar@aut.ac.ir [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ghanbari, A. [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Dadgar, M. [Textile Engineering Department, Neyshabur University, Neyshabur (Iran, Islamic Republic of)

    2015-08-05

    Highlights: • Film formation of Zr-based conversion coating under different conditions was investigated. • We study the effect of some parameters on anticorrosion performance of conversion coating. • Optimization of processing conditions for surface treatment of galvanized steel was obtained. • Modeling and predicting corrosion current density of treated surfaces was performed using ANN and ANFIS. - Abstract: A nano-ceramic Zr-based conversion solution was prepared and optimization of Zr concentration, pH, temperature and immersion time for the treatment of hot-dip galvanized steel (HDG) was performed. SEM microscopy was utilized to investigate the microstructure and film formation of the layer and the anticorrosion performance of conversion coating was studied using polarization test. Artificial intelligence systems (ANN and ANFIS) were applied on the data obtained from polarization test and the models for predicting corrosion current density values were attained. The outcome of these models showed proper predictability of the methods. The influence of input parameters was discussed and the optimized conditions for Zr-based conversion layer formation on the galvanized steel were obtained as follows: pH 3.8–4.5, Zr concentration of about 100 ppm, ambient temperature and immersion time of about 90 s.

  19. Dielectric and Piezoelectric Properties of PZT Composite Thick Films with Variable Solution to Powder Ratios.

    Science.gov (United States)

    Wu, Dawei; Zhou, Qifa; Shung, Koping Kirk; Bharadwaja, Srowthi N; Zhang, Dongshe; Zheng, Haixing

    2009-05-08

    The use of PZT films in sliver-mode high-frequency ultrasonic transducers applications requires thick, dense, and crack-free films with excellent piezoelectric and dielectric properties. In this work, PZT composite solutions were used to deposit PZT films >10 μm in thickness. It was found that the functional properties depend strongly on the mass ratio of PZT sol-gel solution to PZT powder in the composite solution. Both the remanent polarization, P(r), and transverse piezoelectric coefficient, e(31,) (f), increase with increasing proportion of the sol-gel solution in the precursor. Films prepared using a solution-to-powder mass ratio of 0.5 have a remanent polarization of 8 μC/cm(2), a dielectric constant of 450 (at 1 kHz), and e(31,) (f) = -2.8 C/m(2). Increasing the solution-to-powder mass ratio to 6, the films were found to have remanent polarizations as large as 37 μC/cm(2), a dielectric constant of 1250 (at 1 kHz) and e(31,) (f) = -5.8 C/m(2).

  20. Metastable Equilibrium Solubility Distribution of Carbonated Apatite as a Function of Solution Composition.

    Science.gov (United States)

    Chhettry; Wang; Hsu; Fox; Baig; Barry; Zhuang; Otsuka; Higuchi

    1999-10-01

    Previous studies have shown that carbonated apatites (CAPs) exhibit the phenomenon of metastable equilibrium solubility (MES) in weak acid media. The purpose of the present investigation was to examine two questions: first, whether the MES concept is applicable to a broader range of solution conditions and, second, whether a driving force function associated with a surface complex having a constant stoichiometry governs the dissolution of CAP and, if so, what is this stoichiometry. CAP preparations with carbonate contents of 1.8-5.7 wt% (synthesized by hydrolysis of dicalcium phosphate anhydrate in solutions of varying bicarbonate levels or by direct precipitation from supersaturated calcium/phosphate/carbonate solutions) were studied as follows. MES distributions for each of the CAP preparations were determined by equilibrating the CAP under stirred conditions in a series of acetate buffers (0.10 M) containing various levels of calcium and phosphate in the pH range 4.5-6.5 and a solution calcium/phosphate ratio in the range 0.1-10. The amount dissolved in each instance was regarded as the fraction of the CAP possessing an MES value greater than that corresponding to the ion activity product (IAP) of the equilibrating solution. The solution IAPs were calculated from the solution compositions using plausible calcium phosphate stoichiometries, viz., dicalcium phosphate dihydrate, octacalcium phosphate, tricalcium phosphate, hydroxyapatite, carbonated apatite (based on the bulk composition of the particular CAP involved in the experiment), and tetracalcium phosphate. The fraction of CAP dissolved was plotted against the solution IAPs for each experimental set using each of the six assumed stoichiometries for the surface complex. The results demonstrated that the MES concept was applicable to all of the CAP preparations in media of various solution compositions and different pH levels. The most important new outcome of this study was that MES profiles for each of the

  1. A model based bayesian solution for characterization of complex damage scenarios in aerospace composite structures.

    Science.gov (United States)

    Reed, H; Leckey, Cara A C; Dick, A; Harvey, G; Dobson, J

    2018-01-01

    Ultrasonic damage detection and characterization is commonly used in nondestructive evaluation (NDE) of aerospace composite components. In recent years there has been an increased development of guided wave based methods. In real materials and structures, these dispersive waves result in complicated behavior in the presence of complex damage scenarios. Model-based characterization methods utilize accurate three dimensional finite element models (FEMs) of guided wave interaction with realistic damage scenarios to aid in defect identification and classification. This work describes an inverse solution for realistic composite damage characterization by comparing the wavenumber-frequency spectra of experimental and simulated ultrasonic inspections. The composite laminate material properties are first verified through a Bayesian solution (Markov chain Monte Carlo), enabling uncertainty quantification surrounding the characterization. A study is undertaken to assess the efficacy of the proposed damage model and comparative metrics between the experimental and simulated output. The FEM is then parameterized with a damage model capable of describing the typical complex damage created by impact events in composites. The damage is characterized through a transdimensional Markov chain Monte Carlo solution, enabling a flexible damage model capable of adapting to the complex damage geometry investigated here. The posterior probability distributions of the individual delamination petals as well as the overall envelope of the damage site are determined. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A possible NaCl pathway in the bioregenerative human life support system

    Science.gov (United States)

    Polonskiy, V. I.; Gribovskaya, I. V.

    One of the ways to involve NaCl in the mass exchange of the bioregenerative human life support system (BLSS) is to grow some vegetables and leafy greens that can accumulate sodium chloride at high concentrations in their edible biomass. Lettuce, celery cabbage, chard, dill and radish plants were grown hydroponically in Knop's nutrient solution. In the first series of experiments, at the end of the growth period the plants were grown on solutions containing 2-14 g/L of NaCl for 1-5 days. It was found that the amount of sodium in edible biomass of the plants increased with NaCl concentration in the solution and with the time plants were irrigated with that solution. The content of NaCl in the biomass of leaves and edible roots was considerable—up to 10% dry matter. At the same time, the amount of water in the leaves decreased and productivity of the treatment plants was 14-28% lower than that of the control ones, grown on Knop's solution. The treatment plants contained less than half of the amount of nitrates recorded in the control ones. Expert evaluation showed that the taste of the vegetables and leafy greens of the treatment group were not inferior to the taste of the control plants. In the second series of experiments, prior to being grown on the NaCl solution, the plants were irrigated with water for 2, 4 or 6 days. It was found that lower salt status of the plants was not favorable for increased salt accumulation in their biomass. If a human consumes 30 g salad vegetables and follows a low-sodium diet (3 g/d of table salt), it may be feasible to recycle NaCl in the BLSS using vegetables and leafy greens.

  3. Optimization of strontium adsorption from aqueous solution using (mn-Zr) oxide-pan composite spheres

    International Nuclear Information System (INIS)

    Inan, S.; Altas, Y.

    2009-01-01

    The processes based on adsorption and ion exchange have a great role for the pre-concentration and separation of toxic, long lived radionuclides from liquid waste. In Nuclear waste management, the removal of long lived, radiotoxic isotopes from radioactive waste such as strontium reduces the storage problems and facilitates the disposal of the waste. Depending on the waste type, a variety of adsorbents and/or ion exchangers are used. Due to the amorphous structure of hydrous oxides and their mixtures, they don't have reproducible properties. Besides, obtained powders are very fine particles and they can cause operational problems such as pressure drop and filtration. Therefore they are not suitable for column applications. These reasons have recently expedited the study on the preparation of organic-inorganic composite adsorbent beads for industrial applications. PAN, as a stable and porous support for fine particles, provides the utilization of ion exchangers in large scale column applications. The utilization of PAN as a support material with many inorganic ion exchangers was firstly achieved by Sebesta in the beginning of 1990's. Later on, PAN based composite ion exchangers were prepared and used for the removal of radionuclides and heavy metal ions from aqueous solution and waste waters. In this study, spherical (Mn-Zr)oxide-PAN composite were prepared for separation of strontium from aqueous solution in a wide pH range. Sr 2 + adsorption of composite adsorbent was optimized by using experimental design 'Central Composite Design' model.

  4. Pyrene As a New Detector for Determining the Composition of Silver Nanoparticle Dispersions in Aqueous Solutions

    Science.gov (United States)

    Romanovskaya, G. I.; Kazakova, S. Yu.; Koroleva, M. V.; Zuev, B. K.

    2018-03-01

    It is proposed that the fluorescence of monomeric molecules of pyrene in solid matrices or in concentrated micellar solutions be used as a detector for determining the compositional homogeneity of silver nanoparticle (NP) dispersions in aqueous solutions synthesized in different ways. It is found that the morphology of silver NPs affects the change in the fluorescence intensity of monomeric molecules of pyrene in a certain (violet or blue) region of the pyrene optical spectrum. The observed phenomenon is attributed to the resonance of electronic transitions in the monomeric molecules of pyrene in regions with plasmon oscillations in silver nanoparticles. A new way of obtaining fluorescent silver NPs is found.

  5. Composition, Enzymes Analysis and Retraction Time of Columellar ...

    African Journals Online (AJOL)

    With the aid of columellar muscle, snails retract the soft part into the shell when disturbed. The response time of three Giant African Land Snail (GALS) species: Archachatina marginata, Achatina achatina and Achatina fulica to touch and sodium chloride (NaCl) solution was examined. Chemical composition (protein, glucose ...

  6. Equilibrium chemical transformations in NaPO3 + NaCl melts

    International Nuclear Information System (INIS)

    Kovarskaya, E.N.; Rodionov, Yu.I.

    1988-01-01

    Because of the problems of the burial of solidified radioactive wastes into different geological rock formations, in particular into massives of rock-salt, the state of molten polyphosphate-chloride mixtures (taking into account the chemical character of the interaction of their components) for a prolonged period of time. The equilibrium products of the reaction in the NaPO 3 -NaCl system were studied in melts in air in the composition range of 30-70 mole % NaCl. It was shown that with increase in the NaCl content in the mixtures, the polyphosphate gradually depolymerizes to sodium tri-, di-, and monophosphates, and the composition of the equilibrium melts is dependent only on the ratio between the components in the initial molten mixtures. The time until the equilibrium is attained is shorter, the higher is the experimental temperature

  7. Formation of protective composite coatings with the use of solution of TFE telomers

    Science.gov (United States)

    Mashtalyar, D. V.; Gnedenkov, S. V.; Sinebryukhov, S. L.; Nadaraia, K. V.; Kiryukhin, D. P.; Kushch, P. P.; Kichigina, G. A.; Buznik, V. M.

    2017-09-01

    This paper presents the method of fabricate and the results of investigation of electrochemical properties and wettability of the composite coatings obtained on the magnesium alloy by plasma electrolytic oxidation (PEO) and the use of the solution of tetrafluoroethylene (TFE) telomers. The fluoropolymer-containing coatings decrease corrosion current density, increase contact angle in comparison with the base PEO-coating and the bare alloy.

  8. Economical bridge solutions based on innovative composite dowels and integrated abutments ecobridge

    CERN Document Server

    Băncilă, Radu

    2015-01-01

    This book is an outcome of the research project “ECOBRIDGE – Demonstration of ECOnomical BRIDGE solutions based on innovative composite dowels and integrated abutments – RFCS – CT 2010-00024”, which has been co-funded by the Research Fund for Coal and Steel (R.F.C.S.) of the European Community. The main topics of the book are the following: design of integral bridges, innovative composite dowels for the shear transmission, construction of bridges, structural analysis of bridges and monitoring. The book joins the technical experience and the contributions of the involved research partners. The technical content of all the papers is present-day in the field of the design, construction and monitoring of innovative composite bridges. The efficient design and construction improve and consolidate the market position of steel construction and steel producing industry. In addition, the advanced forms of construction are contributing to savings in material and energy consumption for the structure during prod...

  9. Composite Properties of Polyimide Resins Made From "Salt-Like" Solution Precursors

    Science.gov (United States)

    Cano, Roberto J.; Weiser, Erik S.; SaintClair, Terry L.; Echigo, Yoshiaki; Kaneshiro, Hisayasu

    1997-01-01

    Recent work in high temperature materials at NASA Langley Research Center (LaRC (trademark)) have led to the development of new polyimide resin systems with very attractive properties. The majority of the work done with these resin systems has concentrated on determining engineering mechanical properties of composites prepared from a poly(amide acid) precursor. Three NASA Langley-developed polyimide matrix resins, LaRC (trademark) -IA, LaRC (trademark) -IAX, and LaRC (trademark) -8515, were produced via a salt-like process developed by Unitika Ltd. The 'salt-like' solutions (sixty-five percent solids in NMP) were prepregged onto Hexcel IM7 carbon fiber using the NASA LaRC Multipurpose Tape Machine. Process parameters were determined and composite panels fabricated. Mechanical properties are presented for these three intermediate modulus carbon fiber/polyimide matrix composites and compared to existing data on the same polyimide resin systems and IM7 carbon fiber manufactured via poly(amide acid) solutions (thirty-five percent solids in NMP). This work studies the effects of varying the synthetic route on the processing and mechanical properties of polyimide composites.

  10. The effect of flavoring oral rehydration solution on its composition and palatability.

    Science.gov (United States)

    te Loo, D Maroeska; van der Graaf, Fedde; Ten, Walther Tjon A

    2004-11-01

    As a number of mild to moderately dehydrated children refuse to drink oral rehydration solution (ORS) because of its strong salty taste, many parents and health workers flavor ORS with the childs favorite juice. The effects of flavoring ORS on electrolyte content and osmolality were assessed and the palatability of various solutions were compared with commercially flavored ORS. Osmolality, sodium, potassium, chloride and glucose content after flavoring with varying concentrations of apple juice, orange juice or orangeade was determined. Two of the solutions were offered to 30 children and adults to assess palatability. All additions to ORS (apple juice, orange juice or orangeade) caused a decrease of sodium (-30 to -53 mmol/L) and chloride (-27 to -47 mmol/L) content, whereas osmolality increased to greater than 311 mOsm/kg. These homemade oral rehydration solutions did not fulfill ESPGAN criteria for ORS, and rehydration will therefore be less effective. The majority of subjects also preferred the commercially flavored ORS. Only very small amounts of apple juice or orange juice can be added to the ORS without significantly altering electrolyte composition and osmolality. Palatability, however, does not improve compared with commercially flavored ORS. We therefore recommend using commercially flavored ORS, the composition of which fulfills ESPGAN criteria.

  11. Influence of material and solution composition on the extrusion/erosion behaviour of compacted bentonite

    International Nuclear Information System (INIS)

    Schatz, Timothy; Martikainen, Jari; Koskinen, Kari

    2010-01-01

    Document available in extended abstract form only. In principle, in a KBS-3 type repository, the volume of a deposition hole is fixed and the bentonite buffer mass accordingly balanced to lead to the development of a suitable swelling pressure upon saturation. However, fractures intersecting the deposition holes give rise to the possibility that volume constrained conditions do not universally exist. Such fractures may provide pathways for the continued, localised, free swelling of bentonite buffer material. Loss of mass from the deposition hole by extrusion into intersecting fractures may compromise the long-term safety and performance of the buffer component of the engineered barrier system. Furthermore, the continued hydration and expansion of extruded bentonite in these fracture environments could lead to the separation of colloid-sized (or larger) particles by diffusion or shear which may have to be accounted for in possible radionuclide migration scenarios. Geochemical conditions, with respect to both solution and material composition, are considered to play important roles regarding the fracture extrusion/erosion of bentonite buffer material. For example, calcium-montmorillonite exhibits limited free swelling relative to sodium-montmorillonite and the colloidal and rheological properties of montmorillonite dispersions are sensitive to the presence of electrolytes. Insofar as both the buffer material composition (due to ion exchange) and groundwater composition (dilution resulting from infiltration of glacial melt water) are expected to evolve with time, so too might the potential for fracture extrusion/erosion of buffer material vary over time. The hydraulic characteristics of the intersecting fracture are expected to influence the extrusion/erosion process as well. To evaluate the effect of material and solution composition on the potential for extrusion of buffer mass into intersecting fractures, a series of batch experiments were performed. In these

  12. The influence of precipitation temperature on the properties of ceria–zirconia solid solution composites

    International Nuclear Information System (INIS)

    Cui, Yajuan; Fang, Ruimei; Shang, Hongyan; Shi, Zhonghua; Gong, Maochu; Chen, Yaoqiang

    2015-01-01

    Highlights: • The crystallite size of precipitate increases as the precipitation temperature rises. • The stack of large crystallite can form nanoparticles with big pore size. • Big pore sizes are advantageous to improve the thermal stability. • Phase segregation is restricted in CZ solid solution precipitated at 70 °C. • The reducibility and OSC of the solid solution precipitated at 70 °C are improved. - Abstract: The ceria–zirconia composites (CZ) with a Ce/Zr mass ratio of 1/1 were synthesized by a back-titration method, in which the influence of precipitation temperature on the properties of ceria–zirconia precipitates was investigated. The resulting precipitation and mixed oxides at different precipitation temperatures were then characterized by a range of techniques, including textural properties, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), H 2 -temperature programmed reduction (H 2 -TPR) as well as oxygen storage capacity (OSC) measurement. The results revealed that ceria–zirconia composites were formed as solid solution and such structure is favored of thermostability and texture properties. In particular, the composite CZ-70 synthesized at 70 °C exhibited prominent thermostability with a surface area of 32 m 2 /g as well as a pore volume of 0.15 cc/g after aging treatment at 1000 °C for 5 h. And this was found to be associated with the wider pore size distribution which maybe owed to the formation of large crystal at the primary stage of precipitation. Additionally, the composite CZ-70 showed excellent reduction property and OSC benefiting from stable texture and structure

  13. Growth responses of NaCl stressed rice (Oryza sativa L.) plants ...

    African Journals Online (AJOL)

    GREGORY

    2010-09-27

    Sep 27, 2010 ... Growth responses of NaCl stressed rice (Oryza sativa. L.) plants ... 2008), which is a real threat to human's food security. Existed situation may ..... content and composition of essential oil and minerals in black cumin. (Nigella ...

  14. High Dielectric Performance of Solution-Processed Aluminum Oxide-Boron Nitride Composite Films

    Science.gov (United States)

    Yu, Byoung-Soo; Ha, Tae-Jun

    2018-04-01

    The material compositions of oxide films have been extensively investigated in an effort to improve the electrical characteristics of dielectrics which have been utilized in various electronic devices such as field-effect transistors, and storage capacitors. Significantly, solution-based compositions have attracted considerable attention as a highly effective and practical technique to replace vacuum-based process in large-area. Here, we demonstrate solution-processed composite films consisting of aluminum oxide (Al2O3) and boron nitride (BN), which exhibit remarkable dielectric properties through the optimization process. The leakage current of the optimized Al2O3-BN thin films was decreased by a factor of 100 at 3V, compared to pristine Al2O3 thin film without a loss of the dielectric constant or degradation of the morphological roughness. The characterization by X-ray photoelectron spectroscopy measurements revealed that the incorporation of BN with an optimized concentration into the Al2O3 dielectric film reduced the density of oxygen vacancies which act as defect states, thereby improving the dielectric characteristics.

  15. Response of Eucalyptus occidentais to water stress induced by NaCl

    Energy Technology Data Exchange (ETDEWEB)

    Itai, C.

    1978-01-01

    Eucalyptus occidentalis plants were exposed to NaCl in their culture solution for various time. Determination of cytokinin, abscisic acid, /sup 14/C leucine incorporation of E. occidentalis, a xerophyte, does not differ from the response of mesophytes to such treatments. 13 references, 1 figure, 4 tables.

  16. Effect of staining solutions and repolishing on color stability of direct composites

    Directory of Open Access Journals (Sweden)

    Fabrício Mariano Mundim

    2010-06-01

    Full Text Available OBJECTIVES: The purpose of this study was to assess the color change of three types of composite resins exposed to coffee and cola drink, and the effect of repolishing on the color stability of these composites after staining. MATERIALS AND METHODS: Fifteen specimens (15 mm diameter and 2 mm thick were fabricated from microhybrid (Esthet-X; Dentsply and Filtek Z-250; 3M ESPE and high-density hybrid (Surefil; Dentsply composites, and were finished and polished with aluminum oxide discs (Sof-Lex; 3M ESPE. Color of the specimens was measured according to the CIE L*a*b* system in a refection spectrophotometer (PCB 6807; BYK Gardner. After baseline color measurements, 5 specimens of each resin were immersed in different staining solutions for 15 days: G1 - distilled water (control, G2 - coffee, G3 - cola soft drink. Afterwards, new color measurement was performed and the specimens were repolished and submitted to new color reading. Color stability was determined by the difference (ΔE between the coordinates L*, a*, and b* obtained from the specimens before and after immersion into the solutions and after repolishing. RESULTS: There was no statistically signifcant difference (ANOVA, Tukey's test; p>0.05 among the ΔE values for the different types of composites after staining or repolishing. For all composite resins, coffee promoted more color change (ΔE>3.3 than distilled water and the cola soft drink. After repolishing, the ΔE values of the specimens immersed in coffee decreased to clinically acceptable values (ΔE<3.3, but remained signifcantly higher than those of the other groups. CONCLUSIONS: No signifcant difference was found among composite resins or between color values before and after repolishing of specimens immersed in distilled water and cola. Immersing specimens in coffee caused greater color change in all types of composite resins tested in this study and repolishing contributed to decrease staining to clinically acceptable

  17. High strength Ni based composite reinforced by solid solution W(Al) obtained by powder metallurgy

    International Nuclear Information System (INIS)

    Zhao Bo; Zhu Changjun; Ma Xianfeng; Zhao Wei; Tang Huaguo; Cai Shuguang; Qiao Zhuhui

    2007-01-01

    The solid-solution-particle reinforced W(Al)-Ni composites were successfully fabricated by using mechanical alloying (MA) and hot-pressing (HP) technique when the content of Ni is between 45 wt% and 55 wt%. Besides, samples of various original component ratio of Al 50 W 50 to Ni have been fabricated, and the corresponding microcomponents and mechanical properties such as microhardness, ultimate tensile strength and elongation were characterized and discussed. The optimum ultimate tensile strength under the experiment conditions is 1868 MPa with elongation of 10.21% and hardness of 6.62 GPa. X-ray diffraction (XRD), FE-SEM and energy dispersive analysis of X-rays (EDS) were given to analysis the components and morphology of the composite bulk specimens

  18. Formation of soft magnetic high entropy amorphous alloys composites containing in situ solid solution phase

    Science.gov (United States)

    Wei, Ran; Sun, Huan; Chen, Chen; Tao, Juan; Li, Fushan

    2018-03-01

    Fe-Co-Ni-Si-B high entropy amorphous alloys composites (HEAACs), which containing high entropy solid solution phase in amorphous matrix, show good soft magnetic properties and bending ductility even in optimal annealed state, were successfully developed by melt spinning method. The crystallization phase of the HEAACs is solid solution phase with body centered cubic (BCC) structure instead of brittle intermetallic phase. In addition, the BCC phase can transformed into face centered cubic (FCC) phase with temperature rise. Accordingly, Fe-Co-Ni-Si-B high entropy alloys (HEAs) with FCC structure and a small amount of BCC phase was prepared by copper mold casting method. The HEAs exhibit high yield strength (about 1200 MPa) and good plastic strain (about 18%). Meanwhile, soft magnetic characteristics of the HEAs are largely reserved from HEAACs. This work provides a new strategy to overcome the annealing induced brittleness of amorphous alloys and design new advanced materials with excellent comprehensive properties.

  19. Anisotropic perylenediimide/polycarbonate composites produced by a single batch solution based method

    Energy Technology Data Exchange (ETDEWEB)

    Dobruchowska, Ewa, E-mail: ewa.dobruchowska@tu.koszalin.pl [Department of Molecular Physics, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland); Institute of Technology and Education, Koszalin University of Technology, Sniadeckich 2, 75-453 Koszalin (Poland); Marszalek, Tomasz; Ulanski, Jacek [Department of Molecular Physics, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland)

    2014-08-01

    The continuous anisotropic organic semiconductor/dielectric composites consisting of a top, unidirectionally oriented crystalline layer of perylenediimide derivative (2,9-di(pent-3-yl)-anthra[1,9-def:6,5,10-d′e′f′]diisoquinoline-1,3,8, 10-tetrone) (PTCDI-C5(3)) and a bottom layer of poly(bisphenol A carbonate) (PC) support were obtained in a one batch solution process, with the use of the so called the zone-casting method. Scanning electron microscopy images have shown that the top PTCDI-C5(3) layer is made of long, parallel crystallites in the form of ribbons that exhibit birefringence when placed between a pair of crossed polarisers in the optical microscope. Furthermore, the polarised UV–Vis absorbance and photoluminescence experiments revealed that the alignment of the PTCDI-C5(3) molecules is caused by π–π interactions between the conjugated perylene cores, and their stacks are parallel to the long axis of the crystallites and to the polymer surface. The high value of the calculated polarisation ratio, which equals 0.64, constitutes a confirmation of a high degree of molecular order within the semiconducting component of the zone-cast composites. - Highlights: • Bi-layer composites were produced by a single batch solution based method. • The top-layer was made of an n-type organic semiconductor — perylene derivative. • Polarised absorbance and photoluminescence were used to study optical anisotropy. • High polarisation ratio of 0.64 was obtained for the top-layer of the composite.

  20. All-solution processed composite hole transport layer for quantum dot light emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaoli [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072 (China); Synergetic Innovation Center of Chemical Science and Engineering, Tianjin (China); Dai, Haitao, E-mail: htdai@tju.edu.cn [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072 (China); Zhao, Junliang; Wang, Shuguo [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072 (China); Sun, Xiaowei [Department of Electrical & Electronic Engineering, South University of Science and Technology of China, Tangchang Road 1088, Shenzhen, Guangdong 518055 (China)

    2016-03-31

    In the present work, poly-TPD and TCTA composite hole transport layer (HTL) was employed in solution processed CdSe/ZnS quantum dot light emitting diodes (QLEDs). As the doping level of TCTA can determine the carriers transport efficiency of HTL, the proper mixing ratio of TCTA and poly-TPD should be found to optimize the performance of composite HTL for QLEDs. The doping of poly-TPD by low TCTA content can make its HOMO level lower and then reduce the energy barrier height from HTL to quantum dots (QDs), whereas the doping of poly-TPD by the concentrated TCTA results in the degraded performance of QLEDs due to its decreased hole transport mobility. By using the optimized composition with poly-TPD:TCTA (3:1) as the hole transport layer, the luminescence of the device exhibits about double enhancement compared with that of poly-TPD based device. The improvement of luminescence is mainly attributed to the lower energy barrier of hole injection. The Förster resonant energy transfer (FRET) mechanism in the devices was investigated through theoretical and experimental analysis and the results indicate that the TCTA doping makes no difference on FRET. Therefore, the charge injection mechanism dominates the improved performance of the devices. - Highlights: • Quantum dot light emitting diodes (QLEDs) were fabricated by all solution method. • The performance of QLEDs was optimized by varying the composite hole transport layer. • The blend HTL could promote hole injection by optimizing HOMO levels. • The energy transfer mechanism was analyzed by studying Förster resonant energy transfer process.

  1. Effect of solution composition on the adsorption and desorption of 137Cs on forest soils

    International Nuclear Information System (INIS)

    Staunton, S.; Wells, C.; Shaw, G.

    2004-01-01

    There is ongoing debate as to the pertinence of measurements of soil-liquid distribution coefficients in dilute suspension to the understanding and the prediction of the mobility of radionuclides in soil. This debate is particularly active in the case of radiocaesium. Several factors could cause significant discrepancies between measured and effective in situ distributions of radiocaesium. 1. Differences in solution composition, notably ionic strength and concentration in cations such as potassium and ammonium; 2. Differences in soil:solution ratio; 3. Time dependent reactions; 4. Reversibility of the adsorption reaction; 5. Concentration dependence of adsorption. We have attempted to assess the importance of some of these factors by studying 137 Cs adsorption on soils sampled from different horizons of a forest soil. Kd was measured in suspension. Soil:solution ratio and initial 137 Cs concentration and concentration of potassium and stable Cs in solution were varied. Adsorption and desorption Kd values were measured under similar conditions and compared. Kd values were in the lower range of values reported in the literature (5-30 1/kg). Samples from surface layers showed no concentration dependence at trace additions of 137 Cs, whereas some decrease in Kd was observed with increasing 137 Cs concentration on the Ea horizon. Data obtained at different soil:solution ratios all fell on the same adsorption isotherms as those obtained by varying initial 137 Cs concentration. Stable caesium and, to a lesser extent, potassium inhibited 137 Cs adsorption. This effect was greater in the Ea horizon than the surface soils, probably due to the mineral content. For all samples the desorption Kd was greater than the adsorption Kd in the same solution, indicating a small but significant degree of irreversibility. (author)

  2. CO2 Fixation by Membrane Separated NaCl Electrolysis

    DEFF Research Database (Denmark)

    Park, Hyun Sic; Lee, Ju Sung; Han, Junyoung

    2015-01-01

    for converting CO2 into CaCO3 requires high temperature and high pressure as reaction conditions. This study proposes a method to fixate CaCO3 stably by using relatively less energy than existing methods. After forming NaOH absorbent solution through electrolysis of NaCl in seawater, CaCO3 was precipitated...... crystal product was high-purity calcite. The study shows a successful method for fixating CO2 by reducing carbon dioxide released into the atmosphere while forming high-purity CaCO3.......Atmospheric concentrations of carbon dioxide (CO2), a major cause of global warming, have been rising due to industrial development. Carbon capture and storage (CCS), which is regarded as the most effective way to reduce such atmospheric CO2 concentrations, has several environmental and technical...

  3. Thermogravimetric analysis of phase transitions in cement compositions mixed by sodium silicate solution

    Directory of Open Access Journals (Sweden)

    Fedosov Sergey Viktorovich

    2014-01-01

    Full Text Available This paper presents a study of the capability to modify cement by mechanical activation of sodium silicate water solution. Admixtures or blends of binding agents were employed for modifying concrete properties. The liquid glass is applied to protect from chemically or physically unfavorable environmental impacts, such as acidic medium and high temperature. The sodium silicate is a high-capacity setting accelerator. The increasing of the liquid glass proportion in the mix leads to the degradation of the cement paste plasticity and for this reason it is necessary to reduce the amount of liquid glass in the cement paste. The activation of dilute water solution of sodium silicate into rotary pulsating apparatus directly before tempering of the cement paste is an effective way to decrease mass fraction of liquid glass in the cement paste. The results of the combined influence of liquid glass and mechanical activation on physicochemical processes taking place in cement stone are represented in this research. Thermogravimetric analysis was used in order to study cement blends. Thermogravimetric analysis of modified cement stone assays was performed by thermo analyzer SETARAM TGA 92-24. The results of the analysis of phase transition taking place under high-temperature heating of cement stone modified by the mechanical activation of the water solution of the sodium silicate were introduced. Thermograms of cement stone assays were obtained at different hardening age. The comparison of these thermograms allows us to come to a conclusion on the formation and the retention during long time of a more dense structure of the composite matrix mixed by the mechanical activation of sodium silicate water solution. The relation between the concrete composition and its strength properties was stated. Perhaps, the capability of modified concrete to keep calcium ions in sparingly soluble hydrosilicates leads to the increase in its durability and corrosion resistance.

  4. The composite water and solute transport of barley (Hordeum vulgare) roots: effect of suberized barriers.

    Science.gov (United States)

    Ranathunge, Kosala; Kim, Yangmin X; Wassmann, Friedrich; Kreszies, Tino; Zeisler, Viktoria; Schreiber, Lukas

    2017-03-01

    Roots have complex anatomical structures, and certain localized cell layers develop suberized apoplastic barriers. The size and tightness of these barriers depend on the growth conditions and on the age of the root. Such complex anatomical structures result in a composite water and solute transport in roots. Development of apoplastic barriers along barley seminal roots was detected using various staining methods, and the suberin amounts in the apical and basal zones were analysed using gas chromatography-mass spectometry (GC-MS). The hydraulic conductivity of roots ( Lp r ) and of cortical cells ( Lp c ) was measured using root and cell pressure probes. When grown in hydroponics, barley roots did not form an exodermis, even at their basal zones. However, they developed an endodermis. Endodermal Casparian bands first appeared as 'dots' as early as at 20 mm from the apex, whereas a patchy suberin lamellae appeared at 60 mm. The endodermal suberin accounted for the total suberin of the roots. The absolute amount in the basal zone was significantly higher than in the apical zone, which was inversely proportional to the Lp r . Comparison of Lp r and Lp c suggested that cell to cell pathways dominate for water transport in roots. However, the calculation of Lp r from Lp c showed that at least 26 % of water transport occurs through the apoplast. Roots had different solute permeabilities ( P sr ) and reflection coefficients ( σ sr ) for the solutes used. The σ sr was below unity for the solutes, which have virtually zero permeability for semi-permeable membranes. Suberized endodermis significantly reduces Lp r of seminal roots. The water and solute transport across barley roots is composite in nature and they do not behave like ideal osmometers. The composite transport model should be extended by adding components arranged in series (cortex, endodermis) in addition to the currently included components arranged in parallel (apoplastic, cell to cell pathways). © The

  5. HDPE/HA composites obtained in solution: Effect of the gamma radiation

    International Nuclear Information System (INIS)

    Carmen, Albano; Arquimedes, Karam; Rosestela, Perera; Gema, Gonzalez; Nohemy, Dominguez; Jeanette, Gonzalez; Yanixia, Sanchez

    2006-01-01

    Radiation is employed to sterilize composite materials used in the biomedical field. Due to the changes induced by radiation onto polymeric materials, it is important to study variations in their melt flow index (MFI), as well as in their mechanical and thermal properties. In this work, those previous parameters were determined in composites obtained via solution of a high-density polyethylene (HDPE) in decalin, with different amounts of hydroxyapatite (HA), varying from 10 to 30 parts per hundred, after being exposed to gamma radiation at absorbed doses between 25 and 100 kGy. After the irradiation, the MFI of HDPE dissolved in decalin and precipitated afterwards and without filler increased from 6 to 24 g/10 min at the highest absorbed doses. This behavior was also observed in composites with 10 pph of HA, being the increase less pronounced, specifically in the range between 50 and 100 kGy. Composites with 20 and 30 pph of HA showed a maximum MFI value at 50 kGy, which decreased at higher doses. This implies that the filler begin to exert an influence because it does not melt at the test temperature and consequently, it does not flow. It was observed that Young's modulus increased with HA addition due to rigidity of the ceramic filler. Radiation did not significantly affect this tensile property. On the other hand, the tensile strength did not show significant variations at the different doses but the filler content did affect this property improving it. Finally, elongation at break showed a drastic decrease with filler addition. When the thermal behavior was studied it was noticed that crystallization and melting temperatures remained unchanged. Instead, crystallinity degree slightly increased in the composites, and a little decrease was obtained when they were irradiated

  6. Liquid Scintillation counting Standardization of 22 NaCl by the CIEMAT/NIST method

    International Nuclear Information System (INIS)

    Rodriguez Barquero, L.; Grau Carles, A.; Grau Malonda, A.

    1995-09-01

    We describe a procedure for preparing a stable solution of ''22 NaCl for liquid scintillation counting and its counting stability and spectral evolution in Insta-Gel''R is studied. The solution has been standardised in terms of activity concentration by the CIEMAT/NIST method with discrepancies between experimental and computed efficiencies lower than 0.4/% and an overall uncertainty of 0.35%

  7. Liquid Scintillation Counting Standardization of 22NaCl by te CIEMAT/NIST method

    International Nuclear Information System (INIS)

    Rodriguez Barquero, L.; Grau Carles, A.; Grau Malonda, A.

    1995-01-01

    We describe a procedure for preparing a stable solution of ''22NaCl for liquid scintillation counting and its counting stability and spectral evolution in Insta-Gel''R is studied. The solution has been standardised in terms of activity concentration by the CIEMAT/NIST method with discrepancies between experimental and computed efficiencies lower than 0.4 % and an overall uncertainty of 0.35 %. (Author) 4 refs

  8. Controlled Bulk Properties of Composite Polymeric Solutions for Extensive Structural Order of Honeycomb Polysulfone Membranes.

    Science.gov (United States)

    Gugliuzza, Annarosa; Perrotta, Maria Luisa; Drioli, Enrico

    2016-05-16

    This work provides additional insights into the identification of operating conditions necessary to overcome a current limitation to the scale-up of the breath figure method, which is regarded as an outstanding manufacturing approach for structurally ordered porous films. The major restriction concerns, indeed, uncontrolled touching droplets at the boundary. Herein, the bulk of polymeric solutions are properly managed to generate honeycomb membranes with a long-range structurally ordered texture. Water uptake and dynamics are explored as chemical environments are changed with the intent to modify the hydrophilic/hydrophobic balance and local water floatation. In this context, a model surfactant such as the polyoxyethylene sorbitan monolaurate is used in combination with alcohols at different chain length extents and a traditional polymer such as the polyethersufone. Changes in the interfacial tension and kinematic viscosity taking place in the bulk of composite solutions are explored and examined in relation to competitive droplet nucleation and growth rate. As a result, extensive structurally ordered honeycomb textures are obtained with the rising content of the surfactant while a broad range of well-sized pores is targeted as a function of the hydrophilic-hydrophobic balance and viscosity of the composite polymeric mixture. The experimental findings confirm the consistency of the approach and are expected to give propulsion to the commercially production of breath figures films shortly.

  9. Controlled Bulk Properties of Composite Polymeric Solutions for Extensive Structural Order of Honeycomb Polysulfone Membranes

    Directory of Open Access Journals (Sweden)

    Annarosa Gugliuzza

    2016-05-01

    Full Text Available This work provides additional insights into the identification of operating conditions necessary to overcome a current limitation to the scale-up of the breath figure method, which is regarded as an outstanding manufacturing approach for structurally ordered porous films. The major restriction concerns, indeed, uncontrolled touching droplets at the boundary. Herein, the bulk of polymeric solutions are properly managed to generate honeycomb membranes with a long-range structurally ordered texture. Water uptake and dynamics are explored as chemical environments are changed with the intent to modify the hydrophilic/hydrophobic balance and local water floatation. In this context, a model surfactant such as the polyoxyethylene sorbitan monolaurate is used in combination with alcohols at different chain length extents and a traditional polymer such as the polyethersufone. Changes in the interfacial tension and kinematic viscosity taking place in the bulk of composite solutions are explored and examined in relation to competitive droplet nucleation and growth rate. As a result, extensive structurally ordered honeycomb textures are obtained with the rising content of the surfactant while a broad range of well-sized pores is targeted as a function of the hydrophilic-hydrophobic balance and viscosity of the composite polymeric mixture. The experimental findings confirm the consistency of the approach and are expected to give propulsion to the commercially production of breath figures films shortly.

  10. One-parameter families of supersymmetric isospectral potentials from Riccati solutions in function composition form

    Energy Technology Data Exchange (ETDEWEB)

    Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICYT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San José 2055, Col. Lomas 4a Sección, 78216 San Luis Potosí, S.L.P. (Mexico); Mancas, Stefan C., E-mail: mancass@erau.edu [Department of Mathematics, Embry–Riddle Aeronautical University, Daytona Beach, FL 32114-3900 (United States); Chen, Pisin, E-mail: pisinchen@phys.ntu.edu.tw [Leung Center for Cosmology and Particle Astrophysics (LeCosPA) and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China)

    2014-04-15

    In the context of supersymmetric quantum mechanics, we define a potential through a particular Riccati solution of the composition form (F∘f)(x)=F(f(x)) and obtain a generalized Mielnik construction of one-parameter isospectral potentials when we use the general Riccati solution. Some examples for special cases of F and f are given to illustrate the method. An interesting result is obtained in the case of a parametric double well potential generated by this method, for which it is shown that the parameter of the potential controls the heights of the localization probability in the two wells, and for certain values of the parameter the height of the localization probability can be higher in the smaller well. -- Highlights: •Function-composition generalization of parametric isospectral potentials is presented. •Mielnik one-parameter family of harmonic potentials is obtained as a particular case. •Graphical discussion of regular and singular regions in the parameter space is given.

  11. Water activities of ternary mixtures of poly(ethylene glycol), NaCl and water over the temperature range of 293.15 K to 313.15 K

    International Nuclear Information System (INIS)

    Sadeghi, Rahmat; Ziamajidi, Fatemeh

    2006-01-01

    The improved isopiestic method has been used to obtain activities of water for aqueous solutions of poly(ethylene glycol) 400/NaCl at T = (293.15, 298.15, 303.15, 308.15, and 313.15) K. From these measurements, values of the vapour pressure of solutions were determined. The effect of temperature on the (vapour + liquid) equilibrium of {poly(ethylene glycol) + NaCl + H 2 O} systems has been studied. It was found that the slope of the constant activity lines for water increased with increasing temperature. The results have been discussed on the basis of the effect of temperature on the hydrophobicity of the polymer. Also it was found that the vapour pressure depression for an aqueous (PEG + NaCl) system is more than the sum of those for the corresponding binary solutions. Furthermore, the segment-based local composition Wilson model has been used for the correlation of the experimental water activity data. The agreement between the correlation and the experimental data are good

  12. Characteristics of regenerated nanocellulosic fibers from cellulose dissolution in aqueous solutions for wood fiber/polypropylene composites

    Science.gov (United States)

    Sangyeob Lee; Hui Pan; Chung Y. Hse; Alfred R. Gunasekaran; Todd F. Shupe

    2014-01-01

    The effects of aqueous solutions were evaluated on the properties of regenerated cellulosic nanofibers prepared from pure cellulose fibers in various formulations of aqueous solutions. Thermoplastic composites were prepared with reinforcement of the regenerated cellulosic nanofibers. The regenerated cellulosic fibers from cellulosic woody biomass were obtained from...

  13. The Novel Attempt for Finding Minimum Solution in Fuzzy Neutrosophic Relational Geometric Programming (FNRGP with (max,min Composition

    Directory of Open Access Journals (Sweden)

    Huda E. Khalid

    2016-08-01

    Full Text Available This article sheds light on the possibility of finding the minimum solution set of neutrosophic relational geometric programming with (max, min composition. This work examines the privacy enjoyed by both neutrosophic logic and geometric programming, and how it affects the minimum solutions.

  14. Adsorption of methyl orange from aqueous solution using chitosan/diatomite composite.

    Science.gov (United States)

    Zhao, Peng; Zhang, Runhu; Wang, Jianglin

    2017-04-01

    A novel chitosan/diatomite composite was prepared by a simple mixture in the mass ratio to remove methyl orange (MO) from aqueous media in this study. The composite adsorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy analysis. The parameters to influence the adsorption of MO were studied under such conditions as kinetics, adsorption isotherm, pH effect, and thermodynamics. The results revealed that adsorption of MO was initially rapid and the equilibrium time was reached after 40 min. The optimal value of the pH was 5.0 for better adsorption. The equilibrium data were well fitted to the Langmuir isotherm compared to the Freundlich isotherm, and exhibited the highest capacity and a removal rate of 88.37% under an initial dye concentration of 50 mg/L. The kinetic data were well described by the pseudo-second order model. The thermodynamic calculations revealed that the sorption was viable, spontaneous, and exothermic under the conditions studied. In addition, the chitosan/diatomite composite had good adsorption and desorption performance with respect to reusability after six cycles. These results showed that the chitosan/diatomite could be considered as a potential adsorbent for the removal of MO in aqueous solution.

  15. Densities and apparent molar volumes of atmospherically important electrolyte solutions. 1. The solutes H2SO4, HNO3, HCl, Na2SO4, NaNO3, NaCl, (NH4)2SO4, NH4NO3, and NH4Cl from 0 to 50 °C, including extrapolations to very low temperature and to the pure liquid state, and NaHSO4, NaOH, and NH3 at 25 °C.

    Science.gov (United States)

    Clegg, S L; Wexler, A S

    2011-04-21

    Calculations of the size and density of atmospheric aerosols are complicated by the fact that they can exist at concentrations highly supersaturated with respect to dissolved salts and supercooled with respect to ice. Densities and apparent molar volumes of solutes in aqueous solutions containing the solutes H(2)SO(4), HNO(3), HCl, Na(2)SO(4), NaNO(3), NaCl, (NH(4))(2)SO(4), NH(4)NO(3), and NH(4)Cl have been critically evaluated and represented using fitted equations from 0 to 50 °C or greater and from infinite dilution to concentrations saturated or supersaturated with respect to the dissolved salts. Using extrapolated densities of high-temperature solutions and melts, the relationship between density and concentration is extended to the hypothetical pure liquid solutes. Above a given reference concentration of a few mol kg(-1), it is observed that density increases almost linearly with decreasing temperature, and comparisons with available data below 0 °C suggest that the fitted equations for density can be extrapolated to very low temperatures. As concentration is decreased below the reference concentration, the variation of density with temperature tends to that of water (which decreases as temperature is reduced below 3.98 °C). In this region below the reference concentration, and below 0 °C, densities are calculated using extrapolated apparent molar volumes which are constrained to agree at the reference concentrations with an equation for the directly fitted density. Calculated volume properties agree well with available data at low temperatures, for both concentrated and dilute solutions. Comparisons are made with literature data for temperatures of maximum density. Apparent molar volumes at infinite dilution are consistent, on a single ion basis, to better than ±0.1 cm(3) mol(-1) from 0 to 50 °C. Volume properties of aqueous NaHSO(4), NaOH, and NH(3) have also been evaluated, at 25 °C only. In part 2 of this work (ref 1 ) an ion interaction (Pitzer

  16. DESIGN AND TECHNOLOGICAL SOLUTIONS FOR THE RESTORATION OF SEWERS USING ELEMENTS OF RECYCLED POLYMER COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    GONCHARENKO D. F.

    2017-01-01

    Full Text Available Problem statement. Currently sanitary drainage systems of large cities in Ukraine are significantly worn down with prolonged use and due to inefficient solutions for protection of the structures from aggressive effects of the environment, poor quality of materials and construction and installation works during building. Restoration of performance characteristics, reliability and durability of sewer tunnels is the costly and technically complex task, which is urgently needed to be fulfilled to prevent accidents including those with serious environmental impact. Modern work technique and the materials used for restoration allow us to solve these problems with different levels of efficiency, while reducing the cost of restoration due to use of recycled polymeric raw material, as well as to improvement of technological solutions is a currently important direction of research. Purpose of the article. To develop solutions for restoring serviceability, reliability and durability of sewer tunnels taking into account the accumulated experience in renovation of water disposal networks. Conclusion. Use of components made of recycled polymer composite materials during restoring sewer tunnels has significant economic and environmental effects and allows to undertake repair work in hard-to-reach areas.

  17. A compositional multiphase model for groundwater contamination by petroleum products: 2. Numerical solution

    Science.gov (United States)

    Baehr, Arthur L.; Corapcioglu, M. Yavuz

    1987-01-01

    In this paper we develop a numerical solution to equations developed in part 1 (M. Y. Corapcioglu and A. L. Baehr, this issue) to predict the fate of an immiscible organic contaminant such as gasoline in the unsaturated zone subsequent to plume establishment. This solution, obtained by using a finite difference scheme and a method of forward projection to evaluate nonlinear coefficients, provides estimates of the flux of solubilized hydrocarbon constituents to groundwater from the portion of a spill which remains trapped in a soil after routine remedial efforts to recover the product have ceased. The procedure was used to solve the one-dimensional (vertical) form of the system of nonlinear partial differential equations defining the transport for each constituent of the product. Additionally, a homogeneous, isothermal soil with constant water content was assumed. An equilibrium assumption partitions the constituents between air, water, adsorbed, and immiscible phases. Free oxygen transport in the soil was also simulated to provide an upper bound estimate of aerobic biodgradation rates. Results are presented for a hypothetical gasoline consisting of eight groups of hydrocarbon constituents. Rates at which hydrocarbon mass is removed from the soil, entering either the atmosphere or groundwater, or is biodegraded are presented. A significant sensitivity to model parameters, particularly the parameters characterizing diffusive vapor transport, was discovered. We conclude that hydrocarbon solute composition in groundwater beneath a gasoline contaminated soil would be heavily weighted toward aromatic constituents like benzene, toluene, and xylene.

  18. Effect of Solution Treatment Process on Hardness of Alumina Reinforced Al-9Zn Composite Produced by Squeeze Casting

    Directory of Open Access Journals (Sweden)

    Dwi Rahmalina

    2014-10-01

    Full Text Available Characteristics of aluminium matrix composites reinforced by alumina have been developed to improve mechanical properties. One of the determining factors in the development of this material is parameter of solution treatment process. This study discusses the performance of the composite matrix of Al-9Zn-6Mg-3Si reinforced by alumina powder of 5 % volume fraction. Composite are manufactured by squeeze casting process with the pressure of 20 Ton in the metal mould. To improve mechanical properties, the precipitation hardening process is conducted through variation of temperature of solution treatment of 450, 475 and 500 °C and holding time of solution treatment of 30, 60 and 90 minutes. Materials are characterized by hardness testing and microstructure observation. The results showed that the optimum condition of hardness was produced by solution treatment temperature of 500 °C and 90 minutes holding time of 86 HRB.

  19. Dependence of osmotic pressure on solution properties

    International Nuclear Information System (INIS)

    Fritz, S.J.

    1978-01-01

    Hydrostatic pressure, temperature, salt concentration, and the chemical composition of the salt are parameters affecting solution properties. Pressure and temperature have little effect on osmosis, but osmotic pressure variations due to type of dissolved salt may be significant, especially at high concentrations. For a given salt solution, concentration variations cause large differences in osmotic pressure. A representative difference in concentration across a clay layer in a relatively shallow groundwater system might be 100 to 1,000 ppm. When expressed as ppm NaCl, this difference could cause a head difference of 0.8 to 8 meters of water if one of the rock bodies were closed to fluid escape

  20. Heterogeneous Ice Nucleation Ability of NaCl and Sea Salt Aerosol Particles at Cirrus Temperatures

    Science.gov (United States)

    Wagner, Robert; Kaufmann, Julia; Möhler, Ottmar; Saathoff, Harald; Schnaiter, Martin; Ullrich, Romy; Leisner, Thomas

    2018-03-01

    In situ measurements of the composition of heterogeneous cirrus ice cloud residuals have indicated a substantial contribution of sea salt in sampling regions above the ocean. We have investigated the heterogeneous ice nucleation ability of sodium chloride (NaCl) and sea salt aerosol (SSA) particles at cirrus cloud temperatures between 235 and 200 K in the Aerosol Interaction and Dynamics in the Atmosphere aerosol and cloud chamber. Effloresced NaCl particles were found to act as ice nucleating particles in the deposition nucleation mode at temperatures below about 225 K, with freezing onsets in terms of the ice saturation ratio, Sice, between 1.28 and 1.40. Above 225 K, the crystalline NaCl particles deliquesced and nucleated ice homogeneously. The heterogeneous ice nucleation efficiency was rather similar for the two crystalline forms of NaCl (anhydrous NaCl and NaCl dihydrate). Mixed-phase (solid/liquid) SSA particles were found to act as ice nucleating particles in the immersion freezing mode at temperatures below about 220 K, with freezing onsets in terms of Sice between 1.24 and 1.42. Above 220 K, the SSA particles fully deliquesced and nucleated ice homogeneously. Ice nucleation active surface site densities of the SSA particles were found to be in the range between 1.0 · 1010 and 1.0 · 1011 m-2 at T < 220 K. These values are of the same order of magnitude as ice nucleation active surface site densities recently determined for desert dust, suggesting a potential contribution of SSA particles to low-temperature heterogeneous ice nucleation in the atmosphere.

  1. Preparation of functional composite materials based on chemically derived graphene using solution process

    International Nuclear Information System (INIS)

    Kim, M; Hyun, W J; Mun, S C; Park, O O

    2015-01-01

    Chemically derived graphenes were assembled into functional composite materials using solution process from stable solvent dispersion. We have developed foldable electronic circuits on paper substrates using vacuum filtration of graphene nanoplates dispersion and a selective transfer process without need for special equipment. The electronic circuits on paper substrates revealed only a small change in conductance under various folding angles and maintained an electronic path after repetitive folding and unfolding. We also prepared flexible. binder-free graphene paper-like materials by addition of graphene oxide as a film stabilizer. This graphene papers showed outstanding electrical conductivity up to 26,000 S/m and high charge capacity as an anode in lithium-ion battery without any post-treatments. For last case, multi-functional thin film structures of graphene nanoplates were fabricated by using layer-by-layer assembly technique, showing optical transparency, electrical conductivity and enhanced gas barrier property. (paper)

  2. Equilibrium Adsorption of heavy Metals from Aqueous Solutions onto Poly aniline Stannic(IV) Phosphate Composite

    International Nuclear Information System (INIS)

    El-Zahhar, A.A.; EI-Shourbagy, M.M.; Shady, S.A.

    2012-01-01

    An adsorbent material has been prepared by immobilization of stannic(IV) phosphate within poly aniline composite. The produced adsorbent exhibit a high adsorption potential for Pb(II), Cd(Il) and Zn(lI) from aqueous solutions. The influence of initial metal ion concentration, adsorbent dose, ph and temperature on metal ion removal has been studied. The process was found to follow a first order rate kinetics. Thc intra-particle diffusion of metal ions through pores in the adsorbent was to be the main rate limiting step. The equilibrium data fit well with Langmuir adsorption isotherm model. The selectivity order of the adsorbent towards the metal ions was Pb(Il) > Cd(Il) >Zn(II). The adsorption rate constant and thermodynamic parameters were also given to predict the nature of adsorption

  3. Investigation on synergism of composite additives for zinc corrosion inhibition in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Hebing [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), South China Normal University, Guangzhou 510006 (China); Huang Qiming; Liang Man; Lv Dongsheng; Xu Mengqing; Li Hong [Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), South China Normal University, Guangzhou 510006 (China); Li Weishan, E-mail: liwsh@scnu.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), South China Normal University, Guangzhou 510006 (China)

    2011-07-15

    Highlights: {yields} An kind of environmentally benign organic composite additives is used firstly. {yields} The corrosion of zinc is inhibited used the organic compound as additive. {yields} The rate performance of the battery used the organic compound as additive is improved. {yields} The synergism of composite additives for zinc corrosion inhibition is investigated. - Abstract: The synergism of imidazole (IMZ) and poly(ethylene glycol) 600 (PEG) for zinc corrosion inhibition in 3 mol L{sup -1} KOH solution was investigated using a combination of electrochemical and gravimetric methods, and the surface morphology of the zinc was observed by scanning electron microscopy. It is found that there is a synergistic effect between IMZ and PEG for the zinc corrosion inhibition. The difference in molecular structure, ring for IMZ and chain for PEG, and in binding atoms with zinc, nitrogen in IMZ and oxygen in PEG, contributes to this synergistic effect. IMZ inhibits zinc corrosion by mainly depressing the anodic reaction, whereas PEG by depressing the cathodic reaction. The storage performance of the zinc-manganese dioxide batteries using IMZ and/or PEG as inhibitors was determined by discharge test, with a comparison of the battery using mercury as the inhibitor. The battery containing 0.05% IMZ + 0.05% PEG exhibits better performance than the mercury-containing battery, especially when discharged at high rate.

  4. Diffusion of calcium in pure and doped NaCl; Diffusion du calcium dans NaCl pur et dope

    Energy Technology Data Exchange (ETDEWEB)

    Slifkin, L; Brebec, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    We have determined, by diffusion experiments of Ca in pure and doped NaCl, the activation energy for the calcium jumps and the binding energy between calcium ion and vacancy. (authors) [French] Nous avons determine, par des mesures de diffusion du Ca dans NaCl pur et NaCl dope avec CaCl{sub 2}, l'energie d'activation relative aux sauts du calcium et l'energie de liaison lacune-calcium. (auteurs)

  5. Composite templates synthesis of mesoporous titania from industrial titanyl sulfate solution under external outfields

    International Nuclear Information System (INIS)

    Tian Congxue

    2008-01-01

    The precursors of mesoporous titania were synthesized via supra-molecular self-assembly route induced by composite templates (CTAB/P-123) from industrial titanyl sulfate solution under ultrasonic irradiation, microwave and hydrothermal condition. The hydrolysis and polycondensation rates of TiOSO 4 solution were controlled by adjusting the pH value at about 1.0. Mesoporous titania with anatase phase was obtained after templates removal by calcinations. The as-prepared powder was characterized by X-ray diffraction (XRD), N 2 isothermal adsorption-desorption, HRTEM and SAD. External outfields with enhancing polar action and soft hydrothermal condition were beneficial to prepare better mesoporous TiO 2 . Ultrasonic vibration promoted the formation of mesoporous structure. Under microwave irradiation, mesoporous TiO 2 was synthesized with BET specific surface area of 190.6 m 2 g -1 , average pore diameter of 2.57 nm and crystal size of 13.65 nm. And ultrasonic irradiation, microwave and hydrothermal conditions were making for forming and stabilizing the mesoporous structure

  6. Chemical bonding and the equilibrium composition of Grignard reagents in ethereal solutions.

    Science.gov (United States)

    Henriques, André M; Barbosa, André G H

    2011-11-10

    A thorough analysis of the electronic structure and thermodynamic aspects of Grignard reagents and its associated equilibrium composition in ethereal solutions is performed. Considering methylmagnesium halides containing fluorine, chlorine, and bromine, we studied the neutral, charged, and radical species associated with their chemical equilibrium in solution. The ethereal solvents considered, tetrahydrofuran (THF) and ethyl ether (Et(2)O), were modeled using the polarizable continuum model (PCM) and also by explicit coordination to the Mg atoms in a cluster. The chemical bonding of the species that constitute the Grignard reagent is analyzed in detail with generalized valence bond (GVB) wave functions. Equilibrium constants were calculated with the DFT/M06 functional and GVB wave functions, yielding similar results. According to our calculations and existing kinetic and electrochemical evidence, the species R(•), R(-), (•)MgX, and RMgX(2)(-) must be present in low concentration in the equilibrium. We conclude that depending on the halogen, a different route must be followed to produce the relevant equilibrium species in each case. Chloride and bromide must preferably follow a "radical-based" pathway, and fluoride must follow a "carbanionic-based" pathway. These different mechanisms are contrasted against the available experimental results and are proven to be consistent with the existing thermodynamic data on the Grignard reagent equilibria.

  7. Extremophiles in Mineral Sulphide Heaps: Some Bacterial Responses to Variable Temperature, Acidity and Solution Composition

    Directory of Open Access Journals (Sweden)

    Helen R. Watling

    2015-07-01

    Full Text Available In heap bioleaching, acidophilic extremophiles contribute to enhanced metal extraction from mineral sulphides through the oxidation of Fe(II and/or reduced inorganic sulphur compounds (RISC, such as elemental sulphur or mineral sulphides, or the degradation of organic compounds derived from the ore, biota or reagents used during mineral processing. The impacts of variable solution acidity and composition, as well as temperature on the three microbiological functions have been examined for up to four bacterial species found in mineral sulphide heaps. The results indicate that bacteria adapt to sufficiently high metal concentrations (Cu, Ni, Co, Zn, As to allow them to function in mineral sulphide heaps and, by engaging alternative metabolic pathways, to extend the solution pH range over which growth is sustained. Fluctuating temperatures during start up in sulphide heaps pose the greatest threat to efficient bacterial colonisation. The large masses of ores in bioleaching heaps mean that high temperatures arising from sulphide oxidation are hard to control initially, when the sulphide content of the ore is greatest. During that period, mesophilic and moderately thermophilic bacteria are markedly reduced in both numbers and activity.

  8. Energy stored in irradiated NaCl

    International Nuclear Information System (INIS)

    Lidiard, A.B.

    1979-01-01

    Recently reported measurements of the energy stored in heavily irradiated NaCl are reviewed in the light of recent understanding of radiation-damage processes in this material. It is shown that, in the ranges of temperatures and dose rates of these experiments, the F-centres produced by the irradiation are retained principally in the form of colloids: the stored energy is thus a direct measure of the number of F-centres retained in this form. Comparison of these results with the prediction of the recently proposed theory of colloid growth shows that the predictions of the dependence of colloid growth rates upon temperature and dose rate are qualitatively correct. The dependence of stored energy dose, however, appears to require the inclusion of a thermally activated back-reaction and possible modifications to the theory are briefly discussed. However, further experiments in this range of temperatures and dose rates are necessary for more quantitative tests of the theory. This reconsideration of the data does not alter the broad conclusion as to the relative insignificance of stored energy in a natural salt formation used as a radioactive waste repository, although more extensive measurements permitting a more exact test of theory would allow better predictions to be made for such applications. (author)

  9. Secretory NaCl and volume flow in renal tubules.

    Science.gov (United States)

    Beyenbach, K W

    1986-05-01

    This review attempts to give a retrospective survey of the available evidence concerning the secretion of NaCl and fluid in renal tubules of the vertebrate kidney. In the absence of glomerular filtration, epithelial secretory mechanisms, which to this date have not been elucidated, are responsible for the renal excretion of NaCl and water in aglomerular fish. However, proximal tubules isolated from glomerular fish kidneys of the flounder, killifish, and the shark also have the capacity to secrete NaCl and fluid. In shark proximal tubules, fluid secretion appears to be driven via secondary active transport of Cl. In another marine vertebrate, the sea snake, secretion of Na (presumably NaCl) and fluid is observed in freshwater-adapted and water-loaded animals. Proximal tubules of mammals can be made to secrete NaCl in vitro together with secretion of aryl acids. An epithelial cell line derived from dog kidney exhibits secondary active secretion of Cl when stimulated with catecholamines. Tubular secretion of NaCl and fluid may serve a variety of renal functions, all of which are considered here. The occurrence of NaCl and fluid secretion in glomerular proximal tubules of teleosts, elasmobranchs, and reptiles and in mammalian renal tissue cultures suggests that the genetic potential for NaCl secretion is present in every vertebrate kidney.

  10. Explosive phenomena in heavily irradiated NaCl

    NARCIS (Netherlands)

    denHartog, HW; Vainshtein, DI; Matthews, GE; Williams, RT

    1997-01-01

    In heavily irradiated NaCl crystals explosive phenomena can be initiated during irradiation or afterwards when samples are heated to temperatures between 100 and 250 degrees C. During irradiation of NaCl Na and Cl-2 precipitates and void structures are produced along with the accumulation of stored

  11. Preparation and application of attapulgite/iron oxide magnetic composites for the removal of U(VI) from aqueous solution

    International Nuclear Information System (INIS)

    Fan, Qiao-hui; Li, Ping; Chen, Yun-fei; Wu, Wang-suo

    2011-01-01

    Highlights: → We first synthesized ATP/IOM composites as an adsorbents for removal U(VI) from aqueous solution. → The sorption ability of ATP/IOM composites were obviously superior to ATP and iron oxides. → The prevalent species of U(VI) on ATP/IOM composites were =S s OUO 2 + and =S w OUO 2 (CO 3 ) 2 3- . → ATP/IOM composites could be a promising candidate for pre-concentration and immobilization of radionuclides from large volumes of aqueous solutions. - Abstract: Recently, magnetic sorbents have received considerable attention because of their excellent segregative features and sorption capacities. Herein, attapulgite/iron oxide magnetic (ATP/IOM) composites were prepared and characterized. The sorption results indicated that ATP/IOM composites were superior to ATP and iron oxides individually for the removal of U(VI) from aqueous solution. Based on X-ray photoelectron spectroscopy (XPS) analysis and surface complexation model, the main sorption species of U(VI) on ATP were =X 2 UO 2 0 below pH 4.0 and =S s OUO 2 + , =S w OUO 2 CO 3 - , and =S w OUO 2 (CO 3 ) 2 3- above pH 5.0. However the prevalent species on ATP/IOM composites were =S s OUO 2 + and =S w OUO 2 (CO 3 ) 2 3- over the observed pH range. ATP/IOM composites are a promising candidate for pre-concentration and immobilization of radionuclides from large volumes of aqueous solutions, as required for remediation purposes.

  12. A New Class of Ternary Compound for Lithium-Ion Battery: from Composite to Solid Solution.

    Science.gov (United States)

    Wang, Jiali; Wu, Hailong; Cui, Yanhua; Liu, Shengzhou; Tian, Xiaoqing; Cui, Yixiu; Liu, Xiaojiang; Yang, Yin

    2018-02-14

    Searching for high-performance cathode materials is a crucial task to develop advanced lithium-ion batteries (LIBs) with high-energy densities for electrical vehicles (EVs). As a promising lithium-rich material, Li 2 MnO 3 delivers high capacity over 200 mAh g -1 but suffers from poor structural stability and electronic conductivity. Replacing Mn 4+ ions by relatively larger Sn 4+ ions is regarded as a possible strategy to improve structural stability and thus cycling performance of Li 2 MnO 3 material. However, large difference in ionic radii of Mn 4+ and Sn 4+ ions leads to phase separation of Li 2 MnO 3 and Li 2 SnO 3 during high-temperature synthesis. To prepare solid-solution phase of Li 2 MnO 3 -Li 2 SnO 3 , a buffer agent of Ru 4+ , whose ionic radius is in between that of Mn 4+ and Sn 4+ ions, is introduced to assist the formation of a single solid-solution phase. The results show that the Li 2 RuO 3 -Li 2 MnO 3 -Li 2 SnO 3 ternary system evolves from mixed composite phases into a single solid-solution phase with increasing Ru content. Meanwhile, discharge capacity of this ternary system shows significantly increase at the transformation point which is ascribed to the improvement of Li + /e - transportation kinetics and anionic redox chemistry for solid-solution phase. The role of Mn/Sn molar ratio of Li 2 RuO 3 -Li 2 MnO 3 -Li 2 SnO 3 ternary system has also been studied. It is revealed that higher Sn content benefits cycling stability of the system because Sn 4+ ions with larger sizes could partially block the migration of Mn 4+ and Ru 4+ from transition metal layer to Li layer, thus suppressing structural transformation of the system from layered-to-spinel phase. These findings may enable a new route for exploring ternary or even quaternary lithium-rich cathode materials for LIBs.

  13. Effects of exogenous salinity (NaCl) gradient on Cd release in acidified contaminated brown soil

    Science.gov (United States)

    Zhang, Lina; Rong, Yong; Mao, Li; Gao, Zhiyuan; Liu, Xiaoyu; Dong, Zhicheng

    2018-02-01

    Taking acidified Cd contaminated brown soil in Yantai as the research object, based on different exogenous salinity (NaCl) gradient (0%, 0.3%, 0.6%, 0.9%, 1.5%, 2% and 5%), indoor simulation experiments of Cd release were carried out after field investigation. Results showed that there was a significantly positive relation (r>0.90) between Cd release concentration/amount/ratio and exogenous salt (NaCl). Besides, the more exogenous salt (NaCl) was added; maximum release concentration/amount of Cd appeared the earlier. It was found that exogenous salt (NaCl) addition could obviously promote Cd release from acidified Cd contaminated brown soil. It was believed that this could be mainly due to the cation exchange between Cd2+ and Na+, together with the dissociation and/or complexation between Cl- and Cd2+. In addition, available adsorption sites reduction by exchange base in soil causing Cd changed from solid state to soil solution was also a probable reason.

  14. Combinations of nisin with salt (NaCl) to control Listeria ...

    African Journals Online (AJOL)

    This study evaluated the effect of combinations of nisin with salt (NaCl) to control Listeria monocytogenes on sheep natural sausage casings. Casings were inoculated with 3.0 x 105 cfu/g final inocula of L. monocytogenes, stored at 6°C in different solutions of nisin at 0, 100, 150 and 200 ìg/g. Each combined with salt at 0, 4, ...

  15. Titanium Implant Osseointegration Problems with Alternate Solutions Using Epoxy/Carbon-Fiber-Reinforced Composite

    Directory of Open Access Journals (Sweden)

    Richard C. Petersen

    2014-12-01

    Full Text Available The aim of the article is to present recent developments in material research with bisphenyl-polymer/carbon-fiber-reinforced composite that have produced highly influential results toward improving upon current titanium bone implant clinical osseointegration success. Titanium is now the standard intra-oral tooth root/bone implant material with biocompatible interface relationships that confer potential osseointegration. Titanium produces a TiO2 oxide surface layer reactively that can provide chemical bonding through various electron interactions as a possible explanation for biocompatibility. Nevertheless, titanium alloy implants produce corrosion particles and fail by mechanisms generally related to surface interaction on bone to promote an inflammation with fibrous aseptic loosening or infection that can require implant removal. Further, lowered oxygen concentrations from poor vasculature at a foreign metal surface interface promote a build-up of host-cell-related electrons as free radicals and proton acid that can encourage infection and inflammation to greatly influence implant failure. To provide improved osseointegration many different coating processes and alternate polymer matrix composite (PMC solutions have been considered that supply new designing potential to possibly overcome problems with titanium bone implants. Now for important consideration, PMCs have decisive biofunctional fabrication possibilities while maintaining mechanical properties from addition of high-strengthening varied fiber-reinforcement and complex fillers/additives to include hydroxyapatite or antimicrobial incorporation through thermoset polymers that cure at low temperatures. Topics/issues reviewed in this manuscript include titanium corrosion, implant infection, coatings and the new epoxy/carbon-fiber implant results discussing osseointegration with biocompatibility related to nonpolar molecular attractions with secondary bonding, carbon fiber in vivo

  16. Textile Dye Removal from Aqueous Solution using Modified Graphite Waste/Lanthanum/Chitosan Composite

    Science.gov (United States)

    Kusrini, E.; Wicaksono, B.; Yulizar, Y.; Prasetyanto, EA; Gunawan, C.

    2018-03-01

    We investigated various pre-treatment processes of graphite waste using thermal, mechanical and chemical methods. The aim of this work is to study the performance of modified graphite waste/lanthanum/chitosan composite (MG) as adsorbent for textile dye removal from aqueous solution. Effect of graphite waste resources, adsorbent size and lanthanum concentration on the dye removal were studied in batch experiments. Selectivity of MG was also investigated. Pre-heated graphite waste (NMG) was conducted at 80°C for 1 h, followed by mechanical crushing of the resultant graphite to 75 μm particle size, giving adsorption performance of ˜58%, ˜67%, ˜93% and ˜98% of the model dye rhodamine B (concentration determined by UV-vis spectroscopy at 554 nm), methyl orange (464 nm), methylene blue (664 nm) and methyl violet (580 nm), respectively from aqueous solution. For this process, the system required less than ˜5 min for adsorbent material to be completely saturated with the adsorbate. Further chemical modification of the pre-treated graphite waste (MG) with lanthanum (0.01 – V 0.03 M) and chitosan (0.5% w/w) did not improve the performance of dye adsorption. Under comparable experimental conditions, as those of the ‘thermal-mechanical-pre-treated-only’ (NMG), modification of graphite waste (MG) with 0.03 M lanthanum and 0.5% w/w chitosan resulted in ˜14%, ˜47%, ˜72% and ˜85% adsorption of rhodamine B, methyl orange, methylene blue and methyl violet, respectively. Selective adsorption of methylene blue at most to ˜79%, followed by methyl orange, methyl violet and rhodamine B with adsorption efficiency ˜67, ˜38, and ˜9% sequentially using MG with 0.03 M lanthanum and 0.5% w/w chitosan.

  17. Variations in the chemical composition of the solution extracted from a Latosol under fertigation with vinasse

    Directory of Open Access Journals (Sweden)

    João Paulo Francisco

    2016-06-01

    Full Text Available ABSTRACT The aim of this work was to evaluate the change in electrical conductivity and pH of a soil solution and its composition, with regard to the levels of nitrate and potassium, in a Latosol cultivated with pineapple and subjected to applications of different levels of vinasse. The experiment was conducted in a greenhouse at the Department of Biosystems Engineering of ESALQ/USP. The treatments comprised the application of five levels of vinasse: T1 - 0 m3 ha-1, T2 - 231 m3 ha-1, T3 - 347 m3 ha-1, T4 - 462 m3 ha-1, and T5 - 578 m3 ha-1. Application was every 20 days, using a localised irrigation system with emitters having a nominal flow rate of 4 L h-1 and spaced 0.40 m apart. The applied doses of vinasse were calculated by following the recommendations of CETESB standard P4.231, so that treatment T4 would supply the demand of the pineapple plant for potassium. The solution was collected by means of porous capsule extractors at 30, 120 and 210 days from the start of vinasse application. It was found that increases in the volume of the applied levels resulted in greater values for the electrical conductivity of the soil (ECs and in the concentration of potassium (K and nitrate (NO3, with higher values being obtained in the 0.20 m layer. The results demonstrated that pH decreased with increases in the vinasse being applied.

  18. Driving High-Performance n- and p-type Organic Transistors with Carbon Nanotube/Conjugated Polymer Composite Electrodes Patterned Directly from Solution

    KAUST Repository

    Hellstrom, Sondra L.; Jin, Run Zhi; Stoltenberg, Randall M.; Bao, Zhenan

    2010-01-01

    We report patterned deposition of carbon nanotube/conjugated polymer composites from solution with high nanotube densities and excellent feature resolution. Such composites are suited for use as electrodes in high-performance transistors

  19. Solution processed ternary blend nano-composite charge regulation layer to enhance inverted OLED performances

    Science.gov (United States)

    Kaçar, Rifat; Mucur, Selin Pıravadılı; Yıldız, Fikret; Dabak, Salih; Tekin, Emine

    2018-04-01

    Inverted bottom-emission organic light emitting diodes (IBOLEDs) have attracted increasing attention due to their exceptional air stability and applications in active-matrix displays. For gaining high IBOLED device efficiencies, it is crucial to develop an effective strategy to make the bottom electrode easy for charge injection and transport. Charge selectivity, blocking the carrier flow towards the unfavourable side, plays an important role in determining charge carrier balance and accordingly radiative recombination efficiency. It is therefore highly desirable to functionalize an interfacial layer which will perform many different tasks simultaneously. Here, we contribute to the hole-blocking ability of the zinc oxide/polyethyleneimine (ZnO:PEI) nano-composite (NC) interlayer with the intention of increasing the OLED device efficiency. With this purpose in mind, a small amount of 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi) was added as a hole-blocking molecule into the binary blend of ZnO and PEI solution. The device with a ternary ZnO:PEI:TPBi NC interlayer achieved a maximum current efficiency of 38.20 cd A-1 and a power efficiency of 34.29 lm W-1 with a luminance of 123 200 cd m-2, which are high performance parameters for inverted device architecture. The direct comparisons of device performances incorporating ZnO only, ZnO/PEI bilayers, and ZnO:PEI binary NC counterparts were also performed, which shed light on the origin of device performance enhancement.

  20. Effect of solvent composition on the limiting current of anodic dissolution of tungsten in aqueous-ethanol solutions of alkali

    International Nuclear Information System (INIS)

    Konoplyantseva, N.A.; L'vova, L.A.; Davydov, A.D.; AN SSSR, Moscow. Inst. Ehlektrokhimii)

    1987-01-01

    The effect of quantitative composition of solvent on tungsten anodic dissolution in aqueous-ethanol solutions of KOH is studied. It is shown that with an increase in ethanol content in aqueous-ethanol solutions of alkali the limiting current of tungsten anodic dissolution decreases. An increase in KOH concentration in certain limits (in ethanol solutions it is the range between 0.75 and 1.0 M KOH) results in the increase of the limiting current; with further increase in solution concentration the limiting current decreases, which can be related to the change of the limiting stage. An assumption is made that total reaction of tungsten anodic dissolution and the main reasons for the limiting current appearance do not change from aqueous to aqueous-ethanol and ethanol solutions of alkali

  1. Chemical composition of the humus layer, mineral soil and soil solution of 150 forest stands in the Netherlands in 1990

    NARCIS (Netherlands)

    Vries, de W.; Leeters, E.E.J.M.

    2001-01-01

    A nationwide assessment of the chemical composition of the humus layer, mineral topsoil (0-30 cm) and soil solution in both topsoil and subsoil (60-100 cm) was made for 150 forest stands in the year 1990. The stands, which were part of the national forest inventory on vitality, included seven tree

  2. Chemical composition of the humus layer, mineral soil and soil solution of 200 forest stands in the Netherlands in 1995

    NARCIS (Netherlands)

    Leeters, E.E.J.M.; Vries, de W.

    2001-01-01

    A nationwide assessment of the chemical composition of the soil solid phase and the soil solution in the humus layer and two mineral layers (0-10 cm and 10-30 cm) was made for 200 forest stands in the year 1995. The stands were part of the national forest inventory on vitality, included seven tree

  3. Visualization of Problem Solving Related to the Quantitative Composition of Solutions in the Dynamic "GeoGebra" Environment

    Science.gov (United States)

    Kostic, V. Dj.; Jovanovic, V. P. Stankov; Sekulic, T. M.; Takaci, Dj. B.

    2016-01-01

    Problem solving in the field of quantitative composition of solutions (QCS), expressed as mass share and molar concentration, is essential for chemistry students. Since successful chemistry education is based on different mathematical contents, it is important to be proficient in both mathematical and chemistry concepts as well as interconnections…

  4. Possibilities of application of perfect solution model to calculation of equilibrium composition of complex carbonitrides and their solubility in steels

    International Nuclear Information System (INIS)

    Gol'dshtejn, M.I.; Popov, V.V.; Cheremnykh, V.G.

    1980-01-01

    Using the Fe-Nb-V-C-N and Fe-Ti-V-C-N systems' low carbon steels, the earlier suggested model of perfect solid solutions has been experimentally researched. Also studied has been the feasibility to calculate the composition of carbonitrides in steels by the derived equations, that comprise, as parameters, products of respective compounds' solubility and coefficients of components interaction in iron-based solid solutions. A conclusion is drawn that perfect solutions models may be used adequately for complex carbonitrides like Nbsub(p)Vsub(1-p)Csub(q)Nsub(1-q) and Tisub(p)Vsub(1-p)Csub(q)Nsub(1-q) during the calculations of their equilibrium composition and solubility in steels

  5. Effects of atmospheric deposition nitrogen flux and its composition on soil solution chemistry from a red soil farmland, southeast China.

    Science.gov (United States)

    Cui, Jian; Zhou, Jing; Peng, Ying; Chan, Andrew; Mao, Jingdong

    2015-12-01

    A detailed study on the solution chemistry of red soil in South China is presented. Data are collected from two simulated column-leaching experiments with an improved setup to evaluate the effects of atmospheric N deposition (ADN) composition and ADN flux on agricultural soil acidification using a (15)N tracer technique and an in situ soil solution sampler. The results show that solution pH values decline regardless of the increase of the NH4(+)/NO3(-) ratio in the ADN composition or ADN flux, while exchangeable Al(3+), Ca(2+), Mg(2+), and K(+) concentrations increase at different soil depths (20, 40, and 60 cm). Compared with the control, ADN (60 kg per ha per year N, NH4(+)/NO3(-) ratio of 2 : 1) decreases solution pH values, increases solution concentrations of NO3(-)-N, Al(3+), Ca(2+) and Mg(2+) at the middle and lower soil depths, and promotes their removal. NH4(+)-N was not detected in red soil solutions of all the three soil layers, which might be attributed to effects of nitrification, absorption and fixation in farmland red soil. Some of the NO3(-)-N concentrations at 40-60 cm soil depth exceed the safe drinking level of 10 mg L(-1), especially when the ADN flux is beyond 60 kg ha(-1) N. These features are critical for understanding the ADN agro-ecological effects, and for future assessment of ecological critical loads of ADN in red soil farmlands.

  6. Experimental Determination of Solubilities of Tri-calcium Di-Citrate Tetrahydrate [Ca3[C3H5O(COO)3]2•4H2O] Earlandite in NaCl and MgCl2 Solutions to High Ionic Strengths and Its Pitzer Model: Applications to Nuclear Waste Isolation and Other Low Temperature Environments

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Yongliang [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Kirkes, Leslie Dawn [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Westfall, Terry [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Marrs, Cassandra [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Knox, Jandi [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Burton, Heather Lynn [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group

    2017-09-01

    In this study, solubility measurements on tri-calcium di-citrate tetrahydrate [Ca3[C3H5O(COO)3]2•4H2O, abbreviated as Ca3[Citrate]2•4H2O] as a function of ionic strength are conducted in NaCl solutions up to I = 5.0 mol•kg–1 and in MgCl2 solutions up to I = 7.5 mol•kg–1, at room temperature (22.5 ± 0.5°C). The solubility constant (log K$0\\atop{sp}$) for Ca3[Citrate]2•4H2O and formation constant (logβ$0\\atop{1}$) for Ca[C3H5O(COO)3]Ca3[C3H5O(COO)3]2•4H2O (earlandite) = 3Ca2+ + 2[C3H5O(COO)3]3– + 4H2O (1) Ca2+ + [C3H5O(COO)3]3– = Ca[C3H5O(COO)3] (2) are determined as –18.11 ± 0.05 and 4.97 ± 0.05, respectively, based on the Pitzer model with a set of Pitzer parameters describing the specific interactions in NaCl and MgCl2 media.

  7. Solution processable RGO-CdZnS composite for solar light responsive photocatalytic degradation of 4-Nitrophenol

    Science.gov (United States)

    Ibrahim, Sk; Chakraborty, Koushik; Pal, Tanusri; Ghosh, Surajit

    2017-05-01

    We report the one pot single step synthesis and characterization of solution processable reduced graphene oxide (RGO) - cadmium zinc sulfide (CdZnS) nanocomposite materials. The composite was characterized structurally and morphologically by XRD and TEM studies. The reduction of GO in RGO-CdZnS composite, was confirmed by XPS and Raman spectroscopy. The photocatalytic activity of the RGO-CdZnS composite was investigated towards the degradation of 4-Nitrophenol. A notable increase of photocatalytic efficiency of RGO-CdZnS compare to controlled CdZnS was observed. Here RGO plays a crucial role to efficient photo induced charge separation from the CdZnS, and decreases the electron-hole recombination probability and subsequently enhanced the photocatalytic activity of the RGO-CdZnS composite material under simulated solar light irradiation. This work highlights the potential application of RGO-based materials in the field of photocatalytic degradation of organic water pollutant.

  8. Polishing large NaCl windows on a continuous polisher

    International Nuclear Information System (INIS)

    Williamson, R.

    1979-01-01

    The Helios and Antares CO 2 fusion laser systems incorporate numerous large sodium chloride windows. These must be refinished periodically, making necessary a consistent and predictable polishing capability. A continuous polisher (or annular lap) which might at Kirtland's Developmental Optical Facility. Large NaCl windows had not been polished on this type of machine. The machine has proven itself capable of producing lambda/16 figures at 633 nm (HeNe) with extremely smooth surfaces on glass. Since then, we have been working exclusively on NaCl optics. Due to different polishing parameters between NaCl and glass, and the slight solubility of the pitch in the slurry, this phase presents new problems. The work on glass will be reviewed. Results on NaCl to date will be reported. The potential of this type of machine relative to prisms, thin and irregularly shaped optics will be discussed

  9. Effects of different NaCl Concentrations on germination and ...

    African Journals Online (AJOL)

    USER

    Salinity refers to the salt content of any given system. By nature, arid .... Effect of varying concentrations of NaCl on seed germination of Amaranthus hybridus in percentages. .... Osmotic differences could explain this phenomenon where by ...

  10. An Analytical Solution for Transient Heat Conduction in a Composite Slab with Time-Dependent Heat Transfer Coefficient

    Directory of Open Access Journals (Sweden)

    Ryoichi Chiba

    2018-01-01

    Full Text Available An analytical solution is derived for one-dimensional transient heat conduction in a composite slab consisting of n layers, whose heat transfer coefficient on an external boundary is an arbitrary function of time. The composite slab, which has thermal contact resistance at n-1 interfaces, as well as an arbitrary initial temperature distribution and internal heat generation, convectively exchanges heat at the external boundaries with two different time-varying surroundings. To obtain the analytical solution, the shifting function method is first used, which yields new partial differential equations under conventional types of external boundary conditions. The solution for the derived differential equations is then obtained by means of an orthogonal expansion technique. Numerical calculations are performed for two composite slabs, whose heat transfer coefficient on the heated surface is either an exponential or a trigonometric function of time. The numerical results demonstrate the effects of temporal variations in the heat transfer coefficient on the transient temperature field of composite slabs.

  11. Preparation of Organic/Inorganic Siloxane Composite Membranes and Concentration of n-butanol from ABE Solution by Pervaporation

    Energy Technology Data Exchange (ETDEWEB)

    Jee, Ki Yong; Lee, Yong Taek [Kyung Hee University, Yongin (Korea, Republic of)

    2013-10-15

    In this paper, polymer composite membranes and ceramic composite membranes were prepared in order to compare differences in pervaporation performances relative to the support layers. PVDF was used for the polymer support layers, and a-Al{sub 2}O{sub 3} was used for the ceramic support layers. For active layer was coated for PDMS, which is a rubbery polymer. The characterization of membranes were analysed by SEM, contact angle, and XPS. We studied performances relative to the composite membrane support layers in the ABE mixture solutions. The results of the pervaporation, the flux of the ceramic composite membrane was shown to be 250.87 g/m{sup 2}h, which was higher than that of polymer composite membranes, at 195.64 g/m{sup 2}h. However, it was determined that the separation factor of the polymer composite membranes was 31.98 which were higher than that of the ceramic composite membranes, at 20.66.

  12. The Interaction between Zein and Lecithin in Ethanol-Water Solution and Characterization of Zein?Lecithin Composite Colloidal Nanoparticles

    OpenAIRE

    Dai, Lei; Sun, Cuixia; Wang, Di; Gao, Yanxiang

    2016-01-01

    Lecithin, a naturally small molecular surfactant, which is widely used in the food industry, can delay aging, enhance memory, prevent and treat diabetes. The interaction between zein and soy lecithin with different mass ratios (20:1, 10:1, 5:1, 3:1, 2:1, 1:1 and 1:2) in ethanol-water solution and characterisation of zein and lecithin composite colloidal nanoparticles prepared by antisolvent co-precipitation method were investigated. The mean size of zein-lecithin composite colloidal nanoparti...

  13. Synthesis and highly visible-induced photocatalytic activity of CNT-CdSe composite for methylene blue solution

    Directory of Open Access Journals (Sweden)

    Chen Ming-Liang

    2011-01-01

    Full Text Available Abstract Carbon nanotube-cadmium selenide (CNT-CdSe composite was synthesized by a facile hydrothermal method derived from multi-walled carbon nanotubes as a stating material. The as-prepared products were characterized by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy (TEM, and UV-vis diffuse reflectance spectrophotometer. The as-synthesized CNT-CdSe composite efficiently catalyzed the photodegradation of methylene blue in aqueous solutions under visible-light irradiation, exhibiting higher photocatalytic activity.

  14. The combined effect of food-simulating solutions, brushing and staining on color stability of composite resins

    Science.gov (United States)

    Silva, Tânia Mara Da; Sales, Ana Luísa Leme Simões; Pucci, Cesar Rogerio; Borges, Alessandra Bühler; Torres, Carlos Rocha Gomes

    2017-01-01

    Abstract Objective: This study evaluated the effect of food-simulating media associated with brushing and coffee staining on color stability of different composite resins. Materials and methods: Eighty specimens were prepared for each composite: Grandio SO (Voco), Amaris (Voco), Filtek Z350XT (3M/ESPE), Filtek P90 (3M/ESPE). They were divided into four groups according to food-simulating media for 7 days: artificial saliva (control), heptane, citric acid and ethanol. The composite surface was submitted to 10,950 brushing cycles (200 g load) in an automatic toothbrushing machine. The specimens were darkened with coffee solution at 37 °C for 24 h. After each treatment, color measurements were assessed by spectrophotometry, using CIE L*a*b* system. The overall color change (ΔE) was determined for each specimen at baseline (C1) and after the treatments (food-simulating media immersion/C2, brushing/C3 and dye solution/C4). Data were analyzed by two-way repeated measures ANOVA and Tukey’s tests (p composites (p = .001), time (p = .001) and chemical degradation (p = .002). The mean of ΔE for composites were: Z350XT (5.39)a, Amaris (3.89)b, Grandio (3.75)bc, P90 (3.36)c. According to food-simulating media: heptane (4.41)a, citric acid (4.24)a, ethanol (4.02)ab, artificial saliva (3.76)b. For the treatments: dye solution (4.53)a, brushing (4.26)a, after food-simulating media (3.52)b. Conclusions: The composite resin Filtek Z350XT showed significantly higher staining than all other composite resin tested. The immersion in heptane and citric acid produced the highest color alteration than other food-simulating media. The exposure of samples to brushing protocols and darkening in coffee solution resulted in significant color alteration of the composite resins. PMID:28642926

  15. Effect of liquid oil additive on lithium-ion battery ceramic composite separator prepared with an aqueous coating solution

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Woo [Division of Advanced Materials Engineering, Kongju National University, 1223–24, Cheonan-daero, Cheonan, Chungnam, 31080 (Korea, Republic of); Ryou, Myung-Hyun [Department of Chemical & Biological Engineering, Hanbat National University, 125, Dongseodaero, Yuseong-gu, Daejeon, 34158 (Korea, Republic of); Lee, Yong Min, E-mail: yongmin.lee@hanbat.ac.kr [Department of Chemical & Biological Engineering, Hanbat National University, 125, Dongseodaero, Yuseong-gu, Daejeon, 34158 (Korea, Republic of); Cho, Kuk Young, E-mail: kycho@hanyang.ac.kr [Department of Materials Science and Chemical Engineering, Hanyang University, 55, Hanyangdaehak-ro, Sangrok-gu, Ansan, Gyeonggi-do, 15588 (Korea, Republic of)

    2016-08-05

    Ceramic composite separators (CCSs) play a critical role in ensuring safety for lithium-ion batteries (LIBs), especially for mid- and large-sized devices. However, production of CCSs using organic solvents has some cost and environmental concerns. An aqueous process for fabricating CCSs is attractive because of its cost-effectiveness and environmental-friendliness because organic solvents are not used. The success of an aqueous coating system for LIBs is dependent upon minimizing moisture content, as moisture has a negatively impact on LIB performance. In this study, CCSs were fabricated using an aqueous coating solution containing Al{sub 2}O{sub 3} and an acrylic binder. Compared with polyethylene (PE) separators, CCSs coated with an aqueous coating solution showed improved thermal stability, electrolyte uptake, puncture strength, ionic conductivity, and rate capability. In addition, our new approach of introducing a small amount of an oily liquid to the aqueous coating solution reduced the water adsorption by 11.7% compared with coatings that do not contain the oily liquid additive. - Highlights: • Ceramic composite separator is fabricated using aqueous coating process. • Coated separator showed enhanced mechanical and thermal stability. • Liquid oil additive in coating solution reduce moisture reabsorption of separator. • Oil additive in aqueous coating solution does not deteriorate LIB performance.

  16. Chemically and compositionally modified solid solution disordered multiphase nickel hydroxide positive electrode for alkaline rechargeable electrochemical cells

    Science.gov (United States)

    Ovshinsky, Stanford R.; Corrigan, Dennis; Venkatesan, Srini; Young, Rosa; Fierro, Christian; Fetcenko, Michael A.

    1994-01-01

    A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.

  17. The Interaction between Zein and Lecithin in Ethanol-Water Solution and Characterization of Zein–Lecithin Composite Colloidal Nanoparticles

    Science.gov (United States)

    Dai, Lei; Sun, Cuixia; Wang, Di; Gao, Yanxiang

    2016-01-01

    Lecithin, a naturally small molecular surfactant, which is widely used in the food industry, can delay aging, enhance memory, prevent and treat diabetes. The interaction between zein and soy lecithin with different mass ratios (20:1, 10:1, 5:1, 3:1, 2:1, 1:1 and 1:2) in ethanol-water solution and characterisation of zein and lecithin composite colloidal nanoparticles prepared by antisolvent co-precipitation method were investigated. The mean size of zein-lecithin composite colloidal nanoparticles was firstly increased with the rise of lecithin concentration and then siginificantly decreased. The nanoparticles at the zein to lecithin mass ratio of 5:1 had the largest particle size (263 nm), indicating that zein and lecithin formed composite colloidal nanoparticles, which might aggregate due to the enhanced interaction at a higher proportion of lecithin. Continuing to increase lecithin concentration, the zein-lecithin nanoparticles possibly formed a reverse micelle-like or a vesicle-like structure with zein in the core, which prevented the formation of nanoparticle aggregates and decreased the size of composite nanoparticles. The presence of lecithin significantly reduced the ζ-potential of zein-lecithin composite colloidal nanoparticles. The interaction between zein and lecithin enhanced the intensity of the fluorescence emission of zein in ethanol-water solution. The secondary structure of zein was also changed by the addition of lecithin. Differential scanning calorimetry thermograms revealed that the thermal stability of zein-lecithin nanoparticles was enhanced with the rise of lecithin level. The composite nanoparticles were relatively stable to elevated ionic strengths. Possible interaction mechanism between zein and lecithin was proposed. These findings would help further understand the theory of the interaction between the alcohol soluble protein and the natural small molecular surfactant. The composite colloidal nanoparticles formed in this study can

  18. The Interaction between Zein and Lecithin in Ethanol-Water Solution and Characterization of Zein-Lecithin Composite Colloidal Nanoparticles.

    Science.gov (United States)

    Dai, Lei; Sun, Cuixia; Wang, Di; Gao, Yanxiang

    2016-01-01

    Lecithin, a naturally small molecular surfactant, which is widely used in the food industry, can delay aging, enhance memory, prevent and treat diabetes. The interaction between zein and soy lecithin with different mass ratios (20:1, 10:1, 5:1, 3:1, 2:1, 1:1 and 1:2) in ethanol-water solution and characterisation of zein and lecithin composite colloidal nanoparticles prepared by antisolvent co-precipitation method were investigated. The mean size of zein-lecithin composite colloidal nanoparticles was firstly increased with the rise of lecithin concentration and then siginificantly decreased. The nanoparticles at the zein to lecithin mass ratio of 5:1 had the largest particle size (263 nm), indicating that zein and lecithin formed composite colloidal nanoparticles, which might aggregate due to the enhanced interaction at a higher proportion of lecithin. Continuing to increase lecithin concentration, the zein-lecithin nanoparticles possibly formed a reverse micelle-like or a vesicle-like structure with zein in the core, which prevented the formation of nanoparticle aggregates and decreased the size of composite nanoparticles. The presence of lecithin significantly reduced the ζ-potential of zein-lecithin composite colloidal nanoparticles. The interaction between zein and lecithin enhanced the intensity of the fluorescence emission of zein in ethanol-water solution. The secondary structure of zein was also changed by the addition of lecithin. Differential scanning calorimetry thermograms revealed that the thermal stability of zein-lecithin nanoparticles was enhanced with the rise of lecithin level. The composite nanoparticles were relatively stable to elevated ionic strengths. Possible interaction mechanism between zein and lecithin was proposed. These findings would help further understand the theory of the interaction between the alcohol soluble protein and the natural small molecular surfactant. The composite colloidal nanoparticles formed in this study can

  19. Liquid Scintillation Counting Standardization of {sup 2}2NaCl by te CIEMAT/NIST method; Calibracion por Centelleo Liquido del ''22NaCl, mediante el metodo CIEMAT/NIST

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Grau Carles, A.; Grau Malonda, A.

    1995-07-01

    We describe a procedure for preparing a stable solution of ''22NaCl for liquid scintillation counting and its counting stability and spectral evolution in Insta-Gel''R is studied. The solution has been standardised in terms of activity concentration by the CIEMAT/NIST method with discrepancies between experimental and computed efficiencies lower than 0.4 % and an overall uncertainty of 0.35 %. (Author) 4 refs.

  20. Pore solution in alkali-activated slag cement pastes. Relation to the composition and structure of calcium silicate hydrate

    International Nuclear Information System (INIS)

    Puertas, F.; Fernandez-Jimenez, A.; Blanco-Varela, M.T.

    2004-01-01

    In this work, the relationship between the composition of pore solution in alkali-activated slag cement (AAS) pastes activated with different alkaline activator, and the composition and structure of the main reaction products, has been studied. Pore solution was extracted from hardened AAS pastes. The analysis of the liquids was performed through different techniques: Na, Mg and Al by atomic absorption (AA), Ca ions by ionic chromatography (IC) and Si by colorimetry; pH was also determined. The solid phases were analysed by XRD, FTIR, solid-state 29 Si and 27 Al NMR and BSE/EDX. The most significant changes in the ionic composition of the pore solution of the AAS pastes activated with waterglass take place between 3 and 24 h of reaction. These changes are due to the decrease of the Na content and mainly to the Si content. Results of 29 Si MAS NMR and FTIR confirm that the activation process takes place with more intensity after 3 h (although at this age, Q 2 units already exist). The pore solution of the AAS pastes activated with NaOH shows a different evolution to this of pastes activated with waterglass. The decrease of Na and Si contents progresses with time. The nature of the alkaline activator influences the structure and composition of the calcium silicate hydrate formed as a consequence of the alkaline activation of the slag. The characteristic of calcium silicate hydrate in AAS pastes activated with waterglass is characterised by a low structural order with a low Ca/Si ratio. Besides, in this paste, Q 3 units are detected. The calcium silicate hydrate formed in the pastes activated with NaOH has a higher structural order (higher crystallinity) and contains more Al in its structure and a higher Ca/Si ratio than those obtained with waterglass

  1. Adsorption of Pb(II) from aqueous solution using a magnetic chitosan/graphene oxide composite and its toxicity studies.

    Science.gov (United States)

    Melvin Samuel, S; Shah, Sk Sheriff; Bhattacharya, Jayanta; Subramaniam, Kalidass; Pradeep Singh, N D

    2018-05-02

    This study involves the adsorption of lead using magnetic chitosan/graphene oxide (MCGO) composite material in batch mode. The MCGO composite material was synthesized via modified Hummers method. The MCGO composite material was characterized by powder x-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Tunnelling electron microscopy (TEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) and UV-vis diffusive reflectance spectra. The adsorption mechanism of MCGO composite material was well described by Langmuir isotherm and pseudo second order kinetic model, with a high regression coefficient (composite material was applied for the removal of lead metal from aqueous solution. We have also evaluated toxicity of synthesized MCGO composite material by examining on A549 cells. The results have shown that MCGO material showed viable cell percentage of 53.7% at 50 μg and 44.8% at 100 μg. Copyright © 2017. Published by Elsevier B.V.

  2. Rapid removal of uranium from aqueous solutions using magnetic Fe3O4@SiO2 composite particles.

    Science.gov (United States)

    Fan, Fang-Li; Qin, Zhi; Bai, Jing; Rong, Wei-Dong; Fan, Fu-You; Tian, Wei; Wu, Xiao-Lei; Wang, Yang; Zhao, Liang

    2012-04-01

    Rapid removal of U(VI) from aqueous solutions was investigated using magnetic Fe(3)O(4)@SiO(2) composite particles as the novel adsorbent. Batch experiments were conducted to study the effects of initial pH, amount of adsorbent, shaking time and initial U(VI) concentrations on uranium sorption efficiency as well as the desorbing of U(VI). The sorption of uranium on Fe(3)O(4)@SiO(2) composite particles was pH-dependent, and the optimal pH was 6.0. In kinetics studies, the sorption equilibrium can be reached within 180 min, and the experimental data were well fitted by the pseudo-second-order model, and the equilibrium sorption capacities calculated by the model were almost the same as those determined by experiments. The Langmuir sorption isotherm model correlates well with the uranium sorption equilibrium data for the concentration range of 20-200 mg/L. The maximum uranium sorption capacity onto magnetic Fe(3)O(4)@SiO(2) composite particles was estimated to be about 52 mg/g at 25 °C. The highest values of uranium desorption (98%) was achieved using 0.01 M HCl as the desorbing agent. Fe(3)O(4)@SiO(2) composite particles showed a good selectivity for uranium from aqueous solution with other interfering cation ions. Present study suggested that magnetic Fe(3)O(4)@SiO(2) composite particles can be used as a potential adsorbent for sorption uranium and also provided a simple, fast separation method for removal of heavy metal ion from aqueous solution. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Highly porous open cell Ti-foam using NaCl as temporary space holder through powder metallurgy route

    International Nuclear Information System (INIS)

    Jha, Nidhi; Mondal, D.P.; Dutta Majumdar, J.; Badkul, Anshul; Jha, A.K.; Khare, A.K.

    2013-01-01

    Highlights: ► NaCl crystals has been used as space holder. ► Variation of NaCl:Ti ratio varies porosity (65–80%). ► NaCl is cubic but the cells are spherical. ► Two types of pores: micro and macro pores are obtained. ► Foams are suitable for bones scaffolds and engineering applications. - Abstract: Open cell Titanium-foam (Ti-foam) with varying porosities (65–80%) was prepared using sodium chloride (NaCl) particles as space holder through powder metallurgy route. In order to ensure sufficient handling strength in cold compacted pallets, 2 wt.% polyvinyl alcohol (PVA) solutions (5 wt.% PVA in water) was mixed with the mixture of Ti and NaCl powders prior to cold compaction. After sintering, NaCl salt was removed by dissolving it in hot water. Detailed Energy dispersive X-ray (EDX) analysis and X-ray diffraction studies of the prepared Ti-foams were conducted to examine any physical and chemical changes in the phase constituents. The micro-architectural characteristics, density vis-a-vis porosity, and compressive deformation behavior of the synthesized foams were evaluated to examine their suitability as biomaterial and engineering applications

  4. Natural cork agglomerate employed as an environmentally friendly solution for quiet sandwich composites.

    Science.gov (United States)

    Sargianis, James; Kim, Hyung-ick; Suhr, Jonghwan

    2012-01-01

    Carbon fiber-synthetic foam core sandwich composites are widely used for many structural applications due to their superior mechanical performance and low weight. Unfortunately these structures typically have very poor acoustic performance. There is increasingly growing demand in mitigating this noise issue in sandwich composite structures. This study shows that marrying carbon fiber composites with natural cork in a sandwich structure provides a synergistic effect yielding a noise-free sandwich composite structure without the sacrifice of mechanical performance or weight. Moreover the cork-core sandwich composites boast a 250% improvement in damping performance, providing increased durability and lifetime operation. Additionally as the world seeks environmentally friendly materials, the harvesting of cork is a natural, renewable process which reduces subsequent carbon footprints. Such a transition from synthetic foam cores to natural cork cores could provide unprecedented improvements in acoustic and vibrational performance in applications such as aircraft cabins or wind turbine blades.

  5. Effects of NaCl on Fermentative Metabolism of Mature Green Tomatoes cv. Ailsa Craig in Brine

    Directory of Open Access Journals (Sweden)

    Sotirios Fragkostefanakis

    2010-01-01

    Full Text Available The effect of osmotic strength on gene expression and activity of the major enzymes of fermentative metabolism of mature green tomato fruit (Solanum lycopersicum cv. Ailsa Craig has been studied by exposing fruit to brine containing 0 (water, 5 and 10 % NaCl. The fruits were surface sterilized prior to treatment to prevent the growth of microbes naturally present on the skin of the fruit. Changes in fruit expression of fermentation genes and the activity of the respective enzymes as well as physicochemical quality characteristics (soluble solid content, titratable acidity, pH and firmness were studied in both fruit and brine for 0.5, 1, 1.5, 2, 3, 7 and 14 days. Discrepancies in responses that resulted from the different salt concentrations were obtained at molecular and quality levels. The complex kinetics of solutes between the fruit and the surrounding solution due to osmotic potential has led to different responses of the tissue to fermentation. Tomato fruit showed cracking soon after storage in water; water-stored fruit had higher titratable acidity, lower soluble solid content, and higher induction of anaerobic metabolism as indicated by the expression or the activity of the fermentation enzymes compared to fruit stored in brine with 5 or 10 % NaCl. No cracking was observed in fruit stored in 5 (isotonic or 10 % NaCl (hypertonic brine, though in the latter, signs of dehydration were observed. The presence of salt in brine reduced the intensity of fermentative metabolism as indicated by the lower gene expression and enzyme activity. However, fruit stored in brine with 5 % NaCl survived longer than with 0 or 10 % NaCl. The presence of 5 % NaCl in brine caused mild changes of both the fermentative metabolism and the physicochemical characteristics and prevented fruit deterioration during storage.

  6. Inhibitive Behaviour of Corrosion of Aluminium Alloy in NaCl by Mangrove Tannin

    International Nuclear Information System (INIS)

    Solhan Yahya; Afidah Abdul Rahim; Affaizza Mohd Shah; Rohana Adnan

    2011-01-01

    Anticorrosion potential of mangrove tannins on aluminium alloys AA6061 in NaCl solution has been studied using potentiodynamic polarisation method and scanning electron microscopy (SEM). The study was carried out in different pH of corrosive medium in the absence and presence of various concentrations of tannin. The corrosion inhibition behaviour of the mangrove tannin on AA6061 aluminium alloy corrosion was found to be dependant on the pH of NaCl solution. Our results showed that the inhibition efficiency increased with increasing tannins concentration in chloride solution at pH 6. Treatment of aluminium alloy 6061 with all concentrations of mangrove tannins reduced the current density, thus decreased the corrosion rate. Tannins behaved as mixed inhibitors at pH 6 and reduction in current density predominantly affected in cathodic reaction. Meanwhile, at pH 12, addition of tannins shifted the corrosion potential to more cathodic potentials and a passivating effect was observed in anodic potentials. SEM studies have shown that the addition of tannins in chloride solution at pH 12 reduced the surface degradation and the formation of pits. (author)

  7. SOILSOLN: A Program for Teaching Equilibria Modeling of Soil Solution Composition.

    Science.gov (United States)

    Wolt, Jeffrey D.

    1989-01-01

    Presents a computer program for use in teaching ion speciation in soil solutions. Provides information on the structure of the program, execution, and software specifications. The program estimates concentrations of ion pairs, hydrolytic species, metal-organic complexes, and free ions in solutions. (Author/RT)

  8. Generalized solution of design optimization and failure analysis of composite drive shaft

    Energy Technology Data Exchange (ETDEWEB)

    Kollipalli, K.; Shivaramakrishna, K.V.S.; Prabhakaran, R.T.D. [Birla Institute of Technology and Science, Goa (India)

    2012-07-01

    Composites have an edge over conventional metals like steel and aluminum due to higher stiffness-to-weight ratio and strength-to-weight ratio. Due to these advantages, composites can bring out a revolutionary change in materials used in automotive engineering, as weight savings has positive impacts on other attributes like fuel economy and possible noise, vibration and harshness (NVH). In this paper, the drive line system of an automotive system is targeted for use of composites by keeping constraints in view such as such as torque transmission, torsional buckling load and fundamental natural frequency. Composite drive shafts made of three different composites ('HM Carbon/HS Carbon/E-glass'-epoxy) was modeled using Catia V5R16 CPD workbench and a finite element analysis with boundary conditions, fiber orientation and stacking sequence was performed using ANSYS Composite module. Results obtained were compared to theoretical results and were found to be accurate and in the limits. This paper also speaks on drive shaft modeling and analysis generalization i.e., changes in stacking sequence in the future can be incorporated directly into ANSYS model without modeling it again in Catia. Hence the base model and analysis method made up in this analysis generalization facilitated by CAD/CAE can be used to carry out any composite shaft design optimization process. (Author)

  9. Use of Composite Sorbents for the Removal of Copper (II ions from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Rebecca Oyedoyin Adeeyo

    2015-01-01

    Full Text Available Composite adsorbents are synthesized from two or more materials with different chemical and physical properties in order to increase their selectivity and the reusability. Researchers have developed and applied several novel composite materials for enhancing the removal of heavy metal. In this review, extensive list of composites developed via advanced technologies with specified characteristics for the removal of Cu (II ion are discussed. Emphases on their adsorption capacities, reusability, desorption and regeneration with improved mechanical strengths are presented. Conclusively, prospects and other challenges to be checked and addressed in future are outlined.

  10. EXACT SOLUTION OF HEAT CONDUCTION IN A TWO-DOMAIN COMPOSITE CYLINDER WITH AN ORTHOTROPIC OUTER LAYER

    International Nuclear Information System (INIS)

    AVILES-RAMOS, C.; RUDY, C.

    2000-01-01

    The transient exact solution of heat conduction in a two-domain composite cylinder is developed using the separation of variables technique. The inner cylinder is isotropic and the outer cylindrical layer is orthotropic. Temperature solutions are obtained for boundary conditions of the first and second kinds at the outer surface of the orthotropic layer. These solutions are applied to heat flow calorimeters modeling assuming that there is heat generation due to nuclear reactions in the inner cylinder. Heat flow calorimeter simulations are carried out assuming that the inner cylinder is filled with plutonium oxide powder. The first objective in these simulations is to predict the onset of thermal equilibrium of the calorimeter with its environment. Two types of boundary conditions at the outer surface of the orthotropic layer are used to predict thermal equilibrium. The procedure developed to carry out these simulations can be used as a guideline for the design of calorimeters. Another important application of these solutions is on the estimation of thermophysical properties of orthotropic cylinders. The thermal conductivities in the vertical, radial and circumferential directions of the orthotropic outer layer can be estimated using this exact solution and experimental data. Simultaneous estimation of the volumetric heat capacity and thermal conductivities is also possible. Furthermore, this solution has potential applications to the solution of the inverse heat conduction problem in this cylindrical geometry. An interesting feature of the construction of this solution is that two different sets of eigenfunctions need to be considered in the eigenfunction expansion. These eigenfunctions sets depend on the relative values of the thermal diffusivity of the inner cylinder and the thermal diffusivity in the vertical direction of the outer cylindrical layer

  11. Removal of boron from aqueous solution using magnesite and bentonite clay composite

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2015-03-01

    Full Text Available The removal of boron from industrial effluents using the composite was studied in batch equilibration technique. The effects of equilibration time, adsorbent dosage, concentration and pH on removal of boron were investigated. The experiments...

  12. Sorption of technetium on composite chitosan-hydroxyapatite from aqueous solutions

    International Nuclear Information System (INIS)

    Pivarciova, L.; Rosskopfova, O.; Galambos, M.; Rajec, P.

    2013-01-01

    Biomaterials such as natural polymers (chitosan) and hydroxyapatite have an important application in material for bone replacement. Most of chitosan/hydroxyapatite composites are prepared by mixing hydroxyapatite particles with chitosan matrices. Another method of preparation of chitosan/hydroxyapatite composite is in-situ generation of nano-hydroxyapatite in chitosan matrix. The most common biomaterial used in the past years in hard tissue regeneration was hydroxyapatite, owing to its properties as biocompatibility, bioactivity, non-toxicity, non-immunogenicity etc. Chitosan is a polyaminosacharide, partially deacetylated product of chitin. Chitosan can be used in combination with other materials to enhance bone growth such as bone filling paste. The aims of this work were: the influence of the contact time on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of pH on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of foreign ions on sorption of pertechnate anions on chitosan/hydroxyapatite composites. The author concluded: the percentage of technetium sorption after 1 hour of contact time was > 97 %. In the initial pH range of 2.9-10.2, the percentage of technetium sorption on chitosan/hydroxyapatite composites CH/HA(A), CH/HA(B), CH/HA 30:70, ZCH was > 98 % and on CH/HA 50:50 was > 94%. The competition effect of Fe 2+ towards TcO 4 :- sorption is stronger than competition effect of other observed cations for all examined composites with the same weight ratio. The percentage of the technetium sorption was the same for all composites with the weight ratio of 30:70. (authors)

  13. Removal of Cr(VI and Toxic Ions from Aqueous Solutions and Tannery Wastewater Using Polymer-Clay Composites

    Directory of Open Access Journals (Sweden)

    Abd El-Azeem Sallam

    2017-10-01

    Full Text Available Polymer-clay composites were prepared by natural zeolite (clinoptilolite or naturally local clay deposits in an N,N-methylene-bis-acrylamide as cross-linked. The resultant composites were used for the removal of Cr(VI from an aqueous solution. Additionally, their effects on soluble ions of tannery wastewater were investigated. The produced composites were characterized using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR, and scanning electron microscopy (SEM. The results showed that Cr(VI removal is dependent upon initial concentrations and pH. The adsorption quantity of Cr(VI onto the polymerized clay deposit followed by polymerized zeolite exhibited higher values than their original samples. The polymer-clay composite of clay deposit showed the highest removal of 76.3–100% overall initial concentrations of 10–50 mg L−1 and at initial pH of 2. Kinetics of Cr(VI removal by various sorbents was predicted using a pseudo–second order model. Our findings showed that the levels of salinity and various soluble ions (Cr2+, Na+, Cl− and SO42− in tannery wastewater are very high, and their levels were reduced after treatment, especially by polymerized sorbents. It could be concluded that the polymer-clay composites may be employed as a highly efficient sorbent for the removal of Cr(VI and toxic ions from the wastewater.

  14. Properties of PP/MWCNT-COOH /PP composites made by melt mixing versus solution cast /melt mixing methods

    International Nuclear Information System (INIS)

    Reinholds, I; Roja, Z; Zicans, J; Meri, R Merijs; Bitenieks, J

    2015-01-01

    An approach on improvement of the properties of polypropylene / carbon nanotube (PP/CNT) composites is reported. PP blend compositions with carboxylic acid functionalized multi-walled carbon nanotubes (MWCNT-COOH) at filler content 1.0 wt.% were researched. One part of the composites was manufactured by direct thermoplastic mixing PP with the filler, but the other one was made from solution casted masterbatch with the following thermoplastic mixing. An increase of mechanical properties (Young's modulus, storage modulus and tensile strength), compared to an increase of glass transition temperature indicated a reinforcement effect of CNTs on PP matrix, determined from the tensile tests and differential mechanical analysis (DMA), while the elongation was reduced, compared to PP matrix. By differential scanning calorimetry (DSC) analysis, the effect of nanofiller on the reorganization of PP crystallites was observed. A noticeable enhanced effect on increase of the crystallization temperature was indicated for masterbatch manufactured composite. An increase of thermal stability was also observed, compared to pristine PP and the composite made by direct thermoplastic mixing PP with the filler

  15. Field and laboratory investigations on the effects of road salt (NaCl) on stream macroinvertebrate communities

    International Nuclear Information System (INIS)

    Blasius, B.J.; Merritt, R.W.

    2002-01-01

    Short-term exposure to road salt did not significantly affect stream macro-invertebrate communities. - Field and laboratory experiments were conducted to examine the effects of road salt (NaCl) on stream macroinvertebrates. Field studies investigated leaf litter processing rates and functional feeding group composition at locations upstream and downstream from point source salt inputs in two Michigan, USA streams. Laboratory studies determined the effects of increasing NaCl concentrations on aquatic invertebrate drift, behavior, and survival. Field studies revealed that leaves were processed faster at upstream reference sites than at locations downstream from road salt point source inputs. However, it was sediment loading that resulted in partial or complete burial of leaf packs, that affected invertebrate activity and confounded normal leaf pack colonization. There were no significant differences that could be attributed to road salt between upstream and downstream locations in the diversity and composition of invertebrate functional feeding groups. Laboratory drift and acute exposure studies demonstrated that drift of Gammarus (Amphipoda) may be affected by NaCl at concentrations greater than 5000 mg/l for a 24-h period. This amphipod and two species of limnephilid caddisflies exhibited a dose response to salt treatments with 96-h LC 50 values of 7700 and 3526 mg NaCl/l, respectively. Most other invertebrate species and individuals were unaffected by NaCl concentrations up to 10,000 mg/l for 24 and 96 h, respectively

  16. NaCl samples for optical luminescence dosimetry

    International Nuclear Information System (INIS)

    Catli, S.

    2005-01-01

    Optically stimulated luminescence (OSL) have been used broadly for luminescence dosimetry and dating. In many cases, it has been pointed out that the decay of the OSL do not generally behave according to a simple exponential function. In this study the Infra-red stimulated luminescence (IRSL) intensity from NaCl samples were experimentally measured. The decay curves for this sample were fitted to some functions and it is in good agreement with the function y = α + b exp(-cx). The IRSL decay curves from NaCl using different β-doses have been obtained and investigated their dose response

  17. Influence of staining solutions and whitening procedures on discoloration of hybrid composite resins.

    Science.gov (United States)

    Garoushi, Sufyan; Lassila, Lippo; Hatem, Marwa; Shembesh, Muneim; Baady, Lugane; Salim, Ziad; Vallittu, Pekka

    2013-01-01

    The aim was to evaluate the color stability and water uptake of two hybrid composite resins polymerized in two different conditions after exposure to commonly consumed beverages. In addition, the effect of repolishing and bleaching on the stained composite was evaluated. Eighty specimens (12 mm × 12 mm × 3 mm) were made from two hybrid composite resins of shade A2. Forty specimens of each composite were divided into two groups (n = 20 per each) according to the curing method used (hand light cure HLC or oven light cure OLC). Then each group (HLC or OLC) was sub-divided randomly into four sub-groups (n = 5), which were immersed for 60 days in different beverages (distal water, coffee, tea and pepsi) and incubated at 37°C. Water uptake was measured during this time and followed by measurement of color difference (ΔE) by using a spectrophotometer. After complete staining, repolishing (grit 4000 FEPA at 300 rpm under water) and bleaching (40% hydrogen peroxide bleaching gel) were conducted. The repolished and bleached specimens were submitted to new color measurements. Color value of the specimens immersed in tea displayed the highest statistically significant (p pepsi was significantly lower than the others. After staining of the composite resins, both the bleaching and repolishing were able to reduce the ΔE value. All beverages used affected the color stability of tested composite resins. The effect of beverages on color change of composites depends on type of beverage and water uptake value of resins used. A superior whitening effect was obtained with repolishing technique compared to bleaching.

  18. Domain structure of human complement C4b extends with increasing NaCl concentration: implications for its regulatory mechanism.

    Science.gov (United States)

    Fung, Ka Wai; Wright, David W; Gor, Jayesh; Swann, Marcus J; Perkins, Stephen J

    2016-12-01

    During the activation of complement C4 to C4b, the exposure of its thioester domain (TED) is crucial for the attachment of C4b to activator surfaces. In the C4b crystal structure, TED forms an Arg 104 -Glu 1032 salt bridge to tether its neighbouring macroglobulin (MG1) domain. Here, we examined the C4b domain structure to test whether this salt bridge affects its conformation. Dual polarisation interferometry of C4b immobilised at a sensor surface showed that the maximum thickness of C4b increased by 0.46 nm with an increase in NaCl concentration from 50 to 175 mM NaCl. Analytical ultracentrifugation showed that the sedimentation coefficient s 20,w of monomeric C4b of 8.41 S in 50 mM NaCl buffer decreased to 7.98 S in 137 mM NaCl buffer, indicating that C4b became more extended. Small angle X-ray scattering reported similar R G values of 4.89-4.90 nm for C4b in 137-250 mM NaCl. Atomistic scattering modelling of the C4b conformation showed that TED and the MG1 domain were separated by 4.7 nm in 137-250 mM NaCl and this is greater than that of 4.0 nm in the C4b crystal structure. Our data reveal that in low NaCl concentrations, both at surfaces and in solution, C4b forms compact TED-MG1 structures. In solution, physiologically relevant NaCl concentrations lead to the separation of the TED and MG1 domain, making C4b less capable of binding to its complement regulators. These conformational changes are similar to those seen previously for complement C3b, confirming the importance of this salt bridge for regulating both C4b and C3b. © 2016 The Author(s).

  19. Synthesis of titanium oxide nanoparticles using DNA-complex as template for solution-processable hybrid dielectric composites

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, J.C. [Center for Sustainable Materials Chemistry, 153 Gilbert Hall, Oregon State University, Corvallis, OR (United States); Mejia, I.; Murphy, J.; Quevedo, M. [Department of Materials Science and Engineering, University of Texas at Dallas, Dallas, TX (United States); Garcia, P.; Martinez, C.A. [Engineering and Technology Institute, Autonomous University of Ciudad Juarez, Ciudad Juarez, Chihuahua (Mexico)

    2015-09-15

    Highlights: • We developed a synthesis method to produce TiO{sub 2} nanoparticles using a DNA complex. • The nanoparticles were anatase phase (~6 nm diameter), and stable in alcohols. • Composites showed a k of 13.4, 4.6 times larger than the k of polycarbonate. • Maximum processing temperature was 90 °C. • Low temperature enables their use in low-voltage, low-cost, flexible electronics. - Abstract: We report the synthesis of TiO{sub 2} nanoparticles prepared by the hydrolysis of titanium isopropoxide (TTIP) in the presence of a DNA complex for solution processable dielectric composites. The nanoparticles were incorporated as fillers in polycarbonate at low concentrations (1.5, 5 and 7 wt%) to produce hybrid dielectric films with dielectric constant higher than thermally grown silicon oxide. It was found that the DNA complex plays an important role as capping agent in the formation and suspension stability of nanocrystalline anatase phase TiO{sub 2} at room temperature with uniform size (∼6 nm) and narrow distribution. The effective dielectric constant of spin-cast polycarbonate thin-films increased from 2.84 to 13.43 with the incorporation of TiO{sub 2} nanoparticles into the polymer host. These composites can be solution processed with a maximum temperature of 90 °C and could be potential candidates for its application in low-cost macro-electronics.

  20. Solid-solution-like ZnO/C composites as excellent anode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Zhang, Guanhua; Zhang, Hang; Zhang, Xiang; Zeng, Wei; Su, Qingmei; Du, Gaohui; Duan, Huigao

    2015-01-01

    Exploring advanced anode materials to maximize the capacity of lithium ion batteries has been an active research area for decades. Constructing composites materials has been proved to be one of the most effective methods to achieve higher capacity due to the synergistic effect. In this work, we proposed and demonstrated a concept of solid-solution-like ZnO/C composites to approach the largest possible synergistic effect by introducing the most interfaces and minimizing the pulverization. The solid-solution-like ZnO/C electrode could achieve a high reversible capacity of 813.3 mAh g −1 at a current density of 100 mA g −1 after 100 cycles with a decrease rate of only 0.4% per cycle. Moreover, the discharge capacity still maintained 53.5% of the original value even when the current density increased to 40 times as much as the original, showing a distinguished rate performance. In addition, such solid-solution-like nanofibers can be easily prepared because of their compatibility with the existing industrial PAN-based spinning process. This may pave the way to mass produce lithium ion batteries with significantly enhanced performance using existing low-cost commercial facilities and recipes.

  1. Crosslinked cellulose thin film composite nanofiltration membranes with zero salt rejection

    KAUST Repository

    Puspasari, Tiara

    2015-05-14

    We report a new synthetic route of fabricating regenerated cellulose nanofiltration membranes. The membranes are composite membranes with a thin selective layer of cellulose, which was prepared by regeneration of trimethylsilyl cellulose (a hydrophobic cellulose derivative) film followed by crosslinking. Filtration experiments using mixtures of sugar and sodium chloride showed that solutes above 300 Da were highly rejected whereas practically no rejection was observed for NaCl. This is a big advantage for a complete desalination as the existing commercial nanofiltration membranes typically exhibit NaCl rejection in the range of 30–60%. Membranes with zero NaCl rejection are required for recovery and purification applications in food, chemical and pharmaceutical industry.

  2. Specific features of corrosion processes in a crack tip in chloride solution

    International Nuclear Information System (INIS)

    Kurov, O.V.; Vasilenko, I.I.

    1981-01-01

    Electrode potentials of metal and pH solution are measured by means of microelectrodes on structural materials-45 and 12Kh18N10T steels, AT3 titanium alloy and D16 aluminium alloy in the vertex of corrosion crack formed during corrosion cracking in 3% NaCl solution. Metal corrosion is shown to be followed by hydrogen liberation on all the investigated materials at corrosion potentials. The effects of chemical composition of alloys as well as external polarization on the solution pH in the crack vertex are determined

  3. Interpretation of soil-to-plant transfer on the basis of soil solution chemical composition

    International Nuclear Information System (INIS)

    Lembrechts, J.F.; Van Loon, L.R.; Van Ginkel, J.H.; Desmet, G.M.

    1988-01-01

    Soil-to-plant translocation of a radionuclide depends on its availability on the one hand and on the efficiency of the uptake process on the other. Criticism on the use of transfer coefficients for the description of translocation mainly concerns the fact that the complex variety of processes, a.o. dependent on plant characteristics and soil type and treatment, is integrated in a single ratio. For the interpretation of the effect of counter-measures the static transfer coefficient proved to be hard to handle and knowledge of the separate underlying processes and their time dependence showed to be indispensible. Based upon translocation experiments with technetium, cobalt, strontium and zinc transfer was shown to be primarily related to the concentration of the plant available fraction in the soil solution as well as to the soil solution chemistry in general. The transfer factor of the first three elements expressed in the basis of soil solution activity (ml/g), was observed to decrease when the nutrient content of the soil solution -- reflected by its conductivity -- increased. The characteristics of the soil matrix (solid phase) furthermore showed to be of secondary importance for the explanation of the observed accumulation. Since the interstitial soil liquid phase mediates between solid phase and plant root, reliable interpretations of soil-to-plant transfer might as a rule be based on a separate study of the effect of soil properties on availability on the one hand of the uptake from nutrient solutions on the other

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

    Science.gov (United States)

    Jisha, K C; Puthur, Jos T

    2014-07-01

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

  5. Effect of soil compositions on the electrochemical corrosion behavior of carbon steel in simulated soil solution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, T.M. [College of Materials Science and Engineering, Chongqing University (China); Luo, S.X. [Department of Chemistry, Zunyi Normal College, Zunyi (China); Sun, C. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China); Wu, Y.H.

    2010-04-15

    In this study, effect of cations, Ca{sup 2+}, Mg{sup 2+}, K{sup +}, and anions, SO{sub 4}{sup 2-}, HCO{sub 3}{sup -}, NO{sub 3}{sup -} on electrochemical corrosion behavior of carbon steel in simulated soil solution was investigated through potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results indicate that the Ca{sup 2+}and Mg{sup 2+} can decrease the corrosion current density of carbon steel in simulated soil solution, and K{sup +}, SO{sub 4}{sup 2-}, HCO{sub 3}{sup -}, and NO{sub 3}{sup -} can increase the corrosion density. All the above ions in the simulated soil solution can decrease its resistivity, but they have different effect on the charge transfer resistivity. This finding can be useful in evaluating the corrosivity of certain soil through chemical analysis, and provide data for construction engineers. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  6. Lignocellulosic composites prepared utilizing aqueous alkaline/urea solutions with cold temperatures

    Science.gov (United States)

    Lignocellulosic composites (LCs) were fabricated by partially dissolving cotton to create a matrix that was reinforced with Osage orange wood (OOW) particles and/or Blue agave fibers (AF). LCs were composed of 15-35% cotton matrix: 65-85% OWW/AF reinforcement. The matrix was produced by soaking cott...

  7. Nano-sized precipitated formations in irradiated NaCl

    NARCIS (Netherlands)

    Sugonyako, Anton V.

    2007-01-01

    The interest in the formation of radiation damage in alkali halides and in particular, in NaCl, is stimulated by the fact that rock-salt in stable geological formations is a prominent candidate medium for storage of high-level waste (HLW) of nuclear power plants. Since the 1950s, scientists and

  8. Performance assessment of MCM-48 ceramic composite membrane by separation of AlCl3 from aqueous solution.

    Science.gov (United States)

    Kumar Basumatary, Ashim; Kumar Ghoshal, Aloke; Pugazhenthi, G

    2016-12-01

    Three dimensional ordered mesoporous MCM-48 membrane was fabricated on a circular shaped ceramic support by in-situ hydrothermal method. The synthesized MCM-48 powder and MCM-48 ceramic composite membrane were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM). The porosity and pore size of the composite membrane are reduced considerably by the deposition of MCM-48 on the support. The formation of MCM-48 is verified by the XRD analysis. Three stepwise mechanisms for surfactant removal are observed by TGA analysis. FESEM images clearly signify the deposition of MCM-48 on the ceramic support. The pure water flux of the support and MCM-48 composite membrane is found to be 3.63×10 -6 and 4.18×10 -8 m 3 /m 2 skPa, respectively. The above prepared MCM-48 ceramic composite membrane is employed for the removal of AlCl 3 from aqueous solution and the highest rejection of 81% is obtained at an applied pressure of 276kPa with salt concentration of 250ppm. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. TiO2/bone composite materials for the separation of heavy metal impurities from waste water solutions

    Science.gov (United States)

    Dakroury, G.; Labib, Sh.; Abou El-Nour, F. H.

    2012-09-01

    Pure bone material obtained from cow meat, as apatite-rich material, and TiO2-bone composite materials are prepared and studied to be used for heavy metal ions separation from waste water solutions. Meat wastes are chemically and thermally treated to control their microstructure in order to prepare the composite materials that fulfill all the requirements to be used as selective membranes with high performance, stability and mechanical strength. The prepared materials are analyzed using Hg-porosimetry for surface characterization, energy dispersive X-ray spectroscopy (EDAX) for elemental analysis and Fourier transform infrared spectroscopy (FTIR) for chemical composition investigation. Structural studies are performed using X-ray diffraction (XRD). Microstructural properties are studied using scanning electron microscopy (SEM) and specific surface area studies are performed using Brunauer-Emmet-Teller (BET) method. XRD studies show that multiphase structures are obtained as a result of 1h sintering at 700-1200 °C for both pure bone and TiO2-bone composite materials. The factors affecting the transport of different heavy metal ions through the selected membranes are determined from permeation flux measurements. It is found that membrane pore size, membrane surface roughness and membrane surface charge are the key parameters that control the transport or rejection of heavy metal ions through the selected membranes.

  10. Potentiometric titration for determining the composition and stability of metal(II) alginates and pectinates in aqueous solutions

    Science.gov (United States)

    Kaisheva, N. Sh.; Kaishev, A. Sh.

    2015-07-01

    The compositions and stabilities of Cu2+, Mn2+, Pb2+, Ca2+, Zn2+, Cd2+, Co2+, and Ni2+ alginates and pectinates are determined in aqueous solutions via titrimetry and potentiometry with calculations performed using Bjerrum's method, the curve intersection technique, and the equilibrium shift method. It is found that the interaction between Cu2+ and polyuronides is a stepwise process and, depending on the ligand concentration and the method of determination, Cu2+ alginate can be characterized by its ML, ML2, and ML3 compositions (where M is the metal ion and L is the structural unit of polyuronide) and stability constants logβ = 2.65, 5.00-5.70, and 7.18-7.80, respectively. The compositions of Cu2+ pectinates are ML and ML2 with logβ = 3.00 and 7.64-7.94, respectively. It is concluded that Pb2+, Ca2+, Mn2+, Zn2+, Cd2+, Co2+, and Ni2+ ions form only alginates and pectinates of ML2 composition with logβ values of 3.45 (Pb2+ alginate), 2.20 (Ca2+ alginate), 1.06 (Mn2+ alginate), 3.51 (Pb2+ pectinate), 2.35 (Ca2+ pectinate), and 1.24 (Mn2+ pectinate). The pectinates are shown to be more stable than the alginates, the most stable compounds being those formed by polyuronides and Cu2+. The least stable are those with Mn2+.

  11. Synthesis of some Ferromagnetic Composite Resins and their Metal Removal Characteristics in Aqueous Solutions

    International Nuclear Information System (INIS)

    Sheha, R.R.; EI-Zahhar, A.A.

    2008-01-01

    In this study, a procedure for synthesis of new organic-inorganic magnetic composite resins was established. The procedure was based upon immobilization of magnetite as a ferromagnetic material within the polymeric (poly(acrylic acid acrylonitrile) and IRC-120) ion exchange resins. The produced magnetic resins were evaluated as sorbents for CI(VI). The factors influencing the sorption of Cr(Vl), e.g., ph, equilibrium time, initial concentration and temperature were studied. The sorption process was very fast initially and maximum sorption was achieved within 3 h at ph 5.1. Thc kinetics of the system have been evaluated with pseudo first order model, second order model, Elovich equation, intra-particle diffusion model and liquid film diffusion model. Chromium interaction with composite particles followed second-order kinetics with a correlation coefficient extremely high and closer to unity and rate constant (k s ) has the values 1.68 x 10 -4 and 1.9 x 10 -4 g/mg min for IRC-120-P AN-magnetite and P(AA-AN)-magnetite composites, respectively. The values of equilibrium sorption capacity (q e ) are consistent with the modeled data and attain the range 893 - 951 mg/g. Kinetically, both pore diffusion and film diffusion are participating in ruling the diffusion of CI(VI) ions. The sorption data gave good fits with Temkin and Flory-Huggins isotherm models. The isotherm parameters related to the heat of sorption are in the range 8-16 kJ mol -1 which is the range of bonding energy for ion exchange interactions and so suggest an ion exchange mechanism for removal of CI(VI) by the composite sorbents. The adsorption process was exothermic with δH in the range of -73 to -97 kJ/mol. The negative values of Gibbs free energy confirm the feasibility and the spontaneous nature of removal of CI(VI) with these novel composites

  12. Composition, structure and electrical properties of alumina barrier layers grown in fluoride-containing oxalic acid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Jagminas, A. [Institute of Chemistry, A. Gostauto 9, LT-01108 Vilnius (Lithuania)], E-mail: jagmin@ktl.mii.lt; Vrublevsky, I. [Department of Microelectricals, Belarusian State University of Informatics and Radioelectricals, 6 Brovka Street, Minsk 220013 (Belarus); Kuzmarskyte, J.; Jasulaitiene, V. [Institute of Chemistry, A. Gostauto 9, LT-01108 Vilnius (Lithuania)

    2008-04-15

    The composition, structure and electrical properties of alumina barrier layers grown by anodic oxidation in F{sup -}-containing (FC) and F{sup -}-free (FF) oxalic acid solutions were studied using the re-anodizing/dissolution technique, Fourier-transformed infrared and X-ray photoelectron spectroscopy. These results confirmed formation in FC anodizing solutions of films structurally different from ones grown in FF oxalic acid baths. It was found that the barrier layer of FC alumina films is composed of two layers differing in the dissolution rate. These differences are related to the formation in the FC electrolyte of a barrier layer composed of a more microporous outer part and a thin, non-porous and non-scalloped inner part consisting of aluminum oxide and aluminum fluoride.

  13. Chemical composition and electronic structure of the passive layer formed on stainless steels in a glucose-oxidase solution

    Energy Technology Data Exchange (ETDEWEB)

    Marconnet, C. [Laboratoire de Genie des Procedes et des Materiaux, Ecole Centrale Paris, Grande Voie des Vignes, 92290 CHATENAY-MALABRY (France)], E-mail: cyril.marconnet@yahoo.fr; Wouters, Y. [Science et Ingenierie des Materiaux et Procedes, Institut National Polytechnique de Grenoble, F-38402 Saint-Martin d' Heres Cedex (France); Miserque, F. [Laboratoire de Reactivite des Surfaces et des Interfaces, CEA Saclay, Bat. 391, 91191 GIF-SUR-YVETTE (France); Dagbert, C. [Laboratoire de Genie des Procedes et des Materiaux, Ecole Centrale Paris, Grande Voie des Vignes, 92290 CHATENAY-MALABRY (France)], E-mail: catherine.dagbert@ecp.fr; Petit, J.-P. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, INPG, F-38402 Saint-Martin d' Heres Cedex (France); Galerie, A. [Science et Ingenierie des Materiaux et Procedes, Institut National Polytechnique de Grenoble, F-38402 Saint-Martin d' Heres Cedex (France); Feron, D. [Service de Corrosion et du Comportement des Materiaux dans leur Environnement, CEA Saclay, Bat. 458, 91191 GIF-SUR-YVETTE (France)

    2008-12-01

    This article deals with the interaction between the passive layer formed on UNS S30403 and S31254 stainless steels and an enzymatic solution containing glucose oxidase (GOx) and its substrate D-glucose. This enzymatic solution is often used to reproduce in laboratory the ennoblement occuring in non-sterile aerated aqueous environments because of the biofilm settlement on the surface of the metallic material. GOx catalyses the oxidation of D-glucose to gluconic acid by reducing oxygen to hydrogen peroxide and produces an organic acid. Thanks to photocurrent measurements, XPS analysis and Mott-Schottky diagrams, it is here shown that such an environment generates modifications in the chemical composition and electronic structure of the passive layer: it induces a relative enrichment of the n-type semi-conducting phase containing chromium (chromine Cr{sub 2}O{sub 3}) and an increase of the donors density in the space charge region.

  14. Chemical composition and electronic structure of the passive layer formed on stainless steels in a glucose-oxidase solution

    International Nuclear Information System (INIS)

    Marconnet, C.; Wouters, Y.; Miserque, F.; Dagbert, C.; Petit, J.-P.; Galerie, A.; Feron, D.

    2008-01-01

    This article deals with the interaction between the passive layer formed on UNS S30403 and S31254 stainless steels and an enzymatic solution containing glucose oxidase (GOx) and its substrate D-glucose. This enzymatic solution is often used to reproduce in laboratory the ennoblement occuring in non-sterile aerated aqueous environments because of the biofilm settlement on the surface of the metallic material. GOx catalyses the oxidation of D-glucose to gluconic acid by reducing oxygen to hydrogen peroxide and produces an organic acid. Thanks to photocurrent measurements, XPS analysis and Mott-Schottky diagrams, it is here shown that such an environment generates modifications in the chemical composition and electronic structure of the passive layer: it induces a relative enrichment of the n-type semi-conducting phase containing chromium (chromine Cr 2 O 3 ) and an increase of the donors density in the space charge region

  15. Displacement potential solution of a guided deep beam of composite materials under symmetric three-point bending

    Science.gov (United States)

    Rahman, M. Muzibur; Ahmad, S. Reaz

    2017-12-01

    An analytical investigation of elastic fields for a guided deep beam of orthotropic composite material having three point symmetric bending is carried out using displacement potential boundary modeling approach. Here, the formulation is developed as a single function of space variables defined in terms of displacement components, which has to satisfy the mixed type of boundary conditions. The relevant displacement and stress components are derived into infinite series using Fourier integral along with suitable polynomials coincided with boundary conditions. The results are presented mainly in the form of graphs and verified with finite element solutions using ANSYS. This study shows that the analytical and numerical solutions are in good agreement and thus enhances reliability of the displacement potential approach.

  16. Preparation of modified polymer- Alumino silicate composite and their application in removal of some radionuclides from aqueous solutions

    International Nuclear Information System (INIS)

    El- Masry, E.H.

    2012-01-01

    Ion exchange is one of the most common and effective treatment methods for radioactive liquid waste. This technique is well developed and has been employed for many years in both the nuclear industry and in other industries. In this thesis polyacrylamide- zeolite and polyacrylamide- bentonite composites were prepared and characterized using advanced analytical techniques. The prepared materials were used as composite ion exchangers for removal of Cesium, Cobalt and Strontium ions from simulated waste solution. Effect of ph of the medium on the removal of aforementioned ions was investigated. The sorption kinetic was studied and the data were analyzed by different kinetic models which rivaled that the mechanism of the sorption processes is mainly controlled by pseudo-second order reaction, and particle diffusion might be involved in the sorption processes. The values of diffusion coefficient of the three metal ions were calculated and suggested that chemisorption was the predominated sorption mechanism. Several isotherm models were applied for the sorption, and thermodynamic parameters were determined. The positive values of enthalpy change, δH, for the three metal ions confirmed the endothermic nature of the sorption processes. The results indicated that the prepared materials can be used as efficient ion exchange materials for the removal of cesium, cobalt and strontium ions from simulated waste solution. In the present study, immobilization of polyacrylamide- zeolite and/ or polyacrylamide- bentonite composites loaded with cesium, cobalt and/or strontium radionuclides with Ordinary Portland Cement (OPC) has been carried out. Several factors affecting the characteristics of the final solidified waste product towards safe disposal such as mechanical strength and leaching behavior of the radioisotopes have been studied. The obtained results showed that the presence of polyacrylamide- zeolite and/ or polyacrylamide- bentonite composites in the cemented wastes

  17. Retraction of 'Composition design and mechanical properties of BCC Ti solid solution alloys with low Young's modulus'

    International Nuclear Information System (INIS)

    Tulugan, Keli Mu; Park, Cheol Hong; Park, Won Jo; Qing, Wang

    2012-01-01

    The article 'Composition design and mechanical properties of BCC Ti solid solution alloys with low Young's modulus' has been retracted upon the request of the third author (Prof. Wang Qing, the first author's former advisor during his internship at DaLian University of Technology). The article was published without the third author's knowledge and consent. The corresponding author (Prof. Wonjo Park) apologizes to the third author, to the readers, and to the editorial staff of the JMST. The JMST editorial board does not tolerate such actions from authors and we will take appropriate action to prevent this from happening in the future

  18. Effect of compost age and composition on the atrazine removal from solution

    Science.gov (United States)

    Tsui, L.; Roy, W.R.

    2007-01-01

    Compost samples from two composting facilities, the Urbana (Illinois) Landscape Recycling Center (ULRC) and Illinois State University (ISU), were selected to examine the effect of compost age on atrazine removal from solution. The ULRC samples were made from yard waste without an additional nitrogen source. The ISU samples were made from yard waste or sawdust with the addition of manure. The 6-month-old ULRC compost had the greater capacity to remove atrazine from solution, which we attributed to its greater organic carbon content. The addition of nitrate into ULRC compost could influence the extent of atrazine removal, but did not have a significant impact on atrazine removal when applied to ISU compost, probably because manure was added to the yard waste to produce the compost. For both ULRC and ISU samples, the presence of sodium azide inhibited atrazine removal, suggesting that microbial activity contributed to the atrazine removal. Metabolic analysis demonstrated that hydroxyatrazine was the major identified metabolite that accumulated in solution before significant ring mineralization could occur. When compared with the ISU compost, the ULRC compost sample had a greater capacity to remove atrazine from solution during the 120 days of study because of the larger humic acid content. The experimental results suggested that less-mature compost may be better suited for environmental applications such as removing atrazine from tile-drainage waters. ?? 2006 Elsevier B.V. All rights reserved.

  19. Effect of compost age and composition on the atrazine removal from solution.

    Science.gov (United States)

    Tsui, Lo; Roy, William R

    2007-01-02

    Compost samples from two composting facilities, the Urbana (Illinois) Landscape Recycling Center (ULRC) and Illinois State University (ISU), were selected to examine the effect of compost age on atrazine removal from solution. The ULRC samples were made from yard waste without an additional nitrogen source. The ISU samples were made from yard waste or sawdust with the addition of manure. The 6-month-old ULRC compost had the greater capacity to remove atrazine from solution, which we attributed to its greater organic carbon content. The addition of nitrate into ULRC compost could influence the extent of atrazine removal, but did not have a significant impact on atrazine removal when applied to ISU compost, probably because manure was added to the yard waste to produce the compost. For both ULRC and ISU samples, the presence of sodium azide inhibited atrazine removal, suggesting that microbial activity contributed to the atrazine removal. Metabolic analysis demonstrated that hydroxyatrazine was the major identified metabolite that accumulated in solution before significant ring mineralization could occur. When compared with the ISU compost, the ULRC compost sample had a greater capacity to remove atrazine from solution during the 120 days of study because of the larger humic acid content. The experimental results suggested that less-mature compost may be better suited for environmental applications such as removing atrazine from tile-drainage waters.

  20. Meshless Solution of the Problem on the Static Behavior of Thin and Thick Laminated Composite Beams

    Science.gov (United States)

    Xiang, S.; Kang, G. W.

    2018-03-01

    For the first time, the static behavior of laminated composite beams is analyzed using the meshless collocation method based on a thin-plate-spline radial basis function. In the approximation of a partial differential equation by using a radial basis function, the shape parameter has an important role in ensuring the numerical accuracy. The choice of a shape parameter in the thin plate spline radial basis function is easier than in other radial basis functions. The governing differential equations are derived based on Reddy's third-order shear deformation theory. Numerical results are obtained for symmetric cross-ply laminated composite beams with simple-simple and cantilever boundary conditions under a uniform load. The results found are compared with available published ones and demonstrate the accuracy of the present method.

  1. Thermoluminescence analysis of co-doped NaCl at low temperature irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Zaragoza, E., E-mail: ecruz@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico); Ortiz, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico); Unidad Profesional Interdisciplinaria de Ingenieria y Tecnologias Avanzadas, IPN, Av. Instituto Politecnico Nacional 2580, Col. La Laguna Ticoman, 07340 Mexico D.F. (Mexico); Furetta, C. [Touro University Rome, Circne Gianicolense 15-17, 00153 Rome (Italy); Flores J, C.; Hernandez A, J.; Murrieta S, H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 Mexico D.F. (Mexico)

    2011-02-15

    The thermoluminescent response and kinetics parameters of NaCl, doubly activated by Ca-Mn and Cd-Mn ions, exposed to gamma radiation are analyzed. The doped NaCl samples were irradiated at relative low temperature, i.e. at the liquid nitrogen temperature (LNT) and at dry ice temperature (DIT), and the glow curves obtained after 2 Gy of gamma irradiation were analyzed using the computerized glow curve deconvolution (CGCD). An evident variation in the glow curve structure after LNT and DIT was observed. It seems that different kinds of trapping levels are activated at relative low temperature. The original two prominent peaks in compositions A (Ca,Mn) and B (Ca,Mn) have been changed in only one main peak with satellites in the low temperature side of the glow curves. In compositions C (Cd,Mn) and D (Cd,Mn), low temperature peaks become stronger and prominent than the high temperature peaks; this effect could be explained considering that the trapping probability for low temperature traps, the one very close to the conduction band, is enhanced by low temperatures during irradiation.

  2. Analysis of Hanford Cast Stone Supplemental LAW using Composition Adjusted SRS Tank 50 Salt Solution

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Cozzi, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hill, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Ramsey, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-04-25

    Vitrification is the primary disposition path for Low Activity Waste (LAW) at the Department of Energy (DOE) Hanford Site. A cementitious waste form is one of the alternatives being considered for the supplemental immobilization of the LAW that will not be treated by the primary vitrification facility. Washington River Protection Solutions (WRPS) has been directed to generate and collect data on cementitious or pozzolanic waste forms such as Cast Stone.

  3. Effect of Ammonium Chloride on the Efficiency with Which Copper Sulfate Activates Marmatite: Change in Solution Composition and Regulation of Surface Composition

    Directory of Open Access Journals (Sweden)

    Shengdong Zhang

    2018-06-01

    Full Text Available Zinc sulfide minerals are the primary choice for zinc extraction and marmatite is one of the two most common zinc sulphide minerals (sphalerite and marmatite, therefore it is of great significance to study and optimize the flotation of marmatite. To improve the activation of copper sulfate on marmatite, a method involving the addition of ammonium chloride is devised. The method has been proven to be an effective way of improving the activation efficiency of copper sulfate towards marmatite under alkaline conditions. The strengthening mechanism was studied using micro-flotation, adsorption test, X-ray photoelectron spectroscopy, and by analyzing changes in solution composition. Flotation test results show that the activation effect of the copper sulfate towards marmatite is enhanced with the addition of ammonium chloride. According to the results of the adsorption measurements and X-ray photoelectron spectroscopy analysis, when the marmatite surface is activated using copper sulfate with added ammonia chloride, it adsorbs more copper sulfide and less copper hydroxide and zinc hydroxide. These changes in surface composition are believed to occur via the following process: NH3(aq promotes the dissolution of zinc hydroxide and then facilitates the conversion of surface copper hydroxide to copper sulfide. In addition, the occurrence of Cu(NH3n2+ can promote the adsorption of copper ions (Cu2+ can be stored as Cu(NH3n2+ via complexation, and then, when the concentration of copper ions decreases, Cu2+ can be released through the decompositionof Cu(NH3n2+. Hence, the copper ion concentration can be maintained and this can facilitate the adsorption of Cu2+ on marmatite. Based on a comprehensive analysis of all our results, we propose that adding ammonium chloride to the copper sulfate changes the solution components (i.e., the presence of NH3(aq and Cu(NH3n2+ and then regulates the surface composition of marmatite. The change in surface composition

  4. NaCl protects against Cd and Cu-induced toxicity in the halophyte Atriplex halimus

    Energy Technology Data Exchange (ETDEWEB)

    Bankaji, I.; Sleimi, N.; Gómez-Cadenas, A.; Pérez-Clemente, R.M.

    2016-07-01

    The objective of the present work was to evaluate the extent of Cd- and Cu-induced oxidative stress and the antioxidant response triggered in the halophyte species Atriplex halimus after metallic trace elements exposure. Plants were treated for one month with Cd2+ or Cu2+ (400 µM) in the absence or presence of 200 mM NaCl in the irrigation solution. The interaction between salinity and heavy metal stress was analyzed in relation to plant growth, tissue ion contents (Na+, K+ and Mg2+), oxidative damage and antioxidative metabolism. Data indicate that shoot and root weight significantly decreased as a consequence of Cd2+- or Cu2+-induced stress. Metallic stress leads to unbalanced nutrient uptake by reducing the translocation of K+ and Mg2+ from the root to the shoot. The levels of malondialdehyde increased in root tissue when Cd, and especially Cu, were added to the irrigation solution, indicating that oxidative damage occurred. Results showed that NaCl gave a partial protection against Cd and Cu induced toxicity, although these contaminants had distinct influence on plant physiology. It can be concluded that salinity drastically modified heavy metal absorption and improved plant growth. Salinity also decreased oxidative damage, but differently in plants exposed to Cd or Cu stress.

  5. Effect of NaCl Priming on Seed Germination of Tunisian Fenugreek (Trigonella foenum-graecum L. Under Salinity Conditions

    Directory of Open Access Journals (Sweden)

    Souguir, Maher

    2013-04-01

    Full Text Available Salinity is one major problem of increasing production in crop growing areas throughout the world. The objective of this research was to evaluate the effect of NaCl priming on seed germination of Tunisian fenugreek (Trigonella foenum-graecum L. under salinity conditions. Seeds of fenugreek were primed with NaCl (4g/l for 36 h in continuous 25°C. Experimental factors were included 2 priming treatments (NaCl and non-priming as control and five salinity solution (4,6,8,10 and 12 gl-1. Results showed that seed priming increased final germination percentage, germination speed and radicle length over the non-primed treatment. At the lowest levels of salinity, there were no notable differences between primed and non-primed seeds, but with increasing salinity levels, primed seeds showed the better performance than non-primed seeds. These results indicated that NaCl priming significantly improved seed performance under salinity conditions.

  6. Composites

    International Nuclear Information System (INIS)

    Kasen, M.B.

    1983-01-01

    This chapter discusses the roles of composite laminates and aggregates in cryogenic technology. Filamentary-reinforced composites are emphasized because they are the most widely used composite materials. Topics considered include composite systems and terminology, design and fabrication, composite failure, high-pressure reinforced plastic laminates, low-pressure reinforced plastics, reinforced metals, selectively reinforced structures, the effect of cryogenic temperatures, woven-fabric and random-mat composites, uniaxial fiber-reinforced composites, composite joints in cryogenic structures, joining techniques at room temperature, radiation effects, testing laminates at cryogenic temperatures, static and cyclic tensile testing, static and cyclic compression testing, interlaminar shear testing, secondary property tests, and concrete aggregates. It is suggested that cryogenic composite technology would benefit from the development of a fracture mechanics model for predicting the fitness-for-purpose of polymer-matrix composite structures

  7. Color stability of sealed composite resin restorative materials after ultraviolet artificial aging and immersion in staining solutions.

    Science.gov (United States)

    Catelan, Anderson; Briso, André Luiz Fraga; Sundfeld, Renato Hermann; Goiato, Marcelo Coelho; dos Santos, Paulo Henrique

    2011-04-01

    The color alteration of resin-based materials is one of the most common reasons to replace esthetic dental restorations. This study assessed the influence of surface sealant (Biscover) on the color stability of nanofilled (Supreme XT) and microhybrid (Vit-l-escence and Opallis) composite resins after artificial aging. One hundred disc-shaped (6 × 1.5 mm) specimens were made for each composite resin. After 24 hours, all specimens were polished and sealant was applied to 50 specimens of each material. Baseline color was measured according to the CIE L*a*b* system using a reflection spectrophotometer. Ten specimens of each group were aged for 252 h in an ultraviolet (UV)-accelerated aging chamber or immersed for 4 weeks in cola soft drink, orange juice, red wine staining solutions or distilled water as control. Color difference (ΔE) after aging was calculated based on the color coordinates before (baseline) and after aging/staining treatment. Data were analyzed with 2-way ANOVA and Fisher's test (α=.05). The results showed significant changes in color after artificial aging in all the groups (Paging, and the cola soft drink. The lowest values of ΔE were found for specimens stored in distilled water. All composite resins showed some color alteration after the aging methods. The surface sealant did not alter the color stability of the tested materials. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  8. Catalytic wet oxidation of ammonia solution: Activity of the nanoscale platinum-palladium-rhodium composite oxide catalyst

    International Nuclear Information System (INIS)

    Hung, C.-M.

    2009-01-01

    Aqueous solutions of 400-1000 mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H 2 PtCl 6 , Pd(NO 3 ) 3 and Rh(NO 3 ) 3 . Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503 K in an oxygen partial pressure of 2.0 MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9 h -1 in the wet catalytic processes

  9. Catalytic wet oxidation of ammonia solution: Activity of the nanoscale platinum-palladium-rhodium composite oxide catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Hung, C.-M. [Department of Industry Engineering and Management, Yung-Ta Institute of Technology and Commerce, 316 Chung-shan Road, Linlo, Pingtung 909, Taiwan (China)], E-mail: hungcm1031@gmail.com

    2009-04-15

    Aqueous solutions of 400-1000 mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H{sub 2}PtCl{sub 6}, Pd(NO{sub 3}){sub 3} and Rh(NO{sub 3}){sub 3}. Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503 K in an oxygen partial pressure of 2.0 MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9 h{sup -1} in the wet catalytic processes.

  10. Catalytic wet oxidation of ammonia solution: activity of the nanoscale platinum-palladium-rhodium composite oxide catalyst.

    Science.gov (United States)

    Hung, Chang-Mao

    2009-04-15

    Aqueous solutions of 400-1000 mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H(2)PtCl(6), Pd(NO(3))(3) and Rh(NO(3))(3). Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503 K in an oxygen partial pressure of 2.0 MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9 h(-1) in the wet catalytic processes.

  11. Application of composite materials based on various extractants for isolation of lanthanides(III) nitrates from multicomponent aqueous solutions

    International Nuclear Information System (INIS)

    Kopyrin, A.A.; Pyartman, A.K.; Kesnikov, V.A.; Pleshkov, M.A.; Exekov, M.H.

    1999-01-01

    In present work we obtained samples of composite materials mentioned containing tributylphosphate (TBP) and trialkylmethylammonium nitrate (TAMAN). Extraction of lanthanides(III) nitrates of cerium group from multicomponent aqueous solutions by means of these materials was studied. Some systems with different concentration of sodium nitrate up to 5 mol/l and the same systems containing additions of sodium chloride or sulfate along with sodium nitrate was investigated, isotherm of extraction being obtained for all cases. Also we compared in identical conditions extraction process when liquid extractants were used and process with composite materials. It was found that traditional extraction systems and systems based on composite extractants demonstrated almost the same extraction properties in respect to lanthanides(III) nitrates. Extraction isotherms observed in identical conditions and being shown in the same coordinates had no difference with taking into account errors of experiment. This fact allow to use the same mathematical model for those systems. For systems studied it was generated mathematical model that is able to describe extraction process when component concentration vary in wide range, with assumption being used that ratio activity coefficients in organic phase stay constant. (authors)

  12. Kinetic Studies For the Removal of UO22+ and Pb2+ Ions From Aqueous Solution Using Zirconia Composite Material

    International Nuclear Information System (INIS)

    Sharaf El-Deen, G.E.

    2008-01-01

    Zirconia composite material was chemically synthesized previously and prepared by applying the sol-gel polymeric route using MgO as a stabilizer. The prepared composite material was characterized using various techniques: x-ray fluorescence (XRF), scanning electron microscope (SEM), differential thermal analysis and thermogravimetric analysis (DTA-TG), x-ray diffraction (XRD) and surface area using the BET-method. The sorption removal of UO 2 2+ and Pb 2+ ions from aqueous waste solution by zirconia composite material using batch technique was investigated. The sorption was carried out as a function of ph, particle size, shaking time and temperature. In this work, a comparison of kinetic models applied to the sorption process of each ion was evaluated for the pseudo first-order, the pseudo second-order, intra particle diffusion and homogeneous particle diffusion kinetic models, respectively. The results showed that the homogeneous particle diffusion model (HPDM) best correlate the experimental rate data and the numerical values of the rate constants and particle diffusion coefficients were determined from the graphical representation of the proposed models. Activation energy (Ε a ) and thermodynamic parameters of free energy (δ G * ), enthalpy (δ H * ) and entropy (δ S * ) of activation were also computed from the linearized form of Arrhenius equation

  13. Efficient removal of uranium from aqueous solution by zero-valent iron nanoparticle and its graphene composite

    International Nuclear Information System (INIS)

    Li, Zi-Jie; Wang, Lin; Yuan, Li-Yong; Xiao, Cheng-Liang; Mei, Lei; Zheng, Li-Rong; Zhang, Jing; Yang, Ju-Hua; Zhao, Yu-Liang; Zhu, Zhen-Tai; Chai, Zhi-Fang; Shi, Wei-Qun

    2015-01-01

    Highlights: • Uranium removal by ZVI-nps: independent of pH, the presence of CO 3 2− , humic acid, or mimic groundwater constituents. • Rapid removal kinetics and sorption capacity of ZVI-nps is 8173 mg U/g. • Two reaction mechanisms: sufficient Fe 0 → reductive precipitation as U 3 O 7 ; insufficient Fe 0 → hydrolysis precipitation of U(VI). • Fe/graphene composites: improved kinetics and higher U(VI) reduction ratio. - Abstract: Zero-valent iron nanoparticle (ZVI-np) and its graphene composites were prepared and applied in the removal of uranium under anoxic conditions. It was found that solutions containing 24 ppm U(VI) could be completely cleaned up by ZVI-nps, regardless of the presence of NaHCO 3 , humic acid, mimic groundwater constituents or the change of solution pH from 5 to 9, manifesting the promising potential of this reactive material in permeable reactive barrier (PRB) to remediate uranium-contaminated groundwater. In the measurement of maximum sorption capacity, removal efficiency of uranium kept at 100% until C 0 (U) = 643 ppm, and the saturation sorption of 8173 mg U/g ZVI-nps was achieved at C 0 (U) = 714 ppm. In addition, reaction mechanisms were clarified based on the results of SEM, XRD, XANES, and chemical leaching in (NH 4 ) 2 CO 3 solution. Partially reductive precipitation of U(VI) as U 3 O 7 was prevalent when sufficient iron was available; nevertheless, hydrolysis precipitation of U(VI) on surface would be predominant as iron got insufficient, characterized by releases of Fe 2+ ions. The dissolution of Fe 0 cores was assigned to be the driving force of continuous formation of U(VI) (hydr)oxide. The incorporation of graphene supporting matrix was found to facilitate faster removal rate and higher U(VI) reduction ratio, thus benefitting the long-term immobilization of uranium in geochemical environment

  14. Métodos instrumentales para la determinación de NaCl en las salmueras de aceitunas

    OpenAIRE

    García García, P.; Brenes Balbuena, M.; Garrido Fernández, A.

    1991-01-01

    Aplicability of flame photometric and ion selective (sodium or chloride) methods to determinate NaCI concentration in olive brines in comparison with the official one (Volhard), which uses AgNO3, is studied. According to the results using standard solutions or fermentative olive brines without previous lye treatment, no proportional systematic or constant systematic errors are detected and the percentaje of NaCl is evaluated by them with the same accuracy as by the...

  15. Y2O3-MgO Nano-Composite Synthesized by Plasma Spraying and Thermal Decomposition of Solution Precursors

    Science.gov (United States)

    Muoto, Chigozie Kenechukwu

    This research aims to identify the key feedstock characteristics and processing conditions to produce Y2O3-MgO composite coatings with high density and hardness using solution precursor plasma spray (SPPS) and suspension plasma spray (SPS) processes, and also, to explore the phenomena involved in the production of homogenized nano-composite powders of this material system by thermal decomposition of solution precursor mixtures. The material system would find potential application in the fabrication of components for optical applications such as transparent windows. It was shown that a lack of major endothermic events during precursor decomposition and the resultant formation of highly dense particles upon pyrolysis are critical precursor characteristics for the deposition of dense and hard Y2O3-MgO coatings by SPPS. Using these principles, a new Y2O3-MgO precursor solution was developed, which yielded a coating with Vickers hardness of 560 Hv. This was a considerable improvement over the hardness of the coatings obtained using conventional solution precursors, which was as low as 110 Hv. In the thermal decomposition synthesis process, binary solution precursor mixtures of: yttrium nitrate (Y[n]) or yttrium acetate (Y[a]), with magnesium nitrate (Mg[n]) or magnesium acetate (Mg[a]) were used in order to study the effects of precursor chemistry on the structural characteristics of the resultant Y2O3-MgO powders. The phase domains were coarse and distributed rather inhomogeneously in the materials obtained from the Y[n]Mg[n] and Y[a]Mg[a] mixtures; finer and more homogeneously-distributed phase domains were obtained for ceramics produced from the Y[a]Mg[n] and Y[n]Mg[a] mixtures. It was established that these phenomena were related to the thermal characteristics for the decomposition of the precursors and their effect on phase separation during oxide crystallization. Addition of ammonium acetate to the Y[n[Mg[n] mixture changed the endothermic process to exothermic

  16. Effect of finishing and polishing on the color stability of a composite resin immersed in staining solutions

    Directory of Open Access Journals (Sweden)

    Maiara Justo Polli

    2015-01-01

    Full Text Available Objective: To evaluate the influence of finishing/polishing methods and staining solutions using different immersion periods on the color stability of a microhybrid composite resin. Materials and Methods: Ninety specimens were fabricated using a stainless steel mold and polyester strips. The samples were randomly divided into five groups according to the finishing and polishing performed: Control group (no surface treatment was performed, Diamond Pro group, Diamond burs group, Enhance group, and SiC paper group. After finishing and polishing, six samples from each group were immersed in coffee, red wine, or water for 30 days. The color measurements were obtained using digital photography before immersion and after 7, 15, and 30 days of immersion. The red, green, and blue values provided by the Adobe Photoshop software were converted into CIELab values. A three-way analysis of variance and Tukey's test were used for statistical analysis (P ≤ 0.05. Results: The finishing and polishing methods, staining solutions, immersion times, and their interaction had statistically significant effects on the color change (P = 0.00. Coffee and red wine caused intense staining. Among the polishing methods, the highest color change value was observed in the control group (P < 0.05 and the Diamond Pro disks provided the most stain-resistant surfaces (P ≤ 0.05. Conclusion: The finishing and polishing method, staining solution, and immersion time influences the color stability. Finishing and polishing should be applied to obtain a more stain-resistant surface.

  17. Growth and cellular ion content of a salt-sensitive symbiotic system Azolla pinnata-Anabaena azollae under NaCl stress.

    Science.gov (United States)

    Rai, Vandna; Sharma, Naveen Kumar; Rai, Ashwani K

    2006-09-01

    Salinity, at a concentration of 10 mM NaCl affected the growth of Azolla pinnata-Anabaena azollae association and became lethal at 40 mM. Plants exposed up to 30 mM NaCl exhibited longer roots than the control, especially during the beginning of incubation. Average root number in plants exposed to 10 and 20 mM NaCl remained almost the same as in control. A further rise in NaCl concentration to 30 mM reduced the root number, and roots shed off at 40 mM NaCl. Presence of NaCl in the nutrient solution increased the cellular Na+ of the intact association exhibiting differential accumulation by individual partners, while it reduced the cellular Ca2+ level. However, cellular K+ content did not show significant change. Cellular Na+ based on fresh weight of respective individual partners (host tissues and cyanobiont) remained higher in the host tissues than the cyanobiont, while reverse was true for K+ and Ca2+ contents. The contribution of A. azollae in the total cellular ion content of the association was a little because of meagre contribution of the cyanobiont mass (19-21%). High salt sensitivity of Azolla-Anabaena complex is due to an inability of the association to maintain low Na+ and high Ca2+ cellular level.

  18. Effective adsorption of malachite green using magnetic barium phosphate composite from aqueous solution

    Science.gov (United States)

    Zhang, Fan; Wei, Zhong; Zhang, Wanning; Cui, Haiyan

    2017-07-01

    Magnetic Ba3(PO4)2/Fe3O4-nanoparticle (called BPFN) was prepared, characterized, and developed as a low-cost adsorbent for malachite green (MG) from aqueous solution. Factors such as adsorption temperature, pH of solution, dosage of adsorbent, adsorption kinetics and isotherms were investigated. The maximum adsorption capacity obtained in this work was 1639 mg g- 1 at 45 °C and pH 6. The adsorption process fitted the pseudo-first-order kinetic model and Langmuir isotherm model. Evidences from zeta potential, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) data revealed that the adsorption process was driven by electrostatic attraction, the interaction between Lewis base sbnd N(CH3)2 in MG and Lewis acid Ba sites of BPFN. In addition, the BPFN could be easily regenerated by a magnet and the adsorption capacity maintained at 70% after five cycles. The present study suggests that the BPFN had high potential of removing MG from wastewater.

  19. Understanding of electrochemical and structural changes of polypyrrole/polyethylene glycol composite films in aqueous solution

    International Nuclear Information System (INIS)

    Pirvu, Cristian; Manole, Claudiu Constantin; Stoian, Andrei Bogdan; Demetrescu, Ioana

    2011-01-01

    Highlights: → Electrochemical monitoring of PPy and PPy-PEG films over immersion time. → Electrochemical and surface analysis showed that PEG improves the stability of PPy films. → Mott-Schottky analysis reveals p-type conductance for both films. → In situ AFM analysis sustains electrochemical behaviour. → A model of PPy and PPy-PEG films behaviour during immersion was elaborated. - Abstract: Electrochemical monitoring of electrical and structural changes of both PPy and PPy-PEG films electrochemical deposited, in order to highlight if the structural stability offered by PEG has an influence on electrical properties and stability in aqueous solution over immersion time was investigated. Electrochemical analysis suggests that PPy-PEG film inserts cations easier than PPy film for a short immersion time probably due to ability of PEG to form complexes with metal cations. The FTIR spectra showed that the PEG incorporation decreases the rate of PPy overoxidation probably by restraining the electron release and by rendering O 2 inaccessible to PPy. Mott-Schottky analysis based on capacitance measurement reveal p-type conductance for both films. The in situ AFM analysis sustains electrochemical behaviour and has permitted elaboration of a model of PPy and PPy-PEG films behaviour during immersion in testing solution.

  20. Understanding of electrochemical and structural changes of polypyrrole/polyethylene glycol composite films in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Pirvu, Cristian, E-mail: c_pirvu@chim.pub.ro [University Polytechnic of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu, 011061 Bucharest (Romania); Manole, Claudiu Constantin; Stoian, Andrei Bogdan; Demetrescu, Ioana [University Polytechnic of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu, 011061 Bucharest (Romania)

    2011-11-30

    Highlights: > Electrochemical monitoring of PPy and PPy-PEG films over immersion time. > Electrochemical and surface analysis showed that PEG improves the stability of PPy films. > Mott-Schottky analysis reveals p-type conductance for both films. > In situ AFM analysis sustains electrochemical behaviour. > A model of PPy and PPy-PEG films behaviour during immersion was elaborated. - Abstract: Electrochemical monitoring of electrical and structural changes of both PPy and PPy-PEG films electrochemical deposited, in order to highlight if the structural stability offered by PEG has an influence on electrical properties and stability in aqueous solution over immersion time was investigated. Electrochemical analysis suggests that PPy-PEG film inserts cations easier than PPy film for a short immersion time probably due to ability of PEG to form complexes with metal cations. The FTIR spectra showed that the PEG incorporation decreases the rate of PPy overoxidation probably by restraining the electron release and by rendering O{sub 2} inaccessible to PPy. Mott-Schottky analysis based on capacitance measurement reveal p-type conductance for both films. The in situ AFM analysis sustains electrochemical behaviour and has permitted elaboration of a model of PPy and PPy-PEG films behaviour during immersion in testing solution.

  1. Propagating particle density fluctuations in molten NaCl

    International Nuclear Information System (INIS)

    Demmel, F.; Hosokawa, S.; Pilgrim, W.-C.; Lorenzen, M.

    2004-01-01

    In this paper we present the observation of acoustic modes in the spectra of molten NaCl measured over a large momentum transfer range using synchrotron radiation. A surprisingly large positive dispersion was deduced with a mode velocity exceeding the adiabatic value by nearly 70%. The large effect seems to be describable as a viscoelastic reaction of the liquid. Additionally, the derived dispersion resembles the Q-ω relation of the acoustic modes in liquid sodium. As an explanation for the large positive dispersion we propose that the density fluctuations in molten NaCl can be interpreted as a decoupled motion of the lighter and smaller cations on a nearly resting anionic background. These molten alkali halide measurements are the first experimental evidences for the so-called fast sound in a binary ionic liquid

  2. Tolerance of soil flagellates to increased NaCl levels

    DEFF Research Database (Denmark)

    Ekelund, Flemming

    2002-01-01

    The ability of heterotrophic flagellates to survive and adapt to increasing salinities was investigated in this study. Whole soil samples were subjected to salinities corresponding to marine conditions and clonal cultures were used to perform growth and adaptation experiments at a wide range...... of different salinities (0-50 ppm). More morphotypes tolerant to elevated NaCl levels were found in road verge soil that was heavily exposed to de-icing salt than in less exposed soils, though there were fewer tolerant than intolerant morphotypes in all soils examined. Heterotrophic flagellates isolated...... on a freshwater medium from a non-exposed soil were unable to thrive at salinities above 15 ppt, and showed reduced growth rates even at low salt salinities (1-5 ppt). The findings suggest that heterotrophic soil flagellates are less tolerant to NaCl than their aquatic relatives, possibly due to their long...

  3. CT-guided lung biopsy: incidence of pneumothorax after instillation of NaCl into the biopsy track

    Energy Technology Data Exchange (ETDEWEB)

    Billich, Christian; Brenner, Gerhard; Schmidt, Stefan A.; Brambs, Hans-Juergen; Pauls, Sandra [University of Ulm, Department of Diagnostic and Interventional Radiology, Ulm (Germany); Muche, Rainer [University of Ulm, Institute of Biometrics, Ulm (Germany); Krueger, Stefan [University of Ulm, Department of Internal Medicine, Ulm (Germany)

    2008-06-15

    This study was conducted to evaluate whether instillation of NaCl 0.9% solution into the biopsy track reduces the incidence of pneumothoraces after CT-guided lung biopsy. A total of 140 consecutive patients with pulmonary lesions were included in this prospective study. All patients were alternatingly assigned to one of two groups: group A in whom the puncture access was sealed by instillation of NaCl 0.9% solution during extraction of the guide needle (n = 70) or group B for whom no sealing was performed (n = 70). CT-guided biopsy was performed with a 18-G coaxial system. Localization of lesion (pleural, peripheral, central), lesion size, needle-pleural angle, rate of pneumothorax and alveolar hemorrhage were evaluated. In group A, the incidence of pneumothorax was lower compared to group B (8%, 6/70 patients vs. 34%, 24/70 patients; P < 0.001). All pneumothoraces occurred directly post punctionem after extraction of the guide needle. One patient in group A and eight patients in group B developed large pneumothoraces requiring chest tube placement (P = 0.01). The frequency of pneumothorax was independent of other variables. After CT-guided biopsy, instillation of NaCl 0.9% solution into the puncture access during extraction of the needle significantly reduces the incidence of pneumothorax. (orig.)

  4. CT-guided lung biopsy: incidence of pneumothorax after instillation of NaCl into the biopsy track

    International Nuclear Information System (INIS)

    Billich, Christian; Brenner, Gerhard; Schmidt, Stefan A.; Brambs, Hans-Juergen; Pauls, Sandra; Muche, Rainer; Krueger, Stefan

    2008-01-01

    This study was conducted to evaluate whether instillation of NaCl 0.9% solution into the biopsy track reduces the incidence of pneumothoraces after CT-guided lung biopsy. A total of 140 consecutive patients with pulmonary lesions were included in this prospective study. All patients were alternatingly assigned to one of two groups: group A in whom the puncture access was sealed by instillation of NaCl 0.9% solution during extraction of the guide needle (n 70) or group B for whom no sealing was performed (n = 70). CT-guided biopsy was performed with a 18-G coaxial system. Localization of lesion (pleural, peripheral, central), lesion size, needle-pleural angle, rate of pneumothorax and alveolar hemorrhage were evaluated. In group A, the incidence of pneumothorax was lower compared to group B (8%, 6/70 patients vs. 34%, 24/70 patients; P < 0.001). All pneumothoraces occurred directly post punctionem after extraction of the guide needle. One patient in group A and eight patients in group B developed large pneumothoraces requiring chest tube placement (P 0.01). The frequency of pneumothorax was independent of other variables. After CT-guided biopsy, instillation of NaCl 0.9% solution into the puncture access during extraction of the needle significantly reduces the incidence of pneumothorax. (orig.)

  5. Effect of the cationic composition of sorption solution on the quantification of sorption-desorption parameters of heavy metals in soils

    International Nuclear Information System (INIS)

    Sastre, J.; Rauret, G.; Vidal, M.

    2006-01-01

    We obtained the sorption isotherms of Cd, Cu, Pb and Zn in clay, clay saline and organic soils. The distribution coefficients (K d ) were determined in 0.02 eq l -1 CaCl 2 and in a solution that simulated the soil solution cationic composition. The K d values greatly varied with the composition of the sorption solution and the initial metal concentration. The sorption experiments were complemented with the quantification of the extractable metal, to estimate the reversibility of metal sorption. The extraction yields depended on the metal-soil combination, and the initial metal concentration, showing no correlation with previous K d values. The effect of the solution composition in mobility predictions was estimated through a Retention Factor, defined as the ratio of the K d versus the extraction yield. Results showed that risk was over- or underestimated using the CaCl 2 medium in soils with a markedly different soil solution composition. - Sorption solution composition modifies metal sorption-desorption pattern in soils

  6. Determination of Sugar Composition of Polysaccharides in Caesalpinia pulcherrima Galactomannan Solution Using HPTLC

    Directory of Open Access Journals (Sweden)

    Nilima A. THOMBRE

    2015-04-01

    Full Text Available Galactomannans (GM, a group of neutral nontoxic polysaccharides naturally occurring in the seeds of some legumes, are used in the textile, pharmaceutical, biomedical, cosmetics and food industries. As to date there are no documented reports on determination of the sugar composition in polysaccharides by HPTLC and the following study is an attempt in this direction. GM from seeds of Caesalpinia pulcherrima L. (CP was isolated and purified by precipitation method using alcohol. A new, simple, sensitive, selective, precise, and robust HPTLC method for analysis of monosaccharides such as galactose, mannose, xylose and glucose in isolated CP GM has been developed and validated. Chromatograms were developed using a mobile phase of acetone: water (9:1 v/v on pre-coated plate of silica gel GF aluminium TLC plate and quantified by UV spectrophotometer at 254nm. The Rf values were 0.45, 0.34, 0.40 and 0.60 for mannose, galactose, xylose and glucose, respectively. The linearity of method was found to be within the concentration range of 2000-10000 ng/spot for all above monosaccharides. The limit of detection for mannose, galactose, xylose and glucose was found to be 0.14986 ng/spot, 0.31973 ng/spot, 0.27569 ng/spot, and 0.36808 ng/spot, respectively. The limit of quantification for mannose, galactose, xylose and glucose was found to be 1.498 ng/spot, 3.197 ng/spot, 2.756 ng/spot, and 3.680 ng/spot, respectively. The method was also validated for precision, specificity and recovery. This developed method was used to analyze CP GM for monosaccharides compositions

  7. Cement Types, Composition, Uses and Advantages of Nanocement, Environmental Impact on Cement Production, and Possible Solutions

    Directory of Open Access Journals (Sweden)

    S. P. Dunuweera

    2018-01-01

    Full Text Available We first discuss cement production and special nomenclature used by cement industrialists in expressing the composition of their cement products. We reveal different types of cement products, their compositions, properties, and typical uses. Wherever possible, we tend to give reasons as to why a particular cement type is more suitable for a given purpose than other types. Cement manufacturing processes are associated with emissions of large quantities of greenhouse gases and environmental pollutants. We give below quantitative and qualitative analyses of environmental impact of cement manufacturing. Controlling pollution is a mandatory legal and social requirement pertinent to any industry. As cement industry is one of the biggest CO2 emitters, it is appropriate to discuss different ways and means of CO2 capture, which will be done next. Finally, we give an account of production of nanocement and advantages associated with nanocement. Nanofillers such as nanotitania, nanosilica, and nanoalumina can be produced in large industrial scale via top-down approach of reducing size of naturally available bulk raw materials to those in the nanorange of 1 nm–100 nm. We mention the preparation of nanotitania and nanosilica from Sri Lankan mineral sands and quartz deposits, respectively, for the use as additives in cement products to improve performance and reduce the amount and cost of cement production and consequent environmental impacts. As of now, mineral sands and other treasures of minerals are exported without much value addition. Simple chemical modifications or physical treatments would add enormous value to these natural materials. Sri Lanka is gifted with highly pure quartz and graphite from which silica and graphite nanoparticles, respectively, can be prepared by simple size reduction processes. These can be used as additives in cements. Separation of constituents of mineral sands is already an ongoing process.

  8. Preparation of SiO2-KCoFC composite ion-exchanger for removal of Cs in the soil decontamination waste solution

    International Nuclear Information System (INIS)

    Lee, Jung Joon; Moon, Jei kwon; Lee, Kune Woo

    2009-01-01

    The soil decontamination process has been developed for remediate the soil wastes excavated from the TRIGA research reactor sites. Even though the process was proven to be very effective for decontaminate the radioactive nuclides such as cesium and cobalt, the secondary spent solution should be treated with an appropriate method to minimize the waste volume. There are mainly two components in the spent decontamination solution of Cs and Co. The Co in the waste solution can be removed easily by precipitation under a basic condition. However, since the Cs is hardly removed by precipitation, an appropriate selective removal method should be employed. In this study, an inorganic composite ion exchanger of SiO 2 -KCoFC was prepared by sol-gel method for a removal of Cs in the decontamination waste solution. An optimum condition for a preparation of the composite ion exchanger and the adsorption performances of the prepared composite ion exchangers were evaluated

  9. Temperature dependence of thermal pressure for NaCl

    Science.gov (United States)

    Singh, Chandra K.; Pande, Brijesh K.; Pandey, Anjani K.

    2018-05-01

    Engineering applications of the materials can be explored upto the desired limit of accuracy with the better knowledge of its mechanical and thermal properties such as ductility, brittleness and Thermal Pressure. For the resistance to fracture (K) and plastic deformation (G) the ratio K/G is treated as an indication of ductile or brittle character of solids. In the present work we have tested the condition of ductility and brittleness with the calculated values of K/G for the NaCl. It is concluded that the nature of NaCl can be predicted upto high temperature simply with the knowledge of its elastic stiffness constant only. Thermoelastic properties of materials at high temperature is directly related to thermal pressure and volume expansion of the materials. An expression for the temperature dependence of thermal pressure is formulated using basic thermodynamic identities. It is observed that thermal pressure ΔPth calculated for NaCl by using Kushwah formulation is in good agreement with the experimental values also the thermal pressure increases with the increase in temperature.

  10. Adsorption of Ni2+ from aqueous solution by magnetic Fe@graphite nano-composite

    Directory of Open Access Journals (Sweden)

    Konicki Wojciech

    2016-12-01

    Full Text Available The removal of Ni2+ from aqueous solution by iron nanoparticles encapsulated by graphitic layers (Fe@G was investigated. Nanoparticles Fe@G were prepared by chemical vapor deposition CVD process using methane as a carbon source and nanocrystalline iron. The properties of Fe@G were characterized by X-ray Diffraction method (XRD, High-Resolution Transmission Electron Microscopy (HRTEM, Fourier Transform-Infrared Spectroscopy (FTIR, BET surface area and zeta potential measurements. The effects of initial Ni2+ concentration (1–20 mg L−1, pH (4–11 and temperature (20–60°C on adsorption capacity were studied. The adsorption capacity at equilibrium increased from 2.96 to 8.78 mg g−1, with the increase in the initial concentration of Ni2+ from 1 to 20 mg L−1 at pH 7.0 and 20oC. The experimental results indicated that the maximum Ni2+ removal could be attained at a solution pH of 8.2 and the adsorption capacity obtained was 9.33 mg g−1. The experimental data fitted well with the Langmuir model with a monolayer adsorption capacity of 9.20 mg g−1. The adsorption kinetics was found to follow pseudo-second-order kinetic model. Thermodynamics parameters, ΔHO, ΔGO and ΔSO, were calculated, indicating that the adsorption of Ni2+ onto Fe@G was spontaneous and endothermic in nature.

  11. The Systematics of Activity-Composition Relations in Mg-Fe2+ Oxide and Silicate Solid Solutions

    Science.gov (United States)

    O'Neill, H. S.

    2006-12-01

    The need to quantify activity-composition relations of mineral solid solutions for petrologic modelling has prompted many experimental studies, but different studies on the same system often appear to show a startling lack of consistency. A good example is Mg-Fe2+ mixing in garnet (the pyrope-almandine join). This is understandable because the energies of mixing in solid solutions are often obtained experimentally as small difference between large numbers. In particular, the fallacy of using a sequential approach to data fitting to a thermodynamic model leads to the accumulated errors being artificially concentrated onto the last step of the fitting process, which is usually that part of the model dealing with the excess energies of mixing. This gives rise to erroneous activity-composition relations, often apparently showing complex deviations from ideality. Systemizing the results of many studies can reveal underlying patterns of behaviour while also identifying outliers and anomalies that may be worth reinvestigating. Davies and Navrotsky [1] showed that the energies of mixing of many different pairs of ions with the same charge correlated well with the difference in molar volumes of the end-members, within a particular crystal structure. This empirical work is now supported by theoretical calculations. It underlies the modern approach to melt/crystal trace-element partitioning. Provided an internally consistent dataset is used, an analogous correlation may be demonstrated across different crystal structures for the mixing of one pair of ions, such as Mg and Fe2+. Activity-composition relations in MgO-"FeO" magnesiowuestite solutions in equilibrium with iron metal were used to obtain the properties of Mg-Fe olivine solutions from magnesiowuestite/olivine partitioning [2]. New results at 1400 K, 1 bar and 1473 K, 25 kb (O'Neill and Pownceby, in prep.) confirm previous work that mixing in Mg-Fe olivine is regular (symmetrical) with W Mg-Fe = 2.5 kJ/mol, with an

  12. Structural and compositional characterization of synthetic (Ca,Sr)-tremolite and (Ca,Sr)-diopside solid solutions

    Science.gov (United States)

    Gottschalk, M.; Najorka, J.; Andrut, M.

    Tremolite (CaxSr1-x)2Mg5[Si8O22/(OH)2] and diopside (CaxSr1-x)Mg[Si2O6] solid solutions have been synthesized hydrothermally in equilibrium with a 1 molar (Ca,Sr)Cl2 aqueous solution at 750°C and 200 MPa. The solid run products have been investigated by optical, electron scanning and high resolution transmission electron microscopy, electron microprobe, X-ray-powder diffraction and Fourier-transform infrared spectroscopy. The synthesized (Ca,Sr)-tremolites are up to 2000 µm long and 30 µm wide, the (Ca,Sr)-diopsides are up to 150 µm long and 20 µm wide. In most runs the tremolites and diopsides are well ordered and chain multiplicity faults are rare. Nearly pure Sr-tremolite (tr0.02Sr-tr0.98) and Sr-diopside (di0.01Sr-di0.99) have been synthesized. A continuous solid solution series, i.e. complete substitution of Sr2+ for Ca2+ on M4-sites exists for (Ca,Sr)-tremolite. Total substitution of Sr2+ for Ca2+ on M2-sites can be assumed for (Ca,Sr)-diopsides. For (Ca,Sr)-tremolites the lattice parameters a, b and β are linear functions of composition and increase with Sr-content whereas c is constant. For the diopside series all 4 lattice parameters are a linear function of composition; a, b, c increase and β decreases with rising Sr-content. The unit cell volume for tremolite increases 3.47% from 906.68 Å3 for tremolite to 938.21 Å3 for Sr-tremolite. For diopside the unit cell volume increases 4.87 % from 439.91 Å3 for diopside to 461.30 Å3 for Sr-diopside. The observed splitting of the OH stretching band in tremolite is caused by different configurations of the next nearest neighbors (multi mode behavior). Resolved single bands can be attributed to the following configurations on the M4-sites: SrSr, SrCa, CaCa and CaMg. The peak positions of these 4 absorption bands are a linear function of composition. They are shifted to lower wavenumbers with increasing Sr-content. No absorption band due to the SrMg configuration on the M4-site is observed. This indicates

  13. Arsenic removal from aqueous solutions using Fe3O4-HBC composite: effect of calcination on adsorbents performance.

    Directory of Open Access Journals (Sweden)

    Shams Ali Baig

    Full Text Available The presence of elevated concentration of arsenic in water sources is considered to be health hazard globally. Calcination process is known to change the surface efficacy of the adsorbent. In current study, five adsorbent composites: uncalcined and calcined Fe3O4-HBC prepared at different temperatures (400°C and 1000°C and environment (air and nitrogen were investigated for the adsorptive removal of As(V and As(III from aqueous solutions determining the influence of solution's pH, contact time, temperature, arsenic concentration and phosphate anions. Characterizations from FTIR, XRD, HT-XRD, BET and SEM analyses revealed that the Fe3O4-HBC composite at higher calcination temperature under nitrogen formed a new product (fayalite, Fe2SiO4 via phase transformation. In aqueous medium, ligand exchange between arsenic and the effective sorbent site ( = FeOOH was established from the release of hydroxyl group. Langmuir model suggested data of the five adsorbent composites follow the order: Fe3O4-HBC-1000°C(N2>Fe3O4-HBC (uncalcined>Fe3O4-HBC-400°C(N2>Fe3O4-HBC-400°C(air>Fe3O4-HBC-1000°C(air and the maximum As(V and As(III adsorption capacities were found to be about 3.35 mg g(-1 and 3.07 mg g(-1, respectively. The adsorption of As(V and As(III remained stable in a wider pH range (4-10 using Fe3O4-HBC-1000°C(N2. Additionally, adsorption data fitted well in pseudo-second-order (R2>0.99 rather than pseudo-first-order kinetics model. The adsorption of As(V and As(III onto adsorbent composites increase with increase in temperatures indicating that it is an endothermic process. Phosphate concentration (0.0l mM or higher strongly inhibited As(V and As(III removal through the mechanism of competitive adsorption. This study suggests that the selective calcination process could be useful to improve the adsorbent efficiency for enhanced arsenic removal from contaminated water.

  14. Arsenic removal from aqueous solutions using Fe3O4-HBC composite: effect of calcination on adsorbents performance.

    Science.gov (United States)

    Baig, Shams Ali; Sheng, TianTian; Sun, Chen; Xue, XiaoQin; Tan, LiSha; Xu, XinHua

    2014-01-01

    The presence of elevated concentration of arsenic in water sources is considered to be health hazard globally. Calcination process is known to change the surface efficacy of the adsorbent. In current study, five adsorbent composites: uncalcined and calcined Fe3O4-HBC prepared at different temperatures (400°C and 1000°C) and environment (air and nitrogen) were investigated for the adsorptive removal of As(V) and As(III) from aqueous solutions determining the influence of solution's pH, contact time, temperature, arsenic concentration and phosphate anions. Characterizations from FTIR, XRD, HT-XRD, BET and SEM analyses revealed that the Fe3O4-HBC composite at higher calcination temperature under nitrogen formed a new product (fayalite, Fe2SiO4) via phase transformation. In aqueous medium, ligand exchange between arsenic and the effective sorbent site ( = FeOOH) was established from the release of hydroxyl group. Langmuir model suggested data of the five adsorbent composites follow the order: Fe3O4-HBC-1000°C(N2)>Fe3O4-HBC (uncalcined)>Fe3O4-HBC-400°C(N2)>Fe3O4-HBC-400°C(air)>Fe3O4-HBC-1000°C(air) and the maximum As(V) and As(III) adsorption capacities were found to be about 3.35 mg g(-1) and 3.07 mg g(-1), respectively. The adsorption of As(V) and As(III) remained stable in a wider pH range (4-10) using Fe3O4-HBC-1000°C(N2). Additionally, adsorption data fitted well in pseudo-second-order (R2>0.99) rather than pseudo-first-order kinetics model. The adsorption of As(V) and As(III) onto adsorbent composites increase with increase in temperatures indicating that it is an endothermic process. Phosphate concentration (0.0l mM or higher) strongly inhibited As(V) and As(III) removal through the mechanism of competitive adsorption. This study suggests that the selective calcination process could be useful to improve the adsorbent efficiency for enhanced arsenic removal from contaminated water.

  15. Insights From Magnesium Isotopic Compositions on the Oceanic Hydrothermal Circulation: Is Seamount Weathering the Solution?

    Science.gov (United States)

    Galy, A.; Carder, E.; Elderfield, H.

    2006-12-01

    It has been long recognised that the input of Mg in the ocean by river is removed by precipitation of Mg-rich bearing phases, either directly from the ocean such as dolomite or through hydrothermal circulation in the oceanic crust. The sampling of hydrothermal fluids demonstrated the efficiency of Mg consumption by the alteration of the oceanic crust, even at temperatures as low as 15°. For high-temperature fluids vented through black or white smokers in the vicinity of the ridge, the Mg concentration is up to 50 time lower than in seawater, and the close relationship between chlorine and Mg led to the idea that seawater was feeding the hydrothermal system and that Mg is quantitatively removed from it during high-T° alteration, the so called zero Mg hypothesis. Despite some hint for a non zero Mg hydrothermal end-member for a handful sites, the low concentration of Mg in oceanic hydrothermal fluids (around 1 mmol/l) has been mainly attributed to contamination by seawater during the sampling. Here we present Mg isotopic composition of 14 seawater samples from the Atlantic, Pacific and Indian Oceans and the Mediterranean and Red Seas and covering a range of depth of almost 5km and 26 hydrothermal fluids from 7 sites in the Atlantic and Pacific Oceans with temperature from 15° to 380°C. We find the magnesium isotope composition of seawater to be constant, with a δ^{26}Mg = -0.82±0.10 ‰ relative to the DSM3 standard. This value is consistent with a long residence time for Mg in seawater. In addition, out of the 26 hydrothermal fluids studied, more than 58% differ from seawater for their Mg isotopic composition by more than 2σ. This number rises up to 88% at 2σmean level and the shift is systematic with the fluids being either indistinguishable from seawater or enriched in light isotopes by up to 2.4‰ in δ^{26}Mg. This clearly demonstrates that fluids having low Mg concentrations are not solely bearing Mg added by contamination during sampling. The isotopic

  16. A numerical model for the solution of the Shallow Water equations in composite channels with movable bed

    Science.gov (United States)

    minatti, L.

    2013-12-01

    A finite volume model solving the shallow water equations coupled with the sediments continuity equation in composite channels with irregular geometry is presented. The model is essentially 1D but can handle composite cross-sections in which bedload transport is considered to occur inside the main channel only. This assumption is coherent with the observed behavior of rivers on short time scales where main channel areas exhibit more relevant morphological variations than overbanks. Furthermore, such a model allows a more precise prediction of thalweg elevation and cross section shape variations than fully 1D models where bedload transport is considered to occur uniformly over the entire cross section. The coupling of the equations describing water and sediments dynamics results in a hyperbolic non-conservative system that cannot be solved numerically with the use of a conservative scheme. Therefore, a path-conservative scheme, based on the approach proposed by Pares and Castro (2004) has been devised in order to account for the coupling with the sediments continuity equation and for the concurrent presence of bottom elevation and breadth variations of the cross section. In order to correctly compute numerical fluxes related to bedload transport in main channel areas, a special treatment of the equations is employed in the model. The resulting scheme is well balanced and fully coupled and can accurately model abrupt time variations of flow and bedload transport conditions in wide rivers, characterized by the presence of overbank areas that are less active than the main channel. The accuracy of the model has been first tested in fixed bed conditions by solving problems with a known analytical solution: in these tests the model proved to be able to handle shocks and supercritical flow conditions properly(see Fig. 01). A practical application of the model to the Ombrone river, southern Tuscany (Italy) is shown. The river has shown relevant morphological changes during

  17. The Role of Thiosulfate Ions in the Initiation of Crevice Corrosion of 316 Stainless Steel in Chloride Solution

    International Nuclear Information System (INIS)

    Gad, M.M.A.; El-Sayed, A.A.

    2008-01-01

    Electrochemical techniques have been applied to study the crevice corrosion behavior of 316 L stainless steel in both 0.5 and 2 M NaCl solution with and without thiosulfate additions. In this investigation, the crevice corrosion of the tested material was studied in both bulk solution environment (0.5 M NaCl) as well as in chloride solutions simulating those formed inside crevices of stainless steels. A metal to nonmetal assembly, in which disc type specimens were faced to a PTFE crevice former, is used for bulk solution tests. Crevice- free specimens of cylindrical shape were used for the determination of the composition of solutions formed inside crevices (known as CCS). Potentiodynamic runs in extremely low ph solution (2 M NaCl solution with and without 0.01 M Na 2 SO 3 addition) were conducted to determine the ph at which the passive film breaks down (d ph). The d ph value was found to be a function of both chloride and thiosulfate ions. Cyclic potentiodynamic technique was used in evaluating the electrochemical corrosion performance of the tested alloy in bulk 0.5 M NaCl solution with and without 0.01 M Na 2 SO 3 addition. Results indicated that the presence of thiosulfate, combined with chloride ions led to a notable decrease in the corrosion resistance of the tested material. The deleterious effect of thiosulfates was discussed in terms of passivity breakdown and formation of reduced sulfur species within active crevices leading to the formation of H 2 S, which enhances the anodic dissolution of iron

  18. Effect of solution composition on determination of uranium (6) microquantities by laser-induced luminescence method

    International Nuclear Information System (INIS)

    Romanovskaya, G.I.; Zakharova, G.V.; Chibisova, A.K.

    1984-01-01

    The effect of cation and anion composition of natural waters (sea water, ground water, etc.) on the uranium (6) determination in the form of uranyl complexes with Na 2 O3SiO 2 using the laser-induced luminescence method with the determination limit 2x10 -11 g/ml, has been studied. The dependence of the luminescence intensity of uranyl polysilicate complexes on the inorganic ion concentration has been measured. The measurement results permitted to determine the maximum permissible concentrations (MAC) of ions, the values of which are presented. The results reproducibility is characterized by a relative standard deveation within 0.01-0.05. It follows from the data analysis that the MPC of impurities vary from 10 -8 to 10 -2 g/ml. The MPCs of uranium as determined in the form of polysilicate complexes, are shown to be close to the values obtained during uranium determination in the form of complexes with fluoran for the CO 3 2- , Ni, Cu ions and they are by an order higher for the Na, K, Cl - , SO 4 2- , HPO 4 2- , Mn ions

  19. Removal of dieldrin from aqueous solution by a novel triolein-embedded composite adsorbent

    International Nuclear Information System (INIS)

    Ru Jia; Liu Huijuan; Qu Jiuhui; Wang Aimin; Dai Ruihua

    2007-01-01

    In this study, a novel triolein-embedded activated carbon composite adsorbent (CA-T) was prepared and applied for the adsorption and removal of dieldrin from aqueous systems. Experiments were carried out to investigate the adsorption behavior of dieldrin on CA-T, including adsorption isotherms, adsorption kinetics, the influence of initial concentration, temperature, shaking speed, pH and the addition of humic acid (HA) on adsorption. The adsorption isotherms accorded with Freundlich equation. Three kinetics models, including pseudo-first-order, pseudo-second-order and intraparticle diffusion models, were used to fit the experimental data. By comparing the correlation coefficients, it was found that both pseudo-second-order and intraparticle diffusion models were used to well describe the adsorption of dieldrin on CA-T. The addition of HA had little effect on dieldrin adsorption by CA-T. Results indicated that CA-T appeared to be a promising adsorbent for removing lipophilic dieldrin in trace amount, which was advantageous over pure granular activated carbon (GAC). The adsorption rate increased with increasing shaking speed, initial concentration and temperature, and remained almost unchanged in the pH range of 4-8. Thermodynamic calculations indicated that the adsorption reaction was spontaneous with a high affinity and the adsorption was an endothermic reaction

  20. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2011-01-01

    Strategies are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full...

  1. Composition

    DEFF Research Database (Denmark)

    2014-01-01

    Memory Pieces are open compositions to be realised solo by an improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them...

  2. Earliest Results in the Use of Activated Composite Membranes for the Transport of Silver Ions from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Yucundo Mendoza-Tolentino

    2014-01-01

    Full Text Available This paper presents the results concerning the first use of activated composite membranes (ACMs for the facilitated transport of silver ions containing di-(2-ethylhexyl-dithiophosphoric acid (DTPA as the carrier. DTPA was immobilized by interfacial polymerization in a dense layer that was deposited in a porous layer, which was prepared on a nonwoven fabric support by phase inversion. The influence of fundamental parameters affecting the transport of silver ion as the carrier concentration in the membrane phase and stripping agent variation of the stripping solution have been studied. In the optimal conditions, the amount of silver transported across the ACMs was greater than 50%, whereas if the content of the carrier is modified, more than the 90% of the initial silver is removed from the feed phase.

  3. Effect of soaking in water and rumen digeta solutions on metabolizable energy content and chemical composition of barley seeds for use in poultry diet.

    Science.gov (United States)

    Tabatabee, S N; Sadeghi, G H; Tabeidian, S A

    2007-03-15

    An experiment was carried out to evaluate the effect of soaking in water and different rumen digesta solutions on nutritional value of dry barley seeds. Treatments were included distilled water as control and rumen digesta that diluted with distilled water to obtain 20, 40 and 60% digesta solutions. Solutions have added to 10 kg of barley seed samples to achieve final 30% moisture content. After 21 days the chemical composition and energy content of barley seed were determined. Gross energy of barley seeds did not affected by different experimental treatments. Use of 20% rumen digesta solution resulted to a significant (pcontent of barley seeds. Barley seed that treated with 40% of rumen digesta solution had highest TME and TMEn content and its different from seeds that treated with 60 and 100% rumen digesta solutions was significant (prumen digesta solutions increased crud protein, ether extract, crude fiber and ash content of barley seeds numerically.

  4. Beyond temperature: Clumped isotope signatures in dissolved inorganic carbon species and the influence of solution chemistry on carbonate mineral composition

    Science.gov (United States)

    Tripati, Aradhna K.; Hill, Pamela S.; Eagle, Robert A.; Mosenfelder, Jed L.; Tang, Jianwu; Schauble, Edwin A.; Eiler, John M.; Zeebe, Richard E.; Uchikawa, Joji; Coplen, Tyler B.; Ries, Justin B.; Henry, Drew

    2015-01-01

    “Clumped-isotope” thermometry is an emerging tool to probe the temperature history of surface and subsurface environments based on measurements of the proportion of 13C and 18O isotopes bound to each other within carbonate minerals in 13C18O16O22- groups (heavy isotope “clumps”). Although most clumped isotope geothermometry implicitly presumes carbonate crystals have attained lattice equilibrium (i.e., thermodynamic equilibrium for a mineral, which is independent of solution chemistry), several factors other than temperature, including dissolved inorganic carbon (DIC) speciation may influence mineral isotopic signatures. Therefore we used a combination of approaches to understand the potential influence of different variables on the clumped isotope (and oxygen isotope) composition of minerals.We conducted witherite precipitation experiments at a single temperature and at varied pH to empirically determine 13C-18O bond ordering (Δ47) and δ18O of CO32- and HCO3- molecules at a 25 °C equilibrium. Ab initio cluster models based on density functional theory were used to predict equilibrium 13C-18O bond abundances and δ18O of different DIC species and minerals as a function of temperature. Experiments and theory indicate Δ47 and δ18O compositions of CO32- and HCO3- ions are significantly different from each other. Experiments constrain the Δ47-δ18O slope for a pH effect (0.011 ± 0.001; 12 ⩾ pH ⩾ 7). Rapidly-growing temperate corals exhibit disequilibrium mineral isotopic signatures with a Δ47-δ18O slope of 0.011 ± 0.003, consistent with a pH effect.Our theoretical calculations for carbonate minerals indicate equilibrium lattice calcite values for Δ47 and δ18O are intermediate between HCO3− and CO32−. We analyzed synthetic calcites grown at temperatures ranging from 0.5 to 50 °C with and without the enzyme carbonic anhydrase present. This enzyme catalyzes oxygen isotopic exchange between DIC species and is present in many

  5. Beyond temperature: Clumped isotope signatures in dissolved inorganic carbon species and the influence of solution chemistry on carbonate mineral composition

    Science.gov (United States)

    Tripati, Aradhna K.; Hill, Pamela S.; Eagle, Robert A.; Mosenfelder, Jed L.; Tang, Jianwu; Schauble, Edwin A.; Eiler, John M.; Zeebe, Richard E.; Uchikawa, Joji; Coplen, Tyler B.; Ries, Justin B.; Henry, Drew

    2015-10-01

    ;Clumped-isotope; thermometry is an emerging tool to probe the temperature history of surface and subsurface environments based on measurements of the proportion of 13C and 18O isotopes bound to each other within carbonate minerals in 13C18O16O22- groups (heavy isotope ;clumps;). Although most clumped isotope geothermometry implicitly presumes carbonate crystals have attained lattice equilibrium (i.e., thermodynamic equilibrium for a mineral, which is independent of solution chemistry), several factors other than temperature, including dissolved inorganic carbon (DIC) speciation may influence mineral isotopic signatures. Therefore we used a combination of approaches to understand the potential influence of different variables on the clumped isotope (and oxygen isotope) composition of minerals. We conducted witherite precipitation experiments at a single temperature and at varied pH to empirically determine 13C-18O bond ordering (Δ47) and δ18O of CO32- and HCO3- molecules at a 25 °C equilibrium. Ab initio cluster models based on density functional theory were used to predict equilibrium 13C-18O bond abundances and δ18O of different DIC species and minerals as a function of temperature. Experiments and theory indicate Δ47 and δ18O compositions of CO32- and HCO3- ions are significantly different from each other. Experiments constrain the Δ47-δ18O slope for a pH effect (0.011 ± 0.001; 12 ⩾ pH ⩾ 7). Rapidly-growing temperate corals exhibit disequilibrium mineral isotopic signatures with a Δ47-δ18O slope of 0.011 ± 0.003, consistent with a pH effect. Our theoretical calculations for carbonate minerals indicate equilibrium lattice calcite values for Δ47 and δ18O are intermediate between HCO3- and CO32-. We analyzed synthetic calcites grown at temperatures ranging from 0.5 to 50 °C with and without the enzyme carbonic anhydrase present. This enzyme catalyzes oxygen isotopic exchange between DIC species and is present in many natural systems. The two

  6. Lignocellulosic Composites Prepared Utilizing Aqueous Alkaline/Urea Solutions with Cold Temperatures

    Directory of Open Access Journals (Sweden)

    Brent Tisserat

    2018-01-01

    Full Text Available Lignocellulosic composites (LCs were fabricated by partially dissolving cotton to create a matrix that was reinforced with osage orange wood (OOW particles and/or blue agave fibers (AF. LCs were composed of 15–35% cotton matrix and 65–85% OWW/AF reinforcement. The matrix was produced by soaking cotton wool in a cold aqueous alkaline/urea solvent and was stirred for 15 minutes at 350 rpm to create a viscous gel. The gel was then reinforced with lignocellulosic components, mixed, and then pressed into a panel mold. LC panels were soaked in water to remove the aqueous solvent and then oven dried to obtain the final LC product. Several factors involved in the preparation of these LCs were examined including reaction temperatures (−5 to −15°C, matrix concentration (15–35% cotton, aqueous solvent volume (45–105 ml/panel, and the effectiveness of employing various aqueous solvent formulations. The mechanical properties of LCs were determined and reported. Conversion of the cotton into a suitable viscous gel was critical in order to obtain LCs that exhibited high mechanical properties. LCs with the highest mechanical properties were obtained when the cotton wools were subjected to a 4.6% LiOH/15% urea solvent at −12.5°C using an aqueous solvent volume of 60 ml/panel. Cotton wool subjected to excessive cold alkaline solvents volumes resulted in irreversible cellulose breakdown and a resultant LC that exhibited poor mechanical properties.

  7. Fatty acids, essential oil, and phenolics modifications of black cumin fruit under NaCl stress conditions.

    Science.gov (United States)

    Bourgou, Soumaya; Bettaieb, Iness; Saidani, Moufida; Marzouk, Brahim

    2010-12-08

    This research evaluated the effect of saline conditions on fruit yield, fatty acids, and essential oils compositions and phenolics content of black cumin (Nigella sativa). This plant is one of the most commonly found aromatics in the Mediterranean kitchen. Increasing NaCl levels to 60 mM decreased significantly the fruits yield by 58% and the total fatty acids amount by 35%. Fatty acids composition analysis indicated that linoleic acid was the major fatty acid (58.09%) followed by oleic (19.21%) and palmitic (14.77%) acids. Salinity enhanced the linoleic acid percentage but did not affect the unsaturation degree of the fatty acids pool and thus the oil quality. The essential oil yield was 0.39% based on the dry weight and increased to 0.53, 0.56, and 0.72% at 20, 40, and 60 mM NaCl. Salinity results on the modification of the essential oil chemotype from p-cymene in controls to γ-terpinene/p-cymene in salt-stressed plants. The amounts of total phenolics were lower in the treated plants. Salinity decreased mainly the amount of the major class, benzoics acids, by 24, 29, and 44% at 20, 40, and 60 mM NaCl. The results suggest that salt treatment may regulate bioactive compounds production in black cumin fruits, influencing their nutritional and industrial values.

  8. NaCl salinity affects lateral root development in Plantago maritima

    NARCIS (Netherlands)

    Rubinigg, M; Wenisch, J; Elzenga, JTM; Stulen, [No Value

    2004-01-01

    Root growth and morphology were assessed weekly in hydroponically-grown seedlings of the halophyte Plantago maritima L. during exposure to 0, 50, 100 and 200 mM NaCl for 21 d. Relative growth rate was reduced by 25% at 200 mM NaCl. The lower NaCl treatments did not affect relative growth rates.

  9. Preparation of smooth, flexible and stable silver nanowires- polyurethane composite transparent conductive films by transfer method

    Science.gov (United States)

    Bai, Shengchi; Wang, Haifeng; Yang, Hui; Zhang, He; Guo, Xingzhong

    2018-02-01

    Silver nanowires (AgNWs)-polyurethane (PU) composite transparent conductive films were fabricated via transfer method using AgNWs conductive inks and polyurethane as starting materials, and the effects of post-treatments including heat treatment, NaCl solution bath and HCl solution bath for AgNWs film on the sheet resistance and transmittance of the composite films were respectively investigated in detail. AgNWs networks are uniformly embedded in the PU layer to improve the adhesion and reduce the surface roughness of AgNWs-PU composite films. Heat treatment can melt and weld the nanowires, and NaCl and HCl solution baths promote the dissolution and re-deposition of silver and the dissolving of the polymer, both which form conduction pathways and improve contact of AgNWs for reducing the sheet resistance. Smooth and flexible AgNWs-PU composite film with a transmittance of 85% and a sheet resistance of 15 Ω · sq‑1 is obtained after treated in 0.5 wt% HCl solution bath for 60 s, and the optoelectronic properties of the resultant composite film can maintain after 1000 cycles of bending and 100 days.

  10. Lead Sorption from Aqueous Solutions by Pseudomonas putida (p168 and its Composites with Palygorskite and Sepiolite Clays

    Directory of Open Access Journals (Sweden)

    Marzieh tavanaei

    2017-02-01

    Full Text Available Introduction: Heavy metals contamination due to natural and anthropogenic sources is a global environmental concern. Lead (Pb is one of the very toxic heavy metals. Industrial production processes and their emissions, mining operation, smelting, combustion sources and solid waste incinerators are the primary sources of lead. This heavy metal has aberrant effects on the environment and living organisms. Hence, proper treatment of lead from soil and industrial wastewaters is very important. In order to remove toxic heavy metals from contaminated water systems, conventional methods such as chemical precipitation, coagulation, ion exchange, solvent extraction and filtration, evaporation and membrane methods are being used. These conventional methods generally have high costs and technical problems. Therefore, biosorption processes, in which microorganisms are used as sorbents, have been considered as economical and environmentally friendly options for removal of heavy metals from aqueous solution. Clay minerals are another group of sorbents used in removal of heavy metals from polluted environments. Furthermore, bacterial cells can be attached on clay mineral surfaces and form bacteria-mineral composites. These composites adsorb heavy metals and convert them into forms with low mobility and bioavailability. Pseudomonas putida is a unique microorganism with a high tendency to sorb and/or degrade certain environmental pollutants. Palygorskite and sepiolite are the fibrous clay minerals of arid and semiarid regions; their structures consist of ribbons and channels. These fibrous minerals have various applications in industry and the environment because of its large surface area and high adsorption capacity. The present study was conducted in order to determine the ability of Pseudomonas putida (P168, and its composites with palygorskite and sepiolite in lead sorption. Materials and Methods: The bacterial strain used in the present study was Pseudomonas

  11. Surface diffusivity of cleaved NaCl crystals as a function of humidity: Impedance spectroscopy measurements and implications for crack healing in rock salt

    NARCIS (Netherlands)

    Koelemeijer, P.J.; Peach, C.J.; Spiers, C.J.

    2012-01-01

    Rock salt offers an attractive host rock for geological storage applications, because of its naturally low permeability and the ability of excavation-induced cracks to heal by fluid-assisted diffusive mass transfer. However, while diffusive transport rates in bulk NaCl solution are rapid and well

  12. Salt exclusion and mycorrhizal symbiosis increase tolerance to NaCl and CaCl2 salinity in ‘Siam Queen’ basil

    Science.gov (United States)

    A study was conducted to evaluate the effects of salinity on growth and nutrient uptake in basil (Ocimum basilicum L.). Plants were fertilized with a complete nutrient solution and exposed to no, low, or moderate levels of salinity from NaCl or CaCl2. Plants in the control and moderate salinity tre...

  13. AN EXACT ELASTO-PLASTIC SOLUTION OF METAL-MATRIX COMPOSITE CANTILEVER BEAM LOADED BY A SINGLE FORCE AT ITS FREE END

    Directory of Open Access Journals (Sweden)

    Onur SAYMAN

    2001-03-01

    Full Text Available In the present study, an elastic-plastic stress analysis is carried out in a metal matrix composite cantilever beam loaded by a single force at its free end. A composite consisting of stainless-steel reinforced aluminium was produced for this work. The orientation angle of the fibers is chosen as 0°, 30°, 45°, 60° and 90°. The material is assumed to be perfectly plastic in the elasto-plastic solution. An analytical solution is performed for satisfying both the governing differential equation in the plane stress case and boundary conditions for small plastic deformations. The solution is carried out under the assumption of the Bernoulli-Navier hypotheses. The composite material is assumed as hardening linearly. The Tsai-Hill theory is used as a yield criterion.

  14. Electrolytic coloration of O22--doped NaCl crystals

    International Nuclear Information System (INIS)

    Qin Fang; Gu Hongen; Song Cuiying; Wang Na; Guo Meili; Wang Fen; Liu Jia

    2007-01-01

    O 2 2- -doped NaCl crystals are colored electrolytically by using a pointed cathode and a flat anode at various temperatures and voltages, which mainly benefit from appropriate coloration temperatures and voltages as well as anode structure of used electrolysis apparatus. Characteristic OH - , U, V 2 m , U A , V 2 , V 3 , O 2- -V a + complex, F, R 1 , R 2 and M absorption bands are observed in absorption spectra of the colored crystals. Production and conversion of color centers in electrolytic coloration is explained. Current-time curves for electrolytic colorations and their relationships with electrolytic colorations were given

  15. Acetylene Black/Sulfur Composites Synthesized by a Solution Evaporation Concentration Crystallization Method and Their Electrochemical Properties for Li/S Batteries

    Directory of Open Access Journals (Sweden)

    Zhigao Yang

    2013-07-01

    Full Text Available A novel technique to prepare carbon/sulfur composites as cathode materials for Li/S batteries is proposed, which we call the ‘solution evaporation concentration crystallization’ method. Three composites with different S loadings were prepared, subject to two different solvent evaporation rates from acetylene black (AB/sulfur in carbon disulfide solutions. X-ray diffraction, environmental scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller measurements all show that the porous AB structure is well-filled with S. Composites prepared at a lower solvent evaporation rate with 50 wt % S content, had good electrochemical properties, with 1609.67 mAh g−1 after 100 cycles. Composites with better dispersibility at a low solvent evaporation rate can effectively prevent polysulfide from dissolving in the electrolyte, and serve to stabilize the structure of the S cathode during the charge-discharge process.

  16. Six-month color change and water sorption of 9 new-generation flowable composites in 6 staining solutions

    Directory of Open Access Journals (Sweden)

    Maria ARREGUI

    Full Text Available Abstract Color match and water sorption are two factors that affect restorative materials. Discoloration is essential in the lifespan of restorations. The aim of this study was to evaluate color change and water sorption of nine flowable composites at multiple time points over 6 months. 60 samples of each composite were divided into two groups (Color Change and Water Sorption/Solubility. Each Color Change group was divided into six subgroups, which were immersed in distilled water (DW, coffee (CF, Coca-Cola (CC, red wine (RW, tea (TE and orange juice (OJ. The color was measured at the baseline, 1, 2, 3 and 4 weeks, and 3 and 6 months and color change values (ΔE were calculated. Each Water Sorption [WS]/Solubility [WL] group was tested according to ISO 4049:2009. The data were evaluated using two-way ANOVA, Fisher’s post-hoc test and Pearson’s correlation test. The composite with the lowest ΔE differed for each solution: Filtek™ Bulk Fill in DW (∆E = 0.73 (0.17–1.759; Vertise Flow in CF (∆E = 14.75 (7.91–27.41, in TE (∆E = 7.27 (2.81–24.81 and OJ (∆E = 3.17 (0.87–9.92; Tetric EvoFlow® in CC (∆E = 1.27 (0.45–4.02; and Filtek™ Supreme XTE in RW (∆E = 8.88 (5.23–19.59. RW caused the most discoloration (∆E = 23.62 (4.93–51.36. Vertise Flow showed the highest water sorption (WS = 69.10 ± 7.19. The Pearson test showed statistically significant positive correlations between water sorption and solubility and between water sorption and ∆E; the positive solubility-∆E correlation was not statistically significant. The findings suggest that water sorption is one factor associated with the ability of composites to discolor; however, discoloration is a multifactorial problem.

  17. Six-month color change and water sorption of 9 new-generation flowable composites in 6 staining solutions.

    Science.gov (United States)

    Arregui, Maria; Giner, Luis; Ferrari, Marco; Vallés, Marta; Mercadé, Montserrat

    2016-11-28

    Color match and water sorption are two factors that affect restorative materials. Discoloration is essential in the lifespan of restorations. The aim of this study was to evaluate color change and water sorption of nine flowable composites at multiple time points over 6 months. 60 samples of each composite were divided into two groups (Color Change and Water Sorption/Solubility). Each Color Change group was divided into six subgroups, which were immersed in distilled water (DW), coffee (CF), Coca-Cola (CC), red wine (RW), tea (TE) and orange juice (OJ). The color was measured at the baseline, 1, 2, 3 and 4 weeks, and 3 and 6 months and color change values (ΔE) were calculated. Each Water Sorption [WS]/Solubility [WL] group was tested according to ISO 4049:2009. The data were evaluated using two-way ANOVA, Fisher's post-hoc test and Pearson's correlation test. The composite with the lowest ΔE differed for each solution: Filtek™ Bulk Fill in DW (∆E = 0.73 (0.17-1.759)); Vertise Flow in CF (∆E = 14.75 (7.91-27.41)), in TE (∆E = 7.27 (2.81-24.81)) and OJ (∆E = 3.17 (0.87-9.92)); Tetric EvoFlow® in CC (∆E = 1.27 (0.45-4.02)); and Filtek™ Supreme XTE in RW (∆E = 8.88 (5.23-19.59)). RW caused the most discoloration (∆E = 23.62 (4.93-51.36)). Vertise Flow showed the highest water sorption (WS = 69.10 ± 7.19). The Pearson test showed statistically significant positive correlations between water sorption and solubility and between water sorption and ∆E; the positive solubility-∆E correlation was not statistically significant. The findings suggest that water sorption is one factor associated with the ability of composites to discolor; however, discoloration is a multifactorial problem.

  18. Measurement of isotopic composition of lanthanides in reprocessing process solutions by high-performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC/ICP-MS)

    International Nuclear Information System (INIS)

    Okano, Masanori; Jitsukata, Shu; Kuno, Takehiko; Yamada, Keiji

    2011-01-01

    Isotopic compositions of fission products in process solutions and wastes in a reprocessing plant are valuable to proceed safety study of the solutions and research/development concerning treatment/disposal of the wastes. The amount of neodymium-148 is a reliable indication to evaluate irradiation history. The isotopic compositions of samarium and gadolinium in high radioactive wastes are referred to as essential data to evaluate environmental impact in geological repositories. However, pretreatment of analysis must be done with complicated chemical separation such as solvent extraction and ion exchange. The actual measurement data of isotopic compositions of lanthanides comparable to the one of actinides in spent fuel reprocessing process has not been obtained enough. Rapid and high sensitive analytical technique based on high-performance liquid chromatography (HPLC) with an inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the measurement of isotopic compositions of lanthanides in spent fuel reprocessing solutions. HPLC/ICP-MS measurement system was customized for a glove-box to be applied to the radioactive solutions. The cation exchange chromatographic columns (Shim-pack IC-C1) and injection valve (20μL) were located inside of the glove-box except the chromatographic pump. The elements of lanthanide group were separated by a gradient program of HPLC with α-hydroxyisobutyric acid. Isotopic compositions of lanthanides in eluate was sequentially analyzed by a quadruple ICP-MS. Optimization of parameter of HPLC and ICP-MS measurement system was examined with standard solutions containing 14 lanthanide elements. The elements of lanthanides were separated by HPLC and detected by ICP-MS within 25 minutes. The detection limits of Nd-146, Sm-147 and Gd-157 were 0.37 μg L -1 , 0.69 μg L -1 and 0.47 μg L -1 , respectively. The analytical precision of the above three isotopes was better than 10% for standard solutions of 100 μg L -1 with

  19. Irradiation induced creep in whiskers of NaCl

    International Nuclear Information System (INIS)

    Khan, J.A.A.

    1977-09-01

    Whiskers of NaCl have been grown and irradiated under flexion by X-rays (approximately 2x10 7 R/h) at room temperature and the residual curvature measured. Complete recovery of the initial form of the whisker within an hour's annealing at 400 0 C proves clearly that the observed deformation (creep) is due to the presence of dislocation loops. The choice of NaCl extremely simplifies the experiment and its interpretation since X-rays create point defects one by one. Moreover, this mode of irradiation, at room temperature, produces a very simple situation: perfect interstitial dislocation loops and immobile point defects which are little influenced by the applied stress. The flexion leads to a stress system which hardly differs from an uniaxial stress. One can study separately the preferential nucleation of dislocation loops and their differential growth by carrying out an irradiation under stress followed by an irradiation without stress and vice versa. It is shown that the induced creep is mostly due to the preferential nucleation of dislocation loops and is little affected by the differential growth of these loops. The nucleation period of the loops is very short: a dose of approximately 10 -5 d.p.a. is largely sufficient for the quasi completion of dislocation loops in a crystal having an impurity concentration of approximately 10 -3 [fr

  20. Measurement and modeling of CO2 solubility in NaCl brine and CO2–saturated NaCl brine density

    DEFF Research Database (Denmark)

    Yan, Wei; Huang, Shengli; Stenby, Erling Halfdan

    2011-01-01

    over climate change and energy security. This work is an experimental and modeling study of two fundamental properties in high pressure CO2–NaCl brine equilibrium, i.e., CO2 solubility in NaCl brine and CO2–saturated NaCl brine density. A literature review of the available data was presented first...

  1. Composite films of poly-(ester-sulphonated) and poly-(3-methylthiophene) for ion-exchange voltammetry in acetonitrile solutions

    International Nuclear Information System (INIS)

    Scopece, Paolo; Moretto, Ligia M.; Polizzi, Stefano; Ugo, Paolo

    2006-01-01

    This paper describes the preparation and characterisation of a polymeric electrode coating based on a composite of the poly-(ester-sulphonated) Eastman AQ55[reg] (AQ55) and poly-(3-methylthiophene) (PMeT), which is used for the controlled uptake and partial release of electroactive cations in acetonitrile solutions. The film is prepared by electrochemical oxidation in acetonitrile of 3-methylthiophene on glassy carbon disks or Pt-quartz crystal electrodes pre-coated with a thin film of AQ55. The electropolymerisation process is controlled so that the overall number of positive charges of oxidised PMeT is equal to the number of negative charges of the sulphonate groups of AQ55. Cyclic voltammetry and quartz crystal microbalance measurements indicate that the AQ55/PMeT mixed film is stable in acetonitrile and that its cation-exchange properties depend on the applied potential. When the PMeT moieties are reduced, the film incorporate cations; following electrochemical oxidation of the coating causes a release of the incorporated cations which, however, is only partial. Scanning electron microscopy (SEM) examination of cross sections of the composite polymer layer indicate that it is really a bi-layer, made by an inner compact layer of AQ55 on which a thicker and porous PMeT layer is grown. The outer PMeT layer acts as a barrier whose ionic charges can be changed electrochemically from positive (oxidation) to neutral (reduction). These ionic charges hinder or allow, respectively, the permeation of redox cations which tend to interact with the negatively charged sulphonic sites of the AQ55 layer. Direct self-neutralization of part of the positive charges of oxidized PMeT by the AQ55 sulphonic groups allows the release of part of the redox cations incorporated previously in the mixed film when PMeT is in the reduced state. By operating in acetonitrile solutions without added electrolyte it is possible to increase the fraction of redox cations which are released in

  2. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound/video files will in some cases only provide a few minutes' sample, or the visuals will not appear at all....... Please DOWNLOAD them to see/hear them in full length! This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it, performance instructions as well as specially designated recordings, as long as the author is mentioned. Please see http...

  3. Behavioral and neural responses of toads to salt solutions correlate with basolateral membrane potential of epidermal cells of the skin

    DEFF Research Database (Denmark)

    Hillyard, Stanley D; Baula, Victor; Tuttle, Wendy

    2007-01-01

    Dehydrated toads initiated water absorption response (WR) behavior and absorbed water from dilute NaCl solutions. With 200-250 mM NaCl, WR behavior and water absorption were both suppressed. With 200-250 mM Na-gluconate, WR initiation was significantly greater than with NaCl but water loss was gr...

  4. Impact of long-term organic residue recycling in agriculture on soil solution composition and trace metal leaching in soils.

    Science.gov (United States)

    Cambier, Philippe; Pot, Valérie; Mercier, Vincent; Michaud, Aurélia; Benoit, Pierre; Revallier, Agathe; Houot, Sabine

    2014-11-15

    Recycling composted organic residues in agriculture can reduce the need of mineral fertilizers and improve the physicochemical and biological properties of cultivated soils. However, some trace elements may accumulate in soils following repeated applications and impact other compartments of the agrosystems. This study aims at evaluating the long-term impact of such practices on the composition of soil leaching water, especially on trace metal concentrations. The field experiment QualiAgro started in 1998 on typical loess Luvisol of the Paris Basin, with a maize-wheat crop succession and five modalities: spreading of three different urban waste composts, farmyard manure (FYM), and no organic amendment (CTR). Inputs of trace metals have been close to regulatory limits, but supplies of organic matter and nitrogen overpassed common practices. Soil solutions were collected from wick lysimeters at 45 and 100 cm in one plot for each modality, during two drainage periods after the last spreading. Despite wide temporal variations, a significant effect of treatments on major solutes appears at 45 cm: DOC, Ca, K, Mg, Na, nitrate, sulphate and chloride concentrations were higher in most amended plots compared to CTR. Cu concentrations were also significantly higher in leachates of amended plots compared to CTR, whereas no clear effect emerged for Zn. The influence of amendments on solute concentrations appeared weaker at 1 m than at 45 cm, but still significant and positive for major anions and DOC. Average concentrations of Cu and Zn at 1m depth lied in the ranges [2.5; 3.8] and [2.5; 10.5 μg/L], respectively, with values slightly higher for plots amended with sewage sludge compost or FYM than for CTR. However, leaching of both metals was less than 1% of their respective inputs through organic amendments. For Cd, most values were <0.05 μg/L. So, metals added through spreading of compost or manure during 14 years may have increased metal concentrations in leachates of

  5. Composition characteristics and regularities of dissolving of hydroxyapatite materials obtained in water solutions with varied content of silicate ions

    Science.gov (United States)

    Solonenko, A. P.

    2018-01-01

    Research aimed at developing new bioactive materials for the repair of defects in bone tissues, do not lose relevance due to the strengthening of the regenerative approach in medicine. From this point of view, materials based on calcium phosphates, including silicate ions, consider as one of the most promising group of substances. Methods of synthesis and properties of hydroxyapatite doped with various amounts of SiO4 4- ions are described in literature. In the present work synthesis of a solid phase in the systems Ca(NO3)2 - (NH4)2HPO4 - Na2SiO3 - NH4OH - H2O (Cca/CP = 1.70) performed with a wide range of sodium silicate additive concentration (y = CSi/CP = 0 ÷ 5). It is established that under the studied conditions at y ≥ 0.3 highly dispersed poorly crystallized apatite containing isomorphic impurities of CO3 2- and SiO4 4- precipitates in a mixture with calcium hydrosilicate and SiO2. It is shown that the resulting composites can gradually dissolve in physiological solution and initiate passive formation of the mineral component of hard tissues.

  6. Reinforced PEI/PVdF Multicore-Shell Structure Composite Membranes by Phase Prediction on a Ternary Solution

    Directory of Open Access Journals (Sweden)

    Jihye Chae

    2018-04-01

    Full Text Available To construct a polyetherimide (PEI-reinforced polyvinylidene fluoride (PVdF composite membrane with multicore-shell structure, a ternary solution was prepared and electrospun by single-nozzle electrospinning. A theoretical prediction was made for the feasibility of complete distinction of two phases. The diameters of the membrane fibers and the PEI multi-core fibrils varied with the PEI ratio and the spinning time, respectively. The tensile strength and modulus were improved to 48 MPa and 1.5 GPa, respectively. The shrinkage of the membrane was only 6.6% at 180 °C, at which temperature the commercial PE separator melted down. The reinforcement in mechanical and thermal properties is associated with multiple PEI nanofibrils oriented along the fiber axis. Indeed, the unique morphology of self-assembled multicore-shell fibers plays an important role in their properties. All in all, PEI/PVdF membranes are appropriate for a lithium-ion battery application due to their high mechanical strength, excellent thermal stability, and controllable textural properties.

  7. Fluoro-apatite surface composition in aqueous solution deduced from potentiometric, electrokinetic, and solubility measurements, and spectroscopic observations

    International Nuclear Information System (INIS)

    Chairat, C.; Oelkers, E.H.; Schott, J.; Lartigue, J.E.

    2007-01-01

    The surface chemistry of fluoro-apatite in aqueous solution was investigated using electrokinetic techniques, potentiometric titrations, solubility measurements, and attenuated total reflection infrared spectroscopy. All methods indicate the formation of Ca/F depleted, P enriched altered layer via exchange reactions between H + and Ca 2+ , and OH - and F - at the fluoro-apatite (FAP) surface. Observations suggest that this leached layer has a di-calcium phosphate (CaHPO 4 ) composition and that it controls the apparent solubility of FAP. Electrokinetic measurements yield an iso-electric point value of 1 ± 0.5 consistent with a negatively charged FAP surface at pH ≥ 1. In contrast, surface titrations give an apparent pH of point of zero charge of similar to 7.7, consistent with a positively charged surface at pH ≤ 7.7. These differences are shown to stem from proton consumption by both proton exchange and dissolution reactions at the FAP surface. After taking account for these effects, FAP surface charge is shown to be negative to at least pH 4 by surface titration analysis. (authors)

  8. Fabrication of calcite blocks from gypsum blocks by compositional transformation based on dissolution-precipitation reactions in sodium carbonate solution.

    Science.gov (United States)

    Ishikawa, Kunio; Kawachi, Giichiro; Tsuru, Kanji; Yoshimoto, Ayami

    2017-03-01

    Calcium carbonate (CaCO 3 ) has been used as a bone substitute, and is a precursor for carbonate apatite, which is also a promising bone substitute. However, limited studies have been reported on the fabrication of artificial calcite blocks. In the present study, cylindrical calcite blocks (ϕ6×3mm) were fabricated by compositional transformation based on dissolution-precipitation reactions using different calcium sulfate blocks as a precursor. In the dissolution-precipitation reactions, both CaSO 4 ·2H 2 O and CaSO 4 transformed into calcite, a polymorph of CaCO 3 , while maintaining their macroscopic structure when immersed in 1mol/L Na 2 CO 3 solution at 80°C for 1week. The diametral tensile strengths of the calcite blocks formed using CaSO 4 ·2H 2 O and CaSO 4 were 1.0±0.3 and 2.3±0.7MPa, respectively. The fabrication of calcite blocks using CaSO 4 ·2H 2 O and CaSO 4 proposed in this investigation may be a useful method to produce calcite blocks because of the self-setting ability and high temperature stability of gypsum precursors. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Induced liquid-crystalline ordering in solutions of stiff and flexible amphiphilic macromolecules: Effect of mixture composition

    International Nuclear Information System (INIS)

    Glagolev, Mikhail K.; Vasilevskaya, Valentina V.; Khokhlov, Alexei R.

    2016-01-01

    Impact of mixture composition on self-organization in concentrated solutions of stiff helical and flexible macromolecules was studied by means of molecular dynamics simulation. The macromolecules were composed of identical amphiphilic monomer units but a fraction f of macromolecules had stiff helical backbones and the remaining chains were flexible. In poor solvents the compacted flexible macromolecules coexist with bundles or filament clusters from few intertwined stiff helical macromolecules. The increase of relative content f of helical macromolecules leads to increase of the length of helical clusters, to alignment of clusters with each other, and then to liquid-crystalline-like ordering along a single direction. The formation of filament clusters causes segregation of helical and flexible macromolecules and the alignment of the filaments induces effective liquid-like ordering of flexible macromolecules. A visual analysis and calculation of order parameter relaying the anisotropy of diffraction allow concluding that transition from disordered to liquid-crystalline state proceeds sharply at relatively low content of stiff components.

  10. Using Central Composite Experimental Design to Optimize the Degradation of Tylosin from Aqueous Solution by Photo-Fenton Reaction

    Directory of Open Access Journals (Sweden)

    Abd Elaziz Sarrai

    2016-05-01

    Full Text Available The feasibility of the application of the Photo-Fenton process in the treatment of aqueous solution contaminated by Tylosin antibiotic was evaluated. The Response Surface Methodology (RSM based on Central Composite Design (CCD was used to evaluate and optimize the effect of hydrogen peroxide, ferrous ion concentration and initial pH as independent variables on the total organic carbon (TOC removal as the response function. The interaction effects and optimal parameters were obtained by using MODDE software. The significance of the independent variables and their interactions was tested by means of analysis of variance (ANOVA with a 95% confidence level. Results show that the concentration of the ferrous ion and pH were the main parameters affecting TOC removal, while peroxide concentration had a slight effect on the reaction. The optimum operating conditions to achieve maximum TOC removal were determined. The model prediction for maximum TOC removal was compared to the experimental result at optimal operating conditions. A good agreement between the model prediction and experimental results confirms the soundness of the developed model.

  11. Effects of NaCl, pH, and Potential on the Static Creep Behavior of AA1100

    Science.gov (United States)

    Wan, Quanhe; Quesnel, David J.

    2013-03-01

    The creep rates of AA1100 are measured during exposure to a variety of aggressive environments. NaCl solutions of various concentrations have no influence on the steady-state creep behavior, producing creep rates comparable to those measured in lab air at room temperature. However, after an initial incubation period of steady strain rate, a dramatic increase of strain rate is observed on exposure to HCl solutions and NaOH solutions, as well as during cathodic polarization of specimens in NaCl solutions. Creep strain produces a continuous deformation and elongation of the sample surface that is comparable to slow strain rates at crack tips thought to control the kinetics of crack growth during stress corrosion cracking (SCC). In this experiment, we separate the strain and surface deformation from the complex geometry of the crack tip to better understand the processes at work. Based on this concept, two possible explanations for the environmental influences on creep strain rates are discussed relating to the anodic dissolution of the free surface and hydrogen influences on deformation mechanisms. Consistencies of pH dependence between corrosion creep and SCC at low pH prove a creep-involved SCC mechanism, while the discrepancies between corrosion creep behavior and previous SCC results at high pH indicate a rate-limit step change in the crack propagation of the SCC process.

  12. Selective adsorption of cationic dyes from aqueous solution by polyoxometalate-based metal–organic framework composite

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaoxia; Gong, Wenpeng; Luo, Jing; Zou, Chentao; Yang, Yun; Yang, Shuijin, E-mail: yangshuijin@163.com

    2016-01-30

    Graphical abstract: Selective adsorption ability of H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 toward MO (a), Rhb (b) and the removal rate of Rhb, MO and MB (c). - Highlights: • Using metal–organic framework (MOF) composite as an adsorbent was investigated. • Selective adsorption ability of the composite towards cationic dyes was proposed. • The removal rate of MOF was raised greatly by the modification of polyoxometalate. • The adsorption kinetic and isotherm were used to describe the adsorption process. • The thermodynamic parameters of the composite were investigated in detail. - Abstract: A novel environmental friendly adsorbent H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 was synthesized by a simple one-step reaction under solvothermal conditions and characterized by XRD, FTIR, thermogravimetric analyses (TGA) and N{sub 2} adsorption–desorption isotherms. The removal rate of H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 was quite greater (85%) than that of MOF-5 (almost zero), showing that the adsorption performance of porous MOF-5 can be improved through the modification of H{sub 6}P{sub 2}W{sub 18}O{sub 62}. Further study revealed that H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 exhibited a fast adsorption rate and selective adsorption ability towards the cationic dyes in aqueous solution. The removal rate was up to 97% for cationic dyes methylene blue (MB) and 68% for rhodamine B(Rhb) within 10 min. However, anionicdye methyl orange(MO) can only reach to 10%. The influences including initial concentration, contact time, initial solution pH and temperature of MB adsorption onto H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 were investigated in detail. The kinetic study indicated that the adsorption of MB onto H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 followed the pseudo second-order model well. The isotherm obtained from experimental data fitted the Langmuir model, yielding maximum adsorption capacity of 51.81 mg/g. The thermodynamic parameters analysis

  13. Rheological and structural characterization of HA/PVA-SbQ composites film-forming solutions and resulting films as affected by UV irradiation time.

    Science.gov (United States)

    Bai, Huiyu; Sun, Yunlong; Xu, Jing; Dong, Weifu; Liu, Xiaoya

    2015-01-22

    Hyaluronan (HA)/poly (vinyl alcohol) bearing styrylpyridinium groups (PVA-SbQ) composites film-forming solutions were prepared by a negatively charged HA and an oppositely charged PVA-SbQ. The rheological properties and structural characterization of HA/PVA-SbQ composites in aqueous solution were investigated. Zeta potential measurements and TEM were utilized to explore the formation of HA/PVA-SbQ complex micelles in aqueous solution. UV spectra and DLS experiments confirmed that the micelles are photo-crosslinkable. HA/PVA-SbQ composites films were prepared by a casting method. The microstructure and properties of the film were analyzed by SEM, optical transmittance, DSC, XRD and tensile testing. The crosslinked HA/PVA-SbQ composites films exhibited higher UV light shielding and visible light transparency and better mechanical and water vapor barrier properties as well as thermal stability than the uncrosslinked HA/PVA-SbQ composites films, indicating the formation of three-dimensional network structure. This work provided a good way for increasing the mechanical, thermal, water vapor barrier, and optical properties of HA materials for the packaging material. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Analytical solution of the thermo-mechanical stresses in a multilayered composite pressure vessel considering the influence of the closed ends

    International Nuclear Information System (INIS)

    Zhang, Q.; Wang, Z.W.; Tang, C.Y.; Hu, D.P.; Liu, P.Q.; Xia, L.Z.

    2012-01-01

    Limited work has been reported on determining the thermo-mechanical stresses in a multilayered composite pressure vessel when the influence of its closed ends is considered. In this study, an analytical solution was derived for determining the stress distribution of a multilayered composite pressure vessel subjected to an internal fluid pressure and a thermal load, based on thermo-elasticity theory. In the solution, a pseudo extrusion pressure was proposed to emulate the effect of the closed ends of the pressure vessel. To validate the analytical solution, the stress distribution of the pressure vessel was also computed using finite element (FE) method. It was found that the analytical results were in good agreement with the computational ones, and the effect of thermal load on the stress distribution was discussed in detail. The proposed analytical solution provides an exact means to design multilayered composite pressure vessels. Highlights: ► The thermal-mechanical stress was derived for a multilayered pressure vessel. ► A new pseudo extrusion pressure was proposed to emulate the effect of closed ends. ► The analytical results are in good agreement with the computational ones using FEM. ► The solution provides an exact way to design the multilayered pressure vessel.

  15. Kinetic Rate Law Parameter Measurements on a Borosilicate Waste Glass: Effect of Temperature, pH, and Solution Composition on Alkali Ion Exchange

    International Nuclear Information System (INIS)

    Pierce, Eric M.; McGrail, B PETER.; Icenhower, J P.; Rodriguez, Elsa A.; Steele, Jackie L.; Baum, Steven R.

    2004-01-01

    The reaction kinetics of glass is controlled by matrix dissolution and ion exchange (IEX). Dissolution of an alkali-rich simulated borosilicate waste glass was investigated using single-pass flow-through (SPFT) experiments. Experiments were conducted as a function of temperature, pH, and solution composition by varying the SiO 2 (aq) activity in the influent solution. Results showed that under dilute conditions matrix dissolution increased with increasing pH and temperature, and decreased with increasing SiO 2 (aq) activity. IEX rates decreased with increasing pH and temperature, and increased with increasing SiO 2 (aq) activity. Over the solution composition range interrogated in this study the dominant dissolution mechanism changed from matrix dissolution to IEX. These results suggest that ''secondary'' reactions may become dominant under certain environmental conditions and emphasize the need to incorporate these reactions into dissolution rate models

  16. Computer simulation of aqueous Na-Cl electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Hummer, G. [Los Alamos National Lab., NM (United States); Soumpasis, D.M. [Max-Planck-Institut fuer Biophysikalische Chemie (Karl-Friedrich-Bonhoeffer-Institut), Goettingen (Germany); Neumann, M. [Vienna Univ. (Austria). Inst. fuer Experimentalphysik

    1993-11-01

    Equilibrium structure of aqueous Na-Cl electrolytes between 1 and 5 mol/l is studied by means of molecular dynamics computer simulation using interaction site descriptions of water and ionic components. Electrostatic interactions are treated both with the newly developed charged-clouds scheme and with Ewald summation. In the case of a 5 mol/l electrolyte, the results for pair correlations obtained by the two methods are in excellent agreement. However, the charged-clouds technique is much faster than Ewald summation and makes simulations at lower salt concentrations feasible. It is found that both ion-water and ion-ion correlation functions depend only weakly on the ionic concentration. Sodium and chloride ions exhibit only a negligible tendency to form contact pairs. In particular, no chloride ion pairs in contact are observed.

  17. Computer simulation of aqueous Na-Cl electrolytes

    International Nuclear Information System (INIS)

    Hummer, G.; Soumpasis, D.M.; Neumann, M.

    1993-01-01

    Equilibrium structure of aqueous Na-Cl electrolytes between 1 and 5 mol/l is studied by means of molecular dynamics computer simulation using interaction site descriptions of water and ionic components. Electrostatic interactions are treated both with the newly developed charged-clouds scheme and with Ewald summation. In the case of a 5 mol/l electrolyte, the results for pair correlations obtained by the two methods are in excellent agreement. However, the charged-clouds technique is much faster than Ewald summation and makes simulations at lower salt concentrations feasible. It is found that both ion-water and ion-ion correlation functions depend only weakly on the ionic concentration. Sodium and chloride ions exhibit only a negligible tendency to form contact pairs. In particular, no chloride ion pairs in contact are observed

  18. Corrosion behavior of duplex polyaniline/epoxy coating on mild steel in 3% NaCl

    Directory of Open Access Journals (Sweden)

    Gvozdenović Milica M.

    2005-01-01

    Full Text Available The corrosion behavior and thermal stability of epoxy coatings electrodeposited on mild steel and on mild steel with electrochemically deposited polyaniline (PANI film were investigated by electrochemical impedance spectroscopy (EIS and thermo gravimetric analysis (TGA. The aim of the paper was to present new findings on the corrosion protection of mild steel by a duplex PANI/-epoxy coating in 3% NaCI solution and to determine the effect of thin PANI film on the protective properties of the coating. PANI film was deposited electrochemically on mild steel from an aqueous solution of 0.5 mol dm"3 sodium benzoate and 0.1 mol dm"3 aniline at a constant current density of 1.5 mA cm"2. Non-pigmented epoxy coatings on mild steel and on mild steel with PANI film were obtained by cathodic electrode position at constant voltage and stirring conditions. The resin concentration in the electrode position bath was 10 wt.% solid dispersion in water at pH 5.7. The applied voltage was 250 V, the temperature 26°C and the deposition time 3 min. It was shown that thin PANI film could be used to modify the surface of mild steel prior to epoxy coating deposition, due to the increased corrosion protection of a duplex PANI/epoxy coating comparing to an epoxy coating on mild steel in 3% NaCl solution.

  19. Impaired NaCl taste thresholds in Zn deprived rats

    International Nuclear Information System (INIS)

    Brosvic, G.M.; Slotnick, B.M.; Nelson, N.; Henkin, R.I.

    1986-01-01

    Zn deficiency is a relatively common cause of loss of taste acuity in humans. In some patients replacement with exogenous Zn results in rapid reversal of the loss whereas in others prolonged treatment is needed to restore normal taste function. To study this 300 gm outbred Sprague Dawley rats were given Zn deficient diet (< 1 ppm Zn) supplemented with Zn in drinking water (0.1 gm Zn/100 gm body weight). Rats were trained in an automated operant conditions procedure and NaCl taste thresholds determined. During an initial training period and over two replications mean thresholds were 0.006% and mean plasma Zn was 90 +/- 2 μg/dl (M +/- SEM) determined by flame atomic absorption spectrophotometry. Rats were then divided into two groups; in one (3 rats) Zn supplement was removed, in the other (4 rats), pair-fed with the former group, Zn supplement was continued. In 10 days NaCl thresholds in Zn deprived rats increased significantly (0.07%, p < 0.01) and in 17 days increased 13 fold (0.08%) but thresholds for pair fed, supplemented rats remained constant (0.006%). There was no overlap in response between any rat in the two groups. Plasma Zn at 17 days in Zn-deprived rats was significantly below pair-fed rats (52 +/- 13 vs 89 +/- 6 μg/dl, respectively, P < 0.01). At this time Zn-deprived rats were supplemented with Zn for 27 days without any reduction in taste thresholds. These preliminary results are consistent with previous observations in Zn deficient patients

  20. Manufacture of nano graphite oxides derived from aqueous glucose solutions and in-situ synthesis of magnetite–graphite oxide composites

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiang, E-mail: liuxiang@ahut.edu.cn; Zhao, Tiantian; Liu, Pengpeng; Cui, Ping, E-mail: cokecp@sohu.com; Hu, Peng

    2015-03-01

    A “bottom up” approach of manufacturing graphite oxides (GOs) derived from aqueous glucose solutions by virtue of an environmentally-friendly process and the way of in-situ synthesizing magnetite–GOs composites are described in this work in detail. The dehydrations among glucose molecules under hydrothermal condition result in the initial carbon quantum dots and ultimate GOs. The structural information of the GOs is obtained by the infrared, ultraviolet–visible and X-ray photoelectron spectra. The magnetite–GOs composites were obtained by a one-pot method under the same hydrothermal conditions as the one of preparing GOs. The composites perform high activities in catalytic degradation of Rhodamine B in the presence of hydrogen peroxides without extra heating or pH adjusting. Both the GOs and the magnetite–GOs composites are also assured by measurements of transmission electron microscope and X-ray powder diffraction. - Highlights: • Graphite oxides are made from aqueous glucose solutions by hydrothermal reaction. • A way of in-situ synthesizing composites of magnetite–graphite oxides is depicted. • The composites perform high activities in catalytic degradation of Rhodamine B.

  1. Crystallographic characterization of cement pastes hydrated with NaCl; Caracterizacao cristalografica de pastas de cimento hidratadas com NaCl

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Carina Gabriela de Melo e; Martinelli, Antonio Eduardo; Melo, Dulce Maria Araujo; Melo, Marcus Antonio de Freitas; Melo, Vitor Rodrigo de Melo e [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-07-01

    One of the major current challenges faced by oil companies is the exploration of pre salt basins. Salt layers deposited upon the evaporation of ocean water and continental separation are mainly formed by NaCl and isolate immense oil reservoirs. The mechanical stability and zonal isolation of oil wells that run through salt layers must be fulfilled by cement sheaths saturated with NaCl to assure chemical compatibility between cement and salt layer. The present study aimed at evaluating the effect of NaCl addition on the hydration of oil well cement slurries as well as identifying the nature of crystalline phases present in the hardened cement. To that end, cement slurries containing NaCl were mixed, hardened and characterized by X-ray diffraction. The results revealed that the presence of NaCl affects the formation of hydration products by the presence of Friedel's salt. The intensity of the corresponding peaks increase as the contents of NaCl in the slurry increase. High concentrations of NaCl in Portland slurries increase the setting time of cement and the presence of Friedel's salt decreases the strength of the hardened cement. (author)

  2. Theoretical prediction of morphotropic compositions in Na1/2Bi1/2TiO3-based solid solutions from transition pressures

    Science.gov (United States)

    Gröting, Melanie; Albe, Karsten

    2014-02-01

    In this article we present a method based on ab initio calculations to predict compositions at morphotropic phase boundaries in lead-free perovskite solid solutions. This method utilizes the concept of flat free energy surfaces and involves the monitoring of pressure-induced phase transitions as a function of composition. As model systems, solid solutions of Na1/2Bi1/2TiO3 with the alkali substituted Li1/2Bi1/2TiO3 and K1/2Bi1/2TiO3 and the alkaline earth substituted CaTiO3 and BaTiO3 are chosen. The morphotropic compositions are identified by determining the composition at which the phase transition pressure equals zero. In addition, we discuss the different effects of hydrostatic pressure (compression and tension) and chemical substitution on the antiphase tilts about the [111] axis (a-a-a-) present in pure Na1/2Bi1/2TiO3 and how they develop in the two solid solutions Na1/2Bi1/2TiO3-CaTiO3 and Na1/2Bi1/2TiO3-BaTiO3. Finally, we discuss the advantages and shortcomings of this simple computational approach.

  3. 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

  4. 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.

  5. IRSL characteristics of NaCl and KCl relative to dosimeter

    International Nuclear Information System (INIS)

    Tanir, Guenes; Hicabi Boeluekdemir, M.; Catli, Serap; Tel, Eyyuep

    2007-01-01

    The aim of this work is to determine and compare the dosimetric properties of NaCl and KCl samples using infrared-stimulated luminescence (IRSL) technique. For a material to be used as dosimeter, both the IRSL temperature dependence and the radiation dose response have critical importance. In this work the IRSL characteristics from NaCl and KCl samples were experimentally investigated as a function of temperature and laboratory radiation doses. Dosimetric properties of NaCl and KCl samples were found significantly different. The IRSL signals displayed by NaCl were found to be more stable, reliable and agreeable than those of KCl

  6. One-step solution combustion synthesis of Fe{sub 2}O{sub 3}/C nano-composites as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peiyang; Deng, Jiachun; Li, Ying [Nano-Energy Inorganic Materials Laboratory, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Liang, Wei, E-mail: liangwei@tyut.edu.cn [Nano-Energy Inorganic Materials Laboratory, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Wang, Kun [Nano-Energy Inorganic Materials Laboratory, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Kang, Litao, E-mail: kangltxy@gmail.com [Nano-Energy Inorganic Materials Laboratory, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Zeng, Shaozhong; Yin, Shanhui; Zhao, Zhigang [Chery Automobile Co. Ltd., Wuhu 241006 (China); Liu, Xuguang; Yang, Yongzhen [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Gao, Feng [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)

    2014-03-25

    Highlights: • Fe{sub 2}O{sub 3}/C composite anode materials were prepared by a solution combustion process. • The carbon content could be adjusted by regulating the ratio of oxidizer/fuel. • The Fe{sub 2}O{sub 3}/C composite showed capacity 470 mA h g{sup −1} at the 80th cycle at 125 mA g{sup −1}. -- Abstract: This article describes a one-step solution combustion route (within 30 min at 350 °C in air) to prepare Fe{sub 2}O{sub 3} anode materials for lithium ion batteries (LIBs) from Fe(NO{sub 3}){sub 3}⋅9H{sub 2}O solution with citric acid. XRD, SEM-EDX and TEM showed that the product consisted a mixture of nano-sized α-Fe{sub 2}O{sub 3} and γ-Fe{sub 2}O{sub 3} crystals that agglomerated into porous particles. Significantly, in situ formed carbon could be introduced into the product (i.e., Fe{sub 2}O{sub 3}/C nano-composites) by simply increasing the dosage of citric acid in the precursor solution. The as-prepared Fe{sub 2}O{sub 3}/C nano-composite exhibited high reversible capacities of 470 and 419 mA h g{sup −1} at the 80th and 200th cycles with a current density of 125 mA g{sup −1}, which are much higher than those of counterparts without carbon (i.e., Fe{sub 2}O{sub 3} nano-particles). Comparison experiments correlated with the performance improvement of Fe{sub 2}O{sub 3}/C nano-composites with in situ formed carbon, well-developed mesopores and relatively high specific surface areas.

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

    Science.gov (United States)

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

    2016-02-25

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

  8. The effect of biomolecules on the behaviour of CoCrMo alloy in various simulated physiological solutions

    International Nuclear Information System (INIS)

    Milošev, Ingrid

    2012-01-01

    Highlights: ► The behaviour of CoCrMo alloy is investigated in four simulated physiological solutions. ► The effect of synovial fluid significantly differs from the effect of organic components hitherto studied. ► In the presence of organic components carbon and nitrogen containing species are formed. ► Composition, structure and thickness of surface layers were determined by XPS. - Abstract: CoCrMo orthopaedic alloy was oxidized potentiostatically in various simulated physiological solutions in order to reveal differences in the composition, thickness and structure of the surface layers formed as a function of solution composition. X-ray photoelectron spectroscopy, combined with angle-resolved measurements and depth profiling, was used for the purpose. The following simulated physiological solutions were used: (1) 0.9% NaCl, (2) simulated Hanks physiological solution containing various inorganic salts, (3) simulated Hanks physiological solution containing an aliquot of synovial fluid retrieved at a primary operation, and (4) minimum essential medium containing various inorganic salts, amino acids and vitamins. No significant differences between alloy treated in these solutions were observed after oxidation in the passive region; the oxide films are a few nanometres thick and, except in NaCl solution, contain a small amount of calcium phosphate. After oxidation at a potential in the transpassive range, however, the oxide thickness increases considerably due to incorporation of cobalt and molybdenum oxides. Further, the concentration of calcium phosphate increases. The layers formed in minimum essential medium and Hanks solution containing synovial fluid comprise nitrogen and carbon containing species. The addition of synovial fluid significantly affects the behaviour in Hanks solution.

  9. Driving High-Performance n- and p-type Organic Transistors with Carbon Nanotube/Conjugated Polymer Composite Electrodes Patterned Directly from Solution

    KAUST Repository

    Hellstrom, Sondra L.

    2010-07-12

    We report patterned deposition of carbon nanotube/conjugated polymer composites from solution with high nanotube densities and excellent feature resolution. Such composites are suited for use as electrodes in high-performance transistors of pentacene and C60, with bottom-contact mobilities of ?0.5 and ?1 cm2 V-1 s-1, respectively. This represents a clear step towards development of inexpensive, high-performance all-organic circuits. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Studies on the effect of Pu and fission products on extraction selectivity of polymeric composite of ammonium phosphomolybdate towards 137Cs from nitric acid solutions

    International Nuclear Information System (INIS)

    Tripathi, S.C.; Pathak, S.K.; Jambunathan, U.; Dakshinamoorthy, A.; Kumar, Manmohan; Bajaj, P.N.

    2007-01-01

    Ultrafine particle size of ammonium phosphomolybdate (AMP) though selective sorbent for Cs form acidic solution, has limitation due to its incompatibility with column operation under practical conditions. A polymeric composite containing ammonium Phospho molybdate(AMP) developed indigenously in granular form, has shown encouraging results for Cs uptake from acidic solutions. Present investigation describes experimental observations carried out to find out the effect of presence of Pu and fission products on the 137 Cs uptake. The polymeric material shown some tendency for sorption of Pu which is found to decrease with increasing acidity. It has great selectivity with respect to other fission products like cerium, zirconium, and ruthenium. (author)

  11. Chemical synthesis of composite HML / PDMcT / PAni and its application as the trhiodan adsorbent in aqueous solutions

    International Nuclear Information System (INIS)

    Girotto, L.G.; Pacheco, I.; Freitas, L.L. de; Oliveira, R.S.; Amaral, F.A. do; Canobre, S.C.

    2016-01-01

    The mixed hydroxide lamellar [Co -Al- Cl] was synthesize by the co- precipitation method constant pH 8. The synthesis composite HML/PDMcT/PAni was carried out via chemical. The DRX composite HML/PDMcT/PAni showed that one amorphicity in the conductor polymer doesn't hid the diffraction peaks characteristic of HML. The MEV micrographs of composite HDL / PDMcT / PAni showed a large number of crystallites compacts with several shapes characteristic to PDMcT and nanofibers of polyaniline indicating an association between the different constituents forming the composite. The results of the adsorption was 98% of the pesticide in the composite HML / PDMcT / PAni , the composite can contribute so significantly to one Thiodon withdrawal in contaminated pesticide waters. (author)

  12. Raman scattering quantitative analysis of the anion chemical composition in kesterite Cu2ZnSn(SxSe1−x)4 solid solutions

    International Nuclear Information System (INIS)

    Dimitrievska, Mirjana; Gurieva, Galina; Xie, Haibing; Carrete, Alex; Cabot, Andreu; Saucedo, Edgardo; 2UB, Departament d’Electrònica, Universitat de Barcelona, C. Martí i Franquès 1, 08028 Barcelona (Spain))" data-affiliation=" (Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1 2pl., 08930 Sant Adrià del Besòs, Barcelona (Spain); IN2UB, Departament d’Electrònica, Universitat de Barcelona, C. Martí i Franquès 1, 08028 Barcelona (Spain))" >Pérez-Rodríguez, Alejandro

    2015-01-01

    Highlights: • An optical method for the quantitative measurement of [S]/([S] + [Se]) in CZTSSe is presented. • It is based on Raman spectroscopy and covers whole S–Se range of compositions. • The proposed method is independent of crystal quality, experimental conditions and type of material. • The validity of the technique is proven by comparison with independent composition measurements (XRD and EQE). • Test of the method on the data published in the literature has given satisfactory results. - Abstract: A simple and non destructive optical methodology for the quantitative measurement of [S]/([S] + [Se]) anion composition in kesterite Cu 2 ZnSn(S x Se 1−x ) 4 (CZTSSe) solid solutions by means of Raman spectroscopy in the whole S–Se range of compositions has been developed. This methodology is based on the dependence of the integral intensity ratio of Raman bands sensitive to anion vibrations with the [S]/([S] + [Se]) composition of the kesterite solid solutions. The calibration of the parameters used in this analysis involved the synthesis of a set of CZTSSe powders by solid state reaction method, spanning the range from pure Cu 2 ZnSnS 4 to pure Cu 2 ZnSnSe 4 . The validity of the methodology has been tested on different sets of independent samples, including also non-stoichiometric device grade CZTSSe layers with different compositions and films that were synthesized by solution based processes with different crystalline quality. In all cases, the comparison of the results obtained from the analysis of the intensity of the Raman bands with independent composition measurements performed by different techniques as X-ray diffraction and external quantum efficiency has confirmed the satisfactory performance of the developed methodology for the quantitative analysis of these compounds, independently on the crystal quality or the method of synthesis. Further strong support on the methodology performance has been obtained from the analysis of a wider

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

    Czech Academy of Sciences Publication Activity Database

    Cassone, Giuseppe; Creazzo, F.; Giaquinta, P.V.; Saija, F.; Saitta, A. M.

    2016-01-01

    Roč. 18, č. 33 (2016), s. 23164-23173 ISSN 1463-9076 Institutional support: RVO:68081707 Keywords : density-functional theory * liquid water * chloride-ions Subject RIV: BO - Biophysics Impact factor: 4.123, year: 2016

  14. Accurate thermoelastic tensor and acoustic velocities of NaCl

    Energy Technology Data Exchange (ETDEWEB)

    Marcondes, Michel L., E-mail: michel@if.usp.br [Physics Institute, University of Sao Paulo, Sao Paulo, 05508-090 (Brazil); Chemical Engineering and Material Science, University of Minnesota, Minneapolis, 55455 (United States); Shukla, Gaurav, E-mail: shukla@physics.umn.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, 55455 (United States); Minnesota supercomputer Institute, University of Minnesota, Minneapolis, 55455 (United States); Silveira, Pedro da [Chemical Engineering and Material Science, University of Minnesota, Minneapolis, 55455 (United States); Wentzcovitch, Renata M., E-mail: wentz002@umn.edu [Chemical Engineering and Material Science, University of Minnesota, Minneapolis, 55455 (United States); Minnesota supercomputer Institute, University of Minnesota, Minneapolis, 55455 (United States)

    2015-12-15

    Despite the importance of thermoelastic properties of minerals in geology and geophysics, their measurement at high pressures and temperatures are still challenging. Thus, ab initio calculations are an essential tool for predicting these properties at extreme conditions. Owing to the approximate description of the exchange-correlation energy, approximations used in calculations of vibrational effects, and numerical/methodological approximations, these methods produce systematic deviations. Hybrid schemes combining experimental data and theoretical results have emerged as a way to reconcile available information and offer more reliable predictions at experimentally inaccessible thermodynamics conditions. Here we introduce a method to improve the calculated thermoelastic tensor by using highly accurate thermal equation of state (EoS). The corrective scheme is general, applicable to crystalline solids with any symmetry, and can produce accurate results at conditions where experimental data may not exist. We apply it to rock-salt-type NaCl, a material whose structural properties have been challenging to describe accurately by standard ab initio methods and whose acoustic/seismic properties are important for the gas and oil industry.

  15. Enhanced corrosion resistance of A3xx.x/SiCp composites in chloride media by La surface treatments

    International Nuclear Information System (INIS)

    Pardo, A.; Merino, M.C.; Arrabal, R.; Feliu, S.; Viejo, F.; Carboneras, M.

    2006-01-01

    The influence of silicon carbide particles (SiCp) proportion and matrix composition of aluminium metal matrix composites (A3xx.x/SiCp) modified by lanthanum-based conversion or electrolysis coating was evaluated in 3.5 wt% NaCl aerated solution. The intermetallic compounds were preferentially covered by lanthanum-based conversion coatings obtained by immersion in 50 deg. C solution of La(III) salt, and the intermetallic compounds, SiCp and aluminium matrix were covered by lanthanum electrolysis treatment. The corrosion process was studied on the basis of gravimetric tests and electrochemical impedance spectroscopy (EIS) during immersion in 3.5 wt% NaCl aerated solution. The composition of both La coating and corrosion products was analyzed before and after accelerated testing, by scanning electron microscopy (SEM), atomic force microscopy (AFM), low-angle X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) to determine the influence of surface microstructural changes on corrosion behaviour during exposure to the corrosive environment. The corrosion process was more influenced by the concentration of alloy elements in the matrix than by the proportion of SiCp reinforcement. Both lanthanum treated surfaces presented better behaviour to chloride solution corrosion than original composite surfaces without treatment; however, electrolysis afforded a higher degree of protection than the conversion treatment because the coating was more extensive

  16. 2-Mercaptobenzothiazole doped chitosan/11-alkanethiolate acid composite coating: Dual function for copper protection

    International Nuclear Information System (INIS)

    Bao Qi; Zhang Dun; Wan Yi

    2011-01-01

    Chitosan (CS) hydrogel loaded with the well-known corrosion inhibitor 2-mercaptobenzothiazole (MBT) has been introduced into a composite coating to improve copper protection. This composite coating, which has both anticorrosion and antibacterial properties, was fabricated onto the surface of copper by combining a simple self-assembled monolayer technique with a sol-gel method. The anti-corrosion ability of the coating in 3.5 wt.% NaCl solution was investigated by electrochemical methods including potentiodynamic polarization and electrochemical impedance spectroscopy. The protection efficiency of the coating is 97.70%, calculated on the basis of the corrosion current density. The stability and integrity of the composite coating were evaluated by field emission scanning electron microscopy (FESEM) and energy dispersive spectrometry (EDS). The FESEM and EDS results suggest that the composite coating endows the copper substrate with antibacterial properties, as untreated bare copper underwent microbiologically influenced corrosion in the presence of sulphate reducing bacteria (SRB). This antibacterial feature was further confirmed by the SRB culture method. In a 3.5% NaCl solution and highly corrosive SRB culture media, the as-prepared CS based composite coating gave corrosion protection by exhibiting better barrier effects against the attack of aggressive environments.

  17. Degradation of simazine from aqueous solutions by diatomite-supported nanosized zero-valent iron composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhiming [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Zheng, Shuilin [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Ayoko, Godwin A.; Frost, Ray L. [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Xi, Yunfei, E-mail: y.xi@qut.edu.au [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

    2013-12-15

    Graphical abstract: Nanosized zero-valent iron (nZVI) particles were deposited onto acid-leached diatomite through centrifugation or rotary evaporation. The synthesis schematic diagram and morphology of the prepared nZVI/diatomite composites are shown in the illustration. The removal efficiency for herbicide simazine by nZVI/diatomite composites was compared with that of the pristine nZVI and the commercial iron powder. -- Highlights: • Diatomite-supported nanosized zero-valent iron composite was synthesised. • The obtained composites were characterised by XRD, SEM–EDS, TEM and XPS. • The removal efficiency for simazine in water were studied. • The prepared composite showed potential prospects in environmental remediation. -- Abstract: A novel composite material based on deposition of nanosized zero-valent iron (nZVI) particles on acid-leached diatomite was synthesised for the removal of a chlorinated contaminant in water. The nZVI/diatomite composites were characterised by X-ray diffraction, scanning electron microscopy, elemental analysis, transmission electron microscopy and X-ray photoelectron spectroscopy. Compared with the pure nZVI particles, better dispersion of nZVI particles on the surface or inside the pores of diatom shells was observed. The herbicide simazine was selected as the model chlorinated contaminant and the removal efficiency by nZVI/diatomite composite was compared with that of the pristine nZVI and commercial iron powder. It was found that the diatomite supported nZVI composite material prepared by centrifugation exhibits relatively better efficient activity in decomposition of simazine than commercial Fe, lab synthesised nZVI and composite material prepared via rotary evaporation, and the optimum experimental conditions were obtained based on a series of batch experiments. This study on immobilising nZVI particles onto diatomite opens a new avenue for the practical application of nZVI and the diatomite-supported nanosized zero

  18. Hygroscopic properties of internally mixed particles composed of NaCl and water-soluble organic acids.

    Science.gov (United States)

    Ghorai, Suman; Wang, Bingbing; Tivanski, Alexei; Laskin, Alexander

    2014-02-18

    Atmospheric aging of naturally emitted marine aerosol often leads to formation of internally mixed particles composed of sea salts and water-soluble organic compounds of anthropogenic origin. Mixing of sea salt and organic components has profound effects on the evolving chemical composition and hygroscopic properties of the resulted particles, which are poorly understood. Here, we have studied chemical composition and hygroscopic properties of laboratory generated NaCl particles mixed with malonic acid (MA) and glutaric acid (GA) at different molar ratios using micro-FTIR spectroscopy, atomic force microscopy, and X-ray elemental microanalysis. Hygroscopic properties of internally mixed NaCl and organic acid particles were distinctly different from pure components and varied significantly with the type and amount of organic compound present. Experimental results were in a good agreement with the AIM modeling calculations of gas/liquid/solid partitioning in studied systems. X-ray elemental microanalysis of particles showed that Cl/Na ratio decreased with increasing organic acid component in the particles with MA yielding lower ratios relative to GA. We attribute the depletion of chloride to the formation of sodium malonate and sodium glutarate salts resulted by HCl evaporation from dehydrating particles.

  19. Solidification of salt solutions on a horizontal surface

    International Nuclear Information System (INIS)

    Braga, S.L.; Viskanta, R.

    1990-01-01

    The freezing of water-salt solutions on a horizontal wall is investigated experimentally and theoretically. The growth of the solid-liquid region is observed for NaCl - H sub(2)O and N H sub(4)Cl - H sub(2)O systems under different temperature and concentration conditions. A unidirectional mathematical model is used to predict the solidification process. The transport of heat is by diffusion, and convection is absent. The mass diffusion is neglected and the growth of crystal is governed by the transport of heat. In all experiments, the solution salt concentration is smaller than the eutectic composition, and the wall temperature is higher than the eutectic temperature. The predicted temperature and salt concentration profiles, as well as the interface position, are compared with experimental data. (author)

  20. Adsorption of Amido Black 10B from aqueous solutions onto Zr (IV) surface-immobilized cross-linked chitosan/bentonite composite

    International Nuclear Information System (INIS)

    Zhang, Lujie; Hu, Pan; Wang, Jing; Huang, Ruihua

    2016-01-01

    Graphical abstract: - Highlights: • Zr-CCB was prepared and characterized. • The adsorption of AB10B followed the Langmuir isotherm model. • The pseudo-second-order model described the kinetic behavior. - Abstract: Zr(IV) surface-immobilized cross-linked chitosan/bentonite composite was synthesized by immersing cross-linked chitosan/bentonite composite in zirconium oxychloride solution, and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy techniques. The adsorption of an anionic dye, Amido Black 10B, from aqueous solution by Zr(IV) loaded cross-linked chitosan/bentonite composite was investigated as a function of loading amount of Zr(IV), adsorbent dosage, pH value of initial dye solution, and ionic strength. The removal of Amido Black 10B increased with an increase in loading amount of Zr(IV) and adsorbent dosage, but decreased with an increase in pH or ionic strength. The adsorption of AB10B onto Zr(IV) loaded cross-linked chitosan/bentonite composite was favored at lower pH values and higher temperatures. The Langmuir isotherm model fitted well with the equilibrium adsorption isotherm data and the maximum monolayer adsorption capacity was 418.4 mg/g at natural pH value and 298 K. The pseudo-second-order kinetic model well described the adsorption process of Amido Black 10B onto Zr(IV) loaded cross-linked chitosan/bentonite composite. The possible mechanisms controlling Amido Black 10B adsorption included hydrogen bonding and electrostatic interactions.

  1. Adsorption of Amido Black 10B from aqueous solutions onto Zr (IV) surface-immobilized cross-linked chitosan/bentonite composite

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lujie; Hu, Pan; Wang, Jing; Huang, Ruihua, E-mail: hrh20022002@163.com

    2016-04-30

    Graphical abstract: - Highlights: • Zr-CCB was prepared and characterized. • The adsorption of AB10B followed the Langmuir isotherm model. • The pseudo-second-order model described the kinetic behavior. - Abstract: Zr(IV) surface-immobilized cross-linked chitosan/bentonite composite was synthesized by immersing cross-linked chitosan/bentonite composite in zirconium oxychloride solution, and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy techniques. The adsorption of an anionic dye, Amido Black 10B, from aqueous solution by Zr(IV) loaded cross-linked chitosan/bentonite composite was investigated as a function of loading amount of Zr(IV), adsorbent dosage, pH value of initial dye solution, and ionic strength. The removal of Amido Black 10B increased with an increase in loading amount of Zr(IV) and adsorbent dosage, but decreased with an increase in pH or ionic strength. The adsorption of AB10B onto Zr(IV) loaded cross-linked chitosan/bentonite composite was favored at lower pH values and higher temperatures. The Langmuir isotherm model fitted well with the equilibrium adsorption isotherm data and the maximum monolayer adsorption capacity was 418.4 mg/g at natural pH value and 298 K. The pseudo-second-order kinetic model well described the adsorption process of Amido Black 10B onto Zr(IV) loaded cross-linked chitosan/bentonite composite. The possible mechanisms controlling Amido Black 10B adsorption included hydrogen bonding and electrostatic interactions.

  2. Selective removal of Cr(VI) from aqueous solution by polypyrrole/2,5-diaminobenzene sulfonic acid composite

    CSIR Research Space (South Africa)

    Kera, Nazia H

    2016-08-01

    Full Text Available and morphology of the composite were investigated by ATR-FTIR, FE-SEM, EDX, TGA, XRD and XPS studies. The adsorption of Cr(VI) by PPy/DABSA composite was highly pH dependent and optimum removal was achieved at pH 2. Adsorption of Cr(VI) was confirmed by EDX...

  3. Effect of mycorrhiza symbiosis on the Nacl salinity in Sorghum bicolor

    African Journals Online (AJOL)

    In order to determine mycorrhizal symbiosis on the Nacl salinity tolerance in Sorghum bicolor (aspydfyd cultivar), an experiment with two factors was done in Damghan Islamic Azad University laboratory (Iran) in 2007. The first factor with two levels (mycorihizal and non-mycorihizal) and second factor with six levels Nacl ...

  4. Visible laser induced positive ion emissions from NaCl nanoparticles prepared by droplet rapid drying

    International Nuclear Information System (INIS)

    Sun, Mao-Xu; Guo, Deng-Zhu; Xing, Ying-Jie; Zhang, Geng-Min

    2012-01-01

    Highlights: ► NaCl nanoparticles were firstly prepared by heat induced explosion on silicon wafer. ► We found that laser induced ion emissions from NaCl nanoparticles are more prominent. ► We found that water adsorption can efficiently enhance laser induced ion emissions. ► The ultra-photothermal effect in NaCl nanoparticles was observed and explained. - Abstract: A novel convenient way for the formation of sodium chloride (NaCl) nanoparticles on silicon wafer is proposed by using a droplet rapid drying method. The laser induced positive ion emissions from NaCl nanoparticles with and without water treatment is demonstrated by using a laser desorption/ionization time-of-flight mass spectrometer, with laser intensity well below the plasma formation threshold. It is found that the positive ion emissions from NaCl nanoparticles are obviously higher than that from microsize NaCl particles under soft 532 nm laser irradiations, and water adsorption can efficiently enhance the ion emissions from NaCl nanoparticles. The initial kinetic energies of the emitted ions are estimated as 16–17 eV. The synergy of the ultra-thermal effect in nanomaterials, the defect-mediated multiphoton processes, and the existence of intermediate states in NaCl-water interfaces are suggested as the mechanisms.

  5. Combined Effects of Boron and NaCl on Wheat Seedlings

    Directory of Open Access Journals (Sweden)

    ZHEN Mei-nan

    2015-08-01

    Full Text Available To investigate the combined effects of boron(Band NaCl on the growth of wheat, a pot experiment was conducted using wheat (Triticum aestivum Linn.seedlings. Boron concentrations of culture medium were set as 0, 50 mg·kg-1 and 100 mg·kg-1, and NaCl concentrations were 0, 1 g·kg-1 and 2 g·kg-1. The results showed that both boron and NaCl could significantly inhibit wheat growth. At 50 mg B·kg-1, NaCl aggravated growth inhibition caused by boron. At 100 mg B·kg-1, however, NaCl alleviated the inhibition caused by boron. The combined stress of boron and NaCl significantly increased the root to shoot ratio of wheat. NaCl inhibited the uptake of boron by wheat. It suggests that under severe boron stress, NaCl is able to alleviate boron toxicity in wheat by increasing root to shoot ratio and reducing boron uptake.

  6. Effect of a surface sealant on the color stability of composite resins after immersion in staining solution.

    Science.gov (United States)

    Pedroso, Lauana Borges; Barreto, Luma Franciélle Cabreira; Miotti, Leonardo Lamberti; Nicoloso, Gabriel Ferreira; Durand, Leticia Brandão

    2016-01-01

    This study evaluated the influence of surface sealants on the color stability of 2 different composite resins after immersion in coffee. Four groups were created (n = 10): microhybrid composite, microhybrid with surface sealant, nanofilled composite, and nanofilled composite with surface sealant. Half of the specimens of each group were immersed in distilled water and half were immersed in coffee for 48 hours. Color was measured before and after immersion. Groups with surface sealants presented less color variation when compared with the groups without surface sealants. The nanofilled resin specimens presented the greatest color variation within the groups without sealant. The surface sealant positively influenced the color stability of composite resin specimens immersed in coffee. When surface sealant was not applied, the microhybrid specimens had better color stability than the nanofilled.

  7. Thin film composites in the BiFeO3–Bi4Ti3O12 system obtained by an aqueous solution-gel deposition methodology

    Directory of Open Access Journals (Sweden)

    Carlos Gumiel

    2018-01-01

    Full Text Available Thin film multiferroic composites, with a high quantity of interfaces between the different materials, represent a more feasible alternative to single phase systems in which the multifunctional response is usually hampered due to intrinsic physical constraints. Nowadays some of these composites can be produced by applying deposition techniques such as PLD, CVD, MBE or the like, which allow a high degree of crystallographic control. However, despite their effectiveness, all these techniques also involve a high consumption of energy in terms of temperature and/or vacuum. Within this frame, the present contribution proposes a sustainable chemical solution deposition process to prepare thin films of the multiferroic BiFeO3–Bi4Ti3O12 composite system. More specifically an aqueous solution-gel plus spin-coating methodology is employed which also avoids the organic solvents typically used in a conventional sol–gel method, so further keeping an eye on the environmentally friendly conditions. Attempts are conducted that demonstrate how by systematically controlling the processing parameters it is possible to obtain thin film composites with a promising 3-3 type connectivity at temperatures as low as 600 °C.

  8. Thin film composites in the BiFeO3–Bi4Ti3O12 system obtained by an aqueous solution-gel deposition methodology

    International Nuclear Information System (INIS)

    Gumiel, C.; Vranken, T.; Bernardo, M.S.; Jardiel, T.; Hardy, A.; Van Bael, M.K.; Peiteado, M.

    2018-01-01

    Thin film multiferroic composites, with a high quantity of interfaces between the different materials, represent a more feasible alternative to single phase systems in which the multifunctional response is usually hampered due to intrinsic physical constraints. Nowadays some of these composites can be produced by applying deposition techniques such as PLD, CVD, MBE or the like, which allow a high degree of crystallographic control. However, despite their effectiveness, all these techniques also involve a high consumption of energy in terms of temperature and/or vacuum. Within this frame, the present contribution proposes a sustainable chemical solution deposition process to prepare thin films of the multiferroic BiFeO3–Bi4Ti3O12 composite system. More specifically an aqueous solution-gel plus spin-coating methodology is employed which also avoids the organic solvents typically used in a conventional sol–gel method, so further keeping an eye on the environmentally friendly conditions. Attempts are conducted that demonstrate how by systematically controlling the processing parameters it is possible to obtain thin film composites with a promising 3-3 type connectivity at temperatures as low as 600°C. [es

  9. Using petrographic techniques to evaluate the induced effects of NaCl, extreme climatic conditions, and traffic load on Spanish road surfaces

    Directory of Open Access Journals (Sweden)

    A. P. Pérez-Fortes

    2017-10-01

    Full Text Available The asphalt surface layer is the most exposed to weather and traffic conditions on roads, especially those subjected to winter maintenance. Therefore, a deep knowledge of the mechanisms which can damage this layer is necessary to improve its design, construction and long-term use. With this purpose, two types of asphalt mixtures used on roads from NW Spain were subjected to durability tests (freezing-thaw and thermal-stress with a saturated NaCl solution. After the durability tests, a wheel tracking test was performed on the samples, and the resultant material was analyzed by optical polarized light and fluorescence microscopy. This analysis showed that the binder-aggregate low adhesion was the main responsible of the asphalt mixture damage. This damage was concentrated in the aggregates because the binder acted as an impermeable wall. Consequently, the NaCl solution penetrated and degraded the aggregates quickly and strongly.

  10. Using petrographic techniques to evaluate the induced effects of NaCl, extreme climatic conditions, and traffic load on Spanish road surfaces

    International Nuclear Information System (INIS)

    Pérez-Fortes, A.F.; Varas-Muriel, M.J.; Castiñeiras, P.

    2017-01-01

    The asphalt surface layer is the most exposed to weather and traffic conditions on roads, especially those subjected to winter maintenance. Therefore, a deep knowledge of the mechanisms which can damage this layer is necessary to improve its design, construction and long-term use. With this purpose, two types of asphalt mixtures used on roads from NW Spain were subjected to durability tests (freezing-thaw and thermal-stress) with a saturated NaCl solution. After the durability tests, a wheel tracking test was performed on the samples, and the resultant material was analyzed by optical polarized light and fluorescence microscopy. This analysis showed that the binder-aggregate low adhesion was the main responsible of the asphalt mixture damage. This damage was concentrated in the aggregates because the binder acted as an impermeable wall. Consequently, the NaCl solution penetrated and degraded the aggregates quickly and strongly. [es

  11. Adsorption of small NaCl clusters on surfaces of silicon nanostructures

    International Nuclear Information System (INIS)

    Amsler, Maximilian; Alireza Ghasemi, S; Goedecker, Stefan; Neelov, Alexey; Genovese, Luigi

    2009-01-01

    We have studied possible adsorption geometries of neutral NaCl clusters on the disordered surface of a large silicon model tip used in non-contact atomic force microscopy. The minima hopping method was used to determine low energy model tip configurations as well as ground state geometries of isolated NaCl clusters. The combined system was treated with density functional theory. Alkali halides have proven to be strong structure seekers and tend to form highly stable ground state configurations whenever possible. The favored adsorption geometry for four Na and four Cl atoms was found to be an adsorption of four NaCl dimers due to the formation of Cl-Si bonds. However, for larger NaCl clusters, the increasing energy required to dissociate the cluster into NaCl dimers suggests that adsorption of whole clusters in their isolated ground state configuration is preferred.

  12. [Effect of NaCl stress on ion compartmentation, photosynthesis and growth of Salicornia bigelovii Torr].

    Science.gov (United States)

    Wang, Li-Yan; Zhao, Ke-Fu

    2004-02-01

    Seedlings of Salicornia bigelovii Torr. were treated with different concentrations of NaCl (0, 100, 300, 600 mmol/L). Ion contents, Na(+) subcelluar localization, photosynthetic rate, ultrastructure of chloroplast and other parameters were measured. The data showed both fresh and dry weight of whole plant of Salicornia bigelovii Torr. under salinity were higher than the control. When NaCl concentration is about 300 mmol/L Salicornia bigelovii Torr. grow strongest. The contents of Na(+) and Cl(-) and c(Na)/c(K) in shoots increased with the salinity. Both Na(+) and Cl(-) were mainly transported to shoots. Ion X-ray microanalysis indicated Na(+) was mainly compartmentalized into vacuoles. Photosynthetic rate increased with the salinity under NaCl 100-300 mmol/L, but declined under NaCl 600 mmol/L. Ultrastructure of chloroplast was destroyed by NaCl 600 mmol/L.

  13. Self-assembly of poly(vinylidene fluoride–polystyrene block copolymers in solution: Effects of the length of polystyrene block and solvent compositions

    Directory of Open Access Journals (Sweden)

    Yao Wu

    2017-09-01

    Full Text Available We report the first preliminary and extensive study on the solution self-assembly behaviors of poly(vinylidene fluoride–b-polystyrene (PVDF–PS block copolymers. The two PVDF–PS polymers we examined have the same length of PVDF block with number averaged repeating unit of 180, but distinctly different lengths of PS block with number averaged repeating unit of 125 and 1202. The self-assembly experiments were carried out in a series of mixture solutions containing a good solvent N,N-dimethylformamide and a selective solvent with different ratios. Our results showed that the self-assembly process was greatly affected by the two factors we examined, i.e. the length of the PS block and the solvent composition. We hope that our study could stimulate more research on the self-assembly of PVDF-containing polymers in solution.

  14. NaCl responsive taste cells in the mouse fungiform taste buds.

    Science.gov (United States)

    Yoshida, R; Horio, N; Murata, Y; Yasumatsu, K; Shigemura, N; Ninomiya, Y

    2009-03-17

    Previous studies have demonstrated that rodents' chorda tympani (CT) nerve fibers responding to NaCl can be classified according to their sensitivities to the epithelial sodium channel (ENaC) blocker amiloride into two groups: amiloride-sensitive (AS) and -insensitive (AI). The AS fibers were shown to respond specifically to NaCl, whereas AI fibers broadly respond to various electrolytes, including NaCl. These data suggest that salt taste transduction in taste cells may be composed of at least two different systems; AS and AI ones. To further address this issue, we investigated the responses to NaCl, KCl and HCl and the amiloride sensitivity of mouse fungiform papilla taste bud cells which are innervated by the CT nerve. Comparable with the CT data, the results indicated that 56 NaCl-responsive cells tested were classified into two groups; 25 cells ( approximately 44%) narrowly responded to NaCl and their NaCl response were inhibited by amiloride (AS cells), whereas the remaining 31 cells ( approximately 56%) responded not only to NaCl, but to KCl and/or HCl and showed no amiloride inhibition of NaCl responses (AI cells). Amiloride applied to the basolateral side of taste cells had no effect on NaCl responses in the AS and AI cells. Single cell reverse transcription-polymerase chain reaction (RT-PCR) experiments indicated that ENaC subunit mRNA was expressed in a subset of AS cells. These findings suggest that the mouse fungiform taste bud is composed of AS and AI cells that can transmit taste information differently to their corresponding types of CT fibers, and apical ENaCs may be involved in the NaCl responses of AS cells.

  15. Rootstock Effect on the Tolerance of cv. Hass Avocado Plants to Nacl Stress Efecto del Portainjerto en la Tolerancia de Plantas de Palto cv. Hass al Estrés por NaCl

    Directory of Open Access Journals (Sweden)

    Mónica Castro V

    2009-09-01

    Full Text Available The avocado tree (Persea americana Mill. is one of the species most sensitive to salinity. Since the root system of this species is particularly affected by this type of stress, it is crucial to find a rootstock that is tolerant to saline water irrigation. Plant material from the cv. Hass was grafted on five rootstocks to find possible candidates: the clonal ‘Duke 7’, ‘Nabal’, ‘Degania 117’,’Mexicola’, and ‘Zutano’ seedlings. One year-old plants were placed in 55 L pots; river sand was used as substrate, and the plants were fertilized with a modified Hoagland solution. Vegetative growth and internal nutrient content were compared with control plants with 30 mg L-1 of Cl-, and plants treated with 200 mg L-1 Cl- for 130 days using NaCl in the nutrient solution (5.64 mM. No interaction between NaCl and the rootstocks for the vegetative growth variables was detected neither in K+ internal foliar or root content nor Ca+2 root. With regard to the carbon assimilation rate, the Nabal rootstock showed the highest rates under the NaCl treatment by retaining the highest chloride concentration in the roots and greatly limiting the concentration found in the leaves of the cv. Hass cultivar. It is therefore a promising rootstock for salt tolerance.El palto (Persea americana Mill. es una de las especies más sensibles a la salinidad, debido a que su sistema radical es particularmente afectado por este estrés, es importante identificar un portainjerto tolerante al riego con agua salina. Para encontrar posibles candidatos se utilizó material vegetal del cv. Hass injertado sobre cinco portainjertos, el clonal Duke 7 y los provenientes de semilla, Nabal, Degania 117, Mexícola y Zutano. Plantas de 1 año de edad fueron colocadas en macetas de 55 L, con arena de río como sustrato y fertilizadas con una solución Hoagland modificada. Durante 130 días se comparó el crecimiento vegetativo y los contenidos internos de nutrientes en plantas

  16. Dry Process for Manufacturing Hybridized Boron Fiber/Carbon Fiber Thermoplastic Composite Materials from a Solution Coated Precursor

    Science.gov (United States)

    Belvin, Harry L. (Inventor); Cano, Roberto J. (Inventor)

    2003-01-01

    An apparatus for producing a hybrid boron reinforced polymer matrix composite from precursor tape and a linear array of boron fibers. The boron fibers are applied onto the precursor tapes and the precursor tape processed within a processing component having an impregnation bar assembly. After passing through variable-dimension forming nip-rollers, the precursor tape with the boron fibers becomes a hybrid boron reinforced polymer matrix composite. A driving mechanism is used to pulled the precursor tape through the method and a take-up spool is used to collect the formed hybrid boron reinforced polymer matrix composite.

  17. Chitosan composite hydrogels reinforced with natural clay nanotubes.

    Science.gov (United States)

    Huang, Biao; Liu, Mingxian; Zhou, Changren

    2017-11-01

    Here, chitosan composites hydrogels were prepared by addition of halloysite nanotubes (HNTs) in the chitosan KOH/LiOH/urea solution. The raw chitosan and chitosan/HNTs composite hydrogels were obtained by heat treatment at 60°C for 8h and then regeneration in ethanol solution. The viscosity of the composite solution is increased with HNTs content. The Fourier transform infrared spectroscopy (FT-IR) shows that the hydrogen bonds interactions exist between the HNTs and the chitosan. X-ray diffraction (XRD) results show that the crystal structure of HNT is not changed in the composite hydrogels. The compressive property test and storage modulus determination show that the mechanical properties and anti-deformation ability of the composite hydrogel significantly increase owing to the reinforcing effect of HNTs. The composites hydrogel with 66.7% HNTs can undergo 7 times compression cycles without breaking with compressive strength of 0.71MPa at 70% deformation, while pure chitosan hydrogel is broken after bearing 5 compression cycles with compressive strength of 0.14MPa and a maximum deformation of 59%. A porous structure with pore size of 100-500μm is found in the composite hydrogels by scanning electron microscopy (SEM), and the pore size and the swelling ratio in NaCl solution decrease by the addition of HNTs and the immersing of ethanol. Chitosan/HNTs composite hydrogels show low cytotoxicity towards MC3T3-E1 cells. Also, the composite hydrogels show a maximum drug entrapment efficiency of 45.7% for doxorubicin (DOX) which is much higher than that of pure chitosan hydrogel (27.5%). All the results illustrate that the chitosan/HNTs composite hydrogels show promising applications as biomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions. Chemical composition range and flux crystal growth

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, V.A. [N.I. Lobachevsky State University of Nizhni Novgorod, Nizhni Novgorod, 603950 (Russian Federation); Marychev, M.O., E-mail: marychev@yandex.ru [N.I. Lobachevsky State University of Nizhni Novgorod, Nizhni Novgorod, 603950 (Russian Federation); Andreev, P.V.; Lykov, V.A.; Faddeev, M.A. [N.I. Lobachevsky State University of Nizhni Novgorod, Nizhni Novgorod, 603950 (Russian Federation); Koseva, I. [Bulgarian Academy of Science, Institute of General and Inorganic Chemistry, BU-1113 Sofia (Bulgaria); Nikolov, V. [N.I. Lobachevsky State University of Nizhni Novgorod, Nizhni Novgorod, 603950 (Russian Federation)

    2015-11-01

    A series of Ca{sub 2−x}Li{sub 2x}GeO{sub 4} specimens with 0 < 2x < 2, were synthesized by the classical solid state method. X-ray analysis revealed that for 0 < 2x < 0.6 only Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions of Ca{sub 2}GeO{sub 4} structure crystallized. The cell parameters of these solid solutions linearly decreased upon increasing the lithium concentration, which means that the solutions are in accordance with the Vegard's law. For 2x > 0.6 the specimens contained two phases: (i) Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions with maximum lithium concentration approximately equal to that for 2x = 0.6 and minimum values of the cell parameters and (ii) Li{sub 2}CaGeO{sub 4} phase. Li{sub 2}O·MoO{sub 3}–Ca{sub 2}GeO{sub 4} high-temperature solutions were used to grow Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions and Li{sub 2}CaGeO{sub 4} single crystals by the high temperature solution (flux) method. Li{sub 2}CaGeO{sub 4} crystals were grown in the concentration range 8–26 wt. % Ca{sub 2}GeO{sub 4} in the temperature range 830–980 °C. Crystals with chemical compositions of the Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions with different Li concentrations were grown in the concentration range 26–40 wt. % Ca{sub 2}GeO{sub 4} in the temperature range 980–1090 °C. - Highlights: • Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions are established for the first time. • The Li concentration range into the solutions is between 0 and 0.6. • The solid solutions are in accordance to Vegard's law. • Suitable solutions are found out for Ca{sub 2−x}Li{sub 2x}GeO{sub 4} and Li{sub 2}CaGeO{sub 4} crystal growth.

  19. Degradation of simazine from aqueous solutions by diatomite-supported nanosized zero-valent iron composite materials.

    Science.gov (United States)

    Sun, Zhiming; Zheng, Shuilin; Ayoko, Godwin A; Frost, Ray L; Xi, Yunfei

    2013-12-15

    A novel composite material based on deposition of nanosized zero-valent iron (nZVI) particles on acid-leached diatomite was synthesised for the removal of a chlorinated contaminant in water. The nZVI/diatomite composites were characterised by X-ray diffraction, scanning electron microscopy, elemental analysis, transmission electron microscopy and X-ray photoelectron spectroscopy. Compared with the pure nZVI particles, better dispersion of nZVI particles on the surface or inside the pores of diatom shells was observed. The herbicide simazine was selected as the model chlorinated contaminant and the removal efficiency by nZVI/diatomite composite was compared with that of the pristine nZVI and commercial iron powder. It was found that the diatomite supported nZVI composite material prepared by centrifugation exhibits relatively better efficient activity in decomposition of simazine than commercial Fe, lab synthesised nZVI and composite material prepared via rotary evaporation, and the optimum experimental conditions were obtained based on a series of batch experiments. This study on immobilising nZVI particles onto diatomite opens a new avenue for the practical application of nZVI and the diatomite-supported nanosized zero-valent iron composite materials have potential applications in environmental remediation. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Room-temperature solution-processed and metal oxide-free nano-composite for the flexible transparent bottom electrode of perovskite solar cells

    Science.gov (United States)

    Lu, Haifei; Sun, Jingsong; Zhang, Hong; Lu, Shunmian; Choy, Wallace C. H.

    2016-03-01

    The exploration of low-temperature and solution-processed charge transporting and collecting layers can promote the development of low-cost and large-scale perovskite solar cells (PVSCs) through an all solution process. Here, we propose a room-temperature solution-processed and metal oxide-free nano-composite composed of a silver nano-network and graphene oxide (GO) flawless film for the transparent bottom electrode of a PVSC. Our experimental results show that the amount of GO flakes play a critical role in forming the flawless anti-corrosive barrier in the silver nano-network through a self-assembly approach under ambient atmosphere, which can effectively prevent the penetration of liquid or gaseous halides and their corrosion against the silver nano-network underneath. Importantly, we simultaneously achieve good work function alignment and surface wetting properties for a practical bottom electrode by controlling the degree of reduction of GO flakes. Finally, flexible PVSC adopting the room-temperature and solution-processed nano-composite as the flexible transparent bottom electrode has been demonstrated on a polyethylene terephthalate (PET) substrate. As a consequence, the demonstration of our room-temperature solution-processed and metal oxide-free flexible transparent bottom electrode will contribute to the emerging large-area flexible PVSC technologies.The exploration of low-temperature and solution-processed charge transporting and collecting layers can promote the development of low-cost and large-scale perovskite solar cells (PVSCs) through an all solution process. Here, we propose a room-temperature solution-processed and metal oxide-free nano-composite composed of a silver nano-network and graphene oxide (GO) flawless film for the transparent bottom electrode of a PVSC. Our experimental results show that the amount of GO flakes play a critical role in forming the flawless anti-corrosive barrier in the silver nano-network through a self

  1. Atomistic simulation of solid solution hardening in Mg/Al alloys: Examination of composition scaling and thermo-mechanical relationships

    International Nuclear Information System (INIS)

    Yi, Peng; Cammarata, Robert C.; Falk, Michael L.

    2016-01-01

    Dislocation mobility in a solid solution was studied using atomistic simulations of an Mg/Al system. The critical resolved shear stress (CRSS) for the dislocations on the basal plane was calculated at temperatures from 0 K to 500 K with solute concentrations from 0 to 7 at%, and with four different strain rates. Solute hardening of the CRSS is decomposed into two contributions: one scales with c 2/3 , where c is the solute concentration, and the other scales with c 1 . The former was consistent with the Labusch model for local solute obstacles, and the latter was related to the athermal plateau stress due to the long range solute effect. A thermo-mechanical model was then used to analyze the temperature and strain rate dependences of the CRSS, and it yielded self-consistent and realistic results. The scaling laws were confirmed and the thermo-mechanical model was successfully parameterized using experimental measurements of the CRSS for Mg/Al alloys under quasi-static conditions. The predicted strain rate sensitivity from the experimental measurements of the CRSS is in reasonable agreement with separate mechanical tests. The concentration scaling and the thermo-mechanical relationships provide a potential tool to analytically relate the structural and thermodynamic parameters on the microscopic level with the macroscopic mechanical properties arising from dislocation mediated deformation.

  2. Investigation of Fumed Silica/Aqueous NaCl Superdielectric Material

    Directory of Open Access Journals (Sweden)

    Natalie Jenkins

    2016-02-01

    Full Text Available A constant current charge/discharge protocol which showed fumed silica filled to the point of incipient wetness with aqueous NaCl solution to have dielectric constants >108 over the full range of dielectric thicknesses of 0.38–3.9 mm and discharge times of 0.25–>100 s was studied, making this material another example of a superdielectric. The dielectric constant was impacted by both frequency and thickness. For time to discharge greater than 10 s the dielectric constant for all thicknesses needed to be fairly constant, always >109, although trending higher with increasing thickness. At shorter discharge times the dielectric constant consistently decreased, with decreasing time to discharge. Hence, it is reasonable to suggest that for time to discharge >10 s the dielectric constant at all thicknesses will be greater than 109. This in turn implies an energy density for a 5 micron thick dielectric layer in the order of 350 J/cm3 for discharge times greater than 10 s.

  3. Investigation of Fumed Silica/Aqueous NaCl Superdielectric Material.

    Science.gov (United States)

    Jenkins, Natalie; Petty, Clayton; Phillips, Jonathan

    2016-02-20

    A constant current charge/discharge protocol which showed fumed silica filled to the point of incipient wetness with aqueous NaCl solution to have dielectric constants >10⁸ over the full range of dielectric thicknesses of 0.38-3.9 mm and discharge times of 0.25->100 s was studied, making this material another example of a superdielectric. The dielectric constant was impacted by both frequency and thickness. For time to discharge greater than 10 s the dielectric constant for all thicknesses needed to be fairly constant, always >10⁸, although trending higher with increasing thickness. At shorter discharge times the dielectric constant consistently decreased, with decreasing time to discharge. Hence, it is reasonable to suggest that for time to discharge >10 s the dielectric constant at all thicknesses will be greater than 10⁸. This in turn implies an energy density for a 5 micron thick dielectric layer in the order of 350 J/cm³ for discharge times greater than 10 s.

  4. Exposure to buffer solution alters tendon hydration and mechanics.

    Science.gov (United States)

    Safa, Babak N; Meadows, Kyle D; Szczesny, Spencer E; Elliott, Dawn M

    2017-08-16

    A buffer solution is often used to maintain tissue hydration during mechanical testing. The most commonly used buffer solution is a physiological concentration of phosphate buffered saline (PBS); however, PBS increases the tissue's water content and decreases its tensile stiffness. In addition, solutes from the buffer can diffuse into the tissue and interact with its structure and mechanics. These bathing solution effects can confound the outcome and interpretation of mechanical tests. Potential bathing solution artifacts, including solute diffusion, and their effect on mechanical properties, are not well understood. The objective of this study was to measure the effects of long-term exposure of rat tail tendon fascicles to several concentrations (0.9-25%) of NaCl, sucrose, polyethylene glycol (PEG), and SPEG (NaCl+PEG) solutions on water content, solute diffusion, and mechanical properties. We found that with an increase in solute concentration the apparent water content decreased for all solution types. Solutes diffused into the tissue for NaCl and sucrose, however, no solute diffusion was observed for PEG or SPEG. The mechanical properties changed for both NaCl solutions, in particular after long-term (8h) incubation the modulus and equilibrium stress decreased compared to short-term (15min) for 25% NaCl, and the cross sectional area increased for 0.9% NaCl. However, the mechanical properties were unchanged for both PEG and SPEG except for minor alterations in stress relaxation parameters. This study shows that NaCl and sucrose buffer solutions are not suitable for long-term mechanical tests. We therefore propose using PEG or SPEG as alternative buffer solutions that after long-term incubation can maintain tissue hydration without solute diffusion and produce a consistent mechanical response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Effect of NaCl treatments on glucosinolate metabolism in broccoli sprouts*

    Science.gov (United States)

    Guo, Rong-fang; Yuan, Gao-feng; Wang, Qiao-mei

    2013-01-01

    To understand the regulation mechanism of NaCl on glucosinolate metabolism in broccoli sprouts, the germination rate, fresh weight, contents of glucosinolates and sulforaphane, as well as myrosinase activity of broccoli sprouts germinated under 0, 20, 40, 60, 80, and 100 mmol/L of NaCl were investigated in our experiment. The results showed that glucoerucin, glucobrassicin, and 4-hydroxy glucobrassicin in 7-d-old broccoli sprouts were significantly enhanced and the activity of myrosinase was inhibited by 100 mmol/L of NaCl. However, the total glucosinolate content in 7-d-old broccoli sprouts was markedly decreased although the fresh weight was significantly increased after treatment with NaCl at relatively low concentrations (20, 40, and 60 mmol/L). NaCl treatment at the concentration of 60 mmol/L for 5 d maintained higher biomass and comparatively higher content of glucosinolates in sprouts of broccoli with decreased myrosinase activity. A relatively high level of NaCl treatment (100 mmol/L) significantly increased the content of sulforaphane in 7-d-old broccoli sprouts compared with the control. These results indicate that broccoli sprouts grown under a suitable concentration of NaCl could be desirable for human nutrition. PMID:23365011

  6. A new method of accurate determination of isotopic composition and concentration of strontium in a spike solution used for geochronological works

    International Nuclear Information System (INIS)

    Yanagi, Takeru

    1990-01-01

    A new method of accurate determination of isotopic composition and concentration of a strontium-84 spike solution was devised for simultaneous determination of strontium contents and isotopic compositions in rocks and minerals by measuring strontium isotopic ratios in spiked samples. In this method, the isotopic composition of strontium in the spike were determined so as to minimize the sum of squares of deviations of spike strontium-84 concentrations which were calculated from measured isotopic ratios of strontium in five different mixtures of the spike and the standard solution. The method can eliminate all mass discriminations occurred during the measurements on a surface ionization mass spectrometer. The results were tested by measuring 87 Sr/ 86 Sr ratios of Eimer and Amend SrCO 3 and JB-1 geochemical reference material, and by determining the strontium content in JB-1. The measurements of strontium isotope ratios in spiked samples give average values of 0.708007±0.000052 and 0.70417±0.00004 for 87 Sr/ 86 Sr ratios of E and A SrCO 3 and JB-1, respectively. The strontium content in JB-1 was estimated at 457.1±1.3 ppm. These values are very close to reported respective values. (author)

  7. PROPRIEDADES EMULSIONANTES E SOLUBILIDADE DA CASEÍNA BOVINA: 2. EFEITO DA ADIÇÃO DE NaCl EMULSIFYING PROPERTIES AND SOLUBILITY OF CASEIN: 2. EFFECTS OF THE NaCl ADDITION

    Directory of Open Access Journals (Sweden)

    Ângela Jardim DUARTE

    1998-08-01

    Full Text Available O efeito da adição de NaCl sobre algumas propriedades funcionais da caseína e de seus hidrolisados trípticos, foi estudado em dois valores de pH (4,0 e 5,0. Para tal, foi adicionado um teor de 0,02M do sal às soluções-tampão empregadas no preparo das amostras. Foram determinadas a solubilidade protéica, a capacidade emulsificante (EC, o índice de atividade emulsificante (EAI e a estabilidade das emulsões (ES, e o raio médio dos glóbulos de gordura (R foi calculado. Os resultados obtidos indicaram que, nos dois valores de pH estudados, a adição de NaCl levou a um aumento significativo da solubilidade e da EC da caseína e de todos os hidrolisados trípticos. Por outro lado, diminuiu os valores de EAI da caseína e elevou os dos hidrolisados, tendo sido observado o oposto para o tamanho dos glóbulos de gordura. Com relação à ES, a da caseína apresentou ligeiro aumento no pH 5,0, enquanto que apenas alguns hidrolisados trípticos tiveram a sua ES elevada em pH 4,0 ou 5,0.The effect of the NaCl addition on the emulsifying properties of casein and tryptic casein hydrolysates was studied in two pH values (4,0 e 5,0. A 0.02 M concentration of salt was added to the buffer solutions used for preparing the samples. The protein solubility, the emulsifying capacity (EC, the emulsifying activity index (EAI and the emulsion stability (ES were determined. The mean radius (R of fat droplets was also calculated. The results showed that the addition of NaCl increased the solubility and the EC of casein and casein hydrolysates, in both pH values. However, this salt addition reduced the EAI of casein and increased that of the hydrolysates.The opposite was observed relating to the R of fat droplets. Regarding the ES, that of casein presented little increase in pH 5.0, and the same result was obtained for only some hydrolysates in pH 5.0 or 4.0.

  8. Proteomic changes in Debaryomyces hansenii upon exposure to NaCl stress

    DEFF Research Database (Denmark)

    Gori, Klaus; Hébraud, Michel; Chambon, Christophe

    2007-01-01

    The proteome of the highly NaCl-tolerant yeast Debaryomyces hansenii was investigated by two-dimensional polyacrylamide gel electrophoresis (2D PAGE), and 47 protein spots were identified by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) followed by mass spectrometry (MS...... 7% and 4% of the rate in medium without NaCl. In addition, the number of protein spots detected on 2D gels prepared from cells exposed to 8% and 12% (w/v) NaCl exceeded less than 28% of the number of protein spots detected on 2D gels prepared from cells without added NaCl. Several proteins were...

  9. Green preparation of a novel red mud@carbon composite and its application for adsorption of 2,4-dichlorophenoxyacetic acid from aqueous solution.

    Science.gov (United States)

    Kazak, Omer; Eker, Yasin Ramazan; Akin, Ilker; Bingol, Haluk; Tor, Ali

    2017-10-01

    This study reports the eco-friendly preparation of a novel composite material consisting of red mud and carbon spheres, denoted as red mud@C composite, and its application for the removal of 2,4-dichlorophenoxyacetic acid herbicide (2,4-D) from aqueous solution. The preparation route has a green approach because it follows the low-energy consuming one-step hydrothermal process by using starch as a renewable carbon precursor and red mud as a waste from aluminum production industry. Characterization of the red mud@C composite was performed by FT-IR, TGA, SEM, TEM, BET, XRD, and Raman microscopy analyses. The batch adsorption studies revealed that the red mud@C composite has higher 2,4-D adsorption efficiency than those of the red mud and the naked carbon spheres. The maximum removal at initial pH of 3.0 is explained by considering the pKa of 2,4-D and pH of point of zero charge (pH pzc ) of the composite material. The adsorption equilibrium time was 60 min, which followed the pseudo-second-order kinetic model together with intra-particle diffusion model. The isotherm analysis indicated that Freundlich isotherm model better represented the adsorption data, with isotherm parameters of k [15.849 (mg/g) (mg/L) -1/n ] and n (2.985). The prepared composite is reusable at least 5 cycles of adsorption-desorption with no significant decrease in the adsorption capacity.

  10. Electro-volatilization of ruthenium in nitric medium: influences of ruthenium species nature and models solutions composition

    International Nuclear Information System (INIS)

    Mousset, F.

    2004-12-01

    Ruthenium is one of the fission products in the reprocessing of irradiated fuels that requires a specific processing management. Its elimination, upstream by the PUREX process, has been considered. A process, called electro-volatilization, which take advantage of the RuO 4 volatility, has been optimised in the present study. It consists in a continuous electrolysis of ruthenium solutions in order to generate RuO 4 species that is volatilized and easily trapped. This process goes to satisfying ruthenium elimination yields with RuNO(NO 3 ) 3 (H 2 O) 2 synthetic solutions but not with fuel dissolution solutions. Consequently, this work consisted in the speciation studies of dissolved ruthenium species were carried out by simulating fuel solutions produced by hot acid attack of several ruthenium compounds (Ru(0), RuO 2 ,xH 2 O, polymetallic alloy). In parallel with dissolution kinetic studies, the determination of dissolved species was performed using voltammetry, spectrometry and spectro-electrochemistry. The results showed the co-existence of Ru(IV) and RuNO(NO 2 ) 2 (H 2 O) 3 . Although these species are different from synthetic RuNO(NO 3 ) 3 (H 2 O) 2 , their electro-oxidation behaviour are similar. The electro-volatilization tests of these dissolution solutions yielded to comparable results as the synthetic RuNO(NO 3 ) 3 (H 2 O) 2 solutions. Then, complexity increase of models solutions was performed by in-situ generation of nitrous acid during ruthenium dissolution. Nitrous acid showed a catalytic effect on ruthenium dissolution. Its presence goes to quasi exclusively RuNO(NO 2 ) 2 (H 2 O) 3 species. It is also responsible of the strong n-bond formation between Ru 2+ and NO + . In addition, it has been shown that its reducing action on RuO 4 hinders the electro-volatilization process. Mn 2+ and Ce 3+ cations also reveal, but to a lesser extent, an electro-eater behaviour as well as Pu 4+ and Cr 3+ according to the thermodynamics data. These results allow one to

  11. Stress wave propagation in thin long-fiber carbon/epoxy composite panel. Numerical and experimental solutions

    Czech Academy of Sciences Publication Activity Database

    Kroupa, Tomáš; Červ, Jan; Valeš, František

    2007-01-01

    Roč. 1, č. 1 (2007), s. 127-136 ISSN 1802-680X. [Computational Mechanics 2007. Hrad Nečtiny, 05.11.2007-07.11.2007] R&D Projects: GA AV ČR(CZ) IAA200760611 Institutional research plan: CEZ:AV0Z20760514 Keywords : FRP composite * carbon-epoxy * orthotropic material Subject RIV: BI - Acoustics

  12. Textured PbTiO3-Al2O3 composite films prepared by chemical solution deposition

    Czech Academy of Sciences Publication Activity Database

    Buršík, Josef; Vaněk, Přemysl; Kužel, R.; Studnička, Václav; Železný, Vladimír

    2001-01-01

    Roč. 21, 10-11 (2001), s. 1503-1507 ISSN 0955-2219 R&D Projects: GA ČR GA203/01/0408 Institutional research plan: CEZ:AV0Z4032918 Keywords : composites * perovskites * sol-gel processes Subject RIV: CA - Inorganic Chemistry Impact factor: 1.071, year: 2001

  13. Effect of phase composition on the corrosion properties of alloys of the magnesium-yttrium system in neutral solutions

    International Nuclear Information System (INIS)

    Krasnoyarskii, V.V.; Petrova, L.M.; Dobatkina, T.V.; Korol'kova, I.G.

    1992-01-01

    A study is made of the effect of phase composition on the corrosive dissolution of binary alloys of the system magnesium-8.2% yttrium. It is shown that the appearance of the intermetallide Mg 24 Y 5 - being the effective cathode - intensifies self-dissolution of the alloy under conditions of anodic galvanostatic polarization

  14. Ag(I)-bovine serum albumin hydrosol-mediated formation of Ag3PO4/reduced graphene oxide composites for visible-light degradation of Rhodamine B solution.

    Science.gov (United States)

    Ma, Peiyan; Chen, Anliang; Wu, Yan; Fu, Zhengyi; Kong, Wei; Che, Liyuan; Ma, Ruifang

    2014-03-01

    A cost-effective Ag(I)-bovine serum albumin (BSA) supramolecular hydrosol strategy was utilized to assemble Ag3PO4 nanospheres onto reduced graphene oxide (rGO) sheets. The obtained composites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy. Compared with the pure Ag3PO4 crystals and Ag3PO4 particles prepared with Ag(I)-BSA hydrosol as precursor, the Ag3PO4/rGO composites obtained with different content of graphene oxide indicated improved visible-light-driven photocatalysis activity for the decomposition of Rhodamine B aqueous solution. The results pointed to the possibility of synthesizing graphene-based photocatalysts by metal ion-BSA hydrosol. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Influence of Chemical Composition on Rupture Properties at 1200 Degrees F. of Forged Chromium-Cobalt-Nickel-Iron Base Alloys in Solution-Treated and Aged Condition

    Science.gov (United States)

    Reynolds, E E; Freeman, J W; White, A E

    1951-01-01

    The influence of systematic variations of chemical composition on rupture properties at 1200 degrees F. was determined for 62 modifications of a basic alloy containing 20 percent chromium, 20 percent nickel, 20 percent cobalt, 3 percent molybdenum, 2 percent tungsten, 1 percent columbium, 0.15 percent carbon, 1.7 percent manganese, 0.5 percent silicon, 0.12 percent nitrogen and the balance iron. These modifications included individual variations of each of 10 elements present and simultaneous variations of molybdenum, tungsten, and columbium. Laboratory induction furnace heats were hot-forged to round bar stock, solution-treated at 2200 degrees F., and aged at 1400 degrees F. The melting and fabrication conditions were carefully controlled in order to minimize all variable effects on properties except chemical composition. Information is presented which indicates that melting and hot-working conditions play an important role in high-temperature properties of alloys of the type investigated.

  16. Electrocatalytic activity and stability of Ag-MnOx/C composites toward oxygen reduction reaction in alkaline solution

    International Nuclear Information System (INIS)

    Wu, Qiumei; Jiang, Luhua; Qi, Luting; Yuan, Lizhi; Wang, Erdong; Sun, Gongquan

    2014-01-01

    Ag-MnO x /C composites were prepared using AgNO 3 and KMnO 4 as the precursors and Vulcan XC-72 as the support. The physical properties of the Ag-MnO x /C composites were investigated via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The activity and the stability of the series of Ag-MnO x /C composites toward the oxygen reduction reaction (ORR) in alkaline media were investigated through the electrochemical techniques. The results show that the main species MnO 2 and Ag 2 O in the fresh sample convert into Mn 3 O 4 and Ag(0), respectively, after the heat treatment in N 2 at 300 °C (Ag-MnO x /C-300). The Ag-MnO x /C-300 sample shows the highest activity toward the ORR, with the half-wave potential of the ORR shifting negatively only 0.035 V compared to that on the commercial 40 wt. % Pt/C (JM). The electron transfer number during the ORR on the Ag-MnO x /C composite increases with the value close to four after the heat treatment at 300 °C, which is mainly attributed to the formation of Ag(0), rather than Mn 3 O 4 . The heat treatment brings about a better catalytic stability of the composite, and no obviously negative shift takes place for the half-wave potential of the ORR on the Ag-MnO x /C-300 composite after 1000 cycles accelerated aging test. The maximum power density of the zinc-air battery with the Ag-MnO x /C-300 air electrode reaches up to 130 mW cm −2 , higher than those based on the Pd/C and Pt/C cathode catalysts, which shows that the Ag-MnO x /C-300 composite is a promising candidate as the catalyst for the air electrode

  17. Synthesis of high-performance Li2FeSiO4/C composite powder by spray-freezing/freeze-drying a solution with two carbon sources

    Science.gov (United States)

    Fujita, Yukiko; Iwase, Hiroaki; Shida, Kenji; Liao, Jinsun; Fukui, Takehisa; Matsuda, Motohide

    2017-09-01

    Li2FeSiO4 is a promising cathode active material for lithium-ion batteries due to its high theoretical capacity. Spray-freezing/freeze-drying, a practical process reported for the synthesis of various ceramic powders, is applied to the synthesis of Li2FeSiO4/C composite powders and high-performance Li2FeSiO4/C composite powders are successfully synthesized by using starting solutions containing both Indian ink and glucose as carbon sources followed by heating. The synthesized composite powders have a unique structure, composed of Li2FeSiO4 nanoparticles coated with a thin carbon layer formed by the carbonization of glucose and carbon nanoparticles from Indian ink. The carbon layer enhances the electrochemical reactivity of the Li2FeSiO4, and the carbon nanoparticles play a role in the formation of electron-conducting paths in the cathode. The composite powders deliver an initial discharge capacity of 195 and 137 mAh g-1 at 0.1 C and 1 C, respectively, without further addition of conductive additive. The discharge capacity at 1 C is 72 mAh g-1 after the 100th cycle, corresponding to approximately 75% of the capacity at the 2nd cycle.

  18. Application of mutation breeding technique for producing NaCl tolerant plants of banana in tissue culture and greenhouse conditions

    International Nuclear Information System (INIS)

    Vedadi, C.; Rahimi, M.; Naserian, B.; Rahmani, E.; Neshan, N.

    2005-01-01

    Full text: To study of possibility to induce salt tolerant clones in banana by using mutation technique, an experiment was conducted with factorial (gamma irradiation and salt concentration factors) in a CRD design. In this research, plantlets of banana cv. Dwarf Cavendish were produced by subculture of irradiated shoot tips. It deserves to mention that consequent subculturing was aimed at getting rid of chimera. Next, these explants were transferred to MS medium containing 2.5 mg. l- 1 BAP and NaCl concentrations of 0, 6, 7, 8, 9 g.l -1 for 2 months .Then, living buds were transferred to medium without salt. After one month, we repeated the first stage. All living buds rooted and were transferred to potted soil. Acclimatized plants were irrigated weekly with above NaCl solution. Other irrigation was done with salt-free water. There was also a negative relation between salt concentration and survival - proliferation. In second salinity stress, salt had no significant difference on survival percentage. No-significant difference of effect salt on survival in second salinity stress was observed. (author)

  19. Study of the chemical composition of waters in Morro do Ferro (MG), Brazil: transport of thorium and several tracer alements in solution

    International Nuclear Information System (INIS)

    Pivetta, F.R.

    1983-01-01

    The chemical composition of surface and well waters in the Morro do Ferro (Pocos de Caldas-MG.) Brazil, because the transport in solution may represent one important way of environmental contamination is studied. Samples of one stream in the base of the hill, of perfuration wells and of one galery were analysed in the period from 1980 (October) to 1982 (May). The contents of Mn, Fe, SiO 2 , SO 2- 4 , PO 3- 4 , NO - 3 and CO 2 is analysed in situ. (M.J.C.) [pt

  20. Phase Relations in Ternary Systems in the Subsolidus Region: Methods to Formulate Solid Solution Equations and to Find Particular Compositions

    Science.gov (United States)

    Alvarez-Montan~o, Victor E.; Farías, Mario H.; Brown, Francisco; Mun~oz-Palma, Iliana C.; Cubillas, Fernando; Castillon-Barraza, Felipe F.

    2017-01-01

    A good understanding of ternary phase diagrams is required to advance and/or to reproduce experimental research in solid-state and materials chemistry. The aim of this paper is to describe the solutions to problems that appear when studying or determining ternary phase diagrams. A brief description of the principal features shown in phase diagrams…

  1. Effect of the isotopic composition of the solvent (water) in the absolute turbidity of polietilen-glicols solutions

    International Nuclear Information System (INIS)

    Molinari, M.A.; Videla, G.J.

    1975-11-01

    Variation in the absolute turbidity of solutions of carbowax 20 M (about 17%) and carbowax 4000 (about 39%) were observed when the relation D 2 O/H 2 O was changed from 0 to 100%, for incident wavelength of 546 and 436 nm. (author) [es

  2. Changes in growth, physiological parameters and the hormonal status of Myrtus communis L. plants irrigated with water with different chemical compositions.

    Science.gov (United States)

    Acosta-Motos, José Ramón; Ortuño, María Fernanda; Álvarez, Sara; López-Climent, María Fernanda; Gómez-Cadenas, Aurelio; Sánchez-Blanco, María Jesús

    2016-02-01

    Myrtus communis, an important Mediterranean ornamental shrub, was used to study the effect of irrigation water with different chemical compositions in the plant response. A treatment with NaCl was used to establish the plant resistance to high salinity at long term. Plants were subjected to four irrigation treatments with drainage for three months: Control (0.8 dS m(-1)); two treatments using reclaimed water (RWs): RW1 (2.0 dS m(-1)) and RW2 (5.0 dS m(-1)); and NaCl (10.0 dS m(-1)). High levels of electric conductivity of RWs not affected plant growth, while NaCl decreased leaf dry weight. Coinciding with the accumulation of Na(+) and Cl(-) in the roots, soil water potential decreased, which hinders the mobilization of water to the leaves, decreasing leaf water potential. The osmotic adjustment in the NaCl treatment was due to Na(+) and Cl(-) ions, although the proline could contribute as an Osmo compatible solute, increasing the turgor plants. Also changes in cell walls rigidity minimize the negative effects on the water balance; however, a higher lipid peroxidation was observed in these plants. Stomatal closure was associated with a decrease in K(+) and an increase in abscisic acid. NaCl produced an increase in salicylic acid and did not affect jasmonic acid contents at the end of the experiment. Similar behavior in soil and leaf water potentials, although less pronounced than in NaCl, was shown in RW2 plants. The abscisic acid increased in the RW2 with respect to the control and a decrease in stomatal conductance was observed at the end of the experiment. Plants irrigated with RW1 behaved similarly to the control. Copyright © 2015. Published by Elsevier GmbH.

  3. Regeneration of plantlets under NaCl stress from NaN3 treated ...

    African Journals Online (AJOL)

    use

    2011-11-16

    Nov 16, 2011 ... plant regeneration under NaCl stressed conditions was assessed in some sugarcane ( ... cell is a useful work for the establishment of pure form of ... balance. The relative water contents (RWC) were calculated .... J. Life Sci.

  4. Elevated NaCl concentration improves cryotolerance and developmental competence of porcine oocytes

    DEFF Research Database (Denmark)

    Lin, L; Du, Y; Liu, Y

    2009-01-01

    High hydrostatic pressure has been reported to improve the fertilizing or developmental ability of mammalian spermatozoa, oocytes and embryos. This study investigated the effect of another stress, temporarily increased NaCl concentration, on cryotolerance and developmental competence of porcine...

  5. Effect of plasma nitriding on electrodeposited Ni–Al composite coating

    DEFF Research Database (Denmark)

    Daemi, N.; Mahboubi, F.; Alimadadi, Hossein

    2011-01-01

    In this study plasma nitriding is applied on nickel–aluminum composite coating, deposited on steel substrate. Ni–Al composite layers were fabricated by electro-deposition process in Watt’s bath containing Al particles. Electrodeposited specimens were subjected to plasma atmosphere comprising of N2......–20% H2, at 500°C, for 5h. The surface morphology investigated, using a scanning electron microscope (SEM) and the surface roughness was measured by use of contact method. Chemical composition was analyzed by X-ray fluorescence spectroscopy and formation of AlN phase was confirmed by X-ray diffraction....... The corrosion resistance of composite coatings was measured by potentiodynamic polarization in 3.5% NaCl solution. The obtained results show that plasma nitriding process leads to an increase in microhardness and corrosion resistance, simultaneously....

  6. Corrosion behaviour of 2124 aluminium alloy-silicon carbide metal matrix composites in sodium chloride environment

    International Nuclear Information System (INIS)

    Singh, Nirbhay; Vadera, K.K.; Ramesh Kumar, A.V.; Singh, R.S.; Monga, S.S.; Mathur, G.N.

    1999-01-01

    Aluminium alloy based particle reinforced metal matrix composites (MMCs) are being considered for a range of applications. Their mechanical properties have been investigated in detail, but more information about their corrosion resistance is needed. In this investigation, the corrosion behaviour of silicon carbide particulates (SiC p )-2124 aluminium metal matrix composites was studied in 3 wt% sodium chloride solution by means of electrochemical technique and optical microscope. The effects of weight percentages and particle size of silicon carbide particulates on corrosion behaviour of the composite were studied in NaCl and it was observed that corrosion rate increases linearly with the increasing weight percentage of SiC p . The corrosion rate of the MMC increases by increasing the size of SiC particles. Anodization improved corrosion resistance of the composites. (author)

  7. Complex solution of problem of all-season construction of roads and pipelines on universal composite pontoon units

    Science.gov (United States)

    Ryabkov, A. V.; Stafeeva, N. A.; Ivanov, V. A.; Zakuraev, A. F.

    2018-05-01

    A complex construction consisting of a universal floating pontoon road for laying pipelines in automatic mode on its body all year round and in any weather for Siberia and the Far North has been designed. A new method is proposed for the construction of pipelines on pontoon modules, which are made of composite materials. Pontoons made of composite materials for bedding pipelines with track-forming guides for automated wheeled transport, pipelayer, are designed. The proposed system eliminates the construction of a road along the route, ensures the buoyancy and smoothness of the self-propelled automated stacker in the form of a "centipede", which has a number of significant advantages in the construction and operation of the entire complex in the swamp and watered areas without overburden.

  8. Water based, solution-processable, transparent and flexible graphene oxide composite as electrodes in organic solar cell application

    International Nuclear Information System (INIS)

    Lima, L F; Matos, C F; Gonçalves, L C; Roman, L S; Salvatierra, R V; Zarbin, A J G; Cava, C E

    2016-01-01

    In this work we propose an easy method to achieve a conductive, transparent and flexible graphene oxide (GO)-based composite thin film from an aqueous dispersion. We investigated the blend ratio between GO and the conjugated polymer poly(3,4–ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) by comparing the thin film optical transmittance, sheet resistance, morphology and mechanical stability. It was found that reasonable values of transmittance and resistivity coupled with its excellent flexibility – the conductivity remains almost the same even after 1000 bends cycles – make this composite very attracting for flexible optoelectronic applications. Thus, these films were used as transparent electrodes in a bilayer structured organic solar cell and the device architecture PET/GO:PEDOT/F8T2/C 60 /Al could reach a power conversion efficiency around 1.10%. This result presents a better performance compared with pristine PEDOT produced with similar parameters. (paper)

  9. Possible mechanisms for the interaction of polymeric composite resins with Cu(II) ions in aqueous solution

    International Nuclear Information System (INIS)

    El-Zahhhar, A.A.; Abdel-Aziz, H.M.; Siyam, T.

    2005-01-01

    The interaction between the active groups of polymeric composite resins such as Poly(acrylamide-acrylic acid)-ethylenediaminetetra acetic acid disodium salt P(AM-AA)EDTANa 2 , Poly(acrylamide-acrylic acid)- montmorillonite P(AM-AA)-montmorillonite, and Poly(acrylamide-acrylic acid)-potassium nickel hexacyanoferrate P(AM-AA)-KNiHCF, with copper sulfate as a test ion has been studied. The spectroscopic studies show that the mechanism of interaction between polymeric composite resins and copper sulfate is a bond formation between the active groups of polymeric chains and copper ion. The bond formation depends on nature of polymeric chains. It was also found that the amide groups form complexes with hydrated cations, while carboxylate group interact by ion exchange mechanism through complex formation. Montmorillonite and hexacyanoferrate of the resins interact with metal ions by ion exchange mechanism

  10. Synthesis of molybdenum disulfide/reduced graphene oxide composites for effective removal of Pb(Ⅱ) from aqueous solutions

    Institute of Scientific and Technical Information of China (English)

    Yi Du; Xiangke Wang; Jian wang; Yidong Zou; Wen Yao; Jing Hou; Liangshu Xia; Anguo Peng; Ahmed Alsaedi; Tasawar Hayat

    2017-01-01

    In this work,a facile method was adopted to synthesize molybdenum disulfide/reduced graphene oxide (MoS2/rGO) composites through an L-cysteine-assisted hydrothermal technique.The as-prepared MoS2/ rGO composites were firstly applied as adsorbents for efficient elimination of Pb(Ⅱ) ions.Batch adsorption experiments showed that the adsorption of Pb(Ⅱ) on MoS2/rGO followed pseudo-second-order kinetic model well.The adsorption of Pb(Ⅱ) was intensely pH-dependent,ionic strength-dependent at pH < 9.0 and ionic strength-independent at pH > 9.0.The presence of humic acid (HA) enhanced Pb(Ⅱ) adsorption obviously.The MoS2/rGO composites exhibited excellent adsorption capacity of 384.16 mg g-1 at pH 5.0 and T =298.15 K,which was superior to MoS2 (279.93 mg g-1) and many other adsorbents.The thermodynamic parameters suggested that the adsorption process of Pb(Ⅱ) on MoS2/rGO composites was spontaneous (△Gθ < 0) and endothermic (△Hθ > 0).The interaction of Pb(Ⅱ) and MoS2/ rGO was mainly dominated by electrostatic attraction and surface complexation between Pb(Ⅱ) and oxygen-containing functional groups of MoS2/rGO.This work highlighted the application of MoS2/rGO as novel and promising materials in the efficient elimination of Pb(Ⅱ) from contaminated water and industrial effluents in environmental pollution management.

  11. Structural Properties of the Cr(III)-Fe(III) (Oxy)Hydroxide Compositional Series: Insights for a Nanomaterial 'Solid Solution'

    International Nuclear Information System (INIS)

    Tang, Y.; Zhang, L.; Michel, F.M.; Harrington, R.; Parise, J.B.; Reeder, R.J.

    2010-01-01

    Chromium(III) (oxy)hydroxide and mixed Cr(III)-Fe(III) (oxy)hydroxides are environmentally important compounds for controlling chromium speciation and bioaccessibility in soils and aquatic systems and are also industrially important as precursors for materials and catalyst synthesis. However, direct characterization of the atomic arrangements of these materials is complicated because of their amorphous X-ray properties. This study involves synthesis of the complete Cr(III)-Fe(III) (oxy)hydroxide compositional series, and the use of complementary thermal, microscopic, spectroscopic, and scattering techniques for the evaluation of their structural properties. Thermal analysis results show that the Cr end member has a higher hydration state than the Fe end member, likely associated with the difference in water exchange rates in the first hydration spheres of Cr(III) and Fe(III). Three stages of weight loss are observed and are likely related to the loss of surface/structural water and hydroxyl groups. As compared to the Cr end member, the intermediate composition sample shows lower dehydration temperatures and a higher exothermic transition temperature. XANES analysis shows Cr(III) and Fe(III) to be the dominant oxidation states. XANES spectra also show progressive changes in the local structure around Cr and Fe atoms over the series. Pair distribution function (PDF) analysis of synchrotron X-ray total scattering data shows that the Fe end member is nanocrystalline ferrihydrite with an intermediate-range order and average coherent domain size of ∼27 (angstrom). The Cr end member, with a coherent domain size of ∼10 (angstrom), has only short-range order. The PDFs show progressive structural changes across the compositional series. High-resolution transmission electron microscopy (HRTEM) results also show the loss of structural order with increasing Cr content. These observations provide strong structural evidence of chemical substitution and progressive structural

  12. Enhanced Photocatalytic Degradation and Mineralization of Furfural Using UVC/TiO2/GAC Composite in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Bahram Ghasemi

    2016-01-01

    Full Text Available Titanium dioxide nanoparticles were immobilized on granular activated carbon (GAC as a porous and low-density support for photocatalytic degradation of furfural. The TiO2/GAC composite was synthetized using the simple sol-gel method and fully characterized. The effects of the operational parameters of furfural concentration (200–700 mg/L, initial pH (2–12, TiO2/GAC composite dosage (1–3.5 g/L, and irradiation time (20–120 min were studied. The synthetized TiO2/GAC composite exhibited a total pore volume of 0.13 cm3/g and specific surface area of 35.91 m2/g. Removal efficiency of up to 95% was observed at initial pH of 10, TiO2/GAC dosage of 2.5 g/L, irradiation time of 80 min, and initial furfural concentration of 500 mg/L. The photocatalyst could be reused at least four consecutive times with a mere 2% decrease in furfural removal efficiency. Mineralization efficiency of 94% was obtained within 80 min. Pseudo-first-order kinetics best fit the photocatalytic degradation of furfural under experimental conditions.

  13. Utilizing NaCl to increase the porosity of electrospun materials

    International Nuclear Information System (INIS)

    Wright, L.D.; Andric, T.; Freeman, J.W.

    2011-01-01

    Electrospinning has emerged as a popular method for creating scaffolding materials used in tissue engineering applications to repair or replace damaged tissues. To become a viable scaffold material, however, pore sizes in electrospun materials must be increased to improve cell infiltration. Deposition of NaCl crystals during electrospinning was utilized to help overcome this obstacle. The NaCl crystals are released above the rotating collection mandrel and become incorporated into the poly(L-lactide) electrospun material. The NaCl then leaches out of the electrospun material creating larger pores: average pore diameter of 48.7 μm for PLLA-NaCl electrospinning versus 5.5 μm for PLLA alone electrospinning. Electrospun PLLA scaffolds with NaCl pores have a lower elastic modulus (8.05 MPa) and yield stress (349 kPa) and a higher yield strain (0.04) compared to their traditional counterparts (40.36 MPa, 676 kPa, and 0.0188). Decreased elastic modulus and yield stress would be beneficial to tissue engineering of elastic tissues including skin. The presence of NaCl pores did not significantly affect the cellular proliferation of MC3T3 cells but did allow for cell infiltration into the electrospun material. Therefore, the creation of large pores through NaCl leaching can significantly improve the performance of electrospun materials for tissue engineering applications by improving cellular infiltration.

  14. Diquafosol sodium ophthalmic solution for the treatment of dry eye: clinical evaluation and biochemical analysis of tear composition.

    Science.gov (United States)

    Shigeyasu, Chika; Yamada, Masakazu; Akune, Yoko; Tsubota, Kazuo

    2015-11-01

    To evaluate the clinical efficacy of 3% diquafosol sodium ophthalmic solution for dry eye, and to analyze the concentration of tear proteins and mucin-like substances after the treatment. Fifty eyes of 25 patients with dry eye syndrome were prospectively enrolled. The patients were treated with diquafosol solution at a dose of 1 drop in each eye 6 times daily for 4 weeks. The parameters of clinical efficacy were tear osmolarity, tear breakup time (BUT), fluorescein staining scores for the cornea and conjunctiva, Schirmer test values, and subjective symptoms evaluated using the ocular surface disease index (OSDI). Tears collected with Schirmer test strips were analyzed by high-performance liquid chromatography, and the concentrations of the total protein and the 4 major tear proteins, namely, secretory IgA, lactoferrin, lipocalin-1, lysozyme, and N-acetyl-neuraminic acid (Neu5Ac), were measured. Neu5Ac is a major sialic acid, a marker of secretory mucins. The BUT, keratoconjunctival staining scores, and Schirmer test values were improved with statistical significance after the treatment with diquafosol solution, while changes in the other parameters, including tear osmolarity, corneal staining scores, and OSDI scores were not significant. The Neu5Ac concentration was significantly increased, which was not accompanied by changes in tear proteins. Topical application of diquafosol significantly improved the clinical parameters of the BUT, keratoconjunctival staining scores, and Schirmer test values and was accompanied by increased sialic acid content in the tears of patients with dry eye.

  15. Conveyor Cultivation of the Halophytic Plant Salicornia europaea for the Recycling of NaCl from Human Liquid Waste in a Biological Life Support System.

    Science.gov (United States)

    Balnokin, Yurii; Myasoedov, Nikolay; Popova, Larissa; Tikhomirov, Alexander A.; Ushakova, Sofya; Tikhomirova, Natalia; Lasseur, Christophe; Gros, Jean-Bernard

    One problem in designing bioregenerative life support systems (BLSS) is developing technolo-gies to include human liquid and solid waste in intrasystem recycling. A specific task is recycling of NaCl excreted in urine by humans. We showed recently that this could be achieved through inclusion of the salt accumulating halophyte Salicornia europaea in the autotrophic compart-ment of the BLSS (Balnokin et al., ASR, 2010, in press). A model of NaCl circulation in BLSS with inclusion of S. europaea was based on the NaCl turnover in the human -urine -nutrient solution -S. europaea -human cycle. Mineralized urine was used as a basis for preparation of a nutrient solution for the halophyte cultivation. The shoots of the halophyte cultivated in the mineralized urine and containing NaCl could to be used by the BLSS inhabitants in their diets. In this report we describe cultivation of S. europaea which allows turnover of NaCl and produces daily shoot biomass containing Na+ and Cl- in quantities approximately equal to those excreted in daily human urine. The plants were grown in water culture in a climatic chamber under controlled conditions. A solution simulating mineralized urine (SSMU) was used as a basis for preparation of a nutri-ent solution for S. europaea cultivation. For continuous biomass production, seedlings of S. europaea, germinated preliminary in moist sand, were being transferred to the nutrient solu-tion at regular intervals (every two days). Duration of the conveyor operation was 112 days. During the first 56 days, the seedlings were being planted in SSMU diluted by a factor of 1.5 (2/3 SSMU). The same solution was introduced into the growth vessels as volumes of growth medium decreased due to plant transpiration. Starting from the 56th day as conveyor operation was initiated, the plants were being harvested every two days; the solutions from the discharged vessels were mixed with the fresh SSMU and the mixture was introduced into all other growth vessels of

  16. Extrapolation studies on desorption of thorium and uranium at different solution compositions on contaminated soil sediments (Malaysia)

    International Nuclear Information System (INIS)

    Syed Hakimi Sakuma

    2000-01-01

    By means of batch desorption experiments, the thorium and uranium desorption properties of contaminated soil sediments are investigated as a function of the effect of cations present in the groundwater. A phenomenological correlation between the desorption coefficient and the concentration of Ca and Mg in the water is determined. Kd Thorium -0.15849 ± 0.03237 log (Ca + Mg) + 5.06715 ± 0.09106; Kd Uranium = -0.11984 ± 0.03237 log (Ca + Mg) + 2.99909 ± 0.09105. By these models the sorption/desorption behaviour of soils can be predicted phenomenologically as function of the groundwater composition. (author)

  17. Simulation of water movement and NaCl transport

    International Nuclear Information System (INIS)

    Li Xun; Zheng Zhihong; Yang Zeping

    2008-01-01

    Modeling of water flow and solute transport in the near-field of a high-level radioactive waste repository with TOUGH2 is done. The results show that salt accumulation in buffer material is not so significant, precipitation does not occur throughout the period covered by our simualtions. Further more, the changeable law of volumetric water content, liquid velocity and dissolved concentration of sodium chloride with simulated time or distance are attained, which is the base of understanding evolvement of near-field. (authors)

  18. Acrylamide mitigation in potato chips by using NaCl

    DEFF Research Database (Denmark)

    Pedreschi, Franco; Risum, Jørgen; Granby, Kit

    2009-01-01

    Acrylamide is known to cause cancer in laboratory animals but there is no direct evidence that this substance causes cancer in humans. In April 2002, Swedish researchers shocked the world when they presented preliminary findings on the presence of acrylamide in fried and baked foods, most notably...... potato chips and French fries, at levels of 30-2300 ppb. The objective of this research was to study the effect of immersing potato slices in a NaCI solution in relation to acrylamide formation in the prepared potato chips. Potato slices (Verdi variety, diameter: 40 mm, width: 2.0 mm) were fried at 170...

  19. Ti2Al(C, N) Solid Solution Reinforcing TiAl-Based Composites: Evolution of a Core-Shell Structure, Interfaces, and Mechanical Properties.

    Science.gov (United States)

    Song, Xiaojie; Cui, Hongzhi; Han, Ye; Ding, Lei; Song, Qiang

    2018-05-16

    In this work, Ti 2 Al(C, N) solid solution with lamellar structure-enhanced TiAl matrix composites was synthesized by vacuum arc melting, using bulk g-C 3 N 4 , Ti, and Al powders as raw materials. The phases, microstructures, interfaces, and mechanical properties were investigated. MAX phase of Ti 2 Al(C, N) solid solution with lamellar structure was formed. During the melting process, first, C 3 N 4 reacted with Ti to form Ti(C, N) by Ti + C 3 N 4 → Ti(C, N). Then Ti 2 Al(C, N) was formed by a peritectic reaction of TiAl(l) + Ti(C, N)(s) → Ti 2 Al(C, N). C 3 N 4 is the single reactant that provides C and N simultaneously to final product of Ti 2 Al(C, N). The interfaces of TiAl//Ti 2 Al(C, N) and Ti 2 Al(C, N)//Ti(C, N) display perfect orientation relationships with low misfit values. The microhardness, compressive strength, and strain of best-performing TiAl-10 mol % Ti 2 Al(C, N) composite were improved by 45%, 55.7%, and 50% compared with the TiAl alloy, respectively. Uniformly distributed Ti 2 Al(C, N) and unreacted Ti(C, N) particles contributed to the grain refinement and reinforcement of the TiAl matrix. Laminated tearing, particle pull-out, and the crack-arresting of Ti 2 Al(C, N) are crucial for the improvement in compressive strength and plasticity of the composites.

  20. Automatically varying the composition of a mixed refrigerant solution for single mixed refrigerant LNG (liquefied natural gas) process at changing working conditions

    International Nuclear Information System (INIS)

    Xu, Xiongwen; Liu, Jinping; Cao, Le; Pang, Weiqiang

    2014-01-01

    The SMR (single mixed refrigerant) process is widely used in the small- and medium-scale liquefaction of NG (natural gas). Operating the MR (mixed-refrigerant) process outside of the design specifications is difficult but essential to save energy. Nevertheless, it is difficult to realize because the process needs to alter the working refrigerant composition. To address this challenge, this study investigated the performance diagnosis mechanism for SMR process. A control strategy was then proposed to control the changes in working refrigerant composition under different working conditions. This strategy separates the working refrigerant flow in the SMR process into three flows through two phase separators before it flows into the cold box. The first liquid flow is rich in the high-temperature component (isopentane). The second liquid flow is rich in the middle-temperature components (ethylene and propane), and the gas flow is rich in the low-temperature components (nitrogen and methane). By adjusting the flow rates, it is easy to decouple the control variables and automate the system. Finally, this approach was validated by process simulation and shown to be highly adaptive and exergy efficient in response to changing working conditions. - Highlights: • The performance diagnosis mechanism of SMR LNG process is studied. • A measure to automatically change the operation composition as per the working conditions is proposed for SMR process. • SMR process simulation is performed to verify the validity of the control solution. • The control solution notably improves the energy efficiency of SMR process at changing working condition

  1. Synthesis, microstructure and mechanical properties of (Ti1−x,Nbx)2AlC/Al2O3 solid solution composites

    International Nuclear Information System (INIS)

    Zhu, Jianfeng; Han, Na; Wang, Anning

    2012-01-01

    (Ti,Nb) 2 AlC/Al 2 O 3 in-situ solid solution composites were successfully synthesized from the elemental powder mixtures of Nb 2 O 5 , Ti, Al and carbon black using hot-press-aided reaction synthesis. The reaction path was investigated by differential scanning calorimetry (DSC) and X-ray diffractometry (XRD), and a possible reaction mechanism was proposed to explain the formation of (Ti,Nb) 2 AlC/Al 2 O 3 composites in which the thermite reaction between Al and Nb 2 O 5 formed Al 2 O 3 and Nb, and the latter together with TiAl and TiC reacted to form (Ti,Nb) 2 AlC. The synthesized composites show plate-like grains packed in a laminated structure typical of Ti 2 AlC, and the fine Al 2 O 3 particles formed in-situ tend to disperse on the matrix grain boundaries. Compared with the monolithic Ti 2 AlC synthesized using an identical process, the Vickers hardness, maximum compressive stress, flexural strength and fracture toughness of (Ti 0.96 ,Nb 0.04 ) 2 AlC/5 wt% Al 2 O 3 were enhanced by 33.8%, 12.1%, 118.4% and 111.8%, respectively. The mechanisms by which Al 2 O 3 increases the strength and toughness of the material were also discussed.

  2. Uniconazole effect on endogenous hormones, proteins and proline contents of barley plants (Hordium vulgare under salinity stress (NaCl

    Directory of Open Access Journals (Sweden)

    MOHAMED A. BAKHETA

    2014-05-01

    Full Text Available Bakheta MA, Hussein MM. 2014. Uniconazole effect on endogenous hormones, proteins and proline contents of barley plants (Hordium vulgare under salinity stress (NaCl. Nusantara Bioscience 6: 39-44. Pot experiments were carried out during two growth seasons 2010 / 2011 under greenhouse conditions of the National Research Centre, Dokki, Cairo, Egypt to investigate the response of barley plants (Hordium vulgare L grown under salinity stress (2500 or 5000 ppm to spraying with solutions of uniconazole at 150 or 200 ppm. The obtained results showed that irrigation with saline solutions caused increases in the amounts of abscisic acid (ABA, crude protein, total soluble-protein and proline contents. The results showed that spraying barley plants grown under saline solutions with uniconazole increased endogenous hormone contents of ABA, cytokinins, crude protein, total soluble protein and proline but caused decreases in the amounts of endogenous indole acetic acid (IAA and gibberellic acid (GA3. High protection of abscisic acid in treating plants with uniconazole and under salt stress (interaction effect increases proline, proteins and soluble protein which has been proposed to act as compatible solutes that adjust the osmotic potential in the cytoplasm. Thus, these biochemical characters can be used as a metabolic marker in relation to salinity stress.

  3. Polyimide Dielectric Layer on Filaments for Organic Field Effect Transistors: Choice of Solvent, Solution Composition and Dip-Coating Speed

    Directory of Open Access Journals (Sweden)

    Rambausek Lina

    2014-09-01

    Full Text Available In today’s research, smart textiles is an established topic in both electronics and the textile fields. The concept of producing microelectronics directly on a textile substrate is not a mere idea anymore and several research institutes are working on its realisation. Microelectronics like organic field effect transistor (OFET can be manufactured with a layered architecture. The production techniques used for this purpose can also be applied on textile substrates. Besides gate, active and contact layers, the isolating or dielectric layer is of high importance in the OFET architecture. Therefore, generating a high quality dielectric layer that is of low roughness and insulating at the same time is one of the fundamental requirements in building microelectronics on textile surfaces. To evaluate its potential, we have studied polyimide as a dielectric layer, dip-coated onto copper-coated polyester filaments. Accordingly, the copper-coated polyester filament was dip-coated from a polyimide solution with two different solvents, 1-methyl-2-pyrrolidone (NMP and dimethylformaldehyde. A variety of dip-coating speeds, solution concentrations and solvent-solute combinations have been tested. Their effect on the quality of the layer was analysed through microscopy, leak current measurements and atomic force microscopy (AFM. Polyimide dip-coating with polyimide resin dissolved in NMP at a concentration of 15w% in combination with a dip-coating speed of 50 mm/min led to the best results in electrical insulation and roughness. By optimising the dielectric layer’s properties, the way is paved for applying the subsequent semi-conductive layer. In further research, we will be working with the organic semiconductor material TIPS-Pentacene

  4. Stress wave propagation in thin long-fiber carbon/epoxy composite panel. Numerical and experimental solutions

    Directory of Open Access Journals (Sweden)

    Kroupa T.

    2007-10-01

    Full Text Available The article deals with experimental and numerical analysis of stress wave propagation in a thin long fiber carbon/epoxy composite material. Experiments were performed on in-plane loaded square composite panels with dimensions 501mm x 501mm x 2:2 mm. The panels have several fiber orientations (0°, 30°, 60° and 90° measured from the loaded edge. They were loaded by in-plane impact of steel sphere. The impact area was on the edge, exactly 150mm from top left corners corner of the panels. The loading force was approximated by atime dependent function. Its shape was obtained from three dimensional contact analysis, which was performed on smaller area of panel. The function was used in further plane stress analysis of the whole panels. The comparison of the numerical and experimental results was executed. An attempt at determination of velocity of propagation of Rayleigh waves on the loaded edge was performed and the results are discussed in the paper. Further directions of the research are proposed.

  5. High performance hydrophilic pervaporation composite membranes for water desalination

    KAUST Repository

    Liang, Bin

    2014-08-01

    A three-layer thin film nanofibrous pervaporation composite (TFNPVC) membrane was prepared by sequential deposition using electrospraying/electrospinning. The poly(vinyl alcohol) (PVA) top barrier layer was first electrosprayed on aluminum foil and its thickness can be easily controlled by adjusting the collecting time. Next a polyacrylonitrile (PAN) nanofibrous scaffold was deposited by electrospinning as a mid-layer support. A nonwoven PET layer is used to complete the composite membrane. The pervaporation desalination performance of TFNPVC membranes was tested using NaCl solutions at 100. Pa and at room temperature. The TFNPVC membranes show excellent desalination performance (high water flux and salt rejection >. 99.5%) for different salt concentrations with virtually no change in performance after 50. h of operation. © 2014 Elsevier B.V.

  6. An Activity-Based Dissolution Model for Solute-Containing Microdroplets

    DEFF Research Database (Denmark)

    Bitterfield, Deborah L; Madsen, Anders Utoft; Needham, D.

    2016-01-01

    to form and observe the dehydration of single NaCl solution microdroplets in octanol or butyl acetate. The model successfully predicts the droplet diameter as a function of time in both organic solvents. The NaCl concentration in water is measured well into the supersaturated area >5.4 M...

  7. Medium band gap polymer based solution-processed high-κ composite gate dielectrics for ambipolar OFET

    Science.gov (United States)

    Canımkurbey, Betül; Unay, Hande; Çakırlar, Çiğdem; Büyükköse, Serkan; Çırpan, Ali; Berber, Savas; Altürk Parlak, Elif

    2018-03-01

    The authors present a novel ambipolar organic filed-effect transistors (OFETs) composed of a hybrid dielectric thin film of Ta2O5:PMMA nanocomposite material, and solution processed poly(selenophene, benzotriazole and dialkoxy substituted [1,2-b:4, 5-b‧] dithiophene (P-SBTBDT)-based organic semiconducting material as the active layer of the device. We find that the Ta2O5:PMMA insulator shows n-type conduction character, and its combination with the p-type P-SBTBDT organic semiconductor leads to an ambipolar OFET device. Top-gated OFETs were fabricated on glass substrate consisting of interdigitated ITO electrodes. P-SBTBDT-based material was spin coated on the interdigitated ITO electrodes. Subsequently, a solution processed Ta2O5:PMMA nanocomposite material was spin coated, thereby creating the gate dielectric layer. Finally, as a gate metal, an aluminum layer was deposited by thermal evaporation. The fabricated OFETs exhibited an ambipolar performance with good air-stability, high field-induced current and relatively high electron and hole mobilities although Ta2O5:PMMA nanocomposite films have slightly higher leakage current compared to the pure Ta2O5 films. Dielectric properties of the devices with different ratios of Ta2O5:PMMA were also investigated. The dielectric constant varied between 3.6 and 5.3 at 100 Hz, depending on the Ta2O5:PMMA ratio.

  8. Use of Natural-Fiber Bio-Composites in Construction versus Traditional Solutions: Operational and Embodied Energy Assessment.

    Science.gov (United States)

    Galan-Marin, Carmen; Rivera-Gomez, Carlos; Garcia-Martinez, Antonio

    2016-06-13

    During the last decades natural polymers have become more and more frequent to replace traditional inorganic stabilizers in building materials. The purpose of this research is to establish a comparison between the most conventional building material solutions for load-bearing walls and a type of biomaterial. This comparison will focus on load-bearing walls as used in a widespread type of twentieth century dwelling construction in Europe and still used in developing countries nowadays. To carry out this analysis, the structural and thermal insulation characteristics of different construction solutions are balanced. The tool used for this evaluation is the life cycle assessment throughout the whole lifespan of these buildings. This research aims to examine the environmental performance of each material assessed: fired clay brick masonry walls (BW), concrete block masonry walls (CW), and stabilized soil block masonry walls (SW) stabilized with natural fibers and alginates. These conventional and new materials are evaluated from the point of view of both operational and embodied energy.

  9. Effect of solution composition on anatase to rutile transformation of sprayed TiO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Juma, Albert Owino, E-mail: albert.juma@ttu.ee [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, EE-19086 Tallinn (Estonia); Acik, Ilona Oja [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, EE-19086 Tallinn (Estonia); Mikli, Valdek [Chair of Semiconductor Materials Technology, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, EE-19086 Tallinn (Estonia); Mere, Arvo; Krunks, Malle [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, EE-19086 Tallinn (Estonia)

    2015-11-02

    Acetylacetone is used as a chelating agent for titanium(IV) isopropoxide to inhibit hydrolysis and stabilize the precursor solution. The effect of the molar ratio between titanium(IV) isopropoxide and acetylacetone of 1:1, 1:2, 1:3 and 1:4 in the precursor solution on the morphological, structural and optical properties of TiO{sub 2} thin film was investigated. These propert